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 <redacted>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <redacted>
Cc: <redacted>
Cc: <redacted>
---
 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);

                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