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x86/dma-mapping: Fix arch_dma_alloc_attrs() oops with NULL dev

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Commit 6894258eda broke drivers that pass NULL as the device pointer
to dma_alloc. The reason is that arch_dma_alloc_attrs() now calls
dma_alloc_coherent_gfp_flags() which in turn calls
dma_alloc_coherent_mask(), where the device pointer is dereferenced
unconditionally.

Fix things by moving the ISA DMA fallback device assignment before the
call to dma_alloc_coherent_gfp_flags().

Fixes: 6894258eda ("dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent}")
Reported-and-tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/1445807503-8920-1-git-send-email-ville.syrjala@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Ville Syrjälä 2015-10-25 23:11:43 +02:00 committed by Thomas Gleixner
parent 32b88194f7
commit 298a96c12b
1 changed files with 3 additions and 2 deletions
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5
arch/x86/kernel/pci-dma.c
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@ -131,11 +131,12 @@ void dma_generic_free_coherent(struct device *dev, size_t size, void *vaddr,
bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp)
{
if (!*dev)
*dev = &x86_dma_fallback_dev;
*gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
*gfp = dma_alloc_coherent_gfp_flags(*dev, *gfp);
if (!*dev)
*dev = &x86_dma_fallback_dev;
if (!is_device_dma_capable(*dev))
return false;
return true;