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authorStefan Richter <stefanr@s5r6.in-berlin.de>2008-03-19 22:02:40 +0100
committerStefan Richter <stefanr@s5r6.in-berlin.de>2009-01-20 19:29:51 +0100
commita5c7f4710fba334bf613d705f97b4471b36446f8 (patch)
tree85deaf0584aea866a976245bae3c0d99bbca579f
parent1de9e8e70f5acc441550ca75433563d91b269bbe (diff)
firewire: insist on successive self ID complete events
The whole topology code only works if the old and new topologies which are compared come from immediately successive self ID complete events. If there happened bus resets without self ID complete events in the meantime, or self ID complete events with invalid selfIDs, the topology comparison could identify nodes wrongly, or more likely just corrupt kernel memory or panic right away. We now discard all nodes of the old topology and treat all current nodes as new ones if the current self ID generation is not the previous one plus 1. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Jarod Wilson <jwilson@redhat.com>
-rw-r--r--drivers/firewire/fw-topology.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/firewire/fw-topology.c b/drivers/firewire/fw-topology.c
index c9be6e6948c..e7520e4bd6b 100644
--- a/drivers/firewire/fw-topology.c
+++ b/drivers/firewire/fw-topology.c
@@ -518,6 +518,18 @@ fw_core_handle_bus_reset(struct fw_card *card,
struct fw_node *local_node;
unsigned long flags;
+ /*
+ * If the selfID buffer is not the immediate successor of the
+ * previously processed one, we cannot reliably compare the
+ * old and new topologies.
+ */
+ if ((generation & 0xff) != ((card->generation + 1) & 0xff) &&
+ card->local_node != NULL) {
+ fw_notify("skipped bus generations, destroying all nodes\n");
+ fw_destroy_nodes(card);
+ card->bm_retries = 0;
+ }
+
spin_lock_irqsave(&card->lock, flags);
card->node_id = node_id;