Messages in this thread | | | Date | Fri, 3 Jun 2011 17:46:32 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCHSET ptrace] ptrace: implement PTRACE_SEIZE/INTERRUPT and group stop notification, take#4 |
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On 06/03, Denys Vlasenko wrote: > > On Friday 03 June 2011 03:24, Tejun Heo wrote: > > > > Anyways, let's think about that, but SIGSTOP on clone is closely > > linked to why SEIZE is used in the first place and I currently lean > > toward tying it to SEIZE. > > Ok. > > SIGSTOP on clone is less problematic because in practice it's > rather hard to send a real SIGSTOP to a thread which is _just_ created. > So the race window is mostly theoretical
It is not. The new child can dequeue a signal which was sent to the process (thread group). How the tracer can distinguish? Also, SIGSTOP can be sent to pgrp and the new tracee can be forked.
I think that SEIZE should never send SIGSTOP on auto-attach, without any options.
Oleg.
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