Re: Why I want PTRACE_O_TRACESTOP option

From: Oleg Nesterov
Date: Fri Sep 09 2011 - 12:29:34 EST


On 09/09, Indan Zupancic wrote:
>
> It is very useful to set options atomically at SEIZE time.

Nobody argues with this.

> Another important reason to make PTRACE_O_TRACESTOP an option is
> because not everyone uses SEIZE: Users using PTRACE_TRACEME can't
> set this option at all.

Yes. This was already discussed, PTRACE_TRACEME obviously doesn't
work if you need the new features. So far it was decided TRACEME
should be avoided, but perhaps we can add SEIZE_ME. And, unlike
TRACEME it should probably stop immediately to simplify the
synchronization with parent. Afaik, any user of TRACEME does
something like kill(getpid(), SIGSTOP), this doesn't look very
good.

But personally I'd prefer to avoid SEIZE_ME.

Oleg.

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