[for-next][PATCH 1/4] tracing/histograms: Simplify last_cmd_set()

[Steven Rostedt]

From: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>

Turn a kzalloc()+strcpy()+strncat() into an equivalent and less verbose
kasprintf().

Link: https://lore.kernel.org/linux-trace-kernel/30b6fb04dadc10a03cc1ad08f5d8a93ef623a167.1697899346.git.christophe.jaillet@xxxxxxxxxx

Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Reviewed-by: Mukesh ojha <quic_mojha@xxxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
 kernel/trace/trace_events_hist.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index d06938ae0717..1abc07fba1b9 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -774,23 +774,16 @@ static void last_cmd_set(struct trace_event_file *file, char *str)
 {
 	const char *system = NULL, *name = NULL;
 	struct trace_event_call *call;
-	int len;
 
 	if (!str)
 		return;
 
-	/* sizeof() contains the nul byte */
-	len = sizeof(HIST_PREFIX) + strlen(str);
 	kfree(last_cmd);
-	last_cmd = kzalloc(len, GFP_KERNEL);
+
+	last_cmd = kasprintf(GFP_KERNEL, HIST_PREFIX "%s", str);
 	if (!last_cmd)
 		return;
 
-	strcpy(last_cmd, HIST_PREFIX);
-	/* Again, sizeof() contains the nul byte */
-	len -= sizeof(HIST_PREFIX);
-	strncat(last_cmd, str, len);
-
 	if (file) {
 		call = file->event_call;
 		system = call->class->system;
-- 
2.42.0