On Wed, Oct 01, 2014 at 11:13:23AM +0100, Will Deacon wrote: > On Tue, Sep 30, 2014 at 09:15:21PM +0100, Sean Paul wrote: > > This patch replaces the static assignment of ~0 to dma_handle with > > DMA_ERROR_CODE to be consistent with other platforms. > > > > In addition to that, it also adds a check for DMA_ERROR_CODE before > > calling __dma_free_coherent with an invalid dma_handle. > > > > Signed-off-by: Sean Paul <[email protected]> > > --- > > arch/arm64/mm/dma-mapping.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > > index 4164c5a..69fd2c4 100644 > > --- a/arch/arm64/mm/dma-mapping.c > > +++ b/arch/arm64/mm/dma-mapping.c > > @@ -125,7 +125,7 @@ static void *__dma_alloc_noncoherent(struct device > > *dev, size_t size, > > no_map: > > __dma_free_coherent(dev, size, ptr, *dma_handle, attrs); > > no_mem: > > - *dma_handle = ~0; > > + *dma_handle = DMA_ERROR_CODE; > > return NULL; > > } > > > > @@ -136,7 +136,9 @@ static void __dma_free_noncoherent(struct device *dev, > > size_t size, > > void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle)); > > > > vunmap(vaddr); > > - __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs); > > + > > + if (dma_handle != DMA_ERROR_CODE) > > + __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs); > > Is it legal to try and free a DMA buffer after a failed allocation? If so, I > think we need something similar for arch/arm/.
If the allocation failed, we don't even have a vaddr to unmap, so I don't see the reason for the additional check. -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
