我有一个与 cpp/h 文件关联的共享库(即 libXXX.so)。它们包含许多函数指针(指向 .so 函数入口点)和一个将这些函数包装为所述类的方法的类。
即:.h 文件:
typedef void* handle;
/* wrapper functions */
handle okUsbFrontPanel_Construct();
void okUsbFrontPanel_Destruct(handle hnd);
/* wrapper class */
class okCUsbFrontPanel
{
public:
handle h;
public:
okCUsbFrontPanel();
~okCUsbFrontPanel();
};
.cpp 文件
/* class methods */
okCUsbFrontPanel::okCUsbFrontPanel()
{ h=okUsbFrontPanel_Construct(); }
okCUsbFrontPanel::~okCUsbFrontPanel()
{ okUsbFrontPanel_Destruct(h); }
/* function pointers */
typedef handle (*OKUSBFRONTPANEL_CONSTRUCT_FN) (void);
typedef void (*OKUSBFRONTPANEL_DESTRUCT_FN) (handle);
OKUSBFRONTPANEL_CONSTRUCT_FN _okUsbFrontPanel_Construct = NULL;
OKUSBFRONTPANEL_DESTRUCT_FN _okUsbFrontPanel_Destruct = NULL;
/* load lib function */
Bool LoadLib(char *libname){
void *hLib = dlopen(libname, RTLD_NOW);
if(hLib){
_okUsbFrontPanel_Construct = ( OKUSBFRONTPANEL_CONSTRUCT_FN ) dlsym(hLib, "okUsbFrontPanel_Construct");
_okUsbFrontPanel_Destruct = ( OKUSBFRONTPANEL_DESTRUCT_FN ) dlsym( hLib, "okUsbFrontPanel_Destruct" );
}
}
/* construct function */
handle okUsbFrontPanel_Construct(){
if (_okUsbFrontPanel_Construct){
handle h = (*_okUsbFrontPanel_Construct)(); //calls function pointer
return h;
}
return(NULL);
}
void okUsbFrontPanel_Destruct(handle hnd)
{
if (_okUsbFrontPanel_Destruct)
(*_okUsbFrontPanel_Destruct)(hnd);
}
然后我有另一个共享库(我自己制作),它调用:
LoadLib("libXXX.so");
okCusbFrontPanel *device = new okCusbFrontPanel();
导致分段错误。分段错误似乎发生在
handle h = (*_okUsbFrontPanel_Construct)();
但有一个奇怪的行为:一旦我到达
(*_okUsbFrontPanel_Construct)();
我得到了 okUsbFrontPanel_Construct() 的递归。
有谁有想法吗?
编辑:这是通过 gdb 运行获得的回溯。
#0 0x007590b0 in _IO_new_do_write () from /lib/tls/libc.so.6
#1 0x00759bb8 in _IO_new_file_overflow () from /lib/tls/libc.so.6
#2 0x0075a83d in _IO_new_file_xsputn () from /lib/tls/libc.so.6
#3 0x00736db7 in vfprintf () from /lib/tls/libc.so.6
#4 0x0073ecd0 in printf () from /lib/tls/libc.so.6
#5 0x02cb68ca in okCUsbFrontPanel (this=0x9d0ae28) at okFrontPanelDLL.cpp:167
#6 0x03cac343 in okUsbFrontPanel_Construct () from /opt/atlas/tdaq/tdaq-02-00-00/installed/i686-slc4-gcc34-dbg/lib/libokFrontPanel.so
#7 0x02cb8f36 in okUsbFrontPanel_Construct () at okFrontPanelDLL.cpp:1107
#8 0x02cb68db in okCUsbFrontPanel (this=0x9d0ade8) at okFrontPanelDLL.cpp:169
#9 0x03cac343 in okUsbFrontPanel_Construct () from /opt/atlas/tdaq/tdaq-02-00-00/installed/i686-slc4-gcc34-dbg/lib/libokFrontPanel.so
#10 0x02cb8f36 in okUsbFrontPanel_Construct () at okFrontPanelDLL.cpp:1107
#11 0x02cb68db in okCUsbFrontPanel (this=0x9d0ada8) at okFrontPanelDLL.cpp:169
#12 0x03cac343 in okUsbFrontPanel_Construct () from /opt/atlas/tdaq/tdaq-02-00-00/installed/i686-slc4-gcc34-dbg/lib/libokFrontPanel.so
#13 0x02cb8f36 in okUsbFrontPanel_Construct () at okFrontPanelDLL.cpp:1107
等等...恕我直言,由于某种堆栈溢出,我遇到了段错误。递归调用太多,出了点问题..
顺便说一句,我使用的是 Scientific Linux 4 发行版(基于 RH4)。
编辑2:
用于函数 okUsbFrontPanel_Construct 输出的 libokFrontPanel.so 的 objdump:
00009316 <okUsbFrontPanel_Construct>:
9316: 55 push ebp
9317: 89 e5 mov ebp,esp
9319: 56 push esi
931a: 53 push ebx
931b: 83 ec 30 sub esp,0x30
931e: e8 44 f4 ff ff call 8767 <__i686.get_pc_thunk.bx>
9323: 81 c3 dd bd 00 00 add ebx,0xbddd
9329: c7 04 24 38 00 00 00 mov DWORD PTR [esp],0x38
9330: e8 93 ec ff ff call 7fc8 <_Znwj@plt>
9335: 89 45 e4 mov DWORD PTR [ebp-28],eax
9338: 8b 45 e4 mov eax,DWORD PTR [ebp-28]
933b: 89 04 24 mov DWORD PTR [esp],eax
933e: e8 65 ed ff ff call 80a8 <_ZN16okCUsbFrontPanelC1Ev@plt>
9343: 8b 45 e4 mov eax,DWORD PTR [ebp-28]
9346: 89 45 f4 mov DWORD PTR [ebp-12],eax
9349: 8b 45 f4 mov eax,DWORD PTR [ebp-12]
934c: 89 45 e0 mov DWORD PTR [ebp-32],eax
934f: eb 1f jmp 9370 <okUsbFrontPanel_Construct+0x5a>
9351: 89 45 dc mov DWORD PTR [ebp-36],eax
9354: 8b 75 dc mov esi,DWORD PTR [ebp-36]
9357: 8b 45 e4 mov eax,DWORD PTR [ebp-28]
935a: 89 04 24 mov DWORD PTR [esp],eax
935d: e8 d6 f2 ff ff call 8638 <_ZdlPv@plt>
9362: 89 75 dc mov DWORD PTR [ebp-36],esi
9365: 8b 45 dc mov eax,DWORD PTR [ebp-36]
9368: 89 04 24 mov DWORD PTR [esp],eax
936b: e8 a8 f0 ff ff call 8418 <_Unwind_Resume@plt>
9370: 8b 45 e0 mov eax,DWORD PTR [ebp-32]
9373: 83 c4 30 add esp,0x30
9376: 5b pop ebx
9377: 5e pop esi
9378: 5d pop ebp
9379: c3 ret
在 933e 确实有一个对 <_ZN16okCUsbFrontPanelC1Ev@plt> 的调用。这个调用是否与我的 .cpp 中的调用混淆了?