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

[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@gmail.com>
---
 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@redhat.com>
  *
  */
+#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

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

[Steven Rostedt]

On Fri,  4 Apr 2025 19:01:03 +0530
Devaansh Kumar <devaanshk840@gmail.com> wrote:

> 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@gmail.com>
> ---
>  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@redhat.com>
>   *
>   */
> +#include <linux/string.h>
>  #include <linux/sched/task_stack.h>
>  #include <linux/stacktrace.h>
>  #include <linux/security.h>

Is string.h really needed here? And if so, please keep the upside-down
x-mas tree format:

#include <linux/sched/task_stack.h>
#include <linux/stacktrace.h>
#include <linux/security.h>
#include <linux/kallsyms.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
#include <linux/module.h>
#include <linux/sysctl.h>
#include <linux/init.h>

The includes *are* ordered.

-- Steve

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

[Devaansh Kumar]

On Fri, 4 Apr 2025 at 19:15, Steven Rostedt <rostedt@goodmis.org> wrote:
>
> Is string.h really needed here? And if so, please keep the upside-down
> x-mas tree format:

My bad. It was auto added by my IDE. It is not needed.