diff mbox series

[58/78] kasan, arm64: unpoison stack only with CONFIG_KASAN_STACK

Message ID 20201218220436.9KojDJlYY%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [01/78] mm/memcg: bail early from swap accounting if memcg disabled | expand

Commit Message

Andrew Morton Dec. 18, 2020, 10:04 p.m. UTC
From: Andrey Konovalov <andreyknvl@google.com>
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

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>

 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 mbox series


--- 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
 	mov	x0, sp
 	bl	kasan_unpoison_task_stack_below
--- 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
 	 * 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 */
+void kasan_unpoison_task_stack(struct task_struct *task);
+static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
 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);
 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)