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mm/slab_common.c
29.3 KB
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// SPDX-License-Identifier: GPL-2.0 |
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/* * Slab allocator functions that are independent of the allocator strategy * * (C) 2012 Christoph Lameter <cl@linux.com> */ #include <linux/slab.h> #include <linux/mm.h> #include <linux/poison.h> #include <linux/interrupt.h> #include <linux/memory.h> |
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#include <linux/cache.h> |
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#include <linux/compiler.h> #include <linux/module.h> |
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#include <linux/cpu.h> #include <linux/uaccess.h> |
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#include <linux/seq_file.h> #include <linux/proc_fs.h> |
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#include <linux/debugfs.h> |
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#include <asm/cacheflush.h> #include <asm/tlbflush.h> #include <asm/page.h> |
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#include <linux/memcontrol.h> |
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#define CREATE_TRACE_POINTS |
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#include <trace/events/kmem.h> |
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#include "internal.h" |
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#include "slab.h" enum slab_state slab_state; |
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LIST_HEAD(slab_caches); DEFINE_MUTEX(slab_mutex); |
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struct kmem_cache *kmem_cache; |
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|
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#ifdef CONFIG_HARDENED_USERCOPY bool usercopy_fallback __ro_after_init = IS_ENABLED(CONFIG_HARDENED_USERCOPY_FALLBACK); module_param(usercopy_fallback, bool, 0400); MODULE_PARM_DESC(usercopy_fallback, "WARN instead of reject usercopy whitelist violations"); #endif |
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static LIST_HEAD(slab_caches_to_rcu_destroy); static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work); static DECLARE_WORK(slab_caches_to_rcu_destroy_work, slab_caches_to_rcu_destroy_workfn); |
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/* |
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* Set of flags that will prevent slab merging */ #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ |
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SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \ |
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SLAB_FAILSLAB | SLAB_KASAN) |
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|
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#define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \ |
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SLAB_CACHE_DMA32 | SLAB_ACCOUNT) |
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/* * Merge control. If this is set then no merging of slab caches will occur. |
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*/ |
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static bool slab_nomerge = !IS_ENABLED(CONFIG_SLAB_MERGE_DEFAULT); |
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static int __init setup_slab_nomerge(char *str) { |
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slab_nomerge = true; |
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return 1; } #ifdef CONFIG_SLUB __setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0); #endif __setup("slab_nomerge", setup_slab_nomerge); /* |
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* Determine the size of a slab object */ unsigned int kmem_cache_size(struct kmem_cache *s) { return s->object_size; } EXPORT_SYMBOL(kmem_cache_size); |
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#ifdef CONFIG_DEBUG_VM |
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static int kmem_cache_sanity_check(const char *name, unsigned int size) |
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{ |
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if (!name || in_interrupt() || size < sizeof(void *) || size > KMALLOC_MAX_SIZE) { |
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pr_err("kmem_cache_create(%s) integrity check failed ", name); return -EINVAL; |
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} |
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WARN_ON(strchr(name, ' ')); /* It confuses parsers */ |
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return 0; } #else |
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static inline int kmem_cache_sanity_check(const char *name, unsigned int size) |
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{ return 0; } |
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#endif |
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void __kmem_cache_free_bulk(struct kmem_cache *s, size_t nr, void **p) { size_t i; |
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for (i = 0; i < nr; i++) { if (s) kmem_cache_free(s, p[i]); else kfree(p[i]); } |
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} |
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int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr, |
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void **p) { size_t i; for (i = 0; i < nr; i++) { void *x = p[i] = kmem_cache_alloc(s, flags); if (!x) { __kmem_cache_free_bulk(s, i, p); |
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return 0; |
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} } |
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return i; |
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} |
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/* |
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* Figure out what the alignment of the objects will be given a set of * flags, a user specified alignment and the size of the objects. */ |
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static unsigned int calculate_alignment(slab_flags_t flags, unsigned int align, unsigned int size) |
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{ /* * If the user wants hardware cache aligned objects then follow that * suggestion if the object is sufficiently large. * * The hardware cache alignment cannot override the specified * alignment though. If that is greater then use it. */ if (flags & SLAB_HWCACHE_ALIGN) { |
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unsigned int ralign; |
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ralign = cache_line_size(); while (size <= ralign / 2) ralign /= 2; align = max(align, ralign); } if (align < ARCH_SLAB_MINALIGN) align = ARCH_SLAB_MINALIGN; return ALIGN(align, sizeof(void *)); } /* |
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* Find a mergeable slab cache */ int slab_unmergeable(struct kmem_cache *s) { if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE)) return 1; |
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if (s->ctor) return 1; |
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if (s->usersize) return 1; |
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/* * We may have set a slab to be unmergeable during bootstrap. */ if (s->refcount < 0) return 1; return 0; } |
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struct kmem_cache *find_mergeable(unsigned int size, unsigned int align, |
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slab_flags_t flags, const char *name, void (*ctor)(void *)) |
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{ struct kmem_cache *s; |
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if (slab_nomerge) |
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return NULL; if (ctor) return NULL; size = ALIGN(size, sizeof(void *)); align = calculate_alignment(flags, align, size); size = ALIGN(size, align); flags = kmem_cache_flags(size, flags, name, NULL); |
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if (flags & SLAB_NEVER_MERGE) return NULL; |
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list_for_each_entry_reverse(s, &slab_caches, list) { |
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if (slab_unmergeable(s)) continue; if (size > s->size) continue; if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME)) continue; /* * Check if alignment is compatible. * Courtesy of Adrian Drzewiecki */ if ((s->size & ~(align - 1)) != s->size) continue; if (s->size - size >= sizeof(void *)) continue; |
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if (IS_ENABLED(CONFIG_SLAB) && align && (align > s->align || s->align % align)) continue; |
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return s; } return NULL; } |
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static struct kmem_cache *create_cache(const char *name, |
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unsigned int object_size, unsigned int align, |
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slab_flags_t flags, unsigned int useroffset, unsigned int usersize, void (*ctor)(void *), |
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struct kmem_cache *root_cache) |
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{ struct kmem_cache *s; int err; |
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if (WARN_ON(useroffset + usersize > object_size)) useroffset = usersize = 0; |
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err = -ENOMEM; s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); if (!s) goto out; s->name = name; |
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s->size = s->object_size = object_size; |
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s->align = align; s->ctor = ctor; |
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s->useroffset = useroffset; s->usersize = usersize; |
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err = __kmem_cache_create(s, flags); if (err) goto out_free_cache; s->refcount = 1; list_add(&s->list, &slab_caches); |
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out: if (err) return ERR_PTR(err); return s; out_free_cache: |
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kmem_cache_free(kmem_cache, s); |
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goto out; } |
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/** * kmem_cache_create_usercopy - Create a cache with a region suitable * for copying to userspace |
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* @name: A string which is used in /proc/slabinfo to identify this cache. * @size: The size of objects to be created in this cache. * @align: The required alignment for the objects. * @flags: SLAB flags |
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* @useroffset: Usercopy region offset * @usersize: Usercopy region size |
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* @ctor: A constructor for the objects. * |
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* Cannot be called within a interrupt, but can be interrupted. * The @ctor is run when new pages are allocated by the cache. * * The flags are * * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) * to catch references to uninitialised memory. * |
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* %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check |
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* 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. |
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* * Return: a pointer to the cache on success, NULL on failure. |
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*/ |
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struct kmem_cache * |
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kmem_cache_create_usercopy(const char *name, unsigned int size, unsigned int align, |
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slab_flags_t flags, unsigned int useroffset, unsigned int usersize, |
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void (*ctor)(void *)) |
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{ |
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struct kmem_cache *s = NULL; |
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const char *cache_name; |
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int err; |
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get_online_cpus(); |
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get_online_mems(); |
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mutex_lock(&slab_mutex); |
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err = kmem_cache_sanity_check(name, size); |
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if (err) { |
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goto out_unlock; |
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} |
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/* Refuse requests with allocator specific flags */ if (flags & ~SLAB_FLAGS_PERMITTED) { err = -EINVAL; goto out_unlock; } |
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/* * Some allocators will constraint the set of valid flags to a subset * of all flags. We expect them to define CACHE_CREATE_MASK in this * case, and we'll just provide them with a sanitized version of the * passed flags. */ flags &= CACHE_CREATE_MASK; |
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/* Fail closed on bad usersize of useroffset values. */ if (WARN_ON(!usersize && useroffset) || WARN_ON(size < usersize || size - usersize < useroffset)) usersize = useroffset = 0; if (!usersize) s = __kmem_cache_alias(name, size, align, flags, ctor); |
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if (s) |
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goto out_unlock; |
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cache_name = kstrdup_const(name, GFP_KERNEL); |
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if (!cache_name) { err = -ENOMEM; goto out_unlock; } |
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s = create_cache(cache_name, size, |
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calculate_alignment(flags, align, size), |
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flags, useroffset, usersize, ctor, NULL); |
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if (IS_ERR(s)) { err = PTR_ERR(s); |
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kfree_const(cache_name); |
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} |
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out_unlock: |
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mutex_unlock(&slab_mutex); |
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put_online_mems(); |
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put_online_cpus(); |
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if (err) { |
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if (flags & SLAB_PANIC) panic("kmem_cache_create: Failed to create slab '%s'. Error %d ", name, err); else { |
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pr_warn("kmem_cache_create(%s) failed with error %d ", |
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name, err); dump_stack(); } |
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return NULL; } |
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return s; } |
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EXPORT_SYMBOL(kmem_cache_create_usercopy); |
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/** * kmem_cache_create - Create a cache. * @name: A string which is used in /proc/slabinfo to identify this cache. * @size: The size of objects to be created in this cache. * @align: The required alignment for the objects. * @flags: SLAB flags * @ctor: A constructor for the objects. * * Cannot be called within a interrupt, but can be interrupted. * The @ctor is run when new pages are allocated by the cache. * * The flags are * * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) * to catch references to uninitialised memory. * * %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check * for buffer overruns. * * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware * cacheline. This can be beneficial if you're counting cycles as closely * as davem. * * Return: a pointer to the cache on success, NULL on failure. */ |
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struct kmem_cache * |
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kmem_cache_create(const char *name, unsigned int size, unsigned int align, |
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slab_flags_t flags, void (*ctor)(void *)) { |
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return kmem_cache_create_usercopy(name, size, align, flags, 0, 0, |
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ctor); } |
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EXPORT_SYMBOL(kmem_cache_create); |
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static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work) |
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{ |
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LIST_HEAD(to_destroy); struct kmem_cache *s, *s2; |
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/* |
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* On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the |
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* @slab_caches_to_rcu_destroy list. The slab pages are freed |
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* through RCU and the associated kmem_cache are dereferenced |
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* while freeing the pages, so the kmem_caches should be freed only * after the pending RCU operations are finished. As rcu_barrier() * is a pretty slow operation, we batch all pending destructions * asynchronously. */ mutex_lock(&slab_mutex); list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy); mutex_unlock(&slab_mutex); |
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if (list_empty(&to_destroy)) return; rcu_barrier(); list_for_each_entry_safe(s, s2, &to_destroy, list) { #ifdef SLAB_SUPPORTS_SYSFS sysfs_slab_release(s); #else slab_kmem_cache_release(s); #endif } |
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} |
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static int shutdown_cache(struct kmem_cache *s) |
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{ |
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/* free asan quarantined objects */ kasan_cache_shutdown(s); |
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if (__kmem_cache_shutdown(s) != 0) return -EBUSY; |
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list_del(&s->list); |
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if (s->flags & SLAB_TYPESAFE_BY_RCU) { |
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#ifdef SLAB_SUPPORTS_SYSFS sysfs_slab_unlink(s); #endif |
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list_add_tail(&s->list, &slab_caches_to_rcu_destroy); schedule_work(&slab_caches_to_rcu_destroy_work); } else { |
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#ifdef SLAB_SUPPORTS_SYSFS |
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sysfs_slab_unlink(s); |
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sysfs_slab_release(s); |
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#else slab_kmem_cache_release(s); #endif } |
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return 0; |
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} |
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void slab_kmem_cache_release(struct kmem_cache *s) { |
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__kmem_cache_release(s); |
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kfree_const(s->name); |
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kmem_cache_free(kmem_cache, s); } |
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void kmem_cache_destroy(struct kmem_cache *s) { |
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int err; |
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if (unlikely(!s)) return; |
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get_online_cpus(); |
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get_online_mems(); |
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mutex_lock(&slab_mutex); |
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s->refcount--; |
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if (s->refcount) goto out_unlock; |
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err = shutdown_cache(s); |
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if (err) { |
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pr_err("kmem_cache_destroy %s: Slab cache still has objects ", s->name); |
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dump_stack(); } |
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out_unlock: mutex_unlock(&slab_mutex); |
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put_online_mems(); |
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put_online_cpus(); } EXPORT_SYMBOL(kmem_cache_destroy); |
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/** * kmem_cache_shrink - Shrink a cache. * @cachep: The cache to shrink. * * Releases as many slabs as possible for a cache. * To help debugging, a zero exit status indicates all slabs were released. |
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* * Return: %0 if all slabs were released, non-zero otherwise |
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*/ int kmem_cache_shrink(struct kmem_cache *cachep) { int ret; get_online_cpus(); get_online_mems(); |
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kasan_cache_shrink(cachep); |
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ret = __kmem_cache_shrink(cachep); |
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put_online_mems(); put_online_cpus(); return ret; } EXPORT_SYMBOL(kmem_cache_shrink); |
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bool slab_is_available(void) |
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{ return slab_state >= UP; } |
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#ifndef CONFIG_SLOB /* Create a cache during boot when no slab services are available yet */ |
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void __init create_boot_cache(struct kmem_cache *s, const char *name, unsigned int size, slab_flags_t flags, unsigned int useroffset, unsigned int usersize) |
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{ int err; |
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unsigned int align = ARCH_KMALLOC_MINALIGN; |
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s->name = name; s->size = s->object_size = size; |
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521 522 523 524 525 526 527 528 |
/* * For power of two sizes, guarantee natural alignment for kmalloc * caches, regardless of SL*B debugging options. */ if (is_power_of_2(size)) align = max(align, size); s->align = calculate_alignment(flags, align, size); |
8eb8284b4
|
529 530 |
s->useroffset = useroffset; s->usersize = usersize; |
f7ce3190c
|
531 |
|
45530c447
|
532 533 534 |
err = __kmem_cache_create(s, flags); if (err) |
361d575e5
|
535 536 |
panic("Creation of kmalloc slab %s size=%u failed. Reason %d ", |
45530c447
|
537 538 539 540 |
name, size, err); s->refcount = -1; /* Exempt from merging for now */ } |
55de8b9c6
|
541 542 543 |
struct kmem_cache *__init create_kmalloc_cache(const char *name, unsigned int size, slab_flags_t flags, unsigned int useroffset, unsigned int usersize) |
45530c447
|
544 545 546 547 548 549 |
{ struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT); if (!s) panic("Out of memory when creating slab %s ", name); |
6c0c21adc
|
550 |
create_boot_cache(s, name, size, flags, useroffset, usersize); |
45530c447
|
551 552 553 554 |
list_add(&s->list, &slab_caches); s->refcount = 1; return s; } |
cc252eae8
|
555 |
struct kmem_cache * |
a07057dce
|
556 557 |
kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1] __ro_after_init = { /* initialization for https://bugs.llvm.org/show_bug.cgi?id=42570 */ }; |
9425c58e5
|
558 |
EXPORT_SYMBOL(kmalloc_caches); |
f97d5f634
|
559 |
/* |
2c59dd654
|
560 561 562 563 564 |
* Conversion table for small slabs sizes / 8 to the index in the * kmalloc array. This is necessary for slabs < 192 since we have non power * of two cache sizes there. The size of larger slabs can be determined using * fls. */ |
d5f866550
|
565 |
static u8 size_index[24] __ro_after_init = { |
2c59dd654
|
566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 |
3, /* 8 */ 4, /* 16 */ 5, /* 24 */ 5, /* 32 */ 6, /* 40 */ 6, /* 48 */ 6, /* 56 */ 6, /* 64 */ 1, /* 72 */ 1, /* 80 */ 1, /* 88 */ 1, /* 96 */ 7, /* 104 */ 7, /* 112 */ 7, /* 120 */ 7, /* 128 */ 2, /* 136 */ 2, /* 144 */ 2, /* 152 */ 2, /* 160 */ 2, /* 168 */ 2, /* 176 */ 2, /* 184 */ 2 /* 192 */ }; |
ac914d08b
|
591 |
static inline unsigned int size_index_elem(unsigned int bytes) |
2c59dd654
|
592 593 594 595 596 597 598 599 600 601 |
{ return (bytes - 1) / 8; } /* * Find the kmem_cache structure that serves a given size of * allocation */ struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags) { |
d5f866550
|
602 |
unsigned int index; |
2c59dd654
|
603 604 605 606 607 608 |
if (size <= 192) { if (!size) return ZERO_SIZE_PTR; index = size_index[size_index_elem(size)]; |
61448479a
|
609 |
} else { |
221d7da66
|
610 |
if (WARN_ON_ONCE(size > KMALLOC_MAX_CACHE_SIZE)) |
61448479a
|
611 |
return NULL; |
2c59dd654
|
612 |
index = fls(size - 1); |
61448479a
|
613 |
} |
2c59dd654
|
614 |
|
cc252eae8
|
615 |
return kmalloc_caches[kmalloc_type(flags)][index]; |
2c59dd654
|
616 |
} |
cb5d9fb38
|
617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 |
#ifdef CONFIG_ZONE_DMA #define INIT_KMALLOC_INFO(__size, __short_size) \ { \ .name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \ .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size, \ .name[KMALLOC_DMA] = "dma-kmalloc-" #__short_size, \ .size = __size, \ } #else #define INIT_KMALLOC_INFO(__size, __short_size) \ { \ .name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \ .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size, \ .size = __size, \ } #endif |
2c59dd654
|
633 |
/* |
4066c33d0
|
634 635 636 637 |
* kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time. * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is * kmalloc-67108864. */ |
af3b5f876
|
638 |
const struct kmalloc_info_struct kmalloc_info[] __initconst = { |
cb5d9fb38
|
639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 |
INIT_KMALLOC_INFO(0, 0), INIT_KMALLOC_INFO(96, 96), INIT_KMALLOC_INFO(192, 192), INIT_KMALLOC_INFO(8, 8), INIT_KMALLOC_INFO(16, 16), INIT_KMALLOC_INFO(32, 32), INIT_KMALLOC_INFO(64, 64), INIT_KMALLOC_INFO(128, 128), INIT_KMALLOC_INFO(256, 256), INIT_KMALLOC_INFO(512, 512), INIT_KMALLOC_INFO(1024, 1k), INIT_KMALLOC_INFO(2048, 2k), INIT_KMALLOC_INFO(4096, 4k), INIT_KMALLOC_INFO(8192, 8k), INIT_KMALLOC_INFO(16384, 16k), INIT_KMALLOC_INFO(32768, 32k), INIT_KMALLOC_INFO(65536, 64k), INIT_KMALLOC_INFO(131072, 128k), INIT_KMALLOC_INFO(262144, 256k), INIT_KMALLOC_INFO(524288, 512k), INIT_KMALLOC_INFO(1048576, 1M), INIT_KMALLOC_INFO(2097152, 2M), INIT_KMALLOC_INFO(4194304, 4M), INIT_KMALLOC_INFO(8388608, 8M), INIT_KMALLOC_INFO(16777216, 16M), INIT_KMALLOC_INFO(33554432, 32M), INIT_KMALLOC_INFO(67108864, 64M) |
4066c33d0
|
666 667 668 |
}; /* |
34cc6990d
|
669 670 671 672 673 674 675 676 677 |
* Patch up the size_index table if we have strange large alignment * requirements for the kmalloc array. This is only the case for * MIPS it seems. The standard arches will not generate any code here. * * Largest permitted alignment is 256 bytes due to the way we * handle the index determination for the smaller caches. * * Make sure that nothing crazy happens if someone starts tinkering * around with ARCH_KMALLOC_MINALIGN |
f97d5f634
|
678 |
*/ |
34cc6990d
|
679 |
void __init setup_kmalloc_cache_index_table(void) |
f97d5f634
|
680 |
{ |
ac914d08b
|
681 |
unsigned int i; |
f97d5f634
|
682 |
|
2c59dd654
|
683 684 685 686 |
BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 || (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1))); for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) { |
ac914d08b
|
687 |
unsigned int elem = size_index_elem(i); |
2c59dd654
|
688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 |
if (elem >= ARRAY_SIZE(size_index)) break; size_index[elem] = KMALLOC_SHIFT_LOW; } if (KMALLOC_MIN_SIZE >= 64) { /* * The 96 byte size cache is not used if the alignment * is 64 byte. */ for (i = 64 + 8; i <= 96; i += 8) size_index[size_index_elem(i)] = 7; } if (KMALLOC_MIN_SIZE >= 128) { /* * The 192 byte sized cache is not used if the alignment * is 128 byte. Redirect kmalloc to use the 256 byte cache * instead. */ for (i = 128 + 8; i <= 192; i += 8) size_index[size_index_elem(i)] = 8; } |
34cc6990d
|
713 |
} |
1291523f2
|
714 |
static void __init |
13657d0ad
|
715 |
new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags) |
a9730fca9
|
716 |
{ |
cb5d9fb38
|
717 |
if (type == KMALLOC_RECLAIM) |
1291523f2
|
718 |
flags |= SLAB_RECLAIM_ACCOUNT; |
1291523f2
|
719 |
|
cb5d9fb38
|
720 721 |
kmalloc_caches[type][idx] = create_kmalloc_cache( kmalloc_info[idx].name[type], |
6c0c21adc
|
722 723 |
kmalloc_info[idx].size, flags, 0, kmalloc_info[idx].size); |
a9730fca9
|
724 |
} |
34cc6990d
|
725 726 727 728 729 |
/* * Create the kmalloc array. Some of the regular kmalloc arrays * may already have been created because they were needed to * enable allocations for slab creation. */ |
d50112edd
|
730 |
void __init create_kmalloc_caches(slab_flags_t flags) |
34cc6990d
|
731 |
{ |
13657d0ad
|
732 733 |
int i; enum kmalloc_cache_type type; |
34cc6990d
|
734 |
|
1291523f2
|
735 736 737 738 |
for (type = KMALLOC_NORMAL; type <= KMALLOC_RECLAIM; type++) { for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) { if (!kmalloc_caches[type][i]) new_kmalloc_cache(i, type, flags); |
f97d5f634
|
739 |
|
1291523f2
|
740 741 742 743 744 745 746 747 748 749 750 751 |
/* * Caches that are not of the two-to-the-power-of size. * These have to be created immediately after the * earlier power of two caches */ if (KMALLOC_MIN_SIZE <= 32 && i == 6 && !kmalloc_caches[type][1]) new_kmalloc_cache(1, type, flags); if (KMALLOC_MIN_SIZE <= 64 && i == 7 && !kmalloc_caches[type][2]) new_kmalloc_cache(2, type, flags); } |
8a965b3ba
|
752 |
} |
f97d5f634
|
753 754 |
/* Kmalloc array is now usable */ slab_state = UP; |
f97d5f634
|
755 756 |
#ifdef CONFIG_ZONE_DMA for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) { |
cc252eae8
|
757 |
struct kmem_cache *s = kmalloc_caches[KMALLOC_NORMAL][i]; |
f97d5f634
|
758 759 |
if (s) { |
cc252eae8
|
760 |
kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache( |
cb5d9fb38
|
761 |
kmalloc_info[i].name[KMALLOC_DMA], |
dc0a7f755
|
762 |
kmalloc_info[i].size, |
49f2d2419
|
763 764 |
SLAB_CACHE_DMA | flags, 0, kmalloc_info[i].size); |
f97d5f634
|
765 766 767 768 |
} } #endif } |
45530c447
|
769 |
#endif /* !CONFIG_SLOB */ |
444050990
|
770 771 772 773 774 775 776 777 778 779 780 781 |
gfp_t kmalloc_fix_flags(gfp_t flags) { gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK; flags &= ~GFP_SLAB_BUG_MASK; pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code! ", invalid_mask, &invalid_mask, flags, &flags); dump_stack(); return flags; } |
cea371f4f
|
782 783 784 785 786 |
/* * To avoid unnecessary overhead, we pass through large allocation requests * directly to the page allocator. We use __GFP_COMP, because we will need to * know the allocation order to free the pages properly in kfree. */ |
52383431b
|
787 788 |
void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) { |
6a486c0ad
|
789 |
void *ret = NULL; |
52383431b
|
790 |
struct page *page; |
444050990
|
791 792 |
if (unlikely(flags & GFP_SLAB_BUG_MASK)) flags = kmalloc_fix_flags(flags); |
52383431b
|
793 |
flags |= __GFP_COMP; |
4949148ad
|
794 |
page = alloc_pages(flags, order); |
6a486c0ad
|
795 796 |
if (likely(page)) { ret = page_address(page); |
d42f3245c
|
797 798 |
mod_node_page_state(page_pgdat(page), NR_SLAB_UNRECLAIMABLE_B, PAGE_SIZE << order); |
6a486c0ad
|
799 |
} |
0116523cf
|
800 |
ret = kasan_kmalloc_large(ret, size, flags); |
a2f775751
|
801 |
/* As ret might get tagged, call kmemleak hook after KASAN. */ |
53128245b
|
802 |
kmemleak_alloc(ret, size, 1, flags); |
52383431b
|
803 804 805 |
return ret; } EXPORT_SYMBOL(kmalloc_order); |
f1b6eb6e6
|
806 807 808 809 810 811 812 813 814 |
#ifdef CONFIG_TRACING void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) { void *ret = kmalloc_order(size, flags, order); trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags); return ret; } EXPORT_SYMBOL(kmalloc_order_trace); #endif |
45530c447
|
815 |
|
7c00fce98
|
816 817 818 |
#ifdef CONFIG_SLAB_FREELIST_RANDOM /* Randomize a generic freelist */ static void freelist_randomize(struct rnd_state *state, unsigned int *list, |
302d55d51
|
819 |
unsigned int count) |
7c00fce98
|
820 |
{ |
7c00fce98
|
821 |
unsigned int rand; |
302d55d51
|
822 |
unsigned int i; |
7c00fce98
|
823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 |
for (i = 0; i < count; i++) list[i] = i; /* Fisher-Yates shuffle */ for (i = count - 1; i > 0; i--) { rand = prandom_u32_state(state); rand %= (i + 1); swap(list[i], list[rand]); } } /* Create a random sequence per cache */ int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count, gfp_t gfp) { struct rnd_state state; if (count < 2 || cachep->random_seq) return 0; cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp); if (!cachep->random_seq) return -ENOMEM; /* Get best entropy at this stage of boot */ prandom_seed_state(&state, get_random_long()); freelist_randomize(&state, cachep->random_seq, count); return 0; } /* Destroy the per-cache random freelist sequence */ void cache_random_seq_destroy(struct kmem_cache *cachep) { kfree(cachep->random_seq); cachep->random_seq = NULL; } #endif /* CONFIG_SLAB_FREELIST_RANDOM */ |
5b3657710
|
862 |
#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) |
e9b4db2b8
|
863 |
#ifdef CONFIG_SLAB |
0825a6f98
|
864 |
#define SLABINFO_RIGHTS (0600) |
e9b4db2b8
|
865 |
#else |
0825a6f98
|
866 |
#define SLABINFO_RIGHTS (0400) |
e9b4db2b8
|
867 |
#endif |
b047501cd
|
868 |
static void print_slabinfo_header(struct seq_file *m) |
bcee6e2a1
|
869 870 871 872 873 874 875 876 877 878 879 880 |
{ /* * Output format version, so at least we can change it * without _too_ many complaints. */ #ifdef CONFIG_DEBUG_SLAB seq_puts(m, "slabinfo - version: 2.1 (statistics) "); #else seq_puts(m, "slabinfo - version: 2.1 "); #endif |
756a025f0
|
881 |
seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>"); |
bcee6e2a1
|
882 883 884 |
seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); #ifdef CONFIG_DEBUG_SLAB |
756a025f0
|
885 |
seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); |
bcee6e2a1
|
886 887 888 889 890 |
seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); #endif seq_putc(m, ' '); } |
1df3b26f2
|
891 |
void *slab_start(struct seq_file *m, loff_t *pos) |
b7454ad3c
|
892 |
{ |
b7454ad3c
|
893 |
mutex_lock(&slab_mutex); |
c7094406f
|
894 |
return seq_list_start(&slab_caches, *pos); |
b7454ad3c
|
895 |
} |
276a2439c
|
896 |
void *slab_next(struct seq_file *m, void *p, loff_t *pos) |
b7454ad3c
|
897 |
{ |
c7094406f
|
898 |
return seq_list_next(p, &slab_caches, pos); |
b7454ad3c
|
899 |
} |
276a2439c
|
900 |
void slab_stop(struct seq_file *m, void *p) |
b7454ad3c
|
901 902 903 |
{ mutex_unlock(&slab_mutex); } |
b047501cd
|
904 |
static void cache_show(struct kmem_cache *s, struct seq_file *m) |
b7454ad3c
|
905 |
{ |
0d7561c61
|
906 907 908 909 910 911 |
struct slabinfo sinfo; memset(&sinfo, 0, sizeof(sinfo)); get_slabinfo(s, &sinfo); seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", |
10befea91
|
912 |
s->name, sinfo.active_objs, sinfo.num_objs, s->size, |
0d7561c61
|
913 914 915 916 917 918 919 920 921 |
sinfo.objects_per_slab, (1 << sinfo.cache_order)); seq_printf(m, " : tunables %4u %4u %4u", sinfo.limit, sinfo.batchcount, sinfo.shared); seq_printf(m, " : slabdata %6lu %6lu %6lu", sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail); slabinfo_show_stats(m, s); seq_putc(m, ' '); |
b7454ad3c
|
922 |
} |
1df3b26f2
|
923 |
static int slab_show(struct seq_file *m, void *p) |
749c54151
|
924 |
{ |
c7094406f
|
925 |
struct kmem_cache *s = list_entry(p, struct kmem_cache, list); |
749c54151
|
926 |
|
c7094406f
|
927 |
if (p == slab_caches.next) |
1df3b26f2
|
928 |
print_slabinfo_header(m); |
10befea91
|
929 |
cache_show(s, m); |
b047501cd
|
930 931 |
return 0; } |
852d8be0a
|
932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 |
void dump_unreclaimable_slab(void) { struct kmem_cache *s, *s2; struct slabinfo sinfo; /* * Here acquiring slab_mutex is risky since we don't prefer to get * sleep in oom path. But, without mutex hold, it may introduce a * risk of crash. * Use mutex_trylock to protect the list traverse, dump nothing * without acquiring the mutex. */ if (!mutex_trylock(&slab_mutex)) { pr_warn("excessive unreclaimable slab but cannot dump stats "); return; } pr_info("Unreclaimable slab info: "); pr_info("Name Used Total "); list_for_each_entry_safe(s, s2, &slab_caches, list) { |
10befea91
|
956 |
if (s->flags & SLAB_RECLAIM_ACCOUNT) |
852d8be0a
|
957 958 959 960 961 |
continue; get_slabinfo(s, &sinfo); if (sinfo.num_objs > 0) |
10befea91
|
962 963 |
pr_info("%-17s %10luKB %10luKB ", s->name, |
852d8be0a
|
964 965 966 967 968 |
(sinfo.active_objs * s->size) / 1024, (sinfo.num_objs * s->size) / 1024); } mutex_unlock(&slab_mutex); } |
a87425a36
|
969 |
#if defined(CONFIG_MEMCG_KMEM) |
b047501cd
|
970 971 |
int memcg_slab_show(struct seq_file *m, void *p) { |
4330a26bc
|
972 973 974 975 |
/* * Deprecated. * Please, take a look at tools/cgroup/slabinfo.py . */ |
b047501cd
|
976 |
return 0; |
749c54151
|
977 |
} |
b047501cd
|
978 |
#endif |
749c54151
|
979 |
|
b7454ad3c
|
980 981 982 983 984 985 986 987 988 989 990 991 992 993 |
/* * slabinfo_op - iterator that generates /proc/slabinfo * * Output layout: * cache-name * num-active-objs * total-objs * object size * num-active-slabs * total-slabs * num-pages-per-slab * + further values on SMP and with statistics enabled */ static const struct seq_operations slabinfo_op = { |
1df3b26f2
|
994 |
.start = slab_start, |
276a2439c
|
995 996 |
.next = slab_next, .stop = slab_stop, |
1df3b26f2
|
997 |
.show = slab_show, |
b7454ad3c
|
998 999 1000 1001 1002 1003 |
}; static int slabinfo_open(struct inode *inode, struct file *file) { return seq_open(file, &slabinfo_op); } |
97a32539b
|
1004 |
static const struct proc_ops slabinfo_proc_ops = { |
d919b33da
|
1005 |
.proc_flags = PROC_ENTRY_PERMANENT, |
97a32539b
|
1006 1007 1008 1009 1010 |
.proc_open = slabinfo_open, .proc_read = seq_read, .proc_write = slabinfo_write, .proc_lseek = seq_lseek, .proc_release = seq_release, |
b7454ad3c
|
1011 1012 1013 1014 |
}; static int __init slab_proc_init(void) { |
97a32539b
|
1015 |
proc_create("slabinfo", SLABINFO_RIGHTS, NULL, &slabinfo_proc_ops); |
b7454ad3c
|
1016 1017 1018 |
return 0; } module_init(slab_proc_init); |
fcf8a1e48
|
1019 |
|
5b3657710
|
1020 |
#endif /* CONFIG_SLAB || CONFIG_SLUB_DEBUG */ |
928cec9cd
|
1021 1022 1023 1024 1025 |
static __always_inline void *__do_krealloc(const void *p, size_t new_size, gfp_t flags) { void *ret; |
fa9ba3aa8
|
1026 |
size_t ks; |
928cec9cd
|
1027 |
|
fa9ba3aa8
|
1028 |
ks = ksize(p); |
928cec9cd
|
1029 |
|
0316bec22
|
1030 |
if (ks >= new_size) { |
0116523cf
|
1031 |
p = kasan_krealloc((void *)p, new_size, flags); |
928cec9cd
|
1032 |
return (void *)p; |
0316bec22
|
1033 |
} |
928cec9cd
|
1034 1035 1036 1037 1038 1039 1040 1041 1042 |
ret = kmalloc_track_caller(new_size, flags); if (ret && p) memcpy(ret, p, ks); return ret; } /** |
928cec9cd
|
1043 1044 1045 1046 1047 1048 1049 1050 1051 |
* krealloc - reallocate memory. The contents will remain unchanged. * @p: object to reallocate memory for. * @new_size: how many bytes of memory are required. * @flags: the type of memory to allocate. * * The contents of the object pointed to are preserved up to the * lesser of the new and old sizes. If @p is %NULL, krealloc() * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a * %NULL pointer, the object pointed to is freed. |
a862f68a8
|
1052 1053 |
* * Return: pointer to the allocated memory or %NULL in case of error |
928cec9cd
|
1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 |
*/ void *krealloc(const void *p, size_t new_size, gfp_t flags) { void *ret; if (unlikely(!new_size)) { kfree(p); return ZERO_SIZE_PTR; } ret = __do_krealloc(p, new_size, flags); |
772a2fa50
|
1065 |
if (ret && kasan_reset_tag(p) != kasan_reset_tag(ret)) |
928cec9cd
|
1066 1067 1068 1069 1070 1071 1072 |
kfree(p); return ret; } EXPORT_SYMBOL(krealloc); /** |
453431a54
|
1073 |
* kfree_sensitive - Clear sensitive information in memory before freeing |
928cec9cd
|
1074 1075 1076 |
* @p: object to free memory of * * The memory of the object @p points to is zeroed before freed. |
453431a54
|
1077 |
* If @p is %NULL, kfree_sensitive() does nothing. |
928cec9cd
|
1078 1079 1080 1081 1082 |
* * Note: this function zeroes the whole allocated buffer which can be a good * deal bigger than the requested buffer size passed to kmalloc(). So be * careful when using this function in performance sensitive code. */ |
453431a54
|
1083 |
void kfree_sensitive(const void *p) |
928cec9cd
|
1084 1085 1086 |
{ size_t ks; void *mem = (void *)p; |
928cec9cd
|
1087 |
ks = ksize(mem); |
fa9ba3aa8
|
1088 1089 |
if (ks) memzero_explicit(mem, ks); |
928cec9cd
|
1090 1091 |
kfree(mem); } |
453431a54
|
1092 |
EXPORT_SYMBOL(kfree_sensitive); |
928cec9cd
|
1093 |
|
10d1f8cb3
|
1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 |
/** * ksize - get the actual amount of memory allocated for a given object * @objp: Pointer to the object * * kmalloc may internally round up allocations and return more memory * than requested. ksize() can be used to determine the actual amount of * memory allocated. The caller may use this additional memory, even though * a smaller amount of memory was initially specified with the kmalloc call. * The caller must guarantee that objp points to a valid object previously * allocated with either kmalloc() or kmem_cache_alloc(). The object * must not be freed during the duration of the call. * * Return: size of the actual memory used by @objp in bytes */ size_t ksize(const void *objp) { |
0d4ca4c9b
|
1110 |
size_t size; |
0d4ca4c9b
|
1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 |
/* * We need to check that the pointed to object is valid, and only then * unpoison the shadow memory below. We use __kasan_check_read(), to * generate a more useful report at the time ksize() is called (rather * than later where behaviour is undefined due to potential * use-after-free or double-free). * * If the pointed to memory is invalid we return 0, to avoid users of * ksize() writing to and potentially corrupting the memory region. * * We want to perform the check before __ksize(), to avoid potentially * crashing in __ksize() due to accessing invalid metadata. */ |
fa9ba3aa8
|
1124 |
if (unlikely(ZERO_OR_NULL_PTR(objp)) || !__kasan_check_read(objp, 1)) |
0d4ca4c9b
|
1125 1126 1127 |
return 0; size = __ksize(objp); |
10d1f8cb3
|
1128 1129 1130 1131 1132 1133 1134 1135 |
/* * We assume that ksize callers could use whole allocated area, * so we need to unpoison this area. */ kasan_unpoison_shadow(objp, size); return size; } EXPORT_SYMBOL(ksize); |
928cec9cd
|
1136 1137 1138 1139 1140 1141 1142 |
/* Tracepoints definitions. */ EXPORT_TRACEPOINT_SYMBOL(kmalloc); EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc); EXPORT_TRACEPOINT_SYMBOL(kmalloc_node); EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node); EXPORT_TRACEPOINT_SYMBOL(kfree); EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free); |
4f6923fbb
|
1143 1144 1145 1146 1147 1148 1149 1150 |
int should_failslab(struct kmem_cache *s, gfp_t gfpflags) { if (__should_failslab(s, gfpflags)) return -ENOMEM; return 0; } ALLOW_ERROR_INJECTION(should_failslab, ERRNO); |