[2.25 / 2.26 / 2.27 / 2.28 / 2.29 COMMITTED] Add compiler barriers around modifications of the robust mutex list for pthread_mutex_trylock. [BZ #24180]

[Stefan Liebler <stli@linux.ibm.com>]

On 02/06/2019 04:59 PM, Carlos O'Donell wrote:
> On 2/6/19 6:25 AM, Stefan Liebler wrote:
>> Hi Carlos,
>> I've updated the patch with three additional comments and I've mentioned the filed bug.
>> Please review it once again before I commit it to master and cherry pick it to the release branches.
> 
> Thank you! Reviewed.
Committed to master (2.29.9000):
"Add compiler barriers around modifications of the robust mutex list for 
pthread_mutex_trylock. [BZ #24180]"
(https://sourceware.org/git/?p=glibc.git;a=commit;h=823624bdc47f1f80109c9c52dee7939b9386d708)

and backported it to glibc 2.25 ... 2.29 release branches.

Thanks.
Stefan

> 
>>> Yes, I did that backport to RHEL 7.6. These fixes are just "further"
>>> fixes right? I'll work on getting this fixed in RHEL 7.7, and RHEL 8
>>> for all arches.
>> Sounds great.
>> That's the same fix for pthread_mutex_trylock as previously done for pthread_mutex_lock and pthread_mutex_timedlock.
> 
> I've filed these:
> https://bugzilla.redhat.com/show_bug.cgi?id=1672771
> https://bugzilla.redhat.com/show_bug.cgi?id=1672773
> 
> Feel free to comment or verify if they are going to be needed in RHEL7.7
> or RHEL8. I haven't done the analysis of the disassembly yet. If you
> could have a look that would help.
>