Hi Andrey, On 06/12/2018 12:24, Andrey Konovalov wrote: > This commit adds tag-based KASAN specific hooks implementation and > adjusts common generic and tag-based KASAN ones. > > 1. When a new slab cache is created, tag-based KASAN rounds up the size of > the objects in this cache to KASAN_SHADOW_SCALE_SIZE (== 16). > > 2. On each kmalloc tag-based KASAN generates a random tag, sets the shadow > memory, that corresponds to this object to this tag, and embeds this > tag value into the top byte of the returned pointer. > > 3. On each kfree tag-based KASAN poisons the shadow memory with a random > tag to allow detection of use-after-free bugs. > > The rest of the logic of the hook implementation is very much similar to > the one provided by generic KASAN. Tag-based KASAN saves allocation and > free stack metadata to the slab object the same way generic KASAN does. > > Reviewed-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> > Reviewed-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > --- > mm/kasan/common.c | 116 ++++++++++++++++++++++++++++++++++++++-------- > mm/kasan/kasan.h | 8 ++++ > mm/kasan/tags.c | 48 +++++++++++++++++++ > 3 files changed, 153 insertions(+), 19 deletions(-) > [...] > @@ -265,6 +290,8 @@ void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, > return; > } > > + cache->align = round_up(cache->align, KASAN_SHADOW_SCALE_SIZE); > + Did you consider to set ARCH_SLAB_MINALIGN instead of this round up? -- Regards, Vincenzo
