From e7b691b085fda913830e5280ae6f724b2a63c824 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sat, 9 Jun 2012 02:40:03 -0700 Subject: slab/mempolicy: always use local policy from interrupt context slab_node() could access current->mempolicy from interrupt context. However there's a race condition during exit where the mempolicy is first freed and then the pointer zeroed. Using this from interrupts seems bogus anyways. The interrupt will interrupt a random process and therefore get a random mempolicy. Many times, this will be idle's, which noone can change. Just disable this here and always use local for slab from interrupts. I also cleaned up the callers of slab_node a bit which always passed the same argument. I believe the original mempolicy code did that in fact, so it's likely a regression. v2: send version with correct logic v3: simplify. fix typo. Reported-by: Arun Sharma Cc: penberg@kernel.org Cc: cl@linux.com Signed-off-by: Andi Kleen [tdmackey@twitter.com: Rework control flow based on feedback from cl@linux.com, fix logic, and cleanup current task_struct reference] Acked-by: David Rientjes Acked-by: Christoph Lameter Acked-by: KOSAKI Motohiro Signed-off-by: David Mackey Signed-off-by: Pekka Enberg --- include/linux/mempolicy.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/mempolicy.h') diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h index 4aa42732e47f..95b738c7abff 100644 --- a/include/linux/mempolicy.h +++ b/include/linux/mempolicy.h @@ -215,7 +215,7 @@ extern struct zonelist *huge_zonelist(struct vm_area_struct *vma, extern bool init_nodemask_of_mempolicy(nodemask_t *mask); extern bool mempolicy_nodemask_intersects(struct task_struct *tsk, const nodemask_t *mask); -extern unsigned slab_node(struct mempolicy *policy); +extern unsigned slab_node(void); extern enum zone_type policy_zone; -- cgit v1.2.3