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Subject: Re: [PATCH v15 0/8] arm64: ARMv8.5-A: MTE: Add async mode support
To:     Andrey Konovalov <andreyknvl@google.com>
Cc:     Linux ARM <linux-arm-kernel@lists.infradead.org>,
        LKML <linux-kernel@vger.kernel.org>,
        kasan-dev <kasan-dev@googlegroups.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Catalin Marinas <catalin.marinas@arm.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>
References: <20210312142210.21326-1-vincenzo.frascino@arm.com>
 <CAAeHK+wFT7Z5_Jg-8afdu8=mVqTwcnZY65Cgywxbd_0ui+1BEQ@mail.gmail.com>
From:   Vincenzo Frascino <vincenzo.frascino@arm.com>
Message-ID: <7e14b0ae-8aa5-549c-ef77-5f040e0d3813@arm.com>
Date:   Fri, 12 Mar 2021 14:56:30 +0000
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On 3/12/21 2:50 PM, Andrey Konovalov wrote:
> On Fri, Mar 12, 2021 at 3:22 PM Vincenzo Frascino
> <vincenzo.frascino@arm.com> 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.
>>
>> To simplify the testing a tree with the new patches on top has been made
>> available at [1].
>>
>> [1] https://git.gitlab.arm.com/linux-arm/linux-vf.git mte/v13.async.akpm
> 
> Acked-by: Andrey Konovalov <andreyknvl@google.com>
> Tested-by: Andrey Konovalov <andreyknvl@google.com>
> 
> for the series.
> 
> Thank you, Vincenzo!
> 

Thanks to you!

-- 
Regards,
Vincenzo