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Автор SHA1 Сообщение Дата
Yicong Yang 68a04c30cb dma-mapping: benchmark: Don't starve others when doing the test
[ Upstream commit 54624acf8843375a6de3717ac18df3b5104c39c5 ]

The test thread will start N benchmark kthreads and then schedule out
until the test time finished and notify the benchmark kthreads to stop.
The benchmark kthreads will keep running until notified to stop.
There's a problem with current implementation when the benchmark
kthreads number is equal to the CPUs on a non-preemptible kernel:
since the scheduler will balance the kthreads across the CPUs and
when the test time's out the test thread won't get a chance to be
scheduled on any CPU then cannot notify the benchmark kthreads to stop.

This can be easily reproduced on a VM (simulated with 16 CPUs) with
PREEMPT_VOLUNTARY:
estuary:/mnt$ ./dma_map_benchmark -t 16 -s 1
 rcu: INFO: rcu_sched self-detected stall on CPU
 rcu:     10-...!: (5221 ticks this GP) idle=ed24/1/0x4000000000000000 softirq=142/142 fqs=0
 rcu:     (t=5254 jiffies g=-559 q=45 ncpus=16)
 rcu: rcu_sched kthread starved for 5255 jiffies! g-559 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=12
 rcu:     Unless rcu_sched kthread gets sufficient CPU time, OOM is now expected behavior.
 rcu: RCU grace-period kthread stack dump:
 task:rcu_sched       state:R  running task     stack:0     pid:16    tgid:16    ppid:2      flags:0x00000008
 Call trace
  __switch_to+0xec/0x138
  __schedule+0x2f8/0x1080
  schedule+0x30/0x130
  schedule_timeout+0xa0/0x188
  rcu_gp_fqs_loop+0x128/0x528
  rcu_gp_kthread+0x1c8/0x208
  kthread+0xec/0xf8
  ret_from_fork+0x10/0x20
 Sending NMI from CPU 10 to CPUs 0:
 NMI backtrace for cpu 0
 CPU: 0 PID: 332 Comm: dma-map-benchma Not tainted 6.10.0-rc1-vanilla-LSE #8
 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
 pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : arm_smmu_cmdq_issue_cmdlist+0x218/0x730
 lr : arm_smmu_cmdq_issue_cmdlist+0x488/0x730
 sp : ffff80008748b630
 x29: ffff80008748b630 x28: 0000000000000000 x27: ffff80008748b780
 x26: 0000000000000000 x25: 000000000000bc70 x24: 000000000001bc70
 x23: ffff0000c12af080 x22: 0000000000010000 x21: 000000000000ffff
 x20: ffff80008748b700 x19: ffff0000c12af0c0 x18: 0000000000010000
 x17: 0000000000000001 x16: 0000000000000040 x15: ffffffffffffffff
 x14: 0001ffffffffffff x13: 000000000000ffff x12: 00000000000002f1
 x11: 000000000001ffff x10: 0000000000000031 x9 : ffff800080b6b0b8
 x8 : ffff0000c2a48000 x7 : 000000000001bc71 x6 : 0001800000000000
 x5 : 00000000000002f1 x4 : 01ffffffffffffff x3 : 000000000009aaf1
 x2 : 0000000000000018 x1 : 000000000000000f x0 : ffff0000c12af18c
 Call trace:
  arm_smmu_cmdq_issue_cmdlist+0x218/0x730
  __arm_smmu_tlb_inv_range+0xe0/0x1a8
  arm_smmu_iotlb_sync+0xc0/0x128
  __iommu_dma_unmap+0x248/0x320
  iommu_dma_unmap_page+0x5c/0xe8
  dma_unmap_page_attrs+0x38/0x1d0
  map_benchmark_thread+0x118/0x2c0
  kthread+0xec/0xf8
  ret_from_fork+0x10/0x20

Solve this by adding scheduling point in the kthread loop,
so if there're other threads in the system they may have
a chance to run, especially the thread to notify the test
end. However this may degrade the test concurrency so it's
recommended to run this on an idle system.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Acked-by: Barry Song <baohua@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-09-12 11:07:48 +02:00
Rik van Riel 488702d1be dma-debug: avoid deadlock between dma debug vs printk and netconsole
[ Upstream commit bd44ca3de49cc1badcff7a96010fa2c64f04868c ]

Currently the dma debugging code can end up indirectly calling printk
under the radix_lock. This happens when a radix tree node allocation
fails.

This is a problem because the printk code, when used together with
netconsole, can end up inside the dma debugging code while trying to
transmit a message over netcons.

This creates the possibility of either a circular deadlock on the same
CPU, with that CPU trying to grab the radix_lock twice, or an ABBA
deadlock between different CPUs, where one CPU grabs the console lock
first and then waits for the radix_lock, while the other CPU is holding
the radix_lock and is waiting for the console lock.

The trace captured by lockdep is of the ABBA variant.

-> #2 (&dma_entry_hash[i].lock){-.-.}-{2:2}:
                  _raw_spin_lock_irqsave+0x5a/0x90
                  debug_dma_map_page+0x79/0x180
                  dma_map_page_attrs+0x1d2/0x2f0
                  bnxt_start_xmit+0x8c6/0x1540
                  netpoll_start_xmit+0x13f/0x180
                  netpoll_send_skb+0x20d/0x320
                  netpoll_send_udp+0x453/0x4a0
                  write_ext_msg+0x1b9/0x460
                  console_flush_all+0x2ff/0x5a0
                  console_unlock+0x55/0x180
                  vprintk_emit+0x2e3/0x3c0
                  devkmsg_emit+0x5a/0x80
                  devkmsg_write+0xfd/0x180
                  do_iter_readv_writev+0x164/0x1b0
                  vfs_writev+0xf9/0x2b0
                  do_writev+0x6d/0x110
                  do_syscall_64+0x80/0x150
                  entry_SYSCALL_64_after_hwframe+0x4b/0x53

-> #0 (console_owner){-.-.}-{0:0}:
                  __lock_acquire+0x15d1/0x31a0
                  lock_acquire+0xe8/0x290
                  console_flush_all+0x2ea/0x5a0
                  console_unlock+0x55/0x180
                  vprintk_emit+0x2e3/0x3c0
                  _printk+0x59/0x80
                  warn_alloc+0x122/0x1b0
                  __alloc_pages_slowpath+0x1101/0x1120
                  __alloc_pages+0x1eb/0x2c0
                  alloc_slab_page+0x5f/0x150
                  new_slab+0x2dc/0x4e0
                  ___slab_alloc+0xdcb/0x1390
                  kmem_cache_alloc+0x23d/0x360
                  radix_tree_node_alloc+0x3c/0xf0
                  radix_tree_insert+0xf5/0x230
                  add_dma_entry+0xe9/0x360
                  dma_map_page_attrs+0x1d2/0x2f0
                  __bnxt_alloc_rx_frag+0x147/0x180
                  bnxt_alloc_rx_data+0x79/0x160
                  bnxt_rx_skb+0x29/0xc0
                  bnxt_rx_pkt+0xe22/0x1570
                  __bnxt_poll_work+0x101/0x390
                  bnxt_poll+0x7e/0x320
                  __napi_poll+0x29/0x160
                  net_rx_action+0x1e0/0x3e0
                  handle_softirqs+0x190/0x510
                  run_ksoftirqd+0x4e/0x90
                  smpboot_thread_fn+0x1a8/0x270
                  kthread+0x102/0x120
                  ret_from_fork+0x2f/0x40
                  ret_from_fork_asm+0x11/0x20

This bug is more likely than it seems, because when one CPU has run out
of memory, chances are the other has too.

The good news is, this bug is hidden behind the CONFIG_DMA_API_DEBUG, so
not many users are likely to trigger it.

Signed-off-by: Rik van Riel <riel@surriel.com>
Reported-by: Konstantin Ovsepian <ovs@meta.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-09-12 11:07:38 +02:00
Lance Richardson 87b34c8c94 dma: fix call order in dmam_free_coherent
[ Upstream commit 28e8b7406d3a1f5329a03aa25a43aa28e087cb20 ]

dmam_free_coherent() frees a DMA allocation, which makes the
freed vaddr available for reuse, then calls devres_destroy()
to remove and free the data structure used to track the DMA
allocation. Between the two calls, it is possible for a
concurrent task to make an allocation with the same vaddr
and add it to the devres list.

If this happens, there will be two entries in the devres list
with the same vaddr and devres_destroy() can free the wrong
entry, triggering the WARN_ON() in dmam_match.

Fix by destroying the devres entry before freeing the DMA
allocation.

Tested:
  kokonut //net/encryption
    http://sponge2/b9145fe6-0f72-4325-ac2f-a84d81075b03

Fixes: 9ac7849e35 ("devres: device resource management")
Signed-off-by: Lance Richardson <rlance@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-19 05:45:23 +02:00
Fedor Pchelkin 0d30f73012 dma-mapping: benchmark: avoid needless copy_to_user if benchmark fails
[ Upstream commit f7c9ccaadffd13066353332c13d7e9bf73b8f92d ]

If do_map_benchmark() has failed, there is nothing useful to copy back
to userspace.

Suggested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18 13:07:35 +02:00
David Hildenbrand 51163bfef6 cma: factor out minimum alignment requirement
[ Upstream commit e16faf2678 ]

Patch series "mm: enforce pageblock_order < MAX_ORDER".

Having pageblock_order >= MAX_ORDER seems to be able to happen in corner
cases and some parts of the kernel are not prepared for it.

For example, Aneesh has shown [1] that such kernels can be compiled on
ppc64 with 64k base pages by setting FORCE_MAX_ZONEORDER=8, which will
run into a WARN_ON_ONCE(order >= MAX_ORDER) in comapction code right
during boot.

We can get pageblock_order >= MAX_ORDER when the default hugetlb size is
bigger than the maximum allocation granularity of the buddy, in which
case we are no longer talking about huge pages but instead gigantic
pages.

Having pageblock_order >= MAX_ORDER can only make alloc_contig_range()
of such gigantic pages more likely to succeed.

Reliable use of gigantic pages either requires boot time allcoation or
CMA, no need to overcomplicate some places in the kernel to optimize for
corner cases that are broken in other areas of the kernel.

This patch (of 2):

Let's enforce pageblock_order < MAX_ORDER and simplify.

Especially patch #1 can be regarded a cleanup before:
	[PATCH v5 0/6] Use pageblock_order for cma and alloc_contig_range
	alignment. [2]

[1] https://lkml.kernel.org/r/87r189a2ks.fsf@linux.ibm.com
[2] https://lkml.kernel.org/r/20220211164135.1803616-1-zi.yan@sent.com

Link: https://lkml.kernel.org/r/20220214174132.219303-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: Rob Herring <robh@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: John Garry via iommu <iommu@lists.linux-foundation.org>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stable-dep-of: b174f139bdc8 ("mm/cma: drop incorrect alignment check in cma_init_reserved_mem")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05 09:14:13 +02:00
Fedor Pchelkin b41b0018e8 dma-mapping: benchmark: handle NUMA_NO_NODE correctly
[ Upstream commit e64746e74f717961250a155e14c156616fcd981f ]

cpumask_of_node() can be called for NUMA_NO_NODE inside do_map_benchmark()
resulting in the following sanitizer report:

UBSAN: array-index-out-of-bounds in ./arch/x86/include/asm/topology.h:72:28
index -1 is out of range for type 'cpumask [64][1]'
CPU: 1 PID: 990 Comm: dma_map_benchma Not tainted 6.9.0-rc6 #29
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
 <TASK>
dump_stack_lvl (lib/dump_stack.c:117)
ubsan_epilogue (lib/ubsan.c:232)
__ubsan_handle_out_of_bounds (lib/ubsan.c:429)
cpumask_of_node (arch/x86/include/asm/topology.h:72) [inline]
do_map_benchmark (kernel/dma/map_benchmark.c:104)
map_benchmark_ioctl (kernel/dma/map_benchmark.c:246)
full_proxy_unlocked_ioctl (fs/debugfs/file.c:333)
__x64_sys_ioctl (fs/ioctl.c:890)
do_syscall_64 (arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

Use cpumask_of_node() in place when binding a kernel thread to a cpuset
of a particular node.

Note that the provided node id is checked inside map_benchmark_ioctl().
It's just a NUMA_NO_NODE case which is not handled properly later.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 65789daa80 ("dma-mapping: add benchmark support for streaming DMA APIs")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Barry Song <baohua@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-16 13:39:49 +02:00
Fedor Pchelkin 35d31c8bd4 dma-mapping: benchmark: fix node id validation
[ Upstream commit 1ff05e723f7ca30644b8ec3fb093f16312e408ad ]

While validating node ids in map_benchmark_ioctl(), node_possible() may
be provided with invalid argument outside of [0,MAX_NUMNODES-1] range
leading to:

BUG: KASAN: wild-memory-access in map_benchmark_ioctl (kernel/dma/map_benchmark.c:214)
Read of size 8 at addr 1fffffff8ccb6398 by task dma_map_benchma/971
CPU: 7 PID: 971 Comm: dma_map_benchma Not tainted 6.9.0-rc6 #37
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
 <TASK>
dump_stack_lvl (lib/dump_stack.c:117)
kasan_report (mm/kasan/report.c:603)
kasan_check_range (mm/kasan/generic.c:189)
variable_test_bit (arch/x86/include/asm/bitops.h:227) [inline]
arch_test_bit (arch/x86/include/asm/bitops.h:239) [inline]
_test_bit at (include/asm-generic/bitops/instrumented-non-atomic.h:142) [inline]
node_state (include/linux/nodemask.h:423) [inline]
map_benchmark_ioctl (kernel/dma/map_benchmark.c:214)
full_proxy_unlocked_ioctl (fs/debugfs/file.c:333)
__x64_sys_ioctl (fs/ioctl.c:890)
do_syscall_64 (arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

Compare node ids with sane bounds first. NUMA_NO_NODE is considered a
special valid case meaning that benchmarking kthreads won't be bound to a
cpuset of a given node.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 65789daa80 ("dma-mapping: add benchmark support for streaming DMA APIs")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-16 13:39:49 +02:00
John Garry f3e7d9471c dma-mapping: add dma_opt_mapping_size()
[ Upstream commit a229cc14f3 ]

Streaming DMA mapping involving an IOMMU may be much slower for larger
total mapping size. This is because every IOMMU DMA mapping requires an
IOVA to be allocated and freed. IOVA sizes above a certain limit are not
cached, which can have a big impact on DMA mapping performance.

Provide an API for device drivers to know this "optimal" limit, such that
they may try to produce mapping which don't exceed it.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Stable-dep-of: afc5aa46ed56 ("iommu/dma: Force swiotlb_max_mapping_size on an untrusted device")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10 16:18:47 +02:00
Will Deacon 685e8332de swiotlb: Fix alignment checks when both allocation and DMA masks are present
[ Upstream commit 51b30ecb73b481d5fac6ccf2ecb4a309c9ee3310 ]

Nicolin reports that swiotlb buffer allocations fail for an NVME device
behind an IOMMU using 64KiB pages. This is because we end up with a
minimum allocation alignment of 64KiB (for the IOMMU to map the buffer
safely) but a minimum DMA alignment mask corresponding to a 4KiB NVME
page (i.e. preserving the 4KiB page offset from the original allocation).
If the original address is not 4KiB-aligned, the allocation will fail
because swiotlb_search_pool_area() erroneously compares these unmasked
bits with the 64KiB-aligned candidate allocation.

Tweak swiotlb_search_pool_area() so that the DMA alignment mask is
reduced based on the required alignment of the allocation.

Fixes: 82612d66d5 ("iommu: Allow the dma-iommu api to use bounce buffers")
Link: https://lore.kernel.org/r/cover.1707851466.git.nicolinc@nvidia.com
Reported-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10 16:18:47 +02:00
Joakim Zhang ccc94806d0 dma-mapping: clear dev->dma_mem to NULL after freeing it
[ Upstream commit b07bc2347672cc8c7293c64499f1488278c5ca3d ]

Reproduced with below sequence:
dma_declare_coherent_memory()->dma_release_coherent_memory()
->dma_declare_coherent_memory()->"return -EBUSY" error

It will return -EBUSY from the dma_assign_coherent_memory()
in dma_declare_coherent_memory(), the reason is that dev->dma_mem
pointer has not been set to NULL after it's freed.

Fixes: cf65a0f6f6 ("dma-mapping: move all DMA mapping code to kernel/dma")
Signed-off-by: Joakim Zhang <joakim.zhang@cixtech.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 14:52:38 -08:00
Mark-PK Tsai 99326214f9 dma-mapping: Add dma_release_coherent_memory to DMA API
[ Upstream commit e61c451476 ]

Add dma_release_coherent_memory to DMA API to allow dma
user call it to release dev->dma_mem when the device is
removed.

Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220422062436.14384-2-mark-pk.tsai@mediatek.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Stable-dep-of: b07bc2347672 ("dma-mapping: clear dev->dma_mem to NULL after freeing it")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 14:52:38 -08:00
Sergey Senozhatsky ac0d068099 dma-debug: don't call __dma_entry_alloc_check_leak() under free_entries_lock
[ Upstream commit fb5a431559 ]

__dma_entry_alloc_check_leak() calls into printk -> serial console
output (qcom geni) and grabs port->lock under free_entries_lock
spin lock, which is a reverse locking dependency chain as qcom_geni
IRQ handler can call into dma-debug code and grab free_entries_lock
under port->lock.

Move __dma_entry_alloc_check_leak() call out of free_entries_lock
scope so that we don't acquire serial console's port->lock under it.

Trimmed-down lockdep splat:

 The existing dependency chain (in reverse order) is:

               -> #2 (free_entries_lock){-.-.}-{2:2}:
        _raw_spin_lock_irqsave+0x60/0x80
        dma_entry_alloc+0x38/0x110
        debug_dma_map_page+0x60/0xf8
        dma_map_page_attrs+0x1e0/0x230
        dma_map_single_attrs.constprop.0+0x6c/0xc8
        geni_se_rx_dma_prep+0x40/0xcc
        qcom_geni_serial_isr+0x310/0x510
        __handle_irq_event_percpu+0x110/0x244
        handle_irq_event_percpu+0x20/0x54
        handle_irq_event+0x50/0x88
        handle_fasteoi_irq+0xa4/0xcc
        handle_irq_desc+0x28/0x40
        generic_handle_domain_irq+0x24/0x30
        gic_handle_irq+0xc4/0x148
        do_interrupt_handler+0xa4/0xb0
        el1_interrupt+0x34/0x64
        el1h_64_irq_handler+0x18/0x24
        el1h_64_irq+0x64/0x68
        arch_local_irq_enable+0x4/0x8
        ____do_softirq+0x18/0x24
        ...

               -> #1 (&port_lock_key){-.-.}-{2:2}:
        _raw_spin_lock_irqsave+0x60/0x80
        qcom_geni_serial_console_write+0x184/0x1dc
        console_flush_all+0x344/0x454
        console_unlock+0x94/0xf0
        vprintk_emit+0x238/0x24c
        vprintk_default+0x3c/0x48
        vprintk+0xb4/0xbc
        _printk+0x68/0x90
        register_console+0x230/0x38c
        uart_add_one_port+0x338/0x494
        qcom_geni_serial_probe+0x390/0x424
        platform_probe+0x70/0xc0
        really_probe+0x148/0x280
        __driver_probe_device+0xfc/0x114
        driver_probe_device+0x44/0x100
        __device_attach_driver+0x64/0xdc
        bus_for_each_drv+0xb0/0xd8
        __device_attach+0xe4/0x140
        device_initial_probe+0x1c/0x28
        bus_probe_device+0x44/0xb0
        device_add+0x538/0x668
        of_device_add+0x44/0x50
        of_platform_device_create_pdata+0x94/0xc8
        of_platform_bus_create+0x270/0x304
        of_platform_populate+0xac/0xc4
        devm_of_platform_populate+0x60/0xac
        geni_se_probe+0x154/0x160
        platform_probe+0x70/0xc0
        ...

               -> #0 (console_owner){-...}-{0:0}:
        __lock_acquire+0xdf8/0x109c
        lock_acquire+0x234/0x284
        console_flush_all+0x330/0x454
        console_unlock+0x94/0xf0
        vprintk_emit+0x238/0x24c
        vprintk_default+0x3c/0x48
        vprintk+0xb4/0xbc
        _printk+0x68/0x90
        dma_entry_alloc+0xb4/0x110
        debug_dma_map_sg+0xdc/0x2f8
        __dma_map_sg_attrs+0xac/0xe4
        dma_map_sgtable+0x30/0x4c
        get_pages+0x1d4/0x1e4 [msm]
        msm_gem_pin_pages_locked+0x38/0xac [msm]
        msm_gem_pin_vma_locked+0x58/0x88 [msm]
        msm_ioctl_gem_submit+0xde4/0x13ac [msm]
        drm_ioctl_kernel+0xe0/0x15c
        drm_ioctl+0x2e8/0x3f4
        vfs_ioctl+0x30/0x50
        ...

 Chain exists of:
   console_owner --> &port_lock_key --> free_entries_lock

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(free_entries_lock);
                                lock(&port_lock_key);
                                lock(free_entries_lock);
   lock(console_owner);

                *** DEADLOCK ***

 Call trace:
  dump_backtrace+0xb4/0xf0
  show_stack+0x20/0x30
  dump_stack_lvl+0x60/0x84
  dump_stack+0x18/0x24
  print_circular_bug+0x1cc/0x234
  check_noncircular+0x78/0xac
  __lock_acquire+0xdf8/0x109c
  lock_acquire+0x234/0x284
  console_flush_all+0x330/0x454
  console_unlock+0x94/0xf0
  vprintk_emit+0x238/0x24c
  vprintk_default+0x3c/0x48
  vprintk+0xb4/0xbc
  _printk+0x68/0x90
  dma_entry_alloc+0xb4/0x110
  debug_dma_map_sg+0xdc/0x2f8
  __dma_map_sg_attrs+0xac/0xe4
  dma_map_sgtable+0x30/0x4c
  get_pages+0x1d4/0x1e4 [msm]
  msm_gem_pin_pages_locked+0x38/0xac [msm]
  msm_gem_pin_vma_locked+0x58/0x88 [msm]
  msm_ioctl_gem_submit+0xde4/0x13ac [msm]
  drm_ioctl_kernel+0xe0/0x15c
  drm_ioctl+0x2e8/0x3f4
  vfs_ioctl+0x30/0x50
  ...

Reported-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-06 13:18:14 +02:00
gaoxu ff10cd3e9b dma-remap: use kvmalloc_array/kvfree for larger dma memory remap
[ Upstream commit 51ff97d54f ]

If dma_direct_alloc() alloc memory in size of 64MB, the inner function
dma_common_contiguous_remap() will allocate 128KB memory by invoking
the function kmalloc_array(). and the kmalloc_array seems to fail to try to
allocate 128KB mem.

Call trace:
[14977.928623] qcrosvm: page allocation failure: order:5, mode:0x40cc0
[14977.928638] dump_backtrace.cfi_jt+0x0/0x8
[14977.928647] dump_stack_lvl+0x80/0xb8
[14977.928652] warn_alloc+0x164/0x200
[14977.928657] __alloc_pages_slowpath+0x9f0/0xb4c
[14977.928660] __alloc_pages+0x21c/0x39c
[14977.928662] kmalloc_order+0x48/0x108
[14977.928666] kmalloc_order_trace+0x34/0x154
[14977.928668] __kmalloc+0x548/0x7e4
[14977.928673] dma_direct_alloc+0x11c/0x4f8
[14977.928678] dma_alloc_attrs+0xf4/0x138
[14977.928680] gh_vm_ioctl_set_fw_name+0x3c4/0x610 [gunyah]
[14977.928698] gh_vm_ioctl+0x90/0x14c [gunyah]
[14977.928705] __arm64_sys_ioctl+0x184/0x210

work around by doing kvmalloc_array instead.

Signed-off-by: Gao Xu <gaoxu2@hihonor.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-26 14:23:22 +02:00
Tianyu Lan bfe5dc2101 swiotlb: max mapping size takes min align mask into account
commit 82806744fd upstream.

swiotlb_find_slots() skips slots according to io tlb aligned mask
calculated from min aligned mask and original physical address
offset. This affects max mapping size. The mapping size can't
achieve the IO_TLB_SEGSIZE * IO_TLB_SIZE when original offset is
non-zero. This will cause system boot up failure in Hyper-V
Isolation VM where swiotlb force is enabled. Scsi layer use return
value of dma_max_mapping_size() to set max segment size and it
finally calls swiotlb_max_mapping_size(). Hyper-V storage driver
sets min align mask to 4k - 1. Scsi layer may pass 256k length of
request buffer with 0~4k offset and Hyper-V storage driver can't
get swiotlb bounce buffer via DMA API. Swiotlb_find_slots() can't
find 256k length bounce buffer with offset. Make swiotlb_max_mapping
_size() take min align mask into account.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-05 10:39:40 +02:00
Chao Gao 4f8d658848 swiotlb: avoid potential left shift overflow
[ Upstream commit 3f0461613e ]

The second operand passed to slot_addr() is declared as int or unsigned int
in all call sites. The left-shift to get the offset of a slot can overflow
if swiotlb size is larger than 4G.

Convert the macro to an inline function and declare the second argument as
phys_addr_t to avoid the potential overflow.

Fixes: 26a7e09478 ("swiotlb: refactor swiotlb_tbl_map_single")
Signed-off-by: Chao Gao <chao.gao@intel.com>
Reviewed-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-15 11:30:07 +02:00
Robin Murphy 1008e81163 swiotlb: fail map correctly with failed io_tlb_default_mem
[ Upstream commit c51ba246cb ]

In the failure case of trying to use a buffer which we'd previously
failed to allocate, the "!mem" condition is no longer sufficient since
io_tlb_default_mem became static and assigned by default. Update the
condition to work as intended per the rest of that conversion.

Fixes: 463e862ac6 ("swiotlb: Convert io_default_tlb_mem to static allocation")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:24:07 +02:00
Dexuan Cui cced9ce619 dma-direct: use the correct size for dma_set_encrypted()
commit 3be4562584 upstream.

The third parameter of dma_set_encrypted() is a size in bytes rather than
the number of pages.

Fixes: 4d0564785b ("dma-direct: factor out dma_set_{de,en}crypted helpers")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-29 09:03:31 +02:00
Rob Clark e4e166f10e dma-debug: make things less spammy under memory pressure
[ Upstream commit e19f8fa6ce ]

Limit the error msg to avoid flooding the console.  If you have a lot of
threads hitting this at once, they could have already gotten passed the
dma_debug_disabled() check before they get to the point of allocation
failure, resulting in quite a lot of this error message spamming the
log.  Use pr_err_once() to limit that.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-22 14:21:55 +02:00
Robin Murphy a48a7f8949 dma-direct: don't over-decrypt memory
[ Upstream commit 4a37f3dd9a ]

The original x86 sev_alloc() only called set_memory_decrypted() on
memory returned by alloc_pages_node(), so the page order calculation
fell out of that logic. However, the common dma-direct code has several
potential allocators, not all of which are guaranteed to round up the
underlying allocation to a power-of-two size, so carrying over that
calculation for the encryption/decryption size was a mistake. Fix it by
rounding to a *number* of pages, rather than an order.

Until recently there was an even worse interaction with DMA_DIRECT_REMAP
where we could have ended up decrypting part of the next adjacent
vmalloc area, only averted by no architecture actually supporting both
configs at once. Don't ask how I found that one out...

Fixes: c10f07aa27 ("dma/direct: Handle force decryption for DMA coherent buffers in common code")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09 10:23:03 +02:00
Christoph Hellwig 5beb74d11e dma-direct: always leak memory that can't be re-encrypted
[ Upstream commit a90cf30437 ]

We must never let unencrypted memory go back into the general page pool.
So if we fail to set it back to encrypted when freeing DMA memory, leak
the memory instead and warn the user.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09 10:23:03 +02:00
Christoph Hellwig 9ba801c80c dma-direct: don't call dma_set_decrypted for remapped allocations
[ Upstream commit 5570449b68 ]

Remapped allocations handle the encrypted bit through the pgprot passed
to vmap, so there is no call dma_set_decrypted.  Note that this case is
currently entirely theoretical as no valid kernel configuration supports
remapped allocations and memory encryption currently.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09 10:23:03 +02:00
Christoph Hellwig 82b3f045af dma-direct: factor out dma_set_{de,en}crypted helpers
[ Upstream commit 4d0564785b ]

Factor out helpers the make dealing with memory encryption a little less
cumbersome.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09 10:23:03 +02:00
Christoph Hellwig 6635e6ba16 dma-direct: don't fail on highmem CMA pages in dma_direct_alloc_pages
[ Upstream commit 92826e9675 ]

When dma_direct_alloc_pages encounters a highmem page it just gives up
currently.  But what we really should do is to try memory using the
page allocator instead - without this platforms with a global highmem
CMA pool will fail all dma_alloc_pages allocations.

Fixes: efa70f2fdc ("dma-mapping: add a new dma_alloc_pages API")
Reported-by: Mark O'Neill <mao@tumblingdice.co.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09 10:22:56 +02:00
Christoph Hellwig 639518f8e0 dma-direct: factor out a helper for DMA_ATTR_NO_KERNEL_MAPPING allocations
[ Upstream commit d541ae55d5 ]

Split the code for DMA_ATTR_NO_KERNEL_MAPPING allocations into a separate
helper to make dma_direct_alloc a little more readable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09 10:22:56 +02:00
Mikulas Patocka e202dad519 dma-debug: change allocation mode from GFP_NOWAIT to GFP_ATIOMIC
[ Upstream commit 84bc4f1dbb ]

We observed the error "cacheline tracking ENOMEM, dma-debug disabled"
during a light system load (copying some files). The reason for this error
is that the dma_active_cacheline radix tree uses GFP_NOWAIT allocation -
so it can't access the emergency memory reserves and it fails as soon as
anybody reaches the watermark.

This patch changes GFP_NOWAIT to GFP_ATOMIC, so that it can access the
emergency memory reserves.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09 10:22:37 +02:00
Mike Rapoport c01430cf5b dma-mapping: remove bogus test for pfn_valid from dma_map_resource
commit a9c38c5d26 upstream.

dma_map_resource() uses pfn_valid() to ensure the range is not RAM.
However, pfn_valid() only checks for availability of the memory map for a
PFN but it does not ensure that the PFN is actually backed by RAM.

As dma_map_resource() is the only method in DMA mapping APIs that has this
check, simply drop the pfn_valid() test from dma_map_resource().

Link: https://lore.kernel.org/all/20210824173741.GC623@arm.com/
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20210930013039.11260-2-rppt@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Fixes: 859a85ddf9 ("mm: remove pfn_valid_within() and CONFIG_HOLES_IN_ZONE")
Link: https://lore.kernel.org/r/Yl0IZWT2nsiYtqBT@linux.ibm.com
Signed-off-by: Georgi Djakov <quic_c_gdjako@quicinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-27 14:38:50 +02:00
Chao Gao 4ef9951d02 dma-direct: avoid redundant memory sync for swiotlb
commit 9e02977bfa upstream.

When we looked into FIO performance with swiotlb enabled in VM, we found
swiotlb_bounce() is always called one more time than expected for each DMA
read request.

It turns out that the bounce buffer is copied to original DMA buffer twice
after the completion of a DMA request (one is done by in
dma_direct_sync_single_for_cpu(), the other by swiotlb_tbl_unmap_single()).
But the content in bounce buffer actually doesn't change between the two
rounds of copy. So, one round of copy is redundant.

Pass DMA_ATTR_SKIP_CPU_SYNC flag to swiotlb_tbl_unmap_single() to
skip the memory copy in it.

This fix increases FIO 64KB sequential read throughput in a guest with
swiotlb=force by 5.6%.

Fixes: 55897af630 ("dma-direct: merge swiotlb_dma_ops into the dma_direct code")
Reported-by: Wang Zhaoyang1 <zhaoyang1.wang@intel.com>
Reported-by: Gao Liang <liang.gao@intel.com>
Signed-off-by: Chao Gao <chao.gao@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-20 09:34:21 +02:00
David Stevens 3e44e13656 swiotlb: Support aligned swiotlb buffers
commit e81e99bacc upstream.

Add an argument to swiotlb_tbl_map_single that specifies the desired
alignment of the allocated buffer. This is used by dma-iommu to ensure
the buffer is aligned to the iova granule size when using swiotlb with
untrusted sub-granule mappings. This addresses an issue where adjacent
slots could be exposed to the untrusted device if IO_TLB_SIZE < iova
granule < PAGE_SIZE.

Signed-off-by: David Stevens <stevensd@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210929023300.335969-7-stevensd@google.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Cc: Mario Limonciello <Mario.Limonciello@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:24:17 +02:00
Linus Torvalds 7007c89463 Reinstate some of "swiotlb: rework "fix info leak with DMA_FROM_DEVICE""
commit 901c7280ca upstream.

Halil Pasic points out [1] that the full revert of that commit (revert
in bddac7c1e0), and that a partial revert that only reverts the
problematic case, but still keeps some of the cleanups is probably
better.  

And that partial revert [2] had already been verified by Oleksandr
Natalenko to also fix the issue, I had just missed that in the long
discussion.

So let's reinstate the cleanups from commit aa6f8dcbab ("swiotlb:
rework "fix info leak with DMA_FROM_DEVICE""), and effectively only
revert the part that caused problems.

Link: https://lore.kernel.org/all/20220328013731.017ae3e3.pasic@linux.ibm.com/ [1]
Link: https://lore.kernel.org/all/20220324055732.GB12078@lst.de/ [2]
Link: https://lore.kernel.org/all/4386660.LvFx2qVVIh@natalenko.name/ [3]
Suggested-by: Halil Pasic <pasic@linux.ibm.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:24:13 +02:00
Randy Dunlap c39a750b61 dma-debug: fix return value of __setup handlers
[ Upstream commit 80e4390981 ]

When valid kernel command line parameters
  dma_debug=off dma_debug_entries=100
are used, they are reported as Unknown parameters and added to init's
environment strings, polluting it.

  Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc5
    dma_debug=off dma_debug_entries=100", will be passed to user space.

and

 Run /sbin/init as init process
   with arguments:
     /sbin/init
   with environment:
     HOME=/
     TERM=linux
     BOOT_IMAGE=/boot/bzImage-517rc5
     dma_debug=off
     dma_debug_entries=100

Return 1 from these __setup handlers to indicate that the command line
option has been handled.

Fixes: 59d3daafa1 ("dma-debug: add kernel command line parameters")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: iommu@lists.linux-foundation.org
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:23:47 +02:00
Linus Torvalds 890f78e54b Revert "swiotlb: rework "fix info leak with DMA_FROM_DEVICE""
commit bddac7c1e0 upstream.

This reverts commit aa6f8dcbab.

It turns out this breaks at least the ath9k wireless driver, and
possibly others.

What the ath9k driver does on packet receive is to set up the DMA
transfer with:

  int ath_rx_init(..)
  ..
                bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
                                                 common->rx_bufsize,
                                                 DMA_FROM_DEVICE);

and then the receive logic (through ath_rx_tasklet()) will fetch
incoming packets

  static bool ath_edma_get_buffers(..)
  ..
        dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
                                common->rx_bufsize, DMA_FROM_DEVICE);

        ret = ath9k_hw_process_rxdesc_edma(ah, rs, skb->data);
        if (ret == -EINPROGRESS) {
                /*let device gain the buffer again*/
                dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
                                common->rx_bufsize, DMA_FROM_DEVICE);
                return false;
        }

and it's worth noting how that first DMA sync:

    dma_sync_single_for_cpu(..DMA_FROM_DEVICE);

is there to make sure the CPU can read the DMA buffer (possibly by
copying it from the bounce buffer area, or by doing some cache flush).
The iommu correctly turns that into a "copy from bounce bufer" so that
the driver can look at the state of the packets.

In the meantime, the device may continue to write to the DMA buffer, but
we at least have a snapshot of the state due to that first DMA sync.

But that _second_ DMA sync:

    dma_sync_single_for_device(..DMA_FROM_DEVICE);

is telling the DMA mapping that the CPU wasn't interested in the area
because the packet wasn't there.  In the case of a DMA bounce buffer,
that is a no-op.

Note how it's not a sync for the CPU (the "for_device()" part), and it's
not a sync for data written by the CPU (the "DMA_FROM_DEVICE" part).

Or rather, it _should_ be a no-op.  That's what commit aa6f8dcbab
broke: it made the code bounce the buffer unconditionally, and changed
the DMA_FROM_DEVICE to just unconditionally and illogically be
DMA_TO_DEVICE.

[ Side note: purely within the confines of the swiotlb driver it wasn't
  entirely illogical: The reason it did that odd DMA_FROM_DEVICE ->
  DMA_TO_DEVICE conversion thing is because inside the swiotlb driver,
  it uses just a swiotlb_bounce() helper that doesn't care about the
  whole distinction of who the sync is for - only which direction to
  bounce.

  So it took the "sync for device" to mean that the CPU must have been
  the one writing, and thought it meant DMA_TO_DEVICE. ]

Also note how the commentary in that commit was wrong, probably due to
that whole confusion, claiming that the commit makes the swiotlb code

                                  "bounce unconditionally (that is, also
    when dir == DMA_TO_DEVICE) in order do avoid synchronising back stale
    data from the swiotlb buffer"

which is nonsensical for two reasons:

 - that "also when dir == DMA_TO_DEVICE" is nonsensical, as that was
   exactly when it always did - and should do - the bounce.

 - since this is a sync for the device (not for the CPU), we're clearly
   fundamentally not coping back stale data from the bounce buffers at
   all, because we'd be copying *to* the bounce buffers.

So that commit was just very confused.  It confused the direction of the
synchronization (to the device, not the cpu) with the direction of the
DMA (from the device).

Reported-and-bisected-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Reported-by: Olha Cherevyk <olha.cherevyk@gmail.com>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kalle Valo <kvalo@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Toke Høiland-Jørgensen <toke@toke.dk>
Cc: Maxime Bizon <mbizon@freebox.fr>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:22:45 +02:00
Halil Pasic 2c1f97af38 swiotlb: rework "fix info leak with DMA_FROM_DEVICE"
commit aa6f8dcbab upstream.

Unfortunately, we ended up merging an old version of the patch "fix info
leak with DMA_FROM_DEVICE" instead of merging the latest one. Christoph
(the swiotlb maintainer), he asked me to create an incremental fix
(after I have pointed this out the mix up, and asked him for guidance).
So here we go.

The main differences between what we got and what was agreed are:
* swiotlb_sync_single_for_device is also required to do an extra bounce
* We decided not to introduce DMA_ATTR_OVERWRITE until we have exploiters
* The implantation of DMA_ATTR_OVERWRITE is flawed: DMA_ATTR_OVERWRITE
  must take precedence over DMA_ATTR_SKIP_CPU_SYNC

Thus this patch removes DMA_ATTR_OVERWRITE, and makes
swiotlb_sync_single_for_device() bounce unconditionally (that is, also
when dir == DMA_TO_DEVICE) in order do avoid synchronising back stale
data from the swiotlb buffer.

Let me note, that if the size used with dma_sync_* API is less than the
size used with dma_[un]map_*, under certain circumstances we may still
end up with swiotlb not being transparent. In that sense, this is no
perfect fix either.

To get this bullet proof, we would have to bounce the entire
mapping/bounce buffer. For that we would have to figure out the starting
address, and the size of the mapping in
swiotlb_sync_single_for_device(). While this does seem possible, there
seems to be no firm consensus on how things are supposed to work.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Fixes: ddbd89deb7 ("swiotlb: fix info leak with DMA_FROM_DEVICE")
Cc: stable@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-16 14:23:43 +01:00
Halil Pasic 7403f4118a swiotlb: fix info leak with DMA_FROM_DEVICE
[ Upstream commit ddbd89deb7 ]

The problem I'm addressing was discovered by the LTP test covering
cve-2018-1000204.

A short description of what happens follows:
1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO
   interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV
   and a corresponding dxferp. The peculiar thing about this is that TUR
   is not reading from the device.
2) In sg_start_req() the invocation of blk_rq_map_user() effectively
   bounces the user-space buffer. As if the device was to transfer into
   it. Since commit a45b599ad8 ("scsi: sg: allocate with __GFP_ZERO in
   sg_build_indirect()") we make sure this first bounce buffer is
   allocated with GFP_ZERO.
3) For the rest of the story we keep ignoring that we have a TUR, so the
   device won't touch the buffer we prepare as if the we had a
   DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device
   and the  buffer allocated by SG is mapped by the function
   virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here
   scatter-gather and not scsi generics). This mapping involves bouncing
   via the swiotlb (we need swiotlb to do virtio in protected guest like
   s390 Secure Execution, or AMD SEV).
4) When the SCSI TUR is done, we first copy back the content of the second
   (that is swiotlb) bounce buffer (which most likely contains some
   previous IO data), to the first bounce buffer, which contains all
   zeros.  Then we copy back the content of the first bounce buffer to
   the user-space buffer.
5) The test case detects that the buffer, which it zero-initialized,
  ain't all zeros and fails.

One can argue that this is an swiotlb problem, because without swiotlb
we leak all zeros, and the swiotlb should be transparent in a sense that
it does not affect the outcome (if all other participants are well
behaved).

Copying the content of the original buffer into the swiotlb buffer is
the only way I can think of to make swiotlb transparent in such
scenarios. So let's do just that if in doubt, but allow the driver
to tell us that the whole mapped buffer is going to be overwritten,
in which case we can preserve the old behavior and avoid the performance
impact of the extra bounce.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-16 14:23:40 +01:00
Baoquan He bcf64fb327 dma/pool: create dma atomic pool only if dma zone has managed pages
commit a674e48c54 upstream.

Currently three dma atomic pools are initialized as long as the relevant
kernel codes are built in.  While in kdump kernel of x86_64, this is not
right when trying to create atomic_pool_dma, because there's no managed
pages in DMA zone.  In the case, DMA zone only has low 1M memory
presented and locked down by memblock allocator.  So no pages are added
into buddy of DMA zone.  Please check commit f1d4d47c58 ("x86/setup:
Always reserve the first 1M of RAM").

Then in kdump kernel of x86_64, it always prints below failure message:

 DMA: preallocated 128 KiB GFP_KERNEL pool for atomic allocations
 swapper/0: page allocation failure: order:5, mode:0xcc1(GFP_KERNEL|GFP_DMA), nodemask=(null),cpuset=/,mems_allowed=0
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-0.rc5.20210611git929d931f2b40.42.fc35.x86_64 #1
 Hardware name: Dell Inc. PowerEdge R910/0P658H, BIOS 2.12.0 06/04/2018
 Call Trace:
  dump_stack+0x7f/0xa1
  warn_alloc.cold+0x72/0xd6
  __alloc_pages_slowpath.constprop.0+0xf29/0xf50
  __alloc_pages+0x24d/0x2c0
  alloc_page_interleave+0x13/0xb0
  atomic_pool_expand+0x118/0x210
  __dma_atomic_pool_init+0x45/0x93
  dma_atomic_pool_init+0xdb/0x176
  do_one_initcall+0x67/0x320
  kernel_init_freeable+0x290/0x2dc
  kernel_init+0xa/0x111
  ret_from_fork+0x22/0x30
 Mem-Info:
 ......
 DMA: failed to allocate 128 KiB GFP_KERNEL|GFP_DMA pool for atomic allocation
 DMA: preallocated 128 KiB GFP_KERNEL|GFP_DMA32 pool for atomic allocations

Here, let's check if DMA zone has managed pages, then create
atomic_pool_dma if yes.  Otherwise just skip it.

Link: https://lkml.kernel.org/r/20211223094435.248523-3-bhe@redhat.com
Fixes: 6f599d8423 ("x86/kdump: Always reserve the low 1M when the crashkernel option is specified")
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: John Donnelly  <john.p.donnelly@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27 11:03:00 +01:00
Linus Torvalds 515dcc2e02 dma-mapping fixes for Linux 5.15
- fix more dma-debug fallout (Gerald Schaefer, Hamza Mahfooz)
  - fix a kerneldoc warning (Logan Gunthorpe)
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Merge tag 'dma-mapping-5.15-2' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - fix more dma-debug fallout (Gerald Schaefer, Hamza Mahfooz)

 - fix a kerneldoc warning (Logan Gunthorpe)

* tag 'dma-mapping-5.15-2' of git://git.infradead.org/users/hch/dma-mapping:
  dma-debug: teach add_dma_entry() about DMA_ATTR_SKIP_CPU_SYNC
  dma-debug: fix sg checks in debug_dma_map_sg()
  dma-mapping: fix the kerneldoc for dma_map_sgtable()
2021-10-20 10:16:51 -10:00
Hamza Mahfooz c2bbf9d1e9 dma-debug: teach add_dma_entry() about DMA_ATTR_SKIP_CPU_SYNC
Mapping something twice should be possible as long as,
DMA_ATTR_SKIP_CPU_SYNC is passed to the strictly speaking second relevant
mapping operation (that attempts to map the same thing). So, don't issue a
warning if the specified condition is met in add_dma_entry().

Signed-off-by: Hamza Mahfooz <someguy@effective-light.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-10-18 12:46:45 +02:00
Gerald Schaefer 293d92cbbd dma-debug: fix sg checks in debug_dma_map_sg()
The following warning occurred sporadically on s390:
DMA-API: nvme 0006:00:00.0: device driver maps memory from kernel text or rodata [addr=0000000048cc5e2f] [len=131072]
WARNING: CPU: 4 PID: 825 at kernel/dma/debug.c:1083 check_for_illegal_area+0xa8/0x138

It is a false-positive warning, due to broken logic in debug_dma_map_sg().
check_for_illegal_area() checks for overlay of sg elements with kernel text
or rodata. It is called with sg_dma_len(s) instead of s->length as
parameter. After the call to ->map_sg(), sg_dma_len() will contain the
length of possibly combined sg elements in the DMA address space, and not
the individual sg element length, which would be s->length.

The check will then use the physical start address of an sg element, and
add the DMA length for the overlap check, which could result in the false
warning, because the DMA length can be larger than the actual single sg
element length.

In addition, the call to check_for_illegal_area() happens in the iteration
over mapped_ents, which will not include all individual sg elements if
any of them were combined in ->map_sg().

Fix this by using s->length instead of sg_dma_len(s). Also put the call to
check_for_illegal_area() in a separate loop, iterating over all the
individual sg elements ("nents" instead of "mapped_ents").

While at it, as suggested by Robin Murphy, also move check_for_stack()
inside the new loop, as it is similarly concerned with validating the
individual sg elements.

Link: https://lore.kernel.org/lkml/20210705185252.4074653-1-gerald.schaefer@linux.ibm.com
Fixes: 884d05970b ("dma-debug: use sg_dma_len accessor")
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-10-11 13:43:31 +02:00
Logan Gunthorpe 011a9ce807 dma-mapping: fix the kerneldoc for dma_map_sgtable()
htmldocs began producing the following warnings:

  kernel/dma/mapping.c:256: WARNING: Definition list ends without a
             blank line; unexpected unindent.
  kernel/dma/mapping.c:257: WARNING: Bullet list ends without a blank
             line; unexpected unindent.

Reformatting the list without hyphens fixes the warnings and produces
both a readable text and HTML output.

Fixes: fffe3cc8c2 ("dma-mapping: allow map_sg() ops to return negative error code")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-10-11 13:43:04 +02:00
Linus Torvalds b9b11b133b dma-mapping fixes for Linux 5.15
- page align size in sparc32 arch_dma_alloc (Andreas Larsson)
  - tone down a new dma-debug message (Hamza Mahfooz)
  - fix the kerneldoc for dma_map_sg_attrs (me)
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Merge tag 'dma-mapping-5.15-1' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - page align size in sparc32 arch_dma_alloc (Andreas Larsson)

 - tone down a new dma-debug message (Hamza Mahfooz)

 - fix the kerneldoc for dma_map_sg_attrs (me)

* tag 'dma-mapping-5.15-1' of git://git.infradead.org/users/hch/dma-mapping:
  sparc32: page align size in arch_dma_alloc
  dma-debug: prevent an error message from causing runtime problems
  dma-mapping: fix the kerneldoc for dma_map_sg_attrs
2021-09-17 11:54:48 -07:00
Hamza Mahfooz 510e1a724a dma-debug: prevent an error message from causing runtime problems
For some drivers, that use the DMA API. This error message can be reached
several millions of times per second, causing spam to the kernel's printk
buffer and bringing the CPU usage up to 100% (so, it should be rate
limited). However, since there is at least one driver that is in the
mainline and suffers from the error condition, it is more useful to
err_printk() here instead of just rate limiting the error message (in hopes
that it will make it easier for other drivers that suffer from this issue
to be spotted).

Link: https://lkml.kernel.org/r/fd67fbac-64bf-f0ea-01e1-5938ccfab9d0@arm.com
Reported-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Hamza Mahfooz <someguy@effective-light.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-09-13 18:29:24 +02:00
Christoph Hellwig a61cb6017d dma-mapping: fix the kerneldoc for dma_map_sg_attrs
Add the missing description for the nents parameter, and fix a trivial
misalignment.

Fixes: fffe3cc8c2 ("dma-mapping: allow map_sg() ops to return negative error codes")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-09-06 14:40:47 +02:00
Linus Torvalds 3de18c865f Merge branch 'stable/for-linus-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb updates from Konrad Rzeszutek Wilk:
 "A new feature called restricted DMA pools. It allows SWIOTLB to
  utilize per-device (or per-platform) allocated memory pools instead of
  using the global one.

  The first big user of this is ARM Confidential Computing where the
  memory for DMA operations can be set per platform"

* 'stable/for-linus-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: (23 commits)
  swiotlb: use depends on for DMA_RESTRICTED_POOL
  of: restricted dma: Don't fail device probe on rmem init failure
  of: Move of_dma_set_restricted_buffer() into device.c
  powerpc/svm: Don't issue ultracalls if !mem_encrypt_active()
  s390/pv: fix the forcing of the swiotlb
  swiotlb: Free tbl memory in swiotlb_exit()
  swiotlb: Emit diagnostic in swiotlb_exit()
  swiotlb: Convert io_default_tlb_mem to static allocation
  of: Return success from of_dma_set_restricted_buffer() when !OF_ADDRESS
  swiotlb: add overflow checks to swiotlb_bounce
  swiotlb: fix implicit debugfs declarations
  of: Add plumbing for restricted DMA pool
  dt-bindings: of: Add restricted DMA pool
  swiotlb: Add restricted DMA pool initialization
  swiotlb: Add restricted DMA alloc/free support
  swiotlb: Refactor swiotlb_tbl_unmap_single
  swiotlb: Move alloc_size to swiotlb_find_slots
  swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing
  swiotlb: Update is_swiotlb_active to add a struct device argument
  swiotlb: Update is_swiotlb_buffer to add a struct device argument
  ...
2021-09-03 10:34:44 -07:00
Claire Chang f3c4b1341e swiotlb: use depends on for DMA_RESTRICTED_POOL
Use depends on instead of select for DMA_RESTRICTED_POOL; otherwise it
will make SWIOTLB user configurable and cause compile errors for some
arch (e.g. mips).

Fixes: 0b84e4f8b7 ("swiotlb: Add restricted DMA pool initialization")
Acked-by: Will Deacon <will@kernel.org>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Claire Chang <tientzu@chromium.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2021-08-31 14:48:14 -04:00
Christoph Hellwig 22f9feb499 dma-mapping: make the global coherent pool conditional
Only build the code to support the global coherent pool if support for
it is enabled.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-08-19 09:02:39 +02:00
Christoph Hellwig 39a2d3506b dma-mapping: add a dma_init_global_coherent helper
Add a new helper to initialize the global coherent pool.  This both
cleans up the existing initialization which indirects through the
reserved_mem_ops that are normally only used for struct device, and
also allows using the global pool for non-devicetree architectures.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-08-18 16:24:11 +02:00
Christoph Hellwig a6933571f3 dma-mapping: simplify dma_init_coherent_memory
Return the allocated dma_coherent_mem structure, set the
use_dma_pfn_offset and print the failure warning inside of
dma_init_coherent_memory instead of leaving that to the callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-08-18 16:24:10 +02:00
Christoph Hellwig 70d6aa0ecf dma-mapping: allow using the global coherent pool for !ARM
Switch an ifdef so that the global coherent pool is initialized for
any architecture that selects the DMA_GLOBAL_POOL symbol insted of
hardcoding ARM.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-08-18 16:24:10 +02:00
Christoph Hellwig faf4ef823a dma-direct: add support for dma_coherent_default_memory
Add an option to allocate uncached memory for dma_alloc_coherent from
the global dma_coherent_default_memory.  This will allow to move
arm-nommu (and eventually other platforms) to use generic code for
allocating uncached memory from a pre-populated pool.

Note that this is a different pool from the one that platforms that
can remap at runtime use for GFP_ATOMIC allocations for now, although
there might be opportunities to eventually end up with a common codebase
for the two use cases.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-08-18 16:24:09 +02:00
Christoph Hellwig 2a047e0662 dma-mapping: return an unsigned int from dma_map_sg{,_attrs}
These can only return 0 for failure or the number of entries, so turn
the return value into an unsigned int.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
2021-08-14 09:18:36 +02:00
Logan Gunthorpe d03c544192 dma-mapping: disallow .map_sg operations from returning zero on error
Now that all the .map_sg operations have been converted to returning
proper error codes, drop the code to handle a zero return value,
add a warning if a zero is returned.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-08-09 17:15:02 +02:00