From 58be81ed301d96045bca2b85f3b838910efcfde4 Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Fri, 7 Nov 2008 18:19:19 +0000 Subject: uwb: fix races between events and neh timers Always use del_timer_sync() before freeing nehs. Destroy all nehs after stopping the radio controller and before cleaning up the reservation manager. Handle the timer running after an event has removed the neh. This fixes various oopses that may occur if a radio controller is removed while a neh timer is still active. Signed-off-by: David Vrabel --- drivers/uwb/neh.c | 46 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 14 deletions(-) (limited to 'drivers/uwb/neh.c') diff --git a/drivers/uwb/neh.c b/drivers/uwb/neh.c index 9b4eb64327ac..48b4ece1a627 100644 --- a/drivers/uwb/neh.c +++ b/drivers/uwb/neh.c @@ -254,7 +254,6 @@ error_kzalloc: static void __uwb_rc_neh_rm(struct uwb_rc *rc, struct uwb_rc_neh *neh) { - del_timer(&neh->timer); __uwb_rc_ctx_put(rc, neh); list_del(&neh->list_node); } @@ -275,6 +274,7 @@ void uwb_rc_neh_rm(struct uwb_rc *rc, struct uwb_rc_neh *neh) __uwb_rc_neh_rm(rc, neh); spin_unlock_irqrestore(&rc->neh_lock, flags); + del_timer_sync(&neh->timer); uwb_rc_neh_put(neh); } @@ -438,9 +438,10 @@ static void uwb_rc_neh_grok_event(struct uwb_rc *rc, struct uwb_rceb *rceb, size rceb->bEventContext, size); } else { neh = uwb_rc_neh_lookup(rc, rceb); - if (neh) + if (neh) { + del_timer_sync(&neh->timer); uwb_rc_neh_cb(neh, rceb, size); - else + } else dev_warn(dev, "event 0x%02x/%04x/%02x (%zu bytes): nobody cared\n", rceb->bEventType, le16_to_cpu(rceb->wEvent), rceb->bEventContext, size); @@ -562,16 +563,22 @@ EXPORT_SYMBOL_GPL(uwb_rc_neh_grok); */ void uwb_rc_neh_error(struct uwb_rc *rc, int error) { - struct uwb_rc_neh *neh, *next; + struct uwb_rc_neh *neh; unsigned long flags; - BUG_ON(error >= 0); - spin_lock_irqsave(&rc->neh_lock, flags); - list_for_each_entry_safe(neh, next, &rc->neh_list, list_node) { + for (;;) { + spin_lock_irqsave(&rc->neh_lock, flags); + if (list_empty(&rc->neh_list)) { + spin_unlock_irqrestore(&rc->neh_lock, flags); + break; + } + neh = list_first_entry(&rc->neh_list, struct uwb_rc_neh, list_node); __uwb_rc_neh_rm(rc, neh); + spin_unlock_irqrestore(&rc->neh_lock, flags); + + del_timer_sync(&neh->timer); uwb_rc_neh_cb(neh, NULL, error); } - spin_unlock_irqrestore(&rc->neh_lock, flags); } EXPORT_SYMBOL_GPL(uwb_rc_neh_error); @@ -583,10 +590,14 @@ static void uwb_rc_neh_timer(unsigned long arg) unsigned long flags; spin_lock_irqsave(&rc->neh_lock, flags); - __uwb_rc_neh_rm(rc, neh); + if (neh->context) + __uwb_rc_neh_rm(rc, neh); + else + neh = NULL; spin_unlock_irqrestore(&rc->neh_lock, flags); - uwb_rc_neh_cb(neh, NULL, -ETIMEDOUT); + if (neh) + uwb_rc_neh_cb(neh, NULL, -ETIMEDOUT); } /** Initializes the @rc's neh subsystem @@ -605,12 +616,19 @@ void uwb_rc_neh_create(struct uwb_rc *rc) void uwb_rc_neh_destroy(struct uwb_rc *rc) { unsigned long flags; - struct uwb_rc_neh *neh, *next; + struct uwb_rc_neh *neh; - spin_lock_irqsave(&rc->neh_lock, flags); - list_for_each_entry_safe(neh, next, &rc->neh_list, list_node) { + for (;;) { + spin_lock_irqsave(&rc->neh_lock, flags); + if (list_empty(&rc->neh_list)) { + spin_unlock_irqrestore(&rc->neh_lock, flags); + break; + } + neh = list_first_entry(&rc->neh_list, struct uwb_rc_neh, list_node); __uwb_rc_neh_rm(rc, neh); + spin_unlock_irqrestore(&rc->neh_lock, flags); + + del_timer_sync(&neh->timer); uwb_rc_neh_put(neh); } - spin_unlock_irqrestore(&rc->neh_lock, flags); } -- cgit v1.2.2