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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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Dmitry Antipov
4b81d155fe
[ Upstream commit4e86f32a13] Recently the kernel test robot has reported an ARM-specific BUILD_BUG_ON() in an old and unmaintained wil6210 wireless driver. The problem comes from the structure packing rules of old ARM ABI ('-mabi=apcs-gnu'). For example, the following structure is packed to 18 bytes instead of 16: struct poorly_packed { unsigned int a; unsigned int b; unsigned short c; union { struct { unsigned short d; unsigned int e; } __attribute__((packed)); struct { unsigned short d; unsigned int e; } __attribute__((packed)) inner; }; } __attribute__((packed)); To fit it into 16 bytes, it's required to add packed attribute to the container union as well: struct poorly_packed { unsigned int a; unsigned int b; unsigned short c; union { struct { unsigned short d; unsigned int e; } __attribute__((packed)); struct { unsigned short d; unsigned int e; } __attribute__((packed)) inner; } __attribute__((packed)); } __attribute__((packed)); Thanks to Andrew Pinski of GCC team for sorting the things out at https://gcc.gnu.org/pipermail/gcc/2023-November/242888.html. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202311150821.cI4yciFE-lkp@intel.com Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> Link: https://lore.kernel.org/r/20231120110607.98956-1-dmantipov@yandex.ru Fixes:50d7bd38c3("stddef: Introduce struct_group() helper macro") Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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.