Re: Panic `cat /proc/ioports`

[Richard B. Johnson]

On Wed, 12 Feb 2003, Randy.Dunlap wrote:

> On Wed, 12 Feb 2003 09:22:24 -0800
> Andrew Morton <[e-mail]> wrote:
> 
> | "Richard B. Johnson" <[e-mail]> wrote:
> | >
> | > On Tue, 11 Feb 2003, Andrew Morton wrote:
> | > 
> | > > "Richard B. Johnson" <[e-mail]> wrote:
> | > > >
> | > > > Linux version 2.4.18, after it runs for a few days, will panic
> | > > > if I do `cat /proc/ioports`. Has this been reported/fixed in
> | > > > later versions?
> | > > > 
> | > > > : Unable to handle kernel paging request at virtual address d48e2fa0 
> | > > 
> | > > This means that some driver which was previously loaded forgot to do a
> | > > release_region().  Later, the /proc code tries to read stuff from within the
> | > > driver which isn't there any more and oopses.
> | > > 
> | > 
> | > Yes. I just noticed that most network board drivers in version 2.4.18
> | > do not execute release_region() after they have done a request_region(),
> | > if they fail to install because of some error.
> | 
> | Fairly common error.
> | 
> | > The error in this case was
> | > the failure to allocate memory because I told the kernel I only had 4
> | > megabytes (exprimental ioremap() of the rest in another module).
> | > 
> | > Is somebody fixing these drivers (do you know).
> | 
> | There is ongoing janitorial work, and things are getting better.
> | But I'm not aware of anyone specifically auditing for missing
> | release_region()s.  And given that it is a box-killer rather than
> | just a memory leak, yes, it is worth an audit.
> 
> Dick,
> Did you ever determine which driver (or module) was causing this problem?
> 

Yes! pcnet32 to start. Practically all the network drivers end up
doing this if they fail somewhere in the initialization. I didn't
get a chance to look at others. I got called away for a "work break".

Cheers,
Dick Johnson
Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips).
Why is the government concerned about the lunatic fringe? Think about it.