Re: [PATCH] dm ioct: prevent potential specter v1 gadget

[kernel test robot <lkp@intel.com>]

Hi Jordy,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on device-mapper-dm/for-next]
[also build test ERROR on linux/master linus/master v5.17-rc1 next-20220128]
[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]

url:    https://github.com/0day-ci/linux/commits/Jordy-Zomer/dm-ioct-prevent-potential-specter-v1-gadget/20220129-223840
base:   https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git for-next
config: hexagon-buildonly-randconfig-r001-20220129 (https://download.01.org/0day-ci/archive/20220130/202201300033.eThgyeLo-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 33b45ee44b1f32ffdbc995e6fec806271b4b3ba4)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/494fed5461aa05e0efaf098b57a2a47dc19ba226
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jordy-Zomer/dm-ioct-prevent-potential-specter-v1-gadget/20220129-223840
        git checkout 494fed5461aa05e0efaf098b57a2a47dc19ba226
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash drivers/md/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> drivers/md/dm-ioctl.c:1791:8: error: implicit declaration of function 'array_index_nospec' [-Werror,-Wimplicit-function-declaration]
           cmd = array_index_nospec(cmd, ARRAY_SIZE(_ioctls));
                 ^
   1 error generated.


vim +/array_index_nospec +1791 drivers/md/dm-ioctl.c

  1752	
  1753	/*-----------------------------------------------------------------
  1754	 * Implementation of open/close/ioctl on the special char
  1755	 * device.
  1756	 *---------------------------------------------------------------*/
  1757	static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
  1758	{
  1759		static const struct {
  1760			int cmd;
  1761			int flags;
  1762			ioctl_fn fn;
  1763		} _ioctls[] = {
  1764			{DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
  1765			{DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, remove_all},
  1766			{DM_LIST_DEVICES_CMD, 0, list_devices},
  1767	
  1768			{DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_create},
  1769			{DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_remove},
  1770			{DM_DEV_RENAME_CMD, IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_rename},
  1771			{DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
  1772			{DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
  1773			{DM_DEV_WAIT_CMD, 0, dev_wait},
  1774	
  1775			{DM_TABLE_LOAD_CMD, 0, table_load},
  1776			{DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
  1777			{DM_TABLE_DEPS_CMD, 0, table_deps},
  1778			{DM_TABLE_STATUS_CMD, 0, table_status},
  1779	
  1780			{DM_LIST_VERSIONS_CMD, 0, list_versions},
  1781	
  1782			{DM_TARGET_MSG_CMD, 0, target_message},
  1783			{DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry},
  1784			{DM_DEV_ARM_POLL, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll},
  1785			{DM_GET_TARGET_VERSION, 0, get_target_version},
  1786		};
  1787	
  1788		if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
  1789			return NULL;
  1790	
> 1791		cmd = array_index_nospec(cmd, ARRAY_SIZE(_ioctls));
  1792		*ioctl_flags = _ioctls[cmd].flags;
  1793		return _ioctls[cmd].fn;
  1794	}
  1795	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org