Hi Keith, kernel test robot noticed the following build warnings: [auto build test WARNING on axboe-block/for-next] [also build test WARNING on linus/master v6.6 next-20231030] [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#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Keith-Busch/block-bio-integrity-directly-map-user-buffers/20231028-022107 base: https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next patch link: https://lore.kernel.org/r/20231027181929.2589937-2-kbusch%40meta.com patch subject: [PATCHv2 1/4] block: bio-integrity: directly map user buffers config: x86_64-rhel-8.3-rust (https://download.01.org/0day-ci/archive/20231031/202310310704.l4FwoJDd-lkp@xxxxxxxxx/config) compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231031/202310310704.l4FwoJDd-lkp@xxxxxxxxx/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@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202310310704.l4FwoJDd-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> block/bio-integrity.c:215:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (!buf) ^~~~ block/bio-integrity.c:255:9: note: uninitialized use occurs here return ret; ^~~ block/bio-integrity.c:215:2: note: remove the 'if' if its condition is always false if (!buf) ^~~~~~~~~ block/bio-integrity.c:204:9: note: initialize the variable 'ret' to silence this warning int ret; ^ = 0 1 warning generated. vim +215 block/bio-integrity.c 195 196 static int bio_integrity_copy_user(struct bio *bio, struct bio_vec *bvec, 197 int nr_vecs, unsigned int len, 198 unsigned int direction, u32 seed) 199 { 200 struct bio_integrity_payload *bip; 201 struct bio_vec *copy_vec = NULL; 202 struct iov_iter iter; 203 void *buf; 204 int ret; 205 206 /* if bvec is on the stack, we need to allocate a copy for the completion */ 207 if (nr_vecs <= UIO_FASTIOV) { 208 copy_vec = kcalloc(sizeof(*bvec), nr_vecs, GFP_KERNEL); 209 if (!copy_vec) 210 return -ENOMEM; 211 memcpy(copy_vec, bvec, nr_vecs * sizeof(*bvec)); 212 } 213 214 buf = kmalloc(len, GFP_KERNEL); > 215 if (!buf) 216 goto free_copy; 217 218 if (direction == ITER_SOURCE) { 219 iov_iter_bvec(&iter, direction, bvec, nr_vecs, len); 220 if (!copy_from_iter_full(buf, len, &iter)) { 221 ret = -EFAULT; 222 goto free_buf; 223 } 224 } else { 225 memset(buf, 0, len); 226 } 227 228 /* 229 * We just need one vec for this bip, but we need to preserve the 230 * number of vecs in the user bvec for the completion handling, so use 231 * nr_vecs. 232 */ 233 bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs); 234 if (IS_ERR(bip)) { 235 ret = PTR_ERR(bip); 236 goto free_buf; 237 } 238 239 ret = bio_integrity_add_page(bio, virt_to_page(buf), len, 240 offset_in_page(buf)); 241 if (ret != len) { 242 ret = -ENOMEM; 243 goto free_bip; 244 } 245 246 bip->bip_flags |= BIP_INTEGRITY_USER; 247 bip->copy_vec = copy_vec ?: bvec; 248 return 0; 249 free_bip: 250 bio_integrity_free(bio); 251 free_buf: 252 kfree(buf); 253 free_copy: 254 kfree(copy_vec); 255 return ret; 256 } 257 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
