Re: [Linux-usb-users] PROBLEM: Kernel 2.6.x freeze

From: Alan Stern
Date: Tue Oct 03 2006 - 16:35:16 EST


On Tue, 3 Oct 2006, Paolo Ornati wrote:

> The code dumped from memory matches the original one up to, and not
> including, the failing istruction. From that point the code is
> different.
>
>
> The failure is only a natural consequence of:
>
> add %ah,(%eax)
>
> with "eax" pointing to 000f9edf, that belongs to the BIOS reserved
> memory region...
>
>
> The real problem is that the code starting from "0xcd0d18140" has been
> overwritten by something :(
>
>
> Another thing: both panics happened in interrupt context and both times
> uhci driver is involved.

I wonder whether the code in question was supposed to be running at all.
Arkadiusz, what sort of USB devices do you have attached to the computer?

What does /proc/bus/usb/devices say (you may need to do "mount -t usbfs
none /proc/bus/usb" before you can see the file)?

> And this is the data that has overwritten the code:
>
> 00 20 7b 0f 00 00 00 00 69 7f e0 ff 00 00 00 00 00 20 7b 0f 14
> ^^^^^^^^^^^ ^^^^^^^^^^^
>
>
> Maybe someone have an idea of where does this data come from?

In principle that data could be coming from anywhere. It doesn't have to
be related at all to uhci-hcd.

If you move the USB devices over to another Linux computer, does the new
computer then have the same problem?

Alan Stern

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