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=-9.8 required=3.0 tests=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=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 A12E8C55186 for ; Wed, 22 Apr 2020 10:43:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7635620656 for ; Wed, 22 Apr 2020 10:43:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587552210; bh=TX443VW0wwGHwsW3eKFenSBCRAXdimDJM+ENiJ/1qn0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=WApWJI2HiXzLLr/udpgGAnKb9QbY+XDjgAm6mNzM9QQXb9vBsnr6MFBpTZj0aSCR7 TkPXC8Fxk45+7uU8r9XO9lOu7Zo61lm4mINpvp+Khi4d/hnK9TQerqfPjNYmToJnD1 2lk/iimRjs2kb/B+ivcIxuDBNsv1ZLArjn0G+U9Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728231AbgDVKnP (ORCPT ); Wed, 22 Apr 2020 06:43:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:56452 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729523AbgDVKTl (ORCPT ); Wed, 22 Apr 2020 06:19:41 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 54A8020775; Wed, 22 Apr 2020 10:19:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587550780; bh=TX443VW0wwGHwsW3eKFenSBCRAXdimDJM+ENiJ/1qn0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bRVs4AHRDIh91PI6zEHdawUWHLvladc13ijuYkurvcjUVvgBy9IdjDze/7rqROfY2 kgAntolM9OtC7GIqrk8O1OwyW5wj+8WfwZ33sRYjvyKb5pscjA2toNl9gujIGjh2Tl QkSZRBdx5rPVmwmEoN4W2Kfx7kMkq02MHIhRZt50= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Qian Cai , Lu Baolu , Joerg Roedel , Sasha Levin Subject: [PATCH 5.4 091/118] iommu/vt-d: Silence RCU-list debugging warning in dmar_find_atsr() Date: Wed, 22 Apr 2020 11:57:32 +0200 Message-Id: <20200422095046.283048366@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095031.522502705@linuxfoundation.org> References: <20200422095031.522502705@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Qian Cai [ Upstream commit c6f4ebdeba4cff590594df931ff1ee610c426431 ] dmar_find_atsr() calls list_for_each_entry_rcu() outside of an RCU read side critical section but with dmar_global_lock held. Silence this false positive. drivers/iommu/intel-iommu.c:4504 RCU-list traversed in non-reader section!! 1 lock held by swapper/0/1: #0: ffffffff9755bee8 (dmar_global_lock){+.+.}, at: intel_iommu_init+0x1a6/0xe19 Call Trace: dump_stack+0xa4/0xfe lockdep_rcu_suspicious+0xeb/0xf5 dmar_find_atsr+0x1ab/0x1c0 dmar_parse_one_atsr+0x64/0x220 dmar_walk_remapping_entries+0x130/0x380 dmar_table_init+0x166/0x243 intel_iommu_init+0x1ab/0xe19 pci_iommu_init+0x1a/0x44 do_one_initcall+0xae/0x4d0 kernel_init_freeable+0x412/0x4c5 kernel_init+0x19/0x193 Signed-off-by: Qian Cai Acked-by: Lu Baolu Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/intel-iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 0d922eeae3579..773ac2b0d6068 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -4335,7 +4335,8 @@ static struct dmar_atsr_unit *dmar_find_atsr(struct acpi_dmar_atsr *atsr) struct dmar_atsr_unit *atsru; struct acpi_dmar_atsr *tmp; - list_for_each_entry_rcu(atsru, &dmar_atsr_units, list) { + list_for_each_entry_rcu(atsru, &dmar_atsr_units, list, + dmar_rcu_check()) { tmp = (struct acpi_dmar_atsr *)atsru->hdr; if (atsr->segment != tmp->segment) continue; -- 2.20.1