Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 450 insertions, 0 deletions

diff --git a/drivers/misc/tsl2550.c b/drivers/misc/tsl2550.c
new file mode 100644
index 000000000..c871ea860
--- /dev/null
+++ b/drivers/misc/tsl2550.c
@@ -0,0 +1,450 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  tsl2550.c - Linux kernel modules for ambient light sensor
+ *
+ *  Copyright (C) 2007 Rodolfo Giometti <giometti@linux.it>
+ *  Copyright (C) 2007 Eurotech S.p.A. <info@eurotech.it>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+
+#define TSL2550_DRV_NAME	"tsl2550"
+#define DRIVER_VERSION		"1.2"
+
+/*
+ * Defines
+ */
+
+#define TSL2550_POWER_DOWN		0x00
+#define TSL2550_POWER_UP		0x03
+#define TSL2550_STANDARD_RANGE		0x18
+#define TSL2550_EXTENDED_RANGE		0x1d
+#define TSL2550_READ_ADC0		0x43
+#define TSL2550_READ_ADC1		0x83
+
+/*
+ * Structs
+ */
+
+struct tsl2550_data {
+	struct i2c_client *client;
+	struct mutex update_lock;
+
+	unsigned int power_state:1;
+	unsigned int operating_mode:1;
+};
+
+/*
+ * Global data
+ */
+
+static const u8 TSL2550_MODE_RANGE[2] = {
+	TSL2550_STANDARD_RANGE, TSL2550_EXTENDED_RANGE,
+};
+
+/*
+ * Management functions
+ */
+
+static int tsl2550_set_operating_mode(struct i2c_client *client, int mode)
+{
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+
+	int ret = i2c_smbus_write_byte(client, TSL2550_MODE_RANGE[mode]);
+
+	data->operating_mode = mode;
+
+	return ret;
+}
+
+static int tsl2550_set_power_state(struct i2c_client *client, int state)
+{
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+	int ret;
+
+	if (state == 0)
+		ret = i2c_smbus_write_byte(client, TSL2550_POWER_DOWN);
+	else {
+		ret = i2c_smbus_write_byte(client, TSL2550_POWER_UP);
+
+		/* On power up we should reset operating mode also... */
+		tsl2550_set_operating_mode(client, data->operating_mode);
+	}
+
+	data->power_state = state;
+
+	return ret;
+}
+
+static int tsl2550_get_adc_value(struct i2c_client *client, u8 cmd)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(client, cmd);
+	if (ret < 0)
+		return ret;
+	if (!(ret & 0x80))
+		return -EAGAIN;
+	return ret & 0x7f;	/* remove the "valid" bit */
+}
+
+/*
+ * LUX calculation
+ */
+
+#define	TSL2550_MAX_LUX		1846
+
+static const u8 ratio_lut[] = {
+	100, 100, 100, 100, 100, 100, 100, 100,
+	100, 100, 100, 100, 100, 100, 99, 99,
+	99, 99, 99, 99, 99, 99, 99, 99,
+	99, 99, 99, 98, 98, 98, 98, 98,
+	98, 98, 97, 97, 97, 97, 97, 96,
+	96, 96, 96, 95, 95, 95, 94, 94,
+	93, 93, 93, 92, 92, 91, 91, 90,
+	89, 89, 88, 87, 87, 86, 85, 84,
+	83, 82, 81, 80, 79, 78, 77, 75,
+	74, 73, 71, 69, 68, 66, 64, 62,
+	60, 58, 56, 54, 52, 49, 47, 44,
+	42, 41, 40, 40, 39, 39, 38, 38,
+	37, 37, 37, 36, 36, 36, 35, 35,
+	35, 35, 34, 34, 34, 34, 33, 33,
+	33, 33, 32, 32, 32, 32, 32, 31,
+	31, 31, 31, 31, 30, 30, 30, 30,
+	30,
+};
+
+static const u16 count_lut[] = {
+	0, 1, 2, 3, 4, 5, 6, 7,
+	8, 9, 10, 11, 12, 13, 14, 15,
+	16, 18, 20, 22, 24, 26, 28, 30,
+	32, 34, 36, 38, 40, 42, 44, 46,
+	49, 53, 57, 61, 65, 69, 73, 77,
+	81, 85, 89, 93, 97, 101, 105, 109,
+	115, 123, 131, 139, 147, 155, 163, 171,
+	179, 187, 195, 203, 211, 219, 227, 235,
+	247, 263, 279, 295, 311, 327, 343, 359,
+	375, 391, 407, 423, 439, 455, 471, 487,
+	511, 543, 575, 607, 639, 671, 703, 735,
+	767, 799, 831, 863, 895, 927, 959, 991,
+	1039, 1103, 1167, 1231, 1295, 1359, 1423, 1487,
+	1551, 1615, 1679, 1743, 1807, 1871, 1935, 1999,
+	2095, 2223, 2351, 2479, 2607, 2735, 2863, 2991,
+	3119, 3247, 3375, 3503, 3631, 3759, 3887, 4015,
+};
+
+/*
+ * This function is described into Taos TSL2550 Designer's Notebook
+ * pages 2, 3.
+ */
+static int tsl2550_calculate_lux(u8 ch0, u8 ch1)
+{
+	unsigned int lux;
+
+	/* Look up count from channel values */
+	u16 c0 = count_lut[ch0];
+	u16 c1 = count_lut[ch1];
+
+	/* Avoid division by 0 and count 1 cannot be greater than count 0 */
+	if (c1 <= c0)
+		if (c0) {
+			/*
+			 * Calculate ratio.
+			 * Note: the "128" is a scaling factor
+			 */
+			u8 r = c1 * 128 / c0;
+
+			/* Calculate LUX */
+			lux = ((c0 - c1) * ratio_lut[r]) / 256;
+		} else
+			lux = 0;
+	else
+		return 0;
+
+	/* LUX range check */
+	return lux > TSL2550_MAX_LUX ? TSL2550_MAX_LUX : lux;
+}
+
+/*
+ * SysFS support
+ */
+
+static ssize_t tsl2550_show_power_state(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev));
+
+	return sprintf(buf, "%u\n", data->power_state);
+}
+
+static ssize_t tsl2550_store_power_state(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+	unsigned long val;
+	int ret;
+
+	if (kstrtoul(buf, 10, &val) || val > 1)
+		return -EINVAL;
+
+	mutex_lock(&data->update_lock);
+	ret = tsl2550_set_power_state(client, val);
+	mutex_unlock(&data->update_lock);
+
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
+		   tsl2550_show_power_state, tsl2550_store_power_state);
+
+static ssize_t tsl2550_show_operating_mode(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev));
+
+	return sprintf(buf, "%u\n", data->operating_mode);
+}
+
+static ssize_t tsl2550_store_operating_mode(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+	unsigned long val;
+	int ret;
+
+	if (kstrtoul(buf, 10, &val) || val > 1)
+		return -EINVAL;
+
+	if (data->power_state == 0)
+		return -EBUSY;
+
+	mutex_lock(&data->update_lock);
+	ret = tsl2550_set_operating_mode(client, val);
+	mutex_unlock(&data->update_lock);
+
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(operating_mode, S_IWUSR | S_IRUGO,
+		   tsl2550_show_operating_mode, tsl2550_store_operating_mode);
+
+static ssize_t __tsl2550_show_lux(struct i2c_client *client, char *buf)
+{
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+	u8 ch0, ch1;
+	int ret;
+
+	ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC0);
+	if (ret < 0)
+		return ret;
+	ch0 = ret;
+
+	ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC1);
+	if (ret < 0)
+		return ret;
+	ch1 = ret;
+
+	/* Do the job */
+	ret = tsl2550_calculate_lux(ch0, ch1);
+	if (ret < 0)
+		return ret;
+	if (data->operating_mode == 1)
+		ret *= 5;
+
+	return sprintf(buf, "%d\n", ret);
+}
+
+static ssize_t tsl2550_show_lux1_input(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+	int ret;
+
+	/* No LUX data if not operational */
+	if (!data->power_state)
+		return -EBUSY;
+
+	mutex_lock(&data->update_lock);
+	ret = __tsl2550_show_lux(client, buf);
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+static DEVICE_ATTR(lux1_input, S_IRUGO,
+		   tsl2550_show_lux1_input, NULL);
+
+static struct attribute *tsl2550_attributes[] = {
+	&dev_attr_power_state.attr,
+	&dev_attr_operating_mode.attr,
+	&dev_attr_lux1_input.attr,
+	NULL
+};
+
+static const struct attribute_group tsl2550_attr_group = {
+	.attrs = tsl2550_attributes,
+};
+
+/*
+ * Initialization function
+ */
+
+static int tsl2550_init_client(struct i2c_client *client)
+{
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+	int err;
+
+	/*
+	 * Probe the chip. To do so we try to power up the device and then to
+	 * read back the 0x03 code
+	 */
+	err = i2c_smbus_read_byte_data(client, TSL2550_POWER_UP);
+	if (err < 0)
+		return err;
+	if (err != TSL2550_POWER_UP)
+		return -ENODEV;
+	data->power_state = 1;
+
+	/* Set the default operating mode */
+	err = i2c_smbus_write_byte(client,
+				   TSL2550_MODE_RANGE[data->operating_mode]);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+/*
+ * I2C init/probing/exit functions
+ */
+
+static struct i2c_driver tsl2550_driver;
+static int tsl2550_probe(struct i2c_client *client)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	struct tsl2550_data *data;
+	int *opmode, err = 0;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE
+					    | I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
+		err = -EIO;
+		goto exit;
+	}
+
+	data = kzalloc_obj(struct tsl2550_data);
+	if (!data) {
+		err = -ENOMEM;
+		goto exit;
+	}
+	data->client = client;
+	i2c_set_clientdata(client, data);
+
+	/* Check platform data */
+	opmode = client->dev.platform_data;
+	if (opmode) {
+		if (*opmode < 0 || *opmode > 1) {
+			dev_err(&client->dev, "invalid operating_mode (%d)\n",
+					*opmode);
+			err = -EINVAL;
+			goto exit_kfree;
+		}
+		data->operating_mode = *opmode;
+	} else
+		data->operating_mode = 0;	/* default mode is standard */
+	dev_info(&client->dev, "%s operating mode\n",
+			data->operating_mode ? "extended" : "standard");
+
+	mutex_init(&data->update_lock);
+
+	/* Initialize the TSL2550 chip */
+	err = tsl2550_init_client(client);
+	if (err)
+		goto exit_kfree;
+
+	/* Register sysfs hooks */
+	err = sysfs_create_group(&client->dev.kobj, &tsl2550_attr_group);
+	if (err)
+		goto exit_kfree;
+
+	dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION);
+
+	return 0;
+
+exit_kfree:
+	kfree(data);
+exit:
+	return err;
+}
+
+static void tsl2550_remove(struct i2c_client *client)
+{
+	sysfs_remove_group(&client->dev.kobj, &tsl2550_attr_group);
+
+	/* Power down the device */
+	tsl2550_set_power_state(client, 0);
+
+	kfree(i2c_get_clientdata(client));
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int tsl2550_suspend(struct device *dev)
+{
+	return tsl2550_set_power_state(to_i2c_client(dev), 0);
+}
+
+static int tsl2550_resume(struct device *dev)
+{
+	return tsl2550_set_power_state(to_i2c_client(dev), 1);
+}
+
+static SIMPLE_DEV_PM_OPS(tsl2550_pm_ops, tsl2550_suspend, tsl2550_resume);
+#define TSL2550_PM_OPS (&tsl2550_pm_ops)
+
+#else
+
+#define TSL2550_PM_OPS NULL
+
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct i2c_device_id tsl2550_id[] = {
+	{ .name = "tsl2550" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, tsl2550_id);
+
+static const struct of_device_id tsl2550_of_match[] = {
+	{ .compatible = "taos,tsl2550" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tsl2550_of_match);
+
+static struct i2c_driver tsl2550_driver = {
+	.driver = {
+		.name	= TSL2550_DRV_NAME,
+		.of_match_table = tsl2550_of_match,
+		.pm	= TSL2550_PM_OPS,
+	},
+	.probe = tsl2550_probe,
+	.remove	= tsl2550_remove,
+	.id_table = tsl2550_id,
+};
+
+module_i2c_driver(tsl2550_driver);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("TSL2550 ambient light sensor driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRIVER_VERSION);