Messages in this thread Patch in this message | | | Date | Mon, 6 Jun 2005 20:48:27 +0100 (BST) | From | Hugh Dickins <> | Subject | [PATCH 1/2] mbind: fix verify_pages pte_page |
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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> ---
mm/mempolicy.c | 19 ++++++++++++++----- 1 files changed, 14 insertions(+), 5 deletions(-)
--- 2.6.12-rc6/mm/mempolicy.c 2005-05-25 18:09:21.000000000 +0100 +++ linux/mm/mempolicy.c 2005-06-04 20:41:55.000000000 +0100 @@ -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 */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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