Red Hat Bugzilla – Bug 164628
pci_scan_device can cause master abort
Last modified: 2007-11-30 17:07:19 EST
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Description of problem:
pci_scan_device reads the header type from configuration space before checking if a valid vendor id can be read. The vendor id should be read first to verify that a particular pci function exists. Only after a valid vendor id is found should software then read other configuration registers. Failing to adhere to this order causes a master abort, which may be detected and reported on platforms whose pci bridges have that reporting capability.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Turn on error reporting in the pci bridge
2. insert a dual-port gigabit card in a pci hotplug slot
3. bringup the card using pci_scan_slot.
Actual Results: bridge detects master abort from function 2 of the hotplug slot. Function 2 does not exist.
Expected Results: pci_scan_device should have returned from scanning function 2 without having read anything but vendor/device id.
This bug has been fixed upstream already.
--- linux-2.6.9/drivers/pci/probe.c 2005-06-24 13:01:57.000000000 -0400
2005-07-29 09:48:10.000000000 -0400
@@ -590,9 +590,6 @@
- if (pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type))
- return NULL;
if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, &l))
@@ -601,6 +598,9 @@
l == 0x0000ffff || l == 0xffff0000)
+ if (pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type))
+ return NULL;
dev = kmalloc(sizeof(struct pci_dev), GFP_KERNEL);
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.