diff options
| author | Dave Jiang <dave.jiang@intel.com> | 2015-09-17 13:27:04 -0700 |
|---|---|---|
| committer | Jon Mason <jdmason@kudzu.us> | 2015-11-08 16:11:21 -0500 |
| commit | 04afde45e096201f8fd74c1db848a5d85d1aa57d (patch) | |
| tree | b26f609ea9c211e40de16c9d795edc01c38a0e3c /drivers/ntb | |
| parent | 6a13feb9c82803e2b815eca72fa7a9f5561d7861 (diff) | |
| download | lwn-04afde45e096201f8fd74c1db848a5d85d1aa57d.tar.gz lwn-04afde45e096201f8fd74c1db848a5d85d1aa57d.zip | |
NTB: Fix issue where we may be accessing NULL ptr
smatch detected an issue in the function ntb_transport_max_size() where
we could be dereferencing a dma channel pointer when it is NULL.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Diffstat (limited to 'drivers/ntb')
| -rw-r--r-- | drivers/ntb/ntb_transport.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index 6e3ee907d186..3903dfc39975 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -1996,23 +1996,24 @@ EXPORT_SYMBOL_GPL(ntb_transport_qp_num); */ unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp) { - unsigned int max; + unsigned int max_size; unsigned int copy_align; + struct dma_chan *rx_chan, *tx_chan; if (!qp) return 0; - if (!qp->tx_dma_chan && !qp->rx_dma_chan) - return qp->tx_max_frame - sizeof(struct ntb_payload_header); + rx_chan = qp->rx_dma_chan; + tx_chan = qp->tx_dma_chan; - copy_align = max(qp->tx_dma_chan->device->copy_align, - qp->rx_dma_chan->device->copy_align); + copy_align = max(rx_chan ? rx_chan->device->copy_align : 0, + tx_chan ? tx_chan->device->copy_align : 0); /* If DMA engine usage is possible, try to find the max size for that */ - max = qp->tx_max_frame - sizeof(struct ntb_payload_header); - max -= max % (1 << copy_align); + max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header); + max_size = round_down(max_size, 1 << copy_align); - return max; + return max_size; } EXPORT_SYMBOL_GPL(ntb_transport_max_size); |