Hi Greg,
On Tue, Jun 18, 2019 at 9:17 AM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Thu, Jun 13, 2019 at 08:18:48PM +0900, Yoshihiro Shimoda wrote:
> > To avoid the error-proneness of calls to sizeof() in the memcpy,
> > this patch uses struct assignment instead of memcpy.
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> > ---
> > This patch is based on Greg's linux-usb.git / usb-next branch.
> > Note that mod_host.c also has memcpy but we cannot use struct assignment
> > for it because the type of urb->setup_patcket is just "unsigned char *".
> >
> > drivers/usb/renesas_usbhs/common.c | 13 ++++---------
> > 1 file changed, 4 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/usb/renesas_usbhs/common.c b/drivers/usb/renesas_usbhs/common.c
> > index a501ea6..ebbe322 100644
> > --- a/drivers/usb/renesas_usbhs/common.c
> > +++ b/drivers/usb/renesas_usbhs/common.c
> > @@ -651,9 +651,8 @@ static struct renesas_usbhs_platform_info *usbhs_parse_dt(struct device *dev)
> > return NULL;
> >
> > dparam = &info->driver_param;
> > - memcpy(dparam, &data->param, sizeof(data->param));
> > - memcpy(&info->platform_callback, data->platform_callback,
> > - sizeof(*data->platform_callback));
> > + *dparam = data->param;
> > + info->platform_callback = *data->platform_callback;
>
> How are the original calls here "error-prone"? Yes, the compiler will
> end up calling memcpy somehow with this change, but it feels "wrong" to
> hide a memory copy like this.
There are no checks that:
- the source and destination pointers point to the same type,
- the passed size matches the actual object size.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
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
