[PATCH bpf-next v2 0/2] bpf: Nested rcu critical sections

[Puranjay Mohan <puranjay@kernel.org>]

v1: https://lore.kernel.org/bpf/20250916113622.19540-1-puranjay@kernel.org/
Changes in v1->v2:
- Move the addition of new tests to a separate patch (Alexei)
- Avoid incrementing active_rcu_locks at two places (Eduard)

Support nested rcu critical sections by making the boolean flag
active_rcu_lock a counter and use it to manage rcu critical section
state. bpf_rcu_read_lock() increments this counter and
bpf_rcu_read_unlock() decrements it, MEM_RCU -> PTR_UNTRUSTED transition
happens when active_rcu_locks drops to 0.

Puranjay Mohan (2):
  bpf: support nested rcu critical sections
  selftests: bpf: Add tests for unbalanced rcu_read_lock

 include/linux/bpf_verifier.h                  |  2 +-
 kernel/bpf/verifier.c                         | 47 +++++++++----------
 .../selftests/bpf/prog_tests/rcu_read_lock.c  |  4 +-
 .../selftests/bpf/progs/rcu_read_lock.c       | 40 ++++++++++++++++
 4 files changed, 66 insertions(+), 27 deletions(-)

-- 
2.47.1