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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 23E63C433EC for ; Thu, 25 Mar 2021 11:32:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DC50B61A1F for ; Thu, 25 Mar 2021 11:32:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230454AbhCYLcB (ORCPT ); Thu, 25 Mar 2021 07:32:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:36152 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231296AbhCYL0s (ORCPT ); Thu, 25 Mar 2021 07:26:48 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B818261A32; Thu, 25 Mar 2021 11:26:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616671608; bh=sHPB1BgOfR+6+Sqv4errnJauM6CnffGtvyEOvgEw1fc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IQnDvECb4ZAuqvyDUfmq0vp3IKJU8rAOygmNEArBfgXvkMToNa11XwJbwJsxy+kXb MHmIO0Ma9sgRHMdsiS5wmlynT3prrJ4iFf+YH6o3jVyXMnaeb6tdOJrMToPr2KLHbl aCa8g42mCimRoaFQx0ZscI+NPzV6d0GkmfZPaesLX7jK2ViLGje0+EydrNf4tASbc9 vEqErOSTYByNIJ5yxJyxFXfTdCAq/pbtrFSsVtUcl1/liApN27pM3518IGsX+hffQ8 lCKDR9vH59tXYpWlOE+KKnChaB3xKWXYsQNC4JQCY2gPOlwBQ7DY4mAFlxhC7h9cN0 LIWy7jOvfWBtg== 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 5.10 38/39] signal: don't allow STOP on PF_IO_WORKER threads Date: Thu, 25 Mar 2021 07:25:57 -0400 Message-Id: <20210325112558.1927423-38-sashal@kernel.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210325112558.1927423-1-sashal@kernel.org> References: <20210325112558.1927423-1-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: linux-kernel@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 18ed1f853439..1d901a789812 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