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=-10.0 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=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 D4809C4CEC5 for ; Fri, 13 Sep 2019 13:20:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AEA6521734 for ; Fri, 13 Sep 2019 13:20:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568380815; bh=H6rv7gekM6TM7NVq6Lf4Z3odoSAzQlt/TcNxyRz5CRU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PvAb4Yt/FAISJAcRlIYQdNwMumfFZAZzUUf/gEzpnerYjVROITGqeenKFmqBEpO14 Nv0gkbTaw6pFetKV/tqYIwxtUPmS8+87zVQ1SV3nGp616y0kIYjZahD/WzvrFIb4Z3 K0621rx6Bullu5Vo2MsfDJEjq6FMExPTSJeIdwpM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389994AbfIMNUP (ORCPT ); Fri, 13 Sep 2019 09:20:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:48942 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389983AbfIMNUO (ORCPT ); Fri, 13 Sep 2019 09:20:14 -0400 Received: from localhost (unknown [104.132.45.99]) (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 D51E42171F; Fri, 13 Sep 2019 13:20:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568380812; bh=H6rv7gekM6TM7NVq6Lf4Z3odoSAzQlt/TcNxyRz5CRU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CYJURzFfW/+aDaE8qXqjkX834fDoUtiiYHnJRfaYME2OI4GIAfs3oP1nmqhzaKs4f 15MAxwRJNEf8zDFcEr1wlNdehrm8CCycpDvLyON8LIdyKNL6LHBo9F/NX0iJK24nh3 nzyqiVpvGuYVFGTKc4gBpaS0JA9wwapVLF4loAnk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nadav Amit , Andrew Morton , Dan Williams , Borislav Petkov , Toshi Kani , Peter Zijlstra , Dave Hansen , Bjorn Helgaas , Ingo Molnar , Linus Torvalds , Sasha Levin Subject: [PATCH 4.19 164/190] resource: fix locking in find_next_iomem_res() Date: Fri, 13 Sep 2019 14:06:59 +0100 Message-Id: <20190913130613.010643960@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190913130559.669563815@linuxfoundation.org> References: <20190913130559.669563815@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 [ Upstream commit 49f17c26c123b60fd1c74629eef077740d16ffc2 ] 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. [akpm@linux-foundation.org: fix find_next_iomem_res() documentation] Link: http://lkml.kernel.org/r/20190613045903.4922-2-namit@vmware.com Fixes: ff3cc952d3f00 ("resource: Add remove_resource interface") Signed-off-by: Nadav Amit Reviewed-by: Andrew Morton Reviewed-by: Dan Williams Cc: Borislav Petkov Cc: Toshi Kani Cc: Peter Zijlstra Cc: Dave Hansen Cc: Bjorn Helgaas Cc: Ingo Molnar Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- kernel/resource.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 38b8d11c9eaf4..bce773cc5e416 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -325,7 +325,7 @@ EXPORT_SYMBOL(release_resource); * * If a resource is found, returns 0 and *res is overwritten with the part * of the resource that's within [start..end]; if none is found, returns - * -1. + * -ENODEV. Returns -EINVAL for invalid parameters. * * This function walks the whole tree and not just first level children * unless @first_level_children_only is true. @@ -359,16 +359,16 @@ 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