From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1IlzK2-0005gO-4g
	for qemu-devel@nongnu.org; Sun, 28 Oct 2007 00:00:22 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1IlzJx-0005f7-9n
	for qemu-devel@nongnu.org; Sun, 28 Oct 2007 00:00:20 -0400
Received: from [199.232.76.173] (helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1IlzJw-0005f3-O1
	for qemu-devel@nongnu.org; Sun, 28 Oct 2007 00:00:16 -0400
Received: from kuber.nabble.com ([216.139.236.158])
	by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32)
	(Exim 4.60) (envelope-from <bounces@nabble.com>) id 1IlzJv-0002pb-UM
	for qemu-devel@nongnu.org; Sun, 28 Oct 2007 00:00:16 -0400
Received: from isper.nabble.com ([192.168.236.156])
	by kuber.nabble.com with esmtp (Exim 4.63)
	(envelope-from <bounces@nabble.com>) id 1IlzJt-0005Ob-G1
	for qemu-devel@nongnu.org; Sat, 27 Oct 2007 21:00:13 -0700
Message-ID: <13449885.post@talk.nabble.com>
Date: Sat, 27 Oct 2007 21:00:13 -0700 (PDT)
From: TeLeMan <geleman@gmail.com>
Subject: [Qemu-devel] [PATCH]bug fix for softmmu slow_st unaligned access
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Reply-To: qemu-devel@nongnu.org
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: qemu-devel@nongnu.org


For example, the memory address 0x10008000 is on an unwritable page.When the
instruction "add dword ptr [0x10007FFF],0x12345678" is executed,the OS will
set 0x10008000 page be a writable page and re-execute this instruction. But
softmmu has modifed the value of 0x10007FFF,so after re-executing this
instruction, the final result is wrong(double-added on 0x10007FFF).
Reversing the stored byte order can fix this bug.

softmmu.patch:

*** qemu.orig/softmmu_template.h	Sun Oct 28 11:15:52 2007
--- qemu/softmmu_template.h	Sun Oct 28 11:22:24 2007
*************** static void glue(glue(slow_st, SUFFIX), 
*** 282,288 ****
          } else if (((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1) >=
TARGET_PAGE_SIZE) {
          do_unaligned_access:
              /* XXX: not efficient, but simple */
!             for(i = 0;i < DATA_SIZE; i++) {
  #ifdef TARGET_WORDS_BIGENDIAN
                  glue(slow_stb, MMUSUFFIX)(addr + i, val >> (((DATA_SIZE -
1) * 8) - (i * 8)),
                                            mmu_idx, retaddr);
--- 282,288 ----
          } else if (((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1) >=
TARGET_PAGE_SIZE) {
          do_unaligned_access:
              /* XXX: not efficient, but simple */
!             for(i = DATA_SIZE-1;i >= 0; i--) {
  #ifdef TARGET_WORDS_BIGENDIAN
                  glue(slow_stb, MMUSUFFIX)(addr + i, val >> (((DATA_SIZE -
1) * 8) - (i * 8)),
                                            mmu_idx, retaddr);


http://www.nabble.com/file/p13449885/softmmu.patch softmmu.patch 
-- 
View this message in context: http://www.nabble.com/-PATCH-bug-fix-for-softmmu-slow_st-unaligned-access-tf4705397.html#a13449885
Sent from the QEMU - Dev mailing list archive at Nabble.com.