Christophe Leroy <christophe.le...@csgroup.eu> writes:
> Le 21/06/2019 à 10:58, Mathieu Malaterre a écrit :
>> When building with clang-8 the frame size limit is hit:
>>
>> ../arch/powerpc/lib/xor_vmx.c:119:6: error: stack frame size of 1200
>> bytes in function '__xor_altivec_5' [-Werror,-Wframe-larger-than=]
>>
>> Follow the same approach as commit 9c87156cce5a ("powerpc/xmon: Relax
>> frame size for clang") until a proper fix is implemented upstream in
>> clang and relax requirement for clang.
>
> With Clang 14 I get the following errors, but only with KASAN selected.
>
> CC arch/powerpc/lib/xor_vmx.o
> arch/powerpc/lib/xor_vmx.c:95:6: error: stack frame size (1040) exceeds
> limit (1024) in '__xor_altivec_4' [-Werror,-Wframe-larger-than]
> void __xor_altivec_4(unsigned long bytes,
> ^
> arch/powerpc/lib/xor_vmx.c:124:6: error: stack frame size (1312) exceeds
> limit (1024) in '__xor_altivec_5' [-Werror,-Wframe-larger-than]
> void __xor_altivec_5(unsigned long bytes,
> ^
That's a 32-bit build?
> Is this patch still relevant ?
The clang issue was closed because a different change fixed the issue:
https://github.com/ClangBuiltLinux/linux/issues/563
> Or should frame size be relaxed when KASAN is selected ? After all the
> stack size is multiplied by 2 when we have KASAN, so maybe the warning
> limit should be increased as well ?
Yeah that would make some sense.
On 64-bit the largest frame in that file is 1424, which is below the
default 2048 byte limit.
So maybe just increase it for 32-bit && KASAN.
What would be nice is if the FRAME_WARN value could be calculated as a
percentage of the THREAD_SHIFT, but that's not easily doable with the
way things are structured in Kconfig.
cheers
