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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 7679DC2BA19 for ; Wed, 15 Apr 2020 11:46:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 536EC216FD for ; Wed, 15 Apr 2020 11:46:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586951179; bh=TQTUmtRwfA59mBczXOvRQLvaQ8f1E7clOk5n+FfqbQk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=A6f2YdMS51eLpjq8dBuC/43MiGetJ3/E+9JfpPij9NHCK3UbWsSeM0Ws5OeiM8o6L vQkbbFmu8YOU8AZQOvOn8NJgN/yEO3zoCnKY5P893NpQhmA/zEiWgLquYq7ziNvgZo Uu+YOwRUUN/5XX5xMwwHzzwrqKcURNSmHdeV/wh0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2409274AbgDOLqP (ORCPT ); Wed, 15 Apr 2020 07:46:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:40832 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2409263AbgDOLqJ (ORCPT ); Wed, 15 Apr 2020 07:46:09 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9D5D320768; Wed, 15 Apr 2020 11:46:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586951169; bh=TQTUmtRwfA59mBczXOvRQLvaQ8f1E7clOk5n+FfqbQk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UQEWsWCq36OABomQDWd10Kwh7pYD+r79550udm3CfocuXD+sKSMBofo3GtKMDL4yy BAxFVtqBAcYcRjCTWjH+hKw+Ddy/eDt0Ko50vHobOBfe27TQ+j/pWlkXrvGXo43+3C fcgipvgH0kj0COGIF+XUdMC+1XtFn4lor/UFQg5s= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Qian Cai , Lu Baolu , Joerg Roedel , Sasha Levin , iommu@lists.linux-foundation.org Subject: [PATCH AUTOSEL 5.4 73/84] iommu/vt-d: Silence RCU-list debugging warning in dmar_find_atsr() Date: Wed, 15 Apr 2020 07:44:30 -0400 Message-Id: <20200415114442.14166-73-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200415114442.14166-1-sashal@kernel.org> References: <20200415114442.14166-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 9d47b227e5578..86b1fecdd6865 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -4346,7 +4346,8 @@ 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