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authorHugh Dickins <hugh@veritas.com>2005-06-22 04:15:06 +0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-22 05:46:19 +0400
commit941150a326be88af245034ef4b3e9fa00229aa2d (patch)
tree03a058776dccd007150a3f57b1f36bf63b8f6a5d /mm
parent400e65146c428d2ef677a927786fda2cec545a76 (diff)
downloadlinux-941150a326be88af245034ef4b3e9fa00229aa2d.tar.xz
[PATCH] mbind: fix verify_pages pte_page
Strict mbind's check that pages already mapped are on right node has been using pte_page without checking if pfn_valid, and without page_table_lock to prevent spurious failures when try_to_unmap_one intervenes between the pte_present and the pte_page. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/mempolicy.c19
1 files changed, 14 insertions, 5 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 39252c732db2..c512cc911e22 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -242,6 +242,9 @@ static int
verify_pages(struct mm_struct *mm,
unsigned long addr, unsigned long end, unsigned long *nodes)
{
+ int err = 0;
+
+ spin_lock(&mm->page_table_lock);
while (addr < end) {
struct page *p;
pte_t *pte;
@@ -268,17 +271,23 @@ verify_pages(struct mm_struct *mm,
}
p = NULL;
pte = pte_offset_map(pmd, addr);
- if (pte_present(*pte))
- p = pte_page(*pte);
+ if (pte_present(*pte)) {
+ unsigned long pfn = pte_pfn(*pte);
+ if (pfn_valid(pfn))
+ p = pfn_to_page(pfn);
+ }
pte_unmap(pte);
if (p) {
unsigned nid = page_to_nid(p);
- if (!test_bit(nid, nodes))
- return -EIO;
+ if (!test_bit(nid, nodes)) {
+ err = -EIO;
+ break;
+ }
}
addr += PAGE_SIZE;
}
- return 0;
+ spin_unlock(&mm->page_table_lock);
+ return err;
}
/* Step 1: check the range */