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From:   Dmitry Vyukov <dvyukov@google.com>
Date:   Sun, 31 May 2020 11:32:02 +0200
Message-ID: <CACT4Y+YB=J0+w7+SHBC3KpKOzxh1Xaarj1cXOPOLKPKQwAW6nQ@mail.gmail.com>
Subject: Re: PANIC: double fault in fixup_bad_iret
To:     Peter Zijlstra <peterz@infradead.org>,
        Marco Elver <elver@google.com>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        syzbot <syzbot+dc1fa714cb070b184db5@syzkaller.appspotmail.com>,
        LKML <linux-kernel@vger.kernel.org>,
        syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        Oleg Nesterov <oleg@redhat.com>,
        kasan-dev <kasan-dev@googlegroups.com>
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On Fri, May 29, 2020 at 7:11 PM Peter Zijlstra <peterz@infradead.org> wrote:
> > Like with KCSAN, we should blanket kill KASAN/UBSAN and friends (at the
> > very least in arch/x86/) until they get that function attribute stuff
> > sorted.
>
> Something like so.
>
> ---
> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
> index 00e378de8bc0..a90d32b87d7e 100644
> --- a/arch/x86/Makefile
> +++ b/arch/x86/Makefile
> @@ -1,6 +1,14 @@
>  # SPDX-License-Identifier: GPL-2.0
>  # Unified Makefile for i386 and x86_64
>
> +#
> +# Until such a time that __no_kasan and __no_ubsan work as expected (and are
> +# made part of noinstr), don't sanitize anything.
> +#
> +KASAN_SANITIZE := n
> +UBSAN_SANITIZE := n
> +KCOV_INSTRUMENT := n
> +
>  # select defconfig based on actual architecture
>  ifeq ($(ARCH),x86)
>    ifeq ($(shell uname -m),x86_64)

+kasan-dev
+Marco, please send a fix for this