Re: memory corruption in recent -current?

On Tue, Jan 24, 2006 at 12:27:55AM -0800, John-Mark Gurney wrote:
> Kris Kennaway wrote this message on Sun, Jan 22, 2006 at 15:12 -0500:
> > On Sun, Jan 22, 2006 at 11:41:29AM -0800, John-Mark Gurney wrote:
> > > I've been working on a BT878 audio driver (first crack is available
> > > in p4), and with a recent -current (you can sync to my -current as
> > > it's the one in my workspace, jmg_carbon), I get memory corruption:
> > > Memory modified after free 0xc2fb1050(12) val=1c _at_ 0xc2fb1050
> > > panic: Most recently used by ioctlops
> > > or:
> > > Memory modified after free 0xc2ba2b90(12) val=1c _at_ 0xc2ba2b90
> > > panic: Most recently used by Unitno
> > > 
> > > I went back to a kerenl that is pre-Dec 21st, and I haven't had a single
> > > panic yet.  I will admit I haven't done a builtworld between the these
> > > two (the last buildworld matched with the pre-Dec 21st kernel)...  I am
> > > using kld modules for my testing, so I was building modules against an
> > > old world, but I don't know of anything that has changed that would
> > > cause problems..
> > > 
> > > Anyone else seeing this?
> > 
> > Use memguard to track down the cause.
> 
> Well, looks like memguard is broken?  I just ran it, and got this
> panic:

I run it on a number of my 'production' machines, so I don't think it
can be this broken everywhere.  Perhaps it's interacting badly with
your code :(

Kris