Re: [RFC,PATCH 14/14] utrace core

From: Roland McGrath
Date: Mon Dec 14 2009 - 14:45:17 EST


> Yes, I think this is correct. It is fine to miss ->pending_attach == T,
> and in any case the new attacher can come right after the check, even
> if it was checked under utrace->lock.

Right.

> It is important that the tracee can't miss, say, UTRACE_REPORT request
> (as you already explained), and every time the tracee clears ->resume
> it calls splice_attaching().

Right.

> > In the stopped cases, there are lots of locks and barriers and things
> > after resuming. (Oleg?)
>
> Every time the tracee resumes after TASK_TRACED it uses utrace->lock
> to synchronize with utrace_control/etc, it must see any changes.

And TASK_STOPPED?

Please send me patches to add whatever comments would make all this clear
enough to Peter when reading the code.


Thanks,
Roland
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