diff options
| author | Philip Guenther <guenther@cvs.openbsd.org> | 2014-06-17 15:43:28 +0000 |
|---|---|---|
| committer | Philip Guenther <guenther@cvs.openbsd.org> | 2014-06-17 15:43:28 +0000 |
| commit | 740eda0f4ef9c2dbb3fe6341b32e00df804637a2 (patch) | |
| tree | 16c65b0eb0f71d90fc0ad7b0bbedd72a358dd41d | |
| parent | e2af69cba3ebd0ac988f7db6c81d31a76188babd (diff) | |
Add membars to guarantee mtx_oldipl is written after locking and
read before unlocking. Believed to fix some spl problems on MP
that have had landry and tobaisu seeing red.
suggestion to use membar API from matthew@
ok matthew@ kettenis@
| -rw-r--r-- | sys/arch/hppa/hppa/mutex.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/sys/arch/hppa/hppa/mutex.c b/sys/arch/hppa/hppa/mutex.c index 25cb4b371be..ab1df14070e 100644 --- a/sys/arch/hppa/hppa/mutex.c +++ b/sys/arch/hppa/hppa/mutex.c @@ -1,4 +1,4 @@ -/* $OpenBSD: mutex.c,v 1.12 2014/01/30 15:18:51 kettenis Exp $ */ +/* $OpenBSD: mutex.c,v 1.13 2014/06/17 15:43:27 guenther Exp $ */ /* * Copyright (c) 2004 Artur Grabowski <art@openbsd.org> @@ -28,6 +28,7 @@ #include <sys/param.h> #include <sys/mutex.h> #include <sys/systm.h> +#include <sys/atomic.h> #include <machine/intr.h> @@ -69,6 +70,7 @@ mtx_enter(struct mutex *mtx) if (mtx->mtx_wantipl != IPL_NONE) s = splraise(mtx->mtx_wantipl); if (try_lock(mtx)) { + membar_enter(); if (mtx->mtx_wantipl != IPL_NONE) mtx->mtx_oldipl = s; mtx->mtx_owner = curcpu(); @@ -90,6 +92,7 @@ mtx_enter_try(struct mutex *mtx) if (mtx->mtx_wantipl != IPL_NONE) s = splraise(mtx->mtx_wantipl); if (try_lock(mtx)) { + membar_enter(); if (mtx->mtx_wantipl != IPL_NONE) mtx->mtx_oldipl = s; mtx->mtx_owner = curcpu(); @@ -116,6 +119,7 @@ mtx_leave(struct mutex *mtx) #endif s = mtx->mtx_oldipl; mtx->mtx_owner = NULL; + membar_exit(); mtx->mtx_lock[0] = 1; mtx->mtx_lock[1] = 1; |