Add user tag spreading functionality to VM and use in file

User tags in a dynamic trace enabled VM are spread throughout the system
in the same way as seq_trace tokens. This is used by the file module
and various other modules to get hold of the tag from the user process
without changing the protocol.

8 files changed, 235 insertions, 243 deletions

diff --git a/lib/dtrace/c_src/Makefile.in b/lib/dtrace/c_src/Makefile.in
index 831ce5ce75..4d5f59a63d 100644
--- a/lib/dtrace/c_src/Makefile.in
+++ b/lib/dtrace/c_src/Makefile.in
@@ -76,7 +76,7 @@ before_DTrace_OBJS = $(OBJDIR)/dtrace$(TYPEMARKER).o
 ## NIF_MAKEFILE = $(PRIVDIR)/Makefile
 
 # Higher-level makefiles says that we can only compile on UNIX flavors
-NIF_LIB = $(LIBDIR)/dtrace$(TYPEMARKER).so
+NIF_LIB = $(LIBDIR)/dtrace$(TYPEMARKER).@DED_EXT@
 
 ifeq ($(HOST_OS),)
 HOST_OS := $(shell $(ERL_TOP)/erts/autoconf/config.guess)
@@ -121,14 +121,14 @@ $(OBJDIR)/%$(TYPEMARKER).o: %.c $(DTRACE_USER_HEADER)
 	$(INSTALL_DIR) $(OBJDIR)
 	$(CC) -c -o $@ $(ALL_CFLAGS) $<
 
-$(LIBDIR)/dtrace$(TYPEMARKER).so: $(OBJS)
+$(NIF_LIB): $(OBJS)
 	$(INSTALL_DIR) $(LIBDIR)
 	$(LD) $(LDFLAGS) -o $@ $^ $(LDLIBS)
 
 clean:
-	rm -f $(LIBDIR)/dtrace.so
-	rm -f $(LIBDIR)/dtrace.debug.so
-	rm -f $(LIBDIR)/dtrace.valgrind.so
+	rm -f $(LIBDIR)/dtrace.@DED_EXT@
+	rm -f $(LIBDIR)/dtrace.debug.@DED_EXT@
+	rm -f $(LIBDIR)/dtrace.valgrind.@DED_EXT@
 	rm -f $(OBJDIR)/dtrace.o
 	rm -f $(OBJDIR)/dtrace.debug.o
 	rm -f $(OBJDIR)/dtrace.valgrind.o
diff --git a/lib/dtrace/examples/efile_drv.d b/lib/dtrace/examples/efile_drv.d
index c9c8080dba..085995ce58 100644
--- a/lib/dtrace/examples/efile_drv.d
+++ b/lib/dtrace/examples/efile_drv.d
@@ -71,7 +71,8 @@ erlang*:::efile_drv-entry
 	   arg4 == NULL ? "" : copyinstr(arg4),
 	   arg5 == NULL ? "" : copyinstr(arg5), arg6, arg7,
            /* NOTE: port name in args[10] is experimental */
-           copyinstr((user_addr_t) args[10]))
+           (args[10] == NULL) ? 
+	       "?" : copyinstr((user_addr_t) args[10]));
 }
 
 erlang*:::efile_drv-int*
diff --git a/lib/dtrace/src/dtrace.erl b/lib/dtrace/src/dtrace.erl
index 6951c03215..71a1a3480e 100644
--- a/lib/dtrace/src/dtrace.erl
+++ b/lib/dtrace/src/dtrace.erl
@@ -35,12 +35,10 @@
 %%% then the driver will ignore the user's input and use a default
 %%% value of 0 or NULL, respectively.
 
--define(DTRACE_UT_KEY, '_dtrace_utag_@_@'). % Match prim_file:get_dtrace_utag()!
-
 -export([init/0, available/0,
          user_trace_s1/1, % TODO: unify with pid & tag args like user_trace_i4s4
          p/0, p/1, p/2, p/3, p/4, p/5, p/6, p/7, p/8]).
--export([put_utag/1, get_utag/0]).
+-export([put_utag/1, get_utag/0, get_utag_data/0, spread_utag/1, restore_utag/1]).
 
 -export([scaff/0]). % Development only
 -export([user_trace_i4s4/9]). % Know what you're doing!
@@ -188,24 +186,29 @@ user_trace_int(I1, I2, I3, I4, S1, S2, S3, S4) ->
             false
     end.
 
--spec put_utag(undefined | iolist()) -> ok.
-
-put_utag(undefined) ->
-    put_utag(<<>>);
-put_utag(T) when is_binary(T) ->
-    put(?DTRACE_UT_KEY, T),
-    ok;
-put_utag(T) when is_list(T) ->
-    put(?DTRACE_UT_KEY, list_to_binary(T)),
-    ok.
+-spec put_utag(undefined | iodata()) -> binary() | undefined.
+put_utag(Data) ->
+    erlang:put_utag(unicode:characters_to_binary(Data)).
 
+-spec get_utag() -> binary() | undefined.
 get_utag() ->
-    case get(?DTRACE_UT_KEY) of
-        undefined ->
-            <<>>;
-        X ->
-            X
-    end.
+    erlang:get_utag().
+
+-spec get_utag_data() -> binary() | undefined.
+%% Gets utag if set, otherwise the spread utag data from last incoming message
+get_utag_data() ->
+    erlang:get_utag_data().
+
+-spec spread_utag(boolean()) -> true | {non_neg_integer(), binary() | []}.
+%% Makes the utag behave as a sequential trace token, will spread with messages to be picked up by someone using
+%% get_utag_data or get_drv_utag_data. 
+spread_utag(B) ->			   
+    erlang:spread_utag(B).
+
+-spec restore_utag(true | {non_neg_integer(), binary() | []}) -> true.
+restore_utag(T) ->
+    erlang:restore_utag(T).
+    
 
 %% Scaffolding to write tedious code: quick brute force and not 100% correct.
 
diff --git a/lib/hipe/cerl/erl_bif_types.erl b/lib/hipe/cerl/erl_bif_types.erl
index a7ce17eb53..260f216725 100644
--- a/lib/hipe/cerl/erl_bif_types.erl
+++ b/lib/hipe/cerl/erl_bif_types.erl
@@ -614,6 +614,10 @@ type(erlang, adler32_combine, 3, Xs) ->
 type(erlang, append, 2, Xs) -> type(erlang, '++', 2, Xs); % alias
 type(erlang, append_element, 2, Xs) ->
   strict(arg_types(erlang, append_element, 2), Xs, fun (_) -> t_tuple() end);
+type(erlang, append_vm_utag_data, 1, Xs) ->
+  strict(arg_types(erlang, append_vm_utag_data, 1), 
+	 Xs, 
+	 fun(_) -> t_iodata() end);
 type(erlang, apply, 2, Xs) ->
   Fun = fun ([X, _Y]) -> 
 	    case t_is_fun(X) of
@@ -800,6 +804,10 @@ type(erlang, get_module_info, 2, Xs) ->
 type(erlang, get_stacktrace, 0, _) ->
   t_list(t_tuple([t_atom(), t_atom(), t_sup([t_arity(), t_list()]),
 		  t_list()]));
+type(erlang, get_utag, 0, _) ->
+  t_sup(t_binary(), t_atom('undefined'));
+type(erlang, get_utag_data, 0, _) ->
+  t_sup(t_binary(), t_atom('undefined'));
 type(erlang, group_leader, 0, _) -> t_pid();
 type(erlang, group_leader, 2, Xs) ->
   strict(arg_types(erlang, group_leader, 2), Xs,
@@ -1186,6 +1194,10 @@ type(erlang, port_set_data, 2, Xs) ->
   strict(arg_types(erlang, port_set_data, 2), Xs,
 	 fun (_) -> t_atom('true') end);
 type(erlang, pre_loaded, 0, _) -> t_list(t_atom());
+type(erlang, prepend_vm_utag_data, 1, Xs) ->
+  strict(arg_types(erlang, prepend_vm_utag_data, 1), 
+	 Xs, 
+	 fun(_) -> t_iodata() end);
 type(erlang, process_display, 2, _) -> t_atom('true');
 type(erlang, process_flag, 2, Xs) ->
   T_process_flag_returns = t_sup([t_boolean(), t_atom(), t_non_neg_integer()]),
@@ -1303,6 +1315,9 @@ type(erlang, purge_module, 1, Xs) ->
 	 fun (_) -> t_atom('true') end);
 type(erlang, put, 2, Xs) ->
   strict(arg_types(erlang, put, 2), Xs, fun (_) -> t_any() end);
+type(erlang, put_utag, 1, Xs) ->
+  strict(arg_types(erlang, put_utag, 1), Xs, 
+	 fun(_) -> t_sup(t_binary(), t_atom('undefined')) end);
 type(erlang, raise, 3, _) -> t_none();
 type(erlang, read_timer, 1, Xs) ->
   strict(arg_types(erlang, read_timer, 1), Xs,
@@ -1312,6 +1327,8 @@ type(erlang, ref_to_list, 1, Xs) ->
 type(erlang, register, 2, Xs) ->
   strict(arg_types(erlang, register, 2), Xs, fun (_) -> t_atom('true') end);
 type(erlang, registered, 0, _) -> t_list(t_atom());
+type(erlang, restore_utag, 1, Xs) ->
+  strict(arg_types(erlang, restore_utag, 1), Xs, fun(_) -> t_atom('true') end);
 type(erlang, resume_process, 1, Xs) ->
   strict(arg_types(erlang, resume_process, 1), Xs,
 	 fun (_) -> t_any() end); %% TODO: overapproximation -- fix this
@@ -1426,6 +1443,10 @@ type(erlang, spawn_opt, 4, Xs) ->
 type(erlang, split_binary, 2, Xs) ->
   strict(arg_types(erlang, split_binary, 2), Xs,
 	 fun (_) -> t_tuple([t_binary(), t_binary()]) end);
+type(erlang, spread_utag, 1, Xs) ->
+  strict(arg_types(erlang, spread_utag, 1), Xs, 
+	 fun(_) -> t_sup(t_tuple([t_non_neg_integer(), t_sup(t_binary(), t_nil())]),
+			 t_atom('true')) end);
 type(erlang, start_timer, 3, Xs) ->
   strict(arg_types(erlang, start_timer, 3), Xs, fun (_) -> t_reference() end);
 type(erlang, statistics, 1, Xs) ->
@@ -3422,6 +3443,8 @@ arg_types(erlang, append, 2) ->
   arg_types(erlang, '++', 2);
 arg_types(erlang, append_element, 2) ->
   [t_tuple(), t_any()];
+arg_types(erlang, append_vm_utag_data, 1) ->
+  [t_iodata()];
 arg_types(erlang, apply, 2) ->
   [t_sup(t_tuple([t_module(),
 		  t_atom()]),
@@ -3547,6 +3570,10 @@ arg_types(erlang, get_module_info, 1) ->
   [t_atom()];
 arg_types(erlang, get_module_info, 2) ->
   [t_atom(), t_module_info_2()];
+arg_types(erlang, get_utag, 0) ->
+  [];
+arg_types(erlang, get_utag_data, 0) ->
+  [];
 arg_types(erlang, group_leader, 0) ->
   [];
 arg_types(erlang, group_leader, 2) ->
@@ -3763,6 +3790,8 @@ arg_types(erlang, port_set_data, 2) ->
   [t_sup(t_port(), t_atom()), t_any()];
 arg_types(erlang, pre_loaded, 0) ->
   [];
+arg_types(erlang, prepend_vm_utag_data, 1) ->
+  [t_iodata()];
 arg_types(erlang, process_display, 2) ->
   [t_pid(), t_atom('backtrace')];
 arg_types(erlang, process_flag, 2) ->
@@ -3789,6 +3818,8 @@ arg_types(erlang, purge_module, 1) ->
   [t_atom()];
 arg_types(erlang, put, 2) ->
   [t_any(), t_any()];
+arg_types(erlang, put_utag, 1) ->
+  [t_sup(t_binary(), t_atom('undefined'))];
 arg_types(erlang, raise, 3) ->
   OldStyleType = t_list(t_tuple([t_atom(), t_atom(),
 				 t_sup([t_arity(), t_list()])])),
@@ -3802,6 +3833,8 @@ arg_types(erlang, register, 2) ->
   [t_atom(), t_sup(t_port(), t_pid())];
 arg_types(erlang, registered, 0) ->
   [];
+arg_types(erlang, restore_utag, 1) ->
+  [t_sup(t_tuple([t_non_neg_integer(), t_sup(t_binary(), t_nil())]), t_atom('true'))];
 arg_types(erlang, resume_process, 1) ->
   [t_pid()]; % intended for debugging only
 arg_types(erlang, round, 1) ->
@@ -3860,6 +3893,8 @@ arg_types(erlang, spawn_opt, 4) ->
   [t_node(), t_atom(), t_list(), t_list(t_spawn_options())];
 arg_types(erlang, split_binary, 2) ->
   [t_binary(), t_non_neg_integer()];
+arg_types(erlang, spread_utag, 1) ->
+  [t_boolean()];
 arg_types(erlang, start_timer, 3) ->
   [t_non_neg_integer(), t_sup(t_pid(), t_atom()), t_any()];
 arg_types(erlang, statistics, 1) ->
diff --git a/lib/kernel/src/file.erl b/lib/kernel/src/file.erl
index aecb9f7923..3a618976f5 100644
--- a/lib/kernel/src/file.erl
+++ b/lib/kernel/src/file.erl
@@ -39,7 +39,7 @@
 -export([ipread_s32bu_p32bu/3]).
 %% Generic file contents.
 -export([open/2, close/1, advise/4,
-	 read/2, write/2,
+	 read/2, write/2, 
 	 pread/2, pread/3, pwrite/2, pwrite/3,
 	 read_line/1,
 	 position/2, truncate/1, datasync/1, sync/1,
@@ -62,7 +62,7 @@
 
 %% Internal export to prim_file and ram_file until they implement
 %% an efficient copy themselves.
--export([copy_opened/4]).
+-export([copy_opened/3]).
 
 -export([ipread_s32bu_p32bu_int/3]).
 
@@ -166,7 +166,7 @@ pid2name(Pid) when is_pid(Pid) ->
       Reason :: posix().
 
 get_cwd() ->
-    call(get_cwd, [no_drive, get_dtrace_utag()]).
+    call(get_cwd, []).
 
 -spec get_cwd(Drive) -> {ok, Dir} | {error, Reason} when
       Drive :: string(),
@@ -174,21 +174,21 @@ get_cwd() ->
       Reason :: posix() | badarg.
 
 get_cwd(Drive) ->
-    check_and_call(get_cwd, [file_name(Drive), get_dtrace_utag()]).
+    check_and_call(get_cwd, [file_name(Drive)]).
 
 -spec set_cwd(Dir) -> ok | {error, Reason} when
       Dir :: name(),
       Reason :: posix() | badarg.
 
 set_cwd(Dirname) -> 
-    check_and_call(set_cwd, [file_name(Dirname), get_dtrace_utag()]).
+    check_and_call(set_cwd, [file_name(Dirname)]).
 
 -spec delete(Filename) -> ok | {error, Reason} when
       Filename :: name(),
       Reason :: posix() | badarg.
 
 delete(Name) ->
-    check_and_call(delete, [file_name(Name), get_dtrace_utag()]).
+    check_and_call(delete, [file_name(Name)]).
 
 -spec rename(Source, Destination) -> ok | {error, Reason} when
       Source :: name(),
@@ -196,21 +196,21 @@ delete(Name) ->
       Reason :: posix() | badarg.
 
 rename(From, To) ->
-    check_and_call(rename, [file_name(From), file_name(To), get_dtrace_utag()]).
+    check_and_call(rename, [file_name(From), file_name(To)]).
 
 -spec make_dir(Dir) -> ok | {error, Reason} when
       Dir :: name(),
       Reason :: posix() | badarg.
 
 make_dir(Name) ->
-    check_and_call(make_dir, [file_name(Name), get_dtrace_utag()]).
+    check_and_call(make_dir, [file_name(Name)]).
 
 -spec del_dir(Dir) -> ok | {error, Reason} when
       Dir :: name(),
       Reason :: posix() | badarg.
 
 del_dir(Name) ->
-    check_and_call(del_dir, [file_name(Name), get_dtrace_utag()]).
+    check_and_call(del_dir, [file_name(Name)]).
 
 -spec read_file_info(Filename) -> {ok, FileInfo} | {error, Reason} when
       Filename :: name(),
@@ -218,7 +218,7 @@ del_dir(Name) ->
       Reason :: posix() | badarg.
 
 read_file_info(Name) ->
-    check_and_call(read_file_info, [file_name(Name), get_dtrace_utag()]).
+    check_and_call(read_file_info, [file_name(Name)]).
 
 -spec read_file_info(Filename, Opts) -> {ok, FileInfo} | {error, Reason} when
       Filename :: name(),
@@ -227,12 +227,12 @@ read_file_info(Name) ->
       Reason :: posix() | badarg.
 
 read_file_info(Name, Opts) when is_list(Opts) ->
-    check_and_call(read_file_info, [file_name(Name), Opts, get_dtrace_utag()]).
+    check_and_call(read_file_info, [file_name(Name), Opts]).
 
 -spec altname(Name :: name()) -> any().
 
 altname(Name) ->
-    check_and_call(altname, [file_name(Name), get_dtrace_utag()]).
+    check_and_call(altname, [file_name(Name)]).
 
 -spec read_link_info(Name) -> {ok, FileInfo} | {error, Reason} when
       Name :: name(),
@@ -240,7 +240,7 @@ altname(Name) ->
       Reason :: posix() | badarg.
 
 read_link_info(Name) ->
-    check_and_call(read_link_info, [file_name(Name), get_dtrace_utag()]).
+    check_and_call(read_link_info, [file_name(Name)]).
 
 -spec read_link_info(Name, Opts) -> {ok, FileInfo} | {error, Reason} when
       Name :: name(),
@@ -249,7 +249,7 @@ read_link_info(Name) ->
       Reason :: posix() | badarg.
 
 read_link_info(Name, Opts) when is_list(Opts) ->
-    check_and_call(read_link_info, [file_name(Name),Opts, get_dtrace_utag()]).
+    check_and_call(read_link_info, [file_name(Name),Opts]).
 
 
 -spec read_link(Name) -> {ok, Filename} | {error, Reason} when
@@ -258,7 +258,7 @@ read_link_info(Name, Opts) when is_list(Opts) ->
       Reason :: posix() | badarg.
 
 read_link(Name) ->
-    check_and_call(read_link, [file_name(Name), get_dtrace_utag()]).
+    check_and_call(read_link, [file_name(Name)]).
 
 -spec write_file_info(Filename, FileInfo) -> ok | {error, Reason} when
       Filename :: name(),
@@ -266,7 +266,7 @@ read_link(Name) ->
       Reason :: posix() | badarg.
 
 write_file_info(Name, Info = #file_info{}) ->
-    check_and_call(write_file_info, [file_name(Name), Info, get_dtrace_utag()]).
+    check_and_call(write_file_info, [file_name(Name), Info]).
 
 -spec write_file_info(Filename, FileInfo, Opts) -> ok | {error, Reason} when
       Filename :: name(),
@@ -275,7 +275,7 @@ write_file_info(Name, Info = #file_info{}) ->
       Reason :: posix() | badarg.
 
 write_file_info(Name, Info = #file_info{}, Opts) when is_list(Opts) ->
-    check_and_call(write_file_info, [file_name(Name), Info, Opts, get_dtrace_utag()]).
+    check_and_call(write_file_info, [file_name(Name), Info, Opts]).
 
 -spec list_dir(Dir) -> {ok, Filenames} | {error, Reason} when
       Dir :: name(),
@@ -283,7 +283,7 @@ write_file_info(Name, Info = #file_info{}, Opts) when is_list(Opts) ->
       Reason :: posix() | badarg.
 
 list_dir(Name) ->
-    check_and_call(list_dir, [file_name(Name), get_dtrace_utag()]).
+    check_and_call(list_dir, [file_name(Name)]).
 
 -spec read_file(Filename) -> {ok, Binary} | {error, Reason} when
       Filename :: name(),
@@ -291,7 +291,7 @@ list_dir(Name) ->
       Reason :: posix() | badarg | terminated | system_limit.
 
 read_file(Name) ->
-    check_and_call(read_file, [file_name(Name), get_dtrace_utag()]).
+    check_and_call(read_file, [file_name(Name)]).
 
 -spec make_link(Existing, New) -> ok | {error, Reason} when
       Existing :: name(),
@@ -299,7 +299,7 @@ read_file(Name) ->
       Reason :: posix() | badarg.
 
 make_link(Old, New) ->
-    check_and_call(make_link, [file_name(Old), file_name(New), get_dtrace_utag()]).
+    check_and_call(make_link, [file_name(Old), file_name(New)]).
 
 -spec make_symlink(Existing, New) -> ok | {error, Reason} when
       Existing :: name(),
@@ -307,7 +307,7 @@ make_link(Old, New) ->
       Reason :: posix() | badarg.
 
 make_symlink(Old, New) ->
-    check_and_call(make_symlink, [file_name(Old), file_name(New), get_dtrace_utag()]).
+    check_and_call(make_symlink, [file_name(Old), file_name(New)]).
 
 -spec write_file(Filename, Bytes) -> ok | {error, Reason} when
       Filename :: name(),
@@ -315,7 +315,7 @@ make_symlink(Old, New) ->
       Reason :: posix() | badarg | terminated | system_limit.
 
 write_file(Name, Bin) ->
-    check_and_call(write_file, [file_name(Name), make_binary(Bin), get_dtrace_utag()]).
+    check_and_call(write_file, [file_name(Name), make_binary(Bin)]).
 
 %% This whole operation should be moved to the file_server and prim_file
 %% when it is time to change file server protocol again.
@@ -367,7 +367,7 @@ raw_write_file_info(Name, #file_info{} = Info) ->
     case check_args(Args) of
 	ok ->
 	    [FileName] = Args,
-	    ?PRIM_FILE:write_file_info(FileName, Info, get_dtrace_utag());
+	    ?PRIM_FILE:write_file_info(FileName, Info);
 	Error ->
 	    Error
     end.
@@ -400,7 +400,7 @@ open(Item, ModeList) when is_list(ModeList) ->
 			    [FileName | _] = Args,
 			    %% We rely on the returned Handle (in {ok, Handle})
 			    %% being a pid() or a #file_descriptor{}
-			    ?PRIM_FILE:open(FileName, ModeList, get_dtrace_utag());
+			    ?PRIM_FILE:open(FileName, ModeList);
 			Error ->
 			    Error
 		    end
@@ -421,7 +421,7 @@ open(Item, ModeList) when is_list(ModeList) ->
 		    case check_args(Args) of 
 			ok ->
 			    [FileName | _] = Args,
-			    call(open, [FileName, ModeList, get_dtrace_utag()]);
+			    call(open, [FileName, ModeList]);
 			Error ->
 			    Error
 		    end
@@ -466,10 +466,7 @@ close(_) ->
 advise(File, Offset, Length, Advise) when is_pid(File) ->
     R = file_request(File, {advise, Offset, Length, Advise}),
     wait_file_reply(File, R);
-advise(#file_descriptor{module = prim_file = Module} = Handle, Offset, Length, Advise) ->
-    Module:advise(Handle, Offset, Length, Advise, get_dtrace_utag());
 advise(#file_descriptor{module = Module} = Handle, Offset, Length, Advise) ->
-    %% DTrace TODO: ram_file and other file drivers not yet DTrace'ified.
     Module:advise(Handle, Offset, Length, Advise);
 advise(_, _, _, _) ->
     {error, badarg}.
@@ -480,25 +477,17 @@ advise(_, _, _, _) ->
       Data :: string() | binary(),
       Reason :: posix() | badarg | terminated.
 
-read(File, Sz) ->
-    read(File, Sz, get_dtrace_utag()).
-
-read(File, Sz, _DTraceUtag)
-  when (is_pid(File) orelse is_atom(File)), is_integer(Sz), Sz >= 0 ->
+read(File, Sz) when (is_pid(File) orelse is_atom(File)), is_integer(Sz), Sz >= 0 ->
     case io:request(File, {get_chars, '', Sz}) of
 	Data when is_list(Data); is_binary(Data) ->
 	    {ok, Data};
 	Other ->
 	    Other
     end;
-read(#file_descriptor{module = prim_file = Module} = Handle, Sz, DTraceUtag)
-  when is_integer(Sz), Sz >= 0 ->
-    Module:read(Handle, Sz, DTraceUtag);
-read(#file_descriptor{module = Module} = Handle, Sz, _DTraceUtag)
+read(#file_descriptor{module = Module} = Handle, Sz) 
   when is_integer(Sz), Sz >= 0 ->
-    %% DTrace TODO: ram_file and other file drivers not yet DTrace'ified.
     Module:read(Handle, Sz);
-read(_, _, _) ->
+read(_, _) ->
     {error, badarg}.
 
 -spec read_line(IoDevice) -> {ok, Data} | eof | {error, Reason} when
@@ -513,10 +502,7 @@ read_line(File) when (is_pid(File) orelse is_atom(File)) ->
 	Other ->
 	    Other
     end;
-read_line(#file_descriptor{module = prim_file = Module} = Handle) ->
-    Module:read_line(Handle, get_dtrace_utag());
 read_line(#file_descriptor{module = Module} = Handle) ->
-    %% DTrace TODO: ram_file and other file drivers not yet DTrace'ified.
     Module:read_line(Handle);
 read_line(_) ->
     {error, badarg}.
@@ -530,10 +516,7 @@ read_line(_) ->
 
 pread(File, L) when is_pid(File), is_list(L) ->
     pread_int(File, L, []);
-pread(#file_descriptor{module = prim_file = Module} = Handle, L) when is_list(L) ->
-    Module:pread(Handle, L, get_dtrace_utag());
 pread(#file_descriptor{module = Module} = Handle, L) when is_list(L) ->
-    %% DTrace TODO: ram_file and other file drivers not yet DTrace'ified.
     Module:pread(Handle, L);
 pread(_, _) ->
     {error, badarg}.
@@ -565,7 +548,6 @@ pread(File, At, Sz) when is_pid(File), is_integer(Sz), Sz >= 0 ->
     wait_file_reply(File, R);
 pread(#file_descriptor{module = Module} = Handle, Offs, Sz) 
   when is_integer(Sz), Sz >= 0 ->
-    %% DTrace TODO: ram_file and other file drivers not yet DTrace'ified.
     Module:pread(Handle, Offs, Sz);
 pread(_, _, _) ->
     {error, badarg}.
@@ -575,22 +557,16 @@ pread(_, _, _) ->
       Bytes :: iodata(),
       Reason :: posix() | badarg | terminated.
 
-write(File, Bytes) ->
-    write(File, Bytes, get_dtrace_utag()).
-
-write(File, Bytes, _DTraceUtag) when (is_pid(File) orelse is_atom(File)) ->
+write(File, Bytes) when (is_pid(File) orelse is_atom(File)) ->
     case make_binary(Bytes) of
 	Bin when is_binary(Bin) ->
 	    io:request(File, {put_chars,Bin});
 	Error ->
 	    Error
     end;
-write(#file_descriptor{module = prim_file = Module} = Handle, Bytes, DTraceUtag) ->
-    Module:write(Handle, Bytes, DTraceUtag);
-write(#file_descriptor{module = Module} = Handle, Bytes, _DTraceUtag) ->
-    %% DTrace TODO: ram_file and other file drivers not yet DTrace'ified.
+write(#file_descriptor{module = Module} = Handle, Bytes) ->
     Module:write(Handle, Bytes);
-write(_, _, _) ->
+write(_, _) ->
     {error, badarg}.
 
 -spec pwrite(IoDevice, LocBytes) -> ok | {error, {N, Reason}} when
@@ -601,10 +577,7 @@ write(_, _, _) ->
 
 pwrite(File, L) when is_pid(File), is_list(L) ->
     pwrite_int(File, L, 0);
-pwrite(#file_descriptor{module = prim_file = Module} = Handle, L) when is_list(L) ->
-    Module:pwrite(Handle, L, get_dtrace_utag());
 pwrite(#file_descriptor{module = Module} = Handle, L) when is_list(L) ->
-    %% DTrace TODO: ram_file and other file drivers not yet DTrace'ified.
     Module:pwrite(Handle, L);
 pwrite(_, _) ->
     {error, badarg}.
@@ -631,7 +604,6 @@ pwrite(File, At, Bytes) when is_pid(File) ->
     R = file_request(File, {pwrite, At, Bytes}),
     wait_file_reply(File, R);
 pwrite(#file_descriptor{module = Module} = Handle, Offs, Bytes) ->
-    %% DTrace TODO: ram_file and other file drivers not yet DTrace'ified.
     Module:pwrite(Handle, Offs, Bytes);
 pwrite(_, _, _) ->
     {error, badarg}.
@@ -643,10 +615,7 @@ pwrite(_, _, _) ->
 datasync(File) when is_pid(File) ->
     R = file_request(File, datasync),
     wait_file_reply(File, R);
-datasync(#file_descriptor{module = prim_file = Module} = Handle) ->
-    Module:datasync(Handle, get_dtrace_utag());
 datasync(#file_descriptor{module = Module} = Handle) ->
-    %% DTrace TODO: ram_file and other file drivers not yet DTrace'ified.
     Module:datasync(Handle);
 datasync(_) ->
     {error, badarg}.
@@ -658,10 +627,7 @@ datasync(_) ->
 sync(File) when is_pid(File) ->
     R = file_request(File, sync),
     wait_file_reply(File, R);
-sync(#file_descriptor{module = prim_file = Module} = Handle) ->
-    Module:sync(Handle, get_dtrace_utag());
 sync(#file_descriptor{module = Module} = Handle) ->
-    %% DTrace TODO: ram_file and other file drivers not yet DTrace'ified.
     Module:sync(Handle);
 sync(_) ->
     {error, badarg}.
@@ -675,10 +641,7 @@ sync(_) ->
 position(File, At) when is_pid(File) ->
     R = file_request(File, {position,At}),
     wait_file_reply(File, R);
-position(#file_descriptor{module = prim_file = Module} = Handle, At) ->
-    Module:position(Handle, At, get_dtrace_utag());
 position(#file_descriptor{module = Module} = Handle, At) ->
-    %% DTrace TODO: ram_file and other file drivers not yet DTrace'ified.
     Module:position(Handle, At);
 position(_, _) ->
     {error, badarg}.
@@ -690,10 +653,7 @@ position(_, _) ->
 truncate(File) when is_pid(File) ->
     R = file_request(File, truncate),
     wait_file_reply(File, R);
-truncate(#file_descriptor{module = prim_file = Module} = Handle) ->
-    Module:truncate(Handle, get_dtrace_utag());
 truncate(#file_descriptor{module = Module} = Handle) ->
-    %% DTrace TODO: ram_file and other file drivers not yet DTrace'ified.
     Module:truncate(Handle);
 truncate(_) ->
     {error, badarg}.
@@ -734,7 +694,7 @@ copy_int(Source, Dest, Length)
   when is_pid(Source), is_pid(Dest);
        is_pid(Source), is_record(Dest, file_descriptor);
        is_record(Source, file_descriptor), is_pid(Dest) ->
-    copy_opened_int(Source, Dest, Length, get_dtrace_utag());
+    copy_opened_int(Source, Dest, Length, 0);
 %% Copy between open raw files, both handled by the same module
 copy_int(#file_descriptor{module = Module} = Source,
 	 #file_descriptor{module = Module} = Dest,
@@ -743,14 +703,14 @@ copy_int(#file_descriptor{module = Module} = Source,
 %% Copy between open raw files of different modules
 copy_int(#file_descriptor{} = Source, 
 	 #file_descriptor{} = Dest, Length) ->
-    copy_opened_int(Source, Dest, Length, get_dtrace_utag());
+    copy_opened_int(Source, Dest, Length, 0);
 %% Copy between filenames, let the server do the copy
 copy_int({SourceName, SourceOpts}, {DestName, DestOpts}, Length) 
   when is_list(SourceOpts), is_list(DestOpts) ->
     check_and_call(copy, 
 		   [file_name(SourceName), SourceOpts,
 		    file_name(DestName), DestOpts,
-		    Length, get_dtrace_utag()]);
+		    Length]);
 %% Filename -> open file; must open Source and do client copy
 copy_int({SourceName, SourceOpts}, Dest, Length) 
   when is_list(SourceOpts), is_pid(Dest);
@@ -761,8 +721,7 @@ copy_int({SourceName, SourceOpts}, Dest, Length)
 	Source ->
 	    case open(Source, [read | SourceOpts]) of
 		{ok, Handle} ->
-		    Result = copy_opened_int(Handle, Dest, Length,
-                                             get_dtrace_utag()),
+		    Result = copy_opened_int(Handle, Dest, Length, 0),
 		    close(Handle),
 		    Result;
 		{error, _} = Error ->
@@ -779,8 +738,7 @@ copy_int(Source, {DestName, DestOpts}, Length)
 	Dest ->
 	    case open(Dest, [write | DestOpts]) of
 		{ok, Handle} ->
-		    Result = copy_opened_int(Source, Handle, Length,
-                                             get_dtrace_utag()),
+		    Result = copy_opened_int(Source, Handle, Length, 0),
 		    close(Handle),
 		    Result;
 		{error, _} = Error ->
@@ -815,46 +773,45 @@ copy_int(Source, Dest, Length) ->
 
 
 
-copy_opened(Source, Dest, Length, DTraceUtag)
+copy_opened(Source, Dest, Length)
   when is_integer(Length), Length >= 0;
        is_atom(Length) ->
-    copy_opened_int(Source, Dest, Length, DTraceUtag);
-copy_opened(_, _, _, _) ->
+    copy_opened_int(Source, Dest, Length);
+copy_opened(_, _, _) ->
     {error, badarg}.
 
 %% Here we know that Length is either an atom or an integer >= 0
 %% (by the way, atoms > integers)
 
-copy_opened_int(Source, Dest, Length, DTraceUtag)
+copy_opened_int(Source, Dest, Length)
   when is_pid(Source), is_pid(Dest) ->
-    copy_opened_int(Source, Dest, Length, 0, DTraceUtag);
-copy_opened_int(Source, Dest, Length, DTraceUtag)
+    copy_opened_int(Source, Dest, Length, 0);
+copy_opened_int(Source, Dest, Length)
   when is_pid(Source), is_record(Dest, file_descriptor) ->
-    copy_opened_int(Source, Dest, Length, 0, DTraceUtag);
-copy_opened_int(Source, Dest, Length, DTraceUtag)
+    copy_opened_int(Source, Dest, Length, 0);
+copy_opened_int(Source, Dest, Length)
   when is_record(Source, file_descriptor), is_pid(Dest) ->
-    copy_opened_int(Source, Dest, Length, 0, DTraceUtag);
-copy_opened_int(Source, Dest, Length, DTraceUtag)
+    copy_opened_int(Source, Dest, Length, 0);
+copy_opened_int(Source, Dest, Length)
   when is_record(Source, file_descriptor), is_record(Dest, file_descriptor) ->
-    copy_opened_int(Source, Dest, Length, 0, DTraceUtag);
-copy_opened_int(_, _, _, _) ->
+    copy_opened_int(Source, Dest, Length, 0);
+copy_opened_int(_, _, _) ->
     {error, badarg}.
 
 %% Here we know that Source and Dest are handles to open files, Length is
 %% as above, and Copied is an integer >= 0
 
 %% Copy loop in client process
-copy_opened_int(_, _, Length, Copied, _DTraceUtag)
-  when Length =< 0 -> % atom() > integer()
+copy_opened_int(_, _, Length, Copied) when Length =< 0 -> % atom() > integer()
     {ok, Copied};
-copy_opened_int(Source, Dest, Length, Copied, DTraceUtag) ->
+copy_opened_int(Source, Dest, Length, Copied) ->
     N = if Length > 65536 -> 65536; true -> Length end, % atom() > integer() !
-    case read(Source, N, DTraceUtag) of
+    case read(Source, N) of
 	{ok, Data} ->
 	    M = if is_binary(Data) -> byte_size(Data);
 		   is_list(Data)   -> length(Data)
 		end,
-	    case write(Dest, Data, DTraceUtag) of
+	    case write(Dest, Data) of
 		ok ->
 		    if M < N ->
 			    %% Got less than asked for - must be end of file
@@ -864,8 +821,7 @@ copy_opened_int(Source, Dest, Length, Copied, DTraceUtag) ->
 			    NewLength = if is_atom(Length) -> Length;
 					   true         -> Length-M
 					end,
-			    copy_opened_int(Source, Dest, NewLength, Copied+M,
-                                            DTraceUtag)
+			    copy_opened_int(Source, Dest, NewLength, Copied+M)
 		    end;
 		{error, _} = Error ->
 		    Error
@@ -885,8 +841,6 @@ copy_opened_int(Source, Dest, Length, Copied, DTraceUtag) ->
 
 ipread_s32bu_p32bu(File, Pos, MaxSize) when is_pid(File) ->
     ipread_s32bu_p32bu_int(File, Pos, MaxSize);
-ipread_s32bu_p32bu(#file_descriptor{module = prim_file = Module} = Handle, Pos, MaxSize) ->
-    Module:ipread_s32bu_p32bu(Handle, Pos, MaxSize, get_dtrace_utag());
 ipread_s32bu_p32bu(#file_descriptor{module = Module} = Handle, Pos, MaxSize) ->
     Module:ipread_s32bu_p32bu(Handle, Pos, MaxSize);
 ipread_s32bu_p32bu(_, _, _) ->
@@ -1467,7 +1421,10 @@ call(Command, Args) when is_list(Args) ->
 check_and_call(Command, Args) when is_list(Args) ->
     case check_args(Args) of
 	ok ->
-	    call(Command, Args);
+	    X = erlang:spread_utag(true),
+	    Y = call(Command, Args),
+	    erlang:restore_utag(X),
+	    Y;
 	Error ->
 	    Error
     end.
@@ -1502,6 +1459,3 @@ wait_file_reply(From, Ref) ->
 	    %% receive {'EXIT', From, _} -> ok after 0 -> ok end,
 	    {error, terminated}
     end.
-
-get_dtrace_utag() ->
-    dtrace:get_utag().
diff --git a/lib/kernel/src/file_io_server.erl b/lib/kernel/src/file_io_server.erl
index cc0343031b..14da9c1a55 100644
--- a/lib/kernel/src/file_io_server.erl
+++ b/lib/kernel/src/file_io_server.erl
@@ -21,7 +21,7 @@
 %% A simple file server for io to one file instance per server instance.
 
 -export([format_error/1]).
--export([start/4, start_link/4]).
+-export([start/3, start_link/3]).
 
 -export([count_and_find/3]).
 
@@ -43,18 +43,18 @@ format_error({_Line, Mod, Reason}) ->
 format_error(ErrorId) ->
     erl_posix_msg:message(ErrorId).
 
-start(Owner, FileName, ModeList, DTraceUtag)
+start(Owner, FileName, ModeList) 
   when is_pid(Owner), (is_list(FileName) orelse is_binary(FileName)), is_list(ModeList) ->
-    do_start(spawn, Owner, FileName, ModeList, DTraceUtag).
+    do_start(spawn, Owner, FileName, ModeList).
 
-start_link(Owner, FileName, ModeList, DTraceUtag)
+start_link(Owner, FileName, ModeList) 
   when is_pid(Owner), (is_list(FileName) orelse is_binary(FileName)), is_list(ModeList) ->
-    do_start(spawn_link, Owner, FileName, ModeList, DTraceUtag).
+    do_start(spawn_link, Owner, FileName, ModeList).
 
 %%%-----------------------------------------------------------------
 %%% Server starter, dispatcher and helpers
 
-do_start(Spawn, Owner, FileName, ModeList, DTraceUtag) ->
+do_start(Spawn, Owner, FileName, ModeList) ->
     Self = self(),
     Ref = make_ref(),
     Pid = 
@@ -63,12 +63,11 @@ do_start(Spawn, Owner, FileName, ModeList, DTraceUtag) ->
 		  %% process_flag(trap_exit, true),
 		  case parse_options(ModeList) of
 		      {ReadMode, UnicodeMode, Opts} ->
-			  case ?PRIM_FILE:open(FileName, Opts, DTraceUtag) of
+			  case ?PRIM_FILE:open(FileName, Opts) of
 			      {error, Reason} = Error ->
 				  Self ! {Ref, Error},
 				  exit(Reason);
 			      {ok, Handle} ->
-                                  put(dtrace_utag, DTraceUtag), % TODO: API?
 				  %% XXX must I handle R6 nodes here?
 				  M = erlang:monitor(process, Owner),
 				  Self ! {Ref, ok},
diff --git a/lib/kernel/src/file_server.erl b/lib/kernel/src/file_server.erl
index 82adc45795..fc6cd823c9 100644
--- a/lib/kernel/src/file_server.erl
+++ b/lib/kernel/src/file_server.erl
@@ -76,7 +76,6 @@ stop() ->
 
 init([]) ->
     process_flag(trap_exit, true),
-    put(dtrace_utag, atom_to_list(?FILE_SERVER)),
     case ?PRIM_FILE:start() of
 	{ok, Handle} ->
 	    ets:new(?FILE_IO_SERVER_TABLE, [named_table]),
@@ -100,9 +99,9 @@ init([]) ->
 	{'reply', 'eof' | 'ok' | {'error', term()} | {'ok', term()}, state()} |
 	{'stop', 'normal', 'stopped', state()}.
 
-handle_call({open, Name, ModeList, DTraceUtag}, {Pid, _Tag} = _From, Handle)
+handle_call({open, Name, ModeList}, {Pid, _Tag} = _From, Handle)
   when is_list(ModeList) ->
-    Child = ?FILE_IO_SERVER:start_link(Pid, Name, ModeList, DTraceUtag),
+    Child = ?FILE_IO_SERVER:start_link(Pid, Name, ModeList),
     case Child of
 	{ok, P} when is_pid(P) ->
 	    ets:insert(?FILE_IO_SERVER_TABLE, {P, Name});
@@ -111,86 +110,87 @@ handle_call({open, Name, ModeList, DTraceUtag}, {Pid, _Tag} = _From, Handle)
     end,
     {reply, Child, Handle};
 
-handle_call({open, _Name, _Mode, _DTraceUtag}, _From, Handle) ->
+handle_call({open, _Name, _Mode}, _From, Handle) ->
     {reply, {error, einval}, Handle};
 
-handle_call({read_file, Name, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:read_file(Name, DTraceUtag), Handle};
+handle_call({read_file, Name}, _From, Handle) ->
+    {reply, ?PRIM_FILE:read_file(Name), Handle};
 
-handle_call({write_file, Name, Bin, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:write_file(Name, Bin, DTraceUtag), Handle};
+handle_call({write_file, Name, Bin}, _From, Handle) ->
+    {reply, ?PRIM_FILE:write_file(Name, Bin), Handle};
 
-handle_call({set_cwd, Name, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:set_cwd(Handle, Name, DTraceUtag), Handle};
+handle_call({set_cwd, Name}, _From, Handle) ->
+    {reply, ?PRIM_FILE:set_cwd(Handle, Name), Handle};
 
-handle_call({delete, Name, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:delete(Handle, Name, DTraceUtag), Handle};
+handle_call({delete, Name}, _From, Handle) ->
+    {reply, ?PRIM_FILE:delete(Handle, Name), Handle};
 
-handle_call({rename, Fr, To, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:rename(Handle, Fr, To, DTraceUtag), Handle};
+handle_call({rename, Fr, To}, _From, Handle) ->
+    {reply, ?PRIM_FILE:rename(Handle, Fr, To), Handle};
 
-handle_call({make_dir, Name, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:make_dir(Handle, Name, DTraceUtag), Handle};
+handle_call({make_dir, Name}, _From, Handle) ->
+    {reply, ?PRIM_FILE:make_dir(Handle, Name), Handle};
 
-handle_call({del_dir, Name, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:del_dir(Handle, Name, DTraceUtag), Handle};
+handle_call({del_dir, Name}, _From, Handle) ->
+    {reply, ?PRIM_FILE:del_dir(Handle, Name), Handle};
 
-handle_call({list_dir, Name, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:list_dir(Handle, Name, DTraceUtag), Handle};
+handle_call({list_dir, Name}, _From, Handle) ->
+    {reply, ?PRIM_FILE:list_dir(Handle, Name), Handle};
 
 handle_call(get_cwd, _From, Handle) ->
-    {reply, ?PRIM_FILE:get_cwd(Handle, no_drive, "TODO-fixme"), Handle};
-handle_call({get_cwd, no_drive, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:get_cwd(Handle, no_drive, DTraceUtag), Handle};
-handle_call({get_cwd, Name, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:get_cwd(Handle, Name, DTraceUtag), Handle};
+    {reply, ?PRIM_FILE:get_cwd(Handle), Handle};
+handle_call({get_cwd}, _From, Handle) ->
+    {reply, ?PRIM_FILE:get_cwd(Handle), Handle};
+handle_call({get_cwd, Name}, _From, Handle) ->
+    {reply, ?PRIM_FILE:get_cwd(Handle, Name), Handle};
 
-handle_call({read_file_info, Name, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:read_file_info(Handle, Name, [], DTraceUtag), Handle};
-handle_call({read_file_info, Name, Opts, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:read_file_info(Handle, Name, Opts, DTraceUtag), Handle};
+handle_call({read_file_info, Name}, _From, Handle) ->
+    {reply, ?PRIM_FILE:read_file_info(Handle, Name), Handle};
 
-handle_call({altname, Name, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:altname(Handle, Name, DTraceUtag), Handle};
+handle_call({read_file_info, Name, Opts}, _From, Handle) ->
+    {reply, ?PRIM_FILE:read_file_info(Handle, Name, Opts), Handle};
 
-handle_call({write_file_info, Name, Info, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:write_file_info(Handle, Name, Info, [], DTraceUtag), Handle};
-handle_call({write_file_info, Name, Info, Opts, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:write_file_info(Handle, Name, Info, Opts, DTraceUtag), Handle};
+handle_call({altname, Name}, _From, Handle) ->
+    {reply, ?PRIM_FILE:altname(Handle, Name), Handle};
 
-handle_call({read_link_info, Name, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:read_link_info(Handle, Name, [], DTraceUtag), Handle};
-handle_call({read_link_info, Name, Opts, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:read_link_info(Handle, Name, Opts, DTraceUtag), Handle};
+handle_call({write_file_info, Name, Info}, _From, Handle) ->
+    {reply, ?PRIM_FILE:write_file_info(Handle, Name, Info), Handle};
 
-handle_call({read_link, Name, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:read_link(Handle, Name, DTraceUtag), Handle};
+handle_call({write_file_info, Name, Info, Opts}, _From, Handle) ->
+    {reply, ?PRIM_FILE:write_file_info(Handle, Name, Info, Opts), Handle};
 
-handle_call({make_link, Old, New, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:make_link(Handle, Old, New, DTraceUtag), Handle};
+handle_call({read_link_info, Name}, _From, Handle) ->
+    {reply, ?PRIM_FILE:read_link_info(Handle, Name), Handle};
 
-handle_call({make_symlink, Old, New, DTraceUtag}, _From, Handle) ->
-    {reply, ?PRIM_FILE:make_symlink(Handle, Old, New, DTraceUtag), Handle};
+handle_call({read_link_info, Name, Opts}, _From, Handle) ->
+    {reply, ?PRIM_FILE:read_link_info(Handle, Name, Opts), Handle};
 
-handle_call({copy, SourceName, SourceOpts, DestName, DestOpts, Length, DTraceUtag},
+handle_call({read_link, Name}, _From, Handle) ->
+    {reply, ?PRIM_FILE:read_link(Handle, Name), Handle};
+
+handle_call({make_link, Old, New}, _From, Handle) ->
+    {reply, ?PRIM_FILE:make_link(Handle, Old, New), Handle};
+
+handle_call({make_symlink, Old, New}, _From, Handle) ->
+    {reply, ?PRIM_FILE:make_symlink(Handle, Old, New), Handle};
+
+handle_call({copy, SourceName, SourceOpts, DestName, DestOpts, Length},
 	    _From, Handle) ->
     Reply = 
-	case ?PRIM_FILE:open(SourceName, [read, binary | SourceOpts],
-                             DTraceUtag) of
+	case ?PRIM_FILE:open(SourceName, [read, binary | SourceOpts]) of
 	    {ok, Source} ->
 		SourceReply = 
 		    case ?PRIM_FILE:open(DestName, 
-					 [write, binary | DestOpts],
-                                         DTraceUtag) of
+					 [write, binary | DestOpts]) of
 			{ok, Dest} ->
 			    DestReply = 
-				?PRIM_FILE:copy(Source, Dest, Length, DTraceUtag),
-			    ?PRIM_FILE:close(Dest, DTraceUtag),
+				?PRIM_FILE:copy(Source, Dest, Length),
+			    ?PRIM_FILE:close(Dest),
 			    DestReply;
 			{error, _} = Error ->
 			    Error
 		    end,
-		?PRIM_FILE:close(Source, DTraceUtag),
+		?PRIM_FILE:close(Source),
 		SourceReply;
 	    {error, _} = Error ->
 		Error
diff --git a/lib/kernel/test/prim_file_SUITE.erl b/lib/kernel/test/prim_file_SUITE.erl
index 9575762b12..3e2202922c 100644
--- a/lib/kernel/test/prim_file_SUITE.erl
+++ b/lib/kernel/test/prim_file_SUITE.erl
@@ -70,7 +70,7 @@
 %% compile time.
 -define(PRIM_FILE_call(F, H, A), 
 	case H of
-	    [] -> apply(?PRIM_FILE, F, A -- ["utag"]);
+	    [] -> apply(?PRIM_FILE, F, A);
 	    _ ->  apply(?PRIM_FILE, F, [H | A])
 	end).
 
@@ -255,31 +255,31 @@ make_del_dir(Config, Handle, Suffix) ->
     ?line NewDir = filename:join(RootDir, 
 				 atom_to_list(?MODULE)
 				 ++"_mk-dir"++Suffix),
-    ?line ok = ?PRIM_FILE_call(make_dir, Handle, [NewDir, "utag"]),
-    ?line {error, eexist} = ?PRIM_FILE_call(make_dir, Handle, [NewDir, "utag"]),
-    ?line ok = ?PRIM_FILE_call(del_dir, Handle, [NewDir, "utag"]),
-    ?line {error, enoent} = ?PRIM_FILE_call(del_dir, Handle, [NewDir, "utag"]),
+    ?line ok = ?PRIM_FILE_call(make_dir, Handle, [NewDir]),
+    ?line {error, eexist} = ?PRIM_FILE_call(make_dir, Handle, [NewDir]),
+    ?line ok = ?PRIM_FILE_call(del_dir, Handle, [NewDir]),
+    ?line {error, enoent} = ?PRIM_FILE_call(del_dir, Handle, [NewDir]),
 
     % Make sure we are not in a directory directly under test_server
     % as that would result in eacess errors when trying to delere '..',
     % because there are processes having that directory as current.
-    ?line ok = ?PRIM_FILE_call(make_dir, Handle, [NewDir, "utag"]),
+    ?line ok = ?PRIM_FILE_call(make_dir, Handle, [NewDir]),
     ?line {ok, CurrentDir} = ?PRIM_FILE_call(get_cwd, Handle, []),
-    ?line ok = ?PRIM_FILE_call(set_cwd, Handle, [NewDir, "utag"]),
+    ?line ok = ?PRIM_FILE_call(set_cwd, Handle, [NewDir]),
     try
 	%% Check that we get an error when trying to create...
 	%% a deep directory
 	?line NewDir2 = filename:join(RootDir, 
 				      atom_to_list(?MODULE)
 				      ++"_mk-dir-noexist/foo"),
-	?line {error, enoent} = ?PRIM_FILE_call(make_dir, Handle, [NewDir2, "utag"]),
+	?line {error, enoent} = ?PRIM_FILE_call(make_dir, Handle, [NewDir2]),
 	%% a nameless directory
-	?line {error, enoent} = ?PRIM_FILE_call(make_dir, Handle, ["", "utag"]),
+	?line {error, enoent} = ?PRIM_FILE_call(make_dir, Handle, [""]),
 	%% a directory with illegal name
-	?line {error, badarg} = ?PRIM_FILE_call(make_dir, Handle, ['mk-dir', "utag"]),
+	?line {error, badarg} = ?PRIM_FILE_call(make_dir, Handle, ['mk-dir']),
 	
 	%% a directory with illegal name, even if it's a (bad) list
-	?line {error, badarg} = ?PRIM_FILE_call(make_dir, Handle, [[1,2,3,{}], "utag"]),
+	?line {error, badarg} = ?PRIM_FILE_call(make_dir, Handle, [[1,2,3,{}]]),
 	
 	%% Maybe this isn't an error, exactly, but worth mentioning anyway:
 	%% ok = ?PRIM_FILE:make_dir([$f,$o,$o,0,$b,$a,$r])),
@@ -292,17 +292,17 @@ make_del_dir(Config, Handle, Suffix) ->
 	%% Try deleting some bad directories
 	%% Deleting the parent directory to the current, sounds dangerous, huh?
 	%% Don't worry ;-) the parent directory should never be empty, right?
-	?line case ?PRIM_FILE_call(del_dir, Handle, ["..", "utag"]) of
+	?line case ?PRIM_FILE_call(del_dir, Handle, [".."]) of
 		  {error, eexist} -> ok;
 		  {error, eacces} -> ok;	%OpenBSD
 		  {error, einval} -> ok		%FreeBSD
 	      end,
-	?line {error, enoent} = ?PRIM_FILE_call(del_dir, Handle, ["", "utag"]),
-	?line {error, badarg} = ?PRIM_FILE_call(del_dir, Handle, [[3,2,1,{}], "utag"]),
+	?line {error, enoent} = ?PRIM_FILE_call(del_dir, Handle, [""]),
+	?line {error, badarg} = ?PRIM_FILE_call(del_dir, Handle, [[3,2,1,{}]]),
 
 	?line test_server:timetrap_cancel(Dog)
     after
-	?line ok = ?PRIM_FILE_call(set_cwd, Handle, [CurrentDir, "utag"])
+	?line ok = ?PRIM_FILE_call(set_cwd, Handle, [CurrentDir])
     end,
     ok.
 
@@ -324,7 +324,7 @@ cur_dir_0(Config, Handle) ->
     %% Find out the current dir, and cd to it ;-)
     ?line {ok,BaseDir} = ?PRIM_FILE_call(get_cwd, Handle, []),
     ?line Dir1 = BaseDir ++ "", %% Check that it's a string
-    ?line ok = ?PRIM_FILE_call(set_cwd, Handle, [Dir1, "utag"]),
+    ?line ok = ?PRIM_FILE_call(set_cwd, Handle, [Dir1]),
     ?line DirName = atom_to_list(?MODULE) ++
 	case Handle of
 	    [] ->
@@ -336,40 +336,40 @@ cur_dir_0(Config, Handle) ->
     %% Make a new dir, and cd to that
     ?line RootDir = ?config(priv_dir,Config),
     ?line NewDir = filename:join(RootDir, DirName),
-    ?line ok = ?PRIM_FILE_call(make_dir, Handle, [NewDir, "utag"]),
+    ?line ok = ?PRIM_FILE_call(make_dir, Handle, [NewDir]),
     ?line io:format("cd to ~s",[NewDir]),
-    ?line ok = ?PRIM_FILE_call(set_cwd, Handle, [NewDir, "utag"]),
+    ?line ok = ?PRIM_FILE_call(set_cwd, Handle, [NewDir]),
 
     %% Create a file in the new current directory, and check that it
     %% really is created there
     ?line UncommonName = "uncommon.fil",
     ?line {ok,Fd} = ?PRIM_FILE:open(UncommonName, [read, write]),
     ?line ok = ?PRIM_FILE:close(Fd),
-    ?line {ok,NewDirFiles} = ?PRIM_FILE_call(list_dir, Handle, [".", "utag"]),
+    ?line {ok,NewDirFiles} = ?PRIM_FILE_call(list_dir, Handle, ["."]),
     ?line true = lists:member(UncommonName,NewDirFiles),
 
     %% Delete the directory and return to the old current directory
     %% and check that the created file isn't there (too!)
     ?line expect({error, einval}, {error, eacces}, {error, eexist}, 
-		 ?PRIM_FILE_call(del_dir, Handle, [NewDir, "utag"])),
-    ?line ?PRIM_FILE_call(delete, Handle, [UncommonName, "utag"]),
-    ?line {ok,[]} = ?PRIM_FILE_call(list_dir, Handle, [".", "utag"]),
-    ?line ok = ?PRIM_FILE_call(set_cwd, Handle, [Dir1, "utag"]),
+		 ?PRIM_FILE_call(del_dir, Handle, [NewDir])),
+    ?line ?PRIM_FILE_call(delete, Handle, [UncommonName]),
+    ?line {ok,[]} = ?PRIM_FILE_call(list_dir, Handle, ["."]),
+    ?line ok = ?PRIM_FILE_call(set_cwd, Handle, [Dir1]),
     ?line io:format("cd back to ~s",[Dir1]),
-    ?line ok = ?PRIM_FILE_call(del_dir, Handle, [NewDir, "utag"]),
-    ?line {error, enoent} = ?PRIM_FILE_call(set_cwd, Handle, [NewDir, "utag"]),
-    ?line ok = ?PRIM_FILE_call(set_cwd, Handle, [Dir1, "utag"]),
+    ?line ok = ?PRIM_FILE_call(del_dir, Handle, [NewDir]),
+    ?line {error, enoent} = ?PRIM_FILE_call(set_cwd, Handle, [NewDir]),
+    ?line ok = ?PRIM_FILE_call(set_cwd, Handle, [Dir1]),
     ?line io:format("cd back to ~s",[Dir1]),
-    ?line {ok,OldDirFiles} = ?PRIM_FILE_call(list_dir, Handle, [".", "utag"]),
+    ?line {ok,OldDirFiles} = ?PRIM_FILE_call(list_dir, Handle, ["."]),
     ?line false = lists:member(UncommonName,OldDirFiles),
 
     %% Try doing some bad things
     ?line {error, badarg} = 
-	?PRIM_FILE_call(set_cwd, Handle, [{foo,bar}, "utag"]),
+	?PRIM_FILE_call(set_cwd, Handle, [{foo,bar}]),
     ?line {error, enoent} = 
-	?PRIM_FILE_call(set_cwd, Handle, ["", "utag"]),
+	?PRIM_FILE_call(set_cwd, Handle, [""]),
     ?line {error, enoent} = 
-	?PRIM_FILE_call(set_cwd, Handle, [".......a......", "utag"]),
+	?PRIM_FILE_call(set_cwd, Handle, [".......a......"]),
     ?line {ok,BaseDir} = 
 	?PRIM_FILE_call(get_cwd, Handle, []), %% Still there?
 
@@ -405,10 +405,10 @@ cur_dir_1(Config, Handle) ->
     ?line case os:type() of
 	      {unix, _} ->
 		  ?line {error, enotsup} = 
-		      ?PRIM_FILE_call(get_cwd, Handle, ["d:", "utag"]);
+		      ?PRIM_FILE_call(get_cwd, Handle, ["d:"]);
 	      vxworks ->
 		  ?line {error, enotsup} = 
-		      ?PRIM_FILE_call(get_cwd, Handle,  ["d:", "utag"]);
+		      ?PRIM_FILE_call(get_cwd, Handle,  ["d:"]);
 	      {win32, _} ->
 		  win_cur_dir_1(Config, Handle)
 	  end,
@@ -422,7 +422,7 @@ win_cur_dir_1(_Config, Handle) ->
     %% and try to get current directory for that drive.
 
     ?line [Drive, $:|_] = BaseDir,
-    ?line {ok, BaseDir} = ?PRIM_FILE_call(get_cwd, Handle, [[Drive, $:], "utag"]),
+    ?line {ok, BaseDir} = ?PRIM_FILE_call(get_cwd, Handle, [[Drive, $:]]),
     io:format("BaseDir = ~s\n", [BaseDir]),
 
     %% Unfortunately, there is no way to move away from the
@@ -1027,7 +1027,7 @@ file_write_file_info(Config, Handle, Suffix) ->
     ?line ok = ?PRIM_FILE:write_file(Name, "hello"),
     ?line Time = {{1997, 01, 02}, {12, 35, 42}},
     ?line Info = #file_info{mode=8#400, atime=Time, mtime=Time, ctime=Time},
-    ?line ok = ?PRIM_FILE_call(write_file_info, Handle, [Name, Info, "utag"]),
+    ?line ok = ?PRIM_FILE_call(write_file_info, Handle, [Name, Info]),
 
     %% Read back the times.
 
@@ -1050,12 +1050,12 @@ file_write_file_info(Config, Handle, Suffix) ->
     %% Make the file writable again.
 
     ?line ?PRIM_FILE_call(write_file_info, Handle, 
-			  [Name, #file_info{mode=8#600}, "utag"]),
+			  [Name, #file_info{mode=8#600}]),
     ?line ok = ?PRIM_FILE:write_file(Name, "hello again"),
 
     %% And unwritable.
     ?line ?PRIM_FILE_call(write_file_info, Handle, 
-			  [Name, #file_info{mode=8#400}, "utag"]),
+			  [Name, #file_info{mode=8#400}]),
     ?line {error, eacces} = ?PRIM_FILE:write_file(Name, "hello again"),
 
     %% Write the times again.
@@ -1063,7 +1063,7 @@ file_write_file_info(Config, Handle, Suffix) ->
 
     ?line NewTime = {{1997, 02, 15}, {13, 18, 20}},
     ?line NewInfo = #file_info{atime=NewTime, mtime=NewTime, ctime=NewTime},
-    ?line ok = ?PRIM_FILE_call(write_file_info, Handle, [Name, NewInfo, "utag"]),
+    ?line ok = ?PRIM_FILE_call(write_file_info, Handle, [Name, NewInfo]),
     ?line {ok, ActualInfo2} = 
 	?PRIM_FILE_call(read_file_info, Handle, [Name]),
     ?line #file_info{atime=NewActAtime, mtime=NewTime,
@@ -1081,7 +1081,7 @@ file_write_file_info(Config, Handle, Suffix) ->
     %% Make the file writeable again, so that we can remove the
     %% test suites ... :-)
     ?line ?PRIM_FILE_call(write_file_info, Handle, 
-			  [Name, #file_info{mode=8#600}, "utag"]),
+			  [Name, #file_info{mode=8#600}]),
     ?line test_server:timetrap_cancel(Dog),
     ok.
 
@@ -1390,11 +1390,11 @@ delete(Config, Handle, Suffix) ->
     %% Check that the file is readable
     ?line {ok, Fd2} = ?PRIM_FILE:open(Name, [read]),
     ?line ok = ?PRIM_FILE:close(Fd2),
-    ?line ok = ?PRIM_FILE_call(delete, Handle, [Name, "utag"]),
+    ?line ok = ?PRIM_FILE_call(delete, Handle, [Name]),
     %% Check that the file is not readable anymore
     ?line {error, _} = ?PRIM_FILE:open(Name, [read]),
     %% Try deleting a nonexistent file
-    ?line {error, enoent} = ?PRIM_FILE_call(delete, Handle, [Name, "utag"]),
+    ?line {error, enoent} = ?PRIM_FILE_call(delete, Handle, [Name]),
     ?line test_server:timetrap_cancel(Dog),
     ok.
 
@@ -1895,14 +1895,14 @@ make_link(Config, Handle, Suffix) ->
     ?line NewDir = filename:join(RootDir, 
 				 atom_to_list(?MODULE)
 				 ++"_make_link"++Suffix),
-    ?line ok = ?PRIM_FILE_call(make_dir, Handle, [NewDir, "utag"]),
+    ?line ok = ?PRIM_FILE_call(make_dir, Handle, [NewDir]),
     
     ?line Name = filename:join(NewDir, "a_file"),
     ?line ok = ?PRIM_FILE:write_file(Name, "some contents\n"),
     
     ?line Alias = filename:join(NewDir, "an_alias"),
     ?line Result = 
-	case ?PRIM_FILE_call(make_link, Handle, [Name, Alias, "utag"]) of
+	case ?PRIM_FILE_call(make_link, Handle, [Name, Alias]) of
 	    {error, enotsup} ->
 		{skipped, "Links not supported on this platform"};
 	    ok ->
@@ -1913,12 +1913,12 @@ make_link(Config, Handle, Suffix) ->
 		%% since they are not used on symbolic links.
 		
 		?line {ok, Info} = 
-		    ?PRIM_FILE_call(read_link_info, Handle, [Name, "utag"]),
+		    ?PRIM_FILE_call(read_link_info, Handle, [Name]),
 		?line {ok, Info} = 
-		    ?PRIM_FILE_call(read_link_info, Handle, [Alias, "utag"]),
+		    ?PRIM_FILE_call(read_link_info, Handle, [Alias]),
 		?line #file_info{links = 2, type = regular} = Info,
 		?line {error, eexist} = 
-		    ?PRIM_FILE_call(make_link, Handle, [Name, Alias, "utag"]),
+		    ?PRIM_FILE_call(make_link, Handle, [Name, Alias]),
 		ok
 	end,
     
@@ -1956,30 +1956,30 @@ symlinks(Config, Handle, Suffix) ->
     ?line NewDir = filename:join(RootDir, 
 				 atom_to_list(?MODULE)
 				 ++"_make_symlink"++Suffix),
-    ?line ok = ?PRIM_FILE_call(make_dir, Handle, [NewDir, "utag"]),
+    ?line ok = ?PRIM_FILE_call(make_dir, Handle, [NewDir]),
     
     ?line Name = filename:join(NewDir, "a_plain_file"),
     ?line ok = ?PRIM_FILE:write_file(Name, "some stupid content\n"),
     
     ?line Alias = filename:join(NewDir, "a_symlink_alias"),
     ?line Result = 
-	case ?PRIM_FILE_call(make_symlink, Handle, [Name, Alias, "utag"]) of
+	case ?PRIM_FILE_call(make_symlink, Handle, [Name, Alias]) of
 	    {error, enotsup} ->
 		{skipped, "Links not supported on this platform"};
 	    ok ->
 		?line {ok, Info1} = 
-		    ?PRIM_FILE_call(read_file_info, Handle, [Name, "utag"]),
+		    ?PRIM_FILE_call(read_file_info, Handle, [Name]),
 		?line {ok, Info1} = 
-		    ?PRIM_FILE_call(read_file_info, Handle, [Alias, "utag"]),
+		    ?PRIM_FILE_call(read_file_info, Handle, [Alias]),
 		?line {ok, Info1} = 
-		    ?PRIM_FILE_call(read_link_info, Handle, [Name, "utag"]),
+		    ?PRIM_FILE_call(read_link_info, Handle, [Name]),
 		?line #file_info{links = 1, type = regular} = Info1,
 		
 		?line {ok, Info2} = 
-		    ?PRIM_FILE_call(read_link_info, Handle, [Alias, "utag"]),
+		    ?PRIM_FILE_call(read_link_info, Handle, [Alias]),
 		?line #file_info{links=1, type=symlink} = Info2,
 		?line {ok, Name} = 
-		    ?PRIM_FILE_call(read_link, Handle, [Alias, "utag"]),
+		    ?PRIM_FILE_call(read_link, Handle, [Alias]),
 		ok
 	end,
     
@@ -2003,7 +2003,7 @@ list_dir_limit(Config) when is_list(Config) ->
     ?line NewDir = filename:join(RootDir,
 				 atom_to_list(?MODULE)++"_list_dir_limit"),
     ?line {ok, Handle1} = ?PRIM_FILE:start(),
-    ?line ok = ?PRIM_FILE_call(make_dir, Handle1, [NewDir, "utag"]),
+    ?line ok = ?PRIM_FILE_call(make_dir, Handle1, [NewDir]),
     Ref = erlang:start_timer(MaxTime*1000, self(), []),
     ?line Result = list_dir_limit_loop(NewDir, Handle1, Ref, MaxNumber, 0),
     ?line Time = case erlang:cancel_timer(Ref) of
@@ -2054,7 +2054,7 @@ list_dir_limit_loop(Dir, Handle, Ref, N, Cnt) ->
     end.
 
 list_dir_check(Dir, Handle, Cnt) ->
-    case ?PRIM_FILE:list_dir(Handle, Dir, "utag") of
+    case ?PRIM_FILE:list_dir(Handle, Dir) of
 	{ok, ListDir} ->
 	    case length(ListDir) of
 		Cnt ->