Re: PATCH: PR gold/16945: Executable with -fpie and -mcmodel=large gives segfault on start

[Alexander Ivchenko <aivchenk at gmail dot com>]

*ping*


thanks,
Alexander

2014-05-15 22:13 GMT+04:00 Alexander Ivchenko <aivchenk@gmail.com>:
> I just don't get why got_offset sometimes "unsigned int", sometimes
> "section_offset_type" and now "int". I guess it's just a little mess.
> I believe that the right way is having it as "ptrdiff", which is the
> same "section_offset_type".
>
> 2014-05-15 22:09 GMT+04:00 H.J. Lu <hjl.tools@gmail.com>:
>> On Thu, May 15, 2014 at 11:02 AM, Alexander Ivchenko <aivchenk@gmail.com> wrote:
>>> Shouldn't got_offset be the type of section_offset_type ?
>>
>> That also works.
>>
>>> 2014-05-15 21:31 GMT+04:00 H.J. Lu <hongjiu.lu@intel.com>:
>>>> There are 2 issues:
>>>>
>>>> 1. Since the GOT offset is always negative, we need to use signed int
>>>> to support 64-bit GOT relocations.
>>>> 2. R_X86_64_PLTOFF64 uses the address of GLOBAL_OFFSET_TABLE, which is
>>>> the address of the .got.plt section, not the .got section.
>>>>
>>>> This patch fixes both.  OK for master and 2.24 branch?
>>>>
>>>> Thanks.
>>>>
>>>> H.J.
>>>> ---
>>>> 2014-05-15  H.J. Lu  <hongjiu.lu@intel.com>
>>>>
>>>>         PR gold/16945
>>>>         * x86_64.cc (Target_x86_64::Relocate::relocate): Use signed int
>>>>         for got_offset.  Properly get GOT address for R_X86_64_PLTOFF64.
>>>>
>>>> diff --git a/gold/x86_64.cc b/gold/x86_64.cc
>>>> index 479fb42..f58c843 100644
>>>> --- a/gold/x86_64.cc
>>>> +++ b/gold/x86_64.cc
>>>> @@ -3327,7 +3327,9 @@ Target_x86_64<size>::Relocate::relocate(
>>>>    // We need to subtract the size of the GOT section to get
>>>>    // the actual offset to use in the relocation.
>>>>    bool have_got_offset = false;
>>>> -  unsigned int got_offset = 0;
>>>> +  // Since the actual offset is always negative, we use signed int to
>>>> +  // support 64-bit GOT relocations.
>>>
>>
>> --
>> H.J.