On Tue, 2011-05-10 at 18:10 -0700, John Stultz wrote: > On Tue, 2011-05-10 at 17:51 -0700, Joe Perches wrote: > > Could misuse of %ptc (not using current) cause system lockup? > > It very well could. Although I don't see other %p options tring to > handle invalid pointers. Any suggestions on how to best handle this? And just to clarify on this point, I'm responding to if a invalid pointer was provided, causing the dereference to go awry. If a valid non-current task was provided, the locking should be ok as we disable irqs while the write_seqlock is held in set_task_comm(). The only places this could cause a problem was if you tried to printk with a %ptc while holding the task->comm_lock. However, the lock is only shortly held in task_comm_string, and get_task_comm and set_task_comm. So it is fairly easy to audit for correctness. If there is some other situation you had in mind, please let me know. thanks -john -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>