Re: atexit_callback can be a net negative

On 03/07/2014 03:57 PM, Tom Lane wrote:

> I think Florian's right that there's a risk there, but it seems pretty
> remote, and I don't see any reliable way to detect the case anyhow.
> (Process start time?  Where would you get that from portably?)

I don't think there's a portable source for that.  On Linux, you'd have 
to use /proc.

> It's not a reason not to do something about the much larger chance of
> this happening in a direct child process, which certainly won't have a
> matching PID.

Indeed.  Checking getppid() in addition might narrow things down further.

On Linux, linking against pthread_atfork currently requires linking 
against pthread (although this is about to change), and it might incur 
the pthread-induced overhead on some configurations.

-- 
Florian Weimer / Red Hat Product Security Team