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-----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEe7vIQRWZI0iWSE3xu+CwddJFiJoFAmSZtjsACgkQu+CwddJF iJqCTwf/XVhmAD7zMOj6g1aak5oHNZDRG5jufM5UNXmiWjCWT3w4DpltrJkz0PPm mg3Ac5fjNUqesZ1SGtUbvoc363smroBrRudGEFrsUhqBcpR+S4fSneoDk+xqMypf VLXP/8kJlFEBGMiR7ouAWnR4+u6JgY4E8E8JIPNzao5KE/L1lD83nY+Usjc/01ek oqMyYVFRfncsGjGJXc5fOOTTCj768mRroF0sLmEegIonnwQkSHE7HWJ/nyaVraDV bomnTIgMdVIDqharin08ZPIM7qBIWM09Uifaf0lIs6fIA94pQP+5Ko3mum2P/S+U ON/qviSrlNgRXoHPJ3hvPHdfEU9cSg== =1d0v -----END PGP SIGNATURE----- Merge tag 'slab-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab updates from Vlastimil Babka: - SLAB deprecation: Following the discussion at LSF/MM 2023 [1] and no objections, the SLAB allocator is deprecated by renaming the config option (to make its users notice) to CONFIG_SLAB_DEPRECATED with updated help text. SLUB should be used instead. Existing defconfigs with CONFIG_SLAB are also updated. - SLAB_NO_MERGE kmem_cache flag (Jesper Dangaard Brouer): There are (very limited) cases where kmem_cache merging is undesirable, and existing ways to prevent it are hacky. Introduce a new flag to do that cleanly and convert the existing hacky users. Btrfs plans to use this for debug kernel builds (that use case is always fine), networking for performance reasons (that should be very rare). - Replace the usage of weak PRNGs (David Keisar Schmidt): In addition to using stronger RNGs for the security related features, the code is a bit cleaner. - Misc code cleanups (SeongJae Parki, Xiongwei Song, Zhen Lei, and zhaoxinchao) Link: https://lwn.net/Articles/932201/ [1] * tag 'slab-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: mm/slab_common: use SLAB_NO_MERGE instead of negative refcount mm/slab: break up RCU readers on SLAB_TYPESAFE_BY_RCU example code mm/slab: add a missing semicolon on SLAB_TYPESAFE_BY_RCU example code mm/slab_common: reduce an if statement in create_cache() mm/slab: introduce kmem_cache flag SLAB_NO_MERGE mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED mm/slab: remove HAVE_HARDENED_USERCOPY_ALLOCATOR mm/slab_common: Replace invocation of weak PRNG mm/slab: Replace invocation of weak PRNG slub: Don't read nr_slabs and total_objects directly slub: Remove slabs_node() function slub: Remove CONFIG_SMP defined check slub: Put objects_show() into CONFIG_SLUB_DEBUG enabled block slub: Correct the error code when slab_kset is NULL mm/slab: correct return values in comment for _kmem_cache_create()
1475 lines
37 KiB
C
1475 lines
37 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Slab allocator functions that are independent of the allocator strategy
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*
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* (C) 2012 Christoph Lameter <cl@linux.com>
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*/
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#include <linux/slab.h>
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#include <linux/mm.h>
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#include <linux/poison.h>
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#include <linux/interrupt.h>
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#include <linux/memory.h>
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#include <linux/cache.h>
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#include <linux/compiler.h>
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#include <linux/kfence.h>
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#include <linux/module.h>
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#include <linux/cpu.h>
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#include <linux/uaccess.h>
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#include <linux/seq_file.h>
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#include <linux/dma-mapping.h>
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#include <linux/swiotlb.h>
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#include <linux/proc_fs.h>
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#include <linux/debugfs.h>
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#include <linux/kasan.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#include <asm/page.h>
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#include <linux/memcontrol.h>
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#include <linux/stackdepot.h>
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#include "internal.h"
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#include "slab.h"
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#define CREATE_TRACE_POINTS
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#include <trace/events/kmem.h>
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enum slab_state slab_state;
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LIST_HEAD(slab_caches);
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DEFINE_MUTEX(slab_mutex);
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struct kmem_cache *kmem_cache;
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static LIST_HEAD(slab_caches_to_rcu_destroy);
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static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work);
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static DECLARE_WORK(slab_caches_to_rcu_destroy_work,
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slab_caches_to_rcu_destroy_workfn);
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/*
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* Set of flags that will prevent slab merging
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*/
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#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_NO_MERGE | kasan_never_merge())
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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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/*
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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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{
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slab_nomerge = true;
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return 1;
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}
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static int __init setup_slab_merge(char *str)
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{
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slab_nomerge = false;
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return 1;
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}
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#ifdef CONFIG_SLUB
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__setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0);
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__setup_param("slub_merge", slub_merge, setup_slab_merge, 0);
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#endif
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__setup("slab_nomerge", setup_slab_nomerge);
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__setup("slab_merge", setup_slab_merge);
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/*
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* Determine the size of a slab object
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*/
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unsigned int kmem_cache_size(struct kmem_cache *s)
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{
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return s->object_size;
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}
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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 > KMALLOC_MAX_SIZE) {
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pr_err("kmem_cache_create(%s) integrity check failed\n", name);
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return -EINVAL;
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}
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WARN_ON(strchr(name, ' ')); /* It confuses parsers */
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return 0;
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}
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#else
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static inline int kmem_cache_sanity_check(const char *name, unsigned int size)
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{
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return 0;
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}
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#endif
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/*
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* Figure out what the alignment of the objects will be given a set of
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* flags, a user specified alignment and the size of the objects.
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*/
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static unsigned int calculate_alignment(slab_flags_t flags,
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unsigned int align, unsigned int size)
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{
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/*
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* If the user wants hardware cache aligned objects then follow that
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* suggestion if the object is sufficiently large.
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*
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* The hardware cache alignment cannot override the specified
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* alignment though. If that is greater then use it.
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*/
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if (flags & SLAB_HWCACHE_ALIGN) {
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unsigned int ralign;
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ralign = cache_line_size();
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while (size <= ralign / 2)
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ralign /= 2;
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align = max(align, ralign);
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}
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align = max(align, arch_slab_minalign());
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return ALIGN(align, sizeof(void *));
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}
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/*
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* Find a mergeable slab cache
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*/
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int slab_unmergeable(struct kmem_cache *s)
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{
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if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
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return 1;
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if (s->ctor)
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return 1;
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#ifdef CONFIG_HARDENED_USERCOPY
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if (s->usersize)
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return 1;
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#endif
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/*
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* We may have set a slab to be unmergeable during bootstrap.
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*/
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if (s->refcount < 0)
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return 1;
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return 0;
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}
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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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{
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struct kmem_cache *s;
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if (slab_nomerge)
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return NULL;
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if (ctor)
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return NULL;
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size = ALIGN(size, sizeof(void *));
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align = calculate_alignment(flags, align, size);
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size = ALIGN(size, align);
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flags = kmem_cache_flags(size, flags, name);
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if (flags & SLAB_NEVER_MERGE)
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return NULL;
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list_for_each_entry_reverse(s, &slab_caches, list) {
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if (slab_unmergeable(s))
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continue;
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if (size > s->size)
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continue;
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if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
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continue;
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/*
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* Check if alignment is compatible.
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* Courtesy of Adrian Drzewiecki
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*/
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if ((s->size & ~(align - 1)) != s->size)
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continue;
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if (s->size - size >= sizeof(void *))
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continue;
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if (IS_ENABLED(CONFIG_SLAB) && align &&
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(align > s->align || s->align % align))
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continue;
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return s;
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}
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return NULL;
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}
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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,
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unsigned int usersize, void (*ctor)(void *),
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struct kmem_cache *root_cache)
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{
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struct kmem_cache *s;
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int err;
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if (WARN_ON(useroffset + usersize > object_size))
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useroffset = usersize = 0;
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err = -ENOMEM;
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s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
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if (!s)
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goto out;
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s->name = name;
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s->size = s->object_size = object_size;
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s->align = align;
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s->ctor = ctor;
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#ifdef CONFIG_HARDENED_USERCOPY
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s->useroffset = useroffset;
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s->usersize = usersize;
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#endif
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err = __kmem_cache_create(s, flags);
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if (err)
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goto out_free_cache;
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s->refcount = 1;
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list_add(&s->list, &slab_caches);
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return s;
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out_free_cache:
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kmem_cache_free(kmem_cache, s);
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out:
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return ERR_PTR(err);
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}
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/**
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* kmem_cache_create_usercopy - Create a cache with a region suitable
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* for copying to userspace
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* @name: A string which is used in /proc/slabinfo to identify this cache.
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* @size: The size of objects to be created in this cache.
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* @align: The required alignment for the objects.
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* @flags: SLAB flags
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* @useroffset: Usercopy region offset
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* @usersize: Usercopy region size
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* @ctor: A constructor for the objects.
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*
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* Cannot be called within a interrupt, but can be interrupted.
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* The @ctor is run when new pages are allocated by the cache.
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*
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* The flags are
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*
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* %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
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* to catch references to uninitialised memory.
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*
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* %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check
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* for buffer overruns.
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*
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* %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
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* cacheline. This can be beneficial if you're counting cycles as closely
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* as davem.
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*
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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,
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unsigned int size, unsigned int align,
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slab_flags_t flags,
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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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|
|
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#ifdef CONFIG_SLUB_DEBUG
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/*
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* If no slub_debug was enabled globally, the static key is not yet
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* enabled by setup_slub_debug(). Enable it if the cache is being
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* created with any of the debugging flags passed explicitly.
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* It's also possible that this is the first cache created with
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* SLAB_STORE_USER and we should init stack_depot for it.
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*/
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if (flags & SLAB_DEBUG_FLAGS)
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static_branch_enable(&slub_debug_enabled);
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if (flags & SLAB_STORE_USER)
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stack_depot_init();
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#endif
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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 */
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if (flags & ~SLAB_FLAGS_PERMITTED) {
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err = -EINVAL;
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goto out_unlock;
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}
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/*
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* Some allocators will constraint the set of valid flags to a subset
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* of all flags. We expect them to define CACHE_CREATE_MASK in this
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* case, and we'll just provide them with a sanitized version of the
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* passed flags.
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*/
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flags &= CACHE_CREATE_MASK;
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|
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/* Fail closed on bad usersize of useroffset values. */
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if (!IS_ENABLED(CONFIG_HARDENED_USERCOPY) ||
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WARN_ON(!usersize && useroffset) ||
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WARN_ON(size < usersize || size - usersize < useroffset))
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usersize = useroffset = 0;
|
|
|
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if (!usersize)
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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);
|
|
if (!cache_name) {
|
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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)) {
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err = PTR_ERR(s);
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kfree_const(cache_name);
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}
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|
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out_unlock:
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mutex_unlock(&slab_mutex);
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|
|
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if (err) {
|
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if (flags & SLAB_PANIC)
|
|
panic("%s: Failed to create slab '%s'. Error %d\n",
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__func__, name, err);
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else {
|
|
pr_warn("%s(%s) failed with error %d\n",
|
|
__func__, name, err);
|
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dump_stack();
|
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}
|
|
return NULL;
|
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}
|
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return s;
|
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}
|
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EXPORT_SYMBOL(kmem_cache_create_usercopy);
|
|
|
|
/**
|
|
* kmem_cache_create - Create a cache.
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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
|
|
* @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.
|
|
*/
|
|
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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{
|
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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);
|
|
|
|
#ifdef SLAB_SUPPORTS_SYSFS
|
|
/*
|
|
* For a given kmem_cache, kmem_cache_destroy() should only be called
|
|
* once or there will be a use-after-free problem. The actual deletion
|
|
* and release of the kobject does not need slab_mutex or cpu_hotplug_lock
|
|
* protection. So they are now done without holding those locks.
|
|
*
|
|
* Note that there will be a slight delay in the deletion of sysfs files
|
|
* if kmem_cache_release() is called indrectly from a work function.
|
|
*/
|
|
static void kmem_cache_release(struct kmem_cache *s)
|
|
{
|
|
sysfs_slab_unlink(s);
|
|
sysfs_slab_release(s);
|
|
}
|
|
#else
|
|
static void kmem_cache_release(struct kmem_cache *s)
|
|
{
|
|
slab_kmem_cache_release(s);
|
|
}
|
|
#endif
|
|
|
|
static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
|
|
{
|
|
LIST_HEAD(to_destroy);
|
|
struct kmem_cache *s, *s2;
|
|
|
|
/*
|
|
* On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the
|
|
* @slab_caches_to_rcu_destroy list. The slab pages are freed
|
|
* through RCU and the associated kmem_cache are dereferenced
|
|
* while freeing the pages, so the kmem_caches should be freed only
|
|
* after the pending RCU operations are finished. As rcu_barrier()
|
|
* is a pretty slow operation, we batch all pending destructions
|
|
* asynchronously.
|
|
*/
|
|
mutex_lock(&slab_mutex);
|
|
list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy);
|
|
mutex_unlock(&slab_mutex);
|
|
|
|
if (list_empty(&to_destroy))
|
|
return;
|
|
|
|
rcu_barrier();
|
|
|
|
list_for_each_entry_safe(s, s2, &to_destroy, list) {
|
|
debugfs_slab_release(s);
|
|
kfence_shutdown_cache(s);
|
|
kmem_cache_release(s);
|
|
}
|
|
}
|
|
|
|
static int shutdown_cache(struct kmem_cache *s)
|
|
{
|
|
/* free asan quarantined objects */
|
|
kasan_cache_shutdown(s);
|
|
|
|
if (__kmem_cache_shutdown(s) != 0)
|
|
return -EBUSY;
|
|
|
|
list_del(&s->list);
|
|
|
|
if (s->flags & SLAB_TYPESAFE_BY_RCU) {
|
|
list_add_tail(&s->list, &slab_caches_to_rcu_destroy);
|
|
schedule_work(&slab_caches_to_rcu_destroy_work);
|
|
} else {
|
|
kfence_shutdown_cache(s);
|
|
debugfs_slab_release(s);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void slab_kmem_cache_release(struct kmem_cache *s)
|
|
{
|
|
__kmem_cache_release(s);
|
|
kfree_const(s->name);
|
|
kmem_cache_free(kmem_cache, s);
|
|
}
|
|
|
|
void kmem_cache_destroy(struct kmem_cache *s)
|
|
{
|
|
int refcnt;
|
|
bool rcu_set;
|
|
|
|
if (unlikely(!s) || !kasan_check_byte(s))
|
|
return;
|
|
|
|
cpus_read_lock();
|
|
mutex_lock(&slab_mutex);
|
|
|
|
rcu_set = s->flags & SLAB_TYPESAFE_BY_RCU;
|
|
|
|
refcnt = --s->refcount;
|
|
if (refcnt)
|
|
goto out_unlock;
|
|
|
|
WARN(shutdown_cache(s),
|
|
"%s %s: Slab cache still has objects when called from %pS",
|
|
__func__, s->name, (void *)_RET_IP_);
|
|
out_unlock:
|
|
mutex_unlock(&slab_mutex);
|
|
cpus_read_unlock();
|
|
if (!refcnt && !rcu_set)
|
|
kmem_cache_release(s);
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_destroy);
|
|
|
|
/**
|
|
* kmem_cache_shrink - Shrink a cache.
|
|
* @cachep: The cache to shrink.
|
|
*
|
|
* Releases as many slabs as possible for a cache.
|
|
* To help debugging, a zero exit status indicates all slabs were released.
|
|
*
|
|
* Return: %0 if all slabs were released, non-zero otherwise
|
|
*/
|
|
int kmem_cache_shrink(struct kmem_cache *cachep)
|
|
{
|
|
kasan_cache_shrink(cachep);
|
|
|
|
return __kmem_cache_shrink(cachep);
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_shrink);
|
|
|
|
bool slab_is_available(void)
|
|
{
|
|
return slab_state >= UP;
|
|
}
|
|
|
|
#ifdef CONFIG_PRINTK
|
|
/**
|
|
* kmem_valid_obj - does the pointer reference a valid slab object?
|
|
* @object: pointer to query.
|
|
*
|
|
* Return: %true if the pointer is to a not-yet-freed object from
|
|
* kmalloc() or kmem_cache_alloc(), either %true or %false if the pointer
|
|
* is to an already-freed object, and %false otherwise.
|
|
*/
|
|
bool kmem_valid_obj(void *object)
|
|
{
|
|
struct folio *folio;
|
|
|
|
/* Some arches consider ZERO_SIZE_PTR to be a valid address. */
|
|
if (object < (void *)PAGE_SIZE || !virt_addr_valid(object))
|
|
return false;
|
|
folio = virt_to_folio(object);
|
|
return folio_test_slab(folio);
|
|
}
|
|
EXPORT_SYMBOL_GPL(kmem_valid_obj);
|
|
|
|
static void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
|
|
{
|
|
if (__kfence_obj_info(kpp, object, slab))
|
|
return;
|
|
__kmem_obj_info(kpp, object, slab);
|
|
}
|
|
|
|
/**
|
|
* kmem_dump_obj - Print available slab provenance information
|
|
* @object: slab object for which to find provenance information.
|
|
*
|
|
* This function uses pr_cont(), so that the caller is expected to have
|
|
* printed out whatever preamble is appropriate. The provenance information
|
|
* depends on the type of object and on how much debugging is enabled.
|
|
* For a slab-cache object, the fact that it is a slab object is printed,
|
|
* and, if available, the slab name, return address, and stack trace from
|
|
* the allocation and last free path of that object.
|
|
*
|
|
* This function will splat if passed a pointer to a non-slab object.
|
|
* If you are not sure what type of object you have, you should instead
|
|
* use mem_dump_obj().
|
|
*/
|
|
void kmem_dump_obj(void *object)
|
|
{
|
|
char *cp = IS_ENABLED(CONFIG_MMU) ? "" : "/vmalloc";
|
|
int i;
|
|
struct slab *slab;
|
|
unsigned long ptroffset;
|
|
struct kmem_obj_info kp = { };
|
|
|
|
if (WARN_ON_ONCE(!virt_addr_valid(object)))
|
|
return;
|
|
slab = virt_to_slab(object);
|
|
if (WARN_ON_ONCE(!slab)) {
|
|
pr_cont(" non-slab memory.\n");
|
|
return;
|
|
}
|
|
kmem_obj_info(&kp, object, slab);
|
|
if (kp.kp_slab_cache)
|
|
pr_cont(" slab%s %s", cp, kp.kp_slab_cache->name);
|
|
else
|
|
pr_cont(" slab%s", cp);
|
|
if (is_kfence_address(object))
|
|
pr_cont(" (kfence)");
|
|
if (kp.kp_objp)
|
|
pr_cont(" start %px", kp.kp_objp);
|
|
if (kp.kp_data_offset)
|
|
pr_cont(" data offset %lu", kp.kp_data_offset);
|
|
if (kp.kp_objp) {
|
|
ptroffset = ((char *)object - (char *)kp.kp_objp) - kp.kp_data_offset;
|
|
pr_cont(" pointer offset %lu", ptroffset);
|
|
}
|
|
if (kp.kp_slab_cache && kp.kp_slab_cache->object_size)
|
|
pr_cont(" size %u", kp.kp_slab_cache->object_size);
|
|
if (kp.kp_ret)
|
|
pr_cont(" allocated at %pS\n", kp.kp_ret);
|
|
else
|
|
pr_cont("\n");
|
|
for (i = 0; i < ARRAY_SIZE(kp.kp_stack); i++) {
|
|
if (!kp.kp_stack[i])
|
|
break;
|
|
pr_info(" %pS\n", kp.kp_stack[i]);
|
|
}
|
|
|
|
if (kp.kp_free_stack[0])
|
|
pr_cont(" Free path:\n");
|
|
|
|
for (i = 0; i < ARRAY_SIZE(kp.kp_free_stack); i++) {
|
|
if (!kp.kp_free_stack[i])
|
|
break;
|
|
pr_info(" %pS\n", kp.kp_free_stack[i]);
|
|
}
|
|
|
|
}
|
|
EXPORT_SYMBOL_GPL(kmem_dump_obj);
|
|
#endif
|
|
|
|
/* Create a cache during boot when no slab services are available yet */
|
|
void __init create_boot_cache(struct kmem_cache *s, const char *name,
|
|
unsigned int size, slab_flags_t flags,
|
|
unsigned int useroffset, unsigned int usersize)
|
|
{
|
|
int err;
|
|
unsigned int align = ARCH_KMALLOC_MINALIGN;
|
|
|
|
s->name = name;
|
|
s->size = s->object_size = size;
|
|
|
|
/*
|
|
* 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);
|
|
|
|
#ifdef CONFIG_HARDENED_USERCOPY
|
|
s->useroffset = useroffset;
|
|
s->usersize = usersize;
|
|
#endif
|
|
|
|
err = __kmem_cache_create(s, flags);
|
|
|
|
if (err)
|
|
panic("Creation of kmalloc slab %s size=%u failed. Reason %d\n",
|
|
name, size, err);
|
|
|
|
s->refcount = -1; /* Exempt from merging for now */
|
|
}
|
|
|
|
static struct kmem_cache *__init create_kmalloc_cache(const char *name,
|
|
unsigned int size,
|
|
slab_flags_t flags)
|
|
{
|
|
struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
|
|
|
|
if (!s)
|
|
panic("Out of memory when creating slab %s\n", name);
|
|
|
|
create_boot_cache(s, name, size, flags | SLAB_KMALLOC, 0, size);
|
|
list_add(&s->list, &slab_caches);
|
|
s->refcount = 1;
|
|
return s;
|
|
}
|
|
|
|
struct kmem_cache *
|
|
kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1] __ro_after_init =
|
|
{ /* initialization for https://bugs.llvm.org/show_bug.cgi?id=42570 */ };
|
|
EXPORT_SYMBOL(kmalloc_caches);
|
|
|
|
/*
|
|
* Conversion table for small slabs sizes / 8 to the index in the
|
|
* kmalloc array. This is necessary for slabs < 192 since we have non power
|
|
* of two cache sizes there. The size of larger slabs can be determined using
|
|
* fls.
|
|
*/
|
|
static u8 size_index[24] __ro_after_init = {
|
|
3, /* 8 */
|
|
4, /* 16 */
|
|
5, /* 24 */
|
|
5, /* 32 */
|
|
6, /* 40 */
|
|
6, /* 48 */
|
|
6, /* 56 */
|
|
6, /* 64 */
|
|
1, /* 72 */
|
|
1, /* 80 */
|
|
1, /* 88 */
|
|
1, /* 96 */
|
|
7, /* 104 */
|
|
7, /* 112 */
|
|
7, /* 120 */
|
|
7, /* 128 */
|
|
2, /* 136 */
|
|
2, /* 144 */
|
|
2, /* 152 */
|
|
2, /* 160 */
|
|
2, /* 168 */
|
|
2, /* 176 */
|
|
2, /* 184 */
|
|
2 /* 192 */
|
|
};
|
|
|
|
static inline unsigned int size_index_elem(unsigned int bytes)
|
|
{
|
|
return (bytes - 1) / 8;
|
|
}
|
|
|
|
/*
|
|
* Find the kmem_cache structure that serves a given size of
|
|
* allocation
|
|
*/
|
|
struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
|
|
{
|
|
unsigned int index;
|
|
|
|
if (size <= 192) {
|
|
if (!size)
|
|
return ZERO_SIZE_PTR;
|
|
|
|
index = size_index[size_index_elem(size)];
|
|
} else {
|
|
if (WARN_ON_ONCE(size > KMALLOC_MAX_CACHE_SIZE))
|
|
return NULL;
|
|
index = fls(size - 1);
|
|
}
|
|
|
|
return kmalloc_caches[kmalloc_type(flags)][index];
|
|
}
|
|
|
|
size_t kmalloc_size_roundup(size_t size)
|
|
{
|
|
struct kmem_cache *c;
|
|
|
|
/* Short-circuit the 0 size case. */
|
|
if (unlikely(size == 0))
|
|
return 0;
|
|
/* Short-circuit saturated "too-large" case. */
|
|
if (unlikely(size == SIZE_MAX))
|
|
return SIZE_MAX;
|
|
/* Above the smaller buckets, size is a multiple of page size. */
|
|
if (size > KMALLOC_MAX_CACHE_SIZE)
|
|
return PAGE_SIZE << get_order(size);
|
|
|
|
/* The flags don't matter since size_index is common to all. */
|
|
c = kmalloc_slab(size, GFP_KERNEL);
|
|
return c ? c->object_size : 0;
|
|
}
|
|
EXPORT_SYMBOL(kmalloc_size_roundup);
|
|
|
|
#ifdef CONFIG_ZONE_DMA
|
|
#define KMALLOC_DMA_NAME(sz) .name[KMALLOC_DMA] = "dma-kmalloc-" #sz,
|
|
#else
|
|
#define KMALLOC_DMA_NAME(sz)
|
|
#endif
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
#define KMALLOC_CGROUP_NAME(sz) .name[KMALLOC_CGROUP] = "kmalloc-cg-" #sz,
|
|
#else
|
|
#define KMALLOC_CGROUP_NAME(sz)
|
|
#endif
|
|
|
|
#ifndef CONFIG_SLUB_TINY
|
|
#define KMALLOC_RCL_NAME(sz) .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #sz,
|
|
#else
|
|
#define KMALLOC_RCL_NAME(sz)
|
|
#endif
|
|
|
|
#define INIT_KMALLOC_INFO(__size, __short_size) \
|
|
{ \
|
|
.name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \
|
|
KMALLOC_RCL_NAME(__short_size) \
|
|
KMALLOC_CGROUP_NAME(__short_size) \
|
|
KMALLOC_DMA_NAME(__short_size) \
|
|
.size = __size, \
|
|
}
|
|
|
|
/*
|
|
* kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time.
|
|
* kmalloc_index() supports up to 2^21=2MB, so the final entry of the table is
|
|
* kmalloc-2M.
|
|
*/
|
|
const struct kmalloc_info_struct kmalloc_info[] __initconst = {
|
|
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)
|
|
};
|
|
|
|
/*
|
|
* Patch up the size_index table if we have strange large alignment
|
|
* requirements for the kmalloc array. This is only the case for
|
|
* MIPS it seems. The standard arches will not generate any code here.
|
|
*
|
|
* Largest permitted alignment is 256 bytes due to the way we
|
|
* handle the index determination for the smaller caches.
|
|
*
|
|
* Make sure that nothing crazy happens if someone starts tinkering
|
|
* around with ARCH_KMALLOC_MINALIGN
|
|
*/
|
|
void __init setup_kmalloc_cache_index_table(void)
|
|
{
|
|
unsigned int i;
|
|
|
|
BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
|
|
!is_power_of_2(KMALLOC_MIN_SIZE));
|
|
|
|
for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
|
|
unsigned int elem = size_index_elem(i);
|
|
|
|
if (elem >= ARRAY_SIZE(size_index))
|
|
break;
|
|
size_index[elem] = KMALLOC_SHIFT_LOW;
|
|
}
|
|
|
|
if (KMALLOC_MIN_SIZE >= 64) {
|
|
/*
|
|
* The 96 byte sized cache is not used if the alignment
|
|
* is 64 byte.
|
|
*/
|
|
for (i = 64 + 8; i <= 96; i += 8)
|
|
size_index[size_index_elem(i)] = 7;
|
|
|
|
}
|
|
|
|
if (KMALLOC_MIN_SIZE >= 128) {
|
|
/*
|
|
* The 192 byte sized cache is not used if the alignment
|
|
* is 128 byte. Redirect kmalloc to use the 256 byte cache
|
|
* instead.
|
|
*/
|
|
for (i = 128 + 8; i <= 192; i += 8)
|
|
size_index[size_index_elem(i)] = 8;
|
|
}
|
|
}
|
|
|
|
static unsigned int __kmalloc_minalign(void)
|
|
{
|
|
#ifdef CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC
|
|
if (io_tlb_default_mem.nslabs)
|
|
return ARCH_KMALLOC_MINALIGN;
|
|
#endif
|
|
return dma_get_cache_alignment();
|
|
}
|
|
|
|
void __init
|
|
new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
|
|
{
|
|
unsigned int minalign = __kmalloc_minalign();
|
|
unsigned int aligned_size = kmalloc_info[idx].size;
|
|
int aligned_idx = idx;
|
|
|
|
if ((KMALLOC_RECLAIM != KMALLOC_NORMAL) && (type == KMALLOC_RECLAIM)) {
|
|
flags |= SLAB_RECLAIM_ACCOUNT;
|
|
} else if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_CGROUP)) {
|
|
if (mem_cgroup_kmem_disabled()) {
|
|
kmalloc_caches[type][idx] = kmalloc_caches[KMALLOC_NORMAL][idx];
|
|
return;
|
|
}
|
|
flags |= SLAB_ACCOUNT;
|
|
} else if (IS_ENABLED(CONFIG_ZONE_DMA) && (type == KMALLOC_DMA)) {
|
|
flags |= SLAB_CACHE_DMA;
|
|
}
|
|
|
|
/*
|
|
* If CONFIG_MEMCG_KMEM is enabled, disable cache merging for
|
|
* KMALLOC_NORMAL caches.
|
|
*/
|
|
if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_NORMAL))
|
|
flags |= SLAB_NO_MERGE;
|
|
|
|
if (minalign > ARCH_KMALLOC_MINALIGN) {
|
|
aligned_size = ALIGN(aligned_size, minalign);
|
|
aligned_idx = __kmalloc_index(aligned_size, false);
|
|
}
|
|
|
|
if (!kmalloc_caches[type][aligned_idx])
|
|
kmalloc_caches[type][aligned_idx] = create_kmalloc_cache(
|
|
kmalloc_info[aligned_idx].name[type],
|
|
aligned_size, flags);
|
|
if (idx != aligned_idx)
|
|
kmalloc_caches[type][idx] = kmalloc_caches[type][aligned_idx];
|
|
}
|
|
|
|
/*
|
|
* Create the kmalloc array. Some of the regular kmalloc arrays
|
|
* may already have been created because they were needed to
|
|
* enable allocations for slab creation.
|
|
*/
|
|
void __init create_kmalloc_caches(slab_flags_t flags)
|
|
{
|
|
int i;
|
|
enum kmalloc_cache_type type;
|
|
|
|
/*
|
|
* Including KMALLOC_CGROUP if CONFIG_MEMCG_KMEM defined
|
|
*/
|
|
for (type = KMALLOC_NORMAL; type < NR_KMALLOC_TYPES; type++) {
|
|
for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
|
|
if (!kmalloc_caches[type][i])
|
|
new_kmalloc_cache(i, type, flags);
|
|
|
|
/*
|
|
* Caches that are not of the two-to-the-power-of size.
|
|
* These have to be created immediately after the
|
|
* earlier power of two caches
|
|
*/
|
|
if (KMALLOC_MIN_SIZE <= 32 && 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);
|
|
}
|
|
}
|
|
|
|
/* Kmalloc array is now usable */
|
|
slab_state = UP;
|
|
}
|
|
|
|
void free_large_kmalloc(struct folio *folio, void *object)
|
|
{
|
|
unsigned int order = folio_order(folio);
|
|
|
|
if (WARN_ON_ONCE(order == 0))
|
|
pr_warn_once("object pointer: 0x%p\n", object);
|
|
|
|
kmemleak_free(object);
|
|
kasan_kfree_large(object);
|
|
kmsan_kfree_large(object);
|
|
|
|
mod_lruvec_page_state(folio_page(folio, 0), NR_SLAB_UNRECLAIMABLE_B,
|
|
-(PAGE_SIZE << order));
|
|
__free_pages(folio_page(folio, 0), order);
|
|
}
|
|
|
|
static void *__kmalloc_large_node(size_t size, gfp_t flags, int node);
|
|
static __always_inline
|
|
void *__do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller)
|
|
{
|
|
struct kmem_cache *s;
|
|
void *ret;
|
|
|
|
if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) {
|
|
ret = __kmalloc_large_node(size, flags, node);
|
|
trace_kmalloc(caller, ret, size,
|
|
PAGE_SIZE << get_order(size), flags, node);
|
|
return ret;
|
|
}
|
|
|
|
s = kmalloc_slab(size, flags);
|
|
|
|
if (unlikely(ZERO_OR_NULL_PTR(s)))
|
|
return s;
|
|
|
|
ret = __kmem_cache_alloc_node(s, flags, node, size, caller);
|
|
ret = kasan_kmalloc(s, ret, size, flags);
|
|
trace_kmalloc(caller, ret, size, s->size, flags, node);
|
|
return ret;
|
|
}
|
|
|
|
void *__kmalloc_node(size_t size, gfp_t flags, int node)
|
|
{
|
|
return __do_kmalloc_node(size, flags, node, _RET_IP_);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc_node);
|
|
|
|
void *__kmalloc(size_t size, gfp_t flags)
|
|
{
|
|
return __do_kmalloc_node(size, flags, NUMA_NO_NODE, _RET_IP_);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc);
|
|
|
|
void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
|
|
int node, unsigned long caller)
|
|
{
|
|
return __do_kmalloc_node(size, flags, node, caller);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc_node_track_caller);
|
|
|
|
/**
|
|
* kfree - free previously allocated memory
|
|
* @object: pointer returned by kmalloc() or kmem_cache_alloc()
|
|
*
|
|
* If @object is NULL, no operation is performed.
|
|
*/
|
|
void kfree(const void *object)
|
|
{
|
|
struct folio *folio;
|
|
struct slab *slab;
|
|
struct kmem_cache *s;
|
|
|
|
trace_kfree(_RET_IP_, object);
|
|
|
|
if (unlikely(ZERO_OR_NULL_PTR(object)))
|
|
return;
|
|
|
|
folio = virt_to_folio(object);
|
|
if (unlikely(!folio_test_slab(folio))) {
|
|
free_large_kmalloc(folio, (void *)object);
|
|
return;
|
|
}
|
|
|
|
slab = folio_slab(folio);
|
|
s = slab->slab_cache;
|
|
__kmem_cache_free(s, (void *)object, _RET_IP_);
|
|
}
|
|
EXPORT_SYMBOL(kfree);
|
|
|
|
/**
|
|
* __ksize -- Report full size of underlying allocation
|
|
* @object: pointer to the object
|
|
*
|
|
* This should only be used internally to query the true size of allocations.
|
|
* It is not meant to be a way to discover the usable size of an allocation
|
|
* after the fact. Instead, use kmalloc_size_roundup(). Using memory beyond
|
|
* the originally requested allocation size may trigger KASAN, UBSAN_BOUNDS,
|
|
* and/or FORTIFY_SOURCE.
|
|
*
|
|
* Return: size of the actual memory used by @object in bytes
|
|
*/
|
|
size_t __ksize(const void *object)
|
|
{
|
|
struct folio *folio;
|
|
|
|
if (unlikely(object == ZERO_SIZE_PTR))
|
|
return 0;
|
|
|
|
folio = virt_to_folio(object);
|
|
|
|
if (unlikely(!folio_test_slab(folio))) {
|
|
if (WARN_ON(folio_size(folio) <= KMALLOC_MAX_CACHE_SIZE))
|
|
return 0;
|
|
if (WARN_ON(object != folio_address(folio)))
|
|
return 0;
|
|
return folio_size(folio);
|
|
}
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
skip_orig_size_check(folio_slab(folio)->slab_cache, object);
|
|
#endif
|
|
|
|
return slab_ksize(folio_slab(folio)->slab_cache);
|
|
}
|
|
|
|
void *kmalloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
|
|
{
|
|
void *ret = __kmem_cache_alloc_node(s, gfpflags, NUMA_NO_NODE,
|
|
size, _RET_IP_);
|
|
|
|
trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags, NUMA_NO_NODE);
|
|
|
|
ret = kasan_kmalloc(s, ret, size, gfpflags);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmalloc_trace);
|
|
|
|
void *kmalloc_node_trace(struct kmem_cache *s, gfp_t gfpflags,
|
|
int node, size_t size)
|
|
{
|
|
void *ret = __kmem_cache_alloc_node(s, gfpflags, node, size, _RET_IP_);
|
|
|
|
trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags, node);
|
|
|
|
ret = kasan_kmalloc(s, ret, size, gfpflags);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmalloc_node_trace);
|
|
|
|
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!\n",
|
|
invalid_mask, &invalid_mask, flags, &flags);
|
|
dump_stack();
|
|
|
|
return flags;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
|
|
static void *__kmalloc_large_node(size_t size, gfp_t flags, int node)
|
|
{
|
|
struct page *page;
|
|
void *ptr = NULL;
|
|
unsigned int order = get_order(size);
|
|
|
|
if (unlikely(flags & GFP_SLAB_BUG_MASK))
|
|
flags = kmalloc_fix_flags(flags);
|
|
|
|
flags |= __GFP_COMP;
|
|
page = alloc_pages_node(node, flags, order);
|
|
if (page) {
|
|
ptr = page_address(page);
|
|
mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE_B,
|
|
PAGE_SIZE << order);
|
|
}
|
|
|
|
ptr = kasan_kmalloc_large(ptr, size, flags);
|
|
/* As ptr might get tagged, call kmemleak hook after KASAN. */
|
|
kmemleak_alloc(ptr, size, 1, flags);
|
|
kmsan_kmalloc_large(ptr, size, flags);
|
|
|
|
return ptr;
|
|
}
|
|
|
|
void *kmalloc_large(size_t size, gfp_t flags)
|
|
{
|
|
void *ret = __kmalloc_large_node(size, flags, NUMA_NO_NODE);
|
|
|
|
trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << get_order(size),
|
|
flags, NUMA_NO_NODE);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmalloc_large);
|
|
|
|
void *kmalloc_large_node(size_t size, gfp_t flags, int node)
|
|
{
|
|
void *ret = __kmalloc_large_node(size, flags, node);
|
|
|
|
trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << get_order(size),
|
|
flags, node);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmalloc_large_node);
|
|
|
|
#ifdef CONFIG_SLAB_FREELIST_RANDOM
|
|
/* Randomize a generic freelist */
|
|
static void freelist_randomize(unsigned int *list,
|
|
unsigned int count)
|
|
{
|
|
unsigned int rand;
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < count; i++)
|
|
list[i] = i;
|
|
|
|
/* Fisher-Yates shuffle */
|
|
for (i = count - 1; i > 0; i--) {
|
|
rand = get_random_u32_below(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)
|
|
{
|
|
|
|
if (count < 2 || cachep->random_seq)
|
|
return 0;
|
|
|
|
cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp);
|
|
if (!cachep->random_seq)
|
|
return -ENOMEM;
|
|
|
|
freelist_randomize(cachep->random_seq, count);
|
|
return 0;
|
|
}
|
|
|
|
/* Destroy the per-cache random freelist sequence */
|
|
void cache_random_seq_destroy(struct kmem_cache *cachep)
|
|
{
|
|
kfree(cachep->random_seq);
|
|
cachep->random_seq = NULL;
|
|
}
|
|
#endif /* CONFIG_SLAB_FREELIST_RANDOM */
|
|
|
|
#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
|
|
#ifdef CONFIG_SLAB
|
|
#define SLABINFO_RIGHTS (0600)
|
|
#else
|
|
#define SLABINFO_RIGHTS (0400)
|
|
#endif
|
|
|
|
static void print_slabinfo_header(struct seq_file *m)
|
|
{
|
|
/*
|
|
* Output format version, so at least we can change it
|
|
* without _too_ many complaints.
|
|
*/
|
|
#ifdef CONFIG_DEBUG_SLAB
|
|
seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
|
|
#else
|
|
seq_puts(m, "slabinfo - version: 2.1\n");
|
|
#endif
|
|
seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>");
|
|
seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
|
|
seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
|
|
#ifdef CONFIG_DEBUG_SLAB
|
|
seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
|
|
seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
|
|
#endif
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
static void *slab_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
mutex_lock(&slab_mutex);
|
|
return seq_list_start(&slab_caches, *pos);
|
|
}
|
|
|
|
static void *slab_next(struct seq_file *m, void *p, loff_t *pos)
|
|
{
|
|
return seq_list_next(p, &slab_caches, pos);
|
|
}
|
|
|
|
static void slab_stop(struct seq_file *m, void *p)
|
|
{
|
|
mutex_unlock(&slab_mutex);
|
|
}
|
|
|
|
static void cache_show(struct kmem_cache *s, struct seq_file *m)
|
|
{
|
|
struct slabinfo sinfo;
|
|
|
|
memset(&sinfo, 0, sizeof(sinfo));
|
|
get_slabinfo(s, &sinfo);
|
|
|
|
seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
|
|
s->name, sinfo.active_objs, sinfo.num_objs, s->size,
|
|
sinfo.objects_per_slab, (1 << sinfo.cache_order));
|
|
|
|
seq_printf(m, " : tunables %4u %4u %4u",
|
|
sinfo.limit, sinfo.batchcount, sinfo.shared);
|
|
seq_printf(m, " : slabdata %6lu %6lu %6lu",
|
|
sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
|
|
slabinfo_show_stats(m, s);
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
static int slab_show(struct seq_file *m, void *p)
|
|
{
|
|
struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
|
|
|
|
if (p == slab_caches.next)
|
|
print_slabinfo_header(m);
|
|
cache_show(s, m);
|
|
return 0;
|
|
}
|
|
|
|
void dump_unreclaimable_slab(void)
|
|
{
|
|
struct kmem_cache *s;
|
|
struct slabinfo sinfo;
|
|
|
|
/*
|
|
* Here acquiring slab_mutex is risky since we don't prefer to get
|
|
* sleep in oom path. But, without mutex hold, it may introduce a
|
|
* risk of crash.
|
|
* Use mutex_trylock to protect the list traverse, dump nothing
|
|
* without acquiring the mutex.
|
|
*/
|
|
if (!mutex_trylock(&slab_mutex)) {
|
|
pr_warn("excessive unreclaimable slab but cannot dump stats\n");
|
|
return;
|
|
}
|
|
|
|
pr_info("Unreclaimable slab info:\n");
|
|
pr_info("Name Used Total\n");
|
|
|
|
list_for_each_entry(s, &slab_caches, list) {
|
|
if (s->flags & SLAB_RECLAIM_ACCOUNT)
|
|
continue;
|
|
|
|
get_slabinfo(s, &sinfo);
|
|
|
|
if (sinfo.num_objs > 0)
|
|
pr_info("%-17s %10luKB %10luKB\n", s->name,
|
|
(sinfo.active_objs * s->size) / 1024,
|
|
(sinfo.num_objs * s->size) / 1024);
|
|
}
|
|
mutex_unlock(&slab_mutex);
|
|
}
|
|
|
|
/*
|
|
* slabinfo_op - iterator that generates /proc/slabinfo
|
|
*
|
|
* Output layout:
|
|
* cache-name
|
|
* num-active-objs
|
|
* total-objs
|
|
* object size
|
|
* num-active-slabs
|
|
* total-slabs
|
|
* num-pages-per-slab
|
|
* + further values on SMP and with statistics enabled
|
|
*/
|
|
static const struct seq_operations slabinfo_op = {
|
|
.start = slab_start,
|
|
.next = slab_next,
|
|
.stop = slab_stop,
|
|
.show = slab_show,
|
|
};
|
|
|
|
static int slabinfo_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &slabinfo_op);
|
|
}
|
|
|
|
static const struct proc_ops slabinfo_proc_ops = {
|
|
.proc_flags = PROC_ENTRY_PERMANENT,
|
|
.proc_open = slabinfo_open,
|
|
.proc_read = seq_read,
|
|
.proc_write = slabinfo_write,
|
|
.proc_lseek = seq_lseek,
|
|
.proc_release = seq_release,
|
|
};
|
|
|
|
static int __init slab_proc_init(void)
|
|
{
|
|
proc_create("slabinfo", SLABINFO_RIGHTS, NULL, &slabinfo_proc_ops);
|
|
return 0;
|
|
}
|
|
module_init(slab_proc_init);
|
|
|
|
#endif /* CONFIG_SLAB || CONFIG_SLUB_DEBUG */
|
|
|
|
static __always_inline __realloc_size(2) void *
|
|
__do_krealloc(const void *p, size_t new_size, gfp_t flags)
|
|
{
|
|
void *ret;
|
|
size_t ks;
|
|
|
|
/* Check for double-free before calling ksize. */
|
|
if (likely(!ZERO_OR_NULL_PTR(p))) {
|
|
if (!kasan_check_byte(p))
|
|
return NULL;
|
|
ks = ksize(p);
|
|
} else
|
|
ks = 0;
|
|
|
|
/* If the object still fits, repoison it precisely. */
|
|
if (ks >= new_size) {
|
|
p = kasan_krealloc((void *)p, new_size, flags);
|
|
return (void *)p;
|
|
}
|
|
|
|
ret = kmalloc_track_caller(new_size, flags);
|
|
if (ret && p) {
|
|
/* Disable KASAN checks as the object's redzone is accessed. */
|
|
kasan_disable_current();
|
|
memcpy(ret, kasan_reset_tag(p), ks);
|
|
kasan_enable_current();
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* 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 (__GFP_ZERO flag is effectively ignored).
|
|
* 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.
|
|
*
|
|
* Return: pointer to the allocated memory or %NULL in case of error
|
|
*/
|
|
void *krealloc(const void *p, size_t new_size, gfp_t flags)
|
|
{
|
|
void *ret;
|
|
|
|
if (unlikely(!new_size)) {
|
|
kfree(p);
|
|
return ZERO_SIZE_PTR;
|
|
}
|
|
|
|
ret = __do_krealloc(p, new_size, flags);
|
|
if (ret && kasan_reset_tag(p) != kasan_reset_tag(ret))
|
|
kfree(p);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(krealloc);
|
|
|
|
/**
|
|
* kfree_sensitive - Clear sensitive information in memory before freeing
|
|
* @p: object to free memory of
|
|
*
|
|
* The memory of the object @p points to is zeroed before freed.
|
|
* If @p is %NULL, kfree_sensitive() does nothing.
|
|
*
|
|
* Note: this function zeroes the whole allocated buffer which can be a good
|
|
* deal bigger than the requested buffer size passed to kmalloc(). So be
|
|
* careful when using this function in performance sensitive code.
|
|
*/
|
|
void kfree_sensitive(const void *p)
|
|
{
|
|
size_t ks;
|
|
void *mem = (void *)p;
|
|
|
|
ks = ksize(mem);
|
|
if (ks) {
|
|
kasan_unpoison_range(mem, ks);
|
|
memzero_explicit(mem, ks);
|
|
}
|
|
kfree(mem);
|
|
}
|
|
EXPORT_SYMBOL(kfree_sensitive);
|
|
|
|
size_t ksize(const void *objp)
|
|
{
|
|
/*
|
|
* We need to first check that the pointer to the object is valid.
|
|
* The KASAN report printed from ksize() is more useful, then when
|
|
* it's printed later when the behaviour could be undefined due to
|
|
* a potential use-after-free or double-free.
|
|
*
|
|
* We use kasan_check_byte(), which is supported for the hardware
|
|
* tag-based KASAN mode, unlike kasan_check_read/write().
|
|
*
|
|
* 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.
|
|
*/
|
|
if (unlikely(ZERO_OR_NULL_PTR(objp)) || !kasan_check_byte(objp))
|
|
return 0;
|
|
|
|
return kfence_ksize(objp) ?: __ksize(objp);
|
|
}
|
|
EXPORT_SYMBOL(ksize);
|
|
|
|
/* Tracepoints definitions. */
|
|
EXPORT_TRACEPOINT_SYMBOL(kmalloc);
|
|
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
|
|
EXPORT_TRACEPOINT_SYMBOL(kfree);
|
|
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);
|
|
|
|
int should_failslab(struct kmem_cache *s, gfp_t gfpflags)
|
|
{
|
|
if (__should_failslab(s, gfpflags))
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
ALLOW_ERROR_INJECTION(should_failslab, ERRNO);
|