diff options
Diffstat (limited to 'mm/slub.c')
-rw-r--r-- | mm/slub.c | 232 |
1 files changed, 180 insertions, 52 deletions
diff --git a/mm/slub.c b/mm/slub.c index 87e794ab101a..a18a81a52307 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1324,17 +1324,14 @@ static inline int alloc_consistency_checks(struct kmem_cache *s, } static noinline int alloc_debug_processing(struct kmem_cache *s, - struct slab *slab, - void *object, unsigned long addr) + struct slab *slab, void *object) { if (s->flags & SLAB_CONSISTENCY_CHECKS) { if (!alloc_consistency_checks(s, slab, object)) goto bad; } - /* Success perform special debug activities for allocs */ - if (s->flags & SLAB_STORE_USER) - set_track(s, object, TRACK_ALLOC, addr); + /* Success. Perform special debug activities for allocs */ trace(s, slab, object, 1); init_object(s, object, SLUB_RED_ACTIVE); return 1; @@ -1604,16 +1601,18 @@ static inline void setup_slab_debug(struct kmem_cache *s, struct slab *slab, void *addr) {} static inline int alloc_debug_processing(struct kmem_cache *s, - struct slab *slab, void *object, unsigned long addr) { return 0; } + struct slab *slab, void *object) { return 0; } -static inline int free_debug_processing( +static inline void free_debug_processing( struct kmem_cache *s, struct slab *slab, void *head, void *tail, int bulk_cnt, - unsigned long addr) { return 0; } + unsigned long addr) {} 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 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, @@ -1919,11 +1918,13 @@ static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) */ slab = alloc_slab_page(alloc_gfp, node, oo); if (unlikely(!slab)) - goto out; + 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); @@ -1950,15 +1951,6 @@ static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) set_freepointer(s, p, NULL); } - slab->inuse = slab->objects; - slab->frozen = 1; - -out: - if (!slab) - return NULL; - - inc_slabs_node(s, slab_nid(slab), slab->objects); - return slab; } @@ -2046,6 +2038,75 @@ static inline void remove_partial(struct kmem_cache_node *n, } /* + * Called only for kmem_cache_debug() caches instead of acquire_slab(), 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) +{ + 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)) { + 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 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)) + /* + * 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; +} + +/* * Remove slab from the partial list, freeze it and * return the pointer to the freelist. * @@ -2125,6 +2186,13 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n, if (!pfmemalloc_match(slab, gfpflags)) continue; + if (kmem_cache_debug(s)) { + object = alloc_single_from_partial(s, n, slab); + if (object) + break; + continue; + } + t = acquire_slab(s, n, slab, object == NULL); if (!t) break; @@ -2733,31 +2801,39 @@ static inline unsigned long node_nr_objs(struct kmem_cache_node *n) } /* Supports checking bulk free of a constructed freelist */ -static noinline int free_debug_processing( +static noinline void free_debug_processing( 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; void *object = head; int cnt = 0; - unsigned long flags, flags2; - int ret = 0; + unsigned long flags; + bool checks_ok = false; depot_stack_handle_t handle = 0; if (s->flags & SLAB_STORE_USER) handle = set_track_prepare(); spin_lock_irqsave(&n->list_lock, flags); - slab_lock(slab, &flags2); 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: - cnt++; + + if (++cnt > bulk_cnt) + goto out_cnt; if (s->flags & SLAB_CONSISTENCY_CHECKS) { if (!free_consistency_checks(s, slab, object, addr)) @@ -2775,18 +2851,57 @@ next_object: object = get_freepointer(s, object); goto next_object; } - ret = 1; + checks_ok = true; -out: +out_cnt: if (cnt != bulk_cnt) - slab_err(s, slab, "Bulk freelist count(%d) invalid(%d)\n", + slab_err(s, slab, "Bulk free expected %d objects but found %d\n", bulk_cnt, cnt); - slab_unlock(slab, &flags2); +out: + if (checks_ok) { + 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; + + /* Do we need to remove the slab from full or partial list? */ + if (!prior) { + remove_full(s, n, slab); + } else if (slab->inuse == 0 && + n->nr_partial >= s->min_partial) { + remove_partial(n, slab); + stat(s, FREE_REMOVE_PARTIAL); + } + + /* Do we need to discard the slab or add to partial list? */ + if (slab->inuse == 0 && n->nr_partial >= s->min_partial) { + slab_free = slab; + } else if (!prior) { + add_partial(n, slab, DEACTIVATE_TO_TAIL); + stat(s, FREE_ADD_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 (!ret) + + if (!checks_ok) slab_fix(s, "Object at 0x%p not freed", object); - return ret; + + if (slab_free) { + stat(s, FREE_SLAB); + free_slab(s, slab_free); + } } #endif /* CONFIG_SLUB_DEBUG */ @@ -3036,36 +3151,52 @@ new_objects: return NULL; } + stat(s, ALLOC_SLAB); + + if (kmem_cache_debug(s)) { + freelist = alloc_single_from_new_slab(s, slab); + + 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; - stat(s, ALLOC_SLAB); + inc_slabs_node(s, slab_nid(slab), slab->objects); check_new_slab: if (kmem_cache_debug(s)) { - if (!alloc_debug_processing(s, slab, freelist, addr)) { - /* Slab failed checks. Next slab needed */ - goto new_slab; - } else { - /* - * For debug case, we don't load freelist so that all - * allocations go through alloc_debug_processing() - */ - goto return_single; - } + /* + * 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; } - if (unlikely(!pfmemalloc_match(slab, gfpflags))) + 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. */ - goto return_single; + deactivate_slab(s, slab, get_freepointer(s, freelist)); + return freelist; + } retry_load_slab: @@ -3089,11 +3220,6 @@ retry_load_slab: c->slab = slab; goto load_freelist; - -return_single: - - deactivate_slab(s, slab, get_freepointer(s, freelist)); - return freelist; } /* @@ -3341,9 +3467,10 @@ static void __slab_free(struct kmem_cache *s, struct slab *slab, if (kfence_free(head)) return; - if (kmem_cache_debug(s) && - !free_debug_processing(s, slab, head, tail, cnt, addr)) + if (kmem_cache_debug(s)) { + free_debug_processing(s, slab, head, tail, cnt, addr); return; + } do { if (unlikely(n)) { @@ -3936,6 +4063,7 @@ static void early_kmem_cache_node_alloc(int node) slab = new_slab(kmem_cache_node, GFP_NOWAIT, node); BUG_ON(!slab); + inc_slabs_node(kmem_cache_node, slab_nid(slab), slab->objects); 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"); @@ -3950,7 +4078,6 @@ static void early_kmem_cache_node_alloc(int node) n = kasan_slab_alloc(kmem_cache_node, n, GFP_KERNEL, false); slab->freelist = get_freepointer(kmem_cache_node, n); slab->inuse = 1; - slab->frozen = 0; kmem_cache_node->node[node] = n; init_kmem_cache_node(n); inc_slabs_node(kmem_cache_node, node, slab->objects); @@ -4611,6 +4738,7 @@ static int __kmem_cache_do_shrink(struct kmem_cache *s) if (free == slab->objects) { list_move(&slab->slab_list, &discard); n->nr_partial--; + dec_slabs_node(s, node, slab->objects); } else if (free <= SHRINK_PROMOTE_MAX) list_move(&slab->slab_list, promote + free - 1); } @@ -4626,7 +4754,7 @@ static int __kmem_cache_do_shrink(struct kmem_cache *s) /* Release empty slabs */ list_for_each_entry_safe(slab, t, &discard, slab_list) - discard_slab(s, slab); + free_slab(s, slab); if (slabs_node(s, node)) ret = 1; @@ -5601,7 +5729,7 @@ static ssize_t validate_store(struct kmem_cache *s, { int ret = -EINVAL; - if (buf[0] == '1') { + if (buf[0] == '1' && kmem_cache_debug(s)) { ret = validate_slab_cache(s); if (ret >= 0) ret = length; |