linux-kernel - Re: [PATCH printk v2 1/1] printk: nbcon: Allow unsafe write

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Message-ID: <202510281239.CrKvR38C-lkp@intel.com>
Date: Tue, 28 Oct 2025 12:56:20 +0800
From: kernel test robot <lkp@...el.com>
To: John Ogness <john.ogness@...utronix.de>, Petr Mladek <pmladek@...e.com>
Cc: llvm@...ts.linux.dev, oe-kbuild-all@...ts.linux.dev,
	Sergey Senozhatsky <senozhatsky@...omium.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Breno Leitao <leitao@...ian.org>, Mike Galbraith <efault@....de>,
	linux-kernel@...r.kernel.org,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: Re: [PATCH printk v2 1/1] printk: nbcon: Allow unsafe write_atomic()
 for panic

Hi John,

kernel test robot noticed the following build errors:

[auto build test ERROR on 62627bf0cadf6eae87d92fecf604c42160fe16ef]

url:    https://github.com/intel-lab-lkp/linux/commits/John-Ogness/printk-nbcon-Allow-unsafe-write_atomic-for-panic/20251028-001756
base:   62627bf0cadf6eae87d92fecf604c42160fe16ef
patch link:    https://lore.kernel.org/r/20251027161212.334219-2-john.ogness%40linutronix.de
patch subject: [PATCH printk v2 1/1] printk: nbcon: Allow unsafe write_atomic() for panic
config: x86_64-allnoconfig (https://download.01.org/0day-ci/archive/20251028/202510281239.CrKvR38C-lkp@intel.com/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/20251028/202510281239.CrKvR38C-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 <lkp@...el.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202510281239.CrKvR38C-lkp@intel.com/

All errors (new ones prefixed by >>):

>> kernel/printk/nbcon.c:1938:77: error: too many arguments to function call, expected 2, have 3
    1938 |         __nbcon_atomic_flush_pending_con(ctxt->console, prb_next_reserve_seq(prb), false);
         |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~                                           ^~~~~
   kernel/printk/nbcon.c:1519:12: note: '__nbcon_atomic_flush_pending_con' declared here
    1519 | static int __nbcon_atomic_flush_pending_con(struct console *con, u64 stop_seq)
         |            ^                                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   1 error generated.


vim +1938 kernel/printk/nbcon.c

49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1916  
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1917  /**
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1918   * nbcon_kdb_release - Exit unsafe section and release the nbcon console
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1919   *
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1920   * @wctxt:	The nbcon write context initialized by a successful
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1921   *		nbcon_kdb_try_acquire()
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1922   */
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1923  void nbcon_kdb_release(struct nbcon_write_context *wctxt)
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1924  {
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1925  	struct nbcon_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1926  
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1927  	if (!nbcon_context_exit_unsafe(ctxt))
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1928  		return;
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1929  
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1930  	nbcon_context_release(ctxt);
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1931  
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1932  	/*
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1933  	 * Flush any new printk() messages added when the console was blocked.
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1934  	 * Only the console used by the given write context was	blocked.
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1935  	 * The console was locked only when the write_atomic() callback
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1936  	 * was usable.
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16  1937  	 */
49f7d3054e8461 Marcos Paulo de Souza 2025-10-16 @1938  	__nbcon_atomic_flush_pending_con(ctxt->console, prb_next_reserve_seq(prb), false);

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki