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.
WANG Xuerui
authored
As explained by Nick in the original issue: the kernel usually does a good job of providing library helpers that have similar semantics as their ordinary userspace libc equivalents, but -ffreestanding disables such libcall optimization and other related features in the compiler, which can lead to unexpected things such as CONFIG_FORTIFY_SOURCE not working (!). However, due to the desire for better control over unaligned accesses with respect to CONFIG_ARCH_STRICT_ALIGN, and also for avoiding the GCC bug https://gcc.gnu.org/PR109465, we do want to still disable optimizations for the memory libcalls (memcpy, memmove and memset for now). Use finer-grained -fno-builtin-* toggles to achieve this without losing source fortification and other libcall optimizations. Closes: https://github.com/ClangBuiltLinux/linux/issues/1897 Reported-by:Nathan Chancellor <nathan@kernel.org> Suggested-by:
Nick Desaulniers <ndesaulniers@google.com> Signed-off-by:
WANG Xuerui <git@xen0n.name> Signed-off-by:
Huacai Chen <chenhuacai@loongson.cn>