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, 439 insertions, 0 deletions

diff --git a/drivers/hwmon/max31730.c b/drivers/hwmon/max31730.c
new file mode 100644
index 000000000..d132be2d6
--- /dev/null
+++ b/drivers/hwmon/max31730.c
@@ -0,0 +1,439 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for MAX31730 3-Channel Remote Temperature Sensor
+ *
+ * Copyright (c) 2019 Guenter Roeck <linux@roeck-us.net>
+ */
+
+#include <linux/bits.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/hwmon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+/* Addresses scanned */
+static const unsigned short normal_i2c[] = { 0x1c, 0x1d, 0x1e, 0x1f, 0x4c,
+					     0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
+
+/* The MAX31730 registers */
+#define MAX31730_REG_TEMP		0x00
+#define MAX31730_REG_CONF		0x13
+#define  MAX31730_STOP			BIT(7)
+#define  MAX31730_EXTRANGE		BIT(1)
+#define MAX31730_REG_TEMP_OFFSET	0x16
+#define  MAX31730_TEMP_OFFSET_BASELINE	0x77
+#define MAX31730_REG_OFFSET_ENABLE	0x17
+#define MAX31730_REG_TEMP_MAX		0x20
+#define MAX31730_REG_TEMP_MIN		0x30
+#define MAX31730_REG_STATUS_HIGH	0x32
+#define MAX31730_REG_STATUS_LOW		0x33
+#define MAX31730_REG_CHANNEL_ENABLE	0x35
+#define MAX31730_REG_TEMP_FAULT		0x36
+
+#define MAX31730_REG_MFG_ID		0x50
+#define  MAX31730_MFG_ID		0x4d
+#define MAX31730_REG_MFG_REV		0x51
+#define  MAX31730_MFG_REV		0x01
+
+#define MAX31730_TEMP_MIN		(-128000)
+#define MAX31730_TEMP_MAX		127937
+
+/* Each client has this additional data */
+struct max31730_data {
+	struct i2c_client	*client;
+	u8			orig_conf;
+	u8			current_conf;
+	u8			offset_enable;
+	u8			channel_enable;
+};
+
+/*-----------------------------------------------------------------------*/
+
+static inline long max31730_reg_to_mc(s16 temp)
+{
+	return DIV_ROUND_CLOSEST((temp >> 4) * 1000, 16);
+}
+
+static int max31730_write_config(struct max31730_data *data, u8 set_mask,
+				 u8 clr_mask)
+{
+	u8 value;
+
+	clr_mask |= MAX31730_EXTRANGE;
+	value = data->current_conf & ~clr_mask;
+	value |= set_mask;
+
+	if (data->current_conf != value) {
+		s32 err;
+
+		err = i2c_smbus_write_byte_data(data->client, MAX31730_REG_CONF,
+						value);
+		if (err)
+			return err;
+		data->current_conf = value;
+	}
+	return 0;
+}
+
+static int max31730_set_enable(struct i2c_client *client, int reg,
+			       u8 *confdata, int channel, bool enable)
+{
+	u8 regval = *confdata;
+	int err;
+
+	if (enable)
+		regval |= BIT(channel);
+	else
+		regval &= ~BIT(channel);
+
+	if (regval != *confdata) {
+		err = i2c_smbus_write_byte_data(client, reg, regval);
+		if (err)
+			return err;
+		*confdata = regval;
+	}
+	return 0;
+}
+
+static int max31730_set_offset_enable(struct max31730_data *data, int channel,
+				      bool enable)
+{
+	return max31730_set_enable(data->client, MAX31730_REG_OFFSET_ENABLE,
+				   &data->offset_enable, channel, enable);
+}
+
+static int max31730_set_channel_enable(struct max31730_data *data, int channel,
+				       bool enable)
+{
+	return max31730_set_enable(data->client, MAX31730_REG_CHANNEL_ENABLE,
+				   &data->channel_enable, channel, enable);
+}
+
+static int max31730_read(struct device *dev, enum hwmon_sensor_types type,
+			 u32 attr, int channel, long *val)
+{
+	struct max31730_data *data = dev_get_drvdata(dev);
+	int regval, reg, offset;
+
+	if (type != hwmon_temp)
+		return -EINVAL;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		if (!(data->channel_enable & BIT(channel)))
+			return -ENODATA;
+		reg = MAX31730_REG_TEMP + (channel * 2);
+		break;
+	case hwmon_temp_max:
+		reg = MAX31730_REG_TEMP_MAX + (channel * 2);
+		break;
+	case hwmon_temp_min:
+		reg = MAX31730_REG_TEMP_MIN;
+		break;
+	case hwmon_temp_enable:
+		*val = !!(data->channel_enable & BIT(channel));
+		return 0;
+	case hwmon_temp_offset:
+		if (!channel)
+			return -EINVAL;
+		if (!(data->offset_enable & BIT(channel))) {
+			*val = 0;
+			return 0;
+		}
+		offset = i2c_smbus_read_byte_data(data->client,
+						  MAX31730_REG_TEMP_OFFSET);
+		if (offset < 0)
+			return offset;
+		*val = (offset - MAX31730_TEMP_OFFSET_BASELINE) * 125;
+		return 0;
+	case hwmon_temp_fault:
+		regval = i2c_smbus_read_byte_data(data->client,
+						  MAX31730_REG_TEMP_FAULT);
+		if (regval < 0)
+			return regval;
+		*val = !!(regval & BIT(channel));
+		return 0;
+	case hwmon_temp_min_alarm:
+		regval = i2c_smbus_read_byte_data(data->client,
+						  MAX31730_REG_STATUS_LOW);
+		if (regval < 0)
+			return regval;
+		*val = !!(regval & BIT(channel));
+		return 0;
+	case hwmon_temp_max_alarm:
+		regval = i2c_smbus_read_byte_data(data->client,
+						  MAX31730_REG_STATUS_HIGH);
+		if (regval < 0)
+			return regval;
+		*val = !!(regval & BIT(channel));
+		return 0;
+	default:
+		return -EINVAL;
+	}
+	regval = i2c_smbus_read_word_swapped(data->client, reg);
+	if (regval < 0)
+		return regval;
+
+	*val = max31730_reg_to_mc(regval);
+
+	return 0;
+}
+
+static int max31730_write(struct device *dev, enum hwmon_sensor_types type,
+			  u32 attr, int channel, long val)
+{
+	struct max31730_data *data = dev_get_drvdata(dev);
+	int reg, err;
+
+	if (type != hwmon_temp)
+		return -EINVAL;
+
+	switch (attr) {
+	case hwmon_temp_max:
+		reg = MAX31730_REG_TEMP_MAX + channel * 2;
+		break;
+	case hwmon_temp_min:
+		reg = MAX31730_REG_TEMP_MIN;
+		break;
+	case hwmon_temp_enable:
+		if (val != 0 && val != 1)
+			return -EINVAL;
+		return max31730_set_channel_enable(data, channel, val);
+	case hwmon_temp_offset:
+		val = clamp_val(val, -14875, 17000) + 14875;
+		val = DIV_ROUND_CLOSEST(val, 125);
+		err = max31730_set_offset_enable(data, channel,
+					val != MAX31730_TEMP_OFFSET_BASELINE);
+		if (err)
+			return err;
+		return i2c_smbus_write_byte_data(data->client,
+						 MAX31730_REG_TEMP_OFFSET, val);
+	default:
+		return -EINVAL;
+	}
+
+	val = clamp_val(val, MAX31730_TEMP_MIN, MAX31730_TEMP_MAX);
+	val = DIV_ROUND_CLOSEST(val << 4, 1000) << 4;
+
+	return i2c_smbus_write_word_swapped(data->client, reg, (u16)val);
+}
+
+static umode_t max31730_is_visible(const void *data,
+				   enum hwmon_sensor_types type,
+				   u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_input:
+		case hwmon_temp_min_alarm:
+		case hwmon_temp_max_alarm:
+		case hwmon_temp_fault:
+			return 0444;
+		case hwmon_temp_min:
+			return channel ? 0444 : 0644;
+		case hwmon_temp_offset:
+		case hwmon_temp_enable:
+		case hwmon_temp_max:
+			return 0644;
+		}
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static const struct hwmon_channel_info * const max31730_info[] = {
+	HWMON_CHANNEL_INFO(chip,
+			   HWMON_C_REGISTER_TZ),
+	HWMON_CHANNEL_INFO(temp,
+			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			   HWMON_T_ENABLE |
+			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM,
+			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			   HWMON_T_OFFSET | HWMON_T_ENABLE |
+			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
+			   HWMON_T_FAULT,
+			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			   HWMON_T_OFFSET | HWMON_T_ENABLE |
+			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
+			   HWMON_T_FAULT,
+			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			   HWMON_T_OFFSET | HWMON_T_ENABLE |
+			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
+			   HWMON_T_FAULT
+			   ),
+	NULL
+};
+
+static const struct hwmon_ops max31730_hwmon_ops = {
+	.is_visible = max31730_is_visible,
+	.read = max31730_read,
+	.write = max31730_write,
+};
+
+static const struct hwmon_chip_info max31730_chip_info = {
+	.ops = &max31730_hwmon_ops,
+	.info = max31730_info,
+};
+
+static void max31730_remove(void *data)
+{
+	struct max31730_data *max31730 = data;
+	struct i2c_client *client = max31730->client;
+
+	i2c_smbus_write_byte_data(client, MAX31730_REG_CONF,
+				  max31730->orig_conf);
+}
+
+static int
+max31730_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct device *hwmon_dev;
+	struct max31730_data *data;
+	int status, err;
+
+	if (!i2c_check_functionality(client->adapter,
+			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
+		return -EIO;
+
+	data = devm_kzalloc(dev, sizeof(struct max31730_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = client;
+
+	/* Cache original configuration and enable status */
+	status = i2c_smbus_read_byte_data(client, MAX31730_REG_CHANNEL_ENABLE);
+	if (status < 0)
+		return status;
+	data->channel_enable = status;
+
+	status = i2c_smbus_read_byte_data(client, MAX31730_REG_OFFSET_ENABLE);
+	if (status < 0)
+		return status;
+	data->offset_enable = status;
+
+	status = i2c_smbus_read_byte_data(client, MAX31730_REG_CONF);
+	if (status < 0)
+		return status;
+	data->orig_conf = status;
+	data->current_conf = status;
+
+	err = max31730_write_config(data,
+				    data->channel_enable ? 0 : MAX31730_STOP,
+				    data->channel_enable ? MAX31730_STOP : 0);
+	if (err)
+		return err;
+
+	dev_set_drvdata(dev, data);
+
+	err = devm_add_action_or_reset(dev, max31730_remove, data);
+	if (err)
+		return err;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
+							 data,
+							 &max31730_chip_info,
+							 NULL);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id max31730_ids[] = {
+	{ .name = "max31730" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max31730_ids);
+
+static const struct of_device_id __maybe_unused max31730_of_match[] = {
+	{
+		.compatible = "maxim,max31730",
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, max31730_of_match);
+
+static bool max31730_check_reg_temp(struct i2c_client *client,
+				    int reg)
+{
+	int regval;
+
+	regval = i2c_smbus_read_byte_data(client, reg + 1);
+	return regval < 0 || (regval & 0x0f);
+}
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int max31730_detect(struct i2c_client *client,
+			   struct i2c_board_info *info)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	int regval;
+	int i;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+				     I2C_FUNC_SMBUS_WORD_DATA))
+		return -ENODEV;
+
+	regval = i2c_smbus_read_byte_data(client, MAX31730_REG_MFG_ID);
+	if (regval != MAX31730_MFG_ID)
+		return -ENODEV;
+	regval = i2c_smbus_read_byte_data(client, MAX31730_REG_MFG_REV);
+	if (regval != MAX31730_MFG_REV)
+		return -ENODEV;
+
+	/* lower 4 bit of temperature and limit registers must be 0 */
+	if (max31730_check_reg_temp(client, MAX31730_REG_TEMP_MIN))
+		return -ENODEV;
+
+	for (i = 0; i < 4; i++) {
+		if (max31730_check_reg_temp(client, MAX31730_REG_TEMP + i * 2))
+			return -ENODEV;
+		if (max31730_check_reg_temp(client,
+					    MAX31730_REG_TEMP_MAX + i * 2))
+			return -ENODEV;
+	}
+
+	strscpy(info->type, "max31730", I2C_NAME_SIZE);
+
+	return 0;
+}
+
+static int max31730_suspend(struct device *dev)
+{
+	struct max31730_data *data = dev_get_drvdata(dev);
+
+	return max31730_write_config(data, MAX31730_STOP, 0);
+}
+
+static int max31730_resume(struct device *dev)
+{
+	struct max31730_data *data = dev_get_drvdata(dev);
+
+	return max31730_write_config(data, 0, MAX31730_STOP);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(max31730_pm_ops, max31730_suspend, max31730_resume);
+
+static struct i2c_driver max31730_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "max31730",
+		.of_match_table = of_match_ptr(max31730_of_match),
+		.pm	= pm_sleep_ptr(&max31730_pm_ops),
+	},
+	.probe		= max31730_probe,
+	.id_table	= max31730_ids,
+	.detect		= max31730_detect,
+	.address_list	= normal_i2c,
+};
+
+module_i2c_driver(max31730_driver);
+
+MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
+MODULE_DESCRIPTION("MAX31730 driver");
+MODULE_LICENSE("GPL");