<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">sorry, just realized that you are debugging host drivers. Yes, you will have to use 2 physical pcs.<BR><BR>--- On <B>Tue, 3/13/12, Huihong Luo <I><huisinro@yahoo.com></I></B> wrote:<BR>
<BLOCKQUOTE style="BORDER-LEFT: rgb(16,16,255) 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px"><BR>From: Huihong Luo <huisinro@yahoo.com><BR>Subject: Re: [vbox-dev] IoGetDeviceObjectPointer hangs vboxusbmon<BR>To: "Ribhi Kamal" <rbhkamal@gmail.com><BR>Cc: "vbox-dev" <vbox-dev@virtualbox.org><BR>Date: Tuesday, March 13, 2012, 2:41 PM<BR><BR>
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<DIV>do you mean you need 2 pcs to debug?</DIV>
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<DIV>no, you can use same pc. Just run vm on the same pc, and configure COM1 as pipe. Then start windbg this way:</DIV>
<DIV><BR>C:\WinDDK\7600.16385.0\Debuggers\windbg.exe -b -k com:pipe,port=\\.\pipe\com_1,resets=0</DIV>
<DIV><BR>--- On <B>Tue, 3/13/12, Ribhi Kamal <I><rbhkamal@gmail.com></I></B> wrote:<BR></DIV>
<BLOCKQUOTE style="BORDER-LEFT: rgb(16,16,255) 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px"><BR>From: Ribhi Kamal <rbhkamal@gmail.com><BR>Subject: Re: [vbox-dev] IoGetDeviceObjectPointer hangs vboxusbmon<BR>To: "Huihong Luo" <huisinro@yahoo.com><BR>Cc: "vbox-dev" <vbox-dev@virtualbox.org><BR>Date: Tuesday, March 13, 2012, 2:38 PM<BR><BR>
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<DIV>Thanks, that helped me get started. Unfortunately I can't set break points when debugging locally so it is going to take me a while answer your questions. The only dev machine that I use is 100 miles away from me, so it will be very hard to attach a console/USB cable for debugging. I need to go hunt for a laptop somewhere, put windows on it then run a windbg in server mode. That way I can connect via tcp and set breakpoints.</DIV>
<DIV><BR>Thanks again</DIV>
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<DIV class=yiv1610474135gmail_quote>On Tue, Mar 13, 2012 at 3:30 PM, Huihong Luo <SPAN dir=ltr><<A href="http://us.mc1603.mail.yahoo.com/mc/compose?to=huisinro@yahoo.com" rel=nofollow target=_blank>huisinro@yahoo.com</A>></SPAN> wrote:<BR>
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<TD vAlign=top>inside windbg, click Disassembly window, it will display assembly code, then you can set a breakpoint by click the left side of the code line.
<DIV class=yiv1610474135im><BR><BR>--- On <B>Tue, 3/13/12, Ribhi Kamal <I><<A href="http://us.mc1603.mail.yahoo.com/mc/compose?to=rbhkamal@gmail.com" rel=nofollow target=_blank>rbhkamal@gmail.com</A>></I></B> wrote:<BR></DIV>
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<DIV class=yiv1610474135im><BR>From: Ribhi Kamal <<A href="http://us.mc1603.mail.yahoo.com/mc/compose?to=rbhkamal@gmail.com" rel=nofollow target=_blank>rbhkamal@gmail.com</A>><BR>Subject: Re: [vbox-dev] IoGetDeviceObjectPointer hangs vboxusbmon<BR></DIV>To: "Huihong Luo" <<A href="http://us.mc1603.mail.yahoo.com/mc/compose?to=huisinro@yahoo.com" rel=nofollow target=_blank>huisinro@yahoo.com</A>><BR>Cc: "vbox-dev" <<A href="http://us.mc1603.mail.yahoo.com/mc/compose?to=vbox-dev@virtualbox.org" rel=nofollow target=_blank>vbox-dev@virtualbox.org</A>><BR>Date: Tuesday, March 13, 2012, 12:29 PM
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<DIV>The \Device\USBPDO-11 physical device is a sprint hub driver BcmBusCtr.SYS. But I've seen it happen with other devices as well (Apple trackpad)
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<DIV>Will update you once I get windbg working.</DIV>
<DIV><BR>Thanks</DIV>
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<DIV>On Tue, Mar 13, 2012 at 3:08 PM, Ribhi Kamal <SPAN dir=ltr><<A href="http://us.mc1603.mail.yahoo.com/mc/compose?to=rbhkamal@gmail.com" rel=nofollow target=_blank>rbhkamal@gmail.com</A>></SPAN> wrote:<BR>
<BLOCKQUOTE style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex">The hubwalker loops through PDO devices 0-15 and it hangs at number 11. So the device name (hub name) should be "\Device\USBPDO-11". Is that what you wanted?<BR><BR>I'm still trying to figure out how to step through assembly code in windbg. I just started windows in debug mode and connected windbg.
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<DIV>In the mean time, I found the link below which suggests queuing a work item to call IoGetDeviceObjectPointer using ioallocateworkitem routine, should I give that a try?</DIV>
<DIV><A href="http://www.osronline.com/article.cfm?id=24" rel=nofollow target=_blank>http://www.osronline.com/article.cfm?id=24</A><BR></DIV>
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<DIV>Here is a little snippet:</DIV>
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<P style="MARGIN: 0in 0in 0pt; FONT-FAMILY: Arial, Helvetica, sans-serif; COLOR: rgb(51,51,51); FONT-SIZE: 13px" align=center><B>Figure 5 – The <U>wrong</U> way to write a PnP Notification Callback</B></DIV></DIV></BLOCKQUOTE></DIV>
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<P style="TEXT-ALIGN: justify; MARGIN: 0in 0in 0pt; FONT-FAMILY: Arial, Helvetica, sans-serif; COLOR: rgb(51,51,51); FONT-SIZE: 13px">And, while you’d be partially right, you <I>do</I> get a pointer to a device object using its name by calling <B>IoGetDeviceObject Pointer</B>, you’d also get bitten by one of the conditions of PnP Notification routines. As it very clearly states in the documentation:
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<P style="TEXT-ALIGN: justify; MARGIN: 0in 12.95pt 0pt 8.65pt; FONT-FAMILY: Arial, Helvetica, sans-serif; COLOR: rgb(51,51,51); FONT-SIZE: 13px"><I>A callback routine must not open the device directly. If the provider of the interface causes blocking PnP events, the notification callback routine can cause a deadlock if it tries to open the device in the callback thread.</I>
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<P style="TEXT-ALIGN: justify; MARGIN: 0in 12.95pt 0pt 8.65pt; FONT-FAMILY: Arial, Helvetica, sans-serif; COLOR: rgb(51,51,51); FONT-SIZE: 13px"><I> </I>
<P style="TEXT-ALIGN: justify; MARGIN: 0in 0in 0pt; FONT-FAMILY: Arial, Helvetica, sans-serif; COLOR: rgb(51,51,51); FONT-SIZE: 13px">When you call <B>IoGetDeviceObjectPointer, </B>you’re actually issuing an open (IRP_MJ_CREATE) for the specified device. That’s why you get back a File Object pointer, in addition to the Device Object pointer that you wanted. So, the proper thing to do is queue a work item that does the call to <B>IoGetDeviceObjectPointer</B>, as shown in <I>Figure 6</I>.
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<DIV>On Tue, Mar 13, 2012 at 2:10 PM, Huihong Luo <SPAN dir=ltr><<A href="http://us.mc1603.mail.yahoo.com/mc/compose?to=huisinro@yahoo.com" rel=nofollow target=_blank>huisinro@yahoo.com</A>></SPAN> wrote:<BR>
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<DIV>This api simply returns a device object from a name, and usually does not block. What is the <BR>device name? you can examine <FONT size=+0>ObjectName unicode string.</FONT></DIV>
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<DIV>IoGetDeviceObjectPointer() does the following thing:</DIV>
<DIV> <FONT size=+0></FONT></DIV>
<DIV>ZwOpenFile(ObjectName) to get a handle</DIV><FONT size=+0>
<DIV>ObReferenceObjectByHandle(handle) to get the FileObject</DIV><FONT size=+0>
<DIV>IoGetRelatedDeviceObject(FileObject) to get the device object</DIV>
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<DIV>you can further step into the assembly code to nail down which function call causes the lock.</DIV>
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<DIV>you can also list all locks using these commands in windbg:</DIV>
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<DIV>!locks</DIV>
<DIV>!deadlock</DIV></FONT></FONT>
<DIV> <BR>--- On <B>Tue, 3/13/12, Ribhi Kamal <I><<A href="http://us.mc1603.mail.yahoo.com/mc/compose?to=rbhkamal@gmail.com" rel=nofollow target=_blank>rbhkamal@gmail.com</A>></I></B> wrote:<BR></DIV>
<BLOCKQUOTE style="BORDER-LEFT: rgb(16,16,255) 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px"><BR>From: Ribhi Kamal <<A href="http://us.mc1603.mail.yahoo.com/mc/compose?to=rbhkamal@gmail.com" rel=nofollow target=_blank>rbhkamal@gmail.com</A>><BR>Subject: Re: [vbox-dev] IoGetDeviceObjectPointer hangs vboxusbmon<BR>To: "vbox-dev" <<A href="http://us.mc1603.mail.yahoo.com/mc/compose?to=vbox-dev@virtualbox.org" rel=nofollow target=_blank>vbox-dev@virtualbox.org</A>><BR>Date: Tuesday, March 13, 2012, 10:49 AM
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<DIV>Sorry, actually the IRQL == PASSIVE_LEVEL is okay. So just ignore that bit.<BR><BR>
<DIV>On Tue, Mar 13, 2012 at 1:27 PM, Ribhi Kamal <SPAN dir=ltr><<A href="http://us.mc1603.mail.yahoo.com/mc/compose?to=rbhkamal@gmail.com" rel=nofollow target=_blank>rbhkamal@gmail.com</A>></SPAN> wrote:<BR>
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<DIV>I've been troubleshooting an issue that prevents vbox from capturing USB devices when other specific USB devices are plugged in (i.e. Sprint USB crap). I finally managed to track down the problem to IoGetDeviceObjectPointer in VboxUsbMonHubDevWalk. IoGetDeviceObjectPointer was getting called, however, it never returned.
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<DIV>I'm not an expert in windows driver development so I'd like to run things by you before I start fixing it.</DIV>
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<DIV>Firstly, I'm not really sure why it hangs (deadlocks?) there for some devices and not others. However, I believe that it may be due to the fact that some driver interfaces cause blocking PnP events. Due to that, vboxusbmon runs into a deadlock when executing IoGetDeviceObjectPointer because it is being used directly from a callback function, VBoxUsbMonDeviceControl, and IRQL==PASSIVE_LEVEL.<BR>
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<DIV>What led me to that conclusion is that right after IoGetDeviceObjectPointer is executed, I start seeing lots of PnP events.</DIV>
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<DIV>USBMon::vboxUsbMonHubDevWalk: </DIV>
<DIV>IoGetDeviceObjectPointer - Starting </DIV>
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<DIV>USBMon::VBoxUsbMonPnPHook: </DIV>
<DIV>VBoxUsbMonPnPHook In </DIV>
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<DIV>USBMon::VBoxUsbMonPnPHook: </DIV>
<DIV>==>PnP: Mn(IRP_MN_QUERY_DEVICE_RELATIONS), PDO(0x8833d028), IRP(0x882a71a8), Status(0xc00000bb) </DIV>
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<DIV>See attached for complete debug view.</DIV>
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<DIV>Are my assumptions correct? If so how would you go about fixing the problem.<BR></DIV></DIV>
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<DIV>Thanks!</DIV></DIV></DIV></DIV>
<DIV><BR></DIV>-- <BR>-- Ribhi<BR></DIV></DIV></BLOCKQUOTE></DIV><BR><BR clear=all>
<DIV><BR></DIV>-- <BR>-- Ribhi<BR></DIV><BR></DIV></DIV>-----Inline Attachment Follows-----<BR><BR>
<DIV>_______________________________________________<BR>vbox-dev mailing list<BR><A href="http://us.mc1603.mail.yahoo.com/mc/compose?to=vbox-dev@virtualbox.org" rel=nofollow target=_blank>vbox-dev@virtualbox.org</A><BR><A href="https://www.virtualbox.org/mailman/listinfo/vbox-dev" rel=nofollow target=_blank>https://www.virtualbox.org/mailman/listinfo/vbox-dev</A><BR></DIV></BLOCKQUOTE></TD></TR></TBODY></TABLE></BLOCKQUOTE></DIV><BR><BR clear=all>
<DIV><BR></DIV></DIV></DIV><SPAN><FONT color=#888888>-- <BR>-- Ribhi<BR></FONT></SPAN></DIV>
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<DIV><BR></DIV>-- <BR>-- Ribhi<BR></FONT></SPAN></TD></TR></TBODY></TABLE></BLOCKQUOTE><BR><BR clear=all>
<DIV><BR></DIV>-- <BR>-- Ribhi<BR></DIV></DIV></DIV></BLOCKQUOTE>
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