[lttng-dev] [PATCH] disable_channels.c and enable_channels.c

David Goulet dgoulet at efficios.com
Wed Feb 1 13:06:21 EST 2012


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Same here, I can't before stable.

Thanks
David

On 12-01-31 04:41 PM, Thibault, Daniel wrote:
> From c297ddf1295b316d1133a49bc8d2fa08f115dcdc Tue, 31 Jan 2012 16:32:47 -0500
> From: Daniel U. Thibault <daniel.thibault at drdc-rddc.gc.ca>
> Date: Tue, 31 Jan 2012 16:32:33 -0500
> Subject: [PATCH] disable_channels.c : * Also use the enable_channels.c channel name length filter enable_channels.c : * Improve usage() printout * Document and enforce return values * Send --help to stdout * Return CMD_WARNING for bad channel name(s) * Fix session_name memory leak * Use LTTNG_SYMBOL_NAME_LEN instead of NAME_MAX for chan.name * Replace atol/atoi with strtol (because the former's behaviour is undefined for bad input) (this required including errno.h) * Change private function enable_channel() to enable_channels() to be consistent with disable_channels.c
> 
> Signed-off-by: Daniel U. Thibault <daniel.thibault at drdc-rddc.gc.ca>
> 
> diff --git a/src/bin/lttng/commands/disable_channels.c b/src/bin/lttng/commands/disable_channels.c
> index 4202963..f6929e6 100644
> --- a/src/bin/lttng/commands/disable_channels.c
> +++ b/src/bin/lttng/commands/disable_channels.c
> @@ -94,6 +94,8 @@
>  {
>  	int warn = 0, ret;
>  	char *channel_name;
> +	char chan_name[LTTNG_SYMBOL_NAME_LEN];
> +
>  	struct lttng_domain dom;
>  
>  	/* Create lttng domain */
> @@ -120,16 +122,20 @@
>  	while (channel_name != NULL) {
>  		DBG("Disabling channel %s", channel_name);
>  
> -		ret = lttng_disable_channel(handle, channel_name);
> +		/* Copy channel name and normalize it */
> +		strncpy(chan_name, channel_name, LTTNG_SYMBOL_NAME_LEN - 1);
> +		chan_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
> +
> +		ret = lttng_disable_channel(handle, chan_name);
>  		if (ret < 0) {
>  			warn = 1;
>  			ERR("%s channel %s unrecognised for session %s",
> -					opt_kernel ? "Kernel" : "UST", channel_name,
> +					opt_kernel ? "Kernel" : "UST", chan_name,
>  					session_name);
>  		} else {
>  			ret = CMD_SUCCESS;
>  			MSG("%s channel %s disabled for session %s",
> -					opt_kernel ? "Kernel" : "UST", channel_name,
> +					opt_kernel ? "Kernel" : "UST", chan_name,
>  					session_name);
>  		}
>  
> diff --git a/src/bin/lttng/commands/enable_channels.c b/src/bin/lttng/commands/enable_channels.c
> index 03de524..7bebf76 100644
> --- a/src/bin/lttng/commands/enable_channels.c
> +++ b/src/bin/lttng/commands/enable_channels.c
> @@ -21,6 +21,7 @@
>  #include <stdio.h>
>  #include <stdlib.h>
>  #include <string.h>
> +#include <errno.h>
>  #include <sys/stat.h>
>  #include <sys/types.h>
>  #include <unistd.h>
> @@ -84,15 +85,17 @@
>  	fprintf(ofp, "\n");
>  	fprintf(ofp, "  -h, --help               Show this help\n");
>  	fprintf(ofp, "      --list-options       Simple listing of options\n");
> -	fprintf(ofp, "  -s, --session            Apply on session name\n");
> -	fprintf(ofp, "  -k, --kernel             Apply on the kernel tracer\n");
> +	fprintf(ofp, "  -s, --session            Apply to session name\n");
> +	fprintf(ofp, "  -k, --kernel             Apply to the kernel tracer\n");
>  #if 0
> -	fprintf(ofp, "  -u, --userspace [CMD]    Apply for the user-space tracer\n");
> +	fprintf(ofp, "  -u, --userspace [CMD]    Apply to the user-space tracer\n");
>  	fprintf(ofp, "                           If no CMD, the domain used is UST global\n");
> -	fprintf(ofp, "                           or else the domain is UST EXEC_NAME\n");
> +	fprintf(ofp, "                           otherwise the domain is UST EXEC_NAME\n");
> +	fprintf(ofp, "                           (--kernel preempts --userspace)\n");
>  	fprintf(ofp, "  -p, --pid PID            If -u, apply to specific PID (domain: UST PID)\n");
>  #else
> -	fprintf(ofp, "  -u, --userspace          Apply for the user-space tracer\n");
> +	fprintf(ofp, "  -u, --userspace          Apply to the user-space tracer\n");
> +	fprintf(ofp, "                           (--kernel preempts --userspace)\n");
>  #endif
>  	fprintf(ofp, "\n");
>  	fprintf(ofp, "Channel options:\n");
> @@ -100,7 +103,7 @@
>  		DEFAULT_CHANNEL_OVERWRITE ? "" : " (default)");
>  	fprintf(ofp, "      --overwrite          Flight recorder mode%s\n",
>  		DEFAULT_CHANNEL_OVERWRITE ? " (default)" : "");
> -	fprintf(ofp, "      --subbuf-size        Subbuffer size in bytes\n");
> +	fprintf(ofp, "      --subbuf-size        Subbuffer size (in bytes)\n");
>  	fprintf(ofp, "                               (default: %u, kernel default: %u)\n",
>  		DEFAULT_CHANNEL_SUBBUF_SIZE,
>  		DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE);
> @@ -118,14 +121,16 @@
>  /*
>   * Set default attributes depending on those already defined from the command
>   * line.
> + * The domain argument must not be NULL.
>   */
>  static void set_default_attr(struct lttng_domain *dom)
>  {
>  	struct lttng_channel_attr default_attr;
>  
> -	/* Set attributes */
> +	/* Recover default attributes */
>  	lttng_channel_set_default_attr(dom, &default_attr);
>  
> +	/* Set attributes */
>  	if (chan.attr.overwrite == -1) {
>  		chan.attr.overwrite = default_attr.overwrite;
>  	}
> @@ -147,11 +152,13 @@
>  }
>  
>  /*
> - * Adding channel using the lttng API.
> + * Enables channel(s) using the lttng API.
> + * Channel names which are too long will be truncated.
> + * Returns one of the CMD_* result values.
>   */
> -static int enable_channel(char *session_name)
> +static int enable_channels(char *session_name)
>  {
> -	int ret = CMD_SUCCESS;
> +	int warn = 0, ret;
>  	char *channel_name;
>  	struct lttng_domain dom;
>  
> @@ -170,23 +177,29 @@
>  
>  	handle = lttng_create_handle(session_name, &dom);
>  	if (handle == NULL) {
> -		ret = -1;
> +		ret = CMD_FATAL;
>  		goto error;
>  	}
>  
>  	/* Strip channel list (format: chan1,chan2,...) */
>  	channel_name = strtok(opt_channels, ",");
> +	/* Default to a warning in case opt_channels is empty */
> +	ret = CMD_WARNING;
>  	while (channel_name != NULL) {
> -		/* Copy channel name and normalize it */
> -		strncpy(chan.name, channel_name, NAME_MAX);
> -		chan.name[NAME_MAX - 1] = '\0';
> -
>  		DBG("Enabling channel %s", channel_name);
> +
> +		/* Copy channel name and normalize it */
> +		strncpy(chan.name, channel_name, LTTNG_SYMBOL_NAME_LEN - 1);
> +		chan.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
>  
>  		ret = lttng_enable_channel(handle, &chan);
>  		if (ret < 0) {
> -			goto error;
> +			warn = 1;
> +			ERR("%s channel %s unrecognised for session %s",
> +					opt_kernel ? "Kernel" : "UST", channel_name,
> +					session_name);
>  		} else {
> +			ret = CMD_SUCCESS;
>  			MSG("%s channel %s enabled for session %s",
>  					opt_kernel ? "Kernel" : "UST", channel_name,
>  					session_name);
> @@ -194,6 +207,13 @@
>  
>  		/* Next event */
>  		channel_name = strtok(NULL, ",");
> +	}
> +	if (ret == CMD_WARNING) {
> +		ERR("No %s channel specified for session %s",
> +				opt_kernel ? "kernel" : "UST", session_name);
> +	}
> +	if (warn) {
> +		ret = CMD_WARNING;
>  	}
>  
>  error:
> @@ -215,7 +235,8 @@
>  }
>  
>  /*
> - * Add channel to trace session
> + * Add channel(s) to trace session
> + * Returns one of the CMD_* result values.
>   */
>  int cmd_enable_channels(int argc, const char **argv)
>  {
> @@ -231,7 +252,7 @@
>  	while ((opt = poptGetNextOpt(pc)) != -1) {
>  		switch (opt) {
>  		case OPT_HELP:
> -			usage(stderr);
> +			usage(stdout);
>  			ret = CMD_SUCCESS;
>  			goto end;
>  		case OPT_DISCARD:
> @@ -243,20 +264,44 @@
>  			DBG("Channel set to overwrite");
>  			break;
>  		case OPT_SUBBUF_SIZE:
> -			chan.attr.subbuf_size = atol(poptGetOptArg(pc));
> +			errno = 0;
> +			chan.attr.subbuf_size = strtol(poptGetOptArg(pc), (char **)NULL, 10);
> +			if (errno != 0) {
> +				ERR("Subbuffer size not a number");
> +				ret = CMD_ERROR;
> +				goto end;
> +			}
>  			DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
>  			break;
>  		case OPT_NUM_SUBBUF:
> -			chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
> +			errno = 0;
> +			chan.attr.num_subbuf = strtol(poptGetOptArg(pc), (char **)NULL, 10);
> +			if (errno != 0) {
> +				ERR("Number of subbuffers not a number");
> +				ret = CMD_ERROR;
> +				goto end;
> +			}
>  			DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
>  			break;
>  		case OPT_SWITCH_TIMER:
> -			chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
> -			DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
> +			errno = 0;
> +			chan.attr.switch_timer_interval = strtol(poptGetOptArg(pc), (char **)NULL, 10);
> +			if (errno != 0) {
> +				ERR("Switch timer interval not a number");
> +				ret = CMD_ERROR;
> +				goto end;
> +			}
> +			DBG("Channel switch timer interval set to %d usec", chan.attr.switch_timer_interval);
>  			break;
>  		case OPT_READ_TIMER:
> -			chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
> -			DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
> +			errno = 0;
> +			chan.attr.read_timer_interval = strtol(poptGetOptArg(pc), (char **)NULL, 10);
> +			if (errno != 0) {
> +				ERR("Read timer interval not a number");
> +				ret = CMD_ERROR;
> +				goto end;
> +			}
> +			DBG("Channel read timer interval set to %d usec", chan.attr.read_timer_interval);
>  			break;
>  		case OPT_USERSPACE:
>  			opt_userspace = 1;
> @@ -274,24 +319,26 @@
>  
>  	opt_channels = (char*) poptGetArg(pc);
>  	if (opt_channels == NULL) {
> -		ERR("Missing channel name.\n");
> +		ERR("Missing channel name(s).\n");
>  		usage(stderr);
> -		ret = CMD_SUCCESS;
> +		ret = CMD_ERROR;
>  		goto end;
>  	}
>  
> -	if (!opt_session_name) {
> -		session_name = get_session_name();
> -		if (session_name == NULL) {
> -			ret = -1;
> -			goto end;
> -		}
> -	} else {
> -		session_name = opt_session_name;
> +	session_name = (opt_session_name ? opt_session_name : get_session_name() );
> +	if (session_name == NULL) {
> +		ret = CMD_ERROR;
> +		goto cleanup;
>  	}
>  
> -	ret = enable_channel(session_name);
> +	ret = enable_channels(session_name);
> +
> +cleanup:
> +	if (opt_session_name == NULL) {
> +		free(session_name);
> +	}
>  
>  end:
> 	poptFreeContext(pc);
> ------------------------------
> 
> Daniel U. Thibault
> R & D pour la défense Canada - Valcartier (RDDC Valcartier) / Defence R&D Canada - Valcartier (DRDC Valcartier)
> Système de systèmes (SdS) / System of Systems (SoS)
> Solutions informatiques et expérimentations (SIE) / Computing Solutions and Experimentations (CSE)
> 2459 Boul. Pie XI Nord
> Québec, QC  G3J 1X5
> CANADA
> Vox : (418) 844-4000 x4245
> Fax : (418) 844-4538
> NAC: 918V QSDJ
> Gouvernement du Canada / Government of Canada
> <http://www.valcartier.drdc-rddc.gc.ca/>
> 
> _______________________________________________
> lttng-dev mailing list
> lttng-dev at lists.lttng.org
> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
> 
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