diff mbox series

[bpf-next,1/6] bpf: Add __rcu_read_{lock,unlock} into btf id deny list

Message ID 20230417154737.12740-2-laoar.shao@gmail.com
State New
Headers
Series bpf: Tracing recursion prevention mechanism improvement |

Commit Message

Yafang Shao April 17, 2023, 3:47 p.m. UTC 
  The tracing recursion prevention mechanism must be protected by rcu, that
leaves __rcu_read_{lock,unlock} unprotected by this mechanism. If we trace
them, the recursion will happen. Let's add them into the btf id deny list.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
 kernel/bpf/verifier.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 5dae11e..83fb94f 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -18645,6 +18645,10 @@  int bpf_check_attach_target(struct bpf_verifier_log *log,
 BTF_ID(func, preempt_count_add)
 BTF_ID(func, preempt_count_sub)
 #endif
+#ifdef CONFIG_PREEMPT_RCU
+BTF_ID(func, __rcu_read_lock)
+BTF_ID(func, __rcu_read_unlock)
+#endif
 BTF_SET_END(btf_id_deny)
 
 static bool can_be_sleepable(struct bpf_prog *prog)