防止内存泄露 Linux下用Valgrind做检查
| 3DB: main (test.c:8)
==4270== Address 0x4023033 is 1 bytes after a block of size 10 alloc''d ==4270== at 0x40044F6: malloc (vg_replace_malloc.c:149) ==4270== by 0x80483C5: main (test.c:7) ==4270== ==4270== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 12 from 1) ==4270== malloc/free: in use at exit: 10 bytes in 1 blocks. ==4270== malloc/free: 1 allocs, 0 frees, 10 bytes allocated. ==4270== For counts of detected errors, rerun with: -v ==4270== searching for pointers to 1 not-freed blocks. ==4270== checked 51,496 bytes. ==4270== ==4270== ==4270== 10 bytes in 1 blocks are definitely lost in loss record 1 of 1 ==4270== at 0x40044F6: malloc (vg_replace_malloc.c:149) ==4270== by 0x80483C5: main (test.c:7) ==4270== ==4270== LEAK SUMMARY: ==4270== definitely lost: 10 bytes in 1 blocks. ==4270== possibly lost: 0 bytes in 0 blocks. ==4270== still reachable: 0 bytes in 0 blocks. ==4270== suppressed: 0 bytes in 0 blocks. ==4270== Reachable blocks (those to which a pointer was found) are not shown. ==4270== To see them, rerun with: --show-reachable=yes 从这份报告可以看出,进程号是4270,test.c的第8行写内存越界了,引起写内存越界的是strcpy函数, 第7行泄漏了10个字节的内存,引起内存泄漏的是malloc函数. 例子二（test2.c) 拥有帝国一切，皆有可能。欢迎访问phome.net #include <stdio.h> int foo(int x) { if (x < 0) { printf("%d ", x); } return 0; } int main(int argc, char *argv[]) { int x; foo(x); return 0; } 编译程序 gcc -g -o test2 test2.c 用valgrind做内存检查 valgrind --tool=memcheck ./test2 输出报告如下 ==4285== Memcheck, a memory error detector. ==4285== Copyright (C) 2002-2006, and GNU GPL''d, by Julian Seward et al. ==4285== Using LibVEX rev 1606, a library for dynamic binary translation. ==4285== Copyright (C) 2004-2006, and GNU GPL''d, by OpenWorks LLP. ==4285== Using valgrind-3.2.0, a dynamic binary instrumentation framework. ==4285== Copyright (C) 2000-2006, and GNU GPL''d, by Julian Seward et al. ==4285== For more details, rerun with: -v ==4285== ==4285== Conditional jump or move depends on uninitialised value(s) ==4285== at 0x8048372: foo (test2.c:5) ==4285== by 0x80483B4: main (test2.c:16) ==4285==p p ==4285== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 12 from 1) ==4285== malloc/free: in use at exit: 0 bytes in 0 blocks. ==4285== malloc/free: 0 allocs, 0 frees, 0 bytes allocated. ==4285== For counts of detected errors, rerun with: -v ==4285== All heap blocks were freed -- no leaks are possible.
从这份报告可以看出进程PID是4285,test2.c文件的第16行调用了foo函数,在test2.c文件的第5行foo函数使用了一个未初始化的变量. valgrind还有很多使用选项,具体可以查看valgrind的man手册页和valgrind官方网站的在线文档. 文章来自[SVN中文技术 |
凌众科技专业提供服务器租用、服务器托管、企业邮局、虚拟主机等服务，公司网站：http://www.lingzhong.cn 为了给广大客户了解更多的技术信息，本技术文章收集来源于网络,凌众科技尊重文章作者的版权，如果有涉及你的版权有必要删除你的文章，请和我们联系。以上信息与文章正文是不可分割的一部分,如果您要转载本文章,请保留以上信息，谢谢! |
