Move __cleanup into mprotect'ed page to prevent unintentional modifications

similar to the atexit handlers. Idea and help deraadt@, ok deraadt@

2 files changed, 20 insertions, 10 deletions

diff --git a/src/regress/lib/libc/atexit/Makefile b/src/regress/lib/libc/atexit/Makefile
index 89625e2a7b..55c3f3981e 100644
--- a/src/regress/lib/libc/atexit/Makefile
+++ b/src/regress/lib/libc/atexit/Makefile
@@ -1,4 +1,4 @@
-#       $OpenBSD: Makefile,v 1.2 2002/09/02 19:59:51 avsm Exp $
+#       $OpenBSD: Makefile,v 1.3 2002/09/14 22:03:14 dhartmei Exp $
 
 NOMAN=
 PROG=atexit_test
@@ -6,7 +6,9 @@ PROG=atexit_test
 run-regress-atexit_test: ${PROG}
         ./${PROG} -valid 2>${.OBJDIR}/valid.out
         cmp -s ${.OBJDIR}/valid.out ${.CURDIR}/valid.ok
-        ./${PROG} -invalid 2>${.OBJDIR}/invalid.out
+        ./${PROG} -invalid-atexit 2>${.OBJDIR}/invalid.out
+        cmp -s ${.OBJDIR}/invalid.out ${.CURDIR}/invalid.ok
+        ./${PROG} -invalid-cleanup 2>${.OBJDIR}/invalid.out
         cmp -s ${.OBJDIR}/invalid.out ${.CURDIR}/invalid.ok
 
 .include <bsd.regress.mk>
diff --git a/src/regress/lib/libc/atexit/atexit_test.c b/src/regress/lib/libc/atexit/atexit_test.c
index fcfe95cb02..fea95832ab 100644
--- a/src/regress/lib/libc/atexit/atexit_test.c
+++ b/src/regress/lib/libc/atexit/atexit_test.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: atexit_test.c,v 1.1 2002/07/29 19:51:41 dhartmei Exp $ */
+/*      $OpenBSD: atexit_test.c,v 1.2 2002/09/14 22:03:14 dhartmei Exp $ */
 
 /*
  * Copyright (c) 2002 Daniel Hartmeier
@@ -39,9 +39,6 @@
 #include <signal.h>
 #include "/usr/src/lib/libc/stdlib/atexit.h"
 
-extern struct atexit *__atexit;
-extern void (*__cleanup)();
-
 void    handle_first();
 void    handle_middle();
 void    handle_last();
@@ -57,8 +54,10 @@ main(int argc, char *argv[])
         int i;
 
         if (argc != 2 || (strcmp(argv[1], "-valid") &&
-            strcmp(argv[1], "-invalid"))) {
-                fprintf(stderr, "%s -valid/-invalid\n", argv[0]);
+            strcmp(argv[1], "-invalid-atexit") &&
+            strcmp(argv[1], "-invalid-cleanup"))) {
+                fprintf(stderr, "%s -valid/-invalid-atexit/-invalid-cleanup\n",
+                    argv[0]);
                 return (1);
         }
         fprintf(stderr, "main()\n");
@@ -77,11 +76,20 @@ main(int argc, char *argv[])
                 return (1);
         }
         /* this is supposed to segfault */
-        if (strcmp(argv[1], "-valid")) {
+        if (!strcmp(argv[1], "-invalid-atexit")) {
                 signal(SIGSEGV, handle_signal);
                 __atexit->fns[0] = handle_invalid;
+        } else if (!strcmp(argv[1], "-invalid-cleanup")) {
+                struct atexit *p = __atexit;
+
+                signal(SIGSEGV, handle_signal);
+                while (p != NULL && p->next != NULL)
+                        p = p->next;
+                if (p == NULL)
+                        fprintf(stderr, "p == NULL, no page found\n");
+                p->fns[0] = handle_invalid;
         }
-        __cleanup = handle_cleanup;
+        __atexit_register_cleanup(handle_cleanup);
         counter = 0;
         fprintf(stderr, "main() returns\n");
         return (0);