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authorAndrey Konovalov <andreyknvl@google.com>2020-12-10 15:42:17 +1100
committerStephen Rothwell <sfr@canb.auug.org.au>2020-12-16 18:03:03 +1100
commit8800546f36b35dca1e1ce174b991bb99ad61348d (patch)
tree7272ef343a67f8293bfb9ef1af3ece169eaa0db7
parentfa4d67e4c7a02f2ad22dc7582392e6f0d55f648b (diff)
downloadlinux-8800546f36b35dca1e1ce174b991bb99ad61348d.tar.gz
kasan, mm: 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. Link: https://lkml.kernel.org/r/9f90e3c0aa840dbb4833367c2335193299f69023.1606162397.git.andreyknvl@google.com Link: https://linux-review.googlesource.com/id/I2589451d3c96c97abbcbf714baabe6161c6f153e Co-developed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com> Signed-off-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.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: Catalin Marinas <catalin.marinas@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--include/linux/kasan.h213
-rw-r--r--include/linux/mm.h22
-rw-r--r--mm/kasan/common.c56
3 files changed, 210 insertions, 81 deletions
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 7350de3e9fe4..9176849c4934 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/static_key.h>
#include <linux/types.h>
struct kmem_cache;
@@ -75,54 +76,176 @@ static inline void kasan_disable_current(void) {}
#ifdef CONFIG_KASAN
-void kasan_unpoison_range(const void *address, size_t size);
+struct kasan_cache {
+ int alloc_meta_offset;
+ int free_meta_offset;
+};
-void kasan_alloc_pages(struct page *page, unsigned int order);
-void kasan_free_pages(struct page *page, unsigned int order);
+#ifdef CONFIG_KASAN_HW_TAGS
+DECLARE_STATIC_KEY_FALSE(kasan_flag_enabled);
+static __always_inline bool kasan_enabled(void)
+{
+ return static_branch_likely(&kasan_flag_enabled);
+}
+#else
+static inline bool kasan_enabled(void)
+{
+ return true;
+}
+#endif
-void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
- slab_flags_t *flags);
+void __kasan_unpoison_range(const void *addr, size_t size);
+static __always_inline void kasan_unpoison_range(const void *addr, size_t size)
+{
+ if (kasan_enabled())
+ __kasan_unpoison_range(addr, size);
+}
-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_alloc_pages(struct page *page, unsigned int order);
+static __always_inline void kasan_alloc_pages(struct page *page,
+ unsigned int order)
+{
+ if (kasan_enabled())
+ __kasan_alloc_pages(page, order);
+}
-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);
+void __kasan_free_pages(struct page *page, unsigned int order);
+static __always_inline void kasan_free_pages(struct page *page,
+ unsigned int order)
+{
+ if (kasan_enabled())
+ __kasan_free_pages(page, order);
+}
-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_cache_create(struct kmem_cache *cache, unsigned int *size,
+ slab_flags_t *flags);
+static __always_inline void kasan_cache_create(struct kmem_cache *cache,
+ unsigned int *size, slab_flags_t *flags)
+{
+ if (kasan_enabled())
+ __kasan_cache_create(cache, size, flags);
+}
-struct kasan_cache {
- int alloc_meta_offset;
- int free_meta_offset;
-};
+size_t __kasan_metadata_size(struct kmem_cache *cache);
+static __always_inline size_t kasan_metadata_size(struct kmem_cache *cache)
+{
+ if (kasan_enabled())
+ return __kasan_metadata_size(cache);
+ return 0;
+}
+
+void __kasan_poison_slab(struct page *page);
+static __always_inline void kasan_poison_slab(struct page *page)
+{
+ if (kasan_enabled())
+ __kasan_poison_slab(page);
+}
+
+void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object);
+static __always_inline void kasan_unpoison_object_data(struct kmem_cache *cache,
+ void *object)
+{
+ if (kasan_enabled())
+ __kasan_unpoison_object_data(cache, object);
+}
+
+void __kasan_poison_object_data(struct kmem_cache *cache, void *object);
+static __always_inline void kasan_poison_object_data(struct kmem_cache *cache,
+ void *object)
+{
+ if (kasan_enabled())
+ __kasan_poison_object_data(cache, object);
+}
+
+void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,
+ const void *object);
+static __always_inline void * __must_check kasan_init_slab_obj(
+ struct kmem_cache *cache, const void *object)
+{
+ if (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 __always_inline bool kasan_slab_free(struct kmem_cache *s, void *object,
+ unsigned long ip)
+{
+ if (kasan_enabled())
+ return __kasan_slab_free(s, object, ip);
+ return false;
+}
+
+void * __must_check __kasan_slab_alloc(struct kmem_cache *s,
+ void *object, gfp_t flags);
+static __always_inline void * __must_check kasan_slab_alloc(
+ struct kmem_cache *s, void *object, gfp_t flags)
+{
+ if (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 __always_inline void * __must_check kasan_kmalloc(struct kmem_cache *s,
+ const void *object, size_t size, gfp_t flags)
+{
+ if (kasan_enabled())
+ return __kasan_kmalloc(s, object, size, flags);
+ return (void *)object;
+}
-size_t kasan_metadata_size(struct kmem_cache *cache);
+void * __must_check __kasan_kmalloc_large(const void *ptr,
+ size_t size, gfp_t flags);
+static __always_inline void * __must_check kasan_kmalloc_large(const void *ptr,
+ size_t size, gfp_t flags)
+{
+ if (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 __always_inline void * __must_check kasan_krealloc(const void *object,
+ size_t new_size, gfp_t flags)
+{
+ if (kasan_enabled())
+ return __kasan_krealloc(object, new_size, flags);
+ return (void *)object;
+}
+
+void __kasan_poison_kfree(void *ptr, unsigned long ip);
+static __always_inline void kasan_poison_kfree(void *ptr, unsigned long ip)
+{
+ if (kasan_enabled())
+ __kasan_poison_kfree(ptr, ip);
+}
+
+void __kasan_kfree_large(void *ptr, unsigned long ip);
+static __always_inline void kasan_kfree_large(void *ptr, unsigned long ip)
+{
+ if (kasan_enabled())
+ __kasan_kfree_large(ptr, ip);
+}
bool kasan_save_enable_multi_shot(void);
void kasan_restore_multi_shot(bool enabled);
#else /* CONFIG_KASAN */
+static inline bool kasan_enabled(void)
+{
+ return false;
+}
static inline void kasan_unpoison_range(const void *address, size_t size) {}
-
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 size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
static inline void kasan_poison_slab(struct page *page) {}
static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
void *object) {}
@@ -133,36 +256,32 @@ 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_slab_alloc(struct kmem_cache *s, void *object,
+ gfp_t flags)
+{
+ return object;
}
-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)
{
return (void *)object;
}
+static inline void *kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags)
+{
+ return (void *)ptr;
+}
static inline void *kasan_krealloc(const void *object, size_t new_size,
gfp_t flags)
{
return (void *)object;
}
-
-static inline void *kasan_slab_alloc(struct kmem_cache *s, void *object,
- gfp_t flags)
-{
- return object;
-}
-static inline bool kasan_slab_free(struct kmem_cache *s, void *object,
- unsigned long ip)
-{
- return false;
-}
-
-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 024ec0a00c72..5299b90a6c40 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -31,6 +31,7 @@
#include <linux/sizes.h>
#include <linux/sched.h>
#include <linux/pgtable.h>
+#include <linux/kasan.h>
struct mempolicy;
struct anon_vma;
@@ -1422,22 +1423,30 @@ 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)
+
static inline u8 page_kasan_tag(const struct page *page)
{
- return (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK;
+ if (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 (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 (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;
@@ -1445,7 +1454,8 @@ 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 a11e3e75eb08..17918bd20ed9 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -59,7 +59,7 @@ void kasan_disable_current(void)
}
#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
-void kasan_unpoison_range(const void *address, size_t size)
+void __kasan_unpoison_range(const void *address, size_t size)
{
unpoison_range(address, size);
}
@@ -87,7 +87,7 @@ 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;
@@ -101,7 +101,7 @@ void kasan_alloc_pages(struct page *page, unsigned int order)
unpoison_range(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)))
poison_range(page_address(page),
@@ -128,8 +128,8 @@ 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;
@@ -174,7 +174,7 @@ 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 (!kasan_stack_collection_enabled())
return 0;
@@ -197,7 +197,7 @@ struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
return kasan_reset_tag(object) + cache->kasan_info.free_meta_offset;
}
-void kasan_poison_slab(struct page *page)
+void __kasan_poison_slab(struct page *page)
{
unsigned long i;
@@ -207,12 +207,12 @@ 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)
{
unpoison_range(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)
{
poison_range(object,
round_up(cache->object_size, KASAN_GRANULE_SIZE),
@@ -265,7 +265,7 @@ 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;
@@ -284,7 +284,7 @@ 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;
@@ -330,9 +330,9 @@ static bool __kasan_slab_free(struct kmem_cache *cache, void *object,
return IS_ENABLED(CONFIG_KASAN_GENERIC);
}
-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)
@@ -340,7 +340,7 @@ 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;
@@ -375,20 +375,20 @@ 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;
@@ -413,7 +413,7 @@ 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;
@@ -423,13 +423,13 @@ 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;
@@ -442,11 +442,11 @@ void kasan_poison_kfree(void *ptr, unsigned long ip)
}
poison_range(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);