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authorJoe Jin <joe.jin@oracle.com>2007-07-15 23:38:12 -0700
committerWilly Tarreau <w@1wt.eu>2007-08-25 17:24:13 +0200
commit2dd610fa1cc1b8eb9e3f4555078aee7b47691a04 (patch)
tree6f6cc9acdcd8bfb64081f36cecf69fcd49ee6cbc
parent303a2abf3e1c29f0697e9e8f71e9b7b0c506a124 (diff)
[PATCH] hugetlb: fix race in alloc_fresh_huge_page()
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> Signed-off-by: Willy Tarreau <w@1wt.eu>
-rw-r--r--mm/hugetlb.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 36db012b38dd..7c07eb22ed1e 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -101,13 +101,20 @@ static void free_huge_page(struct page *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);