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| author | Oleg Nesterov <oleg@redhat.com> | 2019-10-09 17:02:30 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2019-10-11 08:39:57 -0700 |
| commit | 937c6b27c73e02cd4114f95f5c37ba2c29fadba1 (patch) | |
| tree | e88382aa1b7c257d8c57c43f46a9298e83d0bcdd | |
| parent | 9e208aa06c2109b45eec6be049a8e47034748c20 (diff) | |
| download | linux-937c6b27c73e02cd4114f95f5c37ba2c29fadba1.tar.gz | |
cgroup: freezer: call cgroup_enter_frozen() with preemption disabled in ptrace_stop()
ptrace_stop() does preempt_enable_no_resched() to avoid the preemption,
but after that cgroup_enter_frozen() does spin_lock/unlock and this adds
another preemption point.
Reported-and-tested-by: Bruce Ashfield <bruce.ashfield@gmail.com>
Fixes: 76f969e8948d ("cgroup: cgroup v2 freezer")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | kernel/signal.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index c4da1ef56fdf..bcd46f547db3 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2205,8 +2205,8 @@ static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t */ preempt_disable(); read_unlock(&tasklist_lock); - preempt_enable_no_resched(); cgroup_enter_frozen(); + preempt_enable_no_resched(); freezable_schedule(); cgroup_leave_frozen(true); } else { |