Will Schmidt <[EMAIL PROTECTED]> writes: > On Fri, 2007-06-08 at 12:32 -0700, Andrew Morton wrote: >> On Fri, 08 Jun 2007 14:19:18 -0500 >> Will Schmidt <[EMAIL PROTECTED]> wrote: >> >> > > > > zap_other_threads() requires tasklist_lock. >> > > >> In fact, it's probably the case that rcu_read_lock() is now sufficient >> locking coverage for zap_other_threads() (cc's people). >> >> It had better be, because do_group_exit() forgot to take tasklist_lock. It >> is perhaps relying upon spin_lock()'s hidden rcu_read_lock() properties >> without so much as a code comment, which would be somewhat nasty of it. > >> You could perhaps just call do_group_exit() from within the fault >> handler, >> btw. > > Yup, so looks like I can actually replace the existing do_exit() call > with do_group_exit(). I'll sit on this for a bit to give other folks a > chance to comment on which lock call is sufficient, read_lock() or > rcu_read_lock(), etc; and do_group_exit()'s issue with taking > tasklist_lock.
No. The rcu_read_lock is not sufficient. Yes. sighand->siglock is enough, and we explicitly take it in do_group_exit before calling zap_other_threads. Unless I have completely miss-understood this thread. Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
