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.

6 files changed, 82 insertions, 16 deletions

diff --git a/ChangeLog b/ChangeLog
index d1f79ce3..8ba4c334 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 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.
+
 	* stapprobes.5.in: Added information about utrace probes.
 
 2008-04-17  Josh Stone  <joshua.i.stone@intel.com>
diff --git a/NEWS b/NEWS
index 00cfb70c..03fb7117 100644
--- a/NEWS
+++ b/NEWS
@@ -13,6 +13,18 @@
   vm.pagefault
   vm.write_shared
 
+- More user-space probe types are added:
+
+  probe process(PID).clone { }
+  probe process("PATH").clone { }
+  probe process(PID).exec { }
+  probe process("PATH").exec { }
+  probe process(PID).death { }
+  probe process("PATH").death { }
+  probe process(PID).syscall { }
+  probe process("PATH").syscall { }
+  probe process(PID).syscall.return { }
+  probe process("PATH").syscall.return { }
 
 * What's new in version 0.6
 
diff --git a/stapprobes.5.in b/stapprobes.5.in
index fdba10be..3633fd39 100644
--- a/stapprobes.5.in
+++ b/stapprobes.5.in
@@ -311,6 +311,8 @@ Additional user-space probing is available in the following forms:
 .SAMPLE
 process(PID).clone
 process("PATH").clone
+process(PID).exec
+process("PATH").exec
 process(PID).death
 process("PATH").death
 process(PID).syscall
@@ -324,6 +326,10 @@ A
 probe gets called when a thread described by PID or PATH creates a new
 thread.
 A
+.B .exec
+probe gets called when a thread described by PID or PATH returns from
+.IR exec() .
+A
 .B .death
 probe gets called when a thread described by PID or PATH dies.
 A
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")
diff --git a/testsuite/ChangeLog b/testsuite/ChangeLog
index 86fd83c7..a2382148 100644
--- a/testsuite/ChangeLog
+++ b/testsuite/ChangeLog
@@ -1,5 +1,7 @@
 2008-04-18  David Smith  <dsmith@redhat.com>
 
+	* systemtap.base/utrace_p4.exp: Added exec probe test.
+
 	* buildok/utrace01.stp: Removed.
 	* buildok/utrace02.stp: Ditto.
 	* buildok/utrace03.stp: Ditto.
diff --git a/testsuite/systemtap.base/utrace_p4.exp b/testsuite/systemtap.base/utrace_p4.exp
index 35a3ba15..eb6ea685 100644
--- a/testsuite/systemtap.base/utrace_p4.exp
+++ b/testsuite/systemtap.base/utrace_p4.exp
@@ -53,6 +53,7 @@ set clone_script {"probe process(\"/bin/ls\").clone { print(\"ls clone\") }"}
 set death_script {"probe process(\"/bin/ls\").death { print(\"ls death\") }"}
 set syscall_script {"probe process(\"/bin/ls\").syscall { printf(\"|%d\", \$syscall) }"}
 set syscall_return_script {"probe process(\"/bin/ls\").syscall.return { printf(\"|%d\", \$syscall) }"}
+set exec_script {"probe process(\"/bin/ls\").exec { print(\"ls exec\") }"}
 
 # Try to find utrace_attach symbol in /proc/kallsyms
 set path "/proc/kallsyms"
@@ -95,3 +96,11 @@ if {$utrace_support_found == 0} {
     # Try compiling a syscall return script
     stap_compile $TEST_NAME 1 $syscall_return_script
 }
+
+set TEST_NAME "UTRACE_P4_05"
+if {$utrace_support_found == 0} {
+    untested "$TEST_NAME : no kernel utrace support found"
+} else {
+    # Try compiling an exec script
+    stap_compile $TEST_NAME 1 $exec_script
+}