From b34490879baa847d16fc529c8ea6e6d34f004b38 Mon Sep 17 00:00:00 2001
From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Date: Mon, 25 Mar 2024 10:02:42 +0100
Subject: gpio: cdev: sanitize the label before requesting the interrupt

When an interrupt is requested, a procfs directory is created under
"/proc/irq/<irqnum>/<label>" where <label> is the string passed to one of
the request_irq() variants.

What follows is that the string must not contain the "/" character or
the procfs mkdir operation will fail. We don't have such constraints for
GPIO consumer labels which are used verbatim as interrupt labels for
GPIO irqs. We must therefore sanitize the consumer string before
requesting the interrupt.

Let's replace all "/" with ":".

Cc: stable@vger.kernel.org
Reported-by: Stefan Wahren <wahrenst@gmx.net>
Closes: https://lore.kernel.org/linux-gpio/39fe95cb-aa83-4b8b-8cab-63947a726754@gmx.net/
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
---
 drivers/gpio/gpiolib-cdev.c | 38 ++++++++++++++++++++++++++++++++------
 1 file changed, 32 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index f384fa278764..fa9635610251 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -1083,10 +1083,20 @@ static u32 gpio_v2_line_config_debounce_period(struct gpio_v2_line_config *lc,
 	return 0;
 }
 
+static inline char *make_irq_label(const char *orig)
+{
+	return kstrdup_and_replace(orig, '/', ':', GFP_KERNEL);
+}
+
+static inline void free_irq_label(const char *label)
+{
+	kfree(label);
+}
+
 static void edge_detector_stop(struct line *line)
 {
 	if (line->irq) {
-		free_irq(line->irq, line);
+		free_irq_label(free_irq(line->irq, line));
 		line->irq = 0;
 	}
 
@@ -1110,6 +1120,7 @@ static int edge_detector_setup(struct line *line,
 	unsigned long irqflags = 0;
 	u64 eflags;
 	int irq, ret;
+	char *label;
 
 	eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS;
 	if (eflags && !kfifo_initialized(&line->req->events)) {
@@ -1146,11 +1157,17 @@ static int edge_detector_setup(struct line *line,
 			IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
 	irqflags |= IRQF_ONESHOT;
 
+	label = make_irq_label(line->req->label);
+	if (!label)
+		return -ENOMEM;
+
 	/* Request a thread to read the events */
 	ret = request_threaded_irq(irq, edge_irq_handler, edge_irq_thread,
-				   irqflags, line->req->label, line);
-	if (ret)
+				   irqflags, label, line);
+	if (ret) {
+		free_irq_label(label);
 		return ret;
+	}
 
 	line->irq = irq;
 	return 0;
@@ -1973,7 +1990,7 @@ static void lineevent_free(struct lineevent_state *le)
 		blocking_notifier_chain_unregister(&le->gdev->device_notifier,
 						   &le->device_unregistered_nb);
 	if (le->irq)
-		free_irq(le->irq, le);
+		free_irq_label(free_irq(le->irq, le));
 	if (le->desc)
 		gpiod_free(le->desc);
 	kfree(le->label);
@@ -2114,6 +2131,7 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
 	int fd;
 	int ret;
 	int irq, irqflags = 0;
+	char *label;
 
 	if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
 		return -EFAULT;
@@ -2198,15 +2216,23 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
 	if (ret)
 		goto out_free_le;
 
+	label = make_irq_label(le->label);
+	if (!label) {
+		ret = -ENOMEM;
+		goto out_free_le;
+	}
+
 	/* Request a thread to read the events */
 	ret = request_threaded_irq(irq,
 				   lineevent_irq_handler,
 				   lineevent_irq_thread,
 				   irqflags,
-				   le->label,
+				   label,
 				   le);
-	if (ret)
+	if (ret) {
+		free_irq_label(label);
 		goto out_free_le;
+	}
 
 	le->irq = irq;
 
-- 
cgit v1.2.3


From 52464f59a361a3ba49d6eabc4f65d5c0b9d1de39 Mon Sep 17 00:00:00 2001
From: Mark Brown <broonie@kernel.org>
Date: Mon, 25 Mar 2024 17:00:57 +0000
Subject: gpiolib: Add stubs for GPIO lookup functions

The gpio_device_find_by_() functions do not have stubs which means that if
they are referenced from code with an optiona dependency on gpiolib then
the code will fail to link. Add stubs for lookups via fwnode and label. I
have not added a stub for plain gpio_device_find() since it seems harder to
see a use case for that which does not depend on gpiolib.

With the addition of the GPIO reset controller (which lacks a gpiolib
dependency) to the arm64 defconfig this is causing build breaks for arm64
virtconfig in -next:

aarch64-linux-gnu-ld: drivers/reset/core.o: in function `__reset_add_reset_gpio_lookup':
 /build/stage/linux/drivers/reset/core.c:861:(.text+0xccc): undefined reference to `gpio_device_find_by_fwnode'

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 include/linux/gpio/driver.h | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index dc75f802e284..f8617eaf08ba 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -646,8 +646,6 @@ int devm_gpiochip_add_data_with_key(struct device *dev, struct gpio_chip *gc,
 struct gpio_device *gpio_device_find(const void *data,
 				int (*match)(struct gpio_chip *gc,
 					     const void *data));
-struct gpio_device *gpio_device_find_by_label(const char *label);
-struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode);
 
 struct gpio_device *gpio_device_get(struct gpio_device *gdev);
 void gpio_device_put(struct gpio_device *gdev);
@@ -814,6 +812,9 @@ struct gpio_device *gpiod_to_gpio_device(struct gpio_desc *desc);
 int gpio_device_get_base(struct gpio_device *gdev);
 const char *gpio_device_get_label(struct gpio_device *gdev);
 
+struct gpio_device *gpio_device_find_by_label(const char *label);
+struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode);
+
 #else /* CONFIG_GPIOLIB */
 
 #include <asm/bug.h>
@@ -843,6 +844,18 @@ static inline const char *gpio_device_get_label(struct gpio_device *gdev)
 	return NULL;
 }
 
+static inline struct gpio_device *gpio_device_find_by_label(const char *label)
+{
+	WARN_ON(1);
+	return NULL;
+}
+
+static inline struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode)
+{
+	WARN_ON(1);
+	return NULL;
+}
+
 static inline int gpiochip_lock_as_irq(struct gpio_chip *gc,
 				       unsigned int offset)
 {
-- 
cgit v1.2.3


From 5c887b65bbd1a3fc28e2e20399acede0baa83edb Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Mon, 25 Mar 2024 19:16:25 +0200
Subject: gpiolib: Fix debug messaging in gpiod_find_and_request()

When consolidating GPIO lookups in ACPI code, the debug messaging
had been reworked that the user may see

  [   13.401147] (NULL device *): using ACPI '\_SB.LEDS.led-0' for '(null)' GPIO lookup
  [   13.401378] gpio gpiochip0: Persistence not supported for GPIO 40
  [   13.401402] gpio-40 (?): no flags found for (null)

instead of

  [   14.182962] gpio gpiochip0: Persistence not supported for GPIO 40
  [   14.182994] gpio-40 (?): no flags found for gpios

The '(null)' parts are less informative and likely scare the users.
Replace them by '(default)' which can point out to the default connection
IDs, such as 'gpios'.

While at it, amend other places where con_id is used in the messages.

Reported-by: Ferry Toth <ftoth@exalondelft.nl>
Fixes: 8eb1f71e7acc ("gpiolib: consolidate GPIO lookups")
Suggested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Ferry Toth <ftoth@exalondelft.nl>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/gpio/gpiolib.c | 32 ++++++++++++++++++--------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index ce94e37bcbee..59ccf9a3e153 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2397,6 +2397,11 @@ char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset)
 }
 EXPORT_SYMBOL_GPL(gpiochip_dup_line_label);
 
+static inline const char *function_name_or_default(const char *con_id)
+{
+	return con_id ?: "(default)";
+}
+
 /**
  * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
  * @gc: GPIO chip
@@ -2425,10 +2430,11 @@ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
 					    enum gpiod_flags dflags)
 {
 	struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
+	const char *name = function_name_or_default(label);
 	int ret;
 
 	if (IS_ERR(desc)) {
-		chip_err(gc, "failed to get GPIO descriptor\n");
+		chip_err(gc, "failed to get GPIO %s descriptor\n", name);
 		return desc;
 	}
 
@@ -2438,8 +2444,8 @@ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
 
 	ret = gpiod_configure_flags(desc, label, lflags, dflags);
 	if (ret) {
-		chip_err(gc, "setup of own GPIO %s failed\n", label);
 		gpiod_free_commit(desc);
+		chip_err(gc, "setup of own GPIO %s failed\n", name);
 		return ERR_PTR(ret);
 	}
 
@@ -4153,19 +4159,17 @@ static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode,
 					      enum gpiod_flags *flags,
 					      unsigned long *lookupflags)
 {
+	const char *name = function_name_or_default(con_id);
 	struct gpio_desc *desc = ERR_PTR(-ENOENT);
 
 	if (is_of_node(fwnode)) {
-		dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n",
-			fwnode, con_id);
+		dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", fwnode, name);
 		desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags);
 	} else if (is_acpi_node(fwnode)) {
-		dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n",
-			fwnode, con_id);
+		dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", fwnode, name);
 		desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags);
 	} else if (is_software_node(fwnode)) {
-		dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n",
-			fwnode, con_id);
+		dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", fwnode, name);
 		desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags);
 	}
 
@@ -4181,6 +4185,7 @@ struct gpio_desc *gpiod_find_and_request(struct device *consumer,
 					 bool platform_lookup_allowed)
 {
 	unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
+	const char *name = function_name_or_default(con_id);
 	/*
 	 * scoped_guard() is implemented as a for loop, meaning static
 	 * analyzers will complain about these two not being initialized.
@@ -4203,8 +4208,7 @@ struct gpio_desc *gpiod_find_and_request(struct device *consumer,
 		}
 
 		if (IS_ERR(desc)) {
-			dev_dbg(consumer, "No GPIO consumer %s found\n",
-				con_id);
+			dev_dbg(consumer, "No GPIO consumer %s found\n", name);
 			return desc;
 		}
 
@@ -4226,15 +4230,14 @@ struct gpio_desc *gpiod_find_and_request(struct device *consumer,
 		 *
 		 * FIXME: Make this more sane and safe.
 		 */
-		dev_info(consumer,
-			 "nonexclusive access to GPIO for %s\n", con_id);
+		dev_info(consumer, "nonexclusive access to GPIO for %s\n", name);
 		return desc;
 	}
 
 	ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
 	if (ret < 0) {
-		dev_dbg(consumer, "setup of GPIO %s failed\n", con_id);
 		gpiod_put(desc);
+		dev_dbg(consumer, "setup of GPIO %s failed\n", name);
 		return ERR_PTR(ret);
 	}
 
@@ -4350,6 +4353,7 @@ EXPORT_SYMBOL_GPL(gpiod_get_optional);
 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
 		unsigned long lflags, enum gpiod_flags dflags)
 {
+	const char *name = function_name_or_default(con_id);
 	int ret;
 
 	if (lflags & GPIO_ACTIVE_LOW)
@@ -4393,7 +4397,7 @@ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
 
 	/* No particular flag request, return here... */
 	if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
-		gpiod_dbg(desc, "no flags found for %s\n", con_id);
+		gpiod_dbg(desc, "no flags found for GPIO %s\n", name);
 		return 0;
 	}
 
-- 
cgit v1.2.3