Re: PATCH: PR ld/12730: regression] crash when allocating in a static constructor

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

On Thu, May 5, 2011 at 7:12 AM, Alan Modra <amodra@gmail.com> wrote:
> On Thu, May 05, 2011 at 06:26:15AM -0700, H.J. Lu wrote:
>> On Thu, May 5, 2011 at 1:27 AM, Alan Modra <amodra@gmail.com> wrote:
>> > On Wed, May 04, 2011 at 10:18:32PM -0700, H.J. Lu wrote:
>> >> When we put .ctors into .init_array, we have to reverse copy .ctors secton.
>> >> Otherwise, constructor function may not work with C++ run-time library
>> >> correctly.  OK for trunk?
>> >
>> > What about .dtors?  You have the same problem there.  I suspect, but
>>
>> You are right.  Here is the updated patch to handle .dtors sections
>> with the updated testcase.  OK for trunk?
>
> No.
>
>> > haven't verified, that .ctors.* and .dtors.* also need reversing.  If
>> > that is true then it would be better to do your reversing trick for
>> > anything going to the .init_array output section that isn't named
>> > .init_array* and similarly for .fini_array.
>
> Are you sure there is no need to reverse .ctors.* and .dtors.*?
>
> The reason I recommended testing the output section is that limits
> section reversal to that particular output section.  I will not
> approve a patch that ignores this recommendation.  You also should
> remove reverse_copy_ctors.  That's plain wrong.  Consider people
> linking using a custom (old) script that does not put .ctors into
> .init_array.
>
>> > You also need to reverse any dynamic relocations applying to the
>> > sections you are reversing.
>>
>> It isn't a problem since we apply relocations on the input sections
>> first and copy relocated input sections to output where I reverse
>> copy .ctors/.dtors sections if needed.
>
> Try compiling your testcase as a PIE or shared lib on a target that
> uses RELA.  I haven't tried it, but I think the dynamic RELATIVE
> relocs you'll get in .ctors will undo your section reversing.
>

I will fix it.

-- 
H.J.