File CVE-2016-3710-qemuu-0002-vga-add-vbe_enabled-helper.patch of Package xen.7673

References: bsc#978164 CVE-2016-3710 XSA-179

From 294a6c15a38669f80920b885287191514ab7d9ff Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kraxel@redhat.com>
Date: Tue, 26 Apr 2016 14:11:34 +0200
Subject: [PATCH 2/5] vga: add vbe_enabled() helper

Makes code a bit easier to read.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
---
 hw/display/vga.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

Index: xen-4.4.4-testing/tools/qemu-xen-dir-remote/hw/display/vga.c
===================================================================
--- xen-4.4.4-testing.orig/tools/qemu-xen-dir-remote/hw/display/vga.c
+++ xen-4.4.4-testing/tools/qemu-xen-dir-remote/hw/display/vga.c
@@ -166,6 +166,11 @@ static uint32_t expand4[256];
 static uint16_t expand2[256];
 static uint8_t expand4to8[16];
 
+static inline bool vbe_enabled(VGACommonState *s)
+{
+    return s->vbe_regs[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED;
+}
+
 static void vga_update_memory_access(VGACommonState *s)
 {
     MemoryRegion *region, *old_region = s->chain4_alias;
@@ -593,7 +598,7 @@ static void vbe_fixup_regs(VGACommonStat
     uint16_t *r = s->vbe_regs;
     uint32_t bits, linelength, maxy, offset;
 
-    if (!(r[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED)) {
+    if (!vbe_enabled(s)) {
         /* vbe is turned off -- nothing to do */
         return;
     }
@@ -1174,7 +1179,7 @@ static void vga_get_offsets(VGACommonSta
 {
     uint32_t start_addr, line_offset, line_compare;
 
-    if (s->vbe_regs[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED) {
+    if (vbe_enabled(s)) {
         line_offset = s->vbe_line_offset;
         start_addr = s->vbe_start_addr;
         line_compare = 65535;
@@ -1627,7 +1632,7 @@ static int vga_get_bpp(VGACommonState *s
 {
     int ret;
 
-    if (s->vbe_regs[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED) {
+    if (vbe_enabled(s)) {
         ret = s->vbe_regs[VBE_DISPI_INDEX_BPP];
     } else {
         ret = 0;
@@ -1639,7 +1644,7 @@ static void vga_get_resolution(VGACommon
 {
     int width, height;
 
-    if (s->vbe_regs[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED) {
+    if (vbe_enabled(s)) {
         width = s->vbe_regs[VBE_DISPI_INDEX_XRES];
         height = s->vbe_regs[VBE_DISPI_INDEX_YRES];
     } else {