[SPARC] Segfault when resolving STT_GNU_IFUNC functions

[David Miller]

From: Richard Henderson <rth@twiddle.net>
Date: Tue, 07 Jun 2011 13:24:26 -0700

> On 06/07/2011 12:53 PM, David Miller wrote:
>> The problem in this case is that I'm trying to get at GLRO(dl_hwcap)
>> which lives in the dynamic linker, from IFUNC resolver code which
>> lives in libc.so
> 
> Ah, right, I mis-understood the actual problem.
> 
> I don't see why you wouldn't Define this as part of the Sparc ifunc abi,
> rather than pretending it's private to libc.  It doesn't seem to affect
> any part of the generic ifunc abi.
> 
> If someone actually wanted to use ifunc stuff in third-party libraries,
> they'd be in the same situation.

That's a good point.

However, the thing I was worried about is that if for some reason we
want to add an argument to IFUNC handlers on all architectures, I'd
have to rearrange things on Sparc (move dl_hwcap to the second
argument, etc.) which would break things on people.

Or, keep dl_hwcap as the first argument, and people trying to use the
new IFUNC argument have to do something special on Sparc.

Neither solution would be nice.