[RFC] [MIPS] Enable non-executable PT_GNU_STACK support v2

[Joseph Myers]

On Thu, 22 Dec 2016, Joseph Myers wrote:

> I thought 4 was reserved for IFUNC, meaning that support for 5 implied 
> support for IFUNC (because a simple comparison is all that's available to 
> tell whether glibc supports the features required by an executable / 
> shared library; it's a single ABI version number, not a bitmask of 
> features used) and so the ordering was forced.  Certainly the patch here 
> lists IFUNC before MIPS_GNU_STACK, and I don't think the libc-abis system 
> supports gaps in the numbering (you'd need to put in a dummy name if 4 is 
> now to be unused, but then the dummy name would be visible when you run 
> libc.so.6, which it shouldn't be).

The natural way to address that issue, incidentally, would be to reassign 
number 4 to MIPS_GNU_STACK and say that IFUNC will get number 5 when 
ready.  (All the other comments about patch proposals that are explicitly 
for review not RFC, with rationale, architecture-independent pieces split 
out etc., still apply.)

-- 
Joseph S. Myers
joseph@codesourcery.com