Re: [PATCH 1/1] drivers/staging/pi433: New driver (fwd)

Marcus Wolf
2017-07-16T07:44:11Z

Hi Julia,

thank you very much for your investigation!

I totally agree - on line 894 device->dev must not be used. Any suggestions? Is
there a kind of generic value, I can pass as first argument of dev_dbg() in such
cases? Or switch to printk()?

Regarding second bug:
line 688 modified as follows:
if (bytes_received > 0)
and line 654 modified as follows:
int bytes_received;
The fix will already be included in my next try, to send a well formatted patch
to Greg.

the position of the brackets is wrong throughout the complete source. The source
was developed against an other style guide. It's one of the todos to adjust the
formatting that it fully complies with the kernel coding style guide.

Cheers,

Marcus

> Julia Lawall <julia.lawall@lip6.fr> hat am 15. Juli 2017 um 22:50 geschrieben:
>
>
> Please check on lines 894 and 688 (not shown) for the issues mentioned
> below.
>
> Note that the ifs and {s in the following code snippet don't always follow
> the kernel coding style, eg on line 901.
>
> julia
>
> ---------- Forwarded message ----------
> Date: Sun, 16 Jul 2017 04:35:49 +0800
> From: kbuild test robot <fengguang.wu@intel.com>
> To: kbuild@01.org
> Cc: Julia Lawall <julia.lawall@lip6.fr>
> Subject: Re: [PATCH 1/1] drivers/staging/pi433: New driver
>
> Hi Wolf,
>
> [auto build test WARNING on staging/staging-testing]
> [also build test WARNING on v4.12 next-20170714]
> [if your patch is applied to the wrong git tree, please drop us a note to help
> improve the system]
>
> url:
> https://github.com/0day-ci/linux/commits/Wolf-Entwicklungen/drivers-staging-pi433-New-driver/20170716-021625
> :::::: branch date: 2 hours ago
> :::::: commit date: 2 hours ago
>
> >> drivers/staging/pi433/pi433_if.c:894:18-21: ERROR: device is NULL but
> >> dereferenced.
> --
> >> drivers/staging/pi433/pi433_if.c:688:5-19: WARNING: Unsigned expression
> >> compared with zero: bytes_received >= 0
>
> git remote add linux-review https://github.com/0day-ci/linux
> git remote update linux-review
> git checkout 6b5d85fc273ec7c19addf7770155414da647de7e
> vim +894 drivers/staging/pi433/pi433_if.c
>
> 6b5d85fc Wolf Entwicklungen 2017-07-15 883
> 6b5d85fc Wolf Entwicklungen 2017-07-15 884 static int pi433_open(struct inode
> *inode, struct file *filp)
> 6b5d85fc Wolf Entwicklungen 2017-07-15 885 {
> 6b5d85fc Wolf Entwicklungen 2017-07-15 886 struct pi433_device *device;
> 6b5d85fc Wolf Entwicklungen 2017-07-15 887 struct pi433_instance *instance;
> 6b5d85fc Wolf Entwicklungen 2017-07-15 888
> 6b5d85fc Wolf Entwicklungen 2017-07-15 889 mutex_lock(&minor_lock);
> 6b5d85fc Wolf Entwicklungen 2017-07-15 890 device = idr_find(&pi433_idr,
> iminor(inode));
> 6b5d85fc Wolf Entwicklungen 2017-07-15 891
> 6b5d85fc Wolf Entwicklungen 2017-07-15 892 mutex_unlock(&minor_lock);
> 6b5d85fc Wolf Entwicklungen 2017-07-15 893 if (!device) {
> 6b5d85fc Wolf Entwicklungen 2017-07-15 @894 dev_dbg(device->dev, "device:
> minor %d unknown.\n", iminor(inode));
> 6b5d85fc Wolf Entwicklungen 2017-07-15 895 return -ENODEV;
> 6b5d85fc Wolf Entwicklungen 2017-07-15 896 }
> 6b5d85fc Wolf Entwicklungen 2017-07-15 897
> 6b5d85fc Wolf Entwicklungen 2017-07-15 898 if (!device->rx_buffer) {
> 6b5d85fc Wolf Entwicklungen 2017-07-15 899 device->rx_buffer =
> kmalloc(MAX_MSG_SIZE, GFP_KERNEL);
> 6b5d85fc Wolf Entwicklungen 2017-07-15 900 if (!device->rx_buffer)
> 6b5d85fc Wolf Entwicklungen 2017-07-15 901 {
> 6b5d85fc Wolf Entwicklungen 2017-07-15 902 dev_dbg(device->dev,
> "open/ENOMEM\n");
> 6b5d85fc Wolf Entwicklungen 2017-07-15 903 return -ENOMEM;
> 6b5d85fc Wolf Entwicklungen 2017-07-15 904 }
> 6b5d85fc Wolf Entwicklungen 2017-07-15 905 }
> 6b5d85fc Wolf Entwicklungen 2017-07-15 906
> 6b5d85fc Wolf Entwicklungen 2017-07-15 907 device->users++;
> 6b5d85fc Wolf Entwicklungen 2017-07-15 908 instance =
> kzalloc(sizeof(*instance), GFP_KERNEL);
> 6b5d85fc Wolf Entwicklungen 2017-07-15 909 if (!instance)
> 6b5d85fc Wolf Entwicklungen 2017-07-15 910 {
> 6b5d85fc Wolf Entwicklungen 2017-07-15 911 kfree(device->rx_buffer);
> 6b5d85fc Wolf Entwicklungen 2017-07-15 912 device->rx_buffer = NULL;
> 6b5d85fc Wolf Entwicklungen 2017-07-15 913 return -ENOMEM;
> 6b5d85fc Wolf Entwicklungen 2017-07-15 914 }
> 6b5d85fc Wolf Entwicklungen 2017-07-15 915
> 6b5d85fc Wolf Entwicklungen 2017-07-15 916 /* setup instance data*/
> 6b5d85fc Wolf Entwicklungen 2017-07-15 917 instance->device = device;
> 6b5d85fc Wolf Entwicklungen 2017-07-15 918 instance->tx_cfg.bit_rate = 4711;
> 6b5d85fc Wolf Entwicklungen 2017-07-15 919 // TODO: fill instance->tx_cfg;
> 6b5d85fc Wolf Entwicklungen 2017-07-15 920
> 6b5d85fc Wolf Entwicklungen 2017-07-15 921 /* instance data as context */
> 6b5d85fc Wolf Entwicklungen 2017-07-15 922 filp->private_data = instance;
> 6b5d85fc Wolf Entwicklungen 2017-07-15 923 nonseekable_open(inode, filp);
> 6b5d85fc Wolf Entwicklungen 2017-07-15 924
> 6b5d85fc Wolf Entwicklungen 2017-07-15 925 return 0;
> 6b5d85fc Wolf Entwicklungen 2017-07-15 926 }
> 6b5d85fc Wolf Entwicklungen 2017-07-15 927
>
> ---
> 0-DAY kernel test infrastructure Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all Intel Corporation
>