When checking if there is a stack to free, observe the fact that it

might have been mmapped, and if so, passing the pointer to free() is
really not a good idea.

[ In the next millenium, when I've taken over the world, I'm going
  to ban 8 character tabs. You've been warned. ]

1 files changed, 23 insertions, 6 deletions

diff --git a/lib/libpthread/thread/thr_fork.c b/lib/libpthread/thread/thr_fork.c
index 8ef8a3c..f2e352c 100644
--- a/lib/libpthread/thread/thr_fork.c
+++ b/lib/libpthread/thread/thr_fork.c
@@ -29,7 +29,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: uthread_fork.c,v 1.10 1999/06/20 08:28:23 jb Exp $
+ * $Id: uthread_fork.c,v 1.11 1999/08/05 12:15:11 deischen Exp $
  */
 #include <errno.h>
 #include <string.h>
@@ -131,11 +131,28 @@ fork(void)
 
 					if (pthread_save->attr.stackaddr_attr ==
 					    NULL && pthread_save->stack != NULL)
-						/*
-						 * Free the stack of the
-						 * dead thread:
-						 */
-						free(pthread_save->stack);
+						if (pthread_save->attr.stacksize_attr
+						    == PTHREAD_STACK_DEFAULT) {
+							/*
+							 * Default-size stack.  Cache
+							 * it:
+							 */
+							struct stack	*spare_stack;
+
+							spare_stack
+							    = (pthread_save->stack
+							       + PTHREAD_STACK_DEFAULT
+							       - sizeof(struct stack));
+							SLIST_INSERT_HEAD(
+							    &_stackq,
+						  	    spare_stack,
+							    qe);
+						} else
+							/*
+							 * Free the stack of
+							 * the dead thread:
+							 */
+							free(pthread_save->stack);
 
 					if (pthread_save->specific_data != NULL)
 						free(pthread_save->specific_data);