Module Name: src
Committed By: dholland
Date: Mon Jan 11 00:46:21 UTC 2016
Modified Files:
src/sys/sys: buf.h
Log Message:
Add a CTASSERT for the condition required to make a
conditionally-existing union member sort-of safe.
To generate a diff of this commit:
cvs rdiff -u -r1.121 -r1.122 src/sys/sys/buf.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/sys/buf.h
diff -u src/sys/sys/buf.h:1.121 src/sys/sys/buf.h:1.122
--- src/sys/sys/buf.h:1.121 Sat Mar 28 19:24:04 2015
+++ src/sys/sys/buf.h Mon Jan 11 00:46:21 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: buf.h,v 1.121 2015/03/28 19:24:04 maxv Exp $ */
+/* $NetBSD: buf.h,v 1.122 2016/01/11 00:46:21 dholland Exp $ */
/*-
* Copyright (c) 1999, 2000, 2007, 2008 The NetBSD Foundation, Inc.
@@ -101,13 +101,18 @@ extern kmutex_t buffer_lock;
* For buffers associated with a vnode, b_objlock points to vp->v_interlock.
* If not associated with a vnode, it points to the generic buffer_lock.
*/
+
+/* required for the conditional union member below to be ~safe */
+__CTASSERT(sizeof(struct work) <= sizeof(TAILQ_ENTRY(buf)));
+
struct buf {
union {
TAILQ_ENTRY(buf) u_actq;
rb_node_t u_rbnode;
-#if defined(_KERNEL) /* u_work is smaller than u_actq. XXX */
+#if defined(_KERNEL)
+ /* u_work is smaller than u_actq */
struct work u_work;
-#endif /* defined(_KERNEL) */
+#endif
} b_u; /* b: device driver queue */
#define b_actq b_u.u_actq
#define b_work b_u.u_work
