[PATCH v14 0/9] Add rseq extensible ABI support

[Mathieu Desnoyers]

On 2024-12-27 13:40, Florian Weimer wrote:
> * Florian Weimer:
> 
>> * Mathieu Desnoyers:
>>
>>> On 2024-11-21 14:08, Michael Jeanson wrote:
>>>> Introduced in Linux v6.3 the rseq extensible ABI [1] will allow adding
>>>> rseq features past the initial 32 bytes of the original ABI.
>>>
>>> Hi Florian,
>>>
>>> I am currently implementing a new rseq feature which requires adding
>>> an 8-byte field, which goes beyond the 32 initial bytes (it reaches 36
>>> bytes).
>>>
>>> I need to disable the glibc rseq integration with the tunable for
>>> my development testing, but I am reaching a point where we will shortly
>>> need the extensible rseq integration in glibc.
>>>
>>> How is review progressing ? How can we help ?
>>
>> There doesn't seem to be a __thread_pointer patch for C-SKY.
>>
>> There's a simple to resolve conflict in nptl/descr.h.
>>
>> TLS is currently broken due to the botched GET_ADDR_ARGS removal.  I'm
>> testing the rseq series after reverting 5e249192cac7354af02a7347a0d8c.
> 
> So it looks like that TLS_DTV_AT_TP part doesn't work, unfortunately.  I
> see many new failures (after the mentioned revert) on powerpc64le, which
> is one of those targets.  I haven't tried to reproduce them yet on
> AArch64.  The GCC compile farm has a powerpc64le test machine
> (gcc120.fsffrance.org).

I recall that Michael did test on at least one architecture
with TLS_DTV_AT_TP (aarch64), and one with TLS_TCB_AT_TP (x86-64).

The issue may be specific to powerpc.

> 
> I should be able to look into this in more detail on Monday.

Michael is currently on vacation for the holiday break, he should be
back on January 6.

Thanks!

Mathieu

> 
> Thanks,
> Florian
> 

-- 
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com