Using __chk_fail from libstdc++

[Florian Weimer]

On 06/01/2012 08:52 PM, Roland McGrath wrote:
> I thought of that too but didn't think I cared.  We don't have an
> existing header that seems appropriate.  Since it's an __ function,
> it shouldn't really be declared in a "user" header.  So I guess it
> would be some new header like<bits/fortify.h>.  But then libstdc++
> would require a new-enough libc to have that header.  If this is
> only going to be called from the library itself that doesn't seem
> like a problem since it can just autoconf it.  But if Florian
> intends to call it from libstdc++ header files (e.g. template code)
> then it could be an issue.

I need to call it from template code.  I could conceivably add a wrapper 
which falls back to abort if __chk_fail is not available, but I'm 
working on a libc-only feature anyway (_FORTIFY_SOURCE for some C++ 
constructs).  Thus my preference is to avoid the wrapper.

-- 
Florian Weimer / Red Hat Product Security Team