Re: Use elfcore_write_linux_prstatus in gdb

[Pedro Alves <palves@redhat.com>]

On 01/21/2016 01:24 PM, H.J. Lu wrote:
> On Thu, Jan 21, 2016 at 5:11 AM, Pedro Alves <palves@redhat.com> wrote:
>> On 01/21/2016 12:25 PM, Pedro Alves wrote:
>>> On 01/21/2016 09:28 AM, Alan Modra wrote:
>>>> The gdb side.  Nothing fancy here, and no support for targets that
>>>> need gdbarch_elfcore_write_linux_prstatus, mips n32, sparc64 if
>>>> writing any of pr_{u,s,cu,cs}time, and probably x86-64 x32.
>>>
>>> Thanks a lot for doing all this!  I don't have spare cycles either to
>>> drive this all the way to completion for all archs, I think we can still
>>> move forward with it, by adding a stop-gap implementation those
>>> archs, which just calls elfcore_write_prstatus.  I'll send it along
>>> in a bit.
>>
>> Like this.  I've pushed this to the users/palves/core-prstatus-rework
>> branch.  I've tested on x86_64 with:
>>
>>  make check RUNTESTFLAGS="--target_board unix/-m32" TESTS="*/*core*.exp"
>>  make check RUNTESTFLAGS="--target_board unix/-m64" TESTS="*/*core*.exp"
> 
> It failed
> 
>  make check RUNTESTFLAGS="--target_board unix/-mx32" TESTS="*/*core*.exp"
> 
> Please take a look at bfd/hosts/x86-64linux.h to see how to dump core
> x86-64.

I don't have x32 setup on my machine.  AFAICS, elf_prstatusx32 is exactly
like elf_prstatus32, except it takes a 64-bit regset.
Given gdbarch_ptr_bit==32 on x32, and:

      else if (gdbarch_ptr_bit (data->gdbarch) == 64)
	data->note_data = elfcore_write_linux_prstatus64 (data->obfd,
							  data->note_data,
							  data->note_size,
							  &prstatus);
      else
	data->note_data = elfcore_write_linux_prstatus32 (data->obfd,
							  data->note_data,
							  data->note_size,
							  &prstatus);

elfcore_write_linux_prstatus32 should be reached.  Other than that,
I have no idea (other than installing the stop gap on x32 too).

Thanks,
Pedro Alves