Commit 2c637d2d authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/powermac: Fix low_sleep_handler with KUAP and KUEP 



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.

Fixes: a68c31fc ("powerpc/32s: Implement Kernel Userspace Access Protection")
Fixes: 31ed2b13 ("powerpc/32s: Implement Kernel Userspace Execution Prevention.")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/21b05f7298c1b18f73e6e5b4cd5005aafa24b6da.1599820109.git.christophe.leroy@csgroup.eu
parent c83c192a

arch/powerpc/kernel/head_32.S

+1 −1
Original line number Diff line number Diff line
@@ -996,7 +996,7 @@ 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 */

arch/powerpc/platforms/powermac/sleep.S

+1 −8
Original line number Diff line number Diff line
@@ -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

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