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![Linus Torvalds](/assets/img/avatar_default.png)
documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking". -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZkgQYwAKCRDdBJ7gKXxA jrdKAP9WVJdpEcXxpoub/vVE0UWGtffr8foifi9bCwrQrGh5mgEAx7Yf0+d/oBZB nvA4E0DcPrUAFy144FNM0NTCb7u9vAw= =V3R/ -----END PGP SIGNATURE----- Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...
1278 lines
34 KiB
C
1278 lines
34 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Slab allocator functions that are independent of the allocator strategy
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*
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* (C) 2012 Christoph Lameter <cl@linux.com>
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*/
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#include <linux/slab.h>
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#include <linux/mm.h>
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#include <linux/poison.h>
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#include <linux/interrupt.h>
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#include <linux/memory.h>
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#include <linux/cache.h>
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#include <linux/compiler.h>
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#include <linux/kfence.h>
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#include <linux/module.h>
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#include <linux/cpu.h>
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#include <linux/uaccess.h>
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#include <linux/seq_file.h>
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#include <linux/dma-mapping.h>
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#include <linux/swiotlb.h>
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#include <linux/proc_fs.h>
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#include <linux/debugfs.h>
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#include <linux/kmemleak.h>
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#include <linux/kasan.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#include <asm/page.h>
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#include <linux/memcontrol.h>
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#include <linux/stackdepot.h>
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#include "internal.h"
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#include "slab.h"
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#define CREATE_TRACE_POINTS
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#include <trace/events/kmem.h>
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enum slab_state slab_state;
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LIST_HEAD(slab_caches);
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DEFINE_MUTEX(slab_mutex);
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struct kmem_cache *kmem_cache;
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static LIST_HEAD(slab_caches_to_rcu_destroy);
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static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work);
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static DECLARE_WORK(slab_caches_to_rcu_destroy_work,
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slab_caches_to_rcu_destroy_workfn);
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/*
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* Set of flags that will prevent slab merging
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*/
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#define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
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SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \
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SLAB_FAILSLAB | SLAB_NO_MERGE)
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#define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \
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SLAB_CACHE_DMA32 | SLAB_ACCOUNT)
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/*
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* Merge control. If this is set then no merging of slab caches will occur.
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*/
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static bool slab_nomerge = !IS_ENABLED(CONFIG_SLAB_MERGE_DEFAULT);
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static int __init setup_slab_nomerge(char *str)
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{
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slab_nomerge = true;
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return 1;
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}
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static int __init setup_slab_merge(char *str)
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{
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slab_nomerge = false;
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return 1;
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}
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__setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0);
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__setup_param("slub_merge", slub_merge, setup_slab_merge, 0);
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__setup("slab_nomerge", setup_slab_nomerge);
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__setup("slab_merge", setup_slab_merge);
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/*
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* Determine the size of a slab object
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*/
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unsigned int kmem_cache_size(struct kmem_cache *s)
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{
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return s->object_size;
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}
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EXPORT_SYMBOL(kmem_cache_size);
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#ifdef CONFIG_DEBUG_VM
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static int kmem_cache_sanity_check(const char *name, unsigned int size)
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{
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if (!name || in_interrupt() || size > KMALLOC_MAX_SIZE) {
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pr_err("kmem_cache_create(%s) integrity check failed\n", name);
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return -EINVAL;
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}
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WARN_ON(strchr(name, ' ')); /* It confuses parsers */
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return 0;
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}
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#else
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static inline int kmem_cache_sanity_check(const char *name, unsigned int size)
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{
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return 0;
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}
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#endif
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/*
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* Figure out what the alignment of the objects will be given a set of
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* flags, a user specified alignment and the size of the objects.
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*/
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static unsigned int calculate_alignment(slab_flags_t flags,
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unsigned int align, unsigned int size)
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{
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/*
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* If the user wants hardware cache aligned objects then follow that
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* suggestion if the object is sufficiently large.
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*
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* The hardware cache alignment cannot override the specified
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* alignment though. If that is greater then use it.
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*/
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if (flags & SLAB_HWCACHE_ALIGN) {
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unsigned int ralign;
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ralign = cache_line_size();
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while (size <= ralign / 2)
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ralign /= 2;
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align = max(align, ralign);
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}
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align = max(align, arch_slab_minalign());
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return ALIGN(align, sizeof(void *));
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}
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/*
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* Find a mergeable slab cache
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*/
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int slab_unmergeable(struct kmem_cache *s)
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{
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if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
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return 1;
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if (s->ctor)
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return 1;
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#ifdef CONFIG_HARDENED_USERCOPY
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if (s->usersize)
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return 1;
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#endif
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/*
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* We may have set a slab to be unmergeable during bootstrap.
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*/
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if (s->refcount < 0)
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return 1;
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return 0;
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}
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struct kmem_cache *find_mergeable(unsigned int size, unsigned int align,
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slab_flags_t flags, const char *name, void (*ctor)(void *))
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{
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struct kmem_cache *s;
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if (slab_nomerge)
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return NULL;
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if (ctor)
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return NULL;
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size = ALIGN(size, sizeof(void *));
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align = calculate_alignment(flags, align, size);
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size = ALIGN(size, align);
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flags = kmem_cache_flags(flags, name);
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if (flags & SLAB_NEVER_MERGE)
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return NULL;
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list_for_each_entry_reverse(s, &slab_caches, list) {
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if (slab_unmergeable(s))
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continue;
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if (size > s->size)
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continue;
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if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
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continue;
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/*
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* Check if alignment is compatible.
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* Courtesy of Adrian Drzewiecki
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*/
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if ((s->size & ~(align - 1)) != s->size)
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continue;
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if (s->size - size >= sizeof(void *))
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continue;
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return s;
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}
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return NULL;
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}
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static struct kmem_cache *create_cache(const char *name,
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unsigned int object_size, unsigned int align,
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slab_flags_t flags, unsigned int useroffset,
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unsigned int usersize, void (*ctor)(void *),
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struct kmem_cache *root_cache)
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{
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struct kmem_cache *s;
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int err;
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if (WARN_ON(useroffset + usersize > object_size))
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useroffset = usersize = 0;
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err = -ENOMEM;
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s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
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if (!s)
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goto out;
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s->name = name;
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s->size = s->object_size = object_size;
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s->align = align;
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s->ctor = ctor;
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#ifdef CONFIG_HARDENED_USERCOPY
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s->useroffset = useroffset;
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s->usersize = usersize;
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#endif
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err = __kmem_cache_create(s, flags);
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if (err)
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goto out_free_cache;
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s->refcount = 1;
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list_add(&s->list, &slab_caches);
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return s;
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out_free_cache:
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kmem_cache_free(kmem_cache, s);
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out:
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return ERR_PTR(err);
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}
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/**
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* kmem_cache_create_usercopy - Create a cache with a region suitable
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* for copying to userspace
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* @name: A string which is used in /proc/slabinfo to identify this cache.
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* @size: The size of objects to be created in this cache.
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* @align: The required alignment for the objects.
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* @flags: SLAB flags
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* @useroffset: Usercopy region offset
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* @usersize: Usercopy region size
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* @ctor: A constructor for the objects.
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*
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* Cannot be called within a interrupt, but can be interrupted.
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* The @ctor is run when new pages are allocated by the cache.
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*
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* The flags are
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*
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* %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
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* to catch references to uninitialised memory.
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*
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* %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check
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* for buffer overruns.
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*
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* %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
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* cacheline. This can be beneficial if you're counting cycles as closely
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* as davem.
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*
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* Return: a pointer to the cache on success, NULL on failure.
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*/
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struct kmem_cache *
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kmem_cache_create_usercopy(const char *name,
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unsigned int size, unsigned int align,
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slab_flags_t flags,
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unsigned int useroffset, unsigned int usersize,
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void (*ctor)(void *))
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|
{
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struct kmem_cache *s = NULL;
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const char *cache_name;
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int err;
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|
|
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#ifdef CONFIG_SLUB_DEBUG
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|
/*
|
|
* If no slab_debug was enabled globally, the static key is not yet
|
|
* enabled by setup_slub_debug(). Enable it if the cache is being
|
|
* created with any of the debugging flags passed explicitly.
|
|
* It's also possible that this is the first cache created with
|
|
* SLAB_STORE_USER and we should init stack_depot for it.
|
|
*/
|
|
if (flags & SLAB_DEBUG_FLAGS)
|
|
static_branch_enable(&slub_debug_enabled);
|
|
if (flags & SLAB_STORE_USER)
|
|
stack_depot_init();
|
|
#endif
|
|
|
|
mutex_lock(&slab_mutex);
|
|
|
|
err = kmem_cache_sanity_check(name, size);
|
|
if (err) {
|
|
goto out_unlock;
|
|
}
|
|
|
|
/* Refuse requests with allocator specific flags */
|
|
if (flags & ~SLAB_FLAGS_PERMITTED) {
|
|
err = -EINVAL;
|
|
goto out_unlock;
|
|
}
|
|
|
|
/*
|
|
* Some allocators will constraint the set of valid flags to a subset
|
|
* of all flags. We expect them to define CACHE_CREATE_MASK in this
|
|
* case, and we'll just provide them with a sanitized version of the
|
|
* passed flags.
|
|
*/
|
|
flags &= CACHE_CREATE_MASK;
|
|
|
|
/* Fail closed on bad usersize of useroffset values. */
|
|
if (!IS_ENABLED(CONFIG_HARDENED_USERCOPY) ||
|
|
WARN_ON(!usersize && useroffset) ||
|
|
WARN_ON(size < usersize || size - usersize < useroffset))
|
|
usersize = useroffset = 0;
|
|
|
|
if (!usersize)
|
|
s = __kmem_cache_alias(name, size, align, flags, ctor);
|
|
if (s)
|
|
goto out_unlock;
|
|
|
|
cache_name = kstrdup_const(name, GFP_KERNEL);
|
|
if (!cache_name) {
|
|
err = -ENOMEM;
|
|
goto out_unlock;
|
|
}
|
|
|
|
s = create_cache(cache_name, size,
|
|
calculate_alignment(flags, align, size),
|
|
flags, useroffset, usersize, ctor, NULL);
|
|
if (IS_ERR(s)) {
|
|
err = PTR_ERR(s);
|
|
kfree_const(cache_name);
|
|
}
|
|
|
|
out_unlock:
|
|
mutex_unlock(&slab_mutex);
|
|
|
|
if (err) {
|
|
if (flags & SLAB_PANIC)
|
|
panic("%s: Failed to create slab '%s'. Error %d\n",
|
|
__func__, name, err);
|
|
else {
|
|
pr_warn("%s(%s) failed with error %d\n",
|
|
__func__, name, err);
|
|
dump_stack();
|
|
}
|
|
return NULL;
|
|
}
|
|
return s;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_create_usercopy);
|
|
|
|
/**
|
|
* kmem_cache_create - Create a cache.
|
|
* @name: A string which is used in /proc/slabinfo to identify this cache.
|
|
* @size: The size of objects to be created in this cache.
|
|
* @align: The required alignment for the objects.
|
|
* @flags: SLAB flags
|
|
* @ctor: A constructor for the objects.
|
|
*
|
|
* Cannot be called within a interrupt, but can be interrupted.
|
|
* The @ctor is run when new pages are allocated by the cache.
|
|
*
|
|
* The flags are
|
|
*
|
|
* %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
|
|
* to catch references to uninitialised memory.
|
|
*
|
|
* %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check
|
|
* for buffer overruns.
|
|
*
|
|
* %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
|
|
* cacheline. This can be beneficial if you're counting cycles as closely
|
|
* as davem.
|
|
*
|
|
* Return: a pointer to the cache on success, NULL on failure.
|
|
*/
|
|
struct kmem_cache *
|
|
kmem_cache_create(const char *name, unsigned int size, unsigned int align,
|
|
slab_flags_t flags, void (*ctor)(void *))
|
|
{
|
|
return kmem_cache_create_usercopy(name, size, align, flags, 0, 0,
|
|
ctor);
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_create);
|
|
|
|
#ifdef SLAB_SUPPORTS_SYSFS
|
|
/*
|
|
* For a given kmem_cache, kmem_cache_destroy() should only be called
|
|
* once or there will be a use-after-free problem. The actual deletion
|
|
* and release of the kobject does not need slab_mutex or cpu_hotplug_lock
|
|
* protection. So they are now done without holding those locks.
|
|
*
|
|
* Note that there will be a slight delay in the deletion of sysfs files
|
|
* if kmem_cache_release() is called indrectly from a work function.
|
|
*/
|
|
static void kmem_cache_release(struct kmem_cache *s)
|
|
{
|
|
if (slab_state >= FULL) {
|
|
sysfs_slab_unlink(s);
|
|
sysfs_slab_release(s);
|
|
} else {
|
|
slab_kmem_cache_release(s);
|
|
}
|
|
}
|
|
#else
|
|
static void kmem_cache_release(struct kmem_cache *s)
|
|
{
|
|
slab_kmem_cache_release(s);
|
|
}
|
|
#endif
|
|
|
|
static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
|
|
{
|
|
LIST_HEAD(to_destroy);
|
|
struct kmem_cache *s, *s2;
|
|
|
|
/*
|
|
* On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the
|
|
* @slab_caches_to_rcu_destroy list. The slab pages are freed
|
|
* through RCU and the associated kmem_cache are dereferenced
|
|
* while freeing the pages, so the kmem_caches should be freed only
|
|
* after the pending RCU operations are finished. As rcu_barrier()
|
|
* is a pretty slow operation, we batch all pending destructions
|
|
* asynchronously.
|
|
*/
|
|
mutex_lock(&slab_mutex);
|
|
list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy);
|
|
mutex_unlock(&slab_mutex);
|
|
|
|
if (list_empty(&to_destroy))
|
|
return;
|
|
|
|
rcu_barrier();
|
|
|
|
list_for_each_entry_safe(s, s2, &to_destroy, list) {
|
|
debugfs_slab_release(s);
|
|
kfence_shutdown_cache(s);
|
|
kmem_cache_release(s);
|
|
}
|
|
}
|
|
|
|
static int shutdown_cache(struct kmem_cache *s)
|
|
{
|
|
/* free asan quarantined objects */
|
|
kasan_cache_shutdown(s);
|
|
|
|
if (__kmem_cache_shutdown(s) != 0)
|
|
return -EBUSY;
|
|
|
|
list_del(&s->list);
|
|
|
|
if (s->flags & SLAB_TYPESAFE_BY_RCU) {
|
|
list_add_tail(&s->list, &slab_caches_to_rcu_destroy);
|
|
schedule_work(&slab_caches_to_rcu_destroy_work);
|
|
} else {
|
|
kfence_shutdown_cache(s);
|
|
debugfs_slab_release(s);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void slab_kmem_cache_release(struct kmem_cache *s)
|
|
{
|
|
__kmem_cache_release(s);
|
|
kfree_const(s->name);
|
|
kmem_cache_free(kmem_cache, s);
|
|
}
|
|
|
|
void kmem_cache_destroy(struct kmem_cache *s)
|
|
{
|
|
int err = -EBUSY;
|
|
bool rcu_set;
|
|
|
|
if (unlikely(!s) || !kasan_check_byte(s))
|
|
return;
|
|
|
|
cpus_read_lock();
|
|
mutex_lock(&slab_mutex);
|
|
|
|
rcu_set = s->flags & SLAB_TYPESAFE_BY_RCU;
|
|
|
|
s->refcount--;
|
|
if (s->refcount)
|
|
goto out_unlock;
|
|
|
|
err = shutdown_cache(s);
|
|
WARN(err, "%s %s: Slab cache still has objects when called from %pS",
|
|
__func__, s->name, (void *)_RET_IP_);
|
|
out_unlock:
|
|
mutex_unlock(&slab_mutex);
|
|
cpus_read_unlock();
|
|
if (!err && !rcu_set)
|
|
kmem_cache_release(s);
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_destroy);
|
|
|
|
/**
|
|
* kmem_cache_shrink - Shrink a cache.
|
|
* @cachep: The cache to shrink.
|
|
*
|
|
* Releases as many slabs as possible for a cache.
|
|
* To help debugging, a zero exit status indicates all slabs were released.
|
|
*
|
|
* Return: %0 if all slabs were released, non-zero otherwise
|
|
*/
|
|
int kmem_cache_shrink(struct kmem_cache *cachep)
|
|
{
|
|
kasan_cache_shrink(cachep);
|
|
|
|
return __kmem_cache_shrink(cachep);
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_shrink);
|
|
|
|
bool slab_is_available(void)
|
|
{
|
|
return slab_state >= UP;
|
|
}
|
|
|
|
#ifdef CONFIG_PRINTK
|
|
static void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
|
|
{
|
|
if (__kfence_obj_info(kpp, object, slab))
|
|
return;
|
|
__kmem_obj_info(kpp, object, slab);
|
|
}
|
|
|
|
/**
|
|
* kmem_dump_obj - Print available slab provenance information
|
|
* @object: slab object for which to find provenance information.
|
|
*
|
|
* This function uses pr_cont(), so that the caller is expected to have
|
|
* printed out whatever preamble is appropriate. The provenance information
|
|
* depends on the type of object and on how much debugging is enabled.
|
|
* For a slab-cache object, the fact that it is a slab object is printed,
|
|
* and, if available, the slab name, return address, and stack trace from
|
|
* the allocation and last free path of that object.
|
|
*
|
|
* Return: %true if the pointer is to a not-yet-freed object from
|
|
* kmalloc() or kmem_cache_alloc(), either %true or %false if the pointer
|
|
* is to an already-freed object, and %false otherwise.
|
|
*/
|
|
bool kmem_dump_obj(void *object)
|
|
{
|
|
char *cp = IS_ENABLED(CONFIG_MMU) ? "" : "/vmalloc";
|
|
int i;
|
|
struct slab *slab;
|
|
unsigned long ptroffset;
|
|
struct kmem_obj_info kp = { };
|
|
|
|
/* Some arches consider ZERO_SIZE_PTR to be a valid address. */
|
|
if (object < (void *)PAGE_SIZE || !virt_addr_valid(object))
|
|
return false;
|
|
slab = virt_to_slab(object);
|
|
if (!slab)
|
|
return false;
|
|
|
|
kmem_obj_info(&kp, object, slab);
|
|
if (kp.kp_slab_cache)
|
|
pr_cont(" slab%s %s", cp, kp.kp_slab_cache->name);
|
|
else
|
|
pr_cont(" slab%s", cp);
|
|
if (is_kfence_address(object))
|
|
pr_cont(" (kfence)");
|
|
if (kp.kp_objp)
|
|
pr_cont(" start %px", kp.kp_objp);
|
|
if (kp.kp_data_offset)
|
|
pr_cont(" data offset %lu", kp.kp_data_offset);
|
|
if (kp.kp_objp) {
|
|
ptroffset = ((char *)object - (char *)kp.kp_objp) - kp.kp_data_offset;
|
|
pr_cont(" pointer offset %lu", ptroffset);
|
|
}
|
|
if (kp.kp_slab_cache && kp.kp_slab_cache->object_size)
|
|
pr_cont(" size %u", kp.kp_slab_cache->object_size);
|
|
if (kp.kp_ret)
|
|
pr_cont(" allocated at %pS\n", kp.kp_ret);
|
|
else
|
|
pr_cont("\n");
|
|
for (i = 0; i < ARRAY_SIZE(kp.kp_stack); i++) {
|
|
if (!kp.kp_stack[i])
|
|
break;
|
|
pr_info(" %pS\n", kp.kp_stack[i]);
|
|
}
|
|
|
|
if (kp.kp_free_stack[0])
|
|
pr_cont(" Free path:\n");
|
|
|
|
for (i = 0; i < ARRAY_SIZE(kp.kp_free_stack); i++) {
|
|
if (!kp.kp_free_stack[i])
|
|
break;
|
|
pr_info(" %pS\n", kp.kp_free_stack[i]);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kmem_dump_obj);
|
|
#endif
|
|
|
|
/* Create a cache during boot when no slab services are available yet */
|
|
void __init create_boot_cache(struct kmem_cache *s, const char *name,
|
|
unsigned int size, slab_flags_t flags,
|
|
unsigned int useroffset, unsigned int usersize)
|
|
{
|
|
int err;
|
|
unsigned int align = ARCH_KMALLOC_MINALIGN;
|
|
|
|
s->name = name;
|
|
s->size = s->object_size = size;
|
|
|
|
/*
|
|
* For power of two sizes, guarantee natural alignment for kmalloc
|
|
* caches, regardless of SL*B debugging options.
|
|
*/
|
|
if (is_power_of_2(size))
|
|
align = max(align, size);
|
|
s->align = calculate_alignment(flags, align, size);
|
|
|
|
#ifdef CONFIG_HARDENED_USERCOPY
|
|
s->useroffset = useroffset;
|
|
s->usersize = usersize;
|
|
#endif
|
|
|
|
err = __kmem_cache_create(s, flags);
|
|
|
|
if (err)
|
|
panic("Creation of kmalloc slab %s size=%u failed. Reason %d\n",
|
|
name, size, err);
|
|
|
|
s->refcount = -1; /* Exempt from merging for now */
|
|
}
|
|
|
|
static struct kmem_cache *__init create_kmalloc_cache(const char *name,
|
|
unsigned int size,
|
|
slab_flags_t flags)
|
|
{
|
|
struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
|
|
|
|
if (!s)
|
|
panic("Out of memory when creating slab %s\n", name);
|
|
|
|
create_boot_cache(s, name, size, flags | SLAB_KMALLOC, 0, size);
|
|
list_add(&s->list, &slab_caches);
|
|
s->refcount = 1;
|
|
return s;
|
|
}
|
|
|
|
struct kmem_cache *
|
|
kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1] __ro_after_init =
|
|
{ /* initialization for https://llvm.org/pr42570 */ };
|
|
EXPORT_SYMBOL(kmalloc_caches);
|
|
|
|
#ifdef CONFIG_RANDOM_KMALLOC_CACHES
|
|
unsigned long random_kmalloc_seed __ro_after_init;
|
|
EXPORT_SYMBOL(random_kmalloc_seed);
|
|
#endif
|
|
|
|
/*
|
|
* Conversion table for small slabs sizes / 8 to the index in the
|
|
* kmalloc array. This is necessary for slabs < 192 since we have non power
|
|
* of two cache sizes there. The size of larger slabs can be determined using
|
|
* fls.
|
|
*/
|
|
u8 kmalloc_size_index[24] __ro_after_init = {
|
|
3, /* 8 */
|
|
4, /* 16 */
|
|
5, /* 24 */
|
|
5, /* 32 */
|
|
6, /* 40 */
|
|
6, /* 48 */
|
|
6, /* 56 */
|
|
6, /* 64 */
|
|
1, /* 72 */
|
|
1, /* 80 */
|
|
1, /* 88 */
|
|
1, /* 96 */
|
|
7, /* 104 */
|
|
7, /* 112 */
|
|
7, /* 120 */
|
|
7, /* 128 */
|
|
2, /* 136 */
|
|
2, /* 144 */
|
|
2, /* 152 */
|
|
2, /* 160 */
|
|
2, /* 168 */
|
|
2, /* 176 */
|
|
2, /* 184 */
|
|
2 /* 192 */
|
|
};
|
|
|
|
size_t kmalloc_size_roundup(size_t size)
|
|
{
|
|
if (size && size <= KMALLOC_MAX_CACHE_SIZE) {
|
|
/*
|
|
* The flags don't matter since size_index is common to all.
|
|
* Neither does the caller for just getting ->object_size.
|
|
*/
|
|
return kmalloc_slab(size, GFP_KERNEL, 0)->object_size;
|
|
}
|
|
|
|
/* Above the smaller buckets, size is a multiple of page size. */
|
|
if (size && size <= KMALLOC_MAX_SIZE)
|
|
return PAGE_SIZE << get_order(size);
|
|
|
|
/*
|
|
* Return 'size' for 0 - kmalloc() returns ZERO_SIZE_PTR
|
|
* and very large size - kmalloc() may fail.
|
|
*/
|
|
return size;
|
|
|
|
}
|
|
EXPORT_SYMBOL(kmalloc_size_roundup);
|
|
|
|
#ifdef CONFIG_ZONE_DMA
|
|
#define KMALLOC_DMA_NAME(sz) .name[KMALLOC_DMA] = "dma-kmalloc-" #sz,
|
|
#else
|
|
#define KMALLOC_DMA_NAME(sz)
|
|
#endif
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
#define KMALLOC_CGROUP_NAME(sz) .name[KMALLOC_CGROUP] = "kmalloc-cg-" #sz,
|
|
#else
|
|
#define KMALLOC_CGROUP_NAME(sz)
|
|
#endif
|
|
|
|
#ifndef CONFIG_SLUB_TINY
|
|
#define KMALLOC_RCL_NAME(sz) .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #sz,
|
|
#else
|
|
#define KMALLOC_RCL_NAME(sz)
|
|
#endif
|
|
|
|
#ifdef CONFIG_RANDOM_KMALLOC_CACHES
|
|
#define __KMALLOC_RANDOM_CONCAT(a, b) a ## b
|
|
#define KMALLOC_RANDOM_NAME(N, sz) __KMALLOC_RANDOM_CONCAT(KMA_RAND_, N)(sz)
|
|
#define KMA_RAND_1(sz) .name[KMALLOC_RANDOM_START + 1] = "kmalloc-rnd-01-" #sz,
|
|
#define KMA_RAND_2(sz) KMA_RAND_1(sz) .name[KMALLOC_RANDOM_START + 2] = "kmalloc-rnd-02-" #sz,
|
|
#define KMA_RAND_3(sz) KMA_RAND_2(sz) .name[KMALLOC_RANDOM_START + 3] = "kmalloc-rnd-03-" #sz,
|
|
#define KMA_RAND_4(sz) KMA_RAND_3(sz) .name[KMALLOC_RANDOM_START + 4] = "kmalloc-rnd-04-" #sz,
|
|
#define KMA_RAND_5(sz) KMA_RAND_4(sz) .name[KMALLOC_RANDOM_START + 5] = "kmalloc-rnd-05-" #sz,
|
|
#define KMA_RAND_6(sz) KMA_RAND_5(sz) .name[KMALLOC_RANDOM_START + 6] = "kmalloc-rnd-06-" #sz,
|
|
#define KMA_RAND_7(sz) KMA_RAND_6(sz) .name[KMALLOC_RANDOM_START + 7] = "kmalloc-rnd-07-" #sz,
|
|
#define KMA_RAND_8(sz) KMA_RAND_7(sz) .name[KMALLOC_RANDOM_START + 8] = "kmalloc-rnd-08-" #sz,
|
|
#define KMA_RAND_9(sz) KMA_RAND_8(sz) .name[KMALLOC_RANDOM_START + 9] = "kmalloc-rnd-09-" #sz,
|
|
#define KMA_RAND_10(sz) KMA_RAND_9(sz) .name[KMALLOC_RANDOM_START + 10] = "kmalloc-rnd-10-" #sz,
|
|
#define KMA_RAND_11(sz) KMA_RAND_10(sz) .name[KMALLOC_RANDOM_START + 11] = "kmalloc-rnd-11-" #sz,
|
|
#define KMA_RAND_12(sz) KMA_RAND_11(sz) .name[KMALLOC_RANDOM_START + 12] = "kmalloc-rnd-12-" #sz,
|
|
#define KMA_RAND_13(sz) KMA_RAND_12(sz) .name[KMALLOC_RANDOM_START + 13] = "kmalloc-rnd-13-" #sz,
|
|
#define KMA_RAND_14(sz) KMA_RAND_13(sz) .name[KMALLOC_RANDOM_START + 14] = "kmalloc-rnd-14-" #sz,
|
|
#define KMA_RAND_15(sz) KMA_RAND_14(sz) .name[KMALLOC_RANDOM_START + 15] = "kmalloc-rnd-15-" #sz,
|
|
#else // CONFIG_RANDOM_KMALLOC_CACHES
|
|
#define KMALLOC_RANDOM_NAME(N, sz)
|
|
#endif
|
|
|
|
#define INIT_KMALLOC_INFO(__size, __short_size) \
|
|
{ \
|
|
.name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \
|
|
KMALLOC_RCL_NAME(__short_size) \
|
|
KMALLOC_CGROUP_NAME(__short_size) \
|
|
KMALLOC_DMA_NAME(__short_size) \
|
|
KMALLOC_RANDOM_NAME(RANDOM_KMALLOC_CACHES_NR, __short_size) \
|
|
.size = __size, \
|
|
}
|
|
|
|
/*
|
|
* kmalloc_info[] is to make slab_debug=,kmalloc-xx option work at boot time.
|
|
* kmalloc_index() supports up to 2^21=2MB, so the final entry of the table is
|
|
* kmalloc-2M.
|
|
*/
|
|
const struct kmalloc_info_struct kmalloc_info[] __initconst = {
|
|
INIT_KMALLOC_INFO(0, 0),
|
|
INIT_KMALLOC_INFO(96, 96),
|
|
INIT_KMALLOC_INFO(192, 192),
|
|
INIT_KMALLOC_INFO(8, 8),
|
|
INIT_KMALLOC_INFO(16, 16),
|
|
INIT_KMALLOC_INFO(32, 32),
|
|
INIT_KMALLOC_INFO(64, 64),
|
|
INIT_KMALLOC_INFO(128, 128),
|
|
INIT_KMALLOC_INFO(256, 256),
|
|
INIT_KMALLOC_INFO(512, 512),
|
|
INIT_KMALLOC_INFO(1024, 1k),
|
|
INIT_KMALLOC_INFO(2048, 2k),
|
|
INIT_KMALLOC_INFO(4096, 4k),
|
|
INIT_KMALLOC_INFO(8192, 8k),
|
|
INIT_KMALLOC_INFO(16384, 16k),
|
|
INIT_KMALLOC_INFO(32768, 32k),
|
|
INIT_KMALLOC_INFO(65536, 64k),
|
|
INIT_KMALLOC_INFO(131072, 128k),
|
|
INIT_KMALLOC_INFO(262144, 256k),
|
|
INIT_KMALLOC_INFO(524288, 512k),
|
|
INIT_KMALLOC_INFO(1048576, 1M),
|
|
INIT_KMALLOC_INFO(2097152, 2M)
|
|
};
|
|
|
|
/*
|
|
* Patch up the size_index table if we have strange large alignment
|
|
* requirements for the kmalloc array. This is only the case for
|
|
* MIPS it seems. The standard arches will not generate any code here.
|
|
*
|
|
* Largest permitted alignment is 256 bytes due to the way we
|
|
* handle the index determination for the smaller caches.
|
|
*
|
|
* Make sure that nothing crazy happens if someone starts tinkering
|
|
* around with ARCH_KMALLOC_MINALIGN
|
|
*/
|
|
void __init setup_kmalloc_cache_index_table(void)
|
|
{
|
|
unsigned int i;
|
|
|
|
BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
|
|
!is_power_of_2(KMALLOC_MIN_SIZE));
|
|
|
|
for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
|
|
unsigned int elem = size_index_elem(i);
|
|
|
|
if (elem >= ARRAY_SIZE(kmalloc_size_index))
|
|
break;
|
|
kmalloc_size_index[elem] = KMALLOC_SHIFT_LOW;
|
|
}
|
|
|
|
if (KMALLOC_MIN_SIZE >= 64) {
|
|
/*
|
|
* The 96 byte sized cache is not used if the alignment
|
|
* is 64 byte.
|
|
*/
|
|
for (i = 64 + 8; i <= 96; i += 8)
|
|
kmalloc_size_index[size_index_elem(i)] = 7;
|
|
|
|
}
|
|
|
|
if (KMALLOC_MIN_SIZE >= 128) {
|
|
/*
|
|
* The 192 byte sized cache is not used if the alignment
|
|
* is 128 byte. Redirect kmalloc to use the 256 byte cache
|
|
* instead.
|
|
*/
|
|
for (i = 128 + 8; i <= 192; i += 8)
|
|
kmalloc_size_index[size_index_elem(i)] = 8;
|
|
}
|
|
}
|
|
|
|
static unsigned int __kmalloc_minalign(void)
|
|
{
|
|
unsigned int minalign = dma_get_cache_alignment();
|
|
|
|
if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) &&
|
|
is_swiotlb_allocated())
|
|
minalign = ARCH_KMALLOC_MINALIGN;
|
|
|
|
return max(minalign, arch_slab_minalign());
|
|
}
|
|
|
|
static void __init
|
|
new_kmalloc_cache(int idx, enum kmalloc_cache_type type)
|
|
{
|
|
slab_flags_t flags = 0;
|
|
unsigned int minalign = __kmalloc_minalign();
|
|
unsigned int aligned_size = kmalloc_info[idx].size;
|
|
int aligned_idx = idx;
|
|
|
|
if ((KMALLOC_RECLAIM != KMALLOC_NORMAL) && (type == KMALLOC_RECLAIM)) {
|
|
flags |= SLAB_RECLAIM_ACCOUNT;
|
|
} else if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_CGROUP)) {
|
|
if (mem_cgroup_kmem_disabled()) {
|
|
kmalloc_caches[type][idx] = kmalloc_caches[KMALLOC_NORMAL][idx];
|
|
return;
|
|
}
|
|
flags |= SLAB_ACCOUNT;
|
|
} else if (IS_ENABLED(CONFIG_ZONE_DMA) && (type == KMALLOC_DMA)) {
|
|
flags |= SLAB_CACHE_DMA;
|
|
}
|
|
|
|
#ifdef CONFIG_RANDOM_KMALLOC_CACHES
|
|
if (type >= KMALLOC_RANDOM_START && type <= KMALLOC_RANDOM_END)
|
|
flags |= SLAB_NO_MERGE;
|
|
#endif
|
|
|
|
/*
|
|
* If CONFIG_MEMCG_KMEM is enabled, disable cache merging for
|
|
* KMALLOC_NORMAL caches.
|
|
*/
|
|
if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_NORMAL))
|
|
flags |= SLAB_NO_MERGE;
|
|
|
|
if (minalign > ARCH_KMALLOC_MINALIGN) {
|
|
aligned_size = ALIGN(aligned_size, minalign);
|
|
aligned_idx = __kmalloc_index(aligned_size, false);
|
|
}
|
|
|
|
if (!kmalloc_caches[type][aligned_idx])
|
|
kmalloc_caches[type][aligned_idx] = create_kmalloc_cache(
|
|
kmalloc_info[aligned_idx].name[type],
|
|
aligned_size, flags);
|
|
if (idx != aligned_idx)
|
|
kmalloc_caches[type][idx] = kmalloc_caches[type][aligned_idx];
|
|
}
|
|
|
|
/*
|
|
* Create the kmalloc array. Some of the regular kmalloc arrays
|
|
* may already have been created because they were needed to
|
|
* enable allocations for slab creation.
|
|
*/
|
|
void __init create_kmalloc_caches(void)
|
|
{
|
|
int i;
|
|
enum kmalloc_cache_type type;
|
|
|
|
/*
|
|
* Including KMALLOC_CGROUP if CONFIG_MEMCG_KMEM defined
|
|
*/
|
|
for (type = KMALLOC_NORMAL; type < NR_KMALLOC_TYPES; type++) {
|
|
/* Caches that are NOT of the two-to-the-power-of size. */
|
|
if (KMALLOC_MIN_SIZE <= 32)
|
|
new_kmalloc_cache(1, type);
|
|
if (KMALLOC_MIN_SIZE <= 64)
|
|
new_kmalloc_cache(2, type);
|
|
|
|
/* Caches that are of the two-to-the-power-of size. */
|
|
for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
|
|
new_kmalloc_cache(i, type);
|
|
}
|
|
#ifdef CONFIG_RANDOM_KMALLOC_CACHES
|
|
random_kmalloc_seed = get_random_u64();
|
|
#endif
|
|
|
|
/* Kmalloc array is now usable */
|
|
slab_state = UP;
|
|
}
|
|
|
|
/**
|
|
* __ksize -- Report full size of underlying allocation
|
|
* @object: pointer to the object
|
|
*
|
|
* This should only be used internally to query the true size of allocations.
|
|
* It is not meant to be a way to discover the usable size of an allocation
|
|
* after the fact. Instead, use kmalloc_size_roundup(). Using memory beyond
|
|
* the originally requested allocation size may trigger KASAN, UBSAN_BOUNDS,
|
|
* and/or FORTIFY_SOURCE.
|
|
*
|
|
* Return: size of the actual memory used by @object in bytes
|
|
*/
|
|
size_t __ksize(const void *object)
|
|
{
|
|
struct folio *folio;
|
|
|
|
if (unlikely(object == ZERO_SIZE_PTR))
|
|
return 0;
|
|
|
|
folio = virt_to_folio(object);
|
|
|
|
if (unlikely(!folio_test_slab(folio))) {
|
|
if (WARN_ON(folio_size(folio) <= KMALLOC_MAX_CACHE_SIZE))
|
|
return 0;
|
|
if (WARN_ON(object != folio_address(folio)))
|
|
return 0;
|
|
return folio_size(folio);
|
|
}
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
skip_orig_size_check(folio_slab(folio)->slab_cache, object);
|
|
#endif
|
|
|
|
return slab_ksize(folio_slab(folio)->slab_cache);
|
|
}
|
|
|
|
gfp_t kmalloc_fix_flags(gfp_t flags)
|
|
{
|
|
gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK;
|
|
|
|
flags &= ~GFP_SLAB_BUG_MASK;
|
|
pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n",
|
|
invalid_mask, &invalid_mask, flags, &flags);
|
|
dump_stack();
|
|
|
|
return flags;
|
|
}
|
|
|
|
#ifdef CONFIG_SLAB_FREELIST_RANDOM
|
|
/* Randomize a generic freelist */
|
|
static void freelist_randomize(unsigned int *list,
|
|
unsigned int count)
|
|
{
|
|
unsigned int rand;
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < count; i++)
|
|
list[i] = i;
|
|
|
|
/* Fisher-Yates shuffle */
|
|
for (i = count - 1; i > 0; i--) {
|
|
rand = get_random_u32_below(i + 1);
|
|
swap(list[i], list[rand]);
|
|
}
|
|
}
|
|
|
|
/* Create a random sequence per cache */
|
|
int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
|
|
gfp_t gfp)
|
|
{
|
|
|
|
if (count < 2 || cachep->random_seq)
|
|
return 0;
|
|
|
|
cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp);
|
|
if (!cachep->random_seq)
|
|
return -ENOMEM;
|
|
|
|
freelist_randomize(cachep->random_seq, count);
|
|
return 0;
|
|
}
|
|
|
|
/* Destroy the per-cache random freelist sequence */
|
|
void cache_random_seq_destroy(struct kmem_cache *cachep)
|
|
{
|
|
kfree(cachep->random_seq);
|
|
cachep->random_seq = NULL;
|
|
}
|
|
#endif /* CONFIG_SLAB_FREELIST_RANDOM */
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
#define SLABINFO_RIGHTS (0400)
|
|
|
|
static void print_slabinfo_header(struct seq_file *m)
|
|
{
|
|
/*
|
|
* Output format version, so at least we can change it
|
|
* without _too_ many complaints.
|
|
*/
|
|
seq_puts(m, "slabinfo - version: 2.1\n");
|
|
seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>");
|
|
seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
|
|
seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
static void *slab_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
mutex_lock(&slab_mutex);
|
|
return seq_list_start(&slab_caches, *pos);
|
|
}
|
|
|
|
static void *slab_next(struct seq_file *m, void *p, loff_t *pos)
|
|
{
|
|
return seq_list_next(p, &slab_caches, pos);
|
|
}
|
|
|
|
static void slab_stop(struct seq_file *m, void *p)
|
|
{
|
|
mutex_unlock(&slab_mutex);
|
|
}
|
|
|
|
static void cache_show(struct kmem_cache *s, struct seq_file *m)
|
|
{
|
|
struct slabinfo sinfo;
|
|
|
|
memset(&sinfo, 0, sizeof(sinfo));
|
|
get_slabinfo(s, &sinfo);
|
|
|
|
seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
|
|
s->name, sinfo.active_objs, sinfo.num_objs, s->size,
|
|
sinfo.objects_per_slab, (1 << sinfo.cache_order));
|
|
|
|
seq_printf(m, " : tunables %4u %4u %4u",
|
|
sinfo.limit, sinfo.batchcount, sinfo.shared);
|
|
seq_printf(m, " : slabdata %6lu %6lu %6lu",
|
|
sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
static int slab_show(struct seq_file *m, void *p)
|
|
{
|
|
struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
|
|
|
|
if (p == slab_caches.next)
|
|
print_slabinfo_header(m);
|
|
cache_show(s, m);
|
|
return 0;
|
|
}
|
|
|
|
void dump_unreclaimable_slab(void)
|
|
{
|
|
struct kmem_cache *s;
|
|
struct slabinfo sinfo;
|
|
|
|
/*
|
|
* Here acquiring slab_mutex is risky since we don't prefer to get
|
|
* sleep in oom path. But, without mutex hold, it may introduce a
|
|
* risk of crash.
|
|
* Use mutex_trylock to protect the list traverse, dump nothing
|
|
* without acquiring the mutex.
|
|
*/
|
|
if (!mutex_trylock(&slab_mutex)) {
|
|
pr_warn("excessive unreclaimable slab but cannot dump stats\n");
|
|
return;
|
|
}
|
|
|
|
pr_info("Unreclaimable slab info:\n");
|
|
pr_info("Name Used Total\n");
|
|
|
|
list_for_each_entry(s, &slab_caches, list) {
|
|
if (s->flags & SLAB_RECLAIM_ACCOUNT)
|
|
continue;
|
|
|
|
get_slabinfo(s, &sinfo);
|
|
|
|
if (sinfo.num_objs > 0)
|
|
pr_info("%-17s %10luKB %10luKB\n", s->name,
|
|
(sinfo.active_objs * s->size) / 1024,
|
|
(sinfo.num_objs * s->size) / 1024);
|
|
}
|
|
mutex_unlock(&slab_mutex);
|
|
}
|
|
|
|
/*
|
|
* slabinfo_op - iterator that generates /proc/slabinfo
|
|
*
|
|
* Output layout:
|
|
* cache-name
|
|
* num-active-objs
|
|
* total-objs
|
|
* object size
|
|
* num-active-slabs
|
|
* total-slabs
|
|
* num-pages-per-slab
|
|
* + further values on SMP and with statistics enabled
|
|
*/
|
|
static const struct seq_operations slabinfo_op = {
|
|
.start = slab_start,
|
|
.next = slab_next,
|
|
.stop = slab_stop,
|
|
.show = slab_show,
|
|
};
|
|
|
|
static int slabinfo_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &slabinfo_op);
|
|
}
|
|
|
|
static const struct proc_ops slabinfo_proc_ops = {
|
|
.proc_flags = PROC_ENTRY_PERMANENT,
|
|
.proc_open = slabinfo_open,
|
|
.proc_read = seq_read,
|
|
.proc_lseek = seq_lseek,
|
|
.proc_release = seq_release,
|
|
};
|
|
|
|
static int __init slab_proc_init(void)
|
|
{
|
|
proc_create("slabinfo", SLABINFO_RIGHTS, NULL, &slabinfo_proc_ops);
|
|
return 0;
|
|
}
|
|
module_init(slab_proc_init);
|
|
|
|
#endif /* CONFIG_SLUB_DEBUG */
|
|
|
|
static __always_inline __realloc_size(2) void *
|
|
__do_krealloc(const void *p, size_t new_size, gfp_t flags)
|
|
{
|
|
void *ret;
|
|
size_t ks;
|
|
|
|
/* Check for double-free before calling ksize. */
|
|
if (likely(!ZERO_OR_NULL_PTR(p))) {
|
|
if (!kasan_check_byte(p))
|
|
return NULL;
|
|
ks = ksize(p);
|
|
} else
|
|
ks = 0;
|
|
|
|
/* If the object still fits, repoison it precisely. */
|
|
if (ks >= new_size) {
|
|
p = kasan_krealloc((void *)p, new_size, flags);
|
|
return (void *)p;
|
|
}
|
|
|
|
ret = kmalloc_node_track_caller_noprof(new_size, flags, NUMA_NO_NODE, _RET_IP_);
|
|
if (ret && p) {
|
|
/* Disable KASAN checks as the object's redzone is accessed. */
|
|
kasan_disable_current();
|
|
memcpy(ret, kasan_reset_tag(p), ks);
|
|
kasan_enable_current();
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* krealloc - reallocate memory. The contents will remain unchanged.
|
|
* @p: object to reallocate memory for.
|
|
* @new_size: how many bytes of memory are required.
|
|
* @flags: the type of memory to allocate.
|
|
*
|
|
* The contents of the object pointed to are preserved up to the
|
|
* lesser of the new and old sizes (__GFP_ZERO flag is effectively ignored).
|
|
* If @p is %NULL, krealloc() behaves exactly like kmalloc(). If @new_size
|
|
* is 0 and @p is not a %NULL pointer, the object pointed to is freed.
|
|
*
|
|
* Return: pointer to the allocated memory or %NULL in case of error
|
|
*/
|
|
void *krealloc_noprof(const void *p, size_t new_size, gfp_t flags)
|
|
{
|
|
void *ret;
|
|
|
|
if (unlikely(!new_size)) {
|
|
kfree(p);
|
|
return ZERO_SIZE_PTR;
|
|
}
|
|
|
|
ret = __do_krealloc(p, new_size, flags);
|
|
if (ret && kasan_reset_tag(p) != kasan_reset_tag(ret))
|
|
kfree(p);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(krealloc_noprof);
|
|
|
|
/**
|
|
* kfree_sensitive - Clear sensitive information in memory before freeing
|
|
* @p: object to free memory of
|
|
*
|
|
* The memory of the object @p points to is zeroed before freed.
|
|
* If @p is %NULL, kfree_sensitive() does nothing.
|
|
*
|
|
* Note: this function zeroes the whole allocated buffer which can be a good
|
|
* deal bigger than the requested buffer size passed to kmalloc(). So be
|
|
* careful when using this function in performance sensitive code.
|
|
*/
|
|
void kfree_sensitive(const void *p)
|
|
{
|
|
size_t ks;
|
|
void *mem = (void *)p;
|
|
|
|
ks = ksize(mem);
|
|
if (ks) {
|
|
kasan_unpoison_range(mem, ks);
|
|
memzero_explicit(mem, ks);
|
|
}
|
|
kfree(mem);
|
|
}
|
|
EXPORT_SYMBOL(kfree_sensitive);
|
|
|
|
size_t ksize(const void *objp)
|
|
{
|
|
/*
|
|
* We need to first check that the pointer to the object is valid.
|
|
* The KASAN report printed from ksize() is more useful, then when
|
|
* it's printed later when the behaviour could be undefined due to
|
|
* a potential use-after-free or double-free.
|
|
*
|
|
* We use kasan_check_byte(), which is supported for the hardware
|
|
* tag-based KASAN mode, unlike kasan_check_read/write().
|
|
*
|
|
* If the pointed to memory is invalid, we return 0 to avoid users of
|
|
* ksize() writing to and potentially corrupting the memory region.
|
|
*
|
|
* We want to perform the check before __ksize(), to avoid potentially
|
|
* crashing in __ksize() due to accessing invalid metadata.
|
|
*/
|
|
if (unlikely(ZERO_OR_NULL_PTR(objp)) || !kasan_check_byte(objp))
|
|
return 0;
|
|
|
|
return kfence_ksize(objp) ?: __ksize(objp);
|
|
}
|
|
EXPORT_SYMBOL(ksize);
|
|
|
|
/* Tracepoints definitions. */
|
|
EXPORT_TRACEPOINT_SYMBOL(kmalloc);
|
|
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
|
|
EXPORT_TRACEPOINT_SYMBOL(kfree);
|
|
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);
|
|
|