Hi Ryan, kernel test robot noticed the following build warnings:
[auto build test WARNING on v6.17] [also build test WARNING on linus/master next-20251010] [cannot apply to trace/for-next] [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/Ryan-Chung/docs-tracing-fprobe-document-list-filters-and-entry-exit/20251010-111713 base: v6.17 patch link: https://lore.kernel.org/r/20251004235001.133111-4-seokwoo.chung130%40gmail.com patch subject: [PATCH v3 3/5] tracing: fprobe: support comma-separated symbols and :entry/:exit config: x86_64-randconfig-073-20251010 (https://download.01.org/0day-ci/archive/20251010/[email protected]/config) compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251010/[email protected]/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 <[email protected]> | Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/ All warnings (new ones prefixed by >>): kernel/trace/trace_fprobe.c:274:7: error: read-only variable is not assignable 274 | *p = '\0'; | ~~ ^ kernel/trace/trace_fprobe.c:276:7: error: read-only variable is not assignable 276 | *p = '\0'; | ~~ ^ kernel/trace/trace_fprobe.c:1281:24: error: use of undeclared identifier 'nofilter'; did you mean 'filter'? 1281 | char *filter = NULL; *nofilter = NULL; | ^~~~~~~~ | filter kernel/trace/trace_fprobe.c:1281:8: note: 'filter' declared here 1281 | char *filter = NULL; *nofilter = NULL; | ^ kernel/trace/trace_fprobe.c:1284:26: error: use of undeclared identifier 'nofilter'; did you mean 'filter'? 1284 | &list_mode, &filter, &nofilter); | ^~~~~~~~ | filter kernel/trace/trace_fprobe.c:1281:8: note: 'filter' declared here 1281 | char *filter = NULL; *nofilter = NULL; | ^ kernel/trace/trace_fprobe.c:1298:11: error: use of undeclared identifier 'nofilter'; did you mean 'filter'? 1298 | kfree(nofilter); | ^~~~~~~~ | filter kernel/trace/trace_fprobe.c:1281:8: note: 'filter' declared here 1281 | char *filter = NULL; *nofilter = NULL; | ^ kernel/trace/trace_fprobe.c:1307:8: error: use of undeclared identifier 'nofilter'; did you mean 'filter'? 1307 | kfree(nofilter); | ^~~~~~~~ | filter kernel/trace/trace_fprobe.c:1281:8: note: 'filter' declared here 1281 | char *filter = NULL; *nofilter = NULL; | ^ >> kernel/trace/trace_fprobe.c:1355:7: warning: unused variable 'has_wild' >> [-Wunused-variable] 1355 | bool has_wild = false; | ^~~~~~~~ 1 warning and 6 errors generated. vim +/has_wild +1355 kernel/trace/trace_fprobe.c 1274 1275 static int parse_symbol_and_return(int argc, const char *argv[], 1276 char **symbol, bool *is_return, 1277 bool is_tracepoint) 1278 { 1279 int i, ret; 1280 bool list_mode = false; 1281 char *filter = NULL; *nofilter = NULL; 1282 1283 ret = parse_fprobe_spec(argv[1], is_tracepoint, symbol, is_return, 1284 &list_mode, &filter, &nofilter); 1285 if (ret) 1286 return ret; 1287 1288 for (i = 2; i < argc; i++) { 1289 char *tmp = strstr(argv[i], "$retval"); 1290 1291 if (tmp && !isalnum(tmp[7]) && tmp[7] != '_') { 1292 if (is_tracepoint) { 1293 trace_probe_log_set_index(i); 1294 trace_probe_log_err(tmp - argv[i], RETVAL_ON_PROBE); 1295 kfree(*symbol); 1296 *symbol = NULL; 1297 kfree(filter); 1298 kfree(nofilter); 1299 return -EINVAL; 1300 } 1301 *is_return = true; 1302 break; 1303 } 1304 } 1305 1306 kfree(filter); > 1307 kfree(nofilter); 1308 return 0; 1309 } 1310 1311 static int trace_fprobe_create_internal(int argc, const char *argv[], 1312 struct traceprobe_parse_context *ctx) 1313 { 1314 /* 1315 * Argument syntax: 1316 * - Add fentry probe: 1317 * f[:[GRP/][EVENT]] [MOD:]KSYM [FETCHARGS] 1318 * - Add fexit probe: 1319 * f[N][:[GRP/][EVENT]] [MOD:]KSYM%return [FETCHARGS] 1320 * - Add tracepoint probe: 1321 * t[:[GRP/][EVENT]] TRACEPOINT [FETCHARGS] 1322 * 1323 * Fetch args: 1324 * $retval : fetch return value 1325 * $stack : fetch stack address 1326 * $stackN : fetch Nth entry of stack (N:0-) 1327 * $argN : fetch Nth argument (N:1-) 1328 * $comm : fetch current task comm 1329 * @ADDR : fetch memory at ADDR (ADDR should be in kernel) 1330 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) 1331 * Dereferencing memory fetch: 1332 * +|-offs(ARG) : fetch memory at ARG +|- offs address. 1333 * Alias name of args: 1334 * NAME=FETCHARG : set NAME as alias of FETCHARG. 1335 * Type of args: 1336 * FETCHARG:TYPE : use TYPE instead of unsigned long. 1337 */ 1338 struct trace_fprobe *tf __free(free_trace_fprobe) = NULL; 1339 const char *event = NULL, *group = FPROBE_EVENT_SYSTEM; 1340 struct module *mod __free(module_put) = NULL; 1341 const char **new_argv __free(kfree) = NULL; 1342 char *symbol __free(kfree) = NULL; 1343 char *ebuf __free(kfree) = NULL; 1344 char *gbuf __free(kfree) = NULL; 1345 char *sbuf __free(kfree) = NULL; 1346 char *abuf __free(kfree) = NULL; 1347 char *dbuf __free(kfree) = NULL; 1348 int i, new_argc = 0, ret = 0; 1349 bool is_tracepoint = false; 1350 bool is_return = false; 1351 bool list_mode = false; 1352 1353 char *parsed_filter __free(kfree) = NULL; 1354 char *parsed_nofilter __free(kfree) = NULL; > 1355 bool has_wild = false; 1356 1357 if ((argv[0][0] != 'f' && argv[0][0] != 't') || argc < 2) 1358 return -ECANCELED; 1359 1360 if (argv[0][0] == 't') { 1361 is_tracepoint = true; 1362 group = TRACEPOINT_EVENT_SYSTEM; 1363 } 1364 1365 if (argv[0][1] != '\0') { 1366 if (argv[0][1] != ':') { 1367 trace_probe_log_set_index(0); 1368 trace_probe_log_err(1, BAD_MAXACT); 1369 return -EINVAL; 1370 } 1371 event = &argv[0][2]; 1372 } 1373 1374 trace_probe_log_set_index(1); 1375 1376 /* Parse spec early (single vs list, suffix, base symbol) */ 1377 ret = parse_fprobe_spec(argv[1], is_tracepoint, &symbol, &is_return, 1378 &list_mode, &parsed_filter, &parsed_nofilter); 1379 if (ret < 0) 1380 return -EINVAL; 1381 1382 trace_probe_log_set_index(0); 1383 if (event) { 1384 gbuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL); 1385 if (!gbuf) 1386 return -ENOMEM; 1387 ret = traceprobe_parse_event_name(&event, &group, gbuf, 1388 event - argv[0]); 1389 if (ret) 1390 return -EINVAL; 1391 } 1392 1393 if (!event) { 1394 /* 1395 * Event name rules: 1396 * - For list/wildcard: require explicit [GROUP/]EVENT 1397 * - For single literal: autogenerate symbol__entry/symbol__exit 1398 */ 1399 if (list_mode || has_wildcard(symbol)) { 1400 trace_probe_log_err(0, NO_GROUP_NAME); 1401 return -EINVAL; 1402 } 1403 /* Make a new event name */ 1404 if (is_tracepoint) 1405 snprintf(ebuf, MAX_EVENT_NAME_LEN, "%s%s", 1406 isdigit(*symbol) ? "_" : "", symbol); 1407 else 1408 snprintf(ebuf, MAX_EVENT_NAME_LEN, "%s__%s", symbol, 1409 is_return ? "exit" : "entry"); 1410 sanitize_event_name(ebuf); 1411 event = ebuf; 1412 } 1413 1414 if (is_return) 1415 ctx->flags |= TPARG_FL_RETURN; 1416 else 1417 ctx->flags |= TPARG_FL_FENTRY; 1418 1419 ctx->funcname = NULL; 1420 if (is_tracepoint) { 1421 /* Get tracepoint and lock its module until the end of the registration. */ 1422 struct tracepoint *tpoint; 1423 1424 ctx->flags |= TPARG_FL_TPOINT; 1425 mod = NULL; 1426 tpoint = find_tracepoint(symbol, &mod); 1427 if (tpoint) { 1428 sbuf = kmalloc(KSYM_NAME_LEN, GFP_KERNEL); 1429 if (!sbuf) 1430 return -ENOMEM; 1431 ctx->funcname = kallsyms_lookup((unsigned long)tpoint->probestub, 1432 NULL, NULL, NULL, sbuf); 1433 } 1434 } 1435 1436 if (!list_mode && !has_wildcard(symbol) && !is_tracepoint) 1437 ctx->funcname = symbol; 1438 1439 abuf = kmalloc(MAX_BTF_ARGS_LEN, GFP_KERNEL); 1440 if (!abuf) 1441 return -ENOMEM; 1442 argc -= 2; argv += 2; 1443 new_argv = traceprobe_expand_meta_args(argc, argv, &new_argc, 1444 abuf, MAX_BTF_ARGS_LEN, ctx); 1445 if (IS_ERR(new_argv)) 1446 return PTR_ERR(new_argv); 1447 if (new_argv) { 1448 argc = new_argc; 1449 argv = new_argv; 1450 } 1451 if (argc > MAX_TRACE_ARGS) { 1452 trace_probe_log_set_index(2); 1453 trace_probe_log_err(0, TOO_MANY_ARGS); 1454 return -E2BIG; 1455 } 1456 1457 ret = traceprobe_expand_dentry_args(argc, argv, &dbuf); 1458 if (ret) 1459 return ret; 1460 1461 /* setup a probe */ 1462 tf = alloc_trace_fprobe(group, event, symbol, argc, is_return, is_tracepoint); 1463 if (IS_ERR(tf)) { 1464 ret = PTR_ERR(tf); 1465 /* This must return -ENOMEM, else there is a bug */ 1466 WARN_ON_ONCE(ret != -ENOMEM); 1467 return ret; 1468 } 1469 1470 /* carry list parsing result into tf */ 1471 if (!is_tracepoint) { 1472 tf->list_mode = list_mode; 1473 if (parsed_filter) { 1474 tf->filter = kstrdup(parsed_filter, GFP_KERNEL); 1475 if (!tf->filter) 1476 return -ENOMEM; 1477 } 1478 if (parsed_nofilter) { 1479 tf->nofilter = kstrdup(parsed_nofilter, GFP_KERNEL); 1480 if (!tf->nofilter) 1481 return -ENOMEM; 1482 } 1483 } 1484 1485 /* parse arguments */ 1486 for (i = 0; i < argc; i++) { 1487 trace_probe_log_set_index(i + 2); 1488 ctx->offset = 0; 1489 ret = traceprobe_parse_probe_arg(&tf->tp, i, argv[i], ctx); 1490 if (ret) 1491 return ret; /* This can be -ENOMEM */ 1492 } 1493 1494 if (is_return && tf->tp.entry_arg) { 1495 tf->fp.entry_handler = trace_fprobe_entry_handler; 1496 tf->fp.entry_data_size = traceprobe_get_entry_data_size(&tf->tp); 1497 if (ALIGN(tf->fp.entry_data_size, sizeof(long)) > MAX_FPROBE_DATA_SIZE) { 1498 trace_probe_log_set_index(2); 1499 trace_probe_log_err(0, TOO_MANY_EARGS); 1500 return -E2BIG; 1501 } 1502 } 1503 1504 ret = traceprobe_set_print_fmt(&tf->tp, 1505 is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL); 1506 if (ret < 0) 1507 return ret; 1508 1509 ret = register_trace_fprobe_event(tf); 1510 if (ret) { 1511 trace_probe_log_set_index(1); 1512 if (ret == -EILSEQ) 1513 trace_probe_log_err(0, BAD_INSN_BNDRY); 1514 else if (ret == -ENOENT) 1515 trace_probe_log_err(0, BAD_PROBE_ADDR); 1516 else if (ret != -ENOMEM && ret != -EEXIST) 1517 trace_probe_log_err(0, FAIL_REG_PROBE); 1518 return -EINVAL; 1519 } 1520 1521 /* 'tf' is successfully registered. To avoid freeing, assign NULL. */ 1522 tf = NULL; 1523 1524 return 0; 1525 } 1526 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
