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mm: mmu_notifier fix for tlb_end_vma

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The generic tlb_end_vma does not call invalidate_range mmu notifier, and
it resets resets the mmu_gather range, which means the notifier won't be
called on part of the range in case of an unmap that spans multiple
vmas.

ARM64 seems to be the only arch I could see that has notifiers and uses
the generic tlb_end_vma.  I have not actually tested it.

[ Catalin and Will point out that ARM64 currently only uses the
  notifiers for KVM, which doesn't use the ->invalidate_range()
  callback right now, so it's a bug, but one that happens to
  not affect them.  So not necessary for stable.  - Linus ]

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Nicholas Piggin 2018-08-23 18:47:09 +10:00 committed by Linus Torvalds
parent d86564a2f0
commit fd1102f0aa
2 changed files with 13 additions and 14 deletions
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17
include/asm-generic/tlb.h
View file

@ -15,6 +15,7 @@
#ifndef _ASM_GENERIC__TLB_H
#define _ASM_GENERIC__TLB_H
#include <linux/mmu_notifier.h>
#include <linux/swap.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
@ -138,6 +139,16 @@ static inline void __tlb_reset_range(struct mmu_gather *tlb)
}
}
static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
{
if (!tlb->end)
return;
tlb_flush(tlb);
mmu_notifier_invalidate_range(tlb->mm, tlb->start, tlb->end);
__tlb_reset_range(tlb);
}
static inline void tlb_remove_page_size(struct mmu_gather *tlb,
struct page *page, int page_size)
{
@ -186,10 +197,8 @@ static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb,
#define __tlb_end_vma(tlb, vma) \
do { \
if (!tlb->fullmm && tlb->end) { \
tlb_flush(tlb); \
__tlb_reset_range(tlb); \
} \
if (!tlb->fullmm) \
tlb_flush_mmu_tlbonly(tlb); \
} while (0)
#ifndef tlb_end_vma

10
mm/memory.c
View file

@ -238,16 +238,6 @@ void arch_tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
__tlb_reset_range(tlb);
}
static void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
{
if (!tlb->end)
return;
tlb_flush(tlb);
mmu_notifier_invalidate_range(tlb->mm, tlb->start, tlb->end);
__tlb_reset_range(tlb);
}
static void tlb_flush_mmu_free(struct mmu_gather *tlb)
{
struct mmu_gather_batch *batch;