Re: [PATCH v5] mm: SLAB freelist randomization

[Thomas Garnier]

On Wed, Apr 27, 2016 at 12:16 PM, Andrew Morton
<akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, 27 Apr 2016 10:20:59 -0700 Thomas Garnier <thgarnie@xxxxxxxxxx> wrote:
>
>> Provides an optional config (CONFIG_SLAB_FREELIST_RANDOM) to randomize
>> the SLAB freelist.
>
> Forgot this bit?
>

I thought I would change it when we support other kernel heaps.

> From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Subject: mm-slab-freelist-randomization-v5-fix
>
> propagate gfp_t into cache_random_seq_create()
>
> Cc: Christoph Lameter <cl@xxxxxxxxx>
> Cc: David Rientjes <rientjes@xxxxxxxxxx>
> Cc: Greg Thelen <gthelen@xxxxxxxxxx>
> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Laura Abbott <labbott@xxxxxxxxxxxxxxxxx>
> Cc: Pekka Enberg <penberg@xxxxxxxxxx>
> Cc: Thomas Garnier <thgarnie@xxxxxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>
> --- a/mm/slab.c~mm-slab-freelist-randomization-v5-fix
> +++ a/mm/slab.c
> @@ -1262,7 +1262,7 @@ static void freelist_randomize(struct rn
>  }
>
>  /* Create a random sequence per cache */
> -static int cache_random_seq_create(struct kmem_cache *cachep)
> +static int cache_random_seq_create(struct kmem_cache *cachep, gfp_t gfp)
>  {
>         unsigned int seed, count = cachep->num;
>         struct rnd_state state;
> @@ -1271,7 +1271,7 @@ static int cache_random_seq_create(struc
>                 return 0;
>
>         /* If it fails, we will just use the global lists */
> -       cachep->random_seq = kcalloc(count, sizeof(freelist_idx_t), GFP_KERNEL);
> +       cachep->random_seq = kcalloc(count, sizeof(freelist_idx_t), gfp);
>         if (!cachep->random_seq)
>                 return -ENOMEM;
>
> @@ -1290,7 +1290,7 @@ static void cache_random_seq_destroy(str
>         cachep->random_seq = NULL;
>  }
>  #else
> -static inline int cache_random_seq_create(struct kmem_cache *cachep)
> +static inline int cache_random_seq_create(struct kmem_cache *cachep, gfp_t gfp)
>  {
>         return 0;
>  }
> @@ -3999,7 +3999,7 @@ static int enable_cpucache(struct kmem_c
>         int shared = 0;
>         int batchcount = 0;
>
> -       err = cache_random_seq_create(cachep);
> +       err = cache_random_seq_create(cachep, gfp);
>         if (err)
>                 goto end;
>
> _
>