Preventing preemption of 'protected' symbols in GNU ld 2.26

[Jeff Law]

On 03/30/2016 06:40 PM, Cary Coutant wrote:
>> It would help me immensely on the GCC side if things if you and Alan could
>> easily summarize correct behavior and the impact if we were to just revert
>> HJ's change.  A testcase would be amazingly helpful too.
>
> It looks like it's not just the one change. There's this patch:
>
>     https://gcc.gnu.org/ml/gcc-patches/2015-07/msg01871.html
>
> which took the idea that protected can still be pre-empted by a COPY
> relocation and extended it to three more targets that use COPY
> relocations.
>
> I wonder how many other patches have been based on the same misunderstanding?
I don't think it was many -- I certainly recall the arm/aarch64 variant. 
  There may have been one other varasm.c change in this space or I might 
be conflating it with the arm/aarch64 change.  Tracking those down is 
naturally part of this work.

jeff