On 8/25/23 10:04 AM, Oleg Nesterov wrote:
Forgot to mention in the changelog... In any case this doesn't look right. ->group_leader can exit before other threads, call exit_files(), and in this case task_group_seq_get_next() will check task->files == NULL.
It is okay. This won't be affecting correctness. We will end with calling bpf program for 'next_task'.
On 08/25, Oleg Nesterov wrote:Unless I am notally confused it is wrong. We are going to return or skip next_task so we need to check next_task-files, not task->files. Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> --- kernel/bpf/task_iter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c index 1589ec3faded..2264870ae3fc 100644 --- a/kernel/bpf/task_iter.c +++ b/kernel/bpf/task_iter.c @@ -82,7 +82,7 @@ static struct task_struct *task_group_seq_get_next(struct bpf_iter_seq_task_comm common->pid_visiting = *tid; - if (skip_if_dup_files && task->files == task->group_leader->files) { + if (skip_if_dup_files && next_task->files == next_task->group_leader->files) { task = next_task; goto retry; } -- 2.25.1.362.g51ebf55
