Function sys_clone

api/src/syscall/task/clone.rs:88–229

(
    uctx: &UserContext,
    flags: u32,
    stack: usize,
    parent_tid: usize,
    #[cfg(any(target_arch = "x86_64", target_arch = "loongarch64"))] child_tid: usize,
    tls: usize,
    #[cfg(not(

}

pub fn sys_clone(
    uctx: &UserContext,
    flags: u32,
    stack: usize,
    parent_tid: usize,
    #[cfg(any(target_arch = "x86_64", target_arch = "loongarch64"))] child_tid: usize,
    tls: usize,
    #[cfg(not(any(target_arch = "x86_64", target_arch = "loongarch64")))] child_tid: usize,
) -> AxResult<isize> {
    const FLAG_MASK: u32 = 0xff;
    let exit_signal = flags & FLAG_MASK;
    let mut flags = CloneFlags::from_bits_truncate(flags & !FLAG_MASK);
    if flags.contains(CloneFlags::VFORK) {
        debug!("sys_clone: CLONE_VFORK slow path");
        flags.remove(CloneFlags::VM);
    }

    debug!(
        "sys_clone <= flags: {flags:?}, exit_signal: {exit_signal}, stack: {stack:#x}, ptid: \
         {parent_tid:#x}, ctid: {child_tid:#x}, tls: {tls:#x}"
    );

    if exit_signal != 0 && flags.contains(CloneFlags::THREAD | CloneFlags::PARENT) {
        return Err(AxError::InvalidInput);
    }
    if flags.contains(CloneFlags::THREAD) && !flags.contains(CloneFlags::VM | CloneFlags::SIGHAND) {
        return Err(AxError::InvalidInput);
    }
    if flags.contains(CloneFlags::PIDFD | CloneFlags::PARENT_SETTID) {
        return Err(AxError::InvalidInput);
    }
    let exit_signal = Signo::from_repr(exit_signal as u8);

    let mut new_uctx = *uctx;
    if stack != 0 {
        new_uctx.set_sp(stack);
    }
    if flags.contains(CloneFlags::SETTLS) {
        new_uctx.set_tls(tls);
    }
    new_uctx.set_retval(0);

    let set_child_tid = if flags.contains(CloneFlags::CHILD_SETTID) {
        child_tid
    } else {
        0
    };

    let curr = current();
    let old_proc_data = &curr.as_thread().proc_data;

    let mut new_task = new_user_task(&curr.name(), new_uctx, set_child_tid);

    let tid = new_task.id().as_u64() as Pid;
    if flags.contains(CloneFlags::PARENT_SETTID) {
        (parent_tid as *mut Pid).vm_write(tid).ok();
    }