Commit fd1102f0 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Linus Torvalds
Browse files

mm: mmu_notifier fix for tlb_end_vma 



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: default avatarNicholas Piggin <npiggin@gmail.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d86564a2

include/asm-generic/tlb.h

+13 −4
Original line number Diff line number Diff line
@@ -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

mm/memory.c

+0 −10
Original line number Diff line number Diff line
@@ -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;

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