Add disable kernel event support
authorDavid Goulet <david.goulet@polymtl.ca>
Wed, 29 Jun 2011 16:48:35 +0000 (12:48 -0400)
committerDavid Goulet <david.goulet@polymtl.ca>
Wed, 29 Jun 2011 16:49:04 +0000 (12:49 -0400)
Signed-off-by: David Goulet <david.goulet@polymtl.ca>
ltt-sessiond/kernel-ctl.c
ltt-sessiond/kernel-ctl.h
ltt-sessiond/main.c
ltt-sessiond/trace.h
lttng/Makefile.am
lttng/cmd.h
lttng/commands/disable_events.c [new file with mode: 0644]
lttng/lttng.c

index 3925c6ba5afc8e17f193dea1b497c7291a5ac52f..2f1864d6495ca8092a4a2744ec5a5c301bac9686 100644 (file)
@@ -136,11 +136,12 @@ int kernel_create_event(struct ltt_kernel_channel *channel, struct lttng_event *
 
        ret = kernctl_create_event(channel->fd, event->event);
        if (ret < 0) {
-               ERR("Unable to enable event %s for channel %s", ev->name, channel->channel->name);
-               goto error;
+               perror("create event ioctl");
+               goto free_event;
        }
 
        event->fd = ret;
+       event->enabled = 1;
        /* Prevent fd duplication after execlp() */
        ret = fcntl(event->fd, F_SETFD, FD_CLOEXEC);
        if (ret < 0) {
@@ -149,7 +150,39 @@ int kernel_create_event(struct ltt_kernel_channel *channel, struct lttng_event *
 
        /* Add event to event list */
        cds_list_add(&event->list, &channel->events_list.head);
-       DBG("Event %s enabled (fd: %d)", ev->name, event->fd);
+       DBG("Event %s created (fd: %d)", ev->name, event->fd);
+
+       return 0;
+
+free_event:
+       free(event);
+error:
+       return -1;
+}
+
+/*
+ *  kernel_disable_event
+ *
+ *  Disable a kernel event for a specific channel.
+ */
+int kernel_disable_event(char *event_name, struct ltt_kernel_channel *channel)
+{
+       int ret;
+       struct ltt_kernel_event *iter;
+
+       cds_list_for_each_entry(iter, &channel->events_list.head, list) {
+               if (strcmp(iter->event->name, event_name) == 0) {
+                       ret = kernctl_disable(iter->fd);
+                       if (ret < 0) {
+                               perror("disable event ioctl");
+                               goto error;
+                       }
+
+                       iter->enabled = 0;
+                       DBG("Kernel event %s disabled (fd: %d)", iter->event->name, iter->fd);
+                       break;
+               }
+       }
 
        return 0;
 
index e100c1b084f5d22d00cdd7836d23673e53ecb0b2..adc930d1c0671ff116f979e4233d002818708e15 100644 (file)
@@ -33,6 +33,7 @@
 int kernel_create_session(struct ltt_session *session, int tracer_fd);
 int kernel_create_channel(struct ltt_kernel_session *session, struct lttng_channel *chan);
 int kernel_create_event(struct ltt_kernel_channel *channel, struct lttng_event *ev);
+int kernel_disable_event(char *event_name, struct ltt_kernel_channel *channel);
 int kernel_open_metadata(struct ltt_kernel_session *session);
 int kernel_open_metadata_stream(struct ltt_kernel_session *session);
 int kernel_open_channel_stream(struct ltt_kernel_channel *channel);
index 05114e1f2cbed563814c4f4babd80d963eddd1f6..1c6b6da6fb6bcec1781373c4a586a0d18a941ede 100644 (file)
@@ -876,6 +876,41 @@ static int process_client_msg(struct command_ctx *cmd_ctx)
                ret = LTTCOMM_OK;
                break;
        }
+       case LTTNG_KERNEL_DISABLE_EVENT:
+       {
+               int found = 0;
+               struct ltt_kernel_channel *chan;
+
+               /* Setup lttng message with no payload */
+               ret = setup_lttng_msg(cmd_ctx, 0);
+               if (ret < 0) {
+                       goto setup_error;
+               }
+
+               /* Get channel by name and create event for that channel */
+               cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
+                       if (strcmp(cmd_ctx->lsm->u.disable.channel_name, chan->channel->name) == 0) {
+                               DBG("Disabling kernel event %s for channel %s.",
+                                               cmd_ctx->lsm->u.disable.name, cmd_ctx->lsm->u.disable.channel_name);
+
+                               ret = kernel_disable_event(cmd_ctx->lsm->u.disable.name, chan);
+                               if (ret < 0) {
+                                       ret = LTTCOMM_KERN_DISABLE_FAIL;
+                                       goto error;
+                               }
+                               found = 1;
+                               break;
+                       }
+               }
+
+               if (!found) {
+                       ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
+               } else {
+                       kernel_wait_quiescent(kernel_tracer_fd);
+                       ret = LTTCOMM_OK;
+               }
+               break;
+       }
        case LTTNG_KERNEL_ENABLE_EVENT:
        {
                int found = 0;
index 8fdef2a37721443de94c1fabe92669073cff49d1..8da147230e22a928ec89b7b33f37c9a84d02cc8c 100644 (file)
@@ -44,6 +44,7 @@ struct ltt_kernel_channel_list {
 /* Kernel event */
 struct ltt_kernel_event {
        int fd;
+       int enabled;
        struct lttng_kernel_event *event;
        struct cds_list_head list;
 };
index fcea4668a15ba9b812a80b8450aca92d0d55d314..a2afb9fad1242648b2bed58c129b5a3cc594ebeb 100644 (file)
@@ -5,7 +5,7 @@ bin_PROGRAMS = lttng
 lttng_SOURCES = conf.c commands/start.c commands/add_channel.c \
                                commands/list.c commands/create.c commands/destroy.c \
                                commands/stop.c commands/enable_events.c \
-                               utils.c lttng.c
+                               commands/disable_events.c utils.c lttng.c
 
 lttng_LDADD = \
                $(top_builddir)/liblttngctl/liblttngctl.la
index 02ebfcc1dc6645972b6f025804e4fbf5044db23d..d932d2eb0fde28fc76112ee0d238f513fa631a43 100644 (file)
@@ -44,5 +44,6 @@ extern int cmd_add_channel(int argc, const char **argv);
 extern int cmd_start(int argc, const char **argv);
 extern int cmd_stop(int argc, const char **argv);
 extern int cmd_enable_events(int argc, const char **argv);
+extern int cmd_disable_events(int argc, const char **argv);
 
 #endif /* _LTTNG_CMD_H */
diff --git a/lttng/commands/disable_events.c b/lttng/commands/disable_events.c
new file mode 100644 (file)
index 0000000..5bfe5d5
--- /dev/null
@@ -0,0 +1,192 @@
+/*
+ * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#define _GNU_SOURCE
+#include <popt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "cmd.h"
+#include "conf.h"
+#include "utils.h"
+
+static char *opt_event_list;
+static char *opt_kernel;
+static char *opt_cmd_name;
+static char *opt_channel_name;
+static int opt_pid_all;
+static int opt_userspace;
+static int opt_disable_all;
+static pid_t opt_pid;
+
+enum {
+       OPT_HELP = 1,
+       OPT_USERSPACE,
+};
+
+static struct poptOption long_options[] = {
+       /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
+       {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
+       {"all-events",     'a', POPT_ARG_VAL, &opt_disable_all, 1, 0, 0},
+       {"channel",        'c', POPT_ARG_STRING, &opt_channel_name, 0, 0, 0},
+       {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
+       {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, 0, OPT_USERSPACE, 0, 0},
+       {"all",            0,   POPT_ARG_VAL, &opt_pid_all, 1, 0, 0},
+       {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
+       {0, 0, 0, 0, 0, 0, 0}
+};
+
+/*
+ * usage
+ */
+static void usage(FILE *ofp)
+{
+       fprintf(ofp, "usage: lttng disable-event NAME[,NAME2,...] [options]\n");
+       fprintf(ofp, "\n");
+       fprintf(ofp, "  -h, --help               Show this help\n");
+       fprintf(ofp, "  -c, --channel            Apply on this channel\n");
+       fprintf(ofp, "  -a, --all-events         Enable all tracepoints\n");
+       fprintf(ofp, "  -k, --kernel             Apply for the kernel tracer\n");
+       fprintf(ofp, "  -u, --userspace [CMD]    Apply for the user-space tracer\n");
+       fprintf(ofp, "      --all                If -u, apply on all traceable apps\n");
+       fprintf(ofp, "  -p, --pid PID            If -u, apply on a specific PID\n");
+       fprintf(ofp, "\n");
+}
+
+/*
+ *  disable_events
+ *
+ *  Disabling event using the lttng API.
+ */
+static int disable_events(void)
+{
+       int err, ret = CMD_SUCCESS;
+       char *event_name, *channel_name;
+       struct lttng_event ev;
+
+       if (set_session_name() < 0) {
+               ret = CMD_ERROR;
+               goto error;
+       }
+
+       if (opt_channel_name == NULL) {
+               err = asprintf(&channel_name, DEFAULT_CHANNEL_NAME);
+               if (err < 0) {
+                       ret = CMD_FATAL;
+                       goto error;
+               }
+       } else {
+               channel_name = opt_channel_name;
+       }
+
+       if (opt_disable_all) {
+               if (opt_kernel) {
+                       ret = lttng_kernel_disable_event(NULL, channel_name);
+                       goto error;
+               }
+
+               /* TODO: User-space tracer */
+       }
+
+       /* Strip event list */
+       event_name = strtok(opt_event_list, ",");
+       while (event_name != NULL) {
+               /* Kernel tracer action */
+               if (opt_kernel) {
+                       DBG("Disabling kernel event %s for channel %s",
+                                       event_name, channel_name);
+
+                       /* Copy name and type of the event */
+                       strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
+                       ret = lttng_kernel_disable_event(event_name, channel_name);
+                       if (ret < 0) {
+                               MSG("Unable to disable event %s for channel %s",
+                                               event_name, channel_name);
+                       } else {
+                               MSG("Kernel event %s disabled for channel %s",
+                                               event_name, channel_name);
+                       }
+               } else if (opt_userspace) {             /* User-space tracer action */
+                       /*
+                        * TODO: Waiting on lttng UST 2.0
+                        */
+                       if (opt_pid_all) {
+                       } else if (opt_pid != 0) {
+                       }
+                       ret = CMD_NOT_IMPLEMENTED;
+                       goto error;
+               } else {
+                       ERR("Please specify a tracer (kernel or user-space)");
+                       goto error;
+               }
+
+               /* Next event */
+               event_name = strtok(NULL, ",");
+       }
+
+error:
+       return ret;
+}
+
+/*
+ *  cmd_disable_events
+ *
+ *  Disable event to trace session
+ */
+int cmd_disable_events(int argc, const char **argv)
+{
+       int opt, ret;
+       static poptContext pc;
+
+       pc = poptGetContext(NULL, argc, argv, long_options, 0);
+       poptReadDefaultConfig(pc, 0);
+
+       while ((opt = poptGetNextOpt(pc)) != -1) {
+               switch (opt) {
+               case OPT_HELP:
+                       usage(stderr);
+                       ret = CMD_SUCCESS;
+                       goto end;
+               case OPT_USERSPACE:
+                       opt_userspace = 1;
+                       opt_cmd_name = poptGetOptArg(pc);
+                       break;
+               default:
+                       usage(stderr);
+                       ret = CMD_UNDEFINED;
+                       goto end;
+               }
+       }
+
+       opt_event_list = (char*) poptGetArg(pc);
+       if (opt_event_list == NULL && opt_disable_all == 0) {
+               ERR("Missing event name(s).\n");
+               usage(stderr);
+               ret = CMD_SUCCESS;
+               goto end;
+       }
+
+       ret = disable_events();
+
+end:
+       return ret;
+}
index 5f0699119cc89614644a1cf1bc5ef176d4eeb3f7..84d10eb7222b0e5c72f7db04e0d78cb5c6d275b8 100644 (file)
@@ -63,6 +63,7 @@ static struct cmd_struct commands[] =  {
        { "start", cmd_start},
        { "stop", cmd_stop},
        { "enable-event", cmd_enable_events},
+       { "disable-event", cmd_disable_events},
        { NULL, NULL}   /* Array closure */
 };
 
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