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Re: Preventing preemption of 'protected' symbols in GNU ld 2.26 [aka should we revert the fix for 65248]
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Cary Coutant <ccoutant at gmail dot com>
- Cc: Michael Matz <matz at suse dot de>, Richard Biener <richard dot guenther at gmail dot com>, Alan Modra <amodra at gmail dot com>, Jeff Law <law at redhat dot com>, Joe Groff <jgroff at apple dot com>, Binutils <binutils at sourceware dot org>, GCC <gcc at gcc dot gnu dot org>
- Date: Tue, 19 Apr 2016 08:44:16 -0700
- Subject: Re: Preventing preemption of 'protected' symbols in GNU ld 2.26 [aka should we revert the fix for 65248]
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On Tue, Apr 19, 2016 at 8:37 AM, Cary Coutant <ccoutant@gmail.com> wrote:
>>> So with all this it sounds that current protected visibility is just
>>> broken and we should forgo with it, making it equal to default
>>> visibility?
>>
>> Like how? You mean in GCC regarding protected as default visibility? No,
>> that's just throwing out the baby with the water. We should make
>> protected do what it was intended to do and accept that not all invariants
>> that are true for default visible symbols are also true for protected
>> symbols, possibly by ...
>>
>>> At least I couldn't decipher a solution that solves all of the issues
>>> with protected visibility apart from trying to error at link-time (or
>>> runtime?) for the cases that are tricky (impossible?) to solve.
>>
>> ... this.
>
> Right. Protected visibility worked fine without copy relocations for
> 15 years until HJ's patch. I don't know of anyone with a legitimate
> complaint about that until HJ filed a bug based on his artificial test
> case.
Cary, please stop spreading the incorrect information. There is
at lease one GCC bug against protected symbol:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55012
which was reported by other people.
--
H.J.