Subject: RE: New 745x errata

From: Giuliano Pochini <[email-masked]>
Date: Fri, 14 Nov 2003 11:40:53 +0100 (CET)

On 13-Nov-2003 Adrian Cox wrote:
>
> Since October there are new errata on Motorola's website for the 745x
> family processors. The following patch against linuxppc-2.4-devel
> contains workarounds to two problems:
>
> 1) The BTIC doesn't work reliably: it can cause execution of corrupted
> instructions. (This is listed in the errata for the 7450 and 7457, but
> not for the 7455. I'll only believe that the 7455 escaped this bug if I
> hear confirmation out of Motorola.)

Did you try to ask them about it ?

> 2) dcbt to protected addresses can cause spurious bus cycles. This could
> potentially be exploited from userspace to lock up hardware.

Hm, a 1-cycle window this is very small.  Anyway, if dc* instructions are
used inside the kernel, we could keep them disabled in userspace only.

--
Giuliano.

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