Commit 0540b0d2 authored Oct 10, 2020 by Christophe Leroy Committed by Michael Ellerman Nov 05, 2020

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: 2c74e258 ("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

parent 11522448

arch/powerpc/kernel/head_40x.S

+0 −8

Original line number	Diff line number	Diff line
		@@ -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