[src/trunk]: src/lib/libpthread Only copy the ucontext_t in pthread_setcontex...

[matt <matt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f9edda4122d6
branches:  trunk
changeset: 781523:f9edda4122d6
user:      matt <matt%NetBSD.org@localhost>
date:      Wed Sep 12 14:55:48 2012 +0000

description:
Only copy the ucontext_t in pthread_setcontext if _UC_TLSBASE is set.
Conditionalize the test on _UC_TLSBASE being defined.

diffstat:

 lib/libpthread/pthread_specific.c |  19 +++++++++++++------
 1 files changed, 13 insertions(+), 6 deletions(-)

diffs (39 lines):

diff -r 52f83eedf60a -r f9edda4122d6 lib/libpthread/pthread_specific.c
--- a/lib/libpthread/pthread_specific.c Wed Sep 12 14:13:43 2012 +0000
+++ b/lib/libpthread/pthread_specific.c Wed Sep 12 14:55:48 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pthread_specific.c,v 1.22 2012/09/12 02:00:53 manu Exp $       */
+/*     $NetBSD: pthread_specific.c,v 1.23 2012/09/12 14:55:48 matt Exp $       */
 
 /*-
  * Copyright (c) 2001, 2007 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: pthread_specific.c,v 1.22 2012/09/12 02:00:53 manu Exp $");
+__RCSID("$NetBSD: pthread_specific.c,v 1.23 2012/09/12 14:55:48 matt Exp $");
 
 /* Functions and structures dealing with thread-specific data */
 
@@ -89,9 +89,16 @@
 int
 pthread_setcontext(const ucontext_t *ucp)
 {
+#ifdef _UC_TLSBASE
        ucontext_t uc;
-
-       (void)memcpy(&uc, ucp, sizeof(uc));
-       uc.uc_flags &= ~_UC_TLSBASE;
-       return _sys_setcontext(&uc);
+       /*
+        * Only copy and clear _UC_TLSBASE if it is set.
+        */
+       if (ucp->uc_flags & _UC_TLSBASE) {
+               uc = *ucp;
+               uc.uc_flags &= ~_UC_TLSBASE;
+               ucp = &uc;
+       }
+#endif /* _UC_TLSBASE */
+       return _sys_setcontext(ucp);
 }