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path: root/drivers/spi/spidev.c
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Diffstat (limited to 'drivers/spi/spidev.c')
-rw-r--r--drivers/spi/spidev.c23
1 files changed, 17 insertions, 6 deletions
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index d04242aee40d..c55459c592b8 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -55,9 +55,16 @@
static unsigned long minors[N_SPI_MINORS / BITS_PER_LONG];
-/* Bit masks for spi_device.mode management */
-#define SPI_MODE_MASK (SPI_CPHA | SPI_CPOL)
-
+/* Bit masks for spi_device.mode management. Note that incorrect
+ * settings for CS_HIGH and 3WIRE can cause *lots* of trouble for other
+ * devices on a shared bus: CS_HIGH, because this device will be
+ * active when it shouldn't be; 3WIRE, because when active it won't
+ * behave as it should.
+ *
+ * REVISIT should changing those two modes be privileged?
+ */
+#define SPI_MODE_MASK (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH \
+ | SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP)
struct spidev_data {
struct device dev;
@@ -176,12 +183,15 @@ static int spidev_message(struct spidev_data *spidev,
if (u_tmp->rx_buf) {
k_tmp->rx_buf = buf;
- if (!access_ok(VERIFY_WRITE, u_tmp->rx_buf, u_tmp->len))
+ if (!access_ok(VERIFY_WRITE, (u8 __user *)
+ (ptrdiff_t) u_tmp->rx_buf,
+ u_tmp->len))
goto done;
}
if (u_tmp->tx_buf) {
k_tmp->tx_buf = buf;
- if (copy_from_user(buf, (const u8 __user *)u_tmp->tx_buf,
+ if (copy_from_user(buf, (const u8 __user *)
+ (ptrdiff_t) u_tmp->tx_buf,
u_tmp->len))
goto done;
}
@@ -213,7 +223,8 @@ static int spidev_message(struct spidev_data *spidev,
buf = spidev->buffer;
for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) {
if (u_tmp->rx_buf) {
- if (__copy_to_user((u8 __user *)u_tmp->rx_buf, buf,
+ if (__copy_to_user((u8 __user *)
+ (ptrdiff_t) u_tmp->rx_buf, buf,
u_tmp->len)) {
status = -EFAULT;
goto done;