From: Rong Tao <rongtao@xxxxxxxx>
commit 40f3bf0cb04c("mm: Convert struct page to struct slab in functions
used by other subsystems") introduce 'slab_address()' and 'struct slab'
in slab_def.h(CONFIG_SLAB) and slub_def.h(CONFIG_SLUB). When referencing
a header file <linux/slub_def.h> in a module or BPF code, 'slab_address()'
and 'struct slab' are not recognized, resulting in incomplete and
undefined errors(see bcc slabratetop.py error [0]).
Moving the function definitions of reference data structures such as
struct slab and slab_address() such as nearest_obj(), obj_to_index(),
and objs_per_slab() to the internal header file slab.h solves this
fatal problem.
[0] https://github.com/iovisor/bcc/issues/4438
Signed-off-by: Rong Tao <rongtao@xxxxxxxx>
---
include/linux/slab_def.h | 33 --------------------
include/linux/slub_def.h | 32 -------------------
mm/slab.h | 66 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 66 insertions(+), 65 deletions(-)
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index 5834bad8ad78..5658b5fddf9b 100644
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -88,37 +88,4 @@ struct kmem_cache {
struct kmem_cache_node *node[MAX_NUMNODES];
};
-static inline void *nearest_obj(struct kmem_cache *cache, const struct slab *slab,
- void *x)
-{
- 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;
- else
- return object;
-}
-
-/*
- * We want to avoid an expensive divide : (offset / cache->size)
- * Using the fact that size is a constant for a particular cache,
- * we can replace (offset / cache->size) by
- * reciprocal_divide(offset, cache->reciprocal_buffer_size)
- */
-static inline unsigned int obj_to_index(const struct kmem_cache *cache,
- const struct slab *slab, void *obj)
-{
- u32 offset = (obj - slab->s_mem);
- return reciprocal_divide(offset, cache->reciprocal_buffer_size);
-}
-
-static inline int objs_per_slab(const struct kmem_cache *cache,
- const struct slab *slab)
-{
- if (is_kfence_address(slab_address(slab)))
- return 1;
- return cache->num;
-}
-
#endif /* _LINUX_SLAB_DEF_H */
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index aa0ee1678d29..660fd6b2a748 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -163,36 +163,4 @@ 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, const struct slab *slab,
- void *x) {
- 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);
- return result;
-}
-
-/* Determine object index from a given position */
-static inline unsigned int __obj_to_index(const struct kmem_cache *cache,
- void *addr, void *obj)
-{
- return reciprocal_divide(kasan_reset_tag(obj) - addr,
- cache->reciprocal_size);
-}
-
-static inline unsigned int obj_to_index(const struct kmem_cache *cache,
- const struct slab *slab, void *obj)
-{
- if (is_kfence_address(obj))
- return 0;
- return __obj_to_index(cache, slab_address(slab), obj);
-}
-
-static inline int objs_per_slab(const struct kmem_cache *cache,
- const struct slab *slab)
-{
- return slab->objects;
-}
#endif /* _LINUX_SLUB_DEF_H */
diff --git a/mm/slab.h b/mm/slab.h
index 7cc432969945..38350a0efa91 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -227,10 +227,76 @@ struct kmem_cache {
#ifdef CONFIG_SLAB
#include <linux/slab_def.h>
+
+static inline void *nearest_obj(struct kmem_cache *cache, const struct slab *slab,
+ void *x)
+{
+ 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;
+ else
+ return object;
+}
+
+/*
+ * We want to avoid an expensive divide : (offset / cache->size)
+ * Using the fact that size is a constant for a particular cache,
+ * we can replace (offset / cache->size) by
+ * reciprocal_divide(offset, cache->reciprocal_buffer_size)
+ */
+static inline unsigned int obj_to_index(const struct kmem_cache *cache,
+ const struct slab *slab, void *obj)
+{
+ u32 offset = (obj - slab->s_mem);
+ return reciprocal_divide(offset, cache->reciprocal_buffer_size);
+}
+
+static inline int objs_per_slab(const struct kmem_cache *cache,
+ const struct slab *slab)
+{
+ if (is_kfence_address(slab_address(slab)))
+ return 1;
+ return cache->num;
+}
#endif
#ifdef CONFIG_SLUB
#include <linux/slub_def.h>
+
+static inline void *nearest_obj(struct kmem_cache *cache, const struct slab *slab,
+ void *x) {
+ 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);
+ return result;
+}
+
+/* Determine object index from a given position */
+static inline unsigned int __obj_to_index(const struct kmem_cache *cache,
+ void *addr, void *obj)
+{
+ return reciprocal_divide(kasan_reset_tag(obj) - addr,
+ cache->reciprocal_size);
+}
+
+static inline unsigned int obj_to_index(const struct kmem_cache *cache,
+ const struct slab *slab, void *obj)
+{
+ if (is_kfence_address(obj))
+ return 0;
+ return __obj_to_index(cache, slab_address(slab), obj);
+}
+
+static inline int objs_per_slab(const struct kmem_cache *cache,
+ const struct slab *slab)
+{
+ return slab->objects;
+}
#endif
#include <linux/memcontrol.h>
--
2.39.0
