sparc64: Skip bogus PCI bridge ranges. (4afba24e) · Commits · 戴 / test

It seems that when a PCI Express bridge is not in use and has no devices behind it, the ranges property is bogus. Specifically the size property is of the form [0xffffffff:...], and if you add this size to the resource start address the 64-bit calculation will overflow. Just check specifically for this size value signature and skip them. Signed-off-by:

David S. Miller <davem@davemloft.net>

arch/sparc/kernel/pci.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -489,6 +489,17 @@ static void of_scan_pci_bridge(struct pci_pbm_info *pbm,
		size = GET_64BIT(ranges, 6);
		if (flags == 0 \|\| size == 0)
		continue;

		/* On PCI-Express systems, PCI bridges that have no devices downstream
		* have a bogus size value where the first 32-bit cell is 0xffffffff.
		* This results in a bogus range where start + size overflows.
		*
		* Just skip these otherwise the kernel will complain when the resource
		* tries to be claimed.
		*/
		if (size >> 32 == 0xffffffff)
		continue;

		if (flags & IORESOURCE_IO) {
		res = bus->resource[0];
		if (res->flags) {

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