Re: [PATCH] powerpc/powermac: Fix low_sleep_handler with KUAP and KUEP

From: Michael Ellerman
Date: Fri Sep 11 2020 - 09:46:09 EST


Christophe Leroy <christophe.leroy@xxxxxxxxxx> writes:
> Le 11/09/2020 à 01:56, Michael Ellerman a écrit :
>> Christophe Leroy <christophe.leroy@xxxxxxxxxx> writes:
>>> low_sleep_handler() has an hardcoded restore of segment registers
>>> that doesn't take KUAP and KUEP into account.
>>>
>>> Use head_32's load_segment_registers() routine instead.
>>>
>>> Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
>>> Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection")
>>> Fixes: 31ed2b13c48d ("powerpc/32s: Implement Kernel Userspace Execution Prevention.")
>>> Cc: stable@xxxxxxxxxxxxxxx
>>> ---
>>> arch/powerpc/platforms/powermac/sleep.S | 9 +--------
>>> 1 file changed, 1 insertion(+), 8 deletions(-)
>>
>> Doesn't build? pmac32_defconfig, gcc 9.3.0:
>>
>> ld: arch/powerpc/platforms/powermac/sleep.o: in function `core99_wake_up':
>> (.text+0x25c): undefined reference to `load_segment_registers'
>>
>> Missing _GLOBAL() presumably?
>
> Oops .. :(
>
> v2 sent out.

Thanks.

cheers