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1a1c4e4576
Merge a series from myself that replaces hardcoded SLAB_ cache flag values with an enum, and explicitly deprecates the SLAB_MEM_SPREAD flag that is a no-op sine SLAB removal.
7112 lines
177 KiB
C
7112 lines
177 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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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 or atomic operations
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* and only uses a centralized lock to manage a pool of partial slabs.
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*
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* (C) 2007 SGI, Christoph Lameter
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* (C) 2011 Linux Foundation, Christoph Lameter
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*/
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#include <linux/mm.h>
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#include <linux/swap.h> /* mm_account_reclaimed_pages() */
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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/swab.h>
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#include <linux/bitops.h>
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#include <linux/slab.h>
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#include "slab.h"
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/kasan.h>
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#include <linux/kmsan.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/stackdepot.h>
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#include <linux/debugobjects.h>
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#include <linux/kallsyms.h>
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#include <linux/kfence.h>
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#include <linux/memory.h>
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#include <linux/math64.h>
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#include <linux/fault-inject.h>
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#include <linux/kmemleak.h>
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#include <linux/stacktrace.h>
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#include <linux/prefetch.h>
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#include <linux/memcontrol.h>
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#include <linux/random.h>
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#include <kunit/test.h>
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#include <kunit/test-bug.h>
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#include <linux/sort.h>
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#include <linux/debugfs.h>
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#include <trace/events/kmem.h>
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#include "internal.h"
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/*
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* Lock order:
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* 1. slab_mutex (Global Mutex)
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* 2. node->list_lock (Spinlock)
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* 3. kmem_cache->cpu_slab->lock (Local lock)
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* 4. slab_lock(slab) (Only on some arches)
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* 5. object_map_lock (Only for debugging)
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*
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* slab_mutex
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*
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* The role of the slab_mutex is to protect the list of all the slabs
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* and to synchronize major metadata changes to slab cache structures.
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* Also synchronizes memory hotplug callbacks.
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*
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* slab_lock
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*
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* The slab_lock is a wrapper around the page lock, thus it is a bit
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* spinlock.
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*
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* The slab_lock is only used on arches that do not have the ability
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* to do a cmpxchg_double. It only protects:
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*
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* A. slab->freelist -> List of free objects in a slab
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* B. slab->inuse -> Number of objects in use
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* C. slab->objects -> Number of objects in slab
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* D. slab->frozen -> frozen state
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*
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* Frozen slabs
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*
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* If a slab is frozen then it is exempt from list management. It is
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* the cpu slab which is actively allocated from by the processor that
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* froze it and it is not on any list. The processor that froze the
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* slab is the one who can perform list operations on the slab. Other
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* processors may put objects onto the freelist but the processor that
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* froze the slab is the only one that can retrieve the objects from the
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* slab's freelist.
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*
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* CPU partial slabs
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*
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* The partially empty slabs cached on the CPU partial list are used
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* for performance reasons, which speeds up the allocation process.
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* These slabs are not frozen, but are also exempt from list management,
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* by clearing the PG_workingset flag when moving out of the node
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* partial list. Please see __slab_free() for more details.
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*
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* To sum up, the current scheme is:
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* - node partial slab: PG_Workingset && !frozen
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* - cpu partial slab: !PG_Workingset && !frozen
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* - cpu slab: !PG_Workingset && frozen
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* - full slab: !PG_Workingset && !frozen
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*
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* list_lock
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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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* For debug caches, all allocations are forced to go through a list_lock
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* protected region to serialize against concurrent validation.
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*
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* cpu_slab->lock local lock
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*
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* This locks protect slowpath manipulation of all kmem_cache_cpu fields
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* except the stat counters. This is a percpu structure manipulated only by
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* the local cpu, so the lock protects against being preempted or interrupted
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* by an irq. Fast path operations rely on lockless operations instead.
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*
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* On PREEMPT_RT, the local lock neither disables interrupts nor preemption
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* which means the lockless fastpath cannot be used as it might interfere with
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* an in-progress slow path operations. In this case the local lock is always
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* taken but it still utilizes the freelist for the common operations.
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*
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* lockless fastpaths
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*
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* The fast path allocation (slab_alloc_node()) and freeing (do_slab_free())
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* are fully lockless when satisfied from the percpu slab (and when
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* cmpxchg_double is possible to use, otherwise slab_lock is taken).
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* They also don't disable preemption or migration or irqs. They rely on
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* the transaction id (tid) field to detect being preempted or moved to
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* another cpu.
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*
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* irq, preemption, migration considerations
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*
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* Interrupts are disabled as part of list_lock or local_lock operations, or
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* around the slab_lock operation, in order to make the slab allocator safe
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* to use in the context of an irq.
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*
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* In addition, preemption (or migration on PREEMPT_RT) is disabled in the
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* allocation slowpath, bulk allocation, and put_cpu_partial(), so that the
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* local cpu doesn't change in the process and e.g. the kmem_cache_cpu pointer
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* doesn't have to be revalidated in each section protected by the local lock.
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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 and during regular
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* operations no list for full slabs is used. 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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* We track full slabs for debugging purposes though because otherwise we
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* cannot scan all objects.
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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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* slab->frozen The slab is frozen and exempt from list processing.
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* This means that the slab is dedicated to a purpose
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* such as satisfying allocations for a specific
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* processor. Objects may be freed in the slab while
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* it is frozen but slab_free will then skip the usual
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* list operations. It is up to the processor holding
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* the slab to integrate the slab into the slab lists
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* when the slab is no longer needed.
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*
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* One use of this flag is to mark slabs that are
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* used for allocations. Then such a slab becomes a cpu
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* slab. The cpu slab may be equipped with an additional
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* freelist that allows lockless access to
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* free objects in addition to the regular freelist
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* that requires the slab lock.
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*
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* SLAB_DEBUG_FLAGS 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 and disables lockless freelists.
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*/
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/*
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* We could simply use migrate_disable()/enable() but as long as it's a
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* function call even on !PREEMPT_RT, use inline preempt_disable() there.
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*/
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#ifndef CONFIG_PREEMPT_RT
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#define slub_get_cpu_ptr(var) get_cpu_ptr(var)
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#define slub_put_cpu_ptr(var) put_cpu_ptr(var)
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#define USE_LOCKLESS_FAST_PATH() (true)
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#else
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#define slub_get_cpu_ptr(var) \
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({ \
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migrate_disable(); \
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this_cpu_ptr(var); \
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})
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#define slub_put_cpu_ptr(var) \
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do { \
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(void)(var); \
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migrate_enable(); \
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} while (0)
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#define USE_LOCKLESS_FAST_PATH() (false)
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#endif
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#ifndef CONFIG_SLUB_TINY
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#define __fastpath_inline __always_inline
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#else
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#define __fastpath_inline
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#endif
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#ifdef CONFIG_SLUB_DEBUG
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#ifdef CONFIG_SLUB_DEBUG_ON
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DEFINE_STATIC_KEY_TRUE(slub_debug_enabled);
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#else
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DEFINE_STATIC_KEY_FALSE(slub_debug_enabled);
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#endif
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#endif /* CONFIG_SLUB_DEBUG */
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/* Structure holding parameters for get_partial() call chain */
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struct partial_context {
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gfp_t flags;
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unsigned int orig_size;
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void *object;
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};
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static inline bool kmem_cache_debug(struct kmem_cache *s)
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{
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return kmem_cache_debug_flags(s, SLAB_DEBUG_FLAGS);
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}
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static inline bool slub_debug_orig_size(struct kmem_cache *s)
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{
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return (kmem_cache_debug_flags(s, SLAB_STORE_USER) &&
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(s->flags & SLAB_KMALLOC));
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}
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void *fixup_red_left(struct kmem_cache *s, void *p)
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{
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if (kmem_cache_debug_flags(s, SLAB_RED_ZONE))
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p += s->red_left_pad;
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return p;
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}
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static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
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{
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#ifdef CONFIG_SLUB_CPU_PARTIAL
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return !kmem_cache_debug(s);
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#else
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return false;
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#endif
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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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* - 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 log cmpxchg failures */
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#undef SLUB_DEBUG_CMPXCHG
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#ifndef CONFIG_SLUB_TINY
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/*
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* Minimum 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 5
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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 use.
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*/
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#define MAX_PARTIAL 10
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#else
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#define MIN_PARTIAL 0
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#define MAX_PARTIAL 0
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#endif
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#define DEBUG_DEFAULT_FLAGS (SLAB_CONSISTENCY_CHECKS | SLAB_RED_ZONE | \
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SLAB_POISON | SLAB_STORE_USER)
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/*
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* These debug flags cannot use CMPXCHG because there might be consistency
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* issues when checking or reading debug information
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*/
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#define SLAB_NO_CMPXCHG (SLAB_CONSISTENCY_CHECKS | SLAB_STORE_USER | \
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SLAB_TRACE)
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/*
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* Debugging flags that require metadata to be stored in the slab. These get
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* disabled when slab_debug=O is used and a cache's min order increases with
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* metadata.
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*/
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#define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
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#define OO_SHIFT 16
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#define OO_MASK ((1 << OO_SHIFT) - 1)
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#define MAX_OBJS_PER_PAGE 32767 /* since slab.objects is u15 */
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/* Internal SLUB flags */
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/* Poison object */
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#define __OBJECT_POISON __SLAB_FLAG_BIT(_SLAB_OBJECT_POISON)
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/* Use cmpxchg_double */
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#ifdef system_has_freelist_aba
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#define __CMPXCHG_DOUBLE __SLAB_FLAG_BIT(_SLAB_CMPXCHG_DOUBLE)
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#else
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#define __CMPXCHG_DOUBLE __SLAB_FLAG_UNUSED
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#endif
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/*
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* Tracking user of a slab.
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*/
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#define TRACK_ADDRS_COUNT 16
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struct track {
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unsigned long addr; /* Called from address */
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#ifdef CONFIG_STACKDEPOT
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depot_stack_handle_t handle;
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#endif
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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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#ifdef SLAB_SUPPORTS_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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#else
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static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }
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static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
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{ return 0; }
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#endif
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#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
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static void debugfs_slab_add(struct kmem_cache *);
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#else
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static inline void debugfs_slab_add(struct kmem_cache *s) { }
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#endif
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enum stat_item {
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ALLOC_FASTPATH, /* Allocation from cpu slab */
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ALLOC_SLOWPATH, /* Allocation by getting a new cpu slab */
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FREE_FASTPATH, /* Free to cpu slab */
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FREE_SLOWPATH, /* Freeing not to cpu slab */
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FREE_FROZEN, /* Freeing to frozen slab */
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FREE_ADD_PARTIAL, /* Freeing moves slab to partial list */
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FREE_REMOVE_PARTIAL, /* Freeing removes last object */
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ALLOC_FROM_PARTIAL, /* Cpu slab acquired from node partial list */
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ALLOC_SLAB, /* Cpu slab acquired from page allocator */
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ALLOC_REFILL, /* Refill cpu slab from slab freelist */
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ALLOC_NODE_MISMATCH, /* Switching cpu slab */
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FREE_SLAB, /* Slab freed to the page allocator */
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CPUSLAB_FLUSH, /* Abandoning of the cpu slab */
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DEACTIVATE_FULL, /* Cpu slab was full when deactivated */
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DEACTIVATE_EMPTY, /* Cpu slab was empty when deactivated */
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DEACTIVATE_TO_HEAD, /* Cpu slab was moved to the head of partials */
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DEACTIVATE_TO_TAIL, /* Cpu slab was moved to the tail of partials */
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DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
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DEACTIVATE_BYPASS, /* Implicit deactivation */
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ORDER_FALLBACK, /* Number of times fallback was necessary */
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CMPXCHG_DOUBLE_CPU_FAIL,/* Failures of this_cpu_cmpxchg_double */
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CMPXCHG_DOUBLE_FAIL, /* Failures of slab freelist update */
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CPU_PARTIAL_ALLOC, /* Used cpu partial on alloc */
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CPU_PARTIAL_FREE, /* Refill cpu partial on free */
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CPU_PARTIAL_NODE, /* Refill cpu partial from node partial */
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CPU_PARTIAL_DRAIN, /* Drain cpu partial to node partial */
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NR_SLUB_STAT_ITEMS
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};
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#ifndef CONFIG_SLUB_TINY
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/*
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* When changing the layout, make sure freelist and tid are still compatible
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* with this_cpu_cmpxchg_double() alignment requirements.
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*/
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struct kmem_cache_cpu {
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union {
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struct {
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void **freelist; /* Pointer to next available object */
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unsigned long tid; /* Globally unique transaction id */
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};
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freelist_aba_t freelist_tid;
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};
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struct slab *slab; /* The slab from which we are allocating */
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#ifdef CONFIG_SLUB_CPU_PARTIAL
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struct slab *partial; /* Partially allocated slabs */
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#endif
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local_lock_t lock; /* Protects the fields above */
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#ifdef CONFIG_SLUB_STATS
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unsigned int stat[NR_SLUB_STAT_ITEMS];
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#endif
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};
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#endif /* CONFIG_SLUB_TINY */
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static inline void stat(const struct kmem_cache *s, enum stat_item si)
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{
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#ifdef CONFIG_SLUB_STATS
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/*
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* The rmw is racy on a preemptible kernel but this is acceptable, so
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* avoid this_cpu_add()'s irq-disable overhead.
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*/
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raw_cpu_inc(s->cpu_slab->stat[si]);
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#endif
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}
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static inline
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void stat_add(const struct kmem_cache *s, enum stat_item si, int v)
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{
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#ifdef CONFIG_SLUB_STATS
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raw_cpu_add(s->cpu_slab->stat[si], v);
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#endif
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}
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/*
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* The slab lists for all objects.
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*/
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struct kmem_cache_node {
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spinlock_t list_lock;
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unsigned long nr_partial;
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struct list_head partial;
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#ifdef CONFIG_SLUB_DEBUG
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atomic_long_t nr_slabs;
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atomic_long_t total_objects;
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struct list_head full;
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#endif
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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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return s->node[node];
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}
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/*
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* Iterator over all nodes. The body will be executed for each node that has
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* a kmem_cache_node structure allocated (which is true for all online nodes)
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*/
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#define for_each_kmem_cache_node(__s, __node, __n) \
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for (__node = 0; __node < nr_node_ids; __node++) \
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if ((__n = get_node(__s, __node)))
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/*
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* Tracks for which NUMA nodes we have kmem_cache_nodes allocated.
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* Corresponds to node_state[N_NORMAL_MEMORY], but can temporarily
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* differ during memory hotplug/hotremove operations.
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* Protected by slab_mutex.
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*/
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static nodemask_t slab_nodes;
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#ifndef CONFIG_SLUB_TINY
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/*
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* Workqueue used for flush_cpu_slab().
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*/
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static struct workqueue_struct *flushwq;
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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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/*
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* freeptr_t represents a SLUB freelist pointer, which might be encoded
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* and not dereferenceable if CONFIG_SLAB_FREELIST_HARDENED is enabled.
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*/
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typedef struct { unsigned long v; } freeptr_t;
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/*
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* Returns freelist pointer (ptr). With hardening, this is obfuscated
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* with an XOR of the address where the pointer is held and a per-cache
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* random number.
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*/
|
|
static inline freeptr_t freelist_ptr_encode(const struct kmem_cache *s,
|
|
void *ptr, unsigned long ptr_addr)
|
|
{
|
|
unsigned long encoded;
|
|
|
|
#ifdef CONFIG_SLAB_FREELIST_HARDENED
|
|
encoded = (unsigned long)ptr ^ s->random ^ swab(ptr_addr);
|
|
#else
|
|
encoded = (unsigned long)ptr;
|
|
#endif
|
|
return (freeptr_t){.v = encoded};
|
|
}
|
|
|
|
static inline void *freelist_ptr_decode(const struct kmem_cache *s,
|
|
freeptr_t ptr, unsigned long ptr_addr)
|
|
{
|
|
void *decoded;
|
|
|
|
#ifdef CONFIG_SLAB_FREELIST_HARDENED
|
|
decoded = (void *)(ptr.v ^ s->random ^ swab(ptr_addr));
|
|
#else
|
|
decoded = (void *)ptr.v;
|
|
#endif
|
|
return decoded;
|
|
}
|
|
|
|
static inline void *get_freepointer(struct kmem_cache *s, void *object)
|
|
{
|
|
unsigned long ptr_addr;
|
|
freeptr_t p;
|
|
|
|
object = kasan_reset_tag(object);
|
|
ptr_addr = (unsigned long)object + s->offset;
|
|
p = *(freeptr_t *)(ptr_addr);
|
|
return freelist_ptr_decode(s, p, ptr_addr);
|
|
}
|
|
|
|
#ifndef CONFIG_SLUB_TINY
|
|
static void prefetch_freepointer(const struct kmem_cache *s, void *object)
|
|
{
|
|
prefetchw(object + s->offset);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* When running under KMSAN, get_freepointer_safe() may return an uninitialized
|
|
* pointer value in the case the current thread loses the race for the next
|
|
* memory chunk in the freelist. In that case this_cpu_cmpxchg_double() in
|
|
* slab_alloc_node() will fail, so the uninitialized value won't be used, but
|
|
* KMSAN will still check all arguments of cmpxchg because of imperfect
|
|
* handling of inline assembly.
|
|
* To work around this problem, we apply __no_kmsan_checks to ensure that
|
|
* get_freepointer_safe() returns initialized memory.
|
|
*/
|
|
__no_kmsan_checks
|
|
static inline void *get_freepointer_safe(struct kmem_cache *s, void *object)
|
|
{
|
|
unsigned long freepointer_addr;
|
|
freeptr_t p;
|
|
|
|
if (!debug_pagealloc_enabled_static())
|
|
return get_freepointer(s, object);
|
|
|
|
object = kasan_reset_tag(object);
|
|
freepointer_addr = (unsigned long)object + s->offset;
|
|
copy_from_kernel_nofault(&p, (freeptr_t *)freepointer_addr, sizeof(p));
|
|
return freelist_ptr_decode(s, p, freepointer_addr);
|
|
}
|
|
|
|
static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
|
|
{
|
|
unsigned long freeptr_addr = (unsigned long)object + s->offset;
|
|
|
|
#ifdef CONFIG_SLAB_FREELIST_HARDENED
|
|
BUG_ON(object == fp); /* naive detection of double free or corruption */
|
|
#endif
|
|
|
|
freeptr_addr = (unsigned long)kasan_reset_tag((void *)freeptr_addr);
|
|
*(freeptr_t *)freeptr_addr = freelist_ptr_encode(s, fp, freeptr_addr);
|
|
}
|
|
|
|
/* Loop over all objects in a slab */
|
|
#define for_each_object(__p, __s, __addr, __objects) \
|
|
for (__p = fixup_red_left(__s, __addr); \
|
|
__p < (__addr) + (__objects) * (__s)->size; \
|
|
__p += (__s)->size)
|
|
|
|
static inline unsigned int order_objects(unsigned int order, unsigned int size)
|
|
{
|
|
return ((unsigned int)PAGE_SIZE << order) / size;
|
|
}
|
|
|
|
static inline struct kmem_cache_order_objects oo_make(unsigned int order,
|
|
unsigned int size)
|
|
{
|
|
struct kmem_cache_order_objects x = {
|
|
(order << OO_SHIFT) + order_objects(order, size)
|
|
};
|
|
|
|
return x;
|
|
}
|
|
|
|
static inline unsigned int oo_order(struct kmem_cache_order_objects x)
|
|
{
|
|
return x.x >> OO_SHIFT;
|
|
}
|
|
|
|
static inline unsigned int oo_objects(struct kmem_cache_order_objects x)
|
|
{
|
|
return x.x & OO_MASK;
|
|
}
|
|
|
|
#ifdef CONFIG_SLUB_CPU_PARTIAL
|
|
static void slub_set_cpu_partial(struct kmem_cache *s, unsigned int nr_objects)
|
|
{
|
|
unsigned int nr_slabs;
|
|
|
|
s->cpu_partial = nr_objects;
|
|
|
|
/*
|
|
* We take the number of objects but actually limit the number of
|
|
* slabs on the per cpu partial list, in order to limit excessive
|
|
* growth of the list. For simplicity we assume that the slabs will
|
|
* be half-full.
|
|
*/
|
|
nr_slabs = DIV_ROUND_UP(nr_objects * 2, oo_objects(s->oo));
|
|
s->cpu_partial_slabs = nr_slabs;
|
|
}
|
|
#else
|
|
static inline void
|
|
slub_set_cpu_partial(struct kmem_cache *s, unsigned int nr_objects)
|
|
{
|
|
}
|
|
#endif /* CONFIG_SLUB_CPU_PARTIAL */
|
|
|
|
/*
|
|
* Per slab locking using the pagelock
|
|
*/
|
|
static __always_inline void slab_lock(struct slab *slab)
|
|
{
|
|
struct page *page = slab_page(slab);
|
|
|
|
VM_BUG_ON_PAGE(PageTail(page), page);
|
|
bit_spin_lock(PG_locked, &page->flags);
|
|
}
|
|
|
|
static __always_inline void slab_unlock(struct slab *slab)
|
|
{
|
|
struct page *page = slab_page(slab);
|
|
|
|
VM_BUG_ON_PAGE(PageTail(page), page);
|
|
bit_spin_unlock(PG_locked, &page->flags);
|
|
}
|
|
|
|
static inline bool
|
|
__update_freelist_fast(struct slab *slab,
|
|
void *freelist_old, unsigned long counters_old,
|
|
void *freelist_new, unsigned long counters_new)
|
|
{
|
|
#ifdef system_has_freelist_aba
|
|
freelist_aba_t old = { .freelist = freelist_old, .counter = counters_old };
|
|
freelist_aba_t new = { .freelist = freelist_new, .counter = counters_new };
|
|
|
|
return try_cmpxchg_freelist(&slab->freelist_counter.full, &old.full, new.full);
|
|
#else
|
|
return false;
|
|
#endif
|
|
}
|
|
|
|
static inline bool
|
|
__update_freelist_slow(struct slab *slab,
|
|
void *freelist_old, unsigned long counters_old,
|
|
void *freelist_new, unsigned long counters_new)
|
|
{
|
|
bool ret = false;
|
|
|
|
slab_lock(slab);
|
|
if (slab->freelist == freelist_old &&
|
|
slab->counters == counters_old) {
|
|
slab->freelist = freelist_new;
|
|
slab->counters = counters_new;
|
|
ret = true;
|
|
}
|
|
slab_unlock(slab);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Interrupts must be disabled (for the fallback code to work right), typically
|
|
* by an _irqsave() lock variant. On PREEMPT_RT the preempt_disable(), which is
|
|
* part of bit_spin_lock(), is sufficient because the policy is not to allow any
|
|
* allocation/ free operation in hardirq context. Therefore nothing can
|
|
* interrupt the operation.
|
|
*/
|
|
static inline bool __slab_update_freelist(struct kmem_cache *s, struct slab *slab,
|
|
void *freelist_old, unsigned long counters_old,
|
|
void *freelist_new, unsigned long counters_new,
|
|
const char *n)
|
|
{
|
|
bool ret;
|
|
|
|
if (USE_LOCKLESS_FAST_PATH())
|
|
lockdep_assert_irqs_disabled();
|
|
|
|
if (s->flags & __CMPXCHG_DOUBLE) {
|
|
ret = __update_freelist_fast(slab, freelist_old, counters_old,
|
|
freelist_new, counters_new);
|
|
} else {
|
|
ret = __update_freelist_slow(slab, freelist_old, counters_old,
|
|
freelist_new, counters_new);
|
|
}
|
|
if (likely(ret))
|
|
return true;
|
|
|
|
cpu_relax();
|
|
stat(s, CMPXCHG_DOUBLE_FAIL);
|
|
|
|
#ifdef SLUB_DEBUG_CMPXCHG
|
|
pr_info("%s %s: cmpxchg double redo ", n, s->name);
|
|
#endif
|
|
|
|
return false;
|
|
}
|
|
|
|
static inline bool slab_update_freelist(struct kmem_cache *s, struct slab *slab,
|
|
void *freelist_old, unsigned long counters_old,
|
|
void *freelist_new, unsigned long counters_new,
|
|
const char *n)
|
|
{
|
|
bool ret;
|
|
|
|
if (s->flags & __CMPXCHG_DOUBLE) {
|
|
ret = __update_freelist_fast(slab, freelist_old, counters_old,
|
|
freelist_new, counters_new);
|
|
} else {
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
ret = __update_freelist_slow(slab, freelist_old, counters_old,
|
|
freelist_new, counters_new);
|
|
local_irq_restore(flags);
|
|
}
|
|
if (likely(ret))
|
|
return true;
|
|
|
|
cpu_relax();
|
|
stat(s, CMPXCHG_DOUBLE_FAIL);
|
|
|
|
#ifdef SLUB_DEBUG_CMPXCHG
|
|
pr_info("%s %s: cmpxchg double redo ", n, s->name);
|
|
#endif
|
|
|
|
return false;
|
|
}
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
static unsigned long object_map[BITS_TO_LONGS(MAX_OBJS_PER_PAGE)];
|
|
static DEFINE_SPINLOCK(object_map_lock);
|
|
|
|
static void __fill_map(unsigned long *obj_map, struct kmem_cache *s,
|
|
struct slab *slab)
|
|
{
|
|
void *addr = slab_address(slab);
|
|
void *p;
|
|
|
|
bitmap_zero(obj_map, slab->objects);
|
|
|
|
for (p = slab->freelist; p; p = get_freepointer(s, p))
|
|
set_bit(__obj_to_index(s, addr, p), obj_map);
|
|
}
|
|
|
|
#if IS_ENABLED(CONFIG_KUNIT)
|
|
static bool slab_add_kunit_errors(void)
|
|
{
|
|
struct kunit_resource *resource;
|
|
|
|
if (!kunit_get_current_test())
|
|
return false;
|
|
|
|
resource = kunit_find_named_resource(current->kunit_test, "slab_errors");
|
|
if (!resource)
|
|
return false;
|
|
|
|
(*(int *)resource->data)++;
|
|
kunit_put_resource(resource);
|
|
return true;
|
|
}
|
|
#else
|
|
static inline bool slab_add_kunit_errors(void) { return false; }
|
|
#endif
|
|
|
|
static inline unsigned int size_from_object(struct kmem_cache *s)
|
|
{
|
|
if (s->flags & SLAB_RED_ZONE)
|
|
return s->size - s->red_left_pad;
|
|
|
|
return s->size;
|
|
}
|
|
|
|
static inline void *restore_red_left(struct kmem_cache *s, void *p)
|
|
{
|
|
if (s->flags & SLAB_RED_ZONE)
|
|
p -= s->red_left_pad;
|
|
|
|
return p;
|
|
}
|
|
|
|
/*
|
|
* Debug settings:
|
|
*/
|
|
#if defined(CONFIG_SLUB_DEBUG_ON)
|
|
static slab_flags_t slub_debug = DEBUG_DEFAULT_FLAGS;
|
|
#else
|
|
static slab_flags_t slub_debug;
|
|
#endif
|
|
|
|
static char *slub_debug_string;
|
|
static int disable_higher_order_debug;
|
|
|
|
/*
|
|
* slub is about to manipulate internal object metadata. This memory lies
|
|
* outside the range of the allocated object, so accessing it would normally
|
|
* be reported by kasan as a bounds error. metadata_access_enable() is used
|
|
* to tell kasan that these accesses are OK.
|
|
*/
|
|
static inline void metadata_access_enable(void)
|
|
{
|
|
kasan_disable_current();
|
|
}
|
|
|
|
static inline void metadata_access_disable(void)
|
|
{
|
|
kasan_enable_current();
|
|
}
|
|
|
|
/*
|
|
* Object debugging
|
|
*/
|
|
|
|
/* Verify that a pointer has an address that is valid within a slab page */
|
|
static inline int check_valid_pointer(struct kmem_cache *s,
|
|
struct slab *slab, void *object)
|
|
{
|
|
void *base;
|
|
|
|
if (!object)
|
|
return 1;
|
|
|
|
base = slab_address(slab);
|
|
object = kasan_reset_tag(object);
|
|
object = restore_red_left(s, object);
|
|
if (object < base || object >= base + slab->objects * s->size ||
|
|
(object - base) % s->size) {
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static void print_section(char *level, char *text, u8 *addr,
|
|
unsigned int length)
|
|
{
|
|
metadata_access_enable();
|
|
print_hex_dump(level, text, DUMP_PREFIX_ADDRESS,
|
|
16, 1, kasan_reset_tag((void *)addr), length, 1);
|
|
metadata_access_disable();
|
|
}
|
|
|
|
/*
|
|
* See comment in calculate_sizes().
|
|
*/
|
|
static inline bool freeptr_outside_object(struct kmem_cache *s)
|
|
{
|
|
return s->offset >= s->inuse;
|
|
}
|
|
|
|
/*
|
|
* Return offset of the end of info block which is inuse + free pointer if
|
|
* not overlapping with object.
|
|
*/
|
|
static inline unsigned int get_info_end(struct kmem_cache *s)
|
|
{
|
|
if (freeptr_outside_object(s))
|
|
return s->inuse + sizeof(void *);
|
|
else
|
|
return s->inuse;
|
|
}
|
|
|
|
static struct track *get_track(struct kmem_cache *s, void *object,
|
|
enum track_item alloc)
|
|
{
|
|
struct track *p;
|
|
|
|
p = object + get_info_end(s);
|
|
|
|
return kasan_reset_tag(p + alloc);
|
|
}
|
|
|
|
#ifdef CONFIG_STACKDEPOT
|
|
static noinline depot_stack_handle_t set_track_prepare(void)
|
|
{
|
|
depot_stack_handle_t handle;
|
|
unsigned long entries[TRACK_ADDRS_COUNT];
|
|
unsigned int nr_entries;
|
|
|
|
nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 3);
|
|
handle = stack_depot_save(entries, nr_entries, GFP_NOWAIT);
|
|
|
|
return handle;
|
|
}
|
|
#else
|
|
static inline depot_stack_handle_t set_track_prepare(void)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static void set_track_update(struct kmem_cache *s, void *object,
|
|
enum track_item alloc, unsigned long addr,
|
|
depot_stack_handle_t handle)
|
|
{
|
|
struct track *p = get_track(s, object, alloc);
|
|
|
|
#ifdef CONFIG_STACKDEPOT
|
|
p->handle = handle;
|
|
#endif
|
|
p->addr = addr;
|
|
p->cpu = smp_processor_id();
|
|
p->pid = current->pid;
|
|
p->when = jiffies;
|
|
}
|
|
|
|
static __always_inline void set_track(struct kmem_cache *s, void *object,
|
|
enum track_item alloc, unsigned long addr)
|
|
{
|
|
depot_stack_handle_t handle = set_track_prepare();
|
|
|
|
set_track_update(s, object, alloc, addr, handle);
|
|
}
|
|
|
|
static void init_tracking(struct kmem_cache *s, void *object)
|
|
{
|
|
struct track *p;
|
|
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
return;
|
|
|
|
p = get_track(s, object, TRACK_ALLOC);
|
|
memset(p, 0, 2*sizeof(struct track));
|
|
}
|
|
|
|
static void print_track(const char *s, struct track *t, unsigned long pr_time)
|
|
{
|
|
depot_stack_handle_t handle __maybe_unused;
|
|
|
|
if (!t->addr)
|
|
return;
|
|
|
|
pr_err("%s in %pS age=%lu cpu=%u pid=%d\n",
|
|
s, (void *)t->addr, pr_time - t->when, t->cpu, t->pid);
|
|
#ifdef CONFIG_STACKDEPOT
|
|
handle = READ_ONCE(t->handle);
|
|
if (handle)
|
|
stack_depot_print(handle);
|
|
else
|
|
pr_err("object allocation/free stack trace missing\n");
|
|
#endif
|
|
}
|
|
|
|
void print_tracking(struct kmem_cache *s, void *object)
|
|
{
|
|
unsigned long pr_time = jiffies;
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
return;
|
|
|
|
print_track("Allocated", get_track(s, object, TRACK_ALLOC), pr_time);
|
|
print_track("Freed", get_track(s, object, TRACK_FREE), pr_time);
|
|
}
|
|
|
|
static void print_slab_info(const struct slab *slab)
|
|
{
|
|
struct folio *folio = (struct folio *)slab_folio(slab);
|
|
|
|
pr_err("Slab 0x%p objects=%u used=%u fp=0x%p flags=%pGp\n",
|
|
slab, slab->objects, slab->inuse, slab->freelist,
|
|
folio_flags(folio, 0));
|
|
}
|
|
|
|
/*
|
|
* kmalloc caches has fixed sizes (mostly power of 2), and kmalloc() API
|
|
* family will round up the real request size to these fixed ones, so
|
|
* there could be an extra area than what is requested. Save the original
|
|
* request size in the meta data area, for better debug and sanity check.
|
|
*/
|
|
static inline void set_orig_size(struct kmem_cache *s,
|
|
void *object, unsigned int orig_size)
|
|
{
|
|
void *p = kasan_reset_tag(object);
|
|
unsigned int kasan_meta_size;
|
|
|
|
if (!slub_debug_orig_size(s))
|
|
return;
|
|
|
|
/*
|
|
* KASAN can save its free meta data inside of the object at offset 0.
|
|
* If this meta data size is larger than 'orig_size', it will overlap
|
|
* the data redzone in [orig_size+1, object_size]. Thus, we adjust
|
|
* 'orig_size' to be as at least as big as KASAN's meta data.
|
|
*/
|
|
kasan_meta_size = kasan_metadata_size(s, true);
|
|
if (kasan_meta_size > orig_size)
|
|
orig_size = kasan_meta_size;
|
|
|
|
p += get_info_end(s);
|
|
p += sizeof(struct track) * 2;
|
|
|
|
*(unsigned int *)p = orig_size;
|
|
}
|
|
|
|
static inline unsigned int get_orig_size(struct kmem_cache *s, void *object)
|
|
{
|
|
void *p = kasan_reset_tag(object);
|
|
|
|
if (!slub_debug_orig_size(s))
|
|
return s->object_size;
|
|
|
|
p += get_info_end(s);
|
|
p += sizeof(struct track) * 2;
|
|
|
|
return *(unsigned int *)p;
|
|
}
|
|
|
|
void skip_orig_size_check(struct kmem_cache *s, const void *object)
|
|
{
|
|
set_orig_size(s, (void *)object, s->object_size);
|
|
}
|
|
|
|
static void slab_bug(struct kmem_cache *s, char *fmt, ...)
|
|
{
|
|
struct va_format vaf;
|
|
va_list args;
|
|
|
|
va_start(args, fmt);
|
|
vaf.fmt = fmt;
|
|
vaf.va = &args;
|
|
pr_err("=============================================================================\n");
|
|
pr_err("BUG %s (%s): %pV\n", s->name, print_tainted(), &vaf);
|
|
pr_err("-----------------------------------------------------------------------------\n\n");
|
|
va_end(args);
|
|
}
|
|
|
|
__printf(2, 3)
|
|
static void slab_fix(struct kmem_cache *s, char *fmt, ...)
|
|
{
|
|
struct va_format vaf;
|
|
va_list args;
|
|
|
|
if (slab_add_kunit_errors())
|
|
return;
|
|
|
|
va_start(args, fmt);
|
|
vaf.fmt = fmt;
|
|
vaf.va = &args;
|
|
pr_err("FIX %s: %pV\n", s->name, &vaf);
|
|
va_end(args);
|
|
}
|
|
|
|
static void print_trailer(struct kmem_cache *s, struct slab *slab, u8 *p)
|
|
{
|
|
unsigned int off; /* Offset of last byte */
|
|
u8 *addr = slab_address(slab);
|
|
|
|
print_tracking(s, p);
|
|
|
|
print_slab_info(slab);
|
|
|
|
pr_err("Object 0x%p @offset=%tu fp=0x%p\n\n",
|
|
p, p - addr, get_freepointer(s, p));
|
|
|
|
if (s->flags & SLAB_RED_ZONE)
|
|
print_section(KERN_ERR, "Redzone ", p - s->red_left_pad,
|
|
s->red_left_pad);
|
|
else if (p > addr + 16)
|
|
print_section(KERN_ERR, "Bytes b4 ", p - 16, 16);
|
|
|
|
print_section(KERN_ERR, "Object ", p,
|
|
min_t(unsigned int, s->object_size, PAGE_SIZE));
|
|
if (s->flags & SLAB_RED_ZONE)
|
|
print_section(KERN_ERR, "Redzone ", p + s->object_size,
|
|
s->inuse - s->object_size);
|
|
|
|
off = get_info_end(s);
|
|
|
|
if (s->flags & SLAB_STORE_USER)
|
|
off += 2 * sizeof(struct track);
|
|
|
|
if (slub_debug_orig_size(s))
|
|
off += sizeof(unsigned int);
|
|
|
|
off += kasan_metadata_size(s, false);
|
|
|
|
if (off != size_from_object(s))
|
|
/* Beginning of the filler is the free pointer */
|
|
print_section(KERN_ERR, "Padding ", p + off,
|
|
size_from_object(s) - off);
|
|
|
|
dump_stack();
|
|
}
|
|
|
|
static void object_err(struct kmem_cache *s, struct slab *slab,
|
|
u8 *object, char *reason)
|
|
{
|
|
if (slab_add_kunit_errors())
|
|
return;
|
|
|
|
slab_bug(s, "%s", reason);
|
|
print_trailer(s, slab, object);
|
|
add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
|
|
}
|
|
|
|
static bool freelist_corrupted(struct kmem_cache *s, struct slab *slab,
|
|
void **freelist, void *nextfree)
|
|
{
|
|
if ((s->flags & SLAB_CONSISTENCY_CHECKS) &&
|
|
!check_valid_pointer(s, slab, nextfree) && freelist) {
|
|
object_err(s, slab, *freelist, "Freechain corrupt");
|
|
*freelist = NULL;
|
|
slab_fix(s, "Isolate corrupted freechain");
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static __printf(3, 4) void slab_err(struct kmem_cache *s, struct slab *slab,
|
|
const char *fmt, ...)
|
|
{
|
|
va_list args;
|
|
char buf[100];
|
|
|
|
if (slab_add_kunit_errors())
|
|
return;
|
|
|
|
va_start(args, fmt);
|
|
vsnprintf(buf, sizeof(buf), fmt, args);
|
|
va_end(args);
|
|
slab_bug(s, "%s", buf);
|
|
print_slab_info(slab);
|
|
dump_stack();
|
|
add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
|
|
}
|
|
|
|
static void init_object(struct kmem_cache *s, void *object, u8 val)
|
|
{
|
|
u8 *p = kasan_reset_tag(object);
|
|
unsigned int poison_size = s->object_size;
|
|
|
|
if (s->flags & SLAB_RED_ZONE) {
|
|
memset(p - s->red_left_pad, val, s->red_left_pad);
|
|
|
|
if (slub_debug_orig_size(s) && val == SLUB_RED_ACTIVE) {
|
|
/*
|
|
* Redzone the extra allocated space by kmalloc than
|
|
* requested, and the poison size will be limited to
|
|
* the original request size accordingly.
|
|
*/
|
|
poison_size = get_orig_size(s, object);
|
|
}
|
|
}
|
|
|
|
if (s->flags & __OBJECT_POISON) {
|
|
memset(p, POISON_FREE, poison_size - 1);
|
|
p[poison_size - 1] = POISON_END;
|
|
}
|
|
|
|
if (s->flags & SLAB_RED_ZONE)
|
|
memset(p + poison_size, val, s->inuse - poison_size);
|
|
}
|
|
|
|
static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
|
|
void *from, void *to)
|
|
{
|
|
slab_fix(s, "Restoring %s 0x%p-0x%p=0x%x", message, from, to - 1, data);
|
|
memset(from, data, to - from);
|
|
}
|
|
|
|
static int check_bytes_and_report(struct kmem_cache *s, struct slab *slab,
|
|
u8 *object, char *what,
|
|
u8 *start, unsigned int value, unsigned int bytes)
|
|
{
|
|
u8 *fault;
|
|
u8 *end;
|
|
u8 *addr = slab_address(slab);
|
|
|
|
metadata_access_enable();
|
|
fault = memchr_inv(kasan_reset_tag(start), value, bytes);
|
|
metadata_access_disable();
|
|
if (!fault)
|
|
return 1;
|
|
|
|
end = start + bytes;
|
|
while (end > fault && end[-1] == value)
|
|
end--;
|
|
|
|
if (slab_add_kunit_errors())
|
|
goto skip_bug_print;
|
|
|
|
slab_bug(s, "%s overwritten", what);
|
|
pr_err("0x%p-0x%p @offset=%tu. First byte 0x%x instead of 0x%x\n",
|
|
fault, end - 1, fault - addr,
|
|
fault[0], value);
|
|
print_trailer(s, slab, object);
|
|
add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
|
|
|
|
skip_bug_print:
|
|
restore_bytes(s, what, value, fault, end);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Object layout:
|
|
*
|
|
* object address
|
|
* Bytes of the object to be managed.
|
|
* If the freepointer may overlay the object then the free
|
|
* pointer is at the middle of the object.
|
|
*
|
|
* Poisoning uses 0x6b (POISON_FREE) and the last byte is
|
|
* 0xa5 (POISON_END)
|
|
*
|
|
* object + s->object_size
|
|
* Padding to reach word boundary. This is also used for Redzoning.
|
|
* Padding is extended by another word if Redzoning is enabled and
|
|
* object_size == inuse.
|
|
*
|
|
* We fill with 0xbb (RED_INACTIVE) for inactive objects and with
|
|
* 0xcc (RED_ACTIVE) for objects in use.
|
|
*
|
|
* object + s->inuse
|
|
* Meta data starts here.
|
|
*
|
|
* A. Free pointer (if we cannot overwrite object on free)
|
|
* B. Tracking data for SLAB_STORE_USER
|
|
* C. Original request size for kmalloc object (SLAB_STORE_USER enabled)
|
|
* D. Padding to reach required alignment boundary or at minimum
|
|
* one word if debugging is on to be able to detect writes
|
|
* before the word boundary.
|
|
*
|
|
* Padding is done using 0x5a (POISON_INUSE)
|
|
*
|
|
* object + s->size
|
|
* Nothing is used beyond s->size.
|
|
*
|
|
* If slabcaches are merged then the object_size and inuse boundaries are mostly
|
|
* ignored. And therefore no slab options that rely on these boundaries
|
|
* may be used with merged slabcaches.
|
|
*/
|
|
|
|
static int check_pad_bytes(struct kmem_cache *s, struct slab *slab, u8 *p)
|
|
{
|
|
unsigned long off = get_info_end(s); /* The end of info */
|
|
|
|
if (s->flags & SLAB_STORE_USER) {
|
|
/* We also have user information there */
|
|
off += 2 * sizeof(struct track);
|
|
|
|
if (s->flags & SLAB_KMALLOC)
|
|
off += sizeof(unsigned int);
|
|
}
|
|
|
|
off += kasan_metadata_size(s, false);
|
|
|
|
if (size_from_object(s) == off)
|
|
return 1;
|
|
|
|
return check_bytes_and_report(s, slab, p, "Object padding",
|
|
p + off, POISON_INUSE, size_from_object(s) - off);
|
|
}
|
|
|
|
/* Check the pad bytes at the end of a slab page */
|
|
static void slab_pad_check(struct kmem_cache *s, struct slab *slab)
|
|
{
|
|
u8 *start;
|
|
u8 *fault;
|
|
u8 *end;
|
|
u8 *pad;
|
|
int length;
|
|
int remainder;
|
|
|
|
if (!(s->flags & SLAB_POISON))
|
|
return;
|
|
|
|
start = slab_address(slab);
|
|
length = slab_size(slab);
|
|
end = start + length;
|
|
remainder = length % s->size;
|
|
if (!remainder)
|
|
return;
|
|
|
|
pad = end - remainder;
|
|
metadata_access_enable();
|
|
fault = memchr_inv(kasan_reset_tag(pad), POISON_INUSE, remainder);
|
|
metadata_access_disable();
|
|
if (!fault)
|
|
return;
|
|
while (end > fault && end[-1] == POISON_INUSE)
|
|
end--;
|
|
|
|
slab_err(s, slab, "Padding overwritten. 0x%p-0x%p @offset=%tu",
|
|
fault, end - 1, fault - start);
|
|
print_section(KERN_ERR, "Padding ", pad, remainder);
|
|
|
|
restore_bytes(s, "slab padding", POISON_INUSE, fault, end);
|
|
}
|
|
|
|
static int check_object(struct kmem_cache *s, struct slab *slab,
|
|
void *object, u8 val)
|
|
{
|
|
u8 *p = object;
|
|
u8 *endobject = object + s->object_size;
|
|
unsigned int orig_size, kasan_meta_size;
|
|
|
|
if (s->flags & SLAB_RED_ZONE) {
|
|
if (!check_bytes_and_report(s, slab, object, "Left Redzone",
|
|
object - s->red_left_pad, val, s->red_left_pad))
|
|
return 0;
|
|
|
|
if (!check_bytes_and_report(s, slab, object, "Right Redzone",
|
|
endobject, val, s->inuse - s->object_size))
|
|
return 0;
|
|
|
|
if (slub_debug_orig_size(s) && val == SLUB_RED_ACTIVE) {
|
|
orig_size = get_orig_size(s, object);
|
|
|
|
if (s->object_size > orig_size &&
|
|
!check_bytes_and_report(s, slab, object,
|
|
"kmalloc Redzone", p + orig_size,
|
|
val, s->object_size - orig_size)) {
|
|
return 0;
|
|
}
|
|
}
|
|
} else {
|
|
if ((s->flags & SLAB_POISON) && s->object_size < s->inuse) {
|
|
check_bytes_and_report(s, slab, p, "Alignment padding",
|
|
endobject, POISON_INUSE,
|
|
s->inuse - s->object_size);
|
|
}
|
|
}
|
|
|
|
if (s->flags & SLAB_POISON) {
|
|
if (val != SLUB_RED_ACTIVE && (s->flags & __OBJECT_POISON)) {
|
|
/*
|
|
* KASAN can save its free meta data inside of the
|
|
* object at offset 0. Thus, skip checking the part of
|
|
* the redzone that overlaps with the meta data.
|
|
*/
|
|
kasan_meta_size = kasan_metadata_size(s, true);
|
|
if (kasan_meta_size < s->object_size - 1 &&
|
|
!check_bytes_and_report(s, slab, p, "Poison",
|
|
p + kasan_meta_size, POISON_FREE,
|
|
s->object_size - kasan_meta_size - 1))
|
|
return 0;
|
|
if (kasan_meta_size < s->object_size &&
|
|
!check_bytes_and_report(s, slab, p, "End Poison",
|
|
p + s->object_size - 1, POISON_END, 1))
|
|
return 0;
|
|
}
|
|
/*
|
|
* check_pad_bytes cleans up on its own.
|
|
*/
|
|
check_pad_bytes(s, slab, p);
|
|
}
|
|
|
|
if (!freeptr_outside_object(s) && val == SLUB_RED_ACTIVE)
|
|
/*
|
|
* Object and freepointer overlap. Cannot check
|
|
* freepointer while object is allocated.
|
|
*/
|
|
return 1;
|
|
|
|
/* Check free pointer validity */
|
|
if (!check_valid_pointer(s, slab, get_freepointer(s, p))) {
|
|
object_err(s, slab, p, "Freepointer corrupt");
|
|
/*
|
|
* No choice but to zap it and thus lose the remainder
|
|
* of the free objects in this slab. May cause
|
|
* another error because the object count is now wrong.
|
|
*/
|
|
set_freepointer(s, p, NULL);
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int check_slab(struct kmem_cache *s, struct slab *slab)
|
|
{
|
|
int maxobj;
|
|
|
|
if (!folio_test_slab(slab_folio(slab))) {
|
|
slab_err(s, slab, "Not a valid slab page");
|
|
return 0;
|
|
}
|
|
|
|
maxobj = order_objects(slab_order(slab), s->size);
|
|
if (slab->objects > maxobj) {
|
|
slab_err(s, slab, "objects %u > max %u",
|
|
slab->objects, maxobj);
|
|
return 0;
|
|
}
|
|
if (slab->inuse > slab->objects) {
|
|
slab_err(s, slab, "inuse %u > max %u",
|
|
slab->inuse, slab->objects);
|
|
return 0;
|
|
}
|
|
/* Slab_pad_check fixes things up after itself */
|
|
slab_pad_check(s, slab);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Determine if a certain object in a slab is on the freelist. Must hold the
|
|
* slab lock to guarantee that the chains are in a consistent state.
|
|
*/
|
|
static int on_freelist(struct kmem_cache *s, struct slab *slab, void *search)
|
|
{
|
|
int nr = 0;
|
|
void *fp;
|
|
void *object = NULL;
|
|
int max_objects;
|
|
|
|
fp = slab->freelist;
|
|
while (fp && nr <= slab->objects) {
|
|
if (fp == search)
|
|
return 1;
|
|
if (!check_valid_pointer(s, slab, fp)) {
|
|
if (object) {
|
|
object_err(s, slab, object,
|
|
"Freechain corrupt");
|
|
set_freepointer(s, object, NULL);
|
|
} else {
|
|
slab_err(s, slab, "Freepointer corrupt");
|
|
slab->freelist = NULL;
|
|
slab->inuse = slab->objects;
|
|
slab_fix(s, "Freelist cleared");
|
|
return 0;
|
|
}
|
|
break;
|
|
}
|
|
object = fp;
|
|
fp = get_freepointer(s, object);
|
|
nr++;
|
|
}
|
|
|
|
max_objects = order_objects(slab_order(slab), s->size);
|
|
if (max_objects > MAX_OBJS_PER_PAGE)
|
|
max_objects = MAX_OBJS_PER_PAGE;
|
|
|
|
if (slab->objects != max_objects) {
|
|
slab_err(s, slab, "Wrong number of objects. Found %d but should be %d",
|
|
slab->objects, max_objects);
|
|
slab->objects = max_objects;
|
|
slab_fix(s, "Number of objects adjusted");
|
|
}
|
|
if (slab->inuse != slab->objects - nr) {
|
|
slab_err(s, slab, "Wrong object count. Counter is %d but counted were %d",
|
|
slab->inuse, slab->objects - nr);
|
|
slab->inuse = slab->objects - nr;
|
|
slab_fix(s, "Object count adjusted");
|
|
}
|
|
return search == NULL;
|
|
}
|
|
|
|
static void trace(struct kmem_cache *s, struct slab *slab, void *object,
|
|
int alloc)
|
|
{
|
|
if (s->flags & SLAB_TRACE) {
|
|
pr_info("TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
|
|
s->name,
|
|
alloc ? "alloc" : "free",
|
|
object, slab->inuse,
|
|
slab->freelist);
|
|
|
|
if (!alloc)
|
|
print_section(KERN_INFO, "Object ", (void *)object,
|
|
s->object_size);
|
|
|
|
dump_stack();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Tracking of fully allocated slabs for debugging purposes.
|
|
*/
|
|
static void add_full(struct kmem_cache *s,
|
|
struct kmem_cache_node *n, struct slab *slab)
|
|
{
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
return;
|
|
|
|
lockdep_assert_held(&n->list_lock);
|
|
list_add(&slab->slab_list, &n->full);
|
|
}
|
|
|
|
static void remove_full(struct kmem_cache *s, struct kmem_cache_node *n, struct slab *slab)
|
|
{
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
return;
|
|
|
|
lockdep_assert_held(&n->list_lock);
|
|
list_del(&slab->slab_list);
|
|
}
|
|
|
|
static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
|
|
{
|
|
return atomic_long_read(&n->nr_slabs);
|
|
}
|
|
|
|
static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects)
|
|
{
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
atomic_long_inc(&n->nr_slabs);
|
|
atomic_long_add(objects, &n->total_objects);
|
|
}
|
|
static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects)
|
|
{
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
atomic_long_dec(&n->nr_slabs);
|
|
atomic_long_sub(objects, &n->total_objects);
|
|
}
|
|
|
|
/* Object debug checks for alloc/free paths */
|
|
static void setup_object_debug(struct kmem_cache *s, void *object)
|
|
{
|
|
if (!kmem_cache_debug_flags(s, SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON))
|
|
return;
|
|
|
|
init_object(s, object, SLUB_RED_INACTIVE);
|
|
init_tracking(s, object);
|
|
}
|
|
|
|
static
|
|
void setup_slab_debug(struct kmem_cache *s, struct slab *slab, void *addr)
|
|
{
|
|
if (!kmem_cache_debug_flags(s, SLAB_POISON))
|
|
return;
|
|
|
|
metadata_access_enable();
|
|
memset(kasan_reset_tag(addr), POISON_INUSE, slab_size(slab));
|
|
metadata_access_disable();
|
|
}
|
|
|
|
static inline int alloc_consistency_checks(struct kmem_cache *s,
|
|
struct slab *slab, void *object)
|
|
{
|
|
if (!check_slab(s, slab))
|
|
return 0;
|
|
|
|
if (!check_valid_pointer(s, slab, object)) {
|
|
object_err(s, slab, object, "Freelist Pointer check fails");
|
|
return 0;
|
|
}
|
|
|
|
if (!check_object(s, slab, object, SLUB_RED_INACTIVE))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static noinline bool alloc_debug_processing(struct kmem_cache *s,
|
|
struct slab *slab, void *object, int orig_size)
|
|
{
|
|
if (s->flags & SLAB_CONSISTENCY_CHECKS) {
|
|
if (!alloc_consistency_checks(s, slab, object))
|
|
goto bad;
|
|
}
|
|
|
|
/* Success. Perform special debug activities for allocs */
|
|
trace(s, slab, object, 1);
|
|
set_orig_size(s, object, orig_size);
|
|
init_object(s, object, SLUB_RED_ACTIVE);
|
|
return true;
|
|
|
|
bad:
|
|
if (folio_test_slab(slab_folio(slab))) {
|
|
/*
|
|
* 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 remaining objects.
|
|
*/
|
|
slab_fix(s, "Marking all objects used");
|
|
slab->inuse = slab->objects;
|
|
slab->freelist = NULL;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static inline int free_consistency_checks(struct kmem_cache *s,
|
|
struct slab *slab, void *object, unsigned long addr)
|
|
{
|
|
if (!check_valid_pointer(s, slab, object)) {
|
|
slab_err(s, slab, "Invalid object pointer 0x%p", object);
|
|
return 0;
|
|
}
|
|
|
|
if (on_freelist(s, slab, object)) {
|
|
object_err(s, slab, object, "Object already free");
|
|
return 0;
|
|
}
|
|
|
|
if (!check_object(s, slab, object, SLUB_RED_ACTIVE))
|
|
return 0;
|
|
|
|
if (unlikely(s != slab->slab_cache)) {
|
|
if (!folio_test_slab(slab_folio(slab))) {
|
|
slab_err(s, slab, "Attempt to free object(0x%p) outside of slab",
|
|
object);
|
|
} else if (!slab->slab_cache) {
|
|
pr_err("SLUB <none>: no slab for object 0x%p.\n",
|
|
object);
|
|
dump_stack();
|
|
} else
|
|
object_err(s, slab, object,
|
|
"page slab pointer corrupt.");
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Parse a block of slab_debug options. Blocks are delimited by ';'
|
|
*
|
|
* @str: start of block
|
|
* @flags: returns parsed flags, or DEBUG_DEFAULT_FLAGS if none specified
|
|
* @slabs: return start of list of slabs, or NULL when there's no list
|
|
* @init: assume this is initial parsing and not per-kmem-create parsing
|
|
*
|
|
* returns the start of next block if there's any, or NULL
|
|
*/
|
|
static char *
|
|
parse_slub_debug_flags(char *str, slab_flags_t *flags, char **slabs, bool init)
|
|
{
|
|
bool higher_order_disable = false;
|
|
|
|
/* Skip any completely empty blocks */
|
|
while (*str && *str == ';')
|
|
str++;
|
|
|
|
if (*str == ',') {
|
|
/*
|
|
* No options but restriction on slabs. This means full
|
|
* debugging for slabs matching a pattern.
|
|
*/
|
|
*flags = DEBUG_DEFAULT_FLAGS;
|
|
goto check_slabs;
|
|
}
|
|
*flags = 0;
|
|
|
|
/* Determine which debug features should be switched on */
|
|
for (; *str && *str != ',' && *str != ';'; str++) {
|
|
switch (tolower(*str)) {
|
|
case '-':
|
|
*flags = 0;
|
|
break;
|
|
case 'f':
|
|
*flags |= SLAB_CONSISTENCY_CHECKS;
|
|
break;
|
|
case 'z':
|
|
*flags |= SLAB_RED_ZONE;
|
|
break;
|
|
case 'p':
|
|
*flags |= SLAB_POISON;
|
|
break;
|
|
case 'u':
|
|
*flags |= SLAB_STORE_USER;
|
|
break;
|
|
case 't':
|
|
*flags |= SLAB_TRACE;
|
|
break;
|
|
case 'a':
|
|
*flags |= SLAB_FAILSLAB;
|
|
break;
|
|
case 'o':
|
|
/*
|
|
* Avoid enabling debugging on caches if its minimum
|
|
* order would increase as a result.
|
|
*/
|
|
higher_order_disable = true;
|
|
break;
|
|
default:
|
|
if (init)
|
|
pr_err("slab_debug option '%c' unknown. skipped\n", *str);
|
|
}
|
|
}
|
|
check_slabs:
|
|
if (*str == ',')
|
|
*slabs = ++str;
|
|
else
|
|
*slabs = NULL;
|
|
|
|
/* Skip over the slab list */
|
|
while (*str && *str != ';')
|
|
str++;
|
|
|
|
/* Skip any completely empty blocks */
|
|
while (*str && *str == ';')
|
|
str++;
|
|
|
|
if (init && higher_order_disable)
|
|
disable_higher_order_debug = 1;
|
|
|
|
if (*str)
|
|
return str;
|
|
else
|
|
return NULL;
|
|
}
|
|
|
|
static int __init setup_slub_debug(char *str)
|
|
{
|
|
slab_flags_t flags;
|
|
slab_flags_t global_flags;
|
|
char *saved_str;
|
|
char *slab_list;
|
|
bool global_slub_debug_changed = false;
|
|
bool slab_list_specified = false;
|
|
|
|
global_flags = DEBUG_DEFAULT_FLAGS;
|
|
if (*str++ != '=' || !*str)
|
|
/*
|
|
* No options specified. Switch on full debugging.
|
|
*/
|
|
goto out;
|
|
|
|
saved_str = str;
|
|
while (str) {
|
|
str = parse_slub_debug_flags(str, &flags, &slab_list, true);
|
|
|
|
if (!slab_list) {
|
|
global_flags = flags;
|
|
global_slub_debug_changed = true;
|
|
} else {
|
|
slab_list_specified = true;
|
|
if (flags & SLAB_STORE_USER)
|
|
stack_depot_request_early_init();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* For backwards compatibility, a single list of flags with list of
|
|
* slabs means debugging is only changed for those slabs, so the global
|
|
* slab_debug should be unchanged (0 or DEBUG_DEFAULT_FLAGS, depending
|
|
* on CONFIG_SLUB_DEBUG_ON). We can extended that to multiple lists as
|
|
* long as there is no option specifying flags without a slab list.
|
|
*/
|
|
if (slab_list_specified) {
|
|
if (!global_slub_debug_changed)
|
|
global_flags = slub_debug;
|
|
slub_debug_string = saved_str;
|
|
}
|
|
out:
|
|
slub_debug = global_flags;
|
|
if (slub_debug & SLAB_STORE_USER)
|
|
stack_depot_request_early_init();
|
|
if (slub_debug != 0 || slub_debug_string)
|
|
static_branch_enable(&slub_debug_enabled);
|
|
else
|
|
static_branch_disable(&slub_debug_enabled);
|
|
if ((static_branch_unlikely(&init_on_alloc) ||
|
|
static_branch_unlikely(&init_on_free)) &&
|
|
(slub_debug & SLAB_POISON))
|
|
pr_info("mem auto-init: SLAB_POISON will take precedence over init_on_alloc/init_on_free\n");
|
|
return 1;
|
|
}
|
|
|
|
__setup("slab_debug", setup_slub_debug);
|
|
__setup_param("slub_debug", slub_debug, setup_slub_debug, 0);
|
|
|
|
/*
|
|
* kmem_cache_flags - apply debugging options to the cache
|
|
* @flags: flags to set
|
|
* @name: name of the cache
|
|
*
|
|
* Debug option(s) are applied to @flags. In addition to the debug
|
|
* option(s), if a slab name (or multiple) is specified i.e.
|
|
* slab_debug=<Debug-Options>,<slab name1>,<slab name2> ...
|
|
* then only the select slabs will receive the debug option(s).
|
|
*/
|
|
slab_flags_t kmem_cache_flags(slab_flags_t flags, const char *name)
|
|
{
|
|
char *iter;
|
|
size_t len;
|
|
char *next_block;
|
|
slab_flags_t block_flags;
|
|
slab_flags_t slub_debug_local = slub_debug;
|
|
|
|
if (flags & SLAB_NO_USER_FLAGS)
|
|
return flags;
|
|
|
|
/*
|
|
* If the slab cache is for debugging (e.g. kmemleak) then
|
|
* don't store user (stack trace) information by default,
|
|
* but let the user enable it via the command line below.
|
|
*/
|
|
if (flags & SLAB_NOLEAKTRACE)
|
|
slub_debug_local &= ~SLAB_STORE_USER;
|
|
|
|
len = strlen(name);
|
|
next_block = slub_debug_string;
|
|
/* Go through all blocks of debug options, see if any matches our slab's name */
|
|
while (next_block) {
|
|
next_block = parse_slub_debug_flags(next_block, &block_flags, &iter, false);
|
|
if (!iter)
|
|
continue;
|
|
/* Found a block that has a slab list, search it */
|
|
while (*iter) {
|
|
char *end, *glob;
|
|
size_t cmplen;
|
|
|
|
end = strchrnul(iter, ',');
|
|
if (next_block && next_block < end)
|
|
end = next_block - 1;
|
|
|
|
glob = strnchr(iter, end - iter, '*');
|
|
if (glob)
|
|
cmplen = glob - iter;
|
|
else
|
|
cmplen = max_t(size_t, len, (end - iter));
|
|
|
|
if (!strncmp(name, iter, cmplen)) {
|
|
flags |= block_flags;
|
|
return flags;
|
|
}
|
|
|
|
if (!*end || *end == ';')
|
|
break;
|
|
iter = end + 1;
|
|
}
|
|
}
|
|
|
|
return flags | slub_debug_local;
|
|
}
|
|
#else /* !CONFIG_SLUB_DEBUG */
|
|
static inline void setup_object_debug(struct kmem_cache *s, void *object) {}
|
|
static inline
|
|
void setup_slab_debug(struct kmem_cache *s, struct slab *slab, void *addr) {}
|
|
|
|
static inline bool alloc_debug_processing(struct kmem_cache *s,
|
|
struct slab *slab, void *object, int orig_size) { return true; }
|
|
|
|
static inline bool free_debug_processing(struct kmem_cache *s,
|
|
struct slab *slab, void *head, void *tail, int *bulk_cnt,
|
|
unsigned long addr, depot_stack_handle_t handle) { return true; }
|
|
|
|
static inline void slab_pad_check(struct kmem_cache *s, struct slab *slab) {}
|
|
static inline int check_object(struct kmem_cache *s, struct slab *slab,
|
|
void *object, u8 val) { return 1; }
|
|
static inline depot_stack_handle_t set_track_prepare(void) { return 0; }
|
|
static inline void set_track(struct kmem_cache *s, void *object,
|
|
enum track_item alloc, unsigned long addr) {}
|
|
static inline void add_full(struct kmem_cache *s, struct kmem_cache_node *n,
|
|
struct slab *slab) {}
|
|
static inline void remove_full(struct kmem_cache *s, struct kmem_cache_node *n,
|
|
struct slab *slab) {}
|
|
slab_flags_t kmem_cache_flags(slab_flags_t flags, const char *name)
|
|
{
|
|
return flags;
|
|
}
|
|
#define slub_debug 0
|
|
|
|
#define disable_higher_order_debug 0
|
|
|
|
static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
|
|
{ return 0; }
|
|
static inline void inc_slabs_node(struct kmem_cache *s, int node,
|
|
int objects) {}
|
|
static inline void dec_slabs_node(struct kmem_cache *s, int node,
|
|
int objects) {}
|
|
|
|
#ifndef CONFIG_SLUB_TINY
|
|
static bool freelist_corrupted(struct kmem_cache *s, struct slab *slab,
|
|
void **freelist, void *nextfree)
|
|
{
|
|
return false;
|
|
}
|
|
#endif
|
|
#endif /* CONFIG_SLUB_DEBUG */
|
|
|
|
static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
|
|
{
|
|
return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
|
|
NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
|
|
}
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
static inline void memcg_free_slab_cgroups(struct slab *slab)
|
|
{
|
|
kfree(slab_objcgs(slab));
|
|
slab->memcg_data = 0;
|
|
}
|
|
|
|
static inline size_t obj_full_size(struct kmem_cache *s)
|
|
{
|
|
/*
|
|
* For each accounted object there is an extra space which is used
|
|
* to store obj_cgroup membership. Charge it too.
|
|
*/
|
|
return s->size + sizeof(struct obj_cgroup *);
|
|
}
|
|
|
|
/*
|
|
* Returns false if the allocation should fail.
|
|
*/
|
|
static bool __memcg_slab_pre_alloc_hook(struct kmem_cache *s,
|
|
struct list_lru *lru,
|
|
struct obj_cgroup **objcgp,
|
|
size_t objects, gfp_t flags)
|
|
{
|
|
/*
|
|
* The obtained objcg pointer is safe to use within the current scope,
|
|
* defined by current task or set_active_memcg() pair.
|
|
* obj_cgroup_get() is used to get a permanent reference.
|
|
*/
|
|
struct obj_cgroup *objcg = current_obj_cgroup();
|
|
if (!objcg)
|
|
return true;
|
|
|
|
if (lru) {
|
|
int ret;
|
|
struct mem_cgroup *memcg;
|
|
|
|
memcg = get_mem_cgroup_from_objcg(objcg);
|
|
ret = memcg_list_lru_alloc(memcg, lru, flags);
|
|
css_put(&memcg->css);
|
|
|
|
if (ret)
|
|
return false;
|
|
}
|
|
|
|
if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s)))
|
|
return false;
|
|
|
|
*objcgp = objcg;
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Returns false if the allocation should fail.
|
|
*/
|
|
static __fastpath_inline
|
|
bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, struct list_lru *lru,
|
|
struct obj_cgroup **objcgp, size_t objects,
|
|
gfp_t flags)
|
|
{
|
|
if (!memcg_kmem_online())
|
|
return true;
|
|
|
|
if (likely(!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT)))
|
|
return true;
|
|
|
|
return likely(__memcg_slab_pre_alloc_hook(s, lru, objcgp, objects,
|
|
flags));
|
|
}
|
|
|
|
static void __memcg_slab_post_alloc_hook(struct kmem_cache *s,
|
|
struct obj_cgroup *objcg,
|
|
gfp_t flags, size_t size,
|
|
void **p)
|
|
{
|
|
struct slab *slab;
|
|
unsigned long off;
|
|
size_t i;
|
|
|
|
flags &= gfp_allowed_mask;
|
|
|
|
for (i = 0; i < size; i++) {
|
|
if (likely(p[i])) {
|
|
slab = virt_to_slab(p[i]);
|
|
|
|
if (!slab_objcgs(slab) &&
|
|
memcg_alloc_slab_cgroups(slab, s, flags, false)) {
|
|
obj_cgroup_uncharge(objcg, obj_full_size(s));
|
|
continue;
|
|
}
|
|
|
|
off = obj_to_index(s, slab, p[i]);
|
|
obj_cgroup_get(objcg);
|
|
slab_objcgs(slab)[off] = objcg;
|
|
mod_objcg_state(objcg, slab_pgdat(slab),
|
|
cache_vmstat_idx(s), obj_full_size(s));
|
|
} else {
|
|
obj_cgroup_uncharge(objcg, obj_full_size(s));
|
|
}
|
|
}
|
|
}
|
|
|
|
static __fastpath_inline
|
|
void memcg_slab_post_alloc_hook(struct kmem_cache *s, struct obj_cgroup *objcg,
|
|
gfp_t flags, size_t size, void **p)
|
|
{
|
|
if (likely(!memcg_kmem_online() || !objcg))
|
|
return;
|
|
|
|
return __memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
|
|
}
|
|
|
|
static void __memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
|
|
void **p, int objects,
|
|
struct obj_cgroup **objcgs)
|
|
{
|
|
for (int i = 0; i < objects; i++) {
|
|
struct obj_cgroup *objcg;
|
|
unsigned int off;
|
|
|
|
off = obj_to_index(s, slab, p[i]);
|
|
objcg = objcgs[off];
|
|
if (!objcg)
|
|
continue;
|
|
|
|
objcgs[off] = NULL;
|
|
obj_cgroup_uncharge(objcg, obj_full_size(s));
|
|
mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s),
|
|
-obj_full_size(s));
|
|
obj_cgroup_put(objcg);
|
|
}
|
|
}
|
|
|
|
static __fastpath_inline
|
|
void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, void **p,
|
|
int objects)
|
|
{
|
|
struct obj_cgroup **objcgs;
|
|
|
|
if (!memcg_kmem_online())
|
|
return;
|
|
|
|
objcgs = slab_objcgs(slab);
|
|
if (likely(!objcgs))
|
|
return;
|
|
|
|
__memcg_slab_free_hook(s, slab, p, objects, objcgs);
|
|
}
|
|
|
|
static inline
|
|
void memcg_slab_alloc_error_hook(struct kmem_cache *s, int objects,
|
|
struct obj_cgroup *objcg)
|
|
{
|
|
if (objcg)
|
|
obj_cgroup_uncharge(objcg, objects * obj_full_size(s));
|
|
}
|
|
#else /* CONFIG_MEMCG_KMEM */
|
|
static inline void memcg_free_slab_cgroups(struct slab *slab)
|
|
{
|
|
}
|
|
|
|
static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
|
|
struct list_lru *lru,
|
|
struct obj_cgroup **objcgp,
|
|
size_t objects, gfp_t flags)
|
|
{
|
|
return true;
|
|
}
|
|
|
|
static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
|
|
struct obj_cgroup *objcg,
|
|
gfp_t flags, size_t size,
|
|
void **p)
|
|
{
|
|
}
|
|
|
|
static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
|
|
void **p, int objects)
|
|
{
|
|
}
|
|
|
|
static inline
|
|
void memcg_slab_alloc_error_hook(struct kmem_cache *s, int objects,
|
|
struct obj_cgroup *objcg)
|
|
{
|
|
}
|
|
#endif /* CONFIG_MEMCG_KMEM */
|
|
|
|
/*
|
|
* Hooks for other subsystems that check memory allocations. In a typical
|
|
* production configuration these hooks all should produce no code at all.
|
|
*
|
|
* Returns true if freeing of the object can proceed, false if its reuse
|
|
* was delayed by KASAN quarantine, or it was returned to KFENCE.
|
|
*/
|
|
static __always_inline
|
|
bool slab_free_hook(struct kmem_cache *s, void *x, bool init)
|
|
{
|
|
kmemleak_free_recursive(x, s->flags);
|
|
kmsan_slab_free(s, x);
|
|
|
|
debug_check_no_locks_freed(x, s->object_size);
|
|
|
|
if (!(s->flags & SLAB_DEBUG_OBJECTS))
|
|
debug_check_no_obj_freed(x, s->object_size);
|
|
|
|
/* Use KCSAN to help debug racy use-after-free. */
|
|
if (!(s->flags & SLAB_TYPESAFE_BY_RCU))
|
|
__kcsan_check_access(x, s->object_size,
|
|
KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ASSERT);
|
|
|
|
if (kfence_free(x))
|
|
return false;
|
|
|
|
/*
|
|
* As memory initialization might be integrated into KASAN,
|
|
* kasan_slab_free and initialization memset's must be
|
|
* kept together to avoid discrepancies in behavior.
|
|
*
|
|
* The initialization memset's clear the object and the metadata,
|
|
* but don't touch the SLAB redzone.
|
|
*/
|
|
if (unlikely(init)) {
|
|
int rsize;
|
|
|
|
if (!kasan_has_integrated_init())
|
|
memset(kasan_reset_tag(x), 0, s->object_size);
|
|
rsize = (s->flags & SLAB_RED_ZONE) ? s->red_left_pad : 0;
|
|
memset((char *)kasan_reset_tag(x) + s->inuse, 0,
|
|
s->size - s->inuse - rsize);
|
|
}
|
|
/* KASAN might put x into memory quarantine, delaying its reuse. */
|
|
return !kasan_slab_free(s, x, init);
|
|
}
|
|
|
|
static inline bool slab_free_freelist_hook(struct kmem_cache *s,
|
|
void **head, void **tail,
|
|
int *cnt)
|
|
{
|
|
|
|
void *object;
|
|
void *next = *head;
|
|
void *old_tail = *tail;
|
|
bool init;
|
|
|
|
if (is_kfence_address(next)) {
|
|
slab_free_hook(s, next, false);
|
|
return false;
|
|
}
|
|
|
|
/* Head and tail of the reconstructed freelist */
|
|
*head = NULL;
|
|
*tail = NULL;
|
|
|
|
init = slab_want_init_on_free(s);
|
|
|
|
do {
|
|
object = next;
|
|
next = get_freepointer(s, object);
|
|
|
|
/* If object's reuse doesn't have to be delayed */
|
|
if (likely(slab_free_hook(s, object, init))) {
|
|
/* Move object to the new freelist */
|
|
set_freepointer(s, object, *head);
|
|
*head = object;
|
|
if (!*tail)
|
|
*tail = object;
|
|
} else {
|
|
/*
|
|
* Adjust the reconstructed freelist depth
|
|
* accordingly if object's reuse is delayed.
|
|
*/
|
|
--(*cnt);
|
|
}
|
|
} while (object != old_tail);
|
|
|
|
return *head != NULL;
|
|
}
|
|
|
|
static void *setup_object(struct kmem_cache *s, void *object)
|
|
{
|
|
setup_object_debug(s, object);
|
|
object = kasan_init_slab_obj(s, object);
|
|
if (unlikely(s->ctor)) {
|
|
kasan_unpoison_new_object(s, object);
|
|
s->ctor(object);
|
|
kasan_poison_new_object(s, object);
|
|
}
|
|
return object;
|
|
}
|
|
|
|
/*
|
|
* Slab allocation and freeing
|
|
*/
|
|
static inline struct slab *alloc_slab_page(gfp_t flags, int node,
|
|
struct kmem_cache_order_objects oo)
|
|
{
|
|
struct folio *folio;
|
|
struct slab *slab;
|
|
unsigned int order = oo_order(oo);
|
|
|
|
folio = (struct folio *)alloc_pages_node(node, flags, order);
|
|
if (!folio)
|
|
return NULL;
|
|
|
|
slab = folio_slab(folio);
|
|
__folio_set_slab(folio);
|
|
/* Make the flag visible before any changes to folio->mapping */
|
|
smp_wmb();
|
|
if (folio_is_pfmemalloc(folio))
|
|
slab_set_pfmemalloc(slab);
|
|
|
|
return slab;
|
|
}
|
|
|
|
#ifdef CONFIG_SLAB_FREELIST_RANDOM
|
|
/* Pre-initialize the random sequence cache */
|
|
static int init_cache_random_seq(struct kmem_cache *s)
|
|
{
|
|
unsigned int count = oo_objects(s->oo);
|
|
int err;
|
|
|
|
/* Bailout if already initialised */
|
|
if (s->random_seq)
|
|
return 0;
|
|
|
|
err = cache_random_seq_create(s, count, GFP_KERNEL);
|
|
if (err) {
|
|
pr_err("SLUB: Unable to initialize free list for %s\n",
|
|
s->name);
|
|
return err;
|
|
}
|
|
|
|
/* Transform to an offset on the set of pages */
|
|
if (s->random_seq) {
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < count; i++)
|
|
s->random_seq[i] *= s->size;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Initialize each random sequence freelist per cache */
|
|
static void __init init_freelist_randomization(void)
|
|
{
|
|
struct kmem_cache *s;
|
|
|
|
mutex_lock(&slab_mutex);
|
|
|
|
list_for_each_entry(s, &slab_caches, list)
|
|
init_cache_random_seq(s);
|
|
|
|
mutex_unlock(&slab_mutex);
|
|
}
|
|
|
|
/* Get the next entry on the pre-computed freelist randomized */
|
|
static void *next_freelist_entry(struct kmem_cache *s,
|
|
unsigned long *pos, void *start,
|
|
unsigned long page_limit,
|
|
unsigned long freelist_count)
|
|
{
|
|
unsigned int idx;
|
|
|
|
/*
|
|
* If the target page allocation failed, the number of objects on the
|
|
* page might be smaller than the usual size defined by the cache.
|
|
*/
|
|
do {
|
|
idx = s->random_seq[*pos];
|
|
*pos += 1;
|
|
if (*pos >= freelist_count)
|
|
*pos = 0;
|
|
} while (unlikely(idx >= page_limit));
|
|
|
|
return (char *)start + idx;
|
|
}
|
|
|
|
/* Shuffle the single linked freelist based on a random pre-computed sequence */
|
|
static bool shuffle_freelist(struct kmem_cache *s, struct slab *slab)
|
|
{
|
|
void *start;
|
|
void *cur;
|
|
void *next;
|
|
unsigned long idx, pos, page_limit, freelist_count;
|
|
|
|
if (slab->objects < 2 || !s->random_seq)
|
|
return false;
|
|
|
|
freelist_count = oo_objects(s->oo);
|
|
pos = get_random_u32_below(freelist_count);
|
|
|
|
page_limit = slab->objects * s->size;
|
|
start = fixup_red_left(s, slab_address(slab));
|
|
|
|
/* First entry is used as the base of the freelist */
|
|
cur = next_freelist_entry(s, &pos, start, page_limit, freelist_count);
|
|
cur = setup_object(s, cur);
|
|
slab->freelist = cur;
|
|
|
|
for (idx = 1; idx < slab->objects; idx++) {
|
|
next = next_freelist_entry(s, &pos, start, page_limit,
|
|
freelist_count);
|
|
next = setup_object(s, next);
|
|
set_freepointer(s, cur, next);
|
|
cur = next;
|
|
}
|
|
set_freepointer(s, cur, NULL);
|
|
|
|
return true;
|
|
}
|
|
#else
|
|
static inline int init_cache_random_seq(struct kmem_cache *s)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline void init_freelist_randomization(void) { }
|
|
static inline bool shuffle_freelist(struct kmem_cache *s, struct slab *slab)
|
|
{
|
|
return false;
|
|
}
|
|
#endif /* CONFIG_SLAB_FREELIST_RANDOM */
|
|
|
|
static __always_inline void account_slab(struct slab *slab, int order,
|
|
struct kmem_cache *s, gfp_t gfp)
|
|
{
|
|
if (memcg_kmem_online() && (s->flags & SLAB_ACCOUNT))
|
|
memcg_alloc_slab_cgroups(slab, s, gfp, true);
|
|
|
|
mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
|
|
PAGE_SIZE << order);
|
|
}
|
|
|
|
static __always_inline void unaccount_slab(struct slab *slab, int order,
|
|
struct kmem_cache *s)
|
|
{
|
|
if (memcg_kmem_online())
|
|
memcg_free_slab_cgroups(slab);
|
|
|
|
mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
|
|
-(PAGE_SIZE << order));
|
|
}
|
|
|
|
static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
|
|
{
|
|
struct slab *slab;
|
|
struct kmem_cache_order_objects oo = s->oo;
|
|
gfp_t alloc_gfp;
|
|
void *start, *p, *next;
|
|
int idx;
|
|
bool shuffle;
|
|
|
|
flags &= gfp_allowed_mask;
|
|
|
|
flags |= s->allocflags;
|
|
|
|
/*
|
|
* Let the initial higher-order allocation fail under memory pressure
|
|
* so we fall-back to the minimum order allocation.
|
|
*/
|
|
alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL;
|
|
if ((alloc_gfp & __GFP_DIRECT_RECLAIM) && oo_order(oo) > oo_order(s->min))
|
|
alloc_gfp = (alloc_gfp | __GFP_NOMEMALLOC) & ~__GFP_RECLAIM;
|
|
|
|
slab = alloc_slab_page(alloc_gfp, node, oo);
|
|
if (unlikely(!slab)) {
|
|
oo = s->min;
|
|
alloc_gfp = flags;
|
|
/*
|
|
* Allocation may have failed due to fragmentation.
|
|
* Try a lower order alloc if possible
|
|
*/
|
|
slab = alloc_slab_page(alloc_gfp, node, oo);
|
|
if (unlikely(!slab))
|
|
return NULL;
|
|
stat(s, ORDER_FALLBACK);
|
|
}
|
|
|
|
slab->objects = oo_objects(oo);
|
|
slab->inuse = 0;
|
|
slab->frozen = 0;
|
|
|
|
account_slab(slab, oo_order(oo), s, flags);
|
|
|
|
slab->slab_cache = s;
|
|
|
|
kasan_poison_slab(slab);
|
|
|
|
start = slab_address(slab);
|
|
|
|
setup_slab_debug(s, slab, start);
|
|
|
|
shuffle = shuffle_freelist(s, slab);
|
|
|
|
if (!shuffle) {
|
|
start = fixup_red_left(s, start);
|
|
start = setup_object(s, start);
|
|
slab->freelist = start;
|
|
for (idx = 0, p = start; idx < slab->objects - 1; idx++) {
|
|
next = p + s->size;
|
|
next = setup_object(s, next);
|
|
set_freepointer(s, p, next);
|
|
p = next;
|
|
}
|
|
set_freepointer(s, p, NULL);
|
|
}
|
|
|
|
return slab;
|
|
}
|
|
|
|
static struct slab *new_slab(struct kmem_cache *s, gfp_t flags, int node)
|
|
{
|
|
if (unlikely(flags & GFP_SLAB_BUG_MASK))
|
|
flags = kmalloc_fix_flags(flags);
|
|
|
|
WARN_ON_ONCE(s->ctor && (flags & __GFP_ZERO));
|
|
|
|
return allocate_slab(s,
|
|
flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
|
|
}
|
|
|
|
static void __free_slab(struct kmem_cache *s, struct slab *slab)
|
|
{
|
|
struct folio *folio = slab_folio(slab);
|
|
int order = folio_order(folio);
|
|
int pages = 1 << order;
|
|
|
|
__slab_clear_pfmemalloc(slab);
|
|
folio->mapping = NULL;
|
|
/* Make the mapping reset visible before clearing the flag */
|
|
smp_wmb();
|
|
__folio_clear_slab(folio);
|
|
mm_account_reclaimed_pages(pages);
|
|
unaccount_slab(slab, order, s);
|
|
__free_pages(&folio->page, order);
|
|
}
|
|
|
|
static void rcu_free_slab(struct rcu_head *h)
|
|
{
|
|
struct slab *slab = container_of(h, struct slab, rcu_head);
|
|
|
|
__free_slab(slab->slab_cache, slab);
|
|
}
|
|
|
|
static void free_slab(struct kmem_cache *s, struct slab *slab)
|
|
{
|
|
if (kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS)) {
|
|
void *p;
|
|
|
|
slab_pad_check(s, slab);
|
|
for_each_object(p, s, slab_address(slab), slab->objects)
|
|
check_object(s, slab, p, SLUB_RED_INACTIVE);
|
|
}
|
|
|
|
if (unlikely(s->flags & SLAB_TYPESAFE_BY_RCU))
|
|
call_rcu(&slab->rcu_head, rcu_free_slab);
|
|
else
|
|
__free_slab(s, slab);
|
|
}
|
|
|
|
static void discard_slab(struct kmem_cache *s, struct slab *slab)
|
|
{
|
|
dec_slabs_node(s, slab_nid(slab), slab->objects);
|
|
free_slab(s, slab);
|
|
}
|
|
|
|
/*
|
|
* SLUB reuses PG_workingset bit to keep track of whether it's on
|
|
* the per-node partial list.
|
|
*/
|
|
static inline bool slab_test_node_partial(const struct slab *slab)
|
|
{
|
|
return folio_test_workingset((struct folio *)slab_folio(slab));
|
|
}
|
|
|
|
static inline void slab_set_node_partial(struct slab *slab)
|
|
{
|
|
set_bit(PG_workingset, folio_flags(slab_folio(slab), 0));
|
|
}
|
|
|
|
static inline void slab_clear_node_partial(struct slab *slab)
|
|
{
|
|
clear_bit(PG_workingset, folio_flags(slab_folio(slab), 0));
|
|
}
|
|
|
|
/*
|
|
* Management of partially allocated slabs.
|
|
*/
|
|
static inline void
|
|
__add_partial(struct kmem_cache_node *n, struct slab *slab, int tail)
|
|
{
|
|
n->nr_partial++;
|
|
if (tail == DEACTIVATE_TO_TAIL)
|
|
list_add_tail(&slab->slab_list, &n->partial);
|
|
else
|
|
list_add(&slab->slab_list, &n->partial);
|
|
slab_set_node_partial(slab);
|
|
}
|
|
|
|
static inline void add_partial(struct kmem_cache_node *n,
|
|
struct slab *slab, int tail)
|
|
{
|
|
lockdep_assert_held(&n->list_lock);
|
|
__add_partial(n, slab, tail);
|
|
}
|
|
|
|
static inline void remove_partial(struct kmem_cache_node *n,
|
|
struct slab *slab)
|
|
{
|
|
lockdep_assert_held(&n->list_lock);
|
|
list_del(&slab->slab_list);
|
|
slab_clear_node_partial(slab);
|
|
n->nr_partial--;
|
|
}
|
|
|
|
/*
|
|
* Called only for kmem_cache_debug() caches instead of remove_partial(), with a
|
|
* slab from the n->partial list. Remove only a single object from the slab, do
|
|
* the alloc_debug_processing() checks and leave the slab on the list, or move
|
|
* it to full list if it was the last free object.
|
|
*/
|
|
static void *alloc_single_from_partial(struct kmem_cache *s,
|
|
struct kmem_cache_node *n, struct slab *slab, int orig_size)
|
|
{
|
|
void *object;
|
|
|
|
lockdep_assert_held(&n->list_lock);
|
|
|
|
object = slab->freelist;
|
|
slab->freelist = get_freepointer(s, object);
|
|
slab->inuse++;
|
|
|
|
if (!alloc_debug_processing(s, slab, object, orig_size)) {
|
|
remove_partial(n, slab);
|
|
return NULL;
|
|
}
|
|
|
|
if (slab->inuse == slab->objects) {
|
|
remove_partial(n, slab);
|
|
add_full(s, n, slab);
|
|
}
|
|
|
|
return object;
|
|
}
|
|
|
|
/*
|
|
* Called only for kmem_cache_debug() caches to allocate from a freshly
|
|
* allocated slab. Allocate a single object instead of whole freelist
|
|
* and put the slab to the partial (or full) list.
|
|
*/
|
|
static void *alloc_single_from_new_slab(struct kmem_cache *s,
|
|
struct slab *slab, int orig_size)
|
|
{
|
|
int nid = slab_nid(slab);
|
|
struct kmem_cache_node *n = get_node(s, nid);
|
|
unsigned long flags;
|
|
void *object;
|
|
|
|
|
|
object = slab->freelist;
|
|
slab->freelist = get_freepointer(s, object);
|
|
slab->inuse = 1;
|
|
|
|
if (!alloc_debug_processing(s, slab, object, orig_size))
|
|
/*
|
|
* It's not really expected that this would fail on a
|
|
* freshly allocated slab, but a concurrent memory
|
|
* corruption in theory could cause that.
|
|
*/
|
|
return NULL;
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
|
|
if (slab->inuse == slab->objects)
|
|
add_full(s, n, slab);
|
|
else
|
|
add_partial(n, slab, DEACTIVATE_TO_HEAD);
|
|
|
|
inc_slabs_node(s, nid, slab->objects);
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
|
|
return object;
|
|
}
|
|
|
|
#ifdef CONFIG_SLUB_CPU_PARTIAL
|
|
static void put_cpu_partial(struct kmem_cache *s, struct slab *slab, int drain);
|
|
#else
|
|
static inline void put_cpu_partial(struct kmem_cache *s, struct slab *slab,
|
|
int drain) { }
|
|
#endif
|
|
static inline bool pfmemalloc_match(struct slab *slab, gfp_t gfpflags);
|
|
|
|
/*
|
|
* Try to allocate a partial slab from a specific node.
|
|
*/
|
|
static struct slab *get_partial_node(struct kmem_cache *s,
|
|
struct kmem_cache_node *n,
|
|
struct partial_context *pc)
|
|
{
|
|
struct slab *slab, *slab2, *partial = NULL;
|
|
unsigned long flags;
|
|
unsigned int partial_slabs = 0;
|
|
|
|
/*
|
|
* 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 and there is none available then get_partial()
|
|
* will return NULL.
|
|
*/
|
|
if (!n || !n->nr_partial)
|
|
return NULL;
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
list_for_each_entry_safe(slab, slab2, &n->partial, slab_list) {
|
|
if (!pfmemalloc_match(slab, pc->flags))
|
|
continue;
|
|
|
|
if (IS_ENABLED(CONFIG_SLUB_TINY) || kmem_cache_debug(s)) {
|
|
void *object = alloc_single_from_partial(s, n, slab,
|
|
pc->orig_size);
|
|
if (object) {
|
|
partial = slab;
|
|
pc->object = object;
|
|
break;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
remove_partial(n, slab);
|
|
|
|
if (!partial) {
|
|
partial = slab;
|
|
stat(s, ALLOC_FROM_PARTIAL);
|
|
} else {
|
|
put_cpu_partial(s, slab, 0);
|
|
stat(s, CPU_PARTIAL_NODE);
|
|
partial_slabs++;
|
|
}
|
|
#ifdef CONFIG_SLUB_CPU_PARTIAL
|
|
if (!kmem_cache_has_cpu_partial(s)
|
|
|| partial_slabs > s->cpu_partial_slabs / 2)
|
|
break;
|
|
#else
|
|
break;
|
|
#endif
|
|
|
|
}
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
return partial;
|
|
}
|
|
|
|
/*
|
|
* Get a slab from somewhere. Search in increasing NUMA distances.
|
|
*/
|
|
static struct slab *get_any_partial(struct kmem_cache *s,
|
|
struct partial_context *pc)
|
|
{
|
|
#ifdef CONFIG_NUMA
|
|
struct zonelist *zonelist;
|
|
struct zoneref *z;
|
|
struct zone *zone;
|
|
enum zone_type highest_zoneidx = gfp_zone(pc->flags);
|
|
struct slab *slab;
|
|
unsigned int cpuset_mems_cookie;
|
|
|
|
/*
|
|
* The defrag ratio allows a configuration of the tradeoffs between
|
|
* inter node defragmentation and node local allocations. A lower
|
|
* defrag_ratio increases the tendency to do local allocations
|
|
* instead of attempting to obtain partial slabs from other nodes.
|
|
*
|
|
* If the defrag_ratio is set to 0 then kmalloc() always
|
|
* returns node local objects. If the ratio is higher then kmalloc()
|
|
* may return off node objects because partial slabs are obtained
|
|
* from other nodes and filled up.
|
|
*
|
|
* If /sys/kernel/slab/xx/remote_node_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 expensive if we do it every time we are trying to find a slab
|
|
* with available objects.
|
|
*/
|
|
if (!s->remote_node_defrag_ratio ||
|
|
get_cycles() % 1024 > s->remote_node_defrag_ratio)
|
|
return NULL;
|
|
|
|
do {
|
|
cpuset_mems_cookie = read_mems_allowed_begin();
|
|
zonelist = node_zonelist(mempolicy_slab_node(), pc->flags);
|
|
for_each_zone_zonelist(zone, z, zonelist, highest_zoneidx) {
|
|
struct kmem_cache_node *n;
|
|
|
|
n = get_node(s, zone_to_nid(zone));
|
|
|
|
if (n && cpuset_zone_allowed(zone, pc->flags) &&
|
|
n->nr_partial > s->min_partial) {
|
|
slab = get_partial_node(s, n, pc);
|
|
if (slab) {
|
|
/*
|
|
* Don't check read_mems_allowed_retry()
|
|
* here - if mems_allowed was updated in
|
|
* parallel, that was a harmless race
|
|
* between allocation and the cpuset
|
|
* update
|
|
*/
|
|
return slab;
|
|
}
|
|
}
|
|
}
|
|
} while (read_mems_allowed_retry(cpuset_mems_cookie));
|
|
#endif /* CONFIG_NUMA */
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Get a partial slab, lock it and return it.
|
|
*/
|
|
static struct slab *get_partial(struct kmem_cache *s, int node,
|
|
struct partial_context *pc)
|
|
{
|
|
struct slab *slab;
|
|
int searchnode = node;
|
|
|
|
if (node == NUMA_NO_NODE)
|
|
searchnode = numa_mem_id();
|
|
|
|
slab = get_partial_node(s, get_node(s, searchnode), pc);
|
|
if (slab || node != NUMA_NO_NODE)
|
|
return slab;
|
|
|
|
return get_any_partial(s, pc);
|
|
}
|
|
|
|
#ifndef CONFIG_SLUB_TINY
|
|
|
|
#ifdef CONFIG_PREEMPTION
|
|
/*
|
|
* Calculate the next globally unique transaction for disambiguation
|
|
* during cmpxchg. The transactions start with the cpu number and are then
|
|
* incremented by CONFIG_NR_CPUS.
|
|
*/
|
|
#define TID_STEP roundup_pow_of_two(CONFIG_NR_CPUS)
|
|
#else
|
|
/*
|
|
* No preemption supported therefore also no need to check for
|
|
* different cpus.
|
|
*/
|
|
#define TID_STEP 1
|
|
#endif /* CONFIG_PREEMPTION */
|
|
|
|
static inline unsigned long next_tid(unsigned long tid)
|
|
{
|
|
return tid + TID_STEP;
|
|
}
|
|
|
|
#ifdef SLUB_DEBUG_CMPXCHG
|
|
static inline unsigned int tid_to_cpu(unsigned long tid)
|
|
{
|
|
return tid % TID_STEP;
|
|
}
|
|
|
|
static inline unsigned long tid_to_event(unsigned long tid)
|
|
{
|
|
return tid / TID_STEP;
|
|
}
|
|
#endif
|
|
|
|
static inline unsigned int init_tid(int cpu)
|
|
{
|
|
return cpu;
|
|
}
|
|
|
|
static inline void note_cmpxchg_failure(const char *n,
|
|
const struct kmem_cache *s, unsigned long tid)
|
|
{
|
|
#ifdef SLUB_DEBUG_CMPXCHG
|
|
unsigned long actual_tid = __this_cpu_read(s->cpu_slab->tid);
|
|
|
|
pr_info("%s %s: cmpxchg redo ", n, s->name);
|
|
|
|
#ifdef CONFIG_PREEMPTION
|
|
if (tid_to_cpu(tid) != tid_to_cpu(actual_tid))
|
|
pr_warn("due to cpu change %d -> %d\n",
|
|
tid_to_cpu(tid), tid_to_cpu(actual_tid));
|
|
else
|
|
#endif
|
|
if (tid_to_event(tid) != tid_to_event(actual_tid))
|
|
pr_warn("due to cpu running other code. Event %ld->%ld\n",
|
|
tid_to_event(tid), tid_to_event(actual_tid));
|
|
else
|
|
pr_warn("for unknown reason: actual=%lx was=%lx target=%lx\n",
|
|
actual_tid, tid, next_tid(tid));
|
|
#endif
|
|
stat(s, CMPXCHG_DOUBLE_CPU_FAIL);
|
|
}
|
|
|
|
static void init_kmem_cache_cpus(struct kmem_cache *s)
|
|
{
|
|
int cpu;
|
|
struct kmem_cache_cpu *c;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
c = per_cpu_ptr(s->cpu_slab, cpu);
|
|
local_lock_init(&c->lock);
|
|
c->tid = init_tid(cpu);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Finishes removing the cpu slab. Merges cpu's freelist with slab's freelist,
|
|
* unfreezes the slabs and puts it on the proper list.
|
|
* Assumes the slab has been already safely taken away from kmem_cache_cpu
|
|
* by the caller.
|
|
*/
|
|
static void deactivate_slab(struct kmem_cache *s, struct slab *slab,
|
|
void *freelist)
|
|
{
|
|
struct kmem_cache_node *n = get_node(s, slab_nid(slab));
|
|
int free_delta = 0;
|
|
void *nextfree, *freelist_iter, *freelist_tail;
|
|
int tail = DEACTIVATE_TO_HEAD;
|
|
unsigned long flags = 0;
|
|
struct slab new;
|
|
struct slab old;
|
|
|
|
if (slab->freelist) {
|
|
stat(s, DEACTIVATE_REMOTE_FREES);
|
|
tail = DEACTIVATE_TO_TAIL;
|
|
}
|
|
|
|
/*
|
|
* Stage one: Count the objects on cpu's freelist as free_delta and
|
|
* remember the last object in freelist_tail for later splicing.
|
|
*/
|
|
freelist_tail = NULL;
|
|
freelist_iter = freelist;
|
|
while (freelist_iter) {
|
|
nextfree = get_freepointer(s, freelist_iter);
|
|
|
|
/*
|
|
* If 'nextfree' is invalid, it is possible that the object at
|
|
* 'freelist_iter' is already corrupted. So isolate all objects
|
|
* starting at 'freelist_iter' by skipping them.
|
|
*/
|
|
if (freelist_corrupted(s, slab, &freelist_iter, nextfree))
|
|
break;
|
|
|
|
freelist_tail = freelist_iter;
|
|
free_delta++;
|
|
|
|
freelist_iter = nextfree;
|
|
}
|
|
|
|
/*
|
|
* Stage two: Unfreeze the slab while splicing the per-cpu
|
|
* freelist to the head of slab's freelist.
|
|
*/
|
|
do {
|
|
old.freelist = READ_ONCE(slab->freelist);
|
|
old.counters = READ_ONCE(slab->counters);
|
|
VM_BUG_ON(!old.frozen);
|
|
|
|
/* Determine target state of the slab */
|
|
new.counters = old.counters;
|
|
new.frozen = 0;
|
|
if (freelist_tail) {
|
|
new.inuse -= free_delta;
|
|
set_freepointer(s, freelist_tail, old.freelist);
|
|
new.freelist = freelist;
|
|
} else {
|
|
new.freelist = old.freelist;
|
|
}
|
|
} while (!slab_update_freelist(s, slab,
|
|
old.freelist, old.counters,
|
|
new.freelist, new.counters,
|
|
"unfreezing slab"));
|
|
|
|
/*
|
|
* Stage three: Manipulate the slab list based on the updated state.
|
|
*/
|
|
if (!new.inuse && n->nr_partial >= s->min_partial) {
|
|
stat(s, DEACTIVATE_EMPTY);
|
|
discard_slab(s, slab);
|
|
stat(s, FREE_SLAB);
|
|
} else if (new.freelist) {
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
add_partial(n, slab, tail);
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
stat(s, tail);
|
|
} else {
|
|
stat(s, DEACTIVATE_FULL);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_SLUB_CPU_PARTIAL
|
|
static void __put_partials(struct kmem_cache *s, struct slab *partial_slab)
|
|
{
|
|
struct kmem_cache_node *n = NULL, *n2 = NULL;
|
|
struct slab *slab, *slab_to_discard = NULL;
|
|
unsigned long flags = 0;
|
|
|
|
while (partial_slab) {
|
|
slab = partial_slab;
|
|
partial_slab = slab->next;
|
|
|
|
n2 = get_node(s, slab_nid(slab));
|
|
if (n != n2) {
|
|
if (n)
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
|
|
n = n2;
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
}
|
|
|
|
if (unlikely(!slab->inuse && n->nr_partial >= s->min_partial)) {
|
|
slab->next = slab_to_discard;
|
|
slab_to_discard = slab;
|
|
} else {
|
|
add_partial(n, slab, DEACTIVATE_TO_TAIL);
|
|
stat(s, FREE_ADD_PARTIAL);
|
|
}
|
|
}
|
|
|
|
if (n)
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
|
|
while (slab_to_discard) {
|
|
slab = slab_to_discard;
|
|
slab_to_discard = slab_to_discard->next;
|
|
|
|
stat(s, DEACTIVATE_EMPTY);
|
|
discard_slab(s, slab);
|
|
stat(s, FREE_SLAB);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Put all the cpu partial slabs to the node partial list.
|
|
*/
|
|
static void put_partials(struct kmem_cache *s)
|
|
{
|
|
struct slab *partial_slab;
|
|
unsigned long flags;
|
|
|
|
local_lock_irqsave(&s->cpu_slab->lock, flags);
|
|
partial_slab = this_cpu_read(s->cpu_slab->partial);
|
|
this_cpu_write(s->cpu_slab->partial, NULL);
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, flags);
|
|
|
|
if (partial_slab)
|
|
__put_partials(s, partial_slab);
|
|
}
|
|
|
|
static void put_partials_cpu(struct kmem_cache *s,
|
|
struct kmem_cache_cpu *c)
|
|
{
|
|
struct slab *partial_slab;
|
|
|
|
partial_slab = slub_percpu_partial(c);
|
|
c->partial = NULL;
|
|
|
|
if (partial_slab)
|
|
__put_partials(s, partial_slab);
|
|
}
|
|
|
|
/*
|
|
* Put a slab into a partial slab slot if available.
|
|
*
|
|
* If we did not find a slot then simply move all the partials to the
|
|
* per node partial list.
|
|
*/
|
|
static void put_cpu_partial(struct kmem_cache *s, struct slab *slab, int drain)
|
|
{
|
|
struct slab *oldslab;
|
|
struct slab *slab_to_put = NULL;
|
|
unsigned long flags;
|
|
int slabs = 0;
|
|
|
|
local_lock_irqsave(&s->cpu_slab->lock, flags);
|
|
|
|
oldslab = this_cpu_read(s->cpu_slab->partial);
|
|
|
|
if (oldslab) {
|
|
if (drain && oldslab->slabs >= s->cpu_partial_slabs) {
|
|
/*
|
|
* Partial array is full. Move the existing set to the
|
|
* per node partial list. Postpone the actual unfreezing
|
|
* outside of the critical section.
|
|
*/
|
|
slab_to_put = oldslab;
|
|
oldslab = NULL;
|
|
} else {
|
|
slabs = oldslab->slabs;
|
|
}
|
|
}
|
|
|
|
slabs++;
|
|
|
|
slab->slabs = slabs;
|
|
slab->next = oldslab;
|
|
|
|
this_cpu_write(s->cpu_slab->partial, slab);
|
|
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, flags);
|
|
|
|
if (slab_to_put) {
|
|
__put_partials(s, slab_to_put);
|
|
stat(s, CPU_PARTIAL_DRAIN);
|
|
}
|
|
}
|
|
|
|
#else /* CONFIG_SLUB_CPU_PARTIAL */
|
|
|
|
static inline void put_partials(struct kmem_cache *s) { }
|
|
static inline void put_partials_cpu(struct kmem_cache *s,
|
|
struct kmem_cache_cpu *c) { }
|
|
|
|
#endif /* CONFIG_SLUB_CPU_PARTIAL */
|
|
|
|
static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
|
|
{
|
|
unsigned long flags;
|
|
struct slab *slab;
|
|
void *freelist;
|
|
|
|
local_lock_irqsave(&s->cpu_slab->lock, flags);
|
|
|
|
slab = c->slab;
|
|
freelist = c->freelist;
|
|
|
|
c->slab = NULL;
|
|
c->freelist = NULL;
|
|
c->tid = next_tid(c->tid);
|
|
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, flags);
|
|
|
|
if (slab) {
|
|
deactivate_slab(s, slab, freelist);
|
|
stat(s, CPUSLAB_FLUSH);
|
|
}
|
|
}
|
|
|
|
static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
|
|
{
|
|
struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
|
|
void *freelist = c->freelist;
|
|
struct slab *slab = c->slab;
|
|
|
|
c->slab = NULL;
|
|
c->freelist = NULL;
|
|
c->tid = next_tid(c->tid);
|
|
|
|
if (slab) {
|
|
deactivate_slab(s, slab, freelist);
|
|
stat(s, CPUSLAB_FLUSH);
|
|
}
|
|
|
|
put_partials_cpu(s, c);
|
|
}
|
|
|
|
struct slub_flush_work {
|
|
struct work_struct work;
|
|
struct kmem_cache *s;
|
|
bool skip;
|
|
};
|
|
|
|
/*
|
|
* Flush cpu slab.
|
|
*
|
|
* Called from CPU work handler with migration disabled.
|
|
*/
|
|
static void flush_cpu_slab(struct work_struct *w)
|
|
{
|
|
struct kmem_cache *s;
|
|
struct kmem_cache_cpu *c;
|
|
struct slub_flush_work *sfw;
|
|
|
|
sfw = container_of(w, struct slub_flush_work, work);
|
|
|
|
s = sfw->s;
|
|
c = this_cpu_ptr(s->cpu_slab);
|
|
|
|
if (c->slab)
|
|
flush_slab(s, c);
|
|
|
|
put_partials(s);
|
|
}
|
|
|
|
static bool has_cpu_slab(int cpu, struct kmem_cache *s)
|
|
{
|
|
struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
|
|
|
|
return c->slab || slub_percpu_partial(c);
|
|
}
|
|
|
|
static DEFINE_MUTEX(flush_lock);
|
|
static DEFINE_PER_CPU(struct slub_flush_work, slub_flush);
|
|
|
|
static void flush_all_cpus_locked(struct kmem_cache *s)
|
|
{
|
|
struct slub_flush_work *sfw;
|
|
unsigned int cpu;
|
|
|
|
lockdep_assert_cpus_held();
|
|
mutex_lock(&flush_lock);
|
|
|
|
for_each_online_cpu(cpu) {
|
|
sfw = &per_cpu(slub_flush, cpu);
|
|
if (!has_cpu_slab(cpu, s)) {
|
|
sfw->skip = true;
|
|
continue;
|
|
}
|
|
INIT_WORK(&sfw->work, flush_cpu_slab);
|
|
sfw->skip = false;
|
|
sfw->s = s;
|
|
queue_work_on(cpu, flushwq, &sfw->work);
|
|
}
|
|
|
|
for_each_online_cpu(cpu) {
|
|
sfw = &per_cpu(slub_flush, cpu);
|
|
if (sfw->skip)
|
|
continue;
|
|
flush_work(&sfw->work);
|
|
}
|
|
|
|
mutex_unlock(&flush_lock);
|
|
}
|
|
|
|
static void flush_all(struct kmem_cache *s)
|
|
{
|
|
cpus_read_lock();
|
|
flush_all_cpus_locked(s);
|
|
cpus_read_unlock();
|
|
}
|
|
|
|
/*
|
|
* Use the cpu notifier to insure that the cpu slabs are flushed when
|
|
* necessary.
|
|
*/
|
|
static int slub_cpu_dead(unsigned int cpu)
|
|
{
|
|
struct kmem_cache *s;
|
|
|
|
mutex_lock(&slab_mutex);
|
|
list_for_each_entry(s, &slab_caches, list)
|
|
__flush_cpu_slab(s, cpu);
|
|
mutex_unlock(&slab_mutex);
|
|
return 0;
|
|
}
|
|
|
|
#else /* CONFIG_SLUB_TINY */
|
|
static inline void flush_all_cpus_locked(struct kmem_cache *s) { }
|
|
static inline void flush_all(struct kmem_cache *s) { }
|
|
static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu) { }
|
|
static inline int slub_cpu_dead(unsigned int cpu) { return 0; }
|
|
#endif /* CONFIG_SLUB_TINY */
|
|
|
|
/*
|
|
* Check if the objects in a per cpu structure fit numa
|
|
* locality expectations.
|
|
*/
|
|
static inline int node_match(struct slab *slab, int node)
|
|
{
|
|
#ifdef CONFIG_NUMA
|
|
if (node != NUMA_NO_NODE && slab_nid(slab) != node)
|
|
return 0;
|
|
#endif
|
|
return 1;
|
|
}
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
static int count_free(struct slab *slab)
|
|
{
|
|
return slab->objects - slab->inuse;
|
|
}
|
|
|
|
static inline unsigned long node_nr_objs(struct kmem_cache_node *n)
|
|
{
|
|
return atomic_long_read(&n->total_objects);
|
|
}
|
|
|
|
/* Supports checking bulk free of a constructed freelist */
|
|
static inline bool free_debug_processing(struct kmem_cache *s,
|
|
struct slab *slab, void *head, void *tail, int *bulk_cnt,
|
|
unsigned long addr, depot_stack_handle_t handle)
|
|
{
|
|
bool checks_ok = false;
|
|
void *object = head;
|
|
int cnt = 0;
|
|
|
|
if (s->flags & SLAB_CONSISTENCY_CHECKS) {
|
|
if (!check_slab(s, slab))
|
|
goto out;
|
|
}
|
|
|
|
if (slab->inuse < *bulk_cnt) {
|
|
slab_err(s, slab, "Slab has %d allocated objects but %d are to be freed\n",
|
|
slab->inuse, *bulk_cnt);
|
|
goto out;
|
|
}
|
|
|
|
next_object:
|
|
|
|
if (++cnt > *bulk_cnt)
|
|
goto out_cnt;
|
|
|
|
if (s->flags & SLAB_CONSISTENCY_CHECKS) {
|
|
if (!free_consistency_checks(s, slab, object, addr))
|
|
goto out;
|
|
}
|
|
|
|
if (s->flags & SLAB_STORE_USER)
|
|
set_track_update(s, object, TRACK_FREE, addr, handle);
|
|
trace(s, slab, object, 0);
|
|
/* Freepointer not overwritten by init_object(), SLAB_POISON moved it */
|
|
init_object(s, object, SLUB_RED_INACTIVE);
|
|
|
|
/* Reached end of constructed freelist yet? */
|
|
if (object != tail) {
|
|
object = get_freepointer(s, object);
|
|
goto next_object;
|
|
}
|
|
checks_ok = true;
|
|
|
|
out_cnt:
|
|
if (cnt != *bulk_cnt) {
|
|
slab_err(s, slab, "Bulk free expected %d objects but found %d\n",
|
|
*bulk_cnt, cnt);
|
|
*bulk_cnt = cnt;
|
|
}
|
|
|
|
out:
|
|
|
|
if (!checks_ok)
|
|
slab_fix(s, "Object at 0x%p not freed", object);
|
|
|
|
return checks_ok;
|
|
}
|
|
#endif /* CONFIG_SLUB_DEBUG */
|
|
|
|
#if defined(CONFIG_SLUB_DEBUG) || defined(SLAB_SUPPORTS_SYSFS)
|
|
static unsigned long count_partial(struct kmem_cache_node *n,
|
|
int (*get_count)(struct slab *))
|
|
{
|
|
unsigned long flags;
|
|
unsigned long x = 0;
|
|
struct slab *slab;
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
list_for_each_entry(slab, &n->partial, slab_list)
|
|
x += get_count(slab);
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
return x;
|
|
}
|
|
#endif /* CONFIG_SLUB_DEBUG || SLAB_SUPPORTS_SYSFS */
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
static noinline void
|
|
slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
|
|
{
|
|
static DEFINE_RATELIMIT_STATE(slub_oom_rs, DEFAULT_RATELIMIT_INTERVAL,
|
|
DEFAULT_RATELIMIT_BURST);
|
|
int node;
|
|
struct kmem_cache_node *n;
|
|
|
|
if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slub_oom_rs))
|
|
return;
|
|
|
|
pr_warn("SLUB: Unable to allocate memory on node %d, gfp=%#x(%pGg)\n",
|
|
nid, gfpflags, &gfpflags);
|
|
pr_warn(" cache: %s, object size: %u, buffer size: %u, default order: %u, min order: %u\n",
|
|
s->name, s->object_size, s->size, oo_order(s->oo),
|
|
oo_order(s->min));
|
|
|
|
if (oo_order(s->min) > get_order(s->object_size))
|
|
pr_warn(" %s debugging increased min order, use slab_debug=O to disable.\n",
|
|
s->name);
|
|
|
|
for_each_kmem_cache_node(s, node, n) {
|
|
unsigned long nr_slabs;
|
|
unsigned long nr_objs;
|
|
unsigned long nr_free;
|
|
|
|
nr_free = count_partial(n, count_free);
|
|
nr_slabs = node_nr_slabs(n);
|
|
nr_objs = node_nr_objs(n);
|
|
|
|
pr_warn(" node %d: slabs: %ld, objs: %ld, free: %ld\n",
|
|
node, nr_slabs, nr_objs, nr_free);
|
|
}
|
|
}
|
|
#else /* CONFIG_SLUB_DEBUG */
|
|
static inline void
|
|
slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid) { }
|
|
#endif
|
|
|
|
static inline bool pfmemalloc_match(struct slab *slab, gfp_t gfpflags)
|
|
{
|
|
if (unlikely(slab_test_pfmemalloc(slab)))
|
|
return gfp_pfmemalloc_allowed(gfpflags);
|
|
|
|
return true;
|
|
}
|
|
|
|
#ifndef CONFIG_SLUB_TINY
|
|
static inline bool
|
|
__update_cpu_freelist_fast(struct kmem_cache *s,
|
|
void *freelist_old, void *freelist_new,
|
|
unsigned long tid)
|
|
{
|
|
freelist_aba_t old = { .freelist = freelist_old, .counter = tid };
|
|
freelist_aba_t new = { .freelist = freelist_new, .counter = next_tid(tid) };
|
|
|
|
return this_cpu_try_cmpxchg_freelist(s->cpu_slab->freelist_tid.full,
|
|
&old.full, new.full);
|
|
}
|
|
|
|
/*
|
|
* Check the slab->freelist and either transfer the freelist to the
|
|
* per cpu freelist or deactivate the slab.
|
|
*
|
|
* The slab is still frozen if the return value is not NULL.
|
|
*
|
|
* If this function returns NULL then the slab has been unfrozen.
|
|
*/
|
|
static inline void *get_freelist(struct kmem_cache *s, struct slab *slab)
|
|
{
|
|
struct slab new;
|
|
unsigned long counters;
|
|
void *freelist;
|
|
|
|
lockdep_assert_held(this_cpu_ptr(&s->cpu_slab->lock));
|
|
|
|
do {
|
|
freelist = slab->freelist;
|
|
counters = slab->counters;
|
|
|
|
new.counters = counters;
|
|
|
|
new.inuse = slab->objects;
|
|
new.frozen = freelist != NULL;
|
|
|
|
} while (!__slab_update_freelist(s, slab,
|
|
freelist, counters,
|
|
NULL, new.counters,
|
|
"get_freelist"));
|
|
|
|
return freelist;
|
|
}
|
|
|
|
/*
|
|
* Freeze the partial slab and return the pointer to the freelist.
|
|
*/
|
|
static inline void *freeze_slab(struct kmem_cache *s, struct slab *slab)
|
|
{
|
|
struct slab new;
|
|
unsigned long counters;
|
|
void *freelist;
|
|
|
|
do {
|
|
freelist = slab->freelist;
|
|
counters = slab->counters;
|
|
|
|
new.counters = counters;
|
|
VM_BUG_ON(new.frozen);
|
|
|
|
new.inuse = slab->objects;
|
|
new.frozen = 1;
|
|
|
|
} while (!slab_update_freelist(s, slab,
|
|
freelist, counters,
|
|
NULL, new.counters,
|
|
"freeze_slab"));
|
|
|
|
return freelist;
|
|
}
|
|
|
|
/*
|
|
* Slow path. The lockless freelist is empty or we need to perform
|
|
* debugging duties.
|
|
*
|
|
* Processing is still very fast if new objects have been freed to the
|
|
* regular freelist. In that case we simply take over the regular freelist
|
|
* as the lockless freelist and zap the regular freelist.
|
|
*
|
|
* If that is not working then we fall back to the partial lists. We take the
|
|
* first element of the freelist as the object to allocate now and move the
|
|
* rest of the freelist to the lockless freelist.
|
|
*
|
|
* And if we were unable to get a new slab from the partial slab lists then
|
|
* we need to allocate a new slab. This is the slowest path since it involves
|
|
* a call to the page allocator and the setup of a new slab.
|
|
*
|
|
* Version of __slab_alloc to use when we know that preemption is
|
|
* already disabled (which is the case for bulk allocation).
|
|
*/
|
|
static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
|
|
unsigned long addr, struct kmem_cache_cpu *c, unsigned int orig_size)
|
|
{
|
|
void *freelist;
|
|
struct slab *slab;
|
|
unsigned long flags;
|
|
struct partial_context pc;
|
|
|
|
stat(s, ALLOC_SLOWPATH);
|
|
|
|
reread_slab:
|
|
|
|
slab = READ_ONCE(c->slab);
|
|
if (!slab) {
|
|
/*
|
|
* if the node is not online or has no normal memory, just
|
|
* ignore the node constraint
|
|
*/
|
|
if (unlikely(node != NUMA_NO_NODE &&
|
|
!node_isset(node, slab_nodes)))
|
|
node = NUMA_NO_NODE;
|
|
goto new_slab;
|
|
}
|
|
|
|
if (unlikely(!node_match(slab, node))) {
|
|
/*
|
|
* same as above but node_match() being false already
|
|
* implies node != NUMA_NO_NODE
|
|
*/
|
|
if (!node_isset(node, slab_nodes)) {
|
|
node = NUMA_NO_NODE;
|
|
} else {
|
|
stat(s, ALLOC_NODE_MISMATCH);
|
|
goto deactivate_slab;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* By rights, we should be searching for a slab page that was
|
|
* PFMEMALLOC but right now, we are losing the pfmemalloc
|
|
* information when the page leaves the per-cpu allocator
|
|
*/
|
|
if (unlikely(!pfmemalloc_match(slab, gfpflags)))
|
|
goto deactivate_slab;
|
|
|
|
/* must check again c->slab in case we got preempted and it changed */
|
|
local_lock_irqsave(&s->cpu_slab->lock, flags);
|
|
if (unlikely(slab != c->slab)) {
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, flags);
|
|
goto reread_slab;
|
|
}
|
|
freelist = c->freelist;
|
|
if (freelist)
|
|
goto load_freelist;
|
|
|
|
freelist = get_freelist(s, slab);
|
|
|
|
if (!freelist) {
|
|
c->slab = NULL;
|
|
c->tid = next_tid(c->tid);
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, flags);
|
|
stat(s, DEACTIVATE_BYPASS);
|
|
goto new_slab;
|
|
}
|
|
|
|
stat(s, ALLOC_REFILL);
|
|
|
|
load_freelist:
|
|
|
|
lockdep_assert_held(this_cpu_ptr(&s->cpu_slab->lock));
|
|
|
|
/*
|
|
* freelist is pointing to the list of objects to be used.
|
|
* slab is pointing to the slab from which the objects are obtained.
|
|
* That slab must be frozen for per cpu allocations to work.
|
|
*/
|
|
VM_BUG_ON(!c->slab->frozen);
|
|
c->freelist = get_freepointer(s, freelist);
|
|
c->tid = next_tid(c->tid);
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, flags);
|
|
return freelist;
|
|
|
|
deactivate_slab:
|
|
|
|
local_lock_irqsave(&s->cpu_slab->lock, flags);
|
|
if (slab != c->slab) {
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, flags);
|
|
goto reread_slab;
|
|
}
|
|
freelist = c->freelist;
|
|
c->slab = NULL;
|
|
c->freelist = NULL;
|
|
c->tid = next_tid(c->tid);
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, flags);
|
|
deactivate_slab(s, slab, freelist);
|
|
|
|
new_slab:
|
|
|
|
#ifdef CONFIG_SLUB_CPU_PARTIAL
|
|
while (slub_percpu_partial(c)) {
|
|
local_lock_irqsave(&s->cpu_slab->lock, flags);
|
|
if (unlikely(c->slab)) {
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, flags);
|
|
goto reread_slab;
|
|
}
|
|
if (unlikely(!slub_percpu_partial(c))) {
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, flags);
|
|
/* we were preempted and partial list got empty */
|
|
goto new_objects;
|
|
}
|
|
|
|
slab = slub_percpu_partial(c);
|
|
slub_set_percpu_partial(c, slab);
|
|
|
|
if (likely(node_match(slab, node) &&
|
|
pfmemalloc_match(slab, gfpflags))) {
|
|
c->slab = slab;
|
|
freelist = get_freelist(s, slab);
|
|
VM_BUG_ON(!freelist);
|
|
stat(s, CPU_PARTIAL_ALLOC);
|
|
goto load_freelist;
|
|
}
|
|
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, flags);
|
|
|
|
slab->next = NULL;
|
|
__put_partials(s, slab);
|
|
}
|
|
#endif
|
|
|
|
new_objects:
|
|
|
|
pc.flags = gfpflags;
|
|
pc.orig_size = orig_size;
|
|
slab = get_partial(s, node, &pc);
|
|
if (slab) {
|
|
if (kmem_cache_debug(s)) {
|
|
freelist = pc.object;
|
|
/*
|
|
* For debug caches here we had to go through
|
|
* alloc_single_from_partial() so just store the
|
|
* tracking info and return the object.
|
|
*/
|
|
if (s->flags & SLAB_STORE_USER)
|
|
set_track(s, freelist, TRACK_ALLOC, addr);
|
|
|
|
return freelist;
|
|
}
|
|
|
|
freelist = freeze_slab(s, slab);
|
|
goto retry_load_slab;
|
|
}
|
|
|
|
slub_put_cpu_ptr(s->cpu_slab);
|
|
slab = new_slab(s, gfpflags, node);
|
|
c = slub_get_cpu_ptr(s->cpu_slab);
|
|
|
|
if (unlikely(!slab)) {
|
|
slab_out_of_memory(s, gfpflags, node);
|
|
return NULL;
|
|
}
|
|
|
|
stat(s, ALLOC_SLAB);
|
|
|
|
if (kmem_cache_debug(s)) {
|
|
freelist = alloc_single_from_new_slab(s, slab, orig_size);
|
|
|
|
if (unlikely(!freelist))
|
|
goto new_objects;
|
|
|
|
if (s->flags & SLAB_STORE_USER)
|
|
set_track(s, freelist, TRACK_ALLOC, addr);
|
|
|
|
return freelist;
|
|
}
|
|
|
|
/*
|
|
* No other reference to the slab yet so we can
|
|
* muck around with it freely without cmpxchg
|
|
*/
|
|
freelist = slab->freelist;
|
|
slab->freelist = NULL;
|
|
slab->inuse = slab->objects;
|
|
slab->frozen = 1;
|
|
|
|
inc_slabs_node(s, slab_nid(slab), slab->objects);
|
|
|
|
if (unlikely(!pfmemalloc_match(slab, gfpflags))) {
|
|
/*
|
|
* For !pfmemalloc_match() case we don't load freelist so that
|
|
* we don't make further mismatched allocations easier.
|
|
*/
|
|
deactivate_slab(s, slab, get_freepointer(s, freelist));
|
|
return freelist;
|
|
}
|
|
|
|
retry_load_slab:
|
|
|
|
local_lock_irqsave(&s->cpu_slab->lock, flags);
|
|
if (unlikely(c->slab)) {
|
|
void *flush_freelist = c->freelist;
|
|
struct slab *flush_slab = c->slab;
|
|
|
|
c->slab = NULL;
|
|
c->freelist = NULL;
|
|
c->tid = next_tid(c->tid);
|
|
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, flags);
|
|
|
|
deactivate_slab(s, flush_slab, flush_freelist);
|
|
|
|
stat(s, CPUSLAB_FLUSH);
|
|
|
|
goto retry_load_slab;
|
|
}
|
|
c->slab = slab;
|
|
|
|
goto load_freelist;
|
|
}
|
|
|
|
/*
|
|
* A wrapper for ___slab_alloc() for contexts where preemption is not yet
|
|
* disabled. Compensates for possible cpu changes by refetching the per cpu area
|
|
* pointer.
|
|
*/
|
|
static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
|
|
unsigned long addr, struct kmem_cache_cpu *c, unsigned int orig_size)
|
|
{
|
|
void *p;
|
|
|
|
#ifdef CONFIG_PREEMPT_COUNT
|
|
/*
|
|
* We may have been preempted and rescheduled on a different
|
|
* cpu before disabling preemption. Need to reload cpu area
|
|
* pointer.
|
|
*/
|
|
c = slub_get_cpu_ptr(s->cpu_slab);
|
|
#endif
|
|
|
|
p = ___slab_alloc(s, gfpflags, node, addr, c, orig_size);
|
|
#ifdef CONFIG_PREEMPT_COUNT
|
|
slub_put_cpu_ptr(s->cpu_slab);
|
|
#endif
|
|
return p;
|
|
}
|
|
|
|
static __always_inline void *__slab_alloc_node(struct kmem_cache *s,
|
|
gfp_t gfpflags, int node, unsigned long addr, size_t orig_size)
|
|
{
|
|
struct kmem_cache_cpu *c;
|
|
struct slab *slab;
|
|
unsigned long tid;
|
|
void *object;
|
|
|
|
redo:
|
|
/*
|
|
* Must read kmem_cache cpu data via this cpu ptr. Preemption is
|
|
* enabled. We may switch back and forth between cpus while
|
|
* reading from one cpu area. That does not matter as long
|
|
* as we end up on the original cpu again when doing the cmpxchg.
|
|
*
|
|
* We must guarantee that tid and kmem_cache_cpu are retrieved on the
|
|
* same cpu. We read first the kmem_cache_cpu pointer and use it to read
|
|
* the tid. If we are preempted and switched to another cpu between the
|
|
* two reads, it's OK as the two are still associated with the same cpu
|
|
* and cmpxchg later will validate the cpu.
|
|
*/
|
|
c = raw_cpu_ptr(s->cpu_slab);
|
|
tid = READ_ONCE(c->tid);
|
|
|
|
/*
|
|
* Irqless object alloc/free algorithm used here depends on sequence
|
|
* of fetching cpu_slab's data. tid should be fetched before anything
|
|
* on c to guarantee that object and slab associated with previous tid
|
|
* won't be used with current tid. If we fetch tid first, object and
|
|
* slab could be one associated with next tid and our alloc/free
|
|
* request will be failed. In this case, we will retry. So, no problem.
|
|
*/
|
|
barrier();
|
|
|
|
/*
|
|
* The transaction ids are globally unique per cpu and per operation on
|
|
* a per cpu queue. Thus they can be guarantee that the cmpxchg_double
|
|
* occurs on the right processor and that there was no operation on the
|
|
* linked list in between.
|
|
*/
|
|
|
|
object = c->freelist;
|
|
slab = c->slab;
|
|
|
|
if (!USE_LOCKLESS_FAST_PATH() ||
|
|
unlikely(!object || !slab || !node_match(slab, node))) {
|
|
object = __slab_alloc(s, gfpflags, node, addr, c, orig_size);
|
|
} else {
|
|
void *next_object = get_freepointer_safe(s, object);
|
|
|
|
/*
|
|
* The cmpxchg will only match if there was no additional
|
|
* operation and if we are on the right processor.
|
|
*
|
|
* The cmpxchg does the following atomically (without lock
|
|
* semantics!)
|
|
* 1. Relocate first pointer to the current per cpu area.
|
|
* 2. Verify that tid and freelist have not been changed
|
|
* 3. If they were not changed replace tid and freelist
|
|
*
|
|
* Since this is without lock semantics the protection is only
|
|
* against code executing on this cpu *not* from access by
|
|
* other cpus.
|
|
*/
|
|
if (unlikely(!__update_cpu_freelist_fast(s, object, next_object, tid))) {
|
|
note_cmpxchg_failure("slab_alloc", s, tid);
|
|
goto redo;
|
|
}
|
|
prefetch_freepointer(s, next_object);
|
|
stat(s, ALLOC_FASTPATH);
|
|
}
|
|
|
|
return object;
|
|
}
|
|
#else /* CONFIG_SLUB_TINY */
|
|
static void *__slab_alloc_node(struct kmem_cache *s,
|
|
gfp_t gfpflags, int node, unsigned long addr, size_t orig_size)
|
|
{
|
|
struct partial_context pc;
|
|
struct slab *slab;
|
|
void *object;
|
|
|
|
pc.flags = gfpflags;
|
|
pc.orig_size = orig_size;
|
|
slab = get_partial(s, node, &pc);
|
|
|
|
if (slab)
|
|
return pc.object;
|
|
|
|
slab = new_slab(s, gfpflags, node);
|
|
if (unlikely(!slab)) {
|
|
slab_out_of_memory(s, gfpflags, node);
|
|
return NULL;
|
|
}
|
|
|
|
object = alloc_single_from_new_slab(s, slab, orig_size);
|
|
|
|
return object;
|
|
}
|
|
#endif /* CONFIG_SLUB_TINY */
|
|
|
|
/*
|
|
* If the object has been wiped upon free, make sure it's fully initialized by
|
|
* zeroing out freelist pointer.
|
|
*/
|
|
static __always_inline void maybe_wipe_obj_freeptr(struct kmem_cache *s,
|
|
void *obj)
|
|
{
|
|
if (unlikely(slab_want_init_on_free(s)) && obj)
|
|
memset((void *)((char *)kasan_reset_tag(obj) + s->offset),
|
|
0, sizeof(void *));
|
|
}
|
|
|
|
noinline int should_failslab(struct kmem_cache *s, gfp_t gfpflags)
|
|
{
|
|
if (__should_failslab(s, gfpflags))
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
ALLOW_ERROR_INJECTION(should_failslab, ERRNO);
|
|
|
|
static __fastpath_inline
|
|
struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
|
|
struct list_lru *lru,
|
|
struct obj_cgroup **objcgp,
|
|
size_t size, gfp_t flags)
|
|
{
|
|
flags &= gfp_allowed_mask;
|
|
|
|
might_alloc(flags);
|
|
|
|
if (unlikely(should_failslab(s, flags)))
|
|
return NULL;
|
|
|
|
if (unlikely(!memcg_slab_pre_alloc_hook(s, lru, objcgp, size, flags)))
|
|
return NULL;
|
|
|
|
return s;
|
|
}
|
|
|
|
static __fastpath_inline
|
|
void slab_post_alloc_hook(struct kmem_cache *s, struct obj_cgroup *objcg,
|
|
gfp_t flags, size_t size, void **p, bool init,
|
|
unsigned int orig_size)
|
|
{
|
|
unsigned int zero_size = s->object_size;
|
|
bool kasan_init = init;
|
|
size_t i;
|
|
gfp_t init_flags = flags & gfp_allowed_mask;
|
|
|
|
/*
|
|
* For kmalloc object, the allocated memory size(object_size) is likely
|
|
* larger than the requested size(orig_size). If redzone check is
|
|
* enabled for the extra space, don't zero it, as it will be redzoned
|
|
* soon. The redzone operation for this extra space could be seen as a
|
|
* replacement of current poisoning under certain debug option, and
|
|
* won't break other sanity checks.
|
|
*/
|
|
if (kmem_cache_debug_flags(s, SLAB_STORE_USER | SLAB_RED_ZONE) &&
|
|
(s->flags & SLAB_KMALLOC))
|
|
zero_size = orig_size;
|
|
|
|
/*
|
|
* When slab_debug is enabled, avoid memory initialization integrated
|
|
* into KASAN and instead zero out the memory via the memset below with
|
|
* the proper size. Otherwise, KASAN might overwrite SLUB redzones and
|
|
* cause false-positive reports. This does not lead to a performance
|
|
* penalty on production builds, as slab_debug is not intended to be
|
|
* enabled there.
|
|
*/
|
|
if (__slub_debug_enabled())
|
|
kasan_init = false;
|
|
|
|
/*
|
|
* As memory initialization might be integrated into KASAN,
|
|
* kasan_slab_alloc and initialization memset must be
|
|
* kept together to avoid discrepancies in behavior.
|
|
*
|
|
* As p[i] might get tagged, memset and kmemleak hook come after KASAN.
|
|
*/
|
|
for (i = 0; i < size; i++) {
|
|
p[i] = kasan_slab_alloc(s, p[i], init_flags, kasan_init);
|
|
if (p[i] && init && (!kasan_init ||
|
|
!kasan_has_integrated_init()))
|
|
memset(p[i], 0, zero_size);
|
|
kmemleak_alloc_recursive(p[i], s->object_size, 1,
|
|
s->flags, init_flags);
|
|
kmsan_slab_alloc(s, p[i], init_flags);
|
|
}
|
|
|
|
memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
|
|
}
|
|
|
|
/*
|
|
* Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
|
|
* have the fastpath folded into their functions. So no function call
|
|
* overhead for requests that can be satisfied on the fastpath.
|
|
*
|
|
* The fastpath works by first checking if the lockless freelist can be used.
|
|
* If not then __slab_alloc is called for slow processing.
|
|
*
|
|
* Otherwise we can simply pick the next object from the lockless free list.
|
|
*/
|
|
static __fastpath_inline void *slab_alloc_node(struct kmem_cache *s, struct list_lru *lru,
|
|
gfp_t gfpflags, int node, unsigned long addr, size_t orig_size)
|
|
{
|
|
void *object;
|
|
struct obj_cgroup *objcg = NULL;
|
|
bool init = false;
|
|
|
|
s = slab_pre_alloc_hook(s, lru, &objcg, 1, gfpflags);
|
|
if (unlikely(!s))
|
|
return NULL;
|
|
|
|
object = kfence_alloc(s, orig_size, gfpflags);
|
|
if (unlikely(object))
|
|
goto out;
|
|
|
|
object = __slab_alloc_node(s, gfpflags, node, addr, orig_size);
|
|
|
|
maybe_wipe_obj_freeptr(s, object);
|
|
init = slab_want_init_on_alloc(gfpflags, s);
|
|
|
|
out:
|
|
/*
|
|
* When init equals 'true', like for kzalloc() family, only
|
|
* @orig_size bytes might be zeroed instead of s->object_size
|
|
*/
|
|
slab_post_alloc_hook(s, objcg, gfpflags, 1, &object, init, orig_size);
|
|
|
|
return object;
|
|
}
|
|
|
|
void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
|
|
{
|
|
void *ret = slab_alloc_node(s, NULL, gfpflags, NUMA_NO_NODE, _RET_IP_,
|
|
s->object_size);
|
|
|
|
trace_kmem_cache_alloc(_RET_IP_, ret, s, gfpflags, NUMA_NO_NODE);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc);
|
|
|
|
void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru,
|
|
gfp_t gfpflags)
|
|
{
|
|
void *ret = slab_alloc_node(s, lru, gfpflags, NUMA_NO_NODE, _RET_IP_,
|
|
s->object_size);
|
|
|
|
trace_kmem_cache_alloc(_RET_IP_, ret, s, gfpflags, NUMA_NO_NODE);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc_lru);
|
|
|
|
/**
|
|
* kmem_cache_alloc_node - Allocate an object on the specified node
|
|
* @s: The cache to allocate from.
|
|
* @gfpflags: See kmalloc().
|
|
* @node: node number of the target node.
|
|
*
|
|
* Identical to kmem_cache_alloc but it will allocate memory on the given
|
|
* node, which can improve the performance for cpu bound structures.
|
|
*
|
|
* Fallback to other node is possible if __GFP_THISNODE is not set.
|
|
*
|
|
* Return: pointer to the new object or %NULL in case of error
|
|
*/
|
|
void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
|
|
{
|
|
void *ret = slab_alloc_node(s, NULL, gfpflags, node, _RET_IP_, s->object_size);
|
|
|
|
trace_kmem_cache_alloc(_RET_IP_, ret, s, gfpflags, node);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc_node);
|
|
|
|
/*
|
|
* To avoid unnecessary overhead, we pass through large allocation requests
|
|
* directly to the page allocator. We use __GFP_COMP, because we will need to
|
|
* know the allocation order to free the pages properly in kfree.
|
|
*/
|
|
static void *__kmalloc_large_node(size_t size, gfp_t flags, int node)
|
|
{
|
|
struct folio *folio;
|
|
void *ptr = NULL;
|
|
unsigned int order = get_order(size);
|
|
|
|
if (unlikely(flags & GFP_SLAB_BUG_MASK))
|
|
flags = kmalloc_fix_flags(flags);
|
|
|
|
flags |= __GFP_COMP;
|
|
folio = (struct folio *)alloc_pages_node(node, flags, order);
|
|
if (folio) {
|
|
ptr = folio_address(folio);
|
|
lruvec_stat_mod_folio(folio, NR_SLAB_UNRECLAIMABLE_B,
|
|
PAGE_SIZE << order);
|
|
}
|
|
|
|
ptr = kasan_kmalloc_large(ptr, size, flags);
|
|
/* As ptr might get tagged, call kmemleak hook after KASAN. */
|
|
kmemleak_alloc(ptr, size, 1, flags);
|
|
kmsan_kmalloc_large(ptr, size, flags);
|
|
|
|
return ptr;
|
|
}
|
|
|
|
void *kmalloc_large(size_t size, gfp_t flags)
|
|
{
|
|
void *ret = __kmalloc_large_node(size, flags, NUMA_NO_NODE);
|
|
|
|
trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << get_order(size),
|
|
flags, NUMA_NO_NODE);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmalloc_large);
|
|
|
|
void *kmalloc_large_node(size_t size, gfp_t flags, int node)
|
|
{
|
|
void *ret = __kmalloc_large_node(size, flags, node);
|
|
|
|
trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << get_order(size),
|
|
flags, node);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmalloc_large_node);
|
|
|
|
static __always_inline
|
|
void *__do_kmalloc_node(size_t size, gfp_t flags, int node,
|
|
unsigned long caller)
|
|
{
|
|
struct kmem_cache *s;
|
|
void *ret;
|
|
|
|
if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) {
|
|
ret = __kmalloc_large_node(size, flags, node);
|
|
trace_kmalloc(caller, ret, size,
|
|
PAGE_SIZE << get_order(size), flags, node);
|
|
return ret;
|
|
}
|
|
|
|
if (unlikely(!size))
|
|
return ZERO_SIZE_PTR;
|
|
|
|
s = kmalloc_slab(size, flags, caller);
|
|
|
|
ret = slab_alloc_node(s, NULL, flags, node, caller, size);
|
|
ret = kasan_kmalloc(s, ret, size, flags);
|
|
trace_kmalloc(caller, ret, size, s->size, flags, node);
|
|
return ret;
|
|
}
|
|
|
|
void *__kmalloc_node(size_t size, gfp_t flags, int node)
|
|
{
|
|
return __do_kmalloc_node(size, flags, node, _RET_IP_);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc_node);
|
|
|
|
void *__kmalloc(size_t size, gfp_t flags)
|
|
{
|
|
return __do_kmalloc_node(size, flags, NUMA_NO_NODE, _RET_IP_);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc);
|
|
|
|
void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
|
|
int node, unsigned long caller)
|
|
{
|
|
return __do_kmalloc_node(size, flags, node, caller);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc_node_track_caller);
|
|
|
|
void *kmalloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
|
|
{
|
|
void *ret = slab_alloc_node(s, NULL, gfpflags, NUMA_NO_NODE,
|
|
_RET_IP_, size);
|
|
|
|
trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags, NUMA_NO_NODE);
|
|
|
|
ret = kasan_kmalloc(s, ret, size, gfpflags);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmalloc_trace);
|
|
|
|
void *kmalloc_node_trace(struct kmem_cache *s, gfp_t gfpflags,
|
|
int node, size_t size)
|
|
{
|
|
void *ret = slab_alloc_node(s, NULL, gfpflags, node, _RET_IP_, size);
|
|
|
|
trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags, node);
|
|
|
|
ret = kasan_kmalloc(s, ret, size, gfpflags);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmalloc_node_trace);
|
|
|
|
static noinline void free_to_partial_list(
|
|
struct kmem_cache *s, struct slab *slab,
|
|
void *head, void *tail, int bulk_cnt,
|
|
unsigned long addr)
|
|
{
|
|
struct kmem_cache_node *n = get_node(s, slab_nid(slab));
|
|
struct slab *slab_free = NULL;
|
|
int cnt = bulk_cnt;
|
|
unsigned long flags;
|
|
depot_stack_handle_t handle = 0;
|
|
|
|
if (s->flags & SLAB_STORE_USER)
|
|
handle = set_track_prepare();
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
|
|
if (free_debug_processing(s, slab, head, tail, &cnt, addr, handle)) {
|
|
void *prior = slab->freelist;
|
|
|
|
/* Perform the actual freeing while we still hold the locks */
|
|
slab->inuse -= cnt;
|
|
set_freepointer(s, tail, prior);
|
|
slab->freelist = head;
|
|
|
|
/*
|
|
* If the slab is empty, and node's partial list is full,
|
|
* it should be discarded anyway no matter it's on full or
|
|
* partial list.
|
|
*/
|
|
if (slab->inuse == 0 && n->nr_partial >= s->min_partial)
|
|
slab_free = slab;
|
|
|
|
if (!prior) {
|
|
/* was on full list */
|
|
remove_full(s, n, slab);
|
|
if (!slab_free) {
|
|
add_partial(n, slab, DEACTIVATE_TO_TAIL);
|
|
stat(s, FREE_ADD_PARTIAL);
|
|
}
|
|
} else if (slab_free) {
|
|
remove_partial(n, slab);
|
|
stat(s, FREE_REMOVE_PARTIAL);
|
|
}
|
|
}
|
|
|
|
if (slab_free) {
|
|
/*
|
|
* Update the counters while still holding n->list_lock to
|
|
* prevent spurious validation warnings
|
|
*/
|
|
dec_slabs_node(s, slab_nid(slab_free), slab_free->objects);
|
|
}
|
|
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
|
|
if (slab_free) {
|
|
stat(s, FREE_SLAB);
|
|
free_slab(s, slab_free);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Slow path handling. This may still be called frequently since objects
|
|
* have a longer lifetime than the cpu slabs in most processing loads.
|
|
*
|
|
* So we still attempt to reduce cache line usage. Just take the slab
|
|
* lock and free the item. If there is no additional partial slab
|
|
* handling required then we can return immediately.
|
|
*/
|
|
static void __slab_free(struct kmem_cache *s, struct slab *slab,
|
|
void *head, void *tail, int cnt,
|
|
unsigned long addr)
|
|
|
|
{
|
|
void *prior;
|
|
int was_frozen;
|
|
struct slab new;
|
|
unsigned long counters;
|
|
struct kmem_cache_node *n = NULL;
|
|
unsigned long flags;
|
|
bool on_node_partial;
|
|
|
|
stat(s, FREE_SLOWPATH);
|
|
|
|
if (IS_ENABLED(CONFIG_SLUB_TINY) || kmem_cache_debug(s)) {
|
|
free_to_partial_list(s, slab, head, tail, cnt, addr);
|
|
return;
|
|
}
|
|
|
|
do {
|
|
if (unlikely(n)) {
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
n = NULL;
|
|
}
|
|
prior = slab->freelist;
|
|
counters = slab->counters;
|
|
set_freepointer(s, tail, prior);
|
|
new.counters = counters;
|
|
was_frozen = new.frozen;
|
|
new.inuse -= cnt;
|
|
if ((!new.inuse || !prior) && !was_frozen) {
|
|
/* Needs to be taken off a list */
|
|
if (!kmem_cache_has_cpu_partial(s) || prior) {
|
|
|
|
n = get_node(s, slab_nid(slab));
|
|
/*
|
|
* Speculatively acquire the list_lock.
|
|
* If the cmpxchg does not succeed then we may
|
|
* drop the list_lock without any processing.
|
|
*
|
|
* Otherwise the list_lock will synchronize with
|
|
* other processors updating the list of slabs.
|
|
*/
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
|
|
on_node_partial = slab_test_node_partial(slab);
|
|
}
|
|
}
|
|
|
|
} while (!slab_update_freelist(s, slab,
|
|
prior, counters,
|
|
head, new.counters,
|
|
"__slab_free"));
|
|
|
|
if (likely(!n)) {
|
|
|
|
if (likely(was_frozen)) {
|
|
/*
|
|
* The list lock was not taken therefore no list
|
|
* activity can be necessary.
|
|
*/
|
|
stat(s, FREE_FROZEN);
|
|
} else if (kmem_cache_has_cpu_partial(s) && !prior) {
|
|
/*
|
|
* If we started with a full slab then put it onto the
|
|
* per cpu partial list.
|
|
*/
|
|
put_cpu_partial(s, slab, 1);
|
|
stat(s, CPU_PARTIAL_FREE);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* This slab was partially empty but not on the per-node partial list,
|
|
* in which case we shouldn't manipulate its list, just return.
|
|
*/
|
|
if (prior && !on_node_partial) {
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
return;
|
|
}
|
|
|
|
if (unlikely(!new.inuse && n->nr_partial >= s->min_partial))
|
|
goto slab_empty;
|
|
|
|
/*
|
|
* Objects left in the slab. If it was not on the partial list before
|
|
* then add it.
|
|
*/
|
|
if (!kmem_cache_has_cpu_partial(s) && unlikely(!prior)) {
|
|
add_partial(n, slab, DEACTIVATE_TO_TAIL);
|
|
stat(s, FREE_ADD_PARTIAL);
|
|
}
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
return;
|
|
|
|
slab_empty:
|
|
if (prior) {
|
|
/*
|
|
* Slab on the partial list.
|
|
*/
|
|
remove_partial(n, slab);
|
|
stat(s, FREE_REMOVE_PARTIAL);
|
|
}
|
|
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
stat(s, FREE_SLAB);
|
|
discard_slab(s, slab);
|
|
}
|
|
|
|
#ifndef CONFIG_SLUB_TINY
|
|
/*
|
|
* Fastpath with forced inlining to produce a kfree and kmem_cache_free that
|
|
* can perform fastpath freeing without additional function calls.
|
|
*
|
|
* The fastpath is only possible if we are freeing to the current cpu slab
|
|
* of this processor. This typically the case if we have just allocated
|
|
* the item before.
|
|
*
|
|
* If fastpath is not possible then fall back to __slab_free where we deal
|
|
* with all sorts of special processing.
|
|
*
|
|
* Bulk free of a freelist with several objects (all pointing to the
|
|
* same slab) possible by specifying head and tail ptr, plus objects
|
|
* count (cnt). Bulk free indicated by tail pointer being set.
|
|
*/
|
|
static __always_inline void do_slab_free(struct kmem_cache *s,
|
|
struct slab *slab, void *head, void *tail,
|
|
int cnt, unsigned long addr)
|
|
{
|
|
struct kmem_cache_cpu *c;
|
|
unsigned long tid;
|
|
void **freelist;
|
|
|
|
redo:
|
|
/*
|
|
* Determine the currently cpus per cpu slab.
|
|
* The cpu may change afterward. However that does not matter since
|
|
* data is retrieved via this pointer. If we are on the same cpu
|
|
* during the cmpxchg then the free will succeed.
|
|
*/
|
|
c = raw_cpu_ptr(s->cpu_slab);
|
|
tid = READ_ONCE(c->tid);
|
|
|
|
/* Same with comment on barrier() in slab_alloc_node() */
|
|
barrier();
|
|
|
|
if (unlikely(slab != c->slab)) {
|
|
__slab_free(s, slab, head, tail, cnt, addr);
|
|
return;
|
|
}
|
|
|
|
if (USE_LOCKLESS_FAST_PATH()) {
|
|
freelist = READ_ONCE(c->freelist);
|
|
|
|
set_freepointer(s, tail, freelist);
|
|
|
|
if (unlikely(!__update_cpu_freelist_fast(s, freelist, head, tid))) {
|
|
note_cmpxchg_failure("slab_free", s, tid);
|
|
goto redo;
|
|
}
|
|
} else {
|
|
/* Update the free list under the local lock */
|
|
local_lock(&s->cpu_slab->lock);
|
|
c = this_cpu_ptr(s->cpu_slab);
|
|
if (unlikely(slab != c->slab)) {
|
|
local_unlock(&s->cpu_slab->lock);
|
|
goto redo;
|
|
}
|
|
tid = c->tid;
|
|
freelist = c->freelist;
|
|
|
|
set_freepointer(s, tail, freelist);
|
|
c->freelist = head;
|
|
c->tid = next_tid(tid);
|
|
|
|
local_unlock(&s->cpu_slab->lock);
|
|
}
|
|
stat_add(s, FREE_FASTPATH, cnt);
|
|
}
|
|
#else /* CONFIG_SLUB_TINY */
|
|
static void do_slab_free(struct kmem_cache *s,
|
|
struct slab *slab, void *head, void *tail,
|
|
int cnt, unsigned long addr)
|
|
{
|
|
__slab_free(s, slab, head, tail, cnt, addr);
|
|
}
|
|
#endif /* CONFIG_SLUB_TINY */
|
|
|
|
static __fastpath_inline
|
|
void slab_free(struct kmem_cache *s, struct slab *slab, void *object,
|
|
unsigned long addr)
|
|
{
|
|
memcg_slab_free_hook(s, slab, &object, 1);
|
|
|
|
if (likely(slab_free_hook(s, object, slab_want_init_on_free(s))))
|
|
do_slab_free(s, slab, object, object, 1, addr);
|
|
}
|
|
|
|
static __fastpath_inline
|
|
void slab_free_bulk(struct kmem_cache *s, struct slab *slab, void *head,
|
|
void *tail, void **p, int cnt, unsigned long addr)
|
|
{
|
|
memcg_slab_free_hook(s, slab, p, cnt);
|
|
/*
|
|
* With KASAN enabled slab_free_freelist_hook modifies the freelist
|
|
* to remove objects, whose reuse must be delayed.
|
|
*/
|
|
if (likely(slab_free_freelist_hook(s, &head, &tail, &cnt)))
|
|
do_slab_free(s, slab, head, tail, cnt, addr);
|
|
}
|
|
|
|
#ifdef CONFIG_KASAN_GENERIC
|
|
void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr)
|
|
{
|
|
do_slab_free(cache, virt_to_slab(x), x, x, 1, addr);
|
|
}
|
|
#endif
|
|
|
|
static inline struct kmem_cache *virt_to_cache(const void *obj)
|
|
{
|
|
struct slab *slab;
|
|
|
|
slab = virt_to_slab(obj);
|
|
if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n", __func__))
|
|
return NULL;
|
|
return slab->slab_cache;
|
|
}
|
|
|
|
static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
|
|
if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
|
|
!kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
|
|
return s;
|
|
|
|
cachep = virt_to_cache(x);
|
|
if (WARN(cachep && cachep != s,
|
|
"%s: Wrong slab cache. %s but object is from %s\n",
|
|
__func__, s->name, cachep->name))
|
|
print_tracking(cachep, x);
|
|
return cachep;
|
|
}
|
|
|
|
/**
|
|
* kmem_cache_free - Deallocate an object
|
|
* @s: The cache the allocation was from.
|
|
* @x: The previously allocated object.
|
|
*
|
|
* Free an object which was previously allocated from this
|
|
* cache.
|
|
*/
|
|
void kmem_cache_free(struct kmem_cache *s, void *x)
|
|
{
|
|
s = cache_from_obj(s, x);
|
|
if (!s)
|
|
return;
|
|
trace_kmem_cache_free(_RET_IP_, x, s);
|
|
slab_free(s, virt_to_slab(x), x, _RET_IP_);
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_free);
|
|
|
|
static void free_large_kmalloc(struct folio *folio, void *object)
|
|
{
|
|
unsigned int order = folio_order(folio);
|
|
|
|
if (WARN_ON_ONCE(order == 0))
|
|
pr_warn_once("object pointer: 0x%p\n", object);
|
|
|
|
kmemleak_free(object);
|
|
kasan_kfree_large(object);
|
|
kmsan_kfree_large(object);
|
|
|
|
lruvec_stat_mod_folio(folio, NR_SLAB_UNRECLAIMABLE_B,
|
|
-(PAGE_SIZE << order));
|
|
folio_put(folio);
|
|
}
|
|
|
|
/**
|
|
* kfree - free previously allocated memory
|
|
* @object: pointer returned by kmalloc() or kmem_cache_alloc()
|
|
*
|
|
* If @object is NULL, no operation is performed.
|
|
*/
|
|
void kfree(const void *object)
|
|
{
|
|
struct folio *folio;
|
|
struct slab *slab;
|
|
struct kmem_cache *s;
|
|
void *x = (void *)object;
|
|
|
|
trace_kfree(_RET_IP_, object);
|
|
|
|
if (unlikely(ZERO_OR_NULL_PTR(object)))
|
|
return;
|
|
|
|
folio = virt_to_folio(object);
|
|
if (unlikely(!folio_test_slab(folio))) {
|
|
free_large_kmalloc(folio, (void *)object);
|
|
return;
|
|
}
|
|
|
|
slab = folio_slab(folio);
|
|
s = slab->slab_cache;
|
|
slab_free(s, slab, x, _RET_IP_);
|
|
}
|
|
EXPORT_SYMBOL(kfree);
|
|
|
|
struct detached_freelist {
|
|
struct slab *slab;
|
|
void *tail;
|
|
void *freelist;
|
|
int cnt;
|
|
struct kmem_cache *s;
|
|
};
|
|
|
|
/*
|
|
* This function progressively scans the array with free objects (with
|
|
* a limited look ahead) and extract objects belonging to the same
|
|
* slab. It builds a detached freelist directly within the given
|
|
* slab/objects. This can happen without any need for
|
|
* synchronization, because the objects are owned by running process.
|
|
* The freelist is build up as a single linked list in the objects.
|
|
* The idea is, that this detached freelist can then be bulk
|
|
* transferred to the real freelist(s), but only requiring a single
|
|
* synchronization primitive. Look ahead in the array is limited due
|
|
* to performance reasons.
|
|
*/
|
|
static inline
|
|
int build_detached_freelist(struct kmem_cache *s, size_t size,
|
|
void **p, struct detached_freelist *df)
|
|
{
|
|
int lookahead = 3;
|
|
void *object;
|
|
struct folio *folio;
|
|
size_t same;
|
|
|
|
object = p[--size];
|
|
folio = virt_to_folio(object);
|
|
if (!s) {
|
|
/* Handle kalloc'ed objects */
|
|
if (unlikely(!folio_test_slab(folio))) {
|
|
free_large_kmalloc(folio, object);
|
|
df->slab = NULL;
|
|
return size;
|
|
}
|
|
/* Derive kmem_cache from object */
|
|
df->slab = folio_slab(folio);
|
|
df->s = df->slab->slab_cache;
|
|
} else {
|
|
df->slab = folio_slab(folio);
|
|
df->s = cache_from_obj(s, object); /* Support for memcg */
|
|
}
|
|
|
|
/* Start new detached freelist */
|
|
df->tail = object;
|
|
df->freelist = object;
|
|
df->cnt = 1;
|
|
|
|
if (is_kfence_address(object))
|
|
return size;
|
|
|
|
set_freepointer(df->s, object, NULL);
|
|
|
|
same = size;
|
|
while (size) {
|
|
object = p[--size];
|
|
/* df->slab is always set at this point */
|
|
if (df->slab == virt_to_slab(object)) {
|
|
/* Opportunity build freelist */
|
|
set_freepointer(df->s, object, df->freelist);
|
|
df->freelist = object;
|
|
df->cnt++;
|
|
same--;
|
|
if (size != same)
|
|
swap(p[size], p[same]);
|
|
continue;
|
|
}
|
|
|
|
/* Limit look ahead search */
|
|
if (!--lookahead)
|
|
break;
|
|
}
|
|
|
|
return same;
|
|
}
|
|
|
|
/*
|
|
* Internal bulk free of objects that were not initialised by the post alloc
|
|
* hooks and thus should not be processed by the free hooks
|
|
*/
|
|
static void __kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
|
|
{
|
|
if (!size)
|
|
return;
|
|
|
|
do {
|
|
struct detached_freelist df;
|
|
|
|
size = build_detached_freelist(s, size, p, &df);
|
|
if (!df.slab)
|
|
continue;
|
|
|
|
do_slab_free(df.s, df.slab, df.freelist, df.tail, df.cnt,
|
|
_RET_IP_);
|
|
} while (likely(size));
|
|
}
|
|
|
|
/* Note that interrupts must be enabled when calling this function. */
|
|
void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
|
|
{
|
|
if (!size)
|
|
return;
|
|
|
|
do {
|
|
struct detached_freelist df;
|
|
|
|
size = build_detached_freelist(s, size, p, &df);
|
|
if (!df.slab)
|
|
continue;
|
|
|
|
slab_free_bulk(df.s, df.slab, df.freelist, df.tail, &p[size],
|
|
df.cnt, _RET_IP_);
|
|
} while (likely(size));
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_free_bulk);
|
|
|
|
#ifndef CONFIG_SLUB_TINY
|
|
static inline
|
|
int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
|
|
void **p)
|
|
{
|
|
struct kmem_cache_cpu *c;
|
|
unsigned long irqflags;
|
|
int i;
|
|
|
|
/*
|
|
* Drain objects in the per cpu slab, while disabling local
|
|
* IRQs, which protects against PREEMPT and interrupts
|
|
* handlers invoking normal fastpath.
|
|
*/
|
|
c = slub_get_cpu_ptr(s->cpu_slab);
|
|
local_lock_irqsave(&s->cpu_slab->lock, irqflags);
|
|
|
|
for (i = 0; i < size; i++) {
|
|
void *object = kfence_alloc(s, s->object_size, flags);
|
|
|
|
if (unlikely(object)) {
|
|
p[i] = object;
|
|
continue;
|
|
}
|
|
|
|
object = c->freelist;
|
|
if (unlikely(!object)) {
|
|
/*
|
|
* We may have removed an object from c->freelist using
|
|
* the fastpath in the previous iteration; in that case,
|
|
* c->tid has not been bumped yet.
|
|
* Since ___slab_alloc() may reenable interrupts while
|
|
* allocating memory, we should bump c->tid now.
|
|
*/
|
|
c->tid = next_tid(c->tid);
|
|
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, irqflags);
|
|
|
|
/*
|
|
* Invoking slow path likely have side-effect
|
|
* of re-populating per CPU c->freelist
|
|
*/
|
|
p[i] = ___slab_alloc(s, flags, NUMA_NO_NODE,
|
|
_RET_IP_, c, s->object_size);
|
|
if (unlikely(!p[i]))
|
|
goto error;
|
|
|
|
c = this_cpu_ptr(s->cpu_slab);
|
|
maybe_wipe_obj_freeptr(s, p[i]);
|
|
|
|
local_lock_irqsave(&s->cpu_slab->lock, irqflags);
|
|
|
|
continue; /* goto for-loop */
|
|
}
|
|
c->freelist = get_freepointer(s, object);
|
|
p[i] = object;
|
|
maybe_wipe_obj_freeptr(s, p[i]);
|
|
stat(s, ALLOC_FASTPATH);
|
|
}
|
|
c->tid = next_tid(c->tid);
|
|
local_unlock_irqrestore(&s->cpu_slab->lock, irqflags);
|
|
slub_put_cpu_ptr(s->cpu_slab);
|
|
|
|
return i;
|
|
|
|
error:
|
|
slub_put_cpu_ptr(s->cpu_slab);
|
|
__kmem_cache_free_bulk(s, i, p);
|
|
return 0;
|
|
|
|
}
|
|
#else /* CONFIG_SLUB_TINY */
|
|
static int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags,
|
|
size_t size, void **p)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < size; i++) {
|
|
void *object = kfence_alloc(s, s->object_size, flags);
|
|
|
|
if (unlikely(object)) {
|
|
p[i] = object;
|
|
continue;
|
|
}
|
|
|
|
p[i] = __slab_alloc_node(s, flags, NUMA_NO_NODE,
|
|
_RET_IP_, s->object_size);
|
|
if (unlikely(!p[i]))
|
|
goto error;
|
|
|
|
maybe_wipe_obj_freeptr(s, p[i]);
|
|
}
|
|
|
|
return i;
|
|
|
|
error:
|
|
__kmem_cache_free_bulk(s, i, p);
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_SLUB_TINY */
|
|
|
|
/* Note that interrupts must be enabled when calling this function. */
|
|
int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
|
|
void **p)
|
|
{
|
|
int i;
|
|
struct obj_cgroup *objcg = NULL;
|
|
|
|
if (!size)
|
|
return 0;
|
|
|
|
/* memcg and kmem_cache debug support */
|
|
s = slab_pre_alloc_hook(s, NULL, &objcg, size, flags);
|
|
if (unlikely(!s))
|
|
return 0;
|
|
|
|
i = __kmem_cache_alloc_bulk(s, flags, size, p);
|
|
|
|
/*
|
|
* memcg and kmem_cache debug support and memory initialization.
|
|
* Done outside of the IRQ disabled fastpath loop.
|
|
*/
|
|
if (likely(i != 0)) {
|
|
slab_post_alloc_hook(s, objcg, flags, size, p,
|
|
slab_want_init_on_alloc(flags, s), s->object_size);
|
|
} else {
|
|
memcg_slab_alloc_error_hook(s, size, objcg);
|
|
}
|
|
|
|
return i;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc_bulk);
|
|
|
|
|
|
/*
|
|
* Object placement in a slab is made very easy because we always start at
|
|
* offset 0. If we tune the size of the object to the alignment then we can
|
|
* get the required alignment by putting one properly sized object after
|
|
* another.
|
|
*
|
|
* 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 is therefore a factor in
|
|
* locking overhead.
|
|
*/
|
|
|
|
/*
|
|
* Minimum / 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 unsigned int slub_min_order;
|
|
static unsigned int slub_max_order =
|
|
IS_ENABLED(CONFIG_SLUB_TINY) ? 1 : PAGE_ALLOC_COSTLY_ORDER;
|
|
static unsigned int slub_min_objects;
|
|
|
|
/*
|
|
* Calculate the order of allocation given an slab object size.
|
|
*
|
|
* The order of allocation has significant impact on performance and other
|
|
* system components. Generally order 0 allocations should be preferred since
|
|
* order 0 does not cause fragmentation in the page allocator. Larger objects
|
|
* be problematic to put into order 0 slabs because there may be too much
|
|
* unused space left. We go to a higher order if more than 1/16th 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 which requires taking the list_lock. This is
|
|
* less a concern for large slabs though which are rarely used.
|
|
*
|
|
* slab_max_order specifies the order where we begin to stop considering the
|
|
* number of objects in a slab as critical. If we reach slab_max_order then
|
|
* we try to keep the page order as low as possible. So we accept more waste
|
|
* of space in favor of a small page order.
|
|
*
|
|
* 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 minimum order then we start with that one instead of
|
|
* the smallest order which will fit the object.
|
|
*/
|
|
static inline unsigned int calc_slab_order(unsigned int size,
|
|
unsigned int min_order, unsigned int max_order,
|
|
unsigned int fract_leftover)
|
|
{
|
|
unsigned int order;
|
|
|
|
for (order = min_order; order <= max_order; order++) {
|
|
|
|
unsigned int slab_size = (unsigned int)PAGE_SIZE << order;
|
|
unsigned int rem;
|
|
|
|
rem = slab_size % size;
|
|
|
|
if (rem <= slab_size / fract_leftover)
|
|
break;
|
|
}
|
|
|
|
return order;
|
|
}
|
|
|
|
static inline int calculate_order(unsigned int size)
|
|
{
|
|
unsigned int order;
|
|
unsigned int min_objects;
|
|
unsigned int max_objects;
|
|
unsigned int min_order;
|
|
|
|
min_objects = slub_min_objects;
|
|
if (!min_objects) {
|
|
/*
|
|
* Some architectures will only update present cpus when
|
|
* onlining them, so don't trust the number if it's just 1. But
|
|
* we also don't want to use nr_cpu_ids always, as on some other
|
|
* architectures, there can be many possible cpus, but never
|
|
* onlined. Here we compromise between trying to avoid too high
|
|
* order on systems that appear larger than they are, and too
|
|
* low order on systems that appear smaller than they are.
|
|
*/
|
|
unsigned int nr_cpus = num_present_cpus();
|
|
if (nr_cpus <= 1)
|
|
nr_cpus = nr_cpu_ids;
|
|
min_objects = 4 * (fls(nr_cpus) + 1);
|
|
}
|
|
/* min_objects can't be 0 because get_order(0) is undefined */
|
|
max_objects = max(order_objects(slub_max_order, size), 1U);
|
|
min_objects = min(min_objects, max_objects);
|
|
|
|
min_order = max_t(unsigned int, slub_min_order,
|
|
get_order(min_objects * size));
|
|
if (order_objects(min_order, size) > MAX_OBJS_PER_PAGE)
|
|
return get_order(size * MAX_OBJS_PER_PAGE) - 1;
|
|
|
|
/*
|
|
* Attempt to find best configuration for a slab. This works by first
|
|
* attempting to generate a layout with the best possible configuration
|
|
* and backing off gradually.
|
|
*
|
|
* We start with accepting at most 1/16 waste and try to find the
|
|
* smallest order from min_objects-derived/slab_min_order up to
|
|
* slab_max_order that will satisfy the constraint. Note that increasing
|
|
* the order can only result in same or less fractional waste, not more.
|
|
*
|
|
* If that fails, we increase the acceptable fraction of waste and try
|
|
* again. The last iteration with fraction of 1/2 would effectively
|
|
* accept any waste and give us the order determined by min_objects, as
|
|
* long as at least single object fits within slab_max_order.
|
|
*/
|
|
for (unsigned int fraction = 16; fraction > 1; fraction /= 2) {
|
|
order = calc_slab_order(size, min_order, slub_max_order,
|
|
fraction);
|
|
if (order <= slub_max_order)
|
|
return order;
|
|
}
|
|
|
|
/*
|
|
* Doh this slab cannot be placed using slab_max_order.
|
|
*/
|
|
order = get_order(size);
|
|
if (order <= MAX_PAGE_ORDER)
|
|
return order;
|
|
return -ENOSYS;
|
|
}
|
|
|
|
static void
|
|
init_kmem_cache_node(struct kmem_cache_node *n)
|
|
{
|
|
n->nr_partial = 0;
|
|
spin_lock_init(&n->list_lock);
|
|
INIT_LIST_HEAD(&n->partial);
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
atomic_long_set(&n->nr_slabs, 0);
|
|
atomic_long_set(&n->total_objects, 0);
|
|
INIT_LIST_HEAD(&n->full);
|
|
#endif
|
|
}
|
|
|
|
#ifndef CONFIG_SLUB_TINY
|
|
static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
|
|
{
|
|
BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
|
|
NR_KMALLOC_TYPES * KMALLOC_SHIFT_HIGH *
|
|
sizeof(struct kmem_cache_cpu));
|
|
|
|
/*
|
|
* Must align to double word boundary for the double cmpxchg
|
|
* instructions to work; see __pcpu_double_call_return_bool().
|
|
*/
|
|
s->cpu_slab = __alloc_percpu(sizeof(struct kmem_cache_cpu),
|
|
2 * sizeof(void *));
|
|
|
|
if (!s->cpu_slab)
|
|
return 0;
|
|
|
|
init_kmem_cache_cpus(s);
|
|
|
|
return 1;
|
|
}
|
|
#else
|
|
static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
|
|
{
|
|
return 1;
|
|
}
|
|
#endif /* CONFIG_SLUB_TINY */
|
|
|
|
static struct kmem_cache *kmem_cache_node;
|
|
|
|
/*
|
|
* 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 kmem_cache_node
|
|
* when allocating for the kmem_cache_node. This is used for bootstrapping
|
|
* memory on a fresh node that has no slab structures yet.
|
|
*/
|
|
static void early_kmem_cache_node_alloc(int node)
|
|
{
|
|
struct slab *slab;
|
|
struct kmem_cache_node *n;
|
|
|
|
BUG_ON(kmem_cache_node->size < sizeof(struct kmem_cache_node));
|
|
|
|
slab = new_slab(kmem_cache_node, GFP_NOWAIT, node);
|
|
|
|
BUG_ON(!slab);
|
|
if (slab_nid(slab) != node) {
|
|
pr_err("SLUB: Unable to allocate memory from node %d\n", node);
|
|
pr_err("SLUB: Allocating a useless per node structure in order to be able to continue\n");
|
|
}
|
|
|
|
n = slab->freelist;
|
|
BUG_ON(!n);
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
init_object(kmem_cache_node, n, SLUB_RED_ACTIVE);
|
|
init_tracking(kmem_cache_node, n);
|
|
#endif
|
|
n = kasan_slab_alloc(kmem_cache_node, n, GFP_KERNEL, false);
|
|
slab->freelist = get_freepointer(kmem_cache_node, n);
|
|
slab->inuse = 1;
|
|
kmem_cache_node->node[node] = n;
|
|
init_kmem_cache_node(n);
|
|
inc_slabs_node(kmem_cache_node, node, slab->objects);
|
|
|
|
/*
|
|
* No locks need to be taken here as it has just been
|
|
* initialized and there is no concurrent access.
|
|
*/
|
|
__add_partial(n, slab, DEACTIVATE_TO_HEAD);
|
|
}
|
|
|
|
static void free_kmem_cache_nodes(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
struct kmem_cache_node *n;
|
|
|
|
for_each_kmem_cache_node(s, node, n) {
|
|
s->node[node] = NULL;
|
|
kmem_cache_free(kmem_cache_node, n);
|
|
}
|
|
}
|
|
|
|
void __kmem_cache_release(struct kmem_cache *s)
|
|
{
|
|
cache_random_seq_destroy(s);
|
|
#ifndef CONFIG_SLUB_TINY
|
|
free_percpu(s->cpu_slab);
|
|
#endif
|
|
free_kmem_cache_nodes(s);
|
|
}
|
|
|
|
static int init_kmem_cache_nodes(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
|
|
for_each_node_mask(node, slab_nodes) {
|
|
struct kmem_cache_node *n;
|
|
|
|
if (slab_state == DOWN) {
|
|
early_kmem_cache_node_alloc(node);
|
|
continue;
|
|
}
|
|
n = kmem_cache_alloc_node(kmem_cache_node,
|
|
GFP_KERNEL, node);
|
|
|
|
if (!n) {
|
|
free_kmem_cache_nodes(s);
|
|
return 0;
|
|
}
|
|
|
|
init_kmem_cache_node(n);
|
|
s->node[node] = n;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static void set_cpu_partial(struct kmem_cache *s)
|
|
{
|
|
#ifdef CONFIG_SLUB_CPU_PARTIAL
|
|
unsigned int nr_objects;
|
|
|
|
/*
|
|
* cpu_partial determined the maximum number of objects kept in the
|
|
* per cpu partial lists of a processor.
|
|
*
|
|
* Per cpu partial lists mainly contain slabs that just have one
|
|
* object freed. If they are used for allocation then they can be
|
|
* filled up again with minimal effort. The slab will never hit the
|
|
* per node partial lists and therefore no locking will be required.
|
|
*
|
|
* For backwards compatibility reasons, this is determined as number
|
|
* of objects, even though we now limit maximum number of pages, see
|
|
* slub_set_cpu_partial()
|
|
*/
|
|
if (!kmem_cache_has_cpu_partial(s))
|
|
nr_objects = 0;
|
|
else if (s->size >= PAGE_SIZE)
|
|
nr_objects = 6;
|
|
else if (s->size >= 1024)
|
|
nr_objects = 24;
|
|
else if (s->size >= 256)
|
|
nr_objects = 52;
|
|
else
|
|
nr_objects = 120;
|
|
|
|
slub_set_cpu_partial(s, nr_objects);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* calculate_sizes() determines the order and the distribution of data within
|
|
* a slab object.
|
|
*/
|
|
static int calculate_sizes(struct kmem_cache *s)
|
|
{
|
|
slab_flags_t flags = s->flags;
|
|
unsigned int size = s->object_size;
|
|
unsigned int order;
|
|
|
|
/*
|
|
* 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 *));
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
/*
|
|
* 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_TYPESAFE_BY_RCU) &&
|
|
!s->ctor)
|
|
s->flags |= __OBJECT_POISON;
|
|
else
|
|
s->flags &= ~__OBJECT_POISON;
|
|
|
|
|
|
/*
|
|
* 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 to have some bytes to store Redzone information.
|
|
*/
|
|
if ((flags & SLAB_RED_ZONE) && size == s->object_size)
|
|
size += sizeof(void *);
|
|
#endif
|
|
|
|
/*
|
|
* With that we have determined the number of bytes in actual use
|
|
* by the object and redzoning.
|
|
*/
|
|
s->inuse = size;
|
|
|
|
if (slub_debug_orig_size(s) ||
|
|
(flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) ||
|
|
((flags & SLAB_RED_ZONE) && s->object_size < sizeof(void *)) ||
|
|
s->ctor) {
|
|
/*
|
|
* 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, are poisoning the objects, or are
|
|
* redzoning an object smaller than sizeof(void *).
|
|
*
|
|
* The assumption that s->offset >= s->inuse means free
|
|
* pointer is outside of the object is used in the
|
|
* freeptr_outside_object() function. If that is no
|
|
* longer true, the function needs to be modified.
|
|
*/
|
|
s->offset = size;
|
|
size += sizeof(void *);
|
|
} else {
|
|
/*
|
|
* Store freelist pointer near middle of object to keep
|
|
* it away from the edges of the object to avoid small
|
|
* sized over/underflows from neighboring allocations.
|
|
*/
|
|
s->offset = ALIGN_DOWN(s->object_size / 2, sizeof(void *));
|
|
}
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
if (flags & SLAB_STORE_USER) {
|
|
/*
|
|
* Need to store information about allocs and frees after
|
|
* the object.
|
|
*/
|
|
size += 2 * sizeof(struct track);
|
|
|
|
/* Save the original kmalloc request size */
|
|
if (flags & SLAB_KMALLOC)
|
|
size += sizeof(unsigned int);
|
|
}
|
|
#endif
|
|
|
|
kasan_cache_create(s, &size, &s->flags);
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
if (flags & SLAB_RED_ZONE) {
|
|
/*
|
|
* 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 a user writes before the start
|
|
* of the object.
|
|
*/
|
|
size += sizeof(void *);
|
|
|
|
s->red_left_pad = sizeof(void *);
|
|
s->red_left_pad = ALIGN(s->red_left_pad, s->align);
|
|
size += s->red_left_pad;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* 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, s->align);
|
|
s->size = size;
|
|
s->reciprocal_size = reciprocal_value(size);
|
|
order = calculate_order(size);
|
|
|
|
if ((int)order < 0)
|
|
return 0;
|
|
|
|
s->allocflags = 0;
|
|
if (order)
|
|
s->allocflags |= __GFP_COMP;
|
|
|
|
if (s->flags & SLAB_CACHE_DMA)
|
|
s->allocflags |= GFP_DMA;
|
|
|
|
if (s->flags & SLAB_CACHE_DMA32)
|
|
s->allocflags |= GFP_DMA32;
|
|
|
|
if (s->flags & SLAB_RECLAIM_ACCOUNT)
|
|
s->allocflags |= __GFP_RECLAIMABLE;
|
|
|
|
/*
|
|
* Determine the number of objects per slab
|
|
*/
|
|
s->oo = oo_make(order, size);
|
|
s->min = oo_make(get_order(size), size);
|
|
|
|
return !!oo_objects(s->oo);
|
|
}
|
|
|
|
static int kmem_cache_open(struct kmem_cache *s, slab_flags_t flags)
|
|
{
|
|
s->flags = kmem_cache_flags(flags, s->name);
|
|
#ifdef CONFIG_SLAB_FREELIST_HARDENED
|
|
s->random = get_random_long();
|
|
#endif
|
|
|
|
if (!calculate_sizes(s))
|
|
goto error;
|
|
if (disable_higher_order_debug) {
|
|
/*
|
|
* Disable debugging flags that store metadata if the min slab
|
|
* order increased.
|
|
*/
|
|
if (get_order(s->size) > get_order(s->object_size)) {
|
|
s->flags &= ~DEBUG_METADATA_FLAGS;
|
|
s->offset = 0;
|
|
if (!calculate_sizes(s))
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
#ifdef system_has_freelist_aba
|
|
if (system_has_freelist_aba() && !(s->flags & SLAB_NO_CMPXCHG)) {
|
|
/* Enable fast mode */
|
|
s->flags |= __CMPXCHG_DOUBLE;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* The larger the object size is, the more slabs we want on the partial
|
|
* list to avoid pounding the page allocator excessively.
|
|
*/
|
|
s->min_partial = min_t(unsigned long, MAX_PARTIAL, ilog2(s->size) / 2);
|
|
s->min_partial = max_t(unsigned long, MIN_PARTIAL, s->min_partial);
|
|
|
|
set_cpu_partial(s);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
s->remote_node_defrag_ratio = 1000;
|
|
#endif
|
|
|
|
/* Initialize the pre-computed randomized freelist if slab is up */
|
|
if (slab_state >= UP) {
|
|
if (init_cache_random_seq(s))
|
|
goto error;
|
|
}
|
|
|
|
if (!init_kmem_cache_nodes(s))
|
|
goto error;
|
|
|
|
if (alloc_kmem_cache_cpus(s))
|
|
return 0;
|
|
|
|
error:
|
|
__kmem_cache_release(s);
|
|
return -EINVAL;
|
|
}
|
|
|
|
static void list_slab_objects(struct kmem_cache *s, struct slab *slab,
|
|
const char *text)
|
|
{
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
void *addr = slab_address(slab);
|
|
void *p;
|
|
|
|
slab_err(s, slab, text, s->name);
|
|
|
|
spin_lock(&object_map_lock);
|
|
__fill_map(object_map, s, slab);
|
|
|
|
for_each_object(p, s, addr, slab->objects) {
|
|
|
|
if (!test_bit(__obj_to_index(s, addr, p), object_map)) {
|
|
pr_err("Object 0x%p @offset=%tu\n", p, p - addr);
|
|
print_tracking(s, p);
|
|
}
|
|
}
|
|
spin_unlock(&object_map_lock);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Attempt to free all partial slabs on a node.
|
|
* This is called from __kmem_cache_shutdown(). We must take list_lock
|
|
* because sysfs file might still access partial list after the shutdowning.
|
|
*/
|
|
static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
|
|
{
|
|
LIST_HEAD(discard);
|
|
struct slab *slab, *h;
|
|
|
|
BUG_ON(irqs_disabled());
|
|
spin_lock_irq(&n->list_lock);
|
|
list_for_each_entry_safe(slab, h, &n->partial, slab_list) {
|
|
if (!slab->inuse) {
|
|
remove_partial(n, slab);
|
|
list_add(&slab->slab_list, &discard);
|
|
} else {
|
|
list_slab_objects(s, slab,
|
|
"Objects remaining in %s on __kmem_cache_shutdown()");
|
|
}
|
|
}
|
|
spin_unlock_irq(&n->list_lock);
|
|
|
|
list_for_each_entry_safe(slab, h, &discard, slab_list)
|
|
discard_slab(s, slab);
|
|
}
|
|
|
|
bool __kmem_cache_empty(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
struct kmem_cache_node *n;
|
|
|
|
for_each_kmem_cache_node(s, node, n)
|
|
if (n->nr_partial || node_nr_slabs(n))
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Release all resources used by a slab cache.
|
|
*/
|
|
int __kmem_cache_shutdown(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
struct kmem_cache_node *n;
|
|
|
|
flush_all_cpus_locked(s);
|
|
/* Attempt to free all objects */
|
|
for_each_kmem_cache_node(s, node, n) {
|
|
free_partial(s, n);
|
|
if (n->nr_partial || node_nr_slabs(n))
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PRINTK
|
|
void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
|
|
{
|
|
void *base;
|
|
int __maybe_unused i;
|
|
unsigned int objnr;
|
|
void *objp;
|
|
void *objp0;
|
|
struct kmem_cache *s = slab->slab_cache;
|
|
struct track __maybe_unused *trackp;
|
|
|
|
kpp->kp_ptr = object;
|
|
kpp->kp_slab = slab;
|
|
kpp->kp_slab_cache = s;
|
|
base = slab_address(slab);
|
|
objp0 = kasan_reset_tag(object);
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
objp = restore_red_left(s, objp0);
|
|
#else
|
|
objp = objp0;
|
|
#endif
|
|
objnr = obj_to_index(s, slab, objp);
|
|
kpp->kp_data_offset = (unsigned long)((char *)objp0 - (char *)objp);
|
|
objp = base + s->size * objnr;
|
|
kpp->kp_objp = objp;
|
|
if (WARN_ON_ONCE(objp < base || objp >= base + slab->objects * s->size
|
|
|| (objp - base) % s->size) ||
|
|
!(s->flags & SLAB_STORE_USER))
|
|
return;
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
objp = fixup_red_left(s, objp);
|
|
trackp = get_track(s, objp, TRACK_ALLOC);
|
|
kpp->kp_ret = (void *)trackp->addr;
|
|
#ifdef CONFIG_STACKDEPOT
|
|
{
|
|
depot_stack_handle_t handle;
|
|
unsigned long *entries;
|
|
unsigned int nr_entries;
|
|
|
|
handle = READ_ONCE(trackp->handle);
|
|
if (handle) {
|
|
nr_entries = stack_depot_fetch(handle, &entries);
|
|
for (i = 0; i < KS_ADDRS_COUNT && i < nr_entries; i++)
|
|
kpp->kp_stack[i] = (void *)entries[i];
|
|
}
|
|
|
|
trackp = get_track(s, objp, TRACK_FREE);
|
|
handle = READ_ONCE(trackp->handle);
|
|
if (handle) {
|
|
nr_entries = stack_depot_fetch(handle, &entries);
|
|
for (i = 0; i < KS_ADDRS_COUNT && i < nr_entries; i++)
|
|
kpp->kp_free_stack[i] = (void *)entries[i];
|
|
}
|
|
}
|
|
#endif
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
/********************************************************************
|
|
* Kmalloc subsystem
|
|
*******************************************************************/
|
|
|
|
static int __init setup_slub_min_order(char *str)
|
|
{
|
|
get_option(&str, (int *)&slub_min_order);
|
|
|
|
if (slub_min_order > slub_max_order)
|
|
slub_max_order = slub_min_order;
|
|
|
|
return 1;
|
|
}
|
|
|
|
__setup("slab_min_order=", setup_slub_min_order);
|
|
__setup_param("slub_min_order=", slub_min_order, setup_slub_min_order, 0);
|
|
|
|
|
|
static int __init setup_slub_max_order(char *str)
|
|
{
|
|
get_option(&str, (int *)&slub_max_order);
|
|
slub_max_order = min_t(unsigned int, slub_max_order, MAX_PAGE_ORDER);
|
|
|
|
if (slub_min_order > slub_max_order)
|
|
slub_min_order = slub_max_order;
|
|
|
|
return 1;
|
|
}
|
|
|
|
__setup("slab_max_order=", setup_slub_max_order);
|
|
__setup_param("slub_max_order=", slub_max_order, setup_slub_max_order, 0);
|
|
|
|
static int __init setup_slub_min_objects(char *str)
|
|
{
|
|
get_option(&str, (int *)&slub_min_objects);
|
|
|
|
return 1;
|
|
}
|
|
|
|
__setup("slab_min_objects=", setup_slub_min_objects);
|
|
__setup_param("slub_min_objects=", slub_min_objects, setup_slub_min_objects, 0);
|
|
|
|
#ifdef CONFIG_HARDENED_USERCOPY
|
|
/*
|
|
* Rejects incorrectly sized objects and objects that are to be copied
|
|
* to/from userspace but do not fall entirely within the containing slab
|
|
* cache's usercopy region.
|
|
*
|
|
* Returns NULL if check passes, otherwise const char * to name of cache
|
|
* to indicate an error.
|
|
*/
|
|
void __check_heap_object(const void *ptr, unsigned long n,
|
|
const struct slab *slab, bool to_user)
|
|
{
|
|
struct kmem_cache *s;
|
|
unsigned int offset;
|
|
bool is_kfence = is_kfence_address(ptr);
|
|
|
|
ptr = kasan_reset_tag(ptr);
|
|
|
|
/* Find object and usable object size. */
|
|
s = slab->slab_cache;
|
|
|
|
/* Reject impossible pointers. */
|
|
if (ptr < slab_address(slab))
|
|
usercopy_abort("SLUB object not in SLUB page?!", NULL,
|
|
to_user, 0, n);
|
|
|
|
/* Find offset within object. */
|
|
if (is_kfence)
|
|
offset = ptr - kfence_object_start(ptr);
|
|
else
|
|
offset = (ptr - slab_address(slab)) % s->size;
|
|
|
|
/* Adjust for redzone and reject if within the redzone. */
|
|
if (!is_kfence && kmem_cache_debug_flags(s, SLAB_RED_ZONE)) {
|
|
if (offset < s->red_left_pad)
|
|
usercopy_abort("SLUB object in left red zone",
|
|
s->name, to_user, offset, n);
|
|
offset -= s->red_left_pad;
|
|
}
|
|
|
|
/* Allow address range falling entirely within usercopy region. */
|
|
if (offset >= s->useroffset &&
|
|
offset - s->useroffset <= s->usersize &&
|
|
n <= s->useroffset - offset + s->usersize)
|
|
return;
|
|
|
|
usercopy_abort("SLUB object", s->name, to_user, offset, n);
|
|
}
|
|
#endif /* CONFIG_HARDENED_USERCOPY */
|
|
|
|
#define SHRINK_PROMOTE_MAX 32
|
|
|
|
/*
|
|
* kmem_cache_shrink discards empty slabs and promotes the slabs filled
|
|
* up most to the head of the partial lists. New allocations will then
|
|
* fill those up and thus they can be removed from the partial lists.
|
|
*
|
|
* The slabs with the least items are placed last. This results in them
|
|
* being allocated from last increasing the chance that the last objects
|
|
* are freed in them.
|
|
*/
|
|
static int __kmem_cache_do_shrink(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
int i;
|
|
struct kmem_cache_node *n;
|
|
struct slab *slab;
|
|
struct slab *t;
|
|
struct list_head discard;
|
|
struct list_head promote[SHRINK_PROMOTE_MAX];
|
|
unsigned long flags;
|
|
int ret = 0;
|
|
|
|
for_each_kmem_cache_node(s, node, n) {
|
|
INIT_LIST_HEAD(&discard);
|
|
for (i = 0; i < SHRINK_PROMOTE_MAX; i++)
|
|
INIT_LIST_HEAD(promote + i);
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
|
|
/*
|
|
* Build lists of slabs to discard or promote.
|
|
*
|
|
* Note that concurrent frees may occur while we hold the
|
|
* list_lock. slab->inuse here is the upper limit.
|
|
*/
|
|
list_for_each_entry_safe(slab, t, &n->partial, slab_list) {
|
|
int free = slab->objects - slab->inuse;
|
|
|
|
/* Do not reread slab->inuse */
|
|
barrier();
|
|
|
|
/* We do not keep full slabs on the list */
|
|
BUG_ON(free <= 0);
|
|
|
|
if (free == slab->objects) {
|
|
list_move(&slab->slab_list, &discard);
|
|
slab_clear_node_partial(slab);
|
|
n->nr_partial--;
|
|
dec_slabs_node(s, node, slab->objects);
|
|
} else if (free <= SHRINK_PROMOTE_MAX)
|
|
list_move(&slab->slab_list, promote + free - 1);
|
|
}
|
|
|
|
/*
|
|
* Promote the slabs filled up most to the head of the
|
|
* partial list.
|
|
*/
|
|
for (i = SHRINK_PROMOTE_MAX - 1; i >= 0; i--)
|
|
list_splice(promote + i, &n->partial);
|
|
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
|
|
/* Release empty slabs */
|
|
list_for_each_entry_safe(slab, t, &discard, slab_list)
|
|
free_slab(s, slab);
|
|
|
|
if (node_nr_slabs(n))
|
|
ret = 1;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int __kmem_cache_shrink(struct kmem_cache *s)
|
|
{
|
|
flush_all(s);
|
|
return __kmem_cache_do_shrink(s);
|
|
}
|
|
|
|
static int slab_mem_going_offline_callback(void *arg)
|
|
{
|
|
struct kmem_cache *s;
|
|
|
|
mutex_lock(&slab_mutex);
|
|
list_for_each_entry(s, &slab_caches, list) {
|
|
flush_all_cpus_locked(s);
|
|
__kmem_cache_do_shrink(s);
|
|
}
|
|
mutex_unlock(&slab_mutex);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void slab_mem_offline_callback(void *arg)
|
|
{
|
|
struct memory_notify *marg = arg;
|
|
int offline_node;
|
|
|
|
offline_node = marg->status_change_nid_normal;
|
|
|
|
/*
|
|
* If the node still has available memory. we need kmem_cache_node
|
|
* for it yet.
|
|
*/
|
|
if (offline_node < 0)
|
|
return;
|
|
|
|
mutex_lock(&slab_mutex);
|
|
node_clear(offline_node, slab_nodes);
|
|
/*
|
|
* We no longer free kmem_cache_node structures here, as it would be
|
|
* racy with all get_node() users, and infeasible to protect them with
|
|
* slab_mutex.
|
|
*/
|
|
mutex_unlock(&slab_mutex);
|
|
}
|
|
|
|
static int slab_mem_going_online_callback(void *arg)
|
|
{
|
|
struct kmem_cache_node *n;
|
|
struct kmem_cache *s;
|
|
struct memory_notify *marg = arg;
|
|
int nid = marg->status_change_nid_normal;
|
|
int ret = 0;
|
|
|
|
/*
|
|
* If the node's memory is already available, then kmem_cache_node is
|
|
* already created. Nothing to do.
|
|
*/
|
|
if (nid < 0)
|
|
return 0;
|
|
|
|
/*
|
|
* We are bringing a node online. No memory is available yet. We must
|
|
* allocate a kmem_cache_node structure in order to bring the node
|
|
* online.
|
|
*/
|
|
mutex_lock(&slab_mutex);
|
|
list_for_each_entry(s, &slab_caches, list) {
|
|
/*
|
|
* The structure may already exist if the node was previously
|
|
* onlined and offlined.
|
|
*/
|
|
if (get_node(s, nid))
|
|
continue;
|
|
/*
|
|
* XXX: kmem_cache_alloc_node will fallback to other nodes
|
|
* since memory is not yet available from the node that
|
|
* is brought up.
|
|
*/
|
|
n = kmem_cache_alloc(kmem_cache_node, GFP_KERNEL);
|
|
if (!n) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
init_kmem_cache_node(n);
|
|
s->node[nid] = n;
|
|
}
|
|
/*
|
|
* Any cache created after this point will also have kmem_cache_node
|
|
* initialized for the new node.
|
|
*/
|
|
node_set(nid, slab_nodes);
|
|
out:
|
|
mutex_unlock(&slab_mutex);
|
|
return ret;
|
|
}
|
|
|
|
static int slab_memory_callback(struct notifier_block *self,
|
|
unsigned long action, void *arg)
|
|
{
|
|
int ret = 0;
|
|
|
|
switch (action) {
|
|
case MEM_GOING_ONLINE:
|
|
ret = slab_mem_going_online_callback(arg);
|
|
break;
|
|
case MEM_GOING_OFFLINE:
|
|
ret = slab_mem_going_offline_callback(arg);
|
|
break;
|
|
case MEM_OFFLINE:
|
|
case MEM_CANCEL_ONLINE:
|
|
slab_mem_offline_callback(arg);
|
|
break;
|
|
case MEM_ONLINE:
|
|
case MEM_CANCEL_OFFLINE:
|
|
break;
|
|
}
|
|
if (ret)
|
|
ret = notifier_from_errno(ret);
|
|
else
|
|
ret = NOTIFY_OK;
|
|
return ret;
|
|
}
|
|
|
|
/********************************************************************
|
|
* Basic setup of slabs
|
|
*******************************************************************/
|
|
|
|
/*
|
|
* Used for early kmem_cache structures that were allocated using
|
|
* the page allocator. Allocate them properly then fix up the pointers
|
|
* that may be pointing to the wrong kmem_cache structure.
|
|
*/
|
|
|
|
static struct kmem_cache * __init bootstrap(struct kmem_cache *static_cache)
|
|
{
|
|
int node;
|
|
struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
|
|
struct kmem_cache_node *n;
|
|
|
|
memcpy(s, static_cache, kmem_cache->object_size);
|
|
|
|
/*
|
|
* This runs very early, and only the boot processor is supposed to be
|
|
* up. Even if it weren't true, IRQs are not up so we couldn't fire
|
|
* IPIs around.
|
|
*/
|
|
__flush_cpu_slab(s, smp_processor_id());
|
|
for_each_kmem_cache_node(s, node, n) {
|
|
struct slab *p;
|
|
|
|
list_for_each_entry(p, &n->partial, slab_list)
|
|
p->slab_cache = s;
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
list_for_each_entry(p, &n->full, slab_list)
|
|
p->slab_cache = s;
|
|
#endif
|
|
}
|
|
list_add(&s->list, &slab_caches);
|
|
return s;
|
|
}
|
|
|
|
void __init kmem_cache_init(void)
|
|
{
|
|
static __initdata struct kmem_cache boot_kmem_cache,
|
|
boot_kmem_cache_node;
|
|
int node;
|
|
|
|
if (debug_guardpage_minorder())
|
|
slub_max_order = 0;
|
|
|
|
/* Print slub debugging pointers without hashing */
|
|
if (__slub_debug_enabled())
|
|
no_hash_pointers_enable(NULL);
|
|
|
|
kmem_cache_node = &boot_kmem_cache_node;
|
|
kmem_cache = &boot_kmem_cache;
|
|
|
|
/*
|
|
* Initialize the nodemask for which we will allocate per node
|
|
* structures. Here we don't need taking slab_mutex yet.
|
|
*/
|
|
for_each_node_state(node, N_NORMAL_MEMORY)
|
|
node_set(node, slab_nodes);
|
|
|
|
create_boot_cache(kmem_cache_node, "kmem_cache_node",
|
|
sizeof(struct kmem_cache_node), SLAB_HWCACHE_ALIGN, 0, 0);
|
|
|
|
hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
|
|
|
|
/* Able to allocate the per node structures */
|
|
slab_state = PARTIAL;
|
|
|
|
create_boot_cache(kmem_cache, "kmem_cache",
|
|
offsetof(struct kmem_cache, node) +
|
|
nr_node_ids * sizeof(struct kmem_cache_node *),
|
|
SLAB_HWCACHE_ALIGN, 0, 0);
|
|
|
|
kmem_cache = bootstrap(&boot_kmem_cache);
|
|
kmem_cache_node = bootstrap(&boot_kmem_cache_node);
|
|
|
|
/* Now we can use the kmem_cache to allocate kmalloc slabs */
|
|
setup_kmalloc_cache_index_table();
|
|
create_kmalloc_caches();
|
|
|
|
/* Setup random freelists for each cache */
|
|
init_freelist_randomization();
|
|
|
|
cpuhp_setup_state_nocalls(CPUHP_SLUB_DEAD, "slub:dead", NULL,
|
|
slub_cpu_dead);
|
|
|
|
pr_info("SLUB: HWalign=%d, Order=%u-%u, MinObjects=%u, CPUs=%u, Nodes=%u\n",
|
|
cache_line_size(),
|
|
slub_min_order, slub_max_order, slub_min_objects,
|
|
nr_cpu_ids, nr_node_ids);
|
|
}
|
|
|
|
void __init kmem_cache_init_late(void)
|
|
{
|
|
#ifndef CONFIG_SLUB_TINY
|
|
flushwq = alloc_workqueue("slub_flushwq", WQ_MEM_RECLAIM, 0);
|
|
WARN_ON(!flushwq);
|
|
#endif
|
|
}
|
|
|
|
struct kmem_cache *
|
|
__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
|
|
slab_flags_t flags, void (*ctor)(void *))
|
|
{
|
|
struct kmem_cache *s;
|
|
|
|
s = find_mergeable(size, align, flags, name, ctor);
|
|
if (s) {
|
|
if (sysfs_slab_alias(s, name))
|
|
return NULL;
|
|
|
|
s->refcount++;
|
|
|
|
/*
|
|
* Adjust the object sizes so that we clear
|
|
* the complete object on kzalloc.
|
|
*/
|
|
s->object_size = max(s->object_size, size);
|
|
s->inuse = max(s->inuse, ALIGN(size, sizeof(void *)));
|
|
}
|
|
|
|
return s;
|
|
}
|
|
|
|
int __kmem_cache_create(struct kmem_cache *s, slab_flags_t flags)
|
|
{
|
|
int err;
|
|
|
|
err = kmem_cache_open(s, flags);
|
|
if (err)
|
|
return err;
|
|
|
|
/* Mutex is not taken during early boot */
|
|
if (slab_state <= UP)
|
|
return 0;
|
|
|
|
err = sysfs_slab_add(s);
|
|
if (err) {
|
|
__kmem_cache_release(s);
|
|
return err;
|
|
}
|
|
|
|
if (s->flags & SLAB_STORE_USER)
|
|
debugfs_slab_add(s);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef SLAB_SUPPORTS_SYSFS
|
|
static int count_inuse(struct slab *slab)
|
|
{
|
|
return slab->inuse;
|
|
}
|
|
|
|
static int count_total(struct slab *slab)
|
|
{
|
|
return slab->objects;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
static void validate_slab(struct kmem_cache *s, struct slab *slab,
|
|
unsigned long *obj_map)
|
|
{
|
|
void *p;
|
|
void *addr = slab_address(slab);
|
|
|
|
if (!check_slab(s, slab) || !on_freelist(s, slab, NULL))
|
|
return;
|
|
|
|
/* Now we know that a valid freelist exists */
|
|
__fill_map(obj_map, s, slab);
|
|
for_each_object(p, s, addr, slab->objects) {
|
|
u8 val = test_bit(__obj_to_index(s, addr, p), obj_map) ?
|
|
SLUB_RED_INACTIVE : SLUB_RED_ACTIVE;
|
|
|
|
if (!check_object(s, slab, p, val))
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int validate_slab_node(struct kmem_cache *s,
|
|
struct kmem_cache_node *n, unsigned long *obj_map)
|
|
{
|
|
unsigned long count = 0;
|
|
struct slab *slab;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
|
|
list_for_each_entry(slab, &n->partial, slab_list) {
|
|
validate_slab(s, slab, obj_map);
|
|
count++;
|
|
}
|
|
if (count != n->nr_partial) {
|
|
pr_err("SLUB %s: %ld partial slabs counted but counter=%ld\n",
|
|
s->name, count, n->nr_partial);
|
|
slab_add_kunit_errors();
|
|
}
|
|
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
goto out;
|
|
|
|
list_for_each_entry(slab, &n->full, slab_list) {
|
|
validate_slab(s, slab, obj_map);
|
|
count++;
|
|
}
|
|
if (count != node_nr_slabs(n)) {
|
|
pr_err("SLUB: %s %ld slabs counted but counter=%ld\n",
|
|
s->name, count, node_nr_slabs(n));
|
|
slab_add_kunit_errors();
|
|
}
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
return count;
|
|
}
|
|
|
|
long validate_slab_cache(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
unsigned long count = 0;
|
|
struct kmem_cache_node *n;
|
|
unsigned long *obj_map;
|
|
|
|
obj_map = bitmap_alloc(oo_objects(s->oo), GFP_KERNEL);
|
|
if (!obj_map)
|
|
return -ENOMEM;
|
|
|
|
flush_all(s);
|
|
for_each_kmem_cache_node(s, node, n)
|
|
count += validate_slab_node(s, n, obj_map);
|
|
|
|
bitmap_free(obj_map);
|
|
|
|
return count;
|
|
}
|
|
EXPORT_SYMBOL(validate_slab_cache);
|
|
|
|
#ifdef CONFIG_DEBUG_FS
|
|
/*
|
|
* Generate lists of code addresses where slabcache objects are allocated
|
|
* and freed.
|
|
*/
|
|
|
|
struct location {
|
|
depot_stack_handle_t handle;
|
|
unsigned long count;
|
|
unsigned long addr;
|
|
unsigned long waste;
|
|
long long sum_time;
|
|
long min_time;
|
|
long max_time;
|
|
long min_pid;
|
|
long max_pid;
|
|
DECLARE_BITMAP(cpus, NR_CPUS);
|
|
nodemask_t nodes;
|
|
};
|
|
|
|
struct loc_track {
|
|
unsigned long max;
|
|
unsigned long count;
|
|
struct location *loc;
|
|
loff_t idx;
|
|
};
|
|
|
|
static struct dentry *slab_debugfs_root;
|
|
|
|
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, gfp_t flags)
|
|
{
|
|
struct location *l;
|
|
int order;
|
|
|
|
order = get_order(sizeof(struct location) * max);
|
|
|
|
l = (void *)__get_free_pages(flags, 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,
|
|
const struct track *track,
|
|
unsigned int orig_size)
|
|
{
|
|
long start, end, pos;
|
|
struct location *l;
|
|
unsigned long caddr, chandle, cwaste;
|
|
unsigned long age = jiffies - track->when;
|
|
depot_stack_handle_t handle = 0;
|
|
unsigned int waste = s->object_size - orig_size;
|
|
|
|
#ifdef CONFIG_STACKDEPOT
|
|
handle = READ_ONCE(track->handle);
|
|
#endif
|
|
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;
|
|
|
|
l = &t->loc[pos];
|
|
caddr = l->addr;
|
|
chandle = l->handle;
|
|
cwaste = l->waste;
|
|
if ((track->addr == caddr) && (handle == chandle) &&
|
|
(waste == cwaste)) {
|
|
|
|
l->count++;
|
|
if (track->when) {
|
|
l->sum_time += age;
|
|
if (age < l->min_time)
|
|
l->min_time = age;
|
|
if (age > l->max_time)
|
|
l->max_time = age;
|
|
|
|
if (track->pid < l->min_pid)
|
|
l->min_pid = track->pid;
|
|
if (track->pid > l->max_pid)
|
|
l->max_pid = track->pid;
|
|
|
|
cpumask_set_cpu(track->cpu,
|
|
to_cpumask(l->cpus));
|
|
}
|
|
node_set(page_to_nid(virt_to_page(track)), l->nodes);
|
|
return 1;
|
|
}
|
|
|
|
if (track->addr < caddr)
|
|
end = pos;
|
|
else if (track->addr == caddr && handle < chandle)
|
|
end = pos;
|
|
else if (track->addr == caddr && handle == chandle &&
|
|
waste < cwaste)
|
|
end = pos;
|
|
else
|
|
start = pos;
|
|
}
|
|
|
|
/*
|
|
* Not found. Insert new tracking element.
|
|
*/
|
|
if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC))
|
|
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 = track->addr;
|
|
l->sum_time = age;
|
|
l->min_time = age;
|
|
l->max_time = age;
|
|
l->min_pid = track->pid;
|
|
l->max_pid = track->pid;
|
|
l->handle = handle;
|
|
l->waste = waste;
|
|
cpumask_clear(to_cpumask(l->cpus));
|
|
cpumask_set_cpu(track->cpu, to_cpumask(l->cpus));
|
|
nodes_clear(l->nodes);
|
|
node_set(page_to_nid(virt_to_page(track)), l->nodes);
|
|
return 1;
|
|
}
|
|
|
|
static void process_slab(struct loc_track *t, struct kmem_cache *s,
|
|
struct slab *slab, enum track_item alloc,
|
|
unsigned long *obj_map)
|
|
{
|
|
void *addr = slab_address(slab);
|
|
bool is_alloc = (alloc == TRACK_ALLOC);
|
|
void *p;
|
|
|
|
__fill_map(obj_map, s, slab);
|
|
|
|
for_each_object(p, s, addr, slab->objects)
|
|
if (!test_bit(__obj_to_index(s, addr, p), obj_map))
|
|
add_location(t, s, get_track(s, p, alloc),
|
|
is_alloc ? get_orig_size(s, p) :
|
|
s->object_size);
|
|
}
|
|
#endif /* CONFIG_DEBUG_FS */
|
|
#endif /* CONFIG_SLUB_DEBUG */
|
|
|
|
#ifdef SLAB_SUPPORTS_SYSFS
|
|
enum slab_stat_type {
|
|
SL_ALL, /* All slabs */
|
|
SL_PARTIAL, /* Only partially allocated slabs */
|
|
SL_CPU, /* Only slabs used for cpu caches */
|
|
SL_OBJECTS, /* Determine allocated objects not slabs */
|
|
SL_TOTAL /* Determine object capacity not slabs */
|
|
};
|
|
|
|
#define SO_ALL (1 << SL_ALL)
|
|
#define SO_PARTIAL (1 << SL_PARTIAL)
|
|
#define SO_CPU (1 << SL_CPU)
|
|
#define SO_OBJECTS (1 << SL_OBJECTS)
|
|
#define SO_TOTAL (1 << SL_TOTAL)
|
|
|
|
static ssize_t show_slab_objects(struct kmem_cache *s,
|
|
char *buf, unsigned long flags)
|
|
{
|
|
unsigned long total = 0;
|
|
int node;
|
|
int x;
|
|
unsigned long *nodes;
|
|
int len = 0;
|
|
|
|
nodes = kcalloc(nr_node_ids, sizeof(unsigned long), GFP_KERNEL);
|
|
if (!nodes)
|
|
return -ENOMEM;
|
|
|
|
if (flags & SO_CPU) {
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab,
|
|
cpu);
|
|
int node;
|
|
struct slab *slab;
|
|
|
|
slab = READ_ONCE(c->slab);
|
|
if (!slab)
|
|
continue;
|
|
|
|
node = slab_nid(slab);
|
|
if (flags & SO_TOTAL)
|
|
x = slab->objects;
|
|
else if (flags & SO_OBJECTS)
|
|
x = slab->inuse;
|
|
else
|
|
x = 1;
|
|
|
|
total += x;
|
|
nodes[node] += x;
|
|
|
|
#ifdef CONFIG_SLUB_CPU_PARTIAL
|
|
slab = slub_percpu_partial_read_once(c);
|
|
if (slab) {
|
|
node = slab_nid(slab);
|
|
if (flags & SO_TOTAL)
|
|
WARN_ON_ONCE(1);
|
|
else if (flags & SO_OBJECTS)
|
|
WARN_ON_ONCE(1);
|
|
else
|
|
x = slab->slabs;
|
|
total += x;
|
|
nodes[node] += x;
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
|
|
/*
|
|
* It is impossible to take "mem_hotplug_lock" here with "kernfs_mutex"
|
|
* already held which will conflict with an existing lock order:
|
|
*
|
|
* mem_hotplug_lock->slab_mutex->kernfs_mutex
|
|
*
|
|
* We don't really need mem_hotplug_lock (to hold off
|
|
* slab_mem_going_offline_callback) here because slab's memory hot
|
|
* unplug code doesn't destroy the kmem_cache->node[] data.
|
|
*/
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
if (flags & SO_ALL) {
|
|
struct kmem_cache_node *n;
|
|
|
|
for_each_kmem_cache_node(s, node, n) {
|
|
|
|
if (flags & SO_TOTAL)
|
|
x = node_nr_objs(n);
|
|
else if (flags & SO_OBJECTS)
|
|
x = node_nr_objs(n) - count_partial(n, count_free);
|
|
else
|
|
x = node_nr_slabs(n);
|
|
total += x;
|
|
nodes[node] += x;
|
|
}
|
|
|
|
} else
|
|
#endif
|
|
if (flags & SO_PARTIAL) {
|
|
struct kmem_cache_node *n;
|
|
|
|
for_each_kmem_cache_node(s, node, n) {
|
|
if (flags & SO_TOTAL)
|
|
x = count_partial(n, count_total);
|
|
else if (flags & SO_OBJECTS)
|
|
x = count_partial(n, count_inuse);
|
|
else
|
|
x = n->nr_partial;
|
|
total += x;
|
|
nodes[node] += x;
|
|
}
|
|
}
|
|
|
|
len += sysfs_emit_at(buf, len, "%lu", total);
|
|
#ifdef CONFIG_NUMA
|
|
for (node = 0; node < nr_node_ids; node++) {
|
|
if (nodes[node])
|
|
len += sysfs_emit_at(buf, len, " N%d=%lu",
|
|
node, nodes[node]);
|
|
}
|
|
#endif
|
|
len += sysfs_emit_at(buf, len, "\n");
|
|
kfree(nodes);
|
|
|
|
return len;
|
|
}
|
|
|
|
#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_MODE(_name, 0400)
|
|
|
|
#define SLAB_ATTR(_name) \
|
|
static struct slab_attribute _name##_attr = __ATTR_RW_MODE(_name, 0600)
|
|
|
|
static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%u\n", s->size);
|
|
}
|
|
SLAB_ATTR_RO(slab_size);
|
|
|
|
static ssize_t align_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%u\n", s->align);
|
|
}
|
|
SLAB_ATTR_RO(align);
|
|
|
|
static ssize_t object_size_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%u\n", s->object_size);
|
|
}
|
|
SLAB_ATTR_RO(object_size);
|
|
|
|
static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%u\n", oo_objects(s->oo));
|
|
}
|
|
SLAB_ATTR_RO(objs_per_slab);
|
|
|
|
static ssize_t order_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%u\n", oo_order(s->oo));
|
|
}
|
|
SLAB_ATTR_RO(order);
|
|
|
|
static ssize_t min_partial_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%lu\n", s->min_partial);
|
|
}
|
|
|
|
static ssize_t min_partial_store(struct kmem_cache *s, const char *buf,
|
|
size_t length)
|
|
{
|
|
unsigned long min;
|
|
int err;
|
|
|
|
err = kstrtoul(buf, 10, &min);
|
|
if (err)
|
|
return err;
|
|
|
|
s->min_partial = min;
|
|
return length;
|
|
}
|
|
SLAB_ATTR(min_partial);
|
|
|
|
static ssize_t cpu_partial_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
unsigned int nr_partial = 0;
|
|
#ifdef CONFIG_SLUB_CPU_PARTIAL
|
|
nr_partial = s->cpu_partial;
|
|
#endif
|
|
|
|
return sysfs_emit(buf, "%u\n", nr_partial);
|
|
}
|
|
|
|
static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
|
|
size_t length)
|
|
{
|
|
unsigned int objects;
|
|
int err;
|
|
|
|
err = kstrtouint(buf, 10, &objects);
|
|
if (err)
|
|
return err;
|
|
if (objects && !kmem_cache_has_cpu_partial(s))
|
|
return -EINVAL;
|
|
|
|
slub_set_cpu_partial(s, objects);
|
|
flush_all(s);
|
|
return length;
|
|
}
|
|
SLAB_ATTR(cpu_partial);
|
|
|
|
static ssize_t ctor_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
if (!s->ctor)
|
|
return 0;
|
|
return sysfs_emit(buf, "%pS\n", s->ctor);
|
|
}
|
|
SLAB_ATTR_RO(ctor);
|
|
|
|
static ssize_t aliases_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%d\n", s->refcount < 0 ? 0 : s->refcount - 1);
|
|
}
|
|
SLAB_ATTR_RO(aliases);
|
|
|
|
static ssize_t partial_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return show_slab_objects(s, buf, SO_PARTIAL);
|
|
}
|
|
SLAB_ATTR_RO(partial);
|
|
|
|
static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return show_slab_objects(s, buf, SO_CPU);
|
|
}
|
|
SLAB_ATTR_RO(cpu_slabs);
|
|
|
|
static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS);
|
|
}
|
|
SLAB_ATTR_RO(objects_partial);
|
|
|
|
static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
int objects = 0;
|
|
int slabs = 0;
|
|
int cpu __maybe_unused;
|
|
int len = 0;
|
|
|
|
#ifdef CONFIG_SLUB_CPU_PARTIAL
|
|
for_each_online_cpu(cpu) {
|
|
struct slab *slab;
|
|
|
|
slab = slub_percpu_partial(per_cpu_ptr(s->cpu_slab, cpu));
|
|
|
|
if (slab)
|
|
slabs += slab->slabs;
|
|
}
|
|
#endif
|
|
|
|
/* Approximate half-full slabs, see slub_set_cpu_partial() */
|
|
objects = (slabs * oo_objects(s->oo)) / 2;
|
|
len += sysfs_emit_at(buf, len, "%d(%d)", objects, slabs);
|
|
|
|
#ifdef CONFIG_SLUB_CPU_PARTIAL
|
|
for_each_online_cpu(cpu) {
|
|
struct slab *slab;
|
|
|
|
slab = slub_percpu_partial(per_cpu_ptr(s->cpu_slab, cpu));
|
|
if (slab) {
|
|
slabs = READ_ONCE(slab->slabs);
|
|
objects = (slabs * oo_objects(s->oo)) / 2;
|
|
len += sysfs_emit_at(buf, len, " C%d=%d(%d)",
|
|
cpu, objects, slabs);
|
|
}
|
|
}
|
|
#endif
|
|
len += sysfs_emit_at(buf, len, "\n");
|
|
|
|
return len;
|
|
}
|
|
SLAB_ATTR_RO(slabs_cpu_partial);
|
|
|
|
static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
|
|
}
|
|
SLAB_ATTR_RO(reclaim_account);
|
|
|
|
static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(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 sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
|
|
}
|
|
SLAB_ATTR_RO(cache_dma);
|
|
#endif
|
|
|
|
#ifdef CONFIG_HARDENED_USERCOPY
|
|
static ssize_t usersize_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%u\n", s->usersize);
|
|
}
|
|
SLAB_ATTR_RO(usersize);
|
|
#endif
|
|
|
|
static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_TYPESAFE_BY_RCU));
|
|
}
|
|
SLAB_ATTR_RO(destroy_by_rcu);
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
static ssize_t slabs_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return show_slab_objects(s, buf, SO_ALL);
|
|
}
|
|
SLAB_ATTR_RO(slabs);
|
|
|
|
static ssize_t total_objects_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return show_slab_objects(s, buf, SO_ALL|SO_TOTAL);
|
|
}
|
|
SLAB_ATTR_RO(total_objects);
|
|
|
|
static ssize_t objects_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS);
|
|
}
|
|
SLAB_ATTR_RO(objects);
|
|
|
|
static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_CONSISTENCY_CHECKS));
|
|
}
|
|
SLAB_ATTR_RO(sanity_checks);
|
|
|
|
static ssize_t trace_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_TRACE));
|
|
}
|
|
SLAB_ATTR_RO(trace);
|
|
|
|
static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
|
|
}
|
|
|
|
SLAB_ATTR_RO(red_zone);
|
|
|
|
static ssize_t poison_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_POISON));
|
|
}
|
|
|
|
SLAB_ATTR_RO(poison);
|
|
|
|
static ssize_t store_user_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
|
|
}
|
|
|
|
SLAB_ATTR_RO(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)
|
|
{
|
|
int ret = -EINVAL;
|
|
|
|
if (buf[0] == '1' && kmem_cache_debug(s)) {
|
|
ret = validate_slab_cache(s);
|
|
if (ret >= 0)
|
|
ret = length;
|
|
}
|
|
return ret;
|
|
}
|
|
SLAB_ATTR(validate);
|
|
|
|
#endif /* CONFIG_SLUB_DEBUG */
|
|
|
|
#ifdef CONFIG_FAILSLAB
|
|
static ssize_t failslab_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB));
|
|
}
|
|
|
|
static ssize_t failslab_store(struct kmem_cache *s, const char *buf,
|
|
size_t length)
|
|
{
|
|
if (s->refcount > 1)
|
|
return -EINVAL;
|
|
|
|
if (buf[0] == '1')
|
|
WRITE_ONCE(s->flags, s->flags | SLAB_FAILSLAB);
|
|
else
|
|
WRITE_ONCE(s->flags, s->flags & ~SLAB_FAILSLAB);
|
|
|
|
return length;
|
|
}
|
|
SLAB_ATTR(failslab);
|
|
#endif
|
|
|
|
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')
|
|
kmem_cache_shrink(s);
|
|
else
|
|
return -EINVAL;
|
|
return length;
|
|
}
|
|
SLAB_ATTR(shrink);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%u\n", s->remote_node_defrag_ratio / 10);
|
|
}
|
|
|
|
static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
unsigned int ratio;
|
|
int err;
|
|
|
|
err = kstrtouint(buf, 10, &ratio);
|
|
if (err)
|
|
return err;
|
|
if (ratio > 100)
|
|
return -ERANGE;
|
|
|
|
s->remote_node_defrag_ratio = ratio * 10;
|
|
|
|
return length;
|
|
}
|
|
SLAB_ATTR(remote_node_defrag_ratio);
|
|
#endif
|
|
|
|
#ifdef CONFIG_SLUB_STATS
|
|
static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
|
|
{
|
|
unsigned long sum = 0;
|
|
int cpu;
|
|
int len = 0;
|
|
int *data = kmalloc_array(nr_cpu_ids, sizeof(int), GFP_KERNEL);
|
|
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
for_each_online_cpu(cpu) {
|
|
unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si];
|
|
|
|
data[cpu] = x;
|
|
sum += x;
|
|
}
|
|
|
|
len += sysfs_emit_at(buf, len, "%lu", sum);
|
|
|
|
#ifdef CONFIG_SMP
|
|
for_each_online_cpu(cpu) {
|
|
if (data[cpu])
|
|
len += sysfs_emit_at(buf, len, " C%d=%u",
|
|
cpu, data[cpu]);
|
|
}
|
|
#endif
|
|
kfree(data);
|
|
len += sysfs_emit_at(buf, len, "\n");
|
|
|
|
return len;
|
|
}
|
|
|
|
static void clear_stat(struct kmem_cache *s, enum stat_item si)
|
|
{
|
|
int cpu;
|
|
|
|
for_each_online_cpu(cpu)
|
|
per_cpu_ptr(s->cpu_slab, cpu)->stat[si] = 0;
|
|
}
|
|
|
|
#define STAT_ATTR(si, text) \
|
|
static ssize_t text##_show(struct kmem_cache *s, char *buf) \
|
|
{ \
|
|
return show_stat(s, buf, si); \
|
|
} \
|
|
static ssize_t text##_store(struct kmem_cache *s, \
|
|
const char *buf, size_t length) \
|
|
{ \
|
|
if (buf[0] != '0') \
|
|
return -EINVAL; \
|
|
clear_stat(s, si); \
|
|
return length; \
|
|
} \
|
|
SLAB_ATTR(text); \
|
|
|
|
STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
|
|
STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath);
|
|
STAT_ATTR(FREE_FASTPATH, free_fastpath);
|
|
STAT_ATTR(FREE_SLOWPATH, free_slowpath);
|
|
STAT_ATTR(FREE_FROZEN, free_frozen);
|
|
STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial);
|
|
STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial);
|
|
STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial);
|
|
STAT_ATTR(ALLOC_SLAB, alloc_slab);
|
|
STAT_ATTR(ALLOC_REFILL, alloc_refill);
|
|
STAT_ATTR(ALLOC_NODE_MISMATCH, alloc_node_mismatch);
|
|
STAT_ATTR(FREE_SLAB, free_slab);
|
|
STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush);
|
|
STAT_ATTR(DEACTIVATE_FULL, deactivate_full);
|
|
STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty);
|
|
STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
|
|
STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
|
|
STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
|
|
STAT_ATTR(DEACTIVATE_BYPASS, deactivate_bypass);
|
|
STAT_ATTR(ORDER_FALLBACK, order_fallback);
|
|
STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL, cmpxchg_double_cpu_fail);
|
|
STAT_ATTR(CMPXCHG_DOUBLE_FAIL, cmpxchg_double_fail);
|
|
STAT_ATTR(CPU_PARTIAL_ALLOC, cpu_partial_alloc);
|
|
STAT_ATTR(CPU_PARTIAL_FREE, cpu_partial_free);
|
|
STAT_ATTR(CPU_PARTIAL_NODE, cpu_partial_node);
|
|
STAT_ATTR(CPU_PARTIAL_DRAIN, cpu_partial_drain);
|
|
#endif /* CONFIG_SLUB_STATS */
|
|
|
|
#ifdef CONFIG_KFENCE
|
|
static ssize_t skip_kfence_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_SKIP_KFENCE));
|
|
}
|
|
|
|
static ssize_t skip_kfence_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
int ret = length;
|
|
|
|
if (buf[0] == '0')
|
|
s->flags &= ~SLAB_SKIP_KFENCE;
|
|
else if (buf[0] == '1')
|
|
s->flags |= SLAB_SKIP_KFENCE;
|
|
else
|
|
ret = -EINVAL;
|
|
|
|
return ret;
|
|
}
|
|
SLAB_ATTR(skip_kfence);
|
|
#endif
|
|
|
|
static struct attribute *slab_attrs[] = {
|
|
&slab_size_attr.attr,
|
|
&object_size_attr.attr,
|
|
&objs_per_slab_attr.attr,
|
|
&order_attr.attr,
|
|
&min_partial_attr.attr,
|
|
&cpu_partial_attr.attr,
|
|
&objects_partial_attr.attr,
|
|
&partial_attr.attr,
|
|
&cpu_slabs_attr.attr,
|
|
&ctor_attr.attr,
|
|
&aliases_attr.attr,
|
|
&align_attr.attr,
|
|
&hwcache_align_attr.attr,
|
|
&reclaim_account_attr.attr,
|
|
&destroy_by_rcu_attr.attr,
|
|
&shrink_attr.attr,
|
|
&slabs_cpu_partial_attr.attr,
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
&total_objects_attr.attr,
|
|
&objects_attr.attr,
|
|
&slabs_attr.attr,
|
|
&sanity_checks_attr.attr,
|
|
&trace_attr.attr,
|
|
&red_zone_attr.attr,
|
|
&poison_attr.attr,
|
|
&store_user_attr.attr,
|
|
&validate_attr.attr,
|
|
#endif
|
|
#ifdef CONFIG_ZONE_DMA
|
|
&cache_dma_attr.attr,
|
|
#endif
|
|
#ifdef CONFIG_NUMA
|
|
&remote_node_defrag_ratio_attr.attr,
|
|
#endif
|
|
#ifdef CONFIG_SLUB_STATS
|
|
&alloc_fastpath_attr.attr,
|
|
&alloc_slowpath_attr.attr,
|
|
&free_fastpath_attr.attr,
|
|
&free_slowpath_attr.attr,
|
|
&free_frozen_attr.attr,
|
|
&free_add_partial_attr.attr,
|
|
&free_remove_partial_attr.attr,
|
|
&alloc_from_partial_attr.attr,
|
|
&alloc_slab_attr.attr,
|
|
&alloc_refill_attr.attr,
|
|
&alloc_node_mismatch_attr.attr,
|
|
&free_slab_attr.attr,
|
|
&cpuslab_flush_attr.attr,
|
|
&deactivate_full_attr.attr,
|
|
&deactivate_empty_attr.attr,
|
|
&deactivate_to_head_attr.attr,
|
|
&deactivate_to_tail_attr.attr,
|
|
&deactivate_remote_frees_attr.attr,
|
|
&deactivate_bypass_attr.attr,
|
|
&order_fallback_attr.attr,
|
|
&cmpxchg_double_fail_attr.attr,
|
|
&cmpxchg_double_cpu_fail_attr.attr,
|
|
&cpu_partial_alloc_attr.attr,
|
|
&cpu_partial_free_attr.attr,
|
|
&cpu_partial_node_attr.attr,
|
|
&cpu_partial_drain_attr.attr,
|
|
#endif
|
|
#ifdef CONFIG_FAILSLAB
|
|
&failslab_attr.attr,
|
|
#endif
|
|
#ifdef CONFIG_HARDENED_USERCOPY
|
|
&usersize_attr.attr,
|
|
#endif
|
|
#ifdef CONFIG_KFENCE
|
|
&skip_kfence_attr.attr,
|
|
#endif
|
|
|
|
NULL
|
|
};
|
|
|
|
static const 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;
|
|
|
|
attribute = to_slab_attr(attr);
|
|
s = to_slab(kobj);
|
|
|
|
if (!attribute->show)
|
|
return -EIO;
|
|
|
|
return attribute->show(s, buf);
|
|
}
|
|
|
|
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;
|
|
|
|
attribute = to_slab_attr(attr);
|
|
s = to_slab(kobj);
|
|
|
|
if (!attribute->store)
|
|
return -EIO;
|
|
|
|
return attribute->store(s, buf, len);
|
|
}
|
|
|
|
static void kmem_cache_release(struct kobject *k)
|
|
{
|
|
slab_kmem_cache_release(to_slab(k));
|
|
}
|
|
|
|
static const struct sysfs_ops slab_sysfs_ops = {
|
|
.show = slab_attr_show,
|
|
.store = slab_attr_store,
|
|
};
|
|
|
|
static const struct kobj_type slab_ktype = {
|
|
.sysfs_ops = &slab_sysfs_ops,
|
|
.release = kmem_cache_release,
|
|
};
|
|
|
|
static struct kset *slab_kset;
|
|
|
|
static inline struct kset *cache_kset(struct kmem_cache *s)
|
|
{
|
|
return slab_kset;
|
|
}
|
|
|
|
#define ID_STR_LENGTH 32
|
|
|
|
/* Create a unique string id for a slab cache:
|
|
*
|
|
* Format :[flags-]size
|
|
*/
|
|
static char *create_unique_id(struct kmem_cache *s)
|
|
{
|
|
char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
|
|
char *p = name;
|
|
|
|
if (!name)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
*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_CACHE_DMA32)
|
|
*p++ = 'D';
|
|
if (s->flags & SLAB_RECLAIM_ACCOUNT)
|
|
*p++ = 'a';
|
|
if (s->flags & SLAB_CONSISTENCY_CHECKS)
|
|
*p++ = 'F';
|
|
if (s->flags & SLAB_ACCOUNT)
|
|
*p++ = 'A';
|
|
if (p != name + 1)
|
|
*p++ = '-';
|
|
p += snprintf(p, ID_STR_LENGTH - (p - name), "%07u", s->size);
|
|
|
|
if (WARN_ON(p > name + ID_STR_LENGTH - 1)) {
|
|
kfree(name);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
kmsan_unpoison_memory(name, p - name);
|
|
return name;
|
|
}
|
|
|
|
static int sysfs_slab_add(struct kmem_cache *s)
|
|
{
|
|
int err;
|
|
const char *name;
|
|
struct kset *kset = cache_kset(s);
|
|
int unmergeable = slab_unmergeable(s);
|
|
|
|
if (!unmergeable && disable_higher_order_debug &&
|
|
(slub_debug & DEBUG_METADATA_FLAGS))
|
|
unmergeable = 1;
|
|
|
|
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_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);
|
|
if (IS_ERR(name))
|
|
return PTR_ERR(name);
|
|
}
|
|
|
|
s->kobj.kset = kset;
|
|
err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name);
|
|
if (err)
|
|
goto out;
|
|
|
|
err = sysfs_create_group(&s->kobj, &slab_attr_group);
|
|
if (err)
|
|
goto out_del_kobj;
|
|
|
|
if (!unmergeable) {
|
|
/* Setup first alias */
|
|
sysfs_slab_alias(s, s->name);
|
|
}
|
|
out:
|
|
if (!unmergeable)
|
|
kfree(name);
|
|
return err;
|
|
out_del_kobj:
|
|
kobject_del(&s->kobj);
|
|
goto out;
|
|
}
|
|
|
|
void sysfs_slab_unlink(struct kmem_cache *s)
|
|
{
|
|
kobject_del(&s->kobj);
|
|
}
|
|
|
|
void sysfs_slab_release(struct kmem_cache *s)
|
|
{
|
|
kobject_put(&s->kobj);
|
|
}
|
|
|
|
/*
|
|
* Need to buffer aliases during bootup until sysfs becomes
|
|
* available lest we lose that information.
|
|
*/
|
|
struct saved_alias {
|
|
struct kmem_cache *s;
|
|
const char *name;
|
|
struct saved_alias *next;
|
|
};
|
|
|
|
static struct saved_alias *alias_list;
|
|
|
|
static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
|
|
{
|
|
struct saved_alias *al;
|
|
|
|
if (slab_state == FULL) {
|
|
/*
|
|
* If we have a leftover link then remove it.
|
|
*/
|
|
sysfs_remove_link(&slab_kset->kobj, name);
|
|
return sysfs_create_link(&slab_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;
|
|
kmsan_unpoison_memory(al, sizeof(*al));
|
|
return 0;
|
|
}
|
|
|
|
static int __init slab_sysfs_init(void)
|
|
{
|
|
struct kmem_cache *s;
|
|
int err;
|
|
|
|
mutex_lock(&slab_mutex);
|
|
|
|
slab_kset = kset_create_and_add("slab", NULL, kernel_kobj);
|
|
if (!slab_kset) {
|
|
mutex_unlock(&slab_mutex);
|
|
pr_err("Cannot register slab subsystem.\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
slab_state = FULL;
|
|
|
|
list_for_each_entry(s, &slab_caches, list) {
|
|
err = sysfs_slab_add(s);
|
|
if (err)
|
|
pr_err("SLUB: Unable to add boot slab %s to sysfs\n",
|
|
s->name);
|
|
}
|
|
|
|
while (alias_list) {
|
|
struct saved_alias *al = alias_list;
|
|
|
|
alias_list = alias_list->next;
|
|
err = sysfs_slab_alias(al->s, al->name);
|
|
if (err)
|
|
pr_err("SLUB: Unable to add boot slab alias %s to sysfs\n",
|
|
al->name);
|
|
kfree(al);
|
|
}
|
|
|
|
mutex_unlock(&slab_mutex);
|
|
return 0;
|
|
}
|
|
late_initcall(slab_sysfs_init);
|
|
#endif /* SLAB_SUPPORTS_SYSFS */
|
|
|
|
#if defined(CONFIG_SLUB_DEBUG) && defined(CONFIG_DEBUG_FS)
|
|
static int slab_debugfs_show(struct seq_file *seq, void *v)
|
|
{
|
|
struct loc_track *t = seq->private;
|
|
struct location *l;
|
|
unsigned long idx;
|
|
|
|
idx = (unsigned long) t->idx;
|
|
if (idx < t->count) {
|
|
l = &t->loc[idx];
|
|
|
|
seq_printf(seq, "%7ld ", l->count);
|
|
|
|
if (l->addr)
|
|
seq_printf(seq, "%pS", (void *)l->addr);
|
|
else
|
|
seq_puts(seq, "<not-available>");
|
|
|
|
if (l->waste)
|
|
seq_printf(seq, " waste=%lu/%lu",
|
|
l->count * l->waste, l->waste);
|
|
|
|
if (l->sum_time != l->min_time) {
|
|
seq_printf(seq, " age=%ld/%llu/%ld",
|
|
l->min_time, div_u64(l->sum_time, l->count),
|
|
l->max_time);
|
|
} else
|
|
seq_printf(seq, " age=%ld", l->min_time);
|
|
|
|
if (l->min_pid != l->max_pid)
|
|
seq_printf(seq, " pid=%ld-%ld", l->min_pid, l->max_pid);
|
|
else
|
|
seq_printf(seq, " pid=%ld",
|
|
l->min_pid);
|
|
|
|
if (num_online_cpus() > 1 && !cpumask_empty(to_cpumask(l->cpus)))
|
|
seq_printf(seq, " cpus=%*pbl",
|
|
cpumask_pr_args(to_cpumask(l->cpus)));
|
|
|
|
if (nr_online_nodes > 1 && !nodes_empty(l->nodes))
|
|
seq_printf(seq, " nodes=%*pbl",
|
|
nodemask_pr_args(&l->nodes));
|
|
|
|
#ifdef CONFIG_STACKDEPOT
|
|
{
|
|
depot_stack_handle_t handle;
|
|
unsigned long *entries;
|
|
unsigned int nr_entries, j;
|
|
|
|
handle = READ_ONCE(l->handle);
|
|
if (handle) {
|
|
nr_entries = stack_depot_fetch(handle, &entries);
|
|
seq_puts(seq, "\n");
|
|
for (j = 0; j < nr_entries; j++)
|
|
seq_printf(seq, " %pS\n", (void *)entries[j]);
|
|
}
|
|
}
|
|
#endif
|
|
seq_puts(seq, "\n");
|
|
}
|
|
|
|
if (!idx && !t->count)
|
|
seq_puts(seq, "No data\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void slab_debugfs_stop(struct seq_file *seq, void *v)
|
|
{
|
|
}
|
|
|
|
static void *slab_debugfs_next(struct seq_file *seq, void *v, loff_t *ppos)
|
|
{
|
|
struct loc_track *t = seq->private;
|
|
|
|
t->idx = ++(*ppos);
|
|
if (*ppos <= t->count)
|
|
return ppos;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static int cmp_loc_by_count(const void *a, const void *b, const void *data)
|
|
{
|
|
struct location *loc1 = (struct location *)a;
|
|
struct location *loc2 = (struct location *)b;
|
|
|
|
if (loc1->count > loc2->count)
|
|
return -1;
|
|
else
|
|
return 1;
|
|
}
|
|
|
|
static void *slab_debugfs_start(struct seq_file *seq, loff_t *ppos)
|
|
{
|
|
struct loc_track *t = seq->private;
|
|
|
|
t->idx = *ppos;
|
|
return ppos;
|
|
}
|
|
|
|
static const struct seq_operations slab_debugfs_sops = {
|
|
.start = slab_debugfs_start,
|
|
.next = slab_debugfs_next,
|
|
.stop = slab_debugfs_stop,
|
|
.show = slab_debugfs_show,
|
|
};
|
|
|
|
static int slab_debug_trace_open(struct inode *inode, struct file *filep)
|
|
{
|
|
|
|
struct kmem_cache_node *n;
|
|
enum track_item alloc;
|
|
int node;
|
|
struct loc_track *t = __seq_open_private(filep, &slab_debugfs_sops,
|
|
sizeof(struct loc_track));
|
|
struct kmem_cache *s = file_inode(filep)->i_private;
|
|
unsigned long *obj_map;
|
|
|
|
if (!t)
|
|
return -ENOMEM;
|
|
|
|
obj_map = bitmap_alloc(oo_objects(s->oo), GFP_KERNEL);
|
|
if (!obj_map) {
|
|
seq_release_private(inode, filep);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (strcmp(filep->f_path.dentry->d_name.name, "alloc_traces") == 0)
|
|
alloc = TRACK_ALLOC;
|
|
else
|
|
alloc = TRACK_FREE;
|
|
|
|
if (!alloc_loc_track(t, PAGE_SIZE / sizeof(struct location), GFP_KERNEL)) {
|
|
bitmap_free(obj_map);
|
|
seq_release_private(inode, filep);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
for_each_kmem_cache_node(s, node, n) {
|
|
unsigned long flags;
|
|
struct slab *slab;
|
|
|
|
if (!node_nr_slabs(n))
|
|
continue;
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
list_for_each_entry(slab, &n->partial, slab_list)
|
|
process_slab(t, s, slab, alloc, obj_map);
|
|
list_for_each_entry(slab, &n->full, slab_list)
|
|
process_slab(t, s, slab, alloc, obj_map);
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
}
|
|
|
|
/* Sort locations by count */
|
|
sort_r(t->loc, t->count, sizeof(struct location),
|
|
cmp_loc_by_count, NULL, NULL);
|
|
|
|
bitmap_free(obj_map);
|
|
return 0;
|
|
}
|
|
|
|
static int slab_debug_trace_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct seq_file *seq = file->private_data;
|
|
struct loc_track *t = seq->private;
|
|
|
|
free_loc_track(t);
|
|
return seq_release_private(inode, file);
|
|
}
|
|
|
|
static const struct file_operations slab_debugfs_fops = {
|
|
.open = slab_debug_trace_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = slab_debug_trace_release,
|
|
};
|
|
|
|
static void debugfs_slab_add(struct kmem_cache *s)
|
|
{
|
|
struct dentry *slab_cache_dir;
|
|
|
|
if (unlikely(!slab_debugfs_root))
|
|
return;
|
|
|
|
slab_cache_dir = debugfs_create_dir(s->name, slab_debugfs_root);
|
|
|
|
debugfs_create_file("alloc_traces", 0400,
|
|
slab_cache_dir, s, &slab_debugfs_fops);
|
|
|
|
debugfs_create_file("free_traces", 0400,
|
|
slab_cache_dir, s, &slab_debugfs_fops);
|
|
}
|
|
|
|
void debugfs_slab_release(struct kmem_cache *s)
|
|
{
|
|
debugfs_lookup_and_remove(s->name, slab_debugfs_root);
|
|
}
|
|
|
|
static int __init slab_debugfs_init(void)
|
|
{
|
|
struct kmem_cache *s;
|
|
|
|
slab_debugfs_root = debugfs_create_dir("slab", NULL);
|
|
|
|
list_for_each_entry(s, &slab_caches, list)
|
|
if (s->flags & SLAB_STORE_USER)
|
|
debugfs_slab_add(s);
|
|
|
|
return 0;
|
|
|
|
}
|
|
__initcall(slab_debugfs_init);
|
|
#endif
|
|
/*
|
|
* The /proc/slabinfo ABI
|
|
*/
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo)
|
|
{
|
|
unsigned long nr_slabs = 0;
|
|
unsigned long nr_objs = 0;
|
|
unsigned long nr_free = 0;
|
|
int node;
|
|
struct kmem_cache_node *n;
|
|
|
|
for_each_kmem_cache_node(s, node, n) {
|
|
nr_slabs += node_nr_slabs(n);
|
|
nr_objs += node_nr_objs(n);
|
|
nr_free += count_partial(n, count_free);
|
|
}
|
|
|
|
sinfo->active_objs = nr_objs - nr_free;
|
|
sinfo->num_objs = nr_objs;
|
|
sinfo->active_slabs = nr_slabs;
|
|
sinfo->num_slabs = nr_slabs;
|
|
sinfo->objects_per_slab = oo_objects(s->oo);
|
|
sinfo->cache_order = oo_order(s->oo);
|
|
}
|
|
|
|
void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s)
|
|
{
|
|
}
|
|
|
|
ssize_t slabinfo_write(struct file *file, const char __user *buffer,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
return -EIO;
|
|
}
|
|
#endif /* CONFIG_SLUB_DEBUG */
|