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From: Jens Axboe <[email protected]>
To: [email protected]
Cc: [email protected], [email protected],
	[email protected], [email protected],
	Jens Axboe <[email protected]>, Stefan Metzmacher <[email protected]>
Subject: [PATCH 2/2] signal: don't allow STOP on PF_IO_WORKER threads
Date: Sat, 20 Mar 2021 09:38:32 -0600	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

Just like we don't allow normal signals to IO threads, don't deliver a
STOP to a task that has PF_IO_WORKER set. The IO threads don't take
signals in general, and have no means of flushing out a stop either.

Reported-by: Stefan Metzmacher <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
---
 kernel/signal.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/signal.c b/kernel/signal.c
index 730ecd3d6faf..b113bf647fb4 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2349,6 +2349,10 @@ static bool do_signal_stop(int signr)
 
 		t = current;
 		while_each_thread(current, t) {
+			/* don't STOP PF_IO_WORKER threads */
+			if (t->flags & PF_IO_WORKER)
+				continue;
+
 			/*
 			 * Setting state to TASK_STOPPED for a group
 			 * stop is always done with the siglock held,
-- 
2.31.0


  parent reply	other threads:[~2021-03-20 15:39 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-20 15:38 [PATCHSET 0/2] PF_IO_WORKER signal tweaks Jens Axboe
2021-03-20 15:38 ` [PATCH 1/2] signal: don't allow sending any signals to PF_IO_WORKER threads Jens Axboe
2021-03-20 16:18   ` Eric W. Biederman
2021-03-20 17:56     ` Linus Torvalds
2021-03-20 21:38       ` Eric W. Biederman
2021-03-20 22:42         ` Jens Axboe
2021-03-21 14:54           ` Eric W. Biederman
2021-03-21 15:40             ` Jens Axboe
2021-03-20 15:38 ` Jens Axboe [this message]
2021-03-20 16:21   ` [PATCH 2/2] signal: don't allow STOP on " Eric W. Biederman
2021-03-22 16:18     ` Oleg Nesterov
2021-03-22 16:15   ` Oleg Nesterov
2021-03-20 16:26 ` [PATCHSET 0/2] PF_IO_WORKER signal tweaks Eric W. Biederman
2021-03-20 17:51   ` Linus Torvalds
2021-03-20 19:18     ` Linus Torvalds
2021-03-20 22:08       ` Eric W. Biederman
2021-03-20 22:53         ` Jens Axboe
2021-03-21 15:18           ` Eric W. Biederman
2021-03-21 15:42             ` Jens Axboe
2021-03-20 22:56       ` Jens Axboe
2021-03-20 17:05 ` kernel test robot
2021-03-20 17:05 ` kernel test robot
2021-03-20 19:10 ` kernel test robot
2021-03-22 16:05 ` Oleg Nesterov

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