Rename kconsumerd to ltt-kconsumerd

[lttng-tools.git] / ltt-sessiond / main.c

diff --git a/ltt-sessiond/main.c b/ltt-sessiond/main.c
index 75215b3f23039bb16caa3d5e45af5c854f3689db..0effeb1f5ab51a0c91973505c7efd9629dee5a3c 100644 (file)
--- a/ltt-sessiond/main.c
+++ b/ltt-sessiond/main.c
@@ -28,6 +28,7 @@
 #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>
@@ -580,7 +581,7 @@ static pid_t spawn_kconsumerd(void)
                /*
                 * Exec kconsumerd.
                 */
-               execlp("kconsumerd", "kconsumerd", "--verbose", NULL);
+               execlp("ltt-kconsumerd", "ltt-kconsumerd", "--verbose", NULL);
                if (errno != 0) {
                        perror("kernel start consumer exec");
                }
@@ -641,6 +642,58 @@ error:
        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
  *
@@ -648,14 +701,80 @@ error:
  */
 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(&lttng_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;
 }
 
 /*
@@ -1225,7 +1344,8 @@ static int process_client_msg(struct command_ctx *cmd_ctx)
                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;
@@ -1760,7 +1880,7 @@ static int check_existing_daemon()
  *  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)
 {
@@ -1773,8 +1893,13 @@ 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;
        }
 
@@ -1989,7 +2114,6 @@ int main(int argc, char **argv)
        /* Check if daemon is UID = 0 */
        is_root = !getuid();
 
-       /* Set all sockets path */
        if (is_root) {
                ret = create_lttng_rundir();
                if (ret < 0) {