author: Suren Baghdasaryan <surenb@google.com> 2021-10-28 14:36:14 -0700
committer: Linus Torvalds <torvalds@linux-foundation.org> 2021-10-28 17:18:55 -0700
commit: 337546e83fc7e50917f44846beee936abb9c9f1f
parent: eac96c3efdb593df1a57bb5b95dbe037bfa9a522
Commit Summary:
Diffstat:
1 file changed, 12 insertions, 10 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 831340e7ad8b..989f35a2bbb1 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -1150,7 +1150,7 @@ SYSCALL_DEFINE2(process_mrelease, int, pidfd, unsigned int, flags)
struct task_struct *task;
struct task_struct *p;
unsigned int f_flags;
- bool reap = true;
+ bool reap = false;
struct pid *pid;
long ret = 0;
@@ -1177,15 +1177,15 @@ SYSCALL_DEFINE2(process_mrelease, int, pidfd, unsigned int, flags)
goto put_task;
}
- mm = p->mm;
- mmgrab(mm);
-
- /* If the work has been done already, just exit with success */
- if (test_bit(MMF_OOM_SKIP, &mm->flags))
- reap = false;
- else if (!task_will_free_mem(p)) {
- reap = false;
- ret = -EINVAL;
+ if (mmget_not_zero(p->mm)) {
+ mm = p->mm;
+ if (task_will_free_mem(p))
+ reap = true;
+ else {
+ /* Error only if the work has not been done already */
+ if (!test_bit(MMF_OOM_SKIP, &mm->flags))
+ ret = -EINVAL;
+ }
}
task_unlock(p);
@@ -1201,7 +1201,8 @@ SYSCALL_DEFINE2(process_mrelease, int, pidfd, unsigned int, flags)
mmap_read_unlock(mm);
drop_mm:
- mmdrop(mm);
+ if (mm)
+ mmput(mm);
put_task:
put_task_struct(task);
put_pid: