RHEL 8.5 Linux Beta version and rcu_read_unlock

Latest response

We have downloaded latest version of RHEL 8.5 Linux Beta version. It has kernel version 4.18.0-339.el8.x86_64. Suddenly, in this release of kernel, rcu_read_unlock() function is calling rcu_read_unlock_strict(), which is GPL. This causes rcu_read_unlock() to behave as GPL. It is hurting a lot to proprietary kernel modules. Now, rcu_read_lock() is not GPL, but its key(rcu_read_unlock) is GPL.

Just wanted to check if RedHat is planing to solve this in GA ? It is going to affect many products in field.

Regards,
Tarun

Responses

Hi Tarun,

You may want to report this as a support case

Regards,

Jan Gerrit

Is anyone else facing this issue or any other alternative ?

Hi Tarun,

You might want to file a bug report at http://bugzilla.redhat.com to have the issue fixed.

I see that the rcu_read_unlock_strict(); code was added in the 8.5 beta kernel. It seems that the fix has been proposed in the upstream (kernel.org) kernel. But it will not be in the mainline kernel until v5.16. See, for example:

https://www.spinics.net/lists/rcu/msg06001.html

Thank you all. Created this bugzilla:

[https://bugzilla.redhat.com/show_bug.cgi?id=2015923]

Hope to get it resolved.