Messages in this thread Patch in this message | | | Date | Thu, 11 Dec 2008 23:22:50 +0200 | From | Pekka Enberg <> | Subject | Re: [PATCH 03/15] kmemleak: Add the slab memory allocation/freeing hooks |
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Hi Catalin,
Catalin Marinas wrote: > @@ -2610,6 +2611,13 @@ 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 & ~GFP_THISNODE, nodeid); > + /* > + * Only scan the list member to avoid false negatives > + * (especially caused by the s_mem pointer) > + */
Heh, I run into this part again and as I have a long term memory of a goldfish I had to look up the discussion we had. So may I suggest you change the comment to:
/* * 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. */
> + memleak_scan_area(slabp, offsetof(struct slab, list), > + sizeof(struct list_head), > + local_flags & ~GFP_THISNODE); > if (!slabp) > return NULL; > } else { > @@ -3195,6 +3203,8 @@ static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) > STATS_INC_ALLOCMISS(cachep); > objp = cache_alloc_refill(cachep, flags); > } > + /* avoid false negatives */ > + memleak_erase(&ac->entry[ac->avail]);
For this, maybe something like this:
/* * 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. */ > return objp; > } >
Do you take care of the per-node lists as well?
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