* Thibault, Daniel ([email protected]) wrote:
> In lttng-tools lttng/commands/add_context.c, the instances of struct ctx_type
> that are malloc'ed were not cleaned up in most error cases. Consider for
> example what the original code did with 'lttng add-context -t nice -h'.
> ------------------------------
> From e0b21686e686050369ecb929cb6c6ea78afcdb87 Thu, 26 Jan 2012 13:03:43 -0500
> From: Daniel U. Thibault <[email protected]>
> Date: Thu, 26 Jan 2012 13:03:29 -0500
> Subject: [PATCH] lttng-tools lttng commands add_context.c: Plug memory leaks
>
> diff --git a/src/bin/lttng/commands/add_context.c
> b/src/bin/lttng/commands/add_context.c
> index 075b270..d0f5b6f 100644
> --- a/src/bin/lttng/commands/add_context.c
> +++ b/src/bin/lttng/commands/add_context.c
> @@ -383,7 +383,7 @@
> 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) {
> @@ -420,17 +420,18 @@
> }
>
> /*
> - * Add context on channel or event.
> + * Add context to channel or event.
> */
> int cmd_add_context(int argc, const char **argv)
> {
> - int index, opt, ret = CMD_SUCCESS;
> + int index, opt, ret;
> static poptContext pc;
> struct ctx_type *type, *tmptype;
> char *session_name = NULL;
>
> if (argc < 2) {
> usage(stderr);
> + ret = CMD_ERROR;
> goto end;
> }
>
> @@ -440,24 +441,30 @@
> 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
Please always use
/*
* My comment.
* For a multi-line comment.
*/
style of comment or
/* My comment. For single-line comment. */
Best regards,
Mathieu
> 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);
> }
> @@ -482,7 +489,7 @@
> if (!opt_session_name) {
> session_name = get_session_name();
> if (session_name == NULL) {
> - ret = -1;
> + ret = CMD_ERROR;
> goto end;
> }
> } else {
> @@ -491,11 +498,11 @@
>
> 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/>
>
> _______________________________________________
> lttng-dev mailing list
> [email protected]
> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>
--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
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