Re: address of int80 idt

From: Petr Vandrovec
Date: Thu Jul 15 2004 - 10:39:50 EST


On 15 Jul 04 at 18:27, bugghy wrote:
>
> The problem is that on some kernels 2.4.22 (and I think on 2.6.7, 2.2.26
> and 2.4.26 too) on vmware sidt returns a bogus address for idtr.base:
> idtr.base=0xffc6a370 (2.4.22)
>
> If I try to read from /dev/kmem from this address it doesn't work.

It is feature, not a bug... Well, it is bug, but not easily fixable.
Either check 'Disable acceleration' checkbox in VM configuration, or,
if you want portable solution (if your program has root privileges), call
iopl(3) before issuing sidt. Or issue sidt in the kernel, not in userspace.
Best regards,
Petr Vandrovec


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/