diff options
| -rw-r--r-- | include/linux/slab_def.h | 3 | ||||
| -rw-r--r-- | mm/slab.c | 85 |
2 files changed, 66 insertions, 22 deletions
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h index cf139d3fa513..e878ba35ae91 100644 --- a/include/linux/slab_def.h +++ b/include/linux/slab_def.h @@ -60,6 +60,9 @@ struct kmem_cache { atomic_t allocmiss; atomic_t freehit; atomic_t freemiss; +#ifdef CONFIG_DEBUG_SLAB_LEAK + atomic_t store_user_clean; +#endif /* * If debugging is enabled, then the allocator can add additional diff --git a/mm/slab.c b/mm/slab.c index 3142ec3965cf..907abe9964bf 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -396,20 +396,25 @@ static void set_obj_status(struct page *page, int idx, int val) status[idx] = val; } -static inline unsigned int get_obj_status(struct page *page, int idx) +static inline bool is_store_user_clean(struct kmem_cache *cachep) { - int freelist_size; - char *status; - struct kmem_cache *cachep = page->slab_cache; + return atomic_read(&cachep->store_user_clean) == 1; +} - freelist_size = cachep->num * sizeof(freelist_idx_t); - status = (char *)page->freelist + freelist_size; +static inline void set_store_user_clean(struct kmem_cache *cachep) +{ + atomic_set(&cachep->store_user_clean, 1); +} - return status[idx]; +static inline void set_store_user_dirty(struct kmem_cache *cachep) +{ + if (is_store_user_clean(cachep)) + atomic_set(&cachep->store_user_clean, 0); } #else static inline void set_obj_status(struct page *page, int idx, int val) {} +static inline void set_store_user_dirty(struct kmem_cache *cachep) {} #endif @@ -2550,6 +2555,11 @@ static void *slab_get_obj(struct kmem_cache *cachep, struct page *page) objp = index_to_obj(cachep, page, get_free_obj(page, page->active)); page->active++; +#if DEBUG + if (cachep->flags & SLAB_STORE_USER) + set_store_user_dirty(cachep); +#endif + return objp; } @@ -2725,8 +2735,10 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, *dbg_redzone1(cachep, objp) = RED_INACTIVE; *dbg_redzone2(cachep, objp) = RED_INACTIVE; } - if (cachep->flags & SLAB_STORE_USER) + if (cachep->flags & SLAB_STORE_USER) { + set_store_user_dirty(cachep); *dbg_userword(cachep, objp) = (void *)caller; + } objnr = obj_to_index(cachep, page, objp); @@ -4119,15 +4131,34 @@ static void handle_slab(unsigned long *n, struct kmem_cache *c, struct page *page) { void *p; - int i; + int i, j; + unsigned long v; if (n[0] == n[1]) return; for (i = 0, p = page->s_mem; i < c->num; i++, p += c->size) { - if (get_obj_status(page, i) != OBJECT_ACTIVE) + bool active = true; + + for (j = page->active; j < c->num; j++) { + if (get_free_obj(page, j) == i) { + active = false; + break; + } + } + + if (!active) continue; - if (!add_caller(n, (unsigned long)*dbg_userword(c, p))) + /* + * probe_kernel_read() is used for DEBUG_PAGEALLOC. page table + * mapping is established when actual object allocation and + * we could mistakenly access the unmapped object in the cpu + * cache. + */ + if (probe_kernel_read(&v, dbg_userword(c, p), sizeof(v))) + continue; + + if (!add_caller(n, v)) return; } } @@ -4163,21 +4194,31 @@ static int leaks_show(struct seq_file *m, void *p) if (!(cachep->flags & SLAB_RED_ZONE)) return 0; - /* OK, we can do it */ + /* + * Set store_user_clean and start to grab stored user information + * for all objects on this cache. If some alloc/free requests comes + * during the processing, information would be wrong so restart + * whole processing. + */ + do { + set_store_user_clean(cachep); + drain_cpu_caches(cachep); + + x[1] = 0; - x[1] = 0; + for_each_kmem_cache_node(cachep, node, n) { - for_each_kmem_cache_node(cachep, node, n) { + check_irq_on(); + spin_lock_irq(&n->list_lock); - check_irq_on(); - spin_lock_irq(&n->list_lock); + list_for_each_entry(page, &n->slabs_full, lru) + handle_slab(x, cachep, page); + list_for_each_entry(page, &n->slabs_partial, lru) + handle_slab(x, cachep, page); + spin_unlock_irq(&n->list_lock); + } + } while (!is_store_user_clean(cachep)); - list_for_each_entry(page, &n->slabs_full, lru) - handle_slab(x, cachep, page); - list_for_each_entry(page, &n->slabs_partial, lru) - handle_slab(x, cachep, page); - spin_unlock_irq(&n->list_lock); - } name = cachep->name; if (x[0] == x[1]) { /* Increase the buffer size */ |