Re: [PATCH 1/2 v3] x86: introduce int3-based instruction patching

[Borislav Petkov]

On Thu, Jul 11, 2013 at 01:53:16PM -0700, H. Peter Anvin wrote:
> Has anyone talked to AMD or VIA about this at all?

I guess I can try to take care of the AMD part. Just to confirm, is this
the exact sequence we're interested in:

1. Setup int3 handler for fixup.

2. Put a breakpoint (int3) on the first byte of modifying region, and
synchronize code on all CPUs.

3. Modify other bytes of modifying region.

4. Modify the first byte of modifying region, and synchronize code on
all CPUs.

5. Clear int3 handler.

If a suitable int3 handler is left permanently in place then the
synchronization in step 4 is unnecessary.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--
--
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/