Re: BUG: NULL pointer dereference at 00000000 -- IP: [] :b43:b43_dma_mapping_error+0x16/0x155

Vegard Nossum
2008-06-10T14:29:47Z

On Tue, Jun 10, 2008 at 4:23 PM, Michael Buesch <mb@bu3sch.de> wrote:
> On Tuesday 10 June 2008 16:09:37 Miles Lane wrote:
>> BUG: unable to handle kernel NULL pointer dereference at 00000000
>> IP: [<f8e783d5>] :b43:b43_dma_mapping_error+0x16/0x155
>
>
> It seems to crash at
> 60 extern const struct dma_mapping_ops *dma_ops;
> 61
> 62 static inline int dma_mapping_error(dma_addr_t dma_addr)
> 63 {
> 64 if (dma_ops->mapping_error)
> 65 return dma_ops->mapping_error(dma_addr);
> 66
> 67 return (dma_addr == bad_dma_address);
> 68 }

No, this is wrong.

/* Check if a DMA mapping address is invalid. */
static bool b43_dma_mapping_error(struct b43_dmaring *ring,
dma_addr_t addr,
size_t buffersize, bool dma_to_device)
{
if (unlikely(dma_mapping_error(ring->dev->dev->dma_dev, addr)))

It crashes on this line ---^

Vegard

--
"The animistic metaphor of the bug that maliciously sneaked in while
the programmer was not looking is intellectually dishonest as it
disguises that the error is the programmer's own creation."
-- E. W. Dijkstra, EWD1036