Backports:
commit c617ec63339222f3a44d73e36677a9acc8954ccd
Author: John Ogness <john.ogness@linutronix.de>
Date: Thu Nov 19 02:41:21 2020 +0000
[PATCH 1/2] printk: add support for lockless ringbuffer
* Required for kernel 5.10
Linux 5.10 introduces a new lockless ringbuffer. The new ringbuffer
is structured completely different to the previous iterations.
Add support for retrieving the ringbuffer from debug information
and/or using vmcoreinfo. The new ringbuffer is detected based on
the availability of the "prb" symbol.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com>
Signed-off-by: Kairui Song <kasong@redhat.com>
