linux-stable.git/drivers/dma/dmaengine.c, branch v4.19.321

dmaengine: Fix double increment of client_count in dma_chan_get()

2023-02-06T06:49:39+00:00

[ Upstream commit f3dc1b3b4750851a94212dba249703dd0e50bb20 ]

The first time dma_chan_get() is called for a channel the channel
client_count is incorrectly incremented twice for public channels,
first in balance_ref_count(), and again prior to returning. This
results in an incorrect client count which will lead to the
channel resources not being freed when they should be. A simple
 test of repeated module load and unload of async_tx on a Dell
 Power Edge R7425 also shows this resulting in a kref underflow
 warning.

[  124.329662] async_tx: api initialized (async)
[  129.000627] async_tx: api initialized (async)
[  130.047839] ------------[ cut here ]------------
[  130.052472] refcount_t: underflow; use-after-free.
[  130.057279] WARNING: CPU: 3 PID: 19364 at lib/refcount.c:28
refcount_warn_saturate+0xba/0x110
[  130.065811] Modules linked in: async_tx(-) rfkill intel_rapl_msr
intel_rapl_common amd64_edac edac_mce_amd ipmi_ssif kvm_amd dcdbas kvm
mgag200 drm_shmem_helper acpi_ipmi irqbypass drm_kms_helper ipmi_si
syscopyarea sysfillrect rapl pcspkr ipmi_devintf sysimgblt fb_sys_fops
k10temp i2c_piix4 ipmi_msghandler acpi_power_meter acpi_cpufreq vfat
fat drm fuse xfs libcrc32c sd_mod t10_pi sg ahci crct10dif_pclmul
libahci crc32_pclmul crc32c_intel ghash_clmulni_intel igb megaraid_sas
i40e libata i2c_algo_bit ccp sp5100_tco dca dm_mirror dm_region_hash
dm_log dm_mod [last unloaded: async_tx]
[  130.117361] CPU: 3 PID: 19364 Comm: modprobe Kdump: loaded Not
tainted 5.14.0-185.el9.x86_64 #1
[  130.126091] Hardware name: Dell Inc. PowerEdge R7425/02MJ3T, BIOS
1.18.0 01/17/2022
[  130.133806] RIP: 0010:refcount_warn_saturate+0xba/0x110
[  130.139041] Code: 01 01 e8 6d bd 55 00 0f 0b e9 72 9d 8a 00 80 3d
26 18 9c 01 00 75 85 48 c7 c7 f8 a3 03 9d c6 05 16 18 9c 01 01 e8 4a
bd 55 00 <0f> 0b e9 4f 9d 8a 00 80 3d 01 18 9c 01 00 0f 85 5e ff ff ff
48 c7
[  130.157807] RSP: 0018:ffffbf98898afe68 EFLAGS: 00010286
[  130.163036] RAX: 0000000000000000 RBX: ffff9da06028e598 RCX: 0000000000000000
[  130.170172] RDX: ffff9daf9de26480 RSI: ffff9daf9de198a0 RDI: ffff9daf9de198a0
[  130.177316] RBP: ffff9da7cddf3970 R08: 0000000000000000 R09: 00000000ffff7fff
[  130.184459] R10: ffffbf98898afd00 R11: ffffffff9d9e8c28 R12: ffff9da7cddf1970
[  130.191596] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[  130.198739] FS:  00007f646435c740(0000) GS:ffff9daf9de00000(0000)
knlGS:0000000000000000
[  130.206832] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  130.212586] CR2: 00007f6463b214f0 CR3: 00000008ab98c000 CR4: 00000000003506e0
[  130.219729] Call Trace:
[  130.222192]  
[  130.224305]  dma_chan_put+0x10d/0x110
[  130.227988]  dmaengine_put+0x7a/0xa0
[  130.231575]  __do_sys_delete_module.constprop.0+0x178/0x280
[  130.237157]  ? syscall_trace_enter.constprop.0+0x145/0x1d0
[  130.242652]  do_syscall_64+0x5c/0x90
[  130.246240]  ? exc_page_fault+0x62/0x150
[  130.250178]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[  130.255243] RIP: 0033:0x7f6463a3f5ab
[  130.258830] Code: 73 01 c3 48 8b 0d 75 a8 1b 00 f7 d8 64 89 01 48
83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00
00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 45 a8 1b 00 f7 d8 64 89
01 48
[  130.277591] RSP: 002b:00007fff22f972c8 EFLAGS: 00000206 ORIG_RAX:
00000000000000b0
[  130.285164] RAX: ffffffffffffffda RBX: 000055b6786edd40 RCX: 00007f6463a3f5ab
[  130.292303] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055b6786edda8
[  130.299443] RBP: 000055b6786edd40 R08: 0000000000000000 R09: 0000000000000000
[  130.306584] R10: 00007f6463b9eac0 R11: 0000000000000206 R12: 000055b6786edda8
[  130.313731] R13: 0000000000000000 R14: 000055b6786edda8 R15: 00007fff22f995f8
[  130.320875]  
[  130.323081] ---[ end trace eff7156d56b5cf25 ]---

cat /sys/class/dma/dma0chan*/in_use would get the wrong result.
2
2
2

Fixes: d2f4f99db3e9 ("dmaengine: Rework dma_chan_get")
Signed-off-by: Koba Ko 
Reviewed-by: Jie Hai 
Test-by: Jie Hai 
Reviewed-by: Jerry Snitselaar 
Reviewed-by: Dave Jiang 
Tested-by: Joel Savitz 
Link: https://lore.kernel.org/r/20221201030050.978595-1-koba.ko@canonical.com
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

dmaengine: Store module owner in dma_device struct

2020-02-24T07:34:44+00:00

[ Upstream commit dae7a589c18a4d979d5f14b09374e871b995ceb1 ]

dma_chan_to_owner() dereferences the driver from the struct device to
obtain the owner and call module_[get|put](). However, if the backing
device is unbound before the dma_device is unregistered, the driver
will be cleared and this will cause a NULL pointer dereference.

Instead, store a pointer to the owner module in the dma_device struct
so the module reference can be properly put when the channel is put, even
if the backing device was destroyed first.

This change helps to support a safer unbind of DMA engines.
If the dma_device is unregistered in the driver's remove function,
there's no guarantee that there are no existing clients and a users
action may trigger the WARN_ONCE in dma_async_device_unregister()
which is unlikely to leave the system in a consistent state.
Instead, a better approach is to allow the backing driver to go away
and fail any subsequent requests to it.

Signed-off-by: Logan Gunthorpe 
Link: https://lore.kernel.org/r/20191216190120.21374-2-logang@deltatee.com
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

Merge branch 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax

2018-08-26T18:48:42+00:00

Pull IDA updates from Matthew Wilcox:
 "A better IDA API:

      id = ida_alloc(ida, GFP_xxx);
      ida_free(ida, id);

  rather than the cumbersome ida_simple_get(), ida_simple_remove().

  The new IDA API is similar to ida_simple_get() but better named.  The
  internal restructuring of the IDA code removes the bitmap
  preallocation nonsense.

  I hope the net -200 lines of code is convincing"

* 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax: (29 commits)
  ida: Change ida_get_new_above to return the id
  ida: Remove old API
  test_ida: check_ida_destroy and check_ida_alloc
  test_ida: Convert check_ida_conv to new API
  test_ida: Move ida_check_max
  test_ida: Move ida_check_leaf
  idr-test: Convert ida_check_nomem to new API
  ida: Start new test_ida module
  target/iscsi: Allocate session IDs from an IDA
  iscsi target: fix session creation failure handling
  drm/vmwgfx: Convert to new IDA API
  dmaengine: Convert to new IDA API
  ppc: Convert vas ID allocation to new IDA API
  media: Convert entity ID allocation to new IDA API
  ppc: Convert mmu context allocation to new IDA API
  Convert net_namespace to new IDA API
  cb710: Convert to new IDA API
  rsxx: Convert to new IDA API
  osd: Convert to new IDA API
  sd: Convert to new IDA API
  ...

dmaengine: Convert to new IDA API

2018-08-22T03:54:19+00:00

Simpler and shorter code.

Signed-off-by: Matthew Wilcox 
Acked-by: Vinod Koul

dmaengine: add a new helper dmaenginem_async_device_register

2018-07-30T05:20:22+00:00

This patch adds the dmaenginem_async_device_register for DMA code.
Use the Devres to call the release for the DMA engine driver.

Signed-off-by: Huang Shijie 
Signed-off-by: Vinod Koul

dmaengine: dma_request_chan_by_mask() to handle deferred probing

2018-07-25T12:34:15+00:00

If there are no DMA devices registered yet, return with EPROBE_DEFER
similarly to the case when requesting a slave channel.

Signed-off-by: Peter Ujfalusi 
Signed-off-by: Vinod Koul

dmaengine: add support for reporting pause and resume separately

2018-07-09T17:29:04+00:00

'cmd_pause' DMA channel capability means that respective DMA engine
supports both pausing and resuming given DMA channel. However, in some
cases it is important to know if DMA channel can be paused without the
need to resume it. This is a typical requirement for proper residue
reading on transfer timeout in UART drivers. There are also some DMA
engines with limited hardware, which doesn't really support resuming.

Reporting pause and resume capabilities separately allows UART drivers to
properly check for the really required capabilities and operate in DMA
mode also in systems with limited DMA hardware. On the other hand drivers,
which rely on full channel suspend/resume support, should now check for
both 'pause' and 'resume' features.

Existing clients of dma_get_slave_caps() have been checked and the only
driver which rely on proper channel resuming is soc-generic-dmaengine-pcm
driver, which has been updated to check the newly added capability.
Existing 'cmd_pause' now only indicates that DMA engine support pausing
given DMA channel.

Signed-off-by: Marek Szyprowski 
Acked-by: Mark Brown 
Signed-off-by: Vinod Koul

fix a series of Documentation/ broken file name references

2018-06-15T21:10:01+00:00

As files move around, their previous links break. Fix the
references for them.

Acked-by: Andy Shevchenko 
Signed-off-by: Mauro Carvalho Chehab 
Acked-by: Jonathan Corbet

dmaengine: remove BUG_ON while registering devices

2017-08-28T04:09:46+00:00

DMAengine core has BUG_ON to check for mandatory operations and ones based
on capabilities, but they use BUG_ON, so remove and move to error returns
and logging the errors gracefully

Acked-by: Dan Williams 
Signed-off-by: Vinod Koul

dmaengine: remove DMA_SG as it is dead code in kernel

2017-08-22T03:52:11+00:00

There are no in kernel consumers for DMA_SG op. Removing operation,
dead code, and test code in dmatest.

Signed-off-by: Dave Jiang 
Reviewed-by: Linus Walleij 
Cc: Gary Hook 
Cc: Ludovic Desroches 
Cc: Kedareswara rao Appana 
Cc: Li Yang 
Cc: Michal Simek 
Signed-off-by: Vinod Koul