From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37099) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d1UgF-0001we-Qq for qemu-devel@nongnu.org; Fri, 21 Apr 2017 05:16:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d1UgC-0001EV-EP for qemu-devel@nongnu.org; Fri, 21 Apr 2017 05:16:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34378) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d1UgC-0001Dp-7J for qemu-devel@nongnu.org; Fri, 21 Apr 2017 05:16:40 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 81B74CDF98 for ; Fri, 21 Apr 2017 09:16:38 +0000 (UTC) From: Gerd Hoffmann Date: Fri, 21 Apr 2017 11:16:26 +0200 Message-Id: <20170421091632.30900-4-kraxel@redhat.com> In-Reply-To: <20170421091632.30900-1-kraxel@redhat.com> References: <20170421091632.30900-1-kraxel@redhat.com> Subject: [Qemu-devel] [PATCH 3/9] vga: add vga_scanline_invalidated helper List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Gerd Hoffmann Add vga_scanline_invalidated helper to check whenever a scanline was invalidated. Add a sanity check to fix OOB read access for display heights larger than 2048. Only cirrus uses this, for hardware cursor rendering, so having this work properly for the first 2048 scanlines only shouldn't be a problem as the cirrus can't handle large resolutions anyway. Also changing the invalidated_y_table size would break live migration. Signed-off-by: Gerd Hoffmann --- hw/display/vga.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/hw/display/vga.c b/hw/display/vga.c index 69c3e1d674..3991b88aac 100644 --- a/hw/display/vga.c +++ b/hw/display/vga.c @@ -1434,6 +1434,14 @@ void vga_invalidate_scanlines(VGACommonState *s, int y1, int y2) } } +static bool vga_scanline_invalidated(VGACommonState *s, int y) +{ + if (y >= VGA_MAX_HEIGHT) { + return false; + } + return s->invalidated_y_table[y >> 5] & (1 << (y & 0x1f)); +} + void vga_sync_dirty_bitmap(VGACommonState *s) { memory_region_sync_dirty_bitmap(&s->vram); @@ -1638,8 +1646,8 @@ static void vga_draw_graphic(VGACommonState *s, int full_update) page1 = addr + bwidth - 1; update |= memory_region_get_dirty(&s->vram, page0, page1 - page0, DIRTY_MEMORY_VGA); - /* explicit invalidation for the hardware cursor */ - update |= (s->invalidated_y_table[y >> 5] >> (y & 0x1f)) & 1; + /* explicit invalidation for the hardware cursor (cirrus only) */ + update |= vga_scanline_invalidated(s, y); if (update) { if (y_start < 0) y_start = y; @@ -1686,7 +1694,7 @@ static void vga_draw_graphic(VGACommonState *s, int full_update) page_max - page_min, DIRTY_MEMORY_VGA); } - memset(s->invalidated_y_table, 0, ((height + 31) >> 5) * 4); + memset(s->invalidated_y_table, 0, sizeof(s->invalidated_y_table)); } static void vga_draw_blank(VGACommonState *s, int full_update) -- 2.9.3