1 // Copyright (c) 2005, Google Inc. 2 // All rights reserved. 3 // 4 // Redistribution and use in source and binary forms, with or without 5 // modification, are permitted provided that the following conditions are 6 // met: 7 // 8 // * Redistributions of source code must retain the above copyright 9 // notice, this list of conditions and the following disclaimer. 10 // * Redistributions in binary form must reproduce the above 11 // copyright notice, this list of conditions and the following disclaimer 12 // in the documentation and/or other materials provided with the 13 // distribution. 14 // * Neither the name of Google Inc. nor the names of its 15 // contributors may be used to endorse or promote products derived from 16 // this software without specific prior written permission. 17 // 18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 30 // --- 31 // Author: Sanjay Ghemawat <opensource (at) google.com> 32 33 // We define mmap() and mmap64(), which somewhat reimplements libc's mmap 34 // syscall stubs. Unfortunately libc only exports the stubs via weak symbols 35 // (which we're overriding with our mmap64() and mmap() wrappers) so we can't 36 // just call through to them. 37 38 #ifndef __linux 39 # error Should only be including malloc_hook_mmap_linux.h on linux systems. 40 #endif 41 42 #include <unistd.h> 43 #include <syscall.h> 44 #include <sys/mman.h> 45 #include <errno.h> 46 #include "base/linux_syscall_support.h" 47 48 // The x86-32 case and the x86-64 case differ: 49 // 32b has a mmap2() syscall, 64b does not. 50 // 64b and 32b have different calling conventions for mmap(). 51 52 // I test for 64-bit first so I don't have to do things like 53 // '#if (defined(__mips__) && !defined(__MIPS64__))' as a mips32 check. 54 #if defined(__x86_64__) || defined(__PPC64__) || (defined(_MIPS_SIM) && _MIPS_SIM == _ABI64) 55 56 static inline void* do_mmap64(void *start, size_t length, 57 int prot, int flags, 58 int fd, __off64_t offset) __THROW { 59 return sys_mmap(start, length, prot, flags, fd, offset); 60 } 61 62 #define MALLOC_HOOK_HAVE_DO_MMAP64 1 63 64 #elif defined(__i386__) || defined(__PPC__) || defined(__mips__) || \ 65 defined(__arm__) 66 67 static inline void* do_mmap64(void *start, size_t length, 68 int prot, int flags, 69 int fd, __off64_t offset) __THROW { 70 void *result; 71 72 // Try mmap2() unless it's not supported 73 static bool have_mmap2 = true; 74 if (have_mmap2) { 75 static int pagesize = 0; 76 if (!pagesize) pagesize = getpagesize(); 77 78 // Check that the offset is page aligned 79 if (offset & (pagesize - 1)) { 80 result = MAP_FAILED; 81 errno = EINVAL; 82 goto out; 83 } 84 85 result = (void *)syscall(SYS_mmap2, 86 start, length, prot, flags, fd, 87 (off_t) (offset / pagesize)); 88 if (result != MAP_FAILED || errno != ENOSYS) goto out; 89 90 // We don't have mmap2() after all - don't bother trying it in future 91 have_mmap2 = false; 92 } 93 94 if (((off_t)offset) != offset) { 95 // If we're trying to map a 64-bit offset, fail now since we don't 96 // have 64-bit mmap() support. 97 result = MAP_FAILED; 98 errno = EINVAL; 99 goto out; 100 } 101 102 #ifdef __NR_mmap 103 { 104 // Fall back to old 32-bit offset mmap() call 105 // Old syscall interface cannot handle six args, so pass in an array 106 int32 args[6] = { (int32) start, (int32) length, prot, flags, fd, 107 (off_t) offset }; 108 result = (void *)syscall(SYS_mmap, args); 109 } 110 #else 111 // Some Linux ports like ARM EABI Linux has no mmap, just mmap2. 112 result = MAP_FAILED; 113 #endif 114 115 out: 116 return result; 117 } 118 119 #define MALLOC_HOOK_HAVE_DO_MMAP64 1 120 121 #endif // #if defined(__x86_64__) 122 123 124 #ifdef MALLOC_HOOK_HAVE_DO_MMAP64 125 126 // We use do_mmap64 abstraction to put MallocHook::InvokeMmapHook 127 // calls right into mmap and mmap64, so that the stack frames in the caller's 128 // stack are at the same offsets for all the calls of memory allocating 129 // functions. 130 131 // Put all callers of MallocHook::Invoke* in this module into 132 // malloc_hook section, 133 // so that MallocHook::GetCallerStackTrace can function accurately: 134 135 // Make sure mmap doesn't get #define'd away by <sys/mman.h> 136 # undef mmap 137 138 extern "C" { 139 void* mmap64(void *start, size_t length, int prot, int flags, 140 int fd, __off64_t offset ) __THROW 141 ATTRIBUTE_SECTION(malloc_hook); 142 void* mmap(void *start, size_t length,int prot, int flags, 143 int fd, off_t offset) __THROW 144 ATTRIBUTE_SECTION(malloc_hook); 145 int munmap(void* start, size_t length) __THROW 146 ATTRIBUTE_SECTION(malloc_hook); 147 void* mremap(void* old_addr, size_t old_size, size_t new_size, 148 int flags, ...) __THROW 149 ATTRIBUTE_SECTION(malloc_hook); 150 void* sbrk(ptrdiff_t increment) __THROW 151 ATTRIBUTE_SECTION(malloc_hook); 152 } 153 154 extern "C" void* mmap64(void *start, size_t length, int prot, int flags, 155 int fd, __off64_t offset) __THROW { 156 MallocHook::InvokePreMmapHook(start, length, prot, flags, fd, offset); 157 void *result; 158 if (!MallocHook::InvokeMmapReplacement( 159 start, length, prot, flags, fd, offset, &result)) { 160 result = do_mmap64(start, length, prot, flags, fd, offset); 161 } 162 MallocHook::InvokeMmapHook(result, start, length, prot, flags, fd, offset); 163 return result; 164 } 165 166 # if !defined(__USE_FILE_OFFSET64) || !defined(__REDIRECT_NTH) 167 168 extern "C" void* mmap(void *start, size_t length, int prot, int flags, 169 int fd, off_t offset) __THROW { 170 MallocHook::InvokePreMmapHook(start, length, prot, flags, fd, offset); 171 void *result; 172 if (!MallocHook::InvokeMmapReplacement( 173 start, length, prot, flags, fd, offset, &result)) { 174 result = do_mmap64(start, length, prot, flags, fd, 175 static_cast<size_t>(offset)); // avoid sign extension 176 } 177 MallocHook::InvokeMmapHook(result, start, length, prot, flags, fd, offset); 178 return result; 179 } 180 181 # endif // !defined(__USE_FILE_OFFSET64) || !defined(__REDIRECT_NTH) 182 183 extern "C" int munmap(void* start, size_t length) __THROW { 184 MallocHook::InvokeMunmapHook(start, length); 185 int result; 186 if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) { 187 result = sys_munmap(start, length); 188 } 189 return result; 190 } 191 192 extern "C" void* mremap(void* old_addr, size_t old_size, size_t new_size, 193 int flags, ...) __THROW { 194 va_list ap; 195 va_start(ap, flags); 196 void *new_address = va_arg(ap, void *); 197 va_end(ap); 198 void* result = sys_mremap(old_addr, old_size, new_size, flags, new_address); 199 MallocHook::InvokeMremapHook(result, old_addr, old_size, new_size, flags, 200 new_address); 201 return result; 202 } 203 204 // libc's version: 205 extern "C" void* __sbrk(ptrdiff_t increment); 206 207 extern "C" void* sbrk(ptrdiff_t increment) __THROW { 208 MallocHook::InvokePreSbrkHook(increment); 209 void *result = __sbrk(increment); 210 MallocHook::InvokeSbrkHook(result, increment); 211 return result; 212 } 213 214 /*static*/void* MallocHook::UnhookedMMap(void *start, size_t length, int prot, 215 int flags, int fd, off_t offset) { 216 void* result; 217 if (!MallocHook::InvokeMmapReplacement( 218 start, length, prot, flags, fd, offset, &result)) { 219 result = do_mmap64(start, length, prot, flags, fd, offset); 220 } 221 return result; 222 } 223 224 /*static*/int MallocHook::UnhookedMUnmap(void *start, size_t length) { 225 int result; 226 if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) { 227 result = syscall(SYS_munmap, start, length); 228 } 229 return result; 230 } 231 232 #undef MALLOC_HOOK_HAVE_DO_MMAP64 233 234 #endif // #ifdef MALLOC_HOOK_HAVE_DO_MMAP64 235
