RFC: Add DT_FLAGS_2 and DF_2_GNU_IFUNC

[Florian Weimer]

On 05/25/2018 10:58 PM, H.J. Lu wrote:
> On Fri, May 25, 2018 at 1:35 PM, Florian Weimer <fweimer@redhat.com> wrote:
>> On 05/25/2018 07:47 PM, H.J. Lu wrote:
>>>
>>> This patch extends gABI with DT_FLAGS_2 and DF_2_GNU_IFUNC to indicate
>>> that a shared object or executable has IFUNC symbols so that dynamic
>>> linker can relocate it early.
>>
>>
>> I don't think this will solve any of the thorny cases.  It may help with
>> missing DT_NEEDED entries, but that's only a small subset of the issues, and
>> as far as linking against glibc is concerned, such binaries are invalid
>> anyway.
> 
> In my case, LD_PRELOADed shared library is linked against libc.so.  But there
> is no dependency on it by definition.

Still I don't see what this buys you if the LD_PRELOAD object has 
IFUNCs, too.

Thanks,
Florian