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From:   Patricia Alfonso <trishalfonso@google.com>
Date:   Tue, 11 Feb 2020 16:19:27 -0800
Message-ID: <CAKFsvU+zaY6B_+g=UTpOddKXXgVaKWxH3c8nw6GSLceb1Mg2qA@mail.gmail.com>
Subject: Re: [RFC PATCH] UML: add support for KASAN under x86_64
To:     Dmitry Vyukov <dvyukov@google.com>
Cc:     Jeff Dike <jdike@addtoit.com>, Richard Weinberger <richard@nod.at>,
        anton.ivanov@cambridgegreys.com,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        David Gow <davidgow@google.com>,
        Brendan Higgins <brendanhiggins@google.com>,
        linux-um@lists.infradead.org,
        kasan-dev <kasan-dev@googlegroups.com>,
        LKML <linux-kernel@vger.kernel.org>
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On Thu, Jan 16, 2020 at 12:53 AM Dmitry Vyukov <dvyukov@google.com> wrote:
>
> > +void kasan_init(void)
> > +{
> > +       kasan_map_memory((void *)KASAN_SHADOW_START, KASAN_SHADOW_SIZE);
> > +
> > +       // unpoison the kernel text which is form uml_physmem -> uml_reserved
> > +       kasan_unpoison_shadow((void *)uml_physmem, physmem_size);
> > +
> > +       // unpoison the vmalloc region, which is start_vm -> end_vm
> > +       kasan_unpoison_shadow((void *)start_vm, (end_vm - start_vm + 1));
> > +
> > +       init_task.kasan_depth = 0;
> > +       pr_info("KernelAddressSanitizer initialized\n");
> > +}
>
> Was this tested with stack instrumentation? Stack instrumentation
> changes what shadow is being read/written and when. We don't need to
> get it working right now, but if it does not work it would be nice to
> restrict the setting and leave some comment traces for future
> generations.
If you are referring to KASAN_STACK_ENABLE, I just tested it and it
seems to work fine.

-- 
Patricia Alfonso