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 int result; 88 if (alloc1 > alloc2) { 89 result = -1; 90 } else if (alloc1 < alloc2) { 91 result = 1; 92 } else { 93 if (nbAlloc1 > nbAlloc2) { 94 result = -1; 95 } else if (nbAlloc1 < nbAlloc2) { 96 result = 1; 97 } else { 98 result = 0; 99 } 100 } 101 } 102 return result; 103 } 104 105 /* 106 * Retrieve native heap information. 107 * 108 * "*info" is set to a buffer we allocate 109 * "*overallSize" is set to the size of the "info" buffer 110 * "*infoSize" is set to the size of a single entry 111 * "*totalMemory" is set to the sum of all allocations we're tracking; does 112 * not include heap overhead 113 * "*backtraceSize" is set to the maximum number of entries in the back trace 114 */ 115 void get_malloc_leak_info(uint8_t** info, size_t* overallSize, 116 size_t* infoSize, size_t* totalMemory, size_t* backtraceSize) 117 { 118 // don't do anything if we have invalid arguments 119 if (info == NULL || overallSize == NULL || infoSize == NULL || 120 totalMemory == NULL || backtraceSize == NULL) { 121 return; 122 } 123 124 pthread_mutex_lock(&gAllocationsMutex); 125 126 if (gHashTable.count == 0) { 127 *info = NULL; 128 *overallSize = 0; 129 *infoSize = 0; 130 *totalMemory = 0; 131 *backtraceSize = 0; 132 goto done; 133 } 134 135 void** list = (void**)dlmalloc(sizeof(void*) * gHashTable.count); 136 137 // get the entries into an array to be sorted 138 int index = 0; 139 int i; 140 for (i = 0 ; i < HASHTABLE_SIZE ; i++) { 141 HashEntry* entry = gHashTable.slots[i]; 142 while (entry != NULL) { 143 list[index] = entry; 144 *totalMemory = *totalMemory + 145 ((entry->size & ~SIZE_FLAG_MASK) * entry->allocations); 146 index++; 147 entry = entry->next; 148 } 149 } 150 151 // XXX: the protocol doesn't allow variable size for the stack trace (yet) 152 *infoSize = (sizeof(size_t) * 2) + (sizeof(intptr_t) * BACKTRACE_SIZE); 153 *overallSize = *infoSize * gHashTable.count; 154 *backtraceSize = BACKTRACE_SIZE; 155 156 // now get A byte array big enough for this 157 *info = (uint8_t*)dlmalloc(*overallSize); 158 159 if (*info == NULL) { 160 *overallSize = 0; 161 goto out_nomem_info; 162 } 163 164 qsort((void*)list, gHashTable.count, sizeof(void*), hash_entry_compare); 165 166 uint8_t* head = *info; 167 const int count = gHashTable.count; 168 for (i = 0 ; i < count ; i++) { 169 HashEntry* entry = list[i]; 170 size_t entrySize = (sizeof(size_t) * 2) + (sizeof(intptr_t) * entry->numEntries); 171 if (entrySize < *infoSize) { 172 /* we're writing less than a full entry, clear out the rest */ 173 memset(head + entrySize, 0, *infoSize - entrySize); 174 } else { 175 /* make sure the amount we're copying doesn't exceed the limit */ 176 entrySize = *infoSize; 177 } 178 memcpy(head, &(entry->size), entrySize); 179 head += *infoSize; 180 } 181 182 out_nomem_info: 183 dlfree(list); 184 185 done: 186 pthread_mutex_unlock(&gAllocationsMutex); 187 } 188 189 void free_malloc_leak_info(uint8_t* info) 190 { 191 dlfree(info); 192 } 193 194 struct mallinfo mallinfo() 195 { 196 return dlmallinfo(); 197 } 198 199 void* valloc(size_t bytes) { 200 /* assume page size of 4096 bytes */ 201 return memalign( getpagesize(), bytes ); 202 } 203 204 /* Support for malloc debugging. 205 * Note that if USE_DL_PREFIX is not defined, it's assumed that memory 206 * allocation routines are implemented somewhere else, so all our custom 207 * malloc routines should not be compiled at all. 208 */ 209 #ifdef USE_DL_PREFIX 210 211 /* Table for dispatching malloc calls, initialized with default dispatchers. */ 212 const MallocDebug __libc_malloc_default_dispatch __attribute__((aligned(32))) = 213 { 214 dlmalloc, dlfree, dlcalloc, dlrealloc, dlmemalign 215 }; 216 217 /* Selector of dispatch table to use for dispatching malloc calls. */ 218 const MallocDebug* __libc_malloc_dispatch = &__libc_malloc_default_dispatch; 219 220 void* malloc(size_t bytes) { 221 return __libc_malloc_dispatch->malloc(bytes); 222 } 223 void free(void* mem) { 224 __libc_malloc_dispatch->free(mem); 225 } 226 void* calloc(size_t n_elements, size_t elem_size) { 227 return __libc_malloc_dispatch->calloc(n_elements, elem_size); 228 } 229 void* realloc(void* oldMem, size_t bytes) { 230 return __libc_malloc_dispatch->realloc(oldMem, bytes); 231 } 232 void* memalign(size_t alignment, size_t bytes) { 233 return __libc_malloc_dispatch->memalign(alignment, bytes); 234 } 235 236 /* We implement malloc debugging only in libc.so, so code bellow 237 * must be excluded if we compile this file for static libc.a 238 */ 239 #ifndef LIBC_STATIC 240 #include <sys/system_properties.h> 241 #include <dlfcn.h> 242 #include "logd.h" 243 244 // ============================================================================= 245 // log functions 246 // ============================================================================= 247 248 #define debug_log(format, ...) \ 249 __libc_android_log_print(ANDROID_LOG_DEBUG, "libc", (format), ##__VA_ARGS__ ) 250 #define error_log(format, ...) \ 251 __libc_android_log_print(ANDROID_LOG_ERROR, "libc", (format), ##__VA_ARGS__ ) 252 #define info_log(format, ...) \ 253 __libc_android_log_print(ANDROID_LOG_INFO, "libc", (format), ##__VA_ARGS__ ) 254 255 /* Table for dispatching malloc calls, depending on environment. */ 256 static MallocDebug gMallocUse __attribute__((aligned(32))) = { 257 dlmalloc, dlfree, dlcalloc, dlrealloc, dlmemalign 258 }; 259 260 extern char* __progname; 261 262 /* Handle to shared library where actual memory allocation is implemented. 263 * This library is loaded and memory allocation calls are redirected there 264 * when libc.debug.malloc environment variable contains value other than 265 * zero: 266 * 1 - For memory leak detections. 267 * 5 - For filling allocated / freed memory with patterns defined by 268 * CHK_SENTINEL_VALUE, and CHK_FILL_FREE macros. 269 * 10 - For adding pre-, and post- allocation stubs in order to detect 270 * buffer overruns. 271 * Note that emulator's memory allocation instrumentation is not controlled by 272 * libc.debug.malloc value, but rather by emulator, started with -memcheck 273 * option. Note also, that if emulator has started with -memcheck option, 274 * emulator's instrumented memory allocation will take over value saved in 275 * libc.debug.malloc. In other words, if emulator has started with -memcheck 276 * option, libc.debug.malloc value is ignored. 277 * Actual functionality for debug levels 1-10 is implemented in 278 * libc_malloc_debug_leak.so, while functionality for emultor's instrumented 279 * allocations is implemented in libc_malloc_debug_qemu.so and can be run inside 280 * the emulator only. 281 */ 282 static void* libc_malloc_impl_handle = NULL; 283 284 /* Make sure we have MALLOC_ALIGNMENT that matches the one that is 285 * used in dlmalloc. Emulator's memchecker needs this value to properly 286 * align its guarding zones. 287 */ 288 #ifndef MALLOC_ALIGNMENT 289 #define MALLOC_ALIGNMENT ((size_t)8U) 290 #endif /* MALLOC_ALIGNMENT */ 291 292 /* Initializes memory allocation framework once per process. */ 293 static void malloc_init_impl(void) 294 { 295 const char* so_name = NULL; 296 MallocDebugInit malloc_debug_initialize = NULL; 297 unsigned int qemu_running = 0; 298 unsigned int debug_level = 0; 299 unsigned int memcheck_enabled = 0; 300 char env[PROP_VALUE_MAX]; 301 char memcheck_tracing[PROP_VALUE_MAX]; 302 303 /* Get custom malloc debug level. Note that emulator started with 304 * memory checking option will have priority over debug level set in 305 * libc.debug.malloc system property. */ 306 if (__system_property_get("ro.kernel.qemu", env) && atoi(env)) { 307 qemu_running = 1; 308 if (__system_property_get("ro.kernel.memcheck", memcheck_tracing)) { 309 if (memcheck_tracing[0] != '0') { 310 // Emulator has started with memory tracing enabled. Enforce it. 311 debug_level = 20; 312 memcheck_enabled = 1; 313 } 314 } 315 } 316 317 /* If debug level has not been set by memcheck option in the emulator, 318 * lets grab it from libc.debug.malloc system property. */ 319 if (!debug_level && __system_property_get("libc.debug.malloc", env)) { 320 debug_level = atoi(env); 321 } 322 323 /* Debug level 0 means that we should use dlxxx allocation 324 * routines (default). */ 325 if (!debug_level) { 326 return; 327 } 328 329 // Lets see which .so must be loaded for the requested debug level 330 switch (debug_level) { 331 case 1: 332 case 5: 333 case 10: 334 so_name = "/system/lib/libc_malloc_debug_leak.so"; 335 break; 336 case 20: 337 // Quick check: debug level 20 can only be handled in emulator. 338 if (!qemu_running) { 339 error_log("%s: Debug level %d can only be set in emulator\n", 340 __progname, debug_level); 341 return; 342 } 343 // Make sure that memory checking has been enabled in emulator. 344 if (!memcheck_enabled) { 345 error_log("%s: Memory checking is not enabled in the emulator\n", 346 __progname); 347 return; 348 } 349 so_name = "/system/lib/libc_malloc_debug_qemu.so"; 350 break; 351 default: 352 error_log("%s: Debug level %d is unknown\n", 353 __progname, debug_level); 354 return; 355 } 356 357 // Load .so that implements the required malloc debugging functionality. 358 libc_malloc_impl_handle = dlopen(so_name, RTLD_LAZY); 359 if (libc_malloc_impl_handle == NULL) { 360 error_log("%s: Missing module %s required for malloc debug level %d\n", 361 __progname, so_name, debug_level); 362 return; 363 } 364 365 // Initialize malloc debugging in the loaded module. 366 malloc_debug_initialize = 367 dlsym(libc_malloc_impl_handle, "malloc_debug_initialize"); 368 if (malloc_debug_initialize == NULL) { 369 error_log("%s: Initialization routine is not found in %s\n", 370 __progname, so_name); 371 dlclose(libc_malloc_impl_handle); 372 return; 373 } 374 if (malloc_debug_initialize()) { 375 dlclose(libc_malloc_impl_handle); 376 return; 377 } 378 379 if (debug_level == 20) { 380 // For memory checker we need to do extra initialization. 381 int (*memcheck_initialize)(int, const char*) = 382 dlsym(libc_malloc_impl_handle, "memcheck_initialize"); 383 if (memcheck_initialize == NULL) { 384 error_log("%s: memcheck_initialize routine is not found in %s\n", 385 __progname, so_name); 386 dlclose(libc_malloc_impl_handle); 387 return; 388 } 389 if (memcheck_initialize(MALLOC_ALIGNMENT, memcheck_tracing)) { 390 dlclose(libc_malloc_impl_handle); 391 return; 392 } 393 } 394 395 // Initialize malloc dispatch table with appropriate routines. 396 switch (debug_level) { 397 case 1: 398 __libc_android_log_print(ANDROID_LOG_INFO, "libc", 399 "%s using MALLOC_DEBUG = %d (leak checker)\n", 400 __progname, debug_level); 401 gMallocUse.malloc = 402 dlsym(libc_malloc_impl_handle, "leak_malloc"); 403 gMallocUse.free = 404 dlsym(libc_malloc_impl_handle, "leak_free"); 405 gMallocUse.calloc = 406 dlsym(libc_malloc_impl_handle, "leak_calloc"); 407 gMallocUse.realloc = 408 dlsym(libc_malloc_impl_handle, "leak_realloc"); 409 gMallocUse.memalign = 410 dlsym(libc_malloc_impl_handle, "leak_memalign"); 411 break; 412 case 5: 413 __libc_android_log_print(ANDROID_LOG_INFO, "libc", 414 "%s using MALLOC_DEBUG = %d (fill)\n", 415 __progname, debug_level); 416 gMallocUse.malloc = 417 dlsym(libc_malloc_impl_handle, "fill_malloc"); 418 gMallocUse.free = 419 dlsym(libc_malloc_impl_handle, "fill_free"); 420 gMallocUse.calloc = dlcalloc; 421 gMallocUse.realloc = 422 dlsym(libc_malloc_impl_handle, "fill_realloc"); 423 gMallocUse.memalign = 424 dlsym(libc_malloc_impl_handle, "fill_memalign"); 425 break; 426 case 10: 427 __libc_android_log_print(ANDROID_LOG_INFO, "libc", 428 "%s using MALLOC_DEBUG = %d (sentinels, fill)\n", 429 __progname, debug_level); 430 gMallocUse.malloc = 431 dlsym(libc_malloc_impl_handle, "chk_malloc"); 432 gMallocUse.free = 433 dlsym(libc_malloc_impl_handle, "chk_free"); 434 gMallocUse.calloc = 435 dlsym(libc_malloc_impl_handle, "chk_calloc"); 436 gMallocUse.realloc = 437 dlsym(libc_malloc_impl_handle, "chk_realloc"); 438 gMallocUse.memalign = 439 dlsym(libc_malloc_impl_handle, "chk_memalign"); 440 break; 441 case 20: 442 __libc_android_log_print(ANDROID_LOG_INFO, "libc", 443 "%s[%u] using MALLOC_DEBUG = %d (instrumented for emulator)\n", 444 __progname, getpid(), debug_level); 445 gMallocUse.malloc = 446 dlsym(libc_malloc_impl_handle, "qemu_instrumented_malloc"); 447 gMallocUse.free = 448 dlsym(libc_malloc_impl_handle, "qemu_instrumented_free"); 449 gMallocUse.calloc = 450 dlsym(libc_malloc_impl_handle, "qemu_instrumented_calloc"); 451 gMallocUse.realloc = 452 dlsym(libc_malloc_impl_handle, "qemu_instrumented_realloc"); 453 gMallocUse.memalign = 454 dlsym(libc_malloc_impl_handle, "qemu_instrumented_memalign"); 455 break; 456 default: 457 break; 458 } 459 460 // Make sure dispatch table is initialized 461 if ((gMallocUse.malloc == NULL) || 462 (gMallocUse.free == NULL) || 463 (gMallocUse.calloc == NULL) || 464 (gMallocUse.realloc == NULL) || 465 (gMallocUse.memalign == NULL)) { 466 error_log("%s: Cannot initialize malloc dispatch table for debug level" 467 " %d: %p, %p, %p, %p, %p\n", 468 __progname, debug_level, 469 gMallocUse.malloc, gMallocUse.free, 470 gMallocUse.calloc, gMallocUse.realloc, 471 gMallocUse.memalign); 472 dlclose(libc_malloc_impl_handle); 473 libc_malloc_impl_handle = NULL; 474 } else { 475 __libc_malloc_dispatch = &gMallocUse; 476 } 477 } 478 479 static pthread_once_t malloc_init_once_ctl = PTHREAD_ONCE_INIT; 480 481 #endif // !LIBC_STATIC 482 #endif // USE_DL_PREFIX 483 484 /* Initializes memory allocation framework. 485 * This routine is called from __libc_init routines implemented 486 * in libc_init_static.c and libc_init_dynamic.c files. 487 */ 488 void malloc_debug_init(void) 489 { 490 /* We need to initialize malloc iff we implement here custom 491 * malloc routines (i.e. USE_DL_PREFIX is defined) for libc.so */ 492 #if defined(USE_DL_PREFIX) && !defined(LIBC_STATIC) 493 if (pthread_once(&malloc_init_once_ctl, malloc_init_impl)) { 494 error_log("Unable to initialize malloc_debug component."); 495 } 496 #endif // USE_DL_PREFIX && !LIBC_STATIC 497 } 498