rcu: Backport upstream RCU commits up to v6.4
JIRA: https://issues.redhat.com/browse/RHEL-5228
MR: !3099 (merged)
Omitted-fix: 4d09caec2fab ("arm64: kcsan: Support detecting more missing memory barriers")
This MR backports upstream RCU commits up to v6.1 with related fixes, if applicable. It also includes a number of KCSAN commits which provide helpers and APIs that may be referenced by commits from other subsystems.
Signed-off-by: Waiman Long longman@redhat.com
Edited by Waiman Long