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: 2227b7c74634 ("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
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.