Remove "lib" prefix from .c/.h file names
[lttng-tools.git] / ltt-sessiond / kernel-ctl.c
index 969acfbf437deb51de608fcba7d991e9ba8353b6..cfea8942da7f421d4eeaf272f59b51261fe08e3e 100644 (file)
@@ -3,8 +3,8 @@
  *
  * 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.
+ * as published by the Free Software Foundation; only version 2
+ * of the License.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */
 
+#define _GNU_SOURCE
 #include <errno.h>
+#include <fcntl.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <unistd.h>
 
-#include "ltt-sessiond.h"
-#include "libkernelctl.h"
+#include "lttngerr.h"
+#include "kernelctl.h"
 #include "kernel-ctl.h"
-#include "trace.h"
+
+/*
+ *  kernel_add_channel_context
+ *
+ *  Add context on a kernel channel.
+ */
+int kernel_add_channel_context(struct ltt_kernel_channel *chan,
+               struct lttng_kernel_context *ctx)
+{
+       int ret;
+
+       DBG("Adding context to channel %s", chan->channel->name);
+       ret = kernctl_add_context(chan->fd, ctx);
+       if (ret < 0) {
+               if (errno != EEXIST) {
+                       perror("add context ioctl");
+               } else {
+                       /* If EEXIST, we just ignore the error */
+                       ret = 0;
+               }
+               goto error;
+       }
+
+       chan->ctx = malloc(sizeof(struct lttng_kernel_context));
+       if (chan->ctx == NULL) {
+               perror("malloc event context");
+               goto error;
+       }
+
+       memcpy(chan->ctx, ctx, sizeof(struct lttng_kernel_context));
+
+       return 0;
+
+error:
+       return ret;
+}
+
+/*
+ *  kernel_add_event_context
+ *
+ *  Add context on a kernel event.
+ */
+int kernel_add_event_context(struct ltt_kernel_event *event,
+               struct lttng_kernel_context *ctx)
+{
+       int ret;
+
+       DBG("Adding context to event %s", event->event->name);
+       ret = kernctl_add_context(event->fd, ctx);
+       if (ret < 0) {
+               perror("add context ioctl");
+               goto error;
+       }
+
+       event->ctx = malloc(sizeof(struct lttng_kernel_context));
+       if (event->ctx == NULL) {
+               perror("malloc event context");
+               goto error;
+       }
+
+       memcpy(event->ctx, ctx, sizeof(struct lttng_kernel_context));
+
+       return 0;
+
+error:
+       return ret;
+}
 
 /*
  *  kernel_create_session
  *
- *  Create a new kernel session using the command context session.
+ *  Create a new kernel session, register it to the kernel tracer and add it to
+ *  the session daemon session.
  */
-int kernel_create_session(struct command_ctx *cmd_ctx, int tracer_fd)
+int kernel_create_session(struct ltt_session *session, int tracer_fd)
 {
        int ret;
        struct ltt_kernel_session *lks;
 
-       /* Allocate a new kernel session */
-       lks = malloc(sizeof(struct ltt_kernel_session));
+       /* Allocate data structure */
+       lks = trace_create_kernel_session();
        if (lks == NULL) {
-               perror("kernel session malloc");
-               ret = -errno;
+               ret = -1;
                goto error;
        }
 
+       /* Kernel tracer session creation */
        ret = kernctl_create_session(tracer_fd);
        if (ret < 0) {
+               perror("ioctl kernel create session");
                goto error;
        }
 
-       /* Assigning session fd and to the command context */
        lks->fd = ret;
-       cmd_ctx->session->kernel_session = lks;
-       cmd_ctx->session->kern_session_count++;
+       /* Prevent fd duplication after execlp() */
+       ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC);
+       if (ret < 0) {
+               perror("fcntl session fd");
+       }
+
+       lks->kconsumer_fds_sent = 0;
+       session->kernel_session = lks;
+
+       DBG("Kernel session created (fd: %d)", lks->fd);
 
        return 0;
 
@@ -63,40 +141,134 @@ error:
 /*
  *  kernel_create_channel
  *
- *  Create a kernel channel within the kernel session.
+ *  Create a kernel channel, register it to the kernel tracer and add it to the
+ *  kernel session.
  */
-int kernel_create_channel(struct command_ctx *cmd_ctx)
+int kernel_create_channel(struct ltt_kernel_session *session, struct lttng_channel *chan, char *path)
 {
        int ret;
        struct ltt_kernel_channel *lkc;
-       struct lttng_kernel_channel *chan;
 
-       lkc = malloc(sizeof(struct ltt_kernel_channel));
-       chan = malloc(sizeof(struct lttng_kernel_channel));
+       /* Allocate kernel channel */
+       lkc = trace_create_kernel_channel(chan, path);
+       if (lkc == NULL) {
+               goto error;
+       }
+
+       /* Kernel tracer channel creation */
+       ret = kernctl_create_channel(session->fd, &lkc->channel->attr);
+       if (ret < 0) {
+               perror("ioctl kernel create channel");
+               goto error;
+       }
+
+       /* Setup the channel fd */
+       lkc->fd = ret;
+       /* Prevent fd duplication after execlp() */
+       ret = fcntl(lkc->fd, F_SETFD, FD_CLOEXEC);
+       if (ret < 0) {
+               perror("fcntl session fd");
+       }
+
+       /* Add channel to session */
+       cds_list_add(&lkc->list, &session->channel_list.head);
+       session->channel_count++;
+
+       DBG("Kernel channel %s created (fd: %d and path: %s)",
+                       lkc->channel->name, lkc->fd, lkc->pathname);
+
+       return 0;
+
+error:
+       return -1;
+}
+
+/*
+ *  kernel_create_event
+ *
+ *  Create a kernel event, enable it to the kernel tracer and add it to the
+ *  channel event list of the kernel session.
+ */
+int kernel_create_event(struct lttng_event *ev, struct ltt_kernel_channel *channel)
+{
+       int ret;
+       struct ltt_kernel_event *event;
 
-       if (lkc == NULL || chan == NULL) {
-               perror("kernel channel malloc");
-               ret = -errno;
+       event = trace_create_kernel_event(ev);
+       if (event == NULL) {
                goto error;
        }
 
-       chan->overwrite = DEFAULT_KERNEL_OVERWRITE;
-       chan->subbuf_size = DEFAULT_KERNEL_SUBBUF_SIZE;
-       chan->num_subbuf = DEFAULT_KERNEL_SUBBUF_NUM;
-       chan->switch_timer_interval = DEFAULT_KERNEL_SWITCH_TIMER;
-       chan->read_timer_interval = DEFAULT_KERNEL_READ_TIMER;
+       ret = kernctl_create_event(channel->fd, event->event);
+       if (ret < 0) {
+               perror("create event ioctl");
+               goto free_event;
+       }
+
+       event->fd = ret;
+       /* Prevent fd duplication after execlp() */
+       ret = fcntl(event->fd, F_SETFD, FD_CLOEXEC);
+       if (ret < 0) {
+               perror("fcntl session fd");
+       }
+
+       /* Add event to event list */
+       cds_list_add(&event->list, &channel->events_list.head);
+       channel->event_count++;
+
+       DBG("Event %s created (fd: %d)", ev->name, event->fd);
+
+       return 0;
+
+free_event:
+       free(event);
+error:
+       return -1;
+}
+
+/*
+ *  kernel_disable_channel
+ *
+ *  Disable a kernel channel.
+ */
+int kernel_disable_channel(struct ltt_kernel_channel *chan)
+{
+       int ret;
 
-       ret = kernctl_create_channel(cmd_ctx->session->kernel_session->fd, chan);
+       ret = kernctl_disable(chan->fd);
        if (ret < 0) {
-               perror("ioctl create channel");
+               perror("disable chan ioctl");
+               ret = errno;
                goto error;
        }
 
-       lkc->fd = ret;
-       lkc->channel = chan;
-       CDS_INIT_LIST_HEAD(&lkc->events_list.head);
+       chan->enabled = 0;
+       DBG("Kernel channel %s disabled (fd: %d)", chan->channel->name, chan->fd);
+
+       return 0;
 
-       cmd_ctx->session->kernel_session->channel = lkc;
+error:
+       return ret;
+}
+
+/*
+ *  kernel_enable_channel
+ *
+ *  Enable a kernel channel.
+ */
+int kernel_enable_channel(struct ltt_kernel_channel *chan)
+{
+       int ret;
+
+       ret = kernctl_enable(chan->fd);
+       if (ret < 0) {
+               perror("enable chan ioctl");
+               ret = errno;
+               goto error;
+       }
+
+       chan->enabled = 1;
+       DBG("Kernel channel %s enabled (fd: %d)", chan->channel->name, chan->fd);
 
        return 0;
 
@@ -107,35 +279,47 @@ error:
 /*
  *  kernel_enable_event
  *
- *  Enable kernel event.
+ *  Enable kernel event.
  */
-int kernel_enable_event(struct ltt_kernel_channel *channel, char *name)
+int kernel_enable_event(struct ltt_kernel_event *event)
 {
        int ret;
-       struct ltt_kernel_event *event;
-       struct lttng_kernel_event *lke;
-
-       event = malloc(sizeof(struct ltt_kernel_event));
-       lke = malloc(sizeof(struct lttng_kernel_event));
 
-       if (event == NULL || lke == NULL) {
-               perror("kernel enable event malloc");
-               ret = -errno;
+       ret = kernctl_enable(event->fd);
+       if (ret < 0) {
+               perror("enable event ioctl");
+               if (errno == EEXIST) {
+                       ret = -EEXIST;
+               }
                goto error;
        }
 
-       /* Setting up a kernel event */
-       strncpy(lke->name, name, LTTNG_SYM_NAME_LEN);
-       lke->instrumentation = LTTNG_KERNEL_TRACEPOINTS;
-       event->event = lke;
+       event->enabled = 1;
+       DBG("Kernel event %s enabled (fd: %d)", event->event->name, event->fd);
+
+       return 0;
 
-       ret = kernctl_create_event(channel->fd, lke);
+error:
+       return ret;
+}
+
+/*
+ *  kernel_disable_event
+ *
+ *  Disable a kernel event.
+ */
+int kernel_disable_event(struct ltt_kernel_event *event)
+{
+       int ret;
+
+       ret = kernctl_disable(event->fd);
        if (ret < 0) {
+               perror("disable event ioctl");
                goto error;
        }
 
-       /* Add event to event list */
-       cds_list_add(&event->list, &channel->events_list.head);
+       event->enabled = 0;
+       DBG("Kernel event %s disabled (fd: %d)", event->event->name, event->fd);
 
        return 0;
 
@@ -146,40 +330,296 @@ error:
 /*
  *  kernel_open_metadata
  *
- *  Open metadata stream.
+ *  Create kernel metadata, open from the kernel tracer and add it to the
+ *  kernel session.
  */
-int kernel_open_metadata(struct ltt_kernel_session *session)
+int kernel_open_metadata(struct ltt_kernel_session *session, char *path)
 {
        int ret;
        struct ltt_kernel_metadata *lkm;
-       struct lttng_kernel_channel *conf;
 
-       lkm = malloc(sizeof(struct ltt_kernel_metadata));
-       conf = malloc(sizeof(struct lttng_kernel_channel));
+       /* Allocate kernel metadata */
+       lkm = trace_create_kernel_metadata(path);
+       if (lkm == NULL) {
+               goto error;
+       }
 
-       if (lkm == NULL || conf == NULL) {
-               perror("kernel open metadata malloc");
-               ret = -errno;
+       /* Kernel tracer metadata creation */
+       ret = kernctl_open_metadata(session->fd, &lkm->conf->attr);
+       if (ret < 0) {
                goto error;
        }
 
-       conf->overwrite = DEFAULT_KERNEL_OVERWRITE;
-       conf->subbuf_size = DEFAULT_KERNEL_SUBBUF_SIZE;
-       conf->num_subbuf = DEFAULT_KERNEL_SUBBUF_NUM;
-       conf->switch_timer_interval = DEFAULT_KERNEL_SWITCH_TIMER;
-       conf->read_timer_interval = DEFAULT_KERNEL_READ_TIMER;
+       lkm->fd = ret;
+       /* Prevent fd duplication after execlp() */
+       ret = fcntl(lkm->fd, F_SETFD, FD_CLOEXEC);
+       if (ret < 0) {
+               perror("fcntl session fd");
+       }
+
+       session->metadata = lkm;
+
+       DBG("Kernel metadata opened (fd: %d and path: %s)", lkm->fd, lkm->pathname);
+
+       return 0;
+
+error:
+       return -1;
+}
+
+/*
+ *  kernel_start_session
+ *
+ *  Start tracing session.
+ */
+int kernel_start_session(struct ltt_kernel_session *session)
+{
+       int ret;
 
-       ret = kernctl_open_metadata(session->fd, conf);
+       ret = kernctl_start_session(session->fd);
        if (ret < 0) {
+               perror("ioctl start session");
                goto error;
        }
 
-       session->metadata = lkm;
-       session->metadata->fd = ret;
-       session->metadata->conf = conf;
+       DBG("Kernel session started");
 
        return 0;
 
 error:
        return ret;
 }
+
+/*
+ *  kernel_wait_quiescent
+ *
+ *  Make a kernel wait to make sure in-flight probe have completed.
+ */
+void kernel_wait_quiescent(int fd)
+{
+       int ret;
+
+       DBG("Kernel quiescent wait on %d", fd);
+
+       ret = kernctl_wait_quiescent(fd);
+       if (ret < 0) {
+               perror("wait quiescent ioctl");
+               ERR("Kernel quiescent wait failed");
+       }
+}
+
+/*
+ *  kernel_calibrate
+ */
+int kernel_calibrate(int fd, struct lttng_kernel_calibrate *calibrate)
+{
+       int ret;
+
+       ret = kernctl_calibrate(fd, calibrate);
+       if (ret < 0) {
+               perror("calibrate ioctl");
+               return -1;
+       }
+
+       return 0;
+}
+
+
+/*
+ *  kernel_metadata_flush_buffer
+ *
+ *  Force flush buffer of metadata.
+ */
+int kernel_metadata_flush_buffer(int fd)
+{
+       int ret;
+
+       ret = kernctl_buffer_flush(fd);
+       if (ret < 0) {
+               ERR("Fail to flush metadata buffers %d (ret: %d", fd, ret);
+       }
+
+       return 0;
+}
+
+/*
+ *  kernel_flush_buffer
+ *
+ *  Force flush buffer for channel.
+ */
+int kernel_flush_buffer(struct ltt_kernel_channel *channel)
+{
+       int ret;
+       struct ltt_kernel_stream *stream;
+
+       DBG("Flush buffer for channel %s", channel->channel->name);
+
+       cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
+               DBG("Flushing channel stream %d", stream->fd);
+               ret = kernctl_buffer_flush(stream->fd);
+               if (ret < 0) {
+                       perror("ioctl");
+                       ERR("Fail to flush buffer for stream %d (ret: %d)",
+                                       stream->fd, ret);
+               }
+       }
+
+       return 0;
+}
+
+/*
+ *  kernel_stop_session
+ *
+ *  Stop tracing session.
+ */
+int kernel_stop_session(struct ltt_kernel_session *session)
+{
+       int ret;
+
+       ret = kernctl_stop_session(session->fd);
+       if (ret < 0) {
+               goto error;
+       }
+
+       DBG("Kernel session stopped");
+
+       return 0;
+
+error:
+       return ret;
+}
+
+/*
+ *  kernel_open_channel_stream
+ *
+ *  Open stream of channel, register it to the kernel tracer and add it
+ *  to the stream list of the channel.
+ *
+ *  Return the number of created stream. Else, a negative value.
+ */
+int kernel_open_channel_stream(struct ltt_kernel_channel *channel)
+{
+       int ret;
+       struct ltt_kernel_stream *lks;
+
+       while ((ret = kernctl_create_stream(channel->fd)) > 0) {
+               lks = trace_create_kernel_stream();
+               if (lks == NULL) {
+                       close(ret);
+                       goto error;
+               }
+
+               lks->fd = ret;
+               /* Prevent fd duplication after execlp() */
+               ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC);
+               if (ret < 0) {
+                       perror("fcntl session fd");
+               }
+
+               ret = asprintf(&lks->pathname, "%s/%s_%d",
+                               channel->pathname, channel->channel->name, channel->stream_count);
+               if (ret < 0) {
+                       perror("asprintf kernel create stream");
+                       goto error;
+               }
+
+               /* Add stream to channe stream list */
+               cds_list_add(&lks->list, &channel->stream_list.head);
+               channel->stream_count++;
+
+               DBG("Kernel stream %d created (fd: %d, state: %d, path: %s)",
+                               channel->stream_count, lks->fd, lks->state, lks->pathname);
+       }
+
+       return channel->stream_count;
+
+error:
+       return -1;
+}
+
+/*
+ *  kernel_open_metadata_stream
+ *
+ *  Open the metadata stream and set it to the kernel session.
+ */
+int kernel_open_metadata_stream(struct ltt_kernel_session *session)
+{
+       int ret;
+
+       ret = kernctl_create_stream(session->metadata->fd);
+       if (ret < 0) {
+               perror("kernel create metadata stream");
+               goto error;
+       }
+
+       DBG("Kernel metadata stream created (fd: %d)", ret);
+       session->metadata_stream_fd = ret;
+       /* Prevent fd duplication after execlp() */
+       ret = fcntl(session->metadata_stream_fd, F_SETFD, FD_CLOEXEC);
+       if (ret < 0) {
+               perror("fcntl session fd");
+       }
+
+       return 0;
+
+error:
+       return -1;
+}
+
+/*
+ * Get the event list from the kernel tracer and return the number of elements.
+ */
+ssize_t kernel_list_events(int tracer_fd, struct lttng_event **events)
+{
+       int fd, pos;
+       char *event;
+       size_t nbmem, count = 0;
+       ssize_t size;
+       FILE *fp;
+       struct lttng_event *elist;
+
+       fd = kernctl_tracepoint_list(tracer_fd);
+       if (fd < 0) {
+               perror("kernel tracepoint list");
+               goto error;
+       }
+
+       fp = fdopen(fd, "r");
+       if (fp == NULL) {
+               perror("kernel tracepoint list fdopen");
+               goto error;
+       }
+
+       /*
+        * Init memory size counter
+        * See kernel-ctl.h for explanation of this value
+        */
+       nbmem = KERNEL_EVENT_LIST_SIZE;
+       elist = malloc(sizeof(struct lttng_event) * nbmem);
+
+       while ((size = fscanf(fp, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) {
+               if (count > nbmem) {
+                       DBG("Reallocating event list from %zu to %zu bytes", nbmem,
+                                       nbmem + KERNEL_EVENT_LIST_SIZE);
+                       /* Adding the default size again */
+                       nbmem += KERNEL_EVENT_LIST_SIZE;
+                       elist = realloc(elist, nbmem);
+                       if (elist == NULL) {
+                               perror("realloc list events");
+                               goto error;
+                       }
+               }
+               strncpy(elist[count].name, event, LTTNG_SYMBOL_NAME_LEN);
+               elist[count].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
+               count++;
+       }
+
+       *events = elist;
+
+       DBG("Kernel list events done (%zu events)", count);
+
+       return count;
+
+error:
+       return -1;
+}
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