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From:   Qian Cai <cai@lca.pw>
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Subject: Re: AMD SME + KASAN = doom
Date:   Sat, 13 Jun 2020 13:03:18 -0400
Message-Id: <E41B9DFC-F407-4C6A-BCFB-6E3E6B72BA0C@lca.pw>
References: <20200613155449.GB3090@zn.tnic>
Cc:     Thomas.Lendacky@amd.com, brijesh.singh@amd.com, tglx@linutronix.de,
        glider@google.com, peterz@infradead.org, dvyukov@google.com,
        kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org
In-Reply-To: <20200613155449.GB3090@zn.tnic>
To:     Borislav Petkov <bp@suse.de>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


> On Jun 13, 2020, at 11:54 AM, Borislav Petkov <bp@suse.de> wrote:
>=20
> $ head arch/x86/mm/Makefile
> # SPDX-License-Identifier: GPL-2.0
> # Kernel does not boot with instrumentation of tlb.c and mem_encrypt*.c
> KCOV_INSTRUMENT_tlb.o                   :=3D n
> KCOV_INSTRUMENT_mem_encrypt.o           :=3D n
> KCOV_INSTRUMENT_mem_encrypt_identity.o  :=3D n
>=20
> KASAN_SANITIZE_mem_encrypt.o            :=3D n
> KASAN_SANITIZE_mem_encrypt_identity.o   :=3D n
>=20
> so something else needs to be de-KASAN-ed too.

Okay, I=E2=80=99ll try to figure out what else needs to be done.

>=20
> For now flip your Subject: AMD SME - KASAN =3D boot.

Which is a bit of shame because KASAN is proved useful for testing and at th=
e same time SME could flags some issues with drivers like megasas_raid (wher=
e the driver will do a  firmware dump during the boot which I plan to debug m=
ore a bit later).=