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| author | Oleg Nesterov <oleg@redhat.com> | 2023-09-05 17:46:46 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-09-08 08:42:19 -0700 |
| commit | 1a00ef57d9f120b711b6b1193d12ba3789d47ec2 (patch) | |
| tree | c36fa91e3f80139c3e82cfd267f6f3ee36940149 /kernel/bpf/task_iter.c | |
| parent | 35897c3c5264469cbd45e44d23c165a08cfb6b3c (diff) | |
| download | linux-stable-1a00ef57d9f120b711b6b1193d12ba3789d47ec2.tar.gz linux-stable-1a00ef57d9f120b711b6b1193d12ba3789d47ec2.tar.bz2 linux-stable-1a00ef57d9f120b711b6b1193d12ba3789d47ec2.zip | |
bpf: task_group_seq_get_next: cleanup the usage of next_thread()
1. find_pid_ns() + get_pid_task() under rcu_read_lock() guarantees that we
can safely iterate the task->thread_group list. Even if this task exits
right after get_pid_task() (or goto retry) and pid_alive() returns 0.
Kill the unnecessary pid_alive() check.
2. next_thread() simply can't return NULL, kill the bogus "if (!next_task)"
check.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230905154646.GA24928@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/task_iter.c')
| -rw-r--r-- | kernel/bpf/task_iter.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c index c4ab9d6cdbe9..4d1125108014 100644 --- a/kernel/bpf/task_iter.c +++ b/kernel/bpf/task_iter.c @@ -75,15 +75,8 @@ static struct task_struct *task_group_seq_get_next(struct bpf_iter_seq_task_comm return NULL; retry: - if (!pid_alive(task)) { - put_task_struct(task); - return NULL; - } - next_task = next_thread(task); put_task_struct(task); - if (!next_task) - return NULL; saved_tid = *tid; *tid = __task_pid_nr_ns(next_task, PIDTYPE_PID, common->ns); |