Re: [PATCH 04/10] usb: musb: ux500: harden checks for platform data

From: Sergei Shtylyov
Date: Tue Apr 23 2013 - 16:04:41 EST


Hello.

On 04/23/2013 07:03 PM, Lee Jones wrote:

In its current state, the ux500-musb driver uses platform data pointers
blindly with no prior checking. If no platform data pointer is passed
this will Oops the kernel. In this patch we ensure platform data and
board data are present prior to using them.

Cc: Felipe Balbi <balbi@xxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
---
drivers/usb/musb/ux500_dma.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/musb/ux500_dma.c b/drivers/usb/musb/ux500_dma.c
index c75e07a..02b4a6e 100644
--- a/drivers/usb/musb/ux500_dma.c
+++ b/drivers/usb/musb/ux500_dma.c
@@ -287,7 +287,7 @@ static int ux500_dma_controller_start(struct dma_controller *c)
struct musb *musb = controller->private_data;
struct device *dev = musb->controller;
struct musb_hdrc_platform_data *plat = dev->platform_data;
- struct ux500_musb_board_data *data = plat->board_data;
+ struct ux500_musb_board_data *data;
struct dma_channel *dma_channel = NULL;
u32 ch_num;
u8 dir;
@@ -297,14 +297,19 @@ static int ux500_dma_controller_start(struct dma_controller *c)

[...]

/* Prepare the loop for RX channels */
channel_array = controller->rx_channel;
- param_array = data->dma_rx_param_array;
+ param_array = (data) ? data->dma_rx_param_array : NULL;

Why enclose a simple variable in parens?

for (dir = 0; dir < 2; dir++) {
for (ch_num = 0;
@@ -337,7 +342,7 @@ static int ux500_dma_controller_start(struct dma_controller *c)
/* Prepare the loop for TX channels */
channel_array = controller->tx_channel;
- param_array = data->dma_tx_param_array;
+ param_array = (data) ? data->dma_tx_param_array : NULL;

Again, why?

WBR, Sergei

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