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Re: [PATCH][BZ 18960] setlocale.c: Mark *_used symbols as unaligned.
- From: Florian Weimer <fweimer at redhat dot com>
- To: Rich Felker <dalias at libc dot org>, Marcin KoÅcielnicki <koriakin at 0x04 dot net>, libc-alpha at sourceware dot org
- Date: Mon, 28 Sep 2015 17:22:29 +0200
- Subject: Re: [PATCH][BZ 18960] setlocale.c: Mark *_used symbols as unaligned.
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- References: <1443360385-20079-1-git-send-email-koriakin at 0x04 dot net> <20150928141824 dot GX17773 at brightrain dot aerifal dot cx> <5609541A dot 5070500 at redhat dot com> <20150928151749 dot GK5140 at vapier dot lan>
On 09/28/2015 05:17 PM, Mike Frysinger wrote:
> On 28 Sep 2015 16:52, Florian Weimer wrote:
>> On 09/28/2015 04:18 PM, Rich Felker wrote:
>>> Can you explain how/why you think this is needed? char has no
>>> alignment requirements (inherently) so as far as I can tell, the
>>> compiler may not make any alignment assumptions about an extern object
>>> of type char.
>>
>> s390(x) expects all top-level objects in the data segment to be aligned
>> to at least 2. As far as I can tell, this is not explicitly mentioned
>> in the psABI supplement, but it is heavily implied by .align directives
>> and use of the lalr instruction.
>
> how does that bubble in here though ?
The value of a weak symbol is used as flag, to determine that a
particular piece of code has been linked in. If the object file is
pulled in by other code, the symbol is defined with an absolute address.
> does locale/localeinfo.h need to update
> _NL_CURRENT_DEFINE to use helpers from libc-symbols.h ? this seems to be
> patching a single symptom point rather than addressing the source.
I'm not sure if this occurs in other places.
--
Florian Weimer / Red Hat Product Security