Re: [crash] NULL pointer dereference at IP: [<ffffffff812e9ccb>]uart_close+0x2a/0x1e4

From: Ingo Molnar
Date: Mon Oct 12 2009 - 10:24:53 EST



* Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:

> > BUG: unable to handle kernel NULL pointer dereference at 0000000000000240
> > IP: [<ffffffff812ea215>] uart_close+0x24/0x1e5
>
> Very odd indeed. Can you dump the value of
>
> state (ie tty->driver_data)
>
> and if state is non NULL
>
> state->uart_port
>
> in the crash case
>
> and if state->uart_port is NULL then there is some head scratching
> required

Mind sending a debug patch for all info you'd like to see? (The
advantage of that would be that others who hit this failure can test the
patch too. Plus it's easier for me to get precisely what you want.)

Ingo
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