/*
* Copyright (C) 2009 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Contains definition of structures, global variables, and implementation of
* routines that are used by malloc leak detection code and other components in
* the system. The trick is that some components expect these data and
* routines to be defined / implemented in libc.so library, regardless
* whether or not MALLOC_LEAK_CHECK macro is defined. To make things even
* more tricky, malloc leak detection code, implemented in
* libc_malloc_debug.so also requires access to these variables and routines
* (to fill allocation entry hash table, for example). So, all relevant
* variables and routines are defined / implemented here and exported
* to all, leak detection code and other components via dynamic (libc.so),
* or static (libc.a) linking.
*/
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include "dlmalloc.h"
#include "malloc_debug_common.h"
/*
* In a VM process, this is set to 1 after fork()ing out of zygote.
*/
int gMallocLeakZygoteChild = 0;
pthread_mutex_t gAllocationsMutex = PTHREAD_MUTEX_INITIALIZER;
HashTable gHashTable;
// =============================================================================
// output functions
// =============================================================================
static int hash_entry_compare(const void* arg1, const void* arg2) {
int result;
const HashEntry* e1 = *static_cast<HashEntry* const*>(arg1);
const HashEntry* e2 = *static_cast<HashEntry* const*>(arg2);
// if one or both arg pointers are null, deal gracefully
if (e1 == NULL) {
result = (e2 == NULL) ? 0 : 1;
} else if (e2 == NULL) {
result = -1;
} else {
size_t nbAlloc1 = e1->allocations;
size_t nbAlloc2 = e2->allocations;
size_t size1 = e1->size & ~SIZE_FLAG_MASK;
size_t size2 = e2->size & ~SIZE_FLAG_MASK;
size_t alloc1 = nbAlloc1 * size1;
size_t alloc2 = nbAlloc2 * size2;
// sort in descending order by:
// 1) total size
// 2) number of allocations
//
// This is used for sorting, not determination of equality, so we don't
// need to compare the bit flags.
if (alloc1 > alloc2) {
result = -1;
} else if (alloc1 < alloc2) {
result = 1;
} else {
if (nbAlloc1 > nbAlloc2) {
result = -1;
} else if (nbAlloc1 < nbAlloc2) {
result = 1;
} else {
result = 0;
}
}
}
return result;
}
/*
* Retrieve native heap information.
*
* "*info" is set to a buffer we allocate
* "*overallSize" is set to the size of the "info" buffer
* "*infoSize" is set to the size of a single entry
* "*totalMemory" is set to the sum of all allocations we're tracking; does
* not include heap overhead
* "*backtraceSize" is set to the maximum number of entries in the back trace
*/
extern "C" void get_malloc_leak_info(uint8_t** info, size_t* overallSize,
size_t* infoSize, size_t* totalMemory, size_t* backtraceSize) {
// don't do anything if we have invalid arguments
if (info == NULL || overallSize == NULL || infoSize == NULL ||
totalMemory == NULL || backtraceSize == NULL) {
return;
}
*totalMemory = 0;
ScopedPthreadMutexLocker locker(&gAllocationsMutex);
if (gHashTable.count == 0) {
*info = NULL;
*overallSize = 0;
*infoSize = 0;
*backtraceSize = 0;
return;
}
HashEntry** list = static_cast<HashEntry**>(dlmalloc(sizeof(void*) * gHashTable.count));
// get the entries into an array to be sorted
int index = 0;
for (size_t i = 0 ; i < HASHTABLE_SIZE ; ++i) {
HashEntry* entry = gHashTable.slots[i];
while (entry != NULL) {
list[index] = entry;
*totalMemory = *totalMemory +
((entry->size & ~SIZE_FLAG_MASK) * entry->allocations);
index++;
entry = entry->next;
}
}
// XXX: the protocol doesn't allow variable size for the stack trace (yet)
*infoSize = (sizeof(size_t) * 2) + (sizeof(intptr_t) * BACKTRACE_SIZE);
*overallSize = *infoSize * gHashTable.count;
*backtraceSize = BACKTRACE_SIZE;
// now get a byte array big enough for this
*info = static_cast<uint8_t*>(dlmalloc(*overallSize));
if (*info == NULL) {
*overallSize = 0;
dlfree(list);
return;
}
qsort(list, gHashTable.count, sizeof(void*), hash_entry_compare);
uint8_t* head = *info;
const int count = gHashTable.count;
for (int i = 0 ; i < count ; ++i) {
HashEntry* entry = list[i];
size_t entrySize = (sizeof(size_t) * 2) + (sizeof(intptr_t) * entry->numEntries);
if (entrySize < *infoSize) {
/* we're writing less than a full entry, clear out the rest */
memset(head + entrySize, 0, *infoSize - entrySize);
} else {
/* make sure the amount we're copying doesn't exceed the limit */
entrySize = *infoSize;
}
memcpy(head, &(entry->size), entrySize);
head += *infoSize;
}
dlfree(list);
}
extern "C" void free_malloc_leak_info(uint8_t* info) {
dlfree(info);
}
extern "C" struct mallinfo mallinfo() {
return dlmallinfo();
}
extern "C" size_t malloc_usable_size(void* mem) {
return dlmalloc_usable_size(mem);
}
extern "C" void* valloc(size_t bytes) {
return dlvalloc(bytes);
}
extern "C" void* pvalloc(size_t bytes) {
return dlpvalloc(bytes);
}
extern "C" int posix_memalign(void** memptr, size_t alignment, size_t size) {
return dlposix_memalign(memptr, alignment, size);
}
/* Support for malloc debugging.
* Note that if USE_DL_PREFIX is not defined, it's assumed that memory
* allocation routines are implemented somewhere else, so all our custom
* malloc routines should not be compiled at all.
*/
#ifdef USE_DL_PREFIX
/* Table for dispatching malloc calls, initialized with default dispatchers. */
extern const MallocDebug __libc_malloc_default_dispatch;
const MallocDebug __libc_malloc_default_dispatch __attribute__((aligned(32))) = {
dlmalloc, dlfree, dlcalloc, dlrealloc, dlmemalign
};
/* Selector of dispatch table to use for dispatching malloc calls. */
const MallocDebug* __libc_malloc_dispatch = &__libc_malloc_default_dispatch;
extern "C" void* malloc(size_t bytes) {
return __libc_malloc_dispatch->malloc(bytes);
}
extern "C" void free(void* mem) {
__libc_malloc_dispatch->free(mem);
}
extern "C" void* calloc(size_t n_elements, size_t elem_size) {
return __libc_malloc_dispatch->calloc(n_elements, elem_size);
}
extern "C" void* realloc(void* oldMem, size_t bytes) {
return __libc_malloc_dispatch->realloc(oldMem, bytes);
}
extern "C" void* memalign(size_t alignment, size_t bytes) {
return __libc_malloc_dispatch->memalign(alignment, bytes);
}
/* We implement malloc debugging only in libc.so, so code bellow
* must be excluded if we compile this file for static libc.a
*/
#ifndef LIBC_STATIC
#include <sys/system_properties.h>
#include <dlfcn.h>
#include <stdio.h>
#include "logd.h"
/* Table for dispatching malloc calls, depending on environment. */
static MallocDebug gMallocUse __attribute__((aligned(32))) = {
dlmalloc, dlfree, dlcalloc, dlrealloc, dlmemalign
};
extern char* __progname;
/* Handle to shared library where actual memory allocation is implemented.
* This library is loaded and memory allocation calls are redirected there
* when libc.debug.malloc environment variable contains value other than
* zero:
* 1 - For memory leak detections.
* 5 - For filling allocated / freed memory with patterns defined by
* CHK_SENTINEL_VALUE, and CHK_FILL_FREE macros.
* 10 - For adding pre-, and post- allocation stubs in order to detect
* buffer overruns.
* Note that emulator's memory allocation instrumentation is not controlled by
* libc.debug.malloc value, but rather by emulator, started with -memcheck
* option. Note also, that if emulator has started with -memcheck option,
* emulator's instrumented memory allocation will take over value saved in
* libc.debug.malloc. In other words, if emulator has started with -memcheck
* option, libc.debug.malloc value is ignored.
* Actual functionality for debug levels 1-10 is implemented in
* libc_malloc_debug_leak.so, while functionality for emultor's instrumented
* allocations is implemented in libc_malloc_debug_qemu.so and can be run inside
* the emulator only.
*/
static void* libc_malloc_impl_handle = NULL;
/* Make sure we have MALLOC_ALIGNMENT that matches the one that is
* used in dlmalloc. Emulator's memchecker needs this value to properly
* align its guarding zones.
*/
#ifndef MALLOC_ALIGNMENT
#define MALLOC_ALIGNMENT ((size_t)8U)
#endif /* MALLOC_ALIGNMENT */
/* This variable is set to the value of property libc.debug.malloc.backlog,
* when the value of libc.debug.malloc = 10. It determines the size of the
* backlog we use to detect multiple frees. If the property is not set, the
* backlog length defaults to an internal constant defined in
* malloc_debug_check.cpp.
*/
unsigned int malloc_double_free_backlog;
static void InitMalloc(MallocDebug* table, int debug_level, const char* prefix) {
__libc_android_log_print(ANDROID_LOG_INFO, "libc", "%s: using libc.debug.malloc %d (%s)\n",
__progname, debug_level, prefix);
char symbol[128];
snprintf(symbol, sizeof(symbol), "%s_malloc", prefix);
table->malloc = reinterpret_cast<MallocDebugMalloc>(dlsym(libc_malloc_impl_handle, symbol));
if (table->malloc == NULL) {
error_log("%s: dlsym(\"%s\") failed", __progname, symbol);
}
snprintf(symbol, sizeof(symbol), "%s_free", prefix);
table->free = reinterpret_cast<MallocDebugFree>(dlsym(libc_malloc_impl_handle, symbol));
if (table->free == NULL) {
error_log("%s: dlsym(\"%s\") failed", __progname, symbol);
}
snprintf(symbol, sizeof(symbol), "%s_calloc", prefix);
table->calloc = reinterpret_cast<MallocDebugCalloc>(dlsym(libc_malloc_impl_handle, symbol));
if (table->calloc == NULL) {
error_log("%s: dlsym(\"%s\") failed", __progname, symbol);
}
snprintf(symbol, sizeof(symbol), "%s_realloc", prefix);
table->realloc = reinterpret_cast<MallocDebugRealloc>(dlsym(libc_malloc_impl_handle, symbol));
if (table->realloc == NULL) {
error_log("%s: dlsym(\"%s\") failed", __progname, symbol);
}
snprintf(symbol, sizeof(symbol), "%s_memalign", prefix);
table->memalign = reinterpret_cast<MallocDebugMemalign>(dlsym(libc_malloc_impl_handle, symbol));
if (table->memalign == NULL) {
error_log("%s: dlsym(\"%s\") failed", __progname, symbol);
}
}
/* Initializes memory allocation framework once per process. */
static void malloc_init_impl() {
const char* so_name = NULL;
MallocDebugInit malloc_debug_initialize = NULL;
unsigned int qemu_running = 0;
unsigned int debug_level = 0;
unsigned int memcheck_enabled = 0;
char env[PROP_VALUE_MAX];
char memcheck_tracing[PROP_VALUE_MAX];
char debug_program[PROP_VALUE_MAX];
/* Get custom malloc debug level. Note that emulator started with
* memory checking option will have priority over debug level set in
* libc.debug.malloc system property. */
if (__system_property_get("ro.kernel.qemu", env) && atoi(env)) {
qemu_running = 1;
if (__system_property_get("ro.kernel.memcheck", memcheck_tracing)) {
if (memcheck_tracing[0] != '0') {
// Emulator has started with memory tracing enabled. Enforce it.
debug_level = 20;
memcheck_enabled = 1;
}
}
}
/* If debug level has not been set by memcheck option in the emulator,
* lets grab it from libc.debug.malloc system property. */
if (debug_level == 0 && __system_property_get("libc.debug.malloc", env)) {
debug_level = atoi(env);
}
/* Debug level 0 means that we should use dlxxx allocation
* routines (default). */
if (debug_level == 0) {
return;
}
/* If libc.debug.malloc.program is set and is not a substring of progname,
* then exit.
*/
if (__system_property_get("libc.debug.malloc.program", debug_program)) {
if (!strstr(__progname, debug_program)) {
return;
}
}
// Lets see which .so must be loaded for the requested debug level
switch (debug_level) {
case 1:
case 5:
case 10: {
char debug_backlog[PROP_VALUE_MAX];
if (__system_property_get("libc.debug.malloc.backlog", debug_backlog)) {
malloc_double_free_backlog = atoi(debug_backlog);
info_log("%s: setting backlog length to %d\n",
__progname, malloc_double_free_backlog);
}
so_name = "/system/lib/libc_malloc_debug_leak.so";
break;
}
case 20:
// Quick check: debug level 20 can only be handled in emulator.
if (!qemu_running) {
error_log("%s: Debug level %d can only be set in emulator\n",
__progname, debug_level);
return;
}
// Make sure that memory checking has been enabled in emulator.
if (!memcheck_enabled) {
error_log("%s: Memory checking is not enabled in the emulator\n",
__progname);
return;
}
so_name = "/system/lib/libc_malloc_debug_qemu.so";
break;
default:
error_log("%s: Debug level %d is unknown\n",
__progname, debug_level);
return;
}
// Load .so that implements the required malloc debugging functionality.
libc_malloc_impl_handle = dlopen(so_name, RTLD_LAZY);
if (libc_malloc_impl_handle == NULL) {
error_log("%s: Missing module %s required for malloc debug level %d: %s",
__progname, so_name, debug_level, dlerror());
return;
}
// Initialize malloc debugging in the loaded module.
malloc_debug_initialize = reinterpret_cast<MallocDebugInit>(dlsym(libc_malloc_impl_handle,
"malloc_debug_initialize"));
if (malloc_debug_initialize == NULL) {
error_log("%s: Initialization routine is not found in %s\n",
__progname, so_name);
dlclose(libc_malloc_impl_handle);
return;
}
if (malloc_debug_initialize()) {
dlclose(libc_malloc_impl_handle);
return;
}
if (debug_level == 20) {
// For memory checker we need to do extra initialization.
typedef int (*MemCheckInit)(int, const char*);
MemCheckInit memcheck_initialize =
reinterpret_cast<MemCheckInit>(dlsym(libc_malloc_impl_handle,
"memcheck_initialize"));
if (memcheck_initialize == NULL) {
error_log("%s: memcheck_initialize routine is not found in %s\n",
__progname, so_name);
dlclose(libc_malloc_impl_handle);
return;
}
if (memcheck_initialize(MALLOC_ALIGNMENT, memcheck_tracing)) {
dlclose(libc_malloc_impl_handle);
return;
}
}
// Initialize malloc dispatch table with appropriate routines.
switch (debug_level) {
case 1:
InitMalloc(&gMallocUse, debug_level, "leak");
break;
case 5:
InitMalloc(&gMallocUse, debug_level, "fill");
break;
case 10:
InitMalloc(&gMallocUse, debug_level, "chk");
break;
case 20:
InitMalloc(&gMallocUse, debug_level, "qemu_instrumented");
break;
default:
break;
}
// Make sure dispatch table is initialized
if ((gMallocUse.malloc == NULL) ||
(gMallocUse.free == NULL) ||
(gMallocUse.calloc == NULL) ||
(gMallocUse.realloc == NULL) ||
(gMallocUse.memalign == NULL)) {
error_log("%s: some symbols for libc.debug.malloc level %d were not found (see above)",
__progname, debug_level);
dlclose(libc_malloc_impl_handle);
libc_malloc_impl_handle = NULL;
} else {
__libc_malloc_dispatch = &gMallocUse;
}
}
static void malloc_fini_impl() {
if (libc_malloc_impl_handle) {
MallocDebugFini malloc_debug_finalize =
reinterpret_cast<MallocDebugFini>(dlsym(libc_malloc_impl_handle,
"malloc_debug_finalize"));
if (malloc_debug_finalize) {
malloc_debug_finalize();
}
}
}
static pthread_once_t malloc_init_once_ctl = PTHREAD_ONCE_INIT;
static pthread_once_t malloc_fini_once_ctl = PTHREAD_ONCE_INIT;
#endif // !LIBC_STATIC
#endif // USE_DL_PREFIX
/* Initializes memory allocation framework.
* This routine is called from __libc_init routines implemented
* in libc_init_static.c and libc_init_dynamic.c files.
*/
extern "C" void malloc_debug_init() {
/* We need to initialize malloc iff we implement here custom
* malloc routines (i.e. USE_DL_PREFIX is defined) for libc.so */
#if defined(USE_DL_PREFIX) && !defined(LIBC_STATIC)
if (pthread_once(&malloc_init_once_ctl, malloc_init_impl)) {
error_log("Unable to initialize malloc_debug component.");
}
#endif // USE_DL_PREFIX && !LIBC_STATIC
}
extern "C" void malloc_debug_fini() {
/* We need to finalize malloc iff we implement here custom
* malloc routines (i.e. USE_DL_PREFIX is defined) for libc.so */
#if defined(USE_DL_PREFIX) && !defined(LIBC_STATIC)
if (pthread_once(&malloc_fini_once_ctl, malloc_fini_impl)) {
error_log("Unable to finalize malloc_debug component.");
}
#endif // USE_DL_PREFIX && !LIBC_STATIC
}