diff options
| author | Alexandre Bounine <alexandre.bounine@idt.com> | 2014-07-30 16:08:26 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-08-07 14:30:25 -0700 |
| commit | 7bfa5bfd88fb4c11a78740ea53509cc38b896d84 (patch) | |
| tree | 04bd5ae1a8a15b8308ba00ffdc6334b2c7102896 /drivers/rapidio | |
| parent | 201c26e77bfc4064afc6a630fc336a825047be7b (diff) | |
rapidio/tsi721_dma: fix failure to obtain transaction descriptor
commit 0193ed8225e1a79ed64632106ec3cc81798cb13c upstream.
This is a bug fix for the situation when function tsi721_desc_get() fails
to obtain a free transaction descriptor.
The bug usually results in a memory access crash dump when data transfer
scatter-gather list has more entries than size of hardware buffer
descriptors ring. This fix ensures that error is properly returned to a
caller instead of an invalid entry.
This patch is applicable to kernel versions starting from v3.5.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Cc: Stef van Os <stef.van.os@prodrive-technologies.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/rapidio')
| -rw-r--r-- | drivers/rapidio/devices/tsi721_dma.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/rapidio/devices/tsi721_dma.c b/drivers/rapidio/devices/tsi721_dma.c index 91245f5dbe81..47257b6eea84 100644 --- a/drivers/rapidio/devices/tsi721_dma.c +++ b/drivers/rapidio/devices/tsi721_dma.c @@ -287,6 +287,12 @@ struct tsi721_tx_desc *tsi721_desc_get(struct tsi721_bdma_chan *bdma_chan) "desc %p not ACKed\n", tx_desc); } + if (ret == NULL) { + dev_dbg(bdma_chan->dchan.device->dev, + "%s: unable to obtain tx descriptor\n", __func__); + goto err_out; + } + i = bdma_chan->wr_count_next % bdma_chan->bd_num; if (i == bdma_chan->bd_num - 1) { i = 0; @@ -297,7 +303,7 @@ struct tsi721_tx_desc *tsi721_desc_get(struct tsi721_bdma_chan *bdma_chan) tx_desc->txd.phys = bdma_chan->bd_phys + i * sizeof(struct tsi721_dma_desc); tx_desc->hw_desc = &((struct tsi721_dma_desc *)bdma_chan->bd_base)[i]; - +err_out: spin_unlock_bh(&bdma_chan->lock); return ret; |