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 // Contains a thin layer that calls whatever real native allocator
30 // has been defined. For the libc shared library, this allows the
31 // implementation of a debug malloc that can intercept all of the allocation
32 // calls and add special debugging code to attempt to catch allocation
33 // errors. All of the debugging code is implemented in a separate shared
34 // library that is only loaded when the property "libc.debug.malloc.options"
35 // is set to a non-zero value. There are two functions exported to
36 // allow ddms, or other external users to get information from the debug
37 // allocation.
38 // get_malloc_leak_info: Returns information about all of the known native
39 // allocations that are currently in use.
40 // free_malloc_leak_info: Frees the data allocated by the call to
41 // get_malloc_leak_info.
42
43 #include <pthread.h>
44
45 #include <private/bionic_config.h>
46 #include <private/bionic_globals.h>
47 #include <private/bionic_malloc_dispatch.h>
48
49 #include "jemalloc.h"
50 #define Malloc(function) je_ ## function
51
52 static constexpr MallocDispatch __libc_malloc_default_dispatch
53 __attribute__((unused)) = {
54 Malloc(calloc),
55 Malloc(free),
56 Malloc(mallinfo),
57 Malloc(malloc),
58 Malloc(malloc_usable_size),
59 Malloc(memalign),
60 Malloc(posix_memalign),
61 #if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
62 Malloc(pvalloc),
63 #endif
64 Malloc(realloc),
65 #if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
66 Malloc(valloc),
67 #endif
68 Malloc(iterate),
69 Malloc(malloc_disable),
70 Malloc(malloc_enable),
71 };
72
73 // In a VM process, this is set to 1 after fork()ing out of zygote.
74 int gMallocLeakZygoteChild = 0;
75
76 // =============================================================================
77 // Allocation functions
78 // =============================================================================
calloc(size_t n_elements,size_t elem_size)79 extern "C" void* calloc(size_t n_elements, size_t elem_size) {
80 auto _calloc = __libc_globals->malloc_dispatch.calloc;
81 if (__predict_false(_calloc != nullptr)) {
82 return _calloc(n_elements, elem_size);
83 }
84 return Malloc(calloc)(n_elements, elem_size);
85 }
86
free(void * mem)87 extern "C" void free(void* mem) {
88 auto _free = __libc_globals->malloc_dispatch.free;
89 if (__predict_false(_free != nullptr)) {
90 _free(mem);
91 } else {
92 Malloc(free)(mem);
93 }
94 }
95
mallinfo()96 extern "C" struct mallinfo mallinfo() {
97 auto _mallinfo = __libc_globals->malloc_dispatch.mallinfo;
98 if (__predict_false(_mallinfo != nullptr)) {
99 return _mallinfo();
100 }
101 return Malloc(mallinfo)();
102 }
103
malloc(size_t bytes)104 extern "C" void* malloc(size_t bytes) {
105 auto _malloc = __libc_globals->malloc_dispatch.malloc;
106 if (__predict_false(_malloc != nullptr)) {
107 return _malloc(bytes);
108 }
109 return Malloc(malloc)(bytes);
110 }
111
malloc_usable_size(const void * mem)112 extern "C" size_t malloc_usable_size(const void* mem) {
113 auto _malloc_usable_size = __libc_globals->malloc_dispatch.malloc_usable_size;
114 if (__predict_false(_malloc_usable_size != nullptr)) {
115 return _malloc_usable_size(mem);
116 }
117 return Malloc(malloc_usable_size)(mem);
118 }
119
memalign(size_t alignment,size_t bytes)120 extern "C" void* memalign(size_t alignment, size_t bytes) {
121 auto _memalign = __libc_globals->malloc_dispatch.memalign;
122 if (__predict_false(_memalign != nullptr)) {
123 return _memalign(alignment, bytes);
124 }
125 return Malloc(memalign)(alignment, bytes);
126 }
127
posix_memalign(void ** memptr,size_t alignment,size_t size)128 extern "C" int posix_memalign(void** memptr, size_t alignment, size_t size) {
129 auto _posix_memalign = __libc_globals->malloc_dispatch.posix_memalign;
130 if (__predict_false(_posix_memalign != nullptr)) {
131 return _posix_memalign(memptr, alignment, size);
132 }
133 return Malloc(posix_memalign)(memptr, alignment, size);
134 }
135
realloc(void * old_mem,size_t bytes)136 extern "C" void* realloc(void* old_mem, size_t bytes) {
137 auto _realloc = __libc_globals->malloc_dispatch.realloc;
138 if (__predict_false(_realloc != nullptr)) {
139 return _realloc(old_mem, bytes);
140 }
141 return Malloc(realloc)(old_mem, bytes);
142 }
143
144 #if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
pvalloc(size_t bytes)145 extern "C" void* pvalloc(size_t bytes) {
146 auto _pvalloc = __libc_globals->malloc_dispatch.pvalloc;
147 if (__predict_false(_pvalloc != nullptr)) {
148 return _pvalloc(bytes);
149 }
150 return Malloc(pvalloc)(bytes);
151 }
152
valloc(size_t bytes)153 extern "C" void* valloc(size_t bytes) {
154 auto _valloc = __libc_globals->malloc_dispatch.valloc;
155 if (__predict_false(_valloc != nullptr)) {
156 return _valloc(bytes);
157 }
158 return Malloc(valloc)(bytes);
159 }
160 #endif
161
162 // We implement malloc debugging only in libc.so, so the code below
163 // must be excluded if we compile this file for static libc.a
164 #if !defined(LIBC_STATIC)
165
166 #include <dlfcn.h>
167 #include <stdio.h>
168 #include <stdlib.h>
169
170 #include <private/libc_logging.h>
171 #include <sys/system_properties.h>
172
173 extern "C" int __cxa_atexit(void (*func)(void *), void *arg, void *dso);
174
175 static const char* DEBUG_SHARED_LIB = "libc_malloc_debug.so";
176 static const char* DEBUG_MALLOC_PROPERTY_OPTIONS = "libc.debug.malloc.options";
177 static const char* DEBUG_MALLOC_PROPERTY_PROGRAM = "libc.debug.malloc.program";
178 static const char* DEBUG_MALLOC_PROPERTY_ENV_ENABLED = "libc.debug.malloc.env_enabled";
179 static const char* DEBUG_MALLOC_ENV_ENABLE = "LIBC_DEBUG_MALLOC_ENABLE";
180
181 static void* libc_malloc_impl_handle = nullptr;
182
183 static void (*g_debug_finalize_func)();
184 static void (*g_debug_get_malloc_leak_info_func)(uint8_t**, size_t*, size_t*, size_t*, size_t*);
185 static void (*g_debug_free_malloc_leak_info_func)(uint8_t*);
186 static ssize_t (*g_debug_malloc_backtrace_func)(void*, uintptr_t*, size_t);
187
188 // =============================================================================
189 // Log functions
190 // =============================================================================
191 #define error_log(format, ...) \
192 __libc_format_log(ANDROID_LOG_ERROR, "libc", (format), ##__VA_ARGS__ )
193 #define info_log(format, ...) \
194 __libc_format_log(ANDROID_LOG_INFO, "libc", (format), ##__VA_ARGS__ )
195 // =============================================================================
196
197 // =============================================================================
198 // Exported for use by ddms.
199 // =============================================================================
200
201 // Retrieve native heap information.
202 //
203 // "*info" is set to a buffer we allocate
204 // "*overall_size" is set to the size of the "info" buffer
205 // "*info_size" is set to the size of a single entry
206 // "*total_memory" is set to the sum of all allocations we're tracking; does
207 // not include heap overhead
208 // "*backtrace_size" is set to the maximum number of entries in the back trace
get_malloc_leak_info(uint8_t ** info,size_t * overall_size,size_t * info_size,size_t * total_memory,size_t * backtrace_size)209 extern "C" void get_malloc_leak_info(uint8_t** info, size_t* overall_size,
210 size_t* info_size, size_t* total_memory, size_t* backtrace_size) {
211 if (g_debug_get_malloc_leak_info_func == nullptr) {
212 return;
213 }
214 g_debug_get_malloc_leak_info_func(info, overall_size, info_size, total_memory, backtrace_size);
215 }
216
free_malloc_leak_info(uint8_t * info)217 extern "C" void free_malloc_leak_info(uint8_t* info) {
218 if (g_debug_free_malloc_leak_info_func == nullptr) {
219 return;
220 }
221 g_debug_free_malloc_leak_info_func(info);
222 }
223
224 // =============================================================================
225
226 template<typename FunctionType>
InitMallocFunction(void * malloc_impl_handler,FunctionType * func,const char * prefix,const char * suffix)227 static bool InitMallocFunction(void* malloc_impl_handler, FunctionType* func, const char* prefix, const char* suffix) {
228 char symbol[128];
229 snprintf(symbol, sizeof(symbol), "%s_%s", prefix, suffix);
230 *func = reinterpret_cast<FunctionType>(dlsym(malloc_impl_handler, symbol));
231 if (*func == nullptr) {
232 error_log("%s: dlsym(\"%s\") failed", getprogname(), symbol);
233 return false;
234 }
235 return true;
236 }
237
InitMalloc(void * malloc_impl_handler,MallocDispatch * table,const char * prefix)238 static bool InitMalloc(void* malloc_impl_handler, MallocDispatch* table, const char* prefix) {
239 if (!InitMallocFunction<MallocCalloc>(malloc_impl_handler, &table->calloc,
240 prefix, "calloc")) {
241 return false;
242 }
243 if (!InitMallocFunction<MallocFree>(malloc_impl_handler, &table->free,
244 prefix, "free")) {
245 return false;
246 }
247 if (!InitMallocFunction<MallocMallinfo>(malloc_impl_handler, &table->mallinfo,
248 prefix, "mallinfo")) {
249 return false;
250 }
251 if (!InitMallocFunction<MallocMalloc>(malloc_impl_handler, &table->malloc,
252 prefix, "malloc")) {
253 return false;
254 }
255 if (!InitMallocFunction<MallocMallocUsableSize>(
256 malloc_impl_handler, &table->malloc_usable_size, prefix, "malloc_usable_size")) {
257 return false;
258 }
259 if (!InitMallocFunction<MallocMemalign>(malloc_impl_handler, &table->memalign,
260 prefix, "memalign")) {
261 return false;
262 }
263 if (!InitMallocFunction<MallocPosixMemalign>(malloc_impl_handler, &table->posix_memalign,
264 prefix, "posix_memalign")) {
265 return false;
266 }
267 if (!InitMallocFunction<MallocRealloc>(malloc_impl_handler, &table->realloc,
268 prefix, "realloc")) {
269 return false;
270 }
271 if (!InitMallocFunction<MallocIterate>(malloc_impl_handler, &table->iterate,
272 prefix, "iterate")) {
273 return false;
274 }
275 if (!InitMallocFunction<MallocMallocDisable>(malloc_impl_handler, &table->malloc_disable,
276 prefix, "malloc_disable")) {
277 return false;
278 }
279 if (!InitMallocFunction<MallocMallocEnable>(malloc_impl_handler, &table->malloc_enable,
280 prefix, "malloc_enable")) {
281 return false;
282 }
283 #if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
284 if (!InitMallocFunction<MallocPvalloc>(malloc_impl_handler, &table->pvalloc,
285 prefix, "pvalloc")) {
286 return false;
287 }
288 if (!InitMallocFunction<MallocValloc>(malloc_impl_handler, &table->valloc,
289 prefix, "valloc")) {
290 return false;
291 }
292 #endif
293
294 return true;
295 }
296
malloc_fini_impl(void *)297 static void malloc_fini_impl(void*) {
298 // Our BSD stdio implementation doesn't close the standard streams,
299 // it only flushes them. Other unclosed FILE*s will show up as
300 // malloc leaks, but to avoid the standard streams showing up in
301 // leak reports, close them here.
302 fclose(stdin);
303 fclose(stdout);
304 fclose(stderr);
305
306 g_debug_finalize_func();
307 }
308
309 // Initializes memory allocation framework once per process.
malloc_init_impl(libc_globals * globals)310 static void malloc_init_impl(libc_globals* globals) {
311 char value[PROP_VALUE_MAX];
312 if (__system_property_get(DEBUG_MALLOC_PROPERTY_OPTIONS, value) == 0 || value[0] == '\0') {
313 return;
314 }
315
316 // Check to see if only a specific program should have debug malloc enabled.
317 if (__system_property_get(DEBUG_MALLOC_PROPERTY_PROGRAM, value) != 0 &&
318 strstr(getprogname(), value) == nullptr) {
319 return;
320 }
321
322 // Check for the special environment variable instead.
323 if (__system_property_get(DEBUG_MALLOC_PROPERTY_ENV_ENABLED, value) != 0
324 && value[0] != '\0' && getenv(DEBUG_MALLOC_ENV_ENABLE) == nullptr) {
325 return;
326 }
327
328 // Load the debug malloc shared library.
329 void* malloc_impl_handle = dlopen(DEBUG_SHARED_LIB, RTLD_NOW | RTLD_LOCAL);
330 if (malloc_impl_handle == nullptr) {
331 error_log("%s: Unable to open debug malloc shared library %s: %s",
332 getprogname(), DEBUG_SHARED_LIB, dlerror());
333 return;
334 }
335
336 // Initialize malloc debugging in the loaded module.
337 auto init_func = reinterpret_cast<bool (*)(const MallocDispatch*, int*)>(
338 dlsym(malloc_impl_handle, "debug_initialize"));
339 if (init_func == nullptr) {
340 error_log("%s: debug_initialize routine not found in %s", getprogname(), DEBUG_SHARED_LIB);
341 dlclose(malloc_impl_handle);
342 return;
343 }
344
345 // Get the syms for the external functions.
346 void* finalize_sym = dlsym(malloc_impl_handle, "debug_finalize");
347 if (finalize_sym == nullptr) {
348 error_log("%s: debug_finalize routine not found in %s", getprogname(), DEBUG_SHARED_LIB);
349 dlclose(malloc_impl_handle);
350 return;
351 }
352
353 void* get_leak_info_sym = dlsym(malloc_impl_handle, "debug_get_malloc_leak_info");
354 if (get_leak_info_sym == nullptr) {
355 error_log("%s: debug_get_malloc_leak_info routine not found in %s", getprogname(),
356 DEBUG_SHARED_LIB);
357 dlclose(malloc_impl_handle);
358 return;
359 }
360
361 void* free_leak_info_sym = dlsym(malloc_impl_handle, "debug_free_malloc_leak_info");
362 if (free_leak_info_sym == nullptr) {
363 error_log("%s: debug_free_malloc_leak_info routine not found in %s", getprogname(),
364 DEBUG_SHARED_LIB);
365 dlclose(malloc_impl_handle);
366 return;
367 }
368
369 void* malloc_backtrace_sym = dlsym(malloc_impl_handle, "debug_malloc_backtrace");
370 if (malloc_backtrace_sym == nullptr) {
371 error_log("%s: debug_malloc_backtrace routine not found in %s", getprogname(),
372 DEBUG_SHARED_LIB);
373 dlclose(malloc_impl_handle);
374 return;
375 }
376
377 if (!init_func(&__libc_malloc_default_dispatch, &gMallocLeakZygoteChild)) {
378 dlclose(malloc_impl_handle);
379 return;
380 }
381
382 MallocDispatch malloc_dispatch_table;
383 if (!InitMalloc(malloc_impl_handle, &malloc_dispatch_table, "debug")) {
384 auto finalize_func = reinterpret_cast<void (*)()>(finalize_sym);
385 finalize_func();
386 dlclose(malloc_impl_handle);
387 return;
388 }
389
390 g_debug_finalize_func = reinterpret_cast<void (*)()>(finalize_sym);
391 g_debug_get_malloc_leak_info_func = reinterpret_cast<void (*)(
392 uint8_t**, size_t*, size_t*, size_t*, size_t*)>(get_leak_info_sym);
393 g_debug_free_malloc_leak_info_func = reinterpret_cast<void (*)(uint8_t*)>(free_leak_info_sym);
394 g_debug_malloc_backtrace_func = reinterpret_cast<ssize_t (*)(
395 void*, uintptr_t*, size_t)>(malloc_backtrace_sym);
396
397 globals->malloc_dispatch = malloc_dispatch_table;
398 libc_malloc_impl_handle = malloc_impl_handle;
399
400 info_log("%s: malloc debug enabled", getprogname());
401
402 // Use atexit to trigger the cleanup function. This avoids a problem
403 // where another atexit function is used to cleanup allocated memory,
404 // but the finalize function was already called. This particular error
405 // seems to be triggered by a zygote spawned process calling exit.
406 int ret_value = __cxa_atexit(malloc_fini_impl, nullptr, nullptr);
407 if (ret_value != 0) {
408 error_log("failed to set atexit cleanup function: %d", ret_value);
409 }
410 }
411
412 // Initializes memory allocation framework.
413 // This routine is called from __libc_init routines in libc_init_dynamic.cpp.
__libc_init_malloc(libc_globals * globals)414 __LIBC_HIDDEN__ void __libc_init_malloc(libc_globals* globals) {
415 malloc_init_impl(globals);
416 }
417 #endif // !LIBC_STATIC
418
419 // =============================================================================
420 // Exported for use by libmemunreachable.
421 // =============================================================================
422
423 // Calls callback for every allocation in the anonymous heap mapping
424 // [base, base+size). Must be called between malloc_disable and malloc_enable.
malloc_iterate(uintptr_t base,size_t size,void (* callback)(uintptr_t base,size_t size,void * arg),void * arg)425 extern "C" int malloc_iterate(uintptr_t base, size_t size,
426 void (*callback)(uintptr_t base, size_t size, void* arg), void* arg) {
427 auto _iterate = __libc_globals->malloc_dispatch.iterate;
428 if (__predict_false(_iterate != nullptr)) {
429 return _iterate(base, size, callback, arg);
430 }
431 return Malloc(iterate)(base, size, callback, arg);
432 }
433
434 // Disable calls to malloc so malloc_iterate gets a consistent view of
435 // allocated memory.
malloc_disable()436 extern "C" void malloc_disable() {
437 auto _malloc_disable = __libc_globals->malloc_dispatch.malloc_disable;
438 if (__predict_false(_malloc_disable != nullptr)) {
439 return _malloc_disable();
440 }
441 return Malloc(malloc_disable)();
442 }
443
444 // Re-enable calls to malloc after a previous call to malloc_disable.
malloc_enable()445 extern "C" void malloc_enable() {
446 auto _malloc_enable = __libc_globals->malloc_dispatch.malloc_enable;
447 if (__predict_false(_malloc_enable != nullptr)) {
448 return _malloc_enable();
449 }
450 return Malloc(malloc_enable)();
451 }
452
453 #ifndef LIBC_STATIC
malloc_backtrace(void * pointer,uintptr_t * frames,size_t frame_count)454 extern "C" ssize_t malloc_backtrace(void* pointer, uintptr_t* frames, size_t frame_count) {
455 if (g_debug_malloc_backtrace_func == nullptr) {
456 return 0;
457 }
458 return g_debug_malloc_backtrace_func(pointer, frames, frame_count);
459 }
460 #else
malloc_backtrace(void *,uintptr_t *,size_t)461 extern "C" ssize_t malloc_backtrace(void*, uintptr_t*, size_t) {
462 return 0;
463 }
464 #endif
465