diff options
Diffstat (limited to 'mm/slab.h')
-rw-r--r-- | mm/slab.h | 301 |
1 files changed, 260 insertions, 41 deletions
diff --git a/mm/slab.h b/mm/slab.h index 56ad7eea3ddf..c7f2abc2b154 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -5,6 +5,191 @@ * Internal slab definitions */ +/* Reuses the bits in struct page */ +struct slab { + unsigned long __page_flags; + +#if defined(CONFIG_SLAB) + + union { + struct list_head slab_list; + struct rcu_head rcu_head; + }; + struct kmem_cache *slab_cache; + void *freelist; /* array of free object indexes */ + void *s_mem; /* first object */ + unsigned int active; + +#elif defined(CONFIG_SLUB) + + union { + struct list_head slab_list; + struct rcu_head rcu_head; +#ifdef CONFIG_SLUB_CPU_PARTIAL + struct { + struct slab *next; + int slabs; /* Nr of slabs left */ + }; +#endif + }; + struct kmem_cache *slab_cache; + /* Double-word boundary */ + void *freelist; /* first free object */ + union { + unsigned long counters; + struct { + unsigned inuse:16; + unsigned objects:15; + unsigned frozen:1; + }; + }; + unsigned int __unused; + +#elif defined(CONFIG_SLOB) + + struct list_head slab_list; + void *__unused_1; + void *freelist; /* first free block */ + long units; + unsigned int __unused_2; + +#else +#error "Unexpected slab allocator configured" +#endif + + atomic_t __page_refcount; +#ifdef CONFIG_MEMCG + unsigned long memcg_data; +#endif +}; + +#define SLAB_MATCH(pg, sl) \ + static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl)) +SLAB_MATCH(flags, __page_flags); +SLAB_MATCH(compound_head, slab_list); /* Ensure bit 0 is clear */ +#ifndef CONFIG_SLOB +SLAB_MATCH(rcu_head, rcu_head); +#endif +SLAB_MATCH(_refcount, __page_refcount); +#ifdef CONFIG_MEMCG +SLAB_MATCH(memcg_data, memcg_data); +#endif +#undef SLAB_MATCH +static_assert(sizeof(struct slab) <= sizeof(struct page)); + +/** + * folio_slab - Converts from folio to slab. + * @folio: The folio. + * + * Currently struct slab is a different representation of a folio where + * folio_test_slab() is true. + * + * Return: The slab which contains this folio. + */ +#define folio_slab(folio) (_Generic((folio), \ + const struct folio *: (const struct slab *)(folio), \ + struct folio *: (struct slab *)(folio))) + +/** + * slab_folio - The folio allocated for a slab + * @slab: The slab. + * + * Slabs are allocated as folios that contain the individual objects and are + * using some fields in the first struct page of the folio - those fields are + * now accessed by struct slab. It is occasionally necessary to convert back to + * a folio in order to communicate with the rest of the mm. Please use this + * helper function instead of casting yourself, as the implementation may change + * in the future. + */ +#define slab_folio(s) (_Generic((s), \ + const struct slab *: (const struct folio *)s, \ + struct slab *: (struct folio *)s)) + +/** + * page_slab - Converts from first struct page to slab. + * @p: The first (either head of compound or single) page of slab. + * + * A temporary wrapper to convert struct page to struct slab in situations where + * we know the page is the compound head, or single order-0 page. + * + * Long-term ideally everything would work with struct slab directly or go + * through folio to struct slab. + * + * Return: The slab which contains this page + */ +#define page_slab(p) (_Generic((p), \ + const struct page *: (const struct slab *)(p), \ + struct page *: (struct slab *)(p))) + +/** + * slab_page - The first struct page allocated for a slab + * @slab: The slab. + * + * A convenience wrapper for converting slab to the first struct page of the + * underlying folio, to communicate with code not yet converted to folio or + * struct slab. + */ +#define slab_page(s) folio_page(slab_folio(s), 0) + +/* + * If network-based swap is enabled, sl*b must keep track of whether pages + * were allocated from pfmemalloc reserves. + */ +static inline bool slab_test_pfmemalloc(const struct slab *slab) +{ + return folio_test_active((struct folio *)slab_folio(slab)); +} + +static inline void slab_set_pfmemalloc(struct slab *slab) +{ + folio_set_active(slab_folio(slab)); +} + +static inline void slab_clear_pfmemalloc(struct slab *slab) +{ + folio_clear_active(slab_folio(slab)); +} + +static inline void __slab_clear_pfmemalloc(struct slab *slab) +{ + __folio_clear_active(slab_folio(slab)); +} + +static inline void *slab_address(const struct slab *slab) +{ + return folio_address(slab_folio(slab)); +} + +static inline int slab_nid(const struct slab *slab) +{ + return folio_nid(slab_folio(slab)); +} + +static inline pg_data_t *slab_pgdat(const struct slab *slab) +{ + return folio_pgdat(slab_folio(slab)); +} + +static inline struct slab *virt_to_slab(const void *addr) +{ + struct folio *folio = virt_to_folio(addr); + + if (!folio_test_slab(folio)) + return NULL; + + return folio_slab(folio); +} + +static inline int slab_order(const struct slab *slab) +{ + return folio_order((struct folio *)slab_folio(slab)); +} + +static inline size_t slab_size(const struct slab *slab) +{ + return PAGE_SIZE << slab_order(slab); +} + #ifdef CONFIG_SLOB /* * Common fields provided in kmem_cache by all slab allocators @@ -245,15 +430,33 @@ static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t fla } #ifdef CONFIG_MEMCG_KMEM -int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s, - gfp_t gfp, bool new_page); +/* + * slab_objcgs - get the object cgroups vector associated with a slab + * @slab: a pointer to the slab struct + * + * Returns a pointer to the object cgroups vector associated with the slab, + * or NULL if no such vector has been associated yet. + */ +static inline struct obj_cgroup **slab_objcgs(struct slab *slab) +{ + unsigned long memcg_data = READ_ONCE(slab->memcg_data); + + VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS), + slab_page(slab)); + VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab)); + + return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); +} + +int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, + gfp_t gfp, bool new_slab); void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, enum node_stat_item idx, int nr); -static inline void memcg_free_page_obj_cgroups(struct page *page) +static inline void memcg_free_slab_cgroups(struct slab *slab) { - kfree(page_objcgs(page)); - page->memcg_data = 0; + kfree(slab_objcgs(slab)); + slab->memcg_data = 0; } static inline size_t obj_full_size(struct kmem_cache *s) @@ -298,7 +501,7 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, size_t size, void **p) { - struct page *page; + struct slab *slab; unsigned long off; size_t i; @@ -307,19 +510,19 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, for (i = 0; i < size; i++) { if (likely(p[i])) { - page = virt_to_head_page(p[i]); + slab = virt_to_slab(p[i]); - if (!page_objcgs(page) && - memcg_alloc_page_obj_cgroups(page, s, flags, + 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, page, p[i]); + off = obj_to_index(s, slab, p[i]); obj_cgroup_get(objcg); - page_objcgs(page)[off] = objcg; - mod_objcg_state(objcg, page_pgdat(page), + 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)); @@ -334,7 +537,7 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig, struct kmem_cache *s; struct obj_cgroup **objcgs; struct obj_cgroup *objcg; - struct page *page; + struct slab *slab; unsigned int off; int i; @@ -345,43 +548,52 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig, if (unlikely(!p[i])) continue; - page = virt_to_head_page(p[i]); - objcgs = page_objcgs_check(page); + slab = virt_to_slab(p[i]); + /* we could be given a kmalloc_large() object, skip those */ + if (!slab) + continue; + + objcgs = slab_objcgs(slab); if (!objcgs) continue; if (!s_orig) - s = page->slab_cache; + s = slab->slab_cache; else s = s_orig; - off = obj_to_index(s, page, p[i]); + 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, page_pgdat(page), cache_vmstat_idx(s), + mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s), -obj_full_size(s)); obj_cgroup_put(objcg); } } #else /* CONFIG_MEMCG_KMEM */ +static inline struct obj_cgroup **slab_objcgs(struct slab *slab) +{ + return NULL; +} + static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr) { return NULL; } -static inline int memcg_alloc_page_obj_cgroups(struct page *page, +static inline int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, gfp_t gfp, - bool new_page) + bool new_slab) { return 0; } -static inline void memcg_free_page_obj_cgroups(struct page *page) +static inline void memcg_free_slab_cgroups(struct slab *slab) { } @@ -405,35 +617,35 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s, } #endif /* CONFIG_MEMCG_KMEM */ +#ifndef CONFIG_SLOB static inline struct kmem_cache *virt_to_cache(const void *obj) { - struct page *page; + struct slab *slab; - page = virt_to_head_page(obj); - if (WARN_ONCE(!PageSlab(page), "%s: Object is not a Slab page!\n", + slab = virt_to_slab(obj); + if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n", __func__)) return NULL; - return page->slab_cache; + return slab->slab_cache; } -static __always_inline void account_slab_page(struct page *page, int order, - struct kmem_cache *s, - gfp_t gfp) +static __always_inline void account_slab(struct slab *slab, int order, + struct kmem_cache *s, gfp_t gfp) { if (memcg_kmem_enabled() && (s->flags & SLAB_ACCOUNT)) - memcg_alloc_page_obj_cgroups(page, s, gfp, true); + memcg_alloc_slab_cgroups(slab, s, gfp, true); - mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), + mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), PAGE_SIZE << order); } -static __always_inline void unaccount_slab_page(struct page *page, int order, - struct kmem_cache *s) +static __always_inline void unaccount_slab(struct slab *slab, int order, + struct kmem_cache *s) { if (memcg_kmem_enabled()) - memcg_free_page_obj_cgroups(page); + memcg_free_slab_cgroups(slab); - mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), + mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), -(PAGE_SIZE << order)); } @@ -452,6 +664,7 @@ static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x) print_tracking(cachep, x); return cachep; } +#endif /* CONFIG_SLOB */ static inline size_t slab_ksize(const struct kmem_cache *s) { @@ -575,11 +788,6 @@ static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) #endif -void *slab_start(struct seq_file *m, loff_t *pos); -void *slab_next(struct seq_file *m, void *p, loff_t *pos); -void slab_stop(struct seq_file *m, void *p); -int memcg_slab_show(struct seq_file *m, void *p); - #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) void dump_unreclaimable_slab(void); #else @@ -635,7 +843,7 @@ static inline void debugfs_slab_release(struct kmem_cache *s) { } #define KS_ADDRS_COUNT 16 struct kmem_obj_info { void *kp_ptr; - struct page *kp_page; + struct slab *kp_slab; void *kp_objp; unsigned long kp_data_offset; struct kmem_cache *kp_slab_cache; @@ -643,7 +851,18 @@ struct kmem_obj_info { void *kp_stack[KS_ADDRS_COUNT]; void *kp_free_stack[KS_ADDRS_COUNT]; }; -void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page); +void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab); +#endif + +#ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR +void __check_heap_object(const void *ptr, unsigned long n, + const struct slab *slab, bool to_user); +#else +static inline +void __check_heap_object(const void *ptr, unsigned long n, + const struct slab *slab, bool to_user) +{ +} #endif #endif /* MM_SLAB_H */ |