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From: Dan Carpenter <dan.carpenter@linaro.org>
To: oe-kbuild@lists.linux.dev,
	"Bartosz Golaszewski" <bartosz.golaszewski@oss.qualcomm.com>,
	"Linus Walleij" <linusw@kernel.org>,
	"Bartosz Golaszewski" <brgl@kernel.org>,
	"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Dmitry Torokhov" <dmitry.torokhov@gmail.com>,
	"Arnd Bergmann" <arnd@kernel.org>,
	"Hans de Goede" <hansg@kernel.org>,
	"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: lkp@intel.com, oe-kbuild-all@lists.linux.dev,
	linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
	platform-driver-x86@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH] gpio: swnode: restore the swnode-name-against-chip-label matching
Date: Tue, 10 Feb 2026 22:10:47 +0300	[thread overview]
Message-ID: <202602110128.BInRI9un-lkp@intel.com> (raw)
In-Reply-To: <20260210094806.38146-1-bartosz.golaszewski@oss.qualcomm.com>

Hi Bartosz,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Bartosz-Golaszewski/gpio-swnode-restore-the-swnode-name-against-chip-label-matching/20260210-175012
base:   https://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux.git gpio/for-next
patch link:    https://lore.kernel.org/r/20260210094806.38146-1-bartosz.golaszewski%40oss.qualcomm.com
patch subject: [PATCH] gpio: swnode: restore the swnode-name-against-chip-label matching
config: nios2-randconfig-r071-20260210 (https://download.01.org/0day-ci/archive/20260211/202602110128.BInRI9un-lkp@intel.com/config)
compiler: nios2-linux-gcc (GCC) 8.5.0
smatch version: v0.5.0-8994-gd50c5a4c

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@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202602110128.BInRI9un-lkp@intel.com/

smatch warnings:
drivers/gpio/gpiolib-swnode.c:62 swnode_get_gpio_device() error: we previously assumed 'gdev_node' could be null (see line 32)

vim +/gdev_node +62 drivers/gpio/gpiolib-swnode.c

b7b56e64a345e7 Bartosz Golaszewski 2023-09-27  26  static struct gpio_device *swnode_get_gpio_device(struct fwnode_handle *fwnode)
e7f9ff5dc90c38 Dmitry Torokhov     2022-11-11  27  {
b7b56e64a345e7 Bartosz Golaszewski 2023-09-27  28  	const struct software_node *gdev_node;
b7b56e64a345e7 Bartosz Golaszewski 2023-09-27  29  	struct gpio_device *gdev;
e7f9ff5dc90c38 Dmitry Torokhov     2022-11-11  30  
b7b56e64a345e7 Bartosz Golaszewski 2023-09-27  31  	gdev_node = to_software_node(fwnode);
6774a66d0e103d Bartosz Golaszewski 2025-12-15 @32  	if (!gdev_node)
216c1204757190 Bartosz Golaszewski 2025-11-20  33  		goto fwnode_lookup;

gdev_node is NULL

e7f9ff5dc90c38 Dmitry Torokhov     2022-11-11  34  
9d50f95bc0d5df Charles Keepax      2024-04-16  35  	/*
9d50f95bc0d5df Charles Keepax      2024-04-16  36  	 * Check for a special node that identifies undefined GPIOs, this is
9d50f95bc0d5df Charles Keepax      2024-04-16  37  	 * primarily used as a key for internal chip selects in SPI bindings.
9d50f95bc0d5df Charles Keepax      2024-04-16  38  	 */
9d50f95bc0d5df Charles Keepax      2024-04-16  39  	if (IS_ENABLED(CONFIG_GPIO_SWNODE_UNDEFINED) &&
6774a66d0e103d Bartosz Golaszewski 2025-12-15  40  	    gdev_node == &swnode_gpio_undefined)
9d50f95bc0d5df Charles Keepax      2024-04-16  41  		return ERR_PTR(-ENOENT);
9d50f95bc0d5df Charles Keepax      2024-04-16  42  
216c1204757190 Bartosz Golaszewski 2025-11-20  43  fwnode_lookup:
e5d527be7e6984 Bartosz Golaszewski 2025-11-03  44  	gdev = gpio_device_find_by_fwnode(fwnode);
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  45  	if (!gdev)
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  46  		/*
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  47  		 * FIXME: We shouldn't need to compare the GPIO controller's
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  48  		 * label against the software node that is supposedly attached
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  49  		 * to it. However there are currently GPIO users that - knowing
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  50  		 * the expected label of the GPIO chip whose pins they want to
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  51  		 * control - set up dummy software nodes named after those GPIO
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  52  		 * controllers, which aren't actually attached to them. In this
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  53  		 * case gpio_device_find_by_fwnode() will fail as no device on
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  54  		 * the GPIO bus is actually associated with the fwnode we're
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  55  		 * looking for.
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  56  		 *
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  57  		 * As a fallback: continue checking the label if we have no
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  58  		 * match. However, the situation described above is an abuse
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  59  		 * of the software node API and should be phased out and the
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  60  		 * following line - eventually removed.
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  61  		 */
4a61b0b6de0480 Bartosz Golaszewski 2026-02-10 @62  		gdev = gpio_device_find_by_label(gdev_node->name);
                                                                                                 ^^^^^^^^^^^^^^^
Unchecked dereference

4a61b0b6de0480 Bartosz Golaszewski 2026-02-10  63  
b7b56e64a345e7 Bartosz Golaszewski 2023-09-27  64  	return gdev ?: ERR_PTR(-EPROBE_DEFER);
e7f9ff5dc90c38 Dmitry Torokhov     2022-11-11  65  }

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


      parent reply	other threads:[~2026-02-10 19:10 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-02-10  9:48 [PATCH] gpio: swnode: restore the swnode-name-against-chip-label matching Bartosz Golaszewski
2026-02-10 10:06 ` Andy Shevchenko
2026-02-10 10:41 ` Hans de Goede
2026-02-10 19:10 ` Dan Carpenter [this message]

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