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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
Subject: [PATCH 6/6] mm: proc: Avoid fullmm flush for young/dirty bit toggling
Date: Fri, 20 Nov 2020 14:35:57 +0000	[thread overview]
Message-ID: <20201120143557.6715-7-will@kernel.org> (raw)
In-Reply-To: <20201120143557.6715-1-will@kernel.org>

clear_refs_write() uses the 'fullmm' API for invalidating TLBs after
updating the page-tables for the current mm. However, since the mm is not
being freed, this can result in stale TLB entries on architectures which
elide 'fullmm' invalidation.

Ensure that TLB invalidation is performed after updating soft-dirty
entries via clear_refs_write() by using the non-fullmm API to MMU gather.

Signed-off-by: Will Deacon <will@kernel.org>
---
 fs/proc/task_mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index a76d339b5754..316af047f1aa 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1238,7 +1238,7 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
 			count = -EINTR;
 			goto out_mm;
 		}
-		tlb_gather_mmu_fullmm(&tlb, mm);
+		tlb_gather_mmu(&tlb, mm, 0, TASK_SIZE);
 		if (type == CLEAR_REFS_SOFT_DIRTY) {
 			for (vma = mm->mmap; vma; vma = vma->vm_next) {
 				if (!(vma->vm_flags & VM_SOFTDIRTY))
-- 
2.29.2.454.gaff20da3a2-goog



  parent reply	other threads:[~2020-11-20 14:36 UTC|newest]

Thread overview: 43+ 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 ` [PATCH 2/6] arm64: pgtable: Ensure dirty bit is preserved across pte_wrprotect() Will Deacon
2020-11-20 17:09   ` 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
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 ` Will Deacon [this message]
2020-11-20 17:41   ` [PATCH 6/6] mm: proc: Avoid fullmm flush for young/dirty bit toggling 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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