Merge tag 'gpio-fixes-for-v7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

Pull gpio fixes from Bartosz Golaszewski:

 - add a missing IS_ERR() check in gpio-nomadik

 - fix a NULL-pointer dereference in GPIO character device code

 - restore label matching in swnode-lookup due to reported regressions
   in existing users (this will get removed again once we audit and
   update all drivers)

 - fix remove path in GPIO sysfs code

 - normalize the return value of gpio_chip::get() in gpio-amd-fch

* tag 'gpio-fixes-for-v7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpio: amd-fch: ionly return allowed values from amd_fch_gpio_get()
  gpio: sysfs: fix chip removal with GPIOs exported over sysfs
  gpio: swnode: restore the swnode-name-against-chip-label matching
  gpio: cdev: Avoid NULL dereference in linehandle_create()
  gpio: nomadik: Add missing IS_ERR() check

Author: torvalds

drivers/gpio/gpio-amd-fch.c

@@ -8,6 +8,7 @@
  *
  */
 
+#include <linux/bitfield.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
@@ -120,15 +121,15 @@ static int amd_fch_gpio_get(struct gpio_chip *gc,
 			    unsigned int offset)
 {
 	unsigned long flags;
-	int ret;
+	u32 val;
 	struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
 	void __iomem *ptr = amd_fch_gpio_addr(priv, offset);
 
 	spin_lock_irqsave(&priv->lock, flags);
-	ret = (readl_relaxed(ptr) & AMD_FCH_GPIO_FLAG_READ);
+	val = readl_relaxed(ptr);
 	spin_unlock_irqrestore(&priv->lock, flags);
 
-	return ret;
+	return FIELD_GET(AMD_FCH_GPIO_FLAG_READ, val);
 }
 
 static int amd_fch_gpio_request(struct gpio_chip *chip,

drivers/gpio/gpio-nomadik.c

@@ -430,6 +430,9 @@ void nmk_gpio_dbg_show_one(struct seq_file *s, struct pinctrl_dev *pctldev,
 #ifdef CONFIG_PINCTRL_NOMADIK
 	if (mode == NMK_GPIO_ALT_C && pctldev) {
 		desc = gpio_device_get_desc(chip->gpiodev, offset);
+		if (IS_ERR(desc))
+			return;
+
 		mode = nmk_prcm_gpiocr_get_mode(pctldev, desc_to_gpio(desc));
 	}
 #endif

drivers/gpio/gpiolib-cdev.c

@@ -388,7 +388,7 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
 	fd_publish(fdf);
 
 	dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
-		lh->num_descs);
+		handlereq.lines);
 
 	return 0;
 }

drivers/gpio/gpiolib-swnode.c

@@ -42,6 +42,25 @@ static struct gpio_device *swnode_get_gpio_device(struct fwnode_handle *fwnode)
 
 fwnode_lookup:
 	gdev = gpio_device_find_by_fwnode(fwnode);
+	if (!gdev && gdev_node && gdev_node->name)
+		/*
+		 * FIXME: We shouldn't need to compare the GPIO controller's
+		 * label against the software node that is supposedly attached
+		 * to it. However there are currently GPIO users that - knowing
+		 * the expected label of the GPIO chip whose pins they want to
+		 * control - set up dummy software nodes named after those GPIO
+		 * controllers, which aren't actually attached to them. In this
+		 * case gpio_device_find_by_fwnode() will fail as no device on
+		 * the GPIO bus is actually associated with the fwnode we're
+		 * looking for.
+		 *
+		 * As a fallback: continue checking the label if we have no
+		 * match. However, the situation described above is an abuse
+		 * of the software node API and should be phased out and the
+		 * following line - eventually removed.
+		 */
+		gdev = gpio_device_find_by_label(gdev_node->name);
+
 	return gdev ?: ERR_PTR(-EPROBE_DEFER);
 }
 

drivers/gpio/gpiolib-sysfs.c

@@ -919,63 +919,68 @@ int gpiod_export_link(struct device *dev, const char *name,
 }
 EXPORT_SYMBOL_GPL(gpiod_export_link);
 
-/**
- * gpiod_unexport - reverse effect of gpiod_export()
- * @desc: GPIO to make unavailable
- *
- * This is implicit on gpiod_free().
- */
-void gpiod_unexport(struct gpio_desc *desc)
+static void gpiod_unexport_unlocked(struct gpio_desc *desc)
 {
 	struct gpiod_data *tmp, *desc_data = NULL;
 	struct gpiodev_data *gdev_data;
 	struct gpio_device *gdev;
 
-	if (!desc) {
-		pr_warn("%s: invalid GPIO\n", __func__);
+	if (!test_bit(GPIOD_FLAG_EXPORT, &desc->flags))
 		return;
-	}
 
-	scoped_guard(mutex, &sysfs_lock) {
-		if (!test_bit(GPIOD_FLAG_EXPORT, &desc->flags))
-			return;
-
-		gdev = gpiod_to_gpio_device(desc);
-		gdev_data = gdev_get_data(gdev);
-		if (!gdev_data)
-			return;
+	gdev = gpiod_to_gpio_device(desc);
+	gdev_data = gdev_get_data(gdev);
+	if (!gdev_data)
+		return;
 
-		list_for_each_entry(tmp, &gdev_data->exported_lines, list) {
-			if (gpiod_is_equal(desc, tmp->desc)) {
-				desc_data = tmp;
-				break;
-			}
+	list_for_each_entry(tmp, &gdev_data->exported_lines, list) {
+		if (gpiod_is_equal(desc, tmp->desc)) {
+			desc_data = tmp;
+			break;
 		}
+	}
 
-		if (!desc_data)
-			return;
+	if (!desc_data)
+		return;
 
-		list_del(&desc_data->list);
-		clear_bit(GPIOD_FLAG_EXPORT, &desc->flags);
+	list_del(&desc_data->list);
+	clear_bit(GPIOD_FLAG_EXPORT, &desc->flags);
 #if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
-		sysfs_put(desc_data->value_kn);
-		device_unregister(desc_data->dev);
-
-		/*
-		 * Release irq after deregistration to prevent race with
-		 * edge_store.
-		 */
-		if (desc_data->irq_flags)
-			gpio_sysfs_free_irq(desc_data);
+	sysfs_put(desc_data->value_kn);
+	device_unregister(desc_data->dev);
+
+	/*
+	 * Release irq after deregistration to prevent race with
+	 * edge_store.
+	 */
+	if (desc_data->irq_flags)
+		gpio_sysfs_free_irq(desc_data);
 #endif /* CONFIG_GPIO_SYSFS_LEGACY */
 
-		sysfs_remove_groups(desc_data->parent,
-				    desc_data->chip_attr_groups);
-	}
+	sysfs_remove_groups(desc_data->parent,
+			    desc_data->chip_attr_groups);
 
 	mutex_destroy(&desc_data->mutex);
 	kfree(desc_data);
 }
+
+/**
+ * gpiod_unexport - reverse effect of gpiod_export()
+ * @desc: GPIO to make unavailable
+ *
+ * This is implicit on gpiod_free().
+ */
+void gpiod_unexport(struct gpio_desc *desc)
+{
+	if (!desc) {
+		pr_warn("%s: invalid GPIO\n", __func__);
+		return;
+	}
+
+	guard(mutex)(&sysfs_lock);
+
+	gpiod_unexport_unlocked(desc);
+}
 EXPORT_SYMBOL_GPL(gpiod_unexport);
 
 int gpiochip_sysfs_register(struct gpio_device *gdev)
@@ -1054,29 +1059,28 @@ void gpiochip_sysfs_unregister(struct gpio_device *gdev)
 	struct gpio_desc *desc;
 	struct gpio_chip *chip;
 
-	scoped_guard(mutex, &sysfs_lock) {
-		data = gdev_get_data(gdev);
-		if (!data)
-			return;
+	guard(mutex)(&sysfs_lock);
 
-#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
-		device_unregister(data->cdev_base);
-#endif /* CONFIG_GPIO_SYSFS_LEGACY */
-		device_unregister(data->cdev_id);
-		kfree(data);
-	}
+	data = gdev_get_data(gdev);
+	if (!data)
+		return;
 
 	guard(srcu)(&gdev->srcu);
-
 	chip = srcu_dereference(gdev->chip, &gdev->srcu);
 	if (!chip)
 		return;
 
 	/* unregister gpiod class devices owned by sysfs */
 	for_each_gpio_desc_with_flag(chip, desc, GPIOD_FLAG_SYSFS) {
-		gpiod_unexport(desc);
+		gpiod_unexport_unlocked(desc);
 		gpiod_free(desc);
 	}
+
+#if IS_ENABLED(CONFIG_GPIO_SYSFS_LEGACY)
+	device_unregister(data->cdev_base);
+#endif /* CONFIG_GPIO_SYSFS_LEGACY */
+	device_unregister(data->cdev_id);
+	kfree(data);
 }
 
 /*