v4.19.13 snapshot.
diff --git a/mm/slab.h b/mm/slab.h
new file mode 100644
index 0000000..58c6c1c
--- /dev/null
+++ b/mm/slab.h
@@ -0,0 +1,531 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef MM_SLAB_H
+#define MM_SLAB_H
+/*
+ * Internal slab definitions
+ */
+
+#ifdef CONFIG_SLOB
+/*
+ * Common fields provided in kmem_cache by all slab allocators
+ * This struct is either used directly by the allocator (SLOB)
+ * or the allocator must include definitions for all fields
+ * provided in kmem_cache_common in their definition of kmem_cache.
+ *
+ * Once we can do anonymous structs (C11 standard) we could put a
+ * anonymous struct definition in these allocators so that the
+ * separate allocations in the kmem_cache structure of SLAB and
+ * SLUB is no longer needed.
+ */
+struct kmem_cache {
+ unsigned int object_size;/* The original size of the object */
+ unsigned int size; /* The aligned/padded/added on size */
+ unsigned int align; /* Alignment as calculated */
+ slab_flags_t flags; /* Active flags on the slab */
+ unsigned int useroffset;/* Usercopy region offset */
+ unsigned int usersize; /* Usercopy region size */
+ const char *name; /* Slab name for sysfs */
+ int refcount; /* Use counter */
+ void (*ctor)(void *); /* Called on object slot creation */
+ struct list_head list; /* List of all slab caches on the system */
+};
+
+#endif /* CONFIG_SLOB */
+
+#ifdef CONFIG_SLAB
+#include <linux/slab_def.h>
+#endif
+
+#ifdef CONFIG_SLUB
+#include <linux/slub_def.h>
+#endif
+
+#include <linux/memcontrol.h>
+#include <linux/fault-inject.h>
+#include <linux/kasan.h>
+#include <linux/kmemleak.h>
+#include <linux/random.h>
+#include <linux/sched/mm.h>
+
+/*
+ * State of the slab allocator.
+ *
+ * This is used to describe the states of the allocator during bootup.
+ * Allocators use this to gradually bootstrap themselves. Most allocators
+ * have the problem that the structures used for managing slab caches are
+ * allocated from slab caches themselves.
+ */
+enum slab_state {
+ DOWN, /* No slab functionality yet */
+ PARTIAL, /* SLUB: kmem_cache_node available */
+ PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */
+ UP, /* Slab caches usable but not all extras yet */
+ FULL /* Everything is working */
+};
+
+extern enum slab_state slab_state;
+
+/* The slab cache mutex protects the management structures during changes */
+extern struct mutex slab_mutex;
+
+/* The list of all slab caches on the system */
+extern struct list_head slab_caches;
+
+/* The slab cache that manages slab cache information */
+extern struct kmem_cache *kmem_cache;
+
+/* A table of kmalloc cache names and sizes */
+extern const struct kmalloc_info_struct {
+ const char *name;
+ unsigned int size;
+} kmalloc_info[];
+
+#ifndef CONFIG_SLOB
+/* Kmalloc array related functions */
+void setup_kmalloc_cache_index_table(void);
+void create_kmalloc_caches(slab_flags_t);
+
+/* Find the kmalloc slab corresponding for a certain size */
+struct kmem_cache *kmalloc_slab(size_t, gfp_t);
+#endif
+
+
+/* Functions provided by the slab allocators */
+int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
+
+struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size,
+ slab_flags_t flags, unsigned int useroffset,
+ unsigned int usersize);
+extern void create_boot_cache(struct kmem_cache *, const char *name,
+ unsigned int size, slab_flags_t flags,
+ unsigned int useroffset, unsigned int usersize);
+
+int slab_unmergeable(struct kmem_cache *s);
+struct kmem_cache *find_mergeable(unsigned size, unsigned align,
+ slab_flags_t flags, const char *name, void (*ctor)(void *));
+#ifndef CONFIG_SLOB
+struct kmem_cache *
+__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
+ slab_flags_t flags, void (*ctor)(void *));
+
+slab_flags_t kmem_cache_flags(unsigned int object_size,
+ slab_flags_t flags, const char *name,
+ void (*ctor)(void *));
+#else
+static inline struct kmem_cache *
+__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
+ slab_flags_t flags, void (*ctor)(void *))
+{ return NULL; }
+
+static inline slab_flags_t kmem_cache_flags(unsigned int object_size,
+ slab_flags_t flags, const char *name,
+ void (*ctor)(void *))
+{
+ return flags;
+}
+#endif
+
+
+/* Legal flag mask for kmem_cache_create(), for various configurations */
+#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
+ SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
+
+#if defined(CONFIG_DEBUG_SLAB)
+#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
+#elif defined(CONFIG_SLUB_DEBUG)
+#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
+ SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
+#else
+#define SLAB_DEBUG_FLAGS (0)
+#endif
+
+#if defined(CONFIG_SLAB)
+#define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
+ SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
+ SLAB_ACCOUNT)
+#elif defined(CONFIG_SLUB)
+#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
+ SLAB_TEMPORARY | SLAB_ACCOUNT)
+#else
+#define SLAB_CACHE_FLAGS (0)
+#endif
+
+/* Common flags available with current configuration */
+#define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
+
+/* Common flags permitted for kmem_cache_create */
+#define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
+ SLAB_RED_ZONE | \
+ SLAB_POISON | \
+ SLAB_STORE_USER | \
+ SLAB_TRACE | \
+ SLAB_CONSISTENCY_CHECKS | \
+ SLAB_MEM_SPREAD | \
+ SLAB_NOLEAKTRACE | \
+ SLAB_RECLAIM_ACCOUNT | \
+ SLAB_TEMPORARY | \
+ SLAB_ACCOUNT)
+
+bool __kmem_cache_empty(struct kmem_cache *);
+int __kmem_cache_shutdown(struct kmem_cache *);
+void __kmem_cache_release(struct kmem_cache *);
+int __kmem_cache_shrink(struct kmem_cache *);
+void __kmemcg_cache_deactivate(struct kmem_cache *s);
+void slab_kmem_cache_release(struct kmem_cache *);
+
+struct seq_file;
+struct file;
+
+struct slabinfo {
+ unsigned long active_objs;
+ unsigned long num_objs;
+ unsigned long active_slabs;
+ unsigned long num_slabs;
+ unsigned long shared_avail;
+ unsigned int limit;
+ unsigned int batchcount;
+ unsigned int shared;
+ unsigned int objects_per_slab;
+ unsigned int cache_order;
+};
+
+void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
+void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
+ssize_t slabinfo_write(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos);
+
+/*
+ * Generic implementation of bulk operations
+ * These are useful for situations in which the allocator cannot
+ * perform optimizations. In that case segments of the object listed
+ * may be allocated or freed using these operations.
+ */
+void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
+int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
+
+#ifdef CONFIG_MEMCG_KMEM
+
+/* List of all root caches. */
+extern struct list_head slab_root_caches;
+#define root_caches_node memcg_params.__root_caches_node
+
+/*
+ * Iterate over all memcg caches of the given root cache. The caller must hold
+ * slab_mutex.
+ */
+#define for_each_memcg_cache(iter, root) \
+ list_for_each_entry(iter, &(root)->memcg_params.children, \
+ memcg_params.children_node)
+
+static inline bool is_root_cache(struct kmem_cache *s)
+{
+ return !s->memcg_params.root_cache;
+}
+
+static inline bool slab_equal_or_root(struct kmem_cache *s,
+ struct kmem_cache *p)
+{
+ return p == s || p == s->memcg_params.root_cache;
+}
+
+/*
+ * We use suffixes to the name in memcg because we can't have caches
+ * created in the system with the same name. But when we print them
+ * locally, better refer to them with the base name
+ */
+static inline const char *cache_name(struct kmem_cache *s)
+{
+ if (!is_root_cache(s))
+ s = s->memcg_params.root_cache;
+ return s->name;
+}
+
+/*
+ * Note, we protect with RCU only the memcg_caches array, not per-memcg caches.
+ * That said the caller must assure the memcg's cache won't go away by either
+ * taking a css reference to the owner cgroup, or holding the slab_mutex.
+ */
+static inline struct kmem_cache *
+cache_from_memcg_idx(struct kmem_cache *s, int idx)
+{
+ struct kmem_cache *cachep;
+ struct memcg_cache_array *arr;
+
+ rcu_read_lock();
+ arr = rcu_dereference(s->memcg_params.memcg_caches);
+
+ /*
+ * Make sure we will access the up-to-date value. The code updating
+ * memcg_caches issues a write barrier to match this (see
+ * memcg_create_kmem_cache()).
+ */
+ cachep = READ_ONCE(arr->entries[idx]);
+ rcu_read_unlock();
+
+ return cachep;
+}
+
+static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
+{
+ if (is_root_cache(s))
+ return s;
+ return s->memcg_params.root_cache;
+}
+
+static __always_inline int memcg_charge_slab(struct page *page,
+ gfp_t gfp, int order,
+ struct kmem_cache *s)
+{
+ if (!memcg_kmem_enabled())
+ return 0;
+ if (is_root_cache(s))
+ return 0;
+ return memcg_kmem_charge_memcg(page, gfp, order, s->memcg_params.memcg);
+}
+
+static __always_inline void memcg_uncharge_slab(struct page *page, int order,
+ struct kmem_cache *s)
+{
+ if (!memcg_kmem_enabled())
+ return;
+ memcg_kmem_uncharge(page, order);
+}
+
+extern void slab_init_memcg_params(struct kmem_cache *);
+extern void memcg_link_cache(struct kmem_cache *s);
+extern void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s,
+ void (*deact_fn)(struct kmem_cache *));
+
+#else /* CONFIG_MEMCG_KMEM */
+
+/* If !memcg, all caches are root. */
+#define slab_root_caches slab_caches
+#define root_caches_node list
+
+#define for_each_memcg_cache(iter, root) \
+ for ((void)(iter), (void)(root); 0; )
+
+static inline bool is_root_cache(struct kmem_cache *s)
+{
+ return true;
+}
+
+static inline bool slab_equal_or_root(struct kmem_cache *s,
+ struct kmem_cache *p)
+{
+ return true;
+}
+
+static inline const char *cache_name(struct kmem_cache *s)
+{
+ return s->name;
+}
+
+static inline struct kmem_cache *
+cache_from_memcg_idx(struct kmem_cache *s, int idx)
+{
+ return NULL;
+}
+
+static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
+{
+ return s;
+}
+
+static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order,
+ struct kmem_cache *s)
+{
+ return 0;
+}
+
+static inline void memcg_uncharge_slab(struct page *page, int order,
+ struct kmem_cache *s)
+{
+}
+
+static inline void slab_init_memcg_params(struct kmem_cache *s)
+{
+}
+
+static inline void memcg_link_cache(struct kmem_cache *s)
+{
+}
+
+#endif /* CONFIG_MEMCG_KMEM */
+
+static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
+{
+ struct kmem_cache *cachep;
+ struct page *page;
+
+ /*
+ * When kmemcg is not being used, both assignments should return the
+ * same value. but we don't want to pay the assignment price in that
+ * case. If it is not compiled in, the compiler should be smart enough
+ * to not do even the assignment. In that case, slab_equal_or_root
+ * will also be a constant.
+ */
+ if (!memcg_kmem_enabled() &&
+ !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS))
+ return s;
+
+ page = virt_to_head_page(x);
+ cachep = page->slab_cache;
+ if (slab_equal_or_root(cachep, s))
+ return cachep;
+
+ pr_err("%s: Wrong slab cache. %s but object is from %s\n",
+ __func__, s->name, cachep->name);
+ WARN_ON_ONCE(1);
+ return s;
+}
+
+static inline size_t slab_ksize(const struct kmem_cache *s)
+{
+#ifndef CONFIG_SLUB
+ return s->object_size;
+
+#else /* CONFIG_SLUB */
+# ifdef CONFIG_SLUB_DEBUG
+ /*
+ * Debugging requires use of the padding between object
+ * and whatever may come after it.
+ */
+ if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
+ return s->object_size;
+# endif
+ if (s->flags & SLAB_KASAN)
+ return s->object_size;
+ /*
+ * If we have the need to store the freelist pointer
+ * back there or track user information then we can
+ * only use the space before that information.
+ */
+ if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
+ return s->inuse;
+ /*
+ * Else we can use all the padding etc for the allocation
+ */
+ return s->size;
+#endif
+}
+
+static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
+ gfp_t flags)
+{
+ flags &= gfp_allowed_mask;
+
+ fs_reclaim_acquire(flags);
+ fs_reclaim_release(flags);
+
+ might_sleep_if(gfpflags_allow_blocking(flags));
+
+ if (should_failslab(s, flags))
+ return NULL;
+
+ if (memcg_kmem_enabled() &&
+ ((flags & __GFP_ACCOUNT) || (s->flags & SLAB_ACCOUNT)))
+ return memcg_kmem_get_cache(s);
+
+ return s;
+}
+
+static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
+ size_t size, void **p)
+{
+ size_t i;
+
+ flags &= gfp_allowed_mask;
+ for (i = 0; i < size; i++) {
+ void *object = p[i];
+
+ kmemleak_alloc_recursive(object, s->object_size, 1,
+ s->flags, flags);
+ kasan_slab_alloc(s, object, flags);
+ }
+
+ if (memcg_kmem_enabled())
+ memcg_kmem_put_cache(s);
+}
+
+#ifndef CONFIG_SLOB
+/*
+ * The slab lists for all objects.
+ */
+struct kmem_cache_node {
+ spinlock_t list_lock;
+
+#ifdef CONFIG_SLAB
+ struct list_head slabs_partial; /* partial list first, better asm code */
+ struct list_head slabs_full;
+ struct list_head slabs_free;
+ unsigned long total_slabs; /* length of all slab lists */
+ unsigned long free_slabs; /* length of free slab list only */
+ unsigned long free_objects;
+ unsigned int free_limit;
+ unsigned int colour_next; /* Per-node cache coloring */
+ struct array_cache *shared; /* shared per node */
+ struct alien_cache **alien; /* on other nodes */
+ unsigned long next_reap; /* updated without locking */
+ int free_touched; /* updated without locking */
+#endif
+
+#ifdef CONFIG_SLUB
+ unsigned long nr_partial;
+ struct list_head partial;
+#ifdef CONFIG_SLUB_DEBUG
+ atomic_long_t nr_slabs;
+ atomic_long_t total_objects;
+ struct list_head full;
+#endif
+#endif
+
+};
+
+static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
+{
+ return s->node[node];
+}
+
+/*
+ * Iterator over all nodes. The body will be executed for each node that has
+ * a kmem_cache_node structure allocated (which is true for all online nodes)
+ */
+#define for_each_kmem_cache_node(__s, __node, __n) \
+ for (__node = 0; __node < nr_node_ids; __node++) \
+ if ((__n = get_node(__s, __node)))
+
+#endif
+
+void *slab_start(struct seq_file *m, loff_t *pos);
+void *slab_next(struct seq_file *m, void *p, loff_t *pos);
+void slab_stop(struct seq_file *m, void *p);
+void *memcg_slab_start(struct seq_file *m, loff_t *pos);
+void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos);
+void memcg_slab_stop(struct seq_file *m, void *p);
+int memcg_slab_show(struct seq_file *m, void *p);
+
+#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
+void dump_unreclaimable_slab(void);
+#else
+static inline void dump_unreclaimable_slab(void)
+{
+}
+#endif
+
+void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
+
+#ifdef CONFIG_SLAB_FREELIST_RANDOM
+int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
+ gfp_t gfp);
+void cache_random_seq_destroy(struct kmem_cache *cachep);
+#else
+static inline int cache_random_seq_create(struct kmem_cache *cachep,
+ unsigned int count, gfp_t gfp)
+{
+ return 0;
+}
+static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
+#endif /* CONFIG_SLAB_FREELIST_RANDOM */
+
+#endif /* MM_SLAB_H */