Initial Contribution
diff --git a/libc/bionic/malloc_leak.c b/libc/bionic/malloc_leak.c
new file mode 100644
index 0000000..821ea23
--- /dev/null
+++ b/libc/bionic/malloc_leak.c
@@ -0,0 +1,874 @@
+/*
+ * Copyright (C) 2008 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.
+ */
+#include <errno.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stddef.h>
+#include <stdarg.h>
+#include <fcntl.h>
+#include <unwind.h>
+
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/select.h>
+#include <sys/types.h>
+#include <sys/system_properties.h>
+
+#include "dlmalloc.h"
+#include "logd.h"
+
+// =============================================================================
+// Utilities directly used by Dalvik
+// =============================================================================
+
+#define HASHTABLE_SIZE      1543
+#define BACKTRACE_SIZE      32
+/* flag definitions, currently sharing storage with "size" */
+#define SIZE_FLAG_ZYGOTE_CHILD  (1<<31)
+#define SIZE_FLAG_MASK          (SIZE_FLAG_ZYGOTE_CHILD)
+
+/*
+ * In a VM process, this is set to 1 after fork()ing out of zygote.
+ */
+int gMallocLeakZygoteChild = 0;
+
+// =============================================================================
+// Structures
+// =============================================================================
+
+typedef struct HashEntry HashEntry;
+struct HashEntry {
+    size_t slot;
+    HashEntry* prev;
+    HashEntry* next;
+    size_t numEntries;
+    // fields above "size" are NOT sent to the host
+    size_t size;
+    size_t allocations;
+    intptr_t backtrace[0];
+};
+
+typedef struct HashTable HashTable;
+struct HashTable {
+    size_t count;
+    HashEntry* slots[HASHTABLE_SIZE];
+};
+
+static pthread_mutex_t gAllocationsMutex = PTHREAD_MUTEX_INITIALIZER;
+static HashTable gHashTable;
+
+// =============================================================================
+// output fucntions
+// =============================================================================
+
+static int hash_entry_compare(const void* arg1, const void* arg2)
+{
+    HashEntry* e1 = *(HashEntry**)arg1;
+    HashEntry* e2 = *(HashEntry**)arg2;
+
+    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;
+    }
+
+    pthread_mutex_lock(&gAllocationsMutex);
+
+    if (gHashTable.count == 0) {
+        *info = NULL;
+        *overallSize = 0;
+        *infoSize = 0;
+        *totalMemory = 0;
+        *backtraceSize = 0;
+        goto done;
+    }
+    
+    void** list = (void**)dlmalloc(sizeof(void*) * gHashTable.count);
+
+    // debug_log("*****\ngHashTable.count = %d\n", gHashTable.count);
+    // debug_log("list = %p\n", list);
+
+    // 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;
+        }
+    }
+
+    // debug_log("sorted list!\n");
+    // 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;
+
+    // debug_log("infoSize = 0x%x overall = 0x%x\n", *infoSize, *overallSize);
+    // now get A byte array big enough for this
+    *info = (uint8_t*)dlmalloc(*overallSize);
+
+    // debug_log("info = %p\n", info);
+    if (*info == NULL) {
+        *overallSize = 0;
+        goto done;
+    }
+
+    // debug_log("sorting list...\n");
+    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 */
+            /* TODO: only clear out the part we're not overwriting? */
+            memset(head, 0, *infoSize);
+        } else {
+            /* make sure the amount we're copying doesn't exceed the limit */
+            entrySize = *infoSize;
+        }
+        memcpy(head, &(entry->size), entrySize);
+        head += *infoSize;
+    }
+
+    dlfree(list);
+
+done:
+    // debug_log("+++++ done!\n");
+    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 );
+}
+
+
+/*
+ * Code guarded by MALLOC_LEAK_CHECK is only needed when malloc check is
+ * enabled. Currently we exclude them in libc.so, and only include them in
+ * libc_debug.so.
+ */
+#ifdef MALLOC_LEAK_CHECK
+#define MALLOC_ALIGNMENT    8
+#define GUARD               0x48151642
+
+#define DEBUG               0
+
+// =============================================================================
+// Structures
+// =============================================================================
+typedef struct AllocationEntry AllocationEntry;
+struct AllocationEntry {
+    HashEntry* entry;
+    uint32_t guard;
+};
+
+// =============================================================================
+// log funtions
+// =============================================================================
+
+#define debug_log(format, ...)  \
+    __libc_android_log_print(ANDROID_LOG_DEBUG, "malloc_leak", (format), ##__VA_ARGS__ )
+
+// =============================================================================
+// Hash Table functions
+// =============================================================================
+static uint32_t get_hash(intptr_t* backtrace, size_t numEntries)
+{
+    if (backtrace == NULL) return 0;
+
+    int hash = 0;
+    size_t i;
+    for (i = 0 ; i < numEntries ; i++) {
+        hash = (hash * 33) + (backtrace[i] >> 2);
+    }
+
+    return hash;
+}
+
+static HashEntry* find_entry(HashTable* table, int slot,
+        intptr_t* backtrace, size_t numEntries, size_t size)
+{
+    HashEntry* entry = table->slots[slot];
+    while (entry != NULL) {
+        //debug_log("backtrace: %p, entry: %p entry->backtrace: %p\n",
+        //        backtrace, entry, (entry != NULL) ? entry->backtrace : NULL);
+        /*
+         * See if the entry matches exactly.  We compare the "size" field,
+         * including the flag bits.
+         */
+        if (entry->size == size && entry->numEntries == numEntries &&
+                !memcmp(backtrace, entry->backtrace, numEntries * sizeof(intptr_t))) {
+            return entry;
+        }
+
+        entry = entry->next;
+    }
+
+    return NULL;
+}
+
+static HashEntry* record_backtrace(intptr_t* backtrace, size_t numEntries, size_t size)
+{
+    size_t hash = get_hash(backtrace, numEntries);
+    size_t slot = hash % HASHTABLE_SIZE;
+
+    if (size & SIZE_FLAG_MASK) {
+        debug_log("malloc_debug: allocation %zx exceeds bit width\n", size);
+        abort();
+    }
+
+    if (gMallocLeakZygoteChild)
+        size |= SIZE_FLAG_ZYGOTE_CHILD;
+
+    HashEntry* entry = find_entry(&gHashTable, slot, backtrace, numEntries, size);
+
+    if (entry != NULL) {
+        entry->allocations++;
+    } else {
+        // create a new entry
+        entry = (HashEntry*)dlmalloc(sizeof(HashEntry) + numEntries*sizeof(intptr_t));
+        entry->allocations = 1;
+        entry->slot = slot;
+        entry->prev = NULL;
+        entry->next = gHashTable.slots[slot];
+        entry->numEntries = numEntries;
+        entry->size = size;
+
+        memcpy(entry->backtrace, backtrace, numEntries * sizeof(intptr_t));
+
+        gHashTable.slots[slot] = entry;
+
+        if (entry->next != NULL) {
+            entry->next->prev = entry;
+        }
+
+        // we just added an entry, increase the size of the hashtable
+        gHashTable.count++;
+    }
+
+    return entry;
+}
+
+static int is_valid_entry(HashEntry* entry)
+{
+    if (entry != NULL) {
+        int i;
+        for (i = 0 ; i < HASHTABLE_SIZE ; i++) {
+            HashEntry* e1 = gHashTable.slots[i];
+
+            while (e1 != NULL) {
+                if (e1 == entry) {
+                    return 1;
+                }
+
+                e1 = e1->next;
+            }
+        }
+    }
+
+    return 0;
+}
+
+static void remove_entry(HashEntry* entry)
+{
+    HashEntry* prev = entry->prev;
+    HashEntry* next = entry->next;
+
+    if (prev != NULL) entry->prev->next = next;
+    if (next != NULL) entry->next->prev = prev;
+
+    if (prev == NULL) {
+        // we are the head of the list. set the head to be next
+        gHashTable.slots[entry->slot] = entry->next;
+    }
+
+    // we just removed and entry, decrease the size of the hashtable
+    gHashTable.count--;
+}
+
+
+// =============================================================================
+// stack trace functions
+// =============================================================================
+
+typedef struct
+{
+    size_t count;
+    intptr_t* addrs;
+} stack_crawl_state_t;
+
+static _Unwind_Reason_Code trace_function(_Unwind_Context *context, void *arg)
+{
+    stack_crawl_state_t* state = (stack_crawl_state_t*)arg;
+    if (state->count) {
+        intptr_t ip = (intptr_t)_Unwind_GetIP(context);
+        if (ip) {
+            state->addrs[0] = ip; 
+            state->addrs++;
+            state->count--;
+            return _URC_NO_REASON;
+        }
+    }
+    /* 
+     * If we run out of space to record the address or 0 has been seen, stop
+     * unwinding the stack.
+     */
+    return _URC_END_OF_STACK;
+}
+
+static inline
+int get_backtrace(intptr_t* addrs, size_t max_entries)
+{
+    stack_crawl_state_t state;
+    state.count = max_entries;
+    state.addrs = (intptr_t*)addrs;
+    _Unwind_Backtrace(trace_function, (void*)&state);
+    return max_entries - state.count;
+}
+
+// =============================================================================
+// malloc leak function dispatcher
+// =============================================================================
+
+static void* leak_malloc(size_t bytes);
+static void  leak_free(void* mem);
+static void* leak_calloc(size_t n_elements, size_t elem_size);
+static void* leak_realloc(void* oldMem, size_t bytes);
+static void* leak_memalign(size_t alignment, size_t bytes);
+
+static void* fill_malloc(size_t bytes);
+static void  fill_free(void* mem);
+static void* fill_realloc(void* oldMem, size_t bytes);
+static void* fill_memalign(size_t alignment, size_t bytes);
+
+static void* chk_malloc(size_t bytes);
+static void  chk_free(void* mem);
+static void* chk_calloc(size_t n_elements, size_t elem_size);
+static void* chk_realloc(void* oldMem, size_t bytes);
+static void* chk_memalign(size_t alignment, size_t bytes);
+
+typedef struct {
+    void* (*malloc)(size_t bytes);
+    void  (*free)(void* mem);
+    void* (*calloc)(size_t n_elements, size_t elem_size);
+    void* (*realloc)(void* oldMem, size_t bytes);
+    void* (*memalign)(size_t alignment, size_t bytes);
+} MallocDebug;
+
+static const MallocDebug gMallocEngineTable[] __attribute__((aligned(32))) =
+{
+    { dlmalloc,     dlfree,     dlcalloc,       dlrealloc,     dlmemalign },
+    { leak_malloc,  leak_free,  leak_calloc,    leak_realloc,  leak_memalign },
+    { fill_malloc,  fill_free,  dlcalloc,       fill_realloc,  fill_memalign },
+    { chk_malloc,   chk_free,   chk_calloc,     chk_realloc,   chk_memalign }
+};
+
+enum {
+    INDEX_NORMAL = 0,
+    INDEX_LEAK_CHECK,
+    INDEX_MALLOC_FILL,
+    INDEX_MALLOC_CHECK,
+};
+
+static MallocDebug const * gMallocDispatch = &gMallocEngineTable[INDEX_NORMAL];
+static int gMallocDebugLevel;
+static int gTrapOnError = 1;
+
+void* malloc(size_t bytes) {
+    return gMallocDispatch->malloc(bytes);
+}
+void free(void* mem) {
+    gMallocDispatch->free(mem);
+}
+void* calloc(size_t n_elements, size_t elem_size) {
+    return gMallocDispatch->calloc(n_elements, elem_size);
+}
+void* realloc(void* oldMem, size_t bytes) {
+    return gMallocDispatch->realloc(oldMem, bytes);
+}
+void* memalign(size_t alignment, size_t bytes) {
+    return gMallocDispatch->memalign(alignment, bytes);
+}
+
+// =============================================================================
+// malloc check functions
+// =============================================================================
+
+#define CHK_FILL_FREE           0xef
+#define CHK_SENTINEL_VALUE      0xeb
+#define CHK_SENTINEL_HEAD_SIZE  16
+#define CHK_SENTINEL_TAIL_SIZE  16
+#define CHK_OVERHEAD_SIZE       (   CHK_SENTINEL_HEAD_SIZE +    \
+                                    CHK_SENTINEL_TAIL_SIZE +    \
+                                    sizeof(size_t) )
+
+static void dump_stack_trace()
+{
+    intptr_t addrs[20];
+    int c = get_backtrace(addrs, 20);
+    char buf[16];
+    char tmp[16*20];
+    int i;
+
+    tmp[0] = 0; // Need to initialize tmp[0] for the first strcat
+    for (i=0 ; i<c; i++) {
+        sprintf(buf, "%2d: %08x\n", i, addrs[i]);
+        strcat(tmp, buf);
+    }
+    __libc_android_log_print(ANDROID_LOG_ERROR, "libc", "call stack:\n%s", tmp);
+}
+
+static int is_valid_malloc_pointer(void* addr)
+{
+    return 1;
+}
+
+static void assert_valid_malloc_pointer(void* mem)
+{
+    if (mem && !is_valid_malloc_pointer(mem)) {
+        pthread_mutex_lock(&gAllocationsMutex);
+        gMallocDispatch = &gMallocEngineTable[INDEX_NORMAL];
+            __libc_android_log_print(ANDROID_LOG_ERROR, "libc",
+                    "*** MALLOC CHECK: buffer %p, is not a valid "
+                    "malloc pointer (are you mixing up new/delete "
+                    "and malloc/free?)", mem);
+            dump_stack_trace();
+                if (gTrapOnError) {
+                    __builtin_trap();
+                }
+        gMallocDispatch = &gMallocEngineTable[INDEX_MALLOC_CHECK];
+        pthread_mutex_unlock(&gAllocationsMutex);
+    }
+}
+
+static void chk_out_of_bounds_check__locked(void* buffer, size_t size)
+{
+    int i;
+    char* buf = (char*)buffer - CHK_SENTINEL_HEAD_SIZE;
+    for (i=0 ; i<CHK_SENTINEL_HEAD_SIZE ; i++) {
+        if (buf[i] != CHK_SENTINEL_VALUE) {
+            gMallocDispatch = &gMallocEngineTable[INDEX_NORMAL];
+            __libc_android_log_print(ANDROID_LOG_ERROR, "libc",
+                    "*** MALLOC CHECK: buffer %p, size=%lu, "
+                    "corrupted %d bytes before allocation",
+                    buffer, size, CHK_SENTINEL_HEAD_SIZE-i);
+            dump_stack_trace();
+            if (gTrapOnError) {
+                __builtin_trap();
+            }
+            gMallocDispatch = &gMallocEngineTable[INDEX_MALLOC_CHECK];
+        }
+    }
+    buf = (char*)buffer + size;
+    for (i=CHK_SENTINEL_TAIL_SIZE-1 ; i>=0 ; i--) {
+        if (buf[i] != CHK_SENTINEL_VALUE) {
+            gMallocDispatch = &gMallocEngineTable[INDEX_NORMAL];
+            __libc_android_log_print(ANDROID_LOG_ERROR, "libc",
+                    "*** MALLOC CHECK: buffer %p, size=%lu, "
+                    "corrupted %d bytes after allocation",
+                    buffer, size, i+1);
+            dump_stack_trace();
+            if (gTrapOnError) {
+                __builtin_trap();
+            }
+            gMallocDispatch = &gMallocEngineTable[INDEX_MALLOC_CHECK];
+        }
+    }
+}
+
+void* chk_malloc(size_t bytes)
+{
+    char* buffer = (char*)dlmalloc(bytes + CHK_OVERHEAD_SIZE);
+    if (buffer) {
+        pthread_mutex_lock(&gAllocationsMutex);
+            memset(buffer, CHK_SENTINEL_VALUE, bytes + CHK_OVERHEAD_SIZE);
+            size_t offset = dlmalloc_usable_size(buffer) - sizeof(size_t);
+            *(size_t *)(buffer + offset) = bytes;
+            buffer += CHK_SENTINEL_HEAD_SIZE;
+        pthread_mutex_unlock(&gAllocationsMutex);
+    }
+    return buffer;
+}
+
+void  chk_free(void* mem)
+{
+    assert_valid_malloc_pointer(mem);
+    if (mem) {
+        pthread_mutex_lock(&gAllocationsMutex);
+            char* buffer = (char*)mem - CHK_SENTINEL_HEAD_SIZE;
+            size_t offset = dlmalloc_usable_size(buffer) - sizeof(size_t);
+            size_t bytes = *(size_t *)(buffer + offset);
+            chk_out_of_bounds_check__locked(mem, bytes);
+        pthread_mutex_unlock(&gAllocationsMutex);
+        memset(buffer, CHK_FILL_FREE, bytes);
+        dlfree(buffer);
+    }
+}
+
+void* chk_calloc(size_t n_elements, size_t elem_size)
+{
+    size_t size = n_elements * elem_size;
+    void* ptr = chk_malloc(size);
+    if (ptr != NULL) {
+        memset(ptr, 0, size);
+    }
+    return ptr;
+}
+
+void* chk_realloc(void* mem, size_t bytes)
+{
+    assert_valid_malloc_pointer(mem);
+    char* new_buffer = chk_malloc(bytes);
+    if (mem == NULL) {
+        return new_buffer;
+    }
+
+    pthread_mutex_lock(&gAllocationsMutex);
+        char* buffer = (char*)mem - CHK_SENTINEL_HEAD_SIZE;
+        size_t offset = dlmalloc_usable_size(buffer) - sizeof(size_t);
+        size_t old_bytes = *(size_t *)(buffer + offset);
+        chk_out_of_bounds_check__locked(mem, old_bytes);
+    pthread_mutex_unlock(&gAllocationsMutex);
+
+    if (new_buffer) {
+        size_t size = (bytes < old_bytes)?(bytes):(old_bytes);
+        memcpy(new_buffer, mem, size);
+        chk_free(mem);
+    }
+
+    return new_buffer;
+}
+
+void* chk_memalign(size_t alignment, size_t bytes)
+{
+    // XXX: it's better to use malloc, than being wrong
+    return chk_malloc(bytes);
+}
+
+// =============================================================================
+// malloc fill functions
+// =============================================================================
+
+void* fill_malloc(size_t bytes)
+{
+    void* buffer = dlmalloc(bytes);
+    if (buffer) {
+        memset(buffer, CHK_SENTINEL_VALUE, bytes);
+    }
+    return buffer;
+}
+
+void  fill_free(void* mem)
+{
+    size_t bytes = dlmalloc_usable_size(mem);
+    memset(mem, CHK_FILL_FREE, bytes);
+    dlfree(mem);
+}
+
+void* fill_realloc(void* mem, size_t bytes)
+{
+    void* buffer = fill_malloc(bytes);
+    if (mem == NULL) {
+        return buffer;
+    }
+    if (buffer) {
+        size_t old_size = dlmalloc_usable_size(mem);
+        size_t size = (bytes < old_size)?(bytes):(old_size);
+        memcpy(buffer, mem, size);
+        fill_free(mem);
+    }
+    return buffer;
+}
+
+void* fill_memalign(size_t alignment, size_t bytes)
+{
+    void* buffer = dlmemalign(alignment, bytes);
+    if (buffer) {
+        memset(buffer, CHK_SENTINEL_VALUE, bytes);
+    }
+    return buffer;
+}
+
+// =============================================================================
+// malloc leak functions
+// =============================================================================
+
+#define MEMALIGN_GUARD  ((void*)0xA1A41520)
+
+void* leak_malloc(size_t bytes)
+{
+    // allocate enough space infront of the allocation to store the pointer for
+    // the alloc structure. This will making free'ing the structer really fast!
+
+    // 1. allocate enough memory and include our header
+    // 2. set the base pointer to be right after our header
+
+    void* base = dlmalloc(bytes + sizeof(AllocationEntry));
+    if (base != NULL) {
+        pthread_mutex_lock(&gAllocationsMutex);
+
+            intptr_t backtrace[BACKTRACE_SIZE];
+            size_t numEntries = get_backtrace(backtrace, BACKTRACE_SIZE);
+    
+            AllocationEntry* header = (AllocationEntry*)base;
+            header->entry = record_backtrace(backtrace, numEntries, bytes);
+            header->guard = GUARD;
+    
+            // now increment base to point to after our header.
+            // this should just work since our header is 8 bytes.
+            base = (AllocationEntry*)base + 1;
+
+        pthread_mutex_unlock(&gAllocationsMutex);
+    }
+
+    return base;
+}
+
+void leak_free(void* mem)
+{
+    if (mem != NULL) {
+        pthread_mutex_lock(&gAllocationsMutex);
+
+        // check the guard to make sure it is valid
+        AllocationEntry* header = (AllocationEntry*)mem - 1;
+        
+        if (header->guard != GUARD) {
+            // could be a memaligned block
+            if (((void**)mem)[-1] == MEMALIGN_GUARD) {
+                mem = ((void**)mem)[-2];
+                header = (AllocationEntry*)mem - 1;
+            }
+        }
+        
+        if (header->guard == GUARD || is_valid_entry(header->entry)) {
+            // decrement the allocations
+            HashEntry* entry = header->entry;
+            entry->allocations--;
+            if (entry->allocations <= 0) {
+                remove_entry(entry);
+                dlfree(entry);
+            }
+
+            // now free the memory!
+            dlfree(header);
+        } else {
+            debug_log("WARNING bad header guard: '0x%x'! and invalid entry: %p\n",
+                    header->guard, header->entry);
+        }
+
+        pthread_mutex_unlock(&gAllocationsMutex);
+    }
+}
+
+void* leak_calloc(size_t n_elements, size_t elem_size)
+{
+    size_t size = n_elements * elem_size;
+    void* ptr = leak_malloc(size);
+    if (ptr != NULL) {
+        memset(ptr, 0, size);
+    }
+    return ptr;
+}
+
+void* leak_realloc(void* oldMem, size_t bytes)
+{
+    if (oldMem == NULL) {
+        return leak_malloc(bytes);
+    }
+    void* newMem = NULL;
+    AllocationEntry* header = (AllocationEntry*)oldMem - 1;
+    if (header && header->guard == GUARD) {
+        size_t oldSize = header->entry->size & ~SIZE_FLAG_MASK;
+        newMem = leak_malloc(bytes);
+        if (newMem != NULL) {
+            size_t copySize = (oldSize <= bytes) ? oldSize : bytes;
+            memcpy(newMem, oldMem, copySize);
+            leak_free(oldMem);
+        }
+    } else {
+        newMem = dlrealloc(oldMem, bytes);
+    }
+    return newMem;
+}
+
+void* leak_memalign(size_t alignment, size_t bytes)
+{
+    // we can just use malloc
+    if (alignment <= MALLOC_ALIGNMENT)
+        return leak_malloc(bytes);
+
+    // need to make sure it's a power of two
+    if (alignment & (alignment-1))
+        alignment = 1L << (31 - __builtin_clz(alignment));
+    
+    // here, aligment is at least MALLOC_ALIGNMENT<<1 bytes
+    // we will align by at least MALLOC_ALIGNMENT bytes
+    // and at most alignment-MALLOC_ALIGNMENT bytes
+    size_t size = (alignment-MALLOC_ALIGNMENT) + bytes;
+    void* base = leak_malloc(size);
+    if (base != NULL) {
+        intptr_t ptr = (intptr_t)base;
+        if ((ptr % alignment) == 0)
+            return base;
+
+        // align the pointer
+        ptr += ((-ptr) % alignment);
+        
+        // there is always enough space for the base pointer and the guard
+        ((void**)ptr)[-1] = MEMALIGN_GUARD;
+        ((void**)ptr)[-2] = base;
+
+        return (void*)ptr;
+    }
+    return base;
+}
+#endif /* MALLOC_LEAK_CHECK */
+
+// called from libc_init()
+extern char*  __progname;
+
+void malloc_debug_init()
+{
+    unsigned int level = 0;
+#ifdef MALLOC_LEAK_CHECK
+    // if MALLOC_LEAK_CHECK is enabled, use level=1 by default
+    level = 1;
+#endif
+    char env[PROP_VALUE_MAX];
+    int len = __system_property_get("libc.debug.malloc", env);
+
+    if (len) {
+        level = atoi(env);
+#ifndef MALLOC_LEAK_CHECK
+        /* Alert the user that libc_debug.so needs to be installed as libc.so
+         * when performing malloc checks.
+         */
+        if (level != 0) {
+            __libc_android_log_print(ANDROID_LOG_INFO, "libc",
+                 "Malloc checks need libc_debug.so pushed to the device!\n");
+
+        }
+#endif
+    }
+
+#ifdef MALLOC_LEAK_CHECK
+    gMallocDebugLevel = level;
+    switch (level) {
+    default:
+    case 0:
+        gMallocDispatch = &gMallocEngineTable[INDEX_NORMAL];
+        break;
+    case 1:
+        __libc_android_log_print(ANDROID_LOG_INFO, "libc",
+                "%s using MALLOC_DEBUG = %d (leak checker)\n",
+                __progname, level);
+        gMallocDispatch = &gMallocEngineTable[INDEX_LEAK_CHECK];
+        break;
+    case 5:
+        __libc_android_log_print(ANDROID_LOG_INFO, "libc",
+                "%s using MALLOC_DEBUG = %d (fill)\n", 
+                __progname, level);
+        gMallocDispatch = &gMallocEngineTable[INDEX_MALLOC_FILL];
+        break;
+    case 10:
+        __libc_android_log_print(ANDROID_LOG_INFO, "libc",
+                "%s using MALLOC_DEBUG = %d (sentinels, fill)\n", 
+                __progname, level);
+        gMallocDispatch = &gMallocEngineTable[INDEX_MALLOC_CHECK];
+        break;
+    }
+#endif
+}