[Bug c/39130] New: [libdl] (Now and then) dynamic loading/un-loading of shared libraries not happening

[ykalidas at gmail dot com]

Freshly compiled code calls and excutes a function in a non-existent library.

Details below :

#gcc -v
gcc version 4.3.2 (Ubuntu 4.3.2-1ubuntu11)

How to reproduce the problem :

#Directories required "./shared"

#source code head'ed below

==> 1.c <==
#include 

void fun() {
printf("1\n");
}


==> 2.c <==
#include 

void fun() {
printf("2\n");
}

#include 
#include 

int main(int argc, char **argv) 
{
   void *lib_handle;
   void (*fn)();
   char *error;

while(1) {

   lib_handle = dlopen("./shared/libkali.so", RTLD_LAZY);
   if (!lib_handle) 
   {
  fprintf(stderr, "%s\n", dlerror());
  exit(1);
   }

   fn = dlsym(lib_handle, "fun");
   if ((error = dlerror()) != NULL)  
   {
  fprintf(stderr, "%s\n", error);
  exit(1);
   }

   (*fn)();

   dlclose(lib_handle);

}//while

   return 0;
}


#gcc -Wall -fPIC -c 1.c
#gcc -Wall -fPIC -c 2.c
#gcc -shared -Wl,-soname,lib1.so.1 -o lib1.so.1.0 1.o
#gcc -shared -Wl,-soname,lib2.so.1 -o lib2.so.1.0 2.o
#gcc -rdynamic -o progdl progdl.c -ldl

#Following shared library will be changed to test plug-in (lib1.so.1.0 or
lib2.so.1.0)

#ln -sf `pwd`/lib1.so.1.0 shared/libkali.so; ln -sf `pwd`/lib1.so.1.0
shared/libkali.so.1
#ln -sf `pwd`/lib2.so.1.0 shared/libkali.so; ln -sf `pwd`/lib2.so.1.0
shared/libkali.so.1


-- 
   Summary: [libdl] (Now and then) dynamic loading/un-loading of
shared libraries not happening
   Product: gcc
   Version: 4.3.2
Status: UNCONFIRMED
  Severity: major
  Priority: P3
 Component: c
    AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: ykalidas at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39130

[Bug c/39130] [libdl] (Now and then) dynamic loading/un-loading of shared libraries not happening

[ykalidas at gmail dot com]

--- Comment #1 from ykalidas at gmail dot com  2009-02-08 06:29 ---
Created an attachment (id=17271)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17271&action=view)
Plug-in function

void fun(); is a function that would be made available through a shared object.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39130

[Bug c/39130] [libdl] (Now and then) dynamic loading/un-loading of shared libraries not happening

[ykalidas at gmail dot com]

--- Comment #2 from ykalidas at gmail dot com  2009-02-08 06:29 ---
Created an attachment (id=17272)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17272&action=view)
Plug-in function

void fun(); would be made available through a shared object.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39130

[Bug c/39130] [libdl] (Now and then) dynamic loading/un-loading of shared libraries not happening

[ykalidas at gmail dot com]

--- Comment #3 from ykalidas at gmail dot com  2009-02-08 06:30 ---
Created an attachment (id=17273)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17273&action=view)
program invoking shared lib's function.

Program that loads the function in the shared library.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39130

[Bug c/39130] [libdl] (Now and then) dynamic loading/un-loading of shared libraries not happening

[ykalidas at gmail dot com]

--- Comment #4 from ykalidas at gmail dot com  2009-02-08 06:47 ---
PROBLEM -

when i change the libkali.so.1 and libkali.so in ./shared/ to point to either
of the libraries lib1.so.1.0 or lib2.so.1.0,

the program run only one of the codes to which it pointed earlier.

Example
#ln -sf `pwd`/lib1.so.1.0 shared/libkali.so; ln -sf `pwd`/lib1.so.1.0
shared/libkali.so.1
#./progdl would STILL INVOKE fun() in lib2.so.1.0 EVEN IF THE FILE IS REMOVED.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39130