Messages in this thread | | | Subject | Re: [PATCH] dma-mapping: remove an unnecessary NULL check | From | Ian Abbott <> | Date | Thu, 25 Apr 2019 15:13:49 +0100 |
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On 24/04/2019 15:27, Christoph Hellwig wrote: > On Wed, Apr 24, 2019 at 05:24:37PM +0300, Dan Carpenter wrote: >> We already dereferenced "dev" when we called get_dma_ops() so this NULL >> check is too late. We're not supposed to pass NULL "dev" pointers to >> dma_alloc_attrs(). > > Thanks, applied to the dma-mapping for-next tree. > >> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> >> --- >> There are still at least two drivers which do pass a NULL unfortunately. >> >> drivers/staging/comedi/drivers/comedi_isadma.c:195 comedi_isadma_alloc() error: NULL dereference inside function 'dma_alloc_coherent()' >> drivers/staging/comedi/drivers/comedi_isadma.c:227 comedi_isadma_free() error: NULL dereference inside function 'dma_free_coherent()' > > This is staging code. Per official decree from Linus we can just > ignore it, and I tend to do so to keep my sanity.
So for comedi_isadma, we can just replace the NULL with a pointer to a static dummy device with a 24-bit coherent mask?
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