Commit Graph

5912 Commits

Author SHA1 Message Date
Linus Torvalds
9efa3ed504 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "Eric's s_inodes softlockup fixes + Jan's fix for recent regression
  from pipe rework"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: call fsnotify_sb_delete after evict_inodes
  fs: avoid softlockups in s_inodes iterators
  pipe: Fix bogus dereference in iov_iter_alignment()
2019-12-22 17:00:04 -08:00
Linus Torvalds
44579f35c2 Merge tag 'block-5.5-20191221' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
 "Let's try this one again, this time without the compat_ioctl changes.
  We've got those fixed up, but that can go out next week.

  This contains:

   - block queue flush lockdep annotation (Bart)

   - Type fix for bsg_queue_rq() (Bart)

   - Three dasd fixes (Stefan, Jan)

   - nbd deadlock fix (Mike)

   - Error handling bio user map fix (Yang)

   - iocost fix (Tejun)

   - sbitmap waitqueue addition fix that affects the kyber IO scheduler
     (David)"

* tag 'block-5.5-20191221' of git://git.kernel.dk/linux-block:
  sbitmap: only queue kyber's wait callback if not already active
  block: fix memleak when __blk_rq_map_user_iov() is failed
  s390/dasd: fix typo in copyright statement
  s390/dasd: fix memleak in path handling error case
  s390/dasd/cio: Interpret ccw_device_get_mdc return value correctly
  block: Fix a lockdep complaint triggered by request queue flushing
  block: Fix the type of 'sts' in bsg_queue_rq()
  block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT
  nbd: fix shutdown and recv work deadlock v2
  iocost: over-budget forced IOs should schedule async delay
2019-12-22 10:36:55 -08:00
David Jeffery
df034c93f1 sbitmap: only queue kyber's wait callback if not already active
Under heavy loads where the kyber I/O scheduler hits the token limits for
its scheduling domains, kyber can become stuck.  When active requests
complete, kyber may not be woken up leaving the I/O requests in kyber
stuck.

This stuck state is due to a race condition with kyber and the sbitmap
functions it uses to run a callback when enough requests have completed.
The running of a sbt_wait callback can race with the attempt to insert the
sbt_wait.  Since sbitmap_del_wait_queue removes the sbt_wait from the list
first then sets the sbq field to NULL, kyber can see the item as not on a
list but the call to sbitmap_add_wait_queue will see sbq as non-NULL. This
results in the sbt_wait being inserted onto the wait list but ws_active
doesn't get incremented.  So the sbitmap queue does not know there is a
waiter on a wait list.

Since sbitmap doesn't think there is a waiter, kyber may never be
informed that there are domain tokens available and the I/O never advances.
With the sbt_wait on a wait list, kyber believes it has an active waiter
so cannot insert a new waiter when reaching the domain's full state.

This race can be fixed by only adding the sbt_wait to the queue if the
sbq field is NULL.  If sbq is not NULL, there is already an action active
which will trigger the re-running of kyber.  Let it run and add the
sbt_wait to the wait list if still needing to wait.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Jeffery <djeffery@redhat.com>
Reported-by: John Pittman <jpittman@redhat.com>
Tested-by: John Pittman <jpittman@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-20 16:51:54 -07:00
Changbin Du
045f6d7942 lib/Kconfig.debug: fix some messed up configurations
Some configuration items are messed up during conflict resolving.  For
example, STRICT_DEVMEM should not in testing menu, but kunit should.
This patch fixes all of them.

[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/20191209155653.7509-1-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-17 20:59:59 -08:00
Jan Kara
e0ff126ee7 pipe: Fix bogus dereference in iov_iter_alignment()
We cannot look at 'i->pipe' unless we know the iter is a pipe. Move the
ring_size load to a branch in iov_iter_alignment() where we've already
checked the iter is a pipe to avoid bogus dereference.

Reported-by: syzbot+bea68382bae9490e7dd6@syzkaller.appspotmail.com
Fixes: 8cefc107ca ("pipe: Use head and tail pointers for the ring, not cursor and length")
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-12-16 12:48:10 -05:00
Greg Kroah-Hartman
702600eef7 lib: raid6: fix awk build warnings
Newer versions of awk spit out these fun warnings:
	awk: ../lib/raid6/unroll.awk:16: warning: regexp escape sequence `\#' is not a known regexp operator

As commit 700c1018b8 ("x86/insn: Fix awk regexp warnings") showed, it
turns out that there are a number of awk strings that do not need to be
escaped and newer versions of awk now warn about this.

Fix the string up so that no warning is produced.  The exact same kernel
module gets created before and after this patch, showing that it wasn't
needed.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20191206152600.GA75093@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-09 18:55:03 +01:00
Krzysztof Kozlowski
68d4b3dfca lib/: fix Kconfig indentation
Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
	$ sed -e 's/^        /	/' -i */Kconfig

Link: http://lkml.kernel.org/r/20191120140140.19148-1-krzk@kernel.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-07 11:00:19 -08:00
Changbin Du
ec29a5c197 kernel-hacking: move DEBUG_FS to 'Generic Kernel Debugging Instruments'
DEBUG_FS does not belong to 'Compile-time checks and compiler options'.

Link: http://lkml.kernel.org/r/20190909144453.3520-10-changbin.du@gmail.com
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-07 11:00:19 -08:00
Changbin Du
2b05bb75d1 kernel-hacking: move DEBUG_BUGVERBOSE to 'printk and dmesg options'
I think DEBUG_BUGVERBOSE is a dmesg option which gives more debug info
to dmesg.

Link: http://lkml.kernel.org/r/20190909144453.3520-9-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-07 11:00:19 -08:00
Changbin Du
ebebdd095d kernel-hacking: create a submenu for scheduler debugging options
Create a submenu 'Scheduler Debugging' for scheduler debugging options.

Link: http://lkml.kernel.org/r/20190909144453.3520-8-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-07 11:00:19 -08:00
Changbin Du
dc9b96387e kernel-hacking: move SCHED_STACK_END_CHECK after DEBUG_STACK_USAGE
They are both memory debug options to debug kernel stack issues.

Link: http://lkml.kernel.org/r/20190909144453.3520-7-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-07 11:00:19 -08:00
Changbin Du
f43a289df6 kernel-hacking: move Oops into 'Lockups and Hangs'
They are similar options so place them together.

Link: http://lkml.kernel.org/r/20190909144453.3520-6-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-07 11:00:19 -08:00
Changbin Du
09a7495258 kernel-hacking: move kernel testing and coverage options to same submenu
Move error injection, coverage, testing options to a new top level
submenu 'Kernel Testing and Coverage'.  They are all for test purpose.

Link: http://lkml.kernel.org/r/20190909144453.3520-5-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-07 11:00:19 -08:00
Changbin Du
3be5cbcde9 kernel-hacking: group kernel data structures debugging together
Group these similar runtime data structures verification options
together.

Link: http://lkml.kernel.org/r/20190909144453.3520-4-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-07 11:00:19 -08:00
Changbin Du
ff600a9a69 kernel-hacking: create submenu for arch special debugging options
The arch special options are a little long, so create a submenu for
them.

Link: http://lkml.kernel.org/r/20190909144453.3520-3-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-07 11:00:19 -08:00
Changbin Du
6210b6402f kernel-hacking: group sysrq/kgdb/ubsan into 'Generic Kernel Debugging Instruments'
Patch series "hacking: make 'kernel hacking' menu better structurized", v3.

This series is a trivial improvment for the layout of 'kernel hacking'
configuration menu.  Now we have many items in it which makes takes a
little time to look up them since they are not well structurized yet.

Early discussion is here:
  https://lkml.org/lkml/2019/9/1/39

This patch (of 9):

Group generic kernel debugging instruments sysrq/kgdb/ubsan together
into a new submenu.

Link: http://lkml.kernel.org/r/20190909144453.3520-2-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-07 11:00:19 -08:00
Linus Torvalds
ec939e4c94 Merge tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull ARM SoC driver updates from Olof Johansson:
 "Various driver updates for platforms:

   - A larger set of work on Tegra 2/3 around memory controller and
     regulator features, some fuse cleanups, etc..

   - MMP platform drivers, in particular for USB PHY, and other smaller
     additions.

   - Samsung Exynos 5422 driver for DMC (dynamic memory configuration),
     and ASV (adaptive voltage), allowing the platform to run at more
     optimal operating points.

   - Misc refactorings and support for RZ/G2N and R8A774B1 from Renesas

   - Clock/reset control driver for TI/OMAP

   - Meson-A1 reset controller support

   - Qualcomm sdm845 and sda845 SoC IDs for socinfo"

* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (150 commits)
  firmware: arm_scmi: Fix doorbell ring logic for !CONFIG_64BIT
  soc: fsl: add RCPM driver
  dt-bindings: fsl: rcpm: Add 'little-endian' and update Chassis definition
  memory: tegra: Consolidate registers definition into common header
  memory: tegra: Ensure timing control debug features are disabled
  memory: tegra: Introduce Tegra30 EMC driver
  memory: tegra: Do not handle error from wait_for_completion_timeout()
  memory: tegra: Increase handshake timeout on Tegra20
  memory: tegra: Print a brief info message about EMC timings
  memory: tegra: Pre-configure debug register on Tegra20
  memory: tegra: Include io.h instead of iopoll.h
  memory: tegra: Adapt for Tegra20 clock driver changes
  memory: tegra: Don't set EMC rate to maximum on probe for Tegra20
  memory: tegra: Add gr2d and gr3d to DRM IOMMU group
  memory: tegra: Set DMA mask based on supported address bits
  soc: at91: Add Atmel SFR SN (Serial Number) support
  memory: atmel-ebi: switch to SPDX license identifiers
  memory: atmel-ebi: move NUM_CS definition inside EBI driver
  soc: mediatek: Refactor bus protection control
  soc: mediatek: Refactor sram control
  ...
2019-12-05 11:43:31 -08:00
Andy Shevchenko
30544ed5de lib/bitmap: introduce bitmap_replace() helper
In some drivers we want to have a single operation over bitmap which is
an equivalent to:

	*dst = (*old & ~(*mask)) | (*new & *mask)

Introduce bitmap_replace() helper for this.

Link: http://lkml.kernel.org/r/20191022172922.61232-8-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-04 19:44:14 -08:00
Andy Shevchenko
780ff33b8b lib/test_bitmap: fix comment about this file
This test case file is about bitmap API, and not printf() facility.

Link: http://lkml.kernel.org/r/20191022172922.61232-7-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-04 19:44:14 -08:00
Andy Shevchenko
c21dd8a7bb lib/test_bitmap: move exp1 and exp2 upper for others to use
Some test cases may re-use predefined exp1 and exp2 bitmaps.  Move them
upper in the file.

Link: http://lkml.kernel.org/r/20191022172922.61232-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-04 19:44:14 -08:00
Andy Shevchenko
0ee312e380 lib/test_bitmap: rename exp to exp1 to avoid ambiguous name
One function is using exp as local variable.  Avoid ambiguous naming by
rename global one to exp1.

Link: http://lkml.kernel.org/r/20191022172922.61232-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-04 19:44:14 -08:00
Andy Shevchenko
a4881d1cbc lib/test_bitmap: name EXP_BYTES properly
EXP_BYTES has been wrongly named.  It's a size of the exp array in bits.

While here, go ahead and rename to EXP1_IN_BITS to avoid double renaming
when exp will be renamed to exp1 in the next patch

Link: http://lkml.kernel.org/r/20191022172922.61232-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-04 19:44:14 -08:00
Andy Shevchenko
5422404409 lib/test_bitmap: undefine macros after use
There is no need to keep step and ptest macros defined in entire file.

Link: http://lkml.kernel.org/r/20191022172922.61232-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-04 19:44:14 -08:00
Andy Shevchenko
17b6753ff0 lib/test_bitmap: force argument of bitmap_parselist_user() to proper address space
Patch series "gpio: pca953x: Convert to bitmap (extended) API", v2.

While converting gpio-pca953x driver to bitmap API, I noticed that we
have no function to replace bits.

So, that's how patch 7 appears.

First 6 patches are preparatory of the test suite (including some
warning fixes, etc).

Patches 8-9 are preparatory for the GPIO driver to be easier converted
to bitmap API, conversion to which happens in patch 10.

Patch 11 contains simple indentation fixes.

This patch (of 11):

Sparse complains:

  lib/test_bitmap.c:345:58: warning: incorrect type in argument 1 (different address spaces)
  lib/test_bitmap.c:345:58:    expected char const [noderef] <asn:1> *ubuf
  lib/test_bitmap.c:345:58:    got char const *const in

Force argument of bitmap_parselist_user() to proper address space.

Link: http://lkml.kernel.org/r/20191022172922.61232-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Marek Vasut <marek.vasut+renesas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-04 19:44:14 -08:00
Julien Grall
ce5c31db36 lib/ubsan: don't serialize UBSAN report
At the moment, UBSAN report will be serialized using a spin_lock().  On
RT-systems, spinlocks are turned to rt_spin_lock and may sleep.  This
will result to the following splat if the undefined behavior is in a
context that can sleep:

  BUG: sleeping function called from invalid context at /src/linux/kernel/locking/rtmutex.c:968
  in_atomic(): 1, irqs_disabled(): 128, pid: 3447, name: make
  1 lock held by make/3447:
   #0: 000000009a966332 (&mm->mmap_sem){++++}, at: do_page_fault+0x140/0x4f8
  irq event stamp: 6284
  hardirqs last  enabled at (6283): [<ffff000011326520>] _raw_spin_unlock_irqrestore+0x90/0xa0
  hardirqs last disabled at (6284): [<ffff0000113262b0>] _raw_spin_lock_irqsave+0x30/0x78
  softirqs last  enabled at (2430): [<ffff000010088ef8>] fpsimd_restore_current_state+0x60/0xe8
  softirqs last disabled at (2427): [<ffff000010088ec0>] fpsimd_restore_current_state+0x28/0xe8
  Preemption disabled at:
  [<ffff000011324a4c>] rt_mutex_futex_unlock+0x4c/0xb0
  CPU: 3 PID: 3447 Comm: make Tainted: G        W         5.2.14-rt7-01890-ge6e057589653 #911
  Call trace:
    dump_backtrace+0x0/0x148
    show_stack+0x14/0x20
    dump_stack+0xbc/0x104
    ___might_sleep+0x154/0x210
    rt_spin_lock+0x68/0xa0
    ubsan_prologue+0x30/0x68
    handle_overflow+0x64/0xe0
    __ubsan_handle_add_overflow+0x10/0x18
    __lock_acquire+0x1c28/0x2a28
    lock_acquire+0xf0/0x370
    _raw_spin_lock_irqsave+0x58/0x78
    rt_mutex_futex_unlock+0x4c/0xb0
    rt_spin_unlock+0x28/0x70
    get_page_from_freelist+0x428/0x2b60
    __alloc_pages_nodemask+0x174/0x1708
    alloc_pages_vma+0x1ac/0x238
    __handle_mm_fault+0x4ac/0x10b0
    handle_mm_fault+0x1d8/0x3b0
    do_page_fault+0x1c8/0x4f8
    do_translation_fault+0xb8/0xe0
    do_mem_abort+0x3c/0x98
    el0_da+0x20/0x24

The spin_lock() will protect against multiple CPUs to output a report
together, I guess to prevent them from being interleaved.  However, they
can still interleave with other messages (and even splat from
__might_sleep).

So the lock usefulness seems pretty limited.  Rather than trying to
accomodate RT-system by switching to a raw_spin_lock(), the lock is now
completely dropped.

Link: http://lkml.kernel.org/r/20190920100835.14999-1-julien.grall@arm.com
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reported-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-04 19:44:14 -08:00