Messages in this thread | | | Date | Thu, 11 Dec 2014 12:12:20 +0100 | From | Marek Szyprowski <> | Subject | Re: [PATCH] ARM: DMA: Fix kzalloc flags in __iommu_alloc_buffer() |
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On 2014-12-08 09:39, 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); > > 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 <acourbot@nvidia.com> > Cc: Russell King <linux@arm.linux.org.uk> > Cc: Marek Szyprowski <m.szyprowski@samsung.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Thierry Reding <treding@nvidia.com> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Marek Szyprowski <m.szyprowski@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 e8907117861e..bc495354c802 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)
Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
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