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authorDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>2009-10-26 16:50:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-10-29 07:39:32 -0700
commitc36987e2ef32e1bb7850379515f21187cba44754 (patch)
tree0b0a6b6a54c2a80de86426a74367ec4b1f089b61
parentlis3: add support for the HP HDX 18 (diff)
downloadlinux-dev-c36987e2ef32e1bb7850379515f21187cba44754.tar.xz
linux-dev-c36987e2ef32e1bb7850379515f21187cba44754.zip
mm: don't call pte_unmap() against an improper pte
There are some places where we do like: pte = pte_map(); do { (do break in some conditions) } while (pte++, ...); pte_unmap(pte - 1); But if the loop breaks at the first loop, pte_unmap() unmaps invalid pte. This patch is a fix for this problem. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewd-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
-rw-r--r--mm/memory.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 7e91b5f9f690..60ea601e03ea 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -641,6 +641,7 @@ static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma,
unsigned long addr, unsigned long end)
{
+ pte_t *orig_src_pte, *orig_dst_pte;
pte_t *src_pte, *dst_pte;
spinlock_t *src_ptl, *dst_ptl;
int progress = 0;
@@ -654,6 +655,8 @@ again:
src_pte = pte_offset_map_nested(src_pmd, addr);
src_ptl = pte_lockptr(src_mm, src_pmd);
spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
+ orig_src_pte = src_pte;
+ orig_dst_pte = dst_pte;
arch_enter_lazy_mmu_mode();
do {
@@ -677,9 +680,9 @@ again:
arch_leave_lazy_mmu_mode();
spin_unlock(src_ptl);
- pte_unmap_nested(src_pte - 1);
+ pte_unmap_nested(orig_src_pte);
add_mm_rss(dst_mm, rss[0], rss[1]);
- pte_unmap_unlock(dst_pte - 1, dst_ptl);
+ pte_unmap_unlock(orig_dst_pte, dst_ptl);
cond_resched();
if (addr != end)
goto again;
@@ -1820,10 +1823,10 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
token = pmd_pgtable(*pmd);
do {
- err = fn(pte, token, addr, data);
+ err = fn(pte++, token, addr, data);
if (err)
break;
- } while (pte++, addr += PAGE_SIZE, addr != end);
+ } while (addr += PAGE_SIZE, addr != end);
arch_leave_lazy_mmu_mode();