[PATCH 1/4] tracing: probes: Use __free() for trace_probe_log

["Masami Hiramatsu (Google)" <mhiramat@kernel.org>]

From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Use __free() for trace_probe_log_clear() to cleanup error log interface.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
 kernel/trace/trace_eprobe.c |    5 ++---
 kernel/trace/trace_probe.c  |    3 ++-
 kernel/trace/trace_probe.h  |    4 +++-
 kernel/trace/trace_uprobe.c |    6 ++----
 4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index a1d402124836..aaba765d54cf 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -874,6 +874,7 @@ static int __trace_eprobe_create(int argc, const char *argv[])
 	 * Fetch args (no space):
 	 *  <name>=$<field>[:TYPE]
 	 */
+	const char *trlog __free(trace_probe_log_clear) = NULL;
 	const char *event = NULL, *group = EPROBE_EVENT_SYSTEM;
 	const char *sys_event = NULL, *sys_name = NULL;
 	struct trace_event_call *event_call;
@@ -887,7 +888,7 @@ static int __trace_eprobe_create(int argc, const char *argv[])
 	if (argc < 2 || argv[0][0] != 'e')
 		return -ECANCELED;
 
-	trace_probe_log_init("event_probe", argc, argv);
+	trlog = trace_probe_log_init("event_probe", argc, argv);
 
 	event = strchr(&argv[0][1], ':');
 	if (event) {
@@ -987,7 +988,6 @@ static int __trace_eprobe_create(int argc, const char *argv[])
 			goto error;
 		}
 	}
-	trace_probe_log_clear();
 	return ret;
 
 mem_error:
@@ -996,7 +996,6 @@ static int __trace_eprobe_create(int argc, const char *argv[])
 parse_error:
 	ret = -EINVAL;
 error:
-	trace_probe_log_clear();
 	trace_event_probe_cleanup(ep);
 	return ret;
 }
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 5cbdc423afeb..5b92376a58fc 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -156,7 +156,7 @@ static const struct fetch_type *find_fetch_type(const char *type, unsigned long
 static struct trace_probe_log trace_probe_log;
 extern struct mutex dyn_event_ops_mutex;
 
-void trace_probe_log_init(const char *subsystem, int argc, const char **argv)
+const char *trace_probe_log_init(const char *subsystem, int argc, const char **argv)
 {
 	lockdep_assert_held(&dyn_event_ops_mutex);
 
@@ -164,6 +164,7 @@ void trace_probe_log_init(const char *subsystem, int argc, const char **argv)
 	trace_probe_log.argc = argc;
 	trace_probe_log.argv = argv;
 	trace_probe_log.index = 0;
+	return subsystem;
 }
 
 void trace_probe_log_clear(void)
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 842383fbc03b..76bf2dee8071 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -573,11 +573,13 @@ struct trace_probe_log {
 	int		index;
 };
 
-void trace_probe_log_init(const char *subsystem, int argc, const char **argv);
+const char *trace_probe_log_init(const char *subsystem, int argc, const char **argv);
 void trace_probe_log_set_index(int index);
 void trace_probe_log_clear(void);
 void __trace_probe_log_err(int offset, int err);
 
+DEFINE_FREE(trace_probe_log_clear, const char *, if (_T) trace_probe_log_clear())
+
 #define trace_probe_log_err(offs, err)	\
 	__trace_probe_log_err(offs, TP_ERR_##err)
 
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 8b0bcc0d8f41..722316b3dc16 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -539,6 +539,7 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
  */
 static int __trace_uprobe_create(int argc, const char **argv)
 {
+	const char *trlog __free(trace_probe_log_clear) = NULL;
 	const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
 	char *arg, *filename, *rctr, *rctr_end, *tmp;
 	unsigned long offset, ref_ctr_offset;
@@ -565,7 +566,7 @@ static int __trace_uprobe_create(int argc, const char **argv)
 	if (argc < 2)
 		return -ECANCELED;
 
-	trace_probe_log_init("trace_uprobe", argc, argv);
+	trlog = trace_probe_log_init("trace_uprobe", argc, argv);
 
 	if (argc - 2 > MAX_TRACE_ARGS) {
 		trace_probe_log_set_index(2);
@@ -597,7 +598,6 @@ static int __trace_uprobe_create(int argc, const char **argv)
 	if (ret) {
 		trace_probe_log_err(0, FILE_NOT_FOUND);
 		kfree(filename);
-		trace_probe_log_clear();
 		return ret;
 	}
 	if (!d_is_reg(path.dentry)) {
@@ -728,14 +728,12 @@ static int __trace_uprobe_create(int argc, const char **argv)
 error:
 	free_trace_uprobe(tu);
 out:
-	trace_probe_log_clear();
 	return ret;
 
 fail_mem:
 	ret = -ENOMEM;
 
 fail_address_parse:
-	trace_probe_log_clear();
 	path_put(&path);
 	kfree(filename);