Re: Re: [PATCH 1/1] kasan: Support for r/w instrumentation control

From	Dmitry Vyukov <dvyukov@google.com>
Newsgroups	linux.kernel
Subject	Re: Re: [PATCH 1/1] kasan: Support for r/w instrumentation control
Date	2016-12-12 11:50 +0100
Message-ID	<sNwlc-3eh-33@gated-at.bofh.it> (permalink)
References	<sNvfs-2B3-23@gated-at.bofh.it> <sNw1Q-37y-57@gated-at.bofh.it> <sNw1Q-37y-55@gated-at.bofh.it>
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On Mon, Dec 12, 2016 at 11:29 AM, Vaneet Narang <v.narang@samsung.com> wrote:
>  Hi,
>
>> Do you actually hit an issue with image size? In what context?
>> Do you use inline/outline instrumentation? Does switching to the other
>> option help?
>
> Memory access with KASAN enabled Image has overhead in terms of cpu execution.
> Sometimes we are not able to reproduce race condition issues with these overhead in
> place. So user should have control atleast over read instrumentation.

Don't you want to disable KASAN entirely in such case?


>> Does it make sense to ever disable writes? I assume that you are
>
> Write instrumentation control is majorly kept to be inline with ASAN for user space
> applications.
> Also write is sometimes useful when uImage is already sanitized and some corruption
> is done by kernel modules by doing some direct memory access then both read / write sanity of uImage
> can be avoided.

But then you don't need KASAN at all.


>> disabling reads, right?
>> Disabling both certainly does not make sense.

Thread

[PATCH 1/1] kasan: Support for r/w instrumentation control Maninder Singh <maninder1.s@samsung.com> - 2016-12-12 10:40 +0100
  Re: [PATCH 1/1] kasan: Support for r/w instrumentation control Dmitry Vyukov <dvyukov@google.com> - 2016-12-12 11:10 +0100
  RE: Re: [PATCH 1/1] kasan: Support for r/w instrumentation control Vaneet Narang <v.narang@samsung.com> - 2016-12-12 11:30 +0100
    Re: Re: [PATCH 1/1] kasan: Support for r/w instrumentation control Dmitry Vyukov <dvyukov@google.com> - 2016-12-12 11:50 +0100
    Re: Re: [PATCH 1/1] kasan: Support for r/w instrumentation control Vaneet Narang <v.narang@samsung.com> - 2016-12-12 13:10 +0100
      Re: Re: [PATCH 1/1] kasan: Support for r/w instrumentation control Dmitry Vyukov <dvyukov@google.com> - 2016-12-12 14:50 +0100

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