platform_bionic/libc/bionic/malloc_debug_common.c
tedbo 9d8be5485c get_malloc_leak_info: Fix assumption that totalMemory out parameter was initialized to zero.
The get_malloc_leak_info() currently asssumes that the totalMemory out parameter
was pre-initialized to zero before the routine is called. If it is not then the
accumulated totalMemory value will be incorrect. It is likely that many callers
will simply allocate totalMemory on the stack with no initialization and assume
that get_malloc_leak_info will set the proper value.

As an example, the caller in frameworks/base/core/jni/android_os_Debug.cpp
calls get_malloc_leak_info() with the address uninitiazed stack variable
for totalMemory. It is probably best to fix this in get_malloc_leak_info.

Change-Id: I84c927c3781419585794726115b7d34d8fdd24ae
2010-10-05 13:23:28 -07:00

497 lines
18 KiB
C

/*
* 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;
HashEntry* e1 = *(HashEntry**)arg1;
HashEntry* e2 = *(HashEntry**)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.
int result;
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
*/
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;
pthread_mutex_lock(&gAllocationsMutex);
if (gHashTable.count == 0) {
*info = NULL;
*overallSize = 0;
*infoSize = 0;
*backtraceSize = 0;
goto done;
}
void** list = (void**)dlmalloc(sizeof(void*) * gHashTable.count);
// get the entries into an array to be sorted
int index = 0;
int i;
for (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 = (uint8_t*)dlmalloc(*overallSize);
if (*info == NULL) {
*overallSize = 0;
goto out_nomem_info;
}
qsort((void*)list, gHashTable.count, sizeof(void*), hash_entry_compare);
uint8_t* head = *info;
const int count = gHashTable.count;
for (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;
}
out_nomem_info:
dlfree(list);
done:
pthread_mutex_unlock(&gAllocationsMutex);
}
void free_malloc_leak_info(uint8_t* info)
{
dlfree(info);
}
struct mallinfo mallinfo()
{
return dlmallinfo();
}
void* valloc(size_t bytes) {
/* assume page size of 4096 bytes */
return memalign( getpagesize(), bytes );
}
/* 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. */
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;
void* malloc(size_t bytes) {
return __libc_malloc_dispatch->malloc(bytes);
}
void free(void* mem) {
__libc_malloc_dispatch->free(mem);
}
void* calloc(size_t n_elements, size_t elem_size) {
return __libc_malloc_dispatch->calloc(n_elements, elem_size);
}
void* realloc(void* oldMem, size_t bytes) {
return __libc_malloc_dispatch->realloc(oldMem, bytes);
}
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 "logd.h"
// =============================================================================
// log functions
// =============================================================================
#define debug_log(format, ...) \
__libc_android_log_print(ANDROID_LOG_DEBUG, "libc", (format), ##__VA_ARGS__ )
#define error_log(format, ...) \
__libc_android_log_print(ANDROID_LOG_ERROR, "libc", (format), ##__VA_ARGS__ )
#define info_log(format, ...) \
__libc_android_log_print(ANDROID_LOG_INFO, "libc", (format), ##__VA_ARGS__ )
/* 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 */
/* Initializes memory allocation framework once per process. */
static void malloc_init_impl(void)
{
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];
/* 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 && __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) {
return;
}
// Lets see which .so must be loaded for the requested debug level
switch (debug_level) {
case 1:
case 5:
case 10:
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\n",
__progname, so_name, debug_level);
return;
}
// Initialize malloc debugging in the loaded module.
malloc_debug_initialize =
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.
int (*memcheck_initialize)(int, const char*) =
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:
__libc_android_log_print(ANDROID_LOG_INFO, "libc",
"%s using MALLOC_DEBUG = %d (leak checker)\n",
__progname, debug_level);
gMallocUse.malloc =
dlsym(libc_malloc_impl_handle, "leak_malloc");
gMallocUse.free =
dlsym(libc_malloc_impl_handle, "leak_free");
gMallocUse.calloc =
dlsym(libc_malloc_impl_handle, "leak_calloc");
gMallocUse.realloc =
dlsym(libc_malloc_impl_handle, "leak_realloc");
gMallocUse.memalign =
dlsym(libc_malloc_impl_handle, "leak_memalign");
break;
case 5:
__libc_android_log_print(ANDROID_LOG_INFO, "libc",
"%s using MALLOC_DEBUG = %d (fill)\n",
__progname, debug_level);
gMallocUse.malloc =
dlsym(libc_malloc_impl_handle, "fill_malloc");
gMallocUse.free =
dlsym(libc_malloc_impl_handle, "fill_free");
gMallocUse.calloc = dlcalloc;
gMallocUse.realloc =
dlsym(libc_malloc_impl_handle, "fill_realloc");
gMallocUse.memalign =
dlsym(libc_malloc_impl_handle, "fill_memalign");
break;
case 10:
__libc_android_log_print(ANDROID_LOG_INFO, "libc",
"%s using MALLOC_DEBUG = %d (sentinels, fill)\n",
__progname, debug_level);
gMallocUse.malloc =
dlsym(libc_malloc_impl_handle, "chk_malloc");
gMallocUse.free =
dlsym(libc_malloc_impl_handle, "chk_free");
gMallocUse.calloc =
dlsym(libc_malloc_impl_handle, "chk_calloc");
gMallocUse.realloc =
dlsym(libc_malloc_impl_handle, "chk_realloc");
gMallocUse.memalign =
dlsym(libc_malloc_impl_handle, "chk_memalign");
break;
case 20:
__libc_android_log_print(ANDROID_LOG_INFO, "libc",
"%s[%u] using MALLOC_DEBUG = %d (instrumented for emulator)\n",
__progname, getpid(), debug_level);
gMallocUse.malloc =
dlsym(libc_malloc_impl_handle, "qemu_instrumented_malloc");
gMallocUse.free =
dlsym(libc_malloc_impl_handle, "qemu_instrumented_free");
gMallocUse.calloc =
dlsym(libc_malloc_impl_handle, "qemu_instrumented_calloc");
gMallocUse.realloc =
dlsym(libc_malloc_impl_handle, "qemu_instrumented_realloc");
gMallocUse.memalign =
dlsym(libc_malloc_impl_handle, "qemu_instrumented_memalign");
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: Cannot initialize malloc dispatch table for debug level"
" %d: %p, %p, %p, %p, %p\n",
__progname, debug_level,
gMallocUse.malloc, gMallocUse.free,
gMallocUse.calloc, gMallocUse.realloc,
gMallocUse.memalign);
dlclose(libc_malloc_impl_handle);
libc_malloc_impl_handle = NULL;
} else {
__libc_malloc_dispatch = &gMallocUse;
}
}
static pthread_once_t malloc_init_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.
*/
void malloc_debug_init(void)
{
/* 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
}