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Guilherme G. Piccoli 96414e2cdc coresight: cpu-debug: Replace mutex with mutex_trylock on panic notifier
[ Upstream commit 1adff542d6 ]

The panic notifier infrastructure executes registered callbacks when
a panic event happens - such callbacks are executed in atomic context,
with interrupts and preemption disabled in the running CPU and all other
CPUs disabled. That said, mutexes in such context are not a good idea.

This patch replaces a regular mutex with a mutex_trylock safer approach;
given the nature of the mutex used in the driver, it should be pretty
uncommon being unable to acquire such mutex in the panic path, hence
no functional change should be observed (and if it is, that would be
likely a deadlock with the regular mutex).

Fixes: 2227b7c746 ("coresight: add support for CPU debug module")
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20220427224924.592546-10-gpiccoli@igalia.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:32:32 +02:00
arch MIPS: IP30: Remove incorrect `cpu_has_fpu' override 2022-06-09 10:21:31 +02:00
block block: fix bio_clone_blkg_association() to associate with proper blkcg_gq 2022-06-09 10:21:31 +02:00
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: cryptd - Protect per-CPU resource by disabling BH. 2022-06-09 10:21:17 +02:00
Documentation dt-bindings: gpio: altera: correct interrupt-cells 2022-06-09 10:21:29 +02:00
drivers coresight: cpu-debug: Replace mutex with mutex_trylock on panic notifier 2022-06-14 18:32:32 +02:00
fs ext4: only allow test_dummy_encryption when supported 2022-06-09 10:21:31 +02:00
include nodemask.h: fix compilation error with GCC12 2022-06-09 10:21:27 +02:00
init Kconfig: Add option for asm goto w/ tied outputs to workaround clang-13 bug 2022-06-09 10:21:25 +02:00
ipc ipc/mqueue: use get_tree_nodev() in mqueue_get_tree() 2022-06-09 10:21:17 +02:00
kernel ftrace: Clean up hash direct_functions on register failures 2022-06-09 10:21:26 +02:00
lib lib/crypto: add prompts back to crypto libraries 2022-06-06 08:42:42 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm hugetlb: fix huge_pmd_unshare address update 2022-06-09 10:21:27 +02:00
net mac80211: upgrade passive scan to active scan on DFS channels after beacon rx 2022-06-09 10:21:26 +02:00
samples samples/bpf, xdpsock: Fix race when running for fix duration of time 2022-04-08 14:40:21 +02:00
scripts scripts/faddr2line: Fix overlapping text section failures 2022-06-09 10:21:08 +02:00
security ima: remove the IMA_TEMPLATE Kconfig option 2022-06-09 10:21:25 +02:00
sound ASoC: rt5514: Fix event generation for "DSP Voice Wake Up" control 2022-06-09 10:21:27 +02:00
tools kseltest/cgroup: Make test_stress.sh work if run interactively 2022-06-09 10:21:30 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:25:48 +01:00
virt KVM: Prevent module exit until all VMs are freed 2022-04-08 14:40:38 +02:00
.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: add git tree for random.c 2022-05-30 09:33:24 +02:00
Makefile Linux 5.10.121 2022-06-09 10:21:31 +02:00
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.