v4.19.13 snapshot.
diff --git a/mm/slab_common.c b/mm/slab_common.c
new file mode 100644
index 0000000..3a7ac4f
--- /dev/null
+++ b/mm/slab_common.c
@@ -0,0 +1,1561 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Slab allocator functions that are independent of the allocator strategy
+ *
+ * (C) 2012 Christoph Lameter <cl@linux.com>
+ */
+#include <linux/slab.h>
+
+#include <linux/mm.h>
+#include <linux/poison.h>
+#include <linux/interrupt.h>
+#include <linux/memory.h>
+#include <linux/cache.h>
+#include <linux/compiler.h>
+#include <linux/module.h>
+#include <linux/cpu.h>
+#include <linux/uaccess.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/page.h>
+#include <linux/memcontrol.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/kmem.h>
+
+#include "slab.h"
+
+enum slab_state slab_state;
+LIST_HEAD(slab_caches);
+DEFINE_MUTEX(slab_mutex);
+struct kmem_cache *kmem_cache;
+
+#ifdef CONFIG_HARDENED_USERCOPY
+bool usercopy_fallback __ro_after_init =
+ IS_ENABLED(CONFIG_HARDENED_USERCOPY_FALLBACK);
+module_param(usercopy_fallback, bool, 0400);
+MODULE_PARM_DESC(usercopy_fallback,
+ "WARN instead of reject usercopy whitelist violations");
+#endif
+
+static LIST_HEAD(slab_caches_to_rcu_destroy);
+static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work);
+static DECLARE_WORK(slab_caches_to_rcu_destroy_work,
+ slab_caches_to_rcu_destroy_workfn);
+
+/*
+ * Set of flags that will prevent slab merging
+ */
+#define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
+ SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \
+ SLAB_FAILSLAB | SLAB_KASAN)
+
+#define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \
+ SLAB_ACCOUNT)
+
+/*
+ * Merge control. If this is set then no merging of slab caches will occur.
+ */
+static bool slab_nomerge = !IS_ENABLED(CONFIG_SLAB_MERGE_DEFAULT);
+
+static int __init setup_slab_nomerge(char *str)
+{
+ slab_nomerge = true;
+ return 1;
+}
+
+#ifdef CONFIG_SLUB
+__setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0);
+#endif
+
+__setup("slab_nomerge", setup_slab_nomerge);
+
+/*
+ * Determine the size of a slab object
+ */
+unsigned int kmem_cache_size(struct kmem_cache *s)
+{
+ return s->object_size;
+}
+EXPORT_SYMBOL(kmem_cache_size);
+
+#ifdef CONFIG_DEBUG_VM
+static int kmem_cache_sanity_check(const char *name, unsigned int size)
+{
+ if (!name || in_interrupt() || size < sizeof(void *) ||
+ size > KMALLOC_MAX_SIZE) {
+ pr_err("kmem_cache_create(%s) integrity check failed\n", name);
+ return -EINVAL;
+ }
+
+ WARN_ON(strchr(name, ' ')); /* It confuses parsers */
+ return 0;
+}
+#else
+static inline int kmem_cache_sanity_check(const char *name, unsigned int size)
+{
+ return 0;
+}
+#endif
+
+void __kmem_cache_free_bulk(struct kmem_cache *s, size_t nr, void **p)
+{
+ size_t i;
+
+ for (i = 0; i < nr; i++) {
+ if (s)
+ kmem_cache_free(s, p[i]);
+ else
+ kfree(p[i]);
+ }
+}
+
+int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr,
+ void **p)
+{
+ size_t i;
+
+ for (i = 0; i < nr; i++) {
+ void *x = p[i] = kmem_cache_alloc(s, flags);
+ if (!x) {
+ __kmem_cache_free_bulk(s, i, p);
+ return 0;
+ }
+ }
+ return i;
+}
+
+#ifdef CONFIG_MEMCG_KMEM
+
+LIST_HEAD(slab_root_caches);
+
+void slab_init_memcg_params(struct kmem_cache *s)
+{
+ s->memcg_params.root_cache = NULL;
+ RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL);
+ INIT_LIST_HEAD(&s->memcg_params.children);
+ s->memcg_params.dying = false;
+}
+
+static int init_memcg_params(struct kmem_cache *s,
+ struct mem_cgroup *memcg, struct kmem_cache *root_cache)
+{
+ struct memcg_cache_array *arr;
+
+ if (root_cache) {
+ s->memcg_params.root_cache = root_cache;
+ s->memcg_params.memcg = memcg;
+ INIT_LIST_HEAD(&s->memcg_params.children_node);
+ INIT_LIST_HEAD(&s->memcg_params.kmem_caches_node);
+ return 0;
+ }
+
+ slab_init_memcg_params(s);
+
+ if (!memcg_nr_cache_ids)
+ return 0;
+
+ arr = kvzalloc(sizeof(struct memcg_cache_array) +
+ memcg_nr_cache_ids * sizeof(void *),
+ GFP_KERNEL);
+ if (!arr)
+ return -ENOMEM;
+
+ RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr);
+ return 0;
+}
+
+static void destroy_memcg_params(struct kmem_cache *s)
+{
+ if (is_root_cache(s))
+ kvfree(rcu_access_pointer(s->memcg_params.memcg_caches));
+}
+
+static void free_memcg_params(struct rcu_head *rcu)
+{
+ struct memcg_cache_array *old;
+
+ old = container_of(rcu, struct memcg_cache_array, rcu);
+ kvfree(old);
+}
+
+static int update_memcg_params(struct kmem_cache *s, int new_array_size)
+{
+ struct memcg_cache_array *old, *new;
+
+ new = kvzalloc(sizeof(struct memcg_cache_array) +
+ new_array_size * sizeof(void *), GFP_KERNEL);
+ if (!new)
+ return -ENOMEM;
+
+ old = rcu_dereference_protected(s->memcg_params.memcg_caches,
+ lockdep_is_held(&slab_mutex));
+ if (old)
+ memcpy(new->entries, old->entries,
+ memcg_nr_cache_ids * sizeof(void *));
+
+ rcu_assign_pointer(s->memcg_params.memcg_caches, new);
+ if (old)
+ call_rcu(&old->rcu, free_memcg_params);
+ return 0;
+}
+
+int memcg_update_all_caches(int num_memcgs)
+{
+ struct kmem_cache *s;
+ int ret = 0;
+
+ mutex_lock(&slab_mutex);
+ list_for_each_entry(s, &slab_root_caches, root_caches_node) {
+ ret = update_memcg_params(s, num_memcgs);
+ /*
+ * Instead of freeing the memory, we'll just leave the caches
+ * up to this point in an updated state.
+ */
+ if (ret)
+ break;
+ }
+ mutex_unlock(&slab_mutex);
+ return ret;
+}
+
+void memcg_link_cache(struct kmem_cache *s)
+{
+ if (is_root_cache(s)) {
+ list_add(&s->root_caches_node, &slab_root_caches);
+ } else {
+ list_add(&s->memcg_params.children_node,
+ &s->memcg_params.root_cache->memcg_params.children);
+ list_add(&s->memcg_params.kmem_caches_node,
+ &s->memcg_params.memcg->kmem_caches);
+ }
+}
+
+static void memcg_unlink_cache(struct kmem_cache *s)
+{
+ if (is_root_cache(s)) {
+ list_del(&s->root_caches_node);
+ } else {
+ list_del(&s->memcg_params.children_node);
+ list_del(&s->memcg_params.kmem_caches_node);
+ }
+}
+#else
+static inline int init_memcg_params(struct kmem_cache *s,
+ struct mem_cgroup *memcg, struct kmem_cache *root_cache)
+{
+ return 0;
+}
+
+static inline void destroy_memcg_params(struct kmem_cache *s)
+{
+}
+
+static inline void memcg_unlink_cache(struct kmem_cache *s)
+{
+}
+#endif /* CONFIG_MEMCG_KMEM */
+
+/*
+ * Figure out what the alignment of the objects will be given a set of
+ * flags, a user specified alignment and the size of the objects.
+ */
+static unsigned int calculate_alignment(slab_flags_t flags,
+ unsigned int align, unsigned int size)
+{
+ /*
+ * If the user wants hardware cache aligned objects then follow that
+ * suggestion if the object is sufficiently large.
+ *
+ * The hardware cache alignment cannot override the specified
+ * alignment though. If that is greater then use it.
+ */
+ if (flags & SLAB_HWCACHE_ALIGN) {
+ unsigned int ralign;
+
+ ralign = cache_line_size();
+ while (size <= ralign / 2)
+ ralign /= 2;
+ align = max(align, ralign);
+ }
+
+ if (align < ARCH_SLAB_MINALIGN)
+ align = ARCH_SLAB_MINALIGN;
+
+ return ALIGN(align, sizeof(void *));
+}
+
+/*
+ * Find a mergeable slab cache
+ */
+int slab_unmergeable(struct kmem_cache *s)
+{
+ if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
+ return 1;
+
+ if (!is_root_cache(s))
+ return 1;
+
+ if (s->ctor)
+ return 1;
+
+ if (s->usersize)
+ return 1;
+
+ /*
+ * We may have set a slab to be unmergeable during bootstrap.
+ */
+ if (s->refcount < 0)
+ return 1;
+
+ return 0;
+}
+
+struct kmem_cache *find_mergeable(unsigned int size, unsigned int align,
+ slab_flags_t flags, const char *name, void (*ctor)(void *))
+{
+ struct kmem_cache *s;
+
+ if (slab_nomerge)
+ return NULL;
+
+ if (ctor)
+ return NULL;
+
+ size = ALIGN(size, sizeof(void *));
+ align = calculate_alignment(flags, align, size);
+ size = ALIGN(size, align);
+ flags = kmem_cache_flags(size, flags, name, NULL);
+
+ if (flags & SLAB_NEVER_MERGE)
+ return NULL;
+
+ list_for_each_entry_reverse(s, &slab_root_caches, root_caches_node) {
+ if (slab_unmergeable(s))
+ continue;
+
+ if (size > s->size)
+ continue;
+
+ if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
+ continue;
+ /*
+ * Check if alignment is compatible.
+ * Courtesy of Adrian Drzewiecki
+ */
+ if ((s->size & ~(align - 1)) != s->size)
+ continue;
+
+ if (s->size - size >= sizeof(void *))
+ continue;
+
+ if (IS_ENABLED(CONFIG_SLAB) && align &&
+ (align > s->align || s->align % align))
+ continue;
+
+ return s;
+ }
+ return NULL;
+}
+
+static struct kmem_cache *create_cache(const char *name,
+ unsigned int object_size, unsigned int align,
+ slab_flags_t flags, unsigned int useroffset,
+ unsigned int usersize, void (*ctor)(void *),
+ struct mem_cgroup *memcg, struct kmem_cache *root_cache)
+{
+ struct kmem_cache *s;
+ int err;
+
+ if (WARN_ON(useroffset + usersize > object_size))
+ useroffset = usersize = 0;
+
+ err = -ENOMEM;
+ s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
+ if (!s)
+ goto out;
+
+ s->name = name;
+ s->size = s->object_size = object_size;
+ s->align = align;
+ s->ctor = ctor;
+ s->useroffset = useroffset;
+ s->usersize = usersize;
+
+ err = init_memcg_params(s, memcg, root_cache);
+ if (err)
+ goto out_free_cache;
+
+ err = __kmem_cache_create(s, flags);
+ if (err)
+ goto out_free_cache;
+
+ s->refcount = 1;
+ list_add(&s->list, &slab_caches);
+ memcg_link_cache(s);
+out:
+ if (err)
+ return ERR_PTR(err);
+ return s;
+
+out_free_cache:
+ destroy_memcg_params(s);
+ kmem_cache_free(kmem_cache, s);
+ goto out;
+}
+
+/*
+ * kmem_cache_create_usercopy - Create a cache.
+ * @name: A string which is used in /proc/slabinfo to identify this cache.
+ * @size: The size of objects to be created in this cache.
+ * @align: The required alignment for the objects.
+ * @flags: SLAB flags
+ * @useroffset: Usercopy region offset
+ * @usersize: Usercopy region size
+ * @ctor: A constructor for the objects.
+ *
+ * Returns a ptr to the cache on success, NULL on failure.
+ * Cannot be called within a interrupt, but can be interrupted.
+ * The @ctor is run when new pages are allocated by the cache.
+ *
+ * The flags are
+ *
+ * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
+ * to catch references to uninitialised memory.
+ *
+ * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
+ * for buffer overruns.
+ *
+ * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
+ * cacheline. This can be beneficial if you're counting cycles as closely
+ * as davem.
+ */
+struct kmem_cache *
+kmem_cache_create_usercopy(const char *name,
+ unsigned int size, unsigned int align,
+ slab_flags_t flags,
+ unsigned int useroffset, unsigned int usersize,
+ void (*ctor)(void *))
+{
+ struct kmem_cache *s = NULL;
+ const char *cache_name;
+ int err;
+
+ get_online_cpus();
+ get_online_mems();
+ memcg_get_cache_ids();
+
+ mutex_lock(&slab_mutex);
+
+ err = kmem_cache_sanity_check(name, size);
+ if (err) {
+ goto out_unlock;
+ }
+
+ /* Refuse requests with allocator specific flags */
+ if (flags & ~SLAB_FLAGS_PERMITTED) {
+ err = -EINVAL;
+ goto out_unlock;
+ }
+
+ /*
+ * Some allocators will constraint the set of valid flags to a subset
+ * of all flags. We expect them to define CACHE_CREATE_MASK in this
+ * case, and we'll just provide them with a sanitized version of the
+ * passed flags.
+ */
+ flags &= CACHE_CREATE_MASK;
+
+ /* Fail closed on bad usersize of useroffset values. */
+ if (WARN_ON(!usersize && useroffset) ||
+ WARN_ON(size < usersize || size - usersize < useroffset))
+ usersize = useroffset = 0;
+
+ if (!usersize)
+ s = __kmem_cache_alias(name, size, align, flags, ctor);
+ if (s)
+ goto out_unlock;
+
+ cache_name = kstrdup_const(name, GFP_KERNEL);
+ if (!cache_name) {
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+
+ s = create_cache(cache_name, size,
+ calculate_alignment(flags, align, size),
+ flags, useroffset, usersize, ctor, NULL, NULL);
+ if (IS_ERR(s)) {
+ err = PTR_ERR(s);
+ kfree_const(cache_name);
+ }
+
+out_unlock:
+ mutex_unlock(&slab_mutex);
+
+ memcg_put_cache_ids();
+ put_online_mems();
+ put_online_cpus();
+
+ if (err) {
+ if (flags & SLAB_PANIC)
+ panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
+ name, err);
+ else {
+ pr_warn("kmem_cache_create(%s) failed with error %d\n",
+ name, err);
+ dump_stack();
+ }
+ return NULL;
+ }
+ return s;
+}
+EXPORT_SYMBOL(kmem_cache_create_usercopy);
+
+struct kmem_cache *
+kmem_cache_create(const char *name, unsigned int size, unsigned int align,
+ slab_flags_t flags, void (*ctor)(void *))
+{
+ return kmem_cache_create_usercopy(name, size, align, flags, 0, 0,
+ ctor);
+}
+EXPORT_SYMBOL(kmem_cache_create);
+
+static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
+{
+ LIST_HEAD(to_destroy);
+ struct kmem_cache *s, *s2;
+
+ /*
+ * On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the
+ * @slab_caches_to_rcu_destroy list. The slab pages are freed
+ * through RCU and and the associated kmem_cache are dereferenced
+ * while freeing the pages, so the kmem_caches should be freed only
+ * after the pending RCU operations are finished. As rcu_barrier()
+ * is a pretty slow operation, we batch all pending destructions
+ * asynchronously.
+ */
+ mutex_lock(&slab_mutex);
+ list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy);
+ mutex_unlock(&slab_mutex);
+
+ if (list_empty(&to_destroy))
+ return;
+
+ rcu_barrier();
+
+ list_for_each_entry_safe(s, s2, &to_destroy, list) {
+#ifdef SLAB_SUPPORTS_SYSFS
+ sysfs_slab_release(s);
+#else
+ slab_kmem_cache_release(s);
+#endif
+ }
+}
+
+static int shutdown_cache(struct kmem_cache *s)
+{
+ /* free asan quarantined objects */
+ kasan_cache_shutdown(s);
+
+ if (__kmem_cache_shutdown(s) != 0)
+ return -EBUSY;
+
+ memcg_unlink_cache(s);
+ list_del(&s->list);
+
+ if (s->flags & SLAB_TYPESAFE_BY_RCU) {
+#ifdef SLAB_SUPPORTS_SYSFS
+ sysfs_slab_unlink(s);
+#endif
+ list_add_tail(&s->list, &slab_caches_to_rcu_destroy);
+ schedule_work(&slab_caches_to_rcu_destroy_work);
+ } else {
+#ifdef SLAB_SUPPORTS_SYSFS
+ sysfs_slab_unlink(s);
+ sysfs_slab_release(s);
+#else
+ slab_kmem_cache_release(s);
+#endif
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_MEMCG_KMEM
+/*
+ * memcg_create_kmem_cache - Create a cache for a memory cgroup.
+ * @memcg: The memory cgroup the new cache is for.
+ * @root_cache: The parent of the new cache.
+ *
+ * This function attempts to create a kmem cache that will serve allocation
+ * requests going from @memcg to @root_cache. The new cache inherits properties
+ * from its parent.
+ */
+void memcg_create_kmem_cache(struct mem_cgroup *memcg,
+ struct kmem_cache *root_cache)
+{
+ static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */
+ struct cgroup_subsys_state *css = &memcg->css;
+ struct memcg_cache_array *arr;
+ struct kmem_cache *s = NULL;
+ char *cache_name;
+ int idx;
+
+ get_online_cpus();
+ get_online_mems();
+
+ mutex_lock(&slab_mutex);
+
+ /*
+ * The memory cgroup could have been offlined while the cache
+ * creation work was pending.
+ */
+ if (memcg->kmem_state != KMEM_ONLINE || root_cache->memcg_params.dying)
+ goto out_unlock;
+
+ idx = memcg_cache_id(memcg);
+ arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches,
+ lockdep_is_held(&slab_mutex));
+
+ /*
+ * Since per-memcg caches are created asynchronously on first
+ * allocation (see memcg_kmem_get_cache()), several threads can try to
+ * create the same cache, but only one of them may succeed.
+ */
+ if (arr->entries[idx])
+ goto out_unlock;
+
+ cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf));
+ cache_name = kasprintf(GFP_KERNEL, "%s(%llu:%s)", root_cache->name,
+ css->serial_nr, memcg_name_buf);
+ if (!cache_name)
+ goto out_unlock;
+
+ s = create_cache(cache_name, root_cache->object_size,
+ root_cache->align,
+ root_cache->flags & CACHE_CREATE_MASK,
+ root_cache->useroffset, root_cache->usersize,
+ root_cache->ctor, memcg, root_cache);
+ /*
+ * If we could not create a memcg cache, do not complain, because
+ * that's not critical at all as we can always proceed with the root
+ * cache.
+ */
+ if (IS_ERR(s)) {
+ kfree(cache_name);
+ goto out_unlock;
+ }
+
+ /*
+ * Since readers won't lock (see cache_from_memcg_idx()), we need a
+ * barrier here to ensure nobody will see the kmem_cache partially
+ * initialized.
+ */
+ smp_wmb();
+ arr->entries[idx] = s;
+
+out_unlock:
+ mutex_unlock(&slab_mutex);
+
+ put_online_mems();
+ put_online_cpus();
+}
+
+static void kmemcg_deactivate_workfn(struct work_struct *work)
+{
+ struct kmem_cache *s = container_of(work, struct kmem_cache,
+ memcg_params.deact_work);
+
+ get_online_cpus();
+ get_online_mems();
+
+ mutex_lock(&slab_mutex);
+
+ s->memcg_params.deact_fn(s);
+
+ mutex_unlock(&slab_mutex);
+
+ put_online_mems();
+ put_online_cpus();
+
+ /* done, put the ref from slab_deactivate_memcg_cache_rcu_sched() */
+ css_put(&s->memcg_params.memcg->css);
+}
+
+static void kmemcg_deactivate_rcufn(struct rcu_head *head)
+{
+ struct kmem_cache *s = container_of(head, struct kmem_cache,
+ memcg_params.deact_rcu_head);
+
+ /*
+ * We need to grab blocking locks. Bounce to ->deact_work. The
+ * work item shares the space with the RCU head and can't be
+ * initialized eariler.
+ */
+ INIT_WORK(&s->memcg_params.deact_work, kmemcg_deactivate_workfn);
+ queue_work(memcg_kmem_cache_wq, &s->memcg_params.deact_work);
+}
+
+/**
+ * slab_deactivate_memcg_cache_rcu_sched - schedule deactivation after a
+ * sched RCU grace period
+ * @s: target kmem_cache
+ * @deact_fn: deactivation function to call
+ *
+ * Schedule @deact_fn to be invoked with online cpus, mems and slab_mutex
+ * held after a sched RCU grace period. The slab is guaranteed to stay
+ * alive until @deact_fn is finished. This is to be used from
+ * __kmemcg_cache_deactivate().
+ */
+void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s,
+ void (*deact_fn)(struct kmem_cache *))
+{
+ if (WARN_ON_ONCE(is_root_cache(s)) ||
+ WARN_ON_ONCE(s->memcg_params.deact_fn))
+ return;
+
+ if (s->memcg_params.root_cache->memcg_params.dying)
+ return;
+
+ /* pin memcg so that @s doesn't get destroyed in the middle */
+ css_get(&s->memcg_params.memcg->css);
+
+ s->memcg_params.deact_fn = deact_fn;
+ call_rcu_sched(&s->memcg_params.deact_rcu_head, kmemcg_deactivate_rcufn);
+}
+
+void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg)
+{
+ int idx;
+ struct memcg_cache_array *arr;
+ struct kmem_cache *s, *c;
+
+ idx = memcg_cache_id(memcg);
+
+ get_online_cpus();
+ get_online_mems();
+
+ mutex_lock(&slab_mutex);
+ list_for_each_entry(s, &slab_root_caches, root_caches_node) {
+ arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
+ lockdep_is_held(&slab_mutex));
+ c = arr->entries[idx];
+ if (!c)
+ continue;
+
+ __kmemcg_cache_deactivate(c);
+ arr->entries[idx] = NULL;
+ }
+ mutex_unlock(&slab_mutex);
+
+ put_online_mems();
+ put_online_cpus();
+}
+
+void memcg_destroy_kmem_caches(struct mem_cgroup *memcg)
+{
+ struct kmem_cache *s, *s2;
+
+ get_online_cpus();
+ get_online_mems();
+
+ mutex_lock(&slab_mutex);
+ list_for_each_entry_safe(s, s2, &memcg->kmem_caches,
+ memcg_params.kmem_caches_node) {
+ /*
+ * The cgroup is about to be freed and therefore has no charges
+ * left. Hence, all its caches must be empty by now.
+ */
+ BUG_ON(shutdown_cache(s));
+ }
+ mutex_unlock(&slab_mutex);
+
+ put_online_mems();
+ put_online_cpus();
+}
+
+static int shutdown_memcg_caches(struct kmem_cache *s)
+{
+ struct memcg_cache_array *arr;
+ struct kmem_cache *c, *c2;
+ LIST_HEAD(busy);
+ int i;
+
+ BUG_ON(!is_root_cache(s));
+
+ /*
+ * First, shutdown active caches, i.e. caches that belong to online
+ * memory cgroups.
+ */
+ arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
+ lockdep_is_held(&slab_mutex));
+ for_each_memcg_cache_index(i) {
+ c = arr->entries[i];
+ if (!c)
+ continue;
+ if (shutdown_cache(c))
+ /*
+ * The cache still has objects. Move it to a temporary
+ * list so as not to try to destroy it for a second
+ * time while iterating over inactive caches below.
+ */
+ list_move(&c->memcg_params.children_node, &busy);
+ else
+ /*
+ * The cache is empty and will be destroyed soon. Clear
+ * the pointer to it in the memcg_caches array so that
+ * it will never be accessed even if the root cache
+ * stays alive.
+ */
+ arr->entries[i] = NULL;
+ }
+
+ /*
+ * Second, shutdown all caches left from memory cgroups that are now
+ * offline.
+ */
+ list_for_each_entry_safe(c, c2, &s->memcg_params.children,
+ memcg_params.children_node)
+ shutdown_cache(c);
+
+ list_splice(&busy, &s->memcg_params.children);
+
+ /*
+ * A cache being destroyed must be empty. In particular, this means
+ * that all per memcg caches attached to it must be empty too.
+ */
+ if (!list_empty(&s->memcg_params.children))
+ return -EBUSY;
+ return 0;
+}
+
+static void flush_memcg_workqueue(struct kmem_cache *s)
+{
+ mutex_lock(&slab_mutex);
+ s->memcg_params.dying = true;
+ mutex_unlock(&slab_mutex);
+
+ /*
+ * SLUB deactivates the kmem_caches through call_rcu_sched. Make
+ * sure all registered rcu callbacks have been invoked.
+ */
+ if (IS_ENABLED(CONFIG_SLUB))
+ rcu_barrier_sched();
+
+ /*
+ * SLAB and SLUB create memcg kmem_caches through workqueue and SLUB
+ * deactivates the memcg kmem_caches through workqueue. Make sure all
+ * previous workitems on workqueue are processed.
+ */
+ flush_workqueue(memcg_kmem_cache_wq);
+}
+#else
+static inline int shutdown_memcg_caches(struct kmem_cache *s)
+{
+ return 0;
+}
+
+static inline void flush_memcg_workqueue(struct kmem_cache *s)
+{
+}
+#endif /* CONFIG_MEMCG_KMEM */
+
+void slab_kmem_cache_release(struct kmem_cache *s)
+{
+ __kmem_cache_release(s);
+ destroy_memcg_params(s);
+ kfree_const(s->name);
+ kmem_cache_free(kmem_cache, s);
+}
+
+void kmem_cache_destroy(struct kmem_cache *s)
+{
+ int err;
+
+ if (unlikely(!s))
+ return;
+
+ flush_memcg_workqueue(s);
+
+ get_online_cpus();
+ get_online_mems();
+
+ mutex_lock(&slab_mutex);
+
+ s->refcount--;
+ if (s->refcount)
+ goto out_unlock;
+
+ err = shutdown_memcg_caches(s);
+ if (!err)
+ err = shutdown_cache(s);
+
+ if (err) {
+ pr_err("kmem_cache_destroy %s: Slab cache still has objects\n",
+ s->name);
+ dump_stack();
+ }
+out_unlock:
+ mutex_unlock(&slab_mutex);
+
+ put_online_mems();
+ put_online_cpus();
+}
+EXPORT_SYMBOL(kmem_cache_destroy);
+
+/**
+ * kmem_cache_shrink - Shrink a cache.
+ * @cachep: The cache to shrink.
+ *
+ * Releases as many slabs as possible for a cache.
+ * To help debugging, a zero exit status indicates all slabs were released.
+ */
+int kmem_cache_shrink(struct kmem_cache *cachep)
+{
+ int ret;
+
+ get_online_cpus();
+ get_online_mems();
+ kasan_cache_shrink(cachep);
+ ret = __kmem_cache_shrink(cachep);
+ put_online_mems();
+ put_online_cpus();
+ return ret;
+}
+EXPORT_SYMBOL(kmem_cache_shrink);
+
+bool slab_is_available(void)
+{
+ return slab_state >= UP;
+}
+
+#ifndef CONFIG_SLOB
+/* Create a cache during boot when no slab services are available yet */
+void __init create_boot_cache(struct kmem_cache *s, const char *name,
+ unsigned int size, slab_flags_t flags,
+ unsigned int useroffset, unsigned int usersize)
+{
+ int err;
+
+ s->name = name;
+ s->size = s->object_size = size;
+ s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
+ s->useroffset = useroffset;
+ s->usersize = usersize;
+
+ slab_init_memcg_params(s);
+
+ err = __kmem_cache_create(s, flags);
+
+ if (err)
+ panic("Creation of kmalloc slab %s size=%u failed. Reason %d\n",
+ name, size, err);
+
+ s->refcount = -1; /* Exempt from merging for now */
+}
+
+struct kmem_cache *__init create_kmalloc_cache(const char *name,
+ unsigned int size, slab_flags_t flags,
+ unsigned int useroffset, unsigned int usersize)
+{
+ struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
+
+ if (!s)
+ panic("Out of memory when creating slab %s\n", name);
+
+ create_boot_cache(s, name, size, flags, useroffset, usersize);
+ list_add(&s->list, &slab_caches);
+ memcg_link_cache(s);
+ s->refcount = 1;
+ return s;
+}
+
+struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1] __ro_after_init;
+EXPORT_SYMBOL(kmalloc_caches);
+
+#ifdef CONFIG_ZONE_DMA
+struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1] __ro_after_init;
+EXPORT_SYMBOL(kmalloc_dma_caches);
+#endif
+
+/*
+ * Conversion table for small slabs sizes / 8 to the index in the
+ * kmalloc array. This is necessary for slabs < 192 since we have non power
+ * of two cache sizes there. The size of larger slabs can be determined using
+ * fls.
+ */
+static u8 size_index[24] __ro_after_init = {
+ 3, /* 8 */
+ 4, /* 16 */
+ 5, /* 24 */
+ 5, /* 32 */
+ 6, /* 40 */
+ 6, /* 48 */
+ 6, /* 56 */
+ 6, /* 64 */
+ 1, /* 72 */
+ 1, /* 80 */
+ 1, /* 88 */
+ 1, /* 96 */
+ 7, /* 104 */
+ 7, /* 112 */
+ 7, /* 120 */
+ 7, /* 128 */
+ 2, /* 136 */
+ 2, /* 144 */
+ 2, /* 152 */
+ 2, /* 160 */
+ 2, /* 168 */
+ 2, /* 176 */
+ 2, /* 184 */
+ 2 /* 192 */
+};
+
+static inline unsigned int size_index_elem(unsigned int bytes)
+{
+ return (bytes - 1) / 8;
+}
+
+/*
+ * Find the kmem_cache structure that serves a given size of
+ * allocation
+ */
+struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
+{
+ unsigned int index;
+
+ if (size <= 192) {
+ if (!size)
+ return ZERO_SIZE_PTR;
+
+ index = size_index[size_index_elem(size)];
+ } else {
+ if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) {
+ WARN_ON(1);
+ return NULL;
+ }
+ index = fls(size - 1);
+ }
+
+#ifdef CONFIG_ZONE_DMA
+ if (unlikely((flags & GFP_DMA)))
+ return kmalloc_dma_caches[index];
+
+#endif
+ return kmalloc_caches[index];
+}
+
+/*
+ * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time.
+ * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is
+ * kmalloc-67108864.
+ */
+const struct kmalloc_info_struct kmalloc_info[] __initconst = {
+ {NULL, 0}, {"kmalloc-96", 96},
+ {"kmalloc-192", 192}, {"kmalloc-8", 8},
+ {"kmalloc-16", 16}, {"kmalloc-32", 32},
+ {"kmalloc-64", 64}, {"kmalloc-128", 128},
+ {"kmalloc-256", 256}, {"kmalloc-512", 512},
+ {"kmalloc-1024", 1024}, {"kmalloc-2048", 2048},
+ {"kmalloc-4096", 4096}, {"kmalloc-8192", 8192},
+ {"kmalloc-16384", 16384}, {"kmalloc-32768", 32768},
+ {"kmalloc-65536", 65536}, {"kmalloc-131072", 131072},
+ {"kmalloc-262144", 262144}, {"kmalloc-524288", 524288},
+ {"kmalloc-1048576", 1048576}, {"kmalloc-2097152", 2097152},
+ {"kmalloc-4194304", 4194304}, {"kmalloc-8388608", 8388608},
+ {"kmalloc-16777216", 16777216}, {"kmalloc-33554432", 33554432},
+ {"kmalloc-67108864", 67108864}
+};
+
+/*
+ * Patch up the size_index table if we have strange large alignment
+ * requirements for the kmalloc array. This is only the case for
+ * MIPS it seems. The standard arches will not generate any code here.
+ *
+ * Largest permitted alignment is 256 bytes due to the way we
+ * handle the index determination for the smaller caches.
+ *
+ * Make sure that nothing crazy happens if someone starts tinkering
+ * around with ARCH_KMALLOC_MINALIGN
+ */
+void __init setup_kmalloc_cache_index_table(void)
+{
+ unsigned int i;
+
+ BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
+ (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
+
+ for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
+ unsigned int elem = size_index_elem(i);
+
+ if (elem >= ARRAY_SIZE(size_index))
+ break;
+ size_index[elem] = KMALLOC_SHIFT_LOW;
+ }
+
+ if (KMALLOC_MIN_SIZE >= 64) {
+ /*
+ * The 96 byte size cache is not used if the alignment
+ * is 64 byte.
+ */
+ for (i = 64 + 8; i <= 96; i += 8)
+ size_index[size_index_elem(i)] = 7;
+
+ }
+
+ if (KMALLOC_MIN_SIZE >= 128) {
+ /*
+ * The 192 byte sized cache is not used if the alignment
+ * is 128 byte. Redirect kmalloc to use the 256 byte cache
+ * instead.
+ */
+ for (i = 128 + 8; i <= 192; i += 8)
+ size_index[size_index_elem(i)] = 8;
+ }
+}
+
+static void __init new_kmalloc_cache(int idx, slab_flags_t flags)
+{
+ kmalloc_caches[idx] = create_kmalloc_cache(kmalloc_info[idx].name,
+ kmalloc_info[idx].size, flags, 0,
+ kmalloc_info[idx].size);
+}
+
+/*
+ * Create the kmalloc array. Some of the regular kmalloc arrays
+ * may already have been created because they were needed to
+ * enable allocations for slab creation.
+ */
+void __init create_kmalloc_caches(slab_flags_t flags)
+{
+ int i;
+
+ for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
+ if (!kmalloc_caches[i])
+ new_kmalloc_cache(i, flags);
+
+ /*
+ * Caches that are not of the two-to-the-power-of size.
+ * These have to be created immediately after the
+ * earlier power of two caches
+ */
+ if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
+ new_kmalloc_cache(1, flags);
+ if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
+ new_kmalloc_cache(2, flags);
+ }
+
+ /* Kmalloc array is now usable */
+ slab_state = UP;
+
+#ifdef CONFIG_ZONE_DMA
+ for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
+ struct kmem_cache *s = kmalloc_caches[i];
+
+ if (s) {
+ unsigned int size = kmalloc_size(i);
+ char *n = kasprintf(GFP_NOWAIT,
+ "dma-kmalloc-%u", size);
+
+ BUG_ON(!n);
+ kmalloc_dma_caches[i] = create_kmalloc_cache(n,
+ size, SLAB_CACHE_DMA | flags, 0, 0);
+ }
+ }
+#endif
+}
+#endif /* !CONFIG_SLOB */
+
+/*
+ * To avoid unnecessary overhead, we pass through large allocation requests
+ * directly to the page allocator. We use __GFP_COMP, because we will need to
+ * know the allocation order to free the pages properly in kfree.
+ */
+void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
+{
+ void *ret;
+ struct page *page;
+
+ flags |= __GFP_COMP;
+ page = alloc_pages(flags, order);
+ ret = page ? page_address(page) : NULL;
+ kmemleak_alloc(ret, size, 1, flags);
+ kasan_kmalloc_large(ret, size, flags);
+ return ret;
+}
+EXPORT_SYMBOL(kmalloc_order);
+
+#ifdef CONFIG_TRACING
+void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
+{
+ void *ret = kmalloc_order(size, flags, order);
+ trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
+ return ret;
+}
+EXPORT_SYMBOL(kmalloc_order_trace);
+#endif
+
+#ifdef CONFIG_SLAB_FREELIST_RANDOM
+/* Randomize a generic freelist */
+static void freelist_randomize(struct rnd_state *state, unsigned int *list,
+ unsigned int count)
+{
+ unsigned int rand;
+ unsigned int i;
+
+ for (i = 0; i < count; i++)
+ list[i] = i;
+
+ /* Fisher-Yates shuffle */
+ for (i = count - 1; i > 0; i--) {
+ rand = prandom_u32_state(state);
+ rand %= (i + 1);
+ swap(list[i], list[rand]);
+ }
+}
+
+/* Create a random sequence per cache */
+int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
+ gfp_t gfp)
+{
+ struct rnd_state state;
+
+ if (count < 2 || cachep->random_seq)
+ return 0;
+
+ cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp);
+ if (!cachep->random_seq)
+ return -ENOMEM;
+
+ /* Get best entropy at this stage of boot */
+ prandom_seed_state(&state, get_random_long());
+
+ freelist_randomize(&state, cachep->random_seq, count);
+ return 0;
+}
+
+/* Destroy the per-cache random freelist sequence */
+void cache_random_seq_destroy(struct kmem_cache *cachep)
+{
+ kfree(cachep->random_seq);
+ cachep->random_seq = NULL;
+}
+#endif /* CONFIG_SLAB_FREELIST_RANDOM */
+
+#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
+#ifdef CONFIG_SLAB
+#define SLABINFO_RIGHTS (0600)
+#else
+#define SLABINFO_RIGHTS (0400)
+#endif
+
+static void print_slabinfo_header(struct seq_file *m)
+{
+ /*
+ * Output format version, so at least we can change it
+ * without _too_ many complaints.
+ */
+#ifdef CONFIG_DEBUG_SLAB
+ seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
+#else
+ seq_puts(m, "slabinfo - version: 2.1\n");
+#endif
+ seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>");
+ seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
+ seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
+#ifdef CONFIG_DEBUG_SLAB
+ seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
+ seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
+#endif
+ seq_putc(m, '\n');
+}
+
+void *slab_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&slab_mutex);
+ return seq_list_start(&slab_root_caches, *pos);
+}
+
+void *slab_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ return seq_list_next(p, &slab_root_caches, pos);
+}
+
+void slab_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&slab_mutex);
+}
+
+static void
+memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info)
+{
+ struct kmem_cache *c;
+ struct slabinfo sinfo;
+
+ if (!is_root_cache(s))
+ return;
+
+ for_each_memcg_cache(c, s) {
+ memset(&sinfo, 0, sizeof(sinfo));
+ get_slabinfo(c, &sinfo);
+
+ info->active_slabs += sinfo.active_slabs;
+ info->num_slabs += sinfo.num_slabs;
+ info->shared_avail += sinfo.shared_avail;
+ info->active_objs += sinfo.active_objs;
+ info->num_objs += sinfo.num_objs;
+ }
+}
+
+static void cache_show(struct kmem_cache *s, struct seq_file *m)
+{
+ struct slabinfo sinfo;
+
+ memset(&sinfo, 0, sizeof(sinfo));
+ get_slabinfo(s, &sinfo);
+
+ memcg_accumulate_slabinfo(s, &sinfo);
+
+ seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
+ cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
+ sinfo.objects_per_slab, (1 << sinfo.cache_order));
+
+ seq_printf(m, " : tunables %4u %4u %4u",
+ sinfo.limit, sinfo.batchcount, sinfo.shared);
+ seq_printf(m, " : slabdata %6lu %6lu %6lu",
+ sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
+ slabinfo_show_stats(m, s);
+ seq_putc(m, '\n');
+}
+
+static int slab_show(struct seq_file *m, void *p)
+{
+ struct kmem_cache *s = list_entry(p, struct kmem_cache, root_caches_node);
+
+ if (p == slab_root_caches.next)
+ print_slabinfo_header(m);
+ cache_show(s, m);
+ return 0;
+}
+
+void dump_unreclaimable_slab(void)
+{
+ struct kmem_cache *s, *s2;
+ struct slabinfo sinfo;
+
+ /*
+ * Here acquiring slab_mutex is risky since we don't prefer to get
+ * sleep in oom path. But, without mutex hold, it may introduce a
+ * risk of crash.
+ * Use mutex_trylock to protect the list traverse, dump nothing
+ * without acquiring the mutex.
+ */
+ if (!mutex_trylock(&slab_mutex)) {
+ pr_warn("excessive unreclaimable slab but cannot dump stats\n");
+ return;
+ }
+
+ pr_info("Unreclaimable slab info:\n");
+ pr_info("Name Used Total\n");
+
+ list_for_each_entry_safe(s, s2, &slab_caches, list) {
+ if (!is_root_cache(s) || (s->flags & SLAB_RECLAIM_ACCOUNT))
+ continue;
+
+ get_slabinfo(s, &sinfo);
+
+ if (sinfo.num_objs > 0)
+ pr_info("%-17s %10luKB %10luKB\n", cache_name(s),
+ (sinfo.active_objs * s->size) / 1024,
+ (sinfo.num_objs * s->size) / 1024);
+ }
+ mutex_unlock(&slab_mutex);
+}
+
+#if defined(CONFIG_MEMCG)
+void *memcg_slab_start(struct seq_file *m, loff_t *pos)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+
+ mutex_lock(&slab_mutex);
+ return seq_list_start(&memcg->kmem_caches, *pos);
+}
+
+void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+
+ return seq_list_next(p, &memcg->kmem_caches, pos);
+}
+
+void memcg_slab_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&slab_mutex);
+}
+
+int memcg_slab_show(struct seq_file *m, void *p)
+{
+ struct kmem_cache *s = list_entry(p, struct kmem_cache,
+ memcg_params.kmem_caches_node);
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+
+ if (p == memcg->kmem_caches.next)
+ print_slabinfo_header(m);
+ cache_show(s, m);
+ return 0;
+}
+#endif
+
+/*
+ * slabinfo_op - iterator that generates /proc/slabinfo
+ *
+ * Output layout:
+ * cache-name
+ * num-active-objs
+ * total-objs
+ * object size
+ * num-active-slabs
+ * total-slabs
+ * num-pages-per-slab
+ * + further values on SMP and with statistics enabled
+ */
+static const struct seq_operations slabinfo_op = {
+ .start = slab_start,
+ .next = slab_next,
+ .stop = slab_stop,
+ .show = slab_show,
+};
+
+static int slabinfo_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &slabinfo_op);
+}
+
+static const struct file_operations proc_slabinfo_operations = {
+ .open = slabinfo_open,
+ .read = seq_read,
+ .write = slabinfo_write,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static int __init slab_proc_init(void)
+{
+ proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
+ &proc_slabinfo_operations);
+ return 0;
+}
+module_init(slab_proc_init);
+#endif /* CONFIG_SLAB || CONFIG_SLUB_DEBUG */
+
+static __always_inline void *__do_krealloc(const void *p, size_t new_size,
+ gfp_t flags)
+{
+ void *ret;
+ size_t ks = 0;
+
+ if (p)
+ ks = ksize(p);
+
+ if (ks >= new_size) {
+ kasan_krealloc((void *)p, new_size, flags);
+ return (void *)p;
+ }
+
+ ret = kmalloc_track_caller(new_size, flags);
+ if (ret && p)
+ memcpy(ret, p, ks);
+
+ return ret;
+}
+
+/**
+ * __krealloc - like krealloc() but don't free @p.
+ * @p: object to reallocate memory for.
+ * @new_size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate.
+ *
+ * This function is like krealloc() except it never frees the originally
+ * allocated buffer. Use this if you don't want to free the buffer immediately
+ * like, for example, with RCU.
+ */
+void *__krealloc(const void *p, size_t new_size, gfp_t flags)
+{
+ if (unlikely(!new_size))
+ return ZERO_SIZE_PTR;
+
+ return __do_krealloc(p, new_size, flags);
+
+}
+EXPORT_SYMBOL(__krealloc);
+
+/**
+ * krealloc - reallocate memory. The contents will remain unchanged.
+ * @p: object to reallocate memory for.
+ * @new_size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate.
+ *
+ * The contents of the object pointed to are preserved up to the
+ * lesser of the new and old sizes. If @p is %NULL, krealloc()
+ * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
+ * %NULL pointer, the object pointed to is freed.
+ */
+void *krealloc(const void *p, size_t new_size, gfp_t flags)
+{
+ void *ret;
+
+ if (unlikely(!new_size)) {
+ kfree(p);
+ return ZERO_SIZE_PTR;
+ }
+
+ ret = __do_krealloc(p, new_size, flags);
+ if (ret && p != ret)
+ kfree(p);
+
+ return ret;
+}
+EXPORT_SYMBOL(krealloc);
+
+/**
+ * kzfree - like kfree but zero memory
+ * @p: object to free memory of
+ *
+ * The memory of the object @p points to is zeroed before freed.
+ * If @p is %NULL, kzfree() does nothing.
+ *
+ * Note: this function zeroes the whole allocated buffer which can be a good
+ * deal bigger than the requested buffer size passed to kmalloc(). So be
+ * careful when using this function in performance sensitive code.
+ */
+void kzfree(const void *p)
+{
+ size_t ks;
+ void *mem = (void *)p;
+
+ if (unlikely(ZERO_OR_NULL_PTR(mem)))
+ return;
+ ks = ksize(mem);
+ memset(mem, 0, ks);
+ kfree(mem);
+}
+EXPORT_SYMBOL(kzfree);
+
+/* Tracepoints definitions. */
+EXPORT_TRACEPOINT_SYMBOL(kmalloc);
+EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
+EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
+EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
+EXPORT_TRACEPOINT_SYMBOL(kfree);
+EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);
+
+int should_failslab(struct kmem_cache *s, gfp_t gfpflags)
+{
+ if (__should_failslab(s, gfpflags))
+ return -ENOMEM;
+ return 0;
+}
+ALLOW_ERROR_INJECTION(should_failslab, ERRNO);