From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 59CF417FAB6; Wed, 3 Jul 2024 11:22:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720005733; cv=none; b=ZoYYadIT4gfi513qZvhUy/YSjHqPASlI7f2F+tW5A2vx/rd4jiYyLHW7p/yguEitlqm4fMpAlgutK8VrTW5V7wtLu0+haQ51953zefpr3qVgDAskfhOv7QPj9CWEiUKInjYTq1Ds43QJXo7ROhKAUHqxq6UJ56gTbKO+rndF7bk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720005733; c=relaxed/simple; bh=6l+6sCR/DZ77R+Ta+d82ZVd9TXL1hP0ScEcxRob9pRI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GPBqqpQcyWVH8JEuH9z4NMsEDbyzxMgGLD7FGNefyiMs0on91CMp9YJmjqHL8r/74HG1ifqtewvRsKZvl1lgtJ37DGDx4mJdn7iZC0+qdVWJefaW66QI+WM7z6BAF1JV+Gxyvkxkku+bNlvQDDpPOCXtLivyX8AeQDxLUfxZ16c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nNLLTVSu; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nNLLTVSu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A54A4C4AF0C; Wed, 3 Jul 2024 11:22:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720005733; bh=6l+6sCR/DZ77R+Ta+d82ZVd9TXL1hP0ScEcxRob9pRI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nNLLTVSuMWMaLqZXiqzSVrlcxSjQC1ViNpXt0f1n4K/finwaeeXKmMoCumYyRcKL2 N1ydpV3KjYLnS7qJXESzUD7Edgf20KXumDN2QETLfiHreiLSy+9j/8Qe+FAMKPXSRi rOTBBBgjjeI34+oN1KiLRvokNDv1AXDRFjlguC5k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Oleg Nesterov , Rachel Menge , Boqun Feng , Wei Fu , Jens Axboe , Allen Pais , Christian Brauner , Frederic Weisbecker , "Joel Fernandes (Google)" , Joel Granados , Josh Triplett , Lai Jiangshan , Mateusz Guzik , Mathieu Desnoyers , Mike Christie , Neeraj Upadhyay , "Paul E. McKenney" , "Steven Rostedt (Google)" , Zqiang , Thomas Gleixner , Andrew Morton , Sasha Levin Subject: [PATCH 5.15 147/356] zap_pid_ns_processes: clear TIF_NOTIFY_SIGNAL along with TIF_SIGPENDING Date: Wed, 3 Jul 2024 12:38:03 +0200 Message-ID: <20240703102918.663840332@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703102913.093882413@linuxfoundation.org> References: <20240703102913.093882413@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov [ Upstream commit 7fea700e04bd3f424c2d836e98425782f97b494e ] kernel_wait4() doesn't sleep and returns -EINTR if there is no eligible child and signal_pending() is true. That is why zap_pid_ns_processes() clears TIF_SIGPENDING but this is not enough, it should also clear TIF_NOTIFY_SIGNAL to make signal_pending() return false and avoid a busy-wait loop. Link: https://lkml.kernel.org/r/20240608120616.GB7947@redhat.com Fixes: 12db8b690010 ("entry: Add support for TIF_NOTIFY_SIGNAL") Signed-off-by: Oleg Nesterov Reported-by: Rachel Menge Closes: https://lore.kernel.org/all/1386cd49-36d0-4a5c-85e9-bc42056a5a38@linux.microsoft.com/ Reviewed-by: Boqun Feng Tested-by: Wei Fu Reviewed-by: Jens Axboe Cc: Allen Pais Cc: Christian Brauner Cc: Frederic Weisbecker Cc: Joel Fernandes (Google) Cc: Joel Granados Cc: Josh Triplett Cc: Lai Jiangshan Cc: Mateusz Guzik Cc: Mathieu Desnoyers Cc: Mike Christie Cc: Neeraj Upadhyay Cc: Paul E. McKenney Cc: Steven Rostedt (Google) Cc: Zqiang Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- kernel/pid_namespace.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 259fc4ca0d9cc..40b011f880675 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -214,6 +214,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) */ do { clear_thread_flag(TIF_SIGPENDING); + clear_thread_flag(TIF_NOTIFY_SIGNAL); rc = kernel_wait4(-1, NULL, __WALL, NULL); } while (rc != -ECHILD); -- 2.43.0