Messages in this thread | | | Date | Sun, 13 Jul 2014 14:39:21 +0400 | Subject | Re: [RFC/PATCH -next 00/21] Address sanitizer for kernel (kasan) - dynamic memory error detector. | From | Andrey Ryabinin <> |
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2014-07-12 4:59 GMT+04:00 H. Peter Anvin <hpa@zytor.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? >
Sparsemem configurations currently may not work with kasan. I suppose I will have to move shadow area to vmalloc address space and make it (shadow) sparse too if needed.
> -hpa > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
-- Best regards, Andrey Ryabinin
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