Re: ptrace.2: PTRACE_KILL needs a stopped process too

[Oleg Nesterov]

On 05/09, Pedro Alves wrote:
>
> On 05/09/2012 04:09 PM, Mike Frysinger wrote:
>
> > probably not that big of a deal, but the reason i like using
> > ptrace(PTRACE_KILL) over a raw kill() is that you are less likely to kill the
> > wrong process by accident.  maybe not that big of a deal in practice though.
>
>
> And you can do tgkill instead.  It was specifically invented to handle the
> reuse case.

tgkill() can kill the wrong process/thread too, although it lessens the risk.

But I don't really understand the problem. The traced thread can't go away
until the tracer does wait/detach, and thus its pid can't be reused?

May be, "by accident" above means something else, not pid reuse...

Oleg.

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