From: Will Deacon <will@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: kernel-team@android.com, Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Yu Zhao <yuzhao@google.com>, Minchan Kim <minchan@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Anshuman Khandual <anshuman.khandual@arm.com>,
linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org,
stable@vger.kernel.org
Subject: [PATCH 2/6] arm64: pgtable: Ensure dirty bit is preserved across pte_wrprotect()
Date: Fri, 20 Nov 2020 14:35:53 +0000 [thread overview]
Message-ID: <20201120143557.6715-3-will@kernel.org> (raw)
In-Reply-To: <20201120143557.6715-1-will@kernel.org>
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>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/pgtable.h | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 1bdf51f01e73..a155551863c9 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -162,13 +162,6 @@ 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));
@@ -194,6 +187,20 @@ 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));
@@ -843,12 +850,6 @@ 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));
--
2.29.2.454.gaff20da3a2-goog
next prev parent reply other threads:[~2020-11-20 14:36 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-20 14:35 [PATCH 0/6] tlb: Fix access and (soft-)dirty bit management Will Deacon
2020-11-20 14:35 ` [PATCH 1/6] arm64: pgtable: Fix pte_accessible() Will Deacon
2020-11-20 16:03 ` Minchan Kim
2020-11-20 19:53 ` Yu Zhao
2020-11-23 13:27 ` Catalin Marinas
2020-11-24 10:02 ` Anshuman Khandual
2020-11-20 14:35 ` Will Deacon [this message]
2020-11-20 17:09 ` [PATCH 2/6] arm64: pgtable: Ensure dirty bit is preserved across pte_wrprotect() Minchan Kim
2020-11-23 14:31 ` Catalin Marinas
2020-11-23 14:22 ` Catalin Marinas
2020-11-20 14:35 ` [PATCH 3/6] tlb: mmu_gather: Remove unused start/end arguments from tlb_finish_mmu() Will Deacon
2020-11-20 17:20 ` Linus Torvalds
2020-11-23 16:48 ` Will Deacon
2020-11-20 14:35 ` [PATCH 4/6] mm: proc: Invalidate TLB after clearing soft-dirty page state Will Deacon
2020-11-20 15:00 ` Peter Zijlstra
2020-11-20 15:09 ` Peter Zijlstra
2020-11-20 15:15 ` Will Deacon
2020-11-20 15:27 ` Peter Zijlstra
2020-11-23 18:23 ` Will Deacon
2020-11-20 15:55 ` Minchan Kim
2020-11-23 18:41 ` Will Deacon
2020-11-25 22:51 ` Minchan Kim
2020-11-20 20:22 ` Yu Zhao
2020-11-21 2:49 ` Yu Zhao
2020-11-23 19:21 ` Yu Zhao
2020-11-23 22:04 ` Will Deacon
2020-11-20 14:35 ` [PATCH 5/6] tlb: mmu_gather: Introduce tlb_gather_mmu_fullmm() Will Deacon
2020-11-20 17:22 ` Linus Torvalds
2020-11-20 17:31 ` Linus Torvalds
2020-11-23 16:48 ` Will Deacon
2021-02-01 11:32 ` [tip: core/mm] tlb: mmu_gather: Remove start/end arguments from tlb_gather_mmu() tip-bot2 for Will Deacon
2020-11-22 15:11 ` [tlb] e242a269fa: WARNING:at_mm/mmu_gather.c:#tlb_gather_mmu kernel test robot
2020-11-23 17:51 ` Will Deacon
2020-11-20 14:35 ` [PATCH 6/6] mm: proc: Avoid fullmm flush for young/dirty bit toggling Will Deacon
2020-11-20 17:41 ` Linus Torvalds
2020-11-20 17:45 ` Linus Torvalds
2020-11-20 20:40 ` Yu Zhao
2020-11-23 18:35 ` Will Deacon
2020-11-23 20:04 ` Yu Zhao
2020-11-23 21:17 ` Will Deacon
2020-11-24 1:13 ` Yu Zhao
2020-11-24 14:31 ` Will Deacon
2020-11-25 22:01 ` Minchan Kim
2020-11-24 14:46 ` Peter Zijlstra
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