Skip to content

L
linux
Switch branch/tag
  1. 11 May, 2016 17 commits
  3. 03 May, 2016 16 commits
  5. 02 May, 2016 7 commits
    • Roman Pen's avatar
      workqueue: fix ghost PENDING flag while doing MQ IO · 4aa63af3
      Roman Pen authored 
      commit 346c09f8 upstream.

The bug in a workqueue leads to a stalled IO request in MQ ctx->rq_list
with the following backtrace:

[  601.347452] INFO: task kworker/u129:5:1636 blocked for more than 120 seconds.
[  601.347574]       Tainted: G           O    4.4.5-1-storage+ #6
[  601.347651] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  601.348142] kworker/u129:5  D ffff880803077988     0  1636      2 0x00000000
[  601.348519] Workqueue: ibnbd_server_fileio_wq ibnbd_dev_file_submit_io_worker [ibnbd_server]
[  601.348999]  ffff880803077988 ffff88080466b900 ffff8808033f9c80 ffff880803078000
[  601.349662]  ffff880807c95000 7fffffffffffffff ffffffff815b0920 ffff880803077ad0
[  601.350333]  ffff8808030779a0 ffffffff815b01d5 0000000000000000 ffff880803077a38
[  601.350965] Call Trace:
[  601.351203]  [<ffffffff815b0920>] ? bit_wait+0x60/0x60
[  601.351444]  [<ffffffff815b01d5>] schedule+0x35/0x80
[  601.351709]  [<ffffffff815b2dd2>] schedule_timeout+0x192/0x230
[  601.351958]  [<ffffffff812d43f7>] ? blk_flush_plug_list+0xc7/0x220
[  601.352208]  [<ffffffff810bd737>] ? ktime_get+0x37/0xa0
[  601.352446]  [<ffffffff815b0920>] ? bit_wait+0x60/0x60
[  601.352688]  [<ffffffff815af784>] io_schedule_timeout+0xa4/0x110
[  601.352951]  [<ffffffff815b3a4e>] ? _raw_spin_unlock_irqrestore+0xe/0x10
[  601.353196]  [<ffffffff815b093b>] bit_wait_io+0x1b/0x70
[  601.353440]  [<ffffffff815b056d>] __wait_on_bit+0x5d/0x90
[  601.353689]  [<ffffffff81127bd0>] wait_on_page_bit+0xc0/0xd0
[  601.353958]  [<ffffffff81096db0>] ? autoremove_wake_function+0x40/0x40
[  601.354200]  [<ffffffff81127cc4>] __filemap_fdatawait_range+0xe4/0x140
[  601.354441]  [<ffffffff81127d34>] filemap_fdatawait_range+0x14/0x30
[  601.354688]  [<ffffffff81129a9f>] filemap_write_and_wait_range+0x3f/0x70
[  601.354932]  [<ffffffff811ced3b>] blkdev_fsync+0x1b/0x50
[  601.355193]  [<ffffffff811c82d9>] vfs_fsync_range+0x49/0xa0
[  601.355432]  [<ffffffff811cf45a>] blkdev_write_iter+0xca/0x100
[  601.355679]  [<ffffffff81197b1a>] __vfs_write+0xaa/0xe0
[  601.355925]  [<ffffffff81198379>] vfs_write+0xa9/0x1a0
[  601.356164]  [<ffffffff811c59d8>] kernel_write+0x38/0x50

The underlying device is a null_blk, with default parameters:

  queue_mode    = MQ
  submit_queues = 1

Verification that nullb0 has something inflight:

root@pserver8:~# cat /sys/block/nullb0/inflight
       0        1
root@pserver8:~# find /sys/block/nullb0/mq/0/cpu* -name rq_list -print -exec cat {} \;
...
/sys/block/nullb0/mq/0/cpu2/rq_list
CTX pending:
        ffff8838038e2400
...

During debug it became clear that stalled request is always inserted in
the rq_list from the following path:

   save_stack_trace_tsk + 34
   blk_mq_insert_requests + 231
   blk_mq_flush_plug_list + 281
   blk_flush_plug_list + 199
   wait_on_page_bit + 192
   __filemap_fdatawait_range + 228
   filemap_fdatawait_range + 20
   filemap_write_and_wait_range + 63
   blkdev_fsync + 27
   vfs_fsync_range + 73
   blkdev_write_iter + 202
   __vfs_write + 170
   vfs_write + 169
   kernel_write + 56

So blk_flush_plug_list() was called with from_schedule == true.

If from_schedule is true, that means that finally blk_mq_insert_requests()
offloads execution of __blk_mq_run_hw_queue() and uses kblockd workqueue,
i.e. it calls kblockd_schedule_delayed_work_on().

That means, that we race with another CPU, which is about to execute
__blk_mq_run_hw_queue() work.

Further debugging shows the following traces from different CPUs:

  CPU#0                                  CPU#1
  ----------------------------------     -------------------------------
  reqeust A inserted
  STORE hctx->ctx_map[0] bit marked
  kblockd_schedule...() returns 1
  <schedule to kblockd workqueue>
                                         request B inserted
                                         STORE hctx->ctx_map[1] bit marked
                                         kblockd_schedule...() returns 0
  *** WORK PENDING bit is cleared ***
  flush_busy_ctxs() is executed, but
  bit 1, set by CPU#1, is not observed

As a result request B pended forever.

This behaviour can be explained by speculative LOAD of hctx->ctx_map on
CPU#0, which is reordered with clear of PENDING bit and executed _before_
actual STORE of bit 1 on CPU#1.

The proper fix is an explicit full barrier <mfence>, which guarantees
that clear of PENDING bit is to be executed before all possible
speculative LOADS or STORES inside actual work function.
Signed-off-by: default avatarRoman Pen <roman.penyaev@profitbricks.com>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Michael Wang <yun.wang@profitbricks.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      4aa63af3
    • Laszlo Ersek's avatar
      efi: Fix out-of-bounds read in variable_matches() · 5114cf46
      Laszlo Ersek authored 
      commit 630ba0cc upstream.

The variable_matches() function can currently read "var_name[len]", for
example when:

 - var_name[0] == 'a',
 - len == 1
 - match_name points to the NUL-terminated string "ab".

This function is supposed to accept "var_name" inputs that are not
NUL-terminated (hence the "len" parameter"). Document the function, and
access "var_name[*match]" only if "*match" is smaller than "len".
Reported-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarLaszlo Ersek <lersek@redhat.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Matthew Garrett <mjg59@coreos.com>
Cc: Jason Andryuk <jandryuk@gmail.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Link: http://thread.gmane.org/gmane.comp.freedesktop.xorg.drivers.intel/86906Signed-off-by: default avatarMatt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      5114cf46
    • Sugar Zhang's avatar
      ASoC: rt5640: Correct the digital interface data select · ac0f017d
      Sugar Zhang authored 
      commit 653aa464 upstream.

this patch corrects the interface adc/dac control register definition
according to datasheet.
Signed-off-by: default avatarSugar Zhang <sugar.zhang@rock-chips.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      ac0f017d
    • Arnd Bergmann's avatar
      ASoC: s3c24xx: use const snd_soc_component_driver pointer · c0bc1ca7
      Arnd Bergmann authored 
      commit ba4bc32e upstream.

An older patch to convert the API in the s3c i2s driver
ended up passing a const pointer into a function that takes
a non-const pointer, so we now get a warning:

sound/soc/samsung/s3c2412-i2s.c: In function 's3c2412_iis_dev_probe':
sound/soc/samsung/s3c2412-i2s.c:172:9: error: passing argument 3 of 's3c_i2sv2_register_component' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]

However, the s3c_i2sv2_register_component() function again
passes the pointer into another function taking a const, so
we just need to change its prototype.

Fixes: eca3b01d ("ASoC: switch over to use snd_soc_register_component() on s3c i2s")
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Reviewed-by: default avatarKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      c0bc1ca7
    • Tony Luck's avatar
      EDAC: i7core, sb_edac: Don't return NOTIFY_BAD from mce_decoder callback · a4e2a2d5
      Tony Luck authored 
      commit c4fc1956 upstream.

Both of these drivers can return NOTIFY_BAD, but this terminates
processing other callbacks that were registered later on the chain.
Since the driver did nothing to log the error it seems wrong to prevent
other interested parties from seeing it. E.g. neither of them had even
bothered to check the type of the error to see if it was a memory error
before the return NOTIFY_BAD.
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
Acked-by: default avatarAristeu Rozanski <aris@redhat.com>
Acked-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/72937355dd92318d2630979666063f8a2853495b.1461864507.git.tony.luck@intel.comSigned-off-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      a4e2a2d5
    • Keerthy's avatar
      pinctrl: single: Fix pcs_parse_bits_in_pinctrl_entry to use __ffs than ffs · f03a30db
      Keerthy authored 
      commit 56b367c0 upstream.

pcs_parse_bits_in_pinctrl_entry uses ffs which gives bit indices
ranging from 1 to MAX. This leads to a corner case where we try to request
the pin number = MAX and fails.

bit_pos value is being calculted using ffs. pin_num_from_lsb uses
bit_pos value. pins array is populated with:

pin + pin_num_from_lsb.

The above is 1 more than usual bit indices as bit_pos uses ffs to compute
first set bit. Hence the last of the pins array is populated with the MAX
value and not MAX - 1 which causes error when we call pin_request.

mask_pos is rightly calculated as ((pcs->fmask) << (bit_pos - 1))
Consequently val_pos and submask are correct.

Hence use __ffs which gives (ffs(x) - 1) as the first bit set.

fixes: 4e7e8017 ("pinctrl: pinctrl-single: enhance to configure multiple pins of different modules")
Signed-off-by: default avatarKeerthy <j-keerthy@ti.com>
Acked-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      f03a30db
    • Vladis Dronov's avatar
      Input: gtco - fix crash on detecting device without endpoints · 8c29c640
      Vladis Dronov authored 
      commit 162f98de upstream.

The gtco driver expects at least one valid endpoint. If given malicious
descriptors that specify 0 for the number of endpoints, it will crash in
the probe function. Ensure there is at least one endpoint on the interface
before using it.

Also let's fix a minor coding style issue.

The full correct report of this issue can be found in the public
Red Hat Bugzilla:

https://bugzilla.redhat.com/show_bug.cgi?id=1283385Reported-by: default avatarRalf Spenneberg <ralf@spenneberg.net>
Signed-off-by: default avatarVladis Dronov <vdronov@redhat.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      8c29c640
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7