Re: [PATCH] powerpc/signal32: Use struct_group() to zero spe regs

[Michael Ellerman]

Kees Cook <keescook@xxxxxxxxxxxx> writes:
> On Mon, Nov 22, 2021 at 04:43:36PM +1100, Michael Ellerman wrote:
>> LEROY Christophe <christophe.leroy@xxxxxxxxxx> writes:
>> > Le 18/11/2021 à 21:36, Kees Cook a écrit :
>> >> In preparation for FORTIFY_SOURCE performing compile-time and run-time
>> >> field bounds checking for memset(), avoid intentionally writing across
>> >> neighboring fields.
>> >> 
>> >> Add a struct_group() for the spe registers so that memset() can correctly reason
>> >> about the size:
>> >> 
>> >>     In function 'fortify_memset_chk',
>> >>         inlined from 'restore_user_regs.part.0' at arch/powerpc/kernel/signal_32.c:539:3:
>> >>     >> include/linux/fortify-string.h:195:4: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
>> >>       195 |    __write_overflow_field();
>> >>           |    ^~~~~~~~~~~~~~~~~~~~~~~~
>> >> 
>> >> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>> >> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
>> >
>> > Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
>> 
>> Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
>
> Thanks! Should I take this via my tree, or do you want to take it via
> ppc?

I don't mind. If it's easier for you to take it as part of an existing
series then do that, otherwise I can pick it up.

cheers