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

Le 11/09/2020 à 01:56, Michael Ellerman a écrit :

Christophe Leroy [off-list ref] writes:

quoted

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 <redacted>
Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection")
Fixes: 31ed2b13c48d ("powerpc/32s: Implement Kernel Userspace Execution Prevention.")
Cc: stable@vger.kernel.org
---
  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
Christophe