On Thu, Mar 30, 2023 at 4:06 AM Qing Zhang <zhangqing@xxxxxxxxxxx> wrote: > > > But I don't think you need this check here at all: addr_has_metadata > > already checks that shadow exists. > > > On LongArch, there's a lot of holes between different segments, so kasan > shadow area is some different type of memory that we concatenate, we > can't use if (unlikely((void *)addr < > kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) to determine the > validity, and in arch/loongarch/include/asm/kasan.h I construct invalid > NULL. I get that, but you already added a special case for __HAVE_ARCH_SHADOW_MAP to addr_has_metadata, so you can just call it? > This is because in pagetable_init on loongarch/mips, we populate pmd/pud > with invalid_pmd_table/invalid_pud_table, I see. Please add this into the patch description for v2. > So pmd_init/pud_init(p) is required, perhaps we define them as __weak in > mm/kasan/init.c, like mm/sparse-vmemmap.c. Yes, this makes sense to do, so that KASAN doesn't depend on definitions from sparse-vmemmap.c. Thank you!