From c6637d28b3ca72411273a6044b5ac622089d3bf3 Mon Sep 17 00:00:00 2001
From: jb <jb@FreeBSD.org>
Date: Fri, 20 Aug 1999 12:17:09 +0000
Subject: [PATCH] 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. ]
---
 lib/libc_r/uthread/uthread_fork.c | 29 +++++++++++++++++++++++------
 lib/libkse/thread/thr_fork.c      | 29 +++++++++++++++++++++++------
 lib/libpthread/thread/thr_fork.c  | 29 +++++++++++++++++++++++------
 3 files changed, 69 insertions(+), 18 deletions(-)

diff --git a/lib/libc_r/uthread/uthread_fork.c b/lib/libc_r/uthread/uthread_fork.c
index 8ef8a3c9ce8d..f2e352c210dd 100644
--- a/lib/libc_r/uthread/uthread_fork.c
+++ b/lib/libc_r/uthread/uthread_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);
diff --git a/lib/libkse/thread/thr_fork.c b/lib/libkse/thread/thr_fork.c
index 8ef8a3c9ce8d..f2e352c210dd 100644
--- a/lib/libkse/thread/thr_fork.c
+++ b/lib/libkse/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);
diff --git a/lib/libpthread/thread/thr_fork.c b/lib/libpthread/thread/thr_fork.c
index 8ef8a3c9ce8d..f2e352c210dd 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);