Added utrace exec probes.

2008-04-18  David Smith  <dsmith@redhat.com>

	* tapsets.cxx (struct utrace_builder): Added exec probes.
	(utrace_derived_probe_group::emit_probe_decl): Ditto.
	(utrace_derived_probe_group::emit_module_decls): Ditto.
	(register_standard_tapsets): Ditto.
	* stapprobes.5.in: Added information about exec probes.
	* NEWS: Added information about utrace probes.

2008-04-18  David Smith  <dsmith@redhat.com>

	* systemtap.base/utrace_p4.exp: Added exec probe test.

1 files changed, 46 insertions, 16 deletions

diff --git a/tapsets.cxx b/tapsets.cxx
index c4cfaa25..35d25172 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -4531,6 +4531,8 @@ struct utrace_builder: public derived_probe_builder
       }
     else if (has_null_param (parameters, "clone"))
       flags = UDPF_CLONE;
+    else if (has_null_param (parameters, "exec"))
+      flags = UDPF_EXEC;
 
     // If we have a path, we need to validate it.
     if (has_path)
@@ -4616,11 +4618,15 @@ utrace_derived_probe_group::emit_probe_decl (systemtap_session& s,
   switch (p->flags)
     {
     case UDPF_CLONE:
-      // Notice we're not setting up a .ops/.report_clone handler
-      // here.  Instead, we'll just call the probe directly when we
-      // get notified the clone happened.
+      s.op->line() << " .ops={ .report_clone=stap_utrace_probe_clone },";
       s.op->line() << " .flags=(UTRACE_EVENT(CLONE)),";
       break;
+    case UDPF_EXEC:
+      // Notice we're not setting up a .ops/.report_exec handler here.
+      // Instead, we'll just call the probe directly when we get
+      // notified the exec happened.
+      s.op->line() << " .flags=(UTRACE_EVENT(EXEC)),";
+      break;
     case UDPF_DEATH:
       // Notice we're not setting up a .ops/.report_death handler
       // here.  Instead, we'll just call the probe directly when we
@@ -4662,9 +4668,27 @@ utrace_derived_probe_group::emit_module_decls (systemtap_session& s)
   s.op->newline() << "int engine_attached;";
   s.op->newline(-1) << "};";
 
-  // Output handler function for CLONE and DEATH events
-  if (flags_seen[UDPF_CLONE] || flags_seen[UDPF_DEATH])
-   {
+  // Output handler function for CLONE events
+  if (flags_seen[UDPF_CLONE])
+    {
+      s.op->newline() << "static u32 stap_utrace_probe_clone(struct utrace_attached_engine *engine, struct task_struct *parent, unsigned long clone_flags, struct task_struct *child) {";
+      s.op->indent(1);
+      s.op->newline() << "struct stap_utrace_probe *p = (struct stap_utrace_probe *)engine->data;";
+
+      common_probe_entryfn_prologue (s.op, "STAP_SESSION_RUNNING");
+      s.op->newline() << "c->probe_point = p->pp;";
+
+      // call probe function
+      s.op->newline() << "(*p->ph) (c);";
+      common_probe_entryfn_epilogue (s.op);
+
+      s.op->newline() << "return UTRACE_ACTION_RESUME;";
+      s.op->newline(-1) << "}";
+    }
+
+  // Output handler function for EXEC and DEATH events
+  if (flags_seen[UDPF_EXEC] || flags_seen[UDPF_DEATH])
+    {
       s.op->newline() << "static void stap_utrace_probe_handler(struct task_struct *tsk, struct stap_utrace_probe *p) {";
       s.op->indent(1);
 
@@ -4677,7 +4701,7 @@ utrace_derived_probe_group::emit_module_decls (systemtap_session& s)
 
       s.op->newline() << "return;";
       s.op->newline(-1) << "}";
-   }
+    }
 
   // Output handler function for SYSCALL_ENTRY and SYSCALL_EXIT events
   if (flags_seen[UDPF_SYSCALL_ENTRY] || flags_seen[UDPF_SYSCALL_EXIT])
@@ -4712,23 +4736,23 @@ utrace_derived_probe_group::emit_module_decls (systemtap_session& s)
 
   s.op->newline() << "switch (p->flags) {";
   s.op->indent(1);
-  // For the register/clone case, we can't install a utrace engine,
-  // since we're already in a clone event.  So, we just call the probe
+  // When registering an exec probe, we can't install a utrace engine,
+  // since we're already in a exec event.  So, we just call the probe
   // directly.  Note that for existing threads, this won't really work
   // since our state isn't STAP_SESSION_RUNNING yet.  But that's OK,
-  // since this isn't really a 'clone' event - it is a notification
+  // since this isn't really a 'exec' event - it is a notification
   // that task_finder found an interesting process.
-  if (flags_seen[UDPF_CLONE])
+  if (flags_seen[UDPF_EXEC])
     {
-      s.op->newline() << "case UTRACE_EVENT(CLONE):";
+      s.op->newline() << "case UTRACE_EVENT(EXEC):";
       s.op->indent(1);
       s.op->newline() << "_stp_dbug(__FUNCTION__, __LINE__, \"%s\\n\", p->pp);";
       s.op->newline() << "stap_utrace_probe_handler(tsk, p);";
       s.op->newline() << "break;";
       s.op->indent(-1);
     }
-  // For death probes, do nothing at clone time.  We'll handle these
-  // in the 'register_p == 0' case.
+  // For death probes, do nothing at registration time.  We'll handle
+  // these in the 'register_p == 0' case.
   if (flags_seen[UDPF_DEATH])
     {
       s.op->newline() << "case UTRACE_EVENT(DEATH):";
@@ -4736,9 +4760,11 @@ utrace_derived_probe_group::emit_module_decls (systemtap_session& s)
       s.op->newline() << "break;";
       s.op->indent(-1);
     }
-  // Attach an engine for SYSCALL_ENTRY and SYSCALL_EXIT events.
-  if (flags_seen[UDPF_SYSCALL_ENTRY] || flags_seen[UDPF_SYSCALL_EXIT])
+  // Attach an engine for CLONE, SYSCALL_ENTRY, and SYSCALL_EXIT events.
+  if (flags_seen[UDPF_CLONE] || flags_seen[UDPF_SYSCALL_ENTRY]
+      || flags_seen[UDPF_SYSCALL_EXIT])
     {
+      s.op->newline() << "case UTRACE_EVENT(CLONE):";
       s.op->newline() << "case UTRACE_EVENT(SYSCALL_ENTRY):";
       s.op->newline() << "case UTRACE_EVENT(SYSCALL_EXIT):";
       s.op->indent(1);
@@ -7267,6 +7293,10 @@ register_standard_tapsets(systemtap_session & s)
     ->bind(new utrace_builder ());
   s.pattern_root->bind_num(TOK_PROCESS)->bind("clone")
     ->bind(new utrace_builder ());
+  s.pattern_root->bind_str(TOK_PROCESS)->bind("exec")
+    ->bind(new utrace_builder ());
+  s.pattern_root->bind_num(TOK_PROCESS)->bind("exec")
+    ->bind(new utrace_builder ());
   s.pattern_root->bind_str(TOK_PROCESS)->bind("syscall")
     ->bind(new utrace_builder ());
   s.pattern_root->bind_num(TOK_PROCESS)->bind("syscall")