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 <[email protected]>
Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection")
Fixes: 31ed2b13c48d ("powerpc/32s: Implement Kernel Userspace Execution Prevention.")
Cc: [email protected]
---
v2: Added missing _GLOBAL() to load_segment_registers in head_32.S
---
arch/powerpc/kernel/head_32.S | 2 +-
arch/powerpc/platforms/powermac/sleep.S | 9 +--------
2 files changed, 2 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 5624db0e09a1..0f60743474a2 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -1002,7 +1002,7 @@ BEGIN_MMU_FTR_SECTION
END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
blr
-load_segment_registers:
+_GLOBAL(load_segment_registers)
li r0, NUM_USER_SEGMENTS /* load up user segment register values */
mtctr r0 /* for context 0 */
li r3, 0 /* Kp = 0, Ks = 0, VSID = 0 */
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
On Fri, 11 Sep 2020 10:29:15 +0000 (UTC), Christophe Leroy wrote:
> 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.
Applied to powerpc/next.
[1/1] powerpc/powermac: Fix low_sleep_handler with KUAP and KUEP
https://git.kernel.org/powerpc/c/2c637d2df4ee4830e9d3eb2bd5412250522ce96e
cheers