Re: [PATCH v4 06/12] tracing: Change trace_boot to use synth_event interface

[Tom Zanussi]

Hi Steve,

It looks like you missed this patch when you pulled the other ones into
 for-next.

Tom

On Wed, 2020-01-29 at 12:59 -0600, Tom Zanussi wrote:
> Have trace_boot_add_synth_event() use the synth_event interface.
> 
> Also, rename synth_event_run_cmd() to synth_event_run_command() now
> that trace_boot's version is gone.
> 
> Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx>
> Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> ---
>  kernel/trace/trace_boot.c        | 31 ++++++++++++----------------
> ---
>  kernel/trace/trace_events_hist.c |  9 ++-------
>  2 files changed, 14 insertions(+), 26 deletions(-)
> 
> diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
> index 2f616cd926b0..8f40de349db1 100644
> --- a/kernel/trace/trace_boot.c
> +++ b/kernel/trace/trace_boot.c
> @@ -133,38 +133,31 @@ trace_boot_add_kprobe_event(struct xbc_node
> *node, const char *event)
>  #endif
>  
>  #ifdef CONFIG_HIST_TRIGGERS
> -extern int synth_event_run_command(const char *command);
> -
>  static int __init
>  trace_boot_add_synth_event(struct xbc_node *node, const char *event)
>  {
> +	struct dynevent_cmd cmd;
>  	struct xbc_node *anode;
> -	char buf[MAX_BUF_LEN], *q;
> +	char buf[MAX_BUF_LEN];
>  	const char *p;
> -	int len, delta, ret;
> +	int ret;
>  
> -	len = ARRAY_SIZE(buf);
> -	delta = snprintf(buf, len, "%s", event);
> -	if (delta >= len) {
> -		pr_err("Event name is too long: %s\n", event);
> -		return -E2BIG;
> -	}
> -	len -= delta; q = buf + delta;
> +	synth_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
> +
> +	ret = synth_event_gen_cmd_start(&cmd, event, NULL);
> +	if (ret)
> +		return ret;
>  
>  	xbc_node_for_each_array_value(node, "fields", anode, p) {
> -		delta = snprintf(q, len, " %s;", p);
> -		if (delta >= len) {
> -			pr_err("fields string is too long: %s\n",
> p);
> -			return -E2BIG;
> -		}
> -		len -= delta; q += delta;
> +		ret = synth_event_add_field_str(&cmd, p);
> +		if (ret)
> +			return ret;
>  	}
>  
> -	ret = synth_event_run_command(buf);
> +	ret = synth_event_gen_cmd_end(&cmd);
>  	if (ret < 0)
>  		pr_err("Failed to add synthetic event: %s\n", buf);
>  
> -
>  	return ret;
>  }
>  #else
> diff --git a/kernel/trace/trace_events_hist.c
> b/kernel/trace/trace_events_hist.c
> index 5a910bb193e9..22cd7ecdfb92 100644
> --- a/kernel/trace/trace_events_hist.c
> +++ b/kernel/trace/trace_events_hist.c
> @@ -1752,12 +1752,7 @@ static int create_or_delete_synth_event(int
> argc, char **argv)
>  	return ret == -ECANCELED ? -EINVAL : ret;
>  }
>  
> -int synth_event_run_command(const char *command)
> -{
> -	return trace_run_command(command,
> create_or_delete_synth_event);
> -}
> -
> -static int synth_event_run_cmd(struct dynevent_cmd *cmd)
> +static int synth_event_run_command(struct dynevent_cmd *cmd)
>  {
>  	struct synth_event *se;
>  	int ret;
> @@ -1787,7 +1782,7 @@ static int synth_event_run_cmd(struct
> dynevent_cmd *cmd)
>  void synth_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int
> maxlen)
>  {
>  	dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_SYNTH,
> -			  synth_event_run_cmd);
> +			  synth_event_run_command);
>  }
>  EXPORT_SYMBOL_GPL(synth_event_cmd_init);
>