Re: Fw: Unixodbc crashing on ubuntu-8.04, under static linkage

Jon,

I thought strdup(..) will work only if the types SQLCHAR and char are identical. I admit, that my code doesn't do the perfect char->SQLCHAR conversion as well (what should it be?), but I thought the compiler will at least bark if the types happen to be different...

Mike.


> ----- Original Message -----
> From: "Jon Pounder" <[email protected]>
> To: "Development issues and topics for unixODBC" <[email protected]>
> Subject: Re: [unixODBC-dev] Fw: Unixodbc crashing on ubuntu-8.04, under static linkage
> Date: Mon, 01 Dec 2008 23:27:52 -0500
> 
> 
> Michael Smolsky wrote:
> 
> I'd start by simplifying some of your string stuff.
> 
> usually
> 
> newptr = strdup("some string");
> if !newptr ....
> 
> is about as simple as it gets, then there is no question your 
> trailing ; remains in the connect string.
> I have had trouble in past if that goes missing.
> 
> 
> 
> 
> > Hello,
> >
> > Peter Harvey asked me to cross-post the message to the dev 
> > mailing list. The original is on the support mailing list.
> >
> > I would appreciate your suggestions.
> >
> > Thank you,
> >
> > Mike.
> >
> >
> >
> >
> > ------------------------------------------------------------------------
> >
> > Subject:
> > Unixodbc crashing on ubuntu-8.04, under static linkage
> > From:
> > "Michael Smolsky" <[email protected]>
> > Date:
> > Mon, 1 Dec 2008 17:03:29 -0500
> > To:
> > [email protected]
> >
> > To:
> > [email protected]
> >
> >
> > Hello,
> >
> > First of all, thank you for supporting a very useful product.
> >
> > I'm using unix-odbc on Ubuntu 8.04, x86_64, that is in the fully 
> > updated state. I have the following unixodbc packages installed:
> >
> > unixodbc        2.2.11-16build1
> > unixodbc-dev    2.2.11-16build1
> > odbc-postgresql 1:08.01.0200-2.1
> >
> > Gcc's version is 4.2.4 (Ubuntu 4.2.4-1ubuntu3).
> >
> > I'm using postgres 8.3.5 for my database server. The server runs locally.
> >
> > I have a problem with my app, that is built around unixodbc. When 
> > the app is linked dynamically against unixodbc (besides other 
> > libs), it works fine. However, when my app is linked statically, 
> > it crashes.
> >
> > I've isolated the problem and wrote up a fairly simple app, that 
> > illustrates the issue. The contents of the file odbc_connect.c is 
> > included in this message. To compile, I use the following command 
> > lines (there is no makefile in this directory):
> >
> > To build the app statically (and observe the crash):
> >
> > rm -f ./odbc_connect; make CFLAGS="-Wall" LDFLAGS="-static" 
> > LOADLIBES="-lodbc -lltdl -ldl -lpthread" ./odbc_connect && 
> > ./odbc_connect
> >
> > To build the same app dynamically (and see no crash), use the 
> > same command line, but eliminate LDFLAGS="-static" string from it.
> >
> > When not crashing (under dynamic linkage), the app produces the 
> > following output:
> >
> > $ rm -f odbc_connect; make CFLAGS="-Wall" LOADLIBES="-lodbc 
> > -lltdl -ldl -lpthread" odbc_connect && ./odbc_connect
> > cc -Wall    odbc_connect.c -lodbc -lltdl -ldl -lpthread  -o odbc_connect
> > INFO: Allocated handle for the environment.
> > INFO: Set ODBC environment's version attribute.
> > INFO: Allocated handle for the connection.
> > INFO: Connected to the data source.
> > INFO: Disconnected from data source.
> > INFO: Freed handle for the connection.
> > INFO: Freed handle for the environment.
> > INFO: Exiting with success.
> >
> > When crashing, the app produces the following output:
> >
> > $ rm -f odbc_connect; make CFLAGS="-Wall" LDFLAGS="-static" 
> > LOADLIBES="-lodbc -lltdl -ldl -lpthread" odbc_connect && 
> > ./odbc_connect
> > cc -Wall  -static  odbc_connect.c -lodbc -lltdl -ldl -lpthread  
> > -o odbc_connect
> > /usr/lib/gcc/x86_64-linux-gnu/4.2.4/../../../../lib/libltdl.a(ltdl.o): In 
> > function `sys_dl_open':
> > (.text+0x3687): warning: Using 'dlopen' in statically linked 
> > applications requires at runtime the shared libraries from the 
> > glibc version used for linking
> > /usr/lib/gcc/x86_64-linux-gnu/4.2.4/../../../../lib/libodbc.a(_odbcinst_UserINI.o): In function 
> > `_odbcinst_UserINI':
> > (.text+0x3c): warning: Using 'getpwuid' in statically linked 
> > applications requires at runtime the shared libraries from the 
> > glibc version used for linking
> > INFO: Allocated handle for the environment.
> > INFO: Set ODBC environment's version attribute.
> > INFO: Allocated handle for the connection.
> > Segmentation fault
> >
> > Obviously, one can see, that the linker is also not quite happy, 
> > when linking statically.
> >
> > Here's the backtrace of the crash:
> >
> > (gdb) r
> > Starting program: /bla/bla/bla/odbc_connect
> > [Thread debugging using libthread_db enabled]
> > INFO: Allocated handle for the environment.
> > INFO: Set ODBC environment's version attribute.
> > INFO: Allocated handle for the connection.
> > [New Thread 0x6fa860 (LWP 15533)]
> >
> > Program received signal SIGSEGV, Segmentation fault.
> > [Switching to Thread 0x6fa860 (LWP 15533)]
> > 0x0000000000000000 in ?? ()
> > (gdb) bt
> > #0  0x0000000000000000 in ?? ()
> > #1  0x00007f8b3d7696c2 in __pthread_initialize_minimal_internal ()
> >    from /lib/libpthread.so.0
> > #2  0x00007f8b3d768e19 in _init () from /lib/libpthread.so.0
> > #3  0x000000000071a820 in ?? ()
> > #4  0x000000000049dad6 in call_init ()
> > #5  0x000000000049dc56 in _dl_init ()
> > #6  0x000000000047dbac in dl_open_worker ()
> > #7  0x000000000047bfc6 in _dl_catch_error ()
> > #8  0x000000000047d430 in _dl_open ()
> > #9  0x000000000046480c in dlopen_doit ()
> > #10 0x000000000047bfc6 in _dl_catch_error ()
> > #11 0x0000000000464c01 in _dlerror_run ()
> > #12 0x000000000046478e in __dlopen ()
> > #13 0x0000000000441c7b in sys_dl_open ()
> > #14 0x000000000043f9c5 in tryall_dlopen ()
> > #15 0x0000000000441154 in try_dlopen ()
> > #16 0x00000000004419bd in lt_dlopen ()
> > #17 0x0000000000402b45 in odbc_dlopen ()
> > #18 0x00000000004037fb in __connect_part_one ()
> > #19 0x0000000000407954 in SQLDriverConnect ()
> > #20 0x00000000004004c5 in main ()
> > (gdb)
> >
> > I believe, I had the same issue with Fedora Core 7, but I am not 
> > running this OS any more and cannot reproduce the issue.
> >
> > I would appreciate it, if you could advise me what I'm doing wrong.
> >
> > Thank you in advance,
> >
> > Mike.
> >
> > PS: Here's my app:
> >
> > -------------BEGIN odbc_connect.c-------------
> >
> > #include <stdio.h>
> > #include <stdlib.h>
> > #include <string.h>
> >
> > #include <sql.h>
> > #include <sqlext.h>
> >
> > int isOk(SQLRETURN ret) {
> >
> >   return SQL_SUCCESS == ret || SQL_SUCCESS_WITH_INFO == ret;
> >
> > } /* of isOk(..) */
> >
> > int main() {
> >
> >   char DATA_SOURCE[] = "DSN=testdb;UID=siguc;";
> >   SQLCHAR* sqlDataSource = 0;
> >
> >   SQLHENV env = SQL_NULL_HENV;
> >
> >   SQLHDBC dbc = SQL_NULL_HDBC;
> >
> >   SQLCHAR completeConnectionString[SQL_MAX_OPTION_STRING_LENGTH];
> >
> >   SQLSMALLINT completeConnectionStringLen;
> >
> >   SQLRETURN ret;
> >
> >   int i;
> >
> >   ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
> >
> >   if (!isOk(ret)) {
> >     printf("ERROR: Failed to allocate handle for the environment, 
> > exiting.\n");
> >     exit(1);
> >   } else {
> >     printf("INFO: Allocated handle for the environment.\n");
> >   }
> >
> >   ret = SQLSetEnvAttr(env, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0);
> >
> >   if (!isOk(ret)) {
> >     printf
> >       ("ERROR: Failed to set ODBC environment's version 
> > attribute, exiting.\n");
> >     exit(1);
> >   } else {
> >     printf("INFO: Set ODBC environment's version attribute.\n");
> >   }
> >
> >   ret = SQLAllocHandle(SQL_HANDLE_DBC, env, &dbc);
> >
> >   if (!isOk(ret)) {
> >     printf("ERROR: Failed to allocate handle for the connection, 
> > exiting.\n");
> >     exit(1);
> >   } else {
> >     printf("INFO: Allocated handle for the connection.\n");
> >   }
> >
> >   sqlDataSource = (SQLCHAR*) malloc(sizeof(SQLCHAR) * 
> > (strlen(DATA_SOURCE) + 1));
> >
> >   if (!sqlDataSource) {
> >     printf("Failed to allocate memory for storing SQL data source.\n");
> >     exit(1);
> >   }
> >
> >   for (i = 0; i < strlen(DATA_SOURCE); ++ i)
> >     sqlDataSource[i] = DATA_SOURCE[i];
> >
> >   sqlDataSource[strlen(DATA_SOURCE)] = 0;
> >
> >   ret = SQLDriverConnect
> >     (dbc,                       /* Connection handle. */
> >      NULL,                      /* Always null. Not used. */
> >      &sqlDataSource[0],         /* Connection string. */
> >      SQL_NTS,                   /* The connection string is 
> > null-terminated.. */
> >      completeConnectionString,  /* The complete connection string 
> > (returned). */
> >      sizeof(completeConnectionString) / sizeof(completeConnectionString[0]),
> >      &completeConnectionStringLen,   /* Returned. */
> >      SQL_DRIVER_COMPLETE             /* What the hell is this? */
> >      );
> >
> >   if (!isOk(ret)) {
> >     printf("ERROR: Failed to connect to the data source, exiting.\n");
> >     exit(1);
> >   } else {
> >     printf("INFO: Connected to the data source.\n");
> >   }
> >
> >   free(sqlDataSource);
> >   sqlDataSource = 0;
> >
> >   ret = SQLDisconnect(dbc);
> >
> >   if (!isOk(ret)) {
> >     printf("ERROR: Failed to connect from the data source, exiting.\n");
> >     exit(1);
> >   } else {
> >     printf("INFO: Disconnected from data source.\n");
> >   }
> >
> >   ret = SQLFreeHandle(SQL_HANDLE_DBC, dbc);
> >
> >   if (!isOk(ret)) {
> >     printf("ERROR: Failed to free handle for the connection, exiting.\n");
> >     exit(1);
> >   } else {
> >     printf("INFO: Freed handle for the connection.\n");
> >   }
> >
> >   dbc = SQL_NULL_HDBC;
> >
> >   ret = SQLFreeHandle(SQL_HANDLE_ENV, env);
> >
> >   if (!isOk(ret)) {
> >     printf("ERROR: Failed to free handle for the environment, exiting.\n");
> >     exit(1);
> >   } else {
> >     printf("INFO: Freed handle for the environment.\n");
> >   }
> >
> >   env = SQL_NULL_HENV;
> >
> >   printf("INFO: Exiting with success.\n");
> >
> >   return 0;
> >
> > } /* of main(..) */
> >
> > -------------END odbc_connect.c-------------
> >
> >
> > ------------------------------------------------------------------------
> >
> > _______________________________________________
> > unixODBC-dev mailing list
> > [email protected]
> > http://mailman.unixodbc.org/mailman/listinfo/unixodbc-dev
> >
> 
> _______________________________________________
> unixODBC-dev mailing list
> [email protected]
> http://mailman.unixodbc.org/mailman/listinfo/unixodbc-dev

>


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