From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan, arm64: unpoison stack only with CONFIG_KASAN_STACK 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. Link: https://lkml.kernel.org/r/d09dd3f8abb388da397fd11598c5edeaa83fe559.1606162397.git.andreyknvl@xxxxxxxxxx Link: https://linux-review.googlesource.com/id/If8a891e9fe01ea543e00b576852685afec0887e3 Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reviewed-by: Marco Elver <elver@xxxxxxxxxx> Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx> Reviewed-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Tested-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx> Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx> Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- 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(-) --- a/arch/arm64/kernel/sleep.S~kasan-arm64-unpoison-stack-only-with-config_kasan_stack +++ a/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 --- a/arch/x86/kernel/acpi/wakeup_64.S~kasan-arm64-unpoison-stack-only-with-config_kasan_stack +++ a/arch/x86/kernel/acpi/wakeup_64.S @@ -112,7 +112,7 @@ SYM_FUNC_START(do_suspend_lowlevel) movq pt_regs_r14(%rax), %r14 movq pt_regs_r15(%rax), %r15 -#ifdef CONFIG_KASAN +#if defined(CONFIG_KASAN) && CONFIG_KASAN_STACK /* * The suspend path may have poisoned some areas deeper in the stack, * which we now need to unpoison. --- a/include/linux/kasan.h~kasan-arm64-unpoison-stack-only-with-config_kasan_stack +++ a/include/linux/kasan.h @@ -77,8 +77,6 @@ static inline void kasan_disable_current void kasan_unpoison_range(const void *address, size_t size); -void kasan_unpoison_task_stack(struct task_struct *task); - void kasan_alloc_pages(struct page *page, unsigned int order); void kasan_free_pages(struct page *page, unsigned int order); @@ -123,8 +121,6 @@ void kasan_restore_multi_shot(bool enabl static inline void kasan_unpoison_range(const void *address, size_t size) {} -static inline void kasan_unpoison_task_stack(struct task_struct *task) {} - static inline void kasan_alloc_pages(struct page *page, unsigned int order) {} static inline void kasan_free_pages(struct page *page, unsigned int order) {} @@ -176,6 +172,12 @@ static inline size_t kasan_metadata_size #endif /* CONFIG_KASAN */ +#if defined(CONFIG_KASAN) && CONFIG_KASAN_STACK +void kasan_unpoison_task_stack(struct task_struct *task); +#else +static inline void kasan_unpoison_task_stack(struct task_struct *task) {} +#endif + #ifdef CONFIG_KASAN_GENERIC void kasan_cache_shrink(struct kmem_cache *cache); --- a/mm/kasan/common.c~kasan-arm64-unpoison-stack-only-with-config_kasan_stack +++ a/mm/kasan/common.c @@ -63,6 +63,7 @@ void kasan_unpoison_range(const void *ad unpoison_range(address, size); } +#if CONFIG_KASAN_STACK static void __kasan_unpoison_stack(struct task_struct *task, const void *sp) { void *base = task_stack_page(task); @@ -89,6 +90,7 @@ asmlinkage void kasan_unpoison_task_stac unpoison_range(base, watermark - base); } +#endif /* CONFIG_KASAN_STACK */ void kasan_alloc_pages(struct page *page, unsigned int order) { _
