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Diffstat (limited to 'mm/mremap.c')
-rw-r--r--mm/mremap.c42
1 files changed, 30 insertions, 12 deletions
diff --git a/mm/mremap.c b/mm/mremap.c
index 506fa44403df..d6959cb4df58 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -41,8 +41,7 @@ static pmd_t *get_old_pmd(struct mm_struct *mm, unsigned long addr)
return NULL;
pmd = pmd_offset(pud, addr);
- split_huge_page_pmd(mm, pmd);
- if (pmd_none_or_clear_bad(pmd))
+ if (pmd_none(*pmd))
return NULL;
return pmd;
@@ -65,8 +64,6 @@ static pmd_t *alloc_new_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
return NULL;
VM_BUG_ON(pmd_trans_huge(*pmd));
- if (pmd_none(*pmd) && __pte_alloc(mm, vma, pmd, addr))
- return NULL;
return pmd;
}
@@ -80,11 +77,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
struct mm_struct *mm = vma->vm_mm;
pte_t *old_pte, *new_pte, pte;
spinlock_t *old_ptl, *new_ptl;
- unsigned long old_start;
- old_start = old_addr;
- mmu_notifier_invalidate_range_start(vma->vm_mm,
- old_start, old_end);
if (vma->vm_file) {
/*
* Subtle point from Rajesh Venkatasubramanian: before
@@ -111,7 +104,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
new_pte++, new_addr += PAGE_SIZE) {
if (pte_none(*old_pte))
continue;
- pte = ptep_clear_flush(vma, old_addr, old_pte);
+ pte = ptep_get_and_clear(mm, old_addr, old_pte);
pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr);
set_pte_at(mm, new_addr, new_pte, pte);
}
@@ -123,7 +116,6 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
pte_unmap_unlock(old_pte - 1, old_ptl);
if (mapping)
mutex_unlock(&mapping->i_mmap_mutex);
- mmu_notifier_invalidate_range_end(vma->vm_mm, old_start, old_end);
}
#define LATENCY_LIMIT (64 * PAGE_SIZE)
@@ -134,22 +126,43 @@ 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;
old_end = old_addr + len;
flush_cache_range(vma, old_addr, old_end);
+ mmu_notifier_invalidate_range_start(vma->vm_mm, old_addr, old_end);
+
for (; old_addr < old_end; old_addr += extent, new_addr += extent) {
cond_resched();
next = (old_addr + PMD_SIZE) & PMD_MASK;
- if (next - 1 > old_end)
- next = old_end;
+ /* even if next overflowed, extent below will be ok */
extent = next - old_addr;
+ if (extent > old_end - old_addr)
+ extent = old_end - old_addr;
old_pmd = get_old_pmd(vma->vm_mm, old_addr);
if (!old_pmd)
continue;
new_pmd = alloc_new_pmd(vma->vm_mm, vma, new_addr);
if (!new_pmd)
break;
+ if (pmd_trans_huge(*old_pmd)) {
+ int err = 0;
+ if (extent == HPAGE_PMD_SIZE)
+ err = move_huge_pmd(vma, new_vma, old_addr,
+ new_addr, old_end,
+ old_pmd, new_pmd);
+ if (err > 0) {
+ need_flush = true;
+ continue;
+ } else if (!err) {
+ split_huge_page_pmd(vma->vm_mm, old_pmd);
+ }
+ VM_BUG_ON(pmd_trans_huge(*old_pmd));
+ }
+ if (pmd_none(*new_pmd) && __pte_alloc(new_vma->vm_mm, new_vma,
+ new_pmd, new_addr))
+ break;
next = (new_addr + PMD_SIZE) & PMD_MASK;
if (extent > next - new_addr)
extent = next - new_addr;
@@ -157,7 +170,12 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
extent = LATENCY_LIMIT;
move_ptes(vma, old_pmd, old_addr, old_addr + extent,
new_vma, new_pmd, new_addr);
+ need_flush = true;
}
+ if (likely(need_flush))
+ flush_tlb_range(vma, old_end-len, old_addr);
+
+ mmu_notifier_invalidate_range_end(vma->vm_mm, old_end-len, old_end);
return len + old_addr - old_end; /* how much done */
}