[lttng-dev] [PATCH lttng-tools 1/3] Fix: disable kernel event based on name and event type

Jérémie Galarneau jeremie.galarneau at efficios.com
Mon Sep 21 15:29:04 EDT 2015


This seems to address bug #925. Can you add a mention to your commit
message in v2?

Thanks!
Jérémie

On Thu, Sep 17, 2015 at 4:37 PM, Jonathan Rajotte
<jonathan.rajotte-julien at efficios.com> wrote:
> The -a argument is interpreted as a zero-length event name
> instead of '*' which is actually a valid wildcard event
> name by itself. This simplify how a disable action is handled.
>
> The event type can now be passed as argument
> and is a new criteria while disabling kernel events.
> The default is to disable for all event type.
>
> UST and agent domain do not support yet disabling by event
> type.
>
> e.g:
>         # Only disable kernel event of type tracepoint.
>         lttng disable -a -k --tracepoint
>
>         # Only disable the event with name '*' and type syscall.
>         lttng disable -k '*' --syscall
>
>         # Disable all kernel event of all type.
>         lttng disable -a -k
>
> Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien at efficios.com>
> ---
>  src/bin/lttng-sessiond/cmd.c                       | 45 +++++-----
>  src/bin/lttng-sessiond/event.c                     | 65 +++++---------
>  src/bin/lttng-sessiond/event.h                     |  5 +-
>  src/bin/lttng/commands/disable_events.c            | 98 ++++++++++++++++++----
>  src/lib/lttng-ctl/lttng-ctl.c                      |  4 -
>  .../ust/python-logging/test_python_logging.in      |  2 +-
>  6 files changed, 121 insertions(+), 98 deletions(-)
>
> diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
> index 7878a05..5a1cc7a 100644
> --- a/src/bin/lttng-sessiond/cmd.c
> +++ b/src/bin/lttng-sessiond/cmd.c
> @@ -1225,32 +1225,22 @@ int cmd_disable_event(struct ltt_session *session,
>
>                 switch (event->type) {
>                 case LTTNG_EVENT_ALL:
> -                       ret = event_kernel_disable_event_all(kchan);
> -                       if (ret != LTTNG_OK) {
> -                               goto error_unlock;
> -                       }
> -                       break;
> -               case LTTNG_EVENT_TRACEPOINT:    /* fall-through */
> +               case LTTNG_EVENT_TRACEPOINT:
>                 case LTTNG_EVENT_SYSCALL:
> -                       if (!strcmp(event_name, "*")) {
> -                               ret = event_kernel_disable_event_type(kchan,
> -                                       event->type);
> +               case LTTNG_EVENT_PROBE:
> +               case LTTNG_EVENT_FUNCTION:
> +               case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
> +                       if (event_name[0] == '\0') {
> +                               ret = event_kernel_disable_event(kchan,
> +                                       NULL, event->type);
>                         } else {
>                                 ret = event_kernel_disable_event(kchan,
> -                                       event_name);
> +                                       event_name, event->type);
>                         }
>                         if (ret != LTTNG_OK) {
>                                 goto error_unlock;
>                         }
>                         break;
> -               case LTTNG_EVENT_PROBE:
> -               case LTTNG_EVENT_FUNCTION:
> -               case LTTNG_EVENT_FUNCTION_ENTRY:
> -                       ret = event_kernel_disable_event(kchan, event_name);
> -                       if (ret != LTTNG_OK) {
> -                               goto error_unlock;
> -                       }
> -                       break;
>                 default:
>                         ret = LTTNG_ERR_UNK;
>                         goto error_unlock;
> @@ -1273,7 +1263,7 @@ int cmd_disable_event(struct ltt_session *session,
>
>                 /*
>                  * If a non-default channel has been created in the
> -                * session, explicitely require that -c chan_name needs
> +                * session, explicitly require that -c chan_name needs
>                  * to be provided.
>                  */
>                 if (usess->has_non_default_channel && channel_name[0] == '\0') {
> @@ -1290,10 +1280,12 @@ int cmd_disable_event(struct ltt_session *session,
>
>                 switch (event->type) {
>                 case LTTNG_EVENT_ALL:
> -                       if (strlen(event->name) == 1 &&
> -                                       !strncmp(event->name, "*", 1)) {
> -                               ret = event_ust_disable_all_tracepoints(usess,
> -                                               uchan);
> +                       /*
> +                        * An empty event name means that everything
> +                        * should be disabled.
> +                        */
> +                       if (event->name[0] == '\0') {
> +                               ret = event_ust_disable_all_tracepoints(usess, uchan);
>                         } else {
>                                 ret = event_ust_disable_tracepoint(usess, uchan,
>                                                 event_name);
> @@ -1333,8 +1325,11 @@ int cmd_disable_event(struct ltt_session *session,
>                         ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
>                         goto error_unlock;
>                 }
> -               /* The wild card * means that everything should be disabled. */
> -               if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
> +               /*
> +                * An empty event name means that everything
> +                * should be disabled.
> +                */
> +               if (event->name[0] == '\0') {
>                         ret = event_agent_disable_all(usess, agt);
>                 } else {
>                         ret = event_agent_disable(usess, agt, event_name);
> diff --git a/src/bin/lttng-sessiond/event.c b/src/bin/lttng-sessiond/event.c
> index 13f09a5..a53d4e9 100644
> --- a/src/bin/lttng-sessiond/event.c
> +++ b/src/bin/lttng-sessiond/event.c
> @@ -61,45 +61,15 @@ static void add_unique_ust_event(struct lttng_ht *ht,
>  }
>
>  /*
> - * Disable kernel tracepoint event for a channel from the kernel session.
> + * Disable kernel tracepoint events for a channel from the kernel session of
> + * a specified event_name and event type.
> + * On type LTTNG_EVENT_ALL all events with event_name are disabled.
> + * If event_name if NULL all events of the specified type are disabled.
>   */
>  int event_kernel_disable_event(struct ltt_kernel_channel *kchan,
> -               char *event_name)
> -{
> -       int ret;
> -       struct ltt_kernel_event *kevent;
> -
> -       assert(kchan);
> -
> -       kevent = trace_kernel_get_event_by_name(event_name, kchan,
> -                       LTTNG_EVENT_ALL);
> -       if (kevent == NULL) {
> -               ret = LTTNG_ERR_NO_EVENT;
> -               goto error;
> -       }
> -
> -       ret = kernel_disable_event(kevent);
> -       if (ret < 0) {
> -               ret = LTTNG_ERR_KERN_DISABLE_FAIL;
> -               goto error;
> -       }
> -
> -       DBG("Kernel event %s disable for channel %s.",
> -                       kevent->event->name, kchan->channel->name);
> -
> -       ret = LTTNG_OK;
> -
> -error:
> -       return ret;
> -}
> -
> -/*
> - * Disable kernel tracepoint events for a channel from the kernel session.
> - */
> -int event_kernel_disable_event_type(struct ltt_kernel_channel *kchan,
> -               enum lttng_event_type type)
> +               char *event_name, enum lttng_event_type type)
>  {
> -       int ret;
> +       int ret, error = 0, found = 0;
>         struct ltt_kernel_event *kevent;
>
>         assert(kchan);
> @@ -108,22 +78,25 @@ int event_kernel_disable_event_type(struct ltt_kernel_channel *kchan,
>         cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
>                 if (type != LTTNG_EVENT_ALL && kevent->type != type)
>                         continue;
> +               if (event_name != NULL && strcmp(event_name, kevent->event->name)) {
> +                       continue;
> +               }
> +               found++;
>                 ret = kernel_disable_event(kevent);
>                 if (ret < 0) {
> -                       /* We continue disabling the rest */
> +                       error = 1;
>                         continue;
>                 }
>         }
> -       ret = LTTNG_OK;
> -       return ret;
> -}
> +       DBG("Disable kernel event: found %d events with name: %s and type: %d",
> +                       found, event_name, type);
>
> -/*
> - * Disable all kernel event for a channel from the kernel session.
> - */
> -int event_kernel_disable_event_all(struct ltt_kernel_channel *kchan)
> -{
> -       return event_kernel_disable_event_type(kchan, LTTNG_EVENT_ALL);
> +       if (!found && event_name != NULL) {
> +               error = 1;
> +       }
> +
> +       ret = error ? LTTNG_ERR_KERN_DISABLE_FAIL : LTTNG_OK;
> +       return ret;
>  }
>
>  /*
> diff --git a/src/bin/lttng-sessiond/event.h b/src/bin/lttng-sessiond/event.h
> index 7c5231d..45dd1fc 100644
> --- a/src/bin/lttng-sessiond/event.h
> +++ b/src/bin/lttng-sessiond/event.h
> @@ -23,10 +23,7 @@
>  struct agent;
>
>  int event_kernel_disable_event(struct ltt_kernel_channel *kchan,
> -               char *event_name);
> -int event_kernel_disable_event_type(struct ltt_kernel_channel *kchan,
> -               enum lttng_event_type type);
> -int event_kernel_disable_event_all(struct ltt_kernel_channel *kchan);
> +               char *event_name, enum lttng_event_type event_type);
>
>  int event_kernel_enable_event(struct ltt_kernel_channel *kchan,
>                 struct lttng_event *event, char *filter_expression,
> diff --git a/src/bin/lttng/commands/disable_events.c b/src/bin/lttng/commands/disable_events.c
> index c6ec85f..bcbc78d 100644
> --- a/src/bin/lttng/commands/disable_events.c
> +++ b/src/bin/lttng/commands/disable_events.c
> @@ -44,7 +44,12 @@ static int opt_event_type;
>  enum {
>         OPT_HELP = 1,
>         OPT_USERSPACE,
> -       OPT_SYSCALL,
> +       OPT_TYPE_SYSCALL,
> +       OPT_TYPE_TRACEPOINT,
> +       OPT_TYPE_PROBE,
> +       OPT_TYPE_FUNCTION,
> +       OPT_TYPE_FUNCTION_ENTRY,
> +       OPT_TYPE_ALL,
>         OPT_LIST_OPTIONS,
>  };
>
> @@ -61,8 +66,24 @@ static struct poptOption long_options[] = {
>         {"log4j",          'l', POPT_ARG_VAL, &opt_log4j, 1, 0, 0},
>         {"python",         'p', POPT_ARG_VAL, &opt_python, 1, 0, 0},
>         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
> -       {"syscall",        0,   POPT_ARG_NONE, 0, OPT_SYSCALL, 0, 0},
> +       {"syscall",          0, POPT_ARG_NONE, 0, OPT_TYPE_SYSCALL, 0, 0},
> +       {"probe",            0, POPT_ARG_NONE, 0, OPT_TYPE_PROBE, 0, 0},
> +       {"tracepoint",       0, POPT_ARG_NONE, 0, OPT_TYPE_TRACEPOINT, 0, 0},
> +       {"function",         0, POPT_ARG_NONE, 0, OPT_TYPE_FUNCTION, 0, 0},
> +       {"all",              0, POPT_ARG_NONE, 0, OPT_TYPE_ALL, 0, 0},
> +#if 0
> +       /*
> +        * Function entry exits as a lttng_event_type but is never used on
> +        * enable
> +        */
> +       {"function-entry",   0, POPT_ARG_NONE, 0, OPT_TYPE_FUNCTION_ENTRY, 0, 0},
> +
> +       /* Not implemented yet */
> +       {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_cmd_name, OPT_USERSPACE, 0, 0},
> +       {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
> +#else
>         {"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
> +#endif
>         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
>         {0, 0, 0, 0, 0, 0, 0}
>  };
> @@ -86,8 +107,19 @@ static void usage(FILE *ofp)
>         fprintf(ofp, "  -l, --log4j              Apply to Java application using LOG4j\n");
>         fprintf(ofp, "  -p, --python             Apply to Python application using logging\n");
>         fprintf(ofp, "\n");
> -       fprintf(ofp, "Event options:\n");
> +       fprintf(ofp, "Event type options (Only supported with kernel domain):\n");
> +       fprintf(ofp, "      --all                All event type (default)\n");
> +       fprintf(ofp, "      --tracepoint         Tracepoint event\n");
>         fprintf(ofp, "      --syscall            System call event\n");
> +       fprintf(ofp, "      --probe              Probe event\n");
> +       fprintf(ofp, "      --function           Function event\n");
> +#if 0
> +       /*
> +        * Function entry exits as a lttng_event_type but is never used on
> +        * enable
> +        */
> +       fprintf(ofp, "      --function-entry     Function-entry event\n");
> +#endif
>         fprintf(ofp, "\n");
>  }
>
> @@ -103,6 +135,27 @@ const char *print_raw_channel_name(const char *name)
>         return name ? : "<default>";
>  }
>
> +static
> +const char *print_event_type(const enum lttng_event_type ev_type)
> +{
> +       switch (ev_type) {
> +       case LTTNG_EVENT_ALL:
> +               return "any";
> +       case LTTNG_EVENT_TRACEPOINT:
> +               return "tracepoint";
> +       case LTTNG_EVENT_PROBE:
> +               return "probe";
> +       case LTTNG_EVENT_FUNCTION:
> +               return "function";
> +       case LTTNG_EVENT_FUNCTION_ENTRY:
> +               return "function entry";
> +       case LTTNG_EVENT_SYSCALL:
> +               return "syscall";
> +       default:
> +               return "";
> +       }
> +}
> +
>  /* Mi print a partial event.
>   * enabled is 0 or 1
>   * success is 0 or 1
> @@ -213,14 +266,8 @@ static int disable_events(char *session_name)
>         /* Set default loglevel to any/unknown */
>         event.loglevel = -1;
>
> -       switch (opt_event_type) {
> -       case LTTNG_EVENT_SYSCALL:
> -               event.type = LTTNG_EVENT_SYSCALL;
> -               break;
> -       default:
> -               event.type = LTTNG_EVENT_ALL;
> -               break;
> -       }
> +       /* opt_event_type contain the event type to disable at this point */
> +       event.type = opt_event_type;
>
>         if (opt_disable_all) {
>                 command_ret = lttng_disable_event_ext(handle, &event, channel_name, NULL);
> @@ -232,9 +279,9 @@ static int disable_events(char *session_name)
>                 } else {
>                         enabled = 0;
>                         success = 1;
> -                       MSG("All %s %s are disabled in channel %s",
> +                       MSG("All %s events of type %s are disabled in channel %s",
>                                         get_domain_str(dom.type),
> -                                       opt_event_type == LTTNG_EVENT_SYSCALL ? "system calls" : "events",
> +                                       print_event_type(opt_event_type),
>                                         print_channel_name(channel_name));
>                 }
>
> @@ -255,9 +302,9 @@ static int disable_events(char *session_name)
>                         event.name[sizeof(event.name) - 1] = '\0';
>                         command_ret = lttng_disable_event_ext(handle, &event, channel_name, NULL);
>                         if (command_ret < 0) {
> -                               ERR("%s %s: %s (channel %s, session %s)",
> -                                               opt_event_type == LTTNG_EVENT_SYSCALL ? "System call" : "Event",
> +                               ERR("%s of type %s : %s (channel %s, session %s)",
>                                                 event_name,
> +                                               print_event_type(opt_event_type),
>                                                 lttng_strerror(command_ret),
>                                                 command_ret == -LTTNG_ERR_NEED_CHANNEL_NAME
>                                                         ? print_raw_channel_name(channel_name)
> @@ -271,10 +318,10 @@ static int disable_events(char *session_name)
>                                  */
>                                 enabled = 1;
>                         } else {
> -                               MSG("%s %s %s disabled in channel %s for session %s",
> +                               MSG("%s %s of type %s disabled in channel %s for session %s",
>                                                 get_domain_str(dom.type),
> -                                               opt_event_type == LTTNG_EVENT_SYSCALL ? "system call" : "event",
>                                                 event_name,
> +                                               print_event_type(opt_event_type),
>                                                 print_channel_name(channel_name),
>                                                 session_name);
>                                 success = 1;
> @@ -341,9 +388,24 @@ int cmd_disable_events(int argc, const char **argv)
>                 case OPT_USERSPACE:
>                         opt_userspace = 1;
>                         break;
> -               case OPT_SYSCALL:
> +               case OPT_TYPE_SYSCALL:
>                         opt_event_type = LTTNG_EVENT_SYSCALL;
>                         break;
> +               case OPT_TYPE_TRACEPOINT:
> +                       opt_event_type = LTTNG_EVENT_TRACEPOINT;
> +                       break;
> +               case OPT_TYPE_PROBE:
> +                       opt_event_type = LTTNG_EVENT_PROBE;
> +                       break;
> +               case OPT_TYPE_FUNCTION:
> +                       opt_event_type = LTTNG_EVENT_FUNCTION;
> +                       break;
> +               case OPT_TYPE_FUNCTION_ENTRY:
> +                       opt_event_type = LTTNG_EVENT_FUNCTION_ENTRY;
> +                       break;
> +               case OPT_TYPE_ALL:
> +                       opt_event_type = LTTNG_EVENT_ALL;
> +                       break;
>                 case OPT_LIST_OPTIONS:
>                         list_cmd_options(stdout, long_options);
>                         goto end;
> diff --git a/src/lib/lttng-ctl/lttng-ctl.c b/src/lib/lttng-ctl/lttng-ctl.c
> index 9cbfef5..1007326 100644
> --- a/src/lib/lttng-ctl/lttng-ctl.c
> +++ b/src/lib/lttng-ctl/lttng-ctl.c
> @@ -1091,10 +1091,6 @@ int lttng_disable_event_ext(struct lttng_handle *handle,
>         }
>
>         lsm.cmd_type = LTTNG_DISABLE_EVENT;
> -       if (ev->name[0] == '\0') {
> -               /* Disable all events */
> -               lttng_ctl_copy_string(ev->name, "*", sizeof(ev->name));
> -       }
>
>         lttng_ctl_copy_lttng_domain(&lsm.domain, &handle->domain);
>         /* FIXME: copying non-packed struct to packed struct. */
> diff --git a/tests/regression/ust/python-logging/test_python_logging.in b/tests/regression/ust/python-logging/test_python_logging.in
> index 8aff408..d5a9b80 100755
> --- a/tests/regression/ust/python-logging/test_python_logging.in
> +++ b/tests/regression/ust/python-logging/test_python_logging.in
> @@ -351,7 +351,7 @@ function test_python_disable_all()
>         enable_python_lttng_event $SESSION_NAME $EVENT_NAME
>         enable_python_lttng_event $SESSION_NAME $EVENT_NAME2
>
> -       disable_python_lttng_event $SESSION_NAME '*'
> +       disable_python_lttng_event $SESSION_NAME -a
>
>         start_lttng_tracing_ok $SESSION_NAME
>
> --
> 2.1.4
>



-- 
Jérémie Galarneau
EfficiOS Inc.
http://www.efficios.com



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