[PATCH v2 09/21] mm/slab: remove mm/slab.c and slab_def.h

Vlastimil Babka
2023-11-20T18:34:44Z

Remove the SLAB implementation. Update CREDITS.
Also update and properly sort the SLOB entry there.

RIP SLAB allocator (1996 - 2024)

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
CREDITS | 12 +-
include/linux/slab_def.h | 124 --
mm/slab.c | 4005 ----------------------------------------------
3 files changed, 8 insertions(+), 4133 deletions(-)

diff --git a/CREDITS b/CREDITS
index f33a33fd2371..943a73e96149 100644
--- a/CREDITS
+++ b/CREDITS
@@ -9,10 +9,6 @@
Linus
----------

-N: Matt Mackal
-E: mpm@selenic.com
-D: SLOB slab allocator
-
N: Matti Aarnio
E: mea@nic.funet.fi
D: Alpha systems hacking, IPv6 and other network related stuff
@@ -1572,6 +1568,10 @@ S: Ampferstr. 50 / 4
S: 6020 Innsbruck
S: Austria

+N: Mark Hemment
+E: markhe@nextd.demon.co.uk
+D: SLAB allocator implementation
+
N: Richard Henderson
E: rth@twiddle.net
E: rth@cygnus.com
@@ -2437,6 +2437,10 @@ D: work on suspend-to-ram/disk, killing duplicates from ioctl32,
D: Altera SoCFPGA and Nokia N900 support.
S: Czech Republic

+N: Olivia Mackal
+E: olivia@selenic.com
+D: SLOB slab allocator
+
N: Paul Mackerras
E: paulus@samba.org
D: PPP driver
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
deleted file mode 100644
index a61e7d55d0d3..000000000000
--- a/include/linux/slab_def.h
+++ /dev/null
@@ -1,124 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LINUX_SLAB_DEF_H
-#define _LINUX_SLAB_DEF_H
-
-#include <linux/kfence.h>
-#include <linux/reciprocal_div.h>
-
-/*
- * Definitions unique to the original Linux SLAB allocator.
- */
-
-struct kmem_cache {
- struct array_cache __percpu *cpu_cache;
-
-/* 1) Cache tunables. Protected by slab_mutex */
- unsigned int batchcount;
- unsigned int limit;
- unsigned int shared;
-
- unsigned int size;
- struct reciprocal_value reciprocal_buffer_size;
-/* 2) touched by every alloc & free from the backend */
-
- slab_flags_t flags; /* constant flags */
- unsigned int num; /* # of objs per slab */
-
-/* 3) cache_grow/shrink */
- /* order of pgs per slab (2^n) */
- unsigned int gfporder;
-
- /* force GFP flags, e.g. GFP_DMA */
- gfp_t allocflags;
-
- size_t colour; /* cache colouring range */
- unsigned int colour_off; /* colour offset */
- unsigned int freelist_size;
-
- /* constructor func */
- void (*ctor)(void *obj);
-
-/* 4) cache creation/removal */
- const char *name;
- struct list_head list;
- int refcount;
- int object_size;
- int align;
-
-/* 5) statistics */
-#ifdef CONFIG_DEBUG_SLAB
- unsigned long num_active;
- unsigned long num_allocations;
- unsigned long high_mark;
- unsigned long grown;
- unsigned long reaped;
- unsigned long errors;
- unsigned long max_freeable;
- unsigned long node_allocs;
- unsigned long node_frees;
- unsigned long node_overflow;
- atomic_t allochit;
- atomic_t allocmiss;
- atomic_t freehit;
- atomic_t freemiss;
-
- /*
- * If debugging is enabled, then the allocator can add additional
- * fields and/or padding to every object. 'size' contains the total
- * object size including these internal fields, while 'obj_offset'
- * and 'object_size' contain the offset to the user object and its
- * size.
- */
- int obj_offset;
-#endif /* CONFIG_DEBUG_SLAB */
-
-#ifdef CONFIG_KASAN_GENERIC
- struct kasan_cache kasan_info;
-#endif
-
-#ifdef CONFIG_SLAB_FREELIST_RANDOM
- unsigned int *random_seq;
-#endif
-
-#ifdef CONFIG_HARDENED_USERCOPY
- unsigned int useroffset; /* Usercopy region offset */
- unsigned int usersize; /* Usercopy region size */
-#endif
-
- 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/mm/slab.c b/mm/slab.c
deleted file mode 100644
index 37efe3241f9c..000000000000
--- a/mm/slab.c
+++ /dev/null
@@ -1,4005 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * linux/mm/slab.c
- * Written by Mark Hemment, 1996/97.
- * (markhe@nextd.demon.co.uk)
- *
- * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
- *
- * Major cleanup, different bufctl logic, per-cpu arrays
- * (c) 2000 Manfred Spraul
- *
- * Cleanup, make the head arrays unconditional, preparation for NUMA
- * (c) 2002 Manfred Spraul
- *
- * An implementation of the Slab Allocator as described in outline in;
- * UNIX Internals: The New Frontiers by Uresh Vahalia
- * Pub: Prentice Hall ISBN 0-13-101908-2
- * or with a little more detail in;
- * The Slab Allocator: An Object-Caching Kernel Memory Allocator
- * Jeff Bonwick (Sun Microsystems).
- * Presented at: USENIX Summer 1994 Technical Conference
- *
- * The memory is organized in caches, one cache for each object type.
- * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
- * Each cache consists out of many slabs (they are small (usually one
- * page long) and always contiguous), and each slab contains multiple
- * initialized objects.
- *
- * This means, that your constructor is used only for newly allocated
- * slabs and you must pass objects with the same initializations to
- * kmem_cache_free.
- *
- * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
- * normal). If you need a special memory type, then must create a new
- * cache for that memory type.
- *
- * In order to reduce fragmentation, the slabs are sorted in 3 groups:
- * full slabs with 0 free objects
- * partial slabs
- * empty slabs with no allocated objects
- *
- * If partial slabs exist, then new allocations come from these slabs,
- * otherwise from empty slabs or new slabs are allocated.
- *
- * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
- * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
- *
- * Each cache has a short per-cpu head array, most allocs
- * and frees go into that array, and if that array overflows, then 1/2
- * of the entries in the array are given back into the global cache.
- * The head array is strictly LIFO and should improve the cache hit rates.
- * On SMP, it additionally reduces the spinlock operations.
- *
- * The c_cpuarray may not be read with enabled local interrupts -
- * it's changed with a smp_call_function().
- *
- * SMP synchronization:
- * constructors and destructors are called without any locking.
- * Several members in struct kmem_cache and struct slab never change, they
- * are accessed without any locking.
- * The per-cpu arrays are never accessed from the wrong cpu, no locking,
- * and local interrupts are disabled so slab code is preempt-safe.
- * The non-constant members are protected with a per-cache irq spinlock.
- *
- * Many thanks to Mark Hemment, who wrote another per-cpu slab patch
- * in 2000 - many ideas in the current implementation are derived from
- * his patch.
- *
- * Further notes from the original documentation:
- *
- * 11 April '97. Started multi-threading - markhe
- * The global cache-chain is protected by the mutex 'slab_mutex'.
- * The sem is only needed when accessing/extending the cache-chain, which
- * can never happen inside an interrupt (kmem_cache_create(),
- * kmem_cache_shrink() and kmem_cache_reap()).
- *
- * At present, each engine can be growing a cache. This should be blocked.
- *
- * 15 March 2005. NUMA slab allocator.
- * Shai Fultheim <shai@scalex86.org>.
- * Shobhit Dayal <shobhit@calsoftinc.com>
- * Alok N Kataria <alokk@calsoftinc.com>
- * Christoph Lameter <christoph@lameter.com>
- *
- * Modified the slab allocator to be node aware on NUMA systems.
- * Each node has its own list of partial, free and full slabs.
- * All object allocations for a node occur from node specific slab lists.
- */
-
-#include <linux/slab.h>
-#include <linux/mm.h>
-#include <linux/poison.h>
-#include <linux/swap.h>
-#include <linux/cache.h>
-#include <linux/interrupt.h>
-#include <linux/init.h>
-#include <linux/compiler.h>
-#include <linux/cpuset.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include <linux/notifier.h>
-#include <linux/kallsyms.h>
-#include <linux/kfence.h>
-#include <linux/cpu.h>
-#include <linux/sysctl.h>
-#include <linux/module.h>
-#include <linux/rcupdate.h>
-#include <linux/string.h>
-#include <linux/uaccess.h>
-#include <linux/nodemask.h>
-#include <linux/kmemleak.h>
-#include <linux/mempolicy.h>
-#include <linux/mutex.h>
-#include <linux/fault-inject.h>
-#include <linux/rtmutex.h>
-#include <linux/reciprocal_div.h>
-#include <linux/debugobjects.h>
-#include <linux/memory.h>
-#include <linux/prefetch.h>
-#include <linux/sched/task_stack.h>
-
-#include <net/sock.h>
-
-#include <asm/cacheflush.h>
-#include <asm/tlbflush.h>
-#include <asm/page.h>
-
-#include <trace/events/kmem.h>
-
-#include "internal.h"
-
-#include "slab.h"
-
-/*
- * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON.
- * 0 for faster, smaller code (especially in the critical paths).
- *
- * STATS - 1 to collect stats for /proc/slabinfo.
- * 0 for faster, smaller code (especially in the critical paths).
- *
- * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
- */
-
-#ifdef CONFIG_DEBUG_SLAB
-#define DEBUG 1
-#define STATS 1
-#define FORCED_DEBUG 1
-#else
-#define DEBUG 0
-#define STATS 0
-#define FORCED_DEBUG 0
-#endif
-
-/* Shouldn't this be in a header file somewhere? */
-#define BYTES_PER_WORD sizeof(void *)
-#define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long))
-
-#ifndef ARCH_KMALLOC_FLAGS
-#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
-#endif
-
-#define FREELIST_BYTE_INDEX (((PAGE_SIZE >> BITS_PER_BYTE) \
- <= SLAB_OBJ_MIN_SIZE) ? 1 : 0)
-
-#if FREELIST_BYTE_INDEX
-typedef unsigned char freelist_idx_t;
-#else
-typedef unsigned short freelist_idx_t;
-#endif
-
-#define SLAB_OBJ_MAX_NUM ((1 << sizeof(freelist_idx_t) * BITS_PER_BYTE) - 1)
-
-/*
- * struct array_cache
- *
- * Purpose:
- * - LIFO ordering, to hand out cache-warm objects from _alloc
- * - reduce the number of linked list operations
- * - reduce spinlock operations
- *
- * The limit is stored in the per-cpu structure to reduce the data cache
- * footprint.
- *
- */
-struct array_cache {
- unsigned int avail;
- unsigned int limit;
- unsigned int batchcount;
- unsigned int touched;
- void *entry[]; /*
- * Must have this definition in here for the proper
- * alignment of array_cache. Also simplifies accessing
- * the entries.
- */
-};
-
-struct alien_cache {
- spinlock_t lock;
- struct array_cache ac;
-};
-
-/*
- * Need this for bootstrapping a per node allocator.
- */
-#define NUM_INIT_LISTS (2 * MAX_NUMNODES)
-static struct kmem_cache_node __initdata init_kmem_cache_node[NUM_INIT_LISTS];
-#define CACHE_CACHE 0
-#define SIZE_NODE (MAX_NUMNODES)
-
-static int drain_freelist(struct kmem_cache *cache,
- struct kmem_cache_node *n, int tofree);
-static void free_block(struct kmem_cache *cachep, void **objpp, int len,
- int node, struct list_head *list);
-static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list);
-static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp);
-static void cache_reap(struct work_struct *unused);
-
-static inline void fixup_objfreelist_debug(struct kmem_cache *cachep,
- void **list);
-static inline void fixup_slab_list(struct kmem_cache *cachep,
- struct kmem_cache_node *n, struct slab *slab,
- void **list);
-
-#define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node))
-
-static void kmem_cache_node_init(struct kmem_cache_node *parent)
-{
- INIT_LIST_HEAD(&parent->slabs_full);
- INIT_LIST_HEAD(&parent->slabs_partial);
- INIT_LIST_HEAD(&parent->slabs_free);
- parent->total_slabs = 0;
- parent->free_slabs = 0;
- parent->shared = NULL;
- parent->alien = NULL;
- parent->colour_next = 0;
- raw_spin_lock_init(&parent->list_lock);
- parent->free_objects = 0;
- parent->free_touched = 0;
-}
-
-#define MAKE_LIST(cachep, listp, slab, nodeid) \
- do { \
- INIT_LIST_HEAD(listp); \
- list_splice(&get_node(cachep, nodeid)->slab, listp); \
- } while (0)
-
-#define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
- do { \
- MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
- MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
- MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
- } while (0)
-
-#define CFLGS_OBJFREELIST_SLAB ((slab_flags_t __force)0x40000000U)
-#define CFLGS_OFF_SLAB ((slab_flags_t __force)0x80000000U)
-#define OBJFREELIST_SLAB(x) ((x)->flags & CFLGS_OBJFREELIST_SLAB)
-#define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
-
-#define BATCHREFILL_LIMIT 16
-/*
- * Optimization question: fewer reaps means less probability for unnecessary
- * cpucache drain/refill cycles.
- *
- * OTOH the cpuarrays can contain lots of objects,
- * which could lock up otherwise freeable slabs.
- */
-#define REAPTIMEOUT_AC (2*HZ)
-#define REAPTIMEOUT_NODE (4*HZ)
-
-#if STATS
-#define STATS_INC_ACTIVE(x) ((x)->num_active++)
-#define STATS_DEC_ACTIVE(x) ((x)->num_active--)
-#define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
-#define STATS_INC_GROWN(x) ((x)->grown++)
-#define STATS_ADD_REAPED(x, y) ((x)->reaped += (y))
-#define STATS_SET_HIGH(x) \
- do { \
- if ((x)->num_active > (x)->high_mark) \
- (x)->high_mark = (x)->num_active; \
- } while (0)
-#define STATS_INC_ERR(x) ((x)->errors++)
-#define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
-#define STATS_INC_NODEFREES(x) ((x)->node_frees++)
-#define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
-#define STATS_SET_FREEABLE(x, i) \
- do { \
- if ((x)->max_freeable < i) \
- (x)->max_freeable = i; \
- } while (0)
-#define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
-#define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
-#define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
-#define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
-#else
-#define STATS_INC_ACTIVE(x) do { } while (0)
-#define STATS_DEC_ACTIVE(x) do { } while (0)
-#define STATS_INC_ALLOCED(x) do { } while (0)
-#define STATS_INC_GROWN(x) do { } while (0)
-#define STATS_ADD_REAPED(x, y) do { (void)(y); } while (0)
-#define STATS_SET_HIGH(x) do { } while (0)
-#define STATS_INC_ERR(x) do { } while (0)
-#define STATS_INC_NODEALLOCS(x) do { } while (0)
-#define STATS_INC_NODEFREES(x) do { } while (0)
-#define STATS_INC_ACOVERFLOW(x) do { } while (0)
-#define STATS_SET_FREEABLE(x, i) do { } while (0)
-#define STATS_INC_ALLOCHIT(x) do { } while (0)
-#define STATS_INC_ALLOCMISS(x) do { } while (0)
-#define STATS_INC_FREEHIT(x) do { } while (0)
-#define STATS_INC_FREEMISS(x) do { } while (0)
-#endif
-
-#if DEBUG
-
-/*
- * memory layout of objects:
- * 0 : objp
- * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
- * the end of an object is aligned with the end of the real
- * allocation. Catches writes behind the end of the allocation.
- * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
- * redzone word.
- * cachep->obj_offset: The real object.
- * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
- * cachep->size - 1* BYTES_PER_WORD: last caller address
- * [BYTES_PER_WORD long]
- */
-static int obj_offset(struct kmem_cache *cachep)
-{
- return cachep->obj_offset;
-}
-
-static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
-{
- BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
- return (unsigned long long *) (objp + obj_offset(cachep) -
- sizeof(unsigned long long));
-}
-
-static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
-{
- BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
- if (cachep->flags & SLAB_STORE_USER)
- return (unsigned long long *)(objp + cachep->size -
- sizeof(unsigned long long) -
- REDZONE_ALIGN);
- return (unsigned long long *) (objp + cachep->size -
- sizeof(unsigned long long));
-}
-
-static void **dbg_userword(struct kmem_cache *cachep, void *objp)
-{
- BUG_ON(!(cachep->flags & SLAB_STORE_USER));
- return (void **)(objp + cachep->size - BYTES_PER_WORD);
-}
-
-#else
-
-#define obj_offset(x) 0
-#define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
-#define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
-#define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
-
-#endif
-
-/*
- * Do not go above this order unless 0 objects fit into the slab or
- * overridden on the command line.
- */
-#define SLAB_MAX_ORDER_HI 1
-#define SLAB_MAX_ORDER_LO 0
-static int slab_max_order = SLAB_MAX_ORDER_LO;
-static bool slab_max_order_set __initdata;
-
-static inline void *index_to_obj(struct kmem_cache *cache,
- const struct slab *slab, unsigned int idx)
-{
- return slab->s_mem + cache->size * idx;
-}
-
-#define BOOT_CPUCACHE_ENTRIES 1
-/* internal cache of cache description objs */
-static struct kmem_cache kmem_cache_boot = {
- .batchcount = 1,
- .limit = BOOT_CPUCACHE_ENTRIES,
- .shared = 1,
- .size = sizeof(struct kmem_cache),
- .name = "kmem_cache",
-};
-
-static DEFINE_PER_CPU(struct delayed_work, slab_reap_work);
-
-static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
-{
- return this_cpu_ptr(cachep->cpu_cache);
-}
-
-/*
- * Calculate the number of objects and left-over bytes for a given buffer size.
- */
-static unsigned int cache_estimate(unsigned long gfporder, size_t buffer_size,
- slab_flags_t flags, size_t *left_over)
-{
- unsigned int num;
- size_t slab_size = PAGE_SIZE << gfporder;
-
- /*
- * The slab management structure can be either off the slab or
- * on it. For the latter case, the memory allocated for a
- * slab is used for:
- *
- * - @buffer_size bytes for each object
- * - One freelist_idx_t for each object
- *
- * We don't need to consider alignment of freelist because
- * freelist will be at the end of slab page. The objects will be
- * at the correct alignment.
- *
- * If the slab management structure is off the slab, then the
- * alignment will already be calculated into the size. Because
- * the slabs are all pages aligned, the objects will be at the
- * correct alignment when allocated.
- */
- if (flags & (CFLGS_OBJFREELIST_SLAB | CFLGS_OFF_SLAB)) {
- num = slab_size / buffer_size;
- *left_over = slab_size % buffer_size;
- } else {
- num = slab_size / (buffer_size + sizeof(freelist_idx_t));
- *left_over = slab_size %
- (buffer_size + sizeof(freelist_idx_t));
- }
-
- return num;
-}
-
-#if DEBUG
-#define slab_error(cachep, msg) __slab_error(__func__, cachep, msg)
-
-static void __slab_error(const char *function, struct kmem_cache *cachep,
- char *msg)
-{
- pr_err("slab error in %s(): cache `%s': %s\n",
- function, cachep->name, msg);
- dump_stack();
- add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
-}
-#endif
-
-/*
- * By default on NUMA we use alien caches to stage the freeing of
- * objects allocated from other nodes. This causes massive memory
- * inefficiencies when using fake NUMA setup to split memory into a
- * large number of small nodes, so it can be disabled on the command
- * line
- */
-
-static int use_alien_caches __read_mostly = 1;
-static int __init noaliencache_setup(char *s)
-{
- use_alien_caches = 0;
- return 1;
-}
-__setup("noaliencache", noaliencache_setup);
-
-static int __init slab_max_order_setup(char *str)
-{
- get_option(&str, &slab_max_order);
- slab_max_order = slab_max_order < 0 ? 0 :
- min(slab_max_order, MAX_ORDER);
- slab_max_order_set = true;
-
- return 1;
-}
-__setup("slab_max_order=", slab_max_order_setup);
-
-#ifdef CONFIG_NUMA
-/*
- * Special reaping functions for NUMA systems called from cache_reap().
- * These take care of doing round robin flushing of alien caches (containing
- * objects freed on different nodes from which they were allocated) and the
- * flushing of remote pcps by calling drain_node_pages.
- */
-static DEFINE_PER_CPU(unsigned long, slab_reap_node);
-
-static void init_reap_node(int cpu)
-{
- per_cpu(slab_reap_node, cpu) = next_node_in(cpu_to_mem(cpu),
- node_online_map);
-}
-
-static void next_reap_node(void)
-{
- int node = __this_cpu_read(slab_reap_node);
-
- node = next_node_in(node, node_online_map);
- __this_cpu_write(slab_reap_node, node);
-}
-
-#else
-#define init_reap_node(cpu) do { } while (0)
-#define next_reap_node(void) do { } while (0)
-#endif
-
-/*
- * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
- * via the workqueue/eventd.
- * Add the CPU number into the expiration time to minimize the possibility of
- * the CPUs getting into lockstep and contending for the global cache chain
- * lock.
- */
-static void start_cpu_timer(int cpu)
-{
- struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu);
-
- if (reap_work->work.func == NULL) {
- init_reap_node(cpu);
- INIT_DEFERRABLE_WORK(reap_work, cache_reap);
- schedule_delayed_work_on(cpu, reap_work,
- __round_jiffies_relative(HZ, cpu));
- }
-}
-
-static void init_arraycache(struct array_cache *ac, int limit, int batch)
-{
- if (ac) {
- ac->avail = 0;
- ac->limit = limit;
- ac->batchcount = batch;
- ac->touched = 0;
- }
-}
-
-static struct array_cache *alloc_arraycache(int node, int entries,
- int batchcount, gfp_t gfp)
-{
- size_t memsize = sizeof(void *) * entries + sizeof(struct array_cache);
- struct array_cache *ac = NULL;
-
- ac = kmalloc_node(memsize, gfp, node);
- /*
- * The array_cache structures contain pointers to free object.
- * However, when such objects are allocated or transferred to another
- * cache the pointers are not cleared and they could be counted as
- * valid references during a kmemleak scan. Therefore, kmemleak must
- * not scan such objects.
- */
- kmemleak_no_scan(ac);
- init_arraycache(ac, entries, batchcount);
- return ac;
-}
-
-static noinline void cache_free_pfmemalloc(struct kmem_cache *cachep,
- struct slab *slab, void *objp)
-{
- struct kmem_cache_node *n;
- int slab_node;
- LIST_HEAD(list);
-
- slab_node = slab_nid(slab);
- n = get_node(cachep, slab_node);
-
- raw_spin_lock(&n->list_lock);
- free_block(cachep, &objp, 1, slab_node, &list);
- raw_spin_unlock(&n->list_lock);
-
- slabs_destroy(cachep, &list);
-}
-
-/*
- * Transfer objects in one arraycache to another.
- * Locking must be handled by the caller.
- *
- * Return the number of entries transferred.
- */
-static int transfer_objects(struct array_cache *to,
- struct array_cache *from, unsigned int max)
-{
- /* Figure out how many entries to transfer */
- int nr = min3(from->avail, max, to->limit - to->avail);
-
- if (!nr)
- return 0;
-
- memcpy(to->entry + to->avail, from->entry + from->avail - nr,
- sizeof(void *) *nr);
-
- from->avail -= nr;
- to->avail += nr;
- return nr;
-}
-
-/* &alien->lock must be held by alien callers. */
-static __always_inline void __free_one(struct array_cache *ac, void *objp)
-{
- /* Avoid trivial double-free. */
- if (IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
- WARN_ON_ONCE(ac->avail > 0 && ac->entry[ac->avail - 1] == objp))
- return;
- ac->entry[ac->avail++] = objp;
-}
-
-#ifndef CONFIG_NUMA
-
-#define drain_alien_cache(cachep, alien) do { } while (0)
-#define reap_alien(cachep, n) do { } while (0)
-
-static inline struct alien_cache **alloc_alien_cache(int node,
- int limit, gfp_t gfp)
-{
- return NULL;
-}
-
-static inline void free_alien_cache(struct alien_cache **ac_ptr)
-{
-}
-
-static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
-{
- return 0;
-}
-
-static inline gfp_t gfp_exact_node(gfp_t flags)
-{
- return flags & ~__GFP_NOFAIL;
-}
-
-#else /* CONFIG_NUMA */
-
-static struct alien_cache *__alloc_alien_cache(int node, int entries,
- int batch, gfp_t gfp)
-{
- size_t memsize = sizeof(void *) * entries + sizeof(struct alien_cache);
- struct alien_cache *alc = NULL;
-
- alc = kmalloc_node(memsize, gfp, node);
- if (alc) {
- kmemleak_no_scan(alc);
- init_arraycache(&alc->ac, entries, batch);
- spin_lock_init(&alc->lock);
- }
- return alc;
-}
-
-static struct alien_cache **alloc_alien_cache(int node, int limit, gfp_t gfp)
-{
- struct alien_cache **alc_ptr;
- int i;
-
- if (limit > 1)
- limit = 12;
- alc_ptr = kcalloc_node(nr_node_ids, sizeof(void *), gfp, node);
- if (!alc_ptr)
- return NULL;
-
- for_each_node(i) {
- if (i == node || !node_online(i))
- continue;
- alc_ptr[i] = __alloc_alien_cache(node, limit, 0xbaadf00d, gfp);
- if (!alc_ptr[i]) {
- for (i--; i >= 0; i--)
- kfree(alc_ptr[i]);
- kfree(alc_ptr);
- return NULL;
- }
- }
- return alc_ptr;
-}
-
-static void free_alien_cache(struct alien_cache **alc_ptr)
-{
- int i;
-
- if (!alc_ptr)
- return;
- for_each_node(i)
- kfree(alc_ptr[i]);
- kfree(alc_ptr);
-}
-
-static void __drain_alien_cache(struct kmem_cache *cachep,
- struct array_cache *ac, int node,
- struct list_head *list)
-{
- struct kmem_cache_node *n = get_node(cachep, node);
-
- if (ac->avail) {
- raw_spin_lock(&n->list_lock);
- /*
- * Stuff objects into the remote nodes shared array first.
- * That way we could avoid the overhead of putting the objects
- * into the free lists and getting them back later.
- */
- if (n->shared)
- transfer_objects(n->shared, ac, ac->limit);
-
- free_block(cachep, ac->entry, ac->avail, node, list);
- ac->avail = 0;
- raw_spin_unlock(&n->list_lock);
- }
-}
-
-/*
- * Called from cache_reap() to regularly drain alien caches round robin.
- */
-static void reap_alien(struct kmem_cache *cachep, struct kmem_cache_node *n)
-{
- int node = __this_cpu_read(slab_reap_node);
-
- if (n->alien) {
- struct alien_cache *alc = n->alien[node];
- struct array_cache *ac;
-
- if (alc) {
- ac = &alc->ac;
- if (ac->avail && spin_trylock_irq(&alc->lock)) {
- LIST_HEAD(list);
-
- __drain_alien_cache(cachep, ac, node, &list);
- spin_unlock_irq(&alc->lock);
- slabs_destroy(cachep, &list);
- }
- }
- }
-}
-
-static void drain_alien_cache(struct kmem_cache *cachep,
- struct alien_cache **alien)
-{
- int i = 0;
- struct alien_cache *alc;
- struct array_cache *ac;
- unsigned long flags;
-
- for_each_online_node(i) {
- alc = alien[i];
- if (alc) {
- LIST_HEAD(list);
-
- ac = &alc->ac;
- spin_lock_irqsave(&alc->lock, flags);
- __drain_alien_cache(cachep, ac, i, &list);
- spin_unlock_irqrestore(&alc->lock, flags);
- slabs_destroy(cachep, &list);
- }
- }
-}
-
-static int __cache_free_alien(struct kmem_cache *cachep, void *objp,
- int node, int slab_node)
-{
- struct kmem_cache_node *n;
- struct alien_cache *alien = NULL;
- struct array_cache *ac;
- LIST_HEAD(list);
-
- n = get_node(cachep, node);
- STATS_INC_NODEFREES(cachep);
- if (n->alien && n->alien[slab_node]) {
- alien = n->alien[slab_node];
- ac = &alien->ac;
- spin_lock(&alien->lock);
- if (unlikely(ac->avail == ac->limit)) {
- STATS_INC_ACOVERFLOW(cachep);
- __drain_alien_cache(cachep, ac, slab_node, &list);
- }
- __free_one(ac, objp);
- spin_unlock(&alien->lock);
- slabs_destroy(cachep, &list);
- } else {
- n = get_node(cachep, slab_node);
- raw_spin_lock(&n->list_lock);
- free_block(cachep, &objp, 1, slab_node, &list);
- raw_spin_unlock(&n->list_lock);
- slabs_destroy(cachep, &list);
- }
- return 1;
-}
-
-static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
-{
- int slab_node = slab_nid(virt_to_slab(objp));
- int node = numa_mem_id();
- /*
- * Make sure we are not freeing an object from another node to the array
- * cache on this cpu.
- */
- if (likely(node == slab_node))
- return 0;
-
- return __cache_free_alien(cachep, objp, node, slab_node);
-}
-
-/*
- * Construct gfp mask to allocate from a specific node but do not reclaim or
- * warn about failures.
- */
-static inline gfp_t gfp_exact_node(gfp_t flags)
-{
- return (flags | __GFP_THISNODE | __GFP_NOWARN) & ~(__GFP_RECLAIM|__GFP_NOFAIL);
-}
-#endif
-
-static int init_cache_node(struct kmem_cache *cachep, int node, gfp_t gfp)
-{
- struct kmem_cache_node *n;
-
- /*
- * Set up the kmem_cache_node for cpu before we can
- * begin anything. Make sure some other cpu on this
- * node has not already allocated this
- */
- n = get_node(cachep, node);
- if (n) {
- raw_spin_lock_irq(&n->list_lock);
- n->free_limit = (1 + nr_cpus_node(node)) * cachep->batchcount +
- cachep->num;
- raw_spin_unlock_irq(&n->list_lock);
-
- return 0;
- }
-
- n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node);
- if (!n)
- return -ENOMEM;
-
- kmem_cache_node_init(n);
- n->next_reap = jiffies + REAPTIMEOUT_NODE +
- ((unsigned long)cachep) % REAPTIMEOUT_NODE;
-
- n->free_limit =
- (1 + nr_cpus_node(node)) * cachep->batchcount + cachep->num;
-
- /*
- * The kmem_cache_nodes don't come and go as CPUs
- * come and go. slab_mutex provides sufficient
- * protection here.
- */
- cachep->node[node] = n;
-
- return 0;
-}
-
-#if defined(CONFIG_NUMA) || defined(CONFIG_SMP)
-/*
- * Allocates and initializes node for a node on each slab cache, used for
- * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node
- * will be allocated off-node since memory is not yet online for the new node.
- * When hotplugging memory or a cpu, existing nodes are not replaced if
- * already in use.
- *
- * Must hold slab_mutex.
- */
-static int init_cache_node_node(int node)
-{
- int ret;
- struct kmem_cache *cachep;
-
- list_for_each_entry(cachep, &slab_caches, list) {
- ret = init_cache_node(cachep, node, GFP_KERNEL);
- if (ret)
- return ret;
- }
-
- return 0;
-}
-#endif
-
-static int setup_kmem_cache_node(struct kmem_cache *cachep,
- int node, gfp_t gfp, bool force_change)
-{
- int ret = -ENOMEM;
- struct kmem_cache_node *n;
- struct array_cache *old_shared = NULL;
- struct array_cache *new_shared = NULL;
- struct alien_cache **new_alien = NULL;
- LIST_HEAD(list);
-
- if (use_alien_caches) {
- new_alien = alloc_alien_cache(node, cachep->limit, gfp);
- if (!new_alien)
- goto fail;
- }
-
- if (cachep->shared) {
- new_shared = alloc_arraycache(node,
- cachep->shared * cachep->batchcount, 0xbaadf00d, gfp);
- if (!new_shared)
- goto fail;
- }
-
- ret = init_cache_node(cachep, node, gfp);
- if (ret)
- goto fail;
-
- n = get_node(cachep, node);
- raw_spin_lock_irq(&n->list_lock);
- if (n->shared && force_change) {
- free_block(cachep, n->shared->entry,
- n->shared->avail, node, &list);
- n->shared->avail = 0;
- }
-
- if (!n->shared || force_change) {
- old_shared = n->shared;
- n->shared = new_shared;
- new_shared = NULL;
- }
-
- if (!n->alien) {
- n->alien = new_alien;
- new_alien = NULL;
- }
-
- raw_spin_unlock_irq(&n->list_lock);
- slabs_destroy(cachep, &list);
-
- /*
- * To protect lockless access to n->shared during irq disabled context.
- * If n->shared isn't NULL in irq disabled context, accessing to it is
- * guaranteed to be valid until irq is re-enabled, because it will be
- * freed after synchronize_rcu().
- */
- if (old_shared && force_change)
- synchronize_rcu();
-
-fail:
- kfree(old_shared);
- kfree(new_shared);
- free_alien_cache(new_alien);
-
- return ret;
-}
-
-#ifdef CONFIG_SMP
-
-static void cpuup_canceled(long cpu)
-{
- struct kmem_cache *cachep;
- struct kmem_cache_node *n = NULL;
- int node = cpu_to_mem(cpu);
- const struct cpumask *mask = cpumask_of_node(node);
-
- list_for_each_entry(cachep, &slab_caches, list) {
- struct array_cache *nc;
- struct array_cache *shared;
- struct alien_cache **alien;
- LIST_HEAD(list);
-
- n = get_node(cachep, node);
- if (!n)
- continue;
-
- raw_spin_lock_irq(&n->list_lock);
-
- /* Free limit for this kmem_cache_node */
- n->free_limit -= cachep->batchcount;
-
- /* cpu is dead; no one can alloc from it. */
- nc = per_cpu_ptr(cachep->cpu_cache, cpu);
- free_block(cachep, nc->entry, nc->avail, node, &list);
- nc->avail = 0;
-
- if (!cpumask_empty(mask)) {
- raw_spin_unlock_irq(&n->list_lock);
- goto free_slab;
- }
-
- shared = n->shared;
- if (shared) {
- free_block(cachep, shared->entry,
- shared->avail, node, &list);
- n->shared = NULL;
- }
-
- alien = n->alien;
- n->alien = NULL;
-
- raw_spin_unlock_irq(&n->list_lock);
-
- kfree(shared);
- if (alien) {
- drain_alien_cache(cachep, alien);
- free_alien_cache(alien);
- }
-
-free_slab:
- slabs_destroy(cachep, &list);
- }
- /*
- * In the previous loop, all the objects were freed to
- * the respective cache's slabs, now we can go ahead and
- * shrink each nodelist to its limit.
- */
- list_for_each_entry(cachep, &slab_caches, list) {
- n = get_node(cachep, node);
- if (!n)
- continue;
- drain_freelist(cachep, n, INT_MAX);
- }
-}
-
-static int cpuup_prepare(long cpu)
-{
- struct kmem_cache *cachep;
- int node = cpu_to_mem(cpu);
- int err;
-
- /*
- * We need to do this right in the beginning since
- * alloc_arraycache's are going to use this list.
- * kmalloc_node allows us to add the slab to the right
- * kmem_cache_node and not this cpu's kmem_cache_node
- */
- err = init_cache_node_node(node);
- if (err < 0)
- goto bad;
-
- /*
- * Now we can go ahead with allocating the shared arrays and
- * array caches
- */
- list_for_each_entry(cachep, &slab_caches, list) {
- err = setup_kmem_cache_node(cachep, node, GFP_KERNEL, false);
- if (err)
- goto bad;
- }
-
- return 0;
-bad:
- cpuup_canceled(cpu);
- return -ENOMEM;
-}
-
-int slab_prepare_cpu(unsigned int cpu)
-{
- int err;
-
- mutex_lock(&slab_mutex);
- err = cpuup_prepare(cpu);
- mutex_unlock(&slab_mutex);
- return err;
-}
-
-/*
- * This is called for a failed online attempt and for a successful
- * offline.
- *
- * Even if all the cpus of a node are down, we don't free the
- * kmem_cache_node of any cache. This is to avoid a race between cpu_down, and
- * a kmalloc allocation from another cpu for memory from the node of
- * the cpu going down. The kmem_cache_node structure is usually allocated from
- * kmem_cache_create() and gets destroyed at kmem_cache_destroy().
- */
-int slab_dead_cpu(unsigned int cpu)
-{
- mutex_lock(&slab_mutex);
- cpuup_canceled(cpu);
- mutex_unlock(&slab_mutex);
- return 0;
-}
-#endif
-
-static int slab_online_cpu(unsigned int cpu)
-{
- start_cpu_timer(cpu);
- return 0;
-}
-
-static int slab_offline_cpu(unsigned int cpu)
-{
- /*
- * Shutdown cache reaper. Note that the slab_mutex is held so
- * that if cache_reap() is invoked it cannot do anything
- * expensive but will only modify reap_work and reschedule the
- * timer.
- */
- cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu));
- /* Now the cache_reaper is guaranteed to be not running. */
- per_cpu(slab_reap_work, cpu).work.func = NULL;
- return 0;
-}
-
-#if defined(CONFIG_NUMA)
-/*
- * Drains freelist for a node on each slab cache, used for memory hot-remove.
- * Returns -EBUSY if all objects cannot be drained so that the node is not
- * removed.
- *
- * Must hold slab_mutex.
- */
-static int __meminit drain_cache_node_node(int node)
-{
- struct kmem_cache *cachep;
- int ret = 0;
-
- list_for_each_entry(cachep, &slab_caches, list) {
- struct kmem_cache_node *n;
-
- n = get_node(cachep, node);
- if (!n)
- continue;
-
- drain_freelist(cachep, n, INT_MAX);
-
- if (!list_empty(&n->slabs_full) ||
- !list_empty(&n->slabs_partial)) {
- ret = -EBUSY;
- break;
- }
- }
- return ret;
-}
-
-static int __meminit slab_memory_callback(struct notifier_block *self,
- unsigned long action, void *arg)
-{
- struct memory_notify *mnb = arg;
- int ret = 0;
- int nid;
-
- nid = mnb->status_change_nid;
- if (nid < 0)
- goto out;
-
- switch (action) {
- case MEM_GOING_ONLINE:
- mutex_lock(&slab_mutex);
- ret = init_cache_node_node(nid);
- mutex_unlock(&slab_mutex);
- break;
- case MEM_GOING_OFFLINE:
- mutex_lock(&slab_mutex);
- ret = drain_cache_node_node(nid);
- mutex_unlock(&slab_mutex);
- break;
- case MEM_ONLINE:
- case MEM_OFFLINE:
- case MEM_CANCEL_ONLINE:
- case MEM_CANCEL_OFFLINE:
- break;
- }
-out:
- return notifier_from_errno(ret);
-}
-#endif /* CONFIG_NUMA */
-
-/*
- * swap the static kmem_cache_node with kmalloced memory
- */
-static void __init init_list(struct kmem_cache *cachep, struct kmem_cache_node *list,
- int nodeid)
-{
- struct kmem_cache_node *ptr;
-
- ptr = kmalloc_node(sizeof(struct kmem_cache_node), GFP_NOWAIT, nodeid);
- BUG_ON(!ptr);
-
- memcpy(ptr, list, sizeof(struct kmem_cache_node));
- /*
- * Do not assume that spinlocks can be initialized via memcpy:
- */
- raw_spin_lock_init(&ptr->list_lock);
-
- MAKE_ALL_LISTS(cachep, ptr, nodeid);
- cachep->node[nodeid] = ptr;
-}
-
-/*
- * For setting up all the kmem_cache_node for cache whose buffer_size is same as
- * size of kmem_cache_node.
- */
-static void __init set_up_node(struct kmem_cache *cachep, int index)
-{
- int node;
-
- for_each_online_node(node) {
- cachep->node[node] = &init_kmem_cache_node[index + node];
- cachep->node[node]->next_reap = jiffies +
- REAPTIMEOUT_NODE +
- ((unsigned long)cachep) % REAPTIMEOUT_NODE;
- }
-}
-
-/*
- * Initialisation. Called after the page allocator have been initialised and
- * before smp_init().
- */
-void __init kmem_cache_init(void)
-{
- int i;
-
- kmem_cache = &kmem_cache_boot;
-
- if (!IS_ENABLED(CONFIG_NUMA) || num_possible_nodes() == 1)
- use_alien_caches = 0;
-
- for (i = 0; i < NUM_INIT_LISTS; i++)
- kmem_cache_node_init(&init_kmem_cache_node[i]);
-
- /*
- * Fragmentation resistance on low memory - only use bigger
- * page orders on machines with more than 32MB of memory if
- * not overridden on the command line.
- */
- if (!slab_max_order_set && totalram_pages() > (32 << 20) >> PAGE_SHIFT)
- slab_max_order = SLAB_MAX_ORDER_HI;
-
- /* Bootstrap is tricky, because several objects are allocated
- * from caches that do not exist yet:
- * 1) initialize the kmem_cache cache: it contains the struct
- * kmem_cache structures of all caches, except kmem_cache itself:
- * kmem_cache is statically allocated.
- * Initially an __init data area is used for the head array and the
- * kmem_cache_node structures, it's replaced with a kmalloc allocated
- * array at the end of the bootstrap.
- * 2) Create the first kmalloc cache.
- * The struct kmem_cache for the new cache is allocated normally.
- * An __init data area is used for the head array.
- * 3) Create the remaining kmalloc caches, with minimally sized
- * head arrays.
- * 4) Replace the __init data head arrays for kmem_cache and the first
- * kmalloc cache with kmalloc allocated arrays.
- * 5) Replace the __init data for kmem_cache_node for kmem_cache and
- * the other cache's with kmalloc allocated memory.
- * 6) Resize the head arrays of the kmalloc caches to their final sizes.
- */
-
- /* 1) create the kmem_cache */
-
- /*
- * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids
- */
- create_boot_cache(kmem_cache, "kmem_cache",
- offsetof(struct kmem_cache, node) +
- nr_node_ids * sizeof(struct kmem_cache_node *),
- SLAB_HWCACHE_ALIGN, 0, 0);
- list_add(&kmem_cache->list, &slab_caches);
- slab_state = PARTIAL;
-
- /*
- * Initialize the caches that provide memory for the kmem_cache_node
- * structures first. Without this, further allocations will bug.
- */
- new_kmalloc_cache(INDEX_NODE, KMALLOC_NORMAL, ARCH_KMALLOC_FLAGS);
- slab_state = PARTIAL_NODE;
- setup_kmalloc_cache_index_table();
-
- /* 5) Replace the bootstrap kmem_cache_node */
- {
- int nid;
-
- for_each_online_node(nid) {
- init_list(kmem_cache, &init_kmem_cache_node[CACHE_CACHE + nid], nid);
-
- init_list(kmalloc_caches[KMALLOC_NORMAL][INDEX_NODE],
- &init_kmem_cache_node[SIZE_NODE + nid], nid);
- }
- }
-
- create_kmalloc_caches(ARCH_KMALLOC_FLAGS);
-}
-
-void __init kmem_cache_init_late(void)
-{
- struct kmem_cache *cachep;
-
- /* 6) resize the head arrays to their final sizes */
- mutex_lock(&slab_mutex);
- list_for_each_entry(cachep, &slab_caches, list)
- if (enable_cpucache(cachep, GFP_NOWAIT))
- BUG();
- mutex_unlock(&slab_mutex);
-
- /* Done! */
- slab_state = FULL;
-
-#ifdef CONFIG_NUMA
- /*
- * Register a memory hotplug callback that initializes and frees
- * node.
- */
- hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
-#endif
-
- /*
- * The reap timers are started later, with a module init call: That part
- * of the kernel is not yet operational.
- */
-}
-
-static int __init cpucache_init(void)
-{
- int ret;
-
- /*
- * Register the timers that return unneeded pages to the page allocator
- */
- ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "SLAB online",
- slab_online_cpu, slab_offline_cpu);
- WARN_ON(ret < 0);
-
- return 0;
-}
-__initcall(cpucache_init);
-
-static noinline void
-slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
-{
-#if DEBUG
- struct kmem_cache_node *n;
- unsigned long flags;
- int node;
- static DEFINE_RATELIMIT_STATE(slab_oom_rs, DEFAULT_RATELIMIT_INTERVAL,
- DEFAULT_RATELIMIT_BURST);
-
- if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slab_oom_rs))
- return;
-
- pr_warn("SLAB: Unable to allocate memory on node %d, gfp=%#x(%pGg)\n",
- nodeid, gfpflags, &gfpflags);
- pr_warn(" cache: %s, object size: %d, order: %d\n",
- cachep->name, cachep->size, cachep->gfporder);
-
- for_each_kmem_cache_node(cachep, node, n) {
- unsigned long total_slabs, free_slabs, free_objs;
-
- raw_spin_lock_irqsave(&n->list_lock, flags);
- total_slabs = n->total_slabs;
- free_slabs = n->free_slabs;
- free_objs = n->free_objects;
- raw_spin_unlock_irqrestore(&n->list_lock, flags);
-
- pr_warn(" node %d: slabs: %ld/%ld, objs: %ld/%ld\n",
- node, total_slabs - free_slabs, total_slabs,
- (total_slabs * cachep->num) - free_objs,
- total_slabs * cachep->num);
- }
-#endif
-}
-
-/*
- * Interface to system's page allocator. No need to hold the
- * kmem_cache_node ->list_lock.
- *
- * If we requested dmaable memory, we will get it. Even if we
- * did not request dmaable memory, we might get it, but that
- * would be relatively rare and ignorable.
- */
-static struct slab *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
- int nodeid)
-{
- struct folio *folio;
- struct slab *slab;
-
- flags |= cachep->allocflags;
-
- folio = (struct folio *) __alloc_pages_node(nodeid, flags, cachep->gfporder);
- if (!folio) {
- slab_out_of_memory(cachep, flags, nodeid);
- return NULL;
- }
-
- slab = folio_slab(folio);
-
- account_slab(slab, cachep->gfporder, cachep, flags);
- __folio_set_slab(folio);
- /* Make the flag visible before any changes to folio->mapping */
- smp_wmb();
- /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
- if (sk_memalloc_socks() && folio_is_pfmemalloc(folio))
- slab_set_pfmemalloc(slab);
-
- return slab;
-}
-
-/*
- * Interface to system's page release.
- */
-static void kmem_freepages(struct kmem_cache *cachep, struct slab *slab)
-{
- int order = cachep->gfporder;
- struct folio *folio = slab_folio(slab);
-
- BUG_ON(!folio_test_slab(folio));
- __slab_clear_pfmemalloc(slab);
- page_mapcount_reset(&folio->page);
- folio->mapping = NULL;
- /* Make the mapping reset visible before clearing the flag */
- smp_wmb();
- __folio_clear_slab(folio);
-
- mm_account_reclaimed_pages(1 << order);
- unaccount_slab(slab, order, cachep);
- __free_pages(&folio->page, order);
-}
-
-static void kmem_rcu_free(struct rcu_head *head)
-{
- struct kmem_cache *cachep;
- struct slab *slab;
-
- slab = container_of(head, struct slab, rcu_head);
- cachep = slab->slab_cache;
-
- kmem_freepages(cachep, slab);
-}
-
-#if DEBUG
-static inline bool is_debug_pagealloc_cache(struct kmem_cache *cachep)
-{
- return debug_pagealloc_enabled_static() && OFF_SLAB(cachep) &&
- ((cachep->size % PAGE_SIZE) == 0);
-}
-
-#ifdef CONFIG_DEBUG_PAGEALLOC
-static void slab_kernel_map(struct kmem_cache *cachep, void *objp, int map)
-{
- if (!is_debug_pagealloc_cache(cachep))
- return;
-
- __kernel_map_pages(virt_to_page(objp), cachep->size / PAGE_SIZE, map);
-}
-
-#else
-static inline void slab_kernel_map(struct kmem_cache *cachep, void *objp,
- int map) {}
-
-#endif
-
-static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
-{
- int size = cachep->object_size;
- addr = &((char *)addr)[obj_offset(cachep)];
-
- memset(addr, val, size);
- *(unsigned char *)(addr + size - 1) = POISON_END;
-}
-
-static void dump_line(char *data, int offset, int limit)
-{
- int i;
- unsigned char error = 0;
- int bad_count = 0;
-
- pr_err("%03x: ", offset);
- for (i = 0; i < limit; i++) {
- if (data[offset + i] != POISON_FREE) {
- error = data[offset + i];
- bad_count++;
- }
- }
- print_hex_dump(KERN_CONT, "", 0, 16, 1,
- &data[offset], limit, 1);
-
- if (bad_count == 1) {
- error ^= POISON_FREE;
- if (!(error & (error - 1))) {
- pr_err("Single bit error detected. Probably bad RAM.\n");
-#ifdef CONFIG_X86
- pr_err("Run memtest86+ or a similar memory test tool.\n");
-#else
- pr_err("Run a memory test tool.\n");
-#endif
- }
- }
-}
-#endif
-
-#if DEBUG
-
-static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
-{
- int i, size;
- char *realobj;
-
- if (cachep->flags & SLAB_RED_ZONE) {
- pr_err("Redzone: 0x%llx/0x%llx\n",
- *dbg_redzone1(cachep, objp),
- *dbg_redzone2(cachep, objp));
- }
-
- if (cachep->flags & SLAB_STORE_USER)
- pr_err("Last user: (%pSR)\n", *dbg_userword(cachep, objp));
- realobj = (char *)objp + obj_offset(cachep);
- size = cachep->object_size;
- for (i = 0; i < size && lines; i += 16, lines--) {
- int limit;
- limit = 16;
- if (i + limit > size)
- limit = size - i;
- dump_line(realobj, i, limit);
- }
-}
-
-static void check_poison_obj(struct kmem_cache *cachep, void *objp)
-{
- char *realobj;
- int size, i;
- int lines = 0;
-
- if (is_debug_pagealloc_cache(cachep))
- return;
-
- realobj = (char *)objp + obj_offset(cachep);
- size = cachep->object_size;
-
- for (i = 0; i < size; i++) {
- char exp = POISON_FREE;
- if (i == size - 1)
- exp = POISON_END;
- if (realobj[i] != exp) {
- int limit;
- /* Mismatch ! */
- /* Print header */
- if (lines == 0) {
- pr_err("Slab corruption (%s): %s start=%px, len=%d\n",
- print_tainted(), cachep->name,
- realobj, size);
- print_objinfo(cachep, objp, 0);
- }
- /* Hexdump the affected line */
- i = (i / 16) * 16;
- limit = 16;
- if (i + limit > size)
- limit = size - i;
- dump_line(realobj, i, limit);
- i += 16;
- lines++;
- /* Limit to 5 lines */
- if (lines > 5)
- break;
- }
- }
- if (lines != 0) {
- /* Print some data about the neighboring objects, if they
- * exist:
- */
- struct slab *slab = virt_to_slab(objp);
- unsigned int objnr;
-
- objnr = obj_to_index(cachep, slab, objp);
- if (objnr) {
- objp = index_to_obj(cachep, slab, objnr - 1);
- realobj = (char *)objp + obj_offset(cachep);
- pr_err("Prev obj: start=%px, len=%d\n", realobj, size);
- print_objinfo(cachep, objp, 2);
- }
- if (objnr + 1 < cachep->num) {
- objp = index_to_obj(cachep, slab, objnr + 1);
- realobj = (char *)objp + obj_offset(cachep);
- pr_err("Next obj: start=%px, len=%d\n", realobj, size);
- print_objinfo(cachep, objp, 2);
- }
- }
-}
-#endif
-
-#if DEBUG
-static void slab_destroy_debugcheck(struct kmem_cache *cachep,
- struct slab *slab)
-{
- int i;
-
- if (OBJFREELIST_SLAB(cachep) && cachep->flags & SLAB_POISON) {
- poison_obj(cachep, slab->freelist - obj_offset(cachep),
- POISON_FREE);
- }
-
- for (i = 0; i < cachep->num; i++) {
- void *objp = index_to_obj(cachep, slab, i);
-
- if (cachep->flags & SLAB_POISON) {
- check_poison_obj(cachep, objp);
- slab_kernel_map(cachep, objp, 1);
- }
- if (cachep->flags & SLAB_RED_ZONE) {
- if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
- slab_error(cachep, "start of a freed object was overwritten");
- if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
- slab_error(cachep, "end of a freed object was overwritten");
- }
- }
-}
-#else
-static void slab_destroy_debugcheck(struct kmem_cache *cachep,
- struct slab *slab)
-{
-}
-#endif
-
-/**
- * slab_destroy - destroy and release all objects in a slab
- * @cachep: cache pointer being destroyed
- * @slab: slab being destroyed
- *
- * Destroy all the objs in a slab, and release the mem back to the system.
- * Before calling the slab must have been unlinked from the cache. The
- * kmem_cache_node ->list_lock is not held/needed.
- */
-static void slab_destroy(struct kmem_cache *cachep, struct slab *slab)
-{
- void *freelist;
-
- freelist = slab->freelist;
- slab_destroy_debugcheck(cachep, slab);
- if (unlikely(cachep->flags & SLAB_TYPESAFE_BY_RCU))
- call_rcu(&slab->rcu_head, kmem_rcu_free);
- else
- kmem_freepages(cachep, slab);
-
- /*
- * From now on, we don't use freelist
- * although actual page can be freed in rcu context
- */
- if (OFF_SLAB(cachep))
- kfree(freelist);
-}
-
-/*
- * Update the size of the caches before calling slabs_destroy as it may
- * recursively call kfree.
- */
-static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list)
-{
- struct slab *slab, *n;
-
- list_for_each_entry_safe(slab, n, list, slab_list) {
- list_del(&slab->slab_list);
- slab_destroy(cachep, slab);
- }
-}
-
-/**
- * calculate_slab_order - calculate size (page order) of slabs
- * @cachep: pointer to the cache that is being created
- * @size: size of objects to be created in this cache.
- * @flags: slab allocation flags
- *
- * Also calculates the number of objects per slab.
- *
- * This could be made much more intelligent. For now, try to avoid using
- * high order pages for slabs. When the gfp() functions are more friendly
- * towards high-order requests, this should be changed.
- *
- * Return: number of left-over bytes in a slab
- */
-static size_t calculate_slab_order(struct kmem_cache *cachep,
- size_t size, slab_flags_t flags)
-{
- size_t left_over = 0;
- int gfporder;
-
- for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) {
- unsigned int num;
- size_t remainder;
-
- num = cache_estimate(gfporder, size, flags, &remainder);
- if (!num)
- continue;
-
- /* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */
- if (num > SLAB_OBJ_MAX_NUM)
- break;
-
- if (flags & CFLGS_OFF_SLAB) {
- struct kmem_cache *freelist_cache;
- size_t freelist_size;
- size_t freelist_cache_size;
-
- freelist_size = num * sizeof(freelist_idx_t);
- if (freelist_size > KMALLOC_MAX_CACHE_SIZE) {
- freelist_cache_size = PAGE_SIZE << get_order(freelist_size);
- } else {
- freelist_cache = kmalloc_slab(freelist_size, 0u, _RET_IP_);
- if (!freelist_cache)
- continue;
- freelist_cache_size = freelist_cache->size;
-
- /*
- * Needed to avoid possible looping condition
- * in cache_grow_begin()
- */
- if (OFF_SLAB(freelist_cache))
- continue;
- }
-
- /* check if off slab has enough benefit */
- if (freelist_cache_size > cachep->size / 2)
- continue;
- }
-
- /* Found something acceptable - save it away */
- cachep->num = num;
- cachep->gfporder = gfporder;
- left_over = remainder;
-
- /*
- * A VFS-reclaimable slab tends to have most allocations
- * as GFP_NOFS and we really don't want to have to be allocating
- * higher-order pages when we are unable to shrink dcache.
- */
- if (flags & SLAB_RECLAIM_ACCOUNT)
- break;
-
- /*
- * Large number of objects is good, but very large slabs are
- * currently bad for the gfp()s.
- */
- if (gfporder >= slab_max_order)
- break;
-
- /*
- * Acceptable internal fragmentation?
- */
- if (left_over * 8 <= (PAGE_SIZE << gfporder))
- break;
- }
- return left_over;
-}
-
-static struct array_cache __percpu *alloc_kmem_cache_cpus(
- struct kmem_cache *cachep, int entries, int batchcount)
-{
- int cpu;
- size_t size;
- struct array_cache __percpu *cpu_cache;
-
- size = sizeof(void *) * entries + sizeof(struct array_cache);
- cpu_cache = __alloc_percpu(size, sizeof(void *));
-
- if (!cpu_cache)
- return NULL;
-
- for_each_possible_cpu(cpu) {
- init_arraycache(per_cpu_ptr(cpu_cache, cpu),
- entries, batchcount);
- }
-
- return cpu_cache;
-}
-
-static int __ref setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
-{
- if (slab_state >= FULL)
- return enable_cpucache(cachep, gfp);
-
- cachep->cpu_cache = alloc_kmem_cache_cpus(cachep, 1, 1);
- if (!cachep->cpu_cache)
- return 1;
-
- if (slab_state == DOWN) {
- /* Creation of first cache (kmem_cache). */
- set_up_node(kmem_cache, CACHE_CACHE);
- } else if (slab_state == PARTIAL) {
- /* For kmem_cache_node */
- set_up_node(cachep, SIZE_NODE);
- } else {
- int node;
-
- for_each_online_node(node) {
- cachep->node[node] = kmalloc_node(
- sizeof(struct kmem_cache_node), gfp, node);
- BUG_ON(!cachep->node[node]);
- kmem_cache_node_init(cachep->node[node]);
- }
- }
-
- cachep->node[numa_mem_id()]->next_reap =
- jiffies + REAPTIMEOUT_NODE +
- ((unsigned long)cachep) % REAPTIMEOUT_NODE;
-
- cpu_cache_get(cachep)->avail = 0;
- cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
- cpu_cache_get(cachep)->batchcount = 1;
- cpu_cache_get(cachep)->touched = 0;
- cachep->batchcount = 1;
- cachep->limit = BOOT_CPUCACHE_ENTRIES;
- return 0;
-}
-
-slab_flags_t kmem_cache_flags(unsigned int object_size,
- slab_flags_t flags, const char *name)
-{
- return flags;
-}
-
-struct kmem_cache *
-__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
- slab_flags_t flags, void (*ctor)(void *))
-{
- struct kmem_cache *cachep;
-
- cachep = find_mergeable(size, align, flags, name, ctor);
- if (cachep) {
- cachep->refcount++;
-
- /*
- * Adjust the object sizes so that we clear
- * the complete object on kzalloc.
- */
- cachep->object_size = max_t(int, cachep->object_size, size);
- }
- return cachep;
-}
-
-static bool set_objfreelist_slab_cache(struct kmem_cache *cachep,
- size_t size, slab_flags_t flags)
-{
- size_t left;
-
- cachep->num = 0;
-
- /*
- * If slab auto-initialization on free is enabled, store the freelist
- * off-slab, so that its contents don't end up in one of the allocated
- * objects.
- */
- if (unlikely(slab_want_init_on_free(cachep)))
- return false;
-
- if (cachep->ctor || flags & SLAB_TYPESAFE_BY_RCU)
- return false;
-
- left = calculate_slab_order(cachep, size,
- flags | CFLGS_OBJFREELIST_SLAB);
- if (!cachep->num)
- return false;
-
- if (cachep->num * sizeof(freelist_idx_t) > cachep->object_size)
- return false;
-
- cachep->colour = left / cachep->colour_off;
-
- return true;
-}
-
-static bool set_off_slab_cache(struct kmem_cache *cachep,
- size_t size, slab_flags_t flags)
-{
- size_t left;
-
- cachep->num = 0;
-
- /*
- * Always use on-slab management when SLAB_NOLEAKTRACE
- * to avoid recursive calls into kmemleak.
- */
- if (flags & SLAB_NOLEAKTRACE)
- return false;
-
- /*
- * Size is large, assume best to place the slab management obj
- * off-slab (should allow better packing of objs).
- */
- left = calculate_slab_order(cachep, size, flags | CFLGS_OFF_SLAB);
- if (!cachep->num)
- return false;
-
- /*
- * If the slab has been placed off-slab, and we have enough space then
- * move it on-slab. This is at the expense of any extra colouring.
- */
- if (left >= cachep->num * sizeof(freelist_idx_t))
- return false;
-
- cachep->colour = left / cachep->colour_off;
-
- return true;
-}
-
-static bool set_on_slab_cache(struct kmem_cache *cachep,
- size_t size, slab_flags_t flags)
-{
- size_t left;
-
- cachep->num = 0;
-
- left = calculate_slab_order(cachep, size, flags);
- if (!cachep->num)
- return false;
-
- cachep->colour = left / cachep->colour_off;
-
- return true;
-}
-
-/*
- * __kmem_cache_create - Create a cache.
- * @cachep: cache management descriptor
- * @flags: SLAB flags
- *
- * Returns zero on success, nonzero on failure.
- *
- * 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.
- */
-int __kmem_cache_create(struct kmem_cache *cachep, slab_flags_t flags)
-{
- size_t ralign = BYTES_PER_WORD;
- gfp_t gfp;
- int err;
- unsigned int size = cachep->size;
-
-#if DEBUG
-#if FORCED_DEBUG
- /*
- * Enable redzoning and last user accounting, except for caches with
- * large objects, if the increased size would increase the object size
- * above the next power of two: caches with object sizes just above a
- * power of two have a significant amount of internal fragmentation.
- */
- if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN +
- 2 * sizeof(unsigned long long)))
- flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
- if (!(flags & SLAB_TYPESAFE_BY_RCU))
- flags |= SLAB_POISON;
-#endif
-#endif
-
- /*
- * Check that size is in terms of words. This is needed to avoid
- * unaligned accesses for some archs when redzoning is used, and makes
- * sure any on-slab bufctl's are also correctly aligned.
- */
- size = ALIGN(size, BYTES_PER_WORD);
-
- if (flags & SLAB_RED_ZONE) {
- ralign = REDZONE_ALIGN;
- /* If redzoning, ensure that the second redzone is suitably
- * aligned, by adjusting the object size accordingly. */
- size = ALIGN(size, REDZONE_ALIGN);
- }
-
- /* 3) caller mandated alignment */
- if (ralign < cachep->align) {
- ralign = cachep->align;
- }
- /* disable debug if necessary */
- if (ralign > __alignof__(unsigned long long))
- flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
- /*
- * 4) Store it.
- */
- cachep->align = ralign;
- cachep->colour_off = cache_line_size();
- /* Offset must be a multiple of the alignment. */
- if (cachep->colour_off < cachep->align)
- cachep->colour_off = cachep->align;
-
- if (slab_is_available())
- gfp = GFP_KERNEL;
- else
- gfp = GFP_NOWAIT;
-
-#if DEBUG
-
- /*
- * Both debugging options require word-alignment which is calculated
- * into align above.
- */
- if (flags & SLAB_RED_ZONE) {
- /* add space for red zone words */
- cachep->obj_offset += sizeof(unsigned long long);
- size += 2 * sizeof(unsigned long long);
- }
- if (flags & SLAB_STORE_USER) {
- /* user store requires one word storage behind the end of
- * the real object. But if the second red zone needs to be
- * aligned to 64 bits, we must allow that much space.
- */
- if (flags & SLAB_RED_ZONE)
- size += REDZONE_ALIGN;
- else
- size += BYTES_PER_WORD;
- }
-#endif
-
- kasan_cache_create(cachep, &size, &flags);
-
- size = ALIGN(size, cachep->align);
- /*
- * We should restrict the number of objects in a slab to implement
- * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition.
- */
- if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE)
- size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align);
-
-#if DEBUG
- /*
- * To activate debug pagealloc, off-slab management is necessary
- * requirement. In early phase of initialization, small sized slab
- * doesn't get initialized so it would not be possible. So, we need
- * to check size >= 256. It guarantees that all necessary small
- * sized slab is initialized in current slab initialization sequence.
- */
- if (debug_pagealloc_enabled_static() && (flags & SLAB_POISON) &&
- size >= 256 && cachep->object_size > cache_line_size()) {
- if (size < PAGE_SIZE || size % PAGE_SIZE == 0) {
- size_t tmp_size = ALIGN(size, PAGE_SIZE);
-
- if (set_off_slab_cache(cachep, tmp_size, flags)) {
- flags |= CFLGS_OFF_SLAB;
- cachep->obj_offset += tmp_size - size;
- size = tmp_size;
- goto done;
- }
- }
- }
-#endif
-
- if (set_objfreelist_slab_cache(cachep, size, flags)) {
- flags |= CFLGS_OBJFREELIST_SLAB;
- goto done;
- }
-
- if (set_off_slab_cache(cachep, size, flags)) {
- flags |= CFLGS_OFF_SLAB;
- goto done;
- }
-
- if (set_on_slab_cache(cachep, size, flags))
- goto done;
-
- return -E2BIG;
-
-done:
- cachep->freelist_size = cachep->num * sizeof(freelist_idx_t);
- cachep->flags = flags;
- cachep->allocflags = __GFP_COMP;
- if (flags & SLAB_CACHE_DMA)
- cachep->allocflags |= GFP_DMA;
- if (flags & SLAB_CACHE_DMA32)
- cachep->allocflags |= GFP_DMA32;
- if (flags & SLAB_RECLAIM_ACCOUNT)
- cachep->allocflags |= __GFP_RECLAIMABLE;
- cachep->size = size;
- cachep->reciprocal_buffer_size = reciprocal_value(size);
-
-#if DEBUG
- /*
- * If we're going to use the generic kernel_map_pages()
- * poisoning, then it's going to smash the contents of
- * the redzone and userword anyhow, so switch them off.
- */
- if (IS_ENABLED(CONFIG_PAGE_POISONING) &&
- (cachep->flags & SLAB_POISON) &&
- is_debug_pagealloc_cache(cachep))
- cachep->flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
-#endif
-
- err = setup_cpu_cache(cachep, gfp);
- if (err) {
- __kmem_cache_release(cachep);
- return err;
- }
-
- return 0;
-}
-
-#if DEBUG
-static void check_irq_off(void)
-{
- BUG_ON(!irqs_disabled());
-}
-
-static void check_irq_on(void)
-{
- BUG_ON(irqs_disabled());
-}
-
-static void check_mutex_acquired(void)
-{
- BUG_ON(!mutex_is_locked(&slab_mutex));
-}
-
-static void check_spinlock_acquired(struct kmem_cache *cachep)
-{
-#ifdef CONFIG_SMP
- check_irq_off();
- assert_raw_spin_locked(&get_node(cachep, numa_mem_id())->list_lock);
-#endif
-}
-
-static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
-{
-#ifdef CONFIG_SMP
- check_irq_off();
- assert_raw_spin_locked(&get_node(cachep, node)->list_lock);
-#endif
-}
-
-#else
-#define check_irq_off() do { } while(0)
-#define check_irq_on() do { } while(0)
-#define check_mutex_acquired() do { } while(0)
-#define check_spinlock_acquired(x) do { } while(0)
-#define check_spinlock_acquired_node(x, y) do { } while(0)
-#endif
-
-static void drain_array_locked(struct kmem_cache *cachep, struct array_cache *ac,
- int node, bool free_all, struct list_head *list)
-{
- int tofree;
-
- if (!ac || !ac->avail)
- return;
-
- tofree = free_all ? ac->avail : (ac->limit + 4) / 5;
- if (tofree > ac->avail)
- tofree = (ac->avail + 1) / 2;
-
- free_block(cachep, ac->entry, tofree, node, list);
- ac->avail -= tofree;
- memmove(ac->entry, &(ac->entry[tofree]), sizeof(void *) * ac->avail);
-}
-
-static void do_drain(void *arg)
-{
- struct kmem_cache *cachep = arg;
- struct array_cache *ac;
- int node = numa_mem_id();
- struct kmem_cache_node *n;
- LIST_HEAD(list);
-
- check_irq_off();
- ac = cpu_cache_get(cachep);
- n = get_node(cachep, node);
- raw_spin_lock(&n->list_lock);
- free_block(cachep, ac->entry, ac->avail, node, &list);
- raw_spin_unlock(&n->list_lock);
- ac->avail = 0;
- slabs_destroy(cachep, &list);
-}
-
-static void drain_cpu_caches(struct kmem_cache *cachep)
-{
- struct kmem_cache_node *n;
- int node;
- LIST_HEAD(list);
-
- on_each_cpu(do_drain, cachep, 1);
- check_irq_on();
- for_each_kmem_cache_node(cachep, node, n)
- if (n->alien)
- drain_alien_cache(cachep, n->alien);
-
- for_each_kmem_cache_node(cachep, node, n) {
- raw_spin_lock_irq(&n->list_lock);
- drain_array_locked(cachep, n->shared, node, true, &list);
- raw_spin_unlock_irq(&n->list_lock);
-
- slabs_destroy(cachep, &list);
- }
-}
-
-/*
- * Remove slabs from the list of free slabs.
- * Specify the number of slabs to drain in tofree.
- *
- * Returns the actual number of slabs released.
- */
-static int drain_freelist(struct kmem_cache *cache,
- struct kmem_cache_node *n, int tofree)
-{
- struct list_head *p;
- int nr_freed;
- struct slab *slab;
-
- nr_freed = 0;
- while (nr_freed < tofree && !list_empty(&n->slabs_free)) {
-
- raw_spin_lock_irq(&n->list_lock);
- p = n->slabs_free.prev;
- if (p == &n->slabs_free) {
- raw_spin_unlock_irq(&n->list_lock);
- goto out;
- }
-
- slab = list_entry(p, struct slab, slab_list);
- list_del(&slab->slab_list);
- n->free_slabs--;
- n->total_slabs--;
- /*
- * Safe to drop the lock. The slab is no longer linked
- * to the cache.
- */
- n->free_objects -= cache->num;
- raw_spin_unlock_irq(&n->list_lock);
- slab_destroy(cache, slab);
- nr_freed++;
-
- cond_resched();
- }
-out:
- return nr_freed;
-}
-
-bool __kmem_cache_empty(struct kmem_cache *s)
-{
- int node;
- struct kmem_cache_node *n;
-
- for_each_kmem_cache_node(s, node, n)
- if (!list_empty(&n->slabs_full) ||
- !list_empty(&n->slabs_partial))
- return false;
- return true;
-}
-
-int __kmem_cache_shrink(struct kmem_cache *cachep)
-{
- int ret = 0;
- int node;
- struct kmem_cache_node *n;
-
- drain_cpu_caches(cachep);
-
- check_irq_on();
- for_each_kmem_cache_node(cachep, node, n) {
- drain_freelist(cachep, n, INT_MAX);
-
- ret += !list_empty(&n->slabs_full) ||
- !list_empty(&n->slabs_partial);
- }
- return (ret ? 1 : 0);
-}
-
-int __kmem_cache_shutdown(struct kmem_cache *cachep)
-{
- return __kmem_cache_shrink(cachep);
-}
-
-void __kmem_cache_release(struct kmem_cache *cachep)
-{
- int i;
- struct kmem_cache_node *n;
-
- cache_random_seq_destroy(cachep);
-
- free_percpu(cachep->cpu_cache);
-
- /* NUMA: free the node structures */
- for_each_kmem_cache_node(cachep, i, n) {
- kfree(n->shared);
- free_alien_cache(n->alien);
- kfree(n);
- cachep->node[i] = NULL;
- }
-}
-
-/*
- * Get the memory for a slab management obj.
- *
- * For a slab cache when the slab descriptor is off-slab, the
- * slab descriptor can't come from the same cache which is being created,
- * Because if it is the case, that means we defer the creation of
- * the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point.
- * And we eventually call down to __kmem_cache_create(), which
- * in turn looks up in the kmalloc_{dma,}_caches for the desired-size one.
- * This is a "chicken-and-egg" problem.
- *
- * So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches,
- * which are all initialized during kmem_cache_init().
- */
-static void *alloc_slabmgmt(struct kmem_cache *cachep,
- struct slab *slab, int colour_off,
- gfp_t local_flags, int nodeid)
-{
- void *freelist;
- void *addr = slab_address(slab);
-
- slab->s_mem = addr + colour_off;
- slab->active = 0;
-
- if (OBJFREELIST_SLAB(cachep))
- freelist = NULL;
- else if (OFF_SLAB(cachep)) {
- /* Slab management obj is off-slab. */
- freelist = kmalloc_node(cachep->freelist_size,
- local_flags, nodeid);
- } else {
- /* We will use last bytes at the slab for freelist */
- freelist = addr + (PAGE_SIZE << cachep->gfporder) -
- cachep->freelist_size;
- }
-
- return freelist;
-}
-
-static inline freelist_idx_t get_free_obj(struct slab *slab, unsigned int idx)
-{
- return ((freelist_idx_t *) slab->freelist)[idx];
-}
-
-static inline void set_free_obj(struct slab *slab,
- unsigned int idx, freelist_idx_t val)
-{
- ((freelist_idx_t *)(slab->freelist))[idx] = val;
-}
-
-static void cache_init_objs_debug(struct kmem_cache *cachep, struct slab *slab)
-{
-#if DEBUG
- int i;
-
- for (i = 0; i < cachep->num; i++) {
- void *objp = index_to_obj(cachep, slab, i);
-
- if (cachep->flags & SLAB_STORE_USER)
- *dbg_userword(cachep, objp) = NULL;
-
- if (cachep->flags & SLAB_RED_ZONE) {
- *dbg_redzone1(cachep, objp) = RED_INACTIVE;
- *dbg_redzone2(cachep, objp) = RED_INACTIVE;
- }
- /*
- * Constructors are not allowed to allocate memory from the same
- * cache which they are a constructor for. Otherwise, deadlock.
- * They must also be threaded.
- */
- if (cachep->ctor && !(cachep->flags & SLAB_POISON)) {
- kasan_unpoison_object_data(cachep,
- objp + obj_offset(cachep));
- cachep->ctor(objp + obj_offset(cachep));
- kasan_poison_object_data(
- cachep, objp + obj_offset(cachep));
- }
-
- if (cachep->flags & SLAB_RED_ZONE) {
- if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
- slab_error(cachep, "constructor overwrote the end of an object");
- if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
- slab_error(cachep, "constructor overwrote the start of an object");
- }
- /* need to poison the objs? */
- if (cachep->flags & SLAB_POISON) {
- poison_obj(cachep, objp, POISON_FREE);
- slab_kernel_map(cachep, objp, 0);
- }
- }
-#endif
-}
-
-#ifdef CONFIG_SLAB_FREELIST_RANDOM
-/* Hold information during a freelist initialization */
-struct freelist_init_state {
- unsigned int pos;
- unsigned int *list;
- unsigned int count;
-};
-
-/*
- * Initialize the state based on the randomization method available.
- * return true if the pre-computed list is available, false otherwise.
- */
-static bool freelist_state_initialize(struct freelist_init_state *state,
- struct kmem_cache *cachep,
- unsigned int count)
-{
- bool ret;
- if (!cachep->random_seq) {
- ret = false;
- } else {
- state->list = cachep->random_seq;
- state->count = count;
- state->pos = get_random_u32_below(count);
- ret = true;
- }
- return ret;
-}
-
-/* Get the next entry on the list and randomize it using a random shift */
-static freelist_idx_t next_random_slot(struct freelist_init_state *state)
-{
- if (state->pos >= state->count)
- state->pos = 0;
- return state->list[state->pos++];
-}
-
-/* Swap two freelist entries */
-static void swap_free_obj(struct slab *slab, unsigned int a, unsigned int b)
-{
- swap(((freelist_idx_t *) slab->freelist)[a],
- ((freelist_idx_t *) slab->freelist)[b]);
-}
-
-/*
- * Shuffle the freelist initialization state based on pre-computed lists.
- * return true if the list was successfully shuffled, false otherwise.
- */
-static bool shuffle_freelist(struct kmem_cache *cachep, struct slab *slab)
-{
- unsigned int objfreelist = 0, i, rand, count = cachep->num;
- struct freelist_init_state state;
- bool precomputed;
-
- if (count < 2)
- return false;
-
- precomputed = freelist_state_initialize(&state, cachep, count);
-
- /* Take a random entry as the objfreelist */
- if (OBJFREELIST_SLAB(cachep)) {
- if (!precomputed)
- objfreelist = count - 1;
- else
- objfreelist = next_random_slot(&state);
- slab->freelist = index_to_obj(cachep, slab, objfreelist) +
- obj_offset(cachep);
- count--;
- }
-
- /*
- * On early boot, generate the list dynamically.
- * Later use a pre-computed list for speed.
- */
- if (!precomputed) {
- for (i = 0; i < count; i++)
- set_free_obj(slab, i, i);
-
- /* Fisher-Yates shuffle */
- for (i = count - 1; i > 0; i--) {
- rand = get_random_u32_below(i + 1);
- swap_free_obj(slab, i, rand);
- }
- } else {
- for (i = 0; i < count; i++)
- set_free_obj(slab, i, next_random_slot(&state));
- }
-
- if (OBJFREELIST_SLAB(cachep))
- set_free_obj(slab, cachep->num - 1, objfreelist);
-
- return true;
-}
-#else
-static inline bool shuffle_freelist(struct kmem_cache *cachep,
- struct slab *slab)
-{
- return false;
-}
-#endif /* CONFIG_SLAB_FREELIST_RANDOM */
-
-static void cache_init_objs(struct kmem_cache *cachep,
- struct slab *slab)
-{
- int i;
- void *objp;
- bool shuffled;
-
- cache_init_objs_debug(cachep, slab);
-
- /* Try to randomize the freelist if enabled */
- shuffled = shuffle_freelist(cachep, slab);
-
- if (!shuffled && OBJFREELIST_SLAB(cachep)) {
- slab->freelist = index_to_obj(cachep, slab, cachep->num - 1) +
- obj_offset(cachep);
- }
-
- for (i = 0; i < cachep->num; i++) {
- objp = index_to_obj(cachep, slab, i);
- objp = kasan_init_slab_obj(cachep, objp);
-
- /* constructor could break poison info */
- if (DEBUG == 0 && cachep->ctor) {
- kasan_unpoison_object_data(cachep, objp);
- cachep->ctor(objp);
- kasan_poison_object_data(cachep, objp);
- }
-
- if (!shuffled)
- set_free_obj(slab, i, i);
- }
-}
-
-static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slab)
-{
- void *objp;
-
- objp = index_to_obj(cachep, slab, get_free_obj(slab, slab->active));
- slab->active++;
-
- return objp;
-}
-
-static void slab_put_obj(struct kmem_cache *cachep,
- struct slab *slab, void *objp)
-{
- unsigned int objnr = obj_to_index(cachep, slab, objp);
-#if DEBUG
- unsigned int i;
-
- /* Verify double free bug */
- for (i = slab->active; i < cachep->num; i++) {
- if (get_free_obj(slab, i) == objnr) {
- pr_err("slab: double free detected in cache '%s', objp %px\n",
- cachep->name, objp);
- BUG();
- }
- }
-#endif
- slab->active--;
- if (!slab->freelist)
- slab->freelist = objp + obj_offset(cachep);
-
- set_free_obj(slab, slab->active, objnr);
-}
-
-/*
- * Grow (by 1) the number of slabs within a cache. This is called by
- * kmem_cache_alloc() when there are no active objs left in a cache.
- */
-static struct slab *cache_grow_begin(struct kmem_cache *cachep,
- gfp_t flags, int nodeid)
-{
- void *freelist;
- size_t offset;
- gfp_t local_flags;
- int slab_node;
- struct kmem_cache_node *n;
- struct slab *slab;
-
- /*
- * Be lazy and only check for valid flags here, keeping it out of the
- * critical path in kmem_cache_alloc().
- */
- if (unlikely(flags & GFP_SLAB_BUG_MASK))
- flags = kmalloc_fix_flags(flags);
-
- WARN_ON_ONCE(cachep->ctor && (flags & __GFP_ZERO));
- local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK);
-
- check_irq_off();
- if (gfpflags_allow_blocking(local_flags))
- local_irq_enable();
-
- /*
- * Get mem for the objs. Attempt to allocate a physical page from
- * 'nodeid'.
- */
- slab = kmem_getpages(cachep, local_flags, nodeid);
- if (!slab)
- goto failed;
-
- slab_node = slab_nid(slab);
- n = get_node(cachep, slab_node);
-
- /* Get colour for the slab, and cal the next value. */
- n->colour_next++;
- if (n->colour_next >= cachep->colour)
- n->colour_next = 0;
-
- offset = n->colour_next;
- if (offset >= cachep->colour)
- offset = 0;
-
- offset *= cachep->colour_off;
-
- /*
- * Call kasan_poison_slab() before calling alloc_slabmgmt(), so
- * page_address() in the latter returns a non-tagged pointer,
- * as it should be for slab pages.
- */
- kasan_poison_slab(slab);
-
- /* Get slab management. */
- freelist = alloc_slabmgmt(cachep, slab, offset,
- local_flags & ~GFP_CONSTRAINT_MASK, slab_node);
- if (OFF_SLAB(cachep) && !freelist)
- goto opps1;
-
- slab->slab_cache = cachep;
- slab->freelist = freelist;
-
- cache_init_objs(cachep, slab);
-
- if (gfpflags_allow_blocking(local_flags))
- local_irq_disable();
-
- return slab;
-
-opps1:
- kmem_freepages(cachep, slab);
-failed:
- if (gfpflags_allow_blocking(local_flags))
- local_irq_disable();
- return NULL;
-}
-
-static void cache_grow_end(struct kmem_cache *cachep, struct slab *slab)
-{
- struct kmem_cache_node *n;
- void *list = NULL;
-
- check_irq_off();
-
- if (!slab)
- return;
-
- INIT_LIST_HEAD(&slab->slab_list);
- n = get_node(cachep, slab_nid(slab));
-
- raw_spin_lock(&n->list_lock);
- n->total_slabs++;
- if (!slab->active) {
- list_add_tail(&slab->slab_list, &n->slabs_free);
- n->free_slabs++;
- } else
- fixup_slab_list(cachep, n, slab, &list);
-
- STATS_INC_GROWN(cachep);
- n->free_objects += cachep->num - slab->active;
- raw_spin_unlock(&n->list_lock);
-
- fixup_objfreelist_debug(cachep, &list);
-}
-
-#if DEBUG
-
-/*
- * Perform extra freeing checks:
- * - detect bad pointers.
- * - POISON/RED_ZONE checking
- */
-static void kfree_debugcheck(const void *objp)
-{
- if (!virt_addr_valid(objp)) {
- pr_err("kfree_debugcheck: out of range ptr %lxh\n",
- (unsigned long)objp);
- BUG();
- }
-}
-
-static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
-{
- unsigned long long redzone1, redzone2;
-
- redzone1 = *dbg_redzone1(cache, obj);
- redzone2 = *dbg_redzone2(cache, obj);
-
- /*
- * Redzone is ok.
- */
- if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE)
- return;
-
- if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE)
- slab_error(cache, "double free detected");
- else
- slab_error(cache, "memory outside object was overwritten");
-
- pr_err("%px: redzone 1:0x%llx, redzone 2:0x%llx\n",
- obj, redzone1, redzone2);
-}
-
-static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
- unsigned long caller)
-{
- unsigned int objnr;
- struct slab *slab;
-
- BUG_ON(virt_to_cache(objp) != cachep);
-
- objp -= obj_offset(cachep);
- kfree_debugcheck(objp);
- slab = virt_to_slab(objp);
-
- if (cachep->flags & SLAB_RED_ZONE) {
- verify_redzone_free(cachep, objp);
- *dbg_redzone1(cachep, objp) = RED_INACTIVE;
- *dbg_redzone2(cachep, objp) = RED_INACTIVE;
- }
- if (cachep->flags & SLAB_STORE_USER)
- *dbg_userword(cachep, objp) = (void *)caller;
-
- objnr = obj_to_index(cachep, slab, objp);
-
- BUG_ON(objnr >= cachep->num);
- BUG_ON(objp != index_to_obj(cachep, slab, objnr));
-
- if (cachep->flags & SLAB_POISON) {
- poison_obj(cachep, objp, POISON_FREE);
- slab_kernel_map(cachep, objp, 0);
- }
- return objp;
-}
-
-#else
-#define kfree_debugcheck(x) do { } while(0)
-#define cache_free_debugcheck(x, objp, z) (objp)
-#endif
-
-static inline void fixup_objfreelist_debug(struct kmem_cache *cachep,
- void **list)
-{
-#if DEBUG
- void *next = *list;
- void *objp;
-
- while (next) {
- objp = next - obj_offset(cachep);
- next = *(void **)next;
- poison_obj(cachep, objp, POISON_FREE);
- }
-#endif
-}
-
-static inline void fixup_slab_list(struct kmem_cache *cachep,
- struct kmem_cache_node *n, struct slab *slab,
- void **list)
-{
- /* move slabp to correct slabp list: */
- list_del(&slab->slab_list);
- if (slab->active == cachep->num) {
- list_add(&slab->slab_list, &n->slabs_full);
- if (OBJFREELIST_SLAB(cachep)) {
-#if DEBUG
- /* Poisoning will be done without holding the lock */
- if (cachep->flags & SLAB_POISON) {
- void **objp = slab->freelist;
-
- *objp = *list;
- *list = objp;
- }
-#endif
- slab->freelist = NULL;
- }
- } else
- list_add(&slab->slab_list, &n->slabs_partial);
-}
-
-/* Try to find non-pfmemalloc slab if needed */
-static noinline struct slab *get_valid_first_slab(struct kmem_cache_node *n,
- struct slab *slab, bool pfmemalloc)
-{
- if (!slab)
- return NULL;
-
- if (pfmemalloc)
- return slab;
-
- if (!slab_test_pfmemalloc(slab))
- return slab;
-
- /* No need to keep pfmemalloc slab if we have enough free objects */
- if (n->free_objects > n->free_limit) {
- slab_clear_pfmemalloc(slab);
- return slab;
- }
-
- /* Move pfmemalloc slab to the end of list to speed up next search */
- list_del(&slab->slab_list);
- if (!slab->active) {
- list_add_tail(&slab->slab_list, &n->slabs_free);
- n->free_slabs++;
- } else
- list_add_tail(&slab->slab_list, &n->slabs_partial);
-
- list_for_each_entry(slab, &n->slabs_partial, slab_list) {
- if (!slab_test_pfmemalloc(slab))
- return slab;
- }
-
- n->free_touched = 1;
- list_for_each_entry(slab, &n->slabs_free, slab_list) {
- if (!slab_test_pfmemalloc(slab)) {
- n->free_slabs--;
- return slab;
- }
- }
-
- return NULL;
-}
-
-static struct slab *get_first_slab(struct kmem_cache_node *n, bool pfmemalloc)
-{
- struct slab *slab;
-
- assert_raw_spin_locked(&n->list_lock);
- slab = list_first_entry_or_null(&n->slabs_partial, struct slab,
- slab_list);
- if (!slab) {
- n->free_touched = 1;
- slab = list_first_entry_or_null(&n->slabs_free, struct slab,
- slab_list);
- if (slab)
- n->free_slabs--;
- }
-
- if (sk_memalloc_socks())
- slab = get_valid_first_slab(n, slab, pfmemalloc);
-
- return slab;
-}
-
-static noinline void *cache_alloc_pfmemalloc(struct kmem_cache *cachep,
- struct kmem_cache_node *n, gfp_t flags)
-{
- struct slab *slab;
- void *obj;
- void *list = NULL;
-
- if (!gfp_pfmemalloc_allowed(flags))
- return NULL;
-
- raw_spin_lock(&n->list_lock);
- slab = get_first_slab(n, true);
- if (!slab) {
- raw_spin_unlock(&n->list_lock);
- return NULL;
- }
-
- obj = slab_get_obj(cachep, slab);
- n->free_objects--;
-
- fixup_slab_list(cachep, n, slab, &list);
-
- raw_spin_unlock(&n->list_lock);
- fixup_objfreelist_debug(cachep, &list);
-
- return obj;
-}
-
-/*
- * Slab list should be fixed up by fixup_slab_list() for existing slab
- * or cache_grow_end() for new slab
- */
-static __always_inline int alloc_block(struct kmem_cache *cachep,
- struct array_cache *ac, struct slab *slab, int batchcount)
-{
- /*
- * There must be at least one object available for
- * allocation.
- */
- BUG_ON(slab->active >= cachep->num);
-
- while (slab->active < cachep->num && batchcount--) {
- STATS_INC_ALLOCED(cachep);
- STATS_INC_ACTIVE(cachep);
- STATS_SET_HIGH(cachep);
-
- ac->entry[ac->avail++] = slab_get_obj(cachep, slab);
- }
-
- return batchcount;
-}
-
-static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
-{
- int batchcount;
- struct kmem_cache_node *n;
- struct array_cache *ac, *shared;
- int node;
- void *list = NULL;
- struct slab *slab;
-
- check_irq_off();
- node = numa_mem_id();
-
- ac = cpu_cache_get(cachep);
- batchcount = ac->batchcount;
- if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
- /*
- * If there was little recent activity on this cache, then
- * perform only a partial refill. Otherwise we could generate
- * refill bouncing.
- */
- batchcount = BATCHREFILL_LIMIT;
- }
- n = get_node(cachep, node);
-
- BUG_ON(ac->avail > 0 || !n);
- shared = READ_ONCE(n->shared);
- if (!n->free_objects && (!shared || !shared->avail))
- goto direct_grow;
-
- raw_spin_lock(&n->list_lock);
- shared = READ_ONCE(n->shared);
-
- /* See if we can refill from the shared array */
- if (shared && transfer_objects(ac, shared, batchcount)) {
- shared->touched = 1;
- goto alloc_done;
- }
-
- while (batchcount > 0) {
- /* Get slab alloc is to come from. */
- slab = get_first_slab(n, false);
- if (!slab)
- goto must_grow;
-
- check_spinlock_acquired(cachep);
-
- batchcount = alloc_block(cachep, ac, slab, batchcount);
- fixup_slab_list(cachep, n, slab, &list);
- }
-
-must_grow:
- n->free_objects -= ac->avail;
-alloc_done:
- raw_spin_unlock(&n->list_lock);
- fixup_objfreelist_debug(cachep, &list);
-
-direct_grow:
- if (unlikely(!ac->avail)) {
- /* Check if we can use obj in pfmemalloc slab */
- if (sk_memalloc_socks()) {
- void *obj = cache_alloc_pfmemalloc(cachep, n, flags);
-
- if (obj)
- return obj;
- }
-
- slab = cache_grow_begin(cachep, gfp_exact_node(flags), node);
-
- /*
- * cache_grow_begin() can reenable interrupts,
- * then ac could change.
- */
- ac = cpu_cache_get(cachep);
- if (!ac->avail && slab)
- alloc_block(cachep, ac, slab, batchcount);
- cache_grow_end(cachep, slab);
-
- if (!ac->avail)
- return NULL;
- }
- ac->touched = 1;
-
- return ac->entry[--ac->avail];
-}
-
-#if DEBUG
-static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
- gfp_t flags, void *objp, unsigned long caller)
-{
- WARN_ON_ONCE(cachep->ctor && (flags & __GFP_ZERO));
- if (!objp || is_kfence_address(objp))
- return objp;
- if (cachep->flags & SLAB_POISON) {
- check_poison_obj(cachep, objp);
- slab_kernel_map(cachep, objp, 1);
- poison_obj(cachep, objp, POISON_INUSE);
- }
- if (cachep->flags & SLAB_STORE_USER)
- *dbg_userword(cachep, objp) = (void *)caller;
-
- if (cachep->flags & SLAB_RED_ZONE) {
- if (*dbg_redzone1(cachep, objp) != RED_INACTIVE ||
- *dbg_redzone2(cachep, objp) != RED_INACTIVE) {
- slab_error(cachep, "double free, or memory outside object was overwritten");
- pr_err("%px: redzone 1:0x%llx, redzone 2:0x%llx\n",
- objp, *dbg_redzone1(cachep, objp),
- *dbg_redzone2(cachep, objp));
- }
- *dbg_redzone1(cachep, objp) = RED_ACTIVE;
- *dbg_redzone2(cachep, objp) = RED_ACTIVE;
- }
-
- objp += obj_offset(cachep);
- if (cachep->ctor && cachep->flags & SLAB_POISON)
- cachep->ctor(objp);
- if ((unsigned long)objp & (arch_slab_minalign() - 1)) {
- pr_err("0x%px: not aligned to arch_slab_minalign()=%u\n", objp,
- arch_slab_minalign());
- }
- return objp;
-}
-#else
-#define cache_alloc_debugcheck_after(a, b, objp, d) (objp)
-#endif
-
-static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
-{
- void *objp;
- struct array_cache *ac;
-
- check_irq_off();
-
- ac = cpu_cache_get(cachep);
- if (likely(ac->avail)) {
- ac->touched = 1;
- objp = ac->entry[--ac->avail];
-
- STATS_INC_ALLOCHIT(cachep);
- goto out;
- }
-
- STATS_INC_ALLOCMISS(cachep);
- objp = cache_alloc_refill(cachep, flags);
- /*
- * the 'ac' may be updated by cache_alloc_refill(),
- * and kmemleak_erase() requires its correct value.
- */
- ac = cpu_cache_get(cachep);
-
-out:
- /*
- * To avoid a false negative, if an object that is in one of the
- * per-CPU caches is leaked, we need to make sure kmemleak doesn't
- * treat the array pointers as a reference to the object.
- */
- if (objp)
- kmemleak_erase(&ac->entry[ac->avail]);
- return objp;
-}
-
-#ifdef CONFIG_NUMA
-static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
-
-/*
- * Try allocating on another node if PFA_SPREAD_SLAB is a mempolicy is set.
- *
- * If we are in_interrupt, then process context, including cpusets and
- * mempolicy, may not apply and should not be used for allocation policy.
- */
-static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
-{
- int nid_alloc, nid_here;
-
- if (in_interrupt() || (flags & __GFP_THISNODE))
- return NULL;
- nid_alloc = nid_here = numa_mem_id();
- if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD))
- nid_alloc = cpuset_slab_spread_node();
- else if (current->mempolicy)
- nid_alloc = mempolicy_slab_node();
- if (nid_alloc != nid_here)
- return ____cache_alloc_node(cachep, flags, nid_alloc);
- return NULL;
-}
-
-/*
- * Fallback function if there was no memory available and no objects on a
- * certain node and fall back is permitted. First we scan all the
- * available node for available objects. If that fails then we
- * perform an allocation without specifying a node. This allows the page
- * allocator to do its reclaim / fallback magic. We then insert the
- * slab into the proper nodelist and then allocate from it.
- */
-static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
-{
- struct zonelist *zonelist;
- struct zoneref *z;
- struct zone *zone;
- enum zone_type highest_zoneidx = gfp_zone(flags);
- void *obj = NULL;
- struct slab *slab;
- int nid;
- unsigned int cpuset_mems_cookie;
-
- if (flags & __GFP_THISNODE)
- return NULL;
-
-retry_cpuset:
- cpuset_mems_cookie = read_mems_allowed_begin();
- zonelist = node_zonelist(mempolicy_slab_node(), flags);
-
-retry:
- /*
- * Look through allowed nodes for objects available
- * from existing per node queues.
- */
- for_each_zone_zonelist(zone, z, zonelist, highest_zoneidx) {
- nid = zone_to_nid(zone);
-
- if (cpuset_zone_allowed(zone, flags) &&
- get_node(cache, nid) &&
- get_node(cache, nid)->free_objects) {
- obj = ____cache_alloc_node(cache,
- gfp_exact_node(flags), nid);
- if (obj)
- break;
- }
- }
-
- if (!obj) {
- /*
- * This allocation will be performed within the constraints
- * of the current cpuset / memory policy requirements.
- * We may trigger various forms of reclaim on the allowed
- * set and go into memory reserves if necessary.
- */
- slab = cache_grow_begin(cache, flags, numa_mem_id());
- cache_grow_end(cache, slab);
- if (slab) {
- nid = slab_nid(slab);
- obj = ____cache_alloc_node(cache,
- gfp_exact_node(flags), nid);
-
- /*
- * Another processor may allocate the objects in
- * the slab since we are not holding any locks.
- */
- if (!obj)
- goto retry;
- }
- }
-
- if (unlikely(!obj && read_mems_allowed_retry(cpuset_mems_cookie)))
- goto retry_cpuset;
- return obj;
-}
-
-/*
- * An interface to enable slab creation on nodeid
- */
-static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
- int nodeid)
-{
- struct slab *slab;
- struct kmem_cache_node *n;
- void *obj = NULL;
- void *list = NULL;
-
- VM_BUG_ON(nodeid < 0 || nodeid >= MAX_NUMNODES);
- n = get_node(cachep, nodeid);
- BUG_ON(!n);
-
- check_irq_off();
- raw_spin_lock(&n->list_lock);
- slab = get_first_slab(n, false);
- if (!slab)
- goto must_grow;
-
- check_spinlock_acquired_node(cachep, nodeid);
-
- STATS_INC_NODEALLOCS(cachep);
- STATS_INC_ACTIVE(cachep);
- STATS_SET_HIGH(cachep);
-
- BUG_ON(slab->active == cachep->num);
-
- obj = slab_get_obj(cachep, slab);
- n->free_objects--;
-
- fixup_slab_list(cachep, n, slab, &list);
-
- raw_spin_unlock(&n->list_lock);
- fixup_objfreelist_debug(cachep, &list);
- return obj;
-
-must_grow:
- raw_spin_unlock(&n->list_lock);
- slab = cache_grow_begin(cachep, gfp_exact_node(flags), nodeid);
- if (slab) {
- /* This slab isn't counted yet so don't update free_objects */
- obj = slab_get_obj(cachep, slab);
- }
- cache_grow_end(cachep, slab);
-
- return obj ? obj : fallback_alloc(cachep, flags);
-}
-
-static __always_inline void *
-__do_cache_alloc(struct kmem_cache *cachep, gfp_t flags, int nodeid)
-{
- void *objp = NULL;
- int slab_node = numa_mem_id();
-
- if (nodeid == NUMA_NO_NODE) {
- if (current->mempolicy || cpuset_do_slab_mem_spread()) {
- objp = alternate_node_alloc(cachep, flags);
- if (objp)
- goto out;
- }
- /*
- * Use the locally cached objects if possible.
- * However ____cache_alloc does not allow fallback
- * to other nodes. It may fail while we still have
- * objects on other nodes available.
- */
- objp = ____cache_alloc(cachep, flags);
- nodeid = slab_node;
- } else if (nodeid == slab_node) {
- objp = ____cache_alloc(cachep, flags);
- } else if (!get_node(cachep, nodeid)) {
- /* Node not bootstrapped yet */
- objp = fallback_alloc(cachep, flags);
- goto out;
- }
-
- /*
- * We may just have run out of memory on the local node.
- * ____cache_alloc_node() knows how to locate memory on other nodes
- */
- if (!objp)
- objp = ____cache_alloc_node(cachep, flags, nodeid);
-out:
- return objp;
-}
-#else
-
-static __always_inline void *
-__do_cache_alloc(struct kmem_cache *cachep, gfp_t flags, int nodeid __maybe_unused)
-{
- return ____cache_alloc(cachep, flags);
-}
-
-#endif /* CONFIG_NUMA */
-
-static __always_inline void *
-slab_alloc_node(struct kmem_cache *cachep, struct list_lru *lru, gfp_t flags,
- int nodeid, size_t orig_size, unsigned long caller)
-{
- unsigned long save_flags;
- void *objp;
- struct obj_cgroup *objcg = NULL;
- bool init = false;
-
- flags &= gfp_allowed_mask;
- cachep = slab_pre_alloc_hook(cachep, lru, &objcg, 1, flags);
- if (unlikely(!cachep))
- return NULL;
-
- objp = kfence_alloc(cachep, orig_size, flags);
- if (unlikely(objp))
- goto out;
-
- local_irq_save(save_flags);
- objp = __do_cache_alloc(cachep, flags, nodeid);
- local_irq_restore(save_flags);
- objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller);
- prefetchw(objp);
- init = slab_want_init_on_alloc(flags, cachep);
-
-out:
- slab_post_alloc_hook(cachep, objcg, flags, 1, &objp, init,
- cachep->object_size);
- return objp;
-}
-
-static __always_inline void *
-slab_alloc(struct kmem_cache *cachep, struct list_lru *lru, gfp_t flags,
- size_t orig_size, unsigned long caller)
-{
- return slab_alloc_node(cachep, lru, flags, NUMA_NO_NODE, orig_size,
- caller);
-}
-
-/*
- * Caller needs to acquire correct kmem_cache_node's list_lock
- * @list: List of detached free slabs should be freed by caller
- */
-static void free_block(struct kmem_cache *cachep, void **objpp,
- int nr_objects, int node, struct list_head *list)
-{
- int i;
- struct kmem_cache_node *n = get_node(cachep, node);
- struct slab *slab;
-
- n->free_objects += nr_objects;
-
- for (i = 0; i < nr_objects; i++) {
- void *objp;
- struct slab *slab;
-
- objp = objpp[i];
-
- slab = virt_to_slab(objp);
- list_del(&slab->slab_list);
- check_spinlock_acquired_node(cachep, node);
- slab_put_obj(cachep, slab, objp);
- STATS_DEC_ACTIVE(cachep);
-
- /* fixup slab chains */
- if (slab->active == 0) {
- list_add(&slab->slab_list, &n->slabs_free);
- n->free_slabs++;
- } else {
- /* Unconditionally move a slab to the end of the
- * partial list on free - maximum time for the
- * other objects to be freed, too.
- */
- list_add_tail(&slab->slab_list, &n->slabs_partial);
- }
- }
-
- while (n->free_objects > n->free_limit && !list_empty(&n->slabs_free)) {
- n->free_objects -= cachep->num;
-
- slab = list_last_entry(&n->slabs_free, struct slab, slab_list);
- list_move(&slab->slab_list, list);
- n->free_slabs--;
- n->total_slabs--;
- }
-}
-
-static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
-{
- int batchcount;
- struct kmem_cache_node *n;
- int node = numa_mem_id();
- LIST_HEAD(list);
-
- batchcount = ac->batchcount;
-
- check_irq_off();
- n = get_node(cachep, node);
- raw_spin_lock(&n->list_lock);
- if (n->shared) {
- struct array_cache *shared_array = n->shared;
- int max = shared_array->limit - shared_array->avail;
- if (max) {
- if (batchcount > max)
- batchcount = max;
- memcpy(&(shared_array->entry[shared_array->avail]),
- ac->entry, sizeof(void *) * batchcount);
- shared_array->avail += batchcount;
- goto free_done;
- }
- }
-
- free_block(cachep, ac->entry, batchcount, node, &list);
-free_done:
-#if STATS
- {
- int i = 0;
- struct slab *slab;
-
- list_for_each_entry(slab, &n->slabs_free, slab_list) {
- BUG_ON(slab->active);
-
- i++;
- }
- STATS_SET_FREEABLE(cachep, i);
- }
-#endif
- raw_spin_unlock(&n->list_lock);
- ac->avail -= batchcount;
- memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
- slabs_destroy(cachep, &list);
-}
-
-/*
- * Release an obj back to its cache. If the obj has a constructed state, it must
- * be in this state _before_ it is released. Called with disabled ints.
- */
-static __always_inline void __cache_free(struct kmem_cache *cachep, void *objp,
- unsigned long caller)
-{
- bool init;
-
- memcg_slab_free_hook(cachep, virt_to_slab(objp), &objp, 1);
-
- if (is_kfence_address(objp)) {
- kmemleak_free_recursive(objp, cachep->flags);
- __kfence_free(objp);
- return;
- }
-
- /*
- * As memory initialization might be integrated into KASAN,
- * kasan_slab_free and initialization memset must be
- * kept together to avoid discrepancies in behavior.
- */
- init = slab_want_init_on_free(cachep);
- if (init && !kasan_has_integrated_init())
- memset(objp, 0, cachep->object_size);
- /* KASAN might put objp into memory quarantine, delaying its reuse. */
- if (kasan_slab_free(cachep, objp, init))
- return;
-
- /* Use KCSAN to help debug racy use-after-free. */
- if (!(cachep->flags & SLAB_TYPESAFE_BY_RCU))
- __kcsan_check_access(objp, cachep->object_size,
- KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ASSERT);
-
- ___cache_free(cachep, objp, caller);
-}
-
-void ___cache_free(struct kmem_cache *cachep, void *objp,
- unsigned long caller)
-{
- struct array_cache *ac = cpu_cache_get(cachep);
-
- check_irq_off();
- kmemleak_free_recursive(objp, cachep->flags);
- objp = cache_free_debugcheck(cachep, objp, caller);
-
- /*
- * Skip calling cache_free_alien() when the platform is not numa.
- * This will avoid cache misses that happen while accessing slabp (which
- * is per page memory reference) to get nodeid. Instead use a global
- * variable to skip the call, which is mostly likely to be present in
- * the cache.
- */
- if (nr_online_nodes > 1 && cache_free_alien(cachep, objp))
- return;
-
- if (ac->avail < ac->limit) {
- STATS_INC_FREEHIT(cachep);
- } else {
- STATS_INC_FREEMISS(cachep);
- cache_flusharray(cachep, ac);
- }
-
- if (sk_memalloc_socks()) {
- struct slab *slab = virt_to_slab(objp);
-
- if (unlikely(slab_test_pfmemalloc(slab))) {
- cache_free_pfmemalloc(cachep, slab, objp);
- return;
- }
- }
-
- __free_one(ac, objp);
-}
-
-static __always_inline
-void *__kmem_cache_alloc_lru(struct kmem_cache *cachep, struct list_lru *lru,
- gfp_t flags)
-{
- void *ret = slab_alloc(cachep, lru, flags, cachep->object_size, _RET_IP_);
-
- trace_kmem_cache_alloc(_RET_IP_, ret, cachep, flags, NUMA_NO_NODE);
-
- return ret;
-}
-
-void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
-{
- return __kmem_cache_alloc_lru(cachep, NULL, flags);
-}
-EXPORT_SYMBOL(kmem_cache_alloc);
-
-void *kmem_cache_alloc_lru(struct kmem_cache *cachep, struct list_lru *lru,
- gfp_t flags)
-{
- return __kmem_cache_alloc_lru(cachep, lru, flags);
-}
-EXPORT_SYMBOL(kmem_cache_alloc_lru);
-
-static __always_inline void
-cache_alloc_debugcheck_after_bulk(struct kmem_cache *s, gfp_t flags,
- size_t size, void **p, unsigned long caller)
-{
- size_t i;
-
- for (i = 0; i < size; i++)
- p[i] = cache_alloc_debugcheck_after(s, flags, p[i], caller);
-}
-
-int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
- void **p)
-{
- struct obj_cgroup *objcg = NULL;
- unsigned long irqflags;
- size_t i;
-
- s = slab_pre_alloc_hook(s, NULL, &objcg, size, flags);
- if (!s)
- return 0;
-
- local_irq_save(irqflags);
- for (i = 0; i < size; i++) {
- void *objp = kfence_alloc(s, s->object_size, flags) ?:
- __do_cache_alloc(s, flags, NUMA_NO_NODE);
-
- if (unlikely(!objp))
- goto error;
- p[i] = objp;
- }
- local_irq_restore(irqflags);
-
- cache_alloc_debugcheck_after_bulk(s, flags, size, p, _RET_IP_);
-
- /*
- * memcg and kmem_cache debug support and memory initialization.
- * Done outside of the IRQ disabled section.
- */
- slab_post_alloc_hook(s, objcg, flags, size, p,
- slab_want_init_on_alloc(flags, s), s->object_size);
- /* FIXME: Trace call missing. Christoph would like a bulk variant */
- return size;
-error:
- local_irq_restore(irqflags);
- cache_alloc_debugcheck_after_bulk(s, flags, i, p, _RET_IP_);
- slab_post_alloc_hook(s, objcg, flags, i, p, false, s->object_size);
- kmem_cache_free_bulk(s, i, p);
- return 0;
-}
-EXPORT_SYMBOL(kmem_cache_alloc_bulk);
-
-void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
-{
- void *ret = slab_alloc_node(cachep, NULL, flags, nodeid, cachep->object_size, _RET_IP_);
-
- trace_kmem_cache_alloc(_RET_IP_, ret, cachep, flags, nodeid);
-
- return ret;
-}
-EXPORT_SYMBOL(kmem_cache_alloc_node);
-
-void *__kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
- int nodeid, size_t orig_size,
- unsigned long caller)
-{
- return slab_alloc_node(cachep, NULL, flags, nodeid,
- orig_size, caller);
-}
-
-#ifdef CONFIG_PRINTK
-void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
-{
- struct kmem_cache *cachep;
- unsigned int objnr;
- void *objp;
-
- kpp->kp_ptr = object;
- kpp->kp_slab = slab;
- cachep = slab->slab_cache;
- kpp->kp_slab_cache = cachep;
- objp = object - obj_offset(cachep);
- kpp->kp_data_offset = obj_offset(cachep);
- slab = virt_to_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)
- kpp->kp_ret = *dbg_userword(cachep, objp);
-}
-#endif
-
-static __always_inline
-void __do_kmem_cache_free(struct kmem_cache *cachep, void *objp,
- unsigned long caller)
-{
- unsigned long flags;
-
- local_irq_save(flags);
- debug_check_no_locks_freed(objp, cachep->object_size);
- if (!(cachep->flags & SLAB_DEBUG_OBJECTS))
- debug_check_no_obj_freed(objp, cachep->object_size);
- __cache_free(cachep, objp, caller);
- local_irq_restore(flags);
-}
-
-void __kmem_cache_free(struct kmem_cache *cachep, void *objp,
- unsigned long caller)
-{
- __do_kmem_cache_free(cachep, objp, caller);
-}
-
-void kmem_cache_free(struct kmem_cache *cachep, void *objp)
-{
- cachep = cache_from_obj(cachep, objp);
- if (!cachep)
- return;
-
- trace_kmem_cache_free(_RET_IP_, objp, cachep);
- __do_kmem_cache_free(cachep, objp, _RET_IP_);
-}
-EXPORT_SYMBOL(kmem_cache_free);
-
-void kmem_cache_free_bulk(struct kmem_cache *orig_s, size_t size, void **p)
-{
- unsigned long flags;
-
- local_irq_save(flags);
- for (int i = 0; i < size; i++) {
- void *objp = p[i];
- struct kmem_cache *s;
-
- if (!orig_s) {
- struct folio *folio = virt_to_folio(objp);
-
- /* called via kfree_bulk */
- if (!folio_test_slab(folio)) {
- local_irq_restore(flags);
- free_large_kmalloc(folio, objp);
- local_irq_save(flags);
- continue;
- }
- s = folio_slab(folio)->slab_cache;
- } else {
- s = cache_from_obj(orig_s, objp);
- }
-
- if (!s)
- continue;
-
- debug_check_no_locks_freed(objp, s->object_size);
- if (!(s->flags & SLAB_DEBUG_OBJECTS))
- debug_check_no_obj_freed(objp, s->object_size);
-
- __cache_free(s, objp, _RET_IP_);
- }
- local_irq_restore(flags);
-
- /* FIXME: add tracing */
-}
-EXPORT_SYMBOL(kmem_cache_free_bulk);
-
-/*
- * This initializes kmem_cache_node or resizes various caches for all nodes.
- */
-static int setup_kmem_cache_nodes(struct kmem_cache *cachep, gfp_t gfp)
-{
- int ret;
- int node;
- struct kmem_cache_node *n;
-
- for_each_online_node(node) {
- ret = setup_kmem_cache_node(cachep, node, gfp, true);
- if (ret)
- goto fail;
-
- }
-
- return 0;
-
-fail:
- if (!cachep->list.next) {
- /* Cache is not active yet. Roll back what we did */
- node--;
- while (node >= 0) {
- n = get_node(cachep, node);
- if (n) {
- kfree(n->shared);
- free_alien_cache(n->alien);
- kfree(n);
- cachep->node[node] = NULL;
- }
- node--;
- }
- }
- return -ENOMEM;
-}
-
-/* Always called with the slab_mutex held */
-static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
- int batchcount, int shared, gfp_t gfp)
-{
- struct array_cache __percpu *cpu_cache, *prev;
- int cpu;
-
- cpu_cache = alloc_kmem_cache_cpus(cachep, limit, batchcount);
- if (!cpu_cache)
- return -ENOMEM;
-
- prev = cachep->cpu_cache;
- cachep->cpu_cache = cpu_cache;
- /*
- * Without a previous cpu_cache there's no need to synchronize remote
- * cpus, so skip the IPIs.
- */
- if (prev)
- kick_all_cpus_sync();
-
- check_irq_on();
- cachep->batchcount = batchcount;
- cachep->limit = limit;
- cachep->shared = shared;
-
- if (!prev)
- goto setup_node;
-
- for_each_online_cpu(cpu) {
- LIST_HEAD(list);
- int node;
- struct kmem_cache_node *n;
- struct array_cache *ac = per_cpu_ptr(prev, cpu);
-
- node = cpu_to_mem(cpu);
- n = get_node(cachep, node);
- raw_spin_lock_irq(&n->list_lock);
- free_block(cachep, ac->entry, ac->avail, node, &list);
- raw_spin_unlock_irq(&n->list_lock);
- slabs_destroy(cachep, &list);
- }
- free_percpu(prev);
-
-setup_node:
- return setup_kmem_cache_nodes(cachep, gfp);
-}
-
-/* Called with slab_mutex held always */
-static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp)
-{
- int err;
- int limit = 0;
- int shared = 0;
- int batchcount = 0;
-
- err = cache_random_seq_create(cachep, cachep->num, gfp);
- if (err)
- goto end;
-
- /*
- * The head array serves three purposes:
- * - create a LIFO ordering, i.e. return objects that are cache-warm
- * - reduce the number of spinlock operations.
- * - reduce the number of linked list operations on the slab and
- * bufctl chains: array operations are cheaper.
- * The numbers are guessed, we should auto-tune as described by
- * Bonwick.
- */
- if (cachep->size > 131072)
- limit = 1;
- else if (cachep->size > PAGE_SIZE)
- limit = 8;
- else if (cachep->size > 1024)
- limit = 24;
- else if (cachep->size > 256)
- limit = 54;
- else
- limit = 120;
-
- /*
- * CPU bound tasks (e.g. network routing) can exhibit cpu bound
- * allocation behaviour: Most allocs on one cpu, most free operations
- * on another cpu. For these cases, an efficient object passing between
- * cpus is necessary. This is provided by a shared array. The array
- * replaces Bonwick's magazine layer.
- * On uniprocessor, it's functionally equivalent (but less efficient)
- * to a larger limit. Thus disabled by default.
- */
- shared = 0;
- if (cachep->size <= PAGE_SIZE && num_possible_cpus() > 1)
- shared = 8;
-
-#if DEBUG
- /*
- * With debugging enabled, large batchcount lead to excessively long
- * periods with disabled local interrupts. Limit the batchcount
- */
- if (limit > 32)
- limit = 32;
-#endif
- batchcount = (limit + 1) / 2;
- err = do_tune_cpucache(cachep, limit, batchcount, shared, gfp);
-end:
- if (err)
- pr_err("enable_cpucache failed for %s, error %d\n",
- cachep->name, -err);
- return err;
-}
-
-/*
- * Drain an array if it contains any elements taking the node lock only if
- * necessary. Note that the node listlock also protects the array_cache
- * if drain_array() is used on the shared array.
- */
-static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n,
- struct array_cache *ac, int node)
-{
- LIST_HEAD(list);
-
- /* ac from n->shared can be freed if we don't hold the slab_mutex. */
- check_mutex_acquired();
-
- if (!ac || !ac->avail)
- return;
-
- if (ac->touched) {
- ac->touched = 0;
- return;
- }
-
- raw_spin_lock_irq(&n->list_lock);
- drain_array_locked(cachep, ac, node, false, &list);
- raw_spin_unlock_irq(&n->list_lock);
-
- slabs_destroy(cachep, &list);
-}
-
-/**
- * cache_reap - Reclaim memory from caches.
- * @w: work descriptor
- *
- * Called from workqueue/eventd every few seconds.
- * Purpose:
- * - clear the per-cpu caches for this CPU.
- * - return freeable pages to the main free memory pool.
- *
- * If we cannot acquire the cache chain mutex then just give up - we'll try
- * again on the next iteration.
- */
-static void cache_reap(struct work_struct *w)
-{
- struct kmem_cache *searchp;
- struct kmem_cache_node *n;
- int node = numa_mem_id();
- struct delayed_work *work = to_delayed_work(w);
-
- if (!mutex_trylock(&slab_mutex))
- /* Give up. Setup the next iteration. */
- goto out;
-
- list_for_each_entry(searchp, &slab_caches, list) {
- check_irq_on();
-
- /*
- * We only take the node lock if absolutely necessary and we
- * have established with reasonable certainty that
- * we can do some work if the lock was obtained.
- */
- n = get_node(searchp, node);
-
- reap_alien(searchp, n);
-
- drain_array(searchp, n, cpu_cache_get(searchp), node);
-
- /*
- * These are racy checks but it does not matter
- * if we skip one check or scan twice.
- */
- if (time_after(n->next_reap, jiffies))
- goto next;
-
- n->next_reap = jiffies + REAPTIMEOUT_NODE;
-
- drain_array(searchp, n, n->shared, node);
-
- if (n->free_touched)
- n->free_touched = 0;
- else {
- int freed;
-
- freed = drain_freelist(searchp, n, (n->free_limit +
- 5 * searchp->num - 1) / (5 * searchp->num));
- STATS_ADD_REAPED(searchp, freed);
- }
-next:
- cond_resched();
- }
- check_irq_on();
- mutex_unlock(&slab_mutex);
- next_reap_node();
-out:
- /* Set up the next iteration */
- schedule_delayed_work_on(smp_processor_id(), work,
- round_jiffies_relative(REAPTIMEOUT_AC));
-}
-
-void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo)
-{
- unsigned long active_objs, num_objs, active_slabs;
- unsigned long total_slabs = 0, free_objs = 0, shared_avail = 0;
- unsigned long free_slabs = 0;
- int node;
- struct kmem_cache_node *n;
-
- for_each_kmem_cache_node(cachep, node, n) {
- check_irq_on();
- raw_spin_lock_irq(&n->list_lock);
-
- total_slabs += n->total_slabs;
- free_slabs += n->free_slabs;
- free_objs += n->free_objects;
-
- if (n->shared)
- shared_avail += n->shared->avail;
-
- raw_spin_unlock_irq(&n->list_lock);
- }
- num_objs = total_slabs * cachep->num;
- active_slabs = total_slabs - free_slabs;
- active_objs = num_objs - free_objs;
-
- sinfo->active_objs = active_objs;
- sinfo->num_objs = num_objs;
- sinfo->active_slabs = active_slabs;
- sinfo->num_slabs = total_slabs;
- sinfo->shared_avail = shared_avail;
- sinfo->limit = cachep->limit;
- sinfo->batchcount = cachep->batchcount;
- sinfo->shared = cachep->shared;
- sinfo->objects_per_slab = cachep->num;
- sinfo->cache_order = cachep->gfporder;
-}
-
-void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *cachep)
-{
-#if STATS
- { /* node stats */
- unsigned long high = cachep->high_mark;
- unsigned long allocs = cachep->num_allocations;
- unsigned long grown = cachep->grown;
- unsigned long reaped = cachep->reaped;
- unsigned long errors = cachep->errors;
- unsigned long max_freeable = cachep->max_freeable;
- unsigned long node_allocs = cachep->node_allocs;
- unsigned long node_frees = cachep->node_frees;
- unsigned long overflows = cachep->node_overflow;
-
- seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu %4lu %4lu %4lu %4lu %4lu",
- allocs, high, grown,
- reaped, errors, max_freeable, node_allocs,
- node_frees, overflows);
- }
- /* cpu stats */
- {
- unsigned long allochit = atomic_read(&cachep->allochit);
- unsigned long allocmiss = atomic_read(&cachep->allocmiss);
- unsigned long freehit = atomic_read(&cachep->freehit);
- unsigned long freemiss = atomic_read(&cachep->freemiss);
-
- seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu",
- allochit, allocmiss, freehit, freemiss);
- }
-#endif
-}
-
-#define MAX_SLABINFO_WRITE 128
-/**
- * slabinfo_write - Tuning for the slab allocator
- * @file: unused
- * @buffer: user buffer
- * @count: data length
- * @ppos: unused
- *
- * Return: %0 on success, negative error code otherwise.
- */
-ssize_t slabinfo_write(struct file *file, const char __user *buffer,
- size_t count, loff_t *ppos)
-{
- char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
- int limit, batchcount, shared, res;
- struct kmem_cache *cachep;
-
- if (count > MAX_SLABINFO_WRITE)
- return -EINVAL;
- if (copy_from_user(&kbuf, buffer, count))
- return -EFAULT;
- kbuf[MAX_SLABINFO_WRITE] = '\0';
-
- tmp = strchr(kbuf, ' ');
- if (!tmp)
- return -EINVAL;
- *tmp = '\0';
- tmp++;
- if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3)
- return -EINVAL;
-
- /* Find the cache in the chain of caches. */
- mutex_lock(&slab_mutex);
- res = -EINVAL;
- list_for_each_entry(cachep, &slab_caches, list) {
- if (!strcmp(cachep->name, kbuf)) {
- if (limit < 1 || batchcount < 1 ||
- batchcount > limit || shared < 0) {
- res = 0;
- } else {
- res = do_tune_cpucache(cachep, limit,
- batchcount, shared,
- GFP_KERNEL);
- }
- break;
- }
- }
- mutex_unlock(&slab_mutex);
- if (res >= 0)
- res = count;
- return res;
-}
-
-#ifdef CONFIG_HARDENED_USERCOPY
-/*
- * Rejects incorrectly sized objects and objects that are to be copied
- * to/from userspace but do not fall entirely within the containing slab
- * cache's usercopy region.
- *
- * Returns NULL if check passes, otherwise const char * to name of cache
- * to indicate an error.
- */
-void __check_heap_object(const void *ptr, unsigned long n,
- const struct slab *slab, bool to_user)
-{
- struct kmem_cache *cachep;
- unsigned int objnr;
- unsigned long offset;
-
- ptr = kasan_reset_tag(ptr);
-
- /* Find and validate object. */
- cachep = slab->slab_cache;
- objnr = obj_to_index(cachep, slab, (void *)ptr);
- BUG_ON(objnr >= cachep->num);
-
- /* Find offset within object. */
- if (is_kfence_address(ptr))
- offset = ptr - kfence_object_start(ptr);
- else
- offset = ptr - index_to_obj(cachep, slab, objnr) - obj_offset(cachep);
-
- /* Allow address range falling entirely within usercopy region. */
- if (offset >= cachep->useroffset &&
- offset - cachep->useroffset <= cachep->usersize &&
- n <= cachep->useroffset - offset + cachep->usersize)
- return;
-
- usercopy_abort("SLAB object", cachep->name, to_user, offset, n);
-}
-#endif /* CONFIG_HARDENED_USERCOPY */

--
2.42.1