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, 431 insertions, 0 deletions

diff --git a/drivers/hwmon/lm92.c b/drivers/hwmon/lm92.c
new file mode 100644
index 000000000..4aadbabc2
--- /dev/null
+++ b/drivers/hwmon/lm92.c
@@ -0,0 +1,431 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * lm92 - Hardware monitoring driver
+ * Copyright (C) 2005-2008  Jean Delvare <jdelvare@suse.de>
+ *
+ * Based on the lm90 driver, with some ideas taken from the lm_sensors
+ * lm92 driver as well.
+ *
+ * The LM92 is a sensor chip made by National Semiconductor. It reports
+ * its own temperature with a 0.0625 deg resolution and a 0.33 deg
+ * accuracy. Complete datasheet can be obtained from National's website
+ * at:
+ *   http://www.national.com/pf/LM/LM92.html
+ *
+ * This driver also supports the MAX6635 sensor chip made by Maxim.
+ * This chip is compatible with the LM92, but has a lesser accuracy
+ * (1.0 deg). Complete datasheet can be obtained from Maxim's website
+ * at:
+ *   http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3074
+ *
+ * Since the LM92 was the first chipset supported by this driver, most
+ * comments will refer to this chipset, but are actually general and
+ * concern all supported chipsets, unless mentioned otherwise.
+ *
+ * Support could easily be added for the National Semiconductor LM76
+ * and Maxim MAX6633 and MAX6634 chips, which are mostly compatible
+ * with the LM92.
+ */
+
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+/*
+ * The LM92 and MAX6635 have 2 two-state pins for address selection,
+ * resulting in 4 possible addresses.
+ */
+static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
+						I2C_CLIENT_END };
+/* The LM92 registers */
+#define LM92_REG_CONFIG			0x01 /* 8-bit, RW */
+#define LM92_REG_TEMP			0x00 /* 16-bit, RO */
+#define LM92_REG_TEMP_HYST		0x02 /* 16-bit, RW */
+#define LM92_REG_TEMP_CRIT		0x03 /* 16-bit, RW */
+#define LM92_REG_TEMP_LOW		0x04 /* 16-bit, RW */
+#define LM92_REG_TEMP_HIGH		0x05 /* 16-bit, RW */
+#define LM92_REG_MAN_ID			0x07 /* 16-bit, RO, LM92 only */
+
+/*
+ * The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius,
+ * left-justified in 16-bit registers. No rounding is done, with such
+ * a resolution it's just not worth it. Note that the MAX6635 doesn't
+ * make use of the 4 lower bits for limits (i.e. effective resolution
+ * for limits is 1 degree Celsius).
+ */
+static inline int TEMP_FROM_REG(s16 reg)
+{
+	return reg / 8 * 625 / 10;
+}
+
+static inline s16 TEMP_TO_REG(long val, int resolution)
+{
+	val = clamp_val(val, -60000, 160000);
+	return DIV_ROUND_CLOSEST(val << (resolution - 9), 1000) << (16 - resolution);
+}
+
+/* Alarm flags are stored in the 3 LSB of the temperature register */
+static inline u8 ALARMS_FROM_REG(s16 reg)
+{
+	return reg & 0x0007;
+}
+
+/* Client data (each client gets its own) */
+struct lm92_data {
+	struct regmap *regmap;
+	int resolution;
+};
+
+static int lm92_temp_read(struct lm92_data *data, u32 attr, int channel, long *val)
+{
+	int reg = -1, hyst_reg = -1, alarm_bit = 0;
+	struct regmap *regmap = data->regmap;
+	u32 temp;
+	int ret;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		reg = LM92_REG_TEMP;
+		break;
+	case hwmon_temp_min:
+		reg = LM92_REG_TEMP_LOW;
+		break;
+	case hwmon_temp_max:
+		reg = LM92_REG_TEMP_HIGH;
+		break;
+	case hwmon_temp_crit:
+		reg = LM92_REG_TEMP_CRIT;
+		break;
+	case hwmon_temp_min_hyst:
+		hyst_reg = LM92_REG_TEMP_LOW;
+		break;
+	case hwmon_temp_max_hyst:
+		hyst_reg = LM92_REG_TEMP_HIGH;
+		break;
+	case hwmon_temp_crit_hyst:
+		hyst_reg = LM92_REG_TEMP_CRIT;
+		break;
+	case hwmon_temp_min_alarm:
+		alarm_bit = 0;
+		break;
+	case hwmon_temp_max_alarm:
+		alarm_bit = 1;
+		break;
+	case hwmon_temp_crit_alarm:
+		alarm_bit = 2;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	if (reg >= 0) {
+		ret = regmap_read(regmap, reg, &temp);
+		if (ret < 0)
+			return ret;
+		*val = TEMP_FROM_REG(temp);
+	} else if (hyst_reg >= 0) {
+		u32 regs[2] = { hyst_reg, LM92_REG_TEMP_HYST };
+		u16 regvals[2];
+
+		ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
+		if (ret)
+			return ret;
+		if (attr == hwmon_temp_min_hyst)
+			*val = TEMP_FROM_REG(regvals[0]) + TEMP_FROM_REG(regvals[1]);
+		else
+			*val = TEMP_FROM_REG(regvals[0]) - TEMP_FROM_REG(regvals[1]);
+	} else {
+		ret = regmap_read(regmap, LM92_REG_TEMP, &temp);
+		if (ret)
+			return ret;
+		*val = !!(temp & BIT(alarm_bit));
+	}
+	return 0;
+}
+
+static int lm92_chip_read(struct lm92_data *data, u32 attr, long *val)
+{
+	u32 temp;
+	int ret;
+
+	switch (attr) {
+	case hwmon_chip_alarms:
+		ret = regmap_read(data->regmap, LM92_REG_TEMP, &temp);
+		if (ret)
+			return ret;
+		*val = ALARMS_FROM_REG(temp);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int lm92_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+		     int channel, long *val)
+{
+	struct lm92_data *data = dev_get_drvdata(dev);
+
+	switch (type) {
+	case hwmon_chip:
+		return lm92_chip_read(data, attr, val);
+	case hwmon_temp:
+		return lm92_temp_read(data, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int lm92_temp_write(struct lm92_data *data, u32 attr, long val)
+{
+	struct regmap *regmap = data->regmap;
+	int reg, err;
+	u32 temp;
+
+	switch (attr) {
+	case hwmon_temp_min:
+		reg = LM92_REG_TEMP_LOW;
+		break;
+	case hwmon_temp_max:
+		reg = LM92_REG_TEMP_HIGH;
+		break;
+	case hwmon_temp_crit:
+		reg = LM92_REG_TEMP_CRIT;
+		break;
+	case hwmon_temp_crit_hyst:
+		val = clamp_val(val, -120000, 220000);
+		err = regmap_read(regmap, LM92_REG_TEMP_CRIT, &temp);
+		if (err)
+			return err;
+		val = TEMP_TO_REG(TEMP_FROM_REG(temp) - val, data->resolution);
+		return regmap_write(regmap, LM92_REG_TEMP_HYST, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+	return regmap_write(regmap, reg, TEMP_TO_REG(val, data->resolution));
+}
+
+static int lm92_write(struct device *dev, enum hwmon_sensor_types type,
+		      u32 attr, int channel, long val)
+{
+	struct lm92_data *data = dev_get_drvdata(dev);
+
+	switch (type) {
+	case hwmon_temp:
+		return lm92_temp_write(data, attr, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t lm92_is_visible(const void *_data, enum hwmon_sensor_types type,
+			       u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_chip:
+		switch (attr) {
+		case hwmon_chip_alarms:
+			return 0444;
+		default:
+			break;
+		}
+		break;
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_min:
+		case hwmon_temp_max:
+		case hwmon_temp_crit:
+		case hwmon_temp_crit_hyst:
+			return 0644;
+		case hwmon_temp_input:
+		case hwmon_temp_min_hyst:
+		case hwmon_temp_max_hyst:
+		case hwmon_temp_min_alarm:
+		case hwmon_temp_max_alarm:
+		case hwmon_temp_crit_alarm:
+			return 0444;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static const struct hwmon_channel_info * const lm92_info[] = {
+	HWMON_CHANNEL_INFO(chip, HWMON_C_ALARMS),
+	HWMON_CHANNEL_INFO(temp,
+			   HWMON_T_INPUT |
+			   HWMON_T_MIN | HWMON_T_MIN_HYST |
+			   HWMON_T_MAX | HWMON_T_MAX_HYST |
+			   HWMON_T_CRIT | HWMON_T_CRIT_HYST |
+			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
+			   HWMON_T_CRIT_ALARM),
+	NULL
+};
+
+static const struct hwmon_ops lm92_hwmon_ops = {
+	.is_visible = lm92_is_visible,
+	.read = lm92_read,
+	.write = lm92_write,
+};
+
+static const struct hwmon_chip_info lm92_chip_info = {
+	.ops = &lm92_hwmon_ops,
+	.info = lm92_info,
+};
+
+/*
+ * Detection and registration
+ */
+
+static int lm92_init_client(struct regmap *regmap)
+{
+	return regmap_clear_bits(regmap, LM92_REG_CONFIG, 0x01);
+}
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int lm92_detect(struct i2c_client *new_client,
+		       struct i2c_board_info *info)
+{
+	struct i2c_adapter *adapter = new_client->adapter;
+	u8 config_addr = LM92_REG_CONFIG;
+	u8 man_id_addr = LM92_REG_MAN_ID;
+	int i, regval;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
+					    | I2C_FUNC_SMBUS_WORD_DATA))
+		return -ENODEV;
+
+	/*
+	 * Register values repeat with multiples of 8.
+	 * Read twice to improve detection accuracy.
+	 */
+	for (i = 0; i < 2; i++) {
+		regval = i2c_smbus_read_word_data(new_client, man_id_addr);
+		if (regval != 0x0180)
+			return -ENODEV;
+		regval = i2c_smbus_read_byte_data(new_client, config_addr);
+		if (regval < 0 || (regval & 0xe0))
+			return -ENODEV;
+		config_addr += 8;
+		man_id_addr += 8;
+	}
+
+	strscpy(info->type, "lm92", I2C_NAME_SIZE);
+
+	return 0;
+}
+
+/* regmap */
+
+static int lm92_reg_read(void *context, unsigned int reg, unsigned int *val)
+{
+	int ret;
+
+	if (reg == LM92_REG_CONFIG)
+		ret = i2c_smbus_read_byte_data(context, reg);
+	else
+		ret = i2c_smbus_read_word_swapped(context, reg);
+	if (ret < 0)
+		return ret;
+
+	*val = ret;
+	return 0;
+}
+
+static int lm92_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+	if (reg == LM92_REG_CONFIG)
+		return i2c_smbus_write_byte_data(context, LM92_REG_CONFIG, val);
+
+	return i2c_smbus_write_word_swapped(context, reg, val);
+}
+
+static bool lm92_regmap_is_volatile(struct device *dev, unsigned int reg)
+{
+	return reg == LM92_REG_TEMP;
+}
+
+static bool lm92_regmap_is_writeable(struct device *dev, unsigned int reg)
+{
+	return reg >= LM92_REG_CONFIG;
+}
+
+static const struct regmap_config lm92_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 16,
+	.max_register = LM92_REG_TEMP_HIGH,
+	.cache_type = REGCACHE_MAPLE,
+	.volatile_reg = lm92_regmap_is_volatile,
+	.writeable_reg = lm92_regmap_is_writeable,
+};
+
+static const struct regmap_bus lm92_regmap_bus = {
+	.reg_write = lm92_reg_write,
+	.reg_read = lm92_reg_read,
+};
+
+static int lm92_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct device *hwmon_dev;
+	struct lm92_data *data;
+	struct regmap *regmap;
+	int err;
+
+	regmap = devm_regmap_init(dev, &lm92_regmap_bus, client,
+				  &lm92_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	data = devm_kzalloc(dev, sizeof(struct lm92_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->regmap = regmap;
+	data->resolution = (unsigned long)i2c_get_match_data(client);
+
+	/* Initialize the chipset */
+	err = lm92_init_client(regmap);
+	if (err)
+		return err;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data,
+							 &lm92_chip_info, NULL);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+/*
+ * Module and driver stuff
+ */
+
+/* .driver_data is limit register resolution */
+static const struct i2c_device_id lm92_id[] = {
+	{ .name = "lm92", .driver_data = 13 },
+	{ .name = "max6635", .driver_data = 9 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, lm92_id);
+
+static struct i2c_driver lm92_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "lm92",
+	},
+	.probe		= lm92_probe,
+	.id_table	= lm92_id,
+	.detect		= lm92_detect,
+	.address_list	= normal_i2c,
+};
+
+module_i2c_driver(lm92_driver);
+
+MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
+MODULE_DESCRIPTION("LM92/MAX6635 driver");
+MODULE_LICENSE("GPL");