From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755213Ab0JNXSb (ORCPT ); Thu, 14 Oct 2010 19:18:31 -0400 Received: from g1t0028.austin.hp.com ([15.216.28.35]:4964 "EHLO g1t0028.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753506Ab0JNXS2 (ORCPT ); Thu, 14 Oct 2010 19:18:28 -0400 Subject: [PATCH v4 1/6] resources: ensure alignment callback doesn't allocate below available start To: Jesse Barnes From: Bjorn Helgaas Cc: Bob Picco , Brian Bloniarz , Charles Butterfield , Denys Vlasenko , linux-pci@vger.kernel.org, "Horst H. von Brand" , Ingo Molnar , linux-kernel@vger.kernel.org, Stefan Becker , "H. Peter Anvin" , Yinghai Lu , Leann Ogasawara , Linus Torvalds , Thomas Gleixner Date: Thu, 14 Oct 2010 17:18:26 -0600 Message-ID: <20101014231826.536.51757.stgit@bob.kio> In-Reply-To: <20101014231804.536.62138.stgit@bob.kio> References: <20101014231804.536.62138.stgit@bob.kio> User-Agent: StGit/0.15 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The alignment callback returns a proposed location, which may have been adjusted to avoid ISA aliases or for other architecture-specific reasons. We already had a check ("tmp.start < tmp.end") to make sure the callback doesn't return a location above the available area. This patch adds a check to make sure the callback doesn't return something *below* the available area, as may happen if the callback tries to allocate top-down. Signed-off-by: Bjorn Helgaas --- kernel/resource.c | 10 ++++++++-- 1 files changed, 8 insertions(+), 2 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 7b36976..ace2269 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -371,6 +371,7 @@ static int find_resource(struct resource *root, struct resource *new, { struct resource *this = root->child; struct resource tmp = *new; + resource_size_t start; tmp.start = root->start; /* @@ -391,8 +392,13 @@ static int find_resource(struct resource *root, struct resource *new, if (tmp.end > max) tmp.end = max; tmp.start = ALIGN(tmp.start, align); - if (alignf) - tmp.start = alignf(alignf_data, &tmp, size, align); + if (alignf) { + start = alignf(alignf_data, &tmp, size, align); + if (tmp.start <= start && start <= tmp.end) + tmp.start = start; + else + tmp.start = tmp.end; + } if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) { new->start = tmp.start; new->end = tmp.start + size - 1;