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Linus Torvalds ea1ca66d3c Merge branch 'for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "Nothing too interesting. The only two noticeable changes are a subtle
  cpuset behavior fix and trace event id field being expanded to u64
  from int. Most others are code cleanups"

* 'for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cpuset: convert 'allowed' in __cpuset_node_allowed() to be boolean
  cgroup/rstat: check updated_next only for root
  cgroup: rstat: explicitly put loop variant in while
  cgroup: return early if it is already on preloaded list
  cgroup/cpuset: Don't let child cpusets restrict parent in default hierarchy
  cgroup: Trace event cgroup id fields should be u64
  cgroup: fix a typo in comment
  cgroup: get the wrong css for css_alloc() during cgroup_init_subsys()
  cgroup: rstat: Mark benign data race to silence KCSAN
2022-01-11 09:14:37 -08:00
Yafang Shao 1e9d74660d bpf: Fix mount source show for bpffs
We noticed our tc ebpf tools can't start after we upgrade our in-house kernel
version from 4.19 to 5.10. That is because of the behaviour change in bpffs
caused by commit d2935de7e4 ("vfs: Convert bpf to use the new mount API").

In our tc ebpf tools, we do strict environment check. If the environment is
not matched, we won't allow to start the ebpf progs. One of the check is whether
bpffs is properly mounted. The mount information of bpffs in kernel-4.19 and
kernel-5.10 are as follows:

- kernel 4.19
$ mount -t bpf bpffs /sys/fs/bpf
$ mount -t bpf
bpffs on /sys/fs/bpf type bpf (rw,relatime)

- kernel 5.10
$ mount -t bpf bpffs /sys/fs/bpf
$ mount -t bpf
none on /sys/fs/bpf type bpf (rw,relatime)

The device name in kernel-5.10 is displayed as none instead of bpffs, then our
environment check fails. Currently we modify the tools to adopt to the kernel
behaviour change, but I think we'd better change the kernel code to keep the
behavior consistent.

After this change, the mount information will be displayed the same with the
behavior in kernel-4.19, for example:

$ mount -t bpf bpffs /sys/fs/bpf
$ mount -t bpf
bpffs on /sys/fs/bpf type bpf (rw,relatime)

Fixes: d2935de7e4 ("vfs: Convert bpf to use the new mount API")
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/bpf/20220108134623.32467-1-laoar.shao@gmail.com
2022-01-11 10:48:17 +01:00
Linus Torvalds b35b6d4d71 Power management updates for 5.17-rc1
- Add new P-state driver for AMD processors (Huang Rui).
 
  - Fix initialization of min and max frequency QoS requests in the
    cpufreq core (Rafael Wysocki).
 
  - Fix EPP handling on Alder Lake in intel_pstate (Srinivas Pandruvada).
 
  - Make intel_pstate update cpuinfo.max_freq when notified of HWP
    capabilities changes and drop a redundant function call from that
    driver (Rafael Wysocki).
 
  - Improve IRQ support in the Qcom cpufreq driver (Ard Biesheuvel,
    Stephen Boyd, Vladimir Zapolskiy).
 
  - Fix double devm_remap() in the Mediatek cpufreq driver (Hector Yuan).
 
  - Introduce thermal pressure helpers for cpufreq CPU cooling (Lukasz
    Luba).
 
  - Make cpufreq use default_groups in kobj_type (Greg Kroah-Hartman).
 
  - Make cpuidle use default_groups in kobj_type (Greg Kroah-Hartman).
 
  - Fix two comments in cpuidle code (Jason Wang, Yang Li).
 
  - Allow model-specific normal EPB value to be used in the intel_epb
    sysfs attribute handling code (Srinivas Pandruvada).
 
  - Simplify locking in pm_runtime_put_suppliers() (Rafael Wysocki).
 
  - Add safety net to supplier device release in the runtime PM core
    code (Rafael Wysocki).
 
  - Capture device status before disabling runtime PM for it (Rafael
    Wysocki).
 
  - Add new macros for declaring PM operations to allow drivers to
    avoid guarding them with CONFIG_PM #ifdefs or __maybe_unused and
    update some drivers to use these macros (Paul Cercueil).
 
  - Allow ACPI hardware signature to be honoured during restore from
    hibernation (David Woodhouse).
 
  - Update outdated operating performance points (OPP) documentation
    (Tang Yizhou).
 
  - Reduce log severity for informative message regarding frequency
    transition failures in devfreq (Tzung-Bi Shih).
 
  - Add DRAM frequency controller devfreq driver for Allwinner sunXi
    SoCs (Samuel Holland).
 
  - Add missing COMMON_CLK dependency to sun8i devfreq driver (Arnd
    Bergmann).
 
  - Add support for new layout of Psys PowerLimit Register on SPR to
    the Intel RAPL power capping driver (Zhang Rui).
 
  - Fix typo in a comment in idle_inject.c (Jason Wang).
 
  - Remove unused function definition from the DTPM (Dynamit Thermal
    Power Management) power capping framework (Daniel Lezcano).
 
  - Reduce DTPM trace verbosity (Daniel Lezcano).
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Merge tag 'pm-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "The most signigicant change here is the addition of a new cpufreq
  'P-state' driver for AMD processors as a better replacement for the
  venerable acpi-cpufreq driver.

  There are also other cpufreq updates (in the core, intel_pstate, ARM
  drivers), PM core updates (mostly related to adding new macros for
  declaring PM operations which should make the lives of driver
  developers somewhat easier), and a bunch of assorted fixes and
  cleanups.

  Summary:

   - Add new P-state driver for AMD processors (Huang Rui).

   - Fix initialization of min and max frequency QoS requests in the
     cpufreq core (Rafael Wysocki).

   - Fix EPP handling on Alder Lake in intel_pstate (Srinivas
     Pandruvada).

   - Make intel_pstate update cpuinfo.max_freq when notified of HWP
     capabilities changes and drop a redundant function call from that
     driver (Rafael Wysocki).

   - Improve IRQ support in the Qcom cpufreq driver (Ard Biesheuvel,
     Stephen Boyd, Vladimir Zapolskiy).

   - Fix double devm_remap() in the Mediatek cpufreq driver (Hector
     Yuan).

   - Introduce thermal pressure helpers for cpufreq CPU cooling (Lukasz
     Luba).

   - Make cpufreq use default_groups in kobj_type (Greg Kroah-Hartman).

   - Make cpuidle use default_groups in kobj_type (Greg Kroah-Hartman).

   - Fix two comments in cpuidle code (Jason Wang, Yang Li).

   - Allow model-specific normal EPB value to be used in the intel_epb
     sysfs attribute handling code (Srinivas Pandruvada).

   - Simplify locking in pm_runtime_put_suppliers() (Rafael Wysocki).

   - Add safety net to supplier device release in the runtime PM core
     code (Rafael Wysocki).

   - Capture device status before disabling runtime PM for it (Rafael
     Wysocki).

   - Add new macros for declaring PM operations to allow drivers to
     avoid guarding them with CONFIG_PM #ifdefs or __maybe_unused and
     update some drivers to use these macros (Paul Cercueil).

   - Allow ACPI hardware signature to be honoured during restore from
     hibernation (David Woodhouse).

   - Update outdated operating performance points (OPP) documentation
     (Tang Yizhou).

   - Reduce log severity for informative message regarding frequency
     transition failures in devfreq (Tzung-Bi Shih).

   - Add DRAM frequency controller devfreq driver for Allwinner sunXi
     SoCs (Samuel Holland).

   - Add missing COMMON_CLK dependency to sun8i devfreq driver (Arnd
     Bergmann).

   - Add support for new layout of Psys PowerLimit Register on SPR to
     the Intel RAPL power capping driver (Zhang Rui).

   - Fix typo in a comment in idle_inject.c (Jason Wang).

   - Remove unused function definition from the DTPM (Dynamit Thermal
     Power Management) power capping framework (Daniel Lezcano).

   - Reduce DTPM trace verbosity (Daniel Lezcano)"

* tag 'pm-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (53 commits)
  x86, sched: Fix undefined reference to init_freq_invariance_cppc() build error
  cpufreq: amd-pstate: Fix Kconfig dependencies for AMD P-State
  cpufreq: amd-pstate: Fix struct amd_cpudata kernel-doc comment
  cpuidle: use default_groups in kobj_type
  x86: intel_epb: Allow model specific normal EPB value
  MAINTAINERS: Add AMD P-State driver maintainer entry
  Documentation: amd-pstate: Add AMD P-State driver introduction
  cpufreq: amd-pstate: Add AMD P-State performance attributes
  cpufreq: amd-pstate: Add AMD P-State frequencies attributes
  cpufreq: amd-pstate: Add boost mode support for AMD P-State
  cpufreq: amd-pstate: Add trace for AMD P-State module
  cpufreq: amd-pstate: Introduce the support for the processors with shared memory solution
  cpufreq: amd-pstate: Add fast switch function for AMD P-State
  cpufreq: amd-pstate: Introduce a new AMD P-State driver to support future processors
  ACPI: CPPC: Add CPPC enable register function
  ACPI: CPPC: Check present CPUs for determining _CPC is valid
  ACPI: CPPC: Implement support for SystemIO registers
  x86/msr: Add AMD CPPC MSR definitions
  x86/cpufeatures: Add AMD Collaborative Processor Performance Control feature flag
  cpufreq: use default_groups in kobj_type
  ...
2022-01-10 20:34:00 -08:00
Linus Torvalds 8efd0d9c31 Networking changes for 5.17.
Core
 ----
 
  - Defer freeing TCP skbs to the BH handler, whenever possible,
    or at least perform the freeing outside of the socket lock section
    to decrease cross-CPU allocator work and improve latency.
 
  - Add netdevice refcount tracking to locate sources of netdevice
    and net namespace refcount leaks.
 
  - Make Tx watchdog less intrusive - avoid pausing Tx and restarting
    all queues from a single CPU removing latency spikes.
 
  - Various small optimizations throughout the stack from Eric Dumazet.
 
  - Make netdev->dev_addr[] constant, force modifications to go via
    appropriate helpers to allow us to keep addresses in ordered data
    structures.
 
  - Replace unix_table_lock with per-hash locks, improving performance
    of bind() calls.
 
  - Extend skb drop tracepoint with a drop reason.
 
  - Allow SO_MARK and SO_PRIORITY setsockopt under CAP_NET_RAW.
 
 BPF
 ---
 
  - New helpers:
    - bpf_find_vma(), find and inspect VMAs for profiling use cases
    - bpf_loop(), runtime-bounded loop helper trading some execution
      time for much faster (if at all converging) verification
    - bpf_strncmp(), improve performance, avoid compiler flakiness
    - bpf_get_func_arg(), bpf_get_func_ret(), bpf_get_func_arg_cnt()
      for tracing programs, all inlined by the verifier
 
  - Support BPF relocations (CO-RE) in the kernel loader.
 
  - Further the support for BTF_TYPE_TAG annotations.
 
  - Allow access to local storage in sleepable helpers.
 
  - Convert verifier argument types to a composable form with different
    attributes which can be shared across types (ro, maybe-null).
 
  - Prepare libbpf for upcoming v1.0 release by cleaning up APIs,
    creating new, extensible ones where missing and deprecating those
    to be removed.
 
 Protocols
 ---------
 
  - WiFi (mac80211/cfg80211):
    - notify user space about long "come back in N" AP responses,
      allow it to react to such temporary rejections
    - allow non-standard VHT MCS 10/11 rates
    - use coarse time in airtime fairness code to save CPU cycles
 
  - Bluetooth:
    - rework of HCI command execution serialization to use a common
      queue and work struct, and improve handling errors reported
      in the middle of a batch of commands
    - rework HCI event handling to use skb_pull_data, avoiding packet
      parsing pitfalls
    - support AOSP Bluetooth Quality Report
 
  - SMC:
    - support net namespaces, following the RDMA model
    - improve connection establishment latency by pre-clearing buffers
    - introduce TCP ULP for automatic redirection to SMC
 
  - Multi-Path TCP:
    - support ioctls: SIOCINQ, OUTQ, and OUTQNSD
    - support socket options: IP_TOS, IP_FREEBIND, IP_TRANSPARENT,
      IPV6_FREEBIND, and IPV6_TRANSPARENT, TCP_CORK and TCP_NODELAY
    - support cmsgs: TCP_INQ
    - improvements in the data scheduler (assigning data to subflows)
    - support fastclose option (quick shutdown of the full MPTCP
      connection, similar to TCP RST in regular TCP)
 
  - MCTP (Management Component Transport) over serial, as defined by
    DMTF spec DSP0253 - "MCTP Serial Transport Binding".
 
 Driver API
 ----------
 
  - Support timestamping on bond interfaces in active/passive mode.
 
  - Introduce generic phylink link mode validation for drivers which
    don't have any quirks and where MAC capability bits fully express
    what's supported. Allow PCS layer to participate in the validation.
    Convert a number of drivers.
 
  - Add support to set/get size of buffers on the Rx rings and size of
    the tx copybreak buffer via ethtool.
 
  - Support offloading TC actions as first-class citizens rather than
    only as attributes of filters, improve sharing and device resource
    utilization.
 
  - WiFi (mac80211/cfg80211):
    - support forwarding offload (ndo_fill_forward_path)
    - support for background radar detection hardware
    - SA Query Procedures offload on the AP side
 
 New hardware / drivers
 ----------------------
 
  - tsnep - FPGA based TSN endpoint Ethernet MAC used in PLCs with
    real-time requirements for isochronous communication with protocols
    like OPC UA Pub/Sub.
 
  - Qualcomm BAM-DMUX WWAN - driver for data channels of modems
    integrated into many older Qualcomm SoCs, e.g. MSM8916 or
    MSM8974 (qcom_bam_dmux).
 
  - Microchip LAN966x multi-port Gigabit AVB/TSN Ethernet Switch
    driver with support for bridging, VLANs and multicast forwarding
    (lan966x).
 
  - iwlmei driver for co-operating between Intel's WiFi driver and
    Intel's Active Management Technology (AMT) devices.
 
  - mse102x - Vertexcom MSE102x Homeplug GreenPHY chips
 
  - Bluetooth:
    - MediaTek MT7921 SDIO devices
    - Foxconn MT7922A
    - Realtek RTL8852AE
 
 Drivers
 -------
 
  - Significantly improve performance in the datapaths of:
    lan78xx, ax88179_178a, lantiq_xrx200, bnxt.
 
  - Intel Ethernet NICs:
    - igb: support PTP/time PEROUT and EXTTS SDP functions on
      82580/i354/i350 adapters
    - ixgbevf: new PF -> VF mailbox API which avoids the risk of
      mailbox corruption with ESXi
    - iavf: support configuration of VLAN features of finer granularity,
      stacked tags and filtering
    - ice: PTP support for new E822 devices with sub-ns precision
    - ice: support firmware activation without reboot
 
  - Mellanox Ethernet NICs (mlx5):
    - expose control over IRQ coalescing mode (CQE vs EQE) via ethtool
    - support TC forwarding when tunnel encap and decap happen between
      two ports of the same NIC
    - dynamically size and allow disabling various features to save
      resources for running in embedded / SmartNIC scenarios
 
  - Broadcom Ethernet NICs (bnxt):
    - use page frag allocator to improve Rx performance
    - expose control over IRQ coalescing mode (CQE vs EQE) via ethtool
 
  - Other Ethernet NICs:
    - amd-xgbe: add Ryzen 6000 (Yellow Carp) Ethernet support
 
  - Microsoft cloud/virtual NIC (mana):
    - add XDP support (PASS, DROP, TX)
 
  - Mellanox Ethernet switches (mlxsw):
    - initial support for Spectrum-4 ASICs
    - VxLAN with IPv6 underlay
 
  - Marvell Ethernet switches (prestera):
    - support flower flow templates
    - add basic IP forwarding support
 
  - NXP embedded Ethernet switches (ocelot & felix):
    - support Per-Stream Filtering and Policing (PSFP)
    - enable cut-through forwarding between ports by default
    - support FDMA to improve packet Rx/Tx to CPU
 
  - Other embedded switches:
    - hellcreek: improve trapping management (STP and PTP) packets
    - qca8k: support link aggregation and port mirroring
 
  - Qualcomm 802.11ax WiFi (ath11k):
    - qca6390, wcn6855: enable 802.11 power save mode in station mode
    - BSS color change support
    - WCN6855 hw2.1 support
    - 11d scan offload support
    - scan MAC address randomization support
    - full monitor mode, only supported on QCN9074
    - qca6390/wcn6855: report signal and tx bitrate
    - qca6390: rfkill support
    - qca6390/wcn6855: regdb.bin support
 
  - Intel WiFi (iwlwifi):
    - support SAR GEO Offset Mapping (SGOM) and Time-Aware-SAR (TAS)
      in cooperation with the BIOS
    - support for Optimized Connectivity Experience (OCE) scan
    - support firmware API version 68
    - lots of preparatory work for the upcoming Bz device family
 
  - MediaTek WiFi (mt76):
    - Specific Absorption Rate (SAR) support
    - mt7921: 160 MHz channel support
 
  - RealTek WiFi (rtw88):
    - Specific Absorption Rate (SAR) support
    - scan offload
 
  - Other WiFi NICs
    - ath10k: support fetching (pre-)calibration data from nvmem
    - brcmfmac: configure keep-alive packet on suspend
    - wcn36xx: beacon filter support
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag '5.17-net-next' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core
  ----

   - Defer freeing TCP skbs to the BH handler, whenever possible, or at
     least perform the freeing outside of the socket lock section to
     decrease cross-CPU allocator work and improve latency.

   - Add netdevice refcount tracking to locate sources of netdevice and
     net namespace refcount leaks.

   - Make Tx watchdog less intrusive - avoid pausing Tx and restarting
     all queues from a single CPU removing latency spikes.

   - Various small optimizations throughout the stack from Eric Dumazet.

   - Make netdev->dev_addr[] constant, force modifications to go via
     appropriate helpers to allow us to keep addresses in ordered data
     structures.

   - Replace unix_table_lock with per-hash locks, improving performance
     of bind() calls.

   - Extend skb drop tracepoint with a drop reason.

   - Allow SO_MARK and SO_PRIORITY setsockopt under CAP_NET_RAW.

  BPF
  ---

   - New helpers:
      - bpf_find_vma(), find and inspect VMAs for profiling use cases
      - bpf_loop(), runtime-bounded loop helper trading some execution
        time for much faster (if at all converging) verification
      - bpf_strncmp(), improve performance, avoid compiler flakiness
      - bpf_get_func_arg(), bpf_get_func_ret(), bpf_get_func_arg_cnt()
        for tracing programs, all inlined by the verifier

   - Support BPF relocations (CO-RE) in the kernel loader.

   - Further the support for BTF_TYPE_TAG annotations.

   - Allow access to local storage in sleepable helpers.

   - Convert verifier argument types to a composable form with different
     attributes which can be shared across types (ro, maybe-null).

   - Prepare libbpf for upcoming v1.0 release by cleaning up APIs,
     creating new, extensible ones where missing and deprecating those
     to be removed.

  Protocols
  ---------

   - WiFi (mac80211/cfg80211):
      - notify user space about long "come back in N" AP responses,
        allow it to react to such temporary rejections
      - allow non-standard VHT MCS 10/11 rates
      - use coarse time in airtime fairness code to save CPU cycles

   - Bluetooth:
      - rework of HCI command execution serialization to use a common
        queue and work struct, and improve handling errors reported in
        the middle of a batch of commands
      - rework HCI event handling to use skb_pull_data, avoiding packet
        parsing pitfalls
      - support AOSP Bluetooth Quality Report

   - SMC:
      - support net namespaces, following the RDMA model
      - improve connection establishment latency by pre-clearing buffers
      - introduce TCP ULP for automatic redirection to SMC

   - Multi-Path TCP:
      - support ioctls: SIOCINQ, OUTQ, and OUTQNSD
      - support socket options: IP_TOS, IP_FREEBIND, IP_TRANSPARENT,
        IPV6_FREEBIND, and IPV6_TRANSPARENT, TCP_CORK and TCP_NODELAY
      - support cmsgs: TCP_INQ
      - improvements in the data scheduler (assigning data to subflows)
      - support fastclose option (quick shutdown of the full MPTCP
        connection, similar to TCP RST in regular TCP)

   - MCTP (Management Component Transport) over serial, as defined by
     DMTF spec DSP0253 - "MCTP Serial Transport Binding".

  Driver API
  ----------

   - Support timestamping on bond interfaces in active/passive mode.

   - Introduce generic phylink link mode validation for drivers which
     don't have any quirks and where MAC capability bits fully express
     what's supported. Allow PCS layer to participate in the validation.
     Convert a number of drivers.

   - Add support to set/get size of buffers on the Rx rings and size of
     the tx copybreak buffer via ethtool.

   - Support offloading TC actions as first-class citizens rather than
     only as attributes of filters, improve sharing and device resource
     utilization.

   - WiFi (mac80211/cfg80211):
      - support forwarding offload (ndo_fill_forward_path)
      - support for background radar detection hardware
      - SA Query Procedures offload on the AP side

  New hardware / drivers
  ----------------------

   - tsnep - FPGA based TSN endpoint Ethernet MAC used in PLCs with
     real-time requirements for isochronous communication with protocols
     like OPC UA Pub/Sub.

   - Qualcomm BAM-DMUX WWAN - driver for data channels of modems
     integrated into many older Qualcomm SoCs, e.g. MSM8916 or MSM8974
     (qcom_bam_dmux).

   - Microchip LAN966x multi-port Gigabit AVB/TSN Ethernet Switch driver
     with support for bridging, VLANs and multicast forwarding
     (lan966x).

   - iwlmei driver for co-operating between Intel's WiFi driver and
     Intel's Active Management Technology (AMT) devices.

   - mse102x - Vertexcom MSE102x Homeplug GreenPHY chips

   - Bluetooth:
      - MediaTek MT7921 SDIO devices
      - Foxconn MT7922A
      - Realtek RTL8852AE

  Drivers
  -------

   - Significantly improve performance in the datapaths of: lan78xx,
     ax88179_178a, lantiq_xrx200, bnxt.

   - Intel Ethernet NICs:
      - igb: support PTP/time PEROUT and EXTTS SDP functions on
        82580/i354/i350 adapters
      - ixgbevf: new PF -> VF mailbox API which avoids the risk of
        mailbox corruption with ESXi
      - iavf: support configuration of VLAN features of finer
        granularity, stacked tags and filtering
      - ice: PTP support for new E822 devices with sub-ns precision
      - ice: support firmware activation without reboot

   - Mellanox Ethernet NICs (mlx5):
      - expose control over IRQ coalescing mode (CQE vs EQE) via ethtool
      - support TC forwarding when tunnel encap and decap happen between
        two ports of the same NIC
      - dynamically size and allow disabling various features to save
        resources for running in embedded / SmartNIC scenarios

   - Broadcom Ethernet NICs (bnxt):
      - use page frag allocator to improve Rx performance
      - expose control over IRQ coalescing mode (CQE vs EQE) via ethtool

   - Other Ethernet NICs:
      - amd-xgbe: add Ryzen 6000 (Yellow Carp) Ethernet support

   - Microsoft cloud/virtual NIC (mana):
      - add XDP support (PASS, DROP, TX)

   - Mellanox Ethernet switches (mlxsw):
      - initial support for Spectrum-4 ASICs
      - VxLAN with IPv6 underlay

   - Marvell Ethernet switches (prestera):
      - support flower flow templates
      - add basic IP forwarding support

   - NXP embedded Ethernet switches (ocelot & felix):
      - support Per-Stream Filtering and Policing (PSFP)
      - enable cut-through forwarding between ports by default
      - support FDMA to improve packet Rx/Tx to CPU

   - Other embedded switches:
      - hellcreek: improve trapping management (STP and PTP) packets
      - qca8k: support link aggregation and port mirroring

   - Qualcomm 802.11ax WiFi (ath11k):
      - qca6390, wcn6855: enable 802.11 power save mode in station mode
      - BSS color change support
      - WCN6855 hw2.1 support
      - 11d scan offload support
      - scan MAC address randomization support
      - full monitor mode, only supported on QCN9074
      - qca6390/wcn6855: report signal and tx bitrate
      - qca6390: rfkill support
      - qca6390/wcn6855: regdb.bin support

   - Intel WiFi (iwlwifi):
      - support SAR GEO Offset Mapping (SGOM) and Time-Aware-SAR (TAS)
        in cooperation with the BIOS
      - support for Optimized Connectivity Experience (OCE) scan
      - support firmware API version 68
      - lots of preparatory work for the upcoming Bz device family

   - MediaTek WiFi (mt76):
      - Specific Absorption Rate (SAR) support
      - mt7921: 160 MHz channel support

   - RealTek WiFi (rtw88):
      - Specific Absorption Rate (SAR) support
      - scan offload

   - Other WiFi NICs
      - ath10k: support fetching (pre-)calibration data from nvmem
      - brcmfmac: configure keep-alive packet on suspend
      - wcn36xx: beacon filter support"

* tag '5.17-net-next' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2048 commits)
  tcp: tcp_send_challenge_ack delete useless param `skb`
  net/qla3xxx: Remove useless DMA-32 fallback configuration
  rocker: Remove useless DMA-32 fallback configuration
  hinic: Remove useless DMA-32 fallback configuration
  lan743x: Remove useless DMA-32 fallback configuration
  net: enetc: Remove useless DMA-32 fallback configuration
  cxgb4vf: Remove useless DMA-32 fallback configuration
  cxgb4: Remove useless DMA-32 fallback configuration
  cxgb3: Remove useless DMA-32 fallback configuration
  bnx2x: Remove useless DMA-32 fallback configuration
  et131x: Remove useless DMA-32 fallback configuration
  be2net: Remove useless DMA-32 fallback configuration
  vmxnet3: Remove useless DMA-32 fallback configuration
  bna: Simplify DMA setting
  net: alteon: Simplify DMA setting
  myri10ge: Simplify DMA setting
  qlcnic: Simplify DMA setting
  net: allwinner: Fix print format
  page_pool: remove spinlock in page_pool_refill_alloc_cache()
  amt: fix wrong return type of amt_send_membership_update()
  ...
2022-01-10 19:06:09 -08:00
Linus Torvalds d93aebbd76 Merge branch 'random-5.17-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random
Pull random number generator updates from Jason Donenfeld:
 "These a bit more numerous than usual for the RNG, due to folks
  resubmitting patches that had been pending prior and generally renewed
  interest.

  There are a few categories of patches in here:

   1) Dominik Brodowski and I traded a series back and forth for a some
      weeks that fixed numerous issues related to seeds being provided
      at extremely early boot by the firmware, before other parts of the
      kernel or of the RNG have been initialized, both fixing some
      crashes and addressing correctness around early boot randomness.
      One of these is marked for stable.

   2) I replaced the RNG's usage of SHA-1 with BLAKE2s in the entropy
      extractor, and made the construction a bit safer and more
      standard. This was sort of a long overdue low hanging fruit, as we
      were supposed to have phased out SHA-1 usage quite some time ago
      (even if all we needed here was non-invertibility). Along the way
      it also made extraction 131% faster. This required a bit of
      Kconfig and symbol plumbing to make things work well with the
      crypto libraries, which is one of the reasons why I'm sending you
      this pull early in the cycle.

   3) I got rid of a truly superfluous call to RDRAND in the hot path,
      which resulted in a whopping 370% increase in performance.

   4) Sebastian Andrzej Siewior sent some patches regarding PREEMPT_RT,
      the full series of which wasn't ready yet, but the first two
      preparatory cleanups were good on their own. One of them touches
      files in kernel/irq/, which is the other reason why I'm sending
      you this pull early in the cycle.

   5) Other assorted correctness fixes from Eric Biggers, Jann Horn,
      Mark Brown, Dominik Brodowski, and myself"

* 'random-5.17-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
  random: don't reset crng_init_cnt on urandom_read()
  random: avoid superfluous call to RDRAND in CRNG extraction
  random: early initialization of ChaCha constants
  random: use IS_ENABLED(CONFIG_NUMA) instead of ifdefs
  random: harmonize "crng init done" messages
  random: mix bootloader randomness into pool
  random: do not throw away excess input to crng_fast_load
  random: do not re-init if crng_reseed completes before primary init
  random: fix crash on multiple early calls to add_bootloader_randomness()
  random: do not sign extend bytes for rotation when mixing
  random: use BLAKE2s instead of SHA1 in extraction
  lib/crypto: blake2s: include as built-in
  random: fix data race on crng init time
  random: fix data race on crng_node_pool
  irq: remove unused flags argument from __handle_irq_event_percpu()
  random: remove unused irq_flags argument from add_interrupt_randomness()
  random: document add_hwgenerator_randomness() with other input functions
  MAINTAINERS: add git tree for random.c
2022-01-10 11:52:16 -08:00
Linus Torvalds 48a60bdb2b - Add a set of thread_info.flags accessors which snapshot it before
accesing it in order to prevent any potential data races, and convert
 all users to those new accessors
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Merge tag 'core_entry_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull thread_info flag accessor helper updates from Borislav Petkov:
 "Add a set of thread_info.flags accessors which snapshot it before
  accesing it in order to prevent any potential data races, and convert
  all users to those new accessors"

* tag 'core_entry_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  powerpc: Snapshot thread flags
  powerpc: Avoid discarding flags in system_call_exception()
  openrisc: Snapshot thread flags
  microblaze: Snapshot thread flags
  arm64: Snapshot thread flags
  ARM: Snapshot thread flags
  alpha: Snapshot thread flags
  sched: Snapshot thread flags
  entry: Snapshot thread flags
  x86: Snapshot thread flags
  thread_info: Add helpers to snapshot thread flags
2022-01-10 11:34:10 -08:00
Linus Torvalds 5ba13c1c4d - Return an error when a notifier callback has been registered already
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Merge tag 'core_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull notifier fix from Borislav Petkov:
 "Return an error when a notifier callback has been registered already"

* tag 'core_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  notifier: Return an error when a callback has already been registered
2022-01-10 11:32:57 -08:00
Thomas Gleixner 74a5257a0c genirq/msi: Populate sysfs entry only once
The MSI entries for multi-MSI are populated en bloc for the MSI descriptor,
but the current code invokes the population inside the per interrupt loop
which triggers a warning in the sysfs code and causes the interrupt
allocation to fail.

Move it outside of the loop so it works correctly for single and multi-MSI.

Fixes: bf5e758f02 ("genirq/msi: Simplify sysfs handling")
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/87leznqx2a.ffs@tglx
2022-01-10 19:22:10 +01:00
Tejun Heo 2a8ab0fbd1 Merge branch 'workqueue/for-5.16-fixes' into workqueue/for-5.17
for-5.16-fixes contains two subtle race conditions which were introduced by
scheduler side code cleanups. The branch didn't get pushed out, so merge
into for-5.17.
2022-01-10 07:54:04 -10:00
Rafael J. Wysocki c001a52df4 Merge branches 'pm-cpuidle', 'pm-core' and 'pm-sleep'
Merge cpuidle updates, PM core updates and one hiberation-related
update for 5.17-rc1:

 - Make cpuidle use default_groups in kobj_type (Greg Kroah-Hartman).

 - Fix two comments in cpuidle code (Jason Wang, Yang Li).

 - Simplify locking in pm_runtime_put_suppliers() (Rafael Wysocki).

 - Add safety net to supplier device release in the runtime PM core
   code (Rafael Wysocki).

 - Capture device status before disabling runtime PM for it (Rafael
   Wysocki).

 - Add new macros for declaring PM operations to allow drivers to
   avoid guarding them with CONFIG_PM #ifdefs or __maybe_unused and
   update some drivers to use these macros (Paul Cercueil).

 - Allow ACPI hardware signature to be honoured during restore from
   hibernation (David Woodhouse).

* pm-cpuidle:
  cpuidle: use default_groups in kobj_type
  cpuidle: Fix cpuidle_remove_state_sysfs() kerneldoc comment
  cpuidle: menu: Fix typo in a comment

* pm-core:
  PM: runtime: Simplify locking in pm_runtime_put_suppliers()
  mmc: mxc: Use the new PM macros
  mmc: jz4740: Use the new PM macros
  PM: runtime: Add safety net to supplier device release
  PM: runtime: Capture device status before disabling runtime PM
  PM: core: Add new *_PM_OPS macros, deprecate old ones
  PM: core: Redefine pm_ptr() macro
  r8169: Avoid misuse of pm_ptr() macro

* pm-sleep:
  PM: hibernate: Allow ACPI hardware signature to be honoured
2022-01-10 17:57:13 +01:00
Linus Torvalds 9b9e211360 arm64 updates for 5.17:
- KCSAN enabled for arm64.
 
 - Additional kselftests to exercise the syscall ABI w.r.t. SVE/FPSIMD.
 
 - Some more SVE clean-ups and refactoring in preparation for SME support
   (scalable matrix extensions).
 
 - BTI clean-ups (SYM_FUNC macros etc.)
 
 - arm64 atomics clean-up and codegen improvements.
 
 - HWCAPs for FEAT_AFP (alternate floating point behaviour) and
   FEAT_RPRESS (increased precision of reciprocal estimate and reciprocal
   square root estimate).
 
 - Use SHA3 instructions to speed-up XOR.
 
 - arm64 unwind code refactoring/unification.
 
 - Avoid DC (data cache maintenance) instructions when DCZID_EL0.DZP == 1
   (potentially set by a hypervisor; user-space already does this).
 
 - Perf updates for arm64: support for CI-700, HiSilicon PCIe PMU,
   Marvell CN10K LLC-TAD PMU, miscellaneous clean-ups.
 
 - Other fixes and clean-ups; highlights: fix the handling of erratum
   1418040, correct the calculation of the nomap region boundaries,
   introduce io_stop_wc() mapped to the new DGH instruction (data
   gathering hint).
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - KCSAN enabled for arm64.

 - Additional kselftests to exercise the syscall ABI w.r.t. SVE/FPSIMD.

 - Some more SVE clean-ups and refactoring in preparation for SME
   support (scalable matrix extensions).

 - BTI clean-ups (SYM_FUNC macros etc.)

 - arm64 atomics clean-up and codegen improvements.

 - HWCAPs for FEAT_AFP (alternate floating point behaviour) and
   FEAT_RPRESS (increased precision of reciprocal estimate and
   reciprocal square root estimate).

 - Use SHA3 instructions to speed-up XOR.

 - arm64 unwind code refactoring/unification.

 - Avoid DC (data cache maintenance) instructions when DCZID_EL0.DZP ==
   1 (potentially set by a hypervisor; user-space already does this).

 - Perf updates for arm64: support for CI-700, HiSilicon PCIe PMU,
   Marvell CN10K LLC-TAD PMU, miscellaneous clean-ups.

 - Other fixes and clean-ups; highlights: fix the handling of erratum
   1418040, correct the calculation of the nomap region boundaries,
   introduce io_stop_wc() mapped to the new DGH instruction (data
   gathering hint).

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (81 commits)
  arm64: Use correct method to calculate nomap region boundaries
  arm64: Drop outdated links in comments
  arm64: perf: Don't register user access sysctl handler multiple times
  drivers: perf: marvell_cn10k: fix an IS_ERR() vs NULL check
  perf/smmuv3: Fix unused variable warning when CONFIG_OF=n
  arm64: errata: Fix exec handling in erratum 1418040 workaround
  arm64: Unhash early pointer print plus improve comment
  asm-generic: introduce io_stop_wc() and add implementation for ARM64
  arm64: Ensure that the 'bti' macro is defined where linkage.h is included
  arm64: remove __dma_*_area() aliases
  docs/arm64: delete a space from tagged-address-abi
  arm64: Enable KCSAN
  kselftest/arm64: Add pidbench for floating point syscall cases
  arm64/fp: Add comments documenting the usage of state restore functions
  kselftest/arm64: Add a test program to exercise the syscall ABI
  kselftest/arm64: Allow signal tests to trigger from a function
  kselftest/arm64: Parameterise ptrace vector length information
  arm64/sve: Minor clarification of ABI documentation
  arm64/sve: Generalise vector length configuration prctl() for SME
  arm64/sve: Make sysctl interface for SVE reusable by SME
  ...
2022-01-10 08:49:37 -08:00
Tom Zanussi 86599dbe2c tracing: Add helper functions to simplify event_command.parse() callback handling
The event_command.parse() callback is responsible for parsing and
registering triggers.  The existing command implementions for this
callback duplicate a lot of the same code, so to clean up and
consolidate those implementations, introduce a handful of helper
functions for implementors to use.

This also makes it easier for new commands to be implemented and
allows them to focus more on the customizations they provide rather
than obscuring and complicating it with boilerplate code.

Link: https://lkml.kernel.org/r/c1ff71f594d45177706571132bd3119491097221.1641823001.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-10 11:09:11 -05:00
Tom Zanussi 2378a2d6b6 tracing: Remove ops param from event_command reg()/unreg() callbacks
The event_trigger_ops for an event_command are already accessible via
event_trigger_data.ops so remove the redundant ops from the callback.

Link: https://lkml.kernel.org/r/4c6f2a41820452f9cacddc7634ad442928aa2aa6.1641823001.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-10 11:09:11 -05:00
Tom Zanussi fb339e531b tracing: Change event_trigger_ops func() to trigger()
The name of the func() callback on event_trigger_ops is too generic
and is easily confused with other callbacks with that name, so change
it to something that reflects its actual purpose.

In this case, the main purpose of the callback is to implement an
event trigger, so call it trigger() instead.

Also add some more documentation to event_trigger_ops describing the
callbacks a bit better.

Link: https://lkml.kernel.org/r/36ab812e3ee74ee03ae0043fda41a858ee728c00.1641823001.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-10 11:09:10 -05:00
Tom Zanussi 9ec5a7d168 tracing: Change event_command func() to parse()
The name of the func() callback on event_command is too generic and is
easily confused with other callbacks with that name, so change it to
something that reflects its actual purpose.

In this case, the main purpose of the callback is to parse an event
command, so call it parse() instead.

Link: https://lkml.kernel.org/r/7784e321840752ed88aac0b349c0c685fc9247b1.1641823001.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-10 11:09:10 -05:00
Thomas Gleixner 35e13e9da9 Merge branch 'clocksource' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into timers/core
Pull clocksource watchdog updates from Paul McKenney:

 - Avoid accidental unstable marking of clocksources by rejecting
   clocksource measurements where the source of the skew is the delay
   reading reference clocksource itself.  This change avoids many of the
   current false positives caused by epic cache-thrashing workloads.

 - Reduce the default clocksource_watchdog() retries to 2, thus offsetting
   the increased overhead due to #1 above rereading the reference
   clocksource.

Link: https://lore.kernel.org/lkml/20220105001723.GA536708@paulmck-ThinkPad-P17-Gen-1
2022-01-10 13:57:17 +01:00
Eric W. Biederman 6707d0fc60 ptrace: Remove second setting of PT_SEIZED in ptrace_attach
The code is totally redundant remove it.

Link: https://lkml.kernel.org/r/20220103213312.9144-6-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:57 -06:00
Eric W. Biederman 1b5a42d9c8 taskstats: Cleanup the use of task->exit_code
In the function bacct_add_task the code reading task->exit_code was
introduced in commit f3cef7a994 ("[PATCH] csa: basic accounting over
taskstats"), and it is not entirely clear what the taskstats interface
is trying to return as only returning the exit_code of the first task
in a process doesn't make a lot of sense.

As best as I can figure the intent is to return task->exit_code after
a task exits.  The field is returned with per task fields, so the
exit_code of the entire process is not wanted.  Only the value of the
first task is returned so this is not a useful way to get the per task
ptrace stop code.  The ordinary case of returning this value is
returning after a task exits, which also precludes use for getting
a ptrace value.

It is common to for the first task of a process to also be the last
task of a process so this field may have done something reasonable by
accident in testing.

Make ac_exitcode a reliable per task value by always returning it for
every exited task.

Setting ac_exitcode in a sensible mannter makes it possible to continue
to provide this value going forward.

Cc: Balbir Singh <bsingharora@gmail.com>
Fixes: f3cef7a994 ("[PATCH] csa: basic accounting over taskstats")
Link: https://lkml.kernel.org/r/20220103213312.9144-5-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:57 -06:00
Eric W. Biederman 907c311f37 exit: Fix the exit_code for wait_task_zombie
The function wait_task_zombie is defined to always returns the process not
thread exit status.  Unfortunately when process group exit support
was added to wait_task_zombie the WNOWAIT case was overlooked.

Usually tsk->exit_code and tsk->signal->group_exit_code will be in sync
so fixing this is bug probably has no effect in practice.  But fix
it anyway so that people aren't scratching their heads about why
the two code paths are different.

History-Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Fixes: 2c66151cbc2c ("[PATCH] sys_exit() threading improvements, BK-curr")
Link: https://lkml.kernel.org/r/20220103213312.9144-3-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:57 -06:00
Eric W. Biederman 270b6541e6 exit: Coredumps reach do_group_exit
The comment about coredumps not reaching do_group_exit and the
corresponding BUG_ON are bogus.

What happens and has happened for years is that get_signal calls
do_coredump (which sets SIGNAL_GROUP_EXIT and group_exit_code) and
then do_group_exit passing the signal number.  Then do_group_exit
ignores the exit_code it is passed and uses signal->group_exit_code
from the coredump.

The comment and BUG_ON were correct when they were added during the
2.5 development cycle, but became obsolete and incorrect when
get_signal was changed to fall through to do_group_exit after
do_coredump in 2.6.10-rc2.

So remove the stale comment and BUG_ON

Fixes: 63bd6144f191 ("[PATCH] Invalid BUG_ONs in signal.c")
History-Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Link: https://lkml.kernel.org/r/20220103213312.9144-2-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:57 -06:00
Eric W. Biederman 2873cd31a2 exit: Remove profile_handoff_task
All profile_handoff_task does is notify the task_free_notifier chain.
The helpers task_handoff_register and task_handoff_unregister are used
to add and delete entries from that chain and are never called.

So remove the dead code and make it much easier to read and reason
about __put_task_struct.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/87fspyw6m0.fsf@email.froward.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:57 -06:00
Eric W. Biederman 2d4bcf886e exit: Remove profile_task_exit & profile_munmap
When I say remove I mean remove.  All profile_task_exit and
profile_munmap do is call a blocking notifier chain.  The helpers
profile_task_register and profile_task_unregister are not called
anywhere in the tree.  Which means this is all dead code.

So remove the dead code and make it easier to read do_exit.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lkml.kernel.org/r/20220103213312.9144-1-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:57 -06:00
Randy Dunlap 6410349ea5 signal: clean up kernel-doc comments
Fix kernel-doc warnings in kernel/signal.c:

kernel/signal.c:1830: warning: Function parameter or member 'force_coredump' not described in 'force_sig_seccomp'
kernel/signal.c:2873: warning: missing initial short description on line:
 * signal_delivered -

Also add a closing parenthesis to the comments in signal_delivered().

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Richard Weinberger <richard@nod.at>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Marco Elver <elver@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20211222031027.29694-1-rdunlap@infradead.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2022-01-08 12:43:57 -06:00
Eric W. Biederman 49697335e0 signal: Remove the helper signal_group_exit
This helper is misleading.  It tests for an ongoing exec as well as
the process having received a fatal signal.

Sometimes it is appropriate to treat an on-going exec differently than
a process that is shutting down due to a fatal signal.  In particular
taking the fast path out of exit_signals instead of retargeting
signals is not appropriate during exec, and not changing the the exit
code in do_group_exit during exec.

Removing the helper makes it more obvious what is going on as both
cases must be coded for explicitly.

While removing the helper fix the two cases where I have observed
using signal_group_exit resulted in the wrong result.

In exit_signals only test for SIGNAL_GROUP_EXIT so that signals are
retargetted during an exec.

In do_group_exit use 0 as the exit code during an exec as de_thread
does not set group_exit_code.  As best as I can determine
group_exit_code has been is set to 0 most of the time during
de_thread.  During a thread group stop group_exit_code is set to the
stop signal and when the thread group receives SIGCONT group_exit_code
is reset to 0.

Link: https://lkml.kernel.org/r/20211213225350.27481-8-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:57 -06:00
Eric W. Biederman 60700e38fb signal: Rename group_exit_task group_exec_task
The only remaining user of group_exit_task is exec.  Rename the field
so that it is clear which part of the code uses it.

Update the comment above the definition of group_exec_task to document
how it is currently used.

Link: https://lkml.kernel.org/r/20211213225350.27481-7-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:57 -06:00
Eric W. Biederman 2f824d4d19 signal: Remove SIGNAL_GROUP_COREDUMP
After the previous cleanups "signal->core_state" is set whenever
SIGNAL_GROUP_COREDUMP is set and "signal->core_state" is tested
whenver the code wants to know if a coredump is in progress.  The
remaining tests of SIGNAL_GROUP_COREDUMP also test to see if
SIGNAL_GROUP_EXIT is set.  Similarly the only place that sets
SIGNAL_GROUP_COREDUMP also sets SIGNAL_GROUP_EXIT.

Which makes SIGNAL_GROUP_COREDUMP unecessary and redundant. So stop
setting SIGNAL_GROUP_COREDUMP, stop testing SIGNAL_GROUP_COREDUMP, and
remove it's definition.

With the setting of SIGNAL_GROUP_COREDUMP gone, coredump_finish no
longer needs to clear SIGNAL_GROUP_COREDUMP out of signal->flags
by setting SIGNAL_GROUP_EXIT.

Link: https://lkml.kernel.org/r/20211213225350.27481-5-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:57 -06:00
Eric W. Biederman 7ba03471ac signal: Make coredump handling explicit in complete_signal
Ever since commit 6cd8f0acae ("coredump: ensure that SIGKILL always
kills the dumping thread") it has been possible for a SIGKILL received
during a coredump to set SIGNAL_GROUP_EXIT and trigger a process
shutdown (for a second time).

Update the logic to explicitly allow coredumps so that coredumps can
set SIGNAL_GROUP_EXIT and shutdown like an ordinary process.

Link: https://lkml.kernel.org/r/87zgo6ytyf.fsf_-_@email.froward.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:43:12 -06:00
Eric W. Biederman a0287db0f1 signal: Have prepare_signal detect coredumps using signal->core_state
In preparation for removing the flag SIGNAL_GROUP_COREDUMP, change
prepare_signal to test signal->core_state instead of the flag
SIGNAL_GROUP_COREDUMP.

Both fields are protected by siglock and both live in signal_struct so
there are no real tradeoffs here, just a change to which field is
being tested.

Link: https://lkml.kernel.org/r/20211213225350.27481-1-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/875yqu14co.fsf_-_@email.froward.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 12:42:35 -06:00
Eric W. Biederman de77c3a5b9 exit: Move force_uaccess back into do_exit
With kernel threads on architectures that still have set_fs/get_fs
running as KERNEL_DS moving force_uaccess_begin does not appear safe.
Calling force_uaccess_begin is a noop on anything people care about.

Update the comment to explain why this code while looking like an
obvious candidate for moving to make_task_dead probably needs to
remain in do_exit until set_fs/get_fs are entirely removed from the
kernel.

Fixes: 05ea0424f0 ("exit: Move oops specific logic from do_exit into make_task_dead")
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/YdUxGKRcSiDy8jGg@zeniv-ca.linux.org.uk
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 10:53:07 -06:00
Eric W. Biederman 912616f142 exit: Guarantee make_task_dead leaks the tsk when calling do_task_exit
Change the task state to EXIT_DEAD and take an extra rcu_refernce
to guarantee the task will not be reaped and that it will not be
freed.

Link: https://lkml.kernel.org/r/YdUzjrLAlRiNLQp2@zeniv-ca.linux.org.uk
Pointed-out-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: 7f80a2fd7d ("exit: Stop poorly open coding do_task_dead in make_task_dead")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 10:51:23 -06:00
Eric W. Biederman e32cf5dfbe kthread: Generalize pf_io_worker so it can point to struct kthread
The point of using set_child_tid to hold the kthread pointer was that
it already did what is necessary.  There are now restrictions on when
set_child_tid can be initialized and when set_child_tid can be used in
schedule_tail.  Which indicates that continuing to use set_child_tid
to hold the kthread pointer is a bad idea.

Instead of continuing to use the set_child_tid field of task_struct
generalize the pf_io_worker field of task_struct and use it to hold
the kthread pointer.

Rename pf_io_worker (which is a void * pointer) to worker_private so
it can be used to store kthreads struct kthread pointer.  Update the
kthread code to store the kthread pointer in the worker_private field.
Remove the places where set_child_tid had to be dealt with carefully
because kthreads also used it.

Link: https://lkml.kernel.org/r/CAHk-=wgtFAA9SbVYg0gR1tqPMC17-NYcs0GQkaYg1bGhh1uJQQ@mail.gmail.com
Link: https://lkml.kernel.org/r/87a6grvqy8.fsf_-_@email.froward.int.ebiederm.org
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08 09:39:49 -06:00
Ingo Molnar 0422fe2666 Merge branch 'linus' into irq/core, to fix conflict
Conflicts:
	drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2022-01-08 10:53:57 +01:00
Linus Torvalds d1587f7bfe Merge branch 'for-5.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
 "This contains the cgroup.procs permission check fixes so that they use
  the credentials at the time of open rather than write, which also
  fixes the cgroup namespace lifetime bug"

* 'for-5.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  selftests: cgroup: Test open-time cgroup namespace usage for migration checks
  selftests: cgroup: Test open-time credential usage for migration checks
  selftests: cgroup: Make cg_create() use 0755 for permission instead of 0644
  cgroup: Use open-time cgroup namespace for process migration perm checks
  cgroup: Allocate cgroup_file_ctx for kernfs_open_file->priv
  cgroup: Use open-time credentials for process migraton perm checks
2022-01-07 15:58:06 -08:00
Qi Zheng d4296faebd cpuset: convert 'allowed' in __cpuset_node_allowed() to be boolean
Convert 'allowed' in __cpuset_node_allowed() to be boolean since the
return types of node_isset() and __cpuset_node_allowed() are both
boolean.

Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-07 12:05:52 -10:00
David Vernet f5bdb34bf0 livepatch: Avoid CPU hogging with cond_resched
When initializing a 'struct klp_object' in klp_init_object_loaded(), and
performing relocations in klp_resolve_symbols(), klp_find_object_symbol()
is invoked to look up the address of a symbol in an already-loaded module
(or vmlinux). This, in turn, calls kallsyms_on_each_symbol() or
module_kallsyms_on_each_symbol() to find the address of the symbol that is
being patched.

It turns out that symbol lookups often take up the most CPU time when
enabling and disabling a patch, and may hog the CPU and cause other tasks
on that CPU's runqueue to starve -- even in paths where interrupts are
enabled.  For example, under certain workloads, enabling a KLP patch with
many objects or functions may cause ksoftirqd to be starved, and thus for
interrupts to be backlogged and delayed. This may end up causing TCP
retransmits on the host where the KLP patch is being applied, and in
general, may cause any interrupts serviced by softirqd to be delayed while
the patch is being applied.

So as to ensure that kallsyms_on_each_symbol() does not end up hogging the
CPU, this patch adds a call to cond_resched() in kallsyms_on_each_symbol()
and module_kallsyms_on_each_symbol(), which are invoked when doing a symbol
lookup in vmlinux and a module respectively.  Without this patch, if a
live-patch is applied on a 36-core Intel host with heavy TCP traffic, a
~10x spike is observed in TCP retransmits while the patch is being applied.
Additionally, collecting sched events with perf indicates that ksoftirqd is
awakened ~1.3 seconds before it's eventually scheduled.  With the patch, no
increase in TCP retransmit events is observed, and ksoftirqd is scheduled
shortly after it's awakened.

Signed-off-by: David Vernet <void@manifault.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20211229215646.830451-1-void@manifault.com
2022-01-07 12:00:53 +01:00
Sebastian Andrzej Siewior 5320eb42de irq: remove unused flags argument from __handle_irq_event_percpu()
The __IRQF_TIMER bit from the flags argument was used in
add_interrupt_randomness() to distinguish the timer interrupt from other
interrupts. This is no longer the case.

Remove the flags argument from __handle_irq_event_percpu().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-01-07 00:25:25 +01:00
Sebastian Andrzej Siewior 703f7066f4 random: remove unused irq_flags argument from add_interrupt_randomness()
Since commit
   ee3e00e9e7 ("random: use registers from interrupted code for CPU's w/o a cycle counter")

the irq_flags argument is no longer used.

Remove unused irq_flags.

Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: linux-hyperv@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-01-07 00:25:25 +01:00
Linus Torvalds b2b436ec02 Three minor tracing fixes:
- Fix missing prototypes in sample module for direct functions
 
 - Fix check of valid buffer in get_trace_buf()
 
 - Fix annotations of percpu pointers.
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Merge tag 'trace-v5.16-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Three minor tracing fixes:

   - Fix missing prototypes in sample module for direct functions

   - Fix check of valid buffer in get_trace_buf()

   - Fix annotations of percpu pointers"

* tag 'trace-v5.16-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Tag trace_percpu_buffer as a percpu pointer
  tracing: Fix check for trace_percpu_buffer validity in get_trace_buf()
  ftrace/samples: Add missing prototypes direct functions
2022-01-06 15:00:43 -08:00
Wei Yang f5f60d235e cgroup/rstat: check updated_next only for root
After commit dc26532aed ("cgroup: rstat: punt root-level optimization to
individual controllers"), each rstat on updated_children list has its
->updated_next not NULL.

This means we can remove the check on ->updated_next, if we make sure
the subtree from @root is on list, which could be done by checking
updated_next for root.

tj: Coding style fixes.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-06 11:50:34 -10:00
Wei Yang 0da41f7348 cgroup: rstat: explicitly put loop variant in while
Instead of do while unconditionally, let's put the loop variant in
while.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-06 11:10:06 -10:00
Tejun Heo e574576416 cgroup: Use open-time cgroup namespace for process migration perm checks
cgroup process migration permission checks are performed at write time as
whether a given operation is allowed or not is dependent on the content of
the write - the PID. This currently uses current's cgroup namespace which is
a potential security weakness as it may allow scenarios where a less
privileged process tricks a more privileged one into writing into a fd that
it created.

This patch makes cgroup remember the cgroup namespace at the time of open
and uses it for migration permission checks instad of current's. Note that
this only applies to cgroup2 as cgroup1 doesn't have namespace support.

This also fixes a use-after-free bug on cgroupns reported in

 https://lore.kernel.org/r/00000000000048c15c05d0083397@google.com

Note that backporting this fix also requires the preceding patch.

Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Reported-by: syzbot+50f5cf33a284ce738b62@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/00000000000048c15c05d0083397@google.com
Fixes: 5136f6365c ("cgroup: implement "nsdelegate" mount option")
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-06 11:02:29 -10:00
Tejun Heo 0d2b5955b3 cgroup: Allocate cgroup_file_ctx for kernfs_open_file->priv
of->priv is currently used by each interface file implementation to store
private information. This patch collects the current two private data usages
into struct cgroup_file_ctx which is allocated and freed by the common path.
This allows generic private data which applies to multiple files, which will
be used to in the following patch.

Note that cgroup_procs iterator is now embedded as procs.iter in the new
cgroup_file_ctx so that it doesn't need to be allocated and freed
separately.

v2: union dropped from cgroup_file_ctx and the procs iterator is embedded in
    cgroup_file_ctx as suggested by Linus.

v3: Michal pointed out that cgroup1's procs pidlist uses of->priv too.
    Converted. Didn't change to embedded allocation as cgroup1 pidlists get
    stored for caching.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
2022-01-06 11:02:29 -10:00
Tejun Heo 1756d7994a cgroup: Use open-time credentials for process migraton perm checks
cgroup process migration permission checks are performed at write time as
whether a given operation is allowed or not is dependent on the content of
the write - the PID. This currently uses current's credentials which is a
potential security weakness as it may allow scenarios where a less
privileged process tricks a more privileged one into writing into a fd that
it created.

This patch makes both cgroup2 and cgroup1 process migration interfaces to
use the credentials saved at the time of open (file->f_cred) instead of
current's.

Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Fixes: 187fe84067 ("cgroup: require write perm on common ancestor when moving processes on the default hierarchy")
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-06 11:02:28 -10:00
Toke Høiland-Jørgensen d53ad5d8b2 xdp: Move conversion to xdp_frame out of map functions
All map redirect functions except XSK maps convert xdp_buff to xdp_frame
before enqueueing it. So move this conversion of out the map functions
and into xdp_do_redirect(). This removes a bit of duplicated code, but more
importantly it makes it possible to support caller-allocated xdp_frame
structures, which will be added in a subsequent commit.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220103150812.87914-5-toke@redhat.com
2022-01-05 19:46:32 -08:00
Naveen N. Rao f28439db47 tracing: Tag trace_percpu_buffer as a percpu pointer
Tag trace_percpu_buffer as a percpu pointer to resolve warnings
reported by sparse:
  /linux/kernel/trace/trace.c:3218:46: warning: incorrect type in initializer (different address spaces)
  /linux/kernel/trace/trace.c:3218:46:    expected void const [noderef] __percpu *__vpp_verify
  /linux/kernel/trace/trace.c:3218:46:    got struct trace_buffer_struct *
  /linux/kernel/trace/trace.c:3234:9: warning: incorrect type in initializer (different address spaces)
  /linux/kernel/trace/trace.c:3234:9:    expected void const [noderef] __percpu *__vpp_verify
  /linux/kernel/trace/trace.c:3234:9:    got int *

Link: https://lkml.kernel.org/r/ebabd3f23101d89cb75671b68b6f819f5edc830b.1640255304.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 07d777fe8c ("tracing: Add percpu buffers for trace_printk()")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-05 18:53:49 -05:00
Naveen N. Rao 823e670f7e tracing: Fix check for trace_percpu_buffer validity in get_trace_buf()
With the new osnoise tracer, we are seeing the below splat:
    Kernel attempted to read user page (c7d880000) - exploit attempt? (uid: 0)
    BUG: Unable to handle kernel data access on read at 0xc7d880000
    Faulting instruction address: 0xc0000000002ffa10
    Oops: Kernel access of bad area, sig: 11 [#1]
    LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
    ...
    NIP [c0000000002ffa10] __trace_array_vprintk.part.0+0x70/0x2f0
    LR [c0000000002ff9fc] __trace_array_vprintk.part.0+0x5c/0x2f0
    Call Trace:
    [c0000008bdd73b80] [c0000000001c49cc] put_prev_task_fair+0x3c/0x60 (unreliable)
    [c0000008bdd73be0] [c000000000301430] trace_array_printk_buf+0x70/0x90
    [c0000008bdd73c00] [c0000000003178b0] trace_sched_switch_callback+0x250/0x290
    [c0000008bdd73c90] [c000000000e70d60] __schedule+0x410/0x710
    [c0000008bdd73d40] [c000000000e710c0] schedule+0x60/0x130
    [c0000008bdd73d70] [c000000000030614] interrupt_exit_user_prepare_main+0x264/0x270
    [c0000008bdd73de0] [c000000000030a70] syscall_exit_prepare+0x150/0x180
    [c0000008bdd73e10] [c00000000000c174] system_call_vectored_common+0xf4/0x278

osnoise tracer on ppc64le is triggering osnoise_taint() for negative
duration in get_int_safe_duration() called from
trace_sched_switch_callback()->thread_exit().

The problem though is that the check for a valid trace_percpu_buffer is
incorrect in get_trace_buf(). The check is being done after calculating
the pointer for the current cpu, rather than on the main percpu pointer.
Fix the check to be against trace_percpu_buffer.

Link: https://lkml.kernel.org/r/a920e4272e0b0635cf20c444707cbce1b2c8973d.1640255304.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: e2ace00117 ("tracing: Choose static tp_printk buffer by explicit nesting count")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-05 18:51:25 -05:00
Kris Van Hees a5bebc4f00 bpf: Fix verifier support for validation of async callbacks
Commit bfc6bb74e4 ("bpf: Implement verifier support for validation of async callbacks.")
added support for BPF_FUNC_timer_set_callback to
the __check_func_call() function.  The test in __check_func_call() is
flaweed because it can mis-interpret a regular BPF-to-BPF pseudo-call
as a BPF_FUNC_timer_set_callback callback call.

Consider the conditional in the code:

	if (insn->code == (BPF_JMP | BPF_CALL) &&
	    insn->imm == BPF_FUNC_timer_set_callback) {

The BPF_FUNC_timer_set_callback has value 170.  This means that if you
have a BPF program that contains a pseudo-call with an instruction delta
of 170, this conditional will be found to be true by the verifier, and
it will interpret the pseudo-call as a callback.  This leads to a mess
with the verification of the program because it makes the wrong
assumptions about the nature of this call.

Solution: include an explicit check to ensure that insn->src_reg == 0.
This ensures that calls cannot be mis-interpreted as an async callback
call.

Fixes: bfc6bb74e4 ("bpf: Implement verifier support for validation of async callbacks.")
Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220105210150.GH1559@oracle.com
2022-01-05 13:38:22 -08:00
Daniel Borkmann e60b0d12a9 bpf: Don't promote bogus looking registers after null check.
If we ever get to a point again where we convert a bogus looking <ptr>_or_null
typed register containing a non-zero fixed or variable offset, then lets not
reset these bounds to zero since they are not and also don't promote the register
to a <ptr> type, but instead leave it as <ptr>_or_null. Converting to a unknown
register could be an avenue as well, but then if we run into this case it would
allow to leak a kernel pointer this way.

Fixes: f1174f77b5 ("bpf/verifier: rework value tracking")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-05 12:00:19 -08:00
Catalin Marinas 945409a6ef Merge branches 'for-next/misc', 'for-next/cache-ops-dzp', 'for-next/stacktrace', 'for-next/xor-neon', 'for-next/kasan', 'for-next/armv8_7-fp', 'for-next/atomics', 'for-next/bti', 'for-next/sve', 'for-next/kselftest' and 'for-next/kcsan', remote-tracking branch 'arm64/for-next/perf' into for-next/core
* arm64/for-next/perf: (32 commits)
  arm64: perf: Don't register user access sysctl handler multiple times
  drivers: perf: marvell_cn10k: fix an IS_ERR() vs NULL check
  perf/smmuv3: Fix unused variable warning when CONFIG_OF=n
  arm64: perf: Support new DT compatibles
  arm64: perf: Simplify registration boilerplate
  arm64: perf: Support Denver and Carmel PMUs
  drivers/perf: hisi: Add driver for HiSilicon PCIe PMU
  docs: perf: Add description for HiSilicon PCIe PMU driver
  dt-bindings: perf: Add YAML schemas for Marvell CN10K LLC-TAD pmu bindings
  drivers: perf: Add LLC-TAD perf counter support
  perf/smmuv3: Synthesize IIDR from CoreSight ID registers
  perf/smmuv3: Add devicetree support
  dt-bindings: Add Arm SMMUv3 PMCG binding
  perf/arm-cmn: Add debugfs topology info
  perf/arm-cmn: Add CI-700 Support
  dt-bindings: perf: arm-cmn: Add CI-700
  perf/arm-cmn: Support new IP features
  perf/arm-cmn: Demarcate CMN-600 specifics
  perf/arm-cmn: Move group validation data off-stack
  perf/arm-cmn: Optimise DTC counter accesses
  ...

* for-next/misc:
  : Miscellaneous patches
  arm64: Use correct method to calculate nomap region boundaries
  arm64: Drop outdated links in comments
  arm64: errata: Fix exec handling in erratum 1418040 workaround
  arm64: Unhash early pointer print plus improve comment
  asm-generic: introduce io_stop_wc() and add implementation for ARM64
  arm64: remove __dma_*_area() aliases
  docs/arm64: delete a space from tagged-address-abi
  arm64/fp: Add comments documenting the usage of state restore functions
  arm64: mm: Use asid feature macro for cheanup
  arm64: mm: Rename asid2idx() to ctxid2asid()
  arm64: kexec: reduce calls to page_address()
  arm64: extable: remove unused ex_handler_t definition
  arm64: entry: Use SDEI event constants
  arm64: Simplify checking for populated DT
  arm64/kvm: Fix bitrotted comment for SVE handling in handle_exit.c

* for-next/cache-ops-dzp:
  : Avoid DC instructions when DCZID_EL0.DZP == 1
  arm64: mte: DC {GVA,GZVA} shouldn't be used when DCZID_EL0.DZP == 1
  arm64: clear_page() shouldn't use DC ZVA when DCZID_EL0.DZP == 1

* for-next/stacktrace:
  : Unify the arm64 unwind code
  arm64: Make some stacktrace functions private
  arm64: Make dump_backtrace() use arch_stack_walk()
  arm64: Make profile_pc() use arch_stack_walk()
  arm64: Make return_address() use arch_stack_walk()
  arm64: Make __get_wchan() use arch_stack_walk()
  arm64: Make perf_callchain_kernel() use arch_stack_walk()
  arm64: Mark __switch_to() as __sched
  arm64: Add comment for stack_info::kr_cur
  arch: Make ARCH_STACKWALK independent of STACKTRACE

* for-next/xor-neon:
  : Use SHA3 instructions to speed up XOR
  arm64/xor: use EOR3 instructions when available

* for-next/kasan:
  : Log potential KASAN shadow aliases
  arm64: mm: log potential KASAN shadow alias
  arm64: mm: use die_kernel_fault() in do_mem_abort()

* for-next/armv8_7-fp:
  : Add HWCAPS for ARMv8.7 FEAT_AFP amd FEAT_RPRES
  arm64: cpufeature: add HWCAP for FEAT_RPRES
  arm64: add ID_AA64ISAR2_EL1 sys register
  arm64: cpufeature: add HWCAP for FEAT_AFP

* for-next/atomics:
  : arm64 atomics clean-ups and codegen improvements
  arm64: atomics: lse: define RETURN ops in terms of FETCH ops
  arm64: atomics: lse: improve constraints for simple ops
  arm64: atomics: lse: define ANDs in terms of ANDNOTs
  arm64: atomics lse: define SUBs in terms of ADDs
  arm64: atomics: format whitespace consistently

* for-next/bti:
  : BTI clean-ups
  arm64: Ensure that the 'bti' macro is defined where linkage.h is included
  arm64: Use BTI C directly and unconditionally
  arm64: Unconditionally override SYM_FUNC macros
  arm64: Add macro version of the BTI instruction
  arm64: ftrace: add missing BTIs
  arm64: kexec: use __pa_symbol(empty_zero_page)
  arm64: update PAC description for kernel

* for-next/sve:
  : SVE code clean-ups and refactoring in prepararation of Scalable Matrix Extensions
  arm64/sve: Minor clarification of ABI documentation
  arm64/sve: Generalise vector length configuration prctl() for SME
  arm64/sve: Make sysctl interface for SVE reusable by SME

* for-next/kselftest:
  : arm64 kselftest additions
  kselftest/arm64: Add pidbench for floating point syscall cases
  kselftest/arm64: Add a test program to exercise the syscall ABI
  kselftest/arm64: Allow signal tests to trigger from a function
  kselftest/arm64: Parameterise ptrace vector length information

* for-next/kcsan:
  : Enable KCSAN for arm64
  arm64: Enable KCSAN
2022-01-05 18:14:32 +00:00
Wei Liu 2deb55d9f5 swiotlb: Add CONFIG_HAS_IOMEM check around swiotlb_mem_remap()
HAS_IOMEM option may not be selected on some platforms (e.g, s390) and
this will cause compilation failure due to missing memremap()
implementation.

Fix it by stubbing out swiotlb_mem_remap when CONFIG_HAS_IOMEM is not
set.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2022-01-04 16:11:19 +00:00
Yang Yingliang 50a0f3f55e livepatch: Fix missing unlock on error in klp_enable_patch()
Add missing unlock when try_module_get() fails in klp_enable_patch().

Fixes: 5ef3dd2055 ("livepatch: Fix kobject refcount bug on klp_init_patch_early failure path")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: David Vernet <void@manifault.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20211225025115.475348-1-yangyingliang@huawei.com
2022-01-04 13:57:19 +01:00
David Vernet 5ef3dd2055 livepatch: Fix kobject refcount bug on klp_init_patch_early failure path
When enabling a klp patch with klp_enable_patch(), klp_init_patch_early()
is invoked to initialize the kobjects for the patch itself, as well as the
'struct klp_object' and 'struct klp_func' objects that comprise it.
However, there are some error paths in klp_enable_patch() where some
kobjects may have been initialized with kobject_init(), but an error code
is still returned due to e.g. a 'struct klp_object' having a NULL funcs
pointer.

In these paths, the initial reference of the kobject of the 'struct
klp_patch' may never be released, along with one or more of its objects and
their functions, as kobject_put() is not invoked on the cleanup path if
klp_init_patch_early() returns an error code.

For example, if an object entry such as the following were added to the
sample livepatch module's klp patch, it would cause the vmlinux klp_object,
and its klp_func which updates 'cmdline_proc_show', to never be released:

static struct klp_object objs[] = {
	{
		/* name being NULL means vmlinux */
		.funcs = funcs,
	},
	{
		/* NULL funcs -- would cause reference leak */
		.name = "kvm",
	}, { }
};

Without this change, if CONFIG_DEBUG_KOBJECT is enabled, and the sample klp
patch is loaded, the kobjects (the patch, the vmlinux 'struct klp_object',
and its func) are observed as initialized, but never released, in the dmesg
log output.  With the change, these kobject references no longer fail to be
released as the error case is properly handled before they are initialized.

Signed-off-by: David Vernet <void@manifault.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2022-01-04 13:54:24 +01:00
David S. Miller e63a023489 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-12-30

The following pull-request contains BPF updates for your *net-next* tree.

We've added 72 non-merge commits during the last 20 day(s) which contain
a total of 223 files changed, 3510 insertions(+), 1591 deletions(-).

The main changes are:

1) Automatic setrlimit in libbpf when bpf is memcg's in the kernel, from Andrii.

2) Beautify and de-verbose verifier logs, from Christy.

3) Composable verifier types, from Hao.

4) bpf_strncmp helper, from Hou.

5) bpf.h header dependency cleanup, from Jakub.

6) get_func_[arg|ret|arg_cnt] helpers, from Jiri.

7) Sleepable local storage, from KP.

8) Extend kfunc with PTR_TO_CTX, PTR_TO_MEM argument support, from Kumar.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-31 14:35:40 +00:00
Leon Huayra 9e6b19a66d bpf: Fix typo in a comment in bpf lpm_trie.
Fix typo in a comment in trie_update_elem().

Signed-off-by: Leon Huayra <hffilwlqm@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211229144422.70339-1-hffilwlqm@gmail.com
2021-12-30 18:42:34 -08:00
Jakub Kicinski aec53e60e0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
  commit 077cdda764 ("net/mlx5e: TC, Fix memory leak with rules with internal port")
  commit 31108d142f ("net/mlx5: Fix some error handling paths in 'mlx5e_tc_add_fdb_flow()'")
  commit 4390c6edc0 ("net/mlx5: Fix some error handling paths in 'mlx5e_tc_add_fdb_flow()'")
  https://lore.kernel.org/all/20211229065352.30178-1-saeed@kernel.org/

net/smc/smc_wr.c
  commit 49dc9013e3 ("net/smc: Use the bitmap API when applicable")
  commit 349d43127d ("net/smc: fix kernel panic caused by race of smc_sock")
  bitmap_zero()/memset() is removed by the fix

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-30 12:12:12 -08:00
Jakub Kicinski 3b80b73a4b net: Add includes masked by netdevice.h including uapi/bpf.h
Add missing includes unmasked by the subsequent change.

Mostly network drivers missing an include for XDP_PACKET_HEADROOM.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211230012742.770642-2-kuba@kernel.org
2021-12-29 20:03:05 -08:00
KP Singh 0fe4b381a5 bpf: Allow bpf_local_storage to be used by sleepable programs
Other maps like hashmaps are already available to sleepable programs.
Sleepable BPF programs run under trace RCU. Allow task, sk and inode
storage to be used from sleepable programs. This allows sleepable and
non-sleepable programs to provide shareable annotations on kernel
objects.

Sleepable programs run in trace RCU where as non-sleepable programs run
in a normal RCU critical section i.e.  __bpf_prog_enter{_sleepable}
and __bpf_prog_exit{_sleepable}) (rcu_read_lock or rcu_read_lock_trace).

In order to make the local storage maps accessible to both sleepable
and non-sleepable programs, one needs to call both
call_rcu_tasks_trace and call_rcu to wait for both trace and classical
RCU grace periods to expire before freeing memory.

Paul's work on call_rcu_tasks_trace allows us to have per CPU queueing
for call_rcu_tasks_trace. This behaviour can be achieved by setting
rcupdate.rcu_task_enqueue_lim=<num_cpus> boot parameter.

In light of these new performance changes and to keep the local storage
code simple, avoid adding a new flag for sleepable maps / local storage
to select the RCU synchronization (trace / classical).

Also, update the dereferencing of the pointers to use
rcu_derference_check (with either the trace or normal RCU locks held)
with a common bpf_rcu_lock_held helper method.

Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20211224152916.1550677-2-kpsingh@kernel.org
2021-12-29 17:54:40 -08:00
Haimin Zhang 3ccdcee284 bpf: Add missing map_get_next_key method to bloom filter map.
Without it, kernel crashes in map_get_next_key().

Fixes: 9330986c03 ("bpf: Add bloom filter map implementation")
Reported-by: TCS Robot <tcs_robot@tencent.com>
Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Joanne Koong <joannekoong@fb.com>
Link: https://lore.kernel.org/bpf/1640776802-22421-1-git-send-email-tcs.kernel@gmail.com
2021-12-29 09:38:31 -08:00
Jakub Kicinski b6459415b3 net: Don't include filter.h from net/sock.h
sock.h is pretty heavily used (5k objects rebuilt on x86 after
it's touched). We can drop the include of filter.h from it and
add a forward declaration of struct sk_filter instead.
This decreases the number of rebuilt objects when bpf.h
is touched from ~5k to ~1k.

There's a lot of missing includes this was masking. Primarily
in networking tho, this time.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org
2021-12-29 08:48:14 -08:00
Borislav Petkov 5abb065dca notifier: Return an error when a callback has already been registered
Return -EEXIST when a notifier callback has already been registered on a
notifier chain.

This should avoid any homegrown registration tracking at the callsite
like

  https://lore.kernel.org/amd-gfx/20210512013058.6827-1-mukul.joshi@amd.com

for example.

This version is an alternative of

  https://lore.kernel.org/r/20211108101157.15189-1-bp@alien8.de

which needed to touch every caller not checking the registration
routine's return value.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/YcSWNdUBS8A2ZB3s@zn.tnic
2021-12-29 10:37:33 +01:00
Greg Kroah-Hartman cf6299b610 kobject: remove kset from struct kset_uevent_ops callbacks
There is no need to pass the pointer to the kset in the struct
kset_uevent_ops callbacks as no one uses it, so just remove that pointer
entirely.

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Wedson Almeida Filho <wedsonaf@google.com>
Link: https://lore.kernel.org/r/20211227163924.3970661-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-28 11:26:18 +01:00
Wedson Almeida Filho ee6d3dd4ed driver core: make kobj_type constant.
This way instances of kobj_type (which contain function pointers) can be
stored in .rodata, which means that they cannot be [easily/accidentally]
modified at runtime.

Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Link: https://lore.kernel.org/r/20211224231345.777370-1-wedsonaf@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-27 10:40:00 +01:00
Linus Torvalds d0cc67b278 Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "9 patches.

  Subsystems affected by this patch series: mm (kfence, mempolicy,
  memory-failure, pagemap, pagealloc, damon, and memory-failure),
  core-kernel, and MAINTAINERS"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm/hwpoison: clear MF_COUNT_INCREASED before retrying get_any_page()
  mm/damon/dbgfs: protect targets destructions with kdamond_lock
  mm/page_alloc: fix __alloc_size attribute for alloc_pages_exact_nid
  mm: delete unsafe BUG from page_cache_add_speculative()
  mm, hwpoison: fix condition in free hugetlb page path
  MAINTAINERS: mark more list instances as moderated
  kernel/crash_core: suppress unknown crashkernel parameter warning
  mm: mempolicy: fix THP allocations escaping mempolicy restrictions
  kfence: fix memory leak when cat kfence objects
2021-12-25 12:30:03 -08:00
Philipp Rudo 71d2bcec2d kernel/crash_core: suppress unknown crashkernel parameter warning
When booting with crashkernel= on the kernel command line a warning
similar to

    Kernel command line: ro console=ttyS0 crashkernel=256M
    Unknown kernel command line parameters "crashkernel=256M", will be passed to user space.

is printed.

This comes from crashkernel= being parsed independent from the kernel
parameter handling mechanism.  So the code in init/main.c doesn't know
that crashkernel= is a valid kernel parameter and prints this incorrect
warning.

Suppress the warning by adding a dummy early_param handler for
crashkernel=.

Link: https://lkml.kernel.org/r/20211208133443.6867-1-prudo@redhat.com
Fixes: 86d1919a4f ("init: print out unknown kernel parameters")
Signed-off-by: Philipp Rudo <prudo@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-25 12:20:55 -08:00
Linus Torvalds 7fe2bc1b64 Merge branch 'ucount-rlimit-fixes-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ucount fix from Eric Biederman:
 "This fixes a silly logic bug in the ucount rlimits code, where it was
  comparing against the wrong limit"

* 'ucount-rlimit-fixes-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  ucounts: Fix rlimit max values check
2021-12-23 15:27:02 -08:00
David Vernet e368cd7288 Documentation: livepatch: Add livepatch API page
The livepatch subsystem has several exported functions and objects with
kerneldoc comments. Though the livepatch documentation contains handwritten
descriptions of all of these exported functions, they are currently not
pulled into the docs build using the kernel-doc directive.

In order to allow readers of the documentation to see the full kerneldoc
comments in the generated documentation files, this change adds a new
Documentation/livepatch/api.rst page which contains kernel-doc directives
to link the kerneldoc comments directly in the documentation.  With this,
all of the hand-written descriptions of the APIs now cross-reference the
kerneldoc comments on the new Livepatching APIs page, and running
./scripts/find-unused-docs.sh on kernel/livepatch no longer shows any files
as missing documentation.

Note that all of the handwritten API descriptions were left alone with the
exception of Documentation/livepatch/system-state.rst, which was updated to
allow the cross-referencing to work correctly. The file now follows the
cross-referencing formatting guidance specified in
Documentation/doc-guide/kernel-doc.rst. Furthermore, some comments around
klp_shadow_free_all() were updated to say <_, id> rather than <*, id> to
match the rest of the file, and to prevent the docs build from emitting an
"Inline emphasis start-string without end string" error.

Signed-off-by: David Vernet <void@manifault.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20211221145743.4098360-1-void@manifault.com
2021-12-23 11:35:53 +01:00
Eric W. Biederman 00580f03af kthread: Never put_user the set_child_tid address
Kernel threads abuse set_child_tid.  Historically that has been fine
as set_child_tid was initialized after the kernel thread had been
forked.  Unfortunately storing struct kthread in set_child_tid after
the thread is running makes struct kthread being unusable for storing
result codes of the thread.

When set_child_tid is set to struct kthread during fork that results
in schedule_tail writing the thread id to the beggining of struct
kthread (if put_user does not realize it is a kernel address).

Solve this by skipping the put_user for all kthreads.

Reported-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lkml.kernel.org/r/YcNsG0Lp94V13whH@archlinux-ax161
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-22 16:57:50 -06:00
Xiu Jianfeng 0dd668d208 bpf: Use struct_size() helper
In an effort to avoid open-coded arithmetic in the kernel, use the
struct_size() helper instead of open-coded calculation.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://github.com/KSPP/linux/issues/160
Link: https://lore.kernel.org/bpf/20211220113048.2859-1-xiujianfeng@huawei.com
2021-12-21 15:35:48 -08:00
Eric W. Biederman dd621ee0cf kthread: Warn about failed allocations for the init kthread
Failed allocates are not expected when setting up the initial task and
it is not really possible to handle them either.  So I added a warning
to report if such an allocation failure ever happens.

Correct the sense of the warning so it warns when an allocation failure
happens not when the allocation succeeded.  Oops.

Reported-by: kernel test robot <oliver.sang@intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: https://lkml.kernel.org/r/20211221231611.785b74cf@canb.auug.org.au
Link: https://lkml.kernel.org/r/CA+G9fYvLaR5CF777CKeWTO+qJFTN6vAvm95gtzN+7fw3Wi5hkA@mail.gmail.com
Link: https://lkml.kernel.org/r/20211216102956.GC10708@xsang-OptiPlex-9020
Fixes: 40966e316f ("kthread: Ensure struct kthread is present for all kthreads")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-21 16:20:51 -06:00
Wander Lairson Costa 361c81dbc5 blktrace: switch trace spinlock to a raw spinlock
The running_trace_lock protects running_trace_list and is acquired
within the tracepoint which implies disabled preemption. The spinlock_t
typed lock can not be acquired with disabled preemption on PREEMPT_RT
because it becomes a sleeping lock.
The runtime of the tracepoint depends on the number of entries in
running_trace_list and has no limit. The blk-tracer is considered debug
code and higher latencies here are okay.

Make running_trace_lock a raw_spinlock_t.

Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Link: https://lore.kernel.org/r/20211220192827.38297-1-wander@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-20 13:50:14 -07:00
Xiu Jianfeng 30561b51cc audit: use struct_size() helper in audit_[send|make]_reply()
Make use of struct_size() helper instead of an open-coded calculation.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-12-20 14:42:11 -05:00
Tianyu Lan 1a5e91d837 swiotlb: Add swiotlb bounce buffer remap function for HV IVM
In Isolation VM with AMD SEV, bounce buffer needs to be accessed via
extra address space which is above shared_gpa_boundary (E.G 39 bit
address line) reported by Hyper-V CPUID ISOLATION_CONFIG. The access
physical address will be original physical address + shared_gpa_boundary.
The shared_gpa_boundary in the AMD SEV SNP spec is called virtual top of
memory(vTOM). Memory addresses below vTOM are automatically treated as
private while memory above vTOM is treated as shared.

Expose swiotlb_unencrypted_base for platforms to set unencrypted
memory base offset and platform calls swiotlb_update_mem_attributes()
to remap swiotlb mem to unencrypted address space. memremap() can
not be called in the early stage and so put remapping code into
swiotlb_update_mem_attributes(). Store remap address and use it to copy
data from/to swiotlb bounce buffer.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20211213071407.314309-2-ltykernel@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-12-20 18:01:09 +00:00
Eric W. Biederman ff8288ff47 fork: Rename bad_fork_cleanup_threadgroup_lock to bad_fork_cleanup_delayacct
I just fixed a bug in copy_process when using the label
bad_fork_cleanup_threadgroup_lock.  While fixing the bug I looked
closer at the label and realized it has been misnamed since
568ac88821 ("cgroup: reduce read locked section of
cgroup_threadgroup_rwsem during fork").

Fix the name so that fork is easier to understand.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-20 10:51:00 -06:00
Eric W. Biederman 6692c98c7d fork: Stop protecting back_fork_cleanup_cgroup_lock with CONFIG_NUMA
Mark Brown <broonie@kernel.org> reported:

> This is also causing further build errors including but not limited to:
>
> /tmp/next/build/kernel/fork.c: In function 'copy_process':
> /tmp/next/build/kernel/fork.c:2106:4: error: label 'bad_fork_cleanup_threadgroup_lock' used but not defined
>  2106 |    goto bad_fork_cleanup_threadgroup_lock;
>       |    ^~~~

It turns out that I messed up and was depending upon a label protected
by an ifdef.  Move the label out of the ifdef as the ifdef around the label
no longer makes sense (if it ever did).

Link: https://lkml.kernel.org/r/YbugCP144uxXvRsk@sirena.org.uk
Fixes: 40966e316f ("kthread: Ensure struct kthread is present for all kthreads")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-20 10:50:51 -06:00
Linus Torvalds e1fe1b10e6 - Make sure the CLOCK_REALTIME to CLOCK_MONOTONIC offset is never positive
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Merge tag 'timers_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fix from Borislav Petkov:

 - Make sure the CLOCK_REALTIME to CLOCK_MONOTONIC offset is never
   positive

* tag 'timers_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Really make sure wall_to_monotonic isn't positive
2021-12-19 12:23:18 -08:00
Linus Torvalds 909e1d166c - Fix the condition checking when the optimistic spinning of a waiter needs
to be terminated
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Merge tag 'locking_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fix from Borislav Petkov:

 - Fix the rtmutex condition checking when the optimistic spinning of a
   waiter needs to be terminated

* tag 'locking_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rtmutex: Fix incorrect condition in rtmutex_spin_on_owner()
2021-12-19 12:17:26 -08:00
Linus Torvalds c36d891d78 - Prevent lock contention on the new sigaltstack lock on the common-case
path, when no changes have been made to the alternative signal stack.
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Merge tag 'core_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull signal handlign fix from Borislav Petkov:

 - Prevent lock contention on the new sigaltstack lock on the
   common-case path, when no changes have been made to the alternative
   signal stack.

* tag 'core_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  signal: Skip the altstack update when not needed
2021-12-19 11:46:54 -08:00
Kumar Kartikeya Dwivedi 3363bd0cfb bpf: Extend kfunc with PTR_TO_CTX, PTR_TO_MEM argument support
Allow passing PTR_TO_CTX, if the kfunc expects a matching struct type,
and punt to PTR_TO_MEM block if reg->type does not fall in one of
PTR_TO_BTF_ID or PTR_TO_SOCK* types. This will be used by future commits
to get access to XDP and TC PTR_TO_CTX, and pass various data (flags,
l4proto, netns_id, etc.) encoded in opts struct passed as pointer to
kfunc.

For PTR_TO_MEM support, arguments are currently limited to pointer to
scalar, or pointer to struct composed of scalars. This is done so that
unsafe scenarios (like passing PTR_TO_MEM where PTR_TO_BTF_ID of
in-kernel valid structure is expected, which may have pointers) are
avoided. Since the argument checking happens basd on argument register
type, it is not easy to ascertain what the expected type is. In the
future, support for PTR_TO_MEM for kfunc can be extended to serve other
usecases. The struct type whose pointer is passed in may have maximum
nesting depth of 4, all recursively composed of scalars or struct with
scalars.

Future commits will add negative tests that check whether these
restrictions imposed for kfunc arguments are duly rejected by BPF
verifier or not.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211217015031.1278167-4-memxor@gmail.com
2021-12-18 18:11:47 -08:00
Hao Luo 216e3cd2f2 bpf: Add MEM_RDONLY for helper args that are pointers to rdonly mem.
Some helper functions may modify its arguments, for example,
bpf_d_path, bpf_get_stack etc. Previously, their argument types
were marked as ARG_PTR_TO_MEM, which is compatible with read-only
mem types, such as PTR_TO_RDONLY_BUF. Therefore it's legitimate,
but technically incorrect, to modify a read-only memory by passing
it into one of such helper functions.

This patch tags the bpf_args compatible with immutable memory with
MEM_RDONLY flag. The arguments that don't have this flag will be
only compatible with mutable memory types, preventing the helper
from modifying a read-only memory. The bpf_args that have
MEM_RDONLY are compatible with both mutable memory and immutable
memory.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211217003152.48334-9-haoluo@google.com
2021-12-18 13:27:41 -08:00
Hao Luo 34d3a78c68 bpf: Make per_cpu_ptr return rdonly PTR_TO_MEM.
Tag the return type of {per, this}_cpu_ptr with RDONLY_MEM. The
returned value of this pair of helpers is kernel object, which
can not be updated by bpf programs. Previously these two helpers
return PTR_OT_MEM for kernel objects of scalar type, which allows
one to directly modify the memory. Now with RDONLY_MEM tagging,
the verifier will reject programs that write into RDONLY_MEM.

Fixes: 63d9b80dcf ("bpf: Introducte bpf_this_cpu_ptr()")
Fixes: eaa6bcb71e ("bpf: Introduce bpf_per_cpu_ptr()")
Fixes: 4976b718c3 ("bpf: Introduce pseudo_btf_id")
Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211217003152.48334-8-haoluo@google.com
2021-12-18 13:27:41 -08:00
Hao Luo cf9f2f8d62 bpf: Convert PTR_TO_MEM_OR_NULL to composable types.
Remove PTR_TO_MEM_OR_NULL and replace it with PTR_TO_MEM combined with
flag PTR_MAYBE_NULL.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211217003152.48334-7-haoluo@google.com
2021-12-18 13:27:41 -08:00
Hao Luo 20b2aff4bc bpf: Introduce MEM_RDONLY flag
This patch introduce a flag MEM_RDONLY to tag a reg value
pointing to read-only memory. It makes the following changes:

1. PTR_TO_RDWR_BUF -> PTR_TO_BUF
2. PTR_TO_RDONLY_BUF -> PTR_TO_BUF | MEM_RDONLY

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211217003152.48334-6-haoluo@google.com
2021-12-18 13:27:41 -08:00
Hao Luo c25b2ae136 bpf: Replace PTR_TO_XXX_OR_NULL with PTR_TO_XXX | PTR_MAYBE_NULL
We have introduced a new type to make bpf_reg composable, by
allocating bits in the type to represent flags.

One of the flags is PTR_MAYBE_NULL which indicates a pointer
may be NULL. This patch switches the qualified reg_types to
use this flag. The reg_types changed in this patch include:

1. PTR_TO_MAP_VALUE_OR_NULL
2. PTR_TO_SOCKET_OR_NULL
3. PTR_TO_SOCK_COMMON_OR_NULL
4. PTR_TO_TCP_SOCK_OR_NULL
5. PTR_TO_BTF_ID_OR_NULL
6. PTR_TO_MEM_OR_NULL
7. PTR_TO_RDONLY_BUF_OR_NULL
8. PTR_TO_RDWR_BUF_OR_NULL

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211217003152.48334-5-haoluo@google.com
2021-12-18 13:27:23 -08:00
Hao Luo 3c48073226 bpf: Replace RET_XXX_OR_NULL with RET_XXX | PTR_MAYBE_NULL
We have introduced a new type to make bpf_ret composable, by
reserving high bits to represent flags.

One of the flag is PTR_MAYBE_NULL, which indicates a pointer
may be NULL. When applying this flag to ret_types, it means
the returned value could be a NULL pointer. This patch
switches the qualified arg_types to use this flag.
The ret_types changed in this patch include:

1. RET_PTR_TO_MAP_VALUE_OR_NULL
2. RET_PTR_TO_SOCKET_OR_NULL
3. RET_PTR_TO_TCP_SOCK_OR_NULL
4. RET_PTR_TO_SOCK_COMMON_OR_NULL
5. RET_PTR_TO_ALLOC_MEM_OR_NULL
6. RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL
7. RET_PTR_TO_BTF_ID_OR_NULL

This patch doesn't eliminate the use of these names, instead
it makes them aliases to 'RET_PTR_TO_XXX | PTR_MAYBE_NULL'.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211217003152.48334-4-haoluo@google.com
2021-12-18 12:48:08 -08:00
Hao Luo 48946bd6a5 bpf: Replace ARG_XXX_OR_NULL with ARG_XXX | PTR_MAYBE_NULL
We have introduced a new type to make bpf_arg composable, by
reserving high bits of bpf_arg to represent flags of a type.

One of the flags is PTR_MAYBE_NULL which indicates a pointer
may be NULL. When applying this flag to an arg_type, it means
the arg can take NULL pointer. This patch switches the
qualified arg_types to use this flag. The arg_types changed
in this patch include:

1. ARG_PTR_TO_MAP_VALUE_OR_NULL
2. ARG_PTR_TO_MEM_OR_NULL
3. ARG_PTR_TO_CTX_OR_NULL
4. ARG_PTR_TO_SOCKET_OR_NULL
5. ARG_PTR_TO_ALLOC_MEM_OR_NULL
6. ARG_PTR_TO_STACK_OR_NULL

This patch does not eliminate the use of these arg_types, instead
it makes them an alias to the 'ARG_XXX | PTR_MAYBE_NULL'.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211217003152.48334-3-haoluo@google.com
2021-12-18 12:47:24 -08:00
Thomas Gleixner f16cc980d6 Merge branch 'locking/urgent' into locking/core
Pick up the spin loop condition fix.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2021-12-18 10:57:03 +01:00
Zqiang 8f556a326c locking/rtmutex: Fix incorrect condition in rtmutex_spin_on_owner()
Optimistic spinning needs to be terminated when the spinning waiter is not
longer the top waiter on the lock, but the condition is negated. It
terminates if the waiter is the top waiter, which is defeating the whole
purpose.

Fixes: c3123c4314 ("locking/rtmutex: Dont dereference waiter lockless")
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211217074207.77425-1-qiang1.zhang@intel.com
2021-12-18 10:55:51 +01:00
Yu Liao 4e8c11b6b3 timekeeping: Really make sure wall_to_monotonic isn't positive
Even after commit e1d7ba8735 ("time: Always make sure wall_to_monotonic
isn't positive") it is still possible to make wall_to_monotonic positive
by running the following code:

    int main(void)
    {
        struct timespec time;

        clock_gettime(CLOCK_MONOTONIC, &time);
        time.tv_nsec = 0;
        clock_settime(CLOCK_REALTIME, &time);
        return 0;
    }

The reason is that the second parameter of timespec64_compare(), ts_delta,
may be unnormalized because the delta is calculated with an open coded
substraction which causes the comparison of tv_sec to yield the wrong
result:

  wall_to_monotonic = { .tv_sec = -10, .tv_nsec =  900000000 }
  ts_delta 	    = { .tv_sec =  -9, .tv_nsec = -900000000 }

That makes timespec64_compare() claim that wall_to_monotonic < ts_delta,
but actually the result should be wall_to_monotonic > ts_delta.

After normalization, the result of timespec64_compare() is correct because
the tv_sec comparison is not longer misleading:

  wall_to_monotonic = { .tv_sec = -10, .tv_nsec =  900000000 }
  ts_delta 	    = { .tv_sec = -10, .tv_nsec =  100000000 }

Use timespec64_sub() to ensure that ts_delta is normalized, which fixes the
issue.

Fixes: e1d7ba8735 ("time: Always make sure wall_to_monotonic isn't positive")
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211213135727.1656662-1-liaoyu15@huawei.com
2021-12-17 23:06:22 +01:00
Christy Lee 496f332404 Only output backtracking information in log level 2
Backtracking information is very verbose, don't print it in log
level 1 to improve readability.

Signed-off-by: Christy Lee <christylee@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211216213358.3374427-4-christylee@fb.com
2021-12-16 19:44:34 -08:00
Christy Lee 2e5766483c bpf: Right align verifier states in verifier logs.
Make the verifier logs more readable, print the verifier states
on the corresponding instruction line. If the previous line was
not a bpf instruction, then print the verifier states on its own
line.

Before:

Validating test_pkt_access_subprog3() func#3...
86: R1=invP(id=0) R2=ctx(id=0,off=0,imm=0) R10=fp0
; int test_pkt_access_subprog3(int val, struct __sk_buff *skb)
86: (bf) r6 = r2
87: R2=ctx(id=0,off=0,imm=0) R6_w=ctx(id=0,off=0,imm=0)
87: (bc) w7 = w1
88: R1=invP(id=0) R7_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff))
; return get_skb_len(skb) * get_skb_ifindex(val, skb, get_constant(123));
88: (bf) r1 = r6
89: R1_w=ctx(id=0,off=0,imm=0) R6_w=ctx(id=0,off=0,imm=0)
89: (85) call pc+9
Func#4 is global and valid. Skipping.
90: R0_w=invP(id=0)
90: (bc) w8 = w0
91: R0_w=invP(id=0) R8_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff))
; return get_skb_len(skb) * get_skb_ifindex(val, skb, get_constant(123));
91: (b7) r1 = 123
92: R1_w=invP123
92: (85) call pc+65
Func#5 is global and valid. Skipping.
93: R0=invP(id=0)

After:

86: R1=invP(id=0) R2=ctx(id=0,off=0,imm=0) R10=fp0
; int test_pkt_access_subprog3(int val, struct __sk_buff *skb)
86: (bf) r6 = r2                      ; R2=ctx(id=0,off=0,imm=0) R6_w=ctx(id=0,off=0,imm=0)
87: (bc) w7 = w1                      ; R1=invP(id=0) R7_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff))
; return get_skb_len(skb) * get_skb_ifindex(val, skb, get_constant(123));
88: (bf) r1 = r6                      ; R1_w=ctx(id=0,off=0,imm=0) R6_w=ctx(id=0,off=0,imm=0)
89: (85) call pc+9
Func#4 is global and valid. Skipping.
90: R0_w=invP(id=0)
90: (bc) w8 = w0                      ; R0_w=invP(id=0) R8_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff))
; return get_skb_len(skb) * get_skb_ifindex(val, skb, get_constant(123));
91: (b7) r1 = 123                     ; R1_w=invP123
92: (85) call pc+65
Func#5 is global and valid. Skipping.
93: R0=invP(id=0)

Signed-off-by: Christy Lee <christylee@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-12-16 19:43:49 -08:00
Christy Lee 0f55f9ed21 bpf: Only print scratched registers and stack slots to verifier logs.
When printing verifier state for any log level, print full verifier
state only on function calls or on errors. Otherwise, only print the
registers and stack slots that were accessed.

Log size differences:

verif_scale_loop6 before: 234566564
verif_scale_loop6 after: 72143943
69% size reduction

kfree_skb before: 166406
kfree_skb after: 55386
69% size reduction

Before:

156: (61) r0 = *(u32 *)(r1 +0)
157: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R1=ctx(id=0,off=0,imm=0) R2_w=invP0 R10=fp0 fp-8_w=00000000 fp-16_w=00\
000000 fp-24_w=00000000 fp-32_w=00000000 fp-40_w=00000000 fp-48_w=00000000 fp-56_w=00000000 fp-64_w=00000000 fp-72_w=00000000 fp-80_w=00000\
000 fp-88_w=00000000 fp-96_w=00000000 fp-104_w=00000000 fp-112_w=00000000 fp-120_w=00000000 fp-128_w=00000000 fp-136_w=00000000 fp-144_w=00\
000000 fp-152_w=00000000 fp-160_w=00000000 fp-168_w=00000000 fp-176_w=00000000 fp-184_w=00000000 fp-192_w=00000000 fp-200_w=00000000 fp-208\
_w=00000000 fp-216_w=00000000 fp-224_w=00000000 fp-232_w=00000000 fp-240_w=00000000 fp-248_w=00000000 fp-256_w=00000000 fp-264_w=00000000 f\
p-272_w=00000000 fp-280_w=00000000 fp-288_w=00000000 fp-296_w=00000000 fp-304_w=00000000 fp-312_w=00000000 fp-320_w=00000000 fp-328_w=00000\
000 fp-336_w=00000000 fp-344_w=00000000 fp-352_w=00000000 fp-360_w=00000000 fp-368_w=00000000 fp-376_w=00000000 fp-384_w=00000000 fp-392_w=\
00000000 fp-400_w=00000000 fp-408_w=00000000 fp-416_w=00000000 fp-424_w=00000000 fp-432_w=00000000 fp-440_w=00000000 fp-448_w=00000000
; return skb->len;
157: (95) exit
Func#4 is safe for any args that match its prototype
Validating get_constant() func#5...
158: R1=invP(id=0) R10=fp0
; int get_constant(long val)
158: (bf) r0 = r1
159: R0_w=invP(id=1) R1=invP(id=1) R10=fp0
; return val - 122;
159: (04) w0 += -122
160: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R1=invP(id=1) R10=fp0
; return val - 122;
160: (95) exit
Func#5 is safe for any args that match its prototype
Validating get_skb_ifindex() func#6...
161: R1=invP(id=0) R2=ctx(id=0,off=0,imm=0) R3=invP(id=0) R10=fp0
; int get_skb_ifindex(int val, struct __sk_buff *skb, int var)
161: (bc) w0 = w3
162: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R1=invP(id=0) R2=ctx(id=0,off=0,imm=0) R3=invP(id=0) R10=fp0

After:

156: (61) r0 = *(u32 *)(r1 +0)
157: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R1=ctx(id=0,off=0,imm=0)
; return skb->len;
157: (95) exit
Func#4 is safe for any args that match its prototype
Validating get_constant() func#5...
158: R1=invP(id=0) R10=fp0
; int get_constant(long val)
158: (bf) r0 = r1
159: R0_w=invP(id=1) R1=invP(id=1)
; return val - 122;
159: (04) w0 += -122
160: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff))
; return val - 122;
160: (95) exit
Func#5 is safe for any args that match its prototype
Validating get_skb_ifindex() func#6...
161: R1=invP(id=0) R2=ctx(id=0,off=0,imm=0) R3=invP(id=0) R10=fp0
; int get_skb_ifindex(int val, struct __sk_buff *skb, int var)
161: (bc) w0 = w3
162: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R3=invP(id=0)

Signed-off-by: Christy Lee <christylee@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211216213358.3374427-2-christylee@fb.com
2021-12-16 18:16:41 -08:00
Jakub Kicinski 7cd2802d74 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
No conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-16 16:13:19 -08:00
Linus Torvalds 6441998e2e audit/stable-5.16 PR 20211216
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Merge tag 'audit-pr-20211216' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

Pull audit fix from Paul Moore:
 "A single patch to fix a problem where the audit queue could grow
  unbounded when the audit daemon is forcibly stopped"

* tag 'audit-pr-20211216' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: improve robustness of the audit queue handling
2021-12-16 15:24:46 -08:00
Linus Torvalds 180f3bcfe3 Networking fixes for 5.16-rc6, including fixes from mac80211, wifi, bpf.
Current release - regressions:
 
  - dpaa2-eth: fix buffer overrun when reporting ethtool statistics
 
 Current release - new code bugs:
 
  - bpf: fix incorrect state pruning for <8B spill/fill
 
  - iavf:
      - add missing unlocks in iavf_watchdog_task()
      - do not override the adapter state in the watchdog task (again)
 
  - mlxsw: spectrum_router: consolidate MAC profiles when possible
 
 Previous releases - regressions:
 
  - mac80211, fix:
      - rate control, avoid driver crash for retransmitted frames
      - regression in SSN handling of addba tx
      - a memory leak where sta_info is not freed
      - marking TX-during-stop for TX in in_reconfig, prevent stall
 
  - cfg80211: acquire wiphy mutex on regulatory work
 
  - wifi drivers: fix build regressions and LED config dependency
 
  - virtio_net: fix rx_drops stat for small pkts
 
  - dsa: mv88e6xxx: unforce speed & duplex in mac_link_down()
 
 Previous releases - always broken:
 
  - bpf, fix:
     - kernel address leakage in atomic fetch
     - kernel address leakage in atomic cmpxchg's r0 aux reg
     - signed bounds propagation after mov32
     - extable fixup offset
     - extable address check
 
  - mac80211:
      - fix the size used for building probe request
      - send ADDBA requests using the tid/queue of the aggregation
        session
      - agg-tx: don't schedule_and_wake_txq() under sta->lock,
        avoid deadlocks
      - validate extended element ID is present
 
  - mptcp:
      - never allow the PM to close a listener subflow (null-defer)
      - clear 'kern' flag from fallback sockets, prevent crash
      - fix deadlock in __mptcp_push_pending()
 
  - inet_diag: fix kernel-infoleak for UDP sockets
 
  - xsk: do not sleep in poll() when need_wakeup set
 
  - smc: avoid very long waits in smc_release()
 
  - sch_ets: don't remove idle classes from the round-robin list
 
  - netdevsim:
      - zero-initialize memory for bpf map's value, prevent info leak
      - don't let user space overwrite read only (max) ethtool parms
 
  - ixgbe: set X550 MDIO speed before talking to PHY
 
  - stmmac:
      - fix null-deref in flower deletion w/ VLAN prio Rx steering
      - dwmac-rk: fix oob read in rk_gmac_setup
 
  - ice: time stamping fixes
 
  - systemport: add global locking for descriptor life cycle
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Networking fixes, including fixes from mac80211, wifi, bpf.

  Relatively large batches of fixes from BPF and the WiFi stack, calm in
  general networking.

  Current release - regressions:

   - dpaa2-eth: fix buffer overrun when reporting ethtool statistics

  Current release - new code bugs:

   - bpf: fix incorrect state pruning for <8B spill/fill

   - iavf:
       - add missing unlocks in iavf_watchdog_task()
       - do not override the adapter state in the watchdog task (again)

   - mlxsw: spectrum_router: consolidate MAC profiles when possible

  Previous releases - regressions:

   - mac80211 fixes:
       - rate control, avoid driver crash for retransmitted frames
       - regression in SSN handling of addba tx
       - a memory leak where sta_info is not freed
       - marking TX-during-stop for TX in in_reconfig, prevent stall

   - cfg80211: acquire wiphy mutex on regulatory work

   - wifi drivers: fix build regressions and LED config dependency

   - virtio_net: fix rx_drops stat for small pkts

   - dsa: mv88e6xxx: unforce speed & duplex in mac_link_down()

  Previous releases - always broken:

   - bpf fixes:
       - kernel address leakage in atomic fetch
       - kernel address leakage in atomic cmpxchg's r0 aux reg
       - signed bounds propagation after mov32
       - extable fixup offset
       - extable address check

   - mac80211:
       - fix the size used for building probe request
       - send ADDBA requests using the tid/queue of the aggregation
         session
       - agg-tx: don't schedule_and_wake_txq() under sta->lock, avoid
         deadlocks
       - validate extended element ID is present

   - mptcp:
       - never allow the PM to close a listener subflow (null-defer)
       - clear 'kern' flag from fallback sockets, prevent crash
       - fix deadlock in __mptcp_push_pending()

   - inet_diag: fix kernel-infoleak for UDP sockets

   - xsk: do not sleep in poll() when need_wakeup set

   - smc: avoid very long waits in smc_release()

   - sch_ets: don't remove idle classes from the round-robin list

   - netdevsim:
       - zero-initialize memory for bpf map's value, prevent info leak
       - don't let user space overwrite read only (max) ethtool parms

   - ixgbe: set X550 MDIO speed before talking to PHY

   - stmmac:
       - fix null-deref in flower deletion w/ VLAN prio Rx steering
       - dwmac-rk: fix oob read in rk_gmac_setup

   - ice: time stamping fixes

   - systemport: add global locking for descriptor life cycle"

* tag 'net-5.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (89 commits)
  bpf, selftests: Fix racing issue in btf_skc_cls_ingress test
  selftest/bpf: Add a test that reads various addresses.
  bpf: Fix extable address check.
  bpf: Fix extable fixup offset.
  bpf, selftests: Add test case trying to taint map value pointer
  bpf: Make 32->64 bounds propagation slightly more robust
  bpf: Fix signed bounds propagation after mov32
  sit: do not call ipip6_dev_free() from sit_init_net()
  net: systemport: Add global locking for descriptor lifecycle
  net/smc: Prevent smc_release() from long blocking
  net: Fix double 0x prefix print in SKB dump
  virtio_net: fix rx_drops stat for small pkts
  dsa: mv88e6xxx: fix debug print for SPEED_UNFORCED
  sfc_ef100: potential dereference of null pointer
  net: stmmac: dwmac-rk: fix oob read in rk_gmac_setup
  net: usb: lan78xx: add Allied Telesis AT29M2-AF
  net/packet: rx_owner_map depends on pg_vec
  netdevsim: Zero-initialize memory for new map's value in function nsim_bpf_map_alloc
  dpaa2-eth: fix ethtool statistics
  ixgbe: set X550 MDIO speed before talking to PHY
  ...
2021-12-16 15:02:14 -08:00
Jakub Kicinski aef2feda97 add missing bpf-cgroup.h includes
We're about to break the cgroup-defs.h -> bpf-cgroup.h dependency,
make sure those who actually need more than the definition of
struct cgroup_bpf include bpf-cgroup.h explicitly.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/bpf/20211216025538.1649516-3-kuba@kernel.org
2021-12-16 14:57:09 -08:00
Thomas Gleixner cd6cf06590 genirq/msi: Convert storage to xarray
The current linked list storage for MSI descriptors is suboptimal in
several ways:

  1) Looking up a MSI desciptor requires a O(n) list walk in the worst case

  2) The upcoming support of runtime expansion of MSI-X vectors would need
     to do a full list walk to figure out whether a particular index is
     already associated.

  3) Runtime expansion of sparse allocations is even more complex as the
     current implementation assumes an ordered list (increasing MSI index).

Use an xarray which solves all of the above problems nicely.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210749.280627070@linutronix.de
2021-12-16 22:22:20 +01:00
Thomas Gleixner bf5e758f02 genirq/msi: Simplify sysfs handling
The sysfs handling for MSI is a convoluted maze and it is in the way of
supporting dynamic expansion of the MSI-X vectors because it only supports
a one off bulk population/free of the sysfs entries.

Change it to do:

   1) Creating an empty sysfs attribute group when msi_device_data is
      allocated

   2) Populate the entries when the MSI descriptor is initialized

   3) Free the entries when a MSI descriptor is detached from a Linux
      interrupt.

   4) Provide functions for the legacy non-irqdomain fallback code to
      do a bulk population/free. This code won't support dynamic
      expansion.

This makes the code simpler and reduces the number of allocations as the
empty attribute group can be shared.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210749.224917330@linutronix.de
2021-12-16 22:22:20 +01:00
Thomas Gleixner cc9a246dbf genirq/msi: Mop up old interfaces
Get rid of the old iterators, alloc/free functions and adjust the core code
accordingly.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210749.117395027@linutronix.de
2021-12-16 22:22:20 +01:00
Thomas Gleixner 495c66aca3 genirq/msi: Convert to new functions
Use the new iterator functions and add locking where required.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210749.063705667@linutronix.de
2021-12-16 22:22:20 +01:00
Thomas Gleixner ef8dd01538 genirq/msi: Make interrupt allocation less convoluted
There is no real reason to do several loops over the MSI descriptors
instead of just doing one loop. In case of an error everything is undone
anyway so it does not matter whether it's a partial or a full rollback.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210749.010234767@linutronix.de
2021-12-16 22:22:20 +01:00
Thomas Gleixner a80713fea3 platform-msi: Simplify platform device MSI code
The allocation code is overly complex. It tries to have the MSI index space
packed, which is not working when an interrupt is freed. There is no
requirement for this. The only requirement is that the MSI index is unique.

Move the MSI descriptor allocation into msi_domain_populate_irqs() and use
the Linux interrupt number as MSI index which fulfils the unique
requirement.

This requires to lock the MSI descriptors which makes the lock order
reverse to the regular MSI alloc/free functions vs. the domain
mutex. Assign a seperate lockdep class for these MSI device domains.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210748.956731741@linutronix.de
2021-12-16 22:22:19 +01:00
Thomas Gleixner 645474e2ce genirq/msi: Provide domain flags to allocate/free MSI descriptors automatically
Provide domain info flags which tell the core to allocate simple
descriptors or to free descriptors when the interrupts are freed and
implement the required functionality.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210747.928198636@linutronix.de
2021-12-16 22:22:17 +01:00
Thomas Gleixner 6029052536 genirq/msi: Provide msi_alloc_msi_desc() and a simple allocator
Provide msi_alloc_msi_desc() which takes a template MSI descriptor for
initializing a newly allocated descriptor. This allows to simplify various
usage sites of alloc_msi_entry() and moves the storage handling into the
core code.

For simple cases where only a linear vector space is required provide
msi_add_simple_msi_descs() which just allocates a linear range of MSI
descriptors and fills msi_desc::msi_index accordingly.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210747.873833567@linutronix.de
2021-12-16 22:22:17 +01:00
Thomas Gleixner 1046f71d72 genirq/msi: Provide a set of advanced MSI accessors and iterators
In preparation for dynamic handling of MSI-X interrupts provide a new set
of MSI descriptor accessor functions and iterators. They are benefitial per
se as they allow to cleanup quite some code in various MSI domain
implementations.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210747.818635078@linutronix.de
2021-12-16 22:22:17 +01:00
Thomas Gleixner 0f62d941ac genirq/msi: Provide msi_domain_alloc/free_irqs_descs_locked()
Usage sites which do allocations of the MSI descriptors before invoking
msi_domain_alloc_irqs() require to lock the MSI decriptors accross the
operation.

Provide entry points which can be called with the MSI mutex held and lock
the mutex in the existing entry points.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210747.765371053@linutronix.de
2021-12-16 22:22:17 +01:00
Thomas Gleixner b5f687f97d genirq/msi: Add mutex for MSI list protection
For upcoming runtime extensions of MSI-X interrupts it's required to
protect the MSI descriptor list. Add a mutex to struct msi_device_data and
provide lock/unlock functions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210747.708877269@linutronix.de
2021-12-16 22:22:17 +01:00
Thomas Gleixner 125282cd4f genirq/msi: Move descriptor list to struct msi_device_data
It's only required when MSI is in use.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210747.650487479@linutronix.de
2021-12-16 22:22:16 +01:00
Thomas Gleixner cf15f43aca genirq/msi: Provide interface to retrieve Linux interrupt number
This allows drivers to retrieve the Linux interrupt number instead of
fiddling with MSI descriptors.

msi_get_virq() returns the Linux interrupt number or 0 in case that there
is no entry for the given MSI index.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211210221814.780824745@linutronix.de
2021-12-16 22:16:40 +01:00
Thomas Gleixner 24cff375fd genirq/msi: Remove the original sysfs interfaces
No more users. Refactor the core code accordingly and move the global
interface under CONFIG_PCI_MSI_ARCH_FALLBACKS.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211210221814.168362229@linutronix.de
2021-12-16 22:16:39 +01:00
Thomas Gleixner bf6e054e0e genirq/msi: Provide msi_device_populate/destroy_sysfs()
Add new allocation functions which can be activated by domain info
flags. They store the groups pointer in struct msi_device_data.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211210221813.988659194@linutronix.de
2021-12-16 22:16:39 +01:00
Thomas Gleixner 013bd8e543 device: Add device:: Msi_data pointer and struct msi_device_data
Create struct msi_device_data and add a pointer of that type to struct
dev_msi_info, which is part of struct device. Provide an allocator function
which can be invoked from the MSI interrupt allocation code pathes.

Add a properties field to the data structure as a first member so the
allocation size is not zero bytes. The field will be uses later on.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211210221813.676660809@linutronix.de
2021-12-16 22:16:38 +01:00
Thomas Gleixner 6ef7f771de genirq/msi: Use PCI device property
to determine whether this is MSI or MSIX instead of consulting MSI
descriptors.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211210221813.434156196@linutronix.de
2021-12-16 22:16:37 +01:00
Daniel Borkmann e572ff80f0 bpf: Make 32->64 bounds propagation slightly more robust
Make the bounds propagation in __reg_assign_32_into_64() slightly more
robust and readable by aligning it similarly as we did back in the
__reg_combine_64_into_32() counterpart. Meaning, only propagate or
pessimize them as a smin/smax pair.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-12-16 19:45:56 +01:00
Daniel Borkmann 3cf2b61eb0 bpf: Fix signed bounds propagation after mov32
For the case where both s32_{min,max}_value bounds are positive, the
__reg_assign_32_into_64() directly propagates them to their 64 bit
counterparts, otherwise it pessimises them into [0,u32_max] universe and
tries to refine them later on by learning through the tnum as per comment
in mentioned function. However, that does not always happen, for example,
in mov32 operation we call zext_32_to_64(dst_reg) which invokes the
__reg_assign_32_into_64() as is without subsequent bounds update as
elsewhere thus no refinement based on tnum takes place.

Thus, not calling into the __update_reg_bounds() / __reg_deduce_bounds() /
__reg_bound_offset() triplet as we do, for example, in case of ALU ops via
adjust_scalar_min_max_vals(), will lead to more pessimistic bounds when
dumping the full register state:

Before fix:

  0: (b4) w0 = -1
  1: R0_w=invP4294967295
     (id=0,imm=ffffffff,
      smin_value=4294967295,smax_value=4294967295,
      umin_value=4294967295,umax_value=4294967295,
      var_off=(0xffffffff; 0x0),
      s32_min_value=-1,s32_max_value=-1,
      u32_min_value=-1,u32_max_value=-1)

  1: (bc) w0 = w0
  2: R0_w=invP4294967295
     (id=0,imm=ffffffff,
      smin_value=0,smax_value=4294967295,
      umin_value=4294967295,umax_value=4294967295,
      var_off=(0xffffffff; 0x0),
      s32_min_value=-1,s32_max_value=-1,
      u32_min_value=-1,u32_max_value=-1)

Technically, the smin_value=0 and smax_value=4294967295 bounds are not
incorrect, but given the register is still a constant, they break assumptions
about const scalars that smin_value == smax_value and umin_value == umax_value.

After fix:

  0: (b4) w0 = -1
  1: R0_w=invP4294967295
     (id=0,imm=ffffffff,
      smin_value=4294967295,smax_value=4294967295,
      umin_value=4294967295,umax_value=4294967295,
      var_off=(0xffffffff; 0x0),
      s32_min_value=-1,s32_max_value=-1,
      u32_min_value=-1,u32_max_value=-1)

  1: (bc) w0 = w0
  2: R0_w=invP4294967295
     (id=0,imm=ffffffff,
      smin_value=4294967295,smax_value=4294967295,
      umin_value=4294967295,umax_value=4294967295,
      var_off=(0xffffffff; 0x0),
      s32_min_value=-1,s32_max_value=-1,
      u32_min_value=-1,u32_max_value=-1)

Without the smin_value == smax_value and umin_value == umax_value invariant
being intact for const scalars, it is possible to leak out kernel pointers
from unprivileged user space if the latter is enabled. For example, when such
registers are involved in pointer arithmtics, then adjust_ptr_min_max_vals()
will taint the destination register into an unknown scalar, and the latter
can be exported and stored e.g. into a BPF map value.

Fixes: 3f50f132d8 ("bpf: Verifier, do explicit ALU32 bounds tracking")
Reported-by: Kuee K1r0a <liulin063@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-12-16 19:45:46 +01:00
Paul Moore f4b3ee3c85 audit: improve robustness of the audit queue handling
If the audit daemon were ever to get stuck in a stopped state the
kernel's kauditd_thread() could get blocked attempting to send audit
records to the userspace audit daemon.  With the kernel thread
blocked it is possible that the audit queue could grow unbounded as
certain audit record generating events must be exempt from the queue
limits else the system enter a deadlock state.

This patch resolves this problem by lowering the kernel thread's
socket sending timeout from MAX_SCHEDULE_TIMEOUT to HZ/10 and tweaks
the kauditd_send_queue() function to better manage the various audit
queues when connection problems occur between the kernel and the
audit daemon.  With this patch, the backlog may temporarily grow
beyond the defined limits when the audit daemon is stopped and the
system is under heavy audit pressure, but kauditd_thread() will
continue to make progress and drain the queues as it would for other
connection problems.  For example, with the audit daemon put into a
stopped state and the system configured to audit every syscall it
was still possible to shutdown the system without a kernel panic,
deadlock, etc.; granted, the system was slow to shutdown but that is
to be expected given the extreme pressure of recording every syscall.

The timeout value of HZ/10 was chosen primarily through
experimentation and this developer's "gut feeling".  There is likely
no one perfect value, but as this scenario is limited in scope (root
privileges would be needed to send SIGSTOP to the audit daemon), it
is likely not worth exposing this as a tunable at present.  This can
always be done at a later date if it proves necessary.

Cc: stable@vger.kernel.org
Fixes: 5b52330bbf ("audit: fix auditd/kernel connection state tracking")
Reported-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Tested-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-12-15 13:16:39 -05:00
Paul Moore 8f110f5306 audit: ensure userspace is penalized the same as the kernel when under pressure
Due to the audit control mutex necessary for serializing audit
userspace messages we haven't been able to block/penalize userspace
processes that attempt to send audit records while the system is
under audit pressure.  The result is that privileged userspace
applications have a priority boost with respect to audit as they are
not bound by the same audit queue throttling as the other tasks on
the system.

This patch attempts to restore some balance to the system when under
audit pressure by blocking these privileged userspace tasks after
they have finished their audit processing, and dropped the audit
control mutex, but before they return to userspace.

Reported-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Tested-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-12-15 13:10:32 -05:00
Daniel Borkmann a82fe085f3 bpf: Fix kernel address leakage in atomic cmpxchg's r0 aux reg
The implementation of BPF_CMPXCHG on a high level has the following parameters:

  .-[old-val]                                          .-[new-val]
  BPF_R0 = cmpxchg{32,64}(DST_REG + insn->off, BPF_R0, SRC_REG)
                          `-[mem-loc]          `-[old-val]

Given a BPF insn can only have two registers (dst, src), the R0 is fixed and
used as an auxilliary register for input (old value) as well as output (returning
old value from memory location). While the verifier performs a number of safety
checks, it misses to reject unprivileged programs where R0 contains a pointer as
old value.

Through brute-forcing it takes about ~16sec on my machine to leak a kernel pointer
with BPF_CMPXCHG. The PoC is basically probing for kernel addresses by storing the
guessed address into the map slot as a scalar, and using the map value pointer as
R0 while SRC_REG has a canary value to detect a matching address.

Fix it by checking R0 for pointers, and reject if that's the case for unprivileged
programs.

Fixes: 5ffa25502b ("bpf: Add instructions for atomic_[cmp]xchg")
Reported-by: Ryota Shiga (Flatt Security)
Acked-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-12-14 19:33:06 -08:00
Daniel Borkmann 7d3baf0afa bpf: Fix kernel address leakage in atomic fetch
The change in commit 37086bfdc7 ("bpf: Propagate stack bounds to registers
in atomics w/ BPF_FETCH") around check_mem_access() handling is buggy since
this would allow for unprivileged users to leak kernel pointers. For example,
an atomic fetch/and with -1 on a stack destination which holds a spilled
pointer will migrate the spilled register type into a scalar, which can then
be exported out of the program (since scalar != pointer) by dumping it into
a map value.

The original implementation of XADD was preventing this situation by using
a double call to check_mem_access() one with BPF_READ and a subsequent one
with BPF_WRITE, in both cases passing -1 as a placeholder value instead of
register as per XADD semantics since it didn't contain a value fetch. The
BPF_READ also included a check in check_stack_read_fixed_off() which rejects
the program if the stack slot is of __is_pointer_value() if dst_regno < 0.
The latter is to distinguish whether we're dealing with a regular stack spill/
fill or some arithmetical operation which is disallowed on non-scalars, see
also 6e7e63cbb0 ("bpf: Forbid XADD on spilled pointers for unprivileged
users") for more context on check_mem_access() and its handling of placeholder
value -1.

One minimally intrusive option to fix the leak is for the BPF_FETCH case to
initially check the BPF_READ case via check_mem_access() with -1 as register,
followed by the actual load case with non-negative load_reg to propagate
stack bounds to registers.

Fixes: 37086bfdc7 ("bpf: Propagate stack bounds to registers in atomics w/ BPF_FETCH")
Reported-by: <n4ke4mry@gmail.com>
Acked-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-12-14 19:33:06 -08:00
Xiu Jianfeng bc6e60a4fc audit: use struct_size() helper in kmalloc()
Make use of struct_size() helper instead of an open-coded calucation.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-12-14 17:39:42 -05:00
Chang S. Bae 6c3118c321 signal: Skip the altstack update when not needed
== Background ==

Support for large, "dynamic" fpstates was recently merged.  This
included code to ensure that sigaltstacks are sufficiently sized for
these large states.  A new lock was added to remove races between
enabling large features and setting up sigaltstacks.

== Problem ==

The new lock (sigaltstack_lock()) is acquired in the sigreturn path
before restoring the old sigaltstack.  Unfortunately, contention on the
new lock causes a measurable signal handling performance regression [1].
However, the common case is that no *changes* are made to the
sigaltstack state at sigreturn.

== Solution ==

do_sigaltstack() acquires sigaltstack_lock() and is used for both
sys_sigaltstack() and restoring the sigaltstack in sys_sigreturn().
Check for changes to the sigaltstack before taking the lock.  If no
changes were made, return before acquiring the lock.

This removes lock contention from the common-case sigreturn path.

[1] https://lore.kernel.org/lkml/20211207012128.GA16074@xsang-OptiPlex-9020/

Fixes: 3aac3ebea0 ("x86/signal: Implement sigaltstack size validation")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20211210225503.12734-1-chang.seok.bae@intel.com
2021-12-14 13:08:36 -08:00
Wei Yang 1815775e74 cgroup: return early if it is already on preloaded list
If a cset is already on preloaded list, this means we have already setup
this cset properly for migration.

This patch just relocates the root cgrp lookup which isn't used anyway
when the cset is already on the preloaded list.

[tj@kernel.org: rephrase the commit log]

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-12-14 09:45:20 -10:00
Kefeng Wang dd03762ab6 arm64: Enable KCSAN
This patch enables KCSAN for arm64, with updates to build rules
to not use KCSAN for several incompatible compilation units.

Recent GCC version(at least GCC10) made outline-atomics as the
default option(unlike Clang), which will cause linker errors
for kernel/kcsan/core.o. Disables the out-of-line atomics by
no-outline-atomics to fix the linker errors.

Meanwhile, as Mark said[1], some latent issues are needed to be
fixed which isn't just a KCSAN problem, we make the KCSAN depends
on EXPERT for now.

Tested selftest and kcsan_test(built with GCC11 and Clang 13),
and all passed.

[1] https://lkml.kernel.org/r/YadiUPpJ0gADbiHQ@FVFF77S0Q05N

Acked-by: Marco Elver <elver@google.com> # kernel/kcsan
Tested-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lore.kernel.org/r/20211211131734.126874-1-wangkefeng.wang@huawei.com
[catalin.marinas@arm.com: added comment to justify EXPERT]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-12-14 18:54:34 +00:00
Eric W. Biederman 5eb6f22823 exit/kthread: Fix the kerneldoc comment for kthread_complete_and_exit
I misspelled kthread_complete_and_exit in the kernel doc comment fix
it.

Link: https://lkml.kernel.org/r/202112141329.KBkyJ5ql-lkp@intel.com
Link: https://lkml.kernel.org/r/202112141422.Cykr6YUS-lkp@intel.com
Reported-by: kernel test robot <lkp@intel.com>
Fixes: cead185526 ("exit: Rename complete_and_exit to kthread_complete_and_exit")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-14 11:31:41 -06:00
Thomas Gleixner 09eb3ad55f Merge branch 'irq/urgent' into irq/msi
to pick up the PCI/MSI-x fixes.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2021-12-14 13:30:34 +01:00
Rob Herring 82ff0c022d perf: Add a counter for number of user access events in context
On arm64, user space counter access will be controlled differently
compared to x86. On x86, access in the strictest mode is enabled for all
tasks in an MM when any event is mmap'ed. For arm64, access is
explicitly requested for an event and only enabled when the event's
context is active. This avoids hooks into the arch context switch code
and gives better control of when access is enabled.

In order to configure user space access when the PMU is enabled, it is
necessary to know if any event (currently active or not) in the current
context has user space accessed enabled. Add a counter similar to other
counters in the context to avoid walking the event list every time.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211208201124.310740-3-robh@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-12-14 11:30:54 +00:00
Paolo Abeni c8064e5b4a bpf: Let bpf_warn_invalid_xdp_action() report more info
In non trivial scenarios, the action id alone is not sufficient to
identify the program causing the warning. Before the previous patch,
the generated stack-trace pointed out at least the involved device
driver.

Let's additionally include the program name and id, and the relevant
device name.

If the user needs additional infos, he can fetch them via a kernel
probe, leveraging the arguments added here.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/ddb96bb975cbfddb1546cf5da60e77d5100b533c.1638189075.git.pabeni@redhat.com
2021-12-13 22:28:27 +01:00
Waiman Long 1f1562fcd0 cgroup/cpuset: Don't let child cpusets restrict parent in default hierarchy
In validate_change(), there is a check since v2.6.12 to make sure that
each of the child cpusets must be a subset of a parent cpuset.  IOW, it
allows child cpusets to restrict what changes can be made to a parent's
"cpuset.cpus". This actually violates one of the core principles of the
default hierarchy where a cgroup higher up in the hierarchy should be
able to change configuration however it sees fit as deligation breaks
down otherwise.

To address this issue, the check is now removed for the default hierarchy
to free parent cpusets from being restricted by child cpusets. The
check will still apply for legacy hierarchy.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-12-13 10:41:02 -10:00
Eric W. Biederman 6b1248798e exit/kthread: Move the exit code for kernel threads into struct kthread
The exit code of kernel threads has different semantics than the
exit_code of userspace tasks.  To avoid confusion and allow
the userspace implementation to change as needed move
the kernel thread exit code into struct kthread.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:46 -06:00
Eric W. Biederman 40966e316f kthread: Ensure struct kthread is present for all kthreads
Today the rules are a bit iffy and arbitrary about which kernel
threads have struct kthread present.  Both idle threads and thread
started with create_kthread want struct kthread present so that is
effectively all kernel threads.  Make the rule that if PF_KTHREAD
and the task is running then struct kthread is present.

This will allow the kernel thread code to using tsk->exit_code
with different semantics from ordinary processes.

To make ensure that struct kthread is present for all
kernel threads move it's allocation into copy_process.

Add a deallocation of struct kthread in exec for processes
that were kernel threads.

Move the allocation of struct kthread for the initial thread
earlier so that it is not repeated for each additional idle
thread.

Move the initialization of struct kthread into set_kthread_struct
so that the structure is always and reliably initailized.

Clear set_child_tid in free_kthread_struct to ensure the kthread
struct is reliably freed during exec.  The function
free_kthread_struct does not need to clear vfork_done during exec as
exec_mm_release called from exec_mmap has already cleared vfork_done.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00
Eric W. Biederman cead185526 exit: Rename complete_and_exit to kthread_complete_and_exit
Update complete_and_exit to call kthread_exit instead of do_exit.

Change the name to reflect this change in functionality.  All of the
users of complete_and_exit are causing the current kthread to exit so
this change makes it clear what is happening.

Move the implementation of kthread_complete_and_exit from
kernel/exit.c to to kernel/kthread.c.  As this function is kthread
specific it makes most sense to live with the kthread functions.

There are no functional change.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00
Eric W. Biederman ca3574bd65 exit: Rename module_put_and_exit to module_put_and_kthread_exit
Update module_put_and_exit to call kthread_exit instead of do_exit.

Change the name to reflect this change in functionality.  All of the
users of module_put_and_exit are causing the current kthread to exit
so this change makes it clear what is happening.  There is no
functional change.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00
Eric W. Biederman bbda86e988 exit: Implement kthread_exit
The way the per task_struct exit_code is used by kernel threads is not
quite compatible how it is used by userspace applications.  The low
byte of the userspace exit_code value encodes the exit signal.  While
kthreads just use the value as an int holding ordinary kernel function
exit status like -EPERM.

Add kthread_exit to clearly separate the two kinds of uses.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00
Eric W. Biederman eb55e716ac exit: Stop exporting do_exit
Now that there are no more modular uses of do_exit remove the EXPORT_SYMBOL.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00
Eric W. Biederman 7f80a2fd7d exit: Stop poorly open coding do_task_dead in make_task_dead
When the kernel detects it is oops or otherwise force killing a task
while it exits the code poorly attempts to permanently stop the task
from scheduling.

I say poorly because it is possible for a task in TASK_UINTERRUPTIBLE
to be woken up.

As it makes no sense for the task to continue call do_task_dead
instead which actually does the work and permanently removes the task
from the scheduler.  Guaranteeing the task will never be woken
up again.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00
Eric W. Biederman 05ea0424f0 exit: Move oops specific logic from do_exit into make_task_dead
The beginning of do_exit has become cluttered and difficult to read as
it is filled with checks to handle things that can only happen when
the kernel is operating improperly.

Now that we have a dedicated function for cleaning up a task when the
kernel is operating improperly move the checks there.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00
Eric W. Biederman 0e25498f8c exit: Add and use make_task_dead.
There are two big uses of do_exit.  The first is it's design use to be
the guts of the exit(2) system call.  The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.

Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure.  In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.

Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.

As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00
Jiri Olsa f92c1e1836 bpf: Add get_func_[arg|ret|arg_cnt] helpers
Adding following helpers for tracing programs:

Get n-th argument of the traced function:
  long bpf_get_func_arg(void *ctx, u32 n, u64 *value)

Get return value of the traced function:
  long bpf_get_func_ret(void *ctx, u64 *value)

Get arguments count of the traced function:
  long bpf_get_func_arg_cnt(void *ctx)

The trampoline now stores number of arguments on ctx-8
address, so it's easy to verify argument index and find
return value argument's position.

Moving function ip address on the trampoline stack behind
the number of functions arguments, so it's now stored on
ctx-16 address if it's needed.

All helpers above are inlined by verifier.

Also bit unrelated small change - using newly added function
bpf_prog_has_trampoline in check_get_func_ip.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211208193245.172141-5-jolsa@kernel.org
2021-12-13 09:25:59 -08:00
Jiri Olsa bb6728d756 bpf: Allow access to int pointer arguments in tracing programs
Adding support to access arguments with int pointer arguments
in tracing programs.

Currently we allow tracing programs to access only pointers to
string (char pointer), void pointers and pointers to structs.

If we try to access argument which is pointer to int, verifier
will fail to load the program with;

  R1 type=ctx expected=fp
  ; int BPF_PROG(fmod_ret_test, int _a, __u64 _b, int _ret)
  0: (bf) r6 = r1
  ; int BPF_PROG(fmod_ret_test, int _a, __u64 _b, int _ret)
  1: (79) r9 = *(u64 *)(r6 +8)
  func 'bpf_modify_return_test' arg1 type INT is not a struct

There is no harm for the program to access int pointer argument.
We are already doing that for string pointer, which is pointer
to int with 1 byte size.

Changing the is_string_ptr to generic integer check and renaming
it to btf_type_is_int.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211208193245.172141-2-jolsa@kernel.org
2021-12-13 09:24:21 -08:00
Ingo Molnar 6773cc31a9 Linux 5.16-rc5
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Merge tag 'v5.16-rc5' into locking/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-12-13 10:48:46 +01:00
Alexei Starovoitov f18a499799 bpf: Silence coverity false positive warning.
Coverity issued the following warning:
6685            cands = bpf_core_add_cands(cands, main_btf, 1);
6686            if (IS_ERR(cands))
>>>     CID 1510300:    (RETURN_LOCAL)
>>>     Returning pointer "cands" which points to local variable "local_cand".
6687                    return cands;

It's a false positive.
Add ERR_CAST() to silence it.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-12-11 18:08:19 -08:00
Jiapeng Chong 4674f21071 bpf: Use kmemdup() to replace kmalloc + memcpy
Eliminate the follow coccicheck warning:

./kernel/bpf/btf.c:6537:13-20: WARNING opportunity for kmemdup.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/1639030882-92383-1-git-send-email-jiapeng.chong@linux.alibaba.com
2021-12-11 17:57:33 -08:00
Hou Tao c5fb199374 bpf: Add bpf_strncmp helper
The helper compares two strings: one string is a null-terminated
read-only string, and another string has const max storage size
but doesn't need to be null-terminated. It can be used to compare
file name in tracing or LSM program.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211210141652.877186-2-houtao1@huawei.com
2021-12-11 17:40:23 -08:00
Linus Torvalds df442a4ec7 Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "21 patches.

  Subsystems affected by this patch series: MAINTAINERS, mailmap, and mm
  (mlock, pagecache, damon, slub, memcg, hugetlb, and pagecache)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (21 commits)
  mm: bdi: initialize bdi_min_ratio when bdi is unregistered
  hugetlbfs: fix issue of preallocation of gigantic pages can't work
  mm/memcg: relocate mod_objcg_mlstate(), get_obj_stock() and put_obj_stock()
  mm/slub: fix endianness bug for alloc/free_traces attributes
  selftests/damon: split test cases
  selftests/damon: test debugfs file reads/writes with huge count
  selftests/damon: test wrong DAMOS condition ranges input
  selftests/damon: test DAMON enabling with empty target_ids case
  selftests/damon: skip test if DAMON is running
  mm/damon/vaddr-test: remove unnecessary variables
  mm/damon/vaddr-test: split a test function having >1024 bytes frame size
  mm/damon/vaddr: remove an unnecessary warning message
  mm/damon/core: remove unnecessary error messages
  mm/damon/dbgfs: remove an unnecessary error message
  mm/damon/core: use better timer mechanisms selection threshold
  mm/damon/core: fix fake load reports due to uninterruptible sleeps
  timers: implement usleep_idle_range()
  filemap: remove PageHWPoison check from next_uptodate_page()
  mailmap: update email address for Guo Ren
  MAINTAINERS: update kdump maintainers
  ...
2021-12-11 08:46:52 -08:00
Steven Rostedt (VMware) 2768c1e7f9 tracing: Use trace_iterator_reset() in tracing_read_pipe()
Currently tracing_read_pipe() open codes trace_iterator_reset(). Just have
it use trace_iterator_reset() instead.

Link: https://lkml.kernel.org/r/20211210202616.64d432d2@gandalf.local.home

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-11 09:34:32 -05:00
Xiu Jianfeng dba8796722 tracing: Use memset_startat helper in trace_iterator_reset()
Make use of memset_startat helper to simplify the code, there should be
no functional change as a result of this patch.

Link: https://lkml.kernel.org/r/20211210012245.207489-1-xiujianfeng@huawei.com

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-11 09:34:32 -05:00
Beau Belgrave 4f67cca70c tracing: Do not let synth_events block other dyn_event systems during create
synth_events is returning -EINVAL if the dyn_event create command does
not contain ' \t'. This prevents other systems from getting called back.
synth_events needs to return -ECANCELED in these cases when the command
is not targeting the synth_event system.

Link: https://lore.kernel.org/linux-trace-devel/20210930223821.11025-1-beaub@linux.microsoft.com

Fixes: c9e759b1e8 ("tracing: Rework synthetic event command parsing")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-11 09:34:32 -05:00
Jiri Olsa e161c6bf39 tracing: Iterate trace_[ku]probe objects directly
As suggested by Linus [1] using list_for_each_entry to iterate
directly trace_[ku]probe objects so we can skip another call to
container_of in these loops.

[1] https://lore.kernel.org/r/CAHk-=wjakjw6-rDzDDBsuMoDCqd+9ogifR_EE1F0K-jYek1CdA@mail.gmail.com

Link: https://lkml.kernel.org/r/20211125202852.406405-1-jolsa@kernel.org

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-11 09:34:32 -05:00
Dietmar Eggemann 82762d2af3 sched/fair: Replace CFS internal cpu_util() with cpu_util_cfs()
cpu_util_cfs() was created by commit d4edd662ac ("sched/cpufreq: Use
the DEADLINE utilization signal") to enable the access to CPU
utilization from the Schedutil CPUfreq governor.

Commit a07630b8b2 ("sched/cpufreq/schedutil: Use util_est for OPP
selection") added util_est support later.

The only thing cpu_util() is doing on top of what cpu_util_cfs() already
does is to clamp the return value to the [0..capacity_orig] capacity
range of the CPU. Integrating this into cpu_util_cfs() is not harming
the existing users (Schedutil and CPUfreq cooling (latter via
sched_cpu_util() wrapper)).

For straightforwardness, prefer to keep using `int cpu` as the function
parameter over using `struct rq *rq` which might avoid some calls to
cpu_rq(cpu) -> per_cpu(runqueues, cpu) -> RELOC_HIDE().
Update cfs_util()'s documentation and reuse it for cpu_util_cfs().
Remove cpu_util().

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20211118164240.623551-1-dietmar.eggemann@arm.com
2021-12-11 09:10:00 +01:00
SeongJae Park e4779015fd timers: implement usleep_idle_range()
Patch series "mm/damon: Fix fake /proc/loadavg reports", v3.

This patchset fixes DAMON's fake load report issue.  The first patch
makes yet another variant of usleep_range() for this fix, and the second
patch fixes the issue of DAMON by making it using the newly introduced
function.

This patch (of 2):

Some kernel threads such as DAMON could need to repeatedly sleep in
micro seconds level.  Because usleep_range() sleeps in uninterruptible
state, however, such threads would make /proc/loadavg reports fake load.

To help such cases, this commit implements a variant of usleep_range()
called usleep_idle_range().  It is same to usleep_range() but sets the
state of the current task as TASK_IDLE while sleeping.

Link: https://lkml.kernel.org/r/20211126145015.15862-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211126145015.15862-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: John Stultz <john.stultz@linaro.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10 17:10:55 -08:00
Jakub Kicinski be3158290d Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Andrii Nakryiko says:

====================
bpf-next 2021-12-10 v2

We've added 115 non-merge commits during the last 26 day(s) which contain
a total of 182 files changed, 5747 insertions(+), 2564 deletions(-).

The main changes are:

1) Various samples fixes, from Alexander Lobakin.

2) BPF CO-RE support in kernel and light skeleton, from Alexei Starovoitov.

3) A batch of new unified APIs for libbpf, logging improvements, version
   querying, etc. Also a batch of old deprecations for old APIs and various
   bug fixes, in preparation for libbpf 1.0, from Andrii Nakryiko.

4) BPF documentation reorganization and improvements, from Christoph Hellwig
   and Dave Tucker.

5) Support for declarative initialization of BPF_MAP_TYPE_PROG_ARRAY in
   libbpf, from Hengqi Chen.

6) Verifier log fixes, from Hou Tao.

7) Runtime-bounded loops support with bpf_loop() helper, from Joanne Koong.

8) Extend branch record capturing to all platforms that support it,
   from Kajol Jain.

9) Light skeleton codegen improvements, from Kumar Kartikeya Dwivedi.

10) bpftool doc-generating script improvements, from Quentin Monnet.

11) Two libbpf v0.6 bug fixes, from Shuyi Cheng and Vincent Minet.

12) Deprecation warning fix for perf/bpf_counter, from Song Liu.

13) MAX_TAIL_CALL_CNT unification and MIPS build fix for libbpf,
    from Tiezhu Yang.

14) BTF_KING_TYPE_TAG follow-up fixes, from Yonghong Song.

15) Selftests fixes and improvements, from Ilya Leoshkevich, Jean-Philippe
    Brucker, Jiri Olsa, Maxim Mikityanskiy, Tirthendu Sarkar, Yucong Sun,
    and others.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (115 commits)
  libbpf: Add "bool skipped" to struct bpf_map
  libbpf: Fix typo in btf__dedup@LIBBPF_0.0.2 definition
  bpftool: Switch bpf_object__load_xattr() to bpf_object__load()
  selftests/bpf: Remove the only use of deprecated bpf_object__load_xattr()
  selftests/bpf: Add test for libbpf's custom log_buf behavior
  selftests/bpf: Replace all uses of bpf_load_btf() with bpf_btf_load()
  libbpf: Deprecate bpf_object__load_xattr()
  libbpf: Add per-program log buffer setter and getter
  libbpf: Preserve kernel error code and remove kprobe prog type guessing
  libbpf: Improve logging around BPF program loading
  libbpf: Allow passing user log setting through bpf_object_open_opts
  libbpf: Allow passing preallocated log_buf when loading BTF into kernel
  libbpf: Add OPTS-based bpf_btf_load() API
  libbpf: Fix bpf_prog_load() log_buf logic for log_level 0
  samples/bpf: Remove unneeded variable
  bpf: Remove redundant assignment to pointer t
  selftests/bpf: Fix a compilation warning
  perf/bpf_counter: Use bpf_map_create instead of bpf_create_map
  samples: bpf: Fix 'unknown warning group' build warning on Clang
  samples: bpf: Fix xdp_sample_user.o linking with Clang
  ...
====================

Link: https://lore.kernel.org/r/20211210234746.2100561-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-10 15:56:13 -08:00
Linus Torvalds 257dcf2923 tracing, ftrace and tracefs fixes:
- Have tracefs honor the gid mount option
 
  - Have new files in tracefs inherit the parent ownership
 
  - Have direct_ops unregister when it has no more functions
 
  - Properly clean up the ops when unregistering multi direct ops
 
  - Add a sample module to test the multiple direct ops
 
  - Fix memory leak in error path of __create_synth_event()
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Merge tag 'trace-v5.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Tracing, ftrace and tracefs fixes:

   - Have tracefs honor the gid mount option

   - Have new files in tracefs inherit the parent ownership

   - Have direct_ops unregister when it has no more functions

   - Properly clean up the ops when unregistering multi direct ops

   - Add a sample module to test the multiple direct ops

   - Fix memory leak in error path of __create_synth_event()"

* tag 'trace-v5.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix possible memory leak in __create_synth_event() error path
  ftrace/samples: Add module to test multi direct modify interface
  ftrace: Add cleanup to unregister_ftrace_direct_multi
  ftrace: Use direct_ops hash in unregister_ftrace_direct
  tracefs: Set all files to the same group ownership as the mount option
  tracefs: Have new files inherit the ownership of their parent
2021-12-10 14:24:05 -08:00
Linus Torvalds 0d21e66847 aio poll fixes for 5.16-rc5
Fix three bugs in aio poll, and one issue with POLLFREE more broadly:
 
   - aio poll didn't handle POLLFREE, causing a use-after-free.
   - aio poll could block while the file is ready.
   - aio poll called eventfd_signal() when it isn't allowed.
   - POLLFREE didn't handle multiple exclusive waiters correctly.
 
 This has been tested with the libaio test suite, as well as with test
 programs I wrote that reproduce the first two bugs.  I am sending this
 pull request myself as no one seems to be maintaining this code.
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Merge tag 'aio-poll-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux

Pull aio poll fixes from Eric Biggers:
 "Fix three bugs in aio poll, and one issue with POLLFREE more broadly:

   - aio poll didn't handle POLLFREE, causing a use-after-free.

   - aio poll could block while the file is ready.

   - aio poll called eventfd_signal() when it isn't allowed.

   - POLLFREE didn't handle multiple exclusive waiters correctly.

  This has been tested with the libaio test suite, as well as with test
  programs I wrote that reproduce the first two bugs. I am sending this
  pull request myself as no one seems to be maintaining this code"

* tag 'aio-poll-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux:
  aio: Fix incorrect usage of eventfd_signal_allowed()
  aio: fix use-after-free due to missing POLLFREE handling
  aio: keep poll requests on waitqueue until completed
  signalfd: use wake_up_pollfree()
  binder: use wake_up_pollfree()
  wait: add wake_up_pollfree()
2021-12-10 14:15:39 -08:00
Thomas Gleixner 65c7cdedeb genirq: Provide new interfaces for affinity hints
The discussion about removing the side effect of irq_set_affinity_hint() of
actually applying the cpumask (if not NULL) as affinity to the interrupt,
unearthed a few unpleasantries:

  1) The modular perf drivers rely on the current behaviour for the very
     wrong reasons.

  2) While none of the other drivers prevents user space from changing
     the affinity, a cursorily inspection shows that there are at least
     expectations in some drivers.

#1 needs to be cleaned up anyway, so that's not a problem

#2 might result in subtle regressions especially when irqbalanced (which
   nowadays ignores the affinity hint) is disabled.

Provide new interfaces:

  irq_update_affinity_hint()  - Only sets the affinity hint pointer
  irq_set_affinity_and_hint() - Set the pointer and apply the affinity to
                                the interrupt

Make irq_set_affinity_hint() a wrapper around irq_apply_affinity_hint() and
document it to be phased out.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210501021832.743094-1-jesse.brandeburg@intel.com
Link: https://lore.kernel.org/r/20210903152430.244937-2-nitesh@redhat.com
2021-12-10 20:47:38 +01:00
Paul Chaignon 345e004d02 bpf: Fix incorrect state pruning for <8B spill/fill
Commit 354e8f1970 ("bpf: Support <8-byte scalar spill and refill")
introduced support in the verifier to track <8B spill/fills of scalars.
The backtracking logic for the precision bit was however skipping
spill/fills of less than 8B. That could cause state pruning to consider
two states equivalent when they shouldn't be.

As an example, consider the following bytecode snippet:

  0:  r7 = r1
  1:  call bpf_get_prandom_u32
  2:  r6 = 2
  3:  if r0 == 0 goto pc+1
  4:  r6 = 3
  ...
  8: [state pruning point]
  ...
  /* u32 spill/fill */
  10: *(u32 *)(r10 - 8) = r6
  11: r8 = *(u32 *)(r10 - 8)
  12: r0 = 0
  13: if r8 == 3 goto pc+1
  14: r0 = 1
  15: exit

The verifier first walks the path with R6=3. Given the support for <8B
spill/fills, at instruction 13, it knows the condition is true and skips
instruction 14. At that point, the backtracking logic kicks in but stops
at the fill instruction since it only propagates the precision bit for
8B spill/fill. When the verifier then walks the path with R6=2, it will
consider it safe at instruction 8 because R6 is not marked as needing
precision. Instruction 14 is thus never walked and is then incorrectly
removed as 'dead code'.

It's also possible to lead the verifier to accept e.g. an out-of-bound
memory access instead of causing an incorrect dead code elimination.

This regression was found via Cilium's bpf-next CI where it was causing
a conntrack map update to be silently skipped because the code had been
removed by the verifier.

This commit fixes it by enabling support for <8B spill/fills in the
bactracking logic. In case of a <8B spill/fill, the full 8B stack slot
will be marked as needing precision. Then, in __mark_chain_precision,
any tracked register spilled in a marked slot will itself be marked as
needing precision, regardless of the spill size. This logic makes two
assumptions: (1) only 8B-aligned spill/fill are tracked and (2) spilled
registers are only tracked if the spill and fill sizes are equal. Commit
ef979017b8 ("bpf: selftest: Add verifier tests for <8-byte scalar
spill and refill") covers the first assumption and the next commit in
this patchset covers the second.

Fixes: 354e8f1970 ("bpf: Support <8-byte scalar spill and refill")
Signed-off-by: Paul Chaignon <paul@isovalent.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-12-10 09:13:19 -08:00
Marco Elver b473a3891c kcsan: Only test clear_bit_unlock_is_negative_byte if arch defines it
Some architectures do not define clear_bit_unlock_is_negative_byte().
Only test it when it is actually defined (similar to other usage, such
as in lib/test_kasan.c).

Link: https://lkml.kernel.org/r/202112050757.x67rHnFU-lkp@intel.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:29 -08:00
Marco Elver e3d2b72bbf kcsan: Avoid nested contexts reading inconsistent reorder_access
Nested contexts, such as nested interrupts or scheduler code, share the
same kcsan_ctx. When such a nested context reads an inconsistent
reorder_access due to an interrupt during set_reorder_access(), we can
observe the following warning:

 | ------------[ cut here ]------------
 | Cannot find frame for torture_random kernel/torture.c:456 in stack trace
 | WARNING: CPU: 13 PID: 147 at kernel/kcsan/report.c:343 replace_stack_entry kernel/kcsan/report.c:343
 | ...
 | Call Trace:
 |  <TASK>
 |  sanitize_stack_entries kernel/kcsan/report.c:351 [inline]
 |  print_report kernel/kcsan/report.c:409
 |  kcsan_report_known_origin kernel/kcsan/report.c:693
 |  kcsan_setup_watchpoint kernel/kcsan/core.c:658
 |  rcutorture_one_extend kernel/rcu/rcutorture.c:1475
 |  rcutorture_loop_extend kernel/rcu/rcutorture.c:1558 [inline]
 |  ...
 |  </TASK>
 | ---[ end trace ee5299cb933115f5 ]---
 | ==================================================================
 | BUG: KCSAN: data-race in _raw_spin_lock_irqsave / rcutorture_one_extend
 |
 | write (reordered) to 0xffffffff8c93b300 of 8 bytes by task 154 on cpu 12:
 |  queued_spin_lock                include/asm-generic/qspinlock.h:80 [inline]
 |  do_raw_spin_lock                include/linux/spinlock.h:185 [inline]
 |  __raw_spin_lock_irqsave         include/linux/spinlock_api_smp.h:111 [inline]
 |  _raw_spin_lock_irqsave          kernel/locking/spinlock.c:162
 |  try_to_wake_up                  kernel/sched/core.c:4003
 |  sysvec_apic_timer_interrupt     arch/x86/kernel/apic/apic.c:1097
 |  asm_sysvec_apic_timer_interrupt arch/x86/include/asm/idtentry.h:638
 |  set_reorder_access              kernel/kcsan/core.c:416 [inline]    <-- inconsistent reorder_access
 |  kcsan_setup_watchpoint          kernel/kcsan/core.c:693
 |  rcutorture_one_extend           kernel/rcu/rcutorture.c:1475
 |  rcutorture_loop_extend          kernel/rcu/rcutorture.c:1558 [inline]
 |  rcu_torture_one_read            kernel/rcu/rcutorture.c:1600
 |  rcu_torture_reader              kernel/rcu/rcutorture.c:1692
 |  kthread                         kernel/kthread.c:327
 |  ret_from_fork                   arch/x86/entry/entry_64.S:295
 |
 | read to 0xffffffff8c93b300 of 8 bytes by task 147 on cpu 13:
 |  rcutorture_one_extend           kernel/rcu/rcutorture.c:1475
 |  rcutorture_loop_extend          kernel/rcu/rcutorture.c:1558 [inline]
 |  ...

The warning is telling us that there was a data race which KCSAN wants
to report, but the function where the original access (that is now
reordered) happened cannot be found in the stack trace, which prevents
KCSAN from generating the right stack trace. The stack trace of "write
(reordered)" now only shows where the access was reordered to, but
should instead show the stack trace of the original write, with a final
line saying "reordered to".

At the point where set_reorder_access() is interrupted, it just set
reorder_access->ptr and size, at which point size is non-zero. This is
sufficient (if ctx->disable_scoped is zero) for further accesses from
nested contexts to perform checking of this reorder_access.

That then happened in _raw_spin_lock_irqsave(), which is called by
scheduler code. However, since reorder_access->ip is still stale (ptr
and size belong to a different ip not yet set) this finally leads to
replace_stack_entry() not finding the frame in reorder_access->ip and
generating the above warning.

Fix it by ensuring that a nested context cannot access reorder_access
while we update it in set_reorder_access(): set ctx->disable_scoped for
the duration that reorder_access is updated, which effectively locks
reorder_access and prevents concurrent use by nested contexts. Note,
set_reorder_access() can do the update only if disabled_scoped is zero
on entry, and must therefore set disable_scoped back to non-zero after
the initial check in set_reorder_access().

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:29 -08:00
Marco Elver a70d36e6a0 kcsan: Make barrier tests compatible with lockdep
The barrier tests in selftest and the kcsan_test module only need the
spinlock and mutex to test correct barrier instrumentation. Therefore,
these were initially placed on the stack.

However, lockdep asserts that locks are in static storage, and will
generate this warning:

 | INFO: trying to register non-static key.
 | The code is fine but needs lockdep annotation, or maybe
 | you didn't initialize this object before use?
 | turning off the locking correctness validator.
 | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.16.0-rc1+ #3208
 | Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
 | Call Trace:
 |  <TASK>
 |  dump_stack_lvl+0x88/0xd8
 |  dump_stack+0x15/0x1b
 |  register_lock_class+0x6b3/0x840
 |  ...
 |  test_barrier+0x490/0x14c7
 |  kcsan_selftest+0x47/0xa0
 |  ...

To fix, move the test locks into static storage.

Fixing the above also revealed that lock operations are strengthened on
first use with lockdep enabled, due to lockdep calling out into
non-instrumented files (recall that kernel/locking/lockdep.c is not
instrumented with KCSAN).

Only kcsan_test checks for over-instrumentation of *_lock() operations,
where we can simply "warm up" the test locks to avoid the test case
failing with lockdep.

Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:28 -08:00
Marco Elver 6f3f0c98b5 sched, kcsan: Enable memory barrier instrumentation
There's no fundamental reason to disable KCSAN for scheduler code,
except for excessive noise and performance concerns (instrumenting
scheduler code is usually a good way to stress test KCSAN itself).

However, several core sched functions imply memory barriers that are
invisible to KCSAN without instrumentation, but are required to avoid
false positives. Therefore, unconditionally enable instrumentation of
memory barriers in scheduler code. Also update the comment to reflect
this and be a bit more brief.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:28 -08:00
Marco Elver 71b0e3aeb2 kcsan: selftest: Add test case to check memory barrier instrumentation
Memory barrier instrumentation is crucial to avoid false positives. To
avoid surprises, run a simple test case in the boot-time selftest to
ensure memory barriers are still instrumented correctly.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:27 -08:00
Marco Elver 8bc32b3481 kcsan: test: Add test cases for memory barrier instrumentation
Adds test cases to check that memory barriers are instrumented
correctly, and detection of missing memory barriers is working as
intended if CONFIG_KCSAN_STRICT=y.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:27 -08:00
Marco Elver 7310bd1f3e kcsan: test: Match reordered or normal accesses
Due to reordering accesses with weak memory modeling, any access can now
appear as "(reordered)".

Match any permutation of accesses if CONFIG_KCSAN_WEAK_MEMORY=y, so that
we effectively match an access if it is denoted "(reordered)" or not.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:27 -08:00
Marco Elver be3f6967ec kcsan: Show location access was reordered to
Also show the location the access was reordered to. An example report:

| ==================================================================
| BUG: KCSAN: data-race in test_kernel_wrong_memorder / test_kernel_wrong_memorder
|
| read-write to 0xffffffffc01e61a8 of 8 bytes by task 2311 on cpu 5:
|  test_kernel_wrong_memorder+0x57/0x90
|  access_thread+0x99/0xe0
|  kthread+0x2ba/0x2f0
|  ret_from_fork+0x22/0x30
|
| read-write (reordered) to 0xffffffffc01e61a8 of 8 bytes by task 2310 on cpu 7:
|  test_kernel_wrong_memorder+0x57/0x90
|  access_thread+0x99/0xe0
|  kthread+0x2ba/0x2f0
|  ret_from_fork+0x22/0x30
|   |
|   +-> reordered to: test_kernel_wrong_memorder+0x80/0x90
|
| Reported by Kernel Concurrency Sanitizer on:
| CPU: 7 PID: 2310 Comm: access_thread Not tainted 5.14.0-rc1+ #18
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
| ==================================================================

Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:27 -08:00
Marco Elver 3cc21a5312 kcsan: Call scoped accesses reordered in reports
The scoping of an access simply denotes the scope in which it may be
reordered. However, in reports, it'll be less confusing to say the
access is "reordered". This is more accurate when the race occurred.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:26 -08:00
Marco Elver 0b8b0830ac kcsan: Add core memory barrier instrumentation functions
Add the core memory barrier instrumentation functions. These invalidate
the current in-flight reordered access based on the rules for the
respective barrier types and in-flight access type.

To obtain barrier instrumentation that can be disabled via __no_kcsan
with appropriate compiler-support (and not just with objtool help),
barrier instrumentation repurposes __atomic_signal_fence(), instead of
inserting explicit calls. Crucially, __atomic_signal_fence() normally
does not map to any real instructions, but is still intercepted by
fsanitize=thread. As a result, like any other instrumentation done by
the compiler, barrier instrumentation can be disabled with __no_kcsan.

Unfortunately Clang and GCC currently differ in their __no_kcsan aka
__no_sanitize_thread behaviour with respect to builtin atomics (and
__tsan_func_{entry,exit}) instrumentation. This is already reflected in
Kconfig.kcsan's dependencies for KCSAN_WEAK_MEMORY. A later change will
introduce support for newer versions of Clang that can implement
__no_kcsan to also remove the additional instrumentation introduced by
KCSAN_WEAK_MEMORY.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:26 -08:00
Marco Elver 69562e4983 kcsan: Add core support for a subset of weak memory modeling
Add support for modeling a subset of weak memory, which will enable
detection of a subset of data races due to missing memory barriers.

KCSAN's approach to detecting missing memory barriers is based on
modeling access reordering, and enabled if `CONFIG_KCSAN_WEAK_MEMORY=y`,
which depends on `CONFIG_KCSAN_STRICT=y`. The feature can be enabled or
disabled at boot and runtime via the `kcsan.weak_memory` boot parameter.

Each memory access for which a watchpoint is set up, is also selected
for simulated reordering within the scope of its function (at most 1
in-flight access).

We are limited to modeling the effects of "buffering" (delaying the
access), since the runtime cannot "prefetch" accesses (therefore no
acquire modeling). Once an access has been selected for reordering, it
is checked along every other access until the end of the function scope.
If an appropriate memory barrier is encountered, the access will no
longer be considered for reordering.

When the result of a memory operation should be ordered by a barrier,
KCSAN can then detect data races where the conflict only occurs as a
result of a missing barrier due to reordering accesses.

Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:26 -08:00
Marco Elver 9756f64c8f kcsan: Avoid checking scoped accesses from nested contexts
Avoid checking scoped accesses from nested contexts (such as nested
interrupts or in scheduler code) which share the same kcsan_ctx.

This is to avoid detecting false positive races of accesses in the same
thread with currently scoped accesses: consider setting up a watchpoint
for a non-scoped (normal) access that also "conflicts" with a current
scoped access. In a nested interrupt (or in the scheduler), which shares
the same kcsan_ctx, we cannot check scoped accesses set up in the parent
context -- simply ignore them in this case.

With the introduction of kcsan_ctx::disable_scoped, we can also clean up
kcsan_check_scoped_accesses()'s recursion guard, and do not need to
modify the list's prev pointer.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:26 -08:00
Marco Elver 71f8de7092 kcsan: Remove redundant zero-initialization of globals
They are implicitly zero-initialized, remove explicit initialization.
It keeps the upcoming additions to kcsan_ctx consistent with the rest.

No functional change intended.

Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:26 -08:00
Marco Elver 12305abe98 kcsan: Refactor reading of instrumented memory
Factor out the switch statement reading instrumented memory into a
helper read_instrumented_memory().

No functional change.

Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:26 -08:00
Lai Jiangshan 84f91c62d6 workqueue: Remove the cacheline_aligned for nr_running
nr_running is never modified remotely after the schedule callback in
wakeup path is removed.

Rather nr_running is often accessed with other fields in the pool
together, so the cacheline_aligned for nr_running isn't needed.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-12-09 12:26:54 -10:00
Lai Jiangshan 989442d737 workqueue: Move the code of waking a worker up in unbind_workers()
In unbind_workers(), there are two pool->lock held sections separated
by the code of zapping nr_running.  wake_up_worker() needs to be in
pool->lock held section and after zapping nr_running.  And zapping
nr_running had to be after schedule() when the local wake up
functionality was in use.  Now, the call to schedule() has been removed
along with the local wake up functionality, so the code can be merged
into the same pool->lock held section.

The diffstat shows that it is other code moved down because the diff
tools can not know the meaning of merging lock sections by swapping
two code blocks.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-12-09 12:23:15 -10:00
Lai Jiangshan b4ac9384ac workqueue: Remove schedule() in unbind_workers()
The commit 6d25be5782 ("sched/core, workqueues: Distangle worker
accounting from rq lock") changed the schedule callbacks for workqueue
and moved the schedule callback from the wakeup code to at end of
schedule() in the worker's process context.

It means that the callback wq_worker_running() is guaranteed that
it sees the %WORKER_UNBOUND flag after scheduled since unbind_workers()
is running on the same CPU that all the pool's workers bound to.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-12-09 12:20:24 -10:00
Lai Jiangshan 11b45b0bf4 workqueue: Remove outdated comment about exceptional workers in unbind_workers()
Long time before, workers are not ALL bound after CPU_ONLINE, they can
still be running in other CPUs before self rebinding.

But the commit a9ab775bca ("workqueue: directly restore CPU affinity
of workers from CPU_ONLINE") makes rebind_workers() bind them all.

So all workers are on the CPU before the CPU is down.

And the comment in unbind_workers() refers to the workers "which are
still executing works from before the last CPU down" is outdated.
Just removed it.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-12-09 12:16:08 -10:00
Lai Jiangshan 3e5f39ea33 workqueue: Remove the advanced kicking of the idle workers in rebind_workers()
The commit 6d25be5782 ("sched/core, workqueues: Distangle worker
accounting from rq lock") changed the schedule callbacks for workqueue
and removed the local-wake-up functionality.

Now the wakingup of workers is done by normal fashion and workers not
yet migrated to the specific CPU in concurrency managed pool can also
be woken up by workers that already bound to the specific cpu now.

So this advanced kicking of the idle workers to migrate them to the
associated CPU is unneeded now.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-12-09 12:15:41 -10:00
Lai Jiangshan ccf45156fd workqueue: Remove the outdated comment before wq_worker_sleeping()
It isn't called with preempt disabled now.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-12-09 12:15:15 -10:00
Alexey Gladkov 59ec71575a ucounts: Fix rlimit max values check
The semantics of the rlimit max values differs from ucounts itself. When
creating a new userns, we store the current rlimit of the process in
ucount_max. Thus, the value of the limit in the parent userns is saved
in the created one.

The problem is that now we are taking the maximum value for counter from
the same userns. So for init_user_ns it will always be RLIM_INFINITY.

To fix the problem we need to check the counter value with the max value
stored in userns.

Reproducer:

su - test -c "ulimit -u 3; sleep 5 & sleep 6 & unshare -U --map-root-user sh -c 'sleep 7 & sleep 8 & date; wait'"

Before:

[1] 175
[2] 176
Fri Nov 26 13:48:20 UTC 2021
[1]-  Done                    sleep 5
[2]+  Done                    sleep 6

After:

[1] 167
[2] 168
sh: fork: retry: Resource temporarily unavailable
sh: fork: retry: Resource temporarily unavailable
sh: fork: retry: Resource temporarily unavailable
sh: fork: retry: Resource temporarily unavailable
sh: fork: retry: Resource temporarily unavailable
sh: fork: retry: Resource temporarily unavailable
sh: fork: retry: Resource temporarily unavailable
sh: fork: Interrupted system call
[1]-  Done                    sleep 5
[2]+  Done                    sleep 6

Fixes: c54b245d01 ("Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace")
Reported-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/024ec805f6e16896f0b23e094773790d171d2c1c.1638218242.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2021-12-09 15:37:18 -06:00
Jakub Kicinski 3150a73366 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
No conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-09 13:23:02 -08:00
Paul E. McKenney f80fe66c38 Merge branches 'doc.2021.11.30c', 'exp.2021.12.07a', 'fastnohz.2021.11.30c', 'fixes.2021.11.30c', 'nocb.2021.12.09a', 'nolibc.2021.11.30c', 'tasks.2021.12.09a', 'torture.2021.12.07a' and 'torturescript.2021.11.30c' into HEAD
doc.2021.11.30c: Documentation updates.
exp.2021.12.07a: Expedited-grace-period fixes.
fastnohz.2021.11.30c: Remove CONFIG_RCU_FAST_NO_HZ.
fixes.2021.11.30c: Miscellaneous fixes.
nocb.2021.12.09a: No-CB CPU updates.
nolibc.2021.11.30c: Tiny in-kernel library updates.
tasks.2021.12.09a: RCU-tasks updates, including update-side scalability.
torture.2021.12.07a: Torture-test in-kernel module updates.
torturescript.2021.11.30c: Torture-test scripting updates.
2021-12-09 11:38:09 -08:00
Frederic Weisbecker 10d4703154 rcu/nocb: Merge rcu_spawn_cpu_nocb_kthread() and rcu_spawn_one_nocb_kthread()
The rcu_spawn_one_nocb_kthread() function is called only from
rcu_spawn_cpu_nocb_kthread().  Therefore, inline the former into
the latter, saving a few lines of code.

Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 11:35:16 -08:00
Frederic Weisbecker d2cf0854d7 rcu/nocb: Allow empty "rcu_nocbs" kernel parameter
Allow the rcu_nocbs kernel parameter to be specified just by itself,
without specifying any CPUs.  This allows systems administrators to use
"rcu_nocbs" to specify that none of the CPUs are to be offloaded at boot
time, but than any of them may be offloaded at runtime via cpusets.

In contrast, if the "rcu_nocbs" or "nohz_full" kernel parameters are not
specified at all, then not only are none of the CPUs offloaded at boot,
none of them can be offloaded at runtime, either.

While in the area, modernize the description of the "rcuo" kthreads'
naming scheme.

Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 11:35:11 -08:00
Frederic Weisbecker 2cf4528d6d rcu/nocb: Create kthreads on all CPUs if "rcu_nocbs=" or "nohz_full=" are passed
In order to be able to (de-)offload any CPU using cpusets in the future,
create the NOCB data structures for all possible CPUs.  For now this is
done only as long as the "rcu_nocbs=" or "nohz_full=" kernel parameters
are passed to avoid the unnecessary overhead for most users.

Note that the rcuog and rcuoc kthreads are not created until at least
one of the corresponding CPUs comes online.  This approach avoids the
creation of excess kthreads when firmware lies about the number of CPUs
present on the system.

Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 11:35:06 -08:00
Frederic Weisbecker a81aeaf7a1 rcu/nocb: Optimize kthreads and rdp initialization
Currently cpumask_available() is used to prevent from unwanted NOCB
initialization.  However if neither "rcu_nocbs=" nor "nohz_full="
parameters are passed to a kernel built with CONFIG_CPUMASK_OFFSTACK=n,
the initialization path is still taken, running through all sorts of
needless operations and iterations on an empty cpumask.

Fix this by relying on a real initialization state instead.  This also
optimizes kthread creation, preventing needless iteration over all online
CPUs when the kernel is booted without any offloaded CPUs.

Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 11:34:37 -08:00
Frederic Weisbecker 8d97039646 rcu/nocb: Prepare nocb_cb_wait() to start with a non-offloaded rdp
In order to be able to toggle the offloaded state from cpusets, a nocb
kthread will need to be created for all possible CPUs whenever either
of the "rcu_nocbs=" or "nohz_full=" parameters are specified.

Therefore, the nocb_cb_wait() kthread must be prepared to start running
on a de-offloaded rdp.  To accomplish this, simply move the sleeping
condition to the beginning of the nocb_cb_wait() function, which prevents
this kthread from attempting to invoke callbacks before the corresponding
CPU is offloaded.

Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 11:34:30 -08:00
Frederic Weisbecker 2ebc45c44c rcu/nocb: Remove rcu_node structure from nocb list when de-offloaded
The nocb_gp_wait() function iterates over all CPUs in its group,
including even those CPUs that have been de-offloaded.  This is of
course suboptimal, especially if none of the CPUs within the group are
currently offloaded.  This will become even more of a problem once a
nocb kthread is created for all possible CPUs.

Therefore use a standard double linked list to link all the offloaded
rcu_data structures and safely add or delete these structure as we
offload or de-offload them, respectively.

Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 11:34:07 -08:00
Linus Torvalds ded746bfc9 Networking fixes for 5.16-rc5, including fixes from bpf, can and netfilter.
Current release - regressions:
 
  - bpf, sockmap: re-evaluate proto ops when psock is removed from sockmap
 
 Current release - new code bugs:
 
  - bpf: fix bpf_check_mod_kfunc_call for built-in modules
 
  - ice: fixes for TC classifier offloads
 
  - vrf: don't run conntrack on vrf with !dflt qdisc
 
 Previous releases - regressions:
 
  - bpf: fix the off-by-two error in range markings
 
  - seg6: fix the iif in the IPv6 socket control block
 
  - devlink: fix netns refcount leak in devlink_nl_cmd_reload()
 
  - dsa: mv88e6xxx: fix "don't use PHY_DETECT on internal PHY's"
 
  - dsa: mv88e6xxx: allow use of PHYs on CPU and DSA ports
 
 Previous releases - always broken:
 
  - ethtool: do not perform operations on net devices being unregistered
 
  - udp: use datalen to cap max gso segments
 
  - ice: fix races in stats collection
 
  - fec: only clear interrupt of handling queue in fec_enet_rx_queue()
 
  - m_can: pci: fix incorrect reference clock rate
 
  - m_can: disable and ignore ELO interrupt
 
  - mvpp2: fix XDP rx queues registering
 
 Misc:
 
  - treewide: add missing includes masked by cgroup -> bpf.h dependency
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf, can and netfilter.

  Current release - regressions:

   - bpf, sockmap: re-evaluate proto ops when psock is removed from
     sockmap

  Current release - new code bugs:

   - bpf: fix bpf_check_mod_kfunc_call for built-in modules

   - ice: fixes for TC classifier offloads

   - vrf: don't run conntrack on vrf with !dflt qdisc

  Previous releases - regressions:

   - bpf: fix the off-by-two error in range markings

   - seg6: fix the iif in the IPv6 socket control block

   - devlink: fix netns refcount leak in devlink_nl_cmd_reload()

   - dsa: mv88e6xxx: fix "don't use PHY_DETECT on internal PHY's"

   - dsa: mv88e6xxx: allow use of PHYs on CPU and DSA ports

  Previous releases - always broken:

   - ethtool: do not perform operations on net devices being
     unregistered

   - udp: use datalen to cap max gso segments

   - ice: fix races in stats collection

   - fec: only clear interrupt of handling queue in fec_enet_rx_queue()

   - m_can: pci: fix incorrect reference clock rate

   - m_can: disable and ignore ELO interrupt

   - mvpp2: fix XDP rx queues registering

  Misc:

   - treewide: add missing includes masked by cgroup -> bpf.h
     dependency"

* tag 'net-5.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (82 commits)
  net: dsa: mv88e6xxx: allow use of PHYs on CPU and DSA ports
  net: wwan: iosm: fixes unable to send AT command during mbim tx
  net: wwan: iosm: fixes net interface nonfunctional after fw flash
  net: wwan: iosm: fixes unnecessary doorbell send
  net: dsa: felix: Fix memory leak in felix_setup_mmio_filtering
  MAINTAINERS: s390/net: remove myself as maintainer
  net/sched: fq_pie: prevent dismantle issue
  net: mana: Fix memory leak in mana_hwc_create_wq
  seg6: fix the iif in the IPv6 socket control block
  nfp: Fix memory leak in nfp_cpp_area_cache_add()
  nfc: fix potential NULL pointer deref in nfc_genl_dump_ses_done
  nfc: fix segfault in nfc_genl_dump_devices_done
  udp: using datalen to cap max gso segments
  net: dsa: mv88e6xxx: error handling for serdes_power functions
  can: kvaser_usb: get CAN clock frequency from device
  can: kvaser_pciefd: kvaser_pciefd_rx_error_frame(): increase correct stats->{rx,tx}_errors counter
  net: mvpp2: fix XDP rx queues registering
  vmxnet3: fix minimum vectors alloc issue
  net, neigh: clear whole pneigh_entry at alloc time
  net: dsa: mv88e6xxx: fix "don't use PHY_DETECT on internal PHY's"
  ...
2021-12-09 11:26:44 -08:00
Paul E. McKenney fd796e4139 rcu-tasks: Use fewer callbacks queues if callback flood ends
By default, when lock contention is encountered, the RCU Tasks flavors
of RCU switch to using per-CPU queueing.  However, if the callback
flood ends, per-CPU queueing continues to be used, which introduces
significant additional overhead, especially for callback invocation,
which fans out a series of workqueue handlers.

This commit therefore switches back to single-queue operation if at the
beginning of a grace period there are very few callbacks.  The definition
of "very few" is set by the rcupdate.rcu_task_collapse_lim module
parameter, which defaults to 10.  This switch happens in two phases,
with the first phase causing future callbacks to be enqueued on CPU 0's
queue, but with all queues continuing to be checked for grace periods
and callback invocation.  The second phase checks to see if an RCU grace
period has elapsed and if all remaining RCU-Tasks callbacks are queued
on CPU 0.  If so, only CPU 0 is checked for future grace periods and
callback operation.

Of course, the return of contention anywhere during this process will
result in returning to per-CPU callback queueing.

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 10:52:11 -08:00
Paul E. McKenney 2cee0789b4 rcu-tasks: Use separate ->percpu_dequeue_lim for callback dequeueing
Decreasing the number of callback queues is a bit tricky because it
is necessary to handle callbacks that were queued before the number of
queues decreased, but which were not ready to invoke until afterwards.
This commit takes a first step in this direction by maintaining a separate
->percpu_dequeue_lim to control callback dequeueing, in addition to the
existing ->percpu_enqueue_lim which now controls only enqueueing.

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 10:52:11 -08:00
Paul E. McKenney ab97152f88 rcu-tasks: Use more callback queues if contention encountered
The rcupdate.rcu_task_enqueue_lim module parameter allows system
administrators to tune the number of callback queues used by the RCU
Tasks flavors.  However if callback storms are infrequent, it would
be better to operate with a single queue on a given system unless and
until that system actually needed more queues.  Systems not needing
more queues can then avoid the overhead of checking the extra queues
and especially avoid the overhead of fanning workqueue handlers out to
all CPUs to invoke callbacks.

This commit therefore switches to using all the CPUs' callback queues if
call_rcu_tasks_generic() encounters too much lock contention.  The amount
of lock contention to tolerate defaults to 100 contended lock acquisitions
per jiffy, and can be adjusted using the new rcupdate.rcu_task_contend_lim
module parameter.

Such switching is undertaken only if the rcupdate.rcu_task_enqueue_lim
module parameter is negative, which is its default value (-1).
This allows savvy systems administrators to set the number of queues
to some known good value and to not have to worry about the kernel doing
any second guessing.

[ paulmck: Apply feedback from Guillaume Tucker and kernelci. ]

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 10:52:11 -08:00
Paul E. McKenney 3063b33a34 rcu-tasks: Avoid raw-spinlocked wakeups from call_rcu_tasks_generic()
If the caller of of call_rcu_tasks(), call_rcu_tasks_rude(),
or call_rcu_tasks_trace() holds a raw spinlock, and then if
call_rcu_tasks_generic() determines that the grace-period kthread must
be awakened, then the wakeup might acquire a normal spinlock while a
raw spinlock is held.  This results in lockdep splats when the
kernel is built with CONFIG_PROVE_RAW_LOCK_NESTING=y.

This commit therefore defers the wakeup using irq_work_queue().

It would be nice to directly invoke wakeup when a raw spinlock is not
held, but there is currently no way to check for this in all kernels.

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 10:52:11 -08:00
Paul E. McKenney 7d13d30bb6 rcu-tasks: Count trylocks to estimate call_rcu_tasks() contention
This commit converts the unconditional raw_spin_lock_rcu_node() lock
acquisition in call_rcu_tasks_generic() to a trylock followed by an
unconditional acquisition if the trylock fails.  If the trylock fails,
the failure is counted, but the count is reset to zero on each new jiffy.

This statistic will be used to determine when to move from a single
callback queue to per-CPU callback queues.

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 10:52:11 -08:00
Paul E. McKenney 8610b65680 rcu-tasks: Add rcupdate.rcu_task_enqueue_lim to set initial queueing
This commit adds a rcupdate.rcu_task_enqueue_lim module parameter that
sets the initial number of callback queues to use for the RCU Tasks
family of RCU implementations.  This parameter allows testing of various
fanout values.

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 10:52:11 -08:00
Paul E. McKenney ce9b1c667f rcu-tasks: Make rcu_barrier_tasks*() handle multiple callback queues
Currently, rcu_barrier_tasks(), rcu_barrier_tasks_rude(),
and rcu_barrier_tasks_trace() simply invoke the corresponding
synchronize_rcu_tasks*() function.  This works because there is only
one callback queue.

However, there will soon be multiple callback queues.  This commit
therefore scans the queues currently in use, entraining a callback on
each non-empty queue.  Sequence numbers and reference counts are used
to synchronize this process in a manner similar to the approach taken
by rcu_barrier().

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 10:52:11 -08:00
Paul E. McKenney d363f833c6 rcu-tasks: Use workqueues for multiple rcu_tasks_invoke_cbs() invocations
If there is a flood of callbacks, it is necessary to put multiple
CPUs to work invoking those callbacks.  This commit therefore uses a
workqueue-flooding approach to parallelize RCU Tasks callback execution.

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 10:52:00 -08:00
Paul E. McKenney 57881863ad rcu-tasks: Abstract invocations of callbacks
This commit adds a rcu_tasks_invoke_cbs() function that invokes all
ready callbacks on all of the per-CPU lists that are currently in use.

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 10:51:44 -08:00
Paul E. McKenney 4d1114c054 rcu-tasks: Abstract checking of callback lists
This commit adds a rcu_tasks_need_gpcb() function that returns an
indication of whether another grace period is required, and if no grace
period is required, whether there are callbacks that need to be invoked.
The function scans all per-CPU lists currently in use.

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 10:51:27 -08:00
Eric Biggers 42288cb44c wait: add wake_up_pollfree()
Several ->poll() implementations are special in that they use a
waitqueue whose lifetime is the current task, rather than the struct
file as is normally the case.  This is okay for blocking polls, since a
blocking poll occurs within one task; however, non-blocking polls
require another solution.  This solution is for the queue to be cleared
before it is freed, using 'wake_up_poll(wq, EPOLLHUP | POLLFREE);'.

However, that has a bug: wake_up_poll() calls __wake_up() with
nr_exclusive=1.  Therefore, if there are multiple "exclusive" waiters,
and the wakeup function for the first one returns a positive value, only
that one will be called.  That's *not* what's needed for POLLFREE;
POLLFREE is special in that it really needs to wake up everyone.

Considering the three non-blocking poll systems:

- io_uring poll doesn't handle POLLFREE at all, so it is broken anyway.

- aio poll is unaffected, since it doesn't support exclusive waits.
  However, that's fragile, as someone could add this feature later.

- epoll doesn't appear to be broken by this, since its wakeup function
  returns 0 when it sees POLLFREE.  But this is fragile.

Although there is a workaround (see epoll), it's better to define a
function which always sends POLLFREE to all waiters.  Add such a
function.  Also make it verify that the queue really becomes empty after
all waiters have been woken up.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211209010455.42744-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
2021-12-09 10:49:56 -08:00
Paul E. McKenney 8dd593fddd rcu-tasks: Add a ->percpu_enqueue_lim to the rcu_tasks structure
This commit adds a ->percpu_enqueue_lim field to the rcu_tasks structure.
This field contains two to the power of the ->percpu_enqueue_shift
field, easing construction of iterators over the per-CPU queues that
might contain RCU Tasks callbacks.  Such iterators will be introduced
in later commits.

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 10:13:55 -08:00
Neeraj Upadhyay 65b629e704 rcu-tasks: Inspect stalled task's trc state in locked state
On RCU tasks trace stall, inspect the RCU-tasks-trace specific
states of stalled task in locked down state, using try_invoke_
on_locked_down_task(), to get reliable trc state of a non-running
stalled task.

This was tested using the following command:

tools/testing/selftests/rcutorture/bin/kvm.sh --cpus 8 --configs TRACE01 \
--bootargs "rcutorture.torture_type=tasks-tracing rcutorture.stall_cpu=10 \
rcutorture.stall_cpu_block=1 rcupdate.rcu_task_stall_timeout=100" --trust-make

As expected, this produced the following console output for running and
sleeping tasks.

[   21.520291] INFO: rcu_tasks_trace detected stalls on tasks:
[   21.521292] P85: ... nesting: 1N cpu: 2
[   21.521966] task:rcu_torture_sta state:D stack:15080 pid:   85 ppid:     2
flags:0x00004000
[   21.523384] Call Trace:
[   21.523808]  __schedule+0x273/0x6e0
[   21.524428]  schedule+0x35/0xa0
[   21.524971]  schedule_timeout+0x1ed/0x270
[   21.525690]  ? del_timer_sync+0x30/0x30
[   21.526371]  ? rcu_torture_writer+0x720/0x720
[   21.527106]  rcu_torture_stall+0x24a/0x270
[   21.527816]  kthread+0x115/0x140
[   21.528401]  ? set_kthread_struct+0x40/0x40
[   21.529136]  ret_from_fork+0x22/0x30
[   21.529766]  1 holdouts
[   21.632300] INFO: rcu_tasks_trace detected stalls on tasks:
[   21.632345] rcu_torture_stall end.
[   21.633293] P85: .
[   21.633294] task:rcu_torture_sta state:R  running task stack:15080 pid:
85 ppid:     2 flags:0x00004000
[   21.633299] Call Trace:
[   21.633301]  ? vprintk_emit+0xab/0x180
[   21.633306]  ? vprintk_emit+0x11a/0x180
[   21.633308]  ? _printk+0x4d/0x69
[   21.633311]  ? __default_send_IPI_shortcut+0x1f/0x40

[ paulmck: Update to new v5.16 task_call_func() name. ]

Signed-off-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 10:13:55 -08:00
Paul E. McKenney 381a4f3b38 rcu-tasks: Use spin_lock_rcu_node() and friends
This commit renames the rcu_tasks_percpu structure's ->cbs_pcpu_lock
to ->lock and then uses spin_lock_rcu_node() and friends to acquire and
release this lock, preparing for upcoming commits that will spread the
grace-period process across multiple CPUs and kthreads.

[ paulmck: Apply feedback from kernel test robot. ]

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 10:12:45 -08:00
Miaoqian Lin c24be24aed tracing: Fix possible memory leak in __create_synth_event() error path
There's error paths in __create_synth_event() after the argv is allocated
that fail to free it. Add a jump to free it when necessary.

Link: https://lkml.kernel.org/r/20211209024317.11783-1-linmq006@gmail.com

Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
[ Fixed up the patch and change log ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-09 13:03:05 -05:00
Thomas Gleixner 890337624e genirq/msi: Handle PCI/MSI allocation fail in core code
Get rid of yet another irqdomain callback and let the core code return the
already available information of how many descriptors could be allocated.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>	# PCI
Link: https://lore.kernel.org/r/20211206210225.046615302@linutronix.de
2021-12-09 11:52:22 +01:00
Thomas Gleixner e58f2259b9 genirq/msi, treewide: Use a named struct for PCI/MSI attributes
The unnamed struct sucks and is in the way of further cleanups. Stick the
PCI related MSI data into a real data structure and cleanup all users.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20211206210224.374863119@linutronix.de
2021-12-09 11:52:21 +01:00
Thomas Gleixner 3ba1f050c9 genirq/msi: Fixup includes
Remove the kobject.h include from msi.h as it's not required and add a
sysfs.h include to the core code instead.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20211206210224.103502021@linutronix.de
2021-12-09 11:52:20 +01:00
Thomas Gleixner 1dd2c6a081 genirq/msi: Remove unused domain callbacks
No users and there is no need to grow them.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211126223824.322987915@linutronix.de
Link: https://lore.kernel.org/r/20211206210224.041777889@linutronix.de
2021-12-09 11:52:20 +01:00
Thomas Gleixner 1197528aae genirq/msi: Guard sysfs code
No point in building unused code when CONFIG_SYSFS=n.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20211206210223.985907940@linutronix.de
2021-12-09 11:52:20 +01:00
Colin Ian King 73b6eae583 bpf: Remove redundant assignment to pointer t
The pointer t is being initialized with a value that is never read. The
pointer is re-assigned a value a littler later on, hence the initialization
is redundant and can be removed.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211207224718.59593-1-colin.i.king@gmail.com
2021-12-08 23:14:12 -08:00
Jakub Kicinski 6efcdadc15 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
bpf 2021-12-08

We've added 12 non-merge commits during the last 22 day(s) which contain
a total of 29 files changed, 659 insertions(+), 80 deletions(-).

The main changes are:

1) Fix an off-by-two error in packet range markings and also add a batch of
   new tests for coverage of these corner cases, from Maxim Mikityanskiy.

2) Fix a compilation issue on MIPS JIT for R10000 CPUs, from Johan Almbladh.

3) Fix two functional regressions and a build warning related to BTF kfunc
   for modules, from Kumar Kartikeya Dwivedi.

4) Fix outdated code and docs regarding BPF's migrate_disable() use on non-
   PREEMPT_RT kernels, from Sebastian Andrzej Siewior.

5) Add missing includes in order to be able to detangle cgroup vs bpf header
   dependencies, from Jakub Kicinski.

6) Fix regression in BPF sockmap tests caused by missing detachment of progs
   from sockets when they are removed from the map, from John Fastabend.

7) Fix a missing "no previous prototype" warning in x86 JIT caused by BPF
   dispatcher, from Björn Töpel.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Add selftests to cover packet access corner cases
  bpf: Fix the off-by-two error in range markings
  treewide: Add missing includes masked by cgroup -> bpf dependency
  tools/resolve_btfids: Skip unresolved symbol warning for empty BTF sets
  bpf: Fix bpf_check_mod_kfunc_call for built-in modules
  bpf: Make CONFIG_DEBUG_INFO_BTF depend upon CONFIG_BPF_SYSCALL
  mips, bpf: Fix reference to non-existing Kconfig symbol
  bpf: Make sure bpf_disable_instrumentation() is safe vs preemption.
  Documentation/locking/locktypes: Update migrate_disable() bits.
  bpf, sockmap: Re-evaluate proto ops when psock is removed from sockmap
  bpf, sockmap: Attach map progs to psock early for feature probes
  bpf, x86: Fix "no previous prototype" warning
====================

Link: https://lore.kernel.org/r/20211208155125.11826-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-08 16:06:44 -08:00
Vincent Donnefort ef8df9798d sched/fair: Cleanup task_util and capacity type
task_util and capacity are comparable unsigned long values. There is no
need for an intermidiate implicit signed cast.

Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211207095755.859972-1-vincent.donnefort@arm.com
2021-12-08 22:22:02 +01:00
Jiri Olsa fea3ffa48c ftrace: Add cleanup to unregister_ftrace_direct_multi
Adding ops cleanup to unregister_ftrace_direct_multi,
so it can be reused in another register call.

Link: https://lkml.kernel.org/r/20211206182032.87248-3-jolsa@kernel.org

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Fixes: f64dd4627e ("ftrace: Add multi direct register/unregister interface")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-08 12:12:02 -05:00
Jiri Olsa 7d5b7cad79 ftrace: Use direct_ops hash in unregister_ftrace_direct
Now when we have *direct_multi interface the direct_functions
hash is no longer owned just by direct_ops. It's also used by
any other ftrace_ops passed to *direct_multi interface.

Thus to find out that we are unregistering the last function
from direct_ops, we need to check directly direct_ops's hash.

Link: https://lkml.kernel.org/r/20211206182032.87248-2-jolsa@kernel.org

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Fixes: f64dd4627e ("ftrace: Add multi direct register/unregister interface")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-08 12:12:02 -05:00
Christoph Hellwig 28e4576d55 dma-direct: add a dma_direct_use_pool helper
Add a helper to check if a potentially blocking operation should
dip into the atomic pools.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2021-12-08 16:46:35 +01:00
David Woodhouse 74d9555580 PM: hibernate: Allow ACPI hardware signature to be honoured
Theoretically, when the hardware signature in FACS changes, the OS
is supposed to gracefully decline to attempt to resume from S4:

 "If the signature has changed, OSPM will not restore the system
  context and can boot from scratch"

In practice, Windows doesn't do this and many laptop vendors do allow
the signature to change especially when docking/undocking, so it would
be a bad idea to simply comply with the specification by default in the
general case.

However, there are use cases where we do want the compliant behaviour
and we know it's safe. Specifically, when resuming virtual machines where
we know the hypervisor has changed sufficiently that resume will fail.
We really want to be able to *tell* the guest kernel not to try, so it
boots cleanly and doesn't just crash. This patch provides a way to opt
in to the spec-compliant behaviour on the command line.

A follow-up patch may do this automatically for certain "known good"
machines based on a DMI match, or perhaps just for all hypervisor
guests since there's no good reason a hypervisor would change the
hardware_signature that it exposes to guests *unless* it wants them
to obey the ACPI specification.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-12-08 16:06:10 +01:00
John Keeping 2972e3050e tracing: Make trace_marker{,_raw} stream-like
The tracing marker files are write-only streams with no meaningful
concept of file position.  Using stream_open() to mark them as
stream-link indicates this and has the added advantage that a single
file descriptor can now be used from multiple threads without contention
thanks to clearing FMODE_ATOMIC_POS.

Note that this has the potential to break existing userspace by since
both lseek(2) and pwrite(2) will now return ESPIPE when previously lseek
would have updated the stored offset and pwrite would have appended to
the trace.  A survey of libtracefs and several other projects found to
use trace_marker(_raw) [1][2][3] suggests that everyone limits
themselves to calling write(2) and close(2) on these file descriptors so
there is a good chance this will go unnoticed and the benefits of
reduced overhead and lock contention seem worth the risk.

[1] https://github.com/google/perfetto
[2] https://github.com/intel/media-driver/
[3] https://w1.fi/cgit/hostap/

Link: https://lkml.kernel.org/r/20211207142558.347029-1-john@metanate.com

Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-07 22:05:49 -05:00
Paul E. McKenney 53b541fbdb rcutorture: Combine n_max_cbs from all kthreads in a callback flood
With the addition of multiple callback-flood kthreads, the maximum number
of callbacks from any one of those kthreads is reported in the rcutorture
run summary.  This commit changes this to report the sum of each kthread's
maximum number of callbacks in a given callback-flooding episode.

Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:36:18 -08:00
Paul E. McKenney 613b00fbe6 rcutorture: Add ability to limit callback-flood intensity
The RCU tasks flavors of RCU now need concurrent callback flooding to
test their ability to switch between single-queue mode and per-CPU queue
mode, but their lack of heavy-duty forward-progress features rules out
the use of rcutorture's current callback-flooding code.  This commit
therefore provides the ability to limit the intensity of the callback
floods using a new ->cbflood_max field in the rcu_operations structure.
When this field is zero, there is no limit, otherwise, each callback-flood
kthread allocates at most ->cbflood_max callbacks.

Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:36:18 -08:00
Paul E. McKenney 82e310033d rcutorture: Enable multiple concurrent callback-flood kthreads
This commit converts the rcutorture.fwd_progress module parameter from
bool to int, so that it specifies the number of callback-flood kthreads.
Values less than zero specify one kthread per CPU, however, the number of
kthreads executing concurrently is limited to the number of online CPUs.
This commit also reverse the order of the need-resched and callback-flood
operations to cause the callback flooding to happen more nearly at the
same time.

Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:36:18 -08:00
Wander Lairson Costa 5ff7c9f9d7 rcutorture: Avoid soft lockup during cpu stall
If we use the module stall_cpu option, we may get a soft lockup warning
in case we also don't pass the stall_cpu_block option.

Introduce the stall_no_softlockup option to avoid a soft lockup on
cpu stall even if we don't use the stall_cpu_block option.

Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:36:17 -08:00
Li Zhijian 81faa4f6fb locktorture,rcutorture,torture: Always log error message
Unconditionally log messages corresponding to errors.

Acked-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Li Zhijian <zhijianx.li@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:36:17 -08:00
Li Zhijian 809da9bf80 scftorture: Always log error message
Unconditionally log messages corresponding to errors.

Acked-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Li Zhijian <zhijianx.li@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:36:17 -08:00
Li Zhijian 86e7ed1bd5 rcuscale: Always log error message
Unconditionally log messages corresponding to errors.

Acked-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Li Zhijian <zhijianx.li@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:36:17 -08:00
Li Zhijian 04cf851886 scftorture: Remove unused SCFTORTOUT
There are no longer any users of SCFTORTOUT(), so this commit removes it.

Acked-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Li Zhijian <zhijianx.li@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:36:17 -08:00
Li Zhijian 71f6ea2a0b scftorture: Add missing '\n' to flush message
Add '\n' to macros to flush message for each call.

Acked-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Li Zhijian <zhijianx.li@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:36:17 -08:00
Li Zhijian f71f22b67d refscale: Add missing '\n' to flush message
Add '\n' to macros to flush message for each call.

Acked-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Li Zhijian <zhijianx.li@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:36:12 -08:00
Li Zhijian 4feeb9d5f8 refscale: Always log the error message
An OOM is a serious error that should be logged even in non-verbose runs.
This commit therefore adds an unconditional SCALEOUT_ERRSTRING() macro
and uses it instead of VERBOSE_SCALEOUT_ERRSTRING() when reporting an OOM.

[ paulmck: Drop do-while from SCALEOUT_ERRSTRING() due to only single statement. ]

Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:31:44 -08:00
Paul E. McKenney 9b073de1c7 rcu_tasks: Convert bespoke callback list to rcu_segcblist structure
This commit moves from a bespoke head and tail pointer in the
rcu_tasks_percpu structure to an rcu_segcblist structure, thus allowing
associating the grace-period sequence number with groups of callbacks.
This in turn will allow callbacks to be invoked independently on
different CPUs.

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:26:57 -08:00
Paul E. McKenney b14fb4fbbc rcu-tasks: Convert grace-period counter to grace-period sequence number
This commit moves the rcu_tasks structure's ->n_gps grace-period-counter
field to a ->task_gp_seq grce-period sequence number in order to enable
use of the rcu_segcblist structure for the callback lists.  This in turn
permits CPUs to lag behind the RCU Tasks grace-period sequence number
without suffering long-term slowdowns in callback invocation.

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:26:57 -08:00
Paul E. McKenney 7a30871b6a rcu-tasks: Introduce ->percpu_enqueue_shift for dynamic queue selection
This commit introduces a ->percpu_enqueue_shift field to the rcu_tasks
structure, and uses it to shift down the CPU number in order to
select a rcu_tasks_percpu structure.  This field is currently set to a
sufficiently large shift count to always select the CPU-0 instance of
the rcu_tasks_percpu structure, and later commits will adjust this.

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:26:57 -08:00
Paul E. McKenney cafafd6776 rcu-tasks: Create per-CPU callback lists
Currently, RCU Tasks Trace (as well as the other two flavors of RCU Tasks)
use a single global callback list.  This works well and is simple, but
expected changes in workload will cause this list to become a bottleneck.
This commit therefore creates per-CPU callback lists for the various
flavors of RCU Tasks, but continues queueing on a single list, namely
that of CPU 0.  Later commits will dynamically vary the number of lists
in use to accommodate dynamic changes in workload.

Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Tested-by: kernel test robot <beibei.si@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:26:09 -08:00
Frederic Weisbecker 0598a4d442 rcu/nocb: Don't invoke local rcu core on callback overload from nocb kthread
rcu_core() tries to ensure that its self-invocation in case of callbacks
overload only happen in softirq/rcuc mode. Indeed it doesn't make sense
to trigger local RCU core from nocb_cb kthread since it can execute
on a CPU different from the target rdp. Also in case of overload, the
nocb_cb kthread simply iterates a new loop of callbacks processing.

However the "offloaded" check that aims at preventing misplaced
rcu_core() invocations is wrong. First of all that state is volatile
and second: softirq/rcuc can execute while the target rdp is offloaded.
As a result rcu_core() can be invoked on the wrong CPU while in the
process of (de-)offloading.

Fix that with moving the rcu_core() self-invocation to rcu_core() itself,
irrespective of the rdp offloaded state.

Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:24:44 -08:00
Frederic Weisbecker a554ba2888 rcu: Apply callbacks processing time limit only on softirq
Time limit only makes sense when callbacks are serviced in softirq mode
because:

_ In case we need to get back to the scheduler,
  cond_resched_tasks_rcu_qs() is called after each callback.

_ In case some other softirq vector needs the CPU, the call to
  local_bh_enable() before cond_resched_tasks_rcu_qs() takes care about
  them via a call to do_softirq().

Therefore, make sure the time limit only applies to softirq mode.

Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:24:44 -08:00
Frederic Weisbecker 3e61e95e2d rcu: Fix callbacks processing time limit retaining cond_resched()
The callbacks processing time limit makes sure we are not exceeding a
given amount of time executing the queue.

However its "continue" clause bypasses the cond_resched() call on
rcuc and NOCB kthreads, delaying it until we reach the limit, which can
be very long...

Make sure the scheduler has a higher priority than the time limit.

Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:24:44 -08:00
Frederic Weisbecker 78ad37a2c5 rcu/nocb: Limit number of softirq callbacks only on softirq
The current condition to limit the number of callbacks executed in a
row checks the offloaded state of the rdp. Not only is it volatile
but it is also misleading: the rcu_core() may well be executing
callbacks concurrently with NOCB kthreads, and the offloaded state
would then be verified on both cases. As a result the limit would
spuriously not apply anymore on softirq while in the middle of
(de-)offloading process.

Fix and clarify the condition with those constraints in mind:

_ If callbacks are processed either by rcuc or NOCB kthread, the call
  to cond_resched_tasks_rcu_qs() is enough to take care of the overload.

_ If instead callbacks are processed by softirqs:
  * If need_resched(), exit the callbacks processing
  * Otherwise if CPU is idle we can continue
  * Otherwise exit because a softirq shouldn't interrupt a task for too
    long nor deprive other pending softirq vectors of the CPU.

Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:24:44 -08:00
Frederic Weisbecker 7b65dfa32d rcu/nocb: Use appropriate rcu_nocb_lock_irqsave()
Instead of hardcoding IRQ save and nocb lock, use the consolidated
API (and fix a comment as per Valentin Schneider's suggestion).

Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:24:44 -08:00
Frederic Weisbecker 344e219d7d rcu/nocb: Check a stable offloaded state to manipulate qlen_last_fqs_check
It's not entirely obvious why rdp->qlen_last_fqs_check is updated before
processing the queue only on offloaded rdp. There can be different
effect to that, either in favour of triggering the force quiescent state
path or not. For example:

1) If the number of callbacks has decreased since the last
   rdp->qlen_last_fqs_check update (because we recently called
   rcu_do_batch() and we executed below qhimark callbacks) and the number
   of processed callbacks on a subsequent do_batch() arranges for
   exceeding qhimark on non-offloaded but not on offloaded setup, then we
   may spare a later run to the force quiescent state
   slow path on __call_rcu_nocb_wake(), as compared to the non-offloaded
   counterpart scenario.

   Here is such an offloaded scenario instance:

    qhimark = 1000
    rdp->last_qlen_last_fqs_check = 3000
    rcu_segcblist_n_cbs(rdp) = 2000

    rcu_do_batch() {
        if (offloaded)
            rdp->last_qlen_fqs_check = rcu_segcblist_n_cbs(rdp) // 2000
        // run 1000 callback
        rcu_segcblist_n_cbs(rdp) = 1000
        // Not updating rdp->qlen_last_fqs_check
        if (count < rdp->qlen_last_fqs_check - qhimark)
            rdp->qlen_last_fqs_check = count;
    }

    call_rcu() * 1001 {
        __call_rcu_nocb_wake() {
            // not taking the fqs slowpath:
            // rcu_segcblist_n_cbs(rdp) == 2001
            // rdp->qlen_last_fqs_check == 2000
            // qhimark == 1000
            if (len > rdp->qlen_last_fqs_check + qhimark)
                ...
    }

    In the case of a non-offloaded scenario, rdp->qlen_last_fqs_check
    would be 1000 and the fqs slowpath would have executed.

2) If the number of callbacks has increased since the last
   rdp->qlen_last_fqs_check update (because we recently queued below
   qhimark callbacks) and the number of callbacks executed in rcu_do_batch()
   doesn't exceed qhimark for either offloaded or non-offloaded setup,
   then it's possible that the offloaded scenario later run the force
   quiescent state slow path on __call_rcu_nocb_wake() while the
   non-offloaded doesn't.

    qhimark = 1000
    rdp->last_qlen_last_fqs_check = 3000
    rcu_segcblist_n_cbs(rdp) = 2000

    rcu_do_batch() {
        if (offloaded)
            rdp->last_qlen_last_fqs_check = rcu_segcblist_n_cbs(rdp) // 2000
        // run 100 callbacks
        // concurrent queued 100
        rcu_segcblist_n_cbs(rdp) = 2000
        // Not updating rdp->qlen_last_fqs_check
        if (count < rdp->qlen_last_fqs_check - qhimark)
            rdp->qlen_last_fqs_check = count;
    }

    call_rcu() * 1001 {
        __call_rcu_nocb_wake() {
            // Taking the fqs slowpath:
            // rcu_segcblist_n_cbs(rdp) == 3001
            // rdp->qlen_last_fqs_check == 2000
            // qhimark == 1000
            if (len > rdp->qlen_last_fqs_check + qhimark)
                ...
    }

    In the case of a non-offloaded scenario, rdp->qlen_last_fqs_check
    would be 3000 and the fqs slowpath would have executed.

The reason for updating rdp->qlen_last_fqs_check when invoking callbacks
for offloaded CPUs is that there is usually no point in waking up either
the rcuog or rcuoc kthreads while in this state.  After all, both threads
are prohibited from indefinite sleeps.

The exception is when some huge number of callbacks are enqueued while
rcu_do_batch() is in the midst of invoking, in which case interrupting
the rcuog kthread's timed sleep might get more callbacks set up for the
next grace period.

Reported-and-tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Original-patch-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:24:44 -08:00
Frederic Weisbecker b3bb02fe5a rcu/nocb: Make rcu_core() callbacks acceleration (de-)offloading safe
When callbacks are offloaded, the NOCB kthreads handle the callbacks
progression on behalf of rcu_core().

However during the (de-)offloading process, the kthread may not be
entirely up to the task. As a result some callbacks grace period
sequence number may remain stale for a while because rcu_core() won't
take care of them either.

Fix this with forcing callbacks acceleration from rcu_core() as long
as the offloading process isn't complete.

Reported-and-tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:24:44 -08:00
Thomas Gleixner 24ee940d89 rcu/nocb: Make rcu_core() callbacks acceleration preempt-safe
While reporting a quiescent state for a given CPU, rcu_core() takes
advantage of the freshly loaded grace period sequence number and the
locked rnp to accelerate the callbacks whose sequence number have been
assigned a stale value.

This action is only necessary when the rdp isn't offloaded, otherwise
the NOCB kthreads already take care of the callbacks progression.

However the check for the offloaded state is volatile because it is
performed outside the IRQs disabled section. It's possible for the
offloading process to preempt rcu_core() at that point on PREEMPT_RT.

This is dangerous because rcu_core() may end up accelerating callbacks
concurrently with NOCB kthreads without appropriate locking.

Fix this with moving the offloaded check inside the rnp locking section.

Reported-and-tested-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:24:44 -08:00
Frederic Weisbecker fbb94cbd70 rcu/nocb: Invoke rcu_core() at the start of deoffloading
On PREEMPT_RT, if rcu_core() is preempted by the de-offloading process,
some work, such as callbacks acceleration and invocation, may be left
unattended due to the volatile checks on the offloaded state.

In the worst case this work is postponed until the next rcu_pending()
check that can take a jiffy to reach, which can be a problem in case
of callbacks flooding.

Solve that with invoking rcu_core() early in the de-offloading process.
This way any work dismissed by an ongoing rcu_core() call fooled by
a preempting deoffloading process will be caught up by a nearby future
recall to rcu_core(), this time fully aware of the de-offloading state.

Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:24:44 -08:00
Frederic Weisbecker 213d56bf33 rcu/nocb: Prepare state machine for a new step
Currently SEGCBLIST_SOFTIRQ_ONLY is a bit of an exception among the
segcblist flags because it is an exclusive state that doesn't mix up
with the other flags. Remove it in favour of:

_ A flag specifying that rcu_core() needs to perform callbacks execution
  and acceleration

and

_ A flag specifying we want the nocb lock to be held in any needed
  circumstances

This clarifies the code and is more flexible: It allows to have a state
where rcu_core() runs with locking while offloading hasn't started yet.
This is a necessary step to prepare for triggering rcu_core() at the
very beginning of the de-offloading process so that rcu_core() won't
dismiss work while being preempted by the de-offloading process, at
least not without a pending subsequent rcu_core() that will quickly
catch up.

Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:24:44 -08:00
Frederic Weisbecker 118e0d4a1b rcu/nocb: Make local rcu_nocb_lock_irqsave() safe against concurrent deoffloading
rcu_nocb_lock_irqsave() can be preempted between the call to
rcu_segcblist_is_offloaded() and the actual locking. This matters now
that rcu_core() is preemptible on PREEMPT_RT and the (de-)offloading
process can interrupt the softirq or the rcuc kthread.

As a result we may locklessly call into code that requires nocb locking.
In practice this is a problem while we accelerate callbacks on rcu_core().

Simply disabling interrupts before (instead of after) checking the NOCB
offload state fixes the issue.

Reported-and-tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:24:44 -08:00
Paul E. McKenney 614ddad17f rcu: Tighten rcu_advance_cbs_nowake() checks
Currently, rcu_advance_cbs_nowake() checks that a grace period is in
progress, however, that grace period could end just after the check.
This commit rechecks that a grace period is still in progress while
holding the rcu_node structure's lock.  The grace period cannot end while
the current CPU's rcu_node structure's ->lock is held, thus avoiding
false positives from the WARN_ON_ONCE().

As Daniel Vacek noted, it is not necessary for the rcu_node structure
to have a CPU that has not yet passed through its quiescent state.

Tested-by: Guillaume Morin <guillaume@morinfr.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:23:03 -08:00
Frederic Weisbecker 81f6d49cce rcu/exp: Mark current CPU as exp-QS in IPI loop second pass
Expedited RCU grace periods invoke sync_rcu_exp_select_node_cpus(), which
takes two passes over the leaf rcu_node structure's CPUs.  The first
pass gathers up the current CPU and CPUs that are in dynticks idle mode.
The workqueue will report a quiescent state on their behalf later.
The second pass sends IPIs to the rest of the CPUs, but excludes the
current CPU, incorrectly assuming it has been included in the first
pass's list of CPUs.

Unfortunately the current CPU may have changed between the first and
second pass, due to the fact that the various rcu_node structures'
->lock fields have been dropped, thus momentarily enabling preemption.
This means that if the second pass's CPU was not on the first pass's
list, it will be ignored completely.  There will be no IPI sent to
it, and there will be no reporting of quiescent states on its behalf.
Unfortunately, the expedited grace period will nevertheless be waiting
for that CPU to report a quiescent state, but with that CPU having no
reason to believe that such a report is needed.

The result will be an expedited grace period stall.

Fix this by no longer excluding the current CPU from consideration during
the second pass.

Fixes: b9ad4d6ed1 ("rcu: Avoid self-IPI in sync_rcu_exp_select_node_cpus()")
Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:22:22 -08:00
Paul E. McKenney 790da24897 rcu: Make idle entry report expedited quiescent states
In non-preemptible kernels, an unfortunately timed expedited grace period
can result in the rcu_exp_handler() IPI handler setting the rcu_data
structure's cpu_no_qs.b.exp field just as the target CPU enters idle.
There are situations in which this field will not be checked until after
that CPU exits idle.  The resulting grace-period latency does not qualify
as "expedited".

This commit therefore checks this field upon non-preemptible idle entry in
the rcu_preempt_deferred_qs() function.  It also qualifies the rcu_core()
preempt_count() check with IS_ENABLED(CONFIG_PREEMPT_COUNT) to prevent
false-positive quiescent states from count-free kernels.

Reported-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:22:22 -08:00
Paul E. McKenney 147f04b14a rcu: Prevent expedited GP from enabling tick on offline CPU
If an RCU expedited grace period starts just when a CPU is in the process
of going offline, so that the outgoing CPU has completed its pass through
stop-machine but has not yet completed its final dive into the idle loop,
RCU will attempt to enable that CPU's scheduling-clock tick via a call
to tick_dep_set_cpu().  For this to happen, that CPU has to have been
online when the expedited grace period completed its CPU-selection phase.

This is pointless:  The outgoing CPU has interrupts disabled, so it cannot
take a scheduling-clock tick anyway.  In addition, the tick_dep_set_cpu()
function's eventual call to irq_work_queue_on() will splat as follows:

smpboot: CPU 1 is now offline
WARNING: CPU: 6 PID: 124 at kernel/irq_work.c:95
+irq_work_queue_on+0x57/0x60
Modules linked in:
CPU: 6 PID: 124 Comm: kworker/6:2 Not tainted 5.15.0-rc1+ #3
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
+rel-1.14.0-0-g155821a-rebuilt.opensuse.org 04/01/2014
Workqueue: rcu_gp wait_rcu_exp_gp
RIP: 0010:irq_work_queue_on+0x57/0x60
Code: 8b 05 1d c7 ea 62 a9 00 00 f0 00 75 21 4c 89 ce 44 89 c7 e8
+9b 37 fa ff ba 01 00 00 00 89 d0 c3 4c 89 cf e8 3b ff ff ff eb ee <0f> 0b eb b7
+0f 0b eb db 90 48 c7 c0 98 2a 02 00 65 48 03 05 91
 6f
RSP: 0000:ffffb12cc038fe48 EFLAGS: 00010282
RAX: 0000000000000001 RBX: 0000000000005208 RCX: 0000000000000020
RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff9ad01f45a680
RBP: 000000000004c990 R08: 0000000000000001 R09: ffff9ad01f45a680
R10: ffffb12cc0317db0 R11: 0000000000000001 R12: 00000000fffecee8
R13: 0000000000000001 R14: 0000000000026980 R15: ffffffff9e53ae00
FS:  0000000000000000(0000) GS:ffff9ad01f580000(0000)
+knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000000de0c000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tick_nohz_dep_set_cpu+0x59/0x70
 rcu_exp_wait_wake+0x54e/0x870
 ? sync_rcu_exp_select_cpus+0x1fc/0x390
 process_one_work+0x1ef/0x3c0
 ? process_one_work+0x3c0/0x3c0
 worker_thread+0x28/0x3c0
 ? process_one_work+0x3c0/0x3c0
 kthread+0x115/0x140
 ? set_kthread_struct+0x40/0x40
 ret_from_fork+0x22/0x30
---[ end trace c5bf75eb6aa80bc6 ]---

This commit therefore avoids invoking tick_dep_set_cpu() on offlined
CPUs to limit both futility and false-positive splats.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:22:22 -08:00
Paul E. McKenney 5401cc5264 rcu: Mark sync_sched_exp_online_cleanup() ->cpu_no_qs.b.exp load
The sync_sched_exp_online_cleanup() is called from rcutree_online_cpu(),
which can be invoked with interrupts enabled.  This means that
the ->cpu_no_qs.b.exp field is subject to data races from the
rcu_exp_handler() IPI handler, so this commit marks the load from
that field.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:22:21 -08:00
Frederic Weisbecker 6120b72e25 rcu: Remove rcu_data.exp_deferred_qs and convert to rcu_data.cpu no_qs.b.exp
Having two fields for the same purpose with subtle differences on
different RCU flavours is confusing, especially when both fields always
exist on both RCU flavours.

Fortunately, it is now safe for preemptible RCU to rely on the rcu_data
structure's ->cpu_no_qs.b.exp field, just like non-preemptible RCU.
This commit therefore removes the ad-hoc ->exp_deferred_qs field.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:22:21 -08:00
Frederic Weisbecker 6e16b0f7ba rcu: Move rcu_data.cpu_no_qs.b.exp reset to rcu_export_exp_rdp()
On non-preemptible RCU, move clearing of the rcu_data structure's
->cpu_no_qs.b.exp filed to the actual expedited quiescent state report
function, matching hw preemptible RCU handles the ->exp_deferred_qs field.

This prepares for removing ->exp_deferred_qs in favor of ->cpu_no_qs.b.exp
for both preemptible and non-preemptible RCU.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:22:21 -08:00
Frederic Weisbecker a438265948 rcu: Ignore rdp.cpu_no_qs.b.exp on preemptible RCU's rcu_qs()
Preemptible RCU does not use the rcu_data structure's ->cpu_no_qs.b.exp,
instead using a separate ->exp_deferred_qs field to record the need for
an expedited quiescent state.

In fact ->cpu_no_qs.b.exp should never be set in preemptible RCU because
preemptible RCU's expedited grace periods use other mechanisms to record
quiescent states.

This commit therefore removes the implicit rcu_qs() reference to
->cpu_no_qs.b.exp in favor of a direct reference to ->cpu_no_qs.b.norm.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-07 16:20:59 -08:00
Li Hua 9b58e976b3 sched/rt: Try to restart rt period timer when rt runtime exceeded
When rt_runtime is modified from -1 to a valid control value, it may
cause the task to be throttled all the time. Operations like the following
will trigger the bug. E.g:

  1. echo -1 > /proc/sys/kernel/sched_rt_runtime_us
  2. Run a FIFO task named A that executes while(1)
  3. echo 950000 > /proc/sys/kernel/sched_rt_runtime_us

When rt_runtime is -1, The rt period timer will not be activated when task
A enqueued. And then the task will be throttled after setting rt_runtime to
950,000. The task will always be throttled because the rt period timer is
not activated.

Fixes: d0b27fa778 ("sched: rt-group: synchonised bandwidth period")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Li Hua <hucool.lihua@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211203033618.11895-1-hucool.lihua@huawei.com
2021-12-07 15:14:10 +01:00
Barry Song 2917406c35 sched/fair: Document the slow path and fast path in select_task_rq_fair
All People I know including myself took a long time to figure out that
typical wakeup will always go to fast path and never go to slow path
except WF_FORK and WF_EXEC.

Vincent reminded me once in a linaro meeting and made me understand
slow path won't happen for WF_TTWU. But my other friends repeatedly
wasted a lot of time on testing this path like me before I reminded
them.

So obviously the code needs some document.

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211016111109.5559-1-21cnbao@gmail.com
2021-12-07 15:14:10 +01:00
Christoph Hellwig aea7e2a86a dma-direct: factor the swiotlb code out of __dma_direct_alloc_pages
Add a new helper to deal with the swiotlb case.  This keeps the code
nicely boundled and removes the not required call to
dma_direct_optimal_gfp_mask for the swiotlb case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2021-12-07 12:50:10 +01:00
Christoph Hellwig f5d3939a59 dma-direct: drop two CONFIG_DMA_RESTRICTED_POOL conditionals
swiotlb_alloc and swiotlb_free are properly stubbed out if
CONFIG_DMA_RESTRICTED_POOL is not set, so skip the extra checks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2021-12-07 12:50:10 +01:00