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 #include <sys/linux-syscalls.h> 46 #else 47 #include <syscall.h> 48 #endif 49 #include <sys/mman.h> 50 #include <errno.h> 51 #include "base/linux_syscall_support.h" 52 53 // SYS_mmap2, SYS_munmap, SYS_mremap and __off64_t are not defined in Android. 54 #if defined(__ANDROID__) 55 #if defined(__NR_mmap) && !defined(SYS_mmap) 56 #define SYS_mmap __NR_mmap 57 #endif 58 #ifndef SYS_mmap2 59 #define SYS_mmap2 __NR_mmap2 60 #endif 61 #ifndef SYS_munmap 62 #define SYS_munmap __NR_munmap 63 #endif 64 #ifndef SYS_mremap 65 #define SYS_mremap __NR_mremap 66 #endif 67 typedef off64_t __off64_t; 68 #endif // defined(__ANDROID__) 69 70 // The x86-32 case and the x86-64 case differ: 71 // 32b has a mmap2() syscall, 64b does not. 72 // 64b and 32b have different calling conventions for mmap(). 73 74 // I test for 64-bit first so I don't have to do things like 75 // '#if (defined(__mips__) && !defined(__MIPS64__))' as a mips32 check. 76 #if defined(__x86_64__) || defined(__PPC64__) || (defined(_MIPS_SIM) && _MIPS_SIM == _ABI64) 77 78 static inline void* do_mmap64(void *start, size_t length, 79 int prot, int flags, 80 int fd, __off64_t offset) __THROW { 81 // The original gperftools uses sys_mmap() here. But, it is not allowed by 82 // Chromium's sandbox. 83 return (void *)syscall(SYS_mmap, start, length, prot, flags, fd, offset); 84 } 85 86 #define MALLOC_HOOK_HAVE_DO_MMAP64 1 87 88 #elif defined(__i386__) || defined(__PPC__) || defined(__mips__) || \ 89 defined(__arm__) 90 91 static inline void* do_mmap64(void *start, size_t length, 92 int prot, int flags, 93 int fd, __off64_t offset) __THROW { 94 void *result; 95 96 // Try mmap2() unless it's not supported 97 static bool have_mmap2 = true; 98 if (have_mmap2) { 99 static int pagesize = 0; 100 if (!pagesize) pagesize = getpagesize(); 101 102 // Check that the offset is page aligned 103 if (offset & (pagesize - 1)) { 104 result = MAP_FAILED; 105 errno = EINVAL; 106 goto out; 107 } 108 109 result = (void *)syscall(SYS_mmap2, 110 start, length, prot, flags, fd, 111 (off_t) (offset / pagesize)); 112 if (result != MAP_FAILED || errno != ENOSYS) goto out; 113 114 // We don't have mmap2() after all - don't bother trying it in future 115 have_mmap2 = false; 116 } 117 118 if (((off_t)offset) != offset) { 119 // If we're trying to map a 64-bit offset, fail now since we don't 120 // have 64-bit mmap() support. 121 result = MAP_FAILED; 122 errno = EINVAL; 123 goto out; 124 } 125 126 #ifdef __NR_mmap 127 { 128 // Fall back to old 32-bit offset mmap() call 129 // Old syscall interface cannot handle six args, so pass in an array 130 int32 args[6] = { (int32) start, (int32) length, prot, flags, fd, 131 (off_t) offset }; 132 result = (void *)syscall(SYS_mmap, args); 133 } 134 #else 135 // Some Linux ports like ARM EABI Linux has no mmap, just mmap2. 136 result = MAP_FAILED; 137 #endif 138 139 out: 140 return result; 141 } 142 143 #define MALLOC_HOOK_HAVE_DO_MMAP64 1 144 145 #endif // #if defined(__x86_64__) 146 147 148 #ifdef MALLOC_HOOK_HAVE_DO_MMAP64 149 150 // We use do_mmap64 abstraction to put MallocHook::InvokeMmapHook 151 // calls right into mmap and mmap64, so that the stack frames in the caller's 152 // stack are at the same offsets for all the calls of memory allocating 153 // functions. 154 155 // Put all callers of MallocHook::Invoke* in this module into 156 // malloc_hook section, 157 // so that MallocHook::GetCallerStackTrace can function accurately: 158 159 // Make sure mmap doesn't get #define'd away by <sys/mman.h> 160 # undef mmap 161 162 extern "C" { 163 void* mmap64(void *start, size_t length, int prot, int flags, 164 int fd, __off64_t offset ) __THROW 165 ATTRIBUTE_SECTION(malloc_hook); 166 void* mmap(void *start, size_t length,int prot, int flags, 167 int fd, off_t offset) __THROW 168 ATTRIBUTE_SECTION(malloc_hook); 169 int munmap(void* start, size_t length) __THROW 170 ATTRIBUTE_SECTION(malloc_hook); 171 void* mremap(void* old_addr, size_t old_size, size_t new_size, 172 int flags, ...) __THROW 173 ATTRIBUTE_SECTION(malloc_hook); 174 #if !defined(__ANDROID__) 175 void* sbrk(ptrdiff_t increment) __THROW 176 ATTRIBUTE_SECTION(malloc_hook); 177 #endif 178 } 179 180 extern "C" void* mmap64(void *start, size_t length, int prot, int flags, 181 int fd, __off64_t offset) __THROW { 182 MallocHook::InvokePreMmapHook(start, length, prot, flags, fd, offset); 183 void *result; 184 if (!MallocHook::InvokeMmapReplacement( 185 start, length, prot, flags, fd, offset, &result)) { 186 result = do_mmap64(start, length, prot, flags, fd, offset); 187 } 188 MallocHook::InvokeMmapHook(result, start, length, prot, flags, fd, offset); 189 return result; 190 } 191 192 # if !defined(__USE_FILE_OFFSET64) || !defined(__REDIRECT_NTH) 193 194 extern "C" void* mmap(void *start, size_t length, int prot, int flags, 195 int fd, off_t offset) __THROW { 196 MallocHook::InvokePreMmapHook(start, length, prot, flags, fd, offset); 197 void *result; 198 if (!MallocHook::InvokeMmapReplacement( 199 start, length, prot, flags, fd, offset, &result)) { 200 result = do_mmap64(start, length, prot, flags, fd, 201 static_cast<size_t>(offset)); // avoid sign extension 202 } 203 MallocHook::InvokeMmapHook(result, start, length, prot, flags, fd, offset); 204 return result; 205 } 206 207 # endif // !defined(__USE_FILE_OFFSET64) || !defined(__REDIRECT_NTH) 208 209 extern "C" int munmap(void* start, size_t length) __THROW { 210 MallocHook::InvokeMunmapHook(start, length); 211 int result; 212 if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) { 213 // The original gperftools uses sys_munmap() here. But, it is not allowed 214 // by Chromium's sandbox. 215 result = syscall(SYS_munmap, start, length); 216 } 217 return result; 218 } 219 220 extern "C" void* mremap(void* old_addr, size_t old_size, size_t new_size, 221 int flags, ...) __THROW { 222 va_list ap; 223 va_start(ap, flags); 224 void *new_address = va_arg(ap, void *); 225 va_end(ap); 226 // The original gperftools uses sys_mremap() here. But, it is not allowed by 227 // Chromium's sandbox. 228 void* result = (void *)syscall( 229 SYS_mremap, old_addr, old_size, new_size, flags, new_address); 230 MallocHook::InvokeMremapHook(result, old_addr, old_size, new_size, flags, 231 new_address); 232 return result; 233 } 234 235 // Don't hook sbrk() in Android, since it doesn't expose __sbrk. 236 #if !defined(__ANDROID__) 237 // libc's version: 238 extern "C" void* __sbrk(ptrdiff_t increment); 239 240 extern "C" void* sbrk(ptrdiff_t increment) __THROW { 241 MallocHook::InvokePreSbrkHook(increment); 242 void *result = __sbrk(increment); 243 MallocHook::InvokeSbrkHook(result, increment); 244 return result; 245 } 246 #endif // !defined(__ANDROID__) 247 248 /*static*/void* MallocHook::UnhookedMMap(void *start, size_t length, int prot, 249 int flags, int fd, off_t offset) { 250 void* result; 251 if (!MallocHook::InvokeMmapReplacement( 252 start, length, prot, flags, fd, offset, &result)) { 253 result = do_mmap64(start, length, prot, flags, fd, offset); 254 } 255 return result; 256 } 257 258 /*static*/int MallocHook::UnhookedMUnmap(void *start, size_t length) { 259 int result; 260 if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) { 261 result = syscall(SYS_munmap, start, length); 262 } 263 return result; 264 } 265 266 #undef MALLOC_HOOK_HAVE_DO_MMAP64 267 268 #endif // #ifdef MALLOC_HOOK_HAVE_DO_MMAP64 269
