Re: [PATCH] PR ld/18160: Segmentation Fault in lang_gc_sections when linking elf_x86_64 output

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Wed, Mar 25, 2015 at 7:29 PM, Alan Modra <amodra@gmail.com> wrote:
> On Wed, Mar 25, 2015 at 06:58:25PM -0700, H.J. Lu wrote:
>> On Wed, Mar 25, 2015 at 6:27 PM, Alan Modra <amodra@gmail.com> wrote:
>> > On Wed, Mar 25, 2015 at 06:14:29PM -0700, H.J. Lu wrote:
>> >> On Wed, Mar 25, 2015 at 5:38 PM, Alan Modra <amodra@gmail.com> wrote:
>> >> > On Wed, Mar 25, 2015 at 04:21:14PM -0700, H.J. Lu wrote:
>> >> >> This patch ignores gc-sections if input relocation is incompatible with
>> >> >> output.  OK for master?
>> >> >
>> >> > No.  For one, it looks like you can't call _bfd_elf_relocs_compatible
>> >> > with a non-ELF input, which is either a bug in that function or you
>> >> > need to first test for ELF.
>> >> >
>> >> > Secondly, if you take a look at the gc-sections code you'll see that
>> >> > it handles non-ELF input files by simply not garbage collecting those
>> >> > files.  Your patch would disable gc-sections entirely on finding a
>> >> > non-ELF file.  I'm not sure how important it is to keep the old
>> >> > behaviour, but I'm guessing you did not intend to make that change.
>> >> >
>> >>
>> >> How about this one?
>> >>
>> >> This patch skips gc-sections if input relocation is incompatible with
>> >> output.
>> >
>> > Is the warning really necessary?  Also, it looks to me that the
>> > relocs_compatible test should be in more places, eg. to stop the
>> > backend gc_mark_hook from being confused by incompatible relocs.
>>
>> Like this?
>
> Yes, thanks, this is OK.  Do we need a similar test in the .eh_frame
> loop that you originally patched?  Feel free to add that if you think
> so.

I am checking my patch asis.  We can add additional test later if
we find a need for it.

-- 
H.J.