fix get_kprobe_functions

Fix issue iovisor#1747.

In commit iovisor#1647, we excluded all symbols outside [_stext, _etext].
This is incorrect as it excluded module symbols as well.

This patch changed the algorithm to only skip symbols
in init sections [__init_begin, __init_end].

Signed-off-by: Yonghong Song <[email protected]>

src/python/bcc/__init__.py

@@ -495,17 +495,18 @@ def get_kprobe_functions(event_re):
  blacklist = set([line.rstrip().split()[1] for line in blacklist_f])
  fns = []
 
- found_stext = False
+ in_init_section = 0
  with open("/proc/kallsyms", "rb") as avail_file:
  for line in avail_file:
- (_, t, fn) = line.rstrip().split()[:3]
- if found_stext is False:
- if fn == b'_stext':
- found_stext = True
+ (t, fn) = line.rstrip().split()[1:3]
+ if in_init_section == 0:
+ if fn == b'__init_begin':
+ in_init_section = 1
+ continue
+ elif in_init_section == 1:
+ if fn == b'__init_end':
+ in_init_section = 2
  continue
-
- if fn == b'_etext':
- break
  if (t.lower() in [b't', b'w']) and re.match(event_re, fn) \
  and fn not in blacklist:
  fns.append(fn)