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@google.com
Link: https://linux-review.googlesource.com/id/If8a891e9fe01ea543e00b576852685afec0887e3
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrey Konovalov 2020-12-22 12:02:42 -08:00 committed by Linus Torvalds
parent 8bb0009b19
commit d56a9ef84b
4 changed files with 10 additions and 6 deletions

View File

@ -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

View File

@ -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.

View File

@ -77,8 +77,6 @@ static inline void kasan_disable_current(void) {}
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 enabled);
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(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);

View File

@ -63,6 +63,7 @@ void kasan_unpoison_range(const void *address, size_t size)
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_stack_below(const void *watermark)
unpoison_range(base, watermark - base);
}
#endif /* CONFIG_KASAN_STACK */
void kasan_alloc_pages(struct page *page, unsigned int order)
{