bcc: Make regex helpers publicly accessible

Make the `get_user_functions`, `get_kprobe_functions`, and
`get_tracepoints` methods publicly accessible from the BPF class.
These can then be used by tools that need to do their own work
before attaching programs to a set of functions or tracepoints.

src/python/bcc/__init__.py

@@ -376,7 +376,8 @@ def attach_raw_socket(fn, dev):
  % (dev, errstr))
  fn.sock = sock
 
- def _get_kprobe_functions(self, event_re):
+ @staticmethod
+ def get_kprobe_functions(event_re):
  with open("%s/../kprobes/blacklist" % TRACEFS) as blacklist_file:
  blacklist = set([line.rstrip().split()[1] for line in
  blacklist_file])
@@ -386,7 +387,6 @@ def _get_kprobe_functions(self, event_re):
  fn = line.rstrip().split()[0]
  if re.match(event_re, fn) and fn not in blacklist:
  fns.append(fn)
- self._check_probe_quota(len(fns))
  return fns
 
  def _check_probe_quota(self, num_new_probes):
@@ -409,7 +409,7 @@ def attach_kprobe(self, event="", fn_name="", event_re="",
 
  # allow the caller to glob multiple functions together
  if event_re:
- for line in self._get_kprobe_functions(event_re):
+ for line in BPF.get_kprobe_functions(event_re):
  try:
  self.attach_kprobe(event=line, fn_name=fn_name, pid=pid,
  cpu=cpu, group_fd=group_fd)
@@ -448,7 +448,7 @@ def attach_kretprobe(self, event="", fn_name="", event_re="",
 
  # allow the caller to glob multiple functions together
  if event_re:
- for line in self._get_kprobe_functions(event_re):
+ for line in BPF.get_kprobe_functions(event_re):
  try:
  self.attach_kretprobe(event=line, fn_name=fn_name, pid=pid,
  cpu=cpu, group_fd=group_fd)
@@ -531,7 +531,8 @@ def find_library(libname):
  res = lib.bcc_procutils_which_so(libname.encode("ascii"))
  return res if res is None else res.decode()
 
- def _get_tracepoints(self, tp_re):
+ @staticmethod
+ def get_tracepoints(tp_re):
  results = []
  events_dir = os.path.join(TRACEFS, "events")
  for category in os.listdir(events_dir):
@@ -570,7 +571,7 @@ def attach_tracepoint(self, tp="", tp_re="", fn_name="", pid=-1,
  """
 
  if tp_re:
- for tp in self._get_tracepoints(tp_re):
+ for tp in BPF.get_tracepoints(tp_re):
  self.attach_tracepoint(tp=tp, fn_name=fn_name, pid=pid,
  cpu=cpu, group_fd=group_fd)
  return
@@ -615,7 +616,13 @@ def _del_uprobe(self, name):
  del self.open_uprobes[name]
  _num_open_probes -= 1
 
- def _get_user_functions(self, name, sym_re):
+ @staticmethod
+ def get_user_functions(name, sym_re):
+ return set([name for (name, _) in
+ BPF.get_user_functions_and_addresses(name, sym_re)])
+
+ @staticmethod
+ def get_user_addresses(name, sym_re):
  """
  We are returning addresses here instead of symbol names because it
  turns out that the same name may appear multiple times with different
@@ -624,10 +631,15 @@ def _get_user_functions(self, name, sym_re):
  it makes sense to return the unique set of addresses that are mapped to
  a symbol that matches the provided regular expression.
  """
+ return set([address for (_, address) in
+ BPF.get_user_functions_and_addresses(name, sym_re)])
+
+ @staticmethod
+ def get_user_functions_and_addresses(name, sym_re):
  addresses = []
  def sym_cb(sym_name, addr):
- if re.match(sym_re, sym_name) and addr not in addresses:
- addresses.append(addr)
+ if re.match(sym_re, sym_name):
+ addresses.append((sym_name, addr))
  return 0
 
  res = lib.bcc_foreach_symbol(name, _SYM_CB_TYPE(sym_cb))
@@ -660,7 +672,7 @@ def attach_uprobe(self, name="", sym="", sym_re="", addr=None,
  name = str(name)
 
  if sym_re:
- for sym_addr in self._get_user_functions(name, sym_re):
+ for sym_addr in BPF.get_user_adddresses(name, sym_re):
  self.attach_uprobe(name=name, addr=sym_addr,
  fn_name=fn_name, pid=pid, cpu=cpu,
  group_fd=group_fd)
@@ -711,7 +723,7 @@ def attach_uretprobe(self, name="", sym="", sym_re="", addr=None,
  """
 
  if sym_re:
- for sym_addr in self._get_user_functions(name, sym_re):
+ for sym_addr in BPF.get_user_addresses(name, sym_re):
  self.attach_uretprobe(name=name, addr=sym_addr,
  fn_name=fn_name, pid=pid, cpu=cpu,
  group_fd=group_fd)