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authorAndrey Konovalov <andreyknvl@google.com>2020-12-10 15:42:15 +1100
committerStephen Rothwell <sfr@canb.auug.org.au>2020-12-16 18:03:02 +1100
commit40d2653c1f9d1fefa1dc1060423d41acdd9c132d (patch)
treed5549bdf1296ae68ef1e44ad321dcc2c292f4b90
parentb30c394655a94ed4376853b0770fd680f43f1f9b (diff)
downloadlinux-40d2653c1f9d1fefa1dc1060423d41acdd9c132d.tar.gz
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: Stephen Rothwell <sfr@canb.auug.org.au>
-rw-r--r--arch/arm64/kernel/sleep.S2
-rw-r--r--arch/x86/kernel/acpi/wakeup_64.S2
-rw-r--r--include/linux/kasan.h10
-rw-r--r--mm/kasan/common.c2
4 files changed, 10 insertions, 6 deletions
diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
index 4be7f7eed875..6bdef7362c0e 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 d22ec4c9c1bd..e638255ce906 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -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);
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 0a420f1dbc54..7648a2452a01 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -64,6 +64,7 @@ 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);
@@ -90,6 +91,7 @@ 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)
{