From 5ffd2c37cb7a53d52099e5ed1fd7ccbc9e358791 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Thu, 17 Aug 2023 18:37:08 +0200 Subject: kill do_each_thread() Eric has pointed out that we still have 3 users of do_each_thread(). Change them to use for_each_process_thread() and kill this helper. There is a subtle change, after do_each_thread/while_each_thread g == t == &init_task, while after for_each_process_thread() they both point to nowhere, but this doesn't matter. > Why is for_each_process_thread() better than do_each_thread()? Say, for_each_process_thread() is rcu safe, do_each_thread() is not. And certainly for_each_process_thread(p, t) { do_something(p, t); } looks better than do_each_thread(p, t) { do_something(p, t); } while_each_thread(p, t); And again, there are only 3 users of this awkward helper left. It should have been killed years ago and in fact I thought it had already been killed. It uses while_each_thread() which needs some changes. Link: https://lkml.kernel.org/r/20230817163708.GA8248@redhat.com Signed-off-by: Oleg Nesterov Reviewed-by: Kees Cook Cc: "Christian Brauner (Microsoft)" Cc: Eric W. Biederman Cc: Jiri Slaby # tty/serial Signed-off-by: Andrew Morton --- drivers/tty/tty_io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 63db04b9113a..27d8e3a1aace 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -3031,7 +3031,7 @@ void __do_SAK(struct tty_struct *tty) } while_each_pid_task(session, PIDTYPE_SID, p); /* Now kill any processes that happen to have the tty open */ - do_each_thread(g, p) { + for_each_process_thread(g, p) { if (p->signal->tty == tty) { tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", task_pid_nr(p), p->comm); @@ -3048,7 +3048,7 @@ void __do_SAK(struct tty_struct *tty) PIDTYPE_SID); } task_unlock(p); - } while_each_thread(g, p); + } read_unlock(&tasklist_lock); put_pid(session); } -- cgit v1.2.3