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Commit 62453188 authored by Will Deacon's avatar Will Deacon Committed by Russell King
Browse files

ARM: 8578/1: mm: ensure pmd_present only checks the valid bit 



In a subsequent patch, pmd_mknotpresent will clear the valid bit of the
pmd entry, resulting in a not-present entry from the hardware's
perspective. Unfortunately, pmd_present simply checks for a non-zero pmd
value and will therefore continue to return true even after a
pmd_mknotpresent operation. Since pmd_mknotpresent is only used for
managing huge entries, this is only an issue for the 3-level case.

This patch fixes the 3-level pmd_present implementation to take into
account the valid bit. For bisectability, the change is made before the
fix to pmd_mknotpresent.

[catalin.marinas@arm.com: comment update regarding pmd_mknotpresent patch]

Fixes: 8d962507 ("ARM: mm: Transparent huge page support for LPAE systems.")
Cc: <stable@vger.kernel.org> # 3.11+
Cc: Russell King <linux@armlinux.org.uk>
Cc: Steve Capper <Steve.Capper@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent af8c34ce

arch/arm/include/asm/pgtable-2level.h

+1 −0
Original line number Diff line number Diff line
@@ -193,6 +193,7 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr) 


#define pmd_large(pmd)		(pmd_val(pmd) & 2)

#define pmd_bad(pmd)		(pmd_val(pmd) & 2)

#define pmd_present(pmd)	(pmd_val(pmd))



#define copy_pmd(pmdpd,pmdps)		\

	do {				\

arch/arm/include/asm/pgtable-3level.h

+1 −0
Original line number Diff line number Diff line
@@ -211,6 +211,7 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr) 
						: !!(pmd_val(pmd) & (val)))

#define pmd_isclear(pmd, val)	(!(pmd_val(pmd) & (val)))



#define pmd_present(pmd)	(pmd_isset((pmd), L_PMD_SECT_VALID))

#define pmd_young(pmd)		(pmd_isset((pmd), PMD_SECT_AF))

#define pte_special(pte)	(pte_isset((pte), L_PTE_SPECIAL))

static inline pte_t pte_mkspecial(pte_t pte)

arch/arm/include/asm/pgtable.h

+0 −1
Original line number Diff line number Diff line
@@ -182,7 +182,6 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; 
#define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)



#define pmd_none(pmd)		(!pmd_val(pmd))

#define pmd_present(pmd)	(pmd_val(pmd))



static inline pte_t *pmd_page_vaddr(pmd_t pmd)

{