R_X86_64_COPY bug

[Alexander Ivchenko]

Have you tried  '-z nocopyrelocs' option for linker which tries to
avoid COPY relocations? And also, as far as I understand, you can make
your binary 'pie'

2013/4/6 Suresh Siddha <sbsiddha@gmail.com>:
> On Sat, Apr 6, 2013 at 12:13 AM, Alan Modra <amodra@gmail.com> wrote:
>> On Fri, Apr 05, 2013 at 09:29:09PM -0700, Fredrick Prashanth John Berchmans wrote:
>>> Dear binutils developers,
>>>
>>> We are seeing a issue with copy relocation semantics in ld.
>>>
>>> A struct with zero length array is defined in a shared library.
>>> Because of copy relocation semantics, any binary linking with that
>>> library sees those elements as zero initialized.
>>>
>>> We saw this bug also on ARM with R_ARM_COPY.
>>
>> This is not a bug in gas or ld.  gcc is sizing the struct incorrectly.
>>
>>         .globl  test_dynamic
>>         .data
>>         .align 4
>>         .type   test_dynamic, @object
>>         .size   test_dynamic, 4      # <===========
>> test_dynamic:
>>         .long   6
>>         .long   1
>>         .long   2
>>         .long   3
>>         .long   4
>>         .long   5
>>         .long   6
>
> Thanks for the quick response. Is there any way we can avoid copy
> relocations for these problematic types? We tried even giving the
> attribute of protected visibility. And it doesn't seem to help.
>
> -Suresh Siddha