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-rw-r--r--include/linux/huge_mm.h2
-rw-r--r--mm/huge_memory.c10
-rw-r--r--mm/mremap.c30
3 files changed, 18 insertions, 24 deletions
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 99c19b06d9a4..fdcb45999b26 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -43,7 +43,7 @@ extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
unsigned char *vec);
extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
unsigned long new_addr, unsigned long old_end,
- pmd_t *old_pmd, pmd_t *new_pmd, bool *need_flush);
+ pmd_t *old_pmd, pmd_t *new_pmd);
extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, pgprot_t newprot,
int prot_numa);
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 58269f8ba7c4..deed97fba979 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1780,7 +1780,7 @@ static pmd_t move_soft_dirty_pmd(pmd_t pmd)
bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
unsigned long new_addr, unsigned long old_end,
- pmd_t *old_pmd, pmd_t *new_pmd, bool *need_flush)
+ pmd_t *old_pmd, pmd_t *new_pmd)
{
spinlock_t *old_ptl, *new_ptl;
pmd_t pmd;
@@ -1811,7 +1811,7 @@ bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
if (new_ptl != old_ptl)
spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING);
pmd = pmdp_huge_get_and_clear(mm, old_addr, old_pmd);
- if (pmd_present(pmd) && pmd_dirty(pmd))
+ if (pmd_present(pmd))
force_flush = true;
VM_BUG_ON(!pmd_none(*new_pmd));
@@ -1822,12 +1822,10 @@ bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
}
pmd = move_soft_dirty_pmd(pmd);
set_pmd_at(mm, new_addr, new_pmd, pmd);
- if (new_ptl != old_ptl)
- spin_unlock(new_ptl);
if (force_flush)
flush_tlb_range(vma, old_addr, old_addr + PMD_SIZE);
- else
- *need_flush = true;
+ if (new_ptl != old_ptl)
+ spin_unlock(new_ptl);
spin_unlock(old_ptl);
return true;
}
diff --git a/mm/mremap.c b/mm/mremap.c
index 5c2e18505f75..a9617e72e6b7 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -115,7 +115,7 @@ static pte_t move_soft_dirty_pte(pte_t pte)
static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
unsigned long old_addr, unsigned long old_end,
struct vm_area_struct *new_vma, pmd_t *new_pmd,
- unsigned long new_addr, bool need_rmap_locks, bool *need_flush)
+ unsigned long new_addr, bool need_rmap_locks)
{
struct mm_struct *mm = vma->vm_mm;
pte_t *old_pte, *new_pte, pte;
@@ -163,15 +163,17 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
pte = ptep_get_and_clear(mm, old_addr, old_pte);
/*
- * If we are remapping a dirty PTE, make sure
+ * If we are remapping a valid PTE, make sure
* to flush TLB before we drop the PTL for the
- * old PTE or we may race with page_mkclean().
+ * PTE.
*
- * This check has to be done after we removed the
- * old PTE from page tables or another thread may
- * dirty it after the check and before the removal.
+ * NOTE! Both old and new PTL matter: the old one
+ * for racing with page_mkclean(), the new one to
+ * make sure the physical page stays valid until
+ * the TLB entry for the old mapping has been
+ * flushed.
*/
- if (pte_present(pte) && pte_dirty(pte))
+ if (pte_present(pte))
force_flush = true;
pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr);
pte = move_soft_dirty_pte(pte);
@@ -179,13 +181,11 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
}
arch_leave_lazy_mmu_mode();
+ if (force_flush)
+ flush_tlb_range(vma, old_end - len, old_end);
if (new_ptl != old_ptl)
spin_unlock(new_ptl);
pte_unmap(new_pte - 1);
- if (force_flush)
- flush_tlb_range(vma, old_end - len, old_end);
- else
- *need_flush = true;
pte_unmap_unlock(old_pte - 1, old_ptl);
if (need_rmap_locks)
drop_rmap_locks(vma);
@@ -198,7 +198,6 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
{
unsigned long extent, next, old_end;
pmd_t *old_pmd, *new_pmd;
- bool need_flush = false;
unsigned long mmun_start; /* For mmu_notifiers */
unsigned long mmun_end; /* For mmu_notifiers */
@@ -229,8 +228,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
if (need_rmap_locks)
take_rmap_locks(vma);
moved = move_huge_pmd(vma, old_addr, new_addr,
- old_end, old_pmd, new_pmd,
- &need_flush);
+ old_end, old_pmd, new_pmd);
if (need_rmap_locks)
drop_rmap_locks(vma);
if (moved)
@@ -246,10 +244,8 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
if (extent > next - new_addr)
extent = next - new_addr;
move_ptes(vma, old_pmd, old_addr, old_addr + extent, new_vma,
- new_pmd, new_addr, need_rmap_locks, &need_flush);
+ new_pmd, new_addr, need_rmap_locks);
}
- if (need_flush)
- flush_tlb_range(vma, old_end-len, old_addr);
mmu_notifier_invalidate_range_end(vma->vm_mm, mmun_start, mmun_end);