Thread (4 messages) flat view 4 messages, 2 authors, 2020-09-11
STALE2162d

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

From: Christophe Leroy <hidden>
Date: 2020-09-01 07:35:49
Also in: lkml
Subsystem: linux for power macintosh, linux for powerpc (32-bit and 64-bit), the rest · Maintainers: Madhavan Srinivasan, Linus Torvalds

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(-)
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
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