[PATCH 0/7] Allow call_{s,}rcu() from NMI and BPF environments

[Paul E. McKenney]

Hello!

This series enables call_rcu() and call_srcu() to be invoked in NMI
handlers and from BPF programs attached to these functions.  The
individual patches are as follows:

1.	Make call_rcu() safe to call from any context, courtesy of
	Puranjay Mohan.

2.	Make Tiny call_rcu() safe to call from any context, courtesy of
	Puranjay Mohan.

3.	Make call_srcu() safe to call from any context, courtesy of
	Puranjay Mohan.

4.	Make Tiny call_srcu() safe to call from any context, courtesy
	of Puranjay Mohan.

5.	Disable fragile readers during overload testing.

6.	Exercise ->call() from NMI context, courtesy of Puranjay Mohan.

7.	Add a call_srcu() re-entry reproducer, courtesy of Puranjay Mohan.

						Thanx, Paul

------------------------------------------------------------------------

 b/Documentation/admin-guide/kernel-parameters.txt      |    7 
 b/include/linux/srcutiny.h                             |   12 -
 b/include/linux/srcutree.h                             |    4 
 b/kernel/rcu/Kconfig                                   |    6 
 b/kernel/rcu/rcu.h                                     |   11 +
 b/kernel/rcu/rcutorture.c                              |    8 
 b/kernel/rcu/srcutiny.c                                |   93 ++++++++-
 b/kernel/rcu/srcutree.c                                |  170 ++++++++++++++++-
 b/kernel/rcu/tiny.c                                    |  127 ++++++++++--
 b/kernel/rcu/tree.c                                    |  131 ++++++++++++-
 b/kernel/rcu/tree.h                                    |    6 
 b/tools/testing/selftests/bpf/prog_tests/rcu_reentry.c |   93 +++++++++
 b/tools/testing/selftests/bpf/progs/rcu_reentry.c      |   51 +++++
 kernel/rcu/rcu.h                                       |    3 
 kernel/rcu/rcutorture.c                                |  150 ++++++++++++++-
 kernel/rcu/tree.c                                      |    2 
 16 files changed, 824 insertions(+), 50 deletions(-)