Function _sys_clone

components/lwp/lwp_syscall.c:3336–3459

#ifdef ARCH_MM_MMU

long _sys_clone(void *arg[])
{
    struct rt_lwp *lwp = 0;
    rt_thread_t thread = RT_NULL;
    rt_thread_t self = RT_NULL;
    int tid = 0;
    rt_err_t err;

    unsigned long flags = 0;
    void *user_stack = RT_NULL;
    int *new_tid = RT_NULL;
    void *tls = RT_NULL;
    /*
       musl call flags (CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND
       | CLONE_THREAD | CLONE_SYSVSEM | CLONE_SETTLS
       | CLONE_PARENT_SETTID | CLONE_CHILD_CLEARTID | CLONE_DETACHED);
       */

    /* check args */
    if (!lwp_user_accessable(arg, sizeof(void *[SYS_CLONE_ARGS_NR])))
    {
        return -EFAULT;
    }

    flags = (unsigned long)(size_t)arg[0];
    if ((flags & (CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_THREAD | CLONE_SYSVSEM))
            != (CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_THREAD | CLONE_SYSVSEM))
    {
        return -EINVAL;
    }

    user_stack = arg[1];
    new_tid = (int *)arg[2];
    tls = (void *)arg[3];

    if ((flags & CLONE_PARENT_SETTID) == CLONE_PARENT_SETTID)
    {
        if (!lwp_user_accessable(new_tid, sizeof(int)))
        {
            return -EFAULT;
        }
    }

    self = rt_thread_self();
    lwp = self->lwp;
    lwp_ref_inc(lwp);
    if (!user_stack)
    {
        SET_ERRNO(EINVAL);
        goto fail;
    }
    if ((tid = lwp_tid_get()) == 0)
    {
        SET_ERRNO(ENOMEM);
        goto fail;
    }

    thread = rt_thread_create(self->parent.name,