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From: Andrey Ryabinin <aryabinin@virtuozzo.com>
To: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Potapenko <glider@google.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	kasan-dev <kasan-dev@googlegroups.com>,
	Linux Memory Management List <linux-mm@kvack.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] kasan: report only the first error
Date: Wed, 22 Mar 2017 19:54:17 +0300	[thread overview]
Message-ID: <cbb22acb-1228-0f7b-c7a0-5822ea721b3f@virtuozzo.com> (raw)
In-Reply-To: <CAAeHK+zt9U+_8o4-k1mTvHsNTVGnKbzy7jVz2jn=TkNFf2neHQ@mail.gmail.com>

On 03/22/2017 07:34 PM, Andrey Konovalov wrote:
> On Wed, Mar 22, 2017 at 5:06 PM, Andrey Ryabinin
> <aryabinin@virtuozzo.com> wrote:
>> Disable kasan after the first report. There are several reasons for this:
>>  * Single bug quite often has multiple invalid memory accesses causing
>>     storm in the dmesg.
>>  * Write OOB access might corrupt metadata so the next report will print
>>     bogus alloc/free stacktraces.
>>  * Reports after the first easily could be not bugs by itself but just side
>>     effects of the first one.
>>
>> Given that multiple reports only do harm, it makes sense to disable
>> kasan after the first one. Except for the tests in lib/test_kasan.c
>> as we obviously want to see all reports from test.
> 
> Hi Andrey,
> 
> Could you make it configurable via CONFIG_KASAN_SOMETHING (which can
> default to showing only the first report)?

I'd rather make this boot time configurable, but wouldn't want to without
a good reason.


> I sometimes use KASAN to see what bad accesses a particular bug
> causes, and seeing all of them (even knowing that they may be
> corrupt/induced) helps a lot.

I'm wondering why you need to see all reports?

> 
> Thanks!
> 

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  reply	other threads:[~2017-03-22 16:53 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-22 16:06 Andrey Ryabinin
2017-03-22 16:34 ` Andrey Konovalov
2017-03-22 16:54   ` Andrey Ryabinin [this message]
2017-03-22 17:07     ` Andrey Konovalov
2017-03-22 17:33       ` Alexander Potapenko
2017-03-22 17:42         ` Dmitry Vyukov
2017-03-23 11:49 ` [PATCH v2] kasan: report only the first error by default Andrey Ryabinin
2017-03-23 12:41   ` Mark Rutland
2017-03-23 13:06     ` Andrey Ryabinin
2017-03-23 13:29       ` Mark Rutland
2017-03-23 15:44 ` [PATCH v3] " Andrey Ryabinin

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