For now, we can use rcu_read_lock_dont_migrate() for the case that call
both rcu_read_lock() and migrate_disable(). However, sometimes they can be
called separately.

Therefore, we factor out migrate_enable_rcu and migrate_disable_rcu from
rcu_read_lock_dont_migrate and rcu_read_unlock_migrate.

And we introduce the function bpf_prog_run_pin_on_cpu_rcu(), which is
similar to bpf_prog_run_pin_on_cpu() but use
migrate_disable_rcu/migrate_enable_rcu instead.

The function bpf_prog_run_pin_on_cpu_rcu() is used in following functions:

  sk_psock_msg_verdict
  sk_psock_tls_strp_read
  sk_psock_strp_read
  sk_psock_strp_parse
  sk_psock_verdict_recv
  bpf_prog_run_clear_cb

Menglong Dong (4):
  rcu: factor out migrate_enable_rcu and migrate_disable_rcu
  bpf: introduce bpf_prog_run_pin_on_cpu_rcu()
  bpf: use bpf_prog_run_pin_on_cpu_rcu() in skmsg.c
  bpf: use bpf_prog_run_pin_on_cpu_rcu() in bpf_prog_run_clear_cb

 include/linux/filter.h   | 16 +++++++++++++++-
 include/linux/rcupdate.h | 18 +++++++++++++++---
 net/core/skmsg.c         | 10 +++++-----
 3 files changed, 35 insertions(+), 9 deletions(-)

-- 
2.51.0