Re: [RFC/PATCH -next 00/21] Address sanitizer for kernel (kasan) - dynamic memory error detector.
From: Andrey Ryabinin
Date: Sun Jul 13 2014 - 06:39:47 EST
2014-07-12 4:59 GMT+04:00 H. Peter Anvin <hpa@xxxxxxxxx>:
> 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.
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@xxxxxxxxxx For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/