1 //===---------- Linux implementation of the POSIX munmap function ---------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "src/sys/mman/munmap.h" 10 11 #include "src/__support/OSUtil/syscall.h" // For internal syscall function. 12 #include "src/__support/common.h" 13 14 #include "src/__support/macros/config.h" 15 #include "src/errno/libc_errno.h" 16 #include <sys/syscall.h> // For syscall numbers. 17 18 namespace LIBC_NAMESPACE_DECL { 19 20 // This function is currently linux only. It has to be refactored suitably if 21 // mmap is to be supported on non-linux operating systems also. 22 LLVM_LIBC_FUNCTION(int, munmap, (void *addr, size_t size)) { 23 int ret = LIBC_NAMESPACE::syscall_impl<int>( 24 SYS_munmap, reinterpret_cast<long>(addr), size); 25 26 // A negative return value indicates an error with the magnitude of the 27 // value being the error code. 28 if (ret < 0) { 29 libc_errno = -ret; 30 return -1; 31 } 32 33 return 0; 34 } 35 36 } // namespace LIBC_NAMESPACE_DECL 37