Once CONFIG_KSTACK_ERASE is enabled with Clang on i386, the build warns:
kernel/kstack_erase.c:168:2: warning: function with attribute 'no_caller_saved_registers' should only call a function with attribute 'no_caller_saved_registers' or be compiled with '-mgeneral-regs-only' [-Wexcessive-regsave]
Add -mgeneral-regs-only for the kstack_erase handler, to make Clang feel
better (it is effectively a no-op flag for the kernel). No binary
changes encountered.
Build & boot tested with Clang 21 on x86_64, and i386.
Build tested with GCC 14.2.0 on x86_64, i386, arm64, and arm.
Reported-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/all/20250726004313.GA3650901@ax162
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <kees@kernel.org>
6676fd3c99