Commit 229c4ef8 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Ingo Molnar

ftrace: do_each_pid_task() needs rcu lock

"ftrace: use struct pid" commit 978f3a45
converted ftrace_pid_trace to "struct pid*".

But we can't use do_each_pid_task() without rcu_read_lock() even if
we know the pid itself can't go away (it was pinned in ftrace_pid_write).
The exiting task can detach itself from this pid at any moment.
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent b1792e36
......@@ -1737,9 +1737,12 @@ static void clear_ftrace_pid(struct pid *pid)
{
struct task_struct *p;
rcu_read_lock();
do_each_pid_task(pid, PIDTYPE_PID, p) {
clear_tsk_trace_trace(p);
} while_each_pid_task(pid, PIDTYPE_PID, p);
rcu_read_unlock();
put_pid(pid);
}
......@@ -1747,9 +1750,11 @@ static void set_ftrace_pid(struct pid *pid)
{
struct task_struct *p;
rcu_read_lock();
do_each_pid_task(pid, PIDTYPE_PID, p) {
set_tsk_trace_trace(p);
} while_each_pid_task(pid, PIDTYPE_PID, p);
rcu_read_unlock();
}
static void clear_ftrace_pid_task(struct pid **pid)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment