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 #if defined(__ANDROID__) 44 #include <sys/syscall.h> 45 #ifndef ANDROID_NON_SDK_BUILD 46 #include <sys/linux-syscalls.h> 47 #endif 48 #else 49 #include <syscall.h> 50 #endif 51 #include <sys/mman.h> 52 #include <errno.h> 53 #include "base/linux_syscall_support.h" 54 55 // SYS_mmap2, SYS_munmap, SYS_mremap and __off64_t are not defined in Android. 56 #if defined(__ANDROID__) 57 #ifndef SYS_mmap2 58 #define SYS_mmap2 __NR_mmap2 59 #endif 60 #ifndef SYS_munmap 61 #define SYS_munmap __NR_munmap 62 #endif 63 #ifndef SYS_mremap 64 #define SYS_mremap __NR_mremap 65 #endif 66 typedef off64_t __off64_t; 67 #endif // defined(__ANDROID__) 68 69 // The x86-32 case and the x86-64 case differ: 70 // 32b has a mmap2() syscall, 64b does not. 71 // 64b and 32b have different calling conventions for mmap(). 72 73 // I test for 64-bit first so I don't have to do things like 74 // '#if (defined(__mips__) && !defined(__MIPS64__))' as a mips32 check. 75 #if defined(__x86_64__) || defined(__PPC64__) || (defined(_MIPS_SIM) && _MIPS_SIM == _ABI64) 76 77 static inline void* do_mmap64(void *start, size_t length, 78 int prot, int flags, 79 int fd, __off64_t offset) __THROW { 80 // The original gperftools uses sys_mmap() here. But, it is not allowed by 81 // Chromium's sandbox. 82 return (void *)syscall(SYS_mmap, start, length, prot, flags, fd, offset); 83 } 84 85 #define MALLOC_HOOK_HAVE_DO_MMAP64 1 86 87 #elif defined(__i386__) || defined(__PPC__) || defined(__mips__) || \ 88 defined(__arm__) 89 90 static inline void* do_mmap64(void *start, size_t length, 91 int prot, int flags, 92 int fd, __off64_t offset) __THROW { 93 void *result; 94 95 // Try mmap2() unless it's not supported 96 static bool have_mmap2 = true; 97 if (have_mmap2) { 98 static int pagesize = 0; 99 if (!pagesize) pagesize = getpagesize(); 100 101 // Check that the offset is page aligned 102 if (offset & (pagesize - 1)) { 103 result = MAP_FAILED; 104 errno = EINVAL; 105 goto out; 106 } 107 108 result = (void *)syscall(SYS_mmap2, 109 start, length, prot, flags, fd, 110 (off_t) (offset / pagesize)); 111 if (result != MAP_FAILED || errno != ENOSYS) goto out; 112 113 // We don't have mmap2() after all - don't bother trying it in future 114 have_mmap2 = false; 115 } 116 117 if (((off_t)offset) != offset) { 118 // If we're trying to map a 64-bit offset, fail now since we don't 119 // have 64-bit mmap() support. 120 result = MAP_FAILED; 121 errno = EINVAL; 122 goto out; 123 } 124 125 #ifdef __NR_mmap 126 { 127 // Fall back to old 32-bit offset mmap() call 128 // Old syscall interface cannot handle six args, so pass in an array 129 int32 args[6] = { (int32) start, (int32) length, prot, flags, fd, 130 (off_t) offset }; 131 result = (void *)syscall(SYS_mmap, args); 132 } 133 #else 134 // Some Linux ports like ARM EABI Linux has no mmap, just mmap2. 135 result = MAP_FAILED; 136 #endif 137 138 out: 139 return result; 140 } 141 142 #define MALLOC_HOOK_HAVE_DO_MMAP64 1 143 144 #endif // #if defined(__x86_64__) 145 146 147 #ifdef MALLOC_HOOK_HAVE_DO_MMAP64 148 149 // We use do_mmap64 abstraction to put MallocHook::InvokeMmapHook 150 // calls right into mmap and mmap64, so that the stack frames in the caller's 151 // stack are at the same offsets for all the calls of memory allocating 152 // functions. 153 154 // Put all callers of MallocHook::Invoke* in this module into 155 // malloc_hook section, 156 // so that MallocHook::GetCallerStackTrace can function accurately: 157 158 // Make sure mmap doesn't get #define'd away by <sys/mman.h> 159 # undef mmap 160 161 extern "C" { 162 void* mmap64(void *start, size_t length, int prot, int flags, 163 int fd, __off64_t offset ) __THROW 164 ATTRIBUTE_SECTION(malloc_hook); 165 void* mmap(void *start, size_t length,int prot, int flags, 166 int fd, off_t offset) __THROW 167 ATTRIBUTE_SECTION(malloc_hook); 168 int munmap(void* start, size_t length) __THROW 169 ATTRIBUTE_SECTION(malloc_hook); 170 void* mremap(void* old_addr, size_t old_size, size_t new_size, 171 int flags, ...) __THROW 172 ATTRIBUTE_SECTION(malloc_hook); 173 #if !defined(__ANDROID__) 174 void* sbrk(ptrdiff_t increment) __THROW 175 ATTRIBUTE_SECTION(malloc_hook); 176 #endif 177 } 178 179 extern "C" void* mmap64(void *start, size_t length, int prot, int flags, 180 int fd, __off64_t offset) __THROW { 181 MallocHook::InvokePreMmapHook(start, length, prot, flags, fd, offset); 182 void *result; 183 if (!MallocHook::InvokeMmapReplacement( 184 start, length, prot, flags, fd, offset, &result)) { 185 result = do_mmap64(start, length, prot, flags, fd, offset); 186 } 187 MallocHook::InvokeMmapHook(result, start, length, prot, flags, fd, offset); 188 return result; 189 } 190 191 # if !defined(__USE_FILE_OFFSET64) || !defined(__REDIRECT_NTH) 192 193 extern "C" void* mmap(void *start, size_t length, int prot, int flags, 194 int fd, off_t offset) __THROW { 195 MallocHook::InvokePreMmapHook(start, length, prot, flags, fd, offset); 196 void *result; 197 if (!MallocHook::InvokeMmapReplacement( 198 start, length, prot, flags, fd, offset, &result)) { 199 result = do_mmap64(start, length, prot, flags, fd, 200 static_cast<size_t>(offset)); // avoid sign extension 201 } 202 MallocHook::InvokeMmapHook(result, start, length, prot, flags, fd, offset); 203 return result; 204 } 205 206 # endif // !defined(__USE_FILE_OFFSET64) || !defined(__REDIRECT_NTH) 207 208 extern "C" int munmap(void* start, size_t length) __THROW { 209 MallocHook::InvokeMunmapHook(start, length); 210 int result; 211 if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) { 212 // The original gperftools uses sys_munmap() here. But, it is not allowed 213 // by Chromium's sandbox. 214 result = syscall(SYS_munmap, start, length); 215 } 216 return result; 217 } 218 219 extern "C" void* mremap(void* old_addr, size_t old_size, size_t new_size, 220 int flags, ...) __THROW { 221 va_list ap; 222 va_start(ap, flags); 223 void *new_address = va_arg(ap, void *); 224 va_end(ap); 225 // The original gperftools uses sys_mremap() here. But, it is not allowed by 226 // Chromium's sandbox. 227 void* result = (void *)syscall( 228 SYS_mremap, old_addr, old_size, new_size, flags, new_address); 229 MallocHook::InvokeMremapHook(result, old_addr, old_size, new_size, flags, 230 new_address); 231 return result; 232 } 233 234 // Don't hook sbrk() in Android, since it doesn't expose __sbrk. 235 #if !defined(__ANDROID__) 236 // libc's version: 237 extern "C" void* __sbrk(ptrdiff_t increment); 238 239 extern "C" void* sbrk(ptrdiff_t increment) __THROW { 240 MallocHook::InvokePreSbrkHook(increment); 241 void *result = __sbrk(increment); 242 MallocHook::InvokeSbrkHook(result, increment); 243 return result; 244 } 245 #endif // !defined(__ANDROID__) 246 247 /*static*/void* MallocHook::UnhookedMMap(void *start, size_t length, int prot, 248 int flags, int fd, off_t offset) { 249 void* result; 250 if (!MallocHook::InvokeMmapReplacement( 251 start, length, prot, flags, fd, offset, &result)) { 252 result = do_mmap64(start, length, prot, flags, fd, offset); 253 } 254 return result; 255 } 256 257 /*static*/int MallocHook::UnhookedMUnmap(void *start, size_t length) { 258 int result; 259 if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) { 260 result = syscall(SYS_munmap, start, length); 261 } 262 return result; 263 } 264 265 #undef MALLOC_HOOK_HAVE_DO_MMAP64 266 267 #endif // #ifdef MALLOC_HOOK_HAVE_DO_MMAP64 268
