Remove all the values when deleting a key

When deleting a key using `pthread_key_delete', delete all the values
associated to that key in all the threads available. Otherwise, the
key reuse in `pthread_key_create' can cause new keys to have thread
specific data of the previously used key with the same index.

Add a test for this case, which creates and deletes pairs of keys
checking that they have a NULL thread specific data after creation.

* sysdeps/hurd/pt-key-delete.c (pthread_key_delete): Remove all the
values of the key in all the threads.

* tests/Makefile (CHECK_SRC): Add test-17.c.
* tests/test-17.c: New file.

1 files changed, 19 insertions, 0 deletions

diff --git a/sysdeps/hurd/pt-key-delete.c b/sysdeps/hurd/pt-key-delete.c
index 2426bb1..9d88647 100644
--- a/sysdeps/hurd/pt-key-delete.c
+++ b/sysdeps/hurd/pt-key-delete.c
@@ -35,8 +35,27 @@ pthread_key_delete (pthread_key_t key)
     err = EINVAL;
   else
     {
+      int i;
+
       __pthread_key_destructors[key] = PTHREAD_KEY_INVALID;
       __pthread_key_invalid_count ++;
+
+      pthread_rwlock_rdlock (&__pthread_threads_lock);
+      for (i = 0; i < __pthread_num_threads; ++i)
+	{
+	  struct __pthread *t;
+
+	  t = __pthread_threads[i];
+
+	  if (t == NULL)
+	    continue;
+
+	  /* Just remove the key, no need to care whether it was
+	     already there. */
+	  if (t->thread_specifics)
+	    hurd_ihash_remove (t->thread_specifics, key);
+	}
+      pthread_rwlock_unlock (&__pthread_threads_lock);
     }
 
   __pthread_mutex_unlock (&__pthread_key_lock);