Messages in this thread | | | Date | Tue, 14 Feb 2012 09:31:01 +0200 (EET) | From | Pekka Enberg <> | Subject | Re: [PATCH] slab: warning if total alloc size overflow |
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On Tue, 14 Feb 2012, Yang Bai wrote: > Before, if the total alloc size is overflow, > we just return NULL like alloc fail. But they > are two different type problems. The former looks > more like a programming problem. So add a warning > here. > > Signed-off-by: Yang Bai <hamo.by@gmail.com> > --- > include/linux/slab.h | 4 +++- > 1 files changed, 3 insertions(+), 1 deletions(-) > > diff --git a/include/linux/slab.h b/include/linux/slab.h > index 573c809..5865237 100644 > --- a/include/linux/slab.h > +++ b/include/linux/slab.h > @@ -242,8 +242,10 @@ size_t ksize(const void *); > */ > static inline void *kcalloc(size_t n, size_t size, gfp_t flags) > { > - if (size != 0 && n > ULONG_MAX / size) > + if (size != 0 && n > ULONG_MAX / size) { > + WARN(1, "Alloc memory size (%lu * %lu) overflow.", n, size); > return NULL; > + } > return __kmalloc(n * size, flags | __GFP_ZERO); > }
Did you check how much kernel text size increases? I'm pretty sure we'd need to wrap this with CONFIG_SLAB_OVERFLOW ifdef.
Pekka
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