On Tue, Nov 10, 2020 at 11:20:08PM +0100, Andrey Konovalov wrote: > There's a config option CONFIG_KASAN_STACK that has to be enabled for > KASAN to use stack instrumentation and perform validity checks for > stack variables. > > There's no need to unpoison stack when CONFIG_KASAN_STACK is not enabled. > Only call kasan_unpoison_task_stack[_below]() when CONFIG_KASAN_STACK is > enabled. > > Note, that CONFIG_KASAN_STACK is an option that is currently always > defined when CONFIG_KASAN is enabled, and therefore has to be tested > with #if instead of #ifdef. > > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > Link: https://linux-review.googlesource.com/id/If8a891e9fe01ea543e00b576852685afec0887e3 > --- > arch/arm64/kernel/sleep.S | 2 +- > arch/x86/kernel/acpi/wakeup_64.S | 2 +- > include/linux/kasan.h | 10 ++++++---- > mm/kasan/common.c | 2 ++ > 4 files changed, 10 insertions(+), 6 deletions(-) > > diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S > index ba40d57757d6..bdadfa56b40e 100644 > --- a/arch/arm64/kernel/sleep.S > +++ b/arch/arm64/kernel/sleep.S > @@ -133,7 +133,7 @@ SYM_FUNC_START(_cpu_resume) > */ > bl cpu_do_resume > > -#ifdef CONFIG_KASAN > +#if defined(CONFIG_KASAN) && CONFIG_KASAN_STACK > mov x0, sp > bl kasan_unpoison_task_stack_below > #endif I don't understand why CONFIG_KASAN_STACK is not a bool (do you plan to add more values to it?) but for arm64: Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
