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From: hpa@zytor.com (H. Peter Anvin)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC/PATCH -next 00/21] Address sanitizer for kernel (kasan) - dynamic memory error detector.
Date: Fri, 11 Jul 2014 17:59:34 -0700	[thread overview]
Message-ID: <53C08876.10209@zytor.com> (raw)
In-Reply-To: <1404903678-8257-1-git-send-email-a.ryabinin@samsung.com>

On 07/09/2014 04:00 AM, Andrey Ryabinin wrote:
> 
> Address sanitizer dedicates 1/8 of the low memory to the shadow memory and uses direct
> mapping with a scale and offset to translate a memory address to its corresponding
> shadow address.
> 
> Here is function to translate address to corresponding shadow address:
> 
>      unsigned long kasan_mem_to_shadow(unsigned long addr)
>      {
> 		return ((addr) >> KASAN_SHADOW_SCALE_SHIFT)
>        	             + kasan_shadow_start - (PAGE_OFFSET >> KASAN_SHADOW_SCALE_SHIFT);
>      }
> 
> where KASAN_SHADOW_SCALE_SHIFT = 3.
> 

How does that work when memory is sparsely populated?

	-hpa

  reply	other threads:[~2014-07-12  0:59 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-09 11:00 Andrey Ryabinin
2014-07-12  0:59 ` H. Peter Anvin [this message]
2014-07-13 10:39   ` Andrey Ryabinin
2014-07-14 15:13     ` Christoph Lameter
2014-07-15 14:32       ` Andrey Ryabinin

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