[PATCH] trace-cmd record: Have --module affect function filters listed after it

[Steven Rostedt]

When the --module option is used, have it affect the remaining filters that
come after it. Keep the old behavior that no other filter is needed if only
filtering all modules in function filter.

    '--module snd'  is equivalent to  '-l :mod:snd'

    '--module snd -l "*jack*"' is equivalent to '-l "*jack*:mod:snd"'

    '--module snd -n "*"' is equivalent to '-n :mod:snd'

Cc: Deepak Das <deepak_das@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
 Documentation/trace-cmd-record.1.txt |  9 ++++++-
 trace-local.h                        |  3 ++-
 trace-record.c                       | 52 +++++++++++++++++++++++-------------
 3 files changed, 44 insertions(+), 20 deletions(-)

diff --git a/Documentation/trace-cmd-record.1.txt b/Documentation/trace-cmd-record.1.txt
index c1228bd..ca3cbfe 100644
--- a/Documentation/trace-cmd-record.1.txt
+++ b/Documentation/trace-cmd-record.1.txt
@@ -274,8 +274,15 @@ OPTIONS
 
 *--module* 'module'::
     Filter a module's name in function tracing. It is equivalent to adding
+    ':mod:module' after all other functions being filtered. If no other function
+    filter is listed, then all modules functions will be filtered in the filter.
+
+    '--module snd'  is equivalent to  '-l :mod:snd'
+
+    '--module snd -l "*jack*"' is equivalent to '-l "*jack*:mod:snd"'
+
+    '--module snd -n "*"' is equivalent to '-n :mod:snd'
 
-    *-l :mod:module*
 
 *--profile*::
     With the *--profile* option, "trace-cmd" will enable tracing that can
diff --git a/trace-local.h b/trace-local.h
index ee2f0c9..157b2c6 100644
--- a/trace-local.h
+++ b/trace-local.h
@@ -147,6 +147,7 @@ char *strstrip(char *str);
 struct func_list {
 	struct func_list *next;
 	const char *func;
+	const char *mod;
 };
 
 struct buffer_instance {
@@ -161,9 +162,9 @@ struct buffer_instance {
 	struct event_list	*sched_wakeup_new_event;
 
 	const char		*plugin;
+	char			*filter_mod;
 	struct func_list	*filter_funcs;
 	struct func_list	*notrace_funcs;
-	struct func_list	*filter_mods;
 
 	const char		*clock;
 
diff --git a/trace-record.c b/trace-record.c
index 9623787..020a373 100644
--- a/trace-record.c
+++ b/trace-record.c
@@ -3100,9 +3100,10 @@ static void record_data(char *date2ts, int flags)
 }
 
 static int write_func_file(struct buffer_instance *instance,
-			    const char *file, const char *prefix, struct func_list **list)
+			    const char *file, struct func_list **list)
 {
 	struct func_list *item;
+	const char *prefix = ":mod:";
 	char *path;
 	int fd;
 	int ret = -1;
@@ -3119,14 +3120,17 @@ static int write_func_file(struct buffer_instance *instance,
 	while (*list) {
 		item = *list;
 		*list = item->next;
-		if (prefix) {
+		ret = write(fd, item->func, strlen(item->func));
+		if (ret < 0)
+			goto failed;
+		if (item->mod) {
 			ret = write(fd, prefix, strlen(prefix));
 			if (ret < 0)
 				goto failed;
+			ret = write(fd, item->mod, strlen(item->mod));
+			if (ret < 0)
+				goto failed;
 		}
-		ret = write(fd, item->func, strlen(item->func));
-		if (ret < 0)
-			goto failed;
 		ret = write(fd, " ", 1);
 		if (ret < 0)
 			goto failed;
@@ -3180,32 +3184,29 @@ static void set_funcs(struct buffer_instance *instance)
 	int set_notrace = 0;
 	int ret;
 
-	ret = write_func_file(instance, "set_ftrace_filter", NULL, &instance->filter_funcs);
+	ret = write_func_file(instance, "set_ftrace_filter", &instance->filter_funcs);
 	if (ret < 0)
 		die("set_ftrace_filter does not exist. Can not filter functions");
-	ret = write_func_file(instance, "set_ftrace_filter", ":mod:", &instance->filter_mods);
-	if (ret < 0)
-		die("set_ftrace_filter does not exist. Can not filter modules");
 
 	/* graph tracing currently only works for top instance */
 	if (is_top_instance(instance)) {
-		ret = write_func_file(instance, "set_graph_function", NULL, &graph_funcs);
+		ret = write_func_file(instance, "set_graph_function", &graph_funcs);
 		if (ret < 0)
 			die("set_graph_function does not exist.");
 		if (instance->plugin && strcmp(instance->plugin, "function_graph") == 0) {
-			ret = write_func_file(instance, "set_graph_notrace", NULL,
+			ret = write_func_file(instance, "set_graph_notrace",
 					      &instance->notrace_funcs);
 			if (!ret)
 				set_notrace = 1;
 		}
 		if (!set_notrace) {
-			ret = write_func_file(instance, "set_ftrace_notrace", NULL,
+			ret = write_func_file(instance, "set_ftrace_notrace",
 					      &instance->notrace_funcs);
 			if (ret < 0)
 				die("set_ftrace_notrace does not exist. Can not filter functions");
 		}
 	} else
-		write_func_file(instance, "set_ftrace_notrace", NULL, &instance->notrace_funcs);
+		write_func_file(instance, "set_ftrace_notrace", &instance->notrace_funcs);
 
 	/* make sure we are filtering functions */
 	if (func_stack && is_top_instance(instance)) {
@@ -3216,7 +3217,7 @@ static void set_funcs(struct buffer_instance *instance)
 	clear_function_filters = 1;
 }
 
-static void add_func(struct func_list **list, const char *func)
+static void add_func(struct func_list **list, const char *mod, const char *func)
 {
 	struct func_list *item;
 
@@ -3224,6 +3225,7 @@ static void add_func(struct func_list **list, const char *func)
 	if (!item)
 		die("Failed to allocate function descriptor");
 	item->func = func;
+	item->mod = mod;
 	item->next = *list;
 	*list = item;
 }
@@ -4205,6 +4207,7 @@ void trace_record (int argc, char **argv)
 	int profile = 0;
 	int global = 0;
 	int start = 0;
+	int filtered = 0;
 	int run_command = 0;
 	int neg_event = 0;
 	int date = 0;
@@ -4488,13 +4491,18 @@ void trace_record (int argc, char **argv)
 			neg_event = 1;
 			break;
 		case 'l':
-			add_func(&instance->filter_funcs, optarg);
+			add_func(&instance->filter_funcs,
+				 instance->filter_mod, optarg);
+			filtered = 1;
 			break;
 		case 'n':
-			add_func(&instance->notrace_funcs, optarg);
+			add_func(&instance->notrace_funcs,
+				 instance->filter_mod, optarg);
+			filtered = 1;
 			break;
 		case 'g':
-			add_func(&graph_funcs, optarg);
+			add_func(&graph_funcs, instance->filter_mod, optarg);
+			filtered = 1;
 			break;
 		case 'p':
 			if (instance->plugin)
@@ -4657,7 +4665,11 @@ void trace_record (int argc, char **argv)
 			debug = 1;
 			break;
 		case OPT_module:
-			add_func(&instance->filter_mods, optarg);
+			if (instance->filter_mod)
+				add_func(&instance->filter_funcs,
+					 instance->filter_mod, "*");
+			instance->filter_mod = optarg;
+			filtered = 0;
 			break;
 		case OPT_quiet:
 		case 'q':
@@ -4668,6 +4680,10 @@ void trace_record (int argc, char **argv)
 		}
 	}
 
+	if (!filtered)
+		add_func(&instance->filter_funcs,
+			 instance->filter_mod, "*");
+
 	if (do_ptrace && !filter_task && (filter_pid < 0))
 		die(" -c can only be used with -F (or -P with event-fork support)");
 	if (do_child && !filter_task &&! filter_pid)
-- 
2.9.3