Merge pull request iovisor#909 from goldshtn/tp-str-fixes

trace, tplist, argdist: UDST probe miscellaneous fixes

tools/argdist.py

@@ -258,7 +258,7 @@ def _generate_streq_function(self, string):
  char needle[] = %s;
  char haystack[sizeof(needle)];
  bpf_probe_read(&haystack, sizeof(haystack), (void *)str);
- for (int i = 0; i < sizeof(needle); ++i) {
+ for (int i = 0; i < sizeof(needle) - 1; ++i) {
  if (needle[i] != haystack[i]) {
  return false;
  }

tools/tplist.py

@@ -68,15 +68,15 @@ def print_tracepoints():
 def print_usdt_argument_details(location):
  for idx in xrange(0, location.num_arguments):
  arg = location.get_argument(idx)
- print(" argument #%d %s" % (idx, arg))
+ print(" argument #%d %s" % (idx+1, arg))
 
 def print_usdt_details(probe):
  if args.verbosity > 0:
  print(probe)
  if args.verbosity > 1:
  for idx in xrange(0, probe.num_locations):
  loc = probe.get_location(idx)
- print(" location #%d %s" % (idx, loc))
+ print(" location #%d %s" % (idx+1, loc))
  print_usdt_argument_details(loc)
  else:
  print(" %d location(s)" % probe.num_locations)

tools/trace.py

@@ -217,11 +217,11 @@ def _generate_streq_function(self, string):
  fname = "streq_%d" % Probe.streq_index
  Probe.streq_index += 1
  self.streq_functions += """
-static inline bool %s(char const *ignored, unsigned long str) {
+static inline bool %s(char const *ignored, uintptr_t str) {
  char needle[] = %s;
  char haystack[sizeof(needle)];
  bpf_probe_read(&haystack, sizeof(haystack), (void *)str);
- for (int i = 0; i < sizeof(needle); ++i) {
+ for (int i = 0; i < sizeof(needle) - 1; ++i) {
  if (needle[i] != haystack[i]) {
  return false;
  }
@@ -354,33 +354,35 @@ def _generate_field_assign(self, idx):
 
  def _generate_usdt_filter_read(self):
  text = ""
- if self.probe_type == "u":
- for arg, _ in Probe.aliases.items():
- if not (arg.startswith("arg") and
- (arg in self.filter)):
- continue
- arg_index = int(arg.replace("arg", ""))
- arg_ctype = self.usdt.get_probe_arg_ctype(
- self.usdt_name, arg_index)
- if not arg_ctype:
- self._bail("Unable to determine type of {} "
- "in the filter".format(arg))
- text += """
+ if self.probe_type != "u":
+ return text
+ for arg, _ in Probe.aliases.items():
+ if not (arg.startswith("arg") and
+ (arg in self.filter)):
+ continue
+ arg_index = int(arg.replace("arg", ""))
+ arg_ctype = self.usdt.get_probe_arg_ctype(
+ self.usdt_name, arg_index - 1)
+ if not arg_ctype:
+ self._bail("Unable to determine type of {} "
+ "in the filter".format(arg))
+ text += """
  {} {}_filter;
  bpf_usdt_readarg({}, ctx, &{}_filter);
-  """.format(arg_ctype, arg, arg_index, arg)
-  self.filter = self.filter.replace(
-  arg, "{}_filter".format(arg))
+ """.format(arg_ctype, arg, arg_index, arg)
+ self.filter = self.filter.replace(
+ arg, "{}_filter".format(arg))
  return text
 
  def generate_program(self, include_self):
  data_decl = self._generate_data_decl()
- # kprobes don't have built-in pid filters, so we have to add
- # it to the function body:
- if len(self.library) == 0 and Probe.pid != -1:
+ if Probe.pid != -1:
  pid_filter = """
  if (__pid != %d) { return 0; }
  """ % Probe.pid
+ # uprobes can have a built-in tgid filter passed to
+ # attach_uprobe, hence the check here -- for kprobes, we
+ # need to do the tgid test by hand:
  elif len(self.library) == 0 and Probe.tgid != -1:
  pid_filter = """
  if (__tgid != %d) { return 0; }
@@ -542,12 +544,12 @@ def _attach_u(self, bpf):
  bpf.attach_uretprobe(name=libpath,
  sym=self.function,
  fn_name=self.probe_name,
- pid=Probe.pid)
+ pid=Probe.tgid)
  else:
  bpf.attach_uprobe(name=libpath,
  sym=self.function,
  fn_name=self.probe_name,
- pid=Probe.pid)
+ pid=Probe.tgid)
 
 class Tool(object):
  examples = """