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=-8.7 required=3.0 tests=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 C14F7C31E45 for ; Thu, 13 Jun 2019 16:47:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A02692084D for ; Thu, 13 Jun 2019 16:47:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404191AbfFMQrf (ORCPT ); Thu, 13 Jun 2019 12:47:35 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:35438 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730259AbfFME7Z (ORCPT ); Thu, 13 Jun 2019 00:59:25 -0400 Received: by mail-pg1-f194.google.com with SMTP id s27so10203862pgl.2; Wed, 12 Jun 2019 21:59:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=6wLiv6GN7xAd5Zv2tE3Uvom556HtPMdkccB9NZBaHbY=; b=jltvVX7lsUUTKxPZyeSzWIf018y0fP8y5nQ+NWWAxnPTlVFWwLs85lF2YolJCJS9JB 6GloAfUF+sbPjORm1UzyH8hpS3h1/ZziR5WP5SbBW7RSiNryWvNK5TTpyEAZtDzVcwDM Jyvj3Sa8zkG/rB4Yxzhunjsl2Gtx/p9bKlegqbW+fyXM7iOm8GN5wSnEDDWAokGaP1d3 zeIuD8gtOSYzJV701nDSid73biG0QmRa942s7I+/QMExM3u69N0Sf8+s6McWOW9EQdS7 raZAijhGdEkW7+klw/tN/7HfsI+wQnWGa4tbhVUkEGR3w57Xx6WK7X+XdGMJzs+/PTuo F8ug== X-Gm-Message-State: APjAAAVxNAXmrCIkEsZovLXNNYZ9Lq2BGM9kPyKk3O0gKJLeIBst9zGs 4kineA8lkzGfyIFMHCRB8Ho= X-Google-Smtp-Source: APXvYqyRFetiSrVNAFOs+Vdat5g6tOVK6CHQ8Kpr4jVNenuu39OoAGQYcODaNP5cx3ByfK2aAkX8CQ== X-Received: by 2002:a63:4813:: with SMTP id v19mr2978773pga.124.1560401964368; Wed, 12 Jun 2019 21:59:24 -0700 (PDT) Received: from htb-2n-eng-dhcp405.eng.vmware.com ([66.170.99.1]) by smtp.gmail.com with ESMTPSA id o66sm1215327pfb.86.2019.06.12.21.59.22 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Wed, 12 Jun 2019 21:59:23 -0700 (PDT) From: Nadav Amit To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Nadav Amit , stable@vger.kernel.org, Borislav Petkov , Toshi Kani , Peter Zijlstra , Dave Hansen , Dan Williams , Bjorn Helgaas , Ingo Molnar Subject: [PATCH 1/3] resource: Fix locking in find_next_iomem_res() Date: Wed, 12 Jun 2019 21:59:01 -0700 Message-Id: <20190613045903.4922-2-namit@vmware.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190613045903.4922-1-namit@vmware.com> References: <20190613045903.4922-1-namit@vmware.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since resources can be removed, locking should ensure that the resource is not removed while accessing it. However, find_next_iomem_res() does not hold the lock while copying the data of the resource. Keep holding the lock while the data is copied. While at it, change the return value to a more informative value. It is disregarded by the callers. Fixes: ff3cc952d3f00 ("resource: Add remove_resource interface") Cc: stable@vger.kernel.org Cc: Borislav Petkov Cc: Toshi Kani Cc: Peter Zijlstra Cc: Dave Hansen Cc: Dan Williams Cc: Bjorn Helgaas Cc: Ingo Molnar Signed-off-by: Nadav Amit --- kernel/resource.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 158f04ec1d4f..c0f7ba0ece52 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -365,16 +365,16 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end, break; } + if (p) { + /* copy data */ + res->start = max(start, p->start); + res->end = min(end, p->end); + res->flags = p->flags; + res->desc = p->desc; + } + read_unlock(&resource_lock); - if (!p) - return -1; - - /* copy data */ - res->start = max(start, p->start); - res->end = min(end, p->end); - res->flags = p->flags; - res->desc = p->desc; - return 0; + return p ? 0 : -ENODEV; } static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end, -- 2.20.1