Increase misses stats in case bpf array execution is skipped
because of recursion check in trace_call_bpf.
Adding bpf_prog_missed_array that increase misses counts for
all bpf programs in bpf_prog_array.
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
include/linux/bpf.h | 16 ++++++++++++++++
kernel/trace/bpf_trace.c | 3 +++
2 files changed, 19 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 23a73f52c7bc..71154e991730 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2932,6 +2932,22 @@ static inline int sock_map_bpf_prog_query(const union bpf_attr *attr,
#endif /* CONFIG_BPF_SYSCALL */
#endif /* CONFIG_NET && CONFIG_BPF_SYSCALL */
+static __always_inline void
+bpf_prog_missed_array(const struct bpf_prog_array *array)
+{
+ const struct bpf_prog_array_item *item;
+ struct bpf_prog *prog;
+
+ if (unlikely(!array))
+ return;
+
+ item = &array->items[0];
+ while ((prog = READ_ONCE(item->prog))) {
+ bpf_prog_inc_misses_counter(prog);
+ item++;
+ }
+}
+
#if defined(CONFIG_INET) && defined(CONFIG_BPF_SYSCALL)
void bpf_sk_reuseport_detach(struct sock *sk);
int bpf_fd_reuseport_array_lookup_elem(struct bpf_map *map, void *key,
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index cde6360bf8e8..7961f9d9dd13 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -117,6 +117,9 @@ unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
* and don't send kprobe event into ring-buffer,
* so return zero here
*/
+ rcu_read_lock();
+ bpf_prog_missed_array(rcu_dereference(call->prog_array));
+ rcu_read_unlock();
ret = 0;
goto out;
}
--
2.41.0
