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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2017-02-25 01:57:54 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-25 04:46:55 +0300
commita8fa41ad2f6f7ca08edd1afcf8149ae5a4dcf654 (patch)
tree5ec90b25a6e633bc61df880a9c179c2c094e35cf
parent699fa216808fff47efc9743f92f1b8a9f9bf5321 (diff)
downloadlinux-a8fa41ad2f6f7ca08edd1afcf8149ae5a4dcf654.tar.xz
mm, rmap: check all VMAs that PTE-mapped THP can be part of
Current rmap code can miss a VMA that maps PTE-mapped THP if the first suppage of the THP was unmapped from the VMA. We need to walk rmap for the whole range of offsets that THP covers, not only the first one. vma_address() also need to be corrected to check the range instead of the first subpage. Link: http://lkml.kernel.org/r/20170129173858.45174-6-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/internal.h9
-rw-r--r--mm/rmap.c16
2 files changed, 16 insertions, 9 deletions
diff --git a/mm/internal.h b/mm/internal.h
index 8ab72f4374e0..ccfc2a2969f4 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -335,12 +335,15 @@ __vma_address(struct page *page, struct vm_area_struct *vma)
static inline unsigned long
vma_address(struct page *page, struct vm_area_struct *vma)
{
- unsigned long address = __vma_address(page, vma);
+ unsigned long start, end;
+
+ start = __vma_address(page, vma);
+ end = start + PAGE_SIZE * (hpage_nr_pages(page) - 1);
/* page should be within @vma mapping range */
- VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma);
+ VM_BUG_ON_VMA(end < vma->vm_start || start >= vma->vm_end, vma);
- return address;
+ return max(start, vma->vm_start);
}
#else /* !CONFIG_MMU */
diff --git a/mm/rmap.c b/mm/rmap.c
index 0dff8accd629..c4bad599cc7b 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1757,7 +1757,7 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc,
bool locked)
{
struct anon_vma *anon_vma;
- pgoff_t pgoff;
+ pgoff_t pgoff_start, pgoff_end;
struct anon_vma_chain *avc;
int ret = SWAP_AGAIN;
@@ -1771,8 +1771,10 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc,
if (!anon_vma)
return ret;
- pgoff = page_to_pgoff(page);
- anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) {
+ pgoff_start = page_to_pgoff(page);
+ pgoff_end = pgoff_start + hpage_nr_pages(page) - 1;
+ anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root,
+ pgoff_start, pgoff_end) {
struct vm_area_struct *vma = avc->vma;
unsigned long address = vma_address(page, vma);
@@ -1810,7 +1812,7 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc,
bool locked)
{
struct address_space *mapping = page_mapping(page);
- pgoff_t pgoff;
+ pgoff_t pgoff_start, pgoff_end;
struct vm_area_struct *vma;
int ret = SWAP_AGAIN;
@@ -1825,10 +1827,12 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc,
if (!mapping)
return ret;
- pgoff = page_to_pgoff(page);
+ pgoff_start = page_to_pgoff(page);
+ pgoff_end = pgoff_start + hpage_nr_pages(page) - 1;
if (!locked)
i_mmap_lock_read(mapping);
- vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
+ vma_interval_tree_foreach(vma, &mapping->i_mmap,
+ pgoff_start, pgoff_end) {
unsigned long address = vma_address(page, vma);
cond_resched();