Vlad Yasevich wrote: > > Andrei Pelinescu-Onciul wrote: >> For very small autoclose timeouts (e.g. 0 or close to 0 due to >> overflows) it's possible that the timer is executed immediately >> after is set, before there is a chance to increase the association >> reference counter. To avoid this race, always reference the >> association before calling mod_timer() and dereference it back if >> the timer was already active. >> > > Actually, I don't think this can happen. At worst, you'd trigger > a soft lock-up, since the code modifying the timer is already holding > a socket lock. But that would only happen if that code is pre-empted, > which would mean that a user version of the lock is held, then the > autoclose would get rescheduled anyway. > Even if the timer ends up running on a different CPU, the socket lock guarantees that only 1 instance of the state machine is running per socket. The timer handler will spin on the lock until it's released, so there doesn't appear to be a race. -vlad -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
