Add bcc_usdt_enable_fully_specified_probe to avoid usdt provider coll…

…isions

src/cc/bcc_usdt.h

@@ -70,6 +70,8 @@ int bcc_usdt_get_argument(void *usdt, const char *provider_name,
  struct bcc_usdt_argument *argument);
 
 int bcc_usdt_enable_probe(void *, const char *, const char *);
+#define BCC_USDT_HAS_FULLY_SPECIFIED_PROBE
+int bcc_usdt_enable_fully_specified_probe(void *, const char *, const char *, const char *);
 const char *bcc_usdt_genargs(void **ctx_array, int len);
 const char *bcc_usdt_get_probe_argctype(
  void *ctx, const char* probe_name, const int arg_index

src/cc/usdt.h

@@ -280,6 +280,7 @@ class Context {
  Probe *get(int pos) { return probes_[pos].get(); }
 
  bool enable_probe(const std::string &probe_name, const std::string &fn_name);
+ bool enable_probe(const std::string &provider_name, const std::string &probe_name, const std::string &fn_name);
 
  typedef void (*each_cb)(struct bcc_usdt *);
  void each(each_cb callback);

src/cc/usdt/usdt.cc

@@ -295,24 +295,46 @@ Probe *Context::get(const std::string &provider_name,
 
 bool Context::enable_probe(const std::string &probe_name,
  const std::string &fn_name) {
+ return enable_probe("", probe_name, fn_name);
+}
+
+bool Context::enable_probe(const std::string &provider_name,
+ const std::string &probe_name,
+ const std::string &fn_name) {
  if (pid_stat_ && pid_stat_->is_stale())
  return false;
 
- // FIXME: we may have issues here if the context has two same probes's
- // but different providers. For example, libc:setjmp and rtld:setjmp,
- // libc:lll_futex_wait and rtld:lll_futex_wait.
+ unsigned int matches = 0;
  Probe *found_probe = nullptr;
  for (auto &p : probes_) {
  if (p->name_ == probe_name) {
- if (found_probe != nullptr) {
- fprintf(stderr, "Two same-name probes (%s) but different providers\n",
- probe_name.c_str());
- return false;
+ if (found_probe == nullptr && provider_name == "")
+ {
+ found_probe = p.get();
+ matches++;
+ }
+ else if (found_probe != nullptr && provider_name == "")
+ {
+ fprintf(stderr, "Found duplicate provider (%s) for underspecified probe (%s)\n",
+ p->provider().c_str(), p->name().c_str());
+ matches++;
+ } else if (provider_name != "" && p->provider() == provider_name)
+ {
+ found_probe = p.get();
+ matches++;
  }
- found_probe = p.get();
  }
  }
 
+ if (matches > 1) {
+ fprintf(stderr, "Found %i duplicate providers for underpecified probe (%s)\n",
+ matches, fn_name.c_str());
+ return false;
+ } else if(matches < 1) {
+ fprintf(stderr, "No matches found for probe (%s)\n", fn_name.c_str());
+ return false;
+ }
+
  if (found_probe != nullptr)
  return found_probe->enable(fn_name);
 
@@ -448,6 +470,14 @@ int bcc_usdt_enable_probe(void *usdt, const char *probe_name,
  return ctx->enable_probe(probe_name, fn_name) ? 0 : -1;
 }
 
+int bcc_usdt_enable_fully_specified_probe(void *usdt,
+ const char *provider_name,
+ const char *probe_name,
+ const char *fn_name) {
+ USDT::Context *ctx = static_cast<USDT::Context *>(usdt);
+ return ctx->enable_probe(provider_name, probe_name, fn_name) ? 0 : -1;
+}
+
 const char *bcc_usdt_genargs(void **usdt_array, int len) {
  static std::string storage_;
  std::ostringstream stream;