21b8a1dd56
With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. msc313_rtc_probe() was passing clk_disable_unprepare() directly, which did not have matching prototypes for devm_add_action_or_reset()'s callback argument. Refactor to use devm_clk_get_enabled() instead. This was found as a result of Clang's new -Wcast-function-type-strict flag, which is more sensitive than the simpler -Wcast-function-type, which only checks for type width mismatches. Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/lkml/202211041527.HD8TLSE1-lkp@intel.com Suggested-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Daniel Palmer <daniel@thingy.jp> Cc: Romain Perier <romain.perier@gmail.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-rtc@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Daniel Palmer <daniel@thingy.jp> Tested-by: Daniel Palmer <daniel@thingy.jp> Link: https://lore.kernel.org/r/20221202184525.gonna.423-kees@kernel.org Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.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.