[input:master 1384/1384] drivers/input/evdev.c:719:7: warning: passing argument 1 of 'copy_from_user' discards 'const' qualifier from pointer target type

[input:master 1384/1384] drivers/input/evdev.c:719:7: warning: passing argument 1 of 'copy_from_user' discards 'const' qualifier from pointer target type

[kbuild test robot]

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tree:   https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git master
head:   86f77bf98fdd07cd7e9b65014c5f8d8d233b3449
commit: 86f77bf98fdd07cd7e9b65014c5f8d8d233b3449 [1384/1384] Input: evdev - add event-mask API
config: sparc64-allyesconfig (attached as .config)
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git checkout 86f77bf98fdd07cd7e9b65014c5f8d8d233b3449
        # save the attached .config to linux build tree
        make.cross ARCH=sparc64 

All warnings (new ones prefixed by >>):

   drivers/input/evdev.c: In function 'bits_from_user':
>> drivers/input/evdev.c:719:7: warning: passing argument 1 of 'copy_from_user' discards 'const' qualifier from pointer target type
      if (copy_from_user(p, bits, len))
          ^
   In file included from arch/sparc/include/asm/uaccess.h:4:0,
                    from include/linux/poll.h:11,
                    from drivers/input/evdev.c:18:
   arch/sparc/include/asm/uaccess_64.h:251:1: note: expected 'void *' but argument is of type 'const void *'
    copy_from_user(void *to, const void __user *from, unsigned long size)
    ^

vim +719 drivers/input/evdev.c

   703				if (copy_from_user((compat_long_t *) bits +
   704							i + 1 - ((i % 2) << 1),
   705						   (compat_long_t __user *) p + i,
   706						   sizeof(compat_long_t)))
   707					return -EFAULT;
   708			if (i % 2)
   709				*((compat_long_t *) bits + i - 1) = 0;
   710	
   711		} else {
   712			if (maxlen % sizeof(long))
   713				return -EINVAL;
   714	
   715			len = BITS_TO_LONGS(maxbit) * sizeof(long);
   716			if (len > maxlen)
   717				len = maxlen;
   718	
 > 719			if (copy_from_user(p, bits, len))
   720				return -EFAULT;
   721		}
   722	
   723		return len;
   724	}
   725	
   726	#else
   727	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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Re: [input:master 1384/1384] drivers/input/evdev.c:719:7: warning: passing argument 1 of 'copy_from_user' discards 'const' qualifier from pointer target type

[Dmitry Torokhov]

On Tue, Oct 27, 2015 at 09:52:20AM +0800, kbuild test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git master
> head:   86f77bf98fdd07cd7e9b65014c5f8d8d233b3449
> commit: 86f77bf98fdd07cd7e9b65014c5f8d8d233b3449 [1384/1384] Input: evdev - add event-mask API
> config: sparc64-allyesconfig (attached as .config)
> reproduce:
>         wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         git checkout 86f77bf98fdd07cd7e9b65014c5f8d8d233b3449
>         # save the attached .config to linux build tree
>         make.cross ARCH=sparc64 
> 
> All warnings (new ones prefixed by >>):
> 
>    drivers/input/evdev.c: In function 'bits_from_user':
> >> drivers/input/evdev.c:719:7: warning: passing argument 1 of 'copy_from_user' discards 'const' qualifier from pointer target type
>       if (copy_from_user(p, bits, len))
>           ^
>    In file included from arch/sparc/include/asm/uaccess.h:4:0,
>                     from include/linux/poll.h:11,
>                     from drivers/input/evdev.c:18:
>    arch/sparc/include/asm/uaccess_64.h:251:1: note: expected 'void *' but argument is of type 'const void *'
>     copy_from_user(void *to, const void __user *from, unsigned long size)
>     ^

Should be fixed now.

Thanks.

-- 
Dmitry