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From:   Andrey Konovalov <andreyknvl@google.com>
Date:   Fri, 15 Jan 2021 19:08:59 +0100
Message-ID: <CAAeHK+xGDcd1DQVGU-WX+5aM6+0dO08xp20YBLPUJj0i3RWGKQ@mail.gmail.com>
Subject: Re: [PATCH v3 2/2] kasan, arm64: fix pointer tags in KASAN reports
To:     Catalin Marinas <catalin.marinas@arm.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Alexander Potapenko <glider@google.com>,
        Marco Elver <elver@google.com>,
        Will Deacon <will.deacon@arm.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Peter Collingbourne <pcc@google.com>,
        Evgenii Stepanov <eugenis@google.com>,
        Branislav Rankov <Branislav.Rankov@arm.com>,
        Kevin Brodsky <kevin.brodsky@arm.com>,
        kasan-dev <kasan-dev@googlegroups.com>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux Memory Management List <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Fri, Jan 15, 2021 at 6:59 PM Catalin Marinas <catalin.marinas@arm.com> wrote:
>
> On Fri, Jan 15, 2021 at 06:41:53PM +0100, Andrey Konovalov wrote:
> > As of the "arm64: expose FAR_EL1 tag bits in siginfo" patch, the address
> > that is passed to report_tag_fault has pointer tags in the format of 0x0X,
> > while KASAN uses 0xFX format (note the difference in the top 4 bits).
> >
> > Fix up the pointer tag for kernel pointers in do_tag_check_fault by
> > setting them to the same value as bit 55. Explicitly use __untagged_addr()
> > instead of untagged_addr(), as the latter doesn't affect TTBR1 addresses.
> >
> > Link: https://linux-review.googlesource.com/id/I9ced973866036d8679e8f4ae325de547eb969649
>
> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
>
> Unless there are other comments, I'll queue this for -rc5 through the
> arm64 tree (I already finalised the arm64 for-next/fixes branch for this
> week).

Sounds good, thank you!