[PATCH] Implement _dl_catch_error, _dl_signal_error in libc.so [BZ #16628]

[Florian Weimer]

On 11/30/2016 02:49 PM, Carlos O'Donell wrote:

> Regarding the test case, tst-latepthreadmod, it seems to me that it tests
> only the interposed libc.so versions of the try/catch framework? A test
> that verifies the ld.so try/catch minimal hooks would require a failure
> _before_ relocation, like say loading an LD_AUDIT object early and having
> it fail.

We already have an audit module that exercises the exception handling 
mechanism, tst-auditmod11.c, because unlike all the other audit modules, 
it does not define all audit function.  The equivalent of dlsym fails, 
and this raises an exception.  To my knowledge, this is the only use of 
the catch/receive mechanism in ld.so, and is the reason why we cannot 
have a smaller implementation of the exception handling framework in ld.so.

I think this level of test coverage is completely sufficient, even 
though it was added rather by accident, as part of a completely 
different dynamic linker change.

Thanks,
Florian