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Subject: Re: [PATCH v12 7/7] kasan: don't run tests in async mode
To:     Catalin Marinas <catalin.marinas@arm.com>
Cc:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        kasan-dev@googlegroups.com,
        Andrew Morton <akpm@linux-foundation.org>,
        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>,
        Andrey Konovalov <andreyknvl@google.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
References: <20210208165617.9977-1-vincenzo.frascino@arm.com>
 <20210208165617.9977-8-vincenzo.frascino@arm.com>
 <20210209120241.GF1435@arm.com>
From:   Vincenzo Frascino <vincenzo.frascino@arm.com>
Message-ID: <0e373526-0fa8-c5c0-fb41-5c17aa47f07c@arm.com>
Date:   Tue, 9 Feb 2021 12:20:28 +0000
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On 2/9/21 12:02 PM, Catalin Marinas wrote:
> On Mon, Feb 08, 2021 at 04:56:17PM +0000, Vincenzo Frascino wrote:
>> From: Andrey Konovalov <andreyknvl@google.com>
>>
>> Asynchronous KASAN mode doesn't guarantee that a tag fault will be
>> detected immediately and causes tests to fail. Forbid running them
>> in asynchronous mode.
>>
>> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> 
> That's missing your SoB.
>

Yes, I will add it in the next iteration.

>> diff --git a/lib/test_kasan.c b/lib/test_kasan.c
>> index 7285dcf9fcc1..f82d9630cae1 100644
>> --- a/lib/test_kasan.c
>> +++ b/lib/test_kasan.c
>> @@ -51,6 +51,10 @@ static int kasan_test_init(struct kunit *test)
>>  		kunit_err(test, "can't run KASAN tests with KASAN disabled");
>>  		return -1;
>>  	}
>> +	if (kasan_flag_async) {
>> +		kunit_err(test, "can't run KASAN tests in async mode");
>> +		return -1;
>> +	}
>>  
>>  	multishot = kasan_save_enable_multi_shot();
>>  	hw_set_tagging_report_once(false);
> 
> I think we can still run the kasan tests in async mode if we check the
> TFSR_EL1 at the end of each test by calling mte_check_tfsr_exit().
> 

IIUC this was the plan for the future. But I let Andrey comment for more details.

-- 
Regards,
Vincenzo