diff options
| -rw-r--r-- | include/linux/slab_def.h | 3 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 4 | ||||
| -rw-r--r-- | mm/slab.c | 226 |
3 files changed, 1 insertions, 232 deletions
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h index 9a5eafb7145b..abc7de77b988 100644 --- a/include/linux/slab_def.h +++ b/include/linux/slab_def.h @@ -61,9 +61,6 @@ 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/lib/Kconfig.debug b/lib/Kconfig.debug index fdfa173651eb..eae43952902e 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -542,10 +542,6 @@ config DEBUG_SLAB allocation as well as poisoning memory on free to catch use of freed memory. This can make kmalloc/kfree-intensive workloads much slower. -config DEBUG_SLAB_LEAK - bool "Memory leak debugging" - depends on DEBUG_SLAB - config SLUB_DEBUG_ON bool "SLUB debugging on by default" depends on SLUB && SLUB_DEBUG diff --git a/mm/slab.c b/mm/slab.c index 2915d912e89a..f7117ad9b3a3 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -362,29 +362,6 @@ static void **dbg_userword(struct kmem_cache *cachep, void *objp) #endif -#ifdef CONFIG_DEBUG_SLAB_LEAK - -static inline bool is_store_user_clean(struct kmem_cache *cachep) -{ - return atomic_read(&cachep->store_user_clean) == 1; -} - -static inline void set_store_user_clean(struct kmem_cache *cachep) -{ - atomic_set(&cachep->store_user_clean, 1); -} - -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_store_user_dirty(struct kmem_cache *cachep) {} - -#endif - /* * Do not go above this order unless 0 objects fit into the slab or * overridden on the command line. @@ -2552,11 +2529,6 @@ 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; } @@ -2762,10 +2734,8 @@ 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) { - set_store_user_dirty(cachep); + if (cachep->flags & SLAB_STORE_USER) *dbg_userword(cachep, objp) = (void *)caller; - } objnr = obj_to_index(cachep, page, objp); @@ -4184,200 +4154,6 @@ ssize_t slabinfo_write(struct file *file, const char __user *buffer, return res; } -#ifdef CONFIG_DEBUG_SLAB_LEAK - -static inline int add_caller(unsigned long *n, unsigned long v) -{ - unsigned long *p; - int l; - if (!v) - return 1; - l = n[1]; - p = n + 2; - while (l) { - int i = l/2; - unsigned long *q = p + 2 * i; - if (*q == v) { - q[1]++; - return 1; - } - if (*q > v) { - l = i; - } else { - p = q + 2; - l -= i + 1; - } - } - if (++n[1] == n[0]) - return 0; - memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); - p[0] = v; - p[1] = 1; - return 1; -} - -static void handle_slab(unsigned long *n, struct kmem_cache *c, - struct page *page) -{ - void *p; - 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) { - bool active = true; - - for (j = page->active; j < c->num; j++) { - if (get_free_obj(page, j) == i) { - active = false; - break; - } - } - - if (!active) - continue; - - /* - * 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; - } -} - -static void show_symbol(struct seq_file *m, unsigned long address) -{ -#ifdef CONFIG_KALLSYMS - unsigned long offset, size; - char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; - - if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { - seq_printf(m, "%s+%#lx/%#lx", name, offset, size); - if (modname[0]) - seq_printf(m, " [%s]", modname); - return; - } -#endif - seq_printf(m, "%px", (void *)address); -} - -static int leaks_show(struct seq_file *m, void *p) -{ - struct kmem_cache *cachep = list_entry(p, struct kmem_cache, - root_caches_node); - struct page *page; - struct kmem_cache_node *n; - const char *name; - unsigned long *x = m->private; - int node; - int i; - - if (!(cachep->flags & SLAB_STORE_USER)) - return 0; - if (!(cachep->flags & SLAB_RED_ZONE)) - return 0; - - /* - * 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 { - drain_cpu_caches(cachep); - /* - * drain_cpu_caches() could make kmemleak_object and - * debug_objects_cache dirty, so reset afterwards. - */ - set_store_user_clean(cachep); - - x[1] = 0; - - for_each_kmem_cache_node(cachep, node, n) { - - check_irq_on(); - spin_lock_irq(&n->list_lock); - - list_for_each_entry(page, &n->slabs_full, slab_list) - handle_slab(x, cachep, page); - list_for_each_entry(page, &n->slabs_partial, slab_list) - handle_slab(x, cachep, page); - spin_unlock_irq(&n->list_lock); - } - } while (!is_store_user_clean(cachep)); - - name = cachep->name; - if (x[0] == x[1]) { - /* Increase the buffer size */ - mutex_unlock(&slab_mutex); - m->private = kcalloc(x[0] * 4, sizeof(unsigned long), - GFP_KERNEL); - if (!m->private) { - /* Too bad, we are really out */ - m->private = x; - mutex_lock(&slab_mutex); - return -ENOMEM; - } - *(unsigned long *)m->private = x[0] * 2; - kfree(x); - mutex_lock(&slab_mutex); - /* Now make sure this entry will be retried */ - m->count = m->size; - return 0; - } - for (i = 0; i < x[1]; i++) { - seq_printf(m, "%s: %lu ", name, x[2*i+3]); - show_symbol(m, x[2*i+2]); - seq_putc(m, '\n'); - } - - return 0; -} - -static const struct seq_operations slabstats_op = { - .start = slab_start, - .next = slab_next, - .stop = slab_stop, - .show = leaks_show, -}; - -static int slabstats_open(struct inode *inode, struct file *file) -{ - unsigned long *n; - - n = __seq_open_private(file, &slabstats_op, PAGE_SIZE); - if (!n) - return -ENOMEM; - - *n = PAGE_SIZE / (2 * sizeof(unsigned long)); - - return 0; -} - -static const struct file_operations proc_slabstats_operations = { - .open = slabstats_open, - .read = seq_read, - .llseek = seq_lseek, - .release = seq_release_private, -}; -#endif - -static int __init slab_proc_init(void) -{ -#ifdef CONFIG_DEBUG_SLAB_LEAK - proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations); -#endif - return 0; -} -module_init(slab_proc_init); - #ifdef CONFIG_HARDENED_USERCOPY /* * Rejects incorrectly sized objects and objects that are to be copied |