From: "H.J. Lu" <hjl.tools@gmail.com>
To: Florian Weimer <fweimer@redhat.com>
Cc: "Carlos O'Donell" <carlos@redhat.com>,
GNU C Library <libc-alpha@sourceware.org>
Subject: Re: RFC: x86: Fall back to lazy binding for unrelocated IFUNC symbol [BZ #23240]
Date: Wed, 06 Jun 2018 15:38:00 -0000 [thread overview]
Message-ID: <CAMe9rOpcyGC2GmoNUjTEXtn9bL3wwTwQNMYQ6otd3axYOcPT=w@mail.gmail.com> (raw)
In-Reply-To: <66949fa3-5ebd-f094-3755-75d524f1b36a@redhat.com>
On Wed, Jun 6, 2018 at 7:54 AM, Florian Weimer <fweimer@redhat.com> wrote:
> On 06/06/2018 04:50 PM, H.J. Lu wrote:
>>
>> On Wed, Jun 6, 2018 at 7:04 AM, Florian Weimer <fweimer@redhat.com> wrote:
>>>
>>> On 06/05/2018 09:24 PM, Florian Weimer wrote:
>>>>
>>>>
>>>> On 05/28/2018 09:51 PM, H.J. Lu wrote:
>>>>>
>>>>>
>>>>> Here is the updated patch. It fails to back lazy binding only
>>>>> if GOT is writable.
>>>>
>>>>
>>>>
>>>> I think this still sets a wrong incentive, as in “you need to have a
>>>> writable GOT for full forwards compatibility with future library
>>>> evolution”.
>>>>
>>>> I think if we detect an IFUNC-based relocation against a
>>>> not-yet-fully-relocated object, we need to delay this relocation
>>>> processing
>>>> and perform a second pass of all delayed relocations. I have a patch
>>>> which
>>>> needs a little bit of work, but looks quite promising (to me at least).
>>>
>>>
>>>
>>> Here are my patches:
>>>
>>> https://sourceware.org/ml/libc-alpha/2018-06/msg00076.html
>>> https://sourceware.org/ml/libc-alpha/2018-06/msg00077.html
>>>
>>> I hope they address your needs.
>>
>>
>> Do you have a git branch I can use?
>
>
> I've pushed it to fw/bug21242.
>
I pushed hjl/pr23240/fw, which is fw/bug21242 + tests for [BZ #23176] and
[BZ #23240].
1. On x86-64:
FAIL: elf/reldep6a
2. On i686:
FAIL: elf/ifuncpreload1
FAIL: elf/reldep6a
So your patches didn't fix:
1,. IFUNC on i686.
2. Weak reference.
--
H.J.
next prev parent reply other threads:[~2018-06-06 15:38 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-26 13:52 H.J. Lu
2018-05-26 21:02 ` Florian Weimer
2018-05-27 14:36 ` H.J. Lu
2018-05-28 9:27 ` Florian Weimer
2018-05-28 13:46 ` Carlos O'Donell
2018-05-28 19:51 ` H.J. Lu
2018-06-05 19:25 ` Florian Weimer
2018-06-06 14:04 ` Florian Weimer
2018-06-06 14:50 ` H.J. Lu
2018-06-06 14:54 ` Florian Weimer
2018-06-06 15:38 ` H.J. Lu [this message]
2018-06-06 15:53 ` Florian Weimer
2018-06-06 16:10 ` H.J. Lu
2018-06-06 17:31 ` Florian Weimer
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