Christophe Leroy <christophe.le...@csgroup.eu> 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.le...@csgroup.eu>
> Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access
> Protection")
> Fixes: 31ed2b13c48d ("powerpc/32s: Implement Kernel Userspace Execution
> Prevention.")
> Cc: sta...@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?
cheers
> diff --git a/arch/powerpc/platforms/powermac/sleep.S
> b/arch/powerpc/platforms/powermac/sleep.S
> index f9a680fdd9c4..51bfdfe85058 100644
> --- a/arch/powerpc/platforms/powermac/sleep.S
> +++ b/arch/powerpc/platforms/powermac/sleep.S
> @@ -294,14 +294,7 @@ grackle_wake_up:
> * we do any r1 memory access as we are not sure they
> * are in a sane state above the first 256Mb region
> */
> - li r0,16 /* load up segment register values */
> - mtctr r0 /* for context 0 */
> - lis r3,0x2000 /* Ku = 1, VSID = 0 */
> - li r4,0
> -3: mtsrin r3,r4
> - addi r3,r3,0x111 /* increment VSID */
> - addis r4,r4,0x1000 /* address of next segment */
> - bdnz 3b
> + bl load_segment_registers
> sync
> isync
>
> --
> 2.25.0
