Bug 3738

Do you have example code that breaks between glibc 2.0 and glibc 2.1?

Reply from the e-mail message:

Here is the sem_t structure definition from the include files of Red
Hat 5.1.
It's defined in /usr/include/semaphorebits.h.

        typedef struct {
          long int sem_status;
          int sem_spinlock;
        } sem_t;

Here is the Red Hat 6.0 version, from file /usr/include/semaphore.h.

        typedef struct
        {
          struct
          {
            long int status;
            int spinlock;
          } __sem_lock;
          int __sem_value;
          _pthread_descr __sem_waiting;
        } sem_t;

You'll notice that the second structure is larger than the first.
When a Red
Hat 5.1 program runs on Red Hat 6.0 and calls sem_init, the function
modifies
memory off the end of the space the program allocated for the sem_t
object.

Since the size of the data structure changed, the shared object should
have
been versioned, so that old programs got the older version of
sem_init.

Is this enough explanation?  All of the real applications that break
in my
environment are GUI tools.  If needed I could write a test program
demonstrating the problem.

                                bob

Fixed in glibc-2.1.2-1