Messages in this thread Patch in this message | | | Date | Wed, 19 Mar 2008 20:56:26 +0100 (CET) | From | Stefan Richter <> | Subject | [PATCH 2/2] firewire: insist on successive self ID complete events |
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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 new 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. This should fix another aspect of http://bugzilla.kernel.org/show_bug.cgi?id=10128
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> --- drivers/firewire/fw-topology.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
Index: linux/drivers/firewire/fw-topology.c =================================================================== --- linux.orig/drivers/firewire/fw-topology.c +++ linux/drivers/firewire/fw-topology.c @@ -518,6 +518,17 @@ fw_core_handle_bus_reset(struct fw_card return; } + /* + * 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)) { + fw_notify("skipped bus generations, destroying all nodes\n"); + fw_destroy_nodes(card); + card->bm_retries = 0; + } + spin_lock_irqsave(&card->lock, flags); /* -- Stefan Richter -=====-==--- --== =--== http://arcgraph.de/sr/
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