linux-kernel - Re: [PATCH v3 7/7] serial: 8250

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <202601310404.Rdq0kVXE-lkp@intel.com>
Date: Sat, 31 Jan 2026 04:59:09 +0800
From: kernel test robot <lkp@...el.com>
To: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Jiri Slaby <jirislaby@...nel.org>, linux-serial@...r.kernel.org,
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	qianfan Zhao <qianfanguijin@....com>,
	Adriana Nicolae <adriana@...sta.com>,
	Tim Kryger <tim.kryger@...aro.org>,
	Matt Porter <matt.porter@...aro.org>,
	Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
	Markus Mayer <markus.mayer@...aro.org>,
	Jamie Iles <jamie@...ieiles.com>, linux-kernel@...r.kernel.org
Cc: oe-kbuild-all@...ts.linux.dev,
	"Bandal, Shankar" <shankar.bandal@...el.com>,
	"Murthy, Shanth" <shanth.murthy@...el.com>, stable@...r.kernel.org
Subject: Re: [PATCH v3 7/7] serial: 8250_dw: Ensure BUSY is deasserted

Hi Ilpo,

kernel test robot noticed the following build errors:

[auto build test ERROR on 8f0b4cce4481fb22653697cced8d0d04027cb1e8]

url:    https://github.com/intel-lab-lkp/linux/commits/Ilpo-J-rvinen/serial-8250-Protect-LCR-write-in-shutdown/20260130-213314
base:   8f0b4cce4481fb22653697cced8d0d04027cb1e8
patch link:    https://lore.kernel.org/r/20260130132857.13124-8-ilpo.jarvinen%40linux.intel.com
patch subject: [PATCH v3 7/7] serial: 8250_dw: Ensure BUSY is deasserted
config: parisc-randconfig-001-20260131 (https://download.01.org/0day-ci/archive/20260131/202601310404.Rdq0kVXE-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 8.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260131/202601310404.Rdq0kVXE-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/202601310404.Rdq0kVXE-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/tty/serial/8250/8250_dw.c: In function 'dw8250_check_lcr':
>> drivers/tty/serial/8250/8250_dw.c:267:1: error: label at end of compound statement
    write_err:
    ^~~~~~~~~


vim +267 drivers/tty/serial/8250/8250_dw.c

   234	
   235	/*
   236	 * This function is being called as part of the uart_port::serial_out()
   237	 * routine. Hence, special care must be taken when serial_port_out() or
   238	 * serial_out() against the modified registers here, i.e. LCR (d->in_idle is
   239	 * used to break recursion loop).
   240	 */
   241	static void dw8250_check_lcr(struct uart_port *p, unsigned int offset, u32 value)
   242	{
   243		struct dw8250_data *d = to_dw8250_data(p->private_data);
   244		u32 lcr;
   245		int ret;
   246	
   247		if (offset != UART_LCR || d->uart_16550_compatible)
   248			return;
   249	
   250		lcr = serial_port_in(p, UART_LCR);
   251	
   252		/* Make sure LCR write wasn't ignored */
   253		if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
   254			return;
   255	
   256		if (d->in_idle)
   257			goto write_err;
   258	
   259		ret = dw8250_idle_enter(p);
   260		if (ret < 0)
   261			goto write_err;
   262	
   263		serial_port_out(p, UART_LCR, value);
   264		dw8250_idle_exit(p);
   265		return;
   266	
 > 267	write_err:
   268		/*
   269		 * FIXME: this deadlocks if port->lock is already held
   270		 * dev_err(p->dev, "Couldn't set LCR to %d\n", value);
   271		 */
   272	}
   273	

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