8d16ce1488
Code sections in s390 specific kernel code which use floating point or vector registers all come with a 520 byte stack variable to save already in use registers, if required. With INIT_STACK_ALL_PATTERN or INIT_STACK_ALL_ZERO enabled this variable will always be initialized on function entry in addition to saving register contents, which contradicts the intention (performance improvement) of such code sections. Therefore provide a DECLARE_KERNEL_FPU_ONSTACK() macro which provides struct kernel_fpu variables with an __uninitialized attribute, and convert all existing code to use this. This way only this specific type of stack variable will not be initialized, regardless of config options. Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20240205154844.3757121-3-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.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.