Messages in this thread Patch in this message | | | Date | Sun, 6 Sep 2009 18:50:29 +0200 (CEST) | From | Stefan Richter <> | Subject | [PATCH 4/6] firewire: core: fix race with parallel PCI device probe |
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The config ROM buffer received from generate_config_rom is a globally shared static buffer. Extend the card_mutex protection in fw_add_card until after the config ROM was copied into the card driver's buffer. Otherwise, parallelized card driver probes may end up with ROM contents that were meant for a different card.
firewire-ohci's card->driver->enable hook is safe to be called within the card_mutex. Furthermore, it is safe to reorder card_list update versus card enable, which simplifies the code a little.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> --- drivers/firewire/core-card.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-)
Index: linux-2.6.31-rc9/drivers/firewire/core-card.c =================================================================== --- linux-2.6.31-rc9.orig/drivers/firewire/core-card.c +++ linux-2.6.31-rc9/drivers/firewire/core-card.c @@ -449,16 +449,13 @@ int fw_card_add(struct fw_card *card, card->guid = guid; mutex_lock(&card_mutex); - config_rom = generate_config_rom(card, &length); - list_add_tail(&card->link, &card_list); - mutex_unlock(&card_mutex); + config_rom = generate_config_rom(card, &length); ret = card->driver->enable(card, config_rom, length); - if (ret < 0) { - mutex_lock(&card_mutex); - list_del(&card->link); - mutex_unlock(&card_mutex); - } + if (ret == 0) + list_add_tail(&card->link, &card_list); + + mutex_unlock(&card_mutex); return ret; } -- Stefan Richter -=====-==--= =--= --==- http://arcgraph.de/sr/
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