spi: coldfire-qspi: Prevent NULL pointer dereference

If pdata->cs_control is NULL, we will hit NULL pointer dereference in
mcfqspi_cs_select() and mcfqspi_cs_deselect(). Thus add NULL test for
pdata->cs_control in probe().

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

diff --git a/drivers/spi/spi-coldfire-qspi.c b/drivers/spi/spi-coldfire-qspi.c
index 94d8175..6d78f96 100644 (file)
--- a/drivers/spi/spi-coldfire-qspi.c
+++ b/drivers/spi/spi-coldfire-qspi.c
@@ -133,13 +133,13 @@ static void mcfqspi_cs_deselect(struct mcfqspi *mcfqspi, u8 chip_select,
 
 static int mcfqspi_cs_setup(struct mcfqspi *mcfqspi)
 {
-       return (mcfqspi->cs_control && mcfqspi->cs_control->setup) ?
+       return (mcfqspi->cs_control->setup) ?
                mcfqspi->cs_control->setup(mcfqspi->cs_control) : 0;
 }
 
 static void mcfqspi_cs_teardown(struct mcfqspi *mcfqspi)
 {
-       if (mcfqspi->cs_control && mcfqspi->cs_control->teardown)
+       if (mcfqspi->cs_control->teardown)
                mcfqspi->cs_control->teardown(mcfqspi->cs_control);
 }
 
@@ -372,6 +372,11 @@ static int mcfqspi_probe(struct platform_device *pdev)
                return -ENOENT;
        }
 
+       if (!pdata->cs_control) {
+               dev_dbg(&pdev->dev, "pdata->cs_control is NULL\n");
+               return -EINVAL;
+       }
+
        master = spi_alloc_master(&pdev->dev, sizeof(*mcfqspi));
        if (master == NULL) {
                dev_dbg(&pdev->dev, "spi_alloc_master failed\n");