Always call atexit handlers as if they were registered with __cxa_atexit.

The extra argument doesn't hurt genuine atexit handlers and this fixes a
bug where we didn't provide the argument (effectively passing garbage) for
functions registered with __cxa_atexit in the main executable.

Pointed out by Dmitriy Ivanov <dimitry@google.com> and Elliott Hughes
<enh@google.com>.

ok matthew@

1 files changed, 6 insertions, 9 deletions

diff --git a/src/lib/libc/stdlib/atexit.c b/src/lib/libc/stdlib/atexit.c
index 049da3261d..9b08ebd7e6 100644
--- a/src/lib/libc/stdlib/atexit.c
+++ b/src/lib/libc/stdlib/atexit.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: atexit.c,v 1.17 2013/12/28 18:38:42 kettenis Exp $ */
+/*      $OpenBSD: atexit.c,v 1.18 2014/06/18 19:01:10 kettenis Exp $ */
 /*
  * Copyright (c) 2002 Daniel Hartmeier
  * All rights reserved.
@@ -90,7 +90,7 @@ __cxa_atexit(void (*func)(void *), void *arg, void *dso)
                 __atexit = p;
         }
         fnp = &p->fns[p->ind++];
-        fnp->fn_ptr.cxa_func = func;
+        fnp->fn_ptr = func;
         fnp->fn_arg = arg;
         fnp->fn_dso = dso;
         if (mprotect(p, pgsize, PROT_READ))
@@ -118,7 +118,7 @@ __cxa_finalize(void *dso)
 
         for (p = __atexit; p != NULL; p = p->next) {
                 for (n = p->ind; --n >= 0;) {
-                        if (p->fns[n].fn_ptr.cxa_func == NULL)
+                        if (p->fns[n].fn_ptr == NULL)
                                 continue;       /* already called */
                         if (dso != NULL && dso != p->fns[n].fn_dso)
                                 continue;       /* wrong DSO */
@@ -129,13 +129,10 @@ __cxa_finalize(void *dso)
                          */
                         fn = p->fns[n];
                         if (mprotect(p, pgsize, PROT_READ | PROT_WRITE) == 0) {
-                                p->fns[n].fn_ptr.cxa_func = NULL;
+                                p->fns[n].fn_ptr = NULL;
                                 mprotect(p, pgsize, PROT_READ);
                         }
-                        if (fn.fn_dso != NULL)
-                                (*fn.fn_ptr.cxa_func)(fn.fn_arg);
-                        else
-                                (*fn.fn_ptr.std_func)();
+                        (*fn.fn_ptr)(fn.fn_arg);
                 }
         }
 
@@ -185,7 +182,7 @@ __atexit_register_cleanup(void (*func)(void))
                 if (mprotect(p, pgsize, PROT_READ | PROT_WRITE))
                         goto unlock;
         }
-        p->fns[0].fn_ptr.std_func = func;
+        p->fns[0].fn_ptr = (void (*)(void *))func;
         p->fns[0].fn_arg = NULL;
         p->fns[0].fn_dso = NULL;
         mprotect(p, pgsize, PROT_READ);