Received: by 2002:a25:1985:0:0:0:0:0 with SMTP id 127csp1725882ybz; Sat, 18 Apr 2020 07:14:37 -0700 (PDT) X-Google-Smtp-Source: APiQypIYdPsyAgvFjE9S2Guaw8359VqlhhCV2q2fEdwx3OEf5OLYZBUY5iNj+hnYb2kqvYFekcOs X-Received: by 2002:a17:907:9484:: with SMTP id dm4mr8078246ejc.240.1587219277781; Sat, 18 Apr 2020 07:14:37 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1587219277; cv=none; d=google.com; s=arc-20160816; b=Vb4Ldi0GBLqS/X4PqtpEsGLIX59ggtfUcA5aEBqz5KSLyZ4bTCEaAXTPNL78kvf282 949XYn19u+M2fiwouY+i2KmWOoQFGoBy/UwMpnv3LjfUme46Cj7RtTNGN0TlTEAF7nsH /pqCs5o0deiqwGTUiq254DW3R8QpiYka9LHySdSZ1xEGI2QfRv210WRBWSep3RdDEgaS 4S4NfPJfTNPcimPUUefgEY2R5HdRPoC9PgHH3TFrYFQDsYqowyrXFFuoc3T7zf2Hds7j iMAt/LfNKRSJ63H/6SIR/qIBiSdWdb2/Vcn7B1aJh4viaGCQ80KBiPrCUBcirNz4RVof d0uA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=uc9LZriicGb1V+WKkA3Ptmw6Zapqkp+sxfooAUsd8CA=; b=jqKrYtRI6bly7aMjHxtjZA+rPMZGIF4eyrWoY/PPNTxrzC7UFJlFtGyW+aASjFr9UN 8Dc2CjYZK9Klg5kPb3iVYUNkZ+vW/DZ0ieIYJUKXlCxkf0ygnnqEPfMBZCo4wL260faJ kM0RdRfHJ4E70bB5n7YmndXd0IAwjibMa/ZZ/SXCaPqPOJCCZcknZncf3ip/T/9SO4CY l9mf3deVUM37yyEVFaOM+XsoaBAdgEzCscKU+qnuYgxZ3cuf0Sm1DGfzloBEJ9fC9pLw Ee5RiU44Dj367N3h06DF2M0dAL80/HMs4yr9CE8B1hoHOSosrHytAbPI8o30U/QppRU8 Gcvw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=vuE62ywE; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id l3si11844324edr.46.2020.04.18.07.14.15; Sat, 18 Apr 2020 07:14:37 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=vuE62ywE; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728128AbgDROMU (ORCPT + 99 others); Sat, 18 Apr 2020 10:12:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:38072 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726846AbgDROKK (ORCPT ); Sat, 18 Apr 2020 10:10:10 -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 7191721D79; Sat, 18 Apr 2020 14:10:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587219010; bh=T9ctf/OjrEvQnAxPrSzCi8ZBdl86yOCobW5C1jccqD0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vuE62ywE0d66pB0vaZs0/koy49AORbaJbTJjglOrejalnC80LOm4hLXmGmUGl7vgu BtcLi6BDN1lU388WWfzoOMQbtyOaN3lcTgLLR+FVIKUVrzA6JFivslhFscv0Ma9HeB cnhGxgMrA/p9H/EL2MTc1siSq52maglMgeby4UPo= 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 5.5 47/75] iommu/vt-d: Silence RCU-list debugging warning in dmar_find_atsr() Date: Sat, 18 Apr 2020 10:08:42 -0400 Message-Id: <20200418140910.8280-47-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200418140910.8280-1-sashal@kernel.org> References: <20200418140910.8280-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 87cd68a4e5eab..8e5d6732b48d2 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -4359,7 +4359,8 @@ 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