Subject: Re: panic: multiple frees
To: None <hpeyerl@novatel.ca>
From: Niklas Hallqvist <niklas@appli.se>
List: current-users
Date: 08/09/1995 01:12:30
>>>>> "Herb" == Herb Peyerl <hpeyerl@novatel.ca> writes:

Herb> For the last few days I've been trying to get a -current i386
Herb> machine running (Saturdays sources) and am encountering
Herb> problems.

Herb> I'm seeing "panic: multiple frees" with network traffic and it's
Herb> quite reproducible.  It happens more frequently when bombarded
Herb> with NFS traffic but also happens quite regularly when bombarded
Herb> with "tar cvf | rsh tar xvf - " type activity... The stack trace
Herb> invariable has an "m_freem()" in it and somewhere further down
Herb> the loop has epintr() or epget() in it...

Herb> The machine is a generic i386/33 with an aha1542CF and a 3c509.
Herb> The machine bombarding it has a 3c509 in it as well...

Herb> Christos? Were you seeing similar weirdnesses? Anyone?

Well, we were a group discussing it on IRC and came to the conclusion
that the new ep driver must be writing out of bounds somewhere which
manifests itself like a free problem later.  The backtrace doesn't
necessarily point to the function that is the culprit.  I browsed
through epget and it looked as the lengths given to insw et. al were
correct, but the again, I just skimmed through the code.  For these
types of things it would be nice to have some sort of kernel-purify,
any takers????

I think Berndt Ernesti filed a PR yesterday on it... He'll be trying
some older if_ep versions to see exactly where the error got
introduced.

I myself don't have a 3c509 so don't followup to me with possible
fixes.

Niklas

Niklas Hallqvist	Phone: +46-(0)31-40 75 00
Applitron Datasystem	Fax:   +46-(0)31-83 39 50
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