Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20210315132019.33202-1-vincenzo.frascino@arm.com> <20210318185607.GD10758@arm.com>
In-Reply-To: <20210318185607.GD10758@arm.com>
From:   Andrey Konovalov <andreyknvl@gmail.com>
Date:   Thu, 18 Mar 2021 20:03:02 +0100
Message-ID: <CA+fCnZc9ayxT_u3qJmB1MV0Wi93=8tNYxWFbZK52vK4S21U2qA@mail.gmail.com>
Subject: Re: [PATCH v16 0/9] arm64: ARMv8.5-A: MTE: Add async mode support
To:     Catalin Marinas <catalin.marinas@arm.com>
Cc:     Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-arm-kernel@lists.infradead.org,
        LKML <linux-kernel@vger.kernel.org>, kasan-dev@googlegroups.com,
        Will Deacon <will@kernel.org>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Marco Elver <elver@google.com>,
        Evgenii Stepanov <eugenis@google.com>,
        Branislav Rankov <Branislav.Rankov@arm.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Thu, Mar 18, 2021 at 7:56 PM Catalin Marinas <catalin.marinas@arm.com> wrote:
>
> On Mon, Mar 15, 2021 at 01:20:10PM +0000, Vincenzo Frascino wrote:
> > This patchset implements the asynchronous mode support for ARMv8.5-A
> > Memory Tagging Extension (MTE), which is a debugging feature that allows
> > to detect with the help of the architecture the C and C++ programmatic
> > memory errors like buffer overflow, use-after-free, use-after-return, etc.
> >
> > MTE is built on top of the AArch64 v8.0 virtual address tagging TBI
> > (Top Byte Ignore) feature and allows a task to set a 4 bit tag on any
> > subset of its address space that is multiple of a 16 bytes granule. MTE
> > is based on a lock-key mechanism where the lock is the tag associated to
> > the physical memory and the key is the tag associated to the virtual
> > address.
> > When MTE is enabled and tags are set for ranges of address space of a task,
> > the PE will compare the tag related to the physical memory with the tag
> > related to the virtual address (tag check operation). Access to the memory
> > is granted only if the two tags match. In case of mismatch the PE will raise
> > an exception.
> >
> > The exception can be handled synchronously or asynchronously. When the
> > asynchronous mode is enabled:
> >   - Upon fault the PE updates the TFSR_EL1 register.
> >   - The kernel detects the change during one of the following:
> >     - Context switching
> >     - Return to user/EL0
> >     - Kernel entry from EL1
> >     - Kernel exit to EL1
> >   - If the register has been updated by the PE the kernel clears it and
> >     reports the error.
> >
> > The series is based on linux-next/akpm.
>
> Andrew, could you please pick these patches up via the mm tree? They
> depend on kasan patches already queued.
>
> Andrey, all the kasan patches have your acked-by with the google.com
> address and you've been cc'ed on that. You may want to update the
> .mailmap file in the kernel.

Good point. I was wondering if there's something like that for email
changes. Will send a patch.

Thank you, Catalin.