static int initdebugfsmntdir(void)
{
- char mnt_dir[PATH_MAX];
- char mnt_type[PATH_MAX];
+ return getdebugfsmntdir(debugfsmntdir);
+}
- FILE *fp = fopen("/proc/mounts", "r");
- if (!fp) {
- fprintf(stderr, "%s: Can't open /proc/mounts\n", __func__);
- return 1;
+/*
+ * This function must called posterior to initdebugfsmntdir(),
+ * because it need to use debugfsmntdir[] which is inited in initdebugfsmntdir()
+ */
+static int initmodule(void)
+{
+ char controldirname[PATH_MAX];
+ DIR *dir;
+ int tryload_done = 0;
+
+ sprintf(controldirname, "%s/ltt/control/", debugfsmntdir);
+
+check_again:
+ /*
+ * Check ltt control's debugfs dir
+ *
+ * We don't check is ltt-trace-control module exist, because it maybe
+ * compiled into kernel.
+ */
+ dir = opendir(controldirname);
+ if (dir) {
+ closedir(dir);
+ return 0;
}
- while (1) {
- if (fscanf(fp, "%*s %s %s %*s %*s %*s", mnt_dir, mnt_type)
- <= 0) {
- fprintf(stderr, "%s: debugfs mountpoint not found\n",
- __func__);
- return 1;
- }
- if (!strcmp(mnt_type, "debugfs")) {
- strcpy(debugfsmntdir, mnt_dir);
- return 0;
- }
+ if (!tryload_done) {
+ system("modprobe ltt-trace-control");
+ tryload_done = 1;
+ goto check_again;
}
+
+ return -ENOENT;
}
int lttctl_init(void)
{
int ret;
- DIR *dir;
- char controldirname[PATH_MAX];
+
ret = initdebugfsmntdir();
if (ret) {
- fprintf(stderr, "Debugfs mount point not found\n");
+ fprintf(stderr, "Get debugfs mount point failed\n");
return 1;
}
- /* check ltt control's debugfs dir */
- sprintf(controldirname, "%s/ltt/control/", debugfsmntdir);
-
- dir = opendir(controldirname);
- if (!dir) {
- fprintf(stderr, "ltt-trace-control's debugfs dir not found\n");
- closedir(dir);
- return -errno;
+ ret = initmodule();
+ if (ret) {
+ fprintf(stderr, "Control module seems not work\n");
+ return 1;
}
- closedir(dir);
-
return 0;
}
arg_error:
return ret;
}
+
+int getdebugfsmntdir(char *mntdir)
+{
+ char mnt_dir[PATH_MAX];
+ char mnt_type[PATH_MAX];
+ int trymount_done = 0;
+
+ FILE *fp = fopen("/proc/mounts", "r");
+ if (!fp)
+ return -EINVAL;
+
+find_again:
+ while (1) {
+ if (fscanf(fp, "%*s %s %s %*s %*s %*s", mnt_dir, mnt_type) <= 0)
+ break;
+
+ if (!strcmp(mnt_type, "debugfs")) {
+ strcpy(mntdir, mnt_dir);
+ return 0;
+ }
+ }
+
+ if (!trymount_done) {
+ mount("debugfs", "/sys/kernel/debug/", "debugfs", 0, NULL);
+ trymount_done = 1;
+ goto find_again;
+ }
+
+ return -ENOENT;
+}