From: Yafang Shao laoar.shao@gmail.com
mainline inclusion from mainline-5.2-rc7 commit 432b1de0de02a83f64695e69a2d83cbee10c236f category: bugfix bugzilla: 34611 CVE: NA
------------------------------------------------- In dump_oom_summary() oc->constraint is used to show oom_constraint_text, but it hasn't been set before. So the value of it is always the default value 0. We should inititialize it before.
Bellow is the output when memcg oom occurs,
before this patch: oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null), cpuset=/,mems_allowed=0,oom_memcg=/foo,task_memcg=/foo,task=bash,pid=7997,uid=0
after this patch: oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null), cpuset=/,mems_allowed=0,oom_memcg=/foo,task_memcg=/foo,task=bash,pid=13681,uid=0
Link: http://lkml.kernel.org/r/1560522038-15879-1-git-send-email-laoar.shao@gmail.... Fixes: ef8444ea01d7 ("mm, oom: reorganize the oom report in dump_header") Signed-off-by: Yafang Shao laoar.shao@gmail.com Acked-by: Michal Hocko mhocko@suse.com Cc: Wind Yu yuzhoujian@didichuxing.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org (cherry picked from commit 432b1de0de02a83f64695e69a2d83cbee10c236f) Signed-off-by: Kefeng Wang wangkefeng.wang@huawei.com Signed-off-by: Liu Shixin liushixin2@huawei.com Reviewed-by: Kefeng Wang wangkefeng.wang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- mm/oom_kill.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index a2010620a49d..05e4ec14b588 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -1026,8 +1026,7 @@ static void oom_kill_process(struct oom_control *oc, const char *message) /* * Determines whether the kernel must panic because of the panic_on_oom sysctl. */ -static void check_panic_on_oom(struct oom_control *oc, - enum oom_constraint constraint) +static void check_panic_on_oom(struct oom_control *oc) { if (likely(!sysctl_panic_on_oom)) return; @@ -1037,7 +1036,7 @@ static void check_panic_on_oom(struct oom_control *oc, * does not panic for cpuset, mempolicy, or memcg allocation * failures. */ - if (constraint != CONSTRAINT_NONE) + if (oc->constraint != CONSTRAINT_NONE) return; } /* Do not panic for oom kills triggered by sysrq */ @@ -1114,7 +1113,6 @@ EXPORT_SYMBOL_GPL(unregister_hisi_oom_notifier); bool out_of_memory(struct oom_control *oc) { unsigned long freed = 0; - enum oom_constraint constraint = CONSTRAINT_NONE; #ifdef CONFIG_ASCEND_OOM unsigned long oom_type; #endif @@ -1168,10 +1166,10 @@ bool out_of_memory(struct oom_control *oc) * Check if there were limitations on the allocation (only relevant for * NUMA and memcg) that may require different handling. */ - constraint = constrained_alloc(oc); - if (constraint != CONSTRAINT_MEMORY_POLICY) + oc->constraint = constrained_alloc(oc); + if (oc->constraint != CONSTRAINT_MEMORY_POLICY) oc->nodemask = NULL; - check_panic_on_oom(oc, constraint); + check_panic_on_oom(oc);
if (!is_memcg_oom(oc) && sysctl_oom_kill_allocating_task && current->mm && !oom_unkillable_task(current, NULL, oc->nodemask) &&