[PATCH v2 18/23] mm/sl[au]b: generalize kmalloc subsystem

From: Hyeonggon Yoo
Date: Thu Apr 14 2022 - 05:02:03 EST


Now everything in kmalloc subsystem can be generalized.
Let's do it!

Generalize __kmalloc_node_track_caller(), kfree(), __ksize(),
__kmalloc_node() and move them to slab_common.c.

Signed-off-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
---
mm/slab.c | 94 -----------------------------------------------
mm/slab_common.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++
mm/slub.c | 88 --------------------------------------------
3 files changed, 95 insertions(+), 182 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index d35873da5572..fc00aca62ae3 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3527,36 +3527,6 @@ void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep,
EXPORT_SYMBOL(kmem_cache_alloc_node_trace);
#endif

-static __always_inline void *
-__do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller)
-{
- struct kmem_cache *cachep;
- void *ret;
-
- if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))
- return kmalloc_large_node(size, flags, node);
- cachep = kmalloc_slab(size, flags);
- if (unlikely(ZERO_OR_NULL_PTR(cachep)))
- return cachep;
- ret = kmem_cache_alloc_node_trace(cachep, flags, node, size);
- ret = kasan_kmalloc(cachep, ret, size, flags);
-
- return ret;
-}
-
-void *__kmalloc_node(size_t size, gfp_t flags, int node)
-{
- return __do_kmalloc_node(size, flags, node, _RET_IP_);
-}
-EXPORT_SYMBOL(__kmalloc_node);
-
-void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
- int node, unsigned long caller)
-{
- return __do_kmalloc_node(size, flags, node, caller);
-}
-EXPORT_SYMBOL(__kmalloc_node_track_caller);
-
#ifdef CONFIG_PRINTK
void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
{
@@ -3635,43 +3605,6 @@ void kmem_cache_free_bulk(struct kmem_cache *orig_s, size_t size, void **p)
}
EXPORT_SYMBOL(kmem_cache_free_bulk);

-/**
- * kfree - free previously allocated memory
- * @objp: pointer returned by kmalloc.
- *
- * If @objp is NULL, no operation is performed.
- *
- * Don't free memory not originally allocated by kmalloc()
- * or you will run into trouble.
- */
-void kfree(const void *objp)
-{
- struct kmem_cache *c;
- unsigned long flags;
- struct folio *folio;
-
-
- if (unlikely(ZERO_OR_NULL_PTR(objp)))
- return;
-
- folio = virt_to_folio(objp);
- if (!folio_test_slab(folio)) {
- free_large_kmalloc(folio, (void *)objp);
- return;
- }
-
- c = folio_slab(folio)->slab_cache;
- trace_kmem_cache_free(c->name, _RET_IP_, objp);
-
- local_irq_save(flags);
- kfree_debugcheck(objp);
- debug_check_no_locks_freed(objp, c->object_size);
- debug_check_no_obj_freed(objp, c->object_size);
- __cache_free(c, (void *)objp, _RET_IP_);
- local_irq_restore(flags);
-}
-EXPORT_SYMBOL(kfree);
-
/*
* This initializes kmem_cache_node or resizes various caches for all nodes.
*/
@@ -4074,30 +4007,3 @@ void __check_heap_object(const void *ptr, unsigned long n,
usercopy_abort("SLAB object", cachep->name, to_user, offset, n);
}
#endif /* CONFIG_HARDENED_USERCOPY */
-
-/**
- * __ksize -- Uninstrumented ksize.
- * @objp: pointer to the object
- *
- * Unlike ksize(), __ksize() is uninstrumented, and does not provide the same
- * safety checks as ksize() with KASAN instrumentation enabled.
- *
- * Return: size of the actual memory used by @objp in bytes
- */
-size_t __ksize(const void *objp)
-{
- struct kmem_cache *c;
- struct folio *folio;
-
- BUG_ON(!objp);
- if (unlikely(objp == ZERO_SIZE_PTR))
- return 0;
-
- folio = virt_to_folio(objp);
- if (!folio_test_slab(folio))
- return folio_size(folio);
-
- c = folio_slab(folio)->slab_cache;
- return c->object_size;
-}
-EXPORT_SYMBOL(__ksize);
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 3cd5d7a47ec7..daf626e25e12 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -918,6 +918,101 @@ void free_large_kmalloc(struct folio *folio, void *object)
-(PAGE_SIZE << order));
__free_pages(folio_page(folio, 0), order);
}
+
+void *__kmalloc_node(size_t size, gfp_t flags, int node)
+{
+ struct kmem_cache *s;
+ void *ret;
+
+ if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))
+ return kmalloc_large_node(size, flags, node);
+
+ s = kmalloc_slab(size, flags);
+
+ if (unlikely(ZERO_OR_NULL_PTR(s)))
+ return s;
+
+ ret = __kmem_cache_alloc_node(s, NULL, flags, node, _RET_IP_);
+ ret = kasan_kmalloc(s, ret, size, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(__kmalloc_node);
+
+void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
+ int node, unsigned long caller)
+{
+ struct kmem_cache *s;
+ void *ret;
+
+ if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))
+ return kmalloc_large_node(size, gfpflags, node);
+
+ s = kmalloc_slab(size, gfpflags);
+
+ if (unlikely(ZERO_OR_NULL_PTR(s)))
+ return s;
+
+ ret = __kmem_cache_alloc_node(s, NULL, gfpflags, node, caller);
+
+ return ret;
+}
+EXPORT_SYMBOL(__kmalloc_node_track_caller);
+
+/**
+ * kfree - free previously allocated memory
+ * @objp: pointer returned by kmalloc.
+ *
+ * If @objp is NULL, no operation is performed.
+ *
+ * Don't free memory not originally allocated by kmalloc()
+ * or you will run into trouble.
+ */
+void kfree(const void *object)
+{
+ struct folio *folio;
+ struct slab *slab;
+ struct kmem_cache *s;
+
+ if (unlikely(ZERO_OR_NULL_PTR(object)))
+ return;
+
+ folio = virt_to_folio(object);
+ if (unlikely(!folio_test_slab(folio))) {
+ free_large_kmalloc(folio, (void *)object);
+ return;
+ }
+
+ slab = folio_slab(folio);
+ s = slab->slab_cache;
+ __kmem_cache_free(s, object, _RET_IP_);
+}
+EXPORT_SYMBOL(kfree);
+
+/**
+ * __ksize -- Uninstrumented ksize.
+ * @objp: pointer to the object
+ *
+ * Unlike ksize(), __ksize() is uninstrumented, and does not provide the same
+ * safety checks as ksize() with KASAN instrumentation enabled.
+ *
+ * Return: size of the actual memory used by @objp in bytes
+ */
+size_t __ksize(const void *object)
+{
+ struct folio *folio;
+
+ if (unlikely(object == ZERO_SIZE_PTR))
+ return 0;
+
+ folio = virt_to_folio(object);
+
+ if (unlikely(!folio_test_slab(folio)))
+ return folio_size(folio);
+
+ return slab_ksize(folio_slab(folio)->slab_cache);
+}
+EXPORT_SYMBOL(__ksize);
#endif /* !CONFIG_SLOB */

gfp_t kmalloc_fix_flags(gfp_t flags)
diff --git a/mm/slub.c b/mm/slub.c
index a72a2d08e793..bc9c96ce0521 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4338,30 +4338,6 @@ static int __init setup_slub_min_objects(char *str)

__setup("slub_min_objects=", setup_slub_min_objects);

-void *__kmalloc_node(size_t size, gfp_t flags, int node)
-{
- struct kmem_cache *s;
- void *ret;
-
- if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))
- return kmalloc_large_node(size, flags, node);
-
- s = kmalloc_slab(size, flags);
-
- if (unlikely(ZERO_OR_NULL_PTR(s)))
- return s;
-
- ret = slab_alloc_node(s, NULL, flags, node, _RET_IP_, size);
-
- trace_kmem_cache_alloc(s->name, _RET_IP_, ret, size,
- s->size, flags, node);
-
- ret = kasan_kmalloc(s, ret, size, flags);
-
- return ret;
-}
-EXPORT_SYMBOL(__kmalloc_node);
-
#ifdef CONFIG_HARDENED_USERCOPY
/*
* Rejects incorrectly sized objects and objects that are to be copied
@@ -4412,46 +4388,6 @@ void __check_heap_object(const void *ptr, unsigned long n,
}
#endif /* CONFIG_HARDENED_USERCOPY */

-size_t __ksize(const void *object)
-{
- struct folio *folio;
-
- if (unlikely(object == ZERO_SIZE_PTR))
- return 0;
-
- folio = virt_to_folio(object);
-
- if (unlikely(!folio_test_slab(folio)))
- return folio_size(folio);
-
- return slab_ksize(folio_slab(folio)->slab_cache);
-}
-EXPORT_SYMBOL(__ksize);
-
-void kfree(const void *x)
-{
- struct folio *folio;
- struct slab *slab;
- void *object = (void *)x;
- struct kmem_cache *s;
-
- if (unlikely(ZERO_OR_NULL_PTR(x)))
- return;
-
- folio = virt_to_folio(x);
- if (unlikely(!folio_test_slab(folio))) {
- free_large_kmalloc(folio, object);
- return;
- }
-
- slab = folio_slab(folio);
- s = slab->slab_cache;
-
- trace_kmem_cache_free(s->name, _RET_IP_, x);
- slab_free(s, slab, object, NULL, 1, _RET_IP_);
-}
-EXPORT_SYMBOL(kfree);
-
#define SHRINK_PROMOTE_MAX 32

/*
@@ -4799,30 +4735,6 @@ int __kmem_cache_create(struct kmem_cache *s, slab_flags_t flags)
return 0;
}

-void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
- int node, unsigned long caller)
-{
- struct kmem_cache *s;
- void *ret;
-
- if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))
- return kmalloc_large_node(size, gfpflags, node);
-
- s = kmalloc_slab(size, gfpflags);
-
- if (unlikely(ZERO_OR_NULL_PTR(s)))
- return s;
-
- ret = slab_alloc_node(s, NULL, gfpflags, node, caller, size);
-
- /* Honor the call site pointer we received. */
- trace_kmem_cache_alloc(s->name, caller, ret, size,
- s->size, gfpflags, node);
-
- return ret;
-}
-EXPORT_SYMBOL(__kmalloc_node_track_caller);
-
#ifdef CONFIG_SYSFS
static int count_inuse(struct slab *slab)
{
--
2.32.0