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authorRuiyu Ni <ruiyu.ni@intel.com>2015-09-15 08:47:05 +0000
committerhwu1225 <hwu1225@Edk2>2015-09-15 08:47:05 +0000
commita7757cf69f830bcfb7c6eed4786b303f23f53140 (patch)
treef2ffab1f48b7ec9577d93fb580bb5532f0d3b914 /MdeModulePkg/Bus
parenta6c273bb633cca00c0fa0f79fbf95704a8fec5e9 (diff)
downloadedk2-platforms-a7757cf69f830bcfb7c6eed4786b303f23f53140.tar.xz
MdeModulePkg: Enhance PCI capability looking up logic to avoid hang
Certain PCI device may have capability pointing to itself. Update LocateCapabilityRegBlock() to break when detecting such loop. (Sync patch r18473 from main trunk.) Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com> Reviewed-by: Feng Tian <feng.tian@intel.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/branches/UDK2015@18475 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'MdeModulePkg/Bus')
-rw-r--r--MdeModulePkg/Bus/Pci/PciBusDxe/PciCommand.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciCommand.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciCommand.c
index 8a8b4b8fac..0bc1fbfeff 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciCommand.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciCommand.c
@@ -173,6 +173,14 @@ LocateCapabilityRegBlock (
return EFI_SUCCESS;
}
+ //
+ // Certain PCI device may incorrectly have capability pointing to itself,
+ // break to avoid dead loop.
+ //
+ if (CapabilityPtr == (UINT8) (CapabilityEntry >> 8)) {
+ break;
+ }
+
CapabilityPtr = (UINT8) (CapabilityEntry >> 8);
}