[PATCH v2] tracing: Replace deprecated strncpy() with strscpy() for stack_trace_filter_buf

[Devaansh Kumar]

strncpy() is deprecated for NUL-terminated destination buffers and must
be replaced by strscpy().

See issue: https://github.com/KSPP/linux/issues/90

Signed-off-by: Devaansh Kumar <devaanshk840@xxxxxxxxx>
---
 kernel/trace/trace_stack.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 5a48dba912ea..982b1c88fce2 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -3,6 +3,7 @@
  * Copyright (C) 2008 Steven Rostedt <srostedt@xxxxxxxxxx>
  *
  */
+#include <linux/string.h>
 #include <linux/sched/task_stack.h>
 #include <linux/stacktrace.h>
 #include <linux/security.h>
@@ -543,8 +544,10 @@ static __init int enable_stacktrace(char *str)
 {
 	int len;
 
-	if ((len = str_has_prefix(str, "_filter=")))
-		strncpy(stack_trace_filter_buf, str + len, COMMAND_LINE_SIZE);
+	len = str_has_prefix(str, "_filter=");
+
+	if (len)
+		strscpy(stack_trace_filter_buf, str + len, sizeof(stack_trace_filter_buf));
 
 	stack_tracer_enabled = 1;
 	return 1;
-- 
2.47.1