[PATCH] Remove debug/stack_chk_fail_local.c [BZ #21740]

[H.J. Lu]

On Mon, Jul 10, 2017 at 10:34 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Mon, Jul 10, 2017 at 6:29 AM, Nick Alcock <nix@esperi.org.uk> wrote:
>> On 10 Jul 2017, H. J. Lu said:
>>> On Mon, Jul 10, 2017 at 11:50:02AM +0100, Nick Alcock wrote:
>>>> If it passes a test build with --enable-stack-protector=all without
>>>> pulling junk into ld.so and exploding at ld.so link time, sure. (That's
>>>> what happened every time I tried to remove this stuff before, but I may
>>>> have failed to notice that this may not be necessary any more.)
>>>
>>> Here is the updated patch.  tst-_dl_addr_inside_object should be
>>> linked with $(dummy-stack-chk-fail).  Otherwise, __stack_chk_fail is
>>> undefined.  OK for master branch?
>>
>> I presume this is because it's in $(all-nonlib)? Are other all-nonlib
>> things similarly affected? (If they are, is the code in Makerules
>> perhaps a better place to adjust this?)
>>
>> I guess the only affected nonlib things would be things that directly
>> link against objects that will otherwise end up in the shared libc or
>> ld.so, which means this is the only affected test (since only those
>> things reference the usually-hidden __stack_chk_fail). If so, I have no
>> objection to this patch, but maybe a comment explaining this would be a
>> good idea so that if more such tests turn up in future this unusual
>> piece of linking can be generalized a bit.
>>
>> Modulo that, I have no objections, but of course I also have no actual
>> right to ack anything whatsoever :)
>>
>>>> > -/* On some architectures, this helps needless PIC pointer setup
>>>> > -   that would be needed just for the __stack_chk_fail call.  */
>>>>
>>>> Does anyone know what architectures these might be? Presumably x86-32...
>>>>
>>>
>>> config/i386/i386.c:   __stack_chk_fail_local hidden function instead of calling
>>
>> I presume you tested a build on x86-32 :) I guess that will suffice...
>
> We must keep debug/stack_chk_fail_local.c for libc_nonshared.a.
> Here is the updated patch to add __stack_chk_fail_local alias only
> to libc.so.
>
> Tested on i686 and x86-64 with and without --enable-stack-protector=all.
> OK for master?
>

Any objections?

https://sourceware.org/ml/libc-alpha/2017-07/msg00406.html

-- 
H.J.