介绍：
The GNU C Library lets you modify the behavior of malloc, realloc, and free by specifying appropriate hook functions.
使用：
http://www.gnu.org/software/libc/manual/html_node/Hooks-for-Malloc.html
参考：
http://soft.zdnet.com.cn/software_zone/2009/1221/1567788.shtml
例子：
代码
1 #include <malloc.h> 2 3 /* Prototypes for our hooks. */ 4 static void my_init_hook (void); 5 static void *my_malloc_hook (size_t, const void *); 6 static void my_free_hook (void*, const void *); 7 8 static void* (* old_malloc_hook) (size_t,const void *); 9 static void (* old_free_hook)(void *,const void *); 10 11 /* Override initializing hook from the C library. */ 12 void (*__malloc_initialize_hook) (void) = my_init_hook; 13 14 static void 15 my_init_hook (void) 16 { 17 old_malloc_hook = __malloc_hook; 18 old_free_hook = __free_hook; 19 __malloc_hook = my_malloc_hook; 20 __free_hook = my_free_hook; 21 } 22 23 static void * 24 my_malloc_hook (size_t size, const void *caller) 25 { 26 void *result; 27 /* Restore all old hooks */ 28 __malloc_hook = old_malloc_hook; 29 __free_hook = old_free_hook; 30 /* Call recursively */ 31 result = malloc (size); 32 /* Save underlying hooks */ 33 old_malloc_hook = __malloc_hook; 34 old_free_hook = __free_hook; 35 /* printf might call malloc, so protect it too. */ 36 printf ("malloc (%u) returns %p ", (unsigned int) size, result); 37 /* Restore our own hooks */ 38 __malloc_hook = my_malloc_hook; 39 __free_hook = my_free_hook; 40 return result; 41 } 42 43 static void 44 my_free_hook (void *ptr, const void *caller) 45 { 46 /* Restore all old hooks */ 47 __malloc_hook = old_malloc_hook; 48 __free_hook = old_free_hook; 49 /* Call recursively */ 50 free (ptr); 51 /* Save underlying hooks */ 52 old_malloc_hook = __malloc_hook; 53 old_free_hook = __free_hook; 54 /* printf might call free, so protect it too. */ 55 printf ("freed pointer %p ", ptr); 56 /* Restore our own hooks */ 57 __malloc_hook = my_malloc_hook; 58 __free_hook = my_free_hook; 59 } 60 61 int 62 main (int arg,char **argv) 63 { 64 malloc(100); 65 malloc(100); 66 char* p = malloc(100); 67 free(p); 68 return 0; 69 }
结果分析
root@ubuntu:/home/linux/develop/mem_test/5# gcc test.c
root@ubuntu:/home/linux/develop/mem_test/5# ./a.out
malloc (100) returns 0x9b62008
malloc (100) returns 0x9b62070
malloc (100) returns 0x9b620d8
freed pointer 0x9b620d8