linux-4.16-rc1/drivers/misc/ocxl/file.c:320:broken error checking ?

linux-4.16-rc1/drivers/misc/ocxl/file.c:320:broken error checking ?

[David Binderman]

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Hello there,


linux-4.16-rc1/drivers/misc/ocxl/file.c:320]: (style) Checking if unsigned variable 'used' is less than zero.

Source code is


       used = append_xsl_error(ctx, &header, buf + sizeof(header));
        if (used < 0)
            return used;

Suggest put return value from function into signed variable, sanity check it,

then assign it to an unsigned variable.


Also, use of the gcc compiler flag -Wtype-limits will show up this kind of problem in future.


Regards


David Binderman


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Re: linux-4.16-rc1/drivers/misc/ocxl/file.c:320:broken error checking ?

[Frederic Barrat]

Le 12/02/2018 à 09:58, David Binderman a écrit :
> Hello there,
> 
> 
> linux-4.16-rc1/drivers/misc/ocxl/file.c:320]: (style) Checking if 
> unsigned variable 'used' is less than zero.
> 
> Source code is
> 
> 
>         used = append_xsl_error(ctx, &header, buf + sizeof(header));
>          if (used < 0)
>              return used;
> 
> Suggest put return value from function into signed variable, sanity 
> check it,
> 
> then assign it to an unsigned variable.
> 
> 
> Also, use of the gcc compiler flag -Wtype-limits will show up this kind 
> of problem in future.

Thanks for reporting it. A patch to address it is working its way up and 
should land in the next rc release.

   Fred


> 
> Regards
> 
> 
> David Binderman
> 
>