* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#define _GNU_SOURCE
-#include <errno.h>
+#define _LGPL_SOURCE
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <common/common.h>
#include <common/kernel-ctl/kernel-ctl.h>
+#include <common/kernel-ctl/kernel-ioctl.h>
#include <common/sessiond-comm/sessiond-comm.h>
#include "consumer.h"
#include "kernel.h"
+#include "kernel-consumer.h"
#include "kern-modules.h"
+#include "utils.h"
/*
* Add context on a kernel channel.
+ *
+ * Assumes the ownership of ctx.
*/
int kernel_add_channel_context(struct ltt_kernel_channel *chan,
- struct lttng_kernel_context *ctx)
+ struct ltt_kernel_context *ctx)
{
int ret;
assert(ctx);
DBG("Adding context to channel %s", chan->channel->name);
- ret = kernctl_add_context(chan->fd, ctx);
+ ret = kernctl_add_context(chan->fd, &ctx->ctx);
if (ret < 0) {
- if (errno != EEXIST) {
- PERROR("add context ioctl");
- } else {
+ switch (-ret) {
+ case ENOSYS:
+ /* Exists but not available for this kernel */
+ ret = LTTNG_ERR_KERN_CONTEXT_UNAVAILABLE;
+ goto error;
+ case EEXIST:
/* If EEXIST, we just ignore the error */
ret = 0;
+ goto end;
+ default:
+ PERROR("add context ioctl");
+ ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
+ goto error;
}
- goto error;
- }
-
- chan->ctx = zmalloc(sizeof(struct lttng_kernel_context));
- if (chan->ctx == NULL) {
- PERROR("zmalloc event context");
- goto error;
}
+ ret = 0;
- memcpy(chan->ctx, ctx, sizeof(struct lttng_kernel_context));
-
- return 0;
-
+end:
+ cds_list_add_tail(&ctx->list, &chan->ctx_list);
+ ctx->in_list = true;
+ ctx = NULL;
error:
+ if (ctx) {
+ trace_kernel_destroy_context(ctx);
+ }
return ret;
}
goto error;
}
- DBG3("Kernel create channel %s with attr: %d, %" PRIu64 ", %" PRIu64 ", %u, %u, %d",
+ DBG3("Kernel create channel %s with attr: %d, %" PRIu64 ", %" PRIu64 ", %u, %u, %d, %d",
chan->name, lkc->channel->attr.overwrite,
lkc->channel->attr.subbuf_size, lkc->channel->attr.num_subbuf,
lkc->channel->attr.switch_timer_interval, lkc->channel->attr.read_timer_interval,
- lkc->channel->attr.output);
+ lkc->channel->attr.live_timer_interval, lkc->channel->attr.output);
/* Kernel tracer channel creation */
ret = kernctl_create_channel(session->fd, &lkc->channel->attr);
/*
* Create a kernel event, enable it to the kernel tracer and add it to the
* channel event list of the kernel session.
+ * We own filter_expression and filter.
*/
int kernel_create_event(struct lttng_event *ev,
- struct ltt_kernel_channel *channel)
+ struct ltt_kernel_channel *channel,
+ char *filter_expression,
+ struct lttng_filter_bytecode *filter)
{
int ret;
struct ltt_kernel_event *event;
assert(ev);
assert(channel);
- event = trace_kernel_create_event(ev);
+ /* We pass ownership of filter_expression and filter */
+ event = trace_kernel_create_event(ev, filter_expression,
+ filter);
if (event == NULL) {
ret = -1;
goto error;
ret = kernctl_create_event(channel->fd, event->event);
if (ret < 0) {
- switch (errno) {
+ switch (-ret) {
case EEXIST:
break;
case ENOSYS:
WARN("Event type not implemented");
break;
+ case ENOENT:
+ WARN("Event %s not found!", ev->name);
+ break;
default:
PERROR("create event ioctl");
}
- ret = -errno;
goto free_event;
}
- /*
- * LTTNG_KERNEL_SYSCALL event creation will return 0 on success.
- */
- if (ret == 0 && event->event->instrumentation == LTTNG_KERNEL_SYSCALL) {
- DBG2("Kernel event syscall creation success");
- /*
- * We use fd == -1 to ensure that we never trigger a close of fd
- * 0.
- */
- event->fd = -1;
- goto add_list;
- }
-
+ event->type = ev->type;
event->fd = ret;
/* Prevent fd duplication after execlp() */
ret = fcntl(event->fd, F_SETFD, FD_CLOEXEC);
PERROR("fcntl session fd");
}
-add_list:
+ if (filter) {
+ ret = kernctl_filter(event->fd, filter);
+ if (ret) {
+ goto filter_error;
+ }
+ }
+
+ ret = kernctl_enable(event->fd);
+ if (ret < 0) {
+ switch (-ret) {
+ case EEXIST:
+ ret = LTTNG_ERR_KERN_EVENT_EXIST;
+ break;
+ default:
+ PERROR("enable kernel event");
+ break;
+ }
+ goto enable_error;
+ }
+
/* Add event to event list */
cds_list_add(&event->list, &channel->events_list.head);
channel->event_count++;
return 0;
+enable_error:
+filter_error:
+ {
+ int closeret;
+
+ closeret = close(event->fd);
+ if (closeret) {
+ PERROR("close event fd");
+ }
+ }
free_event:
free(event);
error:
ret = kernctl_disable(chan->fd);
if (ret < 0) {
PERROR("disable chan ioctl");
- ret = errno;
goto error;
}
assert(chan);
ret = kernctl_enable(chan->fd);
- if (ret < 0 && errno != EEXIST) {
+ if (ret < 0 && ret != -EEXIST) {
PERROR("Enable kernel chan");
goto error;
}
ret = kernctl_enable(event->fd);
if (ret < 0) {
- switch (errno) {
+ switch (-ret) {
case EEXIST:
ret = LTTNG_ERR_KERN_EVENT_EXIST;
break;
ret = kernctl_disable(event->fd);
if (ret < 0) {
- switch (errno) {
+ switch (-ret) {
case EEXIST:
ret = LTTNG_ERR_KERN_EVENT_EXIST;
break;
return ret;
}
+
+int kernel_track_pid(struct ltt_kernel_session *session, int pid)
+{
+ int ret;
+
+ DBG("Kernel track PID %d for session id %" PRIu64 ".",
+ pid, session->id);
+ ret = kernctl_track_pid(session->fd, pid);
+ if (!ret) {
+ return LTTNG_OK;
+ }
+ switch (-ret) {
+ case EINVAL:
+ return LTTNG_ERR_INVALID;
+ case ENOMEM:
+ return LTTNG_ERR_NOMEM;
+ case EEXIST:
+ return LTTNG_ERR_PID_TRACKED;
+ default:
+ return LTTNG_ERR_UNK;
+ }
+}
+
+int kernel_untrack_pid(struct ltt_kernel_session *session, int pid)
+{
+ int ret;
+
+ DBG("Kernel untrack PID %d for session id %" PRIu64 ".",
+ pid, session->id);
+ ret = kernctl_untrack_pid(session->fd, pid);
+ if (!ret) {
+ return LTTNG_OK;
+ }
+ switch (-ret) {
+ case EINVAL:
+ return LTTNG_ERR_INVALID;
+ case ENOMEM:
+ return LTTNG_ERR_NOMEM;
+ case ENOENT:
+ return LTTNG_ERR_PID_NOT_TRACKED;
+ default:
+ return LTTNG_ERR_UNK;
+ }
+}
+
+ssize_t kernel_list_tracker_pids(struct ltt_kernel_session *session,
+ int **_pids)
+{
+ int fd, ret;
+ int pid;
+ ssize_t nbmem, count = 0;
+ FILE *fp;
+ int *pids;
+
+ fd = kernctl_list_tracker_pids(session->fd);
+ if (fd < 0) {
+ PERROR("kernel tracker pids list");
+ goto error;
+ }
+
+ fp = fdopen(fd, "r");
+ if (fp == NULL) {
+ PERROR("kernel tracker pids list fdopen");
+ goto error_fp;
+ }
+
+ nbmem = KERNEL_TRACKER_PIDS_INIT_LIST_SIZE;
+ pids = zmalloc(sizeof(*pids) * nbmem);
+ if (pids == NULL) {
+ PERROR("alloc list pids");
+ count = -ENOMEM;
+ goto end;
+ }
+
+ while (fscanf(fp, "process { pid = %u; };\n", &pid) == 1) {
+ if (count >= nbmem) {
+ int *new_pids;
+ size_t new_nbmem;
+
+ new_nbmem = nbmem << 1;
+ DBG("Reallocating pids list from %zu to %zu entries",
+ nbmem, new_nbmem);
+ new_pids = realloc(pids, new_nbmem * sizeof(*new_pids));
+ if (new_pids == NULL) {
+ PERROR("realloc list events");
+ free(pids);
+ count = -ENOMEM;
+ goto end;
+ }
+ /* Zero the new memory */
+ memset(new_pids + nbmem, 0,
+ (new_nbmem - nbmem) * sizeof(*new_pids));
+ nbmem = new_nbmem;
+ pids = new_pids;
+ }
+ pids[count++] = pid;
+ }
+
+ *_pids = pids;
+ DBG("Kernel list tracker pids done (%zd pids)", count);
+end:
+ ret = fclose(fp); /* closes both fp and fd */
+ if (ret) {
+ PERROR("fclose");
+ }
+ return count;
+
+error_fp:
+ ret = close(fd);
+ if (ret) {
+ PERROR("close");
+ }
+error:
+ return -1;
+}
+
/*
* Create kernel metadata, open from the kernel tracer and add it to the
* kernel session.
}
}
-/*
- * Kernel calibrate
- */
-int kernel_calibrate(int fd, struct lttng_kernel_calibrate *calibrate)
-{
- int ret;
-
- assert(calibrate);
-
- ret = kernctl_calibrate(fd, calibrate);
- if (ret < 0) {
- PERROR("calibrate ioctl");
- return -1;
- }
-
- return 0;
-}
-
-
/*
* Force flush buffer of metadata.
*/
* Open stream of channel, register it to the kernel tracer and add it
* to the stream list of the channel.
*
+ * Note: given that the streams may appear in random order wrt CPU
+ * number (e.g. cpu hotplug), the index value of the stream number in
+ * the stream name is not necessarily linked to the CPU number.
+ *
* Return the number of created stream. Else, a negative value.
*/
int kernel_open_channel_stream(struct ltt_kernel_channel *channel)
{
- int ret, count = 0;
+ int ret;
struct ltt_kernel_stream *lks;
assert(channel);
while ((ret = kernctl_create_stream(channel->fd)) >= 0) {
- lks = trace_kernel_create_stream(channel->channel->name, count);
+ lks = trace_kernel_create_stream(channel->channel->name,
+ channel->stream_count);
if (lks == NULL) {
ret = close(ret);
if (ret) {
lks->tracefile_size = channel->channel->attr.tracefile_size;
lks->tracefile_count = channel->channel->attr.tracefile_count;
- /* Add stream to channe stream list */
+ /* Add stream to channel stream list */
cds_list_add(&lks->list, &channel->stream_list.head);
channel->stream_count++;
- /* Increment counter which represent CPU number. */
- count++;
-
DBG("Kernel stream %s created (fd: %d, state: %d)", lks->name, lks->fd,
lks->state);
}
*/
ssize_t kernel_list_events(int tracer_fd, struct lttng_event **events)
{
- int fd, pos, ret;
+ int fd, ret;
char *event;
size_t nbmem, count = 0;
FILE *fp;
goto end;
}
- while (fscanf(fp, "event { name = %m[^;]; };%n\n", &event, &pos) == 1) {
+ while (fscanf(fp, "event { name = %m[^;]; };\n", &event) == 1) {
if (count >= nbmem) {
struct lttng_event *new_elist;
+ size_t new_nbmem;
- DBG("Reallocating event list from %zu to %zu bytes", nbmem,
- nbmem * 2);
- /* Double the size */
- nbmem <<= 1;
- new_elist = realloc(elist, nbmem * sizeof(struct lttng_event));
+ new_nbmem = nbmem << 1;
+ DBG("Reallocating event list from %zu to %zu bytes",
+ nbmem, new_nbmem);
+ new_elist = realloc(elist, new_nbmem * sizeof(struct lttng_event));
if (new_elist == NULL) {
PERROR("realloc list events");
free(event);
count = -ENOMEM;
goto end;
}
+ /* Zero the new memory */
+ memset(new_elist + nbmem, 0,
+ (new_nbmem - nbmem) * sizeof(struct lttng_event));
+ nbmem = new_nbmem;
elist = new_elist;
}
strncpy(elist[count].name, event, LTTNG_SYMBOL_NAME_LEN);
{
int ret;
struct lttng_kernel_tracer_version version;
+ struct lttng_kernel_tracer_abi_version abi_version;
ret = kernctl_tracer_version(tracer_fd, &version);
if (ret < 0) {
- ERR("Failed at getting the lttng-modules version");
+ ERR("Failed to retrieve the lttng-modules version");
goto error;
}
/* Validate version */
- if (version.major != KERN_MODULES_PRE_MAJOR
- && version.major != KERN_MODULES_MAJOR) {
+ if (version.major != VERSION_MAJOR) {
+ ERR("Kernel tracer major version (%d) is not compatible with lttng-tools major version (%d)",
+ version.major, VERSION_MAJOR);
goto error_version;
}
-
- DBG2("Kernel tracer version validated (major version %d)", version.major);
+ ret = kernctl_tracer_abi_version(tracer_fd, &abi_version);
+ if (ret < 0) {
+ ERR("Failed to retrieve lttng-modules ABI version");
+ goto error;
+ }
+ if (abi_version.major != LTTNG_MODULES_ABI_MAJOR_VERSION) {
+ ERR("Kernel tracer ABI version (%d.%d) does not match the expected ABI major version (%d.*)",
+ abi_version.major, abi_version.minor,
+ LTTNG_MODULES_ABI_MAJOR_VERSION);
+ goto error;
+ }
+ DBG2("Kernel tracer version validated (%d.%d, ABI %d.%d)",
+ version.major, version.minor,
+ abi_version.major, abi_version.minor);
return 0;
error_version:
- ERR("Kernel major version %d is not compatible (supporting <= %d)",
- version.major, KERN_MODULES_MAJOR)
ret = -1;
error:
+ ERR("Kernel tracer version check failed; kernel tracing will not be available");
return ret;
}
DBG("Tearing down kernel session");
+ /*
+ * Destroy channels on the consumer if at least one FD has been sent and we
+ * are in no output mode because the streams are in *no* monitor mode so we
+ * have to send a command to clean them up or else they leaked.
+ */
+ if (!ksess->output_traces && ksess->consumer_fds_sent) {
+ int ret;
+ struct consumer_socket *socket;
+ struct lttng_ht_iter iter;
+
+ /* For each consumer socket. */
+ rcu_read_lock();
+ cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
+ socket, node.node) {
+ struct ltt_kernel_channel *chan;
+
+ /* For each channel, ask the consumer to destroy it. */
+ cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
+ ret = kernel_consumer_destroy_channel(socket, chan);
+ if (ret < 0) {
+ /* Consumer is probably dead. Use next socket. */
+ continue;
+ }
+ }
+ }
+ rcu_read_unlock();
+ }
+
/* Close any relayd session */
consumer_output_send_destroy_relayd(ksess->consumer);
ksess->channel_count--;
}
}
+
+/*
+ * Take a snapshot for a given kernel session.
+ *
+ * Return 0 on success or else return a LTTNG_ERR code.
+ */
+int kernel_snapshot_record(struct ltt_kernel_session *ksess,
+ struct snapshot_output *output, int wait,
+ uint64_t nb_packets_per_stream)
+{
+ int err, ret, saved_metadata_fd;
+ struct consumer_socket *socket;
+ struct lttng_ht_iter iter;
+ struct ltt_kernel_metadata *saved_metadata;
+
+ assert(ksess);
+ assert(ksess->consumer);
+ assert(output);
+
+ DBG("Kernel snapshot record started");
+
+ /* Save current metadata since the following calls will change it. */
+ saved_metadata = ksess->metadata;
+ saved_metadata_fd = ksess->metadata_stream_fd;
+
+ rcu_read_lock();
+
+ ret = kernel_open_metadata(ksess);
+ if (ret < 0) {
+ ret = LTTNG_ERR_KERN_META_FAIL;
+ goto error;
+ }
+
+ ret = kernel_open_metadata_stream(ksess);
+ if (ret < 0) {
+ ret = LTTNG_ERR_KERN_META_FAIL;
+ goto error_open_stream;
+ }
+
+ /* Send metadata to consumer and snapshot everything. */
+ cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
+ socket, node.node) {
+ struct consumer_output *saved_output;
+ struct ltt_kernel_channel *chan;
+
+ /*
+ * Temporarly switch consumer output for our snapshot output. As long
+ * as the session lock is taken, this is safe.
+ */
+ saved_output = ksess->consumer;
+ ksess->consumer = output->consumer;
+
+ pthread_mutex_lock(socket->lock);
+ /* This stream must not be monitored by the consumer. */
+ ret = kernel_consumer_add_metadata(socket, ksess, 0);
+ pthread_mutex_unlock(socket->lock);
+ /* Put back the saved consumer output into the session. */
+ ksess->consumer = saved_output;
+ if (ret < 0) {
+ ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
+ goto error_consumer;
+ }
+
+ /* For each channel, ask the consumer to snapshot it. */
+ cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
+ ret = consumer_snapshot_channel(socket, chan->fd, output, 0,
+ ksess->uid, ksess->gid,
+ DEFAULT_KERNEL_TRACE_DIR, wait,
+ nb_packets_per_stream);
+ if (ret < 0) {
+ ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
+ (void) kernel_consumer_destroy_metadata(socket,
+ ksess->metadata);
+ goto error_consumer;
+ }
+ }
+
+ /* Snapshot metadata, */
+ ret = consumer_snapshot_channel(socket, ksess->metadata->fd, output,
+ 1, ksess->uid, ksess->gid,
+ DEFAULT_KERNEL_TRACE_DIR, wait, 0);
+ if (ret < 0) {
+ ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
+ goto error_consumer;
+ }
+
+ /*
+ * The metadata snapshot is done, ask the consumer to destroy it since
+ * it's not monitored on the consumer side.
+ */
+ (void) kernel_consumer_destroy_metadata(socket, ksess->metadata);
+ }
+
+ ret = LTTNG_OK;
+
+error_consumer:
+ /* Close newly opened metadata stream. It's now on the consumer side. */
+ err = close(ksess->metadata_stream_fd);
+ if (err < 0) {
+ PERROR("close snapshot kernel");
+ }
+
+error_open_stream:
+ trace_kernel_destroy_metadata(ksess->metadata);
+error:
+ /* Restore metadata state.*/
+ ksess->metadata = saved_metadata;
+ ksess->metadata_stream_fd = saved_metadata_fd;
+
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Get the syscall mask array from the kernel tracer.
+ *
+ * Return 0 on success else a negative value. In both case, syscall_mask should
+ * be freed.
+ */
+int kernel_syscall_mask(int chan_fd, char **syscall_mask, uint32_t *nr_bits)
+{
+ assert(syscall_mask);
+ assert(nr_bits);
+
+ return kernctl_syscall_mask(chan_fd, syscall_mask, nr_bits);
+}
+
+/*
+ * Check for the support of the RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS via abi
+ * version number.
+ *
+ * Return 1 on success, 0 when feature is not supported, negative value in case
+ * of errors.
+ */
+int kernel_supports_ring_buffer_snapshot_sample_positions(int tracer_fd)
+{
+ int ret = 0; // Not supported by default
+ struct lttng_kernel_tracer_abi_version abi;
+
+ ret = kernctl_tracer_abi_version(tracer_fd, &abi);
+ if (ret < 0) {
+ ERR("Failed to retrieve lttng-modules ABI version");
+ goto error;
+ }
+
+ /*
+ * RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS was introduced in 2.3
+ */
+ if (abi.major >= 2 && abi.minor >= 3) {
+ /* Supported */
+ ret = 1;
+ } else {
+ /* Not supported */
+ ret = 0;
+ }
+error:
+ return ret;
+}