On Wed, Feb 11, 2015 at 09:01:41AM +0000, Alexandre Courbot wrote: > There doesn't seem to be any valid reason to allocate the pages array > with the same flags as the buffer itself. Doing so can eventually lead > to the following safeguard in mm/slab.c to be hit: > > BUG_ON(flags & GFP_SLAB_BUG_MASK);
nit: I can't actually spot this BUG_ON in the kernel. > This happens when buffers are allocated with __GFP_DMA32 or > __GFP_HIGHMEM. > > Fix this by allocating the pages array with GFP_KERNEL to follow what is > done elsewhere in this file. Using GFP_KERNEL in __iommu_alloc_buffer() > is safe because atomic allocations are handled by __iommu_alloc_atomic(). > > Signed-off-by: Alexandre Courbot <acour...@nvidia.com> > Cc: Arnd Bergmann <a...@arndb.de> > Cc: Marek Szyprowski <m.szyprow...@samsung.com> > Cc: Russell King <li...@arm.linux.org.uk> > Acked-by: Marek Szyprowski <m.szyprow...@samsung.com> > --- > arch/arm/mm/dma-mapping.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index 903dba0..170a116 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -1106,7 +1106,7 @@ static struct page **__iommu_alloc_buffer(struct device > *dev, size_t size, > int i = 0; > > if (array_size <= PAGE_SIZE) > - pages = kzalloc(array_size, gfp); > + pages = kzalloc(array_size, GFP_KERNEL); > else > pages = vzalloc(array_size); > if (!pages) > -- > 2.3.0 Looks sensible to me: Acked-by: Will Deacon <will.dea...@arm.com> Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
