Re: [PATCH v2] MIPS: Only use current_stack_pointer on GCC

[Thomas Bogendoerfer]

On Wed, Mar 09, 2022 at 02:09:39PM -0800, Kees Cook wrote:
> Unfortunately, Clang did not have support for "sp" as a global register
> definition, and was crashing after the addition of current_stack_pointer.
> This has been fixed in Clang 15, but earlier Clang versions need to
> avoid this code, so add a versioned test and revert back to the
> open-coded asm instances. Fixes Clang build error:
> 
> fatal error: error in backend: Invalid register name global variable
> 
> Fixes: 200ed341b864 ("mips: Implement "current_stack_pointer"")
> Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> Link: https://lore.kernel.org/lkml/YikTQRql+il3HbrK@dev-arch.thelio-3990X
> Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> Cc: Marc Zyngier <maz@xxxxxxxxxx>
> Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
> Cc: Yanteng Si <siyanteng01@xxxxxxxxx>
> Cc: linux-mips@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> ---
> v1: https://lore.kernel.org/lkml/20220309204537.390428-1-keescook@xxxxxxxxxxxx
> v2: - adjust Clang version (Nathan)
> ---
>  arch/mips/Kconfig                   | 2 +-
>  arch/mips/include/asm/thread_info.h | 2 ++
>  arch/mips/kernel/irq.c              | 3 ++-
>  arch/mips/lib/uncached.c            | 4 +++-
>  4 files changed, 8 insertions(+), 3 deletions(-)

applied to mips-next with the Clang version in the decscription fixed.

Thomas.

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