Messages in this thread Patch in this message | | | Date | Tue, 7 Aug 2007 13:48:05 -0700 | From | Greg KH <> | Subject | [2.6.22.2 review 60/84] hugetlb: fix race in alloc_fresh_huge_page() |
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From: Joe Jin <joe.jin@oracle.com>
That static `nid' index needs locking. Without it we can end up calling alloc_pages_node() with an illegal node ID and the kernel crashes.
Acked-by: Gurudas Pai <gurudas.pai@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- mm/hugetlb.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)
--- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -101,13 +101,20 @@ static void free_huge_page(struct page * static int alloc_fresh_huge_page(void) { - static int nid = 0; + static int prev_nid; struct page *page; - page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN, - HUGETLB_PAGE_ORDER); - nid = next_node(nid, node_online_map); + static DEFINE_SPINLOCK(nid_lock); + int nid; + + spin_lock(&nid_lock); + nid = next_node(prev_nid, node_online_map); if (nid == MAX_NUMNODES) nid = first_node(node_online_map); + prev_nid = nid; + spin_unlock(&nid_lock); + + page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN, + HUGETLB_PAGE_ORDER); if (page) { set_compound_page_dtor(page, free_huge_page); spin_lock(&hugetlb_lock); -- - 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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