Function sys_thread_create 

pub fn sys_thread_create(
    frame: &SyscallFrame,
    entry: u64,
    stack_top: u64,
    arg0: u64,
    flags: u64,
    tls_base: u64,
) -> Result<u64, SyscallError>

SYS_THREAD_CREATE (341): create a userspace thread sharing current process resources.