Re: [PATCH v6] tracing: Preserve repeated boot-time tracing parameters

[Steven Rostedt]

On Mon, 30 Mar 2026 10:43:22 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
> index 9928da636c9d..7754a8adb58a 100644
> --- a/kernel/trace/trace_events.c
> +++ b/kernel/trace/trace_events.c
> @@ -3677,20 +3677,24 @@ static struct boot_triggers {
>  } bootup_triggers[MAX_BOOT_TRIGGERS];
>  
>  static char bootup_trigger_buf[COMMAND_LINE_SIZE];
> +static int boot_trigger_buf_len;
>  static int nr_boot_triggers;
>  
>  static __init int setup_trace_triggers(char *str)
>  {
>  	char *trigger;
>  	char *buf;
> +	int len = boot_trigger_buf_len;
>  	int i;
>  
> -	strscpy(bootup_trigger_buf, str, COMMAND_LINE_SIZE);
> +	strscpy(bootup_trigger_buf + len , str, COMMAND_LINE_SIZE - len);
>  	trace_set_ring_buffer_expanded(NULL);
>  	disable_tracing_selftest("running event triggers");
>  
> -	buf = bootup_trigger_buf;
> -	for (i = 0; i < MAX_BOOT_TRIGGERS; i++) {
> +	buf = bootup_trigger_buf + len;
> +	boot_trigger_buf_len += strlen(buf);

The above needs to skip the '\0' too:

	boot_trigger_buf_len += strlen(buf) + 1;


> +
> +	for (i = nr_boot_triggers; i < MAX_BOOT_TRIGGERS; i++) {
>  		trigger = strsep(&buf, ",");
>  		if (!trigger)
>  			break;