From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9A0E3375F9C for ; Tue, 7 Apr 2026 03:59:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.20 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775534378; cv=none; b=SJDOGE0a83LPyirb5wf/f+w5qMIWyy4CbQSRURQMgOcysYCQPi8YckSOeUBXLVPA3vwd+BQe+FY9IXlVNt3OBDaXoun9NZ+pzdlXGOZijDjuQdbVodowBs4oNlSIcXf/dCRMZEJes8S/f2xq+zO/vgE2K2ynn/xeuQKTC7CSEGs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775534378; c=relaxed/simple; bh=ikiyXDE588mYej/0xaDzXX0rX9Q9SGgGwWE56lFYHZs=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=lMEiDkghLpW2giTmM9AVeg95QqZAEjryETW/auWSKKwze9azgVSMyYvbuY8JDa8xm3CUuR96/c/QYOD27wyYJcSgZxnmZUL6x+oTb0OR7+o41/xD1WwY++2KOo1TOE1eTV+NAbZBRizboBPixsffCS//3Np7aSPY1tjFtKbf6a0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=HO86Ar+Q; arc=none smtp.client-ip=198.175.65.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="HO86Ar+Q" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1775534376; x=1807070376; h=date:from:to:cc:subject:message-id:mime-version; bh=ikiyXDE588mYej/0xaDzXX0rX9Q9SGgGwWE56lFYHZs=; b=HO86Ar+QyqARIDyata8Jn3av+0QPYJ4MA6N+NCeW8Z6MOlHRDApuBcEZ +9Xy3zmzPHet2cTRDA1Gnp/hrMEVdqcsl/Bxd1hMJWlglbD+PeJ8ZBJUa ljrZrxXC9xDz2vGicNKmJrW45R9BZyNoYQSGdh1NRuJ1XjzBNy2pkzC3H X90Hh2mXKQyxPwRvmoy9J4GEVf6Z9VJwttPz6+9zoWVtQfbC7XU1DPx18 fVTqyQrsaFbh5tvJ92aD6IG4/d9mwu0zXBrajjA9yQ+Iqm0Zxh/Shs1Sj nyioTxJoZeT7wKDcBSzCePObHAQJhCBZYuo7F03eRmWy0yQnOizAxh6ss w==; X-CSE-ConnectionGUID: 3ayomVEHRZquVQ3AbTd24w== X-CSE-MsgGUID: S5E3YjIDRWGeXbgYLRrLmA== X-IronPort-AV: E=McAfee;i="6800,10657,11751"; a="76204317" X-IronPort-AV: E=Sophos;i="6.23,164,1770624000"; d="scan'208";a="76204317" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Apr 2026 20:59:36 -0700 X-CSE-ConnectionGUID: mx7c9yDUTzqOAvyW/dZoDg== X-CSE-MsgGUID: 3Tk6zFMLTi+FwI7ohgIedQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,164,1770624000"; d="scan'208";a="251193020" Received: from lkp-server01.sh.intel.com (HELO d00eb8a6782a) ([10.239.97.150]) by fmviesa002.fm.intel.com with ESMTP; 06 Apr 2026 20:59:35 -0700 Received: from kbuild by d00eb8a6782a with local (Exim 4.98.2) (envelope-from ) id 1w9xbB-0000000006b-0x7h; Tue, 07 Apr 2026 03:59:33 +0000 Date: Tue, 7 Apr 2026 11:59:00 +0800 From: kernel test robot To: oe-kbuild@lists.linux.dev Cc: lkp@intel.com Subject: Re: [PATCH] btrfs: make more ASSERTs verbose, part 3 Message-ID: <202604051438.4BSUbQVi-lkp@intel.com> Precedence: bulk X-Mailing-List: oe-kbuild@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline :::::: :::::: Manual check reason: "likely FALSE maybe-used-uninitialized warning on old compiler" :::::: BCC: lkp@intel.com CC: oe-kbuild-all@lists.linux.dev In-Reply-To: <20260331223659.2098718-1-dsterba@suse.com> References: <20260331223659.2098718-1-dsterba@suse.com> TO: David Sterba TO: linux-btrfs@vger.kernel.org CC: David Sterba Hi David, kernel test robot noticed the following build warnings: [auto build test WARNING on kdave/for-next] [also build test WARNING on next-20260403] [cannot apply to linus/master v7.0-rc6] [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/David-Sterba/btrfs-make-more-ASSERTs-verbose-part-3/20260402-233149 base: https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git for-next patch link: https://lore.kernel.org/r/20260331223659.2098718-1-dsterba%40suse.com patch subject: [PATCH] btrfs: make more ASSERTs verbose, part 3 :::::: branch date: 3 days ago :::::: commit date: 3 days ago config: arm-randconfig-001-20260405 (https://download.01.org/0day-ci/archive/20260405/202604051438.4BSUbQVi-lkp@intel.com/config) compiler: arm-linux-gnueabi-gcc (GCC) 11.5.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260405/202604051438.4BSUbQVi-lkp@intel.com/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 | Closes: https://lore.kernel.org/r/202604051438.4BSUbQVi-lkp@intel.com/ Note: it may well be a FALSE warning. FWIW you are at least aware of it now. http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings All warnings (new ones prefixed by >>): In file included from include/asm-generic/bug.h:31, from arch/arm/include/asm/bug.h:60, from include/linux/bug.h:5, from include/linux/instrumented.h:10, from include/linux/atomic/atomic-instrumented.h:17, from include/linux/atomic.h:82, from include/asm-generic/bitops/lock.h:5, from arch/arm/include/asm/bitops.h:245, from include/linux/bitops.h:67, from include/linux/kernel.h:23, from fs/btrfs/ioctl.c:6: fs/btrfs/ioctl.c: In function 'btrfs_ioctl_subvol_sync': >> include/linux/printk.h:511:44: warning: 'root_flags' may be used uninitialized in this function [-Wmaybe-uninitialized] 511 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__) | ^~~~~~~ fs/btrfs/ioctl.c:4984:13: note: 'root_flags' was declared here 4984 | u64 root_flags; | ^~~~~~~~~~ vim +/root_flags +511 include/linux/printk.h 337015573718b1 Chris Down 2021-06-15 459 337015573718b1 Chris Down 2021-06-15 460 /* 337015573718b1 Chris Down 2021-06-15 461 * Some subsystems have their own custom printk that applies a va_format to a 337015573718b1 Chris Down 2021-06-15 462 * generic format, for example, to include a device number or other metadata 337015573718b1 Chris Down 2021-06-15 463 * alongside the format supplied by the caller. 337015573718b1 Chris Down 2021-06-15 464 * 337015573718b1 Chris Down 2021-06-15 465 * In order to store these in the way they would be emitted by the printk 337015573718b1 Chris Down 2021-06-15 466 * infrastructure, the subsystem provides us with the start, fixed string, and 337015573718b1 Chris Down 2021-06-15 467 * any subsequent text in the format string. 337015573718b1 Chris Down 2021-06-15 468 * 337015573718b1 Chris Down 2021-06-15 469 * We take a variable argument list as pr_fmt/dev_fmt/etc are sometimes passed 337015573718b1 Chris Down 2021-06-15 470 * as multiple arguments (eg: `"%s: ", "blah"`), and we must only take the 337015573718b1 Chris Down 2021-06-15 471 * first one. 337015573718b1 Chris Down 2021-06-15 472 * 337015573718b1 Chris Down 2021-06-15 473 * subsys_fmt_prefix must be known at compile time, or compilation will fail 337015573718b1 Chris Down 2021-06-15 474 * (since this is a mistake). If fmt or level is not known at compile time, no 337015573718b1 Chris Down 2021-06-15 475 * index entry will be made (since this can legitimately happen). 337015573718b1 Chris Down 2021-06-15 476 */ 337015573718b1 Chris Down 2021-06-15 477 #define printk_index_subsys_emit(subsys_fmt_prefix, level, fmt, ...) \ 337015573718b1 Chris Down 2021-06-15 478 __printk_index_emit(fmt, level, subsys_fmt_prefix) 337015573718b1 Chris Down 2021-06-15 479 337015573718b1 Chris Down 2021-06-15 480 #define printk_index_wrap(_p_func, _fmt, ...) \ 337015573718b1 Chris Down 2021-06-15 481 ({ \ 337015573718b1 Chris Down 2021-06-15 482 __printk_index_emit(_fmt, NULL, NULL); \ 337015573718b1 Chris Down 2021-06-15 483 _p_func(_fmt, ##__VA_ARGS__); \ 337015573718b1 Chris Down 2021-06-15 484 }) 337015573718b1 Chris Down 2021-06-15 485 337015573718b1 Chris Down 2021-06-15 486 7d9e2661f26858 Jonathan Corbet 2021-07-25 487 /** 7d9e2661f26858 Jonathan Corbet 2021-07-25 488 * printk - print a kernel message 7d9e2661f26858 Jonathan Corbet 2021-07-25 489 * @fmt: format string 7d9e2661f26858 Jonathan Corbet 2021-07-25 490 * 7d9e2661f26858 Jonathan Corbet 2021-07-25 491 * This is printk(). It can be called from any context. We want it to work. 7d9e2661f26858 Jonathan Corbet 2021-07-25 492 * 7d9e2661f26858 Jonathan Corbet 2021-07-25 493 * If printk indexing is enabled, _printk() is called from printk_index_wrap. 7d9e2661f26858 Jonathan Corbet 2021-07-25 494 * Otherwise, printk is simply #defined to _printk. 7d9e2661f26858 Jonathan Corbet 2021-07-25 495 * 7d9e2661f26858 Jonathan Corbet 2021-07-25 496 * We try to grab the console_lock. If we succeed, it's easy - we log the 7d9e2661f26858 Jonathan Corbet 2021-07-25 497 * output and call the console drivers. If we fail to get the semaphore, we 7d9e2661f26858 Jonathan Corbet 2021-07-25 498 * place the output into the log buffer and return. The current holder of 7d9e2661f26858 Jonathan Corbet 2021-07-25 499 * the console_sem will notice the new output in console_unlock(); and will 7d9e2661f26858 Jonathan Corbet 2021-07-25 500 * send it to the consoles before releasing the lock. 7d9e2661f26858 Jonathan Corbet 2021-07-25 501 * 7d9e2661f26858 Jonathan Corbet 2021-07-25 502 * One effect of this deferred printing is that code which calls printk() and 7d9e2661f26858 Jonathan Corbet 2021-07-25 503 * then changes console_loglevel may break. This is because console_loglevel 7d9e2661f26858 Jonathan Corbet 2021-07-25 504 * is inspected when the actual printing occurs. 7d9e2661f26858 Jonathan Corbet 2021-07-25 505 * 7d9e2661f26858 Jonathan Corbet 2021-07-25 506 * See also: 7d9e2661f26858 Jonathan Corbet 2021-07-25 507 * printf(3) 7d9e2661f26858 Jonathan Corbet 2021-07-25 508 * 7d9e2661f26858 Jonathan Corbet 2021-07-25 509 * See the vsnprintf() documentation for format string extensions over C99. 7d9e2661f26858 Jonathan Corbet 2021-07-25 510 */ 337015573718b1 Chris Down 2021-06-15 @511 #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__) 337015573718b1 Chris Down 2021-06-15 512 #define printk_deferred(fmt, ...) \ 337015573718b1 Chris Down 2021-06-15 513 printk_index_wrap(_printk_deferred, fmt, ##__VA_ARGS__) 337015573718b1 Chris Down 2021-06-15 514 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki