tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   e45fb347b630ee76482fe938ba76cf8eab811290
commit: 76d62f24db07f22ccf9bc18ca793c27d4ebef721 [14909/15568] pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion
config: microblaze-randconfig-r034-20221218
compiler: microblaze-linux-gcc (GCC) 12.1.0
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://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=76d62f24db07f22ccf9bc18ca793c27d4ebef721
        git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
        git fetch --no-tags linux-next master
        git checkout 76d62f24db07f22ccf9bc18ca793c27d4ebef721
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=microblaze olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=microblaze SHELL=/bin/bash

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

All errors (new ones prefixed by >>):

   microblaze-linux-ld: fs/pstore/pmsg.o: in function `write_pmsg':
>> fs/pstore/pmsg.c:32: undefined reference to `rt_mutex_lock_nested'
>> microblaze-linux-ld: fs/pstore/pmsg.c:34: undefined reference to `rt_mutex_unlock'


vim +32 fs/pstore/pmsg.c

    14	
    15	static ssize_t write_pmsg(struct file *file, const char __user *buf,
    16				  size_t count, loff_t *ppos)
    17	{
    18		struct pstore_record record;
    19		int ret;
    20	
    21		if (!count)
    22			return 0;
    23	
    24		pstore_record_init(&record, psinfo);
    25		record.type = PSTORE_TYPE_PMSG;
    26		record.size = count;
    27	
    28		/* check outside lock, page in any data. write_user also checks */
    29		if (!access_ok(buf, count))
    30			return -EFAULT;
    31	
  > 32		rt_mutex_lock(&pmsg_lock);
    33		ret = psinfo->write_user(&record, buf);
  > 34		rt_mutex_unlock(&pmsg_lock);
    35		return ret ? ret : count;
    36	}
    37	

-- 
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