1 /* 2 * Copyright (C) 2009 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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 copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 /* 30 * Contains definition of structures, global variables, and implementation of 31 * routines that are used by malloc leak detection code and other components in 32 * the system. The trick is that some components expect these data and 33 * routines to be defined / implemented in libc.so library, regardless 34 * whether or not MALLOC_LEAK_CHECK macro is defined. To make things even 35 * more tricky, malloc leak detection code, implemented in 36 * libc_malloc_debug.so also requires access to these variables and routines 37 * (to fill allocation entry hash table, for example). So, all relevant 38 * variables and routines are defined / implemented here and exported 39 * to all, leak detection code and other components via dynamic (libc.so), 40 * or static (libc.a) linking. 41 */ 42 43 #include <stdlib.h> 44 #include <pthread.h> 45 #include <unistd.h> 46 #include "dlmalloc.h" 47 #include "malloc_debug_common.h" 48 49 /* 50 * In a VM process, this is set to 1 after fork()ing out of zygote. 51 */ 52 int gMallocLeakZygoteChild = 0; 53 54 pthread_mutex_t gAllocationsMutex = PTHREAD_MUTEX_INITIALIZER; 55 HashTable gHashTable; 56 57 // ============================================================================= 58 // output functions 59 // ============================================================================= 60 61 static int hash_entry_compare(const void* arg1, const void* arg2) 62 { 63 int result; 64 65 HashEntry* e1 = *(HashEntry**)arg1; 66 HashEntry* e2 = *(HashEntry**)arg2; 67 68 // if one or both arg pointers are null, deal gracefully 69 if (e1 == NULL) { 70 result = (e2 == NULL) ? 0 : 1; 71 } else if (e2 == NULL) { 72 result = -1; 73 } else { 74 size_t nbAlloc1 = e1->allocations; 75 size_t nbAlloc2 = e2->allocations; 76 size_t size1 = e1->size & ~SIZE_FLAG_MASK; 77 size_t size2 = e2->size & ~SIZE_FLAG_MASK; 78 size_t alloc1 = nbAlloc1 * size1; 79 size_t alloc2 = nbAlloc2 * size2; 80 81 // sort in descending order by: 82 // 1) total size 83 // 2) number of allocations 84 // 85 // This is used for sorting, not determination of equality, so we don't 86 // need to compare the bit flags. 87 if (alloc1 > alloc2) { 88 result = -1; 89 } else if (alloc1 < alloc2) { 90 result = 1; 91 } else { 92 if (nbAlloc1 > nbAlloc2) { 93 result = -1; 94 } else if (nbAlloc1 < nbAlloc2) { 95 result = 1; 96 } else { 97 result = 0; 98 } 99 } 100 } 101 return result; 102 } 103 104 /* 105 * Retrieve native heap information. 106 * 107 * "*info" is set to a buffer we allocate 108 * "*overallSize" is set to the size of the "info" buffer 109 * "*infoSize" is set to the size of a single entry 110 * "*totalMemory" is set to the sum of all allocations we're tracking; does 111 * not include heap overhead 112 * "*backtraceSize" is set to the maximum number of entries in the back trace 113 */ 114 void get_malloc_leak_info(uint8_t** info, size_t* overallSize, 115 size_t* infoSize, size_t* totalMemory, size_t* backtraceSize) 116 { 117 // don't do anything if we have invalid arguments 118 if (info == NULL || overallSize == NULL || infoSize == NULL || 119 totalMemory == NULL || backtraceSize == NULL) { 120 return; 121 } 122 *totalMemory = 0; 123 124 pthread_mutex_lock(&gAllocationsMutex); 125 126 if (gHashTable.count == 0) { 127 *info = NULL; 128 *overallSize = 0; 129 *infoSize = 0; 130 *backtraceSize = 0; 131 goto done; 132 } 133 134 void** list = (void**)dlmalloc(sizeof(void*) * gHashTable.count); 135 136 // get the entries into an array to be sorted 137 int index = 0; 138 int i; 139 for (i = 0 ; i < HASHTABLE_SIZE ; i++) { 140 HashEntry* entry = gHashTable.slots[i]; 141 while (entry != NULL) { 142 list[index] = entry; 143 *totalMemory = *totalMemory + 144 ((entry->size & ~SIZE_FLAG_MASK) * entry->allocations); 145 index++; 146 entry = entry->next; 147 } 148 } 149 150 // XXX: the protocol doesn't allow variable size for the stack trace (yet) 151 *infoSize = (sizeof(size_t) * 2) + (sizeof(intptr_t) * BACKTRACE_SIZE); 152 *overallSize = *infoSize * gHashTable.count; 153 *backtraceSize = BACKTRACE_SIZE; 154 155 // now get A byte array big enough for this 156 *info = (uint8_t*)dlmalloc(*overallSize); 157 158 if (*info == NULL) { 159 *overallSize = 0; 160 goto out_nomem_info; 161 } 162 163 qsort((void*)list, gHashTable.count, sizeof(void*), hash_entry_compare); 164 165 uint8_t* head = *info; 166 const int count = gHashTable.count; 167 for (i = 0 ; i < count ; i++) { 168 HashEntry* entry = list[i]; 169 size_t entrySize = (sizeof(size_t) * 2) + (sizeof(intptr_t) * entry->numEntries); 170 if (entrySize < *infoSize) { 171 /* we're writing less than a full entry, clear out the rest */ 172 memset(head + entrySize, 0, *infoSize - entrySize); 173 } else { 174 /* make sure the amount we're copying doesn't exceed the limit */ 175 entrySize = *infoSize; 176 } 177 memcpy(head, &(entry->size), entrySize); 178 head += *infoSize; 179 } 180 181 out_nomem_info: 182 dlfree(list); 183 184 done: 185 pthread_mutex_unlock(&gAllocationsMutex); 186 } 187 188 void free_malloc_leak_info(uint8_t* info) 189 { 190 dlfree(info); 191 } 192 193 struct mallinfo mallinfo() 194 { 195 return dlmallinfo(); 196 } 197 198 void* valloc(size_t bytes) { 199 /* assume page size of 4096 bytes */ 200 return memalign( getpagesize(), bytes ); 201 } 202 203 /* Support for malloc debugging. 204 * Note that if USE_DL_PREFIX is not defined, it's assumed that memory 205 * allocation routines are implemented somewhere else, so all our custom 206 * malloc routines should not be compiled at all. 207 */ 208 #ifdef USE_DL_PREFIX 209 210 /* Table for dispatching malloc calls, initialized with default dispatchers. */ 211 const MallocDebug __libc_malloc_default_dispatch __attribute__((aligned(32))) = 212 { 213 dlmalloc, dlfree, dlcalloc, dlrealloc, dlmemalign 214 }; 215 216 /* Selector of dispatch table to use for dispatching malloc calls. */ 217 const MallocDebug* __libc_malloc_dispatch = &__libc_malloc_default_dispatch; 218 219 void* malloc(size_t bytes) { 220 return __libc_malloc_dispatch->malloc(bytes); 221 } 222 void free(void* mem) { 223 __libc_malloc_dispatch->free(mem); 224 } 225 void* calloc(size_t n_elements, size_t elem_size) { 226 return __libc_malloc_dispatch->calloc(n_elements, elem_size); 227 } 228 void* realloc(void* oldMem, size_t bytes) { 229 return __libc_malloc_dispatch->realloc(oldMem, bytes); 230 } 231 void* memalign(size_t alignment, size_t bytes) { 232 return __libc_malloc_dispatch->memalign(alignment, bytes); 233 } 234 235 /* We implement malloc debugging only in libc.so, so code bellow 236 * must be excluded if we compile this file for static libc.a 237 */ 238 #ifndef LIBC_STATIC 239 #include <sys/system_properties.h> 240 #include <dlfcn.h> 241 #include "logd.h" 242 243 // ============================================================================= 244 // log functions 245 // ============================================================================= 246 247 #define debug_log(format, ...) \ 248 __libc_android_log_print(ANDROID_LOG_DEBUG, "libc", (format), ##__VA_ARGS__ ) 249 #define error_log(format, ...) \ 250 __libc_android_log_print(ANDROID_LOG_ERROR, "libc", (format), ##__VA_ARGS__ ) 251 #define info_log(format, ...) \ 252 __libc_android_log_print(ANDROID_LOG_INFO, "libc", (format), ##__VA_ARGS__ ) 253 254 /* Table for dispatching malloc calls, depending on environment. */ 255 static MallocDebug gMallocUse __attribute__((aligned(32))) = { 256 dlmalloc, dlfree, dlcalloc, dlrealloc, dlmemalign 257 }; 258 259 extern char* __progname; 260 261 /* Handle to shared library where actual memory allocation is implemented. 262 * This library is loaded and memory allocation calls are redirected there 263 * when libc.debug.malloc environment variable contains value other than 264 * zero: 265 * 1 - For memory leak detections. 266 * 5 - For filling allocated / freed memory with patterns defined by 267 * CHK_SENTINEL_VALUE, and CHK_FILL_FREE macros. 268 * 10 - For adding pre-, and post- allocation stubs in order to detect 269 * buffer overruns. 270 * Note that emulator's memory allocation instrumentation is not controlled by 271 * libc.debug.malloc value, but rather by emulator, started with -memcheck 272 * option. Note also, that if emulator has started with -memcheck option, 273 * emulator's instrumented memory allocation will take over value saved in 274 * libc.debug.malloc. In other words, if emulator has started with -memcheck 275 * option, libc.debug.malloc value is ignored. 276 * Actual functionality for debug levels 1-10 is implemented in 277 * libc_malloc_debug_leak.so, while functionality for emultor's instrumented 278 * allocations is implemented in libc_malloc_debug_qemu.so and can be run inside 279 * the emulator only. 280 */ 281 static void* libc_malloc_impl_handle = NULL; 282 283 /* Make sure we have MALLOC_ALIGNMENT that matches the one that is 284 * used in dlmalloc. Emulator's memchecker needs this value to properly 285 * align its guarding zones. 286 */ 287 #ifndef MALLOC_ALIGNMENT 288 #define MALLOC_ALIGNMENT ((size_t)8U) 289 #endif /* MALLOC_ALIGNMENT */ 290 291 /* Initializes memory allocation framework once per process. */ 292 static void malloc_init_impl(void) 293 { 294 const char* so_name = NULL; 295 MallocDebugInit malloc_debug_initialize = NULL; 296 unsigned int qemu_running = 0; 297 unsigned int debug_level = 0; 298 unsigned int memcheck_enabled = 0; 299 char env[PROP_VALUE_MAX]; 300 char memcheck_tracing[PROP_VALUE_MAX]; 301 302 /* Get custom malloc debug level. Note that emulator started with 303 * memory checking option will have priority over debug level set in 304 * libc.debug.malloc system property. */ 305 if (__system_property_get("ro.kernel.qemu", env) && atoi(env)) { 306 qemu_running = 1; 307 if (__system_property_get("ro.kernel.memcheck", memcheck_tracing)) { 308 if (memcheck_tracing[0] != '0') { 309 // Emulator has started with memory tracing enabled. Enforce it. 310 debug_level = 20; 311 memcheck_enabled = 1; 312 } 313 } 314 } 315 316 /* If debug level has not been set by memcheck option in the emulator, 317 * lets grab it from libc.debug.malloc system property. */ 318 if (!debug_level && __system_property_get("libc.debug.malloc", env)) { 319 debug_level = atoi(env); 320 } 321 322 /* Debug level 0 means that we should use dlxxx allocation 323 * routines (default). */ 324 if (!debug_level) { 325 return; 326 } 327 328 // Lets see which .so must be loaded for the requested debug level 329 switch (debug_level) { 330 case 1: 331 case 5: 332 case 10: 333 so_name = "/system/lib/libc_malloc_debug_leak.so"; 334 break; 335 case 20: 336 // Quick check: debug level 20 can only be handled in emulator. 337 if (!qemu_running) { 338 error_log("%s: Debug level %d can only be set in emulator\n", 339 __progname, debug_level); 340 return; 341 } 342 // Make sure that memory checking has been enabled in emulator. 343 if (!memcheck_enabled) { 344 error_log("%s: Memory checking is not enabled in the emulator\n", 345 __progname); 346 return; 347 } 348 so_name = "/system/lib/libc_malloc_debug_qemu.so"; 349 break; 350 default: 351 error_log("%s: Debug level %d is unknown\n", 352 __progname, debug_level); 353 return; 354 } 355 356 // Load .so that implements the required malloc debugging functionality. 357 libc_malloc_impl_handle = dlopen(so_name, RTLD_LAZY); 358 if (libc_malloc_impl_handle == NULL) { 359 error_log("%s: Missing module %s required for malloc debug level %d\n", 360 __progname, so_name, debug_level); 361 return; 362 } 363 364 // Initialize malloc debugging in the loaded module. 365 malloc_debug_initialize = 366 dlsym(libc_malloc_impl_handle, "malloc_debug_initialize"); 367 if (malloc_debug_initialize == NULL) { 368 error_log("%s: Initialization routine is not found in %s\n", 369 __progname, so_name); 370 dlclose(libc_malloc_impl_handle); 371 return; 372 } 373 if (malloc_debug_initialize()) { 374 dlclose(libc_malloc_impl_handle); 375 return; 376 } 377 378 if (debug_level == 20) { 379 // For memory checker we need to do extra initialization. 380 int (*memcheck_initialize)(int, const char*) = 381 dlsym(libc_malloc_impl_handle, "memcheck_initialize"); 382 if (memcheck_initialize == NULL) { 383 error_log("%s: memcheck_initialize routine is not found in %s\n", 384 __progname, so_name); 385 dlclose(libc_malloc_impl_handle); 386 return; 387 } 388 if (memcheck_initialize(MALLOC_ALIGNMENT, memcheck_tracing)) { 389 dlclose(libc_malloc_impl_handle); 390 return; 391 } 392 } 393 394 // Initialize malloc dispatch table with appropriate routines. 395 switch (debug_level) { 396 case 1: 397 __libc_android_log_print(ANDROID_LOG_INFO, "libc", 398 "%s using MALLOC_DEBUG = %d (leak checker)\n", 399 __progname, debug_level); 400 gMallocUse.malloc = 401 dlsym(libc_malloc_impl_handle, "leak_malloc"); 402 gMallocUse.free = 403 dlsym(libc_malloc_impl_handle, "leak_free"); 404 gMallocUse.calloc = 405 dlsym(libc_malloc_impl_handle, "leak_calloc"); 406 gMallocUse.realloc = 407 dlsym(libc_malloc_impl_handle, "leak_realloc"); 408 gMallocUse.memalign = 409 dlsym(libc_malloc_impl_handle, "leak_memalign"); 410 break; 411 case 5: 412 __libc_android_log_print(ANDROID_LOG_INFO, "libc", 413 "%s using MALLOC_DEBUG = %d (fill)\n", 414 __progname, debug_level); 415 gMallocUse.malloc = 416 dlsym(libc_malloc_impl_handle, "fill_malloc"); 417 gMallocUse.free = 418 dlsym(libc_malloc_impl_handle, "fill_free"); 419 gMallocUse.calloc = dlcalloc; 420 gMallocUse.realloc = 421 dlsym(libc_malloc_impl_handle, "fill_realloc"); 422 gMallocUse.memalign = 423 dlsym(libc_malloc_impl_handle, "fill_memalign"); 424 break; 425 case 10: 426 __libc_android_log_print(ANDROID_LOG_INFO, "libc", 427 "%s using MALLOC_DEBUG = %d (sentinels, fill)\n", 428 __progname, debug_level); 429 gMallocUse.malloc = 430 dlsym(libc_malloc_impl_handle, "chk_malloc"); 431 gMallocUse.free = 432 dlsym(libc_malloc_impl_handle, "chk_free"); 433 gMallocUse.calloc = 434 dlsym(libc_malloc_impl_handle, "chk_calloc"); 435 gMallocUse.realloc = 436 dlsym(libc_malloc_impl_handle, "chk_realloc"); 437 gMallocUse.memalign = 438 dlsym(libc_malloc_impl_handle, "chk_memalign"); 439 break; 440 case 20: 441 __libc_android_log_print(ANDROID_LOG_INFO, "libc", 442 "%s[%u] using MALLOC_DEBUG = %d (instrumented for emulator)\n", 443 __progname, getpid(), debug_level); 444 gMallocUse.malloc = 445 dlsym(libc_malloc_impl_handle, "qemu_instrumented_malloc"); 446 gMallocUse.free = 447 dlsym(libc_malloc_impl_handle, "qemu_instrumented_free"); 448 gMallocUse.calloc = 449 dlsym(libc_malloc_impl_handle, "qemu_instrumented_calloc"); 450 gMallocUse.realloc = 451 dlsym(libc_malloc_impl_handle, "qemu_instrumented_realloc"); 452 gMallocUse.memalign = 453 dlsym(libc_malloc_impl_handle, "qemu_instrumented_memalign"); 454 break; 455 default: 456 break; 457 } 458 459 // Make sure dispatch table is initialized 460 if ((gMallocUse.malloc == NULL) || 461 (gMallocUse.free == NULL) || 462 (gMallocUse.calloc == NULL) || 463 (gMallocUse.realloc == NULL) || 464 (gMallocUse.memalign == NULL)) { 465 error_log("%s: Cannot initialize malloc dispatch table for debug level" 466 " %d: %p, %p, %p, %p, %p\n", 467 __progname, debug_level, 468 gMallocUse.malloc, gMallocUse.free, 469 gMallocUse.calloc, gMallocUse.realloc, 470 gMallocUse.memalign); 471 dlclose(libc_malloc_impl_handle); 472 libc_malloc_impl_handle = NULL; 473 } else { 474 __libc_malloc_dispatch = &gMallocUse; 475 } 476 } 477 478 static pthread_once_t malloc_init_once_ctl = PTHREAD_ONCE_INIT; 479 480 #endif // !LIBC_STATIC 481 #endif // USE_DL_PREFIX 482 483 /* Initializes memory allocation framework. 484 * This routine is called from __libc_init routines implemented 485 * in libc_init_static.c and libc_init_dynamic.c files. 486 */ 487 void malloc_debug_init(void) 488 { 489 /* We need to initialize malloc iff we implement here custom 490 * malloc routines (i.e. USE_DL_PREFIX is defined) for libc.so */ 491 #if defined(USE_DL_PREFIX) && !defined(LIBC_STATIC) 492 if (pthread_once(&malloc_init_once_ctl, malloc_init_impl)) { 493 error_log("Unable to initialize malloc_debug component."); 494 } 495 #endif // USE_DL_PREFIX && !LIBC_STATIC 496 } 497
