Re: [PATCH 2/7] drivers/staging: Return -ENOMEM on memory allocationfailure

[Julia Lawall]

On Fri, 15 Oct 2010, walter harms wrote:

> This looks like a case for kasprintf().

OK, I will take a look at it.

julia

> re
>  wh
> 
> Julia Lawall schrieb:
> > From: Julia Lawall <julia@xxxxxxx>
> > 
> > Each of these functions defines a variable err and a variable retval.  err
> > is always 0 and is returned in the error case.  At one point near the end
> > of the function, retval is initialized to an error code.  For each
> > function, the patch drops err, stores -ENOMEM in retval in two cases where
> > memory allocation fails, and changes the return value in the error case
> > from err to retval.
> > 
> > A simplified version of the semantic match that finds this problem is as
> > follows: (http://coccinelle.lip6.fr/)
> > 
> > // <smpl>
> > @@
> > expression ret;
> > expression x,e1,e2,e3;
> > @@
> > 
> > ret = 0
> > ... when != ret = e1
> > *x = \(kmalloc\|kcalloc\|kzalloc\)(...)
> > ... when != ret = e2
> > if (x == NULL) { ... when != ret = e3
> >   return ret;
> > }
> > // </smpl>
> > 
> > Signed-off-by: Julia Lawall <julia@xxxxxxx>
> > 
> > ---
> >  drivers/staging/cx25821/cx25821-audio-upstream.c     |   11 +++++++----
> >  drivers/staging/cx25821/cx25821-video-upstream-ch2.c |   11 +++++++----
> >  drivers/staging/cx25821/cx25821-video-upstream.c     |   11 +++++++----
> >  3 files changed, 21 insertions(+), 12 deletions(-)
> > 
> > diff -u -p a/drivers/staging/cx25821/cx25821-audio-upstream.c b/drivers/staging/cx25821/cx25821-audio-upstream.c
> > --- a/drivers/staging/cx25821/cx25821-audio-upstream.c
> > +++ b/drivers/staging/cx25821/cx25821-audio-upstream.c
> > @@ -723,7 +723,6 @@ int cx25821_audio_upstream_init(struct c
> >  {
> >  	struct sram_channel *sram_ch;
> >  	int retval = 0;
> > -	int err = 0;
> >  	int str_length = 0;
> >  
> >  	if (dev->_audio_is_running) {
> > @@ -756,8 +755,10 @@ int cx25821_audio_upstream_init(struct c
> >  		str_length = strlen(dev->input_audiofilename);
> >  		dev->_audiofilename = kmalloc(str_length + 1, GFP_KERNEL);
> >  
> > -		if (!dev->_audiofilename)
> > +		if (!dev->_audiofilename) {
> > +			retval = -ENOMEM;
> >  			goto error;
> > +		}
> >  
> >  		memcpy(dev->_audiofilename, dev->input_audiofilename,
> >  		       str_length + 1);
> > @@ -770,8 +771,10 @@ int cx25821_audio_upstream_init(struct c
> >  		str_length = strlen(_defaultAudioName);
> >  		dev->_audiofilename = kmalloc(str_length + 1, GFP_KERNEL);
> >  
> > -		if (!dev->_audiofilename)
> > +		if (!dev->_audiofilename) {
> > +			retval = -ENOMEM;
> >  			goto error;
> > +		}
> >  
> >  		memcpy(dev->_audiofilename, _defaultAudioName, str_length + 1);
> >  	}
> > @@ -802,5 +805,5 @@ int cx25821_audio_upstream_init(struct c
> >  error:
> >  	cx25821_dev_unregister(dev);
> >  
> > -	return err;
> > +	return retval;
> >  }
> > diff -u -p a/drivers/staging/cx25821/cx25821-video-upstream-ch2.c b/drivers/staging/cx25821/cx25821-video-upstream-ch2.c
> > --- a/drivers/staging/cx25821/cx25821-video-upstream-ch2.c
> > +++ b/drivers/staging/cx25821/cx25821-video-upstream-ch2.c
> > @@ -747,7 +747,6 @@ int cx25821_vidupstream_init_ch2(struct 
> >  	struct sram_channel *sram_ch;
> >  	u32 tmp;
> >  	int retval = 0;
> > -	int err = 0;
> >  	int data_frame_size = 0;
> >  	int risc_buffer_size = 0;
> >  	int str_length = 0;
> > @@ -792,8 +791,10 @@ int cx25821_vidupstream_init_ch2(struct 
> >  		str_length = strlen(dev->input_filename_ch2);
> >  		dev->_filename_ch2 = kmalloc(str_length + 1, GFP_KERNEL);
> >  
> > -		if (!dev->_filename_ch2)
> > +		if (!dev->_filename_ch2) {
> > +			retval = -ENOMEM;
> >  			goto error;
> > +		}
> >  
> >  		memcpy(dev->_filename_ch2, dev->input_filename_ch2,
> >  		       str_length + 1);
> > @@ -801,8 +802,10 @@ int cx25821_vidupstream_init_ch2(struct 
> >  		str_length = strlen(dev->_defaultname_ch2);
> >  		dev->_filename_ch2 = kmalloc(str_length + 1, GFP_KERNEL);
> >  
> > -		if (!dev->_filename_ch2)
> > +		if (!dev->_filename_ch2) {
> > +			retval = -ENOMEM;
> >  			goto error;
> > +		}
> >  
> >  		memcpy(dev->_filename_ch2, dev->_defaultname_ch2,
> >  		       str_length + 1);
> > @@ -851,5 +854,5 @@ int cx25821_vidupstream_init_ch2(struct 
> >        error:
> >  	cx25821_dev_unregister(dev);
> >  
> > -	return err;
> > +	return retval;
> >  }
> > diff -u -p a/drivers/staging/cx25821/cx25821-video-upstream.c b/drivers/staging/cx25821/cx25821-video-upstream.c
> > --- a/drivers/staging/cx25821/cx25821-video-upstream.c
> > +++ b/drivers/staging/cx25821/cx25821-video-upstream.c
> > @@ -800,7 +800,6 @@ int cx25821_vidupstream_init_ch1(struct 
> >  	struct sram_channel *sram_ch;
> >  	u32 tmp;
> >  	int retval = 0;
> > -	int err = 0;
> >  	int data_frame_size = 0;
> >  	int risc_buffer_size = 0;
> >  	int str_length = 0;
> > @@ -844,16 +843,20 @@ int cx25821_vidupstream_init_ch1(struct 
> >  		str_length = strlen(dev->input_filename);
> >  		dev->_filename = kmalloc(str_length + 1, GFP_KERNEL);
> >  
> > -		if (!dev->_filename)
> > +		if (!dev->_filename) {
> > +			retval = -ENOMEM;
> >  			goto error;
> > +		}
> >  
> >  		memcpy(dev->_filename, dev->input_filename, str_length + 1);
> >  	} else {
> >  		str_length = strlen(dev->_defaultname);
> >  		dev->_filename = kmalloc(str_length + 1, GFP_KERNEL);
> >  
> > -		if (!dev->_filename)
> > +		if (!dev->_filename) {
> > +			retval = -ENOMEM;
> >  			goto error;
> > +		}
> >  
> >  		memcpy(dev->_filename, dev->_defaultname, str_length + 1);
> >  	}
> > @@ -908,5 +911,5 @@ int cx25821_vidupstream_init_ch1(struct 
> >  error:
> >  	cx25821_dev_unregister(dev);
> >  
> > -	return err;
> > +	return retval;
> >  }
> > --
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> > 
> > 
> 
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