Messages in this thread |  | | From | Alexander Potapenko <> | Date | Wed, 30 Sep 2020 14:50:59 +0200 | Subject | Re: [PATCH RFC v2 2/6] mm/slab: Perform init_on_free earlier |
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On Tue, Sep 29, 2020 at 8:35 PM Alexander Popov <alex.popov@linux.com> wrote: > > Currently in CONFIG_SLAB init_on_free happens too late, and heap > objects go to the heap quarantine being dirty. Lets move memory > clearing before calling kasan_slab_free() to fix that. > > Signed-off-by: Alexander Popov <alex.popov@linux.com> Reviewed-by: Alexander Potapenko <glider@google.com>
> --- > mm/slab.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/mm/slab.c b/mm/slab.c > index 3160dff6fd76..5140203c5b76 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -3414,6 +3414,9 @@ static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) > static __always_inline void __cache_free(struct kmem_cache *cachep, void *objp, > unsigned long caller) > { > + if (unlikely(slab_want_init_on_free(cachep))) > + memset(objp, 0, cachep->object_size); > + > /* Put the object into the quarantine, don't touch it for now. */ > if (kasan_slab_free(cachep, objp, _RET_IP_)) > return; > @@ -3432,8 +3435,6 @@ void ___cache_free(struct kmem_cache *cachep, void *objp, > struct array_cache *ac = cpu_cache_get(cachep); > > check_irq_off(); > - if (unlikely(slab_want_init_on_free(cachep))) > - memset(objp, 0, cachep->object_size); > kmemleak_free_recursive(objp, cachep->flags); > objp = cache_free_debugcheck(cachep, objp, caller); > memcg_slab_free_hook(cachep, virt_to_head_page(objp), objp); > -- > 2.26.2 >
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