getpwnam_r内存泄漏

Question

我使用getpwnam_r来处理程序中的客户端连接.可悲的是,它似乎分配了一个永远不会释放的缓冲区.相关的valgrind输出:

==15774== 536 (104 direct, 432 indirect) bytes in 2 blocks are definitely lost in loss record 1 of 3
==15774==    at 0x4C24CFE: malloc (in /usr/lib64/valgrind/amd64-linux/vgpreload_memcheck.so)
==15774==    by 0x5143B5A: nss_parse_service_list (in /lib64/libc-2.10.1.so)
==15774==    by 0x51442E6: __nss_database_lookup (in /lib64/libc-2.10.1.so)
==15774==    by 0x57BE35F: ???
==15774==    by 0x57BF3F6: ???
==15774==    by 0x51014D2: getpwnam_r@@GLIBC_2.2.5 (in /lib64/libc-2.10.1.so)
==15774==    by 0x407906: dopass (auth.c:71)
==15774==    by 0x40393E: do_cmd (command.c:127)
==15774==    by 0x402496: ftp_main (server.c:58)
==15774==    by 0x40224C: handle_client (daemon.c:211)
==15774==    by 0x402073: daemon_main (daemon.c:123)
==15774==    by 0x4043CC: main (main.c:48)
==15774== 
==15774== LEAK SUMMARY:
==15774==    definitely lost: 104 bytes in 2 blocks.
==15774==    indirectly lost: 432 bytes in 18 blocks.
==15774==      possibly lost: 0 bytes in 0 blocks.
==15774==    still reachable: 0 bytes in 0 blocks.
==15774==         suppressed: 0 bytes in 0 blocks.

我有办法告诉getpwnam_r释放它的缓冲区吗？或者我是否必须压制这些Valgrind错误？

谢谢,卡斯帕

Answer 1

内存并没有特别为getpwnam分配.相反,它代表了配置/etc/nsswitch.conf.AFAICT,让libc释放这个内存的唯一方法是通过调用__libc_freeres:

extern void __libc_freeres (void);

这应该释放C库保存的所有内存(而不仅仅是NSS保留的内存).