On Sat, May 6, 2017 at 5:42 PM, Geliang Tang <geliangt...@gmail.com> wrote:
> Use memdup_user() helper instead of open-coding to simplify the code.
>
> Signed-off-by: Geliang Tang <geliangt...@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+rene...@glider.be>
> --- a/drivers/spi/spidev.c
> +++ b/drivers/spi/spidev.c
> @@ -325,7 +325,6 @@ static struct spi_ioc_transfer *
> spidev_get_ioc_message(unsigned int cmd, struct spi_ioc_transfer __user
> *u_ioc,
> unsigned *n_ioc)
> {
> - struct spi_ioc_transfer *ioc;
> u32 tmp;
>
> /* Check type, command number and direction */
> @@ -342,14 +341,7 @@ spidev_get_ioc_message(unsigned int cmd, struct
> spi_ioc_transfer __user *u_ioc,
> return NULL;
>
> /* copy into scratch area */
> - ioc = kmalloc(tmp, GFP_KERNEL);
> - if (!ioc)
> - return ERR_PTR(-ENOMEM);
> - if (__copy_from_user(ioc, u_ioc, tmp)) {
Note that as memdup_user() calls copy_from_user(), it repeats the access_ok()
check already done by spidev_ioctl().
> - kfree(ioc);
> - return ERR_PTR(-EFAULT);
> - }
> - return ioc;
> + return memdup_user(u_ioc, tmp);
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
