[amir73il:sb_write_barrier 19/30] include/linux/fsnotify.h:126:3: warning: variable 'fsnotify_mask' is uninitialized when used here

From: kernel test robot <lkp@intel.com>
To: Amir Goldstein <amir73il@gmail.com>
Cc: oe-kbuild-all@lists.linux.dev
Subject: [amir73il:sb_write_barrier 19/30] include/linux/fsnotify.h:126:3: warning: variable 'fsnotify_mask' is uninitialized when used here
Date: Fri, 21 Jul 2023 11:18:17 +0800	[thread overview]
Message-ID: <202307211105.zGLTcrGx-lkp@intel.com> (raw)

tree:   https://github.com/amir73il/linux sb_write_barrier
head:   bf9a41c874c7b090a3eb10204ac607fde16fdfb3
commit: 96f25a6844cc4a544a7003caee9e966c6e7f0195 [19/30] fsnotify: introduce pre-content permission event
config: x86_64-randconfig-r011-20230720 (https://download.01.org/0day-ci/archive/20230721/202307211105.zGLTcrGx-lkp@intel.com/config)
compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project.git 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
reproduce: (https://download.01.org/0day-ci/archive/20230721/202307211105.zGLTcrGx-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/202307211105.zGLTcrGx-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from fs/nfs/unlink.c:12:
   In file included from include/linux/sunrpc/sched.h:19:
   include/linux/sunrpc/xdr.h:778:10: warning: result of comparison of constant 4611686018427387903 with expression of type '__u32' (aka 'unsigned int') is always false [-Wtautological-constant-out-of-range-compare]
           if (len > SIZE_MAX / sizeof(*p))
               ~~~ ^ ~~~~~~~~~~~~~~~~~~~~~
   In file included from fs/nfs/unlink.c:18:
>> include/linux/fsnotify.h:126:3: warning: variable 'fsnotify_mask' is uninitialized when used here [-Wuninitialized]
                   fsnotify_mask |= FS_PRE_MODIFY;
                   ^~~~~~~~~~~~~
   include/linux/fsnotify.h:110:21: note: initialize the variable 'fsnotify_mask' to silence this warning
           __u32 fsnotify_mask;
                              ^
                               = 0
   2 warnings generated.

vim +/fsnotify_mask +126 include/linux/fsnotify.h

   103	
   104	/*
   105	 * fsnotify_file_perm - permission hook before file access/modify
   106	 */
   107	static inline int fsnotify_file_perm(struct file *file, int mask)
   108	{
   109		struct inode *inode = file_inode(file);
   110		__u32 fsnotify_mask;
   111	
   112		/*
   113		 * Content of file may be written on pre-content events, so sb freeze
   114		 * protection must not be held.
   115		 */
   116		lockdep_assert_once(file_write_not_started(file));
   117	
   118		/*
   119		 * Pre-content events are onlt reported for regular files and dirs.
   120		 */
   121		if (mask & MAY_READ) {
   122			fsnotify_mask = FS_ACCESS_PERM;
   123			if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode))
   124				fsnotify_mask |= FS_PRE_ACCESS;
   125		} else if (mask & MAY_WRITE && S_ISREG(inode->i_mode)) {
 > 126			fsnotify_mask |= FS_PRE_MODIFY;
   127		} else {
   128			return 0;
   129		}
   130	
   131		return fsnotify_file(file, fsnotify_mask);
   132	}
   133	

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