rseq enablement patches overview

[Florian Weimer]

* Mathieu Desnoyers:

>>>> Since my patchwork looks rather horrible right now and I posted a bunch
>>>> of vaguely-related cleanups first, here are the patches that currently
>>>> need review for rseq enablement:
>>>>
>>>>   Introduce <elf_machine_sym_no_match.h>
>>>>   <https://sourceware.org/ml/libc-alpha/2019-10/msg00339.html>
>>>>
>>>>     This is needed in the implementation of _dl_lookup_direct in the
>>>>     next patch.
>>>>
>>>>   Implement __libc_early_init
>>>>   <https://sourceware.org/ml/libc-alpha/2019-10/msg00340.html>
>>>>
>>>>     This is the main patch.  rseq should be hooked into
>>>>     __libc_early_init, around the __ctype_init call.
>>>>
>>>>   nptl: Start new threads with all signals blocked [BZ #25098]
>>>>   <https://sourceware.org/ml/libc-alpha/2019-10/msg00383.html>
>>>>
>>>>     This is a long-standing issue which will affect rseq as well.
>>> 
>> 
>> Hi Florian,
>> 
>> Sorry for the delayed reply,
>> 
>>> I reposted these patches:
>>> 
>>>  <https://sourceware.org/ml/libc-alpha/2019-11/msg00976.html>
>>>  <https://sourceware.org/ml/libc-alpha/2019-11/msg00977.html>
>> 
>> For some reason I have issues applying this last patch (00977) on
>> top of glibc master at commit a059f9505bb. Is there a specific commit
>> I should use as a baseline ?
>
> I found the conflicting patch:
>
> commit 440b7f865 "Avoid late failure in dlopen in global scope update [BZ #25112]"
>
> The conflict resolution was straightforward. I'll start updating the rseq
> patchset.

I'm going to repost my patches, too, as follow-ups.

A new set of patches for built-in system call tables is available, too:

  <https://sourceware.org/ml/libc-alpha/2019-12/msg00567.html>

Thanks,
Florian