Hi Steven, kernel test robot noticed the following build warnings:
[auto build test WARNING on trace/for-next] [also build test WARNING on linus/master v6.18-rc6 next-20251121] [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/Steven-Rostedt/tracing-Add-system-trigger-file-to-enable-triggers-for-all-the-system-s-events/20251121-050454 base: https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace for-next patch link: https://lore.kernel.org/r/20251120160003.2fa33d80%40gandalf.local.home patch subject: [PATCH] tracing: Add system trigger file to enable triggers for all the system's events config: sparc64-defconfig (https://download.01.org/0day-ci/archive/20251122/[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/20251122/[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_events_trigger.c:432:6: warning: variable 'len' set but >> not used [-Wunused-but-set-variable] 432 | int len; | ^ 1 warning generated. vim +/len +432 kernel/trace/trace_events_trigger.c 420 421 static ssize_t 422 event_system_trigger_write(struct file *filp, const char __user *ubuf, 423 size_t cnt, loff_t *ppos) 424 { 425 struct trace_subsystem_dir *dir = filp->private_data; 426 struct event_command *p; 427 char *command, *next; 428 char *buf __free(kfree) = get_user_buf(ubuf, cnt); 429 bool remove = false; 430 bool found = false; 431 ssize_t ret; > 432 int len; 433 434 if (!buf) 435 return 0; 436 437 if (IS_ERR(buf)) 438 return PTR_ERR(buf); 439 440 /* system triggers are not allowed to have counters */ 441 if (strchr(buf, ':')) 442 return -EINVAL; 443 444 /* If opened for read too, dir is in the seq_file descriptor */ 445 if (filp->f_mode & FMODE_READ) { 446 struct seq_file *m = filp->private_data; 447 dir = m->private; 448 } 449 450 /* Skip added space at beginning of buf */ 451 next = buf; 452 strim(next); 453 454 command = strsep(&next, " \t"); 455 if (next) { 456 next = skip_spaces(next); 457 if (!*next) 458 next = NULL; 459 } 460 if (command[0] == '!') { 461 remove = true; 462 command++; 463 } 464 465 len = strlen(command); 466 if (next) 467 len += strlen(next) + 1; 468 469 guard(mutex)(&event_mutex); 470 guard(mutex)(&trigger_cmd_mutex); 471 472 list_for_each_entry(p, &trigger_commands, list) { 473 /* Allow to remove any trigger */ 474 if (!remove && !(p->flags & EVENT_CMD_FL_SYSTEM)) 475 continue; 476 if (strcmp(p->name, command) == 0) { 477 found = true; 478 ret = process_system_events(dir, p, buf, command, next); 479 break; 480 } 481 } 482 483 if (!found) 484 ret = -ENODEV; 485 486 if (!ret) 487 *ppos += cnt; 488 489 if (remove || ret < 0) 490 return ret ? : cnt; 491 492 return cnt; 493 } 494 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
