On Tue, Nov 16, 2021 at 1:16 AM Vlastimil Babka <vbabka@xxxxxxx> wrote:
>
> KASAN, KFENCE and memcg interact with SLAB or SLUB internals through functions
> nearest_obj(), obj_to_index() and objs_per_slab() that use struct page as
> parameter. This patch converts it to struct slab including all callers, through
> a coccinelle semantic patch.
>
> // Options: --include-headers --no-includes --smpl-spacing include/linux/slab_def.h include/linux/slub_def.h mm/slab.h mm/kasan/*.c mm/kfence/kfence_test.c mm/memcontrol.c mm/slab.c mm/slub.c
> // Note: needs coccinelle 1.1.1 to avoid breaking whitespace
>
> @@
> @@
>
> -objs_per_slab_page(
> +objs_per_slab(
> ...
> )
> { ... }
>
> @@
> @@
>
> -objs_per_slab_page(
> +objs_per_slab(
> ...
> )
>
> @@
> identifier fn =~ "obj_to_index|objs_per_slab";
> @@
>
> fn(...,
> - const struct page *page
> + const struct slab *slab
> ,...)
> {
> <...
> (
> - page_address(page)
> + slab_address(slab)
> |
> - page
> + slab
> )
> ...>
> }
>
> @@
> identifier fn =~ "nearest_obj";
> @@
>
> fn(...,
> - struct page *page
> + const struct slab *slab
> ,...)
> {
> <...
> (
> - page_address(page)
> + slab_address(slab)
> |
> - page
> + slab
> )
> ...>
> }
>
> @@
> identifier fn =~ "nearest_obj|obj_to_index|objs_per_slab";
> expression E;
> @@
>
> fn(...,
> (
> - slab_page(E)
> + E
> |
> - virt_to_page(E)
> + virt_to_slab(E)
> |
> - virt_to_head_page(E)
> + virt_to_slab(E)
> |
> - page
> + page_slab(page)
> )
> ,...)
>
> Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
> Cc: Julia Lawall <julia.lawall@xxxxxxxx>
> Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
> Cc: Alexander Potapenko <glider@xxxxxxxxxx>
> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx>
> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Cc: Marco Elver <elver@xxxxxxxxxx>
> Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxxxx>
> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
> Cc: <kasan-dev@xxxxxxxxxxxxxxxx>
> Cc: <cgroups@xxxxxxxxxxxxxxx>
> ---
> include/linux/slab_def.h | 16 ++++++++--------
> include/linux/slub_def.h | 18 +++++++++---------
> mm/kasan/common.c | 4 ++--
> mm/kasan/generic.c | 2 +-
> mm/kasan/report.c | 2 +-
> mm/kasan/report_tags.c | 2 +-
> mm/kfence/kfence_test.c | 4 ++--
> mm/memcontrol.c | 4 ++--
> mm/slab.c | 10 +++++-----
> mm/slab.h | 4 ++--
> mm/slub.c | 2 +-
> 11 files changed, 34 insertions(+), 34 deletions(-)
>
> diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
> index 3aa5e1e73ab6..e24c9aff6fed 100644
> --- a/include/linux/slab_def.h
> +++ b/include/linux/slab_def.h
> @@ -87,11 +87,11 @@ struct kmem_cache {
> struct kmem_cache_node *node[MAX_NUMNODES];
> };
>
> -static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
> +static inline void *nearest_obj(struct kmem_cache *cache, const struct slab *slab,
> void *x)
> {
> - void *object = x - (x - page->s_mem) % cache->size;
> - void *last_object = page->s_mem + (cache->num - 1) * cache->size;
> + void *object = x - (x - slab->s_mem) % cache->size;
> + void *last_object = slab->s_mem + (cache->num - 1) * cache->size;
>
> if (unlikely(object > last_object))
> return last_object;
> @@ -106,16 +106,16 @@ static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
> * reciprocal_divide(offset, cache->reciprocal_buffer_size)
> */
> static inline unsigned int obj_to_index(const struct kmem_cache *cache,
> - const struct page *page, void *obj)
> + const struct slab *slab, void *obj)
> {
> - u32 offset = (obj - page->s_mem);
> + u32 offset = (obj - slab->s_mem);
> return reciprocal_divide(offset, cache->reciprocal_buffer_size);
> }
>
> -static inline int objs_per_slab_page(const struct kmem_cache *cache,
> - const struct page *page)
> +static inline int objs_per_slab(const struct kmem_cache *cache,
> + const struct slab *slab)
> {
> - if (is_kfence_address(page_address(page)))
> + if (is_kfence_address(slab_address(slab)))
> return 1;
> return cache->num;
> }
> diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
> index 8a9c2876ca89..33c5c0e3bd8d 100644
> --- a/include/linux/slub_def.h
> +++ b/include/linux/slub_def.h
> @@ -158,11 +158,11 @@ static inline void sysfs_slab_release(struct kmem_cache *s)
>
> void *fixup_red_left(struct kmem_cache *s, void *p);
>
> -static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
> +static inline void *nearest_obj(struct kmem_cache *cache, const struct slab *slab,
> void *x) {
> - void *object = x - (x - page_address(page)) % cache->size;
> - void *last_object = page_address(page) +
> - (page->objects - 1) * cache->size;
> + void *object = x - (x - slab_address(slab)) % cache->size;
> + void *last_object = slab_address(slab) +
> + (slab->objects - 1) * cache->size;
> void *result = (unlikely(object > last_object)) ? last_object : object;
>
> result = fixup_red_left(cache, result);
> @@ -178,16 +178,16 @@ static inline unsigned int __obj_to_index(const struct kmem_cache *cache,
> }
>
> static inline unsigned int obj_to_index(const struct kmem_cache *cache,
> - const struct page *page, void *obj)
> + const struct slab *slab, void *obj)
> {
> if (is_kfence_address(obj))
> return 0;
> - return __obj_to_index(cache, page_address(page), obj);
> + return __obj_to_index(cache, slab_address(slab), obj);
> }
>
> -static inline int objs_per_slab_page(const struct kmem_cache *cache,
> - const struct page *page)
> +static inline int objs_per_slab(const struct kmem_cache *cache,
> + const struct slab *slab)
> {
> - return page->objects;
> + return slab->objects;
> }
> #endif /* _LINUX_SLUB_DEF_H */
> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> index 8428da2aaf17..6a1cd2d38bff 100644
> --- a/mm/kasan/common.c
> +++ b/mm/kasan/common.c
> @@ -298,7 +298,7 @@ static inline u8 assign_tag(struct kmem_cache *cache,
> /* For caches that either have a constructor or SLAB_TYPESAFE_BY_RCU: */
> #ifdef CONFIG_SLAB
> /* For SLAB assign tags based on the object index in the freelist. */
> - return (u8)obj_to_index(cache, virt_to_head_page(object), (void *)object);
> + return (u8)obj_to_index(cache, virt_to_slab(object), (void *)object);
> #else
> /*
> * For SLUB assign a random tag during slab creation, otherwise reuse
> @@ -341,7 +341,7 @@ static inline bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
> if (is_kfence_address(object))
> return false;
>
> - if (unlikely(nearest_obj(cache, virt_to_head_page(object), object) !=
> + if (unlikely(nearest_obj(cache, virt_to_slab(object), object) !=
> object)) {
> kasan_report_invalid_free(tagged_object, ip);
> return true;
> diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
> index 84a038b07c6f..5d0b79416c4e 100644
> --- a/mm/kasan/generic.c
> +++ b/mm/kasan/generic.c
> @@ -339,7 +339,7 @@ static void __kasan_record_aux_stack(void *addr, bool can_alloc)
> return;
>
> cache = page->slab_cache;
> - object = nearest_obj(cache, page, addr);
> + object = nearest_obj(cache, page_slab(page), addr);
> alloc_meta = kasan_get_alloc_meta(cache, object);
> if (!alloc_meta)
> return;
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index 0bc10f452f7e..e00999dc6499 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -249,7 +249,7 @@ static void print_address_description(void *addr, u8 tag)
>
> if (page && PageSlab(page)) {
> struct kmem_cache *cache = page->slab_cache;
> - void *object = nearest_obj(cache, page, addr);
> + void *object = nearest_obj(cache, page_slab(page), addr);
The tab before addr should be a space. checkpatch should probably report this.
>
> describe_object(cache, object, addr, tag);
> }
> diff --git a/mm/kasan/report_tags.c b/mm/kasan/report_tags.c
> index 8a319fc16dab..06c21dd77493 100644
> --- a/mm/kasan/report_tags.c
> +++ b/mm/kasan/report_tags.c
> @@ -23,7 +23,7 @@ const char *kasan_get_bug_type(struct kasan_access_info *info)
> page = kasan_addr_to_page(addr);
> if (page && PageSlab(page)) {
> cache = page->slab_cache;
> - object = nearest_obj(cache, page, (void *)addr);
> + object = nearest_obj(cache, page_slab(page), (void *)addr);
> alloc_meta = kasan_get_alloc_meta(cache, object);
>
> if (alloc_meta) {
> diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c
> index 695030c1fff8..f7276711d7b9 100644
> --- a/mm/kfence/kfence_test.c
> +++ b/mm/kfence/kfence_test.c
> @@ -291,8 +291,8 @@ static void *test_alloc(struct kunit *test, size_t size, gfp_t gfp, enum allocat
> * even for KFENCE objects; these are required so that
> * memcg accounting works correctly.
> */
> - KUNIT_EXPECT_EQ(test, obj_to_index(s, page, alloc), 0U);
> - KUNIT_EXPECT_EQ(test, objs_per_slab_page(s, page), 1);
> + KUNIT_EXPECT_EQ(test, obj_to_index(s, page_slab(page), alloc), 0U);
> + KUNIT_EXPECT_EQ(test, objs_per_slab(s, page_slab(page)), 1);
>
> if (policy == ALLOCATE_ANY)
> return alloc;
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 781605e92015..c8b53ec074b4 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2819,7 +2819,7 @@ static struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg)
> int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s,
> gfp_t gfp, bool new_page)
> {
> - unsigned int objects = objs_per_slab_page(s, page);
> + unsigned int objects = objs_per_slab(s, page_slab(page));
> unsigned long memcg_data;
> void *vec;
>
> @@ -2881,7 +2881,7 @@ struct mem_cgroup *mem_cgroup_from_obj(void *p)
> struct obj_cgroup *objcg;
> unsigned int off;
>
> - off = obj_to_index(page->slab_cache, page, p);
> + off = obj_to_index(page->slab_cache, page_slab(page), p);
> objcg = page_objcgs(page)[off];
> if (objcg)
> return obj_cgroup_memcg(objcg);
> diff --git a/mm/slab.c b/mm/slab.c
> index 78ef4d94e3de..adf688d2da64 100644
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -1560,7 +1560,7 @@ static void check_poison_obj(struct kmem_cache *cachep, void *objp)
> struct slab *slab = virt_to_slab(objp);
> unsigned int objnr;
>
> - objnr = obj_to_index(cachep, slab_page(slab), objp);
> + objnr = obj_to_index(cachep, slab, objp);
> if (objnr) {
> objp = index_to_obj(cachep, slab, objnr - 1);
> realobj = (char *)objp + obj_offset(cachep);
> @@ -2530,7 +2530,7 @@ static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slab)
> static void slab_put_obj(struct kmem_cache *cachep,
> struct slab *slab, void *objp)
> {
> - unsigned int objnr = obj_to_index(cachep, slab_page(slab), objp);
> + unsigned int objnr = obj_to_index(cachep, slab, objp);
> #if DEBUG
> unsigned int i;
>
> @@ -2717,7 +2717,7 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
> if (cachep->flags & SLAB_STORE_USER)
> *dbg_userword(cachep, objp) = (void *)caller;
>
> - objnr = obj_to_index(cachep, slab_page(slab), objp);
> + objnr = obj_to_index(cachep, slab, objp);
>
> BUG_ON(objnr >= cachep->num);
> BUG_ON(objp != index_to_obj(cachep, slab, objnr));
> @@ -3663,7 +3663,7 @@ void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
> objp = object - obj_offset(cachep);
> kpp->kp_data_offset = obj_offset(cachep);
> slab = virt_to_slab(objp);
> - objnr = obj_to_index(cachep, slab_page(slab), objp);
> + objnr = obj_to_index(cachep, slab, objp);
> objp = index_to_obj(cachep, slab, objnr);
> kpp->kp_objp = objp;
> if (DEBUG && cachep->flags & SLAB_STORE_USER)
> @@ -4182,7 +4182,7 @@ void __check_heap_object(const void *ptr, unsigned long n,
>
> /* Find and validate object. */
> cachep = slab->slab_cache;
> - objnr = obj_to_index(cachep, slab_page(slab), (void *)ptr);
> + objnr = obj_to_index(cachep, slab, (void *)ptr);
> BUG_ON(objnr >= cachep->num);
>
> /* Find offset within object. */
> diff --git a/mm/slab.h b/mm/slab.h
> index d6c993894c02..b07e842b5cfc 100644
> --- a/mm/slab.h
> +++ b/mm/slab.h
> @@ -483,7 +483,7 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
> continue;
> }
>
> - off = obj_to_index(s, page, p[i]);
> + off = obj_to_index(s, page_slab(page), p[i]);
> obj_cgroup_get(objcg);
> page_objcgs(page)[off] = objcg;
> mod_objcg_state(objcg, page_pgdat(page),
> @@ -522,7 +522,7 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
> else
> s = s_orig;
>
> - off = obj_to_index(s, page, p[i]);
> + off = obj_to_index(s, page_slab(page), p[i]);
> objcg = objcgs[off];
> if (!objcg)
> continue;
> diff --git a/mm/slub.c b/mm/slub.c
> index 7759f3dde64b..981e40a88bab 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -4342,7 +4342,7 @@ void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
> #else
> objp = objp0;
> #endif
> - objnr = obj_to_index(s, slab_page(slab), objp);
> + objnr = obj_to_index(s, slab, objp);
> kpp->kp_data_offset = (unsigned long)((char *)objp0 - (char *)objp);
> objp = base + s->size * objnr;
> kpp->kp_objp = objp;
> --
> 2.33.1
>
