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 <errno.h>
15 #include <sys/syscall.h>          // For syscall numbers.
16 
17 namespace __llvm_libc {
18 
19 // This function is currently linux only. It has to be refactored suitably if
20 // mmap is to be supported on non-linux operating systems also.
21 LLVM_LIBC_FUNCTION(int, munmap, (void *addr, size_t size)) {
22   long ret_val =
23       __llvm_libc::syscall(SYS_munmap, reinterpret_cast<long>(addr), size);
24 
25   // A negative return value indicates an error with the magnitude of the
26   // value being the error code.
27   if (ret_val < 0) {
28     errno = -ret_val;
29     return -1;
30   }
31 
32   return 0;
33 }
34 
35 } // namespace __llvm_libc
36