Re: [PATCH] tracing: Replace strncpy() with strscpy() when copying comm

[Justin Stitt]

Hi,

On Wed, Jul 31, 2024 at 03:50:58PM GMT, Jinjie Ruan wrote:
> Replace the depreciated[1] strncpy() calls with strscpy()
> when copying comm.
> 
> Link: https://github.com/KSPP/linux/issues/90 [1]
> Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>

Reviewed-by: Justin Stitt <justinstitt@xxxxxxxxxx>

> ---
>  kernel/trace/trace.c              | 2 +-
>  kernel/trace/trace_events_hist.c  | 4 ++--
>  kernel/trace/trace_sched_switch.c | 2 +-
>  3 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index d0af984a5337..73cfdc704eec 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -1907,7 +1907,7 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
>  	max_data->critical_start = data->critical_start;
>  	max_data->critical_end = data->critical_end;
>  
> -	strncpy(max_data->comm, tsk->comm, TASK_COMM_LEN);
> +	strscpy(max_data->comm, tsk->comm);
>  	max_data->pid = tsk->pid;
>  	/*
>  	 * If tsk == current, then use current_uid(), as that does not use
> diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> index 6ece1308d36a..4ee0e64719fa 100644
> --- a/kernel/trace/trace_events_hist.c
> +++ b/kernel/trace/trace_events_hist.c
> @@ -1599,7 +1599,7 @@ static inline void save_comm(char *comm, struct task_struct *task)
>  		return;
>  	}
>  
> -	strncpy(comm, task->comm, TASK_COMM_LEN);
> +	strscpy(comm, task->comm);
>  }
>  
>  static void hist_elt_data_free(struct hist_elt_data *elt_data)
> @@ -3405,7 +3405,7 @@ static bool cond_snapshot_update(struct trace_array *tr, void *cond_data)
>  	elt_data = context->elt->private_data;
>  	track_elt_data = track_data->elt.private_data;
>  	if (elt_data->comm)
> -		strncpy(track_elt_data->comm, elt_data->comm, TASK_COMM_LEN);
> +		strscpy(track_elt_data->comm, elt_data->comm);
>  
>  	track_data->updated = true;
>  
> diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
> index 8a407adb0e1c..573b5d8e8a28 100644
> --- a/kernel/trace/trace_sched_switch.c
> +++ b/kernel/trace/trace_sched_switch.c
> @@ -187,7 +187,7 @@ static inline char *get_saved_cmdlines(int idx)
>  
>  static inline void set_cmdline(int idx, const char *cmdline)
>  {
> -	strncpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN);
> +	strscpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN);
>  }
>  
>  static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s)
> -- 
> 2.34.1
> 

Thanks
Justin