cgropu+bpf prog array has a maximum number of 64 programs.
Let us apply the same limit here.
Fixes: e87c6bc3852b ("bpf: permit multiple bpf attachments for a single perf event")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
rcu_read_lock();
prog = rcu_dereference(progs)->progs;
for (; *prog; prog++)
- cnt++;
+ if (*prog != &dummy_bpf_prog.prog)
+ cnt++;
rcu_read_unlock();
return cnt;
}
static DEFINE_MUTEX(bpf_event_mutex);
+#define BPF_TRACE_MAX_PROGS 64
+
int perf_event_attach_bpf_prog(struct perf_event *event,
struct bpf_prog *prog)
{
goto unlock;
old_array = event->tp_event->prog_array;
+ if (old_array &&
+ bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
+ ret = -E2BIG;
+ goto unlock;
+ }
+
ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array);
if (ret < 0)
goto unlock;