From: Joonsoo Kim <[email protected]> To prepare per object memory for vchecker, we need to change the layout of the object when kmem_cache initialization. Add such code on vchecker_cache_create() which is called when kmem_cache initialization.
And, this memory should be initialized when object is populated. Do it with another hook. This memory will be used in the following patch. Signed-off-by: Joonsoo Kim <[email protected]> --- mm/kasan/vchecker.c | 15 +++++++++++++++ mm/kasan/vchecker.h | 4 ++++ mm/slab.c | 2 ++ mm/slub.c | 2 ++ 4 files changed, 23 insertions(+) diff --git a/mm/kasan/vchecker.c b/mm/kasan/vchecker.c index 0b8a1e7..be0f0cd 100644 --- a/mm/kasan/vchecker.c +++ b/mm/kasan/vchecker.c @@ -31,6 +31,10 @@ enum vchecker_type_num { VCHECKER_TYPE_MAX, }; +struct vchecker_data { + void *dummy; +}; + struct vchecker_type { char *name; const struct file_operations *fops; @@ -109,10 +113,21 @@ static int remove_cbs(struct kmem_cache *s, struct vchecker_type *t) return 0; } +void vchecker_init_slab_obj(struct kmem_cache *s, const void *object) +{ + struct vchecker_data *data; + + data = (void *)object + s->vchecker_cache.data_offset; + __memset(data, 0, sizeof(*data)); +} + void vchecker_cache_create(struct kmem_cache *s, size_t *size, slab_flags_t *flags) { *flags |= SLAB_VCHECKER; + + s->vchecker_cache.data_offset = *size; + *size += sizeof(struct vchecker_data); } void vchecker_kmalloc(struct kmem_cache *s, const void *object, size_t size) diff --git a/mm/kasan/vchecker.h b/mm/kasan/vchecker.h index aa22e8d..efebc63 100644 --- a/mm/kasan/vchecker.h +++ b/mm/kasan/vchecker.h @@ -7,6 +7,7 @@ struct vchecker_cb; struct vchecker_cache { struct vchecker *checker; struct dentry *dir; + int data_offset; }; @@ -18,6 +19,7 @@ int init_vchecker(struct kmem_cache *s); void fini_vchecker(struct kmem_cache *s); void vchecker_cache_create(struct kmem_cache *s, size_t *size, slab_flags_t *flags); +void vchecker_init_slab_obj(struct kmem_cache *s, const void *object); void vchecker_enable_cache(struct kmem_cache *s, bool enable); void vchecker_enable_obj(struct kmem_cache *s, const void *object, size_t size, bool enable); @@ -31,6 +33,8 @@ static inline int init_vchecker(struct kmem_cache *s) { return 0; } static inline void fini_vchecker(struct kmem_cache *s) { } static inline void vchecker_cache_create(struct kmem_cache *s, size_t *size, slab_flags_t *flags) {} +static inline void vchecker_init_slab_obj(struct kmem_cache *s, + const void *object) {} #endif diff --git a/mm/slab.c b/mm/slab.c index ba45c15..64d768b 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2076,6 +2076,7 @@ int __kmem_cache_create(struct kmem_cache *cachep, slab_flags_t flags) } #endif + vchecker_cache_create(cachep, &size, &flags); kasan_cache_create(cachep, &size, &flags); size = ALIGN(size, cachep->align); @@ -2601,6 +2602,7 @@ static void cache_init_objs(struct kmem_cache *cachep, for (i = 0; i < cachep->num; i++) { objp = index_to_obj(cachep, page, i); + vchecker_init_slab_obj(cachep, objp); kasan_init_slab_obj(cachep, objp); /* constructor could break poison info */ diff --git a/mm/slub.c b/mm/slub.c index 67364cb..c099b33 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1418,6 +1418,7 @@ static void setup_object(struct kmem_cache *s, struct page *page, void *object) { setup_object_debug(s, page, object); + vchecker_init_slab_obj(s, object); kasan_init_slab_obj(s, object); if (unlikely(s->ctor)) { kasan_unpoison_object_data(s, object); @@ -3550,6 +3551,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order) size += 2 * sizeof(struct track); #endif + vchecker_cache_create(s, &size, &s->flags); kasan_cache_create(s, &size, &s->flags); #ifdef CONFIG_SLUB_DEBUG if (flags & SLAB_RED_ZONE) { -- 2.7.4
