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1/*2 * This code is derived from uClibc (original license follows).3 * https://git.uclibc.org/uClibc/tree/utils/mmap-windows.c4 */5 /* mmap() replacement for Windows6 *7 * Author: Mike Frysinger <vapier@gentoo.org>8 * Placed into the public domain9 */10 11/* References:12 * CreateFileMapping: http://msdn.microsoft.com/en-us/library/aa366537(VS.85).aspx13 * CloseHandle: http://msdn.microsoft.com/en-us/library/ms724211(VS.85).aspx14 * MapViewOfFile: http://msdn.microsoft.com/en-us/library/aa366761(VS.85).aspx15 * UnmapViewOfFile: http://msdn.microsoft.com/en-us/library/aa366882(VS.85).aspx16 */17 18#if defined(_WIN32)19 20#include "WindowsMMap.h"21 22#define WIN32_LEAN_AND_MEAN23#include <windows.h>24 25#include "InstrProfiling.h"26 27COMPILER_RT_VISIBILITY28void *mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)29{30 if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC))31 return MAP_FAILED;32 if (fd == -1) {33 if (!(flags & MAP_ANON) || offset)34 return MAP_FAILED;35 } else if (flags & MAP_ANON)36 return MAP_FAILED;37 38 DWORD flProtect;39 if (prot & PROT_WRITE) {40 if (prot & PROT_EXEC)41 flProtect = PAGE_EXECUTE_READWRITE;42 else43 flProtect = PAGE_READWRITE;44 } else if (prot & PROT_EXEC) {45 if (prot & PROT_READ)46 flProtect = PAGE_EXECUTE_READ;47 else if (prot & PROT_EXEC)48 flProtect = PAGE_EXECUTE;49 } else50 flProtect = PAGE_READONLY;51 52 off_t end = length + offset;53 HANDLE mmap_fd, h;54 if (fd == -1)55 mmap_fd = INVALID_HANDLE_VALUE;56 else57 mmap_fd = (HANDLE)_get_osfhandle(fd);58 h = CreateFileMapping(mmap_fd, NULL, flProtect, DWORD_HI(end), DWORD_LO(end), NULL);59 if (h == NULL)60 return MAP_FAILED;61 62 DWORD dwDesiredAccess;63 if (prot & PROT_WRITE)64 dwDesiredAccess = FILE_MAP_WRITE;65 else66 dwDesiredAccess = FILE_MAP_READ;67 if (prot & PROT_EXEC)68 dwDesiredAccess |= FILE_MAP_EXECUTE;69 if (flags & MAP_PRIVATE)70 dwDesiredAccess |= FILE_MAP_COPY;71 void *ret = MapViewOfFile(h, dwDesiredAccess, DWORD_HI(offset), DWORD_LO(offset), length);72 if (ret == NULL) {73 CloseHandle(h);74 ret = MAP_FAILED;75 }76 return ret;77}78 79COMPILER_RT_VISIBILITY80void munmap(void *addr, size_t length)81{82 UnmapViewOfFile(addr);83 /* ruh-ro, we leaked handle from CreateFileMapping() ... */84}85 86COMPILER_RT_VISIBILITY87int msync(void *addr, size_t length, int flags)88{89 if (flags & MS_INVALIDATE)90 return -1; /* Not supported. */91 92 /* Exactly one of MS_ASYNC or MS_SYNC must be specified. */93 switch (flags & (MS_ASYNC | MS_SYNC)) {94 case MS_SYNC:95 case MS_ASYNC:96 break;97 default:98 return -1;99 }100 101 if (!FlushViewOfFile(addr, length))102 return -1;103 104 if (flags & MS_SYNC) {105 /* FIXME: No longer have access to handle from CreateFileMapping(). */106 /*107 * if (!FlushFileBuffers(h))108 * return -1;109 */110 }111 112 return 0;113}114 115COMPILER_RT_VISIBILITY116int madvise(void *addr, size_t length, int advice)117{118 if (advice != MADV_DONTNEED)119 return -1; /* Not supported. */120 121 if (!VirtualUnlock(addr, length))122 return -1;123 124 return 0;125}126 127static int lock(HANDLE handle, DWORD lockType, BOOL blocking) {128 DWORD flags = lockType;129 if (!blocking)130 flags |= LOCKFILE_FAIL_IMMEDIATELY;131 132 OVERLAPPED overlapped;133 ZeroMemory(&overlapped, sizeof(OVERLAPPED));134 overlapped.hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);135 BOOL result = LockFileEx(handle, flags, 0, MAXDWORD, MAXDWORD, &overlapped);136 if (!result) {137 DWORD dw = GetLastError();138 139 // In non-blocking mode, return an error if the file is locked.140 if (!blocking && dw == ERROR_LOCK_VIOLATION)141 return -1; // EWOULDBLOCK142 143 // If the error is ERROR_IO_PENDING, we need to wait until the operation144 // finishes. Otherwise, we return an error.145 if (dw != ERROR_IO_PENDING)146 return -1;147 148 DWORD dwNumBytes;149 if (!GetOverlappedResult(handle, &overlapped, &dwNumBytes, TRUE))150 return -1;151 }152 153 return 0;154}155 156COMPILER_RT_VISIBILITY157int flock(int fd, int operation) {158 HANDLE handle = (HANDLE)_get_osfhandle(fd);159 if (handle == INVALID_HANDLE_VALUE)160 return -1;161 162 BOOL blocking = (operation & LOCK_NB) == 0;163 int op = operation & ~LOCK_NB;164 165 switch (op) {166 case LOCK_EX:167 return lock(handle, LOCKFILE_EXCLUSIVE_LOCK, blocking);168 169 case LOCK_SH:170 return lock(handle, 0, blocking);171 172 case LOCK_UN:173 if (!UnlockFile(handle, 0, 0, MAXDWORD, MAXDWORD))174 return -1;175 break;176 177 default:178 return -1;179 }180 181 return 0;182}183 184#undef DWORD_HI185#undef DWORD_LO186 187#endif /* _WIN32 */188