Merge commit 'origin/master' into pr4225

* commit 'origin/master':
  Fix memory access error in nfs.proc.read_setup, nfs.proc.write_setup and nfs.proc.commit_setup
  Update NEWS regarding the systemtap client/server.
  New man page for the systemtap client/server and related utilities.
  Repopulate symbol/type info.
  Pushed quiesce logic down into the task_finder layer.
  Added bug 6841 fix utrace syscall test.
  PR6731: improve listing mode to list variables

16 files changed, 483 insertions, 210 deletions

diff --git a/ChangeLog b/ChangeLog
index e346a764..d9eccaef 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,28 @@
+2008-08-29  Dave Brolley  <brolley@redhat.com>
+
+	* stap-server.8.in: New man page.
+	* NEWS: Announce the availability of the client/server.
+	* Makefile.am (man_MANS): Add stap-server.8.
+	* configure.ac (AC_CONFIG_FILE): Add stap-server.8.
+	* Makefile.in: Regenerated.
+	* configure: Regenerated.
+
+2008-08-29  Stan Cox  <scox@redhat.com>
+
+	* elaborate.cxx (add_global_var_display): Repopulate symbol/type info.
+
+2008-08-29  David Smith  <dsmith@redhat.com>
+
+	* tapsets.cxx (utrace_derived_probe_group::emit_probe_decl):
+	Pushed quiesce logic down into the task_finder layer.
+	(utrace_derived_probe_group::emit_module_decls): Removed quiesce
+	handler routines.  Syscall probe handler detaches if systemtap
+	state isn't correct.
+
+2008-08-29  Wenji Huang <wenji.huang@oracle.com>
+
+	* main.cxx (printscript): Print variable name and type for listing mode.
+
 2008-08-28  Frank Ch. Eigler  <fche@elastic.org>
 
 	* elaborate.cxx (add_global_var_display): Render array indexes
diff --git a/Makefile.am b/Makefile.am
index 867066bb..fe0fc408 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -10,7 +10,7 @@ AM_CPPFLAGS = -DBINDIR='"$(bindir)"' -DPKGDATADIR='"${pkgdatadir}"' -DPKGLIBDIR=
 AM_CFLAGS = -D_GNU_SOURCE -fexceptions -Wall -Werror -Wunused -Wformat=2 -W
 AM_CXXFLAGS = -Wall -Werror
 
-man_MANS =  stap.1 stapprobes.5 stapfuncs.5 stapvars.5 stapex.5 staprun.8 man/stapprobes.iosched.5 man/stapprobes.netdev.5 man/stapprobes.nfs.5 man/stapprobes.nfsd.5 man/stapprobes.pagefault.5 man/stapprobes.process.5 man/stapprobes.rpc.5 man/stapprobes.scsi.5 man/stapprobes.signal.5 man/stapprobes.socket.5 man/stapprobes.tcp.5 man/stapprobes.udp.5
+man_MANS =  stap.1 stapprobes.5 stapfuncs.5 stapvars.5 stapex.5 staprun.8 stap-server.8 man/stapprobes.iosched.5 man/stapprobes.netdev.5 man/stapprobes.nfs.5 man/stapprobes.nfsd.5 man/stapprobes.pagefault.5 man/stapprobes.process.5 man/stapprobes.rpc.5 man/stapprobes.scsi.5 man/stapprobes.signal.5 man/stapprobes.socket.5 man/stapprobes.tcp.5 man/stapprobes.udp.5
 # see also configure.ac
 
 bin_PROGRAMS = stap staprun
diff --git a/Makefile.in b/Makefile.in
index 1d3225b8..ebd158dc 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -50,7 +50,7 @@ DIST_COMMON = INSTALL NEWS README AUTHORS ChangeLog \
 	$(srcdir)/config.in $(srcdir)/stap.1.in \
 	$(srcdir)/stapprobes.5.in $(srcdir)/stapfuncs.5.in \
 	$(srcdir)/stapvars.5.in $(srcdir)/stapex.5.in \
-	$(srcdir)/staprun.8.in \
+	$(srcdir)/staprun.8.in $(srcdir)/stap-server.8.in \
 	$(top_srcdir)/man/stapprobes.iosched.5.in \
 	$(top_srcdir)/man/stapprobes.netdev.5.in \
 	$(top_srcdir)/man/stapprobes.nfs.5.in \
@@ -72,7 +72,7 @@ am__CONFIG_DISTCLEAN_FILES = config.status config.cache config.log \
 mkinstalldirs = $(install_sh) -d
 CONFIG_HEADER = config.h
 CONFIG_CLEAN_FILES = stap.1 stapprobes.5 stapfuncs.5 stapvars.5 \
-	stapex.5 staprun.8 man/stapprobes.iosched.5 \
+	stapex.5 staprun.8 stap-server.8 man/stapprobes.iosched.5 \
 	man/stapprobes.netdev.5 man/stapprobes.nfs.5 \
 	man/stapprobes.nfsd.5 man/stapprobes.pagefault.5 \
 	man/stapprobes.process.5 man/stapprobes.rpc.5 \
@@ -260,7 +260,7 @@ pkglibexecdir = ${libexecdir}/${PACKAGE}
 AM_CPPFLAGS = -DBINDIR='"$(bindir)"' -DPKGDATADIR='"${pkgdatadir}"' -DPKGLIBDIR='"$(pkglibexecdir)"'
 AM_CFLAGS = -D_GNU_SOURCE -fexceptions -Wall -Werror -Wunused -Wformat=2 -W
 AM_CXXFLAGS = -Wall -Werror
-man_MANS = stap.1 stapprobes.5 stapfuncs.5 stapvars.5 stapex.5 staprun.8 man/stapprobes.iosched.5 man/stapprobes.netdev.5 man/stapprobes.nfs.5 man/stapprobes.nfsd.5 man/stapprobes.pagefault.5 man/stapprobes.process.5 man/stapprobes.rpc.5 man/stapprobes.scsi.5 man/stapprobes.signal.5 man/stapprobes.socket.5 man/stapprobes.tcp.5 man/stapprobes.udp.5
+man_MANS = stap.1 stapprobes.5 stapfuncs.5 stapvars.5 stapex.5 staprun.8 stap-server.8 man/stapprobes.iosched.5 man/stapprobes.netdev.5 man/stapprobes.nfs.5 man/stapprobes.nfsd.5 man/stapprobes.pagefault.5 man/stapprobes.process.5 man/stapprobes.rpc.5 man/stapprobes.scsi.5 man/stapprobes.signal.5 man/stapprobes.socket.5 man/stapprobes.tcp.5 man/stapprobes.udp.5
 bin_SCRIPTS = stap-client stap-server stap-serverd stap-find-servers stap-start-server stap-find-or-start-server stap-stop-server
 stap_SOURCES = main.cxx \
 	parse.cxx staptree.cxx elaborate.cxx translate.cxx \
@@ -388,6 +388,8 @@ stapex.5: $(top_builddir)/config.status $(srcdir)/stapex.5.in
 	cd $(top_builddir) && $(SHELL) ./config.status $@
 staprun.8: $(top_builddir)/config.status $(srcdir)/staprun.8.in
 	cd $(top_builddir) && $(SHELL) ./config.status $@
+stap-server.8: $(top_builddir)/config.status $(srcdir)/stap-server.8.in
+	cd $(top_builddir) && $(SHELL) ./config.status $@
 man/stapprobes.iosched.5: $(top_builddir)/config.status $(top_srcdir)/man/stapprobes.iosched.5.in
 	cd $(top_builddir) && $(SHELL) ./config.status $@
 man/stapprobes.netdev.5: $(top_builddir)/config.status $(top_srcdir)/man/stapprobes.netdev.5.in
diff --git a/NEWS b/NEWS
index 398964d9..fec89559 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,14 @@
 * What's new
 
+- Prototype systemtap client and compile server are now available.
+  These allow you to compile a systemtap module on a host other than
+  the one which it will be run, providing the client and server
+  are compatible. Other than using a server for passes 1 through
+  4, the client behaves like the 'stap' front end itself. This
+  means, among other things, that the client will automatically
+  load the resulting module on the local host unless -p[1234]
+  was specified. See stap-server(8) for more details.
+
 - Global variables which are written to but never read are now
   automatically displayed when the session does a shutdown.  For example: 
 
diff --git a/configure b/configure
index d1fe6a30..71413615 100755
--- a/configure
+++ b/configure
@@ -7190,7 +7190,7 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 ac_config_headers="$ac_config_headers config.h:config.in"
 
-ac_config_files="$ac_config_files Makefile doc/Makefile stap.1 stapprobes.5 stapfuncs.5 stapvars.5 stapex.5 staprun.8 man/stapprobes.iosched.5 man/stapprobes.netdev.5 man/stapprobes.nfs.5 man/stapprobes.nfsd.5 man/stapprobes.pagefault.5 man/stapprobes.process.5 man/stapprobes.rpc.5 man/stapprobes.scsi.5 man/stapprobes.signal.5 man/stapprobes.socket.5 man/stapprobes.tcp.5 man/stapprobes.udp.5"
+ac_config_files="$ac_config_files Makefile doc/Makefile stap.1 stapprobes.5 stapfuncs.5 stapvars.5 stapex.5 staprun.8 stap-server.8 man/stapprobes.iosched.5 man/stapprobes.netdev.5 man/stapprobes.nfs.5 man/stapprobes.nfsd.5 man/stapprobes.pagefault.5 man/stapprobes.process.5 man/stapprobes.rpc.5 man/stapprobes.scsi.5 man/stapprobes.signal.5 man/stapprobes.socket.5 man/stapprobes.tcp.5 man/stapprobes.udp.5"
 
 subdirs="$subdirs testsuite"
 
@@ -7824,6 +7824,7 @@ do
     "stapvars.5") CONFIG_FILES="$CONFIG_FILES stapvars.5" ;;
     "stapex.5") CONFIG_FILES="$CONFIG_FILES stapex.5" ;;
     "staprun.8") CONFIG_FILES="$CONFIG_FILES staprun.8" ;;
+    "stap-server.8") CONFIG_FILES="$CONFIG_FILES stap-server.8" ;;
     "man/stapprobes.iosched.5") CONFIG_FILES="$CONFIG_FILES man/stapprobes.iosched.5" ;;
     "man/stapprobes.netdev.5") CONFIG_FILES="$CONFIG_FILES man/stapprobes.netdev.5" ;;
     "man/stapprobes.nfs.5") CONFIG_FILES="$CONFIG_FILES man/stapprobes.nfs.5" ;;
diff --git a/configure.ac b/configure.ac
index 4ad54f7c..123ac657 100644
--- a/configure.ac
+++ b/configure.ac
@@ -231,7 +231,7 @@ AC_CHECK_HEADERS([tr1/unordered_map])
 AC_LANG_POP(C++)
 
 AC_CONFIG_HEADERS([config.h:config.in])
-AC_CONFIG_FILES(Makefile doc/Makefile stap.1 stapprobes.5 stapfuncs.5 stapvars.5 stapex.5 staprun.8 man/stapprobes.iosched.5 man/stapprobes.netdev.5 man/stapprobes.nfs.5 man/stapprobes.nfsd.5 man/stapprobes.pagefault.5 man/stapprobes.process.5 man/stapprobes.rpc.5 man/stapprobes.scsi.5 man/stapprobes.signal.5 man/stapprobes.socket.5 man/stapprobes.tcp.5 man/stapprobes.udp.5)
+AC_CONFIG_FILES(Makefile doc/Makefile stap.1 stapprobes.5 stapfuncs.5 stapvars.5 stapex.5 staprun.8 stap-server.8 man/stapprobes.iosched.5 man/stapprobes.netdev.5 man/stapprobes.nfs.5 man/stapprobes.nfsd.5 man/stapprobes.pagefault.5 man/stapprobes.process.5 man/stapprobes.rpc.5 man/stapprobes.scsi.5 man/stapprobes.signal.5 man/stapprobes.socket.5 man/stapprobes.tcp.5 man/stapprobes.udp.5)
 AC_CONFIG_SUBDIRS(testsuite)
 
 AC_OUTPUT
diff --git a/elaborate.cxx b/elaborate.cxx
index 88133c31..7ecba049 100644
--- a/elaborate.cxx
+++ b/elaborate.cxx
@@ -1170,6 +1170,7 @@ void add_global_var_display (systemtap_session& s)
       probe_point::component* c = new probe_point::component("end");
       token* print_tok = new token;
       vector<derived_probe*> dps;
+      block *b = new block;
 
       pl->components.push_back (c);
       token* p_tok = new token;
@@ -1206,17 +1207,7 @@ void add_global_var_display (systemtap_session& s)
 	  expr_statement* feb = new expr_statement;
 	  feb->value = pf;
 	  feb->tok = print_tok;
-	  block *b = new block;
 	  b->statements.push_back(feb);
-	  p->body = b;
-
-	  derive_probes (s, p, dps);
-
-	  // Repopulate the type info.  Should semantic_pass_types do this?
-	  ((class symbol*)
-	   ((class print_format*)
-	    ((class expr_statement*)
-	     ((class block*)dps[0]->body)->statements[0])->value)->args[0])->type = g_sym->type;
 	}
       else			// Array
 	{
@@ -1283,44 +1274,28 @@ void add_global_var_display (systemtap_session& s)
 	  pf->components = print_format::string_to_components(pf->raw_components);
 	  expr_statement* feb = new expr_statement;
 	  feb->value = pf;
-	  block *b = new block;
 	  fe->base = g_sym;
 	  fe->block = (statement*)feb;
 	  b->statements.push_back(fe);
-	  p->body = b;
-
-	  derive_probes (s, p, dps);
-
-	  // Repopulate the type info.  Should semantic_pass_types do this?
-	  print_format* dpf = ((print_format*)
-			       ((expr_statement*)
-				((foreach_loop*)
-				 ((block*)dps[0]->body)->statements[0])->block)->value);
-	  for (int i=0; i < idx_count; i++)
-	    {
-	      // printf argument types
-	      dpf->args[i]->type = l->index_types[i];
-	      // arrayindex indices types
-	      ((struct arrayindex*)dpf->args[idx_count])->indexes[i]->type = l->index_types[i];
-	      dps[0]->locals.push_back(idx_v[i]);
-	    }
-	  // arrayindex type
-	  dpf->args[idx_count]->type = l->type;
 	}
 
-      symresolution_info sym (s);
-      sym.current_function = 0;
-      sym.current_probe = dps[0];
-      dps[0]->body->visit (& sym);
-
       // Add created probe
+      p->body = b;
+      derive_probes (s, p, dps);
       for (unsigned i = 0; i < dps.size(); i++)
 	{
 	  derived_probe* dp = dps[i];
 	  s.probes.push_back (dp);
 	  dp->join_group (s);
 	}
+      // Repopulate symbol and type info
+      symresolution_info sym (s);
+      sym.current_function = 0;
+      sym.current_probe = dps[0];
+      dps[0]->body->visit (& sym);
 
+      semantic_pass_types(s);
+      // Mark that variable is read
       vut.read.insert (l);
     }
 }
diff --git a/main.cxx b/main.cxx
index 8807a03d..11244d8d 100644
--- a/main.cxx
+++ b/main.cxx
@@ -179,6 +179,18 @@ printscript(systemtap_session& s, ostream& o)
           if (seen.find (pp) == seen.end())
             {
               o << pp << endl;
+              if (s.verbose) {
+	              for (unsigned j=0; j<p->locals.size(); j++)
+		            {
+        		      vardecl* v = p->locals[j];
+	        	      if (j>0)
+			      	o << ", ";
+        		      else
+		      		o << "  ";
+		              v->printsig (o);
+		            }
+	              o << endl;
+              }
               seen.insert (pp);
             }
         }
@@ -581,6 +593,7 @@ main (int argc, char * const argv [])
         case 'l':
 	  s.suppress_warnings = true;
           s.listing_mode = true;
+          s.unoptimized = true;
           s.last_pass = 2;
           if (have_script)
             {
diff --git a/runtime/ChangeLog b/runtime/ChangeLog
index 926e05d9..b7e44a0f 100644
--- a/runtime/ChangeLog
+++ b/runtime/ChangeLog
@@ -1,3 +1,11 @@
+2008-08-29  David Smith  <dsmith@redhat.com>
+
+	* task_finder.c (__stp_utrace_attach_match_filename): Don't call
+	the callback when the interesting thread is found, call it when
+	the tread is quiesced.
+	(stap_start_task_finder): Ditto.
+	(__stp_utrace_task_finder_target_quiesce): Call the callback.
+
 2008-08-26  David Smith  <dsmith@redhat.com>
 
 	* autoconf-d_path-path.c: New file.
diff --git a/runtime/task_finder.c b/runtime/task_finder.c
index b8a0ae7f..9c0dd55b 100644
--- a/runtime/task_finder.c
+++ b/runtime/task_finder.c
@@ -351,23 +351,41 @@ __stp_get_mm_path(struct mm_struct *mm, char *buf, int buflen)
 	return rc;
 }
 
+/*
+ * All user threads get an engine with __STP_TASK_FINDER_EVENTS events
+ * attached to it so the task_finder layer can monitor new thread
+ * creation/death.
+ */
 #define __STP_TASK_FINDER_EVENTS (UTRACE_EVENT(CLONE)		\
 				  | UTRACE_EVENT(EXEC)		\
 				  | UTRACE_EVENT(DEATH))
 
-#define __STP_ATTACHED_TASK_BASE_EVENTS (UTRACE_EVENT(DEATH))
-
-#define __STP_ATTACHED_TASK_VM_BASE_EVENTS (__STP_ATTACHED_TASK_BASE_EVENTS \
-					    | UTRACE_EVENT(SYSCALL_ENTRY) \
-					    | UTRACE_EVENT(SYSCALL_EXIT))
-
-#define __STP_ATTACHED_TASK_VM_EVENTS (__STP_ATTACHED_TASK_BASE_EVENTS	\
-				       | UTRACE_STOP			\
-				       | UTRACE_EVENT(QUIESCE))
-
-#define __STP_ATTACHED_TASK_EVENTS(tgt) \
-	((((tgt)->vm_callback) == NULL) ? __STP_ATTACHED_TASK_BASE_EVENTS \
-	 : __STP_ATTACHED_TASK_VM_EVENTS)
+/* 
+ * __STP_TASK_BASE_EVENTS: base events for stap_task_finder_target's
+ * without a vm_callback
+ *
+ * __STP_TASK_VM_BASE_EVENTS: base events for
+ * stap_task_finder_target's with a vm_callback
+ */
+#define __STP_TASK_BASE_EVENTS	(UTRACE_EVENT(DEATH))
+
+#define __STP_TASK_VM_BASE_EVENTS (__STP_TASK_BASE_EVENTS	\
+				   | UTRACE_EVENT(SYSCALL_ENTRY)\
+				   | UTRACE_EVENT(SYSCALL_EXIT))
+
+/*
+ * All "interesting" threads get an engine with
+ * __STP_ATTACHED_TASK_EVENTS events attached to it.  After the thread
+ * quiesces, we reset the events to __STP_ATTACHED_TASK_BASE_EVENTS
+ * events.
+ */
+#define __STP_ATTACHED_TASK_EVENTS (__STP_TASK_BASE_EVENTS	\
+				    | UTRACE_STOP		\
+				    | UTRACE_EVENT(QUIESCE))
+
+#define __STP_ATTACHED_TASK_BASE_EVENTS(tgt) \
+	((((tgt)->vm_callback) == NULL) ? __STP_TASK_BASE_EVENTS \
+	 : __STP_TASK_VM_BASE_EVENTS)
 
 static int
 stap_utrace_attach(struct task_struct *tsk,
@@ -454,31 +472,40 @@ __stp_utrace_attach_match_filename(struct task_struct *tsk,
 			if (cb_tgt == NULL)
 				continue;
 
-			if (cb_tgt->callback != NULL) {
-				int rc = cb_tgt->callback(cb_tgt, tsk,
-							  register_p,
-							  process_p);
-				if (rc != 0) {
-					_stp_error("callback for %d failed: %d",
-						   (int)tsk->pid, rc);
-					break;
-				}
-			}
-
 			// Set up events we need for attached tasks.
+			// When register_p is set, we won't actually
+			// call the callback here - we'll call it when
+			// the thread gets quiesced.  When register_p
+			// isn't set, we can go ahead and call the
+			// callback.
 			if (register_p) {
 				rc = stap_utrace_attach(tsk, &cb_tgt->ops,
 							cb_tgt,
-							__STP_ATTACHED_TASK_EVENTS(cb_tgt));
+							__STP_ATTACHED_TASK_EVENTS);
 				if (rc != 0 && rc != EPERM)
 					break;
 				cb_tgt->engine_attached = 1;
 			}
 			else {
+				if (cb_tgt->callback != NULL) {
+					rc = cb_tgt->callback(cb_tgt, tsk,
+							      register_p,
+							      process_p);
+					if (rc != 0) {
+						_stp_error("callback for %d failed: %d",
+							   (int)tsk->pid, rc);
+						break;
+					}
+				}
+
 				rc = stap_utrace_detach(tsk, &cb_tgt->ops);
 				if (rc != 0)
 					break;
-				cb_tgt->engine_attached = 0;
+
+				// Note that we don't want to set
+				// engine_attached to 0 here - only
+				// when *all* threads using this
+				// engine have been detached.
 			}
 		}
 	}
@@ -695,18 +722,32 @@ __stp_utrace_task_finder_target_quiesce(enum utrace_resume_action action,
 	struct stap_task_finder_target *tgt = engine->data;
 	int rc;
 
-	// Turn off quiesce handling (and turn on syscall handling).
-	rc = utrace_set_events(tsk, engine, __STP_ATTACHED_TASK_VM_BASE_EVENTS);
+	if (atomic_read(&__stp_task_finder_state) != __STP_TF_RUNNING) {
+		debug_task_finder_detach();
+		return UTRACE_DETACH;
+	}
+
+	if (tgt == NULL)
+		return UTRACE_DETACH;
+
+	// Turn off quiesce handling
+	rc = utrace_set_events(tsk, engine,
+			       __STP_ATTACHED_TASK_BASE_EVENTS(tgt));
 	if (rc != 0)
 		_stp_error("utrace_set_events returned error %d on pid %d",
 			   rc, (int)tsk->pid);
 
-	if (atomic_read(&__stp_task_finder_state) != __STP_TF_RUNNING) {
-		debug_task_finder_detach();
-		return UTRACE_DETACH;
+	if (tgt->callback != NULL) {
+		/* Call the callback.  Assume that if the thread is a
+		 * thread group leader, it is a process. */
+		rc = tgt->callback(tgt, tsk, 1, (tsk->pid == tsk->tgid));
+		if (rc != 0) {
+			_stp_error("callback for %d failed: %d",
+				   (int)tsk->pid, rc);
+		}
 	}
 
-	if (tgt != NULL && tgt->vm_callback != NULL) {
+	if (tgt->vm_callback != NULL) {
 		struct mm_struct *mm;
 		char *mmpath_buf;
 		char *mmpath;
@@ -1159,24 +1200,11 @@ stap_start_task_finder(void)
 						    callback_list);
 				if (cb_tgt == NULL)
 					continue;
-					
-				// Call the callback.  Assume that if
-				// the thread is a thread group
-				// leader, it is a process.
-				if (cb_tgt->callback != NULL) {
-					rc = cb_tgt->callback(cb_tgt, tsk, 1,
-							      (tsk->pid == tsk->tgid));
-					if (rc != 0) {
-						_stp_error("attach callback for %d failed: %d",
-							   (int)tsk->pid, rc);
-						goto stf_err;
-					}
-				}
 
 				// Set up events we need for attached tasks.
 				rc = stap_utrace_attach(tsk, &cb_tgt->ops,
 							cb_tgt,
-							__STP_ATTACHED_TASK_EVENTS(cb_tgt));
+							__STP_ATTACHED_TASK_EVENTS);
 				if (rc != 0 && rc != EPERM)
 					goto stf_err;
 				cb_tgt->engine_attached = 1;
diff --git a/stap-server.8.in b/stap-server.8.in
new file mode 100644
index 00000000..9bfaa789
--- /dev/null
+++ b/stap-server.8.in
@@ -0,0 +1,177 @@
+.\" -*- nroff -*-
+.TH STAP-SERVER 8 @DATE@ "Red Hat"
+.SH NAME
+stap-server \- systemtap server and related utilities
+
+.SH SYNOPSIS
+
+.br
+.B stap-start-server
+.br
+.B stap-find-servers
+[
+.B --all
+]
+.br
+.B stap-find-or-start-server
+.br
+.B stap-stop-server
+.I PID
+.br
+.B stap-client
+[
+.I ARGUMENTS
+]
+
+.SH DESCRIPTION
+
+The systemtap server listens for connections from
+.I stap-client
+on the local network and accepts requests to run the
+.I stap
+front end.
+
+.PP
+The
+.I stap-start-server
+program attempts to start a systemtap server (
+.I stap-serverd
+) on the local host. Upon
+successful startup, the server listens for connections on a random port and
+advertises its presence on the local network using the
+.I avahi
+daemon. If the server is successfully started, its process id is
+echoed to stdout and the exit code is 0. Otherwise, nothing is echoed and the exit code is 1.
+
+.PP
+The
+.I stap-find-servers
+program attempts to find systemtap servers running on the local network.
+The details of any servers found are echoed to stdout.
+If servers are found, then the exit code is 0, otherwise it is 1.
+
+.PP
+The
+.I stap-find-or-start-server
+program attempts to find a compatible systemtap server running on the local network
+using
+.I stap-find-servers.
+If a compatible server is found,
+.I stap-find-or-start-server
+echos '0' to stdout and the exit code is 0. Otherwise
+.I stap-find-or-start-server
+attempts to start a server on the local network using
+.I stap-start-server.
+If successful, the process id of the new server is echoed to stdout and the
+exit code is 0. If no server can be found or started, nothing is echoed
+to stdout and the exit code is 1.
+
+.PP
+The
+.I stap-stop-server
+program verifies that the given process id is that of a running systemtap server
+on the local host and, if so, attempts to shut down the server by sending it the
+SIGTERM signal. If a process id is provided and it is that of a running systemtap
+server, the exit code is 0. Otherwise the exit code is 1.
+.I stap-stop-server
+does not verify that the server actually shuts down.
+
+.PP
+The
+.I stap-client
+program is analagous to the
+.I stap
+front end except that it attempts to find a compatible systemtap server on the
+local network and then attempts to use that server for actions related to
+passes 1 through 4. Pass 5 actions, if requested, are performed on the localhost
+using
+.I staprun
+. Upon successful completion, the exit code is 0. Otherwise the exit code
+is 1.
+
+.SH OPTIONS
+The
+.I stap-find-servers
+program supports the following option.  Any other option
+is ignored.
+.TP
+.B \--all
+Instructs
+.I stap-find-servers
+to report all systemtap servers on the local network regardless of compatibility.
+The default behavior is to report only servers which are compatible with
+systemtap on the local host.
+
+.SH ARGUMENTS
+The
+.I stap-stop-server
+program requires a process id argument which identifies the server to be stopped.
+
+.PP
+The
+.I stap-client
+program accepts the same arguments and options as the
+.I stap
+front end.
+
+.SH EXAMPLES
+See the 
+.IR stapex (5)
+manual page for a collection of sample scripts.
+.PP
+Here is a very basic example of how to use
+.I stap-client.
+.PP
+To find out if a compatible systemtap server is running on your local network
+.PP
+\& $ stap-find-servers
+.PP
+If no servers are reported, you can start one using
+.PP
+\& $ stap-start-server
+.PP
+You could also have accomplished both of the previous two steps using
+.PP
+\& $ stap-find-or-start-server
+.PP
+To compile and execute a simple example using the server
+.PP
+\& $ stap-client \-e \[aq]probe begin { printf("Hello World!\\n"); exit() }\[aq]
+.br
+\& Hello World!
+.PP
+If a process id was echoed by
+.I stap-start-server
+or
+.I stap-find-or-start-server
+then you can stop the server using
+.PP
+\& $ stap-stop-server PID
+.PP
+where PID is the process id that was echoed.
+
+
+.SH SAFETY AND SECURITY
+Systemtap is an administrative tool.  It exposes kernel internal data
+structures and potentially private user information.  See the 
+.IR stap (1)
+manual page for additional information on safety and security.
+
+.PP
+The systemtap server and its related utilities are prototypes only. NO NETWORK
+SECURITY OF ANY KIND IS CURRENTLY PROVIDED. These programs should only be used
+among trusted hosts on a trusted network.
+
+.SH SEE ALSO
+.IR stap (1),
+.IR staprun (8),
+.IR stapprobes (5),
+.IR stapfuncs (5),
+.IR stapex (5),
+
+.SH BUGS
+Use the Bugzilla link off of the project web page or our mailing list.
+.nh
+.BR http://sources.redhat.com/systemtap/ ", " <systemtap@sources.redhat.com> .
+.hy
+
diff --git a/tapset/ChangeLog b/tapset/ChangeLog
index 85b0ff96..bac3bf3e 100644
--- a/tapset/ChangeLog
+++ b/tapset/ChangeLog
@@ -1,3 +1,7 @@
+2008-09-01  Zhaolei  <zhaolei@cn.fujitsu.com>
+	* nfs_proc.stp: Fix memory access error in nfs.proc.read_setup,
+	nfs.proc.write_setup and nfs.proc.commit_setup.
+
 2008-08-28  Zhaolei  <zhaolei@cn.fujitsu.com>
 	* socket.stp: Make _get_sock_addr return correct address in kernel
 	before 2.6.16.
@@ -8,12 +12,12 @@
 
 2008-08-04  Wenji Huang <wenji.huang@oracle.com>
 
-        * syscall.stp: Change $path to $pathname for 2.6.27.
-        * syscall2.stp: Ditto.
+	* syscall.stp: Change $path to $pathname for 2.6.27.
+	* syscall2.stp: Ditto.
 
 2008-08-03  Wenji Huang <wenji.huang@oracle.com>
 
-        * vfs.stp(add_to_page_cache): Correct for 2.6.27.
+	* vfs.stp(add_to_page_cache): Correct for 2.6.27.
 
 2008-07-25  Zhaolei  <zhaolei@cn.fujitsu.com>
 
diff --git a/tapset/nfs_proc.stp b/tapset/nfs_proc.stp
index 6ffdf646..4f841836 100644
--- a/tapset/nfs_proc.stp
+++ b/tapset/nfs_proc.stp
@@ -4,39 +4,81 @@
 %}
 
 %{
+/*Get rpc_clnt from inode, same as kernel function NFS_CLIENT*/
+	struct rpc_clnt *_stap_NFS_CLIENT(struct inode *inode, struct context * __restrict__ c);
+/*Get ip address from a rpc_clnt*/
+	__u32 _get_ip_from_client(struct rpc_clnt *clnt, struct context * __restrict__ c);
+/*Get protocol types from a rpc_clnt*/
+	int _get_prot_from_client(struct rpc_clnt *clnt, struct context * __restrict__ c);
 /*Get ip address from a rpc_task*/
 	__u32 get_ip(struct rpc_task *, struct context * __restrict__);
 /*Get protocol types from a rpc_task*/
 	int get_prot(struct rpc_task *, struct context * __restrict__);
 %}
 %{
-     __u32 get_ip(struct rpc_task * task, struct context * __restrict__ c)
-     {
-        struct rpc_clnt * tk_client;
-        struct rpc_xprt * cl_xprt;
-        struct sockaddr_in *addr;
-        tk_client = kread(&(task->tk_client));
-        cl_xprt= kread(&(tk_client->cl_xprt));
-        addr = (struct sockaddr_in *)&(cl_xprt->addr);
-        if (kread(&(addr->sin_family)) != AF_INET)
-                /* Now consider ipv4 only */
-                return 0;
-        return kread(&(addr->sin_addr.s_addr));
+    struct rpc_clnt *_stap_NFS_CLIENT(struct inode *inode, struct context * __restrict__ c) {
+	struct super_block *i_sb;
+	struct nfs_server *server;
+	i_sb = kread(&(inode->i_sb));
+	server = kread(&(i_sb->s_fs_info));
+	return kread(&(server->client));
+	CATCH_DEREF_FAULT();
+	return NULL;
+    }
+
+    __u32 _get_ip_from_client(struct rpc_clnt *clnt, struct context * __restrict__ c) {
+	struct rpc_xprt * cl_xprt;
+	struct sockaddr_in *addr;
+	cl_xprt= kread(&(clnt->cl_xprt));
+	addr = (struct sockaddr_in *)&(cl_xprt->addr);
+	if (kread(&(addr->sin_family)) != AF_INET)
+		/* Now consider ipv4 only */
+		return 0;
+	return kread(&(addr->sin_addr.s_addr));
+	CATCH_DEREF_FAULT();
+	return -1;
+    }
+
+    int _get_prot_from_client(struct rpc_clnt *clnt, struct context * __restrict__ c) {
+	struct rpc_xprt * cl_xprt;
+	cl_xprt= kread(&(clnt->cl_xprt));
+	return kread(&(cl_xprt->prot));
+	CATCH_DEREF_FAULT();
+	return -1;
+    }
+
+    __u32 get_ip(struct rpc_task * task, struct context * __restrict__ c) {
+	struct rpc_clnt * clnt;
+	clnt = kread(&(task->tk_client));
+	return _get_ip_from_client(clnt, c);
 	CATCH_DEREF_FAULT();
 	return -1;
-     }
-     int get_prot(struct rpc_task * task, struct context * __restrict__ c)
-     {
-        struct rpc_clnt * tk_client;
-        struct rpc_xprt * cl_xprt;
-        tk_client = kread(&(task->tk_client));
-        cl_xprt= kread(&(tk_client->cl_xprt));
-
-        return kread(&(cl_xprt->prot));
+    }
+
+    int get_prot(struct rpc_task * task, struct context * __restrict__ c) {
+	struct rpc_clnt * clnt;
+	clnt = kread(&(task->tk_client));
+	return _get_prot_from_client(clnt, c);
 	CATCH_DEREF_FAULT();
 	return -1;
     }
 %}
+
+function stap_NFS_CLIENT:long(inode:long) %{ /* pure */
+	struct inode *inode = (struct inode *)(long)THIS->inode;
+	THIS->__retvalue = (long)_stap_NFS_CLIENT(inode, CONTEXT);
+%}
+
+function get_ip_from_client:long(clnt:long) %{ /* pure */
+	struct rpc_clnt *clnt = (struct rpc_clnt *)(long)THIS->clnt;
+	THIS->__retvalue = _get_ip_from_client(clnt, CONTEXT);
+%}
+
+function get_prot_from_client:long(clnt:long) %{ /* pure */
+	struct rpc_clnt *clnt = (struct rpc_clnt *)(long)THIS->clnt;
+	THIS->__retvalue = _get_prot_from_client(clnt, CONTEXT);
+%}
+
 /*
   0:get ip address
   1:get proto
@@ -656,8 +698,9 @@ probe nfs.proc.read_setup.return = nfs.proc2.read_setup.return ,
 probe nfs.proc2.read_setup = kernel.function("nfs_proc_read_setup") ?,
                        module("nfs").function("nfs_proc_read_setup")?
 {
-	server_ip = __nfs_read_data_info($data,0)
-        prot = __nfs_read_data_info($data,1)
+	client = stap_NFS_CLIENT($data->inode)
+	server_ip = get_ip_from_client(client)
+	prot = get_prot_from_client(client)
         version =2
 
         count = $data->args->count
@@ -680,8 +723,9 @@ probe nfs.proc2.read_setup.return = kernel.function("nfs_proc_read_setup").retur
 probe nfs.proc3.read_setup = kernel.function("nfs3_proc_read_setup") ?,
                        module("nfs").function("nfs3_proc_read_setup")?
 {
-	server_ip = __nfs_read_data_info($data,0)
-        prot = __nfs_read_data_info($data,1)
+	client = stap_NFS_CLIENT($data->inode)
+	server_ip = get_ip_from_client(client)
+	prot = get_prot_from_client(client)
         version =3
 	fh = 
 
@@ -705,8 +749,9 @@ probe nfs.proc3.read_setup.return = kernel.function("nfs3_proc_read_setup").retu
 probe nfs.proc4.read_setup = kernel.function("nfs4_proc_read_setup") ?,
                        module("nfs").function("nfs4_proc_read_setup")?
 {
-	server_ip = __nfs_read_data_info($data,0)
-        prot = __nfs_read_data_info($data,1)
+	client = stap_NFS_CLIENT($data->inode)
+	server_ip = get_ip_from_client(client)
+	prot = get_prot_from_client(client)
         version =4
 
         count = $data->args->count
@@ -877,8 +922,9 @@ probe nfs.proc.write_setup.return = nfs.proc2.write_setup.return,
 probe nfs.proc2.write_setup = kernel.function("nfs_proc_write_setup") ?,
                               module("nfs").function("nfs_proc_write_setup") ?
 {
-	server_ip = __nfs_write_data_info($data,0)
-        prot = __nfs_write_data_info($data,1)
+	client = stap_NFS_CLIENT($data->inode)
+	server_ip = get_ip_from_client(client)
+	prot = get_prot_from_client(client)
         version =2
 
         count = $data->args->count
@@ -901,8 +947,9 @@ probe nfs.proc2.write_setup.return = kernel.function("nfs_proc_write_setup").ret
 probe nfs.proc3.write_setup = kernel.function("nfs3_proc_write_setup") ?,
                               module("nfs").function("nfs3_proc_write_setup") ?
 {
-	server_ip = __nfs_write_data_info($data,0)
-        prot = __nfs_write_data_info($data,1)
+	client = stap_NFS_CLIENT($data->inode)
+	server_ip = get_ip_from_client(client)
+	prot = get_prot_from_client(client)
         version =3
 
         count = $data->args->count
@@ -925,8 +972,9 @@ probe nfs.proc3.write_setup.return = kernel.function("nfs3_proc_write_setup").re
 probe nfs.proc4.write_setup = kernel.function("nfs4_proc_write_setup") ?,
                               module("nfs").function("nfs4_proc_write_setup") ?
 {
-	server_ip = __nfs_write_data_info($data,0)
-        prot = __nfs_write_data_info($data,1)
+	client = stap_NFS_CLIENT($data->inode)
+	server_ip = get_ip_from_client(client)
+	prot = get_prot_from_client(client)
         version =4
 
         count = $data->args->count
@@ -1100,8 +1148,9 @@ probe nfs.proc.commit_setup.return =nfs.proc3.commit_setup.return,
 probe nfs.proc3.commit_setup = kernel.function("nfs3_proc_commit_setup") ?,
                               module("nfs").function("nfs3_proc_commit_setup") ?
 {
-	server_ip = __nfs_write_data_info($data,0)
-        prot = __nfs_write_data_info($data,1)
+	client = stap_NFS_CLIENT($data->inode)
+	server_ip = get_ip_from_client(client)
+	prot = get_prot_from_client(client)
         version =3
 
         count = $data->args->count
@@ -1123,8 +1172,9 @@ probe nfs.proc3.commit_setup.return = kernel.function("nfs3_proc_commit_setup")
 probe nfs.proc4.commit_setup = kernel.function("nfs4_proc_commit_setup") ?,
                               module("nfs").function("nfs4_proc_commit_setup") ?
 {
-	server_ip = __nfs_write_data_info($data,0)
-        prot = __nfs_write_data_info($data,1)
+	client = stap_NFS_CLIENT($data->inode)
+	server_ip = get_ip_from_client(client)
+	prot = get_prot_from_client(client)
         version =4
 
         count = $data->args->count
diff --git a/tapsets.cxx b/tapsets.cxx
index 3c67eed7..8f5ed287 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -6072,17 +6072,13 @@ utrace_derived_probe_group::emit_probe_decl (systemtap_session& s,
   // Handle flags
   switch (p->flags)
     {
-    // Look in _stp_utrace_probe_cb for description of why quiesce is
-    // used here.
+    // Notice that we'll just call the probe directly when we get
+    // notified, since the task_finder layer stops the thread for us.
     case UDPF_BEGIN:				// process begin
       s.op->line() << " .flags=(UDPF_BEGIN),";
-      s.op->line() << " .ops={ .report_quiesce=stap_utrace_probe_quiesce },";
-      s.op->line() << " .events=(UTRACE_STOP|UTRACE_EVENT(QUIESCE)),";
       break;
     case UDPF_THREAD_BEGIN:			// thread begin
       s.op->line() << " .flags=(UDPF_THREAD_BEGIN),";
-      s.op->line() << " .ops={ .report_quiesce=stap_utrace_probe_quiesce },";
-      s.op->line() << " .events=(UTRACE_STOP|UTRACE_EVENT(QUIESCE)),";
       break;
 
     // Notice we're not setting up a .ops/.report_death handler for
@@ -6097,17 +6093,17 @@ utrace_derived_probe_group::emit_probe_decl (systemtap_session& s,
 
     // For UDPF_SYSCALL/UDPF_SYSCALL_RETURN probes, the .report_death
     // handler isn't strictly necessary.  However, it helps to keep
-    // our attaches/detaches symmetrical.  Notice we're using quiesce
-    // as a workaround for bug 6841.
+    // our attaches/detaches symmetrical.  Since the task_finder layer
+    // stops the thread, that works around bug 6841.
     case UDPF_SYSCALL:
       s.op->line() << " .flags=(UDPF_SYSCALL),";
-      s.op->line() << " .ops={ .report_syscall_entry=stap_utrace_probe_syscall,  .report_death=stap_utrace_task_finder_report_death, .report_quiesce=stap_utrace_probe_syscall_quiesce },";
-      s.op->line() << " .events=(UTRACE_STOP|UTRACE_EVENT(QUIESCE)|UTRACE_EVENT(DEATH)),";
+      s.op->line() << " .ops={ .report_syscall_entry=stap_utrace_probe_syscall,  .report_death=stap_utrace_task_finder_report_death },";
+      s.op->line() << " .events=(UTRACE_EVENT(SYSCALL_ENTRY)|UTRACE_EVENT(DEATH)),";
       break;
     case UDPF_SYSCALL_RETURN:
       s.op->line() << " .flags=(UDPF_SYSCALL_RETURN),";
-      s.op->line() << " .ops={ .report_syscall_exit=stap_utrace_probe_syscall, .report_death=stap_utrace_task_finder_report_death, .report_quiesce=stap_utrace_probe_syscall_quiesce },";
-      s.op->line() << " .events=(UTRACE_STOP|UTRACE_EVENT(QUIESCE)|UTRACE_EVENT(DEATH)),";
+      s.op->line() << " .ops={ .report_syscall_exit=stap_utrace_probe_syscall, .report_death=stap_utrace_task_finder_report_death },";
+      s.op->line() << " .events=(UTRACE_EVENT(SYSCALL_EXIT)|UTRACE_EVENT(DEATH)),";
       break;
 
     case UDPF_NONE:
@@ -6192,32 +6188,10 @@ utrace_derived_probe_group::emit_module_decls (systemtap_session& s)
   s.op->newline(-1) << "};";
 
 
-  // Output handler function for UDPF_BEGIN and UDPF_THREAD_BEGIN
-  if (flags_seen[UDPF_BEGIN] || flags_seen[UDPF_THREAD_BEGIN])
-    {
-      s.op->newline() << "#ifdef UTRACE_ORIG_VERSION";
-      s.op->newline() << "static u32 stap_utrace_probe_quiesce(struct utrace_attached_engine *engine, struct task_struct *tsk) {";
-      s.op->newline() << "#else";
-      s.op->newline() << "static u32 stap_utrace_probe_quiesce(enum utrace_resume_action action, struct utrace_attached_engine *engine, struct task_struct *tsk, unsigned long event) {";
-      s.op->newline() << "#endif";
-      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);
-
-      // we're detaching, so utrace automatically restarts the thread.
-      s.op->newline() << "debug_task_finder_detach();";
-      s.op->newline() << "return UTRACE_DETACH;";
-      s.op->newline(-1) << "}";
-    }
-
-  // Output handler function for UDPF_END and UDPF_THREAD_END
-  if (flags_seen[UDPF_END] || flags_seen[UDPF_THREAD_END])
+  // Output handler function for UDPF_BEGIN, UDPF_THREAD_BEGIN,
+  // UDPF_END, and UDPF_THREAD_END
+  if (flags_seen[UDPF_BEGIN] || flags_seen[UDPF_THREAD_BEGIN]
+      || flags_seen[UDPF_END] || flags_seen[UDPF_THREAD_END])
     {
       s.op->newline() << "static void stap_utrace_probe_handler(struct task_struct *tsk, struct stap_utrace_probe *p) {";
       s.op->indent(1);
@@ -6237,33 +6211,6 @@ utrace_derived_probe_group::emit_module_decls (systemtap_session& s)
   if (flags_seen[UDPF_SYSCALL] || flags_seen[UDPF_SYSCALL_RETURN])
     {
       s.op->newline() << "#ifdef UTRACE_ORIG_VERSION";
-      s.op->newline() << "static u32 stap_utrace_probe_syscall_quiesce(struct utrace_attached_engine *engine, struct task_struct *tsk) {";
-      s.op->newline() << "#else";
-      s.op->newline() << "static u32 stap_utrace_probe_syscall_quiesce(enum utrace_resume_action action, struct utrace_attached_engine *engine, struct task_struct *tsk, unsigned long event) {";
-      s.op->newline() << "#endif";
-      s.op->indent(1);
-      s.op->newline() << "struct stap_utrace_probe *p = (struct stap_utrace_probe *)engine->data;";
-      s.op->newline() << "int rc = 0;";
-
-      // Turn off quiesce handling and turn on either syscall entry
-      // or exit events.
-      s.op->newline() << "if (p->flags == UDPF_SYSCALL)";
-      s.op->indent(1);
-      s.op->newline() << "rc = utrace_set_events(tsk, engine, UTRACE_EVENT(SYSCALL_ENTRY)|UTRACE_EVENT(DEATH));";
-      s.op->indent(-1);
-      s.op->newline() << "else if (p->flags == UDPF_SYSCALL_RETURN)";
-      s.op->indent(1);
-      s.op->newline() << "rc = utrace_set_events(tsk, engine, UTRACE_EVENT(SYSCALL_EXIT)|UTRACE_EVENT(DEATH));";
-      s.op->indent(-1);
-      s.op->newline() << "if (rc != 0)";
-      s.op->indent(1);
-      s.op->newline() << "_stp_error(\"utrace_set_events returned error %d on pid %d\", rc, (int)tsk->pid);";
-      s.op->indent(-1);
-
-      s.op->newline() << "return UTRACE_RESUME;";
-      s.op->newline(-1) << "}";
-
-      s.op->newline() << "#ifdef UTRACE_ORIG_VERSION";
       s.op->newline() << "static u32 stap_utrace_probe_syscall(struct utrace_attached_engine *engine, struct task_struct *tsk, struct pt_regs *regs) {";
       s.op->newline() << "#else";
       s.op->newline() << "static u32 stap_utrace_probe_syscall(enum utrace_resume_action action, struct utrace_attached_engine *engine, struct task_struct *tsk, struct pt_regs *regs) {";
@@ -6280,6 +6227,11 @@ utrace_derived_probe_group::emit_module_decls (systemtap_session& s)
       s.op->newline() << "(*p->ph) (c);";
       common_probe_entryfn_epilogue (s.op);
 
+      s.op->newline() << "if ((atomic_read (&session_state) != STAP_SESSION_STARTING) && (atomic_read (&session_state) != STAP_SESSION_RUNNING)) {";
+      s.op->indent(1);
+      s.op->newline() << "debug_task_finder_detach();";
+      s.op->newline() << "return UTRACE_DETACH;";
+      s.op->newline(-1) << "}";
       s.op->newline() << "return UTRACE_RESUME;";
       s.op->newline(-1) << "}";
     }
@@ -6308,11 +6260,7 @@ utrace_derived_probe_group::emit_module_decls (systemtap_session& s)
       s.op->indent(1);
       s.op->newline() << "if (process_p) {";
       s.op->indent(1);
-      s.op->newline() << "rc = stap_utrace_attach(tsk, &p->ops, p, p->events);";
-      s.op->newline() << "if (rc == 0) {";
-      s.op->indent(1);
-      s.op->newline() << "p->engine_attached = 1;";
-      s.op->newline(-1) << "}";
+      s.op->newline() << "stap_utrace_probe_handler(tsk, p);";
       s.op->newline(-1) << "}";
       s.op->newline() << "break;";
       s.op->indent(-1);
@@ -6323,11 +6271,7 @@ utrace_derived_probe_group::emit_module_decls (systemtap_session& s)
       s.op->indent(1);
       s.op->newline() << "if (! process_p) {";
       s.op->indent(1);
-      s.op->newline() << "rc = stap_utrace_attach(tsk, &p->ops, p, p->events);";
-      s.op->newline() << "if (rc == 0) {";
-      s.op->indent(1);
-      s.op->newline() << "p->engine_attached = 1;";
-      s.op->newline(-1) << "}";
+      s.op->newline() << "stap_utrace_probe_handler(tsk, p);";
       s.op->newline(-1) << "}";
       s.op->newline() << "break;";
       s.op->indent(-1);
@@ -6368,7 +6312,8 @@ utrace_derived_probe_group::emit_module_decls (systemtap_session& s)
   s.op->newline(-1) << "}";
 
   // Since this engine could be attached to multiple threads, don't
-  // call stap_utrace_detach_ops() here.
+  // call stap_utrace_detach_ops() here, only call
+  // stap_utrace_detach() as necessary.
   s.op->newline() << "else {";
   s.op->indent(1);
   s.op->newline() << "switch (p->flags) {";
@@ -6397,15 +6342,18 @@ utrace_derived_probe_group::emit_module_decls (systemtap_session& s)
       s.op->indent(-1);
     }
 
-  // For begin/thread_begin probes, at deregistration time we'll try
-  // to detach.  This will only be necessary if the new thread/process
-  // got killed before the probe got run in the UTRACE_EVENT(QUIESCE)
-  // handler.
-  if (flags_seen[UDPF_BEGIN] || flags_seen[UDPF_THREAD_BEGIN]
-      || flags_seen[UDPF_SYSCALL] || flags_seen[UDPF_SYSCALL_RETURN])
-    {
+  // For begin/thread_begin probes, we don't need to do anything.
+  if (flags_seen[UDPF_BEGIN] || flags_seen[UDPF_THREAD_BEGIN])
+  {
       s.op->newline() << "case UDPF_BEGIN:";
       s.op->newline() << "case UDPF_THREAD_BEGIN:";
+      s.op->indent(1);
+      s.op->newline() << "break;";
+      s.op->indent(-1);
+  }
+      
+  if (flags_seen[UDPF_SYSCALL] || flags_seen[UDPF_SYSCALL_RETURN])
+    {
       s.op->newline() << "case UDPF_SYSCALL:";
       s.op->newline() << "case UDPF_SYSCALL_RETURN:";
       s.op->indent(1);
diff --git a/testsuite/ChangeLog b/testsuite/ChangeLog
index e6649a36..a0e19521 100644
--- a/testsuite/ChangeLog
+++ b/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2008-08-29  David Smith  <dsmith@redhat.com>
+
+	PR6841
+	* systemtap.base/utrace_p5.exp: Added system-wide syscall test for
+	bug 6841 fix.
+
 2008-08-27  Stan Cox  <scox@redhat.com>
 
 	* systemtap.base/global_end.exp: New.
diff --git a/testsuite/systemtap.base/utrace_p5.exp b/testsuite/systemtap.base/utrace_p5.exp
index fcd617fe..33281350 100644
--- a/testsuite/systemtap.base/utrace_p5.exp
+++ b/testsuite/systemtap.base/utrace_p5.exp
@@ -73,6 +73,23 @@ set thread_end_script {
 }
 set thread_end_script_output "thread_ends = \\d+\r\n"
 
+# Script that tests the bug 6841 fix.
+set bz6841_script {
+    global proc,name
+    probe begin { printf("systemtap starting probe\n") }
+    probe process.syscall {
+	proc[pid()] <<< 1
+	name[pid()] = execname()
+    }
+    probe end { printf("systemtap ending probe\n")
+	foreach(p+ in proc) {
+	    printf("%s(%d) issues syscall %d times\n",
+		   name[p], p, @sum(proc[p]))
+	}
+    }
+}
+set bz6841_script_output ".+ issues syscall \\d+ times\r\n"
+
 # Try to find utrace_attach symbol in /proc/kallsyms
 set path "/proc/kallsyms"
 if {! [catch {exec grep -q utrace_attach $path} dummy]} {
@@ -182,5 +199,15 @@ if {$utrace_support_found == 0} {
 	-e $script
 }
 
+set TEST_NAME "UTRACE_P5_07"
+if {$utrace_support_found == 0} {
+    untested "$TEST_NAME : no kernel utrace support found"
+} elseif {![installtest_p]} {
+    untested "$TEST_NAME"
+} else {
+    stap_run $TEST_NAME run_utrace_p5_multi $bz6841_script_output \
+	-e $bz6841_script
+}
+
 # Cleanup
 exec rm -f $exepath $multi_exepath