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Message-Id: <21fa5f4eb6ee132a57b716ff6245f2c98de2d204.1603372719.git.andreyknvl@google.com>
Date: Thu, 22 Oct 2020 15:19:07 +0200
From: Andrey Konovalov <andreyknvl@...gle.com>
To: Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>,
Vincenzo Frascino <vincenzo.frascino@....com>,
Dmitry Vyukov <dvyukov@...gle.com>,
Alexander Potapenko <glider@...gle.com>,
Marco Elver <elver@...gle.com>
Cc: Evgenii Stepanov <eugenis@...gle.com>,
Kostya Serebryany <kcc@...gle.com>,
Peter Collingbourne <pcc@...gle.com>,
Serban Constantinescu <serbanc@...gle.com>,
Andrey Ryabinin <aryabinin@...tuozzo.com>,
Elena Petrova <lenaptr@...gle.com>,
Branislav Rankov <Branislav.Rankov@....com>,
Kevin Brodsky <kevin.brodsky@....com>,
Andrew Morton <akpm@...ux-foundation.org>,
kasan-dev@...glegroups.com, linux-arm-kernel@...ts.infradead.org,
linux-mm@...ck.org, linux-kernel@...r.kernel.org,
Andrey Konovalov <andreyknvl@...gle.com>
Subject: [PATCH RFC v2 15/21] kasan: check kasan_enabled in annotations
Declare the kasan_enabled static key in include/linux/kasan.h and in
include/linux/mm.h and check it in all kasan annotations. This allows to
avoid any slowdown caused by function calls when kasan_enabled is
disabled.
Signed-off-by: Andrey Konovalov <andreyknvl@...gle.com>
Link: https://linux-review.googlesource.com/id/I2589451d3c96c97abbcbf714baabe6161c6f153e
---
include/linux/kasan.h | 210 ++++++++++++++++++++++++++++++++----------
include/linux/mm.h | 27 ++++--
mm/kasan/common.c | 60 ++++++------
3 files changed, 211 insertions(+), 86 deletions(-)
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 2b9023224474..8654275aa62e 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -2,6 +2,7 @@
#ifndef _LINUX_KASAN_H
#define _LINUX_KASAN_H
+#include <linux/jump_label.h>
#include <linux/types.h>
struct kmem_cache;
@@ -66,40 +67,154 @@ static inline void kasan_disable_current(void) {}
#ifdef CONFIG_KASAN
-void kasan_alloc_pages(struct page *page, unsigned int order);
-void kasan_free_pages(struct page *page, unsigned int order);
+struct kasan_cache {
+ int alloc_meta_offset;
+ int free_meta_offset;
+};
+
+#ifdef CONFIG_KASAN_HW_TAGS
+DECLARE_STATIC_KEY_FALSE(kasan_enabled);
+#else
+DECLARE_STATIC_KEY_TRUE(kasan_enabled);
+#endif
-void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
- slab_flags_t *flags);
+void __kasan_alloc_pages(struct page *page, unsigned int order);
+static inline void kasan_alloc_pages(struct page *page, unsigned int order)
+{
+ if (static_branch_likely(&kasan_enabled))
+ __kasan_alloc_pages(page, order);
+}
-void kasan_unpoison_data(const void *address, size_t size);
-void kasan_unpoison_slab(const void *ptr);
+void __kasan_free_pages(struct page *page, unsigned int order);
+static inline void kasan_free_pages(struct page *page, unsigned int order)
+{
+ if (static_branch_likely(&kasan_enabled))
+ __kasan_free_pages(page, order);
+}
-void kasan_poison_slab(struct page *page);
-void kasan_unpoison_object_data(struct kmem_cache *cache, void *object);
-void kasan_poison_object_data(struct kmem_cache *cache, void *object);
-void * __must_check kasan_init_slab_obj(struct kmem_cache *cache,
- const void *object);
+void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
+ slab_flags_t *flags);
+static inline void kasan_cache_create(struct kmem_cache *cache,
+ unsigned int *size, slab_flags_t *flags)
+{
+ if (static_branch_likely(&kasan_enabled))
+ __kasan_cache_create(cache, size, flags);
+}
-void * __must_check kasan_kmalloc_large(const void *ptr, size_t size,
- gfp_t flags);
-void kasan_kfree_large(void *ptr, unsigned long ip);
-void kasan_poison_kfree(void *ptr, unsigned long ip);
-void * __must_check kasan_kmalloc(struct kmem_cache *s, const void *object,
- size_t size, gfp_t flags);
-void * __must_check kasan_krealloc(const void *object, size_t new_size,
- gfp_t flags);
+size_t __kasan_metadata_size(struct kmem_cache *cache);
+static inline size_t kasan_metadata_size(struct kmem_cache *cache)
+{
+ if (static_branch_likely(&kasan_enabled))
+ return __kasan_metadata_size(cache);
+ return 0;
+}
-void * __must_check kasan_slab_alloc(struct kmem_cache *s, void *object,
- gfp_t flags);
-bool kasan_slab_free(struct kmem_cache *s, void *object, unsigned long ip);
+void __kasan_unpoison_data(const void *addr, size_t size);
+static inline void kasan_unpoison_data(const void *addr, size_t size)
+{
+ if (static_branch_likely(&kasan_enabled))
+ __kasan_unpoison_data(addr, size);
+}
-struct kasan_cache {
- int alloc_meta_offset;
- int free_meta_offset;
-};
+void __kasan_unpoison_slab(const void *ptr);
+static inline void kasan_unpoison_slab(const void *ptr)
+{
+ if (static_branch_likely(&kasan_enabled))
+ __kasan_unpoison_slab(ptr);
+}
+
+void __kasan_poison_slab(struct page *page);
+static inline void kasan_poison_slab(struct page *page)
+{
+ if (static_branch_likely(&kasan_enabled))
+ return __kasan_poison_slab(page);
+}
+
+void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object);
+static inline void kasan_unpoison_object_data(struct kmem_cache *cache, void *object)
+{
+ if (static_branch_likely(&kasan_enabled))
+ return __kasan_unpoison_object_data(cache, object);
+}
+
+void __kasan_poison_object_data(struct kmem_cache *cache, void *object);
+static inline void kasan_poison_object_data(struct kmem_cache *cache, void *object)
+{
+ if (static_branch_likely(&kasan_enabled))
+ __kasan_poison_object_data(cache, object);
+}
+
+void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,
+ const void *object);
+static inline void * __must_check kasan_init_slab_obj(struct kmem_cache *cache,
+ const void *object)
+{
+ if (static_branch_likely(&kasan_enabled))
+ return __kasan_init_slab_obj(cache, object);
+ return (void *)object;
+}
+
+bool __kasan_slab_free(struct kmem_cache *s, void *object, unsigned long ip);
+static inline bool kasan_slab_free(struct kmem_cache *s, void *object, unsigned long ip)
+{
+ if (static_branch_likely(&kasan_enabled))
+ return __kasan_slab_free(s, object, ip);
+ return false;
+}
-size_t kasan_metadata_size(struct kmem_cache *cache);
+void * __must_check __kasan_slab_alloc(struct kmem_cache *s,
+ void *object, gfp_t flags);
+static inline void * __must_check kasan_slab_alloc(struct kmem_cache *s,
+ void *object, gfp_t flags)
+{
+ if (static_branch_likely(&kasan_enabled))
+ return __kasan_slab_alloc(s, object, flags);
+ return object;
+}
+
+void * __must_check __kasan_kmalloc(struct kmem_cache *s, const void *object,
+ size_t size, gfp_t flags);
+static inline void * __must_check kasan_kmalloc(struct kmem_cache *s, const void *object,
+ size_t size, gfp_t flags)
+{
+ if (static_branch_likely(&kasan_enabled))
+ return __kasan_kmalloc(s, object, size, flags);
+ return (void *)object;
+}
+
+void * __must_check __kasan_kmalloc_large(const void *ptr,
+ size_t size, gfp_t flags);
+static inline void * __must_check kasan_kmalloc_large(const void *ptr,
+ size_t size, gfp_t flags)
+{
+ if (static_branch_likely(&kasan_enabled))
+ return __kasan_kmalloc_large(ptr, size, flags);
+ return (void *)ptr;
+}
+
+void * __must_check __kasan_krealloc(const void *object,
+ size_t new_size, gfp_t flags);
+static inline void * __must_check kasan_krealloc(const void *object,
+ size_t new_size, gfp_t flags)
+{
+ if (static_branch_likely(&kasan_enabled))
+ return __kasan_krealloc(object, new_size, flags);
+ return (void *)object;
+}
+
+void __kasan_poison_kfree(void *ptr, unsigned long ip);
+static inline void kasan_poison_kfree(void *ptr, unsigned long ip)
+{
+ if (static_branch_likely(&kasan_enabled))
+ __kasan_poison_kfree(ptr, ip);
+}
+
+void __kasan_kfree_large(void *ptr, unsigned long ip);
+static inline void kasan_kfree_large(void *ptr, unsigned long ip)
+{
+ if (static_branch_likely(&kasan_enabled))
+ __kasan_kfree_large(ptr, ip);
+}
bool kasan_save_enable_multi_shot(void);
void kasan_restore_multi_shot(bool enabled);
@@ -108,14 +223,12 @@ void kasan_restore_multi_shot(bool enabled);
static inline void kasan_alloc_pages(struct page *page, unsigned int order) {}
static inline void kasan_free_pages(struct page *page, unsigned int order) {}
-
static inline void kasan_cache_create(struct kmem_cache *cache,
unsigned int *size,
slab_flags_t *flags) {}
-
-static inline void kasan_unpoison_data(const void *address, size_t size) { }
-static inline void kasan_unpoison_slab(const void *ptr) { }
-
+static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
+static inline void kasan_unpoison_data(const void *address, size_t size) {}
+static inline void kasan_unpoison_slab(const void *ptr) {}
static inline void kasan_poison_slab(struct page *page) {}
static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
void *object) {}
@@ -126,36 +239,33 @@ static inline void *kasan_init_slab_obj(struct kmem_cache *cache,
{
return (void *)object;
}
-
-static inline void *kasan_kmalloc_large(void *ptr, size_t size, gfp_t flags)
+static inline bool kasan_slab_free(struct kmem_cache *s, void *object,
+ unsigned long ip)
{
- return ptr;
+ return false;
}
-static inline void kasan_kfree_large(void *ptr, unsigned long ip) {}
-static inline void kasan_poison_kfree(void *ptr, unsigned long ip) {}
-static inline void *kasan_kmalloc(struct kmem_cache *s, const void *object,
- size_t size, gfp_t flags)
+static inline void *kasan_slab_alloc(struct kmem_cache *s, void *object,
+ gfp_t flags)
{
- return (void *)object;
+ return object;
}
-static inline void *kasan_krealloc(const void *object, size_t new_size,
- gfp_t flags)
+static inline void *kasan_kmalloc(struct kmem_cache *s, const void *object,
+ size_t size, gfp_t flags)
{
return (void *)object;
}
-static inline void *kasan_slab_alloc(struct kmem_cache *s, void *object,
- gfp_t flags)
+static inline void *kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags)
{
- return object;
+ return (void *)ptr;
}
-static inline bool kasan_slab_free(struct kmem_cache *s, void *object,
- unsigned long ip)
+static inline void *kasan_krealloc(const void *object, size_t new_size,
+ gfp_t flags)
{
- return false;
+ return (void *)object;
}
-
-static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
+static inline void kasan_poison_kfree(void *ptr, unsigned long ip) {}
+static inline void kasan_kfree_large(void *ptr, unsigned long ip) {}
#endif /* CONFIG_KASAN */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a3cac68c737c..701e9d7666d6 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1412,22 +1412,36 @@ static inline bool cpupid_match_pid(struct task_struct *task, int cpupid)
#endif /* CONFIG_NUMA_BALANCING */
#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
+
+#ifdef CONFIG_KASAN_HW_TAGS
+DECLARE_STATIC_KEY_FALSE(kasan_enabled);
+#else
+DECLARE_STATIC_KEY_TRUE(kasan_enabled);
+#endif
+
static inline u8 page_kasan_tag(const struct page *page)
{
- return (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK;
+ if (static_branch_likely(&kasan_enabled))
+ return (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK;
+ return 0xff;
}
static inline void page_kasan_tag_set(struct page *page, u8 tag)
{
- page->flags &= ~(KASAN_TAG_MASK << KASAN_TAG_PGSHIFT);
- page->flags |= (tag & KASAN_TAG_MASK) << KASAN_TAG_PGSHIFT;
+ if (static_branch_likely(&kasan_enabled)) {
+ page->flags &= ~(KASAN_TAG_MASK << KASAN_TAG_PGSHIFT);
+ page->flags |= (tag & KASAN_TAG_MASK) << KASAN_TAG_PGSHIFT;
+ }
}
static inline void page_kasan_tag_reset(struct page *page)
{
- page_kasan_tag_set(page, 0xff);
+ if (static_branch_likely(&kasan_enabled))
+ page_kasan_tag_set(page, 0xff);
}
-#else
+
+#else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
+
static inline u8 page_kasan_tag(const struct page *page)
{
return 0xff;
@@ -1435,7 +1449,8 @@ static inline u8 page_kasan_tag(const struct page *page)
static inline void page_kasan_tag_set(struct page *page, u8 tag) { }
static inline void page_kasan_tag_reset(struct page *page) { }
-#endif
+
+#endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
static inline struct zone *page_zone(const struct page *page)
{
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index cc129ef62ab1..c5ec60e1a4d2 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -81,7 +81,7 @@ asmlinkage void kasan_unpoison_task_stack_below(const void *watermark)
}
#endif /* CONFIG_KASAN_STACK */
-void kasan_alloc_pages(struct page *page, unsigned int order)
+void __kasan_alloc_pages(struct page *page, unsigned int order)
{
u8 tag;
unsigned long i;
@@ -95,7 +95,7 @@ void kasan_alloc_pages(struct page *page, unsigned int order)
kasan_unpoison_memory(page_address(page), PAGE_SIZE << order);
}
-void kasan_free_pages(struct page *page, unsigned int order)
+void __kasan_free_pages(struct page *page, unsigned int order)
{
if (likely(!PageHighMem(page)))
kasan_poison_memory(page_address(page),
@@ -122,8 +122,8 @@ static inline unsigned int optimal_redzone(unsigned int object_size)
object_size <= (1 << 16) - 1024 ? 1024 : 2048;
}
-void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
- slab_flags_t *flags)
+void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
+ slab_flags_t *flags)
{
unsigned int orig_size = *size;
unsigned int redzone_size;
@@ -165,7 +165,7 @@ void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
*flags |= SLAB_KASAN;
}
-size_t kasan_metadata_size(struct kmem_cache *cache)
+size_t __kasan_metadata_size(struct kmem_cache *cache)
{
if (static_branch_unlikely(&kasan_stack))
return (cache->kasan_info.alloc_meta_offset ?
@@ -188,17 +188,17 @@ struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
return (void *)reset_tag(object) + cache->kasan_info.free_meta_offset;
}
-void kasan_unpoison_data(const void *address, size_t size)
+void __kasan_unpoison_data(const void *addr, size_t size)
{
- kasan_unpoison_memory(address, size);
+ kasan_unpoison_memory(addr, size);
}
-void kasan_unpoison_slab(const void *ptr)
+void __kasan_unpoison_slab(const void *ptr)
{
kasan_unpoison_memory(ptr, __ksize(ptr));
}
-void kasan_poison_slab(struct page *page)
+void __kasan_poison_slab(struct page *page)
{
unsigned long i;
@@ -208,12 +208,12 @@ void kasan_poison_slab(struct page *page)
KASAN_KMALLOC_REDZONE);
}
-void kasan_unpoison_object_data(struct kmem_cache *cache, void *object)
+void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object)
{
kasan_unpoison_memory(object, cache->object_size);
}
-void kasan_poison_object_data(struct kmem_cache *cache, void *object)
+void __kasan_poison_object_data(struct kmem_cache *cache, void *object)
{
kasan_poison_memory(object,
round_up(cache->object_size, KASAN_GRANULE_SIZE),
@@ -266,7 +266,7 @@ static u8 assign_tag(struct kmem_cache *cache, const void *object,
#endif
}
-void * __must_check kasan_init_slab_obj(struct kmem_cache *cache,
+void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,
const void *object)
{
struct kasan_alloc_meta *alloc_meta;
@@ -285,7 +285,7 @@ void * __must_check kasan_init_slab_obj(struct kmem_cache *cache,
return (void *)object;
}
-static bool __kasan_slab_free(struct kmem_cache *cache, void *object,
+static bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
unsigned long ip, bool quarantine)
{
u8 tag;
@@ -329,9 +329,9 @@ static bool __kasan_slab_free(struct kmem_cache *cache, void *object,
return false;
}
-bool kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip)
+bool __kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip)
{
- return __kasan_slab_free(cache, object, ip, true);
+ return ____kasan_slab_free(cache, object, ip, true);
}
static void set_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)
@@ -339,7 +339,7 @@ static void set_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)
kasan_set_track(&kasan_get_alloc_meta(cache, object)->alloc_track, flags);
}
-static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object,
+static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object,
size_t size, gfp_t flags, bool keep_tag)
{
unsigned long redzone_start;
@@ -371,20 +371,20 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object,
return set_tag(object, tag);
}
-void * __must_check kasan_slab_alloc(struct kmem_cache *cache, void *object,
- gfp_t flags)
+void * __must_check __kasan_slab_alloc(struct kmem_cache *cache,
+ void *object, gfp_t flags)
{
- return __kasan_kmalloc(cache, object, cache->object_size, flags, false);
+ return ____kasan_kmalloc(cache, object, cache->object_size, flags, false);
}
-void * __must_check kasan_kmalloc(struct kmem_cache *cache, const void *object,
- size_t size, gfp_t flags)
+void * __must_check __kasan_kmalloc(struct kmem_cache *cache, const void *object,
+ size_t size, gfp_t flags)
{
- return __kasan_kmalloc(cache, object, size, flags, true);
+ return ____kasan_kmalloc(cache, object, size, flags, true);
}
-EXPORT_SYMBOL(kasan_kmalloc);
+EXPORT_SYMBOL(__kasan_kmalloc);
-void * __must_check kasan_kmalloc_large(const void *ptr, size_t size,
+void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
gfp_t flags)
{
struct page *page;
@@ -409,7 +409,7 @@ void * __must_check kasan_kmalloc_large(const void *ptr, size_t size,
return (void *)ptr;
}
-void * __must_check kasan_krealloc(const void *object, size_t size, gfp_t flags)
+void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flags)
{
struct page *page;
@@ -419,13 +419,13 @@ void * __must_check kasan_krealloc(const void *object, size_t size, gfp_t flags)
page = virt_to_head_page(object);
if (unlikely(!PageSlab(page)))
- return kasan_kmalloc_large(object, size, flags);
+ return __kasan_kmalloc_large(object, size, flags);
else
- return __kasan_kmalloc(page->slab_cache, object, size,
+ return ____kasan_kmalloc(page->slab_cache, object, size,
flags, true);
}
-void kasan_poison_kfree(void *ptr, unsigned long ip)
+void __kasan_poison_kfree(void *ptr, unsigned long ip)
{
struct page *page;
@@ -438,11 +438,11 @@ void kasan_poison_kfree(void *ptr, unsigned long ip)
}
kasan_poison_memory(ptr, page_size(page), KASAN_FREE_PAGE);
} else {
- __kasan_slab_free(page->slab_cache, ptr, ip, false);
+ ____kasan_slab_free(page->slab_cache, ptr, ip, false);
}
}
-void kasan_kfree_large(void *ptr, unsigned long ip)
+void __kasan_kfree_large(void *ptr, unsigned long ip)
{
if (ptr != page_address(virt_to_head_page(ptr)))
kasan_report_invalid_free(ptr, ip);
--
2.29.0.rc1.297.gfa9743e501-goog
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