support gcc 8's cold subfunctions (iovisor#2228)

* support gcc 8's cold subfunctions GCC 8 can split functions bodies into hot and cold regions, causing extra symbols with a ".cold.N" suffix to be emitted. Exclude these extra symbols and only allow the parent function to be traced. Signed-off-by: Andrea Righi <[email protected]> * use byte string with function names read from /proc/kallsyms Function names are read from /proc/kallsyms, that is opened in binary mode. Regex pattern must be bytes as well. Signed-off-by: Andrea Righi <[email protected]>
e-dant · Feb 25, 2019 · e8ece56 · e8ece56
1 parent eba6beb
commit e8ece56
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/src/python/bcc/__init__.py b/src/python/bcc/__init__.py
@@ -564,6 +564,9 @@ def get_kprobe_functions(event_re):
  # non-attachable.
  elif fn.startswith(b'__perf') or fn.startswith(b'perf_'):
  continue
+ # Exclude all gcc 8's extra .cold functions
+ elif re.match(b'^.*\.cold\.\d+$', fn):
+ continue
  if (t.lower() in [b't', b'w']) and re.match(event_re, fn) \
  and fn not in blacklist:
  fns.append(fn)