Re: [PATCH 6/9] staging: vme_user: return -EFAULT on __copy_*_user errors

From: Dan Carpenter
Date: Tue Jun 23 2015 - 09:51:45 EST


On Tue, Jun 23, 2015 at 03:42:30PM +0300, Dmitry Kalinkin wrote:
> @@ -178,38 +167,24 @@ static ssize_t buffer_to_user(unsigned int minor, char __user *buf,
> size_t count, loff_t *ppos)
> {
> void *image_ptr;
> - ssize_t retval;
>
> image_ptr = image[minor].kern_buf + *ppos;
> + if (__copy_to_user(buf, image_ptr, (unsigned long)count))
> + return -EINVAL;

s/EINVAL/EFAULT/

>
> - retval = __copy_to_user(buf, image_ptr, (unsigned long)count);
> - if (retval != 0) {
> - retval = (count - retval);
> - pr_warn("Partial copy to userspace\n");
> - } else
> - retval = count;
> -
> - /* Return number of bytes successfully read */
> - return retval;
> + return count;
> }
>
> static ssize_t buffer_from_user(unsigned int minor, const char __user *buf,
> size_t count, loff_t *ppos)
> {
> void *image_ptr;
> - size_t retval;
>
> image_ptr = image[minor].kern_buf + *ppos;
> + if (__copy_from_user(image_ptr, buf, (unsigned long)count))
> + return -EINVAL;

s/EINVAL/EFAULT/

>
> - retval = __copy_from_user(image_ptr, buf, (unsigned long)count);
> - if (retval != 0) {
> - retval = (count - retval);
> - pr_warn("Partial copy to userspace\n");
> - } else
> - retval = count;
> -
> - /* Return number of bytes successfully read */
> - return retval;
> + return count;
> }

regards,
dan carpenter

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