tests: Test new tracepoint support

src/python/bcc/__init__.py

@@ -610,10 +610,10 @@ def detach_uretprobe(cls, name="", sym="", addr=None):
  def _trace_autoload(self):
  for i in range(0, lib.bpf_num_functions(self.module)):
  func_name = lib.bpf_function_name(self.module, i).decode()
- if func_name.startswith("kprobe__"):
+ if len(open_kprobes) == 0 and func_name.startswith("kprobe__"):
  fn = self.load_func(func_name, BPF.KPROBE)
  self.attach_kprobe(event=fn.name[8:], fn_name=fn.name)
- elif func_name.startswith("kretprobe__"):
+ elif len(open_kprobes) == 0 and func_name.startswith("kretprobe__"):
  fn = self.load_func(func_name, BPF.KPROBE)
  self.attach_kretprobe(event=fn.name[11:], fn_name=fn.name)
  elif func_name.startswith("tracepoint__"):

tests/python/test_tracepoint.py

@@ -22,21 +22,9 @@ def kernel_version_ge(major, minor):
 @unittest.skipUnless(kernel_version_ge(4,7), "requires kernel >= 4.7")
 class TestTracepoint(unittest.TestCase):
  def test_tracepoint(self):
- text = """#include <linux/ptrace.h>
- struct tp_args {
- unsigned long long __unused__;
- char prev_comm[16];
- pid_t prev_pid;
- int prev_prio;
- long prev_state;
- char next_comm[16];
- pid_t next_pid;
- int next_prio;
- };
+ text = """
  BPF_HASH(switches, u32, u64);
- int probe_switch(struct tp_args *args) {
- if (args == 0)
- return 0;
+ TRACEPOINT_PROBE(sched, sched_switch) {
  u64 val = 0;
  u32 pid = args->next_pid;
  u64 *existing = switches.lookup_or_init(&pid, &val);
@@ -45,13 +33,11 @@ def test_tracepoint(self):
  }
  """
  b = bcc.BPF(text=text)
- b.attach_tracepoint("sched:sched_switch", "probe_switch")
  sleep(1)
  total_switches = 0
  for k, v in b["switches"].items():
  total_switches += v.value
  self.assertNotEqual(0, total_switches)
- b.detach_tracepoint("sched:sched_switch")
 
 if __name__ == "__main__":
  unittest.main()