Hi Nitesh, kernel test robot noticed the following build warnings: [auto build test WARNING on f7dc24b3413851109c4047b22997bd0d95ed52a2] url: https://github.com/intel-lab-lkp/linux/commits/Nitesh-Shetty/block-Introduce-queue-limits-and-sysfs-for-copy-offload-support/20230811-192259 base: f7dc24b3413851109c4047b22997bd0d95ed52a2 patch link: https://lore.kernel.org/r/20230811105300.15889-12-nj.shetty%40samsung.com patch subject: [PATCH v14 11/11] null_blk: add support for copy offload config: hexagon-randconfig-r032-20230811 (https://download.01.org/0day-ci/archive/20230812/202308120029.elW3y1RM-lkp@xxxxxxxxx/config) compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a) reproduce: (https://download.01.org/0day-ci/archive/20230812/202308120029.elW3y1RM-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/202308120029.elW3y1RM-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from drivers/block/null_blk/main.c:12: In file included from drivers/block/null_blk/null_blk.h:8: In file included from include/linux/blkdev.h:9: In file included from include/linux/blk_types.h:10: In file included from include/linux/bvec.h:10: In file included from include/linux/highmem.h:12: In file included from include/linux/hardirq.h:11: In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/hexagon/include/asm/io.h:337: include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 547 | val = __raw_readb(PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 560 | val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); | ~~~~~~~~~~ ^ include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu' 37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) | ^ In file included from drivers/block/null_blk/main.c:12: In file included from drivers/block/null_blk/null_blk.h:8: In file included from include/linux/blkdev.h:9: In file included from include/linux/blk_types.h:10: In file included from include/linux/bvec.h:10: In file included from include/linux/highmem.h:12: In file included from include/linux/hardirq.h:11: In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/hexagon/include/asm/io.h:337: include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 573 | val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); | ~~~~~~~~~~ ^ include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu' 35 | #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) | ^ In file included from drivers/block/null_blk/main.c:12: In file included from drivers/block/null_blk/null_blk.h:8: In file included from include/linux/blkdev.h:9: In file included from include/linux/blk_types.h:10: In file included from include/linux/bvec.h:10: In file included from include/linux/highmem.h:12: In file included from include/linux/hardirq.h:11: In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/hexagon/include/asm/io.h:337: include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 584 | __raw_writeb(value, PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 594 | __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 604 | __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); | ~~~~~~~~~~ ^ >> drivers/block/null_blk/main.c:1303:2: warning: variable 'sector_in' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] 1303 | __rq_for_each_bio(bio, req) { | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/blk-mq.h:1008:6: note: expanded from macro '__rq_for_each_bio' 1008 | if ((rq->bio)) \ | ^~~~~~~~~ drivers/block/null_blk/main.c:1316:8: note: uninitialized use occurs here 1316 | sector_in << SECTOR_SHIFT, rem); | ^~~~~~~~~ drivers/block/null_blk/main.c:1303:2: note: remove the 'if' if its condition is always true 1303 | __rq_for_each_bio(bio, req) { | ^ include/linux/blk-mq.h:1008:2: note: expanded from macro '__rq_for_each_bio' 1008 | if ((rq->bio)) \ | ^ drivers/block/null_blk/main.c:1287:20: note: initialize the variable 'sector_in' to silence this warning 1287 | sector_t sector_in, sector_out; | ^ | = 0 >> drivers/block/null_blk/main.c:1303:2: warning: variable 'sector_out' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] 1303 | __rq_for_each_bio(bio, req) { | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/blk-mq.h:1008:6: note: expanded from macro '__rq_for_each_bio' 1008 | if ((rq->bio)) \ | ^~~~~~~~~ drivers/block/null_blk/main.c:1315:27: note: uninitialized use occurs here 1315 | trace_nullb_copy_op(req, sector_out << SECTOR_SHIFT, | ^~~~~~~~~~ drivers/block/null_blk/main.c:1303:2: note: remove the 'if' if its condition is always true 1303 | __rq_for_each_bio(bio, req) { | ^ include/linux/blk-mq.h:1008:2: note: expanded from macro '__rq_for_each_bio' 1008 | if ((rq->bio)) \ | ^ drivers/block/null_blk/main.c:1287:32: note: initialize the variable 'sector_out' to silence this warning 1287 | sector_t sector_in, sector_out; | ^ | = 0 8 warnings generated. vim +1303 drivers/block/null_blk/main.c 1283 1284 static inline int nullb_setup_copy(struct nullb *nullb, struct request *req, 1285 bool is_fua) 1286 { 1287 sector_t sector_in, sector_out; 1288 loff_t offset_in, offset_out; 1289 void *in, *out; 1290 ssize_t chunk, rem = 0; 1291 struct bio *bio; 1292 struct nullb_page *t_page_in, *t_page_out; 1293 u16 seg = 1; 1294 int status = -EIO; 1295 1296 if (blk_rq_nr_phys_segments(req) != COPY_MAX_SEGMENTS) 1297 return status; 1298 1299 /* 1300 * First bio contains information about source and last bio contains 1301 * information about destination. 1302 */ > 1303 __rq_for_each_bio(bio, req) { 1304 if (seg == blk_rq_nr_phys_segments(req)) { 1305 sector_out = bio->bi_iter.bi_sector; 1306 if (rem != bio->bi_iter.bi_size) 1307 return status; 1308 } else { 1309 sector_in = bio->bi_iter.bi_sector; 1310 rem = bio->bi_iter.bi_size; 1311 } 1312 seg++; 1313 } 1314 1315 trace_nullb_copy_op(req, sector_out << SECTOR_SHIFT, 1316 sector_in << SECTOR_SHIFT, rem); 1317 1318 spin_lock_irq(&nullb->lock); 1319 while (rem > 0) { 1320 chunk = min_t(size_t, nullb->dev->blocksize, rem); 1321 offset_in = (sector_in & SECTOR_MASK) << SECTOR_SHIFT; 1322 offset_out = (sector_out & SECTOR_MASK) << SECTOR_SHIFT; 1323 1324 if (null_cache_active(nullb) && !is_fua) 1325 null_make_cache_space(nullb, PAGE_SIZE); 1326 1327 t_page_in = null_lookup_page(nullb, sector_in, false, 1328 !null_cache_active(nullb)); 1329 if (!t_page_in) 1330 goto err; 1331 t_page_out = null_insert_page(nullb, sector_out, 1332 !null_cache_active(nullb) || 1333 is_fua); 1334 if (!t_page_out) 1335 goto err; 1336 1337 in = kmap_local_page(t_page_in->page); 1338 out = kmap_local_page(t_page_out->page); 1339 1340 memcpy(out + offset_out, in + offset_in, chunk); 1341 kunmap_local(out); 1342 kunmap_local(in); 1343 __set_bit(sector_out & SECTOR_MASK, t_page_out->bitmap); 1344 1345 if (is_fua) 1346 null_free_sector(nullb, sector_out, true); 1347 1348 rem -= chunk; 1349 sector_in += chunk >> SECTOR_SHIFT; 1350 sector_out += chunk >> SECTOR_SHIFT; 1351 } 1352 1353 status = 0; 1354 err: 1355 spin_unlock_irq(&nullb->lock); 1356 return status; 1357 } 1358 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
