[patch] Staging: cx25821: off by on in cx25821_vidioc_s_input()

[patch] Staging: cx25821: off by on in cx25821_vidioc_s_input()

[Dan Carpenter]

If "i" is 2 then when we call cx25821_video_mux() we'd end up going
past the end of the cx25821_boards[dev->board]->input[].

The INPUT() macro obfuscates what's going on in that function so it's
a bit hard to follow.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
I don't have this hardware, so I can't actually test this.  Please
review this carefully.

diff --git a/drivers/staging/cx25821/cx25821-video.c b/drivers/staging/cx25821/cx25821-video.c
index 084fc08..acd7c4b 100644
--- a/drivers/staging/cx25821/cx25821-video.c
+++ b/drivers/staging/cx25821/cx25821-video.c
@@ -1312,7 +1312,7 @@ int cx25821_vidioc_s_input(struct file *file, void *priv, unsigned int i)
 			return err;
 	}
 
-	if (i > 2) {
+	if (i >= 2) {
 		dprintk(1, "%s(): -EINVAL\n", __func__);
 		return -EINVAL;
 	}

Re: [patch] Staging: cx25821: off by on in cx25821_vidioc_s_input()

[Mauro Carvalho Chehab]

Hi Dan,

Em 07-10-2011 10:26, Dan Carpenter escreveu:
> If "i" is 2 then when we call cx25821_video_mux() we'd end up going
> past the end of the cx25821_boards[dev->board]->input[].
> 
> The INPUT() macro obfuscates what's going on in that function so it's
> a bit hard to follow.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> I don't have this hardware, so I can't actually test this.  Please
> review this carefully.
> 
> diff --git a/drivers/staging/cx25821/cx25821-video.c b/drivers/staging/cx25821/cx25821-video.c
> index 084fc08..acd7c4b 100644
> --- a/drivers/staging/cx25821/cx25821-video.c
> +++ b/drivers/staging/cx25821/cx25821-video.c
> @@ -1312,7 +1312,7 @@ int cx25821_vidioc_s_input(struct file *file, void *priv, unsigned int i)
>  			return err;
>  	}
>  
> -	if (i > 2) {
> +	if (i >= 2) {

It would be better to add a NUM_INPUT macro (or something like that, defined together
with the INPUT macro) that would do an ARRAY_SIZE(cx25821_boards) and use it here, 
instead of a "2" magic number.

Thanks,
Mauro

>  		dprintk(1, "%s(): -EINVAL\n", __func__);
>  		return -EINVAL;
>  	}
> --
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Re: [patch] Staging: cx25821: off by on in cx25821_vidioc_s_input()

[Dan Carpenter]

On Tue, Oct 11, 2011 at 05:59:25PM -0300, Mauro Carvalho Chehab wrote:
> > -	if (i > 2) {
> > +	if (i >= 2) {
> 
> It would be better to add a NUM_INPUT macro (or something like that, defined together
> with the INPUT macro) that would do an ARRAY_SIZE(cx25821_boards) and use it here, 
> instead of a "2" magic number.

You're right.  The hard coded 2 is not helpful...  Why not just an:

	if (i >= ARRAY_SIZE(cx25821_boards)) {...

I'll send a patch to do that.

regards,
dan carpenter

Re: [patch] Staging: cx25821: off by on in cx25821_vidioc_s_input()

[Dan Carpenter]

Never mind.  I figured out what you meant.  I've fixed my patch and
I will send v2 this evening.

regards,
dan carpenter

[patch v2] Staging: cx25821: off by one in cx25821_vidioc_s_input()

[Dan Carpenter]

If "i" is 2 then when we call cx25821_video_mux() we'd end up going
past the end of the cx25821_boards[dev->board]->input[].

The INPUT() macro obfuscates what's going on in that function so it's
a bit hard to follow.  And as Mauro points out the hard coded 2 is
not very helpful.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: Use a define instead of the hard coded number 2

diff --git a/drivers/staging/cx25821/cx25821-video.c b/drivers/staging/cx25821/cx25821-video.c
index 084fc08..4d6907c 100644
--- a/drivers/staging/cx25821/cx25821-video.c
+++ b/drivers/staging/cx25821/cx25821-video.c
@@ -1312,7 +1312,7 @@ int cx25821_vidioc_s_input(struct file *file, void *priv, unsigned int i)
 			return err;
 	}
 
-	if (i > 2) {
+	if (i >= CX25821_NR_INPUT) {
 		dprintk(1, "%s(): -EINVAL\n", __func__);
 		return -EINVAL;
 	}
diff --git a/drivers/staging/cx25821/cx25821.h b/drivers/staging/cx25821/cx25821.h
index db2615b..2d2d009 100644
--- a/drivers/staging/cx25821/cx25821.h
+++ b/drivers/staging/cx25821/cx25821.h
@@ -98,6 +98,7 @@
 #define CX25821_BOARD_CONEXANT_ATHENA10 1
 #define MAX_VID_CHANNEL_NUM     12
 #define VID_CHANNEL_NUM 8
+#define CX25821_NR_INPUT 2
 
 struct cx25821_fmt {
 	char *name;
@@ -196,7 +197,7 @@ struct cx25821_board {
 	unsigned char radio_addr;
 
 	u32 clk_freq;
-	struct cx25821_input input[2];
+	struct cx25821_input input[CX25821_NR_INPUT];
 };
 
 struct cx25821_subid {