On Tue, 2011-05-10 at 18:10 -0700, John Stultz wrote: > On Tue, 2011-05-10 at 17:51 -0700, Joe Perches wrote: > > On Tue, 2011-05-10 at 17:23 -0700, John Stultz wrote: > > > Acessing task->comm requires proper locking. However in the past > > > access to current->comm could be done without locking. This > > > is no longer the case, so all comm access needs to be done > > > while holding the comm_lock. > > 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? The only one I know of is ipv6 which copies a 16 byte buffer in case the pointed to value is unaligned. I suppose %pI6c could be a problem or maybe %pS too, but it hasn't been in practice. The use of %ptc somehow seemed more error prone. > Most users are current, so forcing the more rare > non-current users to copy it to a buffer first and use the normal %s > would not be of much impact. > > Although I'm not sure if there's precedent for a %p value that didn't > take a argument. Thoughts on that? Anyone else have an opinion here? The uses of %ptc must add an argument or else gcc will complain. I suggest you just ignore the argument value and use current. -- 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>