linux c程序内存泄漏检测工具-mtrace工具介绍

Posted 2020-11-21 biaodi1900

     笔者也是最近去面试被问到怎么做内存泄漏检查，之前都是靠人工屏蔽代码、或者PC-link/KW一类的检查工具进行检查，回来后搜索了下，才知道linux自带的就有mtrace工具。

     具体操作步骤如下：

   1.在linux下创建test.c文件，编写如下代码：

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <string.h>
 4 
 5 #include <mcheck.h>
 6 
 7 
 8 int main()
 9 {
10     setenv("MALLOC_TRACE","malloc.log",1);
11     mtrace();
12 
13 
14     char* text = (char*)malloc(sizeof(char)*100);
15     memset(text,0,100);
16     memcpy(text,"hello,world!",12);
17     printf("%s
",text);
18     return 0;
19 }

2.保存退出后用，gcc -g text.c -o test.out进行编译；

3.执行./test.out

4.执行命令mtrace test.out malloc.log，2-4步骤的结果如下

[email protected]:~$ gcc -g test.c -o test.out
[email protected]-virtual-machine:~$ ./test.out 
hello,world!
[email protected]-virtual-machine:~$ mtrace test.out malloc.log
- 0x0000000000700010 Free 4 was never alloc‘d 0x7fc09fee4e9d
- 0x0000000000700210 Free 5 was never alloc‘d 0x7fc09ffaf91f
- 0x0000000000700230 Free 6 was never alloc‘d 0x7fc0a001f23c

Memory not freed:
-----------------
           Address     Size     Caller
0x00000000007006a0     0x64  at /home/wqb/test.c:14
[email protected]-virtual-machine:~$ 

其中0x00000000007006a0 0x64 at /home/wqb/test.c:14 表明test.c的14行有内存泄漏。