[lttng-dev] [PATCH lttng-tool] Fix: parse_prob_opts return the actual success of the function

[David Goulet]

Merged

On 27 Aug (15:46:57), Jonathan Rajotte Julien wrote:
> This bug have been triggered by the mi merging and the use of a
> command_ret in enable_events functions. Previously, enable_events was
> reusing the ret variable for another operation and always replacing ret.
> Parse_probe_event returned the last output of sscanf which represent
> the number of match and not the success of the operation.
> 
> Fixes #830
> 
> Signed-off-by: Jonathan Rajotte Julien <jonathan.r.julien at gmail.com>
> ---
>  src/bin/lttng/commands/enable_events.c | 27 ++++++++++++++-------------
>  1 file changed, 14 insertions(+), 13 deletions(-)
> 
> diff --git a/src/bin/lttng/commands/enable_events.c b/src/bin/lttng/commands/enable_events.c
> index f62dadb..3263c58 100644
> --- a/src/bin/lttng/commands/enable_events.c
> +++ b/src/bin/lttng/commands/enable_events.c
> @@ -247,26 +247,27 @@ static void usage(FILE *ofp)
>   */
>  static int parse_probe_opts(struct lttng_event *ev, char *opt)
>  {
> -	int ret;
> +	int ret = CMD_SUCCESS;
> +	int match;
>  	char s_hex[19];
>  #define S_HEX_LEN_SCANF_IS_A_BROKEN_API "18"	/* 18 is (19 - 1) (\0 is extra) */
>  	char name[LTTNG_SYMBOL_NAME_LEN];
>  
>  	if (opt == NULL) {
> -		ret = -1;
> +		ret = CMD_ERROR;
>  		goto end;
>  	}
>  
>  	/* Check for symbol+offset */
> -	ret = sscanf(opt, "%" LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API
> +	match = sscanf(opt, "%" LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API
>  			"[^'+']+%" S_HEX_LEN_SCANF_IS_A_BROKEN_API "s", name, s_hex);
> -	if (ret == 2) {
> +	if (match == 2) {
>  		strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
>  		ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
>  		DBG("probe symbol %s", ev->attr.probe.symbol_name);
>  		if (*s_hex == '\0') {
>  			ERR("Invalid probe offset %s", s_hex);
> -			ret = -1;
> +			ret = CMD_ERROR;
>  			goto end;
>  		}
>  		ev->attr.probe.offset = strtoul(s_hex, NULL, 0);
> @@ -277,9 +278,9 @@ static int parse_probe_opts(struct lttng_event *ev, char *opt)
>  
>  	/* Check for symbol */
>  	if (isalpha(name[0])) {
> -		ret = sscanf(opt, "%" LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API "s",
> +		match = sscanf(opt, "%" LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API "s",
>  			name);
> -		if (ret == 1) {
> +		if (match == 1) {
>  			strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
>  			ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
>  			DBG("probe symbol %s", ev->attr.probe.symbol_name);
> @@ -291,11 +292,11 @@ static int parse_probe_opts(struct lttng_event *ev, char *opt)
>  	}
>  
>  	/* Check for address */
> -	ret = sscanf(opt, "%" S_HEX_LEN_SCANF_IS_A_BROKEN_API "s", s_hex);
> -	if (ret > 0) {
> +	match = sscanf(opt, "%" S_HEX_LEN_SCANF_IS_A_BROKEN_API "s", s_hex);
> +	if (match > 0) {
>  		if (*s_hex == '\0') {
>  			ERR("Invalid probe address %s", s_hex);
> -			ret = -1;
> +			ret = CMD_ERROR;
>  			goto end;
>  		}
>  		ev->attr.probe.addr = strtoul(s_hex, NULL, 0);
> @@ -306,7 +307,7 @@ static int parse_probe_opts(struct lttng_event *ev, char *opt)
>  	}
>  
>  	/* No match */
> -	ret = -1;
> +	ret = CMD_ERROR;
>  
>  end:
>  	return ret;
> @@ -906,7 +907,7 @@ static int enable_events(char *session_name)
>  				break;
>  			case LTTNG_EVENT_PROBE:
>  				ret = parse_probe_opts(&ev, opt_probe);
> -				if (ret < 0) {
> +				if (ret) {
>  					ERR("Unable to parse probe options");
>  					ret = 0;
>  					goto error;
> @@ -914,7 +915,7 @@ static int enable_events(char *session_name)
>  				break;
>  			case LTTNG_EVENT_FUNCTION:
>  				ret = parse_probe_opts(&ev, opt_function);
> -				if (ret < 0) {
> +				if (ret) {
>  					ERR("Unable to parse function probe options");
>  					ret = 0;
>  					goto error;
> -- 
> 2.0.4
> 
> 
> _______________________________________________
> lttng-dev mailing list
> lttng-dev at lists.lttng.org
> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
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