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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 2AB8EC2D0A3 for ; Tue, 3 Nov 2020 21:03:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2C7B21534 for ; Tue, 3 Nov 2020 21:03:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604437407; bh=8IoPhvaNi50VZ4kDbgG2391J0F0bfxVrFVK+xANb+9Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=n0fgHCFB20DLB/ozsnbvGCKP+rmRMy1gnh2NHqE/kUFGmrQKDDHsgg9Jz5CChqf5C YeJ+Mi3ZTBEt60CZRug0h5PJ4lV6Imv5BxvRCjy0gRSC5u9xsYl3UHebmLPX2YJbKO jg9Y16flConPt95aqbPKwB4F2UNAUWSfr6UBpEaY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387823AbgKCVDZ (ORCPT ); Tue, 3 Nov 2020 16:03:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:40792 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387774AbgKCVDV (ORCPT ); Tue, 3 Nov 2020 16:03:21 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D1BBE20658; Tue, 3 Nov 2020 21:03:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604437400; bh=8IoPhvaNi50VZ4kDbgG2391J0F0bfxVrFVK+xANb+9Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sYE0uT/NJj0S7Xu5jE4/lhHdoJzXtClXaSRRTE9D8452XHwmPAn+WY0EhanNXIBOv xyraC/VPQqt8wvahXCB1gLJf1/niIyWnTy20felaw0y1ccXetJIpu2BJ4Zmu9uQsOR wnXWL02DJSqDy7CdsdbHmOpacqPFtxCNLPT2/WAI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johannes Berg , Richard Weinberger , Sasha Levin Subject: [PATCH 4.19 061/191] um: change sigio_spinlock to a mutex Date: Tue, 3 Nov 2020 21:35:53 +0100 Message-Id: <20201103203240.381853885@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201103203232.656475008@linuxfoundation.org> References: <20201103203232.656475008@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johannes Berg [ Upstream commit f2d05059e15af3f70502074f4e3a504530af504a ] Lockdep complains at boot: ============================= [ BUG: Invalid wait context ] 5.7.0-05093-g46d91ecd597b #98 Not tainted ----------------------------- swapper/1 is trying to lock: 0000000060931b98 (&desc[i].request_mutex){+.+.}-{3:3}, at: __setup_irq+0x11d/0x623 other info that might help us debug this: context-{4:4} 1 lock held by swapper/1: #0: 000000006074fed8 (sigio_spinlock){+.+.}-{2:2}, at: sigio_lock+0x1a/0x1c stack backtrace: CPU: 0 PID: 1 Comm: swapper Not tainted 5.7.0-05093-g46d91ecd597b #98 Stack: 7fa4fab0 6028dfd1 0000002a 6008bea5 7fa50700 7fa50040 7fa4fac0 6028e016 7fa4fb50 6007f6da 60959c18 00000000 Call Trace: [<60023a0e>] show_stack+0x13b/0x155 [<6028e016>] dump_stack+0x2a/0x2c [<6007f6da>] __lock_acquire+0x515/0x15f2 [<6007eb50>] lock_acquire+0x245/0x273 [<6050d9f1>] __mutex_lock+0xbd/0x325 [<6050dc76>] mutex_lock_nested+0x1d/0x1f [<6008e27e>] __setup_irq+0x11d/0x623 [<6008e8ed>] request_threaded_irq+0x169/0x1a6 [<60021eb0>] um_request_irq+0x1ee/0x24b [<600234ee>] write_sigio_irq+0x3b/0x76 [<600383ca>] sigio_broken+0x146/0x2e4 [<60020bd8>] do_one_initcall+0xde/0x281 Because we hold sigio_spinlock and then get into requesting an interrupt with a mutex. Change the spinlock to a mutex to avoid that. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin --- arch/um/kernel/sigio.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/um/kernel/sigio.c b/arch/um/kernel/sigio.c index b5e0cbb343828..476ded92affac 100644 --- a/arch/um/kernel/sigio.c +++ b/arch/um/kernel/sigio.c @@ -36,14 +36,14 @@ int write_sigio_irq(int fd) } /* These are called from os-Linux/sigio.c to protect its pollfds arrays. */ -static DEFINE_SPINLOCK(sigio_spinlock); +static DEFINE_MUTEX(sigio_mutex); void sigio_lock(void) { - spin_lock(&sigio_spinlock); + mutex_lock(&sigio_mutex); } void sigio_unlock(void) { - spin_unlock(&sigio_spinlock); + mutex_unlock(&sigio_mutex); } -- 2.27.0