Panic on boot with new ACPI-CA

Giorgos Keramidas keramida at
Wed Nov 2 17:49:03 PST 2005

On 2005-11-02 17:03, Nate Lawson <nate at> wrote:
> As I mentioned to Jung-uk, the problem is likely an error in
> acpi-ca modifying memory after it has freed it.  The way to
> track this down is to enable memguard(9).  See the man page for
> info.  You need to add options DEBUG_MEMGUARD to your kernel,
> set the malloc type to watch to M_ACPICA, and rebuild your
> kernel and modules.  Memguard sets page permissions so we can
> catch the culprit who is modifying the memory.

This is exactly the messgae printed on my console at panic time
-- of memory modified after free.  I'm building a kernel with
MEMGUARD now, but it's probably going to be a bit hard to get a
kernel dump, because the panic happens before disks are available
and I don't have a serial console here.

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