Messages in this thread |  | | Date | Sat, 8 Sep 2001 19:11:08 +0200 | From | Andrea Arcangeli <> | Subject | Re: [patch] proposed fix for ptrace() SMP race |
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On Fri, Sep 07, 2001 at 08:35:31AM -0700, David Mosberger wrote: > Also, other signals will still wake up the task. Yes, it won't get > very far as do_signal() will notify the parent instead, but still, the > task will run and that could be enough to create some race condition.
this is the real issue, agreed.
However still I don't like the cpus_allowed racy approch. I either prefer to force the deschedule with a new ptrace bitflag with new hooks in the scheduler or with a blocker (delayer) to the signals again with a new ptrace bitflag but in this case with hooks in the signal code. I think putting the hooks in the signal code is better.
BTW, checking this stuff I found two bugs, one is the check for cpus_allowed before calling reschedule_idle, such check has to be removed, then it also seems the signals seems to wakeup the task two times unless I've overlooked something.
You may want to make a new patch at the light of those considerations otherwise I'll put this in my todo list once more important things are solved.
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