bionic: import heaptracker as chk_malloc
This patch is a rewrite of libc.debug.malloc = 10 (chk_malloc). It provides
the same features as the original (poison freed memory, detect heap overruns
and underruns), except that it provides more debugging information whenever it
detects a problem.
In addition to the original features, the new chk_malloc() implementation
detects multiple frees within a given range of the last N allocations, N being
configurable via the system property libc.debug.malloc.backlog.
Finally, this patch keeps track of all outstanding memory allocations. On
program exit, we walk that list and report each outstanding allocation.
(There is support (not enabled) for a scanner thread periodically walks over
the list of outstanding allocations as well as the backlog of recently-freed
allocations, checking for heap-usage errors.)
Feature overview:
1) memory leaks
2) multiple frees
3) use after free
4) overrun
Implementation:
-- for each allocation, there is a:
1) stack trace at the time the allocation is made
2) if the memory is freed, there is also a stack trace at the point
3) a front and rear guard (fence)
4) the stack traces are kept together with the allocation
-- the following lists and maintained
1) all outstanding memory allocations
3) a backlog of allocations what are freed; when you call free(), instead of
actually freed, the allocation is moved to this backlog;
4) when the backlog of allocations gets full, the oldest entry gets evicted
from it; at that point, the allocation is checked for overruns or
use-after-free errors, and then actually freed.
5) when the program exits, the list of outstanding allocations and the
backlog are inspected for errors, then freed;
To use this, set the following system properties before running the process or
processes you want to inspect:
libc.malloc.debug.backlog # defaults to 100
libc.malloc.debug 10
When a problem is detected, you will see the following on logcat for a multiple
free:
E/libc ( 7233): +++ ALLOCATION 0x404b9278 SIZE 10 BYTES MULTIPLY FREED!
E/libc ( 7233): +++ ALLOCATION 0x404b9278 SIZE 10 ALLOCATED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c658 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d80 /system/lib/libc.so
E/libc ( 7233): #03 pc 4009647c /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
E/libc ( 7233): +++ ALLOCATION 0x404b9278 SIZE 10 FIRST FREED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c7d2 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d94 /system/lib/libc.so
E/libc ( 7233): #03 pc 40096490 /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
E/libc ( 7233): +++ ALLOCATION 0x404b9278 SIZE 10 NOW BEING FREED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c6ac /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d94 /system/lib/libc.so
E/libc ( 7233): #03 pc 400964a0 /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
The following for a heap overrun and underrun:
E/libc ( 7233): +++ REAR GUARD MISMATCH [10, 11)
E/libc ( 7233): +++ ALLOCATION 0x404b9198 SIZE 10 HAS A CORRUPTED REAR GUARD
E/libc ( 7233): +++ ALLOCATION 0x404b9198 SIZE 10 ALLOCATED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c658 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d80 /system/lib/libc.so
E/libc ( 7233): #03 pc 40096438 /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
E/libc ( 7233): +++ ALLOCATION 0x404b9198 SIZE 10 FREED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c7d2 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d94 /system/lib/libc.so
E/libc ( 7233): #03 pc 40096462 /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
E/libc ( 7233): +++ ALLOCATION 0x404b9358 SIZE 10 HAS A CORRUPTED FRONT GUARD
E/libc ( 7233): +++ ALLOCATION 0x404b9358 SIZE 10 ALLOCATED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c658 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d80 /system/lib/libc.so
E/libc ( 7233): #03 pc 400964ba /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
E/libc ( 7233): +++ ALLOCATION 0x404b9358 SIZE 10 FREED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c7d2 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d94 /system/lib/libc.so
E/libc ( 7233): #03 pc 400964e4 /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
The following for a memory leak:
E/libc ( 7233): +++ THERE ARE 1 LEAKED ALLOCATIONS
E/libc ( 7233): +++ DELETING 4096 BYTES OF LEAKED MEMORY AT 0x404b95e8 (1 REMAINING)
E/libc ( 7233): +++ ALLOCATION 0x404b95e8 SIZE 4096 ALLOCATED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c658 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d80 /system/lib/libc.so
E/libc ( 7233): #03 pc 0001bc94 /system/lib/libc.so
E/libc ( 7233): #04 pc 0001edf6 /system/lib/libc.so
E/libc ( 7233): #05 pc 0001b80a /system/lib/libc.so
E/libc ( 7233): #06 pc 0001c086 /system/lib/libc.so
E/libc ( 7233): #07 pc 40096402 /system/bin/malloctest
E/libc ( 7233): #08 pc 00016f24 /system/lib/libc.so
Change-Id: Ic440e9d05a01e2ea86b25e8998714e88bc2d16e0
Signed-off-by: Iliyan Malchev <malchev@google.com>
diff --git a/libc/bionic/malloc_debug_check.c b/libc/bionic/malloc_debug_check.c
new file mode 100644
index 0000000..4ae21fe
--- /dev/null
+++ b/libc/bionic/malloc_debug_check.c
@@ -0,0 +1,574 @@
+/*
+ * Copyright (C) 2012 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 <time.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 <dlfcn.h>
+#include <stdbool.h>
+
+#include <sys/types.h>
+#include <sys/system_properties.h>
+
+#include "dlmalloc.h"
+#include "logd.h"
+
+#include "malloc_debug_common.h"
+#include "malloc_debug_check_mapinfo.h"
+
+static mapinfo *milist;
+
+/* libc.debug.malloc.backlog */
+extern unsigned int malloc_double_free_backlog;
+
+#define MAX_BACKTRACE_DEPTH 15
+#define ALLOCATION_TAG 0x1ee7d00d
+#define BACKLOG_TAG 0xbabecafe
+#define FREE_POISON 0xa5
+#define BACKLOG_DEFAULT_LEN 100
+#define FRONT_GUARD 0xaa
+#define FRONT_GUARD_LEN (1<<5)
+#define REAR_GUARD 0xbb
+#define REAR_GUARD_LEN (1<<5)
+
+static void print_backtrace(const intptr_t *bt, unsigned int depth);
+
+static void log_message(const char* format, ...)
+{
+ extern pthread_mutex_t gAllocationsMutex;
+ extern const MallocDebug __libc_malloc_default_dispatch;
+ extern const MallocDebug* __libc_malloc_dispatch;
+
+ va_list args;
+
+ pthread_mutex_lock(&gAllocationsMutex);
+ {
+ const MallocDebug* current_dispatch = __libc_malloc_dispatch;
+ __libc_malloc_dispatch = &__libc_malloc_default_dispatch;
+ va_start(args, format);
+ __libc_android_log_vprint(ANDROID_LOG_ERROR, "libc",
+ format, args);
+ va_end(args);
+ __libc_malloc_dispatch = current_dispatch;
+ }
+ pthread_mutex_unlock(&gAllocationsMutex);
+}
+
+struct hdr {
+ uint32_t tag;
+ struct hdr *prev;
+ struct hdr *next;
+ intptr_t bt[MAX_BACKTRACE_DEPTH];
+ int bt_depth;
+ intptr_t freed_bt[MAX_BACKTRACE_DEPTH];
+ int freed_bt_depth;
+ size_t size;
+ char front_guard[FRONT_GUARD_LEN];
+} __attribute__((packed));
+
+struct ftr {
+ char rear_guard[REAR_GUARD_LEN];
+} __attribute__((packed));
+
+static inline struct ftr * to_ftr(struct hdr *hdr)
+{
+ return (struct ftr *)(((char *)(hdr + 1)) + hdr->size);
+}
+
+static inline void *user(struct hdr *hdr)
+{
+ return hdr + 1;
+}
+
+static inline struct hdr *meta(void *user)
+{
+ return ((struct hdr *)user) - 1;
+}
+
+/* Call this on exit() to get leaked memory */
+void free_leaked_memory(void);
+
+static unsigned num;
+static struct hdr *tail;
+static struct hdr *head;
+static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
+
+static unsigned backlog_num;
+static struct hdr *backlog_tail;
+static struct hdr *backlog_head;
+static pthread_mutex_t backlog_lock = PTHREAD_MUTEX_INITIALIZER;
+
+extern __LIBC_HIDDEN__
+int get_backtrace(intptr_t* addrs, size_t max_entries);
+
+static void print_backtrace(const intptr_t *bt, unsigned int depth)
+{
+ const mapinfo *mi;
+ unsigned int cnt;
+ unsigned int rel_pc;
+ intptr_t self_bt[MAX_BACKTRACE_DEPTH];
+
+ if (!bt) {
+ depth = get_backtrace(self_bt, MAX_BACKTRACE_DEPTH);
+ bt = self_bt;
+ }
+
+ log_message("*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n");
+ for (cnt = 0; cnt < depth && cnt < MAX_BACKTRACE_DEPTH; cnt++) {
+ mi = pc_to_mapinfo(milist, bt[cnt], &rel_pc);
+ log_message("\t#%02d pc %08x %s\n", cnt,
+ mi ? (intptr_t)rel_pc : bt[cnt],
+ mi ? mi->name : "(unknown)");
+ }
+}
+
+static inline void init_front_guard(struct hdr *hdr)
+{
+ memset(hdr->front_guard, FRONT_GUARD, FRONT_GUARD_LEN);
+}
+
+static inline bool is_front_guard_valid(struct hdr *hdr)
+{
+ unsigned i;
+ for (i = 0; i < FRONT_GUARD_LEN; i++)
+ if (hdr->front_guard[i] != FRONT_GUARD)
+ return 0;
+ return 1;
+}
+
+static inline void init_rear_guard(struct hdr *hdr)
+{
+ struct ftr *ftr = to_ftr(hdr);
+ memset(ftr->rear_guard, REAR_GUARD, REAR_GUARD_LEN);
+}
+
+static inline bool is_rear_guard_valid(struct hdr *hdr)
+{
+ unsigned i;
+ int valid = 1;
+ int first_mismatch = -1;
+ struct ftr *ftr = to_ftr(hdr);
+ for (i = 0; i < REAR_GUARD_LEN; i++) {
+ if (ftr->rear_guard[i] != REAR_GUARD) {
+ if (first_mismatch < 0)
+ first_mismatch = i;
+ valid = 0;
+ }
+ else if (first_mismatch >= 0) {
+ log_message("+++ REAR GUARD MISMATCH [%d, %d)\n", first_mismatch, i);
+ first_mismatch = -1;
+ }
+ }
+
+ if (first_mismatch >= 0)
+ log_message("+++ REAR GUARD MISMATCH [%d, %d)\n", first_mismatch, i);
+ return valid;
+}
+
+static inline void add_locked(struct hdr *hdr, struct hdr **tail, struct hdr **head)
+{
+ hdr->prev = NULL;
+ hdr->next = *head;
+ if (*head)
+ (*head)->prev = hdr;
+ else
+ *tail = hdr;
+ *head = hdr;
+}
+
+static inline int del_locked(struct hdr *hdr, struct hdr **tail, struct hdr **head)
+{
+ if (hdr->prev)
+ hdr->prev->next = hdr->next;
+ else
+ *head = hdr->next;
+ if (hdr->next)
+ hdr->next->prev = hdr->prev;
+ else
+ *tail = hdr->prev;
+ return 0;
+}
+
+static inline void add(struct hdr *hdr, size_t size)
+{
+ pthread_mutex_lock(&lock);
+ hdr->tag = ALLOCATION_TAG;
+ hdr->size = size;
+ init_front_guard(hdr);
+ init_rear_guard(hdr);
+ num++;
+ add_locked(hdr, &tail, &head);
+ pthread_mutex_unlock(&lock);
+}
+
+static inline int del(struct hdr *hdr)
+{
+ if (hdr->tag != ALLOCATION_TAG)
+ return -1;
+
+ pthread_mutex_lock(&lock);
+ del_locked(hdr, &tail, &head);
+ num--;
+ pthread_mutex_unlock(&lock);
+ return 0;
+}
+
+static inline void poison(struct hdr *hdr)
+{
+ memset(user(hdr), FREE_POISON, hdr->size);
+}
+
+static int was_used_after_free(struct hdr *hdr)
+{
+ unsigned i;
+ const char *data = (const char *)user(hdr);
+ for (i = 0; i < hdr->size; i++)
+ if (data[i] != FREE_POISON)
+ return 1;
+ return 0;
+}
+
+/* returns 1 if valid, *safe == 1 if safe to dump stack */
+static inline int check_guards(struct hdr *hdr, int *safe)
+{
+ *safe = 1;
+ if (!is_front_guard_valid(hdr)) {
+ if (hdr->front_guard[0] == FRONT_GUARD) {
+ log_message("+++ ALLOCATION %p SIZE %d HAS A CORRUPTED FRONT GUARD\n",
+ user(hdr), hdr->size);
+ } else {
+ log_message("+++ ALLOCATION %p HAS A CORRUPTED FRONT GUARD "\
+ "(NOT DUMPING STACKTRACE)\n", user(hdr));
+ /* Allocation header is probably corrupt, do not print stack trace */
+ *safe = 0;
+ }
+ return 0;
+ }
+
+ if (!is_rear_guard_valid(hdr)) {
+ log_message("+++ ALLOCATION %p SIZE %d HAS A CORRUPTED REAR GUARD\n",
+ user(hdr), hdr->size);
+ return 0;
+ }
+
+ return 1;
+}
+
+/* returns 1 if valid, *safe == 1 if safe to dump stack */
+static inline int check_allocation_locked(struct hdr *hdr, int *safe)
+{
+ int valid = 1;
+ *safe = 1;
+
+ if (hdr->tag != ALLOCATION_TAG && hdr->tag != BACKLOG_TAG) {
+ log_message("+++ ALLOCATION %p HAS INVALID TAG %08x (NOT DUMPING STACKTRACE)\n",
+ user(hdr), hdr->tag);
+ /* Allocation header is probably corrupt, do not dequeue or dump stack
+ * trace.
+ */
+ *safe = 0;
+ return 0;
+ }
+
+ if (hdr->tag == BACKLOG_TAG && was_used_after_free(hdr)) {
+ log_message("+++ ALLOCATION %p SIZE %d WAS USED AFTER BEING FREED\n",
+ user(hdr), hdr->size);
+ valid = 0;
+ /* check the guards to see if it's safe to dump a stack trace */
+ (void)check_guards(hdr, safe);
+ }
+ else
+ valid = check_guards(hdr, safe);
+
+ if (!valid && *safe) {
+ log_message("+++ ALLOCATION %p SIZE %d ALLOCATED HERE:\n",
+ user(hdr), hdr->size);
+ print_backtrace(hdr->bt, hdr->bt_depth);
+ if (hdr->tag == BACKLOG_TAG) {
+ log_message("+++ ALLOCATION %p SIZE %d FREED HERE:\n",
+ user(hdr), hdr->size);
+ print_backtrace(hdr->freed_bt, hdr->freed_bt_depth);
+ }
+ }
+
+ return valid;
+}
+
+static inline int del_and_check_locked(struct hdr *hdr,
+ struct hdr **tail, struct hdr **head, unsigned *cnt,
+ int *safe)
+{
+ int valid;
+ valid = check_allocation_locked(hdr, safe);
+ if (safe) {
+ (*cnt)--;
+ del_locked(hdr, tail, head);
+ }
+ return valid;
+}
+
+static inline void del_from_backlog_locked(struct hdr *hdr)
+{
+ int safe;
+ (void)del_and_check_locked(hdr,
+ &backlog_tail, &backlog_head, &backlog_num,
+ &safe);
+ hdr->tag = 0; /* clear the tag */
+}
+
+static inline void del_from_backlog(struct hdr *hdr)
+{
+ pthread_mutex_lock(&backlog_lock);
+ del_from_backlog_locked(hdr);
+ pthread_mutex_unlock(&backlog_lock);
+}
+
+static inline int del_leak(struct hdr *hdr, int *safe)
+{
+ int valid;
+ pthread_mutex_lock(&lock);
+ valid = del_and_check_locked(hdr,
+ &tail, &head, &num,
+ safe);
+ pthread_mutex_unlock(&lock);
+ return valid;
+}
+
+static inline void add_to_backlog(struct hdr *hdr)
+{
+ pthread_mutex_lock(&backlog_lock);
+ hdr->tag = BACKLOG_TAG;
+ backlog_num++;
+ add_locked(hdr, &backlog_tail, &backlog_head);
+ poison(hdr);
+ /* If we've exceeded the maximum backlog, clear it up */
+ while (backlog_num > malloc_double_free_backlog) {
+ struct hdr *gone = backlog_tail;
+ del_from_backlog_locked(gone);
+ dlfree(gone);
+ }
+ pthread_mutex_unlock(&backlog_lock);
+}
+
+void* chk_malloc(size_t size)
+{
+ struct hdr *hdr;
+
+// log_message("%s: %s\n", __FILE__, __FUNCTION__);
+
+ hdr = dlmalloc(sizeof(struct hdr) + size + sizeof(struct ftr));
+ if (hdr) {
+ hdr->bt_depth = get_backtrace(hdr->bt, MAX_BACKTRACE_DEPTH);
+ add(hdr, size);
+ return user(hdr);
+ }
+ return NULL;
+}
+
+void* chk_memalign(size_t alignment, size_t bytes)
+{
+// log_message("%s: %s\n", __FILE__, __FUNCTION__);
+ // XXX: it's better to use malloc, than being wrong
+ return chk_malloc(bytes);
+}
+
+void chk_free(void *ptr)
+{
+ struct hdr *hdr;
+
+// log_message("%s: %s\n", __FILE__, __FUNCTION__);
+
+ if (!ptr) /* ignore free(NULL) */
+ return;
+
+ hdr = meta(ptr);
+
+ if (del(hdr) < 0) {
+ intptr_t bt[MAX_BACKTRACE_DEPTH];
+ int depth;
+ depth = get_backtrace(bt, MAX_BACKTRACE_DEPTH);
+ if (hdr->tag == BACKLOG_TAG) {
+ log_message("+++ ALLOCATION %p SIZE %d BYTES MULTIPLY FREED!\n",
+ user(hdr), hdr->size);
+ log_message("+++ ALLOCATION %p SIZE %d ALLOCATED HERE:\n",
+ user(hdr), hdr->size);
+ print_backtrace(hdr->bt, hdr->bt_depth);
+ /* hdr->freed_bt_depth should be nonzero here */
+ log_message("+++ ALLOCATION %p SIZE %d FIRST FREED HERE:\n",
+ user(hdr), hdr->size);
+ print_backtrace(hdr->freed_bt, hdr->freed_bt_depth);
+ log_message("+++ ALLOCATION %p SIZE %d NOW BEING FREED HERE:\n",
+ user(hdr), hdr->size);
+ print_backtrace(bt, depth);
+ }
+ else {
+ log_message("+++ ALLOCATION %p IS CORRUPTED OR NOT ALLOCATED VIA TRACKER!\n",
+ user(hdr));
+ print_backtrace(bt, depth);
+ /* Leak here so that we do not crash */
+ //dlfree(user(hdr));
+ }
+ }
+ else {
+ hdr->freed_bt_depth = get_backtrace(hdr->freed_bt,
+ MAX_BACKTRACE_DEPTH);
+ add_to_backlog(hdr);
+ }
+}
+
+void *chk_realloc(void *ptr, size_t size)
+{
+ struct hdr *hdr;
+
+// log_message("%s: %s\n", __FILE__, __FUNCTION__);
+
+ if (!size) {
+ chk_free(ptr);
+ return NULL;
+ }
+
+ if (!ptr)
+ return chk_malloc(size);
+
+ hdr = meta(ptr);
+
+ if (del(hdr) < 0) {
+ intptr_t bt[MAX_BACKTRACE_DEPTH];
+ int depth;
+ depth = get_backtrace(bt, MAX_BACKTRACE_DEPTH);
+ if (hdr->tag == BACKLOG_TAG) {
+ log_message("+++ REALLOCATION %p SIZE %d OF FREED MEMORY!\n",
+ user(hdr), size, hdr->size);
+ log_message("+++ ALLOCATION %p SIZE %d ALLOCATED HERE:\n",
+ user(hdr), hdr->size);
+ print_backtrace(hdr->bt, hdr->bt_depth);
+ /* hdr->freed_bt_depth should be nonzero here */
+ log_message("+++ ALLOCATION %p SIZE %d FIRST FREED HERE:\n",
+ user(hdr), hdr->size);
+ print_backtrace(hdr->freed_bt, hdr->freed_bt_depth);
+ log_message("+++ ALLOCATION %p SIZE %d NOW BEING REALLOCATED HERE:\n",
+ user(hdr), hdr->size);
+ print_backtrace(bt, depth);
+
+ /* We take the memory out of the backlog and fall through so the
+ * reallocation below succeeds. Since we didn't really free it, we
+ * can default to this behavior.
+ */
+ del_from_backlog(hdr);
+ }
+ else {
+ log_message("+++ REALLOCATION %p SIZE %d IS CORRUPTED OR NOT ALLOCATED VIA TRACKER!\n",
+ user(hdr), size);
+ print_backtrace(bt, depth);
+ // just get a whole new allocation and leak the old one
+ return dlrealloc(0, size);
+ // return dlrealloc(user(hdr), size); // assuming it was allocated externally
+ }
+ }
+
+ hdr = dlrealloc(hdr, sizeof(struct hdr) + size + sizeof(struct ftr));
+ if (hdr) {
+ hdr->bt_depth = get_backtrace(hdr->bt, MAX_BACKTRACE_DEPTH);
+ add(hdr, size);
+ return user(hdr);
+ }
+
+ return NULL;
+}
+
+void *chk_calloc(int nmemb, size_t size)
+{
+// log_message("%s: %s\n", __FILE__, __FUNCTION__);
+ struct hdr *hdr;
+ size_t total_size = nmemb * size;
+ hdr = dlcalloc(1, sizeof(struct hdr) + total_size + sizeof(struct ftr));
+ if (hdr) {
+ hdr->bt_depth = get_backtrace(
+ hdr->bt, MAX_BACKTRACE_DEPTH);
+ add(hdr, total_size);
+ return user(hdr);
+ }
+ return NULL;
+}
+
+static void heaptracker_free_leaked_memory(void)
+{
+ struct hdr *del; int cnt;
+
+ if (num)
+ log_message("+++ THERE ARE %d LEAKED ALLOCATIONS\n", num);
+
+ while (head) {
+ int safe;
+ del = head;
+ log_message("+++ DELETING %d BYTES OF LEAKED MEMORY AT %p (%d REMAINING)\n",
+ del->size, user(del), num);
+ if (del_leak(del, &safe)) {
+ /* safe == 1, because the allocation is valid */
+ log_message("+++ ALLOCATION %p SIZE %d ALLOCATED HERE:\n",
+ user(del), del->size);
+ print_backtrace(del->bt, del->bt_depth);
+ }
+ dlfree(del);
+ }
+
+// log_message("+++ DELETING %d BACKLOGGED ALLOCATIONS\n", backlog_num);
+ while (backlog_head) {
+ del = backlog_tail;
+ del_from_backlog(del);
+ dlfree(del);
+ }
+}
+
+/* Initializes malloc debugging framework.
+ * See comments on MallocDebugInit in malloc_debug_common.h
+ */
+int malloc_debug_initialize(void)
+{
+ if (!malloc_double_free_backlog)
+ malloc_double_free_backlog = BACKLOG_DEFAULT_LEN;
+ milist = init_mapinfo(getpid());
+ return 0;
+}
+
+void malloc_debug_finalize(void)
+{
+ heaptracker_free_leaked_memory();
+ deinit_mapinfo(milist);
+}