mm/oom_kill: fix the wrong task->mm == mm checks in oom_kill_process()

Both "child->mm == mm" and "p->mm != mm" checks in oom_kill_process() are
wrong.  task->mm can be NULL if the task is the exited group leader.  This
means in particular that "kill sharing same memory" loop can miss a
process with a zombie leader which uses the same ->mm.

Note: the process_has_mm(child, p->mm) check is still not 100% correct,
p->mm can be NULL too.  This is minor, but probably deserves a fix or a
comment anyway.

[[email protected]: document process_shares_mm() a bit]
Signed-off-by: Oleg Nesterov <[email protected]>
Acked-by: David Rientjes <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Cc: Kyle Walker <[email protected]>
Cc: Stanislav Kozina <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions