3521 lines
81 KiB
C
3521 lines
81 KiB
C
/*
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* SLUB: A slab allocator that limits cache line use instead of queuing
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* objects in per cpu and per node lists.
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*
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* The allocator synchronizes using per slab locks and only
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* uses a centralized lock to manage a pool of partial slabs.
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*
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* (C) 2007 SGI, Christoph Lameter <clameter@sgi.com>
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*/
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/bit_spinlock.h>
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#include <linux/interrupt.h>
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#include <linux/bitops.h>
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#include <linux/slab.h>
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#include <linux/seq_file.h>
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#include <linux/cpu.h>
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#include <linux/cpuset.h>
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#include <linux/mempolicy.h>
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#include <linux/ctype.h>
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#include <linux/kallsyms.h>
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/*
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* Lock order:
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* 1. slab_lock(page)
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* 2. slab->list_lock
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*
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* The slab_lock protects operations on the object of a particular
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* slab and its metadata in the page struct. If the slab lock
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* has been taken then no allocations nor frees can be performed
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* on the objects in the slab nor can the slab be added or removed
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* from the partial or full lists since this would mean modifying
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* the page_struct of the slab.
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*
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* The list_lock protects the partial and full list on each node and
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* the partial slab counter. If taken then no new slabs may be added or
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* removed from the lists nor make the number of partial slabs be modified.
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* (Note that the total number of slabs is an atomic value that may be
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* modified without taking the list lock).
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*
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* The list_lock is a centralized lock and thus we avoid taking it as
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* much as possible. As long as SLUB does not have to handle partial
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* slabs, operations can continue without any centralized lock. F.e.
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* allocating a long series of objects that fill up slabs does not require
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* the list lock.
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*
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* The lock order is sometimes inverted when we are trying to get a slab
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* off a list. We take the list_lock and then look for a page on the list
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* to use. While we do that objects in the slabs may be freed. We can
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* only operate on the slab if we have also taken the slab_lock. So we use
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* a slab_trylock() on the slab. If trylock was successful then no frees
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* can occur anymore and we can use the slab for allocations etc. If the
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* slab_trylock() does not succeed then frees are in progress in the slab and
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* we must stay away from it for a while since we may cause a bouncing
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* cacheline if we try to acquire the lock. So go onto the next slab.
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* If all pages are busy then we may allocate a new slab instead of reusing
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* a partial slab. A new slab has noone operating on it and thus there is
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* no danger of cacheline contention.
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*
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* Interrupts are disabled during allocation and deallocation in order to
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* make the slab allocator safe to use in the context of an irq. In addition
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* interrupts are disabled to ensure that the processor does not change
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* while handling per_cpu slabs, due to kernel preemption.
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*
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* SLUB assigns one slab for allocation to each processor.
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* Allocations only occur from these slabs called cpu slabs.
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*
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* Slabs with free elements are kept on a partial list.
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* There is no list for full slabs. If an object in a full slab is
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* freed then the slab will show up again on the partial lists.
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* Otherwise there is no need to track full slabs unless we have to
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* track full slabs for debugging purposes.
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*
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* Slabs are freed when they become empty. Teardown and setup is
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* minimal so we rely on the page allocators per cpu caches for
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* fast frees and allocs.
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*
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* Overloading of page flags that are otherwise used for LRU management.
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*
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* PageActive The slab is used as a cpu cache. Allocations
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* may be performed from the slab. The slab is not
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* on any slab list and cannot be moved onto one.
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*
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* PageError Slab requires special handling due to debug
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* options set. This moves slab handling out of
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* the fast path.
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*/
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/*
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* Issues still to be resolved:
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*
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* - The per cpu array is updated for each new slab and and is a remote
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* cacheline for most nodes. This could become a bouncing cacheline given
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* enough frequent updates. There are 16 pointers in a cacheline.so at
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* max 16 cpus could compete. Likely okay.
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*
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* - Support PAGE_ALLOC_DEBUG. Should be easy to do.
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*
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* - Variable sizing of the per node arrays
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*/
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/* Enable to test recovery from slab corruption on boot */
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#undef SLUB_RESILIENCY_TEST
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#if PAGE_SHIFT <= 12
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/*
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* Small page size. Make sure that we do not fragment memory
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*/
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#define DEFAULT_MAX_ORDER 1
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#define DEFAULT_MIN_OBJECTS 4
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#else
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/*
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* Large page machines are customarily able to handle larger
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* page orders.
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*/
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#define DEFAULT_MAX_ORDER 2
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#define DEFAULT_MIN_OBJECTS 8
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#endif
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/*
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* Mininum number of partial slabs. These will be left on the partial
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* lists even if they are empty. kmem_cache_shrink may reclaim them.
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*/
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#define MIN_PARTIAL 2
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/*
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* Maximum number of desirable partial slabs.
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* The existence of more partial slabs makes kmem_cache_shrink
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* sort the partial list by the number of objects in the.
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*/
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#define MAX_PARTIAL 10
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#define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
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SLAB_POISON | SLAB_STORE_USER)
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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 SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
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SLAB_TRACE | SLAB_DESTROY_BY_RCU)
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#define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
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SLAB_CACHE_DMA)
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#ifndef ARCH_KMALLOC_MINALIGN
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#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
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#endif
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#ifndef ARCH_SLAB_MINALIGN
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#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
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#endif
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/* Internal SLUB flags */
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#define __OBJECT_POISON 0x80000000 /* Poison object */
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static int kmem_size = sizeof(struct kmem_cache);
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#ifdef CONFIG_SMP
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static struct notifier_block slab_notifier;
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#endif
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static enum {
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DOWN, /* No slab functionality available */
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PARTIAL, /* kmem_cache_open() works but kmalloc does not */
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UP, /* Everything works */
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SYSFS /* Sysfs up */
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} slab_state = DOWN;
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/* A list of all slab caches on the system */
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static DECLARE_RWSEM(slub_lock);
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LIST_HEAD(slab_caches);
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#ifdef CONFIG_SYSFS
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static int sysfs_slab_add(struct kmem_cache *);
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static int sysfs_slab_alias(struct kmem_cache *, const char *);
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static void sysfs_slab_remove(struct kmem_cache *);
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#else
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static int sysfs_slab_add(struct kmem_cache *s) { return 0; }
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static int sysfs_slab_alias(struct kmem_cache *s, const char *p) { return 0; }
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static void sysfs_slab_remove(struct kmem_cache *s) {}
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#endif
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/********************************************************************
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* Core slab cache functions
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*******************************************************************/
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int slab_is_available(void)
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{
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return slab_state >= UP;
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}
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static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
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{
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#ifdef CONFIG_NUMA
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return s->node[node];
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#else
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return &s->local_node;
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#endif
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}
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/*
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* Object debugging
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*/
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static void print_section(char *text, u8 *addr, unsigned int length)
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{
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int i, offset;
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int newline = 1;
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char ascii[17];
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ascii[16] = 0;
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for (i = 0; i < length; i++) {
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if (newline) {
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printk(KERN_ERR "%10s 0x%p: ", text, addr + i);
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newline = 0;
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}
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printk(" %02x", addr[i]);
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offset = i % 16;
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ascii[offset] = isgraph(addr[i]) ? addr[i] : '.';
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if (offset == 15) {
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printk(" %s\n",ascii);
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newline = 1;
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}
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}
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if (!newline) {
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i %= 16;
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while (i < 16) {
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printk(" ");
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ascii[i] = ' ';
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i++;
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}
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printk(" %s\n", ascii);
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}
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}
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/*
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* Slow version of get and set free pointer.
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*
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* This requires touching the cache lines of kmem_cache.
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* The offset can also be obtained from the page. In that
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* case it is in the cacheline that we already need to touch.
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*/
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static void *get_freepointer(struct kmem_cache *s, void *object)
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{
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return *(void **)(object + s->offset);
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}
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static void set_freepointer(struct kmem_cache *s, void *object, void *fp)
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{
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*(void **)(object + s->offset) = fp;
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}
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/*
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* Tracking user of a slab.
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*/
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struct track {
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void *addr; /* Called from address */
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int cpu; /* Was running on cpu */
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int pid; /* Pid context */
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unsigned long when; /* When did the operation occur */
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};
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enum track_item { TRACK_ALLOC, TRACK_FREE };
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static struct track *get_track(struct kmem_cache *s, void *object,
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enum track_item alloc)
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{
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struct track *p;
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if (s->offset)
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p = object + s->offset + sizeof(void *);
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else
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p = object + s->inuse;
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return p + alloc;
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}
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static void set_track(struct kmem_cache *s, void *object,
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enum track_item alloc, void *addr)
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{
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struct track *p;
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if (s->offset)
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p = object + s->offset + sizeof(void *);
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else
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p = object + s->inuse;
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p += alloc;
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if (addr) {
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p->addr = addr;
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p->cpu = smp_processor_id();
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p->pid = current ? current->pid : -1;
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p->when = jiffies;
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} else
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memset(p, 0, sizeof(struct track));
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}
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static void init_tracking(struct kmem_cache *s, void *object)
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{
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if (s->flags & SLAB_STORE_USER) {
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set_track(s, object, TRACK_FREE, NULL);
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set_track(s, object, TRACK_ALLOC, NULL);
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}
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}
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static void print_track(const char *s, struct track *t)
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{
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if (!t->addr)
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return;
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printk(KERN_ERR "%s: ", s);
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__print_symbol("%s", (unsigned long)t->addr);
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printk(" jiffies_ago=%lu cpu=%u pid=%d\n", jiffies - t->when, t->cpu, t->pid);
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}
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static void print_trailer(struct kmem_cache *s, u8 *p)
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{
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unsigned int off; /* Offset of last byte */
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if (s->flags & SLAB_RED_ZONE)
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print_section("Redzone", p + s->objsize,
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s->inuse - s->objsize);
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printk(KERN_ERR "FreePointer 0x%p -> 0x%p\n",
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p + s->offset,
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get_freepointer(s, p));
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if (s->offset)
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off = s->offset + sizeof(void *);
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else
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off = s->inuse;
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if (s->flags & SLAB_STORE_USER) {
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print_track("Last alloc", get_track(s, p, TRACK_ALLOC));
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print_track("Last free ", get_track(s, p, TRACK_FREE));
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off += 2 * sizeof(struct track);
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}
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if (off != s->size)
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/* Beginning of the filler is the free pointer */
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print_section("Filler", p + off, s->size - off);
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}
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static void object_err(struct kmem_cache *s, struct page *page,
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u8 *object, char *reason)
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{
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u8 *addr = page_address(page);
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printk(KERN_ERR "*** SLUB %s: %s@0x%p slab 0x%p\n",
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s->name, reason, object, page);
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printk(KERN_ERR " offset=%tu flags=0x%04lx inuse=%u freelist=0x%p\n",
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object - addr, page->flags, page->inuse, page->freelist);
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if (object > addr + 16)
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print_section("Bytes b4", object - 16, 16);
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print_section("Object", object, min(s->objsize, 128));
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print_trailer(s, object);
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dump_stack();
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}
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static void slab_err(struct kmem_cache *s, struct page *page, char *reason, ...)
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{
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va_list args;
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char buf[100];
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va_start(args, reason);
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vsnprintf(buf, sizeof(buf), reason, args);
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va_end(args);
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printk(KERN_ERR "*** SLUB %s: %s in slab @0x%p\n", s->name, buf,
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page);
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dump_stack();
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}
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static void init_object(struct kmem_cache *s, void *object, int active)
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{
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u8 *p = object;
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if (s->flags & __OBJECT_POISON) {
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memset(p, POISON_FREE, s->objsize - 1);
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p[s->objsize -1] = POISON_END;
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}
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if (s->flags & SLAB_RED_ZONE)
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memset(p + s->objsize,
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active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE,
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s->inuse - s->objsize);
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}
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static int check_bytes(u8 *start, unsigned int value, unsigned int bytes)
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{
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while (bytes) {
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if (*start != (u8)value)
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return 0;
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start++;
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bytes--;
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}
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return 1;
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}
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static int check_valid_pointer(struct kmem_cache *s, struct page *page,
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void *object)
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{
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void *base;
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if (!object)
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return 1;
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base = page_address(page);
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if (object < base || object >= base + s->objects * s->size ||
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(object - base) % s->size) {
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return 0;
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}
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return 1;
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}
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/*
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* Object layout:
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*
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* object address
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* Bytes of the object to be managed.
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* If the freepointer may overlay the object then the free
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* pointer is the first word of the object.
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* Poisoning uses 0x6b (POISON_FREE) and the last byte is
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* 0xa5 (POISON_END)
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*
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* object + s->objsize
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* Padding to reach word boundary. This is also used for Redzoning.
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* Padding is extended to word size if Redzoning is enabled
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* and objsize == inuse.
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* We fill with 0xbb (RED_INACTIVE) for inactive objects and with
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* 0xcc (RED_ACTIVE) for objects in use.
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*
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* object + s->inuse
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* A. Free pointer (if we cannot overwrite object on free)
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* B. Tracking data for SLAB_STORE_USER
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* C. Padding to reach required alignment boundary
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* Padding is done using 0x5a (POISON_INUSE)
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*
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* object + s->size
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*
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* If slabcaches are merged then the objsize and inuse boundaries are to
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* be ignored. And therefore no slab options that rely on these boundaries
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* may be used with merged slabcaches.
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*/
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static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
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void *from, void *to)
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{
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printk(KERN_ERR "@@@ SLUB %s: Restoring %s (0x%x) from 0x%p-0x%p\n",
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s->name, message, data, from, to - 1);
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memset(from, data, to - from);
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}
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|
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static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p)
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{
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unsigned long off = s->inuse; /* The end of info */
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if (s->offset)
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/* Freepointer is placed after the object. */
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off += sizeof(void *);
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if (s->flags & SLAB_STORE_USER)
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/* We also have user information there */
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off += 2 * sizeof(struct track);
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if (s->size == off)
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return 1;
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|
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if (check_bytes(p + off, POISON_INUSE, s->size - off))
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return 1;
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object_err(s, page, p, "Object padding check fails");
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|
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/*
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* Restore padding
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*/
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restore_bytes(s, "object padding", POISON_INUSE, p + off, p + s->size);
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return 0;
|
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}
|
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|
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static int slab_pad_check(struct kmem_cache *s, struct page *page)
|
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{
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u8 *p;
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int length, remainder;
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|
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if (!(s->flags & SLAB_POISON))
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return 1;
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p = page_address(page);
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length = s->objects * s->size;
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remainder = (PAGE_SIZE << s->order) - length;
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if (!remainder)
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return 1;
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|
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if (!check_bytes(p + length, POISON_INUSE, remainder)) {
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slab_err(s, page, "Padding check failed");
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restore_bytes(s, "slab padding", POISON_INUSE, p + length,
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p + length + remainder);
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return 0;
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}
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return 1;
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}
|
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|
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static int check_object(struct kmem_cache *s, struct page *page,
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void *object, int active)
|
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{
|
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u8 *p = object;
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u8 *endobject = object + s->objsize;
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|
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if (s->flags & SLAB_RED_ZONE) {
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unsigned int red =
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active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE;
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|
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if (!check_bytes(endobject, red, s->inuse - s->objsize)) {
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object_err(s, page, object,
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active ? "Redzone Active" : "Redzone Inactive");
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restore_bytes(s, "redzone", red,
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endobject, object + s->inuse);
|
|
return 0;
|
|
}
|
|
} else {
|
|
if ((s->flags & SLAB_POISON) && s->objsize < s->inuse &&
|
|
!check_bytes(endobject, POISON_INUSE,
|
|
s->inuse - s->objsize)) {
|
|
object_err(s, page, p, "Alignment padding check fails");
|
|
/*
|
|
* Fix it so that there will not be another report.
|
|
*
|
|
* Hmmm... We may be corrupting an object that now expects
|
|
* to be longer than allowed.
|
|
*/
|
|
restore_bytes(s, "alignment padding", POISON_INUSE,
|
|
endobject, object + s->inuse);
|
|
}
|
|
}
|
|
|
|
if (s->flags & SLAB_POISON) {
|
|
if (!active && (s->flags & __OBJECT_POISON) &&
|
|
(!check_bytes(p, POISON_FREE, s->objsize - 1) ||
|
|
p[s->objsize - 1] != POISON_END)) {
|
|
|
|
object_err(s, page, p, "Poison check failed");
|
|
restore_bytes(s, "Poison", POISON_FREE,
|
|
p, p + s->objsize -1);
|
|
restore_bytes(s, "Poison", POISON_END,
|
|
p + s->objsize - 1, p + s->objsize);
|
|
return 0;
|
|
}
|
|
/*
|
|
* check_pad_bytes cleans up on its own.
|
|
*/
|
|
check_pad_bytes(s, page, p);
|
|
}
|
|
|
|
if (!s->offset && active)
|
|
/*
|
|
* Object and freepointer overlap. Cannot check
|
|
* freepointer while object is allocated.
|
|
*/
|
|
return 1;
|
|
|
|
/* Check free pointer validity */
|
|
if (!check_valid_pointer(s, page, get_freepointer(s, p))) {
|
|
object_err(s, page, p, "Freepointer corrupt");
|
|
/*
|
|
* No choice but to zap it and thus loose the remainder
|
|
* of the free objects in this slab. May cause
|
|
* another error because the object count maybe
|
|
* wrong now.
|
|
*/
|
|
set_freepointer(s, p, NULL);
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int check_slab(struct kmem_cache *s, struct page *page)
|
|
{
|
|
VM_BUG_ON(!irqs_disabled());
|
|
|
|
if (!PageSlab(page)) {
|
|
slab_err(s, page, "Not a valid slab page flags=%lx "
|
|
"mapping=0x%p count=%d", page->flags, page->mapping,
|
|
page_count(page));
|
|
return 0;
|
|
}
|
|
if (page->offset * sizeof(void *) != s->offset) {
|
|
slab_err(s, page, "Corrupted offset %lu flags=0x%lx "
|
|
"mapping=0x%p count=%d",
|
|
(unsigned long)(page->offset * sizeof(void *)),
|
|
page->flags,
|
|
page->mapping,
|
|
page_count(page));
|
|
return 0;
|
|
}
|
|
if (page->inuse > s->objects) {
|
|
slab_err(s, page, "inuse %u > max %u @0x%p flags=%lx "
|
|
"mapping=0x%p count=%d",
|
|
s->name, page->inuse, s->objects, page->flags,
|
|
page->mapping, page_count(page));
|
|
return 0;
|
|
}
|
|
/* Slab_pad_check fixes things up after itself */
|
|
slab_pad_check(s, page);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Determine if a certain object on a page is on the freelist and
|
|
* therefore free. Must hold the slab lock for cpu slabs to
|
|
* guarantee that the chains are consistent.
|
|
*/
|
|
static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
|
|
{
|
|
int nr = 0;
|
|
void *fp = page->freelist;
|
|
void *object = NULL;
|
|
|
|
while (fp && nr <= s->objects) {
|
|
if (fp == search)
|
|
return 1;
|
|
if (!check_valid_pointer(s, page, fp)) {
|
|
if (object) {
|
|
object_err(s, page, object,
|
|
"Freechain corrupt");
|
|
set_freepointer(s, object, NULL);
|
|
break;
|
|
} else {
|
|
slab_err(s, page, "Freepointer 0x%p corrupt",
|
|
fp);
|
|
page->freelist = NULL;
|
|
page->inuse = s->objects;
|
|
printk(KERN_ERR "@@@ SLUB %s: Freelist "
|
|
"cleared. Slab 0x%p\n",
|
|
s->name, page);
|
|
return 0;
|
|
}
|
|
break;
|
|
}
|
|
object = fp;
|
|
fp = get_freepointer(s, object);
|
|
nr++;
|
|
}
|
|
|
|
if (page->inuse != s->objects - nr) {
|
|
slab_err(s, page, "Wrong object count. Counter is %d but "
|
|
"counted were %d", s, page, page->inuse,
|
|
s->objects - nr);
|
|
page->inuse = s->objects - nr;
|
|
printk(KERN_ERR "@@@ SLUB %s: Object count adjusted. "
|
|
"Slab @0x%p\n", s->name, page);
|
|
}
|
|
return search == NULL;
|
|
}
|
|
|
|
/*
|
|
* Tracking of fully allocated slabs for debugging
|
|
*/
|
|
static void add_full(struct kmem_cache_node *n, struct page *page)
|
|
{
|
|
spin_lock(&n->list_lock);
|
|
list_add(&page->lru, &n->full);
|
|
spin_unlock(&n->list_lock);
|
|
}
|
|
|
|
static void remove_full(struct kmem_cache *s, struct page *page)
|
|
{
|
|
struct kmem_cache_node *n;
|
|
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
return;
|
|
|
|
n = get_node(s, page_to_nid(page));
|
|
|
|
spin_lock(&n->list_lock);
|
|
list_del(&page->lru);
|
|
spin_unlock(&n->list_lock);
|
|
}
|
|
|
|
static int alloc_object_checks(struct kmem_cache *s, struct page *page,
|
|
void *object)
|
|
{
|
|
if (!check_slab(s, page))
|
|
goto bad;
|
|
|
|
if (object && !on_freelist(s, page, object)) {
|
|
slab_err(s, page, "Object 0x%p already allocated", object);
|
|
goto bad;
|
|
}
|
|
|
|
if (!check_valid_pointer(s, page, object)) {
|
|
object_err(s, page, object, "Freelist Pointer check fails");
|
|
goto bad;
|
|
}
|
|
|
|
if (!object)
|
|
return 1;
|
|
|
|
if (!check_object(s, page, object, 0))
|
|
goto bad;
|
|
|
|
return 1;
|
|
bad:
|
|
if (PageSlab(page)) {
|
|
/*
|
|
* If this is a slab page then lets do the best we can
|
|
* to avoid issues in the future. Marking all objects
|
|
* as used avoids touching the remainder.
|
|
*/
|
|
printk(KERN_ERR "@@@ SLUB: %s slab 0x%p. Marking all objects used.\n",
|
|
s->name, page);
|
|
page->inuse = s->objects;
|
|
page->freelist = NULL;
|
|
/* Fix up fields that may be corrupted */
|
|
page->offset = s->offset / sizeof(void *);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int free_object_checks(struct kmem_cache *s, struct page *page,
|
|
void *object)
|
|
{
|
|
if (!check_slab(s, page))
|
|
goto fail;
|
|
|
|
if (!check_valid_pointer(s, page, object)) {
|
|
slab_err(s, page, "Invalid object pointer 0x%p", object);
|
|
goto fail;
|
|
}
|
|
|
|
if (on_freelist(s, page, object)) {
|
|
slab_err(s, page, "Object 0x%p already free", object);
|
|
goto fail;
|
|
}
|
|
|
|
if (!check_object(s, page, object, 1))
|
|
return 0;
|
|
|
|
if (unlikely(s != page->slab)) {
|
|
if (!PageSlab(page))
|
|
slab_err(s, page, "Attempt to free object(0x%p) "
|
|
"outside of slab", object);
|
|
else
|
|
if (!page->slab) {
|
|
printk(KERN_ERR
|
|
"SLUB <none>: no slab for object 0x%p.\n",
|
|
object);
|
|
dump_stack();
|
|
}
|
|
else
|
|
slab_err(s, page, "object at 0x%p belongs "
|
|
"to slab %s", object, page->slab->name);
|
|
goto fail;
|
|
}
|
|
return 1;
|
|
fail:
|
|
printk(KERN_ERR "@@@ SLUB: %s slab 0x%p object at 0x%p not freed.\n",
|
|
s->name, page, object);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Slab allocation and freeing
|
|
*/
|
|
static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
|
|
{
|
|
struct page * page;
|
|
int pages = 1 << s->order;
|
|
|
|
if (s->order)
|
|
flags |= __GFP_COMP;
|
|
|
|
if (s->flags & SLAB_CACHE_DMA)
|
|
flags |= SLUB_DMA;
|
|
|
|
if (node == -1)
|
|
page = alloc_pages(flags, s->order);
|
|
else
|
|
page = alloc_pages_node(node, flags, s->order);
|
|
|
|
if (!page)
|
|
return NULL;
|
|
|
|
mod_zone_page_state(page_zone(page),
|
|
(s->flags & SLAB_RECLAIM_ACCOUNT) ?
|
|
NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
|
|
pages);
|
|
|
|
return page;
|
|
}
|
|
|
|
static void setup_object(struct kmem_cache *s, struct page *page,
|
|
void *object)
|
|
{
|
|
if (PageError(page)) {
|
|
init_object(s, object, 0);
|
|
init_tracking(s, object);
|
|
}
|
|
|
|
if (unlikely(s->ctor))
|
|
s->ctor(object, s, SLAB_CTOR_CONSTRUCTOR);
|
|
}
|
|
|
|
static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
|
|
{
|
|
struct page *page;
|
|
struct kmem_cache_node *n;
|
|
void *start;
|
|
void *end;
|
|
void *last;
|
|
void *p;
|
|
|
|
BUG_ON(flags & ~(GFP_DMA | GFP_LEVEL_MASK));
|
|
|
|
if (flags & __GFP_WAIT)
|
|
local_irq_enable();
|
|
|
|
page = allocate_slab(s, flags & GFP_LEVEL_MASK, node);
|
|
if (!page)
|
|
goto out;
|
|
|
|
n = get_node(s, page_to_nid(page));
|
|
if (n)
|
|
atomic_long_inc(&n->nr_slabs);
|
|
page->offset = s->offset / sizeof(void *);
|
|
page->slab = s;
|
|
page->flags |= 1 << PG_slab;
|
|
if (s->flags & (SLAB_DEBUG_FREE | SLAB_RED_ZONE | SLAB_POISON |
|
|
SLAB_STORE_USER | SLAB_TRACE))
|
|
page->flags |= 1 << PG_error;
|
|
|
|
start = page_address(page);
|
|
end = start + s->objects * s->size;
|
|
|
|
if (unlikely(s->flags & SLAB_POISON))
|
|
memset(start, POISON_INUSE, PAGE_SIZE << s->order);
|
|
|
|
last = start;
|
|
for (p = start + s->size; p < end; p += s->size) {
|
|
setup_object(s, page, last);
|
|
set_freepointer(s, last, p);
|
|
last = p;
|
|
}
|
|
setup_object(s, page, last);
|
|
set_freepointer(s, last, NULL);
|
|
|
|
page->freelist = start;
|
|
page->inuse = 0;
|
|
out:
|
|
if (flags & __GFP_WAIT)
|
|
local_irq_disable();
|
|
return page;
|
|
}
|
|
|
|
static void __free_slab(struct kmem_cache *s, struct page *page)
|
|
{
|
|
int pages = 1 << s->order;
|
|
|
|
if (unlikely(PageError(page) || s->dtor)) {
|
|
void *start = page_address(page);
|
|
void *end = start + (pages << PAGE_SHIFT);
|
|
void *p;
|
|
|
|
slab_pad_check(s, page);
|
|
for (p = start; p <= end - s->size; p += s->size) {
|
|
if (s->dtor)
|
|
s->dtor(p, s, 0);
|
|
check_object(s, page, p, 0);
|
|
}
|
|
}
|
|
|
|
mod_zone_page_state(page_zone(page),
|
|
(s->flags & SLAB_RECLAIM_ACCOUNT) ?
|
|
NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
|
|
- pages);
|
|
|
|
page->mapping = NULL;
|
|
__free_pages(page, s->order);
|
|
}
|
|
|
|
static void rcu_free_slab(struct rcu_head *h)
|
|
{
|
|
struct page *page;
|
|
|
|
page = container_of((struct list_head *)h, struct page, lru);
|
|
__free_slab(page->slab, page);
|
|
}
|
|
|
|
static void free_slab(struct kmem_cache *s, struct page *page)
|
|
{
|
|
if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) {
|
|
/*
|
|
* RCU free overloads the RCU head over the LRU
|
|
*/
|
|
struct rcu_head *head = (void *)&page->lru;
|
|
|
|
call_rcu(head, rcu_free_slab);
|
|
} else
|
|
__free_slab(s, page);
|
|
}
|
|
|
|
static void discard_slab(struct kmem_cache *s, struct page *page)
|
|
{
|
|
struct kmem_cache_node *n = get_node(s, page_to_nid(page));
|
|
|
|
atomic_long_dec(&n->nr_slabs);
|
|
reset_page_mapcount(page);
|
|
page->flags &= ~(1 << PG_slab | 1 << PG_error);
|
|
free_slab(s, page);
|
|
}
|
|
|
|
/*
|
|
* Per slab locking using the pagelock
|
|
*/
|
|
static __always_inline void slab_lock(struct page *page)
|
|
{
|
|
bit_spin_lock(PG_locked, &page->flags);
|
|
}
|
|
|
|
static __always_inline void slab_unlock(struct page *page)
|
|
{
|
|
bit_spin_unlock(PG_locked, &page->flags);
|
|
}
|
|
|
|
static __always_inline int slab_trylock(struct page *page)
|
|
{
|
|
int rc = 1;
|
|
|
|
rc = bit_spin_trylock(PG_locked, &page->flags);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Management of partially allocated slabs
|
|
*/
|
|
static void add_partial_tail(struct kmem_cache_node *n, struct page *page)
|
|
{
|
|
spin_lock(&n->list_lock);
|
|
n->nr_partial++;
|
|
list_add_tail(&page->lru, &n->partial);
|
|
spin_unlock(&n->list_lock);
|
|
}
|
|
|
|
static void add_partial(struct kmem_cache_node *n, struct page *page)
|
|
{
|
|
spin_lock(&n->list_lock);
|
|
n->nr_partial++;
|
|
list_add(&page->lru, &n->partial);
|
|
spin_unlock(&n->list_lock);
|
|
}
|
|
|
|
static void remove_partial(struct kmem_cache *s,
|
|
struct page *page)
|
|
{
|
|
struct kmem_cache_node *n = get_node(s, page_to_nid(page));
|
|
|
|
spin_lock(&n->list_lock);
|
|
list_del(&page->lru);
|
|
n->nr_partial--;
|
|
spin_unlock(&n->list_lock);
|
|
}
|
|
|
|
/*
|
|
* Lock page and remove it from the partial list
|
|
*
|
|
* Must hold list_lock
|
|
*/
|
|
static int lock_and_del_slab(struct kmem_cache_node *n, struct page *page)
|
|
{
|
|
if (slab_trylock(page)) {
|
|
list_del(&page->lru);
|
|
n->nr_partial--;
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Try to get a partial slab from a specific node
|
|
*/
|
|
static struct page *get_partial_node(struct kmem_cache_node *n)
|
|
{
|
|
struct page *page;
|
|
|
|
/*
|
|
* Racy check. If we mistakenly see no partial slabs then we
|
|
* just allocate an empty slab. If we mistakenly try to get a
|
|
* partial slab then get_partials() will return NULL.
|
|
*/
|
|
if (!n || !n->nr_partial)
|
|
return NULL;
|
|
|
|
spin_lock(&n->list_lock);
|
|
list_for_each_entry(page, &n->partial, lru)
|
|
if (lock_and_del_slab(n, page))
|
|
goto out;
|
|
page = NULL;
|
|
out:
|
|
spin_unlock(&n->list_lock);
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Get a page from somewhere. Search in increasing NUMA
|
|
* distances.
|
|
*/
|
|
static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
|
|
{
|
|
#ifdef CONFIG_NUMA
|
|
struct zonelist *zonelist;
|
|
struct zone **z;
|
|
struct page *page;
|
|
|
|
/*
|
|
* The defrag ratio allows to configure the tradeoffs between
|
|
* inter node defragmentation and node local allocations.
|
|
* A lower defrag_ratio increases the tendency to do local
|
|
* allocations instead of scanning throught the partial
|
|
* lists on other nodes.
|
|
*
|
|
* If defrag_ratio is set to 0 then kmalloc() always
|
|
* returns node local objects. If its higher then kmalloc()
|
|
* may return off node objects in order to avoid fragmentation.
|
|
*
|
|
* A higher ratio means slabs may be taken from other nodes
|
|
* thus reducing the number of partial slabs on those nodes.
|
|
*
|
|
* If /sys/slab/xx/defrag_ratio is set to 100 (which makes
|
|
* defrag_ratio = 1000) then every (well almost) allocation
|
|
* will first attempt to defrag slab caches on other nodes. This
|
|
* means scanning over all nodes to look for partial slabs which
|
|
* may be a bit expensive to do on every slab allocation.
|
|
*/
|
|
if (!s->defrag_ratio || get_cycles() % 1024 > s->defrag_ratio)
|
|
return NULL;
|
|
|
|
zonelist = &NODE_DATA(slab_node(current->mempolicy))
|
|
->node_zonelists[gfp_zone(flags)];
|
|
for (z = zonelist->zones; *z; z++) {
|
|
struct kmem_cache_node *n;
|
|
|
|
n = get_node(s, zone_to_nid(*z));
|
|
|
|
if (n && cpuset_zone_allowed_hardwall(*z, flags) &&
|
|
n->nr_partial > MIN_PARTIAL) {
|
|
page = get_partial_node(n);
|
|
if (page)
|
|
return page;
|
|
}
|
|
}
|
|
#endif
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Get a partial page, lock it and return it.
|
|
*/
|
|
static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
|
|
{
|
|
struct page *page;
|
|
int searchnode = (node == -1) ? numa_node_id() : node;
|
|
|
|
page = get_partial_node(get_node(s, searchnode));
|
|
if (page || (flags & __GFP_THISNODE))
|
|
return page;
|
|
|
|
return get_any_partial(s, flags);
|
|
}
|
|
|
|
/*
|
|
* Move a page back to the lists.
|
|
*
|
|
* Must be called with the slab lock held.
|
|
*
|
|
* On exit the slab lock will have been dropped.
|
|
*/
|
|
static void putback_slab(struct kmem_cache *s, struct page *page)
|
|
{
|
|
struct kmem_cache_node *n = get_node(s, page_to_nid(page));
|
|
|
|
if (page->inuse) {
|
|
|
|
if (page->freelist)
|
|
add_partial(n, page);
|
|
else if (PageError(page) && (s->flags & SLAB_STORE_USER))
|
|
add_full(n, page);
|
|
slab_unlock(page);
|
|
|
|
} else {
|
|
if (n->nr_partial < MIN_PARTIAL) {
|
|
/*
|
|
* Adding an empty page to the partial slabs in order
|
|
* to avoid page allocator overhead. This page needs to
|
|
* come after all the others that are not fully empty
|
|
* in order to make sure that we do maximum
|
|
* defragmentation.
|
|
*/
|
|
add_partial_tail(n, page);
|
|
slab_unlock(page);
|
|
} else {
|
|
slab_unlock(page);
|
|
discard_slab(s, page);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Remove the cpu slab
|
|
*/
|
|
static void deactivate_slab(struct kmem_cache *s, struct page *page, int cpu)
|
|
{
|
|
s->cpu_slab[cpu] = NULL;
|
|
ClearPageActive(page);
|
|
|
|
putback_slab(s, page);
|
|
}
|
|
|
|
static void flush_slab(struct kmem_cache *s, struct page *page, int cpu)
|
|
{
|
|
slab_lock(page);
|
|
deactivate_slab(s, page, cpu);
|
|
}
|
|
|
|
/*
|
|
* Flush cpu slab.
|
|
* Called from IPI handler with interrupts disabled.
|
|
*/
|
|
static void __flush_cpu_slab(struct kmem_cache *s, int cpu)
|
|
{
|
|
struct page *page = s->cpu_slab[cpu];
|
|
|
|
if (likely(page))
|
|
flush_slab(s, page, cpu);
|
|
}
|
|
|
|
static void flush_cpu_slab(void *d)
|
|
{
|
|
struct kmem_cache *s = d;
|
|
int cpu = smp_processor_id();
|
|
|
|
__flush_cpu_slab(s, cpu);
|
|
}
|
|
|
|
static void flush_all(struct kmem_cache *s)
|
|
{
|
|
#ifdef CONFIG_SMP
|
|
on_each_cpu(flush_cpu_slab, s, 1, 1);
|
|
#else
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
flush_cpu_slab(s);
|
|
local_irq_restore(flags);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* slab_alloc is optimized to only modify two cachelines on the fast path
|
|
* (aside from the stack):
|
|
*
|
|
* 1. The page struct
|
|
* 2. The first cacheline of the object to be allocated.
|
|
*
|
|
* The only cache lines that are read (apart from code) is the
|
|
* per cpu array in the kmem_cache struct.
|
|
*
|
|
* Fastpath is not possible if we need to get a new slab or have
|
|
* debugging enabled (which means all slabs are marked with PageError)
|
|
*/
|
|
static void *slab_alloc(struct kmem_cache *s,
|
|
gfp_t gfpflags, int node, void *addr)
|
|
{
|
|
struct page *page;
|
|
void **object;
|
|
unsigned long flags;
|
|
int cpu;
|
|
|
|
local_irq_save(flags);
|
|
cpu = smp_processor_id();
|
|
page = s->cpu_slab[cpu];
|
|
if (!page)
|
|
goto new_slab;
|
|
|
|
slab_lock(page);
|
|
if (unlikely(node != -1 && page_to_nid(page) != node))
|
|
goto another_slab;
|
|
redo:
|
|
object = page->freelist;
|
|
if (unlikely(!object))
|
|
goto another_slab;
|
|
if (unlikely(PageError(page)))
|
|
goto debug;
|
|
|
|
have_object:
|
|
page->inuse++;
|
|
page->freelist = object[page->offset];
|
|
slab_unlock(page);
|
|
local_irq_restore(flags);
|
|
return object;
|
|
|
|
another_slab:
|
|
deactivate_slab(s, page, cpu);
|
|
|
|
new_slab:
|
|
page = get_partial(s, gfpflags, node);
|
|
if (likely(page)) {
|
|
have_slab:
|
|
s->cpu_slab[cpu] = page;
|
|
SetPageActive(page);
|
|
goto redo;
|
|
}
|
|
|
|
page = new_slab(s, gfpflags, node);
|
|
if (page) {
|
|
cpu = smp_processor_id();
|
|
if (s->cpu_slab[cpu]) {
|
|
/*
|
|
* Someone else populated the cpu_slab while we enabled
|
|
* interrupts, or we have got scheduled on another cpu.
|
|
* The page may not be on the requested node.
|
|
*/
|
|
if (node == -1 ||
|
|
page_to_nid(s->cpu_slab[cpu]) == node) {
|
|
/*
|
|
* Current cpuslab is acceptable and we
|
|
* want the current one since its cache hot
|
|
*/
|
|
discard_slab(s, page);
|
|
page = s->cpu_slab[cpu];
|
|
slab_lock(page);
|
|
goto redo;
|
|
}
|
|
/* Dump the current slab */
|
|
flush_slab(s, s->cpu_slab[cpu], cpu);
|
|
}
|
|
slab_lock(page);
|
|
goto have_slab;
|
|
}
|
|
local_irq_restore(flags);
|
|
return NULL;
|
|
debug:
|
|
if (!alloc_object_checks(s, page, object))
|
|
goto another_slab;
|
|
if (s->flags & SLAB_STORE_USER)
|
|
set_track(s, object, TRACK_ALLOC, addr);
|
|
if (s->flags & SLAB_TRACE) {
|
|
printk(KERN_INFO "TRACE %s alloc 0x%p inuse=%d fp=0x%p\n",
|
|
s->name, object, page->inuse,
|
|
page->freelist);
|
|
dump_stack();
|
|
}
|
|
init_object(s, object, 1);
|
|
goto have_object;
|
|
}
|
|
|
|
void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
|
|
{
|
|
return slab_alloc(s, gfpflags, -1, __builtin_return_address(0));
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
|
|
{
|
|
return slab_alloc(s, gfpflags, node, __builtin_return_address(0));
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc_node);
|
|
#endif
|
|
|
|
/*
|
|
* The fastpath only writes the cacheline of the page struct and the first
|
|
* cacheline of the object.
|
|
*
|
|
* No special cachelines need to be read
|
|
*/
|
|
static void slab_free(struct kmem_cache *s, struct page *page,
|
|
void *x, void *addr)
|
|
{
|
|
void *prior;
|
|
void **object = (void *)x;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
slab_lock(page);
|
|
|
|
if (unlikely(PageError(page)))
|
|
goto debug;
|
|
checks_ok:
|
|
prior = object[page->offset] = page->freelist;
|
|
page->freelist = object;
|
|
page->inuse--;
|
|
|
|
if (unlikely(PageActive(page)))
|
|
/*
|
|
* Cpu slabs are never on partial lists and are
|
|
* never freed.
|
|
*/
|
|
goto out_unlock;
|
|
|
|
if (unlikely(!page->inuse))
|
|
goto slab_empty;
|
|
|
|
/*
|
|
* Objects left in the slab. If it
|
|
* was not on the partial list before
|
|
* then add it.
|
|
*/
|
|
if (unlikely(!prior))
|
|
add_partial(get_node(s, page_to_nid(page)), page);
|
|
|
|
out_unlock:
|
|
slab_unlock(page);
|
|
local_irq_restore(flags);
|
|
return;
|
|
|
|
slab_empty:
|
|
if (prior)
|
|
/*
|
|
* Slab on the partial list.
|
|
*/
|
|
remove_partial(s, page);
|
|
|
|
slab_unlock(page);
|
|
discard_slab(s, page);
|
|
local_irq_restore(flags);
|
|
return;
|
|
|
|
debug:
|
|
if (!free_object_checks(s, page, x))
|
|
goto out_unlock;
|
|
if (!PageActive(page) && !page->freelist)
|
|
remove_full(s, page);
|
|
if (s->flags & SLAB_STORE_USER)
|
|
set_track(s, x, TRACK_FREE, addr);
|
|
if (s->flags & SLAB_TRACE) {
|
|
printk(KERN_INFO "TRACE %s free 0x%p inuse=%d fp=0x%p\n",
|
|
s->name, object, page->inuse,
|
|
page->freelist);
|
|
print_section("Object", (void *)object, s->objsize);
|
|
dump_stack();
|
|
}
|
|
init_object(s, object, 0);
|
|
goto checks_ok;
|
|
}
|
|
|
|
void kmem_cache_free(struct kmem_cache *s, void *x)
|
|
{
|
|
struct page *page;
|
|
|
|
page = virt_to_head_page(x);
|
|
|
|
slab_free(s, page, x, __builtin_return_address(0));
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_free);
|
|
|
|
/* Figure out on which slab object the object resides */
|
|
static struct page *get_object_page(const void *x)
|
|
{
|
|
struct page *page = virt_to_head_page(x);
|
|
|
|
if (!PageSlab(page))
|
|
return NULL;
|
|
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* kmem_cache_open produces objects aligned at "size" and the first object
|
|
* is placed at offset 0 in the slab (We have no metainformation on the
|
|
* slab, all slabs are in essence "off slab").
|
|
*
|
|
* In order to get the desired alignment one just needs to align the
|
|
* size.
|
|
*
|
|
* Notice that the allocation order determines the sizes of the per cpu
|
|
* caches. Each processor has always one slab available for allocations.
|
|
* Increasing the allocation order reduces the number of times that slabs
|
|
* must be moved on and off the partial lists and therefore may influence
|
|
* locking overhead.
|
|
*
|
|
* The offset is used to relocate the free list link in each object. It is
|
|
* therefore possible to move the free list link behind the object. This
|
|
* is necessary for RCU to work properly and also useful for debugging.
|
|
*/
|
|
|
|
/*
|
|
* Mininum / Maximum order of slab pages. This influences locking overhead
|
|
* and slab fragmentation. A higher order reduces the number of partial slabs
|
|
* and increases the number of allocations possible without having to
|
|
* take the list_lock.
|
|
*/
|
|
static int slub_min_order;
|
|
static int slub_max_order = DEFAULT_MAX_ORDER;
|
|
|
|
/*
|
|
* Minimum number of objects per slab. This is necessary in order to
|
|
* reduce locking overhead. Similar to the queue size in SLAB.
|
|
*/
|
|
static int slub_min_objects = DEFAULT_MIN_OBJECTS;
|
|
|
|
/*
|
|
* Merge control. If this is set then no merging of slab caches will occur.
|
|
*/
|
|
static int slub_nomerge;
|
|
|
|
/*
|
|
* Debug settings:
|
|
*/
|
|
static int slub_debug;
|
|
|
|
static char *slub_debug_slabs;
|
|
|
|
/*
|
|
* Calculate the order of allocation given an slab object size.
|
|
*
|
|
* The order of allocation has significant impact on other elements
|
|
* of the system. Generally order 0 allocations should be preferred
|
|
* since they do not cause fragmentation in the page allocator. Larger
|
|
* objects may have problems with order 0 because there may be too much
|
|
* space left unused in a slab. We go to a higher order if more than 1/8th
|
|
* of the slab would be wasted.
|
|
*
|
|
* In order to reach satisfactory performance we must ensure that
|
|
* a minimum number of objects is in one slab. Otherwise we may
|
|
* generate too much activity on the partial lists. This is less a
|
|
* concern for large slabs though. slub_max_order specifies the order
|
|
* where we begin to stop considering the number of objects in a slab.
|
|
*
|
|
* Higher order allocations also allow the placement of more objects
|
|
* in a slab and thereby reduce object handling overhead. If the user
|
|
* has requested a higher mininum order then we start with that one
|
|
* instead of zero.
|
|
*/
|
|
static int calculate_order(int size)
|
|
{
|
|
int order;
|
|
int rem;
|
|
|
|
for (order = max(slub_min_order, fls(size - 1) - PAGE_SHIFT);
|
|
order < MAX_ORDER; order++) {
|
|
unsigned long slab_size = PAGE_SIZE << order;
|
|
|
|
if (slub_max_order > order &&
|
|
slab_size < slub_min_objects * size)
|
|
continue;
|
|
|
|
if (slab_size < size)
|
|
continue;
|
|
|
|
rem = slab_size % size;
|
|
|
|
if (rem <= (PAGE_SIZE << order) / 8)
|
|
break;
|
|
|
|
}
|
|
if (order >= MAX_ORDER)
|
|
return -E2BIG;
|
|
return order;
|
|
}
|
|
|
|
/*
|
|
* Function to figure out which alignment to use from the
|
|
* various ways of specifying it.
|
|
*/
|
|
static unsigned long calculate_alignment(unsigned long flags,
|
|
unsigned long align, unsigned long size)
|
|
{
|
|
/*
|
|
* If the user wants hardware cache aligned objects then
|
|
* follow that suggestion if the object is sufficiently
|
|
* large.
|
|
*
|
|
* The hardware cache alignment cannot override the
|
|
* specified alignment though. If that is greater
|
|
* then use it.
|
|
*/
|
|
if ((flags & SLAB_HWCACHE_ALIGN) &&
|
|
size > L1_CACHE_BYTES / 2)
|
|
return max_t(unsigned long, align, L1_CACHE_BYTES);
|
|
|
|
if (align < ARCH_SLAB_MINALIGN)
|
|
return ARCH_SLAB_MINALIGN;
|
|
|
|
return ALIGN(align, sizeof(void *));
|
|
}
|
|
|
|
static void init_kmem_cache_node(struct kmem_cache_node *n)
|
|
{
|
|
n->nr_partial = 0;
|
|
atomic_long_set(&n->nr_slabs, 0);
|
|
spin_lock_init(&n->list_lock);
|
|
INIT_LIST_HEAD(&n->partial);
|
|
INIT_LIST_HEAD(&n->full);
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
/*
|
|
* No kmalloc_node yet so do it by hand. We know that this is the first
|
|
* slab on the node for this slabcache. There are no concurrent accesses
|
|
* possible.
|
|
*
|
|
* Note that this function only works on the kmalloc_node_cache
|
|
* when allocating for the kmalloc_node_cache.
|
|
*/
|
|
static struct kmem_cache_node * __init early_kmem_cache_node_alloc(gfp_t gfpflags,
|
|
int node)
|
|
{
|
|
struct page *page;
|
|
struct kmem_cache_node *n;
|
|
|
|
BUG_ON(kmalloc_caches->size < sizeof(struct kmem_cache_node));
|
|
|
|
page = new_slab(kmalloc_caches, gfpflags | GFP_THISNODE, node);
|
|
/* new_slab() disables interupts */
|
|
local_irq_enable();
|
|
|
|
BUG_ON(!page);
|
|
n = page->freelist;
|
|
BUG_ON(!n);
|
|
page->freelist = get_freepointer(kmalloc_caches, n);
|
|
page->inuse++;
|
|
kmalloc_caches->node[node] = n;
|
|
init_object(kmalloc_caches, n, 1);
|
|
init_kmem_cache_node(n);
|
|
atomic_long_inc(&n->nr_slabs);
|
|
add_partial(n, page);
|
|
return n;
|
|
}
|
|
|
|
static void free_kmem_cache_nodes(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
|
|
for_each_online_node(node) {
|
|
struct kmem_cache_node *n = s->node[node];
|
|
if (n && n != &s->local_node)
|
|
kmem_cache_free(kmalloc_caches, n);
|
|
s->node[node] = NULL;
|
|
}
|
|
}
|
|
|
|
static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
|
|
{
|
|
int node;
|
|
int local_node;
|
|
|
|
if (slab_state >= UP)
|
|
local_node = page_to_nid(virt_to_page(s));
|
|
else
|
|
local_node = 0;
|
|
|
|
for_each_online_node(node) {
|
|
struct kmem_cache_node *n;
|
|
|
|
if (local_node == node)
|
|
n = &s->local_node;
|
|
else {
|
|
if (slab_state == DOWN) {
|
|
n = early_kmem_cache_node_alloc(gfpflags,
|
|
node);
|
|
continue;
|
|
}
|
|
n = kmem_cache_alloc_node(kmalloc_caches,
|
|
gfpflags, node);
|
|
|
|
if (!n) {
|
|
free_kmem_cache_nodes(s);
|
|
return 0;
|
|
}
|
|
|
|
}
|
|
s->node[node] = n;
|
|
init_kmem_cache_node(n);
|
|
}
|
|
return 1;
|
|
}
|
|
#else
|
|
static void free_kmem_cache_nodes(struct kmem_cache *s)
|
|
{
|
|
}
|
|
|
|
static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
|
|
{
|
|
init_kmem_cache_node(&s->local_node);
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* calculate_sizes() determines the order and the distribution of data within
|
|
* a slab object.
|
|
*/
|
|
static int calculate_sizes(struct kmem_cache *s)
|
|
{
|
|
unsigned long flags = s->flags;
|
|
unsigned long size = s->objsize;
|
|
unsigned long align = s->align;
|
|
|
|
/*
|
|
* Determine if we can poison the object itself. If the user of
|
|
* the slab may touch the object after free or before allocation
|
|
* then we should never poison the object itself.
|
|
*/
|
|
if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
|
|
!s->ctor && !s->dtor)
|
|
s->flags |= __OBJECT_POISON;
|
|
else
|
|
s->flags &= ~__OBJECT_POISON;
|
|
|
|
/*
|
|
* Round up object size to the next word boundary. We can only
|
|
* place the free pointer at word boundaries and this determines
|
|
* the possible location of the free pointer.
|
|
*/
|
|
size = ALIGN(size, sizeof(void *));
|
|
|
|
/*
|
|
* If we are redzoning then check if there is some space between the
|
|
* end of the object and the free pointer. If not then add an
|
|
* additional word, so that we can establish a redzone between
|
|
* the object and the freepointer to be able to check for overwrites.
|
|
*/
|
|
if ((flags & SLAB_RED_ZONE) && size == s->objsize)
|
|
size += sizeof(void *);
|
|
|
|
/*
|
|
* With that we have determined how much of the slab is in actual
|
|
* use by the object. This is the potential offset to the free
|
|
* pointer.
|
|
*/
|
|
s->inuse = size;
|
|
|
|
if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) ||
|
|
s->ctor || s->dtor)) {
|
|
/*
|
|
* Relocate free pointer after the object if it is not
|
|
* permitted to overwrite the first word of the object on
|
|
* kmem_cache_free.
|
|
*
|
|
* This is the case if we do RCU, have a constructor or
|
|
* destructor or are poisoning the objects.
|
|
*/
|
|
s->offset = size;
|
|
size += sizeof(void *);
|
|
}
|
|
|
|
if (flags & SLAB_STORE_USER)
|
|
/*
|
|
* Need to store information about allocs and frees after
|
|
* the object.
|
|
*/
|
|
size += 2 * sizeof(struct track);
|
|
|
|
if (flags & DEBUG_DEFAULT_FLAGS)
|
|
/*
|
|
* Add some empty padding so that we can catch
|
|
* overwrites from earlier objects rather than let
|
|
* tracking information or the free pointer be
|
|
* corrupted if an user writes before the start
|
|
* of the object.
|
|
*/
|
|
size += sizeof(void *);
|
|
/*
|
|
* Determine the alignment based on various parameters that the
|
|
* user specified (this is unecessarily complex due to the attempt
|
|
* to be compatible with SLAB. Should be cleaned up some day).
|
|
*/
|
|
align = calculate_alignment(flags, align, s->objsize);
|
|
|
|
/*
|
|
* SLUB stores one object immediately after another beginning from
|
|
* offset 0. In order to align the objects we have to simply size
|
|
* each object to conform to the alignment.
|
|
*/
|
|
size = ALIGN(size, align);
|
|
s->size = size;
|
|
|
|
s->order = calculate_order(size);
|
|
if (s->order < 0)
|
|
return 0;
|
|
|
|
/*
|
|
* Determine the number of objects per slab
|
|
*/
|
|
s->objects = (PAGE_SIZE << s->order) / size;
|
|
|
|
/*
|
|
* Verify that the number of objects is within permitted limits.
|
|
* The page->inuse field is only 16 bit wide! So we cannot have
|
|
* more than 64k objects per slab.
|
|
*/
|
|
if (!s->objects || s->objects > 65535)
|
|
return 0;
|
|
return 1;
|
|
|
|
}
|
|
|
|
static int __init finish_bootstrap(void)
|
|
{
|
|
struct list_head *h;
|
|
int err;
|
|
|
|
slab_state = SYSFS;
|
|
|
|
list_for_each(h, &slab_caches) {
|
|
struct kmem_cache *s =
|
|
container_of(h, struct kmem_cache, list);
|
|
|
|
err = sysfs_slab_add(s);
|
|
BUG_ON(err);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags,
|
|
const char *name, size_t size,
|
|
size_t align, unsigned long flags,
|
|
void (*ctor)(void *, struct kmem_cache *, unsigned long),
|
|
void (*dtor)(void *, struct kmem_cache *, unsigned long))
|
|
{
|
|
memset(s, 0, kmem_size);
|
|
s->name = name;
|
|
s->ctor = ctor;
|
|
s->dtor = dtor;
|
|
s->objsize = size;
|
|
s->flags = flags;
|
|
s->align = align;
|
|
|
|
/*
|
|
* The page->offset field is only 16 bit wide. This is an offset
|
|
* in units of words from the beginning of an object. If the slab
|
|
* size is bigger then we cannot move the free pointer behind the
|
|
* object anymore.
|
|
*
|
|
* On 32 bit platforms the limit is 256k. On 64bit platforms
|
|
* the limit is 512k.
|
|
*
|
|
* Debugging or ctor/dtors may create a need to move the free
|
|
* pointer. Fail if this happens.
|
|
*/
|
|
if (s->size >= 65535 * sizeof(void *)) {
|
|
BUG_ON(flags & (SLAB_RED_ZONE | SLAB_POISON |
|
|
SLAB_STORE_USER | SLAB_DESTROY_BY_RCU));
|
|
BUG_ON(ctor || dtor);
|
|
}
|
|
else
|
|
/*
|
|
* Enable debugging if selected on the kernel commandline.
|
|
*/
|
|
if (slub_debug && (!slub_debug_slabs ||
|
|
strncmp(slub_debug_slabs, name,
|
|
strlen(slub_debug_slabs)) == 0))
|
|
s->flags |= slub_debug;
|
|
|
|
if (!calculate_sizes(s))
|
|
goto error;
|
|
|
|
s->refcount = 1;
|
|
#ifdef CONFIG_NUMA
|
|
s->defrag_ratio = 100;
|
|
#endif
|
|
|
|
if (init_kmem_cache_nodes(s, gfpflags & ~SLUB_DMA))
|
|
return 1;
|
|
error:
|
|
if (flags & SLAB_PANIC)
|
|
panic("Cannot create slab %s size=%lu realsize=%u "
|
|
"order=%u offset=%u flags=%lx\n",
|
|
s->name, (unsigned long)size, s->size, s->order,
|
|
s->offset, flags);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_open);
|
|
|
|
/*
|
|
* Check if a given pointer is valid
|
|
*/
|
|
int kmem_ptr_validate(struct kmem_cache *s, const void *object)
|
|
{
|
|
struct page * page;
|
|
void *addr;
|
|
|
|
page = get_object_page(object);
|
|
|
|
if (!page || s != page->slab)
|
|
/* No slab or wrong slab */
|
|
return 0;
|
|
|
|
addr = page_address(page);
|
|
if (object < addr || object >= addr + s->objects * s->size)
|
|
/* Out of bounds */
|
|
return 0;
|
|
|
|
if ((object - addr) % s->size)
|
|
/* Improperly aligned */
|
|
return 0;
|
|
|
|
/*
|
|
* We could also check if the object is on the slabs freelist.
|
|
* But this would be too expensive and it seems that the main
|
|
* purpose of kmem_ptr_valid is to check if the object belongs
|
|
* to a certain slab.
|
|
*/
|
|
return 1;
|
|
}
|
|
EXPORT_SYMBOL(kmem_ptr_validate);
|
|
|
|
/*
|
|
* Determine the size of a slab object
|
|
*/
|
|
unsigned int kmem_cache_size(struct kmem_cache *s)
|
|
{
|
|
return s->objsize;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_size);
|
|
|
|
const char *kmem_cache_name(struct kmem_cache *s)
|
|
{
|
|
return s->name;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_name);
|
|
|
|
/*
|
|
* Attempt to free all slabs on a node
|
|
*/
|
|
static int free_list(struct kmem_cache *s, struct kmem_cache_node *n,
|
|
struct list_head *list)
|
|
{
|
|
int slabs_inuse = 0;
|
|
unsigned long flags;
|
|
struct page *page, *h;
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
list_for_each_entry_safe(page, h, list, lru)
|
|
if (!page->inuse) {
|
|
list_del(&page->lru);
|
|
discard_slab(s, page);
|
|
} else
|
|
slabs_inuse++;
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
return slabs_inuse;
|
|
}
|
|
|
|
/*
|
|
* Release all resources used by slab cache
|
|
*/
|
|
static int kmem_cache_close(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
|
|
flush_all(s);
|
|
|
|
/* Attempt to free all objects */
|
|
for_each_online_node(node) {
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
n->nr_partial -= free_list(s, n, &n->partial);
|
|
if (atomic_long_read(&n->nr_slabs))
|
|
return 1;
|
|
}
|
|
free_kmem_cache_nodes(s);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Close a cache and release the kmem_cache structure
|
|
* (must be used for caches created using kmem_cache_create)
|
|
*/
|
|
void kmem_cache_destroy(struct kmem_cache *s)
|
|
{
|
|
down_write(&slub_lock);
|
|
s->refcount--;
|
|
if (!s->refcount) {
|
|
list_del(&s->list);
|
|
if (kmem_cache_close(s))
|
|
WARN_ON(1);
|
|
sysfs_slab_remove(s);
|
|
kfree(s);
|
|
}
|
|
up_write(&slub_lock);
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_destroy);
|
|
|
|
/********************************************************************
|
|
* Kmalloc subsystem
|
|
*******************************************************************/
|
|
|
|
struct kmem_cache kmalloc_caches[KMALLOC_SHIFT_HIGH + 1] __cacheline_aligned;
|
|
EXPORT_SYMBOL(kmalloc_caches);
|
|
|
|
#ifdef CONFIG_ZONE_DMA
|
|
static struct kmem_cache *kmalloc_caches_dma[KMALLOC_SHIFT_HIGH + 1];
|
|
#endif
|
|
|
|
static int __init setup_slub_min_order(char *str)
|
|
{
|
|
get_option (&str, &slub_min_order);
|
|
|
|
return 1;
|
|
}
|
|
|
|
__setup("slub_min_order=", setup_slub_min_order);
|
|
|
|
static int __init setup_slub_max_order(char *str)
|
|
{
|
|
get_option (&str, &slub_max_order);
|
|
|
|
return 1;
|
|
}
|
|
|
|
__setup("slub_max_order=", setup_slub_max_order);
|
|
|
|
static int __init setup_slub_min_objects(char *str)
|
|
{
|
|
get_option (&str, &slub_min_objects);
|
|
|
|
return 1;
|
|
}
|
|
|
|
__setup("slub_min_objects=", setup_slub_min_objects);
|
|
|
|
static int __init setup_slub_nomerge(char *str)
|
|
{
|
|
slub_nomerge = 1;
|
|
return 1;
|
|
}
|
|
|
|
__setup("slub_nomerge", setup_slub_nomerge);
|
|
|
|
static int __init setup_slub_debug(char *str)
|
|
{
|
|
if (!str || *str != '=')
|
|
slub_debug = DEBUG_DEFAULT_FLAGS;
|
|
else {
|
|
str++;
|
|
if (*str == 0 || *str == ',')
|
|
slub_debug = DEBUG_DEFAULT_FLAGS;
|
|
else
|
|
for( ;*str && *str != ','; str++)
|
|
switch (*str) {
|
|
case 'f' : case 'F' :
|
|
slub_debug |= SLAB_DEBUG_FREE;
|
|
break;
|
|
case 'z' : case 'Z' :
|
|
slub_debug |= SLAB_RED_ZONE;
|
|
break;
|
|
case 'p' : case 'P' :
|
|
slub_debug |= SLAB_POISON;
|
|
break;
|
|
case 'u' : case 'U' :
|
|
slub_debug |= SLAB_STORE_USER;
|
|
break;
|
|
case 't' : case 'T' :
|
|
slub_debug |= SLAB_TRACE;
|
|
break;
|
|
default:
|
|
printk(KERN_ERR "slub_debug option '%c' "
|
|
"unknown. skipped\n",*str);
|
|
}
|
|
}
|
|
|
|
if (*str == ',')
|
|
slub_debug_slabs = str + 1;
|
|
return 1;
|
|
}
|
|
|
|
__setup("slub_debug", setup_slub_debug);
|
|
|
|
static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s,
|
|
const char *name, int size, gfp_t gfp_flags)
|
|
{
|
|
unsigned int flags = 0;
|
|
|
|
if (gfp_flags & SLUB_DMA)
|
|
flags = SLAB_CACHE_DMA;
|
|
|
|
down_write(&slub_lock);
|
|
if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN,
|
|
flags, NULL, NULL))
|
|
goto panic;
|
|
|
|
list_add(&s->list, &slab_caches);
|
|
up_write(&slub_lock);
|
|
if (sysfs_slab_add(s))
|
|
goto panic;
|
|
return s;
|
|
|
|
panic:
|
|
panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
|
|
}
|
|
|
|
static struct kmem_cache *get_slab(size_t size, gfp_t flags)
|
|
{
|
|
int index = kmalloc_index(size);
|
|
|
|
if (!index)
|
|
return NULL;
|
|
|
|
/* Allocation too large? */
|
|
BUG_ON(index < 0);
|
|
|
|
#ifdef CONFIG_ZONE_DMA
|
|
if ((flags & SLUB_DMA)) {
|
|
struct kmem_cache *s;
|
|
struct kmem_cache *x;
|
|
char *text;
|
|
size_t realsize;
|
|
|
|
s = kmalloc_caches_dma[index];
|
|
if (s)
|
|
return s;
|
|
|
|
/* Dynamically create dma cache */
|
|
x = kmalloc(kmem_size, flags & ~SLUB_DMA);
|
|
if (!x)
|
|
panic("Unable to allocate memory for dma cache\n");
|
|
|
|
if (index <= KMALLOC_SHIFT_HIGH)
|
|
realsize = 1 << index;
|
|
else {
|
|
if (index == 1)
|
|
realsize = 96;
|
|
else
|
|
realsize = 192;
|
|
}
|
|
|
|
text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d",
|
|
(unsigned int)realsize);
|
|
s = create_kmalloc_cache(x, text, realsize, flags);
|
|
kmalloc_caches_dma[index] = s;
|
|
return s;
|
|
}
|
|
#endif
|
|
return &kmalloc_caches[index];
|
|
}
|
|
|
|
void *__kmalloc(size_t size, gfp_t flags)
|
|
{
|
|
struct kmem_cache *s = get_slab(size, flags);
|
|
|
|
if (s)
|
|
return slab_alloc(s, flags, -1, __builtin_return_address(0));
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
void *__kmalloc_node(size_t size, gfp_t flags, int node)
|
|
{
|
|
struct kmem_cache *s = get_slab(size, flags);
|
|
|
|
if (s)
|
|
return slab_alloc(s, flags, node, __builtin_return_address(0));
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc_node);
|
|
#endif
|
|
|
|
size_t ksize(const void *object)
|
|
{
|
|
struct page *page = get_object_page(object);
|
|
struct kmem_cache *s;
|
|
|
|
BUG_ON(!page);
|
|
s = page->slab;
|
|
BUG_ON(!s);
|
|
|
|
/*
|
|
* Debugging requires use of the padding between object
|
|
* and whatever may come after it.
|
|
*/
|
|
if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
|
|
return s->objsize;
|
|
|
|
/*
|
|
* If we have the need to store the freelist pointer
|
|
* back there or track user information then we can
|
|
* only use the space before that information.
|
|
*/
|
|
if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
|
|
return s->inuse;
|
|
|
|
/*
|
|
* Else we can use all the padding etc for the allocation
|
|
*/
|
|
return s->size;
|
|
}
|
|
EXPORT_SYMBOL(ksize);
|
|
|
|
void kfree(const void *x)
|
|
{
|
|
struct kmem_cache *s;
|
|
struct page *page;
|
|
|
|
if (!x)
|
|
return;
|
|
|
|
page = virt_to_head_page(x);
|
|
s = page->slab;
|
|
|
|
slab_free(s, page, (void *)x, __builtin_return_address(0));
|
|
}
|
|
EXPORT_SYMBOL(kfree);
|
|
|
|
/*
|
|
* kmem_cache_shrink removes empty slabs from the partial lists
|
|
* and then sorts the partially allocated slabs by the number
|
|
* of items in use. The slabs with the most items in use
|
|
* come first. New allocations will remove these from the
|
|
* partial list because they are full. The slabs with the
|
|
* least items are placed last. If it happens that the objects
|
|
* are freed then the page can be returned to the page allocator.
|
|
*/
|
|
int kmem_cache_shrink(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
int i;
|
|
struct kmem_cache_node *n;
|
|
struct page *page;
|
|
struct page *t;
|
|
struct list_head *slabs_by_inuse =
|
|
kmalloc(sizeof(struct list_head) * s->objects, GFP_KERNEL);
|
|
unsigned long flags;
|
|
|
|
if (!slabs_by_inuse)
|
|
return -ENOMEM;
|
|
|
|
flush_all(s);
|
|
for_each_online_node(node) {
|
|
n = get_node(s, node);
|
|
|
|
if (!n->nr_partial)
|
|
continue;
|
|
|
|
for (i = 0; i < s->objects; i++)
|
|
INIT_LIST_HEAD(slabs_by_inuse + i);
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
|
|
/*
|
|
* Build lists indexed by the items in use in
|
|
* each slab or free slabs if empty.
|
|
*
|
|
* Note that concurrent frees may occur while
|
|
* we hold the list_lock. page->inuse here is
|
|
* the upper limit.
|
|
*/
|
|
list_for_each_entry_safe(page, t, &n->partial, lru) {
|
|
if (!page->inuse && slab_trylock(page)) {
|
|
/*
|
|
* Must hold slab lock here because slab_free
|
|
* may have freed the last object and be
|
|
* waiting to release the slab.
|
|
*/
|
|
list_del(&page->lru);
|
|
n->nr_partial--;
|
|
slab_unlock(page);
|
|
discard_slab(s, page);
|
|
} else {
|
|
if (n->nr_partial > MAX_PARTIAL)
|
|
list_move(&page->lru,
|
|
slabs_by_inuse + page->inuse);
|
|
}
|
|
}
|
|
|
|
if (n->nr_partial <= MAX_PARTIAL)
|
|
goto out;
|
|
|
|
/*
|
|
* Rebuild the partial list with the slabs filled up
|
|
* most first and the least used slabs at the end.
|
|
*/
|
|
for (i = s->objects - 1; i >= 0; i--)
|
|
list_splice(slabs_by_inuse + i, n->partial.prev);
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
}
|
|
|
|
kfree(slabs_by_inuse);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_shrink);
|
|
|
|
/**
|
|
* 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 @size is 0 and @p is not a
|
|
* %NULL pointer, the object pointed to is freed.
|
|
*/
|
|
void *krealloc(const void *p, size_t new_size, gfp_t flags)
|
|
{
|
|
struct kmem_cache *new_cache;
|
|
void *ret;
|
|
struct page *page;
|
|
|
|
if (unlikely(!p))
|
|
return kmalloc(new_size, flags);
|
|
|
|
if (unlikely(!new_size)) {
|
|
kfree(p);
|
|
return NULL;
|
|
}
|
|
|
|
page = virt_to_head_page(p);
|
|
|
|
new_cache = get_slab(new_size, flags);
|
|
|
|
/*
|
|
* If new size fits in the current cache, bail out.
|
|
*/
|
|
if (likely(page->slab == new_cache))
|
|
return (void *)p;
|
|
|
|
ret = kmalloc(new_size, flags);
|
|
if (ret) {
|
|
memcpy(ret, p, min(new_size, ksize(p)));
|
|
kfree(p);
|
|
}
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(krealloc);
|
|
|
|
/********************************************************************
|
|
* Basic setup of slabs
|
|
*******************************************************************/
|
|
|
|
void __init kmem_cache_init(void)
|
|
{
|
|
int i;
|
|
|
|
#ifdef CONFIG_NUMA
|
|
/*
|
|
* Must first have the slab cache available for the allocations of the
|
|
* struct kmalloc_cache_node's. There is special bootstrap code in
|
|
* kmem_cache_open for slab_state == DOWN.
|
|
*/
|
|
create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node",
|
|
sizeof(struct kmem_cache_node), GFP_KERNEL);
|
|
#endif
|
|
|
|
/* Able to allocate the per node structures */
|
|
slab_state = PARTIAL;
|
|
|
|
/* Caches that are not of the two-to-the-power-of size */
|
|
create_kmalloc_cache(&kmalloc_caches[1],
|
|
"kmalloc-96", 96, GFP_KERNEL);
|
|
create_kmalloc_cache(&kmalloc_caches[2],
|
|
"kmalloc-192", 192, GFP_KERNEL);
|
|
|
|
for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
|
|
create_kmalloc_cache(&kmalloc_caches[i],
|
|
"kmalloc", 1 << i, GFP_KERNEL);
|
|
|
|
slab_state = UP;
|
|
|
|
/* Provide the correct kmalloc names now that the caches are up */
|
|
for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
|
|
kmalloc_caches[i]. name =
|
|
kasprintf(GFP_KERNEL, "kmalloc-%d", 1 << i);
|
|
|
|
#ifdef CONFIG_SMP
|
|
register_cpu_notifier(&slab_notifier);
|
|
#endif
|
|
|
|
if (nr_cpu_ids) /* Remove when nr_cpu_ids is fixed upstream ! */
|
|
kmem_size = offsetof(struct kmem_cache, cpu_slab)
|
|
+ nr_cpu_ids * sizeof(struct page *);
|
|
|
|
printk(KERN_INFO "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
|
|
" Processors=%d, Nodes=%d\n",
|
|
KMALLOC_SHIFT_HIGH, L1_CACHE_BYTES,
|
|
slub_min_order, slub_max_order, slub_min_objects,
|
|
nr_cpu_ids, nr_node_ids);
|
|
}
|
|
|
|
/*
|
|
* Find a mergeable slab cache
|
|
*/
|
|
static int slab_unmergeable(struct kmem_cache *s)
|
|
{
|
|
if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
|
|
return 1;
|
|
|
|
if (s->ctor || s->dtor)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct kmem_cache *find_mergeable(size_t size,
|
|
size_t align, unsigned long flags,
|
|
void (*ctor)(void *, struct kmem_cache *, unsigned long),
|
|
void (*dtor)(void *, struct kmem_cache *, unsigned long))
|
|
{
|
|
struct list_head *h;
|
|
|
|
if (slub_nomerge || (flags & SLUB_NEVER_MERGE))
|
|
return NULL;
|
|
|
|
if (ctor || dtor)
|
|
return NULL;
|
|
|
|
size = ALIGN(size, sizeof(void *));
|
|
align = calculate_alignment(flags, align, size);
|
|
size = ALIGN(size, align);
|
|
|
|
list_for_each(h, &slab_caches) {
|
|
struct kmem_cache *s =
|
|
container_of(h, struct kmem_cache, list);
|
|
|
|
if (slab_unmergeable(s))
|
|
continue;
|
|
|
|
if (size > s->size)
|
|
continue;
|
|
|
|
if (((flags | slub_debug) & SLUB_MERGE_SAME) !=
|
|
(s->flags & SLUB_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;
|
|
|
|
return s;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
struct kmem_cache *kmem_cache_create(const char *name, size_t size,
|
|
size_t align, unsigned long flags,
|
|
void (*ctor)(void *, struct kmem_cache *, unsigned long),
|
|
void (*dtor)(void *, struct kmem_cache *, unsigned long))
|
|
{
|
|
struct kmem_cache *s;
|
|
|
|
down_write(&slub_lock);
|
|
s = find_mergeable(size, align, flags, dtor, ctor);
|
|
if (s) {
|
|
s->refcount++;
|
|
/*
|
|
* Adjust the object sizes so that we clear
|
|
* the complete object on kzalloc.
|
|
*/
|
|
s->objsize = max(s->objsize, (int)size);
|
|
s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
|
|
if (sysfs_slab_alias(s, name))
|
|
goto err;
|
|
} else {
|
|
s = kmalloc(kmem_size, GFP_KERNEL);
|
|
if (s && kmem_cache_open(s, GFP_KERNEL, name,
|
|
size, align, flags, ctor, dtor)) {
|
|
if (sysfs_slab_add(s)) {
|
|
kfree(s);
|
|
goto err;
|
|
}
|
|
list_add(&s->list, &slab_caches);
|
|
} else
|
|
kfree(s);
|
|
}
|
|
up_write(&slub_lock);
|
|
return s;
|
|
|
|
err:
|
|
up_write(&slub_lock);
|
|
if (flags & SLAB_PANIC)
|
|
panic("Cannot create slabcache %s\n", name);
|
|
else
|
|
s = NULL;
|
|
return s;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_create);
|
|
|
|
void *kmem_cache_zalloc(struct kmem_cache *s, gfp_t flags)
|
|
{
|
|
void *x;
|
|
|
|
x = slab_alloc(s, flags, -1, __builtin_return_address(0));
|
|
if (x)
|
|
memset(x, 0, s->objsize);
|
|
return x;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_zalloc);
|
|
|
|
#ifdef CONFIG_SMP
|
|
static void for_all_slabs(void (*func)(struct kmem_cache *, int), int cpu)
|
|
{
|
|
struct list_head *h;
|
|
|
|
down_read(&slub_lock);
|
|
list_for_each(h, &slab_caches) {
|
|
struct kmem_cache *s =
|
|
container_of(h, struct kmem_cache, list);
|
|
|
|
func(s, cpu);
|
|
}
|
|
up_read(&slub_lock);
|
|
}
|
|
|
|
/*
|
|
* Use the cpu notifier to insure that the slab are flushed
|
|
* when necessary.
|
|
*/
|
|
static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb,
|
|
unsigned long action, void *hcpu)
|
|
{
|
|
long cpu = (long)hcpu;
|
|
|
|
switch (action) {
|
|
case CPU_UP_CANCELED:
|
|
case CPU_DEAD:
|
|
for_all_slabs(__flush_cpu_slab, cpu);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block __cpuinitdata slab_notifier =
|
|
{ &slab_cpuup_callback, NULL, 0 };
|
|
|
|
#endif
|
|
|
|
#ifdef CONFIG_NUMA
|
|
|
|
/*****************************************************************
|
|
* Generic reaper used to support the page allocator
|
|
* (the cpu slabs are reaped by a per slab workqueue).
|
|
*
|
|
* Maybe move this to the page allocator?
|
|
****************************************************************/
|
|
|
|
static DEFINE_PER_CPU(unsigned long, reap_node);
|
|
|
|
static void init_reap_node(int cpu)
|
|
{
|
|
int node;
|
|
|
|
node = next_node(cpu_to_node(cpu), node_online_map);
|
|
if (node == MAX_NUMNODES)
|
|
node = first_node(node_online_map);
|
|
|
|
__get_cpu_var(reap_node) = node;
|
|
}
|
|
|
|
static void next_reap_node(void)
|
|
{
|
|
int node = __get_cpu_var(reap_node);
|
|
|
|
/*
|
|
* Also drain per cpu pages on remote zones
|
|
*/
|
|
if (node != numa_node_id())
|
|
drain_node_pages(node);
|
|
|
|
node = next_node(node, node_online_map);
|
|
if (unlikely(node >= MAX_NUMNODES))
|
|
node = first_node(node_online_map);
|
|
__get_cpu_var(reap_node) = node;
|
|
}
|
|
#else
|
|
#define init_reap_node(cpu) do { } while (0)
|
|
#define next_reap_node(void) do { } while (0)
|
|
#endif
|
|
|
|
#define REAPTIMEOUT_CPUC (2*HZ)
|
|
|
|
#ifdef CONFIG_SMP
|
|
static DEFINE_PER_CPU(struct delayed_work, reap_work);
|
|
|
|
static void cache_reap(struct work_struct *unused)
|
|
{
|
|
next_reap_node();
|
|
refresh_cpu_vm_stats(smp_processor_id());
|
|
schedule_delayed_work(&__get_cpu_var(reap_work),
|
|
REAPTIMEOUT_CPUC);
|
|
}
|
|
|
|
static void __devinit start_cpu_timer(int cpu)
|
|
{
|
|
struct delayed_work *reap_work = &per_cpu(reap_work, cpu);
|
|
|
|
/*
|
|
* When this gets called from do_initcalls via cpucache_init(),
|
|
* init_workqueues() has already run, so keventd will be setup
|
|
* at that time.
|
|
*/
|
|
if (keventd_up() && reap_work->work.func == NULL) {
|
|
init_reap_node(cpu);
|
|
INIT_DELAYED_WORK(reap_work, cache_reap);
|
|
schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu);
|
|
}
|
|
}
|
|
|
|
static int __init cpucache_init(void)
|
|
{
|
|
int cpu;
|
|
|
|
/*
|
|
* Register the timers that drain pcp pages and update vm statistics
|
|
*/
|
|
for_each_online_cpu(cpu)
|
|
start_cpu_timer(cpu);
|
|
return 0;
|
|
}
|
|
__initcall(cpucache_init);
|
|
#endif
|
|
|
|
#ifdef SLUB_RESILIENCY_TEST
|
|
static unsigned long validate_slab_cache(struct kmem_cache *s);
|
|
|
|
static void resiliency_test(void)
|
|
{
|
|
u8 *p;
|
|
|
|
printk(KERN_ERR "SLUB resiliency testing\n");
|
|
printk(KERN_ERR "-----------------------\n");
|
|
printk(KERN_ERR "A. Corruption after allocation\n");
|
|
|
|
p = kzalloc(16, GFP_KERNEL);
|
|
p[16] = 0x12;
|
|
printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer"
|
|
" 0x12->0x%p\n\n", p + 16);
|
|
|
|
validate_slab_cache(kmalloc_caches + 4);
|
|
|
|
/* Hmmm... The next two are dangerous */
|
|
p = kzalloc(32, GFP_KERNEL);
|
|
p[32 + sizeof(void *)] = 0x34;
|
|
printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab"
|
|
" 0x34 -> -0x%p\n", p);
|
|
printk(KERN_ERR "If allocated object is overwritten then not detectable\n\n");
|
|
|
|
validate_slab_cache(kmalloc_caches + 5);
|
|
p = kzalloc(64, GFP_KERNEL);
|
|
p += 64 + (get_cycles() & 0xff) * sizeof(void *);
|
|
*p = 0x56;
|
|
printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
|
|
p);
|
|
printk(KERN_ERR "If allocated object is overwritten then not detectable\n\n");
|
|
validate_slab_cache(kmalloc_caches + 6);
|
|
|
|
printk(KERN_ERR "\nB. Corruption after free\n");
|
|
p = kzalloc(128, GFP_KERNEL);
|
|
kfree(p);
|
|
*p = 0x78;
|
|
printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p);
|
|
validate_slab_cache(kmalloc_caches + 7);
|
|
|
|
p = kzalloc(256, GFP_KERNEL);
|
|
kfree(p);
|
|
p[50] = 0x9a;
|
|
printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n", p);
|
|
validate_slab_cache(kmalloc_caches + 8);
|
|
|
|
p = kzalloc(512, GFP_KERNEL);
|
|
kfree(p);
|
|
p[512] = 0xab;
|
|
printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p);
|
|
validate_slab_cache(kmalloc_caches + 9);
|
|
}
|
|
#else
|
|
static void resiliency_test(void) {};
|
|
#endif
|
|
|
|
/*
|
|
* These are not as efficient as kmalloc for the non debug case.
|
|
* We do not have the page struct available so we have to touch one
|
|
* cacheline in struct kmem_cache to check slab flags.
|
|
*/
|
|
void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, void *caller)
|
|
{
|
|
struct kmem_cache *s = get_slab(size, gfpflags);
|
|
|
|
if (!s)
|
|
return NULL;
|
|
|
|
return slab_alloc(s, gfpflags, -1, caller);
|
|
}
|
|
|
|
void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
|
|
int node, void *caller)
|
|
{
|
|
struct kmem_cache *s = get_slab(size, gfpflags);
|
|
|
|
if (!s)
|
|
return NULL;
|
|
|
|
return slab_alloc(s, gfpflags, node, caller);
|
|
}
|
|
|
|
#ifdef CONFIG_SYSFS
|
|
|
|
static int validate_slab(struct kmem_cache *s, struct page *page)
|
|
{
|
|
void *p;
|
|
void *addr = page_address(page);
|
|
unsigned long map[BITS_TO_LONGS(s->objects)];
|
|
|
|
if (!check_slab(s, page) ||
|
|
!on_freelist(s, page, NULL))
|
|
return 0;
|
|
|
|
/* Now we know that a valid freelist exists */
|
|
bitmap_zero(map, s->objects);
|
|
|
|
for(p = page->freelist; p; p = get_freepointer(s, p)) {
|
|
set_bit((p - addr) / s->size, map);
|
|
if (!check_object(s, page, p, 0))
|
|
return 0;
|
|
}
|
|
|
|
for(p = addr; p < addr + s->objects * s->size; p += s->size)
|
|
if (!test_bit((p - addr) / s->size, map))
|
|
if (!check_object(s, page, p, 1))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
static void validate_slab_slab(struct kmem_cache *s, struct page *page)
|
|
{
|
|
if (slab_trylock(page)) {
|
|
validate_slab(s, page);
|
|
slab_unlock(page);
|
|
} else
|
|
printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n",
|
|
s->name, page);
|
|
|
|
if (s->flags & DEBUG_DEFAULT_FLAGS) {
|
|
if (!PageError(page))
|
|
printk(KERN_ERR "SLUB %s: PageError not set "
|
|
"on slab 0x%p\n", s->name, page);
|
|
} else {
|
|
if (PageError(page))
|
|
printk(KERN_ERR "SLUB %s: PageError set on "
|
|
"slab 0x%p\n", s->name, page);
|
|
}
|
|
}
|
|
|
|
static int validate_slab_node(struct kmem_cache *s, struct kmem_cache_node *n)
|
|
{
|
|
unsigned long count = 0;
|
|
struct page *page;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
|
|
list_for_each_entry(page, &n->partial, lru) {
|
|
validate_slab_slab(s, page);
|
|
count++;
|
|
}
|
|
if (count != n->nr_partial)
|
|
printk(KERN_ERR "SLUB %s: %ld partial slabs counted but "
|
|
"counter=%ld\n", s->name, count, n->nr_partial);
|
|
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
goto out;
|
|
|
|
list_for_each_entry(page, &n->full, lru) {
|
|
validate_slab_slab(s, page);
|
|
count++;
|
|
}
|
|
if (count != atomic_long_read(&n->nr_slabs))
|
|
printk(KERN_ERR "SLUB: %s %ld slabs counted but "
|
|
"counter=%ld\n", s->name, count,
|
|
atomic_long_read(&n->nr_slabs));
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
return count;
|
|
}
|
|
|
|
static unsigned long validate_slab_cache(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
unsigned long count = 0;
|
|
|
|
flush_all(s);
|
|
for_each_online_node(node) {
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
count += validate_slab_node(s, n);
|
|
}
|
|
return count;
|
|
}
|
|
|
|
/*
|
|
* Generate lists of locations where slabcache objects are allocated
|
|
* and freed.
|
|
*/
|
|
|
|
struct location {
|
|
unsigned long count;
|
|
void *addr;
|
|
};
|
|
|
|
struct loc_track {
|
|
unsigned long max;
|
|
unsigned long count;
|
|
struct location *loc;
|
|
};
|
|
|
|
static void free_loc_track(struct loc_track *t)
|
|
{
|
|
if (t->max)
|
|
free_pages((unsigned long)t->loc,
|
|
get_order(sizeof(struct location) * t->max));
|
|
}
|
|
|
|
static int alloc_loc_track(struct loc_track *t, unsigned long max)
|
|
{
|
|
struct location *l;
|
|
int order;
|
|
|
|
if (!max)
|
|
max = PAGE_SIZE / sizeof(struct location);
|
|
|
|
order = get_order(sizeof(struct location) * max);
|
|
|
|
l = (void *)__get_free_pages(GFP_KERNEL, order);
|
|
|
|
if (!l)
|
|
return 0;
|
|
|
|
if (t->count) {
|
|
memcpy(l, t->loc, sizeof(struct location) * t->count);
|
|
free_loc_track(t);
|
|
}
|
|
t->max = max;
|
|
t->loc = l;
|
|
return 1;
|
|
}
|
|
|
|
static int add_location(struct loc_track *t, struct kmem_cache *s,
|
|
void *addr)
|
|
{
|
|
long start, end, pos;
|
|
struct location *l;
|
|
void *caddr;
|
|
|
|
start = -1;
|
|
end = t->count;
|
|
|
|
for ( ; ; ) {
|
|
pos = start + (end - start + 1) / 2;
|
|
|
|
/*
|
|
* There is nothing at "end". If we end up there
|
|
* we need to add something to before end.
|
|
*/
|
|
if (pos == end)
|
|
break;
|
|
|
|
caddr = t->loc[pos].addr;
|
|
if (addr == caddr) {
|
|
t->loc[pos].count++;
|
|
return 1;
|
|
}
|
|
|
|
if (addr < caddr)
|
|
end = pos;
|
|
else
|
|
start = pos;
|
|
}
|
|
|
|
/*
|
|
* Not found. Insert new tracking element
|
|
*/
|
|
if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max))
|
|
return 0;
|
|
|
|
l = t->loc + pos;
|
|
if (pos < t->count)
|
|
memmove(l + 1, l,
|
|
(t->count - pos) * sizeof(struct location));
|
|
t->count++;
|
|
l->count = 1;
|
|
l->addr = addr;
|
|
return 1;
|
|
}
|
|
|
|
static void process_slab(struct loc_track *t, struct kmem_cache *s,
|
|
struct page *page, enum track_item alloc)
|
|
{
|
|
void *addr = page_address(page);
|
|
unsigned long map[BITS_TO_LONGS(s->objects)];
|
|
void *p;
|
|
|
|
bitmap_zero(map, s->objects);
|
|
for (p = page->freelist; p; p = get_freepointer(s, p))
|
|
set_bit((p - addr) / s->size, map);
|
|
|
|
for (p = addr; p < addr + s->objects * s->size; p += s->size)
|
|
if (!test_bit((p - addr) / s->size, map)) {
|
|
void *addr = get_track(s, p, alloc)->addr;
|
|
|
|
add_location(t, s, addr);
|
|
}
|
|
}
|
|
|
|
static int list_locations(struct kmem_cache *s, char *buf,
|
|
enum track_item alloc)
|
|
{
|
|
int n = 0;
|
|
unsigned long i;
|
|
struct loc_track t;
|
|
int node;
|
|
|
|
t.count = 0;
|
|
t.max = 0;
|
|
|
|
/* Push back cpu slabs */
|
|
flush_all(s);
|
|
|
|
for_each_online_node(node) {
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
unsigned long flags;
|
|
struct page *page;
|
|
|
|
if (!atomic_read(&n->nr_slabs))
|
|
continue;
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
list_for_each_entry(page, &n->partial, lru)
|
|
process_slab(&t, s, page, alloc);
|
|
list_for_each_entry(page, &n->full, lru)
|
|
process_slab(&t, s, page, alloc);
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
}
|
|
|
|
for (i = 0; i < t.count; i++) {
|
|
void *addr = t.loc[i].addr;
|
|
|
|
if (n > PAGE_SIZE - 100)
|
|
break;
|
|
n += sprintf(buf + n, "%7ld ", t.loc[i].count);
|
|
if (addr)
|
|
n += sprint_symbol(buf + n, (unsigned long)t.loc[i].addr);
|
|
else
|
|
n += sprintf(buf + n, "<not-available>");
|
|
n += sprintf(buf + n, "\n");
|
|
}
|
|
|
|
free_loc_track(&t);
|
|
if (!t.count)
|
|
n += sprintf(buf, "No data\n");
|
|
return n;
|
|
}
|
|
|
|
static unsigned long count_partial(struct kmem_cache_node *n)
|
|
{
|
|
unsigned long flags;
|
|
unsigned long x = 0;
|
|
struct page *page;
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
list_for_each_entry(page, &n->partial, lru)
|
|
x += page->inuse;
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
return x;
|
|
}
|
|
|
|
enum slab_stat_type {
|
|
SL_FULL,
|
|
SL_PARTIAL,
|
|
SL_CPU,
|
|
SL_OBJECTS
|
|
};
|
|
|
|
#define SO_FULL (1 << SL_FULL)
|
|
#define SO_PARTIAL (1 << SL_PARTIAL)
|
|
#define SO_CPU (1 << SL_CPU)
|
|
#define SO_OBJECTS (1 << SL_OBJECTS)
|
|
|
|
static unsigned long slab_objects(struct kmem_cache *s,
|
|
char *buf, unsigned long flags)
|
|
{
|
|
unsigned long total = 0;
|
|
int cpu;
|
|
int node;
|
|
int x;
|
|
unsigned long *nodes;
|
|
unsigned long *per_cpu;
|
|
|
|
nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL);
|
|
per_cpu = nodes + nr_node_ids;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct page *page = s->cpu_slab[cpu];
|
|
int node;
|
|
|
|
if (page) {
|
|
node = page_to_nid(page);
|
|
if (flags & SO_CPU) {
|
|
int x = 0;
|
|
|
|
if (flags & SO_OBJECTS)
|
|
x = page->inuse;
|
|
else
|
|
x = 1;
|
|
total += x;
|
|
nodes[node] += x;
|
|
}
|
|
per_cpu[node]++;
|
|
}
|
|
}
|
|
|
|
for_each_online_node(node) {
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
if (flags & SO_PARTIAL) {
|
|
if (flags & SO_OBJECTS)
|
|
x = count_partial(n);
|
|
else
|
|
x = n->nr_partial;
|
|
total += x;
|
|
nodes[node] += x;
|
|
}
|
|
|
|
if (flags & SO_FULL) {
|
|
int full_slabs = atomic_read(&n->nr_slabs)
|
|
- per_cpu[node]
|
|
- n->nr_partial;
|
|
|
|
if (flags & SO_OBJECTS)
|
|
x = full_slabs * s->objects;
|
|
else
|
|
x = full_slabs;
|
|
total += x;
|
|
nodes[node] += x;
|
|
}
|
|
}
|
|
|
|
x = sprintf(buf, "%lu", total);
|
|
#ifdef CONFIG_NUMA
|
|
for_each_online_node(node)
|
|
if (nodes[node])
|
|
x += sprintf(buf + x, " N%d=%lu",
|
|
node, nodes[node]);
|
|
#endif
|
|
kfree(nodes);
|
|
return x + sprintf(buf + x, "\n");
|
|
}
|
|
|
|
static int any_slab_objects(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu)
|
|
if (s->cpu_slab[cpu])
|
|
return 1;
|
|
|
|
for_each_node(node) {
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
if (n->nr_partial || atomic_read(&n->nr_slabs))
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
|
|
#define to_slab(n) container_of(n, struct kmem_cache, kobj);
|
|
|
|
struct slab_attribute {
|
|
struct attribute attr;
|
|
ssize_t (*show)(struct kmem_cache *s, char *buf);
|
|
ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count);
|
|
};
|
|
|
|
#define SLAB_ATTR_RO(_name) \
|
|
static struct slab_attribute _name##_attr = __ATTR_RO(_name)
|
|
|
|
#define SLAB_ATTR(_name) \
|
|
static struct slab_attribute _name##_attr = \
|
|
__ATTR(_name, 0644, _name##_show, _name##_store)
|
|
|
|
static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", s->size);
|
|
}
|
|
SLAB_ATTR_RO(slab_size);
|
|
|
|
static ssize_t align_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", s->align);
|
|
}
|
|
SLAB_ATTR_RO(align);
|
|
|
|
static ssize_t object_size_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", s->objsize);
|
|
}
|
|
SLAB_ATTR_RO(object_size);
|
|
|
|
static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", s->objects);
|
|
}
|
|
SLAB_ATTR_RO(objs_per_slab);
|
|
|
|
static ssize_t order_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", s->order);
|
|
}
|
|
SLAB_ATTR_RO(order);
|
|
|
|
static ssize_t ctor_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
if (s->ctor) {
|
|
int n = sprint_symbol(buf, (unsigned long)s->ctor);
|
|
|
|
return n + sprintf(buf + n, "\n");
|
|
}
|
|
return 0;
|
|
}
|
|
SLAB_ATTR_RO(ctor);
|
|
|
|
static ssize_t dtor_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
if (s->dtor) {
|
|
int n = sprint_symbol(buf, (unsigned long)s->dtor);
|
|
|
|
return n + sprintf(buf + n, "\n");
|
|
}
|
|
return 0;
|
|
}
|
|
SLAB_ATTR_RO(dtor);
|
|
|
|
static ssize_t aliases_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", s->refcount - 1);
|
|
}
|
|
SLAB_ATTR_RO(aliases);
|
|
|
|
static ssize_t slabs_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU);
|
|
}
|
|
SLAB_ATTR_RO(slabs);
|
|
|
|
static ssize_t partial_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return slab_objects(s, buf, SO_PARTIAL);
|
|
}
|
|
SLAB_ATTR_RO(partial);
|
|
|
|
static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return slab_objects(s, buf, SO_CPU);
|
|
}
|
|
SLAB_ATTR_RO(cpu_slabs);
|
|
|
|
static ssize_t objects_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU|SO_OBJECTS);
|
|
}
|
|
SLAB_ATTR_RO(objects);
|
|
|
|
static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE));
|
|
}
|
|
|
|
static ssize_t sanity_checks_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
s->flags &= ~SLAB_DEBUG_FREE;
|
|
if (buf[0] == '1')
|
|
s->flags |= SLAB_DEBUG_FREE;
|
|
return length;
|
|
}
|
|
SLAB_ATTR(sanity_checks);
|
|
|
|
static ssize_t trace_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE));
|
|
}
|
|
|
|
static ssize_t trace_store(struct kmem_cache *s, const char *buf,
|
|
size_t length)
|
|
{
|
|
s->flags &= ~SLAB_TRACE;
|
|
if (buf[0] == '1')
|
|
s->flags |= SLAB_TRACE;
|
|
return length;
|
|
}
|
|
SLAB_ATTR(trace);
|
|
|
|
static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
|
|
}
|
|
|
|
static ssize_t reclaim_account_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
s->flags &= ~SLAB_RECLAIM_ACCOUNT;
|
|
if (buf[0] == '1')
|
|
s->flags |= SLAB_RECLAIM_ACCOUNT;
|
|
return length;
|
|
}
|
|
SLAB_ATTR(reclaim_account);
|
|
|
|
static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
|
|
}
|
|
SLAB_ATTR_RO(hwcache_align);
|
|
|
|
#ifdef CONFIG_ZONE_DMA
|
|
static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
|
|
}
|
|
SLAB_ATTR_RO(cache_dma);
|
|
#endif
|
|
|
|
static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU));
|
|
}
|
|
SLAB_ATTR_RO(destroy_by_rcu);
|
|
|
|
static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
|
|
}
|
|
|
|
static ssize_t red_zone_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
if (any_slab_objects(s))
|
|
return -EBUSY;
|
|
|
|
s->flags &= ~SLAB_RED_ZONE;
|
|
if (buf[0] == '1')
|
|
s->flags |= SLAB_RED_ZONE;
|
|
calculate_sizes(s);
|
|
return length;
|
|
}
|
|
SLAB_ATTR(red_zone);
|
|
|
|
static ssize_t poison_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON));
|
|
}
|
|
|
|
static ssize_t poison_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
if (any_slab_objects(s))
|
|
return -EBUSY;
|
|
|
|
s->flags &= ~SLAB_POISON;
|
|
if (buf[0] == '1')
|
|
s->flags |= SLAB_POISON;
|
|
calculate_sizes(s);
|
|
return length;
|
|
}
|
|
SLAB_ATTR(poison);
|
|
|
|
static ssize_t store_user_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
|
|
}
|
|
|
|
static ssize_t store_user_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
if (any_slab_objects(s))
|
|
return -EBUSY;
|
|
|
|
s->flags &= ~SLAB_STORE_USER;
|
|
if (buf[0] == '1')
|
|
s->flags |= SLAB_STORE_USER;
|
|
calculate_sizes(s);
|
|
return length;
|
|
}
|
|
SLAB_ATTR(store_user);
|
|
|
|
static ssize_t validate_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t validate_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
if (buf[0] == '1')
|
|
validate_slab_cache(s);
|
|
else
|
|
return -EINVAL;
|
|
return length;
|
|
}
|
|
SLAB_ATTR(validate);
|
|
|
|
static ssize_t shrink_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t shrink_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
if (buf[0] == '1') {
|
|
int rc = kmem_cache_shrink(s);
|
|
|
|
if (rc)
|
|
return rc;
|
|
} else
|
|
return -EINVAL;
|
|
return length;
|
|
}
|
|
SLAB_ATTR(shrink);
|
|
|
|
static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
return -ENOSYS;
|
|
return list_locations(s, buf, TRACK_ALLOC);
|
|
}
|
|
SLAB_ATTR_RO(alloc_calls);
|
|
|
|
static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
return -ENOSYS;
|
|
return list_locations(s, buf, TRACK_FREE);
|
|
}
|
|
SLAB_ATTR_RO(free_calls);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
static ssize_t defrag_ratio_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", s->defrag_ratio / 10);
|
|
}
|
|
|
|
static ssize_t defrag_ratio_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
int n = simple_strtoul(buf, NULL, 10);
|
|
|
|
if (n < 100)
|
|
s->defrag_ratio = n * 10;
|
|
return length;
|
|
}
|
|
SLAB_ATTR(defrag_ratio);
|
|
#endif
|
|
|
|
static struct attribute * slab_attrs[] = {
|
|
&slab_size_attr.attr,
|
|
&object_size_attr.attr,
|
|
&objs_per_slab_attr.attr,
|
|
&order_attr.attr,
|
|
&objects_attr.attr,
|
|
&slabs_attr.attr,
|
|
&partial_attr.attr,
|
|
&cpu_slabs_attr.attr,
|
|
&ctor_attr.attr,
|
|
&dtor_attr.attr,
|
|
&aliases_attr.attr,
|
|
&align_attr.attr,
|
|
&sanity_checks_attr.attr,
|
|
&trace_attr.attr,
|
|
&hwcache_align_attr.attr,
|
|
&reclaim_account_attr.attr,
|
|
&destroy_by_rcu_attr.attr,
|
|
&red_zone_attr.attr,
|
|
&poison_attr.attr,
|
|
&store_user_attr.attr,
|
|
&validate_attr.attr,
|
|
&shrink_attr.attr,
|
|
&alloc_calls_attr.attr,
|
|
&free_calls_attr.attr,
|
|
#ifdef CONFIG_ZONE_DMA
|
|
&cache_dma_attr.attr,
|
|
#endif
|
|
#ifdef CONFIG_NUMA
|
|
&defrag_ratio_attr.attr,
|
|
#endif
|
|
NULL
|
|
};
|
|
|
|
static struct attribute_group slab_attr_group = {
|
|
.attrs = slab_attrs,
|
|
};
|
|
|
|
static ssize_t slab_attr_show(struct kobject *kobj,
|
|
struct attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct slab_attribute *attribute;
|
|
struct kmem_cache *s;
|
|
int err;
|
|
|
|
attribute = to_slab_attr(attr);
|
|
s = to_slab(kobj);
|
|
|
|
if (!attribute->show)
|
|
return -EIO;
|
|
|
|
err = attribute->show(s, buf);
|
|
|
|
return err;
|
|
}
|
|
|
|
static ssize_t slab_attr_store(struct kobject *kobj,
|
|
struct attribute *attr,
|
|
const char *buf, size_t len)
|
|
{
|
|
struct slab_attribute *attribute;
|
|
struct kmem_cache *s;
|
|
int err;
|
|
|
|
attribute = to_slab_attr(attr);
|
|
s = to_slab(kobj);
|
|
|
|
if (!attribute->store)
|
|
return -EIO;
|
|
|
|
err = attribute->store(s, buf, len);
|
|
|
|
return err;
|
|
}
|
|
|
|
static struct sysfs_ops slab_sysfs_ops = {
|
|
.show = slab_attr_show,
|
|
.store = slab_attr_store,
|
|
};
|
|
|
|
static struct kobj_type slab_ktype = {
|
|
.sysfs_ops = &slab_sysfs_ops,
|
|
};
|
|
|
|
static int uevent_filter(struct kset *kset, struct kobject *kobj)
|
|
{
|
|
struct kobj_type *ktype = get_ktype(kobj);
|
|
|
|
if (ktype == &slab_ktype)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static struct kset_uevent_ops slab_uevent_ops = {
|
|
.filter = uevent_filter,
|
|
};
|
|
|
|
decl_subsys(slab, &slab_ktype, &slab_uevent_ops);
|
|
|
|
#define ID_STR_LENGTH 64
|
|
|
|
/* Create a unique string id for a slab cache:
|
|
* format
|
|
* :[flags-]size:[memory address of kmemcache]
|
|
*/
|
|
static char *create_unique_id(struct kmem_cache *s)
|
|
{
|
|
char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
|
|
char *p = name;
|
|
|
|
BUG_ON(!name);
|
|
|
|
*p++ = ':';
|
|
/*
|
|
* First flags affecting slabcache operations. We will only
|
|
* get here for aliasable slabs so we do not need to support
|
|
* too many flags. The flags here must cover all flags that
|
|
* are matched during merging to guarantee that the id is
|
|
* unique.
|
|
*/
|
|
if (s->flags & SLAB_CACHE_DMA)
|
|
*p++ = 'd';
|
|
if (s->flags & SLAB_RECLAIM_ACCOUNT)
|
|
*p++ = 'a';
|
|
if (s->flags & SLAB_DEBUG_FREE)
|
|
*p++ = 'F';
|
|
if (p != name + 1)
|
|
*p++ = '-';
|
|
p += sprintf(p, "%07d", s->size);
|
|
BUG_ON(p > name + ID_STR_LENGTH - 1);
|
|
return name;
|
|
}
|
|
|
|
static int sysfs_slab_add(struct kmem_cache *s)
|
|
{
|
|
int err;
|
|
const char *name;
|
|
int unmergeable;
|
|
|
|
if (slab_state < SYSFS)
|
|
/* Defer until later */
|
|
return 0;
|
|
|
|
unmergeable = slab_unmergeable(s);
|
|
if (unmergeable) {
|
|
/*
|
|
* Slabcache can never be merged so we can use the name proper.
|
|
* This is typically the case for debug situations. In that
|
|
* case we can catch duplicate names easily.
|
|
*/
|
|
sysfs_remove_link(&slab_subsys.kset.kobj, s->name);
|
|
name = s->name;
|
|
} else {
|
|
/*
|
|
* Create a unique name for the slab as a target
|
|
* for the symlinks.
|
|
*/
|
|
name = create_unique_id(s);
|
|
}
|
|
|
|
kobj_set_kset_s(s, slab_subsys);
|
|
kobject_set_name(&s->kobj, name);
|
|
kobject_init(&s->kobj);
|
|
err = kobject_add(&s->kobj);
|
|
if (err)
|
|
return err;
|
|
|
|
err = sysfs_create_group(&s->kobj, &slab_attr_group);
|
|
if (err)
|
|
return err;
|
|
kobject_uevent(&s->kobj, KOBJ_ADD);
|
|
if (!unmergeable) {
|
|
/* Setup first alias */
|
|
sysfs_slab_alias(s, s->name);
|
|
kfree(name);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void sysfs_slab_remove(struct kmem_cache *s)
|
|
{
|
|
kobject_uevent(&s->kobj, KOBJ_REMOVE);
|
|
kobject_del(&s->kobj);
|
|
}
|
|
|
|
/*
|
|
* Need to buffer aliases during bootup until sysfs becomes
|
|
* available lest we loose that information.
|
|
*/
|
|
struct saved_alias {
|
|
struct kmem_cache *s;
|
|
const char *name;
|
|
struct saved_alias *next;
|
|
};
|
|
|
|
struct saved_alias *alias_list;
|
|
|
|
static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
|
|
{
|
|
struct saved_alias *al;
|
|
|
|
if (slab_state == SYSFS) {
|
|
/*
|
|
* If we have a leftover link then remove it.
|
|
*/
|
|
sysfs_remove_link(&slab_subsys.kset.kobj, name);
|
|
return sysfs_create_link(&slab_subsys.kset.kobj,
|
|
&s->kobj, name);
|
|
}
|
|
|
|
al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL);
|
|
if (!al)
|
|
return -ENOMEM;
|
|
|
|
al->s = s;
|
|
al->name = name;
|
|
al->next = alias_list;
|
|
alias_list = al;
|
|
return 0;
|
|
}
|
|
|
|
static int __init slab_sysfs_init(void)
|
|
{
|
|
int err;
|
|
|
|
err = subsystem_register(&slab_subsys);
|
|
if (err) {
|
|
printk(KERN_ERR "Cannot register slab subsystem.\n");
|
|
return -ENOSYS;
|
|
}
|
|
|
|
finish_bootstrap();
|
|
|
|
while (alias_list) {
|
|
struct saved_alias *al = alias_list;
|
|
|
|
alias_list = alias_list->next;
|
|
err = sysfs_slab_alias(al->s, al->name);
|
|
BUG_ON(err);
|
|
kfree(al);
|
|
}
|
|
|
|
resiliency_test();
|
|
return 0;
|
|
}
|
|
|
|
__initcall(slab_sysfs_init);
|
|
#else
|
|
__initcall(finish_bootstrap);
|
|
#endif
|