Typedef int (* Func_CallFunc) (char * pSrcName, char * pSrcPath, char * pOutName, int * iRecordCount, char * pMsg);

PCallFunc=(Func_CallFunc) dlsym (pLibHandle, "CallFunc");
If (pCallFunc==NULL)
{
Sprintf (pMsg, "open the library [CallFunc] [% s] function failure. ERR: % s", pLibName, dlerror ());
return -1;
}
Here is normal, dynamic link library CallFunc function called error

The Program received signal SIGSEGV, Segmentation fault.
0 x00007fffef9393ea in CallFunc (pSrcName=& lt; Error reading variable: always access the memory at address 0 x7fffffcf4108 & gt; ,
PSrcPath=& lt; Error reading variable: always access the memory at address 0 x7fffffcf4100 & gt; ,
POutName=& lt; Error reading variable: always access the memory at address 0 x7fffffcf40f8 & gt; ,
IRecordCount=& lt; Error reading variable: always access the memory at address 0 x7fffffcf40f0 & gt; ,
PMsg=& lt; Error reading variable: always access the memory at address 0 x7fffffcf40e8 & gt;) The at PGWDecode. CPP: 54

CodePudding user response:

PLibHandle=dlopen (pLibName RTLD_LAZY);
If (pLibHandle==NULL)
{
Sprintf (pMsg, "open the library [% s] failure. ERR: % s", pLibName, dlerror ());
return -1;
}

PCallFunc=(Func_CallFunc) dlsym (pLibHandle, "CallFunc");
If (pCallFunc==NULL)
{
Sprintf (pMsg, "open the library [CallFunc] [% s] function failure. ERR: % s", pLibName, dlerror ());
return -1;
}

Int ftplib: : CallLibFunc (char * pSrcName, char * pSrcPath, char * pOutName, int * iRecordCount, char * pMsg)
{
Return pCallFunc (pSrcName, pSrcPath pOutName, iRecordCount, pMsg);
}

GDB error message

Ftplib: : CallLibFunc (pSrcName=0 x7fffffff8b60 "bss96.ecld.com _DATA_TEST30_BB000000003300. Dat,"
PSrcPath=0 x7fffffff9f80 "/home/bill/data/collect/data/collect_tmp0/12155", pOutName=0 x685884 ", "iRecordCount x7fffffffa698=0,
PMsg=0 x7fffffff9980 "") at the/home/bill/src_smz/collect_multiprocess/ftplib CPP: 48
Return pCallFunc (pSrcName, pSrcPath pOutName, iRecordCount, pMsg);

The Program received signal SIGSEGV, Segmentation fault.
0 x00007fffef9393ea in CallFunc (pSrcName=& lt; Error reading variable: always access the memory at address 0 x7fffffcf4108 & gt; ,
PSrcPath=& lt; Error reading variable: always access the memory at address 0 x7fffffcf4100 & gt; ,
POutName=& lt; Error reading variable: always access the memory at address 0 x7fffffcf40f8 & gt; ,
IRecordCount=& lt; Error reading variable: always access the memory at address 0 x7fffffcf40f0 & gt; ,
PMsg=& lt; Error reading variable: always access the memory at address 0 x7fffffcf40e8 & gt;) The at PGWDecode. CPP: 54
54 {

CodePudding user response:

Looks like the problem, the key should be the call

CodePudding user response:

Use GDB step through into the function, check the calling convention (parameter passing way, the number of parameters, a stack is balance, parameter types, parameter value scope,... )

Calling convention https://msdn.microsoft.com/zh-cn/magazine/9b372w95.aspx

CodePudding user response:

I wrote a test program manual, there is no any business logic
C
g + + - g test.
./a.out./libPGWDecode. So a.t xt. Can call normal libPGWDecode. So the dynamic link library

With our application in the paper is the error,

But our application calls the other dynamic libraries can be successful, the dynamic library has a problem, the test program code below

# include & lt; DLFCN. H>
# include & lt; String. H>
# include & lt; Stdio. H>

//initialize the library environment
PMsg Func_InitEnv typedef int (*) (char *);

//perform the conversion function
Typedef int (* Func_CallFunc) (char * pSrcName, char * pSrcPath, char * pOutName, int * iRecordCount, char * pMsg);

//release the library environment
PMsg Func_UnInitEnv typedef int (*) (char *);

Void * pLibHandle;//handle dynamic library

Func_InitEnv pInit;//initialization function handles

Func_CallFunc pCallFunc;//handle to perform function

Func_UnInitEnv pUnInit;//handle to release function

Int InitFtpLib (char * pLibName, char * pMsg)
{
PLibHandle=dlopen (pLibName RTLD_LAZY);
If (pLibHandle==NULL)
{
Sprintf (pMsg, "open the library [% s] failure. ERR: % s", pLibName, dlerror ());
return -1;
}

PInit=(Func_InitEnv) dlsym (pLibHandle, "InitEnv");
If (pInit==NULL)
{
Sprintf (pMsg, "open the library [InitEnv] [% s] function failure. ERR: % s", pLibName, dlerror ());
return -1;
}

PUnInit=(Func_InitEnv) dlsym (pLibHandle, "UnInitEnv");
If (pUnInit==NULL)
{
Sprintf (pMsg, "open the library [UnInitEnv] [% s] function failure. ERR: % s", pLibName, dlerror ());
return -1;
}

PCallFunc=(Func_CallFunc) dlsym (pLibHandle, "CallFunc");
If (pCallFunc==NULL)
{
Sprintf (pMsg, "open the library [CallFunc] [% s] function failure. ERR: % s", pLibName, dlerror ());
return -1;
}

//performs initialization

Return pInit (pMsg);
}

Int CallLibFunc (char * pSrcName, char * pSrcPath, char * pOutName, int * iRecordCount, char * pMsg)
{
Return pCallFunc (pSrcName, pSrcPath pOutName, iRecordCount, pMsg);
}

Int UnInitFtpLib (char * pMsg)
{
Return pUnInit (pMsg);
}

//char * libname, char * pSrcName, char * pSrcPath
//a.out libgetrecordnum. So GetRecordNum. CPP./

Int main (int arg c, char * * argv)
{
Char MSG [256].
Char outname [256].
int count=0;

If (arg c & lt; 3)
{
nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull