Messages in this thread | | | Date | Wed, 20 Apr 2022 13:35:48 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH 2/5] sched,ptrace: Fix ptrace_check_attach() vs PREEMPT_RT |
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On 04/20, Peter Zijlstra wrote: > > On Fri, Apr 15, 2022 at 12:57:56PM +0200, Oleg Nesterov wrote: > > > > ptrace_resume() does wake_up_state(child, __TASK_TRACED) but doesn't > > clear JOBCTL_TRACED. The "else" branch in ptrace_stop() leaks this flag > > too. Perhaps I missed something, I'll reread 1/5 again, but the main > > question to me is whether 1-2 actually need the JOBCTL_TRACED_FROZEN flag. > > Ok, getting back to this. So I did the change to ptrace_resume(), but > I'm not entirely sure I understand the issue with the else branch of > ptrace_stop(). > > My understanding is that if we hit that else branch, we've raced wth > __ptrace_unlink(), and that will have done:
Yes, thanks for correcting me, I forgot that may_ptrace_stop() has gone.
Oleg.
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