mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-11-01 17:08:10 +00:00
Code Issues Releases Wiki Activity
No description
874747 commits 105 branches 5128 tags 5.6 GiB
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%
Find a file
Marco Elver c120c3dbeb locking/spinlock/debug: Fix various data races 
[ Upstream commit 1a365e8223 ]

This fixes various data races in spinlock_debug. By testing with KCSAN,
it is observable that the console gets spammed with data races reports,
suggesting these are extremely frequent.

Example data race report:

  read to 0xffff8ab24f403c48 of 4 bytes by task 221 on cpu 2:
   debug_spin_lock_before kernel/locking/spinlock_debug.c:85 [inline]
   do_raw_spin_lock+0x9b/0x210 kernel/locking/spinlock_debug.c:112
   __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline]
   _raw_spin_lock+0x39/0x40 kernel/locking/spinlock.c:151
   spin_lock include/linux/spinlock.h:338 [inline]
   get_partial_node.isra.0.part.0+0x32/0x2f0 mm/slub.c:1873
   get_partial_node mm/slub.c:1870 [inline]
  <snip>

  write to 0xffff8ab24f403c48 of 4 bytes by task 167 on cpu 3:
   debug_spin_unlock kernel/locking/spinlock_debug.c:103 [inline]
   do_raw_spin_unlock+0xc9/0x1a0 kernel/locking/spinlock_debug.c:138
   __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:159 [inline]
   _raw_spin_unlock_irqrestore+0x2d/0x50 kernel/locking/spinlock.c:191
   spin_unlock_irqrestore include/linux/spinlock.h:393 [inline]
   free_debug_processing+0x1b3/0x210 mm/slub.c:1214
   __slab_free+0x292/0x400 mm/slub.c:2864
  <snip>

As a side-effect, with KCSAN, this eventually locks up the console, most
likely due to deadlock, e.g. .. -> printk lock -> spinlock_debug ->
KCSAN detects data race -> kcsan_print_report() -> printk lock ->
deadlock.

This fix will 1) avoid the data races, and 2) allow using lock debugging
together with KCSAN.

Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Marco Elver <elver@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/r/20191120155715.28089-1-elver@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-12 12:21:13 +01:00
arch powerpc/pmem: Fix kernel crash due to wrong range value usage in flush_dcache_range 2020-01-09 10:25:53 +01:00
block compat_ioctl: block: handle BLKGETZONESZ/BLKGETNRZONES 2020-01-09 10:19:58 +01:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto KEYS: asymmetric: return ENOMEM if akcipher_request_alloc() fails 2019-12-31 16:46:07 +01:00
Documentation dt-bindings: clock: renesas: rcar-usb2-clock-sel: Fix typo in example 2020-01-09 10:20:05 +01:00
drivers spi: fsl: Handle the single hardwired chipselect case 2020-01-12 12:21:13 +01:00
fs Btrfs: only associate the locked page with one async_chunk struct 2020-01-09 10:20:06 +01:00
include net: annotate lockless accesses to sk->sk_pacing_shift 2020-01-09 10:20:07 +01:00
init Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
ipc ipc/sem.c: convert to use built-in RCU list checking 2019-09-25 17:51:41 -07:00
kernel locking/spinlock/debug: Fix various data races 2020-01-12 12:21:13 +01:00
lib lib/ubsan: don't serialize UBSAN report 2020-01-09 10:20:07 +01:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm/hugetlb: defer freeing of huge pages if in non-task context 2020-01-09 10:20:07 +01:00
net hsr: fix a race condition in node list insertion and deletion 2020-01-09 10:20:07 +01:00
samples samples/trace_printk: Wait for IRQ work to finish 2020-01-09 10:20:00 +01:00
scripts gcc-plugins: make it possible to disable CONFIG_GCC_PLUGINS again 2020-01-09 10:19:57 +01:00
security apparmor: fix aa_xattrs_match() may sleep while holding a RCU lock 2020-01-09 10:20:00 +01:00
sound ASoC: max98090: fix possible race conditions 2020-01-12 12:21:12 +01:00
tools perf callchain: Fix segfault in thread__resolve_callchain_sample() 2020-01-09 10:20:02 +01:00
usr gen_initramfs_list.sh: fix 'bad variable name' error 2020-01-09 10:20:00 +01:00
virt KVM: arm/arm64: Properly handle faulting of device mappings 2019-12-31 16:46:24 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-22 14:28:14 -08:00
Makefile Linux 5.4.10 2020-01-09 10:25:53 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.