From: Yonghong Song <yhs@xxxxxx> [ Upstream commit e60572b8d4c39572be6857d1ec91fdf979f8775f ] Currently when traversing all tasks, the next tid is always increased by one. This may result in visiting the same task multiple times in a pid namespace. This patch fixed the issue by seting the next tid as pid_nr_ns(pid, ns) + 1, similar to funciton next_tgid(). Signed-off-by: Yonghong Song <yhs@xxxxxx> Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxxx> Link: https://lore.kernel.org/bpf/20200818222310.2181500-1-yhs@xxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- kernel/bpf/task_iter.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c index a4a0fb4f94cc1..323def936be24 100644 --- a/kernel/bpf/task_iter.c +++ b/kernel/bpf/task_iter.c @@ -28,8 +28,9 @@ static struct task_struct *task_seq_get_next(struct pid_namespace *ns, rcu_read_lock(); retry: - pid = idr_get_next(&ns->idr, tid); + pid = find_ge_pid(*tid, ns); if (pid) { + *tid = pid_nr_ns(pid, ns); task = get_pid_task(pid, PIDTYPE_PID); if (!task) { ++*tid; -- 2.25.1
