1 /*
2 * This code is derived from uClibc (original license follows).
3 * https://git.uclibc.org/uClibc/tree/utils/mmap-windows.c
4 */
5 /* mmap() replacement for Windows
6 *
7 * Author: Mike Frysinger <vapier@gentoo.org>
8 * Placed into the public domain
9 */
10
11 /* References:
12 * CreateFileMapping: http://msdn.microsoft.com/en-us/library/aa366537(VS.85).aspx
13 * CloseHandle: http://msdn.microsoft.com/en-us/library/ms724211(VS.85).aspx
14 * MapViewOfFile: http://msdn.microsoft.com/en-us/library/aa366761(VS.85).aspx
15 * UnmapViewOfFile: http://msdn.microsoft.com/en-us/library/aa366882(VS.85).aspx
16 */
17
18 #if defined(_WIN32)
19
20 #include "WindowsMMap.h"
21 #include "InstrProfiling.h"
22
23 #ifdef __USE_FILE_OFFSET64
24 # define DWORD_HI(x) (x >> 32)
25 # define DWORD_LO(x) ((x) & 0xffffffff)
26 #else
27 # define DWORD_HI(x) (0)
28 # define DWORD_LO(x) (x)
29 #endif
30
31 COMPILER_RT_VISIBILITY
mmap(void * start,size_t length,int prot,int flags,int fd,off_t offset)32 void *mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
33 {
34 if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC))
35 return MAP_FAILED;
36 if (fd == -1) {
37 if (!(flags & MAP_ANON) || offset)
38 return MAP_FAILED;
39 } else if (flags & MAP_ANON)
40 return MAP_FAILED;
41
42 DWORD flProtect;
43 if (prot & PROT_WRITE) {
44 if (prot & PROT_EXEC)
45 flProtect = PAGE_EXECUTE_READWRITE;
46 else
47 flProtect = PAGE_READWRITE;
48 } else if (prot & PROT_EXEC) {
49 if (prot & PROT_READ)
50 flProtect = PAGE_EXECUTE_READ;
51 else if (prot & PROT_EXEC)
52 flProtect = PAGE_EXECUTE;
53 } else
54 flProtect = PAGE_READONLY;
55
56 off_t end = length + offset;
57 HANDLE mmap_fd, h;
58 if (fd == -1)
59 mmap_fd = INVALID_HANDLE_VALUE;
60 else
61 mmap_fd = (HANDLE)_get_osfhandle(fd);
62 h = CreateFileMapping(mmap_fd, NULL, flProtect, DWORD_HI(end), DWORD_LO(end), NULL);
63 if (h == NULL)
64 return MAP_FAILED;
65
66 DWORD dwDesiredAccess;
67 if (prot & PROT_WRITE)
68 dwDesiredAccess = FILE_MAP_WRITE;
69 else
70 dwDesiredAccess = FILE_MAP_READ;
71 if (prot & PROT_EXEC)
72 dwDesiredAccess |= FILE_MAP_EXECUTE;
73 if (flags & MAP_PRIVATE)
74 dwDesiredAccess |= FILE_MAP_COPY;
75 void *ret = MapViewOfFile(h, dwDesiredAccess, DWORD_HI(offset), DWORD_LO(offset), length);
76 if (ret == NULL) {
77 CloseHandle(h);
78 ret = MAP_FAILED;
79 }
80 return ret;
81 }
82
83 COMPILER_RT_VISIBILITY
munmap(void * addr,size_t length)84 void munmap(void *addr, size_t length)
85 {
86 UnmapViewOfFile(addr);
87 /* ruh-ro, we leaked handle from CreateFileMapping() ... */
88 }
89
90 COMPILER_RT_VISIBILITY
msync(void * addr,size_t length,int flags)91 int msync(void *addr, size_t length, int flags)
92 {
93 if (flags & MS_INVALIDATE)
94 return -1; /* Not supported. */
95
96 /* Exactly one of MS_ASYNC or MS_SYNC must be specified. */
97 switch (flags & (MS_ASYNC | MS_SYNC)) {
98 case MS_SYNC:
99 case MS_ASYNC:
100 break;
101 default:
102 return -1;
103 }
104
105 if (!FlushViewOfFile(addr, length))
106 return -1;
107
108 if (flags & MS_SYNC) {
109 /* FIXME: No longer have access to handle from CreateFileMapping(). */
110 /*
111 * if (!FlushFileBuffers(h))
112 * return -1;
113 */
114 }
115
116 return 0;
117 }
118
119 COMPILER_RT_VISIBILITY
flock(int fd,int operation)120 int flock(int fd, int operation)
121 {
122 return -1; /* Not supported. */
123 }
124
125 #undef DWORD_HI
126 #undef DWORD_LO
127
128 #endif /* _WIN32 */
129