Messages in this thread | | | Date | Wed, 27 Apr 2022 16:43:00 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH 6/9] signal: Always call do_notify_parent_cldstop with siglock held |
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On 04/27, Eric W. Biederman wrote: > > The ptrace parental relationship definitely has the potential to be a > graph with cycles. Which as you point out is not fine. > > The result is very nice and I don't want to give it up. I suspect > something ptrace cycles are always a problem and can simply be > forbidden.
OK, please consider another case.
We have a parent P and its child C. C traces P.
This is not that unusual, I don't think we can forbid this case.
P reports an event and calls do_notify_parent_cldstop().
C receives SIGSTOP and calls do_notify_parent_cldstop() too.
Oleg.
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