mm/kasan: simplify and refine kasan_cache code

struct 'kasan_cache' has a member 'is_kmalloc' indicating whether its host
kmem_cache is a kmalloc cache.  With newly introduced is_kmalloc_cache()
helper, 'is_kmalloc' and its related function can be replaced and removed.

Also 'kasan_cache' is only needed by KASAN generic mode, and not by SW/HW
tag modes, so refine its protection macro accordingly, suggested by Andrey
Konoval.

Link: https://lkml.kernel.org/r/20230104060605.930910-2-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 5ebbaf6..f7ef706 100644 (file)
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -96,15 +96,6 @@ static inline bool kasan_has_integrated_init(void)
 }
 
 #ifdef CONFIG_KASAN
-
-struct kasan_cache {
-#ifdef CONFIG_KASAN_GENERIC
-       int alloc_meta_offset;
-       int free_meta_offset;
-#endif
-       bool is_kmalloc;
-};
-
 void __kasan_unpoison_range(const void *addr, size_t size);
 static __always_inline void kasan_unpoison_range(const void *addr, size_t size)
 {
@@ -129,13 +120,6 @@ static __always_inline bool kasan_unpoison_pages(struct page *page,
        return false;
 }
 
-void __kasan_cache_create_kmalloc(struct kmem_cache *cache);
-static __always_inline void kasan_cache_create_kmalloc(struct kmem_cache *cache)
-{
-       if (kasan_enabled())
-               __kasan_cache_create_kmalloc(cache);
-}
-
 void __kasan_poison_slab(struct slab *slab);
 static __always_inline void kasan_poison_slab(struct slab *slab)
 {
@@ -255,7 +239,6 @@ static inline bool kasan_unpoison_pages(struct page *page, unsigned int order,
 {
        return false;
 }
-static inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) {}
 static inline void kasan_poison_slab(struct slab *slab) {}
 static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
                                        void *object) {}
@@ -306,6 +289,11 @@ static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
 
 #ifdef CONFIG_KASAN_GENERIC
 
+struct kasan_cache {
+       int alloc_meta_offset;
+       int free_meta_offset;
+};
+
 size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object);
 slab_flags_t kasan_never_merge(void);
 void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,

diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index 5834bad..a61e7d5 100644 (file)
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -72,7 +72,7 @@ struct kmem_cache {
        int obj_offset;
 #endif /* CONFIG_DEBUG_SLAB */
 
-#ifdef CONFIG_KASAN
+#ifdef CONFIG_KASAN_GENERIC
        struct kasan_cache kasan_info;
 #endif
 

diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index aa0ee16..f6df03f 100644 (file)
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -136,7 +136,7 @@ struct kmem_cache {
        unsigned int *random_seq;
 #endif
 
-#ifdef CONFIG_KASAN
+#ifdef CONFIG_KASAN_GENERIC
        struct kasan_cache kasan_info;
 #endif
 

diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 1d0008e..6b8e9c8 100644 (file)
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -122,11 +122,6 @@ void __kasan_poison_pages(struct page *page, unsigned int order, bool init)
                             KASAN_PAGE_FREE, init);
 }
 
-void __kasan_cache_create_kmalloc(struct kmem_cache *cache)
-{
-       cache->kasan_info.is_kmalloc = true;
-}
-
 void __kasan_poison_slab(struct slab *slab)
 {
        struct page *page = slab_page(slab);
@@ -326,7 +321,7 @@ void * __must_check __kasan_slab_alloc(struct kmem_cache *cache,
        kasan_unpoison(tagged_object, cache->object_size, init);
 
        /* Save alloc info (if possible) for non-kmalloc() allocations. */
-       if (kasan_stack_collection_enabled() && !cache->kasan_info.is_kmalloc)
+       if (kasan_stack_collection_enabled() && !is_kmalloc_cache(cache))
                kasan_save_alloc_info(cache, tagged_object, flags);
 
        return tagged_object;
@@ -372,7 +367,7 @@ static inline void *____kasan_kmalloc(struct kmem_cache *cache,
         * Save alloc info (if possible) for kmalloc() allocations.
         * This also rewrites the alloc info when called from kasan_krealloc().
         */
-       if (kasan_stack_collection_enabled() && cache->kasan_info.is_kmalloc)
+       if (kasan_stack_collection_enabled() && is_kmalloc_cache(cache))
                kasan_save_alloc_info(cache, (void *)object, flags);
 
        /* Keep the tag that was set by kasan_slab_alloc(). */

diff --git a/mm/slab_common.c b/mm/slab_common.c
index 1cba98a..bf4e777 100644 (file)
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -670,7 +670,6 @@ struct kmem_cache *__init create_kmalloc_cache(const char *name,
 
        create_boot_cache(s, name, size, flags | SLAB_KMALLOC, useroffset,
                                                                usersize);
-       kasan_cache_create_kmalloc(s);
        list_add(&s->list, &slab_caches);
        s->refcount = 1;
        return s;