Messages in this thread Patch in this message | | | From | Greg Thelen <> | Subject | [PATCH] memcg: avoid overflow in memcg_hierarchical_free_pages() | Date | Mon, 8 Nov 2010 17:15:20 -0800 |
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Use page counts rather than byte counts to avoid overflowing unsigned long local variables.
Signed-off-by: Greg Thelen <gthelen@google.com> --- mm/memcontrol.c | 10 +++++----- 1 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 6c7115d..b287afd 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1345,17 +1345,17 @@ memcg_hierarchical_free_pages(struct mem_cgroup *mem) { unsigned long free, min_free; - min_free = global_page_state(NR_FREE_PAGES) << PAGE_SHIFT; + min_free = global_page_state(NR_FREE_PAGES); while (mem) { - free = res_counter_read_u64(&mem->res, RES_LIMIT) - - res_counter_read_u64(&mem->res, RES_USAGE); + free = (res_counter_read_u64(&mem->res, RES_LIMIT) - + res_counter_read_u64(&mem->res, RES_USAGE)) >> + PAGE_SHIFT; min_free = min(min_free, free); mem = parent_mem_cgroup(mem); } - /* Translate free memory in pages */ - return min_free >> PAGE_SHIFT; + return min_free; } /* -- 1.7.3.1
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