Merge branch 'master' into pr6866

18 files changed, 187 insertions, 79 deletions

diff --git a/Makefile.in b/Makefile.in
index 73ef5bac..12a5e6ea 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -288,6 +288,7 @@ staplog_CPPFLAGS = @staplog_CPPFLAGS@
 subdirs = @subdirs@
 sysconfdir = @sysconfdir@
 target_alias = @target_alias@
+top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 
diff --git a/NEWS b/NEWS
index 74fd1df5..fff8afc9 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,10 @@
 * What's new
 
+- In guru mode (-g), the kernel probing blacklist is disabled, leaving 
+  only a subset - the kernel's own internal kprobe blacklist - to attempt
+  to filter out areas unsafe to probe.  The differences may be enough to
+  probe more interrupt handlers.
+
 - Variables unavailable in current context may be skipped by setting a 
   session level flag with command line option --skip-badvars now available. 
   This will simply substitute the otherwise error causing variable with a 
diff --git a/buildrun.cxx b/buildrun.cxx
index b9d648ef..0e9e0e17 100644
--- a/buildrun.cxx
+++ b/buildrun.cxx
@@ -148,6 +148,7 @@ compile_pass (systemtap_session& s)
   output_autoconf(s, o, "autoconf-vm-area.c", "STAPCONF_VM_AREA", NULL);
   output_autoconf(s, o, "autoconf-procfs-owner.c", "STAPCONF_PROCFS_OWNER", NULL);
   output_autoconf(s, o, "autoconf-alloc-percpu-align.c", "STAPCONF_ALLOC_PERCPU_ALIGN", NULL);
+  output_autoconf(s, o, "autoconf-find-task-pid.c", "STAPCONF_FIND_TASK_PID", NULL);
 
 #if 0
   /* NB: For now, the performance hit of probe_kernel_read/write (vs. our
diff --git a/doc/Makefile.in b/doc/Makefile.in
index 93753666..e23a6699 100644
--- a/doc/Makefile.in
+++ b/doc/Makefile.in
@@ -163,6 +163,7 @@ staplog_CPPFLAGS = @staplog_CPPFLAGS@
 subdirs = @subdirs@
 sysconfdir = @sysconfdir@
 target_alias = @target_alias@
+top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 PDF_FILES = tutorial.pdf langref.pdf
diff --git a/doc/SystemTap_Tapset_Reference/Makefile.am b/doc/SystemTap_Tapset_Reference/Makefile.am
index 9e7d2069..68dfd971 100644
--- a/doc/SystemTap_Tapset_Reference/Makefile.am
+++ b/doc/SystemTap_Tapset_Reference/Makefile.am
@@ -2,7 +2,7 @@
 ## process this file with automake to produce Makefile.in
 
 DOC_INSTALL_DIR = $(DESTDIR)$(datadir)/doc/systemtap
-MAN_INSTALL_DIR = $(DESTDIR)$(mandir)/man5
+MAN_INSTALL_DIR = $(DESTDIR)$(mandir)/man3stap
 HTML_INSTALL_DIR = $(DESTDIR)$(datadir)/doc/systemtap/tapsets
 
 
@@ -36,7 +36,7 @@ tapsets.pdf: tapsets.xml
 	xmlto pdf tapsets.xml
 
 stamp-mandocs: tapsets.xml
-	xmlto man -o man5 tapsets.xml
+	xmlto man -o man3stap tapsets.xml
 	touch stamp-mandocs
 
 #FIXME need to figure out where to install things appropriately
@@ -45,7 +45,7 @@ install-data-hook:
 	$(MKDIR_P)  $(DOC_INSTALL_DIR)
 	$(INSTALL_DATA) tapsets.pdf $(DOC_INSTALL_DIR)
 	$(MKDIR_P)  $(MAN_INSTALL_DIR)
-	$(INSTALL_DATA) man5/* $(MAN_INSTALL_DIR)
+	$(INSTALL_DATA) man3stap/* $(MAN_INSTALL_DIR)
 	$(MKDIR_P)  $(HTML_INSTALL_DIR)
 	$(INSTALL_DATA) tapsets/* $(HTML_INSTALL_DIR)
 endif
diff --git a/doc/SystemTap_Tapset_Reference/Makefile.in b/doc/SystemTap_Tapset_Reference/Makefile.in
index 84d2114c..2f8a5294 100644
--- a/doc/SystemTap_Tapset_Reference/Makefile.in
+++ b/doc/SystemTap_Tapset_Reference/Makefile.in
@@ -166,10 +166,11 @@ staplog_CPPFLAGS = @staplog_CPPFLAGS@
 subdirs = @subdirs@
 sysconfdir = @sysconfdir@
 target_alias = @target_alias@
+top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 DOC_INSTALL_DIR = $(DESTDIR)$(datadir)/doc/systemtap
-MAN_INSTALL_DIR = $(DESTDIR)$(mandir)/man5
+MAN_INSTALL_DIR = $(DESTDIR)$(mandir)/man3stap
 HTML_INSTALL_DIR = $(DESTDIR)$(datadir)/doc/systemtap/tapsets
 SRCTREE = $(abs_top_srcdir)/
 DOCPROC = $(abs_builddir)/docproc
@@ -429,7 +430,7 @@ uninstall-am:
 @BUILD_REFDOCS_TRUE@	xmlto pdf tapsets.xml
 
 @BUILD_REFDOCS_TRUE@stamp-mandocs: tapsets.xml
-@BUILD_REFDOCS_TRUE@	xmlto man -o man5 tapsets.xml
+@BUILD_REFDOCS_TRUE@	xmlto man -o man3stap tapsets.xml
 @BUILD_REFDOCS_TRUE@	touch stamp-mandocs
 
 #FIXME need to figure out where to install things appropriately
@@ -438,7 +439,7 @@ uninstall-am:
 @BUILD_REFDOCS_TRUE@	$(MKDIR_P)  $(DOC_INSTALL_DIR)
 @BUILD_REFDOCS_TRUE@	$(INSTALL_DATA) tapsets.pdf $(DOC_INSTALL_DIR)
 @BUILD_REFDOCS_TRUE@	$(MKDIR_P)  $(MAN_INSTALL_DIR)
-@BUILD_REFDOCS_TRUE@	$(INSTALL_DATA) man5/* $(MAN_INSTALL_DIR)
+@BUILD_REFDOCS_TRUE@	$(INSTALL_DATA) man3stap/* $(MAN_INSTALL_DIR)
 @BUILD_REFDOCS_TRUE@	$(MKDIR_P)  $(HTML_INSTALL_DIR)
 @BUILD_REFDOCS_TRUE@	$(INSTALL_DATA) tapsets/* $(HTML_INSTALL_DIR)
 # Tell versions [3.59,3.63) of GNU make to not export all variables.
diff --git a/doc/Tapset_Reference_Guide/manpager.sh b/doc/Tapset_Reference_Guide/manpager.sh
index 0051d208..0051d208 100644..100755
--- a/doc/Tapset_Reference_Guide/manpager.sh
+++ b/doc/Tapset_Reference_Guide/manpager.sh
diff --git a/parse.cxx b/parse.cxx
index ac7e652c..a26d594c 100644
--- a/parse.cxx
+++ b/parse.cxx
@@ -2341,6 +2341,12 @@ parser::parse_symbol ()
 	  cop->operand = parse_expression ();
           expect_op(",");
           expect_unknown(tok_string, cop->type);
+          // types never start with "struct<space>" or "union<space>",
+          // so gobble it up.
+          if (cop->type.compare(0, 7, "struct ") == 0)
+            cop->type = cop->type.substr(7);
+          if (cop->type.compare(0, 6, "union ") == 0)
+            cop->type = cop->type.substr(6);
           if (peek_op (","))
             {
               next();
diff --git a/runtime/autoconf-find-task-pid.c b/runtime/autoconf-find-task-pid.c
new file mode 100644
index 00000000..549d5ac3
--- /dev/null
+++ b/runtime/autoconf-find-task-pid.c
@@ -0,0 +1,6 @@
+#include <linux/sched.h>
+
+void foo (pid_t k) {
+  struct task_struct *tsk = find_task_by_pid (k);
+  (void) tsk;
+}
diff --git a/runtime/itrace.c b/runtime/itrace.c
index ed32b0bc..3d9ded2f 100644
--- a/runtime/itrace.c
+++ b/runtime/itrace.c
@@ -1,6 +1,7 @@
 /*
  * user space instruction tracing
  * Copyright (C) 2005, 2006, 2007, 2008, 2009 IBM Corp.
+ * Copyright (C) 2009 Red Hat Inc.
  *
  * This file is part of systemtap, and is free software.  You can
  * redistribute it and/or modify it under the terms of the GNU General
@@ -19,6 +20,7 @@
 #include <linux/utrace.h>
 #include <asm/string.h>
 #include "uprobes/uprobes.h"
+#include "utrace_compatibility.h"
 
 #ifndef put_task_struct
 #define put_task_struct(t)	\
@@ -55,7 +57,7 @@ struct itrace_info {
 	struct list_head link;
 };
 
-static u32 debug = 1;
+static u32 debug = 0 /* 1 */;
 
 static LIST_HEAD(usr_itrace_info);
 static spinlock_t itrace_lock;
@@ -118,10 +120,15 @@ static int __access_process_vm(struct task_struct *tsk, unsigned long addr, void
 	return buf - old_buf;
 }
 
+#ifdef UTRACE_ORIG_VERSION
+static u32 usr_itrace_report_quiesce(struct utrace_attached_engine *engine,
+					struct task_struct *tsk)
+#else
 static u32 usr_itrace_report_quiesce(enum utrace_resume_action action,
 				struct utrace_attached_engine *engine,
 				struct task_struct *tsk,
 				unsigned long event)
+#endif
 {
 	int status;
 	struct itrace_info *ui;
@@ -129,10 +136,23 @@ static u32 usr_itrace_report_quiesce(enum utrace_resume_action action,
 	ui = rcu_dereference(engine->data);
 	WARN_ON(!ui);
 
+#ifdef UTRACE_ORIG_VERSION
+	return (ui->step_flag); // XXX XXX XXX 
+#else
 	return (event == 0 ? ui->step_flag : UTRACE_RESUME);
+#endif
 }
 
 
+#ifdef UTRACE_ORIG_VERSION
+static u32 usr_itrace_report_signal(
+			     struct utrace_attached_engine *engine,
+			     struct task_struct *tsk,
+			     struct pt_regs *regs,
+                             u32 action, siginfo_t *info,
+			     const struct k_sigaction *orig_ka,
+			     struct k_sigaction *return_ka)
+#else
 static u32 usr_itrace_report_signal(u32 action,
 			     struct utrace_attached_engine *engine,
 			     struct task_struct *tsk,
@@ -140,6 +160,7 @@ static u32 usr_itrace_report_signal(u32 action,
 			     siginfo_t *info,
 			     const struct k_sigaction *orig_ka,
 			     struct k_sigaction *return_ka)
+#endif
 {
 	struct itrace_info *ui;
 	u32 return_flags;
@@ -174,16 +195,31 @@ static u32 usr_itrace_report_signal(u32 action,
 	return return_flags;
 }
 
+
+
+#ifdef UTRACE_ORIG_VERSION
+static u32 usr_itrace_report_clone(
+		struct utrace_attached_engine *engine,
+		struct task_struct *parent,
+                unsigned long clone_flags,
+		struct task_struct *child)
+#else
 static u32 usr_itrace_report_clone(enum utrace_resume_action action,
 		struct utrace_attached_engine *engine,
 		struct task_struct *parent, unsigned long clone_flags,
 		struct task_struct *child)
+#endif
 {
 	return UTRACE_RESUME;
 }
 
+#ifdef UTRACE_ORIG_VERSION
+static u32 usr_itrace_report_death(struct utrace_attached_engine *e,
+                                   struct task_struct *tsk)
+#else
 static u32 usr_itrace_report_death(struct utrace_attached_engine *e,
 	struct task_struct *tsk, bool group_dead, int signal)
+#endif
 {
 	struct itrace_info *ui = rcu_dereference(e->data);
 	WARN_ON(!ui);
@@ -275,8 +311,13 @@ static int usr_itrace_init(int single_step, pid_t tid, struct stap_itrace_probe
 	struct itrace_info *ui;
 	struct task_struct *tsk;
 
+	spin_lock_init(&itrace_lock);
 	rcu_read_lock();
+#ifdef STAPCONF_FIND_TASK_PID
+	tsk = find_task_by_pid(tid);
+#else
 	tsk = find_task_by_vpid(tid);
+#endif
 	if (!tsk) {
 		printk(KERN_ERR "usr_itrace_init: Cannot find process %d\n", tid);
 		rcu_read_unlock();
@@ -293,11 +334,6 @@ static int usr_itrace_init(int single_step, pid_t tid, struct stap_itrace_probe
 	put_task_struct(tsk);
 	rcu_read_unlock();
 
-	spin_lock_init(&itrace_lock);
-
-	/* set initial state */
-	spin_lock(&itrace_lock);
-	spin_unlock(&itrace_lock);
 	printk(KERN_INFO "usr_itrace_init: completed for tid = %d\n", tid);
 
 	return 0;
@@ -314,7 +350,6 @@ void static remove_usr_itrace_info(struct itrace_info *ui)
 	if (debug)
 		printk(KERN_INFO "remove_usr_itrace_info: tid=%d\n", ui->tid);
 
-	spin_lock(&itrace_lock);
 	if (ui->tsk && ui->engine) {
 		status = utrace_control(ui->tsk, ui->engine, UTRACE_DETACH);
 		if (status < 0 && status != -ESRCH && status != -EALREADY)
@@ -322,6 +357,7 @@ void static remove_usr_itrace_info(struct itrace_info *ui)
 			       "utrace_control(UTRACE_DETACH) returns %d\n",
 			       status);
 	}
+	spin_lock(&itrace_lock);
 	list_del(&ui->link);
 	spin_unlock(&itrace_lock);
 	kfree(ui);
diff --git a/runtime/task_finder.c b/runtime/task_finder.c
index 1db2bc2a..cc24dc10 100644
--- a/runtime/task_finder.c
+++ b/runtime/task_finder.c
@@ -992,6 +992,7 @@ __stp_utrace_task_finder_target_syscall_entry(enum utrace_resume_action action,
 static void
 __stp_call_vm_callbacks_with_vma(struct stap_task_finder_target *tgt,
 				 struct task_struct *tsk,
+				 int map_p,
 				 struct vm_area_struct *vma)
 {
 	char *mmpath_buf;
@@ -1018,7 +1019,7 @@ __stp_call_vm_callbacks_with_vma(struct stap_task_finder_target *tgt,
 			   rc, (int)tsk->pid);
 	}
 	else {
-		__stp_call_vm_callbacks(tgt, tsk, 1, mmpath,
+		__stp_call_vm_callbacks(tgt, tsk, map_p, mmpath,
 					vma->vm_start, vma->vm_end,
 					(vma->vm_pgoff << PAGE_SHIFT));
 	}
@@ -1111,7 +1112,7 @@ __stp_utrace_task_finder_target_syscall_exit(enum utrace_resume_action action,
 			down_read(&mm->mmap_sem);
 			vma = __stp_find_file_based_vma(mm, rv);
 			if (vma != NULL) {
-				__stp_call_vm_callbacks_with_vma(tgt, tsk, vma);
+				__stp_call_vm_callbacks_with_vma(tgt, tsk, 0, vma);
 			}
 			up_read(&mm->mmap_sem);
 			mmput(mm);
@@ -1184,6 +1185,7 @@ __stp_utrace_task_finder_target_syscall_exit(enum utrace_resume_action action,
 				       && vma->vm_end <= entry->vm_end) {
 					__stp_call_vm_callbacks_with_vma(tgt,
 									 tsk,
+									 1,
 									 vma);
 					if (vma->vm_end >= entry->vm_end)
 						break;
diff --git a/runtime/utrace_compatibility.h b/runtime/utrace_compatibility.h
index 00b841d2..4a70da42 100644
--- a/runtime/utrace_compatibility.h
+++ b/runtime/utrace_compatibility.h
@@ -1,6 +1,6 @@
 /*
  * utrace compatibility defines and inlines
- * Copyright (C) 2008 Red Hat Inc.
+ * Copyright (C) 2008-2009 Red Hat Inc.
  *
  * This file is part of systemtap, and is free software.  You can
  * redistribute it and/or modify it under the terms of the GNU General
@@ -28,6 +28,8 @@ enum utrace_resume_action {
 	UTRACE_STOP = UTRACE_ACTION_QUIESCE,
 	UTRACE_RESUME = UTRACE_ACTION_RESUME,
 	UTRACE_DETACH = UTRACE_ACTION_DETACH,
+	UTRACE_SINGLESTEP = UTRACE_ACTION_SINGLESTEP,
+	UTRACE_BLOCKSTEP = UTRACE_ACTION_BLOCKSTEP,
 };
 
 static inline struct utrace_attached_engine *
@@ -48,6 +50,11 @@ utrace_control(struct task_struct *target,
 	case UTRACE_STOP:
 		return utrace_set_flags(target, engine,
 					(engine->flags | UTRACE_ACTION_QUIESCE));
+        case UTRACE_SINGLESTEP:
+        case UTRACE_BLOCKSTEP:
+          return utrace_set_flags(target, engine,
+                                  engine->flags | action);
+
 	default:
 		return -EINVAL;
 	}
diff --git a/scripts/kernel-doc b/scripts/kernel-doc
index add4ba3c..9947882d 100755
--- a/scripts/kernel-doc
+++ b/scripts/kernel-doc
@@ -981,7 +981,7 @@ sub output_probe_xml(%) {
     print "</refentryinfo>\n";
     print "<refmeta>\n";
     print " <refentrytitle><phrase>".$args{'probe'}."</phrase></refentrytitle>\n";
-    print " <manvolnum>5</manvolnum>\n";
+    print " <manvolnum>3stap</manvolnum>\n";
 #    print " <refmiscinfo class=\"version\">" . $kernelversion . "</refmiscinfo>\n";
     print "</refmeta>\n";
     print "<refnamediv>\n";
@@ -1039,7 +1039,7 @@ sub output_sfunction_xml(%) {
     print "</refentryinfo>\n";
     print "<refmeta>\n";
     print " <refentrytitle><phrase>".$args{'sfunction'}."</phrase></refentrytitle>\n";
-    print " <manvolnum>5</manvolnum>\n";
+    print " <manvolnum>3stap</manvolnum>\n";
 #    print " <refmiscinfo class=\"version\">" . $kernelversion . "</refmiscinfo>\n";
     print "</refmeta>\n";
     print "<refnamediv>\n";
diff --git a/stapprobes.5.in b/stapprobes.5.in
index 70d045c4..f4a872cb 100644
--- a/stapprobes.5.in
+++ b/stapprobes.5.in
@@ -407,8 +407,10 @@ process.syscall
 process(PID).syscall.return
 process("PATH").syscall.return
 process.syscall.return
-process(PID).itrace
-process("PATH").itrace
+process(PID).insn
+process("PATH").insn
+process(PID).insn.block
+process("PATH").insn.block
 process("PATH").mark("LABEL")
 .ESAMPLE
 .PP
@@ -443,8 +445,11 @@ in the
 .BR $return
 context variable.
 A
-.B .itrace
-probe gets called for every single step of the process described by PID or PATH.
+.B .insn
+probe gets called for every single-stepped instruction of the process described by PID or PATH.
+A
+.B .insn.block
+probe gets called for every block-stepped instruction of the process described by PID or PATH.
 A
 .B .mark
 probe gets called via a static probe which is defined in the
diff --git a/systemtap.spec b/systemtap.spec
index 7277f92a..540a9d93 100644
--- a/systemtap.spec
+++ b/systemtap.spec
@@ -1,4 +1,3 @@
-%{!?release: %define release 1}
 %{!?with_sqlite: %define with_sqlite 1}
 %{!?with_docs: %define with_docs 1}
 %{!?with_crash: %define with_crash 0}
@@ -6,9 +5,9 @@
 %{!?elfutils_version: %define elfutils_version 0.127}
 
 Name: systemtap
-# for version, see also configure.ac
 Version: 0.9
-Release: %{release}%{?dist}
+Release: 3%{?dist}
+# for version, see also configure.ac
 Summary: Instrumentation System
 Group: Development/System
 License: GPLv2+
@@ -246,6 +245,7 @@ exit 0
 %if %{with_docs}
 %doc docs.installed/*.pdf
 %doc docs.installed/tapsets
+%{_mandir}/man3stap/*
 %endif
 
 %{_bindir}/stap
@@ -317,6 +317,9 @@ exit 0
 
 
 %changelog
+* Wed Mar 18 2009 Will Cohen <wcohen@redhat.com> - 0.9-2
+- Add location of man pages.
+
 * Tue Feb 17 2009 Frank Ch. Eigler <fche@redhat.com> - 0.9-1
 - Upstream release.
 
diff --git a/tapset/aux_syscalls.stp b/tapset/aux_syscalls.stp
index d2e43903..87ea4e04 100644
--- a/tapset/aux_syscalls.stp
+++ b/tapset/aux_syscalls.stp
@@ -322,17 +322,10 @@ function _struct_sockaddr_u:string(uaddr:long, len:long)
 	}
 	else if ((sa->sa_family == AF_PACKET)&&(len == sizeof(struct sockaddr_ll))) 
 	{
-		/* FIXME. This needs tested */
 		struct sockaddr_ll *sll = (struct sockaddr_ll *)buf;
-#if defined(__powerpc__) || defined(__ia64__) || defined(__s390x__)
-		snprintf(str, strlen, "{AF_PACKET, proto=%d, ind=%d, hatype=%d, pkttype=%d, halen=%d, addr=0x%lx}", 
-			(int)sll->sll_protocol, sll->sll_ifindex, (int)sll->sll_hatype, (int)sll->sll_pkttype,
-			(int)sll->sll_halen, *(uint64_t *)sll->sll_addr);
-#else
 		snprintf(str, strlen, "{AF_PACKET, proto=%d, ind=%d, hatype=%d, pkttype=%d, halen=%d, addr=0x%llx}", 
 			(int)sll->sll_protocol, sll->sll_ifindex, (int)sll->sll_hatype, (int)sll->sll_pkttype,
 			(int)sll->sll_halen, *(uint64_t *)sll->sll_addr);
-#endif
 	}
 	else
 	{
diff --git a/tapsets.cxx b/tapsets.cxx
index 89e011c4..d7b55e33 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -3521,9 +3521,17 @@ dwarf_query::blacklisted_p(const string& funcname,
 
   if (! (goodfn && goodfile))
     {
-      if (sess.verbose>1)
-	clog << " skipping - blacklisted";
-      return true;
+      if (sess.guru_mode)
+        {
+	  if (sess.verbose>1)
+	    clog << " guru mode enabled - ignoring blacklist";
+        }
+      else
+        {
+	  if (sess.verbose>1)
+	    clog << " skipping - blacklisted";
+	  return true;
+        }
     }
 
   // This probe point is not blacklisted.
@@ -5059,7 +5067,8 @@ void dwarf_cast_expanding_visitor::visit_cast_op (cast_op* e)
       // cast_op to the next pass.  We hope that this value ends
       // up not being referenced after all, so it can be optimized out
       // quietly.
-      semantic_error* er = new semantic_error ("type definition not found", e->tok);
+      string msg = "type definition '" + e->type + "' not found";
+      semantic_error* er = new semantic_error (msg, e->tok);
       // NB: we can have multiple errors, since a @cast
       // may be expanded in several different contexts:
       //     function ("*") { @cast(...) }
@@ -6240,6 +6249,9 @@ task_finder_derived_probe_group::emit_module_exit (systemtap_session& s)
 // ------------------------------------------------------------------------
 
 
+static string TOK_INSN("insn");
+static string TOK_BLOCK("block");
+
 struct itrace_derived_probe: public derived_probe
 {
   bool has_path;
@@ -6314,7 +6326,7 @@ struct itrace_builder: public derived_probe_builder
     // XXX: PR 6445 needs !has_path && !has_pid support
     assert (has_path || has_pid);
 
-    single_step = 1;
+    single_step = ! has_null_param (parameters, TOK_BLOCK);
 
     // If we have a path, we need to validate it.
     if (has_path)
@@ -9269,10 +9281,10 @@ mark_builder::build(systemtap_session & sess,
 
 struct tracepoint_arg
 {
-  string name, c_type;
-  bool used, isptr;
+  string name, c_type, typecast;
+  bool usable, used, isptr;
   Dwarf_Die type_die;
-  tracepoint_arg(): used(false), isptr(false) {}
+  tracepoint_arg(): usable(false), used(false), isptr(false) {}
 };
 
 struct tracepoint_derived_probe: public derived_probe
@@ -9324,7 +9336,7 @@ tracepoint_var_expanding_visitor::visit_target_symbol_arg (target_symbol* e)
   // search for a tracepoint parameter matching this name
   tracepoint_arg *arg = NULL;
   for (unsigned i = 0; i < args.size(); ++i)
-    if (args[i].name == argname)
+    if (args[i].usable && args[i].name == argname)
       {
         arg = &args[i];
         arg->used = true;
@@ -9372,6 +9384,9 @@ tracepoint_var_expanding_visitor::visit_target_symbol_arg (target_symbol* e)
   if (lvalue && (!dw.sess.guru_mode || e->components.empty()))
     throw semantic_error("write to tracepoint variable '" + e->base_name
                          + "' not permitted", e->tok);
+  // XXX: if a struct/union arg is passed by value, then writing to its fields
+  // is also meaningless until you dereference past a pointer member.  It's
+  // harder to detect and prevent that though...
 
   if (e->components.empty())
     {
@@ -9543,6 +9558,8 @@ tracepoint_var_expanding_visitor::visit_target_symbol_context (target_symbol* e)
 
       for (unsigned i = 0; i < args.size(); ++i)
         {
+          if (!args[i].usable)
+            continue;
           if (i > 0)
             pf->raw_components += " ";
           pf->raw_components += args[i].name;
@@ -9625,32 +9642,39 @@ tracepoint_derived_probe::tracepoint_derived_probe (systemtap_session& s,
 static bool
 dwarf_type_name(Dwarf_Die& type_die, string& c_type)
 {
-  // if this die has a direct name, then we're done
-  const char *diename = dwarf_diename_integrate(&type_die);
-  if (diename != NULL)
+  // if we've gotten down to a basic type, then we're done
+  bool done = true;
+  switch (dwarf_tag(&type_die))
     {
-      switch (dwarf_tag(&type_die))
-        {
-        case DW_TAG_structure_type:
-          c_type.append("struct ");
-          break;
-        case DW_TAG_union_type:
-          c_type.append("union ");
-          break;
-        }
-      c_type.append(diename);
+    case DW_TAG_structure_type:
+      c_type.append("struct ");
+      break;
+    case DW_TAG_union_type:
+      c_type.append("union ");
+      break;
+    case DW_TAG_typedef:
+    case DW_TAG_base_type:
+      break;
+    default:
+      done = false;
+      break;
+    }
+  if (done)
+    {
+      c_type.append(dwarf_diename_integrate(&type_die));
       return true;
     }
 
   // otherwise, this die is a type modifier.
 
   // recurse into the referent type
+  // if it can't be named, just call it "void"
   Dwarf_Attribute subtype_attr;
   Dwarf_Die subtype_die;
   if (!dwarf_attr_integrate(&type_die, DW_AT_type, &subtype_attr)
       || !dwarf_formref_die(&subtype_attr, &subtype_die)
       || !dwarf_type_name(subtype_die, c_type))
-    return false;
+    c_type = "void";
 
   const char *suffix = NULL;
   switch (dwarf_tag(&type_die))
@@ -9671,33 +9695,47 @@ dwarf_type_name(Dwarf_Die& type_die, string& c_type)
       return false;
     }
   c_type.append(suffix);
+
+  // XXX HACK!  The va_list isn't usable as found in the debuginfo...
+  if (c_type == "struct __va_list_tag*")
+    c_type = "va_list";
+
   return true;
 }
 
 
 static bool
-resolve_tracepoint_arg_type(Dwarf_Die& type_die, bool& isptr)
+resolve_tracepoint_arg_type(tracepoint_arg& arg)
 {
   Dwarf_Attribute type_attr;
-  switch (dwarf_tag(&type_die))
+  switch (dwarf_tag(&arg.type_die))
     {
     case DW_TAG_typedef:
     case DW_TAG_const_type:
     case DW_TAG_volatile_type:
       // iterate on the referent type
-      return (dwarf_attr_integrate(&type_die, DW_AT_type, &type_attr)
-              && dwarf_formref_die(&type_attr, &type_die)
-              && resolve_tracepoint_arg_type(type_die, isptr));
+      return (dwarf_attr_integrate(&arg.type_die, DW_AT_type, &type_attr)
+              && dwarf_formref_die(&type_attr, &arg.type_die)
+              && resolve_tracepoint_arg_type(arg));
     case DW_TAG_base_type:
       // base types will simply be treated as script longs
-      isptr = false;
+      arg.isptr = false;
       return true;
     case DW_TAG_pointer_type:
-      // pointers can be either script longs,
-      // or dereferenced with their referent type
-      isptr = true;
-      return (dwarf_attr_integrate(&type_die, DW_AT_type, &type_attr)
-              && dwarf_formref_die(&type_attr, &type_die));
+      // pointers can be treated as script longs,
+      // and if we know their type, they can also be dereferenced
+      if (dwarf_attr_integrate(&arg.type_die, DW_AT_type, &type_attr)
+          && dwarf_formref_die(&type_attr, &arg.type_die))
+        arg.isptr = true;
+      arg.typecast = "(intptr_t)";
+      return true;
+    case DW_TAG_structure_type:
+    case DW_TAG_union_type:
+      // for structs/unions which are passed by value, we turn it into
+      // a pointer that can be dereferenced.
+      arg.isptr = true;
+      arg.typecast = "(intptr_t)&";
+      return true;
     default:
       // should we consider other types too?
       return false;
@@ -9721,12 +9759,12 @@ tracepoint_derived_probe::build_args(dwflpp& dw, Dwarf_Die& func_die)
           Dwarf_Attribute type_attr;
           if (!dwarf_attr_integrate (&arg, DW_AT_type, &type_attr)
               || !dwarf_formref_die (&type_attr, &tparg.type_die)
-              || !dwarf_type_name(tparg.type_die, tparg.c_type)
-              || !resolve_tracepoint_arg_type(tparg.type_die, tparg.isptr))
+              || !dwarf_type_name(tparg.type_die, tparg.c_type))
             throw semantic_error ("cannot get type of tracepoint '"
                                   + tracepoint_name + "' parameter '"
                                   + tparg.name + "'");
 
+          tparg.usable = resolve_tracepoint_arg_type(tparg);
           args.push_back(tparg);
           if (sess.verbose > 4)
             clog << "found parameter for tracepoint '" << tracepoint_name
@@ -9739,8 +9777,9 @@ tracepoint_derived_probe::build_args(dwflpp& dw, Dwarf_Die& func_die)
 void
 tracepoint_derived_probe::printargs(std::ostream &o) const
 {
-      for (unsigned i = 0; i < args.size(); ++i)
-       o << " $" << args[i].name << ":" << args[i].c_type;
+  for (unsigned i = 0; i < args.size(); ++i)
+    if (args[i].usable)
+      o << " $" << args[i].name << ":" << args[i].c_type;
 }
 
 void
@@ -9778,6 +9817,8 @@ tracepoint_derived_probe_group::emit_module_decls (systemtap_session& s)
       // don't provide any sort of context pointer.
       s.op->newline() << "#include <" << p->header << ">";
       s.op->newline() << "static void enter_tracepoint_probe_" << i << "(";
+      if (p->args.size() == 0)
+        s.op->line() << "void";
       for (unsigned j = 0; j < p->args.size(); ++j)
         {
           if (j > 0)
@@ -9796,8 +9837,7 @@ tracepoint_derived_probe_group::emit_module_decls (systemtap_session& s)
           {
             s.op->newline() << "c->locals[0]." << p->name << ".__tracepoint_arg_"
                             << p->args[j].name << " = (int64_t)";
-            if (p->args[j].isptr)
-              s.op->line() << "(intptr_t)";
+            s.op->line() << p->args[j].typecast;
             s.op->line() << "__tracepoint_arg_" << p->args[j].name << ";";
           }
       s.op->newline() << p->name << " (c);";
@@ -10812,9 +10852,13 @@ register_standard_tapsets(systemtap_session & s)
     ->bind(new utrace_builder ());
 
   // itrace user-space probes
-  s.pattern_root->bind_str(TOK_PROCESS)->bind("itrace")
+  s.pattern_root->bind_str(TOK_PROCESS)->bind(TOK_INSN)
+    ->bind(new itrace_builder ());
+  s.pattern_root->bind_num(TOK_PROCESS)->bind(TOK_INSN)
+    ->bind(new itrace_builder ());
+  s.pattern_root->bind_str(TOK_PROCESS)->bind(TOK_INSN)->bind(TOK_BLOCK)
     ->bind(new itrace_builder ());
-  s.pattern_root->bind_num(TOK_PROCESS)->bind("itrace")
+  s.pattern_root->bind_num(TOK_PROCESS)->bind(TOK_INSN)->bind(TOK_BLOCK)
     ->bind(new itrace_builder ());
 
   // marker-based parts
diff --git a/testsuite/systemtap.base/itrace.exp b/testsuite/systemtap.base/itrace.exp
index f19af977..e215bfe7 100644
--- a/testsuite/systemtap.base/itrace.exp
+++ b/testsuite/systemtap.base/itrace.exp
@@ -1,8 +1,5 @@
 # itrace test
 
-# temporarily disabled
-return
-
 
 # Initialize variables
 set utrace_support_found 0
@@ -11,7 +8,7 @@ set exepath "[pwd]/ls_[pid]"
 set itrace1_script {
     global instrs = 0
     probe begin { printf("systemtap starting probe\n") }
-    probe process("%s").itrace
+    probe process("%s").insn
     {
         instrs += 1
 	if (instrs == 5)
@@ -28,7 +25,7 @@ set itrace1_script_output "itraced = 5\r\n"
 set itrace2_script {
     global instrs = 0, itrace_on = 0, start_timer = 0
     probe begin { start_timer = 1; printf("systemtap starting probe\n") }
-    probe process("%s").itrace if (itrace_on)
+    probe process("%s").insn if (itrace_on)
     {
         instrs += 1
 	if (instrs == 5)