From: Florian Weimer <fweimer@redhat.com>
To: "H.J. Lu" <hjl.tools@gmail.com>
Cc: libc-alpha@sourceware.org
Subject: Re: [PATCH] Don't use PLT nor GOT in libc.a [BZ #20750]
Date: Mon, 07 Nov 2016 16:03:00 -0000 [thread overview]
Message-ID: <1129b1b2-5f7a-26c3-76a7-727a14fdadfb@redhat.com> (raw)
In-Reply-To: <CAMe9rOrBerHaGT4M00nnyayQZsD41b+SPateKMOdfHZE5dF11Q@mail.gmail.com>
On 11/04/2016 08:25 PM, H.J. Lu wrote:
> On Fri, Nov 4, 2016 at 12:03 PM, Florian Weimer <fweimer@redhat.com> wrote:
>> On 11/04/2016 06:47 PM, H.J. Lu wrote:
>>>
>>> There is no need to use PLT nor GOT in libc.a to branch to a function,
>>> regardless whether libc.a is compiled with PIC or not.
>>>
>>> Tested on x86-64. OK for master?
>>
>>
>> Isn't this header file used outside of libc as well?
>
> It is used for other .a files. If they aren't used to create static binaries,
> PLT/GOT may be used. The resulting executable will work correctly.
You mean because ânameâ is automatically mapped to âname@pltâ?
I find this comment not very illuminating:
+/* For libc.a, we want to branch to target directly. */
# define JUMPTARGET(name) name
And cheating the static linker in this way seems like a future
maintenance hazard.
Thanks,
Florian
next prev parent reply other threads:[~2016-11-07 16:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-04 17:47 H.J. Lu
2016-11-04 19:03 ` Florian Weimer
2016-11-04 19:25 ` H.J. Lu
2016-11-07 16:03 ` Florian Weimer [this message]
2016-11-07 17:14 ` H.J. Lu
2016-11-24 11:58 ` Allan McRae
2016-11-25 8:43 ` Florian Weimer
2016-11-28 17:46 ` H.J. Lu
2016-11-28 18:27 ` Joseph Myers
2016-11-28 21:32 ` H.J. Lu
2016-11-28 17:54 ` Szabolcs Nagy
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