On Fri, Oct 02, 2020 at 01:10:30AM +0200, Andrey Konovalov wrote: > diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c > index 7c67ac6f08df..d1847f29f59b 100644 > --- a/arch/arm64/kernel/mte.c > +++ b/arch/arm64/kernel/mte.c > @@ -23,6 +23,8 @@ > #include <asm/ptrace.h> > #include <asm/sysreg.h> > > +u64 gcr_kernel_excl __ro_after_init; > + > static void mte_sync_page_tags(struct page *page, pte_t *ptep, bool check_swap) > { > pte_t old_pte = READ_ONCE(*ptep); > @@ -120,6 +122,13 @@ void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag) > return ptr; > } > > +void mte_init_tags(u64 max_tag) > +{ > + u64 incl = GENMASK(max_tag & MTE_TAG_MAX, 0); Nitpick: it's not obvious that MTE_TAG_MAX is a mask, so better write this as GENMASK(min(max_tag, MTE_TAG_MAX), 0). Otherwise it looks fine. Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>