Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d3813fcf authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds
Browse files

[PATCH] x86_64: Don't oops at boot when empty Opteron node has IO 



The code to detect IO links on Opteron would not check
if the node had actually memory. This could lead to pci_bus_to_node
returning an invalid node, which might cause crashes later
when dma_alloc_coherent passes it to page_alloc_node().

The bug has been there forever but for some reason
it is causing now crashes.

Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 2bbfb16b

arch/x86_64/pci/k8-bus.c

+11 −2
Original line number Diff line number Diff line
@@ -47,13 +47,22 @@ fill_mp_bus_to_cpumask(void) 
			 * if there are no busses hanging off of the current

			 * ldt link then both the secondary and subordinate

			 * bus number fields are set to 0.

			 * 

			 * RED-PEN

			 * This is slightly broken because it assumes

 			 * HT node IDs == Linux node ids, which is not always

			 * true. However it is probably mostly true.

			 */

			if (!(SECONDARY_LDT_BUS_NUMBER(ldtbus) == 0

				&& SUBORDINATE_LDT_BUS_NUMBER(ldtbus) == 0)) {

				for (j = SECONDARY_LDT_BUS_NUMBER(ldtbus);

				     j <= SUBORDINATE_LDT_BUS_NUMBER(ldtbus);

				     j++)

					pci_bus_to_node[j] = NODE_ID(nid);

				     j++) { 

					int node = NODE_ID(nid);

					if (!node_online(node))

						node = 0;

					pci_bus_to_node[j] = node;

				}		

			}

		}

	}