On 11/23, Alexey Dobriyan wrote: > > On Thu, Nov 22, 2007 at 07:14:59PM +0300, Oleg Nesterov wrote: > > If the tracer went away (may_ptrace_stop() failed), ptrace_stop() drops > > tasklist > > and then changes the ->state from TASK_TRACED to TASK_RUNNING. > > > > This can fool another tracer which attaches to us in between. Change the > > ->state > > under tasklist_lock to ensure that ptrace_check_attach() can't wrongly > > succeed. > > ptrace_check_attach? Both do read_lock -- can run in parallel,
Yep. > so how can it help? read_lock prevents ptrace_attach(), so the new tracer can't attach and then do ptrace_check_attach(). Oleg. - 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/
