使用valgrind检查内存越界

• 下载

http://valgrind.org/downloads/current.html

• 解压
• 编译

./configure
 
make
 
sudo make install      

• 测试

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
  
int main(int argc, char **argv)
{
    //char  array[32] = {0};
    char* buffer = NULL;
 
    buffer = (char*)malloc(32);
    //崩溃
    buffer[56] = 0;
 
    free(buffer);
 
    return 0;
}      

编译运行

gcc -g test.c
 
valgrind --tool=memcheck --leak-check=full ./a.out      

显示如下：

==13794== Memcheck, a memory error detector
==13794== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==13794== Using Valgrind-3.14.0 and LibVEX; rerun with -h for copyright info
==13794== Command: ./a.out
==13794== 
==13794== Invalid write of size 1
==13794==    at 0x400593: main (test.c:11)
==13794==  Address 0x5205078 is 24 bytes after a block of size 32 in arena "client"
==13794== 
==13794== 
==13794== HEAP SUMMARY:
==13794==     in use at exit: 0 bytes in 0 blocks
==13794==   total heap usage: 1 allocs, 1 frees, 32 bytes allocated
==13794== 
==13794== All heap blocks were freed -- no leaks are possible
==13794== 
==13794== For counts of detected and suppressed errors, rerun with: -v
==13794== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)      

注意其中：

==13794== Invalid write of size 1

==13794==    at 0x400593: main (test.c:11)

• 实用性探讨

需要说明的是，对于类似char  array[32] = {0};，提示上就要差一些

==13772== Invalid read of size 1
==13772==    at 0x4E5B800: (below main) (libc-start.c:285)
==13772==  Address 0x0 is not stack'd, malloc'd or (recently) free'd      

具体情况，以后通过试用再做补充．