From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966313Ab0GQAtx (ORCPT ); Fri, 16 Jul 2010 20:49:53 -0400 Received: from hera.kernel.org ([140.211.167.34]:55535 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759520Ab0GQAtS (ORCPT ); Fri, 16 Jul 2010 20:49:18 -0400 Date: Sat, 17 Jul 2010 00:49:04 GMT From: tip-bot for Jacob Pan Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, jbarnes@virtuousgeek.org, tglx@linutronix.de, hpa@linux.intel.com, jacob.jun.pan@linux.intel.com Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, jbarnes@virtuousgeek.org, tglx@linutronix.de, jacob.jun.pan@linux.intel.com, hpa@linux.intel.com In-Reply-To: <1279306706-27087-1-git-send-email-jacob.jun.pan@linux.intel.com> References: <1279306706-27087-1-git-send-email-jacob.jun.pan@linux.intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86, pci, mrst: Add extra sanity check in walking the PCI extended cap chain Message-ID: Git-Commit-ID: f82c3d71d6fd2e6a3e3416f09099e29087e39abf X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Sat, 17 Jul 2010 00:49:05 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: f82c3d71d6fd2e6a3e3416f09099e29087e39abf Gitweb: http://git.kernel.org/tip/f82c3d71d6fd2e6a3e3416f09099e29087e39abf Author: Jacob Pan AuthorDate: Fri, 16 Jul 2010 11:58:26 -0700 Committer: H. Peter Anvin CommitDate: Fri, 16 Jul 2010 16:52:15 -0700 x86, pci, mrst: Add extra sanity check in walking the PCI extended cap chain The fixed bar capability structure is searched in PCI extended configuration space. We need to make sure there is a valid capability ID to begin with otherwise, the search code may stuck in a infinite loop which results in boot hang. This patch adds additional check for cap ID 0, which is also invalid, and indicates end of chain. End of chain is supposed to have all fields zero, but that doesn't seem to always be the case in the field. Suggested-by: "H. Peter Anvin" Signed-off-by: Jacob Pan Reviewed-by: Jesse Barnes LKML-Reference: <1279306706-27087-1-git-send-email-jacob.jun.pan@linux.intel.com> Signed-off-by: H. Peter Anvin --- arch/x86/pci/mrst.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/x86/pci/mrst.c b/arch/x86/pci/mrst.c index 7ef3a27..cb29191 100644 --- a/arch/x86/pci/mrst.c +++ b/arch/x86/pci/mrst.c @@ -66,8 +66,9 @@ static int fixed_bar_cap(struct pci_bus *bus, unsigned int devfn) devfn, pos, 4, &pcie_cap)) return 0; - if (pcie_cap == 0xffffffff) - return 0; + if (PCI_EXT_CAP_ID(pcie_cap) == 0x0000 || + PCI_EXT_CAP_ID(pcie_cap) == 0xffff) + break; if (PCI_EXT_CAP_ID(pcie_cap) == PCI_EXT_CAP_ID_VNDR) { raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number, @@ -76,7 +77,7 @@ static int fixed_bar_cap(struct pci_bus *bus, unsigned int devfn) return pos; } - pos = pcie_cap >> 20; + pos = PCI_EXT_CAP_NEXT(pcie_cap); } return 0;