On 05/14/2015 06:50 PM, Quentin Casasnovas wrote: >>> The only way for us to work-around this behaviour was to have >>> PTRACE_O_TRACEEXIT and detach from the threads when we were notified of a >>> thread termination, without PTRACE_O_TRACEEXIT I don't think one can be >>> notified in way, leading to hangs almost certainly when tracing multiple >>> threads and some are in ptrace-stop. >> >> Why do you do that waitpid on thread group leader? >> >> strace is the user of ptrace, and it has no problem with this behavior. >> It simply waits for all tracees via waitpid(-1). Whichever sends the next >> notification is processed. >> > > That's because strace has all threads running; in our use-case, we attach > to all threads of a group and restart a single thread to do some work. In > this particular case, waitpid(-1, ...) does not help because to exit, the > other threads need to be PTRACE_CONT'ed. Can you be more specific? IF you have thread(s) which "do some work", then waitpid(-1) would work for you - presumably, you wait for them to finish doing work, or otherwise terminate, get a signal, whatever? -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
