Re: [PATCH v19 2/5] fs/proc/task_mmu: Implement IOCTL to get and optionally clear info about PTEs

[kernel test robot]

Hi Muhammad,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on next-20230615]
[cannot apply to linus/master v6.4-rc6]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Muhammad-Usama-Anjum/userfaultfd-UFFD_FEATURE_WP_ASYNC/20230615-225037
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20230615141144.665148-3-usama.anjum%40collabora.com
patch subject: [PATCH v19 2/5] fs/proc/task_mmu: Implement IOCTL to get and optionally clear info about PTEs
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20230616/202306160006.dNg0cOoc-lkp@xxxxxxxxx/config)
compiler: m68k-linux-gcc (GCC) 12.3.0
reproduce (this is a W=1 build):
        mkdir -p ~/bin
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git remote add akpm-mm https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git
        git fetch akpm-mm mm-everything
        git checkout akpm-mm/mm-everything
        b4 shazam https://lore.kernel.org/r/20230615141144.665148-3-usama.anjum@xxxxxxxxxxxxx
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=m68k olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash fs/proc/

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306160006.dNg0cOoc-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

   In file included from include/asm-generic/bug.h:5,
                    from arch/m68k/include/asm/bug.h:32,
                    from include/linux/bug.h:5,
                    from include/linux/mmdebug.h:5,
                    from include/linux/mm.h:6,
                    from include/linux/pagewalk.h:5,
                    from fs/proc/task_mmu.c:2:
   fs/proc/task_mmu.c: In function 'pagemap_scan_args_valid':
>> fs/proc/task_mmu.c:2148:32: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    2148 |                 if (!access_ok((void __user *)arg->vec,
         |                                ^
   include/linux/compiler.h:76:45: note: in definition of macro 'likely'
      76 | # define likely(x)      __builtin_expect(!!(x), 1)
         |                                             ^
   fs/proc/task_mmu.c:2148:22: note: in expansion of macro 'access_ok'
    2148 |                 if (!access_ok((void __user *)arg->vec,
         |                      ^~~~~~~~~


vim +2148 fs/proc/task_mmu.c

  2115	
  2116	static int pagemap_scan_args_valid(struct pm_scan_arg *arg, unsigned long start,
  2117					   struct page_region __user *vec)
  2118	{
  2119		/* Detect illegal size, flags, len and masks */
  2120		if (arg->size != sizeof(struct pm_scan_arg))
  2121			return -EINVAL;
  2122		if (!arg->flags)
  2123			return -EINVAL;
  2124		if (arg->flags & ~PM_SCAN_OPS)
  2125			return -EINVAL;
  2126		if (!arg->len)
  2127			return -EINVAL;
  2128		if ((arg->required_mask | arg->anyof_mask | arg->excluded_mask |
  2129		     arg->return_mask) & ~PM_SCAN_BITS_ALL)
  2130			return -EINVAL;
  2131		if (!arg->required_mask && !arg->anyof_mask &&
  2132		    !arg->excluded_mask)
  2133			return -EINVAL;
  2134		if (!arg->return_mask)
  2135			return -EINVAL;
  2136	
  2137		/* Validate memory range */
  2138		if (!IS_ALIGNED(start, PAGE_SIZE))
  2139			return -EINVAL;
  2140		if (!access_ok((void __user *)start, arg->len))
  2141			return -EFAULT;
  2142	
  2143		if (IS_PM_SCAN_GET(arg->flags)) {
  2144			if (!arg->vec)
  2145				return -EINVAL;
  2146			if (arg->vec_len == 0)
  2147				return -EINVAL;
> 2148			if (!access_ok((void __user *)arg->vec,
  2149				       arg->vec_len * sizeof(struct page_region)))
  2150				return -EFAULT;
  2151		}
  2152	
  2153		if (IS_PM_SCAN_WP(arg->flags) && !IS_PM_SCAN_GET(arg->flags) &&
  2154		    arg->max_pages)
  2155			return -EINVAL;
  2156	
  2157		return 0;
  2158	}
  2159	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki