From 5f7865f3e44db4c73fdc454fb2af40806212a7ca Mon Sep 17 00:00:00 2001 From: Tang Chen Date: Tue, 25 Sep 2012 21:12:30 +0800 Subject: [PATCH] sched: Ensure 'sched_domains_numa_levels' is safe to use in other functions We should temporarily reset 'sched_domains_numa_levels' to 0 after it is reset to 'level' in sched_init_numa(). If it fails to allocate memory for array sched_domains_numa_masks[][], the array will contain less then 'level' members. This could be dangerous when we use it to iterate array sched_domains_numa_masks[][] in other functions. This patch set sched_domains_numa_levels to 0 before initializing array sched_domains_numa_masks[][], and reset it to 'level' when sched_domains_numa_masks[][] is fully initialized. Signed-off-by: Tang Chen Signed-off-by: Wen Congyang Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1348578751-16904-2-git-send-email-tangchen@cn.fujitsu.com Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c177472..f895fdd 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6122,6 +6122,17 @@ static void sched_init_numa(void) * numbers. */ + /* + * Here, we should temporarily reset sched_domains_numa_levels to 0. + * If it fails to allocate memory for array sched_domains_numa_masks[][], + * the array will contain less then 'level' members. This could be + * dangerous when we use it to iterate array sched_domains_numa_masks[][] + * in other functions. + * + * We reset it to 'level' at the end of this function. + */ + sched_domains_numa_levels = 0; + sched_domains_numa_masks = kzalloc(sizeof(void *) * level, GFP_KERNEL); if (!sched_domains_numa_masks) return; @@ -6176,6 +6187,8 @@ static void sched_init_numa(void) } sched_domain_topology = tl; + + sched_domains_numa_levels = level; } #else static inline void sched_init_numa(void) -- 2.7.4