From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 572E0C433F1 for ; Thu, 25 Mar 2021 11:27:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3274861A5E for ; Thu, 25 Mar 2021 11:27:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230459AbhCYL0j (ORCPT ); Thu, 25 Mar 2021 07:26:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:34274 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229533AbhCYLZz (ORCPT ); Thu, 25 Mar 2021 07:25:55 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 79D6561A3A; Thu, 25 Mar 2021 11:25:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616671555; bh=MbeWw4oWC2p3Gafd3OBzJSSDSyVlQMJTbqPQjbSF3rs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=b8C4mQ8D52uJl4Q1Wbigtwp0MNMGg7tivDey09gJDhDNWCM4kPmMfAc1DvI/1MFKn 9exPLcOztptfric4Yjxsjexd8X/eh1ElaQCDjKgF6S2Hc3rEezQ89ZQJMJpOPS4TMx 9n+s4/o2OIE2CX/L0xU2IkneTg73AloY4WnrJap+oj8M7dXRkWhBJzpA9n9IaL7ZSI rUethOk0mOpwuSEjWPC89QSqYA0a1y4N/AXl2ObsiE+9Lu1mo2bwNsvm40InJ8mlkv kNXaP0NOIuoMIyi5rKMQCEUfovTplvPATYEHALPMFoIO69V2EB4yF3Hs+gYnbWWBoB VdMsRawCEWhVg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Eric W. Biederman" , Stefan Metzmacher , Jens Axboe , Sasha Levin Subject: [PATCH AUTOSEL 5.11 43/44] signal: don't allow STOP on PF_IO_WORKER threads Date: Thu, 25 Mar 2021 07:24:58 -0400 Message-Id: <20210325112459.1926846-43-sashal@kernel.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210325112459.1926846-1-sashal@kernel.org> References: <20210325112459.1926846-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: "Eric W. Biederman" [ Upstream commit 4db4b1a0d1779dc159f7b87feb97030ec0b12597 ] 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. Longer term, we may want to look into allowing stop of these threads, as it relates to eg process freezing. For now, this prevents a spin issue if a SIGSTOP is delivered to the parent task. Reported-by: Stefan Metzmacher Signed-off-by: Jens Axboe Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin --- kernel/signal.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/signal.c b/kernel/signal.c index 55526b941011..00a3840f6037 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -288,7 +288,8 @@ bool task_set_jobctl_pending(struct task_struct *task, unsigned long mask) JOBCTL_STOP_SIGMASK | JOBCTL_TRAPPING)); BUG_ON((mask & JOBCTL_TRAPPING) && !(mask & JOBCTL_PENDING_MASK)); - if (unlikely(fatal_signal_pending(task) || (task->flags & PF_EXITING))) + if (unlikely(fatal_signal_pending(task) || + (task->flags & (PF_EXITING | PF_IO_WORKER)))) return false; if (mask & JOBCTL_STOP_SIGMASK) -- 2.30.1