Re: net/can/isotp.c:1240:13: sparse: sparse: incorrect type in initializer (different address spaces)

[Marc Kleine-Budde]

On 12/26/20 8:29 PM, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   f838f8d2b694cf9d524dc4423e9dd2db13892f3f
> commit: e057dd3fc20ffb3d7f150af46542a51b59b90127 can: add ISO 15765-2:2016 transport protocol
> date:   3 months ago
> config: sh-randconfig-s032-20201225 (attached as .config)
> compiler: sh4-linux-gcc (GCC) 9.3.0
> reproduce:
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # apt-get install sparse
>         # sparse version: v0.6.3-184-g1b896707-dirty
>         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e057dd3fc20ffb3d7f150af46542a51b59b90127
>         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>         git fetch --no-tags linus master
>         git checkout e057dd3fc20ffb3d7f150af46542a51b59b90127
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=sh 
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> 
> 
> "sparse warnings: (new ones prefixed by >>)"
>>> net/can/isotp.c:1240:13: sparse: sparse: incorrect type in initializer (different address spaces) @@     expected int const *__gu_addr @@     got int [noderef] __user *optlen @@
>    net/can/isotp.c:1240:13: sparse:     expected int const *__gu_addr
>    net/can/isotp.c:1240:13: sparse:     got int [noderef] __user *optlen
>>> net/can/isotp.c:1240:13: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void const volatile [noderef] __user *ptr @@     got int const *__gu_addr @@
>    net/can/isotp.c:1240:13: sparse:     expected void const volatile [noderef] __user *ptr
>    net/can/isotp.c:1240:13: sparse:     got int const *__gu_addr

From my point of view, it looks like the get_user() on the sh platform is
somehow different to the other platform, which all accept a __user pointer. IMHO
this should be fixed in sh.

> vim +1240 net/can/isotp.c
> 
>   1229	
>   1230	static int isotp_getsockopt(struct socket *sock, int level, int optname,
>   1231				    char __user *optval, int __user *optlen)
>   1232	{
>   1233		struct sock *sk = sock->sk;
>   1234		struct isotp_sock *so = isotp_sk(sk);
>   1235		int len;
>   1236		void *val;
>   1237	
>   1238		if (level != SOL_CAN_ISOTP)
>   1239			return -EINVAL;
>> 1240		if (get_user(len, optlen))

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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