<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;"><DIV>Hi Alexander,</DIV>
<DIV> </DIV>
<DIV>I checked out the fix, yes, it indeed fixed the ASMBitTest() crash bug.</DIV>
<DIV> </DIV>
<DIV>However, there is another weird thing happening. With this newest fix, my vm starts to behaves differently, the audio drivers are no longer auto installed inside the xp vm. When I plugged back VBoxDDU.dll before the fix, then audio drivers are auto installed for the vm. I use exactly the same .vhd base image. The only diff is your fix on VBoxDDU.dll. Is there any chance something went wrong?</DIV>
<DIV> </DIV>
<DIV>Thanks,</DIV>
<DIV> </DIV>
<DIV>- Huihong</DIV>
<DIV><BR><BR>--- On <B>Mon, 6/22/09, Alexander Eichner <I><Alexander.Eichner@Sun.COM></I></B> wrote:<BR></DIV>
<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: rgb(16,16,255) 2px solid"><BR>From: Alexander Eichner <Alexander.Eichner@Sun.COM><BR>Subject: Re: [vbox-dev] vhd format not stable?<BR>To: "Huihong Luo" <huisinro@yahoo.com><BR>Cc: vbox-dev@virtualbox.org, "Frank Mehnert" <Frank.Mehnert@Sun.COM><BR>Date: Monday, June 22, 2009, 12:25 PM<BR><BR>
<DIV class=plainMail>Hi Huihong,<BR><BR>the crash should be really fixed now. I also fixed the crash with<BR>snapshots you reported in another mail. They will appear soon in the<BR>public svn. Thanks again for your help!<BR><BR>Kind regards,<BR>Alexander Eichner<BR><BR>Am Montag, den 22.06.2009, 08:59 -0700 schrieb Huihong Luo:<BR>> Frank,<BR>> <BR>> Right, that would be the correct fix.<BR>> <BR>> I was wondering if there are other places that have similar issues.<BR>> This problem would be very rare in happening, as the memory address<BR>> would be still ok to be read even if it's less then DWORD in len.<BR>> <BR>> Inside kernel mode, this becomes a severe problem, throwing invalid<BR>> memory access crashes.<BR>> <BR>> - Huihong<BR>> <BR>> --- On Mon, 6/22/09, Frank Mehnert <<A href="http://us.mc343.mail.yahoo.com/mc/compose?to=Frank.Mehnert@Sun.COM"
ymailto="mailto:Frank.Mehnert@Sun.COM">Frank.Mehnert@Sun.COM</A>> wrote:<BR>> <BR>> <BR>> From: Frank Mehnert <<A href="http://us.mc343.mail.yahoo.com/mc/compose?to=Frank.Mehnert@Sun.COM" ymailto="mailto:Frank.Mehnert@Sun.COM">Frank.Mehnert@Sun.COM</A>><BR>> Subject: Re: [vbox-dev] vhd format not stable?<BR>> To: <A href="http://us.mc343.mail.yahoo.com/mc/compose?to=vbox-dev@virtualbox.org" ymailto="mailto:vbox-dev@virtualbox.org">vbox-dev@virtualbox.org</A><BR>> Date: Monday, June 22, 2009, 3:30 AM<BR>> <BR>> Huihong,<BR>> <BR>> On Friday 19 June 2009, Huihong Luo
wrote:<BR>> > I tested it again, but it still crashed.<BR>> > <BR>> > I think I now found the cause, it's quite delicate, but you<BR>> should be able<BR>> > to fix it right away. <BR>> > a8bd6ffd ff ff<BR>> ff ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??<BR>> > <BR>> > The above is the bitmap when crashed. You can see the<BR>> beginnig there are<BR>> > only 3 bytes are valid, the 4th byte will cause crash. <BR>> > But when you
call<BR>> > ASMBitTest(const volatile void *pvBitmap, int32_t iBit)<BR>> > <BR>> > it will the 1st 4-byte int, thus caused the crash.<BR>> <BR>> Good catch!<BR>> <BR>> > The easiest fix is to allocate 8 byte length more for the<BR>> bitmap, and zero<BR>> > fill them, that will definitely solve the issue. You can<BR>> also change<BR>> > ASMBitTest method impl. <BR>> <BR>> I think a better fix would be to
ensure that ASMBitTest isn't<BR>> called<BR>> with non-word-aligned memory addresses.<BR>> <BR>> Kind regards,<BR>> <BR>> Frank<BR>> -- <BR>> Dr.-Ing. Frank Mehnert Sun Microsystems, Inc.<BR>> www.sun.com<BR>> <BR>> <BR>> -----Inline Attachment Follows-----<BR>> <BR>> _______________________________________________<BR>> vbox-dev mailing
list<BR>> <A href="http://us.mc343.mail.yahoo.com/mc/compose?to=vbox-dev@virtualbox.org" ymailto="mailto:vbox-dev@virtualbox.org">vbox-dev@virtualbox.org</A><BR>> <A href="http://vbox.innotek.de/mailman/listinfo/vbox-dev" target=_blank>http://vbox.innotek.de/mailman/listinfo/vbox-dev</A><BR>> <BR>> _______________________________________________<BR>> vbox-dev mailing list<BR>> <A href="http://us.mc343.mail.yahoo.com/mc/compose?to=vbox-dev@virtualbox.org" ymailto="mailto:vbox-dev@virtualbox.org">vbox-dev@virtualbox.org</A><BR>> <A href="http://vbox.innotek.de/mailman/listinfo/vbox-dev" target=_blank>http://vbox.innotek.de/mailman/listinfo/vbox-dev</A><BR><BR></DIV></BLOCKQUOTE></td></tr></table>