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 diff --git a/arch/x86/kernel/acpi/wakeup_64.S b/arch/x86/kernel/acpi/wakeup_64.S index c8daa92f38dc..5d3a0b8fd379 100644 --- a/arch/x86/kernel/acpi/wakeup_64.S +++ b/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. diff --git a/include/linux/kasan.h b/include/linux/kasan.h index f22bdef82111..b9b9db335d87 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -76,8 +76,6 @@ static inline void kasan_disable_current(void) {} void kasan_unpoison_memory(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); @@ -122,8 +120,6 @@ void kasan_restore_multi_shot(bool enabled); static inline void kasan_unpoison_memory(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) {} @@ -175,6 +171,12 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; } #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); diff --git a/mm/kasan/common.c b/mm/kasan/common.c index a880e5a547ed..a3e67d49b893 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -58,6 +58,7 @@ void kasan_disable_current(void) } #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ +#if CONFIG_KASAN_STACK static void __kasan_unpoison_stack(struct task_struct *task, const void *sp) { void *base = task_stack_page(task); @@ -84,6 +85,7 @@ asmlinkage void kasan_unpoison_task_stack_below(const void *watermark) kasan_unpoison_memory(base, watermark - base); } +#endif /* CONFIG_KASAN_STACK */ void kasan_alloc_pages(struct page *page, unsigned int order) { -- 2.29.2.222.g5d2a92d10f8-goog
