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authorNicolas Ferre <nicolas.ferre@atmel.com>2012-09-11 17:21:45 +0200
committerVinod Koul <vinod.koul@linux.intel.com>2012-09-14 08:26:40 +0530
commitc456797681db814f4f5b36909e8e94047bf53d9c (patch)
treee50e29b88da24c9145a212611bb4ea249473d263 /drivers/dma
parentc618a9be0e8c0f36baee2560860a0118a428fb26 (diff)
dmaengine: at_hdmac: check that each sg data length is non-null
Avoid the construction of a malformed DMA request sent to the DMA controller. Log message is for debug only because this condition is unlikely to append and may only trigger at driver development time. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Stable <stable@vger.kernel.org> [2.6.31+] Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/at_hdmac.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 6c09e186e96..7ab6e26664a 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -689,6 +689,11 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
mem = sg_dma_address(sg);
len = sg_dma_len(sg);
+ if (unlikely(!len)) {
+ dev_dbg(chan2dev(chan),
+ "prep_slave_sg: sg(%d) data length is zero\n", i);
+ goto err;
+ }
mem_width = 2;
if (unlikely(mem & 3 || len & 3))
mem_width = 0;
@@ -724,6 +729,11 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
mem = sg_dma_address(sg);
len = sg_dma_len(sg);
+ if (unlikely(!len)) {
+ dev_dbg(chan2dev(chan),
+ "prep_slave_sg: sg(%d) data length is zero\n", i);
+ goto err;
+ }
mem_width = 2;
if (unlikely(mem & 3 || len & 3))
mem_width = 0;
@@ -757,6 +767,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
err_desc_get:
dev_err(chan2dev(chan), "not enough descriptors available\n");
+err:
atc_desc_put(atchan, first);
return NULL;
}