[lttng-dev] [PATCH] lttng-tools add_context.c : Fixing memory leaks

[David Goulet]

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Hash: SHA1

Finally merged! :)

Thanks
David

On 12-01-30 04:58 PM, Thibault, Daniel wrote:
>> For some reason, this patch does not apply ...
> 
>    Okay, my git repository is now properly connected, and below is the patch rewritten for the current commit.  Besides enforcing the return values and outputting --help to stdout, the problem lay with the instances of struct ctx_type *type being created but not assigned to the doubly-linked list under various error conditions.
> 
> ------------------------------
> From e8e3c1db9311fda3b01a9318e263ce55b476222f Mon, 30 Jan 2012 16:55:02 -0500
> From: Daniel U. Thibault <daniel.thibault at drdc-rddc.gc.ca>
> Date: Mon, 30 Jan 2012 16:54:47 -0500
> Subject: [PATCH] lttng-tools add_context : Fixing memory leaks
> 
> Signed-off-by: Daniel U. Thibault <daniel.thibault at drdc-rddc.gc.ca>
> 
> diff --git a/src/bin/lttng/commands/add_context.c b/src/bin/lttng/commands/add_context.c
> index 2f3bce1..2fec520 100644
> --- a/src/bin/lttng/commands/add_context.c
> +++ b/src/bin/lttng/commands/add_context.c
> @@ -313,14 +313,14 @@
>  	fprintf(ofp, "Options:\n");
>  	fprintf(ofp, "  -h, --help               Show this help\n");
>  	fprintf(ofp, "      --list-options       Simple listing of options\n");
> -	fprintf(ofp, "  -s, --session NAME       Apply on session name\n");
> -	fprintf(ofp, "  -c, --channel NAME       Apply on channel\n");
> -	fprintf(ofp, "  -e, --event NAME         Apply on event\n");
> +	fprintf(ofp, "  -s, --session NAME       Apply to session name\n");
> +	fprintf(ofp, "  -c, --channel NAME       Apply to channel\n");
> +	fprintf(ofp, "  -e, --event NAME         Apply to event\n");
>  	fprintf(ofp, "  -k, --kernel             Apply to the kernel tracer\n");
>  #if 0
>  	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, "  -p, --pid PID            If -u, apply to specific PID (domain: UST PID)\n");
>  #else
>  	fprintf(ofp, "  -u, --userspace          Apply to the user-space tracer\n");
> @@ -385,7 +385,7 @@
>  		goto error;
>  	}
>  
> -	/* Iterate over all context type given */
> +	/* Iterate over all the context types given */
>  	cds_list_for_each_entry(type, &ctx_type_list.head, list) {
>  		context.ctx = type->opt->ctx_type;
>  		if (context.ctx == LTTNG_EVENT_CONTEXT_PERF_COUNTER) {
> @@ -444,7 +444,7 @@
>  }
>  
>  /*
> - * Add context on channel or event.
> + * Add context to channel or event.
>   */
>  int cmd_add_context(int argc, const char **argv)
>  {
> @@ -455,6 +455,7 @@
>  
>  	if (argc < 2) {
>  		usage(stderr);
> +		ret = CMD_ERROR;
>  		goto end;
>  	}
>  
> @@ -464,17 +465,10 @@
>  	while ((opt = poptGetNextOpt(pc)) != -1) {
>  		switch (opt) {
>  		case OPT_HELP:
> -			usage(stderr);
> +			usage(stdout);
>  			ret = CMD_SUCCESS;
>  			goto end;
>  		case OPT_TYPE:
> -			type = malloc(sizeof(struct ctx_type));
> -			if (type == NULL) {
> -				perror("malloc ctx_type");
> -				ret = -1;
> -				goto end;
> -			}
> -
>  			/*
>  			 * Look up the index of opt_type in ctx_opts[] first, so we don't
>  			 * have to free(type) on failure.
> @@ -482,11 +476,21 @@
>  			index = find_ctx_type_idx(opt_type);
>  			if (index < 0) {
>  				ERR("Unknown context type %s", opt_type);
> +				ret = CMD_ERROR;
> +				goto end;
> +			}
> +			type = malloc(sizeof(struct ctx_type));
> +			if (type == NULL) {
> +				perror("malloc ctx_type");
> +				ret = CMD_FATAL;
>  				goto end;
>  			}
>  			type->opt = &ctx_opts[index];
>  			if (type->opt->ctx_type == -1) {
>  				ERR("Unknown context type %s", opt_type);
> +				free(type);
> +				ret = CMD_ERROR;
> +				goto end;
>  			} else {
>  				cds_list_add(&type->list, &ctx_type_list.head);
>  			}
> @@ -511,7 +515,7 @@
>  	if (!opt_session_name) {
>  		session_name = get_session_name();
>  		if (session_name == NULL) {
> -			ret = -1;
> +			ret = CMD_ERROR;
>  			goto end;
>  		}
>  	} else {
> @@ -520,11 +524,11 @@
>  
>  	ret = add_context(session_name);
>  
> +end:
>  	/* Cleanup allocated memory */
>  	cds_list_for_each_entry_safe(type, tmptype, &ctx_type_list.head, list) {
>  		free(type);
>  	}
>  
> -end:
>  	return ret;
>  }
> ------------------------------
> 
> 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/>
> 
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