我有两个用于
linux平台的外包共享库(没有源代码,没有文档).当它们分别链接到程序时(g xx.cpp lib1.so或g xx.cpp lib2.so),这些库工作正常.
但是,当任何c程序同时链接到这两个共享库时,程序不可避免地会因“双重释放”错误而崩溃(g xx.cpp lib1.so lib2.so).
即使c程序是一个空的hello world程序并且与这些库无关,它仍然会崩溃.
#include <iostream> using namespace std; int main(){ cout<<"haha,I crash again. Catch me if you can"<<endl; return 0; }
Makefile文件:
g++ helloword.cpp lib1.so lib2.so
我得到了一些线索,这些lib1.so lib2.so库可能共享一些常见的全局变量,并且它们会破坏一些变量两次.我尝试过gdb和valgrind,但是无法从backtrace中提取有用的信息.
有什么方法可以隔离这两个共享库并使它们以沙盒方式工作?
EDITED(添加核心转储和gdb回溯):
我只是将前面提到的玩具空helloword程序与两个库(平台:带有gcc4.8.2的centos 7.0 64bits)联系起来:
g++ helloworld.cpp lib1.so lib2.so -o check
Valgrind的:
==29953== Invalid free() / delete / delete[] / realloc() ==29953== at 0x4C29991: operator delete(void*) (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==29953== by 0x613E589: __cxa_finalize (in /usr/lib64/libc-2.17.so) ==29953== by 0x549B725: ??? (in /home/fanbin/InventoryManagment/lib1.so) ==29953== by 0x5551720: ??? (in /home/fanbin/InventoryManagment/lib1.so) ==29953== by 0x613E218: __run_exit_handlers (in /usr/lib64/libc-2.17.so) ==29953== by 0x613E264: exit (in /usr/lib64/libc-2.17.so) ==29953== by 0x6126AFB: (below main) (in /usr/lib64/libc-2.17.so) ==29953== Address 0x6afb780 is 0 bytes inside a block of size 624 free'd ==29953== at 0x4C29991: operator delete(void*) (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==29953== by 0x613E589: __cxa_finalize (in /usr/lib64/libc-2.17.so) ==29953== by 0x4F07AC5: ??? (in /home/fanbin/InventoryManagment/lib2.so) ==29953== by 0x5039900: ??? (in /home/fanbin/InventoryManagment/lib2.so) ==29953== by 0x613E218: __run_exit_handlers (in /usr/lib64/libc-2.17.so) ==29953== by 0x613E264: exit (in /usr/lib64/libc-2.17.so) ==29953== by 0x6126AFB: (below main) (in /usr/lib64/libc-2.17.so)
gdb回溯消息:
(gdb) bt #0 0x00007ffff677d989 in raise () from /lib64/libc.so.6 #1 0x00007ffff677f098 in abort () from /lib64/libc.so.6 #2 0x00007ffff67be197 in __libc_message () from /lib64/libc.so.6 #3 0x00007ffff67c556d in _int_free () from /lib64/libc.so.6 #4 0x00007ffff7414aa2 in __tcf_0 () from ./lib1.so #5 0x00007ffff678158a in __cxa_finalize () from /lib64/libc.so.6 #6 0x00007ffff739f726 in __do_global_dtors_aux () from ./lib1.so #7 0x0000000000600dc8 in __init_array_start () #8 0x00007fffffffe2c0 in ?? () #9 0x00007ffff7455721 in _fini () from ./lib1.so #10 0x00007fffffffe2c0 in ?? () #11 0x00007ffff7debb98 in _dl_fini () from /lib64/ld-linux-x86-64.so.2 Backtrace stopped: prevIoUs frame inner to this frame (corrupt stack?)
更新
感谢@RaduChivu的帮助,我发现了一个非常类似的场景:segmentation fault at __tcf_0 when program exits,看起来确实两个库之间存在全局变量冲突.考虑到我没有这两个外部共享库的源文件,除了使用两个单独的进程外,还有其他方法可以解决这个冲突吗?