Re: [PATCH] staging: goldfish_audio.c: sparse warning of incorrect type

2014-09-01 Thread Alan Cox 
On Sun, 2014-08-31 at 13:02 -0700, Greg Kroah-Hartman wrote:
> Adding Alan Cox, as he pushed this driver upstream...

It's sort of a false positive. The existing code will work fine. 

Arguably all of this should be using the dma_ APIs.

Alan


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Re: [PATCH] staging: goldfish_audio.c: sparse warning of incorrect type

2014-09-01 Thread Sudip Mukherjee 
On Mon, Sep 01, 2014 at 12:35:14PM +0300, Dan Carpenter wrote:
> On Sun, Aug 31, 2014 at 09:46:22PM +0530, Sudip Mukherjee wrote:
> > @@ -133,9 +134,15 @@ static ssize_t goldfish_audio_read(struct file *fp, 
> > char __user *buf,
> > AUDIO_READ_BUFFER_AVAILABLE);
> >  
> > /* copy data to user space */
> > -   if (copy_to_user(buf, data->read_buffer, length))
> > +   buffer = kzalloc(length, GFP_KERNEL);
> > +   if (buffer == NULL)
> > +   return -ENOMEM;
> > +   memcpy_fromio(buffer, data->read_buffer, length);
> > +   if (copy_to_user((void __user *)buf, buffer, length)) {
>  ^^^
> This cast shouldn't be needed.
> 
> regards,
> dan carpenter
> 

yes , its not needed . I just checked it again after removing the cast. 
Actually I gave it as sparse was showing warning for argument 1 also. I should 
have rechecked it after fixing the warning for argument2. Sorry for it.
Anyways, if Alan confirms that this patch is actually needed then I will 
resubmit a modified patch.

thanks
Sudip
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Re: [PATCH] staging: goldfish_audio.c: sparse warning of incorrect type

2014-09-01 Thread Dan Carpenter 
On Sun, Aug 31, 2014 at 09:46:22PM +0530, Sudip Mukherjee wrote:
> @@ -133,9 +134,15 @@ static ssize_t goldfish_audio_read(struct file *fp, char 
> __user *buf,
>   AUDIO_READ_BUFFER_AVAILABLE);
>  
>   /* copy data to user space */
> - if (copy_to_user(buf, data->read_buffer, length))
> + buffer = kzalloc(length, GFP_KERNEL);
> + if (buffer == NULL)
> + return -ENOMEM;
> + memcpy_fromio(buffer, data->read_buffer, length);
> + if (copy_to_user((void __user *)buf, buffer, length)) {
 ^^^
This cast shouldn't be needed.

regards,
dan carpenter

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Re: [PATCH] staging: goldfish_audio.c: sparse warning of incorrect type

2014-08-31 Thread Greg Kroah-Hartman 
Adding Alan Cox, as he pushed this driver upstream...

On Sun, Aug 31, 2014 at 09:46:22PM +0530, Sudip Mukherjee wrote:
> fixed sparse warning of incorrect type in argument 1 and incorrect type in 
> argument 2
> it was directly dereferencing a __iomem pointer , which will work in x86 but 
> will fail in other architectures.

Please wrap your changelog comments at 72 columns...

> Signed-off-by: Sudip Mukherjee 
> ---
> 
> hi,
> can you please reveiew the patch and check if the approach is correct. If it 
> is correct then I can send another patch to correct the other similar 
> warnings present in this file. 

I don't think this is correct, because:

> 
>  drivers/staging/goldfish/goldfish_audio.c | 11 +--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/goldfish/goldfish_audio.c 
> b/drivers/staging/goldfish/goldfish_audio.c
> index c89d0b8..f9a13e7 100644
> --- a/drivers/staging/goldfish/goldfish_audio.c
> +++ b/drivers/staging/goldfish/goldfish_audio.c
> @@ -118,6 +118,7 @@ static ssize_t goldfish_audio_read(struct file *fp, char 
> __user *buf,
>   struct goldfish_audio *data = fp->private_data;
>   int length;
>   int result = 0;
> + void *buffer;
>  
>   if (!data->read_supported)
>   return -ENODEV;
> @@ -133,9 +134,15 @@ static ssize_t goldfish_audio_read(struct file *fp, char 
> __user *buf,
>   AUDIO_READ_BUFFER_AVAILABLE);
>  
>   /* copy data to user space */
> - if (copy_to_user(buf, data->read_buffer, length))
> + buffer = kzalloc(length, GFP_KERNEL);
> + if (buffer == NULL)
> + return -ENOMEM;
> + memcpy_fromio(buffer, data->read_buffer, length);
> + if (copy_to_user((void __user *)buf, buffer, length)) {
> + kfree(buffer);
>   return -EFAULT;
> -
> + }
> + kfree(buffer);

The goldfish platform is an "emulator" so iomem is (or should be?) the
same as "normal" memory here.  So I think this is a false-positive.

But I could be totally wrong here, Alan?

thanks,

greg k-h
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[PATCH] staging: goldfish_audio.c: sparse warning of incorrect type

2014-08-31 Thread Sudip Mukherjee 
fixed sparse warning of incorrect type in argument 1 and incorrect type in 
argument 2
it was directly dereferencing a __iomem pointer , which will work in x86 but 
will fail in other architectures.

Signed-off-by: Sudip Mukherjee 
---

hi,
can you please reveiew the patch and check if the approach is correct. If it is 
correct then I can send another patch to correct the other similar warnings 
present in this file. 

 drivers/staging/goldfish/goldfish_audio.c | 11 +--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/goldfish/goldfish_audio.c 
b/drivers/staging/goldfish/goldfish_audio.c
index c89d0b8..f9a13e7 100644
--- a/drivers/staging/goldfish/goldfish_audio.c
+++ b/drivers/staging/goldfish/goldfish_audio.c
@@ -118,6 +118,7 @@ static ssize_t goldfish_audio_read(struct file *fp, char 
__user *buf,
struct goldfish_audio *data = fp->private_data;
int length;
int result = 0;
+   void *buffer;
 
if (!data->read_supported)
return -ENODEV;
@@ -133,9 +134,15 @@ static ssize_t goldfish_audio_read(struct file *fp, char 
__user *buf,
AUDIO_READ_BUFFER_AVAILABLE);
 
/* copy data to user space */
-   if (copy_to_user(buf, data->read_buffer, length))
+   buffer = kzalloc(length, GFP_KERNEL);
+   if (buffer == NULL)
+   return -ENOMEM;
+   memcpy_fromio(buffer, data->read_buffer, length);
+   if (copy_to_user((void __user *)buf, buffer, length)) {
+   kfree(buffer);
return -EFAULT;
-
+   }
+   kfree(buffer);
result += length;
buf += length;
count -= length;
-- 
1.8.1.2

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