Linux kernel source tree
Go to file
Nicholas Piggin 75e2cfa5fa powerpc/watchdog: Fix missed watchdog reset due to memory ordering race
[ Upstream commit 5dad4ba68a ]

It is possible for all CPUs to miss the pending cpumask becoming clear,
and then nobody resetting it, which will cause the lockup detector to
stop working. It will eventually expire, but watchdog_smp_panic will
avoid doing anything if the pending mask is clear and it will never be
reset.

Order the cpumask clear vs the subsequent test to close this race.

Add an extra check for an empty pending mask when the watchdog fires and
finds its bit still clear, to try to catch any other possible races or
bugs here and keep the watchdog working. The extra test in
arch_touch_nmi_watchdog is required to prevent the new warning from
firing off.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Debugged-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211110025056.2084347-2-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 10:54:21 +01:00
arch powerpc/watchdog: Fix missed watchdog reset due to memory ordering race 2022-01-27 10:54:21 +01:00
block scsi: block: pm: Always set request queue runtime active in blk_post_runtime_resume() 2022-01-27 10:54:08 +01:00
certs certs: Trigger creation of RSA module signing key if it's not an RSA key 2021-09-15 09:50:29 +02:00
crypto crypto: jitter - consider 32 LSB for APT 2022-01-27 10:54:12 +01:00
Documentation counter: stm32-lptimer-cnt: remove iio counter abi 2022-01-27 10:54:08 +01:00
drivers random: do not throw away excess input to crng_fast_load 2022-01-27 10:54:20 +01:00
fs btrfs: remove BUG_ON(!eie) in find_parent_nodes 2022-01-27 10:54:19 +01:00
include ACPICA: actypes.h: Expand the ACPI_ACCESS_ definitions 2022-01-27 10:54:18 +01:00
init bpf: Add kconfig knob for disabling unpriv bpf by default 2022-01-05 12:40:34 +01:00
ipc shm: extend forced shm destroy to support objects from several IPC nses 2021-12-01 09:19:10 +01:00
kernel audit: ensure userspace is penalized the same as the kernel when under pressure 2022-01-27 10:54:16 +01:00
lib lib/mpi: Add the return value check of kcalloc() 2022-01-27 10:54:02 +01:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm shmem: fix a race between shmem_unused_huge_shrink and shmem_evict_inode 2022-01-27 10:53:44 +01:00
net mac80211: allow non-standard VHT MCS-10/11 2022-01-27 10:54:19 +01:00
samples ftrace/samples: Add missing prototypes direct functions 2022-01-11 15:25:00 +01:00
scripts recordmcount.pl: fix typo in s390 mcount regex 2022-01-05 12:40:29 +01:00
security selinux: fix potential memleak in selinux_add_opt() 2022-01-27 10:53:58 +01:00
sound ASoC: fsl_asrc: refine the check of available clock divider 2022-01-27 10:54:09 +01:00
tools selftests/ftrace: make kprobe profile testcase description unique 2022-01-27 10:54:15 +01:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: downgrade two BUG_ONs to WARN_ON_ONCE 2021-12-22 09:30:50 +01:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: adjust GCC PLUGINS after gcc-plugin.sh removal 2021-12-14 11:32:46 +01:00
Makefile Linux 5.10.93 2022-01-20 09:17:52 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.