From: Christophe Leroy <christophe.leroy@csgroup.eu>
Date: Sat, 10 Oct 2020 15:14:29 +0000 (+0000)
Subject: powerpc/40x: Always fault when _PAGE_ACCESSED is not set
X-Git-Tag: howlett/maple_spf/20210104~603^2~3
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=0540b0d2ce9073fd2a736d636218faa61c99e572;p=users%2Fjedix%2Flinux-maple.git

powerpc/40x: Always fault when _PAGE_ACCESSED is not set

The kernel expects pte_young() to work regardless of CONFIG_SWAP.

Make sure a minor fault is taken to set _PAGE_ACCESSED when it
is not already set, regardless of the selection of CONFIG_SWAP.

Fixes: 2c74e2586bb9 ("powerpc/40x: Rework 40x PTE access and TLB miss")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b02ca2ed2d3676a096219b48c0f69ec982a75bcf.1602342801.git.christophe.leroy@csgroup.eu
---

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 44c9018aed1b..a1ae00689e0f 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -284,11 +284,7 @@ _ENTRY(saved_ksp_limit)
 
 	rlwimi	r11, r10, 22, 20, 29	/* Compute PTE address */
 	lwz	r11, 0(r11)		/* Get Linux PTE */
-#ifdef CONFIG_SWAP
 	li	r9, _PAGE_PRESENT | _PAGE_ACCESSED
-#else
-	li	r9, _PAGE_PRESENT
-#endif
 	andc.	r9, r9, r11		/* Check permission */
 	bne	5f
 
@@ -369,11 +365,7 @@ _ENTRY(saved_ksp_limit)
 
 	rlwimi	r11, r10, 22, 20, 29	/* Compute PTE address */
 	lwz	r11, 0(r11)		/* Get Linux PTE */
-#ifdef CONFIG_SWAP
 	li	r9, _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
-#else
-	li	r9, _PAGE_PRESENT | _PAGE_EXEC
-#endif
 	andc.	r9, r9, r11		/* Check permission */
 	bne	5f