Module Name: src
Committed By: jdolecek
Date: Wed Jul 28 21:38:50 UTC 2021
Modified Files:
src/sys/arch/xen/xen: xbdback_xenbus.c
Log Message:
fix intentional, but eventually faulty off-by-one for the maximum number
of segments for I/O - this was supposed to allow MAXPHYS-size I/O even
with page offset, but actually ended up letting through I/O up to
MAXPHYS+PAGE_SIZE
the KASSERT(bcount < MAXPHYS) is kept as-is, since at that place the number
of segments should already be validated, so it's kernel bug if the size
is still too big there
fixes PR port-xen/56328 by Greg Oster
To generate a diff of this commit:
cvs rdiff -u -r1.97 -r1.98 src/sys/arch/xen/xen/xbdback_xenbus.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/xen/xen/xbdback_xenbus.c
diff -u src/sys/arch/xen/xen/xbdback_xenbus.c:1.97 src/sys/arch/xen/xen/xbdback_xenbus.c:1.98
--- src/sys/arch/xen/xen/xbdback_xenbus.c:1.97 Sun Feb 21 20:02:25 2021
+++ src/sys/arch/xen/xen/xbdback_xenbus.c Wed Jul 28 21:38:50 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: xbdback_xenbus.c,v 1.97 2021/02/21 20:02:25 jdolecek Exp $ */
+/* $NetBSD: xbdback_xenbus.c,v 1.98 2021/07/28 21:38:50 jdolecek Exp $ */
/*
* Copyright (c) 2006 Manuel Bouyer.
@@ -26,7 +26,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xbdback_xenbus.c,v 1.97 2021/02/21 20:02:25 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xbdback_xenbus.c,v 1.98 2021/07/28 21:38:50 jdolecek Exp $");
#include <sys/buf.h>
#include <sys/condvar.h>
@@ -71,8 +71,7 @@ __KERNEL_RCSID(0, "$NetBSD: xbdback_xenb
#define VBD_BSIZE 512
#define VBD_MAXSECT ((PAGE_SIZE / VBD_BSIZE) - 1)
-/* Need to alloc one extra page to account for possible mapping offset */
-#define VBD_VA_SIZE (MAXPHYS + PAGE_SIZE)
+#define VBD_VA_SIZE MAXPHYS
#define VBD_MAX_INDIRECT_SEGMENTS VBD_VA_SIZE >> PAGE_SHIFT
CTASSERT(XENSHM_MAX_PAGES_PER_REQUEST >= VBD_MAX_INDIRECT_SEGMENTS);
