diff options
| author | Will Deacon <will@kernel.org> | 2020-11-20 13:57:48 +0000 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-11-23 16:13:18 +0000 |
| commit | ff1712f953e27f0b0718762ec17d0adb15c9fd0b (patch) | |
| tree | 1c6478eb4d7c2454a16df7c38f34ef5d4b567ed3 /arch | |
| parent | 07509e10dcc77627f8b6a57381e878fe269958d3 (diff) | |
| download | linux-ff1712f953e27f0b0718762ec17d0adb15c9fd0b.tar.gz | |
arm64: pgtable: Ensure dirty bit is preserved across pte_wrprotect()
With hardware dirty bit management, calling pte_wrprotect() on a writable,
dirty PTE will lose the dirty state and return a read-only, clean entry.
Move the logic from ptep_set_wrprotect() into pte_wrprotect() to ensure that
the dirty bit is preserved for writable entries, as this is required for
soft-dirty bit management if we enable it in the future.
Cc: <stable@vger.kernel.org>
Fixes: 2f4b829c625e ("arm64: Add support for hardware updates of the access and dirty pte bits")
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20201120143557.6715-3-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/include/asm/pgtable.h | 27 |
1 files changed, 14 insertions, 13 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 326c34677e86..5628289b9d5e 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -165,13 +165,6 @@ static inline pmd_t set_pmd_bit(pmd_t pmd, pgprot_t prot) return pmd; } -static inline pte_t pte_wrprotect(pte_t pte) -{ - pte = clear_pte_bit(pte, __pgprot(PTE_WRITE)); - pte = set_pte_bit(pte, __pgprot(PTE_RDONLY)); - return pte; -} - static inline pte_t pte_mkwrite(pte_t pte) { pte = set_pte_bit(pte, __pgprot(PTE_WRITE)); @@ -197,6 +190,20 @@ static inline pte_t pte_mkdirty(pte_t pte) return pte; } +static inline pte_t pte_wrprotect(pte_t pte) +{ + /* + * If hardware-dirty (PTE_WRITE/DBM bit set and PTE_RDONLY + * clear), set the PTE_DIRTY bit. + */ + if (pte_hw_dirty(pte)) + pte = pte_mkdirty(pte); + + pte = clear_pte_bit(pte, __pgprot(PTE_WRITE)); + pte = set_pte_bit(pte, __pgprot(PTE_RDONLY)); + return pte; +} + static inline pte_t pte_mkold(pte_t pte) { return clear_pte_bit(pte, __pgprot(PTE_AF)); @@ -846,12 +853,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres pte = READ_ONCE(*ptep); do { old_pte = pte; - /* - * If hardware-dirty (PTE_WRITE/DBM bit set and PTE_RDONLY - * clear), set the PTE_DIRTY bit. - */ - if (pte_hw_dirty(pte)) - pte = pte_mkdirty(pte); pte = pte_wrprotect(pte); pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep), pte_val(old_pte), pte_val(pte)); |