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* [PATCH 1/4] tc358743: don't use variable length array for I2C writes
@ 2015-08-11 15:13 Mauro Carvalho Chehab
  0 siblings, 0 replies; 6+ messages in thread
From: Mauro Carvalho Chehab @ 2015-08-11 15:13 UTC (permalink / raw)
  To: Linux Media Mailing List; +Cc: Mauro Carvalho Chehab, Mauro Carvalho Chehab

drivers/media/i2c/tc358743.c:148:19: warning: Variable length array is used.

As the maximum size is 1026, we can't use dynamic var, as it
would otherwise spend 1056 bytes of the stack at i2c_wr() function.

So, allocate a buffer with the allowed maximum size together with
the state var.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
---
 drivers/media/i2c/tc358743.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/tc358743.c b/drivers/media/i2c/tc358743.c
index 2e926317d7e9..fe42c9a1cb78 100644
--- a/drivers/media/i2c/tc358743.c
+++ b/drivers/media/i2c/tc358743.c
@@ -59,6 +59,9 @@ MODULE_LICENSE("GPL");
 #define EDID_NUM_BLOCKS_MAX 8
 #define EDID_BLOCK_SIZE 128
 
+/* Max transfer size done by I2C transfer functions */
+#define MAX_XFER_SIZE  (EDID_NUM_BLOCKS_MAX * EDID_BLOCK_SIZE + 2)
+
 static const struct v4l2_dv_timings_cap tc358743_timings_cap = {
 	.type = V4L2_DV_BT_656_1120,
 	/* keep this initialization for compatibility with GCC < 4.4.6 */
@@ -94,6 +97,9 @@ struct tc358743_state {
 	/* edid  */
 	u8 edid_blocks_written;
 
+	/* used by i2c_wr() */
+	u8 wr_data[MAX_XFER_SIZE];
+
 	struct v4l2_dv_timings timings;
 	u32 mbus_fmt_code;
 
@@ -143,9 +149,13 @@ static void i2c_wr(struct v4l2_subdev *sd, u16 reg, u8 *values, u32 n)
 {
 	struct tc358743_state *state = to_state(sd);
 	struct i2c_client *client = state->i2c_client;
+	u8 *data = state->wr_data;
 	int err, i;
 	struct i2c_msg msg;
-	u8 data[2 + n];
+
+	if ((2 + n) > sizeof(state->wr_data))
+		v4l2_warn(sd, "i2c wr reg=%04x: len=%d is too big!\n",
+			  reg, 2 + n);
 
 	msg.addr = client->addr;
 	msg.buf = data;
-- 
2.4.3


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH 1/4] tc358743: don't use variable length array for I2C writes
@ 2015-08-11 15:18 Mauro Carvalho Chehab
  2015-08-11 15:18 ` [PATCH 2/4] ov9650: remove an extra space Mauro Carvalho Chehab
                   ` (3 more replies)
  0 siblings, 4 replies; 6+ messages in thread
From: Mauro Carvalho Chehab @ 2015-08-11 15:18 UTC (permalink / raw)
  To: Linux Media Mailing List
  Cc: Mauro Carvalho Chehab, Mauro Carvalho Chehab, Mats Randgaard

drivers/media/i2c/tc358743.c:148:19: warning: Variable length array is used.

As the maximum size is 1026, we can't use dynamic var, as it
would otherwise spend 1056 bytes of the stack at i2c_wr() function.

So, allocate a buffer with the allowed maximum size together with
the state var.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/i2c/tc358743.c b/drivers/media/i2c/tc358743.c
index 2e926317d7e9..fe42c9a1cb78 100644
--- a/drivers/media/i2c/tc358743.c
+++ b/drivers/media/i2c/tc358743.c
@@ -59,6 +59,9 @@ MODULE_LICENSE("GPL");
 #define EDID_NUM_BLOCKS_MAX 8
 #define EDID_BLOCK_SIZE 128
 
+/* Max transfer size done by I2C transfer functions */
+#define MAX_XFER_SIZE  (EDID_NUM_BLOCKS_MAX * EDID_BLOCK_SIZE + 2)
+
 static const struct v4l2_dv_timings_cap tc358743_timings_cap = {
 	.type = V4L2_DV_BT_656_1120,
 	/* keep this initialization for compatibility with GCC < 4.4.6 */
@@ -94,6 +97,9 @@ struct tc358743_state {
 	/* edid  */
 	u8 edid_blocks_written;
 
+	/* used by i2c_wr() */
+	u8 wr_data[MAX_XFER_SIZE];
+
 	struct v4l2_dv_timings timings;
 	u32 mbus_fmt_code;
 
@@ -143,9 +149,13 @@ static void i2c_wr(struct v4l2_subdev *sd, u16 reg, u8 *values, u32 n)
 {
 	struct tc358743_state *state = to_state(sd);
 	struct i2c_client *client = state->i2c_client;
+	u8 *data = state->wr_data;
 	int err, i;
 	struct i2c_msg msg;
-	u8 data[2 + n];
+
+	if ((2 + n) > sizeof(state->wr_data))
+		v4l2_warn(sd, "i2c wr reg=%04x: len=%d is too big!\n",
+			  reg, 2 + n);
 
 	msg.addr = client->addr;
 	msg.buf = data;
-- 
2.4.3


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH 2/4] ov9650: remove an extra space
  2015-08-11 15:18 [PATCH 1/4] tc358743: don't use variable length array for I2C writes Mauro Carvalho Chehab
@ 2015-08-11 15:18 ` Mauro Carvalho Chehab
  2015-08-11 15:18 ` [PATCH 3/4] ov2659: get rid of unused values Mauro Carvalho Chehab
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 6+ messages in thread
From: Mauro Carvalho Chehab @ 2015-08-11 15:18 UTC (permalink / raw)
  To: Linux Media Mailing List
  Cc: Mauro Carvalho Chehab, Mauro Carvalho Chehab, Hans Verkuil,
	Prabhakar Lad, Sakari Ailus, Laurent Pinchart, Boris BREZILLON

drivers/media/i2c/ov9650.c:1439 ov965x_detect_sensor() warn: inconsistent indenting

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/i2c/ov9650.c b/drivers/media/i2c/ov9650.c
index 2bc473385c91..e691bba1945b 100644
--- a/drivers/media/i2c/ov9650.c
+++ b/drivers/media/i2c/ov9650.c
@@ -1436,7 +1436,7 @@ static int ov965x_detect_sensor(struct v4l2_subdev *sd)
 	int ret;
 
 	mutex_lock(&ov965x->lock);
-	 __ov965x_set_power(ov965x, 1);
+	__ov965x_set_power(ov965x, 1);
 	usleep_range(25000, 26000);
 
 	/* Check sensor revision */
-- 
2.4.3


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH 3/4] ov2659: get rid of unused values
  2015-08-11 15:18 [PATCH 1/4] tc358743: don't use variable length array for I2C writes Mauro Carvalho Chehab
  2015-08-11 15:18 ` [PATCH 2/4] ov9650: remove an extra space Mauro Carvalho Chehab
@ 2015-08-11 15:18 ` Mauro Carvalho Chehab
  2015-08-11 15:18 ` [PATCH 4/4] sr030pc30: don't read a new pointer Mauro Carvalho Chehab
  2015-08-12 12:24 ` [PATCH 1/4] tc358743: don't use variable length array for I2C writes Mats Randgaard (matrandg)
  3 siblings, 0 replies; 6+ messages in thread
From: Mauro Carvalho Chehab @ 2015-08-11 15:18 UTC (permalink / raw)
  To: Linux Media Mailing List
  Cc: Mauro Carvalho Chehab, Mauro Carvalho Chehab, Prabhakar Lad

Why to store the chosed values for prediv, postdiv and mult if
those won't be used?

drivers/media/i2c/ov2659.c: In function 'ov2659_pll_calc_params':
drivers/media/i2c/ov2659.c:912:35: warning: variable 's_mult' set but not used [-Wunused-but-set-variable]
  u32 s_prediv = 1, s_postdiv = 1, s_mult = 1;
                                   ^
drivers/media/i2c/ov2659.c:912:20: warning: variable 's_postdiv' set but not used [-Wunused-but-set-variable]
  u32 s_prediv = 1, s_postdiv = 1, s_mult = 1;
                    ^
drivers/media/i2c/ov2659.c:912:6: warning: variable 's_prediv' set but not used [-Wunused-but-set-variable]
  u32 s_prediv = 1, s_postdiv = 1, s_mult = 1;
      ^

This is likely some leftover from some past change.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/i2c/ov2659.c b/drivers/media/i2c/ov2659.c
index 6edffc7b74e3..49109f4f5bb4 100644
--- a/drivers/media/i2c/ov2659.c
+++ b/drivers/media/i2c/ov2659.c
@@ -909,7 +909,6 @@ static void ov2659_pll_calc_params(struct ov2659 *ov2659)
 	u8 ctrl1_reg = 0, ctrl2_reg = 0, ctrl3_reg = 0;
 	struct i2c_client *client = ov2659->client;
 	unsigned int desired = pdata->link_frequency;
-	u32 s_prediv = 1, s_postdiv = 1, s_mult = 1;
 	u32 prediv, postdiv, mult;
 	u32 bestdelta = -1;
 	u32 delta, actual;
@@ -929,9 +928,6 @@ static void ov2659_pll_calc_params(struct ov2659 *ov2659)
 
 				if ((delta < bestdelta) || (bestdelta == -1)) {
 					bestdelta = delta;
-					s_mult    = mult;
-					s_prediv  = prediv;
-					s_postdiv = postdiv;
 					ctrl1_reg = ctrl1[i].reg;
 					ctrl2_reg = mult;
 					ctrl3_reg = ctrl3[j].reg;
-- 
2.4.3


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH 4/4] sr030pc30: don't read a new pointer
  2015-08-11 15:18 [PATCH 1/4] tc358743: don't use variable length array for I2C writes Mauro Carvalho Chehab
  2015-08-11 15:18 ` [PATCH 2/4] ov9650: remove an extra space Mauro Carvalho Chehab
  2015-08-11 15:18 ` [PATCH 3/4] ov2659: get rid of unused values Mauro Carvalho Chehab
@ 2015-08-11 15:18 ` Mauro Carvalho Chehab
  2015-08-12 12:24 ` [PATCH 1/4] tc358743: don't use variable length array for I2C writes Mats Randgaard (matrandg)
  3 siblings, 0 replies; 6+ messages in thread
From: Mauro Carvalho Chehab @ 2015-08-11 15:18 UTC (permalink / raw)
  To: Linux Media Mailing List
  Cc: Mauro Carvalho Chehab, Mauro Carvalho Chehab, Hans Verkuil,
	Prabhakar Lad, Guennadi Liakhovetski, Sakari Ailus,
	Boris BREZILLON, Ricardo Ribalda Delgado

sr030pc30_get_fmt() can only succeed if both info->curr_win and
info->curr_fmt are not NULL.

If one of those vars are null, the curent code would call:
	ret = sr030pc30_set_params(sd);

If the curr_win is null, it will return -EINVAL, as it would be
expected. However, if curr_fmt is NULL, the function won't
set it.

The code will then try to read from it:

        mf->code        = info->curr_fmt->code;
        mf->colorspace  = info->curr_fmt->colorspace;

with obviouly won't work.

This got reported by smatch:
	drivers/media/i2c/sr030pc30.c:505 sr030pc30_get_fmt() error: we previously assumed 'info->curr_win' could be null (see line 499)
	drivers/media/i2c/sr030pc30.c:507 sr030pc30_get_fmt() error: we previously assumed 'info->curr_fmt' could be null (see line 499)

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/i2c/sr030pc30.c b/drivers/media/i2c/sr030pc30.c
index 229dc76c44a5..47ebe27cb00e 100644
--- a/drivers/media/i2c/sr030pc30.c
+++ b/drivers/media/i2c/sr030pc30.c
@@ -496,11 +496,8 @@ static int sr030pc30_get_fmt(struct v4l2_subdev *sd,
 
 	mf = &format->format;
 
-	if (!info->curr_win || !info->curr_fmt) {
-		ret = sr030pc30_set_params(sd);
-		if (ret)
-			return ret;
-	}
+	if (!info->curr_win || !info->curr_fmt)
+		return -EINVAL;
 
 	mf->width	= info->curr_win->width;
 	mf->height	= info->curr_win->height;
-- 
2.4.3


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH 1/4] tc358743: don't use variable length array for I2C writes
  2015-08-11 15:18 [PATCH 1/4] tc358743: don't use variable length array for I2C writes Mauro Carvalho Chehab
                   ` (2 preceding siblings ...)
  2015-08-11 15:18 ` [PATCH 4/4] sr030pc30: don't read a new pointer Mauro Carvalho Chehab
@ 2015-08-12 12:24 ` Mats Randgaard (matrandg)
  3 siblings, 0 replies; 6+ messages in thread
From: Mats Randgaard (matrandg) @ 2015-08-12 12:24 UTC (permalink / raw)
  To: Mauro Carvalho Chehab, Linux Media Mailing List; +Cc: Mauro Carvalho Chehab

On 08/11/2015 05:18 PM, Mauro Carvalho Chehab wrote:
> drivers/media/i2c/tc358743.c:148:19: warning: Variable length array is used.
>
> As the maximum size is 1026, we can't use dynamic var, as it
> would otherwise spend 1056 bytes of the stack at i2c_wr() function.
>
> So, allocate a buffer with the allowed maximum size together with
> the state var.
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
>
> diff --git a/drivers/media/i2c/tc358743.c b/drivers/media/i2c/tc358743.c
> index 2e926317d7e9..fe42c9a1cb78 100644
> --- a/drivers/media/i2c/tc358743.c
> +++ b/drivers/media/i2c/tc358743.c
> @@ -59,6 +59,9 @@ MODULE_LICENSE("GPL");
>   #define EDID_NUM_BLOCKS_MAX 8
>   #define EDID_BLOCK_SIZE 128
>   
> +/* Max transfer size done by I2C transfer functions */
> +#define MAX_XFER_SIZE  (EDID_NUM_BLOCKS_MAX * EDID_BLOCK_SIZE + 2)
> +
>   static const struct v4l2_dv_timings_cap tc358743_timings_cap = {
>   	.type = V4L2_DV_BT_656_1120,
>   	/* keep this initialization for compatibility with GCC < 4.4.6 */
> @@ -94,6 +97,9 @@ struct tc358743_state {
>   	/* edid  */
>   	u8 edid_blocks_written;
>   
> +	/* used by i2c_wr() */
> +	u8 wr_data[MAX_XFER_SIZE];
> +
>   	struct v4l2_dv_timings timings;
>   	u32 mbus_fmt_code;
>   
> @@ -143,9 +149,13 @@ static void i2c_wr(struct v4l2_subdev *sd, u16 reg, u8 *values, u32 n)
>   {
>   	struct tc358743_state *state = to_state(sd);
>   	struct i2c_client *client = state->i2c_client;
> +	u8 *data = state->wr_data;
>   	int err, i;
>   	struct i2c_msg msg;
> -	u8 data[2 + n];
> +
> +	if ((2 + n) > sizeof(state->wr_data))
> +		v4l2_warn(sd, "i2c wr reg=%04x: len=%d is too big!\n",
> +			  reg, 2 + n);
>   
>   	msg.addr = client->addr;
>   	msg.buf = data;

Acked-by: Mats Randgaard <matrandg@cisco.com>


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2015-08-12 12:24 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-08-11 15:18 [PATCH 1/4] tc358743: don't use variable length array for I2C writes Mauro Carvalho Chehab
2015-08-11 15:18 ` [PATCH 2/4] ov9650: remove an extra space Mauro Carvalho Chehab
2015-08-11 15:18 ` [PATCH 3/4] ov2659: get rid of unused values Mauro Carvalho Chehab
2015-08-11 15:18 ` [PATCH 4/4] sr030pc30: don't read a new pointer Mauro Carvalho Chehab
2015-08-12 12:24 ` [PATCH 1/4] tc358743: don't use variable length array for I2C writes Mats Randgaard (matrandg)
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2015-08-11 15:13 Mauro Carvalho Chehab

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