[merged mm-nonmm-stable] taskstats-fill_stats_for_tgid-use-for_each_thread.patch removed from -mm tree

[merged mm-nonmm-stable] taskstats-fill_stats_for_tgid-use-for_each_thread.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: taskstats: fill_stats_for_tgid: use for_each_thread()
has been removed from the -mm tree.  Its filename was
     taskstats-fill_stats_for_tgid-use-for_each_thread.patch

This patch was dropped because it was merged into the mm-nonmm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Oleg Nesterov <oleg@redhat.com>
Subject: taskstats: fill_stats_for_tgid: use for_each_thread()
Date: Sat, 9 Sep 2023 23:49:51 +0200

do/while_each_thread should be avoided when possible.

Plus I _think_ this change allows to avoid lock_task_sighand() but I am
not sure, I forgot everything about taskstats.  In any case, this code
does not look right in that the same thread can be accounted twice:
taskstats_exit() can account the exiting thread in signal->stats and drop
->siglock but this thread is still on the thread-group list, so
lock_task_sighand() can't help.

Link: https://lkml.kernel.org/r/20230909214951.GA24274@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/taskstats.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/kernel/taskstats.c~taskstats-fill_stats_for_tgid-use-for_each_thread
+++ a/kernel/taskstats.c
@@ -233,9 +233,8 @@ static int fill_stats_for_tgid(pid_t tgi
 	else
 		memset(stats, 0, sizeof(*stats));
 
-	tsk = first;
 	start_time = ktime_get_ns();
-	do {
+	for_each_thread(first, tsk) {
 		if (tsk->exit_state)
 			continue;
 		/*
@@ -258,7 +257,7 @@ static int fill_stats_for_tgid(pid_t tgi
 
 		stats->nvcsw += tsk->nvcsw;
 		stats->nivcsw += tsk->nivcsw;
-	} while_each_thread(first, tsk);
+	}
 
 	unlock_task_sighand(first, &flags);
 	rc = 0;
_

Patches currently in -mm which might be from oleg@redhat.com are