From 3147d8aaa03eac0e68742621e8f05323459aa37d Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 24 Feb 2020 18:53:09 -0600 Subject: [PATCH] proc: Use PIDTYPE_TGID in next_tgid Combine the pid_task and thes test has_group_leader_pid into a single dereference by using pid_task(PIDTYPE_TGID). This makes the code simpler and proof against needing to even think about any shenanigans that de_thread might get up to. Acked-by: Oleg Nesterov Signed-off-by: "Eric W. Biederman" --- fs/proc/base.c | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index aa7b39a114c9..5a307b3bb2d1 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3359,20 +3359,8 @@ retry: pid = find_ge_pid(iter.tgid, ns); if (pid) { iter.tgid = pid_nr_ns(pid, ns); - iter.task = pid_task(pid, PIDTYPE_PID); - /* What we to know is if the pid we have find is the - * pid of a thread_group_leader. Testing for task - * being a thread_group_leader is the obvious thing - * todo but there is a window when it fails, due to - * the pid transfer logic in de_thread. - * - * So we perform the straight forward test of seeing - * if the pid we have found is the pid of a thread - * group leader, and don't worry if the task we have - * found doesn't happen to be a thread group leader. - * As we don't care in the case of readdir. - */ - if (!iter.task || !has_group_leader_pid(iter.task)) { + iter.task = pid_task(pid, PIDTYPE_TGID); + if (!iter.task) { iter.tgid += 1; goto retry; }