10     syscall::{Syscall, SystemError},
70     pub fn brk(new_addr: VirtAddr) -> Result<VirtAddr, SystemError> {  in brk()  argument
91     pub fn sbrk(incr: isize) -> Result<VirtAddr, SystemError> {  in sbrk()  argument
125     ) -> Result<usize, SystemError> {  in mmap()  argument
136             return Err(SystemError::EINVAL);  in mmap()
141             return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP);  in mmap()
147             return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP);  in mmap()
170     pub fn munmap(start_vaddr: VirtAddr, len: usize) -> Result<usize, SystemError> {  in munmap()  argument
175             return Err(SystemError::EINVAL);  in munmap()
178             return Err(SystemError::EINVAL);  in munmap()
188             .map_err(|_| SystemError::EINVAL)?;  in munmap()
203     ) -> Result<usize, SystemError> {  in mprotect()  argument
208             return Err(SystemError::EINVAL);  in mprotect()
211             return Err(SystemError::EINVAL);  in mprotect()
214         let prot_flags = ProtFlags::from_bits(prot_flags as u64).ok_or(SystemError::EINVAL)?;  in mprotect()
223             .map_err(|_| SystemError::EINVAL)?;  in mprotect()