Received: by 2002:a25:1985:0:0:0:0:0 with SMTP id 127csp643717ybz; Wed, 22 Apr 2020 05:22:19 -0700 (PDT) X-Google-Smtp-Source: APiQypLqSVEAw7HrSdO0TRaBwur+wpqtDYaRHn9i3hXt/j1NPYKZnEsnk1KTT20R35a9g1r6uZ2I X-Received: by 2002:aa7:cc92:: with SMTP id p18mr22824844edt.166.1587558139742; Wed, 22 Apr 2020 05:22:19 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1587558139; cv=none; d=google.com; s=arc-20160816; b=IxgVfMyKin5GIyep9Qy2vEGl+5x0rBWnb4aRwxHrz59bOq4rBB68DMIG3CVKMrxXOS xWqJwV6EOhrsYtLK86B9RlEU+WAJ14sHWWs9GkfWL3W/zpxvWymCYnKiz3oCltAbDKq0 rkGtLiTgwpsJCW4LqYoOo/E+oS6kF7uEMEiimbxU4pJbJhyq7H7MheybRJBCWFaljbEE TlSZ7xUAYYYof3SSdjcQ3JYnz3uy4/vG/kVtqjJ0at7SGAwrrMjWUrwBGw026ekbYnIz 7U4r7f5BdFx3WSF1DhywIYFN6jhuVobT893BAZoPS7u1C73qcDVy9TBjMkzndVTYbujg fIJw== 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 :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=PUm3Th+0r+lSddwjUSITKPnWtSml9gj4pxARIXeFePw=; b=DzZ7GVD2ZPU0/4MlUfgrKyG5+sYutJbXfHu4r2BFzdfv2rPeDp4ibUH1Uh8RjSHaCJ BwI9UILeoy7YpWjCKta/DG3+9fEnSStH9WxEeY7lLUZwhneWTa9+wxrNI0JZHaov0M5w O+DhIPp1T81AJjqB+tYrqkDIRvpn66bpM6omdHaaHRQgEUJCqwkfEZ9eyG6rjvmyipwS q9MujaQNWW1WrU6P0Z1uszKwSDpL8wYez7Gj//SQB0ijm8YHLqlfkxW1aZF2n9BVLzHL AgLoijEkIJE0h7O9aUJZuYRQORixrerZoZibMSoelRV1OFp1W5qy8cwHjFEIs+4C4gQf ELOQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=fcj9RF3Y; 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 Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id w10si3469311ejk.157.2020.04.22.05.21.56; Wed, 22 Apr 2020 05:22:19 -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=fcj9RF3Y; 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 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730537AbgDVKaU (ORCPT + 99 others); Wed, 22 Apr 2020 06:30:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:35250 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730722AbgDVK0X (ORCPT ); Wed, 22 Apr 2020 06:26:23 -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 491F42075A; Wed, 22 Apr 2020 10:26:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587551182; bh=fGz7a64lWYFN33TvpNVh9lbizXvizlbW6RS4o/D26oI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fcj9RF3Yuk1qWYCkIYRZa84LxB2oIArh8FxoYaloLMXuPm9JZ8bUB8WdTBuDnqB5S h5aU7slLfxEnQkMBa40gNkC8flCJAwKtPDr3KDK9pUwks3gnVgDAaazpL0XRzaX1gt yC88SNi0UBIkNUBNM+8S/pHGK9EBWNCLHCHFr9Cc= 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 5.6 134/166] iommu/vt-d: Silence RCU-list debugging warning in dmar_find_atsr() Date: Wed, 22 Apr 2020 11:57:41 +0200 Message-Id: <20200422095103.005670022@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095047.669225321@linuxfoundation.org> References: <20200422095047.669225321@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 4be5494786918..ef0a5246700e5 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -4501,7 +4501,8 @@ 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