On Thu, Aug 27, 2020 at 12:05:55PM +0100, Vincenzo Frascino wrote: > On 8/27/20 11:40 AM, Catalin Marinas wrote: > > On Fri, Aug 14, 2020 at 07:27:08PM +0200, Andrey Konovalov wrote: > >> diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S > >> index 152d74f2cc9c..6880ddaa5144 100644 > >> --- a/arch/arm64/mm/proc.S > >> +++ b/arch/arm64/mm/proc.S > >> @@ -38,7 +38,7 @@ > >> /* PTWs cacheable, inner/outer WBWA */ > >> #define TCR_CACHE_FLAGS TCR_IRGN_WBWA | TCR_ORGN_WBWA > >> > >> -#ifdef CONFIG_KASAN_SW_TAGS > >> +#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS) > >> #define TCR_KASAN_FLAGS TCR_TBI1 > >> #else > >> #define TCR_KASAN_FLAGS 0 > > > > I prefer to turn TBI1 on only if MTE is present. So on top of the v8 > > user series, just do this in __cpu_setup. > > Not sure I understand... Enabling TBI1 only if MTE is present would break > KASAN_SW_TAGS which is based on TBI1 but not on MTE. You keep the KASAN_SW_TAGS as above but for HW_TAGS, only set TBI1 later in __cpu_setup(). -- Catalin
