> diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
> new file mode 100644
> index 000000000000..4888084ecdfc
> --- /dev/null
> +++ b/mm/kasan/shadow.c
> @@ -0,0 +1,509 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * This file contains KASAN shadow runtime code.
I think it will be nice to mention here which KASAN modes are going to
use this file.
> +#undef memset
> +void *memset(void *addr, int c, size_t len)
> +{
> + if (!check_memory_region((unsigned long)addr, len, true, _RET_IP_))
> + return NULL;
> +
> + return __memset(addr, c, len);
> +}
> +
OOC, don't we need memset and memmove implementations in the
hardware-based mode as well?
> + region_start = ALIGN(start, PAGE_SIZE * KASAN_GRANULE_SIZE);
> + region_end = ALIGN_DOWN(end, PAGE_SIZE * KASAN_GRANULE_SIZE);
"PAGE_SIZE * KASAN_GRANULE_SIZE" seems to be a common thing, can we
give it a name?
