drivers/md/md-ctl.c:501:27: warning: variable 'mddev' is uninitialized when used here

drivers/md/md-ctl.c:501:27: warning: variable 'mddev' is uninitialized when used here

[kernel test robot]

tree:   https://github.com/intel-lab-lkp/linux/commits/Abd-Alrhman-Masalkhi/md-make-mddev-lookup-and-ioctl-helpers-non-static/20260928-201223
head:   6b0c58a68cb9e72a888a76dac60d49a88d347118
commit: 6b0c58a68cb9e72a888a76dac60d49a88d347118 md: add a control device for array management
date:   2 days ago
config: arm-randconfig-r2106-20260930 (https://download.01.org/0day-ci/archive/20260930/202609301727.iVitGFeh-lkp@intel.com/config)
compiler: clang version 22.1.8 (https://github.com/llvm/llvm-project ca7933e47d3a3451d81e72ac174dcb5aa28b59d1)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260930/202609301727.iVitGFeh-lkp@intel.com/reproduce)

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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202609301727.iVitGFeh-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/md/md-ctl.c:501:27: warning: variable 'mddev' is uninitialized when used here [-Wuninitialized]
     501 |                 return get_raid_version(mddev, (struct mdu_version64 __user *)u);
         |                                         ^~~~~
   drivers/md/md-ctl.c:492:21: note: initialize the variable 'mddev' to silence this warning
     492 |         struct mddev *mddev;
         |                            ^
         |                             = NULL
   1 warning generated.


vim +/mddev +501 drivers/md/md-ctl.c

   486	
   487	static long md_ctl_ioctl(struct file *filp, uint cmd, ulong u)
   488	{
   489		int err;
   490		unsigned int old_cmd;
   491		unsigned int noio_flags = 0;
   492		struct mddev *mddev;
   493		void __user *arg;
   494		struct mdu_ioctl md_ctl;
   495	
   496		err = ctl_ioctl_valid(cmd);
   497		if (err)
   498			return err;
   499	
   500		if (cmd == MD_RAID_VERSION)
 > 501			return get_raid_version(mddev, (struct mdu_version64 __user *)u);
   502	
   503		if (copy_from_user(&md_ctl, (void __user *)u, sizeof(md_ctl)))
   504			return -EFAULT;
   505	
   506		err = ctl_flags_valid(cmd, md_ctl.flags);
   507		if (err)
   508			return err;
   509	
   510		mddev = ctl_find_mddev(&md_ctl);
   511		if (IS_ERR(mddev))
   512			return PTR_ERR(mddev);
   513	
   514		old_cmd = try_convert_ioctl_cmd(cmd, md_ctl.flags);
   515		if (old_cmd) {
   516			err = md_do_ioctl(mddev->gendisk->part0, 0, old_cmd, md_ctl.arg);
   517			goto out;
   518		}
   519	
   520		arg = (void __user *)md_ctl.arg;
   521		switch (cmd) {
   522		case MD_GET_ARRAY_INFO:
   523			err = ctl_get_array_info(mddev, arg);
   524			goto out;
   525	
   526		case MD_GET_DISK_INFO:
   527			err = ctl_get_disk_info(mddev, arg);
   528			goto out;
   529	
   530		case MD_GET_BITMAP_FILE:
   531			err = ctl_get_bitmap_file(mddev, arg);
   532			goto out;
   533		};
   534	
   535		if (!md_is_rdwr(mddev))
   536			flush_work(&mddev->sync_work);
   537	
   538		err = mddev_suspend_and_lock(mddev);
   539		if (err) {
   540			pr_debug("md: ioctl lock interrupted, reason %d, cmd %d\n",
   541				 err, cmd);
   542			goto out;
   543		}
   544		noio_flags = memalloc_noio_save();
   545	
   546		switch (cmd) {
   547		case MD_SET_ARRAY_INFO:
   548			err = ctl_set_array_info(mddev, arg);
   549			break;
   550	
   551		case MD_ADD_NEW_DISK:
   552			err = ctl_add_new_disk(mddev, arg);
   553			break;
   554		}
   555	
   556		if (mddev->hold_active == UNTIL_IOCTL && err != -EINVAL)
   557			mddev->hold_active = 0;
   558	
   559		memalloc_noio_restore(noio_flags);
   560		mddev_unlock_and_resume(mddev);
   561	out:
   562		mddev_put(mddev);
   563		return err;
   564	}
   565	

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