tree: https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git cache_files head: c9c53507520b2eb523a0ac7102a89bf3b960e4be commit: c9c53507520b2eb523a0ac7102a89bf3b960e4be [1/1] cachefiles: do not yet allow on idmapped mounts config: powerpc64-randconfig-r005-20210316 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 50c7504a93fdb90c26870db8c8ea7add895c7725) 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 # install powerpc64 cross compiling tool for clang build # apt-get install binutils-powerpc64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git/commit/... git remote add brauner https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git git fetch --no-tags brauner cache_files git checkout c9c53507520b2eb523a0ac7102a89bf3b960e4be # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): if (mnt_user_ns(path.mnt) != &init_user_ns) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:56:28: note: expanded from macro 'if' #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:58:30: note: expanded from macro '__trace_if_var' #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/cachefiles/bind.c:247:7: note: uninitialized use occurs here dput(root); ^~~~ fs/cachefiles/bind.c:119:2: note: remove the 'if' if its condition is always false if (mnt_user_ns(path.mnt) != &init_user_ns) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:56:23: note: expanded from macro 'if' #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) ^ fs/cachefiles/bind.c:86:44: note: initialize the variable 'root' to silence this warning struct dentry *graveyard, *cachedir, *root; ^ = NULL 1 warning generated. vim +119 fs/cachefiles/bind.c 77 78 /* 79 * add a cache 80 */ 81 static int cachefiles_daemon_add_cache(struct cachefiles_cache *cache) 82 { 83 struct cachefiles_object *fsdef; 84 struct path path; 85 struct kstatfs stats; 86 struct dentry *graveyard, *cachedir, *root; 87 const struct cred *saved_cred; 88 int ret; 89 90 _enter(""); 91 92 /* we want to work under the module's security ID */ 93 ret = cachefiles_get_security_ID(cache); 94 if (ret < 0) 95 return ret; 96 97 cachefiles_begin_secure(cache, &saved_cred); 98 99 /* allocate the root index object */ 100 ret = -ENOMEM; 101 102 fsdef = kmem_cache_alloc(cachefiles_object_jar, GFP_KERNEL); 103 if (!fsdef) 104 goto error_root_object; 105 106 ASSERTCMP(fsdef->backer, ==, NULL); 107 108 atomic_set(&fsdef->usage, 1); 109 fsdef->type = FSCACHE_COOKIE_TYPE_INDEX; 110 111 _debug("- fsdef %p", fsdef); 112 113 /* look up the directory at the root of the cache */ 114 ret = kern_path(cache->rootdirname, LOOKUP_DIRECTORY, &path); 115 if (ret < 0) 116 goto error_open_root; 117 118 ret = -EINVAL; 120 goto error_unsupported; 121 122 cache->mnt = path.mnt; 123 root = path.dentry; 124 125 /* check parameters */ 126 ret = -EOPNOTSUPP; 127 if (d_is_negative(root) || 128 !d_backing_inode(root)->i_op->lookup || 129 !d_backing_inode(root)->i_op->mkdir || 130 !(d_backing_inode(root)->i_opflags & IOP_XATTR) || 131 !root->d_sb->s_op->statfs || 132 !root->d_sb->s_op->sync_fs) 133 goto error_unsupported; 134 135 ret = -EROFS; 136 if (sb_rdonly(root->d_sb)) 137 goto error_unsupported; 138 139 /* determine the security of the on-disk cache as this governs 140 * security ID of files we create */ 141 ret = cachefiles_determine_cache_security(cache, root, &saved_cred); 142 if (ret < 0) 143 goto error_unsupported; 144 145 /* get the cache size and blocksize */ 146 ret = vfs_statfs(&path, &stats); 147 if (ret < 0) 148 goto error_unsupported; 149 150 ret = -ERANGE; 151 if (stats.f_bsize <= 0) 152 goto error_unsupported; 153 154 ret = -EOPNOTSUPP; 155 if (stats.f_bsize > PAGE_SIZE) 156 goto error_unsupported; 157 158 cache->bsize = stats.f_bsize; 159 cache->bshift = 0; 160 if (stats.f_bsize < PAGE_SIZE) 161 cache->bshift = PAGE_SHIFT - ilog2(stats.f_bsize); 162 163 _debug("blksize %u (shift %u)", 164 cache->bsize, cache->bshift); 165 166 _debug("size %llu, avail %llu", 167 (unsigned long long) stats.f_blocks, 168 (unsigned long long) stats.f_bavail); 169 170 /* set up caching limits */ 171 do_div(stats.f_files, 100); 172 cache->fstop = stats.f_files * cache->fstop_percent; 173 cache->fcull = stats.f_files * cache->fcull_percent; 174 cache->frun = stats.f_files * cache->frun_percent; 175 176 _debug("limits {%llu,%llu,%llu} files", 177 (unsigned long long) cache->frun, 178 (unsigned long long) cache->fcull, 179 (unsigned long long) cache->fstop); 180 181 stats.f_blocks >>= cache->bshift; 182 do_div(stats.f_blocks, 100); 183 cache->bstop = stats.f_blocks * cache->bstop_percent; 184 cache->bcull = stats.f_blocks * cache->bcull_percent; 185 cache->brun = stats.f_blocks * cache->brun_percent; 186 187 _debug("limits {%llu,%llu,%llu} blocks", 188 (unsigned long long) cache->brun, 189 (unsigned long long) cache->bcull, 190 (unsigned long long) cache->bstop); 191 192 /* get the cache directory and check its type */ 193 cachedir = cachefiles_get_directory(cache, root, "cache"); 194 if (IS_ERR(cachedir)) { 195 ret = PTR_ERR(cachedir); 196 goto error_unsupported; 197 } 198 199 fsdef->dentry = cachedir; 200 fsdef->fscache.cookie = NULL; 201 202 ret = cachefiles_check_object_type(fsdef); 203 if (ret < 0) 204 goto error_unsupported; 205 206 /* get the graveyard directory */ 207 graveyard = cachefiles_get_directory(cache, root, "graveyard"); 208 if (IS_ERR(graveyard)) { 209 ret = PTR_ERR(graveyard); 210 goto error_unsupported; 211 } 212 213 cache->graveyard = graveyard; 214 215 /* publish the cache */ 216 fscache_init_cache(&cache->cache, 217 &cachefiles_cache_ops, 218 "%s", 219 fsdef->dentry->d_sb->s_id); 220 221 fscache_object_init(&fsdef->fscache, &fscache_fsdef_index, 222 &cache->cache); 223 224 ret = fscache_add_cache(&cache->cache, &fsdef->fscache, cache->tag); 225 if (ret < 0) 226 goto error_add_cache; 227 228 /* done */ 229 set_bit(CACHEFILES_READY, &cache->flags); 230 dput(root); 231 232 pr_info("File cache on %s registered\n", cache->cache.identifier); 233 234 /* check how much space the cache has */ 235 cachefiles_has_space(cache, 0, 0); 236 cachefiles_end_secure(cache, saved_cred); 237 return 0; 238 239 error_add_cache: 240 dput(cache->graveyard); 241 cache->graveyard = NULL; 242 error_unsupported: 243 mntput(cache->mnt); 244 cache->mnt = NULL; 245 dput(fsdef->dentry); 246 fsdef->dentry = NULL; 247 dput(root); 248 error_open_root: 249 kmem_cache_free(cachefiles_object_jar, fsdef); 250 error_root_object: 251 cachefiles_end_secure(cache, saved_cred); 252 pr_err("Failed to register: %d\n", ret); 253 return ret; 254 } 255 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org