Re: [PATCH v3 05/23] trace-cmd: Add new local function to check if a trace clock is supported

From: Steven Rostedt <rostedt@goodmis.org>
To: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Cc: linux-trace-devel@vger.kernel.org
Subject: Re: [PATCH v3 05/23] trace-cmd: Add new local function to check if a trace clock is supported
Date: Wed, 24 Mar 2021 13:49:58 -0400	[thread overview]
Message-ID: <20210324134958.68c77b49@gandalf.local.home> (raw)
In-Reply-To: <20210324130418.436206-6-tz.stoyanov@gmail.com>

On Wed, 24 Mar 2021 15:04:00 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:

> diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
> index 635897e1..5f7f5b3d 100644
> --- a/tracecmd/trace-record.c
> +++ b/tracecmd/trace-record.c
> @@ -5683,6 +5683,33 @@ check_instance_die(struct buffer_instance *instance, char *param)
>  		    tracefs_instance_get_name(instance->tracefs), param);
>  }
>  
> +static bool clock_is_supported(struct tracefs_instance *instance, char *clock)
> +{
> +	char *all_clocks = NULL;
> +	char *ret = NULL;
> +
> +	all_clocks  = tracefs_instance_file_read(instance, "trace_clock", NULL);
> +	if (!all_clocks)
> +		return false;
> +
> +	ret = strstr(all_clocks, clock);
> +	if (ret && (ret == all_clocks || ret[-1] == ' ' || ret[-1] == '[')) {
> +		switch (ret[strlen(clock)]) {
> +		case ' ':
> +		case '\0':

Testing this, I found we also need:

		case '\n':

-- Steve

> +		case ']':
> +			break;
> +		default:
> +			ret = NULL;
> +		}
> +	} else {
> +		ret = NULL;
> +	}
> +	free(all_clocks);
> +
> +	return ret != NULL;
> +}
> +
>  static void parse_record_options(int argc,
>  				 char **argv,
>  				 enum trace_cmd curr_cmd,
> -- 