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authorJacob Pan <jacob.jun.pan@linux.intel.com>2010-07-16 11:58:26 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-02 10:29:56 -0700
commitb55e938d07d4af42af8997a78bce880b5778f41d (patch)
treee14065b032902b90e189e69e877d90b676bcbf55 /arch
parentf3cc1d7b74d0d128da2cc39cf88390ed4f95e08d (diff)
x86, pci, mrst: Add extra sanity check in walking the PCI extended cap chain
commit f82c3d71d6fd2e6a3e3416f09099e29087e39abf upstream. 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" <hpa@zytor.com> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> LKML-Reference: <1279306706-27087-1-git-send-email-jacob.jun.pan@linux.intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/pci/mrst.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/x86/pci/mrst.c b/arch/x86/pci/mrst.c
index 1cdc02cf8fa4..1699ea80e911 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;