#include <getopt.h>
#include <grp.h>
#include <limits.h>
+#include <poll.h>
#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ipc.h>
+#include <sys/mount.h>
#include <sys/shm.h>
#include <sys/socket.h>
#include <sys/stat.h>
static int is_root; /* Set to 1 if the daemon is running as root */
static pid_t ppid; /* Parent PID for --sig-parent option */
static pid_t kconsumerd_pid;
+static struct pollfd *kernel_pollfd;
static char apps_unix_sock_path[PATH_MAX]; /* Global application Unix socket path */
static char client_unix_sock_path[PATH_MAX]; /* Global client Unix socket path */
static int kconsumerd_err_sock;
static int kconsumerd_cmd_sock;
static int kernel_tracer_fd;
+static int kernel_poll_pipe[2];
/* Pthread, Mutexes and Semaphores */
static pthread_t kconsumerd_thread;
static pthread_t apps_thread;
static pthread_t client_thread;
+static pthread_t kernel_thread;
static sem_t kconsumerd_sem;
static pthread_mutex_t kconsumerd_pid_mutex; /* Mutex to control kconsumerd pid assignation */
+/*
+ * Pointer initialized before thread creation.
+ *
+ * This points to the tracing session list containing the session count and a
+ * mutex lock. The lock MUST be taken if you iterate over the list. The lock
+ * MUST NOT be taken if you call a public function in session.c.
+ */
+static struct ltt_session_list *session_list_ptr;
+
/*
* teardown_kernel_session
*
- * Complete teardown of a kernel session. This free all data structure
- * related to a kernel session and update counter.
+ * Complete teardown of a kernel session. This free all data structure related
+ * to a kernel session and update counter.
*/
static void teardown_kernel_session(struct ltt_session *session)
{
trace_destroy_kernel_session(session->kernel_session);
/* Extra precaution */
session->kernel_session = NULL;
- /* Decrement session count */
- session->kern_session_count--;
}
}
DBG("Terminating all threads");
pthread_cancel(client_thread);
pthread_cancel(apps_thread);
+ pthread_cancel(kernel_thread);
if (kconsumerd_pid != 0) {
pthread_cancel(kconsumerd_thread);
}
DBG("Cleaning up all session");
/* Cleanup ALL session */
- cds_list_for_each_entry(sess, <t_session_list.head, list) {
+ cds_list_for_each_entry(sess, &session_list_ptr->head, list) {
teardown_kernel_session(sess);
// TODO complete session cleanup (including UST)
}
+ /* Destroy session list mutex */
+ pthread_mutex_destroy(&session_list_ptr->lock);
+
DBG("Closing kernel fd");
close(kernel_tracer_fd);
+ close(kernel_poll_pipe[0]);
+ close(kernel_poll_pipe[1]);
}
/*
}
/*
- * send_kconsumerd_fds
+ * send_kconsumerd_channel_fds
*
- * Send all stream fds of the kernel session to the consumer.
+ * Send all stream fds of kernel channel to the consumer.
*/
-static int send_kconsumerd_fds(int sock, struct ltt_kernel_session *session)
+static int send_kconsumerd_channel_fds(int sock, struct ltt_kernel_channel *channel)
{
int ret;
size_t nb_fd;
struct ltt_kernel_stream *stream;
- struct ltt_kernel_channel *chan;
struct lttcomm_kconsumerd_header lkh;
struct lttcomm_kconsumerd_msg lkm;
- nb_fd = session->stream_count_global;
+ DBG("Sending fds of channel %s to kernel consumer", channel->channel->name);
+
+ nb_fd = channel->stream_count;
/* Setup header */
- lkh.payload_size = (nb_fd + 1) * sizeof(struct lttcomm_kconsumerd_msg);
+ lkh.payload_size = nb_fd * sizeof(struct lttcomm_kconsumerd_msg);
lkh.cmd_type = ADD_STREAM;
DBG("Sending kconsumerd header");
goto error;
}
- DBG("Sending metadata stream fd");
-
- /* Send metadata stream fd first */
- lkm.fd = session->metadata_stream_fd;
- lkm.state = ACTIVE_FD;
- lkm.max_sb_size = session->metadata->conf->attr.subbuf_size;
- strncpy(lkm.path_name, session->metadata->pathname, PATH_MAX);
-
- ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
- if (ret < 0) {
- perror("send kconsumerd fd");
- goto error;
- }
-
- cds_list_for_each_entry(chan, &session->channel_list.head, list) {
- cds_list_for_each_entry(stream, &chan->stream_list.head, list) {
+ cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
+ if (stream->fd != 0) {
lkm.fd = stream->fd;
lkm.state = stream->state;
- lkm.max_sb_size = chan->channel->attr.subbuf_size;
+ lkm.max_sb_size = channel->channel->attr.subbuf_size;
strncpy(lkm.path_name, stream->pathname, PATH_MAX);
DBG("Sending fd %d to kconsumerd", lkm.fd);
}
}
- DBG("Kconsumerd fds sent");
+ DBG("Kconsumerd channel fds sent");
return 0;
}
/*
- * create_trace_dir
+ * send_kconsumerd_fds
*
- * Create the trace output directory.
+ * Send all stream fds of the kernel session to the consumer.
*/
-static int create_trace_dir(struct ltt_kernel_session *session)
+static int send_kconsumerd_fds(int sock, struct ltt_kernel_session *session)
{
int ret;
struct ltt_kernel_channel *chan;
+ struct lttcomm_kconsumerd_header lkh;
+ struct lttcomm_kconsumerd_msg lkm;
+
+ /* Setup header */
+ lkh.payload_size = sizeof(struct lttcomm_kconsumerd_msg);
+ lkh.cmd_type = ADD_STREAM;
+
+ DBG("Sending kconsumerd header for metadata");
+
+ ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header));
+ if (ret < 0) {
+ perror("send kconsumerd header");
+ goto error;
+ }
+
+ DBG("Sending metadata stream fd");
+
+ if (session->metadata_stream_fd != 0) {
+ /* Send metadata stream fd first */
+ lkm.fd = session->metadata_stream_fd;
+ lkm.state = ACTIVE_FD;
+ lkm.max_sb_size = session->metadata->conf->attr.subbuf_size;
+ strncpy(lkm.path_name, session->metadata->pathname, PATH_MAX);
+
+ ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
+ if (ret < 0) {
+ perror("send kconsumerd fd");
+ goto error;
+ }
+ }
- /* Create all channel directories */
cds_list_for_each_entry(chan, &session->channel_list.head, list) {
- DBG("Creating trace directory at %s", chan->pathname);
- ret = mkdir_recursive(chan->pathname, S_IRWXU | S_IRWXG );
+ ret = send_kconsumerd_channel_fds(sock, chan);
if (ret < 0) {
- if (ret != EEXIST) {
- ERR("Trace directory creation error");
- goto error;
- }
+ goto error;
}
}
+ DBG("Kconsumerd fds (metadata and channel streams) sent");
+
return 0;
error:
return ret;
}
+/*
+ * update_kernel_pollfd
+ *
+ * Update the kernel pollfd set of all channel fd available over
+ * all tracing session. Add the wakeup pipe at the end of the set.
+ */
+static int update_kernel_pollfd(void)
+{
+ int i = 0;
+ unsigned int nb_fd = 1;
+ struct ltt_session *session;
+ struct ltt_kernel_channel *channel;
+
+ DBG("Updating kernel_pollfd");
+
+ /* Get the number of channel of all kernel session */
+ pthread_mutex_lock(&session_list_ptr->lock);
+ cds_list_for_each_entry(session, &session_list_ptr->head, list) {
+ lock_session(session);
+ if (session->kernel_session == NULL) {
+ unlock_session(session);
+ continue;
+ }
+ nb_fd += session->kernel_session->channel_count;
+ unlock_session(session);
+ }
+
+ DBG("Resizing kernel_pollfd to size %d", nb_fd);
+
+ kernel_pollfd = realloc(kernel_pollfd, nb_fd * sizeof(struct pollfd));
+ if (kernel_pollfd == NULL) {
+ perror("malloc kernel_pollfd");
+ goto error;
+ }
+
+ cds_list_for_each_entry(session, &session_list_ptr->head, list) {
+ lock_session(session);
+ if (session->kernel_session == NULL) {
+ unlock_session(session);
+ continue;
+ }
+ if (i >= nb_fd) {
+ ERR("To much channel for kernel_pollfd size");
+ unlock_session(session);
+ break;
+ }
+ cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
+ kernel_pollfd[i].fd = channel->fd;
+ kernel_pollfd[i].events = POLLIN | POLLRDNORM;
+ i++;
+ }
+ unlock_session(session);
+ }
+ pthread_mutex_unlock(&session_list_ptr->lock);
+
+ /* Adding wake up pipe */
+ kernel_pollfd[nb_fd - 1].fd = kernel_poll_pipe[0];
+ kernel_pollfd[nb_fd - 1].events = POLLIN;
+
+ return nb_fd;
+
+error:
+ pthread_mutex_unlock(&session_list_ptr->lock);
+ return -1;
+}
+
+/*
+ * update_kernel_stream
+ *
+ * Find the channel fd from 'fd' over all tracing session. When found, check
+ * for new channel stream and send those stream fds to the kernel consumer.
+ *
+ * Useful for CPU hotplug feature.
+ */
+static int update_kernel_stream(int fd)
+{
+ int ret = 0;
+ struct ltt_session *session;
+ struct ltt_kernel_channel *channel;
+
+ DBG("Updating kernel streams for channel fd %d", fd);
+
+ pthread_mutex_lock(&session_list_ptr->lock);
+ cds_list_for_each_entry(session, &session_list_ptr->head, list) {
+ lock_session(session);
+ if (session->kernel_session == NULL) {
+ unlock_session(session);
+ continue;
+ }
+ cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
+ if (channel->fd == fd) {
+ DBG("Channel found, updating kernel streams");
+ ret = kernel_open_channel_stream(channel);
+ if (ret < 0) {
+ goto end;
+ }
+ /*
+ * Have we already sent fds to the consumer? If yes, it means that
+ * tracing is started so it is safe to send our updated stream fds.
+ */
+ if (session->kernel_session->kconsumer_fds_sent == 1) {
+ ret = send_kconsumerd_channel_fds(kconsumerd_cmd_sock, channel);
+ if (ret < 0) {
+ goto end;
+ }
+ }
+ goto end;
+ }
+ }
+ unlock_session(session);
+ }
+
+end:
+ if (session) {
+ unlock_session(session);
+ }
+ pthread_mutex_unlock(&session_list_ptr->lock);
+ return ret;
+}
+
+/*
+ * thread_manage_kernel
+ *
+ * This thread manage event coming from the kernel.
+ *
+ * Features supported in this thread:
+ * -) CPU Hotplug
+ */
+static void *thread_manage_kernel(void *data)
+{
+ int ret, i, nb_fd = 0;
+ char tmp;
+ int update_poll_flag = 1;
+
+ DBG("Thread manage kernel started");
+
+ while (1) {
+ if (update_poll_flag == 1) {
+ nb_fd = update_kernel_pollfd();
+ if (nb_fd < 0) {
+ goto error;
+ }
+ update_poll_flag = 0;
+ }
+
+ DBG("Polling on %d fds", nb_fd);
+
+ /* Poll infinite value of time */
+ ret = poll(kernel_pollfd, nb_fd, -1);
+ if (ret < 0) {
+ perror("poll kernel thread");
+ goto error;
+ } else if (ret == 0) {
+ /* Should not happen since timeout is infinite */
+ continue;
+ }
+
+ DBG("Kernel poll event triggered");
+
+ /*
+ * Check if the wake up pipe was triggered. If so, the kernel_pollfd
+ * must be updated.
+ */
+ switch (kernel_pollfd[nb_fd - 1].revents) {
+ case POLLIN:
+ ret = read(kernel_poll_pipe[0], &tmp, 1);
+ update_poll_flag = 1;
+ continue;
+ case POLLERR:
+ goto error;
+ default:
+ break;
+ }
+
+ for (i = 0; i < nb_fd; i++) {
+ switch (kernel_pollfd[i].revents) {
+ /*
+ * New CPU detected by the kernel. Adding kernel stream to kernel
+ * session and updating the kernel consumer
+ */
+ case POLLIN | POLLRDNORM:
+ ret = update_kernel_stream(kernel_pollfd[i].fd);
+ if (ret < 0) {
+ continue;
+ }
+ break;
+ }
+ }
+ }
+
+error:
+ DBG("Kernel thread dying");
+ if (kernel_pollfd) {
+ free(kernel_pollfd);
+ }
+ return NULL;
+}
+
/*
* thread_manage_kconsumerd
*
/*
* Exec kconsumerd.
*/
- execlp("kconsumerd", "kconsumerd", "--verbose", NULL);
+ execlp("ltt-kconsumerd", "ltt-kconsumerd", "--verbose", NULL);
if (errno != 0) {
perror("kernel start consumer exec");
}
return ret;
}
+/*
+ * modprobe_kernel_modules
+ */
+static int modprobe_kernel_modules(void)
+{
+ int ret = 0, i = 0;
+ char modprobe[256];
+
+ while (kernel_modules_list[i] != NULL) {
+ ret = snprintf(modprobe, sizeof(modprobe), "/sbin/modprobe %s",
+ kernel_modules_list[i]);
+ if (ret < 0) {
+ perror("snprintf modprobe");
+ goto error;
+ }
+ ret = system(modprobe);
+ if (ret < 0) {
+ ERR("Unable to load module %s", kernel_modules_list[i]);
+ }
+ DBG("Modprobe successfully %s", kernel_modules_list[i]);
+ i++;
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * mount_debugfs
+ */
+static int mount_debugfs(char *path)
+{
+ int ret;
+ char *type = "debugfs";
+
+ ret = mkdir_recursive(path, S_IRWXU | S_IRWXG);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = mount(type, path, type, 0, NULL);
+ if (ret < 0) {
+ perror("mount debugfs");
+ goto error;
+ }
+
+ DBG("Mounted debugfs successfully at %s", path);
+
+error:
+ return ret;
+}
+
/*
* init_kernel_tracer
*
*/
static void init_kernel_tracer(void)
{
- /* Set the global kernel tracer fd */
- kernel_tracer_fd = open(DEFAULT_KERNEL_TRACER_PATH, O_RDWR);
+ int ret;
+ char *proc_mounts = "/proc/mounts";
+ char line[256];
+ char *debugfs_path = NULL, *lttng_path;
+ FILE *fp;
+
+ /* Detect debugfs */
+ fp = fopen(proc_mounts, "r");
+ if (fp == NULL) {
+ ERR("Unable to probe %s", proc_mounts);
+ goto error;
+ }
+
+ while (fgets(line, sizeof(line), fp) != NULL) {
+ if (strstr(line, "debugfs") != NULL) {
+ /* Remove first string */
+ strtok(line, " ");
+ /* Dup string here so we can reuse line later on */
+ debugfs_path = strdup(strtok(NULL, " "));
+ DBG("Got debugfs path : %s", debugfs_path);
+ break;
+ }
+ }
+
+ fclose(fp);
+
+ /* Mount debugfs if needded */
+ if (debugfs_path == NULL) {
+ ret = asprintf(&debugfs_path, "/mnt/debugfs");
+ if (ret < 0) {
+ perror("asprintf debugfs path");
+ goto error;
+ }
+ ret = mount_debugfs(debugfs_path);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+
+ /* Modprobe lttng kernel modules */
+ ret = modprobe_kernel_modules();
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Setup lttng kernel path */
+ ret = asprintf(<tng_path, "%s/lttng", debugfs_path);
+ if (ret < 0) {
+ perror("asprintf lttng path");
+ goto error;
+ }
+
+ /* Open debugfs lttng */
+ kernel_tracer_fd = open(lttng_path, O_RDWR);
if (kernel_tracer_fd < 0) {
- WARN("No kernel tracer available");
- kernel_tracer_fd = 0;
+ DBG("Failed to open %s", lttng_path);
+ goto error;
}
+ free(lttng_path);
+ free(debugfs_path);
DBG("Kernel tracer fd %d", kernel_tracer_fd);
+ return;
+
+error:
+ if (lttng_path) {
+ free(lttng_path);
+ }
+ if (debugfs_path) {
+ free(debugfs_path);
+ }
+ WARN("No kernel tracer available");
+ kernel_tracer_fd = 0;
+ return;
}
/*
{
int ret;
- /* Create trace directory */
- ret = create_trace_dir(session);
- if (ret < 0) {
- if (ret == -EEXIST) {
- ret = LTTCOMM_KERN_DIR_EXIST;
- } else {
- ret = LTTCOMM_KERN_DIR_FAIL;
- goto error;
- }
- }
-
if (session->kconsumer_fds_sent == 0) {
ret = send_kconsumerd_fds(kconsumerd_cmd_sock, session);
if (ret < 0) {
return ret;
}
+/*
+ * Notify kernel thread to update it's pollfd.
+ */
+static int notify_kernel_pollfd(void)
+{
+ int ret;
+
+ /* Inform kernel thread of the new kernel channel */
+ ret = write(kernel_poll_pipe[1], "!", 1);
+ if (ret < 0) {
+ perror("write kernel poll pipe");
+ }
+
+ return ret;
+}
+
/*
* init_default_channel
*
goto error;
}
+ ret = mkdir_recursive(session->path, S_IRWXU | S_IRWXG );
+ if (ret < 0) {
+ if (ret != EEXIST) {
+ ERR("Trace directory creation error");
+ goto error;
+ }
+ }
+
DBG("Creating default kernel channel %s", DEFAULT_CHANNEL_NAME);
ret = kernel_create_channel(session->kernel_session, chan, session->path);
goto error;
}
+ ret = notify_kernel_pollfd();
+
error:
return ret;
}
ret = LTTCOMM_SELECT_SESS;
}
goto error;
+ } else {
+ /* Acquire lock for the session */
+ lock_session(cmd_ctx->session);
}
break;
}
goto error;
}
+ ret = notify_kernel_pollfd();
+ if (ret < 0) {
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+
ret = LTTCOMM_OK;
break;
}
if (cmd_ctx->session->kernel_session != NULL) {
if (cmd_ctx->session->kernel_session->metadata == NULL) {
DBG("Open kernel metadata");
- ret = kernel_open_metadata(cmd_ctx->session->kernel_session);
+ ret = kernel_open_metadata(cmd_ctx->session->kernel_session,
+ cmd_ctx->session->path);
if (ret < 0) {
ret = LTTCOMM_KERN_META_FAIL;
goto error;
goto error;
}
+ /*
+ * Must notify the kernel thread here to update it's pollfd in order to
+ * remove the channel(s)' fd just destroyed.
+ */
+ ret = notify_kernel_pollfd();
+ if (ret < 0) {
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+
ret = LTTCOMM_OK;
break;
}
/* Set return code */
cmd_ctx->llm->ret_code = ret;
+ if (cmd_ctx->session) {
+ unlock_session(cmd_ctx->session);
+ }
+
return ret;
error:
cmd_ctx->llm->ret_code = ret;
setup_error:
+ if (cmd_ctx->session) {
+ unlock_session(cmd_ctx->session);
+ }
return ret;
}
* Set the tracing group gid onto the client socket.
*
* Race window between mkdir and chown is OK because we are going from
- * less permissive (root.root) to more permissive (root.tracing).
+ * more permissive (root.root) to les permissive (root.tracing).
*/
static int set_permissions(void)
{
(grp = getgrnam(default_tracing_group));
if (grp == NULL) {
- ERR("Missing tracing group. Aborting execution.\n");
- ret = -1;
+ if (is_root) {
+ WARN("No tracing group detected");
+ ret = 0;
+ } else {
+ ERR("Missing tracing group. Aborting execution.");
+ ret = -1;
+ }
goto end;
}
return ret;
}
+/*
+ * create_kernel_poll_pipe
+ *
+ * Create the pipe used to wake up the kernel thread.
+ */
+static int create_kernel_poll_pipe(void)
+{
+ return pipe2(kernel_poll_pipe, O_CLOEXEC);
+}
+
/*
* create_lttng_rundir
*
/* Check if daemon is UID = 0 */
is_root = !getuid();
- /* Set all sockets path */
if (is_root) {
ret = create_lttng_rundir();
if (ret < 0) {
ppid = getppid();
}
+ /* Setup the kernel pipe for waking up the kernel thread */
+ if (create_kernel_poll_pipe() < 0) {
+ goto error;
+ }
+
+ /* Get session list pointer */
+ session_list_ptr = get_session_list();
+
while (1) {
/* Create thread to manage the client socket */
ret = pthread_create(&client_thread, NULL, thread_manage_clients, (void *) NULL);
goto error;
}
+ /* Create kernel thread to manage kernel event */
+ ret = pthread_create(&kernel_thread, NULL, thread_manage_kernel, (void *) NULL);
+ if (ret != 0) {
+ perror("pthread_create");
+ goto error;
+ }
+
ret = pthread_join(client_thread, &status);
if (ret != 0) {
perror("pthread_join");
projects / lttng-tools.git / blobdiff