Re: PROBLEM: Kernel Oops on cat /proc/ioports

From: Matt (
Date: Tue Dec 11 2001 - 21:57:13 EST

On Tue, Dec 11, 2001 at 05:06:57PM -0800, Andrew Morton wrote:
> Berend De Schouwer wrote:

>> [1.] One line summary of the problem:

>> Running "cat /proc/ioports" causes a segfault and kernel oops.

>> ...
>> [7.3.] Module information (from /proc/modules):

>> cyclades 147616 16 (autoclean)

> cyclades does request_region(), but forgets to do release_region().
> This will leave the region allocated in kernel data structures, but
> its "name" field resides in module memory.

> So if you load cyclades.o, then rmmod it, then cat /proc/ioports,
> you'll touch unmapped memory and go boom.

> Some brave soul needs to teach cyclades about release_region().
> Shame the Nobel prizes are all gone this year.

speaking of living in module memory, a similar thing happens with the
via-rhine driver. after my machine has been up for a few hours the
"via-rhine" string in /proc/iomem and /proc/ioports gets over written
and prints garbage. since this has never been the cause for an oops on
my machine i never bothered reporting it. if anyone wants details i'll


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This archive was generated by hypermail 2b29 : Sat Dec 15 2001 - 21:00:22 EST