From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758957Ab0GPTHP (ORCPT ); Fri, 16 Jul 2010 15:07:15 -0400 Received: from mga02.intel.com ([134.134.136.20]:57479 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756633Ab0GPTHN (ORCPT ); Fri, 16 Jul 2010 15:07:13 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.55,215,1278313200"; d="scan'208";a="536202867" From: Jacob Pan To: "H. Peter Anvin" , Ben Greear , Jesse Barnes , LKML Cc: Jacob Pan Subject: [PATCH] x86/pci/mrst: add extra check in fixed bar detection Date: Fri, 16 Jul 2010 11:58:26 -0700 Message-Id: <1279306706-27087-1-git-send-email-jacob.jun.pan@linux.intel.com> X-Mailer: git-send-email 1.6.3.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Suggested-by: "H. Peter Anvin" Signed-off-by: Jacob Pan --- 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 c9649d0..8636567 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; -- 1.7.0.4