diff options
| -rw-r--r-- | include/linux/slab.h | 2 | ||||
| -rw-r--r-- | mm/slab.c | 32 |
2 files changed, 32 insertions, 2 deletions
diff --git a/include/linux/slab.h b/include/linux/slab.h index 24c5602bee9..48803064ced 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -62,6 +62,8 @@ # define SLAB_DEBUG_OBJECTS 0x00000000UL #endif +#define SLAB_NOLEAKTRACE 0x00800000UL /* Avoid kmemleak tracing */ + /* The following flags affect the page allocator grouping pages by mobility */ #define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */ #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ diff --git a/mm/slab.c b/mm/slab.c index f85831da908..859067f8e4f 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -107,6 +107,7 @@ #include <linux/string.h> #include <linux/uaccess.h> #include <linux/nodemask.h> +#include <linux/kmemleak.h> #include <linux/mempolicy.h> #include <linux/mutex.h> #include <linux/fault-inject.h> @@ -178,13 +179,13 @@ SLAB_STORE_USER | \ SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ - SLAB_DEBUG_OBJECTS) + SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE) #else # define CREATE_MASK (SLAB_HWCACHE_ALIGN | \ SLAB_CACHE_DMA | \ SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ - SLAB_DEBUG_OBJECTS) + SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE) #endif /* @@ -964,6 +965,14 @@ static struct array_cache *alloc_arraycache(int node, int entries, struct array_cache *nc = NULL; nc = kmalloc_node(memsize, GFP_KERNEL, node); + /* + * The array_cache structures contain pointers to free object. + * However, when such objects are allocated or transfered to another + * cache the pointers are not cleared and they could be counted as + * valid references during a kmemleak scan. Therefore, kmemleak must + * not scan such objects. + */ + kmemleak_no_scan(nc); if (nc) { nc->avail = 0; nc->limit = entries; @@ -2621,6 +2630,14 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, /* Slab management obj is off-slab. */ slabp = kmem_cache_alloc_node(cachep->slabp_cache, local_flags, nodeid); + /* + * If the first object in the slab is leaked (it's allocated + * but no one has a reference to it), we want to make sure + * kmemleak does not treat the ->s_mem pointer as a reference + * to the object. Otherwise we will not report the leak. + */ + kmemleak_scan_area(slabp, offsetof(struct slab, list), + sizeof(struct list_head), local_flags); if (!slabp) return NULL; } else { @@ -3141,6 +3158,12 @@ static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) STATS_INC_ALLOCMISS(cachep); objp = cache_alloc_refill(cachep, flags); } + /* + * To avoid a false negative, if an object that is in one of the + * per-CPU caches is leaked, we need to make sure kmemleak doesn't + * treat the array pointers as a reference to the object. + */ + kmemleak_erase(&ac->entry[ac->avail]); return objp; } @@ -3360,6 +3383,8 @@ __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, out: local_irq_restore(save_flags); ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); + kmemleak_alloc_recursive(ptr, obj_size(cachep), 1, cachep->flags, + flags); if (unlikely((flags & __GFP_ZERO) && ptr)) memset(ptr, 0, obj_size(cachep)); @@ -3415,6 +3440,8 @@ __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller) objp = __do_cache_alloc(cachep, flags); local_irq_restore(save_flags); objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); + kmemleak_alloc_recursive(objp, obj_size(cachep), 1, cachep->flags, + flags); prefetchw(objp); if (unlikely((flags & __GFP_ZERO) && objp)) @@ -3530,6 +3557,7 @@ static inline void __cache_free(struct kmem_cache *cachep, void *objp) struct array_cache *ac = cpu_cache_get(cachep); check_irq_off(); + kmemleak_free_recursive(objp, cachep->flags); objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0)); /* |