lkml.org 
[lkml]   [2018]   [Aug]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] USB: core: devio: Restructured proc_ioctl for readability
On Sun, 12 Aug 2018, Tom Todd wrote:

> On, Sun, 12 Aug 2018 11:34:59 -0700 Joe Perches wrote:
> >On Sun, 2018-08-12 at 19:06 +0100, Tom Todd wrote:
> >> Fixed a code styling issue
> >while it's OK to fix style only issues, it's much better
> >to reorganize the code for reader clarity.
>
> Ok, thank you, I've taken your suggestions and created the a new version
>
> Restructured method proc_ioctl for readability and fixed code style
> errors.
>
> Signed-off-by: Tom Todd <thomas.m.a.todd@gmail.com>

"Style fixes" that introduce bugs are quite annoying...

> ---
> drivers/usb/core/devio.c | 67 ++++++++++++++++++++++------------------
> 1 file changed, 37 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
> index 476dcc5f2da3..740e60e086e2 100644
> --- a/drivers/usb/core/devio.c
> +++ b/drivers/usb/core/devio.c
> @@ -2117,46 +2117,52 @@ static int proc_ioctl(struct usb_dev_state *ps, struct usbdevfs_ioctl *ctl)
> /* alloc buffer */
> size = _IOC_SIZE(ctl->ioctl_code);
> if (size > 0) {
> - buf = kmalloc(size, GFP_KERNEL);
> - if (buf == NULL)
> - return -ENOMEM;
> - if ((_IOC_DIR(ctl->ioctl_code) & _IOC_WRITE)) {
> - if (copy_from_user(buf, ctl->data, size)) {
> - kfree(buf);
> + if (_IOC_DIR(ctl->ioctl_code) & _IOC_WRITE) {
> + buf = memdup_user(ctl->data, size);
> + if (!buf)
> return -EFAULT;
> - }
> } else {
> - memset(buf, 0, size);
> + buf = kmalloc(size, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;

Where do the contents of buf get set to 0 now?

> }
> }
>
> if (!connected(ps)) {
> - kfree(buf);
> - return -ENODEV;
> + retval = -ENODEV;
> + goto exit;
> }
>
> - if (ps->dev->state != USB_STATE_CONFIGURED)
> + if (ps->dev->state != USB_STATE_CONFIGURED) {
> retval = -EHOSTUNREACH;
> - else if (!(intf = usb_ifnum_to_if(ps->dev, ctl->ifno)))
> + goto exit;
> + }
> +
> + intf = usb_ifnum_to_if(ps->dev, ctl->ifno);
> + if (!intf) {
> retval = -EINVAL;
> - else switch (ctl->ioctl_code) {
> + goto exit;
> + }
>
> + switch (ctl->ioctl_code) {
> /* disconnect kernel driver from interface */
> case USBDEVFS_DISCONNECT:
> - if (intf->dev.driver) {
> - driver = to_usb_driver(intf->dev.driver);
> - dev_dbg(&intf->dev, "disconnect by usbfs\n");
> - usb_driver_release_interface(driver, intf);
> - } else
> + if (!intf->dev.driver) {
> retval = -ENODATA;
> + goto exit;
> + }
> + driver = to_usb_driver(intf->dev.driver);
> + dev_dbg(&intf->dev, "disconnect by usbfs\n");
> + usb_driver_release_interface(driver, intf);
> break;
>
> /* let kernel drivers try to (re)bind to the interface */
> case USBDEVFS_CONNECT:
> - if (!intf->dev.driver)
> - retval = device_attach(&intf->dev);
> - else
> + if (!intf->dev.driver) {

Now !intf->dev.driver generates an error instead of working?

> retval = -EBUSY;
> + goto exit;
> + }
> + retval = device_attach(&intf->dev);
> break;
>
> /* talk directly to the interface's driver */
> @@ -2165,20 +2171,21 @@ static int proc_ioctl(struct usb_dev_state *ps, struct usbdevfs_ioctl *ctl)
> driver = to_usb_driver(intf->dev.driver);
> if (driver == NULL || driver->unlocked_ioctl == NULL) {
> retval = -ENOTTY;
> - } else {
> - retval = driver->unlocked_ioctl(intf, ctl->ioctl_code, buf);
> - if (retval == -ENOIOCTLCMD)
> - retval = -ENOTTY;
> + goto exit;
> }
> + retval = driver->unlocked_ioctl(intf, ctl->ioctl_code, buf);
> + if (retval == -ENOIOCTLCMD) {
> + retval = -ENOTTY;
> + goto exit;
> + }
> + break;
> }
>
> /* cleanup and return */
> - if (retval >= 0
> - && (_IOC_DIR(ctl->ioctl_code) & _IOC_READ) != 0
> - && size > 0
> - && copy_to_user(ctl->data, buf, size) != 0)
> + if (retval >= 0 && (_IOC_DIR(ctl->ioctl_code) & _IOC_READ) != 0 &&
> + size > 0 && copy_to_user(ctl->data, buf, size) != 0)
> retval = -EFAULT;

Isn't the style in this file to indent continuation lines by two tab
stops?

> -
> +exit:
> kfree(buf);
> return retval;
> }

Alan Stern

\
 
 \ /
  Last update: 2018-08-13 00:47    [W:0.039 / U:13.508 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site