Maciej Fijalkowski says:
====================
Hi!
This small set can be considered as a followup after recent addition of
support for tailcalls in bpf subprograms and is focused on optimizing
x64 JIT prologue and epilogue sections.
Turns out the popping tail call counter is not needed anymore and %rsp
handling when stack depth is 0 can be skipped.
For longer explanations, please see commit messages.
Thank you,
Maciej
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
There is no particular reason for keeping the "sub 0, %rsp" insn within
the BPF's x64 JIT prologue.
When tail call code was skipping the whole prologue section these 7
bytes that represent the rsp subtraction could not be simply discarded
as the jump target address would be broken. An option to address that
would be to substitute it with nop7.
Right now tail call is skipping only first 11 bytes of target program's
prologue and "sub X, %rsp" is the first insn that is processed, so if
stack depth is zero then this insn could be omitted without the need for
nop7 swap.
Therefore, do not emit the "sub 0, %rsp" in prologue when program is not
making use of R10 register. Also, make the emission of "add X, %rsp"
conditional in tail call code logic and take into account the presence
of mentioned insn when calculating the jump offsets.
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200929204653.4325-3-maciej.fijalkowski@intel.com
Back when all of the callee-saved registers where always pushed to stack
in x64 JIT prologue, tail call counter was placed at the bottom of the
BPF program's stack frame that had a following layout:
+-------------+
| ret addr |
+-------------+
| rbp | <- rbp
+-------------+
| |
| free space |
| from: |
| sub $x,%rsp |
| |
+-------------+
| rbx |
+-------------+
| r13 |
+-------------+
| r14 |
+-------------+
| r15 |
+-------------+
| tail call | <- rsp
| counter |
+-------------+
In order to restore the callee saved registers, epilogue needed to
explicitly toss away the tail call counter via "pop %rbx" insn, so that
%rsp would be back at the place where %r15 was stored.
Currently, the tail call counter is placed on stack *before* the callee
saved registers (brackets on rbx through r15 mean that they are now
pushed to stack only if they are used):
+-------------+
| ret addr |
+-------------+
| rbp | <- rbp
+-------------+
| |
| free space |
| from: |
| sub $x,%rsp |
| |
+-------------+
| tail call |
| counter |
+-------------+
( rbx )
+-------------+
( r13 )
+-------------+
( r14 )
+-------------+
( r15 ) <- rsp
+-------------+
For the record, the epilogue insns consist of (assuming all of the
callee saved registers are used by program):
pop %r15
pop %r14
pop %r13
pop %rbx
pop %rcx
leaveq
retq
"pop %rbx" for getting rid of tail call counter was not an option
anymore as it would overwrite the restored value of %rbx register, so it
was changed to use the %rcx register.
Since epilogue can start popping the callee saved registers right away
without any additional work, the "pop %rcx" could be dropped altogether
as "leave" insn will simply move the %rbp to %rsp. IOW, tail call
counter does not need the explicit handling.
Having in mind the explanation above and the actual reason for that,
let's piggy back on "leave" insn for discarding the tail call counter
from stack and remove the "pop %rcx" from epilogue.
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200929204653.4325-2-maciej.fijalkowski@intel.com
This test makes a lot of narrow load checks while assuming little
endian architecture, and therefore fails on s390.
Fix by introducing LSB and LSW macros and using them to perform narrow
loads.
Fixes: 0ab5539f85 ("selftests/bpf: Tests for BPF_SK_LOOKUP attach point")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200929201814.44360-1-iii@linux.ibm.com
Replace panic() call in lib8390.c with BUILD_BUG_ON()
since checking the size of struct e8390_pkt_hdr should
happen at compile-time.
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Thomas Gleixner says:
====================
net: in_interrupt() cleanup and fixes
in the discussion about preempt count consistency accross kernel configurations:
https://lore.kernel.org/r/20200914204209.256266093@linutronix.de/
Linus clearly requested that code in drivers and libraries which changes
behaviour based on execution context should either be split up so that
e.g. task context invocations and BH invocations have different interfaces
or if that's not possible the context information has to be provided by the
caller which knows in which context it is executing.
This includes conditional locking, allocation mode (GFP_*) decisions and
avoidance of code paths which might sleep.
In the long run, usage of 'preemptible, in_*irq etc.' should be banned from
driver code completely.
This is the second version of the first batch of related changes. V1 can be
found here:
https://lore.kernel.org/r/20200927194846.045411263@linutronix.de
Changes vs. V1:
- Rebased to net-next
- Fixed the half done rename sillyness in the ENIC patch.
- Fixed the IONIC driver fallout.
- Picked up the SFC fix from Edward and adjusted the GFP_KERNEL change
accordingly.
- Addressed the review comments vs. BCRFMAC.
- Collected Reviewed/Acked-by tags as appropriate.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
rtl_lps_enter() and rtl_lps_leave() are using in_interrupt() to detect
whether it is safe to acquire a mutex or if it is required to defer to a
workqueue.
The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be seperated or the context be conveyed in an argument passed by the
caller, which usually knows the context.
in_interrupt() also is only partially correct because it fails to chose the
correct code path when just preemption or interrupts are disabled.
Add an argument 'may_block' to both functions and adjust the callers to
pass the context information.
The following call chains were analyzed to be safe to block:
rtl_watchdog_wq_callback()
rlf_lps_leave/enter()
rtl_op_suspend()
rtl_lps_leave()
rtl_op_bss_info_changed()
rtl_lps_leave()
rtl_op_sw_scan_start()
rtl_lps_leave()
The following call chains were analyzed to be unsafe to block:
_rtl_pci_interrupt()
_rtl_pci_rx_interrupt()
rtl_lps_leave()
_rtl_pci_interrupt()
_rtl_pci_rx_interrupt()
rtl_is_special_data()
rtl_lps_leave()
_rtl_pci_interrupt()
_rtl_pci_rx_interrupt()
rtl_is_special_data()
setup_special_tx()
rtl_lps_leave()
_rtl_pci_interrupt()
_rtl_pci_tx_isr
rtl_lps_leave()
halbtc_leave_lps()
rtl_lps_leave()
This leaves four callers of rtl_lps_enter/leave() where the analyzis
stopped dead in the maze of several nested pointer based callchains and
lack of rtlwifi hardware to debug this via tracing:
halbtc_leave_lps(), halbtc_enter_lps(), halbtc_normal_lps(),
halbtc_pre_normal_lps()
These four have been cautionally marked to be unable to block which is the
safe option, but the rtwifi wizards should be able to clarify that.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The usage of in_interrupt() in drivers in is phased out.
rtl_dbg() a printk based debug aid is using in_interrupt() in the
underlying C function _rtl_dbg_out() which is almost identical to
_rtl_dbg_print(). The only difference is the printout of in_interrupt().
The decoding of in_interrupt() as hexvalue is non-trivial and aside of
being phased out for driver usage the return value is just by chance the
masked preempt count value and not a boolean.
These home brewn printk debug aids are tedious to work with and provide
only minimal context. They should be replaced by trace_printk() or a debug
tracepoint which automatically records all context information.
To make progress on the in_interrupt() cleanup, make rtl_dbg() use
_rtl_dbg_print() and remove _rtl_dbg_out().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
INIT_DELAYED_WORK() takes two arguments: A pointer to the delayed work and
a function reference for the callback.
The rtl code casts all function references to (void *) because the
callbacks in use are not matching the required function signature. That's
error prone and bad pratice.
Some of the callback functions are also global, but only used in a single
file.
Clean the mess up by:
- Adding the proper arguments to the callback functions and using them in
the container_of() constructs correctly which removes the hideous
container_of_dwork_rtl() macro as well.
- Removing the type cast at the initializers
- Making the unnecessary global functions static
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The usage of in_interrupt() in non-core code is phased out. Ideally the
information of the calling context should be passed by the callers or the
functions be split as appropriate.
libertas uses in_interupt() to select the netif_rx*() variant which matches
the calling context. The attempt to consolidate the code by passing an
arguemnt or by distangling it failed due lack of knowledge about this
driver and because the call chains are hard to follow.
As a stop gap use netif_rx_any_context() which invokes the correct code
path depending on context and confines the in_interrupt() usage to core
code.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The debug macro prints (INT) when in_interrupt() returns true. The value of
this information is dubious as it does not distinguish between the various
contexts which are covered by in_interrupt().
As the usage of in_interrupt() in drivers is phased out and the same
information can be more precisely obtained with tracing, remove the
in_interrupt() conditional from this debug printk.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The usage of in_interrupt() in non-core code is phased out. Ideally the
information of the calling context should be passed by the callers or the
functions be split as appropriate.
mwifiex uses in_interupt() to select the netif_rx*() variant which matches
the calling context. The attempt to consolidate the code by passing an
arguemnt or by distangling it failed due lack of knowledge about this
driver and because the call chains are hard to follow.
As a stop gap use netif_rx_any_context() which invokes the correct code
path depending on context and confines the in_interrupt() usage to core
code.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
in_interrupt() is ill defined and does not provide what the name
suggests. The usage especially in driver code is deprecated and a tree wide
effort to clean up and consolidate the (ab)usage of in_interrupt() and
related checks is happening.
hfa384x_cmd() and prism2_hw_reset() check in_interrupt() at function entry
and if true emit a printk at debug loglevel and return. This is clearly debug
code.
Both functions invoke functions which can sleep. These functions already
have appropriate debug checks which cover all invalid contexts, while
in_interrupt() fails to detect context which just has preemption or
interrupts disabled.
Remove both checks as they are incomplete, debug only and already covered
by the subsequently invoked functions properly. If called from invalid
context the resulting back trace is definitely more helpful to analyze the
problem than a printk at debug loglevel.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The usage of in_interrupt) in driver code is phased out.
The iwlwifi_dbg tracepoint records in_interrupt() seperately, but that's
superfluous because the trace header already records all kind of state and
context information like hardirq status, softirq status, preemption count
etc.
Aside of that the recording of in_interrupt() as boolean does not allow to
distinguish between the possible contexts (hard interrupt, soft interrupt,
bottom half disabled) while the trace header gives precise information.
Remove the duplicate information from the tracepoint and fixup the caller.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Luca Coelho <luca@coelho.fi>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The usage of in_interrupt() in non-core code is phased out.
The debugging macros in these drivers use in_interrupt() to print 'I' or
'U' depending on the return value of in_interrupt(). While 'U' is confusing
at best and 'I' is not really describing the actual context (hard interupt,
soft interrupt, bottom half disabled section) these debug macros originate
from the pre ftrace kernel era and their value today is questionable. They
probably should be removed completely.
The macros weere added initially for ipw2100 and then spreaded when the
driver was forked.
Remove the in_interrupt() usage at least..
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be seperated or the context be conveyed in an argument passed by the
caller, which usually knows the context.
brcmf_fweh_process_event() uses in_interrupt() to select the allocation
mode GFP_KERNEL/GFP_ATOMIC. Aside of the above reasons this check is
incomplete as it cannot detect contexts which just have preemption or
interrupts disabled.
All callchains leading to brcmf_fweh_process_event() can clearly identify
the calling context. Convey a 'gfp' argument through the callchains and let
the callers hand in the appropriate GFP mode.
This has also the advantage that any change of execution context or
preemption/interrupt state in these callchains will be detected by the
memory allocator for all GFP_KERNEL allocations.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
bcrmgf_netif_rx() uses in_interrupt to chose between netif_rx() and
netif_rx_ni(). in_interrupt() usage in drivers is phased out.
Convey the execution mode via an 'inirq' argument through the various
callchains leading to brcmf_netif_rx():
brcmf_pcie_isr_thread() <- Task context
brcmf_proto_msgbuf_rx_trigger()
brcmf_msgbuf_process_rx()
brcmf_msgbuf_process_msgtype()
brcmf_msgbuf_process_rx_complete()
brcmf_netif_mon_rx()
brcmf_netif_rx(isirq = false)
brcmf_netif_rx(isirq = false)
brcmf_sdio_readframes() <- Task context sdio_claim_host() might sleep
brcmf_rx_frame(isirq = false)
brcmf_sdio_rxglom() <- Task context sdio_claim_host() might sleep
brcmf_rx_frame(isirq = false)
brcmf_usb_rx_complete() <- Interrupt context
brcmf_rx_frame(isirq = true)
brcmf_rx_frame()
brcmf_proto_rxreorder()
brcmf_proto_bcdc_rxreorder()
brcmf_fws_rxreorder()
brcmf_netif_rx()
brcmf_netif_rx()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arend van Spriel <arend.vanspriel@broadcom.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
brcmf_sdio_isr() is using in_interrupt() to distinguish if it is called
from a interrupt service routine or from a worker thread.
Passing such information from the calling context is preferred and
requested by Linus, so add an argument `in_isr' to brcmf_sdio_isr() and let
the callers pass the information about the calling context.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
lmc_trace() was first introduced in commit e7a392d5158af ("Import
2.3.99pre6-5") and was not touched ever since.
The reason for looking at this was to get rid of the in_interrupt() usage,
but while looking at it the following observations were made:
- At least lmc_get_stats() (->ndo_get_stats()) is invoked with disabled
preemption which is not detected by the in_interrupt() check, which
would cause schedule() to be called from invalid context.
- The code is hidden behind #ifdef LMC_TRACE which is not defined within
the kernel and wasn't at the time it was introduced.
- Three jiffies don't match 50ms. msleep() would be a better match which
would also avoid the schedule() invocation. But why have it to begin
with?
- Nobody would do something like this today. Either netdev_dbg() or
trace_printk() or a trace event would be used. If only the functions
related to this driver are interesting then ftrace can be used with
filtering.
As it is obviously broken for years, simply remove it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The comment above nc_vendor_write() suggests that the function could become
async so that is usable in `in_interrupt()' context or that it already is
safe to be called from such a context.
Eitherway: The function did not become async since v2.4.9.2 (2002) and it
must be not be called from `in_interrupt()' context because it sleeps on
mutltiple occations.
Remove the misleading comment.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
kaweth_async_set_rx_mode() invokes kaweth_contol() and has two callers:
- kaweth_open() which is invoked from preemptible context
.
- kaweth_start_xmit() which holds a spinlock and has bottom halfs disabled.
If called from kaweth_start_xmit() kaweth_async_set_rx_mode() obviously
cannot block, which means it can't call kaweth_control(). This is detected
with an in_interrupt() check.
Replace the in_interrupt() check in kaweth_async_set_rx_mode() with an
argument which is set true by the caller if the context is safe to sleep,
otherwise false.
Now kaweth_control() is only called from preemptible context which means
there is no need for GFP_ATOMIC allocations anymore. Replace it with
usb_control_msg(). Cleanup the code a bit while at it.
Finally remove kaweth_control() since the last user is gone.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
kaweth_control() is almost the same as usb_control_msg() except for the
memory allocation mode (GFP_ATOMIC vs GFP_NOIO) and the in_interrupt()
check.
All the invocations of kaweth_control() are within the probe function in
fully preemtible context so there is no reason to use atomic allocations,
GFP_NOIO which is used by usb_control_msg() is perfectly fine.
Replace kaweth_control() invocations from probe with usb_control_msg().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
in_interrupt() is ill defined and does not provide what the name
suggests. The usage especially in driver code is deprecated and
a tree wide effort to clean up and consolidate the (ab)usage of
in_interrupt() and related checks is happening.
handle_regs_int() is always invoked as part of URB callback which is either
invoked from hard or soft interrupt context.
Remove the magic assertion.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
vxge_os_dma_malloc() and vxge_os_dma_malloc_async() are both called from
callchains which use GFP_KERNEL allocations unconditionally or have other
requirements to be called from fully preemptible task context..
vxge_os_dma_malloc():
1) __vxge_hw_blockpool_create() <- GFP_KERNEL
2) __vxge_hw_mempool_grow() <- vzalloc()
__vxge_hw_blockpool_malloc()
vxge_os_dma_malloc_async():
1 __vxge_hw_mempool_grow() <- vzalloc()
__vxge_hw_blockpool_malloc()
__vxge_hw_blockpool_blocks_add()
2) vxge_hw_vpath_open() <- vzalloc()
__vxge_hw_blockpool_block_allocate()
That means neither of these functions needs a conditional allocation mode.
Remove the in_interrupt() conditional and use GFP_KERNEL.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
lance_interrupt() contains two pointless checks:
- A check whether the 'dev_id' argument is NULL. 'dev_id' is the pointer
which was handed in to request_irq() and the interrupt handler will
always be invoked with that pointer as 'dev_id' argument by the core
code.
- A check for interrupt reentrancy. The core code already guarantees
non-reentrancy of interrupt handlers.
Remove these check.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
bigmac_init_rings() has an argument signaling if it is called from the
interrupt handler. This is used to decide between GFP_KERNEL and GFP_ATOMIC
for memory allocations.
But it also checks in_interrupt() to handle invocations which come from the
timer callback bigmac_timer() via bigmac_hw_init(), which is invoked with
'in_irq = 0'. While the timer callback is clearly not in hard interrupt
context it is still not sleepable context.
Rename the argument to `non_blocking' and set it to true if invoked from
the timer callback or the interrupt handler which allows to remove the
in_interrupt() check and makes the code consistent.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
efx_ef10_try_update_nic_stats_vf() is now only invoked from thread context
and can sleep after efx::stats_lock is dropped.
Change the allocation mode from GFP_ATOMIC to GFP_KERNEL.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
efx_ef10_try_update_nic_stats_vf() used in_interrupt() to figure out
whether it is safe to sleep (for MCDI) or not.
The only caller from which it was not is efx_net_stats(), which can be
invoked under dev_base_lock from net-sysfs::netstat_show().
So add a new update_stats_atomic() method to struct efx_nic_type, and call
it from efx_net_stats(), removing the need for
efx_ef10_try_update_nic_stats_vf() to behave differently for this case
(which it wasn't doing correctly anyway).
For all nic_types other than EF10 VF, this method is NULL so the the
regular update_stats() methods are invoked , which are happy with being
called from atomic contexts.
Fixes: f00bf2305c ("sfc: don't update stats on VF when called in atomic context")
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Martin Habets <mhabets@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be seperated or the context be conveyed in an argument passed by the
caller, which usually knows the context.
sonic_quiesce() uses 'in_interrupt() || irqs_disabled()' to chose either
udelay() or usleep_range() in the wait loop.
In all callchains leading to it the context is well defined and known.
Add a 'may_sleep' argument and pass it through the various callchains
leading to this function.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
in_interrupt() is ill defined and does not provide what the name
suggests. The usage especially in driver code is deprecated and a tree wide
effort to clean up and consolidate the (ab)usage of in_interrupt() and
related checks is happening.
In this case the check covers only parts of the contexts in which these
functions cannot be called. It fails to detect preemption or interrupt
disabled invocations.
As the functions which contain these warnings invoke mutex_lock() which
contains a broad variety of checks (always enabled or debug option
dependent) and therefore covers all invalid conditions already, there is no
point in having inconsistent warnings in those drivers. The conditional
return is not really valuable in practice either.
Just remove them.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
in_interrupt() is ill defined and does not provide what the name
suggests. The usage especially in driver code is deprecated and a tree wide
effort to clean up and consolidate the (ab)usage of in_interrupt() and
related checks is happening.
In this case the check covers only parts of the contexts in which these
functions cannot be called. It fails to detect preemption or interrupt
disabled invocations.
As the functions which are invoked from ionic_adminq_post() and
ionic_dev_cmd_wait() contain a broad variety of checks (always enabled or
debug option dependent) which cover all invalid conditions already, there
is no point in having inconsistent warnings in those drivers.
Just remove them.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>
The in_interrupt() usage in this driver tries to figure out which context
may sleep and which context may not sleep. in_interrupt() is not really
suitable as it misses both preemption disabled and interrupt disabled
invocations from task context.
Conditionals like that in driver code are frowned upon in general because
invocations of functions from invalid contexts might not be detected
as the conditional papers over it.
ionic_lif_addr() and _ionoc_lif_rx_mode() can be called from:
1) ->ndo_set_rx_mode() which is under netif_addr_lock_bh()) so it must not
sleep.
2) Init and setup functions which are in fully preemptible task context.
ionic_link_status_check_request() has two call paths:
1) NAPI which obviously cannot sleep
2) Setup which is again fully preemptible task context
Add arguments which convey the execution context to the affected functions
and let the callers provide the context instead of letting the functions
deduce it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
in_interrupt() is ill defined and does not provide what the name
suggests. The usage especially in driver code is deprecated and a tree wide
effort to clean up and consolidate the (ab)usage of in_interrupt() and
related checks is happening.
In this case the checks cover only parts of the contexts in which these
functions cannot be called. They fail to detect preemption or interrupt
disabled invocations.
As the functions which are invoked from the various places contain already
a broad variety of checks (always enabled or debug option dependent) cover
all invalid conditions already, there is no point in having inconsistent
warnings in those drivers.
Just remove them.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be seperated or the context be conveyed in an argument passed by the
caller, which usually knows the context.
mpc52xx_fec_stop() uses in_interrupt() to check if it is safe to sleep. All
callers run in well defined contexts.
Pass an argument from the callers indicating whether it is safe to sleep.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
e100_hw_init() invokes e100_self_test() only if in_interrupt() returns
false as e100_self_test() uses msleep() which requires sleepable task
context. The in_interrupt() check is incomplete because in_interrupt()
cannot catch callers from contexts which have just preemption or interrupts
disabled.
e100_hw_init() is invoked from:
- e100_loopback_test() which clearly is sleepable task context as the
function uses msleep() itself.
- e100_up() which clearly is sleepable task context as well because it
invokes e100_alloc_cbs() abd request_irq() which both require sleepable
task context due to GFP_KERNEL allocations and mutex_lock() operations.
Remove the pointless in_interrupt() check.
As a side effect of this analysis it turned out that e100_rx_alloc_list()
which is only invoked from e100_loopback_test() and e100_up() pointlessly
uses a GFP_ATOMIC allocation. The next invoked function e100_alloc_cbs() is
using GFP_KERNEL already.
Change the allocation mode in e100_rx_alloc_list() to GFP_KERNEL as well.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
t4_sge_stop() is only ever called from task context and the in_interrupt()
check is presumably a leftover from copying t3_sge_stop().
Aside of in_interrupt() being deprecated because it's not providing what it
claims to provide, this check would paper over illegitimate callers.
The functions invoked from t4_sge_stop() contain already warnings to catch
invocations from invalid contexts.
Remove it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
t3_sge_stop() is called from task context and from error handlers in
interrupt context. It relies on in_interrupt() to differentiate the
contexts.
in_interrupt() is deprecated as it is ill defined and does not provide what
it suggests.
Instead of replacing it with some other construct, simply split the
function into t3_sge_stop_dma(), which can be called from any context, and
t3_sge_stop() which can be only called from task context.
This has the advantage that any bogus invocation of t3_sge_stop() from
wrong contexts can be caught by debug kernels instead of being papered over
by the conditional.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
in_interrupt() is ill defined and does not provide what the name
suggests. The usage especially in driver code is deprecated and a tree wide
effort to clean up and consolidate the (ab)usage of in_interrupt() and
related checks is happening.
In this case the check covers only parts of the contexts in which these
functions cannot be called. It fails to detect preemption or interrupt
disabled invocations.
As the functions which are invoked from at*_reinit_locked() contain a broad
variety of checks (always enabled or debug option dependent) which cover
all invalid conditions already, there is no point in having inconsistent
warnings in those drivers.
Just remove them.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The usage of in_interrupt() in non-core code is phased out. Ideally the
information of the calling context should be passed by the callers or the
functions be split as appropriate.
cfhsi_rx_desc() and cfhsi_rx_pld() use in_interrupt() to distinguish if
they should use netif_rx() or netif_rx_ni() for receiving packets.
The attempt to consolidate the code by passing an arguemnt or by
distangling it failed due lack of knowledge about this driver and because
the call chains are hard to follow.
As a stop gap use netif_rx_any_context() which invokes the correct code path
depending on context and confines the in_interrupt() usage to core code.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Quite some drivers make conditional decisions based on in_interrupt() to
invoke either netif_rx() or netif_rx_ni().
Conditionals based on in_interrupt() or other variants of preempt count
checks in drivers should not exist for various reasons and Linus clearly
requested to either split the code pathes or pass an argument to the
common functions which provides the context.
This is obviously the correct solution, but for some of the affected
drivers this needs a major rewrite due to their convoluted structure.
As in_interrupt() usage in drivers needs to be phased out, provide
netif_rx_any_context() as a stop gap for these drivers.
This confines the in_interrupt() conditional to core code which in turn
allows to remove the access to this check for driver code and provides one
central place to do further modifications once the driver maze is cleaned
up.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
While chasing in_interrupt() (ab)use in drivers it turned out that the
caif_spi driver has never been in use since the driver was merged 10 years
ago. There never was any matching code which provides a platform device.
The driver has not seen any update (asided of treewide changes and
cleanups) since 8 years and the maintainers vanished from the planet.
So analysing the potential contexts and the (in)correctness of
in_interrupt() usage is just a pointless exercise.
Remove the cruft.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
enic_dev_wait() has a BUG_ON(in_interrupt()).
Chasing the callers of enic_dev_wait() revealed the gems of enic_reset()
and enic_tx_hang_reset() which are both invoked through work queues in
order to be able to call rtnl_lock(). So far so good.
After locking rtnl both functions acquire enic::enic_api_lock which
serializes against the (ab)use from infiniband. This is where the
trainwreck starts.
enic::enic_api_lock is a spin_lock() which implicitly disables preemption,
but both functions invoke a ton of functions under that lock which can
sleep. The BUG_ON(in_interrupt()) does not trigger in that case because it
can't detect the preempt disabled condition.
This clearly has never been tested with any of the mandatory debug options
for 7+ years, which would have caught that for sure.
Cure it by adding a enic_api_busy member to struct enic, which is modified
and evaluated with enic::enic_api_lock held.
If enic_api_devcmd_proxy_by_index() observes enic::enic_api_busy as true,
it drops enic::enic_api_lock and busy waits for enic::enic_api_busy to
become false.
It would be smarter to wait for a completion of that busy period, but
enic_api_devcmd_proxy_by_index() is called with other spin locks held which
obviously can't sleep.
Remove the BUG_ON(in_interrupt()) check as well because it's incomplete and
with proper debugging enabled the problem would have been caught from the
debug checks in schedule_timeout().
Fixes: 0b038566c0 ("drivers/net: enic: Add an interface for USNIC to interact with firmware")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 5d5b4128c4 ("devlink: introduce flash update overwrite mask")
added a usage of _BITUL to the UAPI <linux/devlink.h> header, but failed
to include the header file where it was defined. It happens that this
does not break any existing kernel include chains because it gets
included through other sources. However, when including the UAPI headers
in a userspace application (such as devlink in iproute2), _BITUL is not
defined.
Fixes: 5d5b4128c4 ("devlink: introduce flash update overwrite mask")
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rohit Maheshwari says:
====================
cxgb4/ch_ktls: updates in net-next
This series of patches improves connections setup and statistics.
This series is broken down as follows:
Patch 1 fixes the handling of connection setup failure in HW. Driver
shouldn't return success to tls_dev_add, until HW returns success.
Patch 2 avoids the log flood.
Patch 3 adds ktls statistics at port level.
v1->v2:
- removed conn_up from all places.
v2->v3:
- Corrected timeout handling.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
All the ktls stats were at adapter level, but now changing it
to port level.
Fixes: 62370a4f34 ("cxgb4/chcr: Add ipv6 support and statistics")
Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Changing these logs to dynamic debugs. If issue is seen, these
logs can be enabled at run time.
Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since driver first return success to tls_dev_add, if req to HW is
successful, but later if HW returns failure, that connection traffic
fails permanently and connection status remains unknown to stack.
v1->v2:
- removed conn_up from all places.
v2->v3:
- Corrected timeout handling.
Fixes: 34aba2c450 ("cxgb4/chcr : Register to tls add and del callback")
Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When an L2TPv3 session receives a data frame with an incorrect cookie
l2tp_core logs a warning message and bumps a stats counter to reflect
the fact that the packet has been dropped.
However, the stats counter in question is missing from the l2tp_netlink
get message for tunnel and session instances.
Include the statistic in the netlink get response.
Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Johan Hedberg says:
====================
pull request: bluetooth-next 2020-09-29
Here's the main bluetooth-next pull request for 5.10:
- Multiple fixes to suspend/resume handling
- Added mgmt events for controller suspend/resume state
- Improved extended advertising support
- btintel: Enhanced support for next generation controllers
- Added Qualcomm Bluetooth SoC WCN6855 support
- Several other smaller fixes & improvements
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Alexei Starovoitov
Maciej Fijalkowski
Ilya Leoshkevich
Armin Wolf
David S. Miller
Sebastian Andrzej Siewior
Thomas Gleixner
Edward Cree
Jacob Keller
Rohit Maheshwari
Gustavo A. R. Silva
Tom Parkin