Re: (ITS#3932) regex/librewrite concurrency issue

[ando@sys-net.it]

> There may be concurrent accesses to regex_t datum by librewrite; if
> regexec is
> not thread safe (which I suppose is not) this may result in concurrency
> issues.
> I randomly experienced this with test039 on a 4 CPU machine; never
> experienced
> it on single CPU machine.

I'm not sure the one committed is the right fix: if the non-reentrancy
issue is in regexec(3), then also ACLs should suffer from it.  In this
case either we assume regex is not reentrant, or require it is, or provide
compile switches or function wrappers to handle the case it's not.  I note
there are a few past ITSes that point in this direction and that have
never been fixed (e.g. ITS#3634).

On the machine I'm able to experience this issue the OS is CentOS release
4.1 (Final) and regex is part of glibc 2.3.4

p.

-- 
Pierangelo Masarati
mailto:pierangelo.masarati@sys-net.it


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