Re: [PATCH] staging/dt3155: make copy_{to/from}_user and put_usertypesafe

From: Simon Horman
Date: Wed Mar 10 2010 - 19:01:19 EST


On Thu, Mar 04, 2010 at 10:20:18AM -0700, H Hartley Sweeten wrote:
> This makes the kernel to user space data transfers typesafe and removes
> a number of unnecessary (void *) casts.

Could you be more specific about what you mean by typesafe?
There still seem to be casts in there. Although fewer than before :-)

> Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
> Cc: Greg Kroah-Hartman <greg@xxxxxxxxx>
> Cc: Scott Smedley <ss@xxxxxxxxxx>
>
> ---
>
> diff --git a/drivers/staging/dt3155/dt3155_drv.c b/drivers/staging/dt3155/dt3155_drv.c
> index a67c622..76c9d94 100644
> --- a/drivers/staging/dt3155/dt3155_drv.c
> +++ b/drivers/staging/dt3155/dt3155_drv.c
> @@ -528,6 +528,7 @@ static int dt3155_ioctl(struct inode *inode,
> unsigned long arg)
> {
> int minor = MINOR(inode->i_rdev); /* What device are we ioctl()'ing? */
> + void __user *up = (void __user *)arg;
>
> if ( minor >= MAXBOARDS || minor < 0 )
> return -ENODEV;
> @@ -554,7 +555,7 @@ static int dt3155_ioctl(struct inode *inode,
>
> {
> struct dt3155_config_s tmp;
> - if (copy_from_user((void *)&tmp, (void *) arg, sizeof(tmp)))
> + if (copy_from_user(&tmp, up, sizeof(tmp)))
> return -EFAULT;
> /* check for valid settings */
> if (tmp.rows > DT3155_MAX_ROWS ||
> @@ -572,8 +573,7 @@ static int dt3155_ioctl(struct inode *inode,
> }
> case DT3155_GET_CONFIG:
> {
> - if (copy_to_user((void *) arg, (void *) &dt3155_status[minor],
> - sizeof(dt3155_status_t) ))
> + if (copy_to_user(up, &dt3155_status[minor], sizeof(dt3155_status_t)))
> return -EFAULT;
> return 0;
> }
> @@ -593,8 +593,7 @@ static int dt3155_ioctl(struct inode *inode,
> return 0;
>
> quick_stop(minor);
> - if (copy_to_user((void *) arg, (void *) &dt3155_status[minor],
> - sizeof(dt3155_status_t)))
> + if (copy_to_user(up, &dt3155_status[minor], sizeof(dt3155_status_t)))
> return -EFAULT;
> return 0;
> }
> @@ -617,8 +616,7 @@ static int dt3155_ioctl(struct inode *inode,
> }
>
> dt3155_init_isr(minor);
> - if (copy_to_user( (void *) arg, (void *) &dt3155_status[minor],
> - sizeof(dt3155_status_t)))
> + if (copy_to_user(up, &dt3155_status[minor], sizeof(dt3155_status_t)))
> return -EFAULT;
> return 0;
> }
> @@ -819,11 +817,11 @@ static ssize_t dt3155_read(struct file *filep, char __user *buf,
> /* make this an offset */
> offset = frame_info_p->addr - dt3155_status[minor].mem_addr;
>
> - put_user(offset, (unsigned int *) buf);
> + put_user(offset, (unsigned int __user *)buf);
> buf += sizeof(u32);
> - put_user( dt3155_status[minor].fbuffer.frame_count, (unsigned int *) buf);
> + put_user( dt3155_status[minor].fbuffer.frame_count, (unsigned int __user *)buf);
> buf += sizeof(u32);
> - put_user(dt3155_status[minor].state, (unsigned int *) buf);
> + put_user(dt3155_status[minor].state, (unsigned int __user *)buf);
> buf += sizeof(u32);
> if (copy_to_user(buf, frame_info_p, sizeof(frame_info_t)))
> return -EFAULT;
> --
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