Re: 2.2.17 --- extreme format string weirdness in /proc

From: Nix (nix@esperi.demon.co.uk)
Date: Sat Sep 30 2000 - 14:02:07 EST


Andries Brouwer <aeb@veritas.com> writes:

> On Sat, Sep 30, 2000 at 03:09:10PM +0100, Nix wrote:
>
> > Yesterday, I noticed that netstat had stopped working on my 2.2.17 box
> > The reason is fairly self-evident:
> >
> > : loki:/# cat /proc/net/dev
> ...
> > : lo:%lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu
> > : eth0:%lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu
>
> This could be explained by a single-bit corruption of your kernel,
> namely if the place where printk tests a format character against '%'
> is broken. Maybe the '%' is bad, or maybe the comparison instruction.

Agreed. /proc/{pid}/stat backs you up there too. %u is fine, only %lu is
mangled by something.

It's certainly an amusing failure; I'm surprised by how well everything
runs with the system in this state; netstat and top fall over, uptime
calculations go wrong, and ps and inndwatch complain. Everything else is
happy as could be.

Whatever it is it probably isn't memory error; I do lots of gcc
compilations on this machine, and don't get nonrepeatable bootstrap
comparison failures...

I'll try pulling out some of the patches and modules (lm-sensors can go
easily; reiserfs not so easily) and see what happens.

-- 
`ERGOTISM is what you get if you overuse the word "therefore". Egotism
 on the other hand is a form of "I" strain.' --- Paul Martin
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sat Sep 30 2000 - 21:00:27 EST