gistfile1.txt

function pid_file_handle_path:string(pid:long, fd:long) %{
    struct task_struct *task = NULL;
    struct pid *pid;
    struct file *file;
    struct path *path;
    char buf[256];
    char *p;

    pid = find_get_pid((pid_t)(long)THIS->pid);
    task = pid_task(pid, PIDTYPE_PID);
    put_pid(pid);

    if (task) {
        task_lock(task);

        /*
         * We are not taking a ref to the file structure, so we must hold
         * ->file_lock.
         */
        spin_lock(&task->files->file_lock);
        file = fcheck_files(task->files, (long)THIS->fd);
        if (file) {
            path = &file->f_path;
            p = d_path(path, buf, sizeof(buf));

            if (!IS_ERR(p)) {
                memmove(THIS->__retvalue, p, strlen(p) + 1);
            }
        }
        spin_unlock(&task->files->file_lock);

        task_unlock(task);
    }
%}