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=-19.0 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 7E3D0C43381 for ; Wed, 24 Feb 2021 13:38:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 519B764E6C for ; Wed, 24 Feb 2021 13:38:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237134AbhBXNe0 (ORCPT ); Wed, 24 Feb 2021 08:34:26 -0500 Received: from mail.kernel.org ([198.145.29.99]:54608 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230019AbhBXM7R (ORCPT ); Wed, 24 Feb 2021 07:59:17 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id E11B564F4C; Wed, 24 Feb 2021 12:52:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614171164; bh=LSqG/AgBKzhrBYsEh38qHjLpJTdNkRR67jS3bAEubLI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gE7v9nKiN58KRclPAh8vX91IGr5OU2diKHUoQRIFmNB++7Qqlp1OhqHEGFo7Z0SYm z35cgzYaklnXLol4+UWvhH0WKNieMSdVLYaHjpnWeBr+oddiYsgh01HH8QNC/9rm3m EzUCWRCwn15a/o+3VBZ/YO6SSruq7QfmSLHI+kaRwqxKNQNx5c4xh/ZFnsvWSM6c4Q 1YtGQDAAtd6JVi/3LpJtRbmt1f/k/HAjQEZ7tEN2QLoRZWXNgDHXaPS88x5zRVA7BW qSqA6ASWrZDgabLl2K0IUe9MV/+QuX3sIOTFx2nEfTnZ5AoNCWOZiERoO/y2o0fovG 7l4t3WSzNH/8A== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Peter Zijlstra , syzbot+cb3b69ae80afd6535b0e@syzkaller.appspotmail.com, "Paul E . McKenney" , Sasha Levin Subject: [PATCH AUTOSEL 5.10 24/56] sched/core: Allow try_invoke_on_locked_down_task() with irqs disabled Date: Wed, 24 Feb 2021 07:51:40 -0500 Message-Id: <20210224125212.482485-24-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210224125212.482485-1-sashal@kernel.org> References: <20210224125212.482485-1-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: Peter Zijlstra [ Upstream commit 1b7af295541d75535374325fd617944534853919 ] The try_invoke_on_locked_down_task() function currently requires that interrupts be enabled, but it is called with interrupts disabled from rcu_print_task_stall(), resulting in an "IRQs not enabled as expected" diagnostic. This commit therefore updates try_invoke_on_locked_down_task() to use raw_spin_lock_irqsave() instead of raw_spin_lock_irq(), thus allowing use from either context. Link: https://lore.kernel.org/lkml/000000000000903d5805ab908fc4@google.com/ Link: https://lore.kernel.org/lkml/20200928075729.GC2611@hirez.programming.kicks-ass.net/ Reported-by: syzbot+cb3b69ae80afd6535b0e@syzkaller.appspotmail.com Signed-off-by: Peter Zijlstra Signed-off-by: Paul E. McKenney Signed-off-by: Sasha Levin --- kernel/sched/core.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 77aa0e788b9b7..269165bf440af 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2989,7 +2989,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) /** * try_invoke_on_locked_down_task - Invoke a function on task in fixed state - * @p: Process for which the function is to be invoked. + * @p: Process for which the function is to be invoked, can be @current. * @func: Function to invoke. * @arg: Argument to function. * @@ -3007,12 +3007,11 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) */ bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct task_struct *t, void *arg), void *arg) { - bool ret = false; struct rq_flags rf; + bool ret = false; struct rq *rq; - lockdep_assert_irqs_enabled(); - raw_spin_lock_irq(&p->pi_lock); + raw_spin_lock_irqsave(&p->pi_lock, rf.flags); if (p->on_rq) { rq = __task_rq_lock(p, &rf); if (task_rq(p) == rq) @@ -3029,7 +3028,7 @@ bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct t ret = func(p, arg); } } - raw_spin_unlock_irq(&p->pi_lock); + raw_spin_unlock_irqrestore(&p->pi_lock, rf.flags); return ret; } -- 2.27.0