1 files changed, 124 insertions, 102 deletions

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index e9faeaf65d14..1631727bf0da 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -428,6 +428,12 @@ struct line {
 	 */
 	struct linereq *req;
 	unsigned int irq;
+	/*
+	 * eflags is set by edge_detector_setup(), edge_detector_stop() and
+	 * edge_detector_update(), which are themselves mutually exclusive,
+	 * and is accessed by edge_irq_thread() and debounce_work_func(),
+	 * which can both live with a slightly stale value.
+	 */
 	u64 eflags;
 	/*
 	 * timestamp_ns and req_seqno are accessed only by
@@ -504,11 +510,14 @@ struct linereq {
 	(GPIO_V2_LINE_FLAG_EDGE_RISING | \
 	 GPIO_V2_LINE_FLAG_EDGE_FALLING)
 
+#define GPIO_V2_LINE_FLAG_EDGE_BOTH GPIO_V2_LINE_EDGE_FLAGS
+
 #define GPIO_V2_LINE_VALID_FLAGS \
 	(GPIO_V2_LINE_FLAG_ACTIVE_LOW | \
 	 GPIO_V2_LINE_DIRECTION_FLAGS | \
 	 GPIO_V2_LINE_DRIVE_FLAGS | \
 	 GPIO_V2_LINE_EDGE_FLAGS | \
+	 GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME | \
 	 GPIO_V2_LINE_BIAS_FLAGS)
 
 static void linereq_put_event(struct linereq *lr,
@@ -529,11 +538,20 @@ static void linereq_put_event(struct linereq *lr,
 		pr_debug_ratelimited("event FIFO is full - event dropped\n");
 }
 
+static u64 line_event_timestamp(struct line *line)
+{
+	if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &line->desc->flags))
+		return ktime_get_real_ns();
+
+	return ktime_get_ns();
+}
+
 static irqreturn_t edge_irq_thread(int irq, void *p)
 {
 	struct line *line = p;
 	struct linereq *lr = line->req;
 	struct gpio_v2_line_event le;
+	u64 eflags;
 
 	/* Do not leak kernel stack to userspace */
 	memset(&le, 0, sizeof(le));
@@ -546,14 +564,14 @@ static irqreturn_t edge_irq_thread(int irq, void *p)
 		 * which case we didn't get the timestamp from
 		 * edge_irq_handler().
 		 */
-		le.timestamp_ns = ktime_get_ns();
+		le.timestamp_ns = line_event_timestamp(line);
 		if (lr->num_lines != 1)
 			line->req_seqno = atomic_inc_return(&lr->seqno);
 	}
 	line->timestamp_ns = 0;
 
-	if (line->eflags == (GPIO_V2_LINE_FLAG_EDGE_RISING |
-			     GPIO_V2_LINE_FLAG_EDGE_FALLING)) {
+	eflags = READ_ONCE(line->eflags);
+	if (eflags == GPIO_V2_LINE_FLAG_EDGE_BOTH) {
 		int level = gpiod_get_value_cansleep(line->desc);
 
 		if (level)
@@ -562,10 +580,10 @@ static irqreturn_t edge_irq_thread(int irq, void *p)
 		else
 			/* Emit high-to-low event */
 			le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE;
-	} else if (line->eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) {
+	} else if (eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) {
 		/* Emit low-to-high event */
 		le.id = GPIO_V2_LINE_EVENT_RISING_EDGE;
-	} else if (line->eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) {
+	} else if (eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) {
 		/* Emit high-to-low event */
 		le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE;
 	} else {
@@ -590,7 +608,7 @@ static irqreturn_t edge_irq_handler(int irq, void *p)
 	 * Just store the timestamp in hardirq context so we get it as
 	 * close in time as possible to the actual event.
 	 */
-	line->timestamp_ns = ktime_get_ns();
+	line->timestamp_ns = line_event_timestamp(line);
 
 	if (lr->num_lines != 1)
 		line->req_seqno = atomic_inc_return(&lr->seqno);
@@ -634,6 +652,7 @@ static void debounce_work_func(struct work_struct *work)
 	struct line *line = container_of(work, struct line, work.work);
 	struct linereq *lr;
 	int level;
+	u64 eflags;
 
 	level = gpiod_get_raw_value_cansleep(line->desc);
 	if (level < 0) {
@@ -647,7 +666,8 @@ static void debounce_work_func(struct work_struct *work)
 	WRITE_ONCE(line->level, level);
 
 	/* -- edge detection -- */
-	if (!line->eflags)
+	eflags = READ_ONCE(line->eflags);
+	if (!eflags)
 		return;
 
 	/* switch from physical level to logical - if they differ */
@@ -655,15 +675,15 @@ static void debounce_work_func(struct work_struct *work)
 		level = !level;
 
 	/* ignore edges that are not being monitored */
-	if (((line->eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) && !level) ||
-	    ((line->eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) && level))
+	if (((eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) && !level) ||
+	    ((eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) && level))
 		return;
 
 	/* Do not leak kernel stack to userspace */
 	memset(&le, 0, sizeof(le));
 
 	lr = line->req;
-	le.timestamp_ns = ktime_get_ns();
+	le.timestamp_ns = line_event_timestamp(line);
 	le.offset = gpio_chip_hwgpio(line->desc);
 	line->line_seqno++;
 	le.line_seqno = line->line_seqno;
@@ -755,7 +775,9 @@ static void edge_detector_stop(struct line *line)
 
 	cancel_delayed_work_sync(&line->work);
 	WRITE_ONCE(line->sw_debounced, 0);
-	line->eflags = 0;
+	WRITE_ONCE(line->eflags, 0);
+	if (line->desc)
+		WRITE_ONCE(line->desc->debounce_period_us, 0);
 	/* do not change line->level - see comment in debounced_value() */
 }
 
@@ -774,7 +796,7 @@ static int edge_detector_setup(struct line *line,
 		if (ret)
 			return ret;
 	}
-	line->eflags = eflags;
+	WRITE_ONCE(line->eflags, eflags);
 	if (gpio_v2_line_config_debounced(lc, line_idx)) {
 		debounce_period_us = gpio_v2_line_config_debounce_period(lc, line_idx);
 		ret = debounce_setup(line, debounce_period_us);
@@ -817,13 +839,13 @@ static int edge_detector_update(struct line *line,
 	unsigned int debounce_period_us =
 		gpio_v2_line_config_debounce_period(lc, line_idx);
 
-	if ((line->eflags == eflags) && !polarity_change &&
+	if ((READ_ONCE(line->eflags) == eflags) && !polarity_change &&
 	    (READ_ONCE(line->desc->debounce_period_us) == debounce_period_us))
 		return 0;
 
 	/* sw debounced and still will be...*/
 	if (debounce_period_us && READ_ONCE(line->sw_debounced)) {
-		line->eflags = eflags;
+		WRITE_ONCE(line->eflags, eflags);
 		WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
 		return 0;
 	}
@@ -967,6 +989,9 @@ static void gpio_v2_line_config_flags_to_desc_flags(u64 flags,
 		   flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN);
 	assign_bit(FLAG_BIAS_DISABLE, flagsp,
 		   flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED);
+
+	assign_bit(FLAG_EVENT_CLOCK_REALTIME, flagsp,
+		   flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME);
 }
 
 static long linereq_get_values(struct linereq *lr, void __user *ip)
@@ -1479,21 +1504,10 @@ static __poll_t lineevent_poll(struct file *file,
 	return events;
 }
 
-static ssize_t lineevent_get_size(void)
-{
-#if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
-	/* i386 has no padding after 'id' */
-	if (in_ia32_syscall()) {
-		struct compat_gpioeevent_data {
-			compat_u64	timestamp;
-			u32		id;
-		};
-
-		return sizeof(struct compat_gpioeevent_data);
-	}
-#endif
-	return sizeof(struct gpioevent_data);
-}
+struct compat_gpioeevent_data {
+	compat_u64	timestamp;
+	u32		id;
+};
 
 static ssize_t lineevent_read(struct file *file,
 			      char __user *buf,
@@ -1515,7 +1529,10 @@ static ssize_t lineevent_read(struct file *file,
 	 * actual sizeof() and pass this as an argument to copy_to_user() to
 	 * drop unneeded bytes from the output.
 	 */
-	ge_size = lineevent_get_size();
+	if (compat_need_64bit_alignment_fixup())
+		ge_size = sizeof(struct compat_gpioeevent_data);
+	else
+		ge_size = sizeof(struct gpioevent_data);
 	if (count < ge_size)
 		return -EINVAL;
 
@@ -1910,6 +1927,7 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
 	    test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
 	    test_bit(FLAG_EXPORT, &desc->flags) ||
 	    test_bit(FLAG_SYSFS, &desc->flags) ||
+	    !gpiochip_line_is_valid(gc, info->offset) ||
 	    !ok_for_pinctrl)
 		info->flags |= GPIO_V2_LINE_FLAG_USED;
 
@@ -1938,6 +1956,9 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
 	if (test_bit(FLAG_EDGE_FALLING, &desc->flags))
 		info->flags |= GPIO_V2_LINE_FLAG_EDGE_FALLING;
 
+	if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &desc->flags))
+		info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME;
+
 	debounce_period_us = READ_ONCE(desc->debounce_period_us);
 	if (debounce_period_us) {
 		info->attrs[num_attrs].id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE;
@@ -1960,6 +1981,21 @@ struct gpio_chardev_data {
 #endif
 };
 
+static int chipinfo_get(struct gpio_chardev_data *cdev, void __user *ip)
+{
+	struct gpio_device *gdev = cdev->gdev;
+	struct gpiochip_info chipinfo;
+
+	memset(&chipinfo, 0, sizeof(chipinfo));
+
+	strscpy(chipinfo.name, dev_name(&gdev->dev), sizeof(chipinfo.name));
+	strscpy(chipinfo.label, gdev->label, sizeof(chipinfo.label));
+	chipinfo.lines = gdev->ngpio;
+	if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
+		return -EFAULT;
+	return 0;
+}
+
 #ifdef CONFIG_GPIO_CDEV_V1
 /*
  * returns 0 if the versions match, else the previously selected ABI version
@@ -1974,6 +2010,41 @@ static int lineinfo_ensure_abi_version(struct gpio_chardev_data *cdata,
 
 	return abiv;
 }
+
+static int lineinfo_get_v1(struct gpio_chardev_data *cdev, void __user *ip,
+			   bool watch)
+{
+	struct gpio_desc *desc;
+	struct gpioline_info lineinfo;
+	struct gpio_v2_line_info lineinfo_v2;
+
+	if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
+		return -EFAULT;
+
+	/* this doubles as a range check on line_offset */
+	desc = gpiochip_get_desc(cdev->gdev->chip, lineinfo.line_offset);
+	if (IS_ERR(desc))
+		return PTR_ERR(desc);
+
+	if (watch) {
+		if (lineinfo_ensure_abi_version(cdev, 1))
+			return -EPERM;
+
+		if (test_and_set_bit(lineinfo.line_offset, cdev->watched_lines))
+			return -EBUSY;
+	}
+
+	gpio_desc_to_lineinfo(desc, &lineinfo_v2);
+	gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo);
+
+	if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) {
+		if (watch)
+			clear_bit(lineinfo.line_offset, cdev->watched_lines);
+		return -EFAULT;
+	}
+
+	return 0;
+}
 #endif
 
 static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip,
@@ -2011,6 +2082,22 @@ static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip,
 	return 0;
 }
 
+static int lineinfo_unwatch(struct gpio_chardev_data *cdev, void __user *ip)
+{
+	__u32 offset;
+
+	if (copy_from_user(&offset, ip, sizeof(offset)))
+		return -EFAULT;
+
+	if (offset >= cdev->gdev->ngpio)
+		return -EINVAL;
+
+	if (!test_and_clear_bit(offset, cdev->watched_lines))
+		return -EBUSY;
+
+	return 0;
+}
+
 /*
  * gpio_ioctl() - ioctl handler for the GPIO chardev
  */
@@ -2018,80 +2105,24 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct gpio_chardev_data *cdev = file->private_data;
 	struct gpio_device *gdev = cdev->gdev;
-	struct gpio_chip *gc = gdev->chip;
 	void __user *ip = (void __user *)arg;
-	__u32 offset;
 
 	/* We fail any subsequent ioctl():s when the chip is gone */
-	if (!gc)
+	if (!gdev->chip)
 		return -ENODEV;
 
 	/* Fill in the struct and pass to userspace */
 	if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
-		struct gpiochip_info chipinfo;
-
-		memset(&chipinfo, 0, sizeof(chipinfo));
-
-		strscpy(chipinfo.name, dev_name(&gdev->dev),
-			sizeof(chipinfo.name));
-		strscpy(chipinfo.label, gdev->label,
-			sizeof(chipinfo.label));
-		chipinfo.lines = gdev->ngpio;
-		if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
-			return -EFAULT;
-		return 0;
+		return chipinfo_get(cdev, ip);
 #ifdef CONFIG_GPIO_CDEV_V1
-	} else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
-		struct gpio_desc *desc;
-		struct gpioline_info lineinfo;
-		struct gpio_v2_line_info lineinfo_v2;
-
-		if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
-			return -EFAULT;
-
-		/* this doubles as a range check on line_offset */
-		desc = gpiochip_get_desc(gc, lineinfo.line_offset);
-		if (IS_ERR(desc))
-			return PTR_ERR(desc);
-
-		gpio_desc_to_lineinfo(desc, &lineinfo_v2);
-		gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo);
-
-		if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
-			return -EFAULT;
-		return 0;
 	} else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
 		return linehandle_create(gdev, ip);
 	} else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
 		return lineevent_create(gdev, ip);
-	} else if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) {
-		struct gpio_desc *desc;
-		struct gpioline_info lineinfo;
-		struct gpio_v2_line_info lineinfo_v2;
-
-		if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
-			return -EFAULT;
-
-		/* this doubles as a range check on line_offset */
-		desc = gpiochip_get_desc(gc, lineinfo.line_offset);
-		if (IS_ERR(desc))
-			return PTR_ERR(desc);
-
-		if (lineinfo_ensure_abi_version(cdev, 1))
-			return -EPERM;
-
-		if (test_and_set_bit(lineinfo.line_offset, cdev->watched_lines))
-			return -EBUSY;
-
-		gpio_desc_to_lineinfo(desc, &lineinfo_v2);
-		gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo);
-
-		if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) {
-			clear_bit(lineinfo.line_offset, cdev->watched_lines);
-			return -EFAULT;
-		}
-
-		return 0;
+	} else if (cmd == GPIO_GET_LINEINFO_IOCTL ||
+		   cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) {
+		return lineinfo_get_v1(cdev, ip,
+				       cmd == GPIO_GET_LINEINFO_WATCH_IOCTL);
 #endif /* CONFIG_GPIO_CDEV_V1 */
 	} else if (cmd == GPIO_V2_GET_LINEINFO_IOCTL ||
 		   cmd == GPIO_V2_GET_LINEINFO_WATCH_IOCTL) {
@@ -2100,16 +2131,7 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	} else if (cmd == GPIO_V2_GET_LINE_IOCTL) {
 		return linereq_create(gdev, ip);
 	} else if (cmd == GPIO_GET_LINEINFO_UNWATCH_IOCTL) {
-		if (copy_from_user(&offset, ip, sizeof(offset)))
-			return -EFAULT;
-
-		if (offset >= cdev->gdev->ngpio)
-			return -EINVAL;
-
-		if (!test_and_clear_bit(offset, cdev->watched_lines))
-			return -EBUSY;
-
-		return 0;
+		return lineinfo_unwatch(cdev, ip);
 	}
 	return -EINVAL;
 }