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, 467 insertions, 0 deletions

diff --git a/drivers/hwmon/lm83.c b/drivers/hwmon/lm83.c
new file mode 100644
index 000000000..8d49df8c9
--- /dev/null
+++ b/drivers/hwmon/lm83.c
@@ -0,0 +1,467 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
+ *          monitoring
+ * Copyright (C) 2003-2009  Jean Delvare <jdelvare@suse.de>
+ *
+ * Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
+ * a sensor chip made by National Semiconductor. It reports up to four
+ * temperatures (its own plus up to three external ones) with a 1 deg
+ * resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
+ * from National's website at:
+ *   http://www.national.com/pf/LM/LM83.html
+ * Since the datasheet omits to give the chip stepping code, I give it
+ * here: 0x03 (at register 0xff).
+ *
+ * Also supports the LM82 temp sensor, which is basically a stripped down
+ * model of the LM83.  Datasheet is here:
+ * http://www.national.com/pf/LM/LM82.html
+ */
+
+#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/regmap.h>
+#include <linux/slab.h>
+
+/*
+ * Addresses to scan
+ * Address is selected using 2 three-level pins, resulting in 9 possible
+ * addresses.
+ */
+
+static const unsigned short normal_i2c[] = {
+	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
+
+enum chips { lm83, lm82 };
+
+/*
+ * The LM83 registers
+ * Manufacturer ID is 0x01 for National Semiconductor.
+ */
+
+#define LM83_REG_R_MAN_ID		0xFE
+#define LM83_REG_R_CHIP_ID		0xFF
+#define LM83_REG_R_CONFIG		0x03
+#define LM83_REG_W_CONFIG		0x09
+#define LM83_REG_R_STATUS1		0x02
+#define LM83_REG_R_STATUS2		0x35
+#define LM83_REG_R_LOCAL_TEMP		0x00
+#define LM83_REG_R_LOCAL_HIGH		0x05
+#define LM83_REG_W_LOCAL_HIGH		0x0B
+#define LM83_REG_R_REMOTE1_TEMP		0x30
+#define LM83_REG_R_REMOTE1_HIGH		0x38
+#define LM83_REG_W_REMOTE1_HIGH		0x50
+#define LM83_REG_R_REMOTE2_TEMP		0x01
+#define LM83_REG_R_REMOTE2_HIGH		0x07
+#define LM83_REG_W_REMOTE2_HIGH		0x0D
+#define LM83_REG_R_REMOTE3_TEMP		0x31
+#define LM83_REG_R_REMOTE3_HIGH		0x3A
+#define LM83_REG_W_REMOTE3_HIGH		0x52
+#define LM83_REG_R_TCRIT		0x42
+#define LM83_REG_W_TCRIT		0x5A
+
+static const u8 LM83_REG_TEMP[] = {
+	LM83_REG_R_LOCAL_TEMP,
+	LM83_REG_R_REMOTE1_TEMP,
+	LM83_REG_R_REMOTE2_TEMP,
+	LM83_REG_R_REMOTE3_TEMP,
+};
+
+static const u8 LM83_REG_MAX[] = {
+	LM83_REG_R_LOCAL_HIGH,
+	LM83_REG_R_REMOTE1_HIGH,
+	LM83_REG_R_REMOTE2_HIGH,
+	LM83_REG_R_REMOTE3_HIGH,
+};
+
+/* alarm and fault registers and bits, indexed by channel */
+static const u8 LM83_ALARM_REG[] = {
+	LM83_REG_R_STATUS1, LM83_REG_R_STATUS2, LM83_REG_R_STATUS1, LM83_REG_R_STATUS2
+};
+
+static const u8 LM83_MAX_ALARM_BIT[] = {
+	BIT(6), BIT(7), BIT(4), BIT(4)
+};
+
+static const u8 LM83_CRIT_ALARM_BIT[] = {
+	BIT(0), BIT(0), BIT(1), BIT(1)
+};
+
+static const u8 LM83_FAULT_BIT[] = {
+	0, BIT(5), BIT(2), BIT(2)
+};
+
+/*
+ * Client data (each client gets its own)
+ */
+
+struct lm83_data {
+	struct regmap *regmap;
+	enum chips type;
+};
+
+/* regmap code */
+
+static int lm83_regmap_reg_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct i2c_client *client = context;
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(client, reg);
+	if (ret < 0)
+		return ret;
+
+	*val = ret;
+	return 0;
+}
+
+/*
+ * The regmap write function maps read register addresses to write register
+ * addresses. This is necessary for regmap register caching to work.
+ * An alternative would be to clear the regmap cache whenever a register is
+ * written, but that would be much more expensive.
+ */
+static int lm83_regmap_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct i2c_client *client = context;
+
+	switch (reg) {
+	case LM83_REG_R_CONFIG:
+	case LM83_REG_R_LOCAL_HIGH:
+	case LM83_REG_R_REMOTE2_HIGH:
+		reg += 0x06;
+		break;
+	case LM83_REG_R_REMOTE1_HIGH:
+	case LM83_REG_R_REMOTE3_HIGH:
+	case LM83_REG_R_TCRIT:
+		reg += 0x18;
+		break;
+	default:
+		break;
+	}
+
+	return i2c_smbus_write_byte_data(client, reg, val);
+}
+
+static bool lm83_regmap_is_volatile(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case LM83_REG_R_LOCAL_TEMP:
+	case LM83_REG_R_REMOTE1_TEMP:
+	case LM83_REG_R_REMOTE2_TEMP:
+	case LM83_REG_R_REMOTE3_TEMP:
+	case LM83_REG_R_STATUS1:
+	case LM83_REG_R_STATUS2:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config lm83_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.cache_type = REGCACHE_MAPLE,
+	.volatile_reg = lm83_regmap_is_volatile,
+	.reg_read = lm83_regmap_reg_read,
+	.reg_write = lm83_regmap_reg_write,
+};
+
+/* hwmon API */
+
+static int lm83_temp_read(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct lm83_data *data = dev_get_drvdata(dev);
+	unsigned int regval;
+	int err;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		err = regmap_read(data->regmap, LM83_REG_TEMP[channel], &regval);
+		if (err < 0)
+			return err;
+		*val = (s8)regval * 1000;
+		break;
+	case hwmon_temp_max:
+		err = regmap_read(data->regmap, LM83_REG_MAX[channel], &regval);
+		if (err < 0)
+			return err;
+		*val = (s8)regval * 1000;
+		break;
+	case hwmon_temp_crit:
+		err = regmap_read(data->regmap, LM83_REG_R_TCRIT, &regval);
+		if (err < 0)
+			return err;
+		*val = (s8)regval * 1000;
+		break;
+	case hwmon_temp_max_alarm:
+		err = regmap_read(data->regmap, LM83_ALARM_REG[channel], &regval);
+		if (err < 0)
+			return err;
+		*val = !!(regval & LM83_MAX_ALARM_BIT[channel]);
+		break;
+	case hwmon_temp_crit_alarm:
+		err = regmap_read(data->regmap, LM83_ALARM_REG[channel], &regval);
+		if (err < 0)
+			return err;
+		*val = !!(regval & LM83_CRIT_ALARM_BIT[channel]);
+		break;
+	case hwmon_temp_fault:
+		err = regmap_read(data->regmap, LM83_ALARM_REG[channel], &regval);
+		if (err < 0)
+			return err;
+		*val = !!(regval & LM83_FAULT_BIT[channel]);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int lm83_temp_write(struct device *dev, u32 attr, int channel, long val)
+{
+	struct lm83_data *data = dev_get_drvdata(dev);
+	unsigned int regval;
+	int err;
+
+	regval = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);
+
+	switch (attr) {
+	case hwmon_temp_max:
+		err = regmap_write(data->regmap, LM83_REG_MAX[channel], regval);
+		if (err < 0)
+			return err;
+		break;
+	case hwmon_temp_crit:
+		err = regmap_write(data->regmap, LM83_REG_R_TCRIT, regval);
+		if (err < 0)
+			return err;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int lm83_chip_read(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct lm83_data *data = dev_get_drvdata(dev);
+	unsigned int regval;
+	int err;
+
+	switch (attr) {
+	case hwmon_chip_alarms:
+		err = regmap_read(data->regmap, LM83_REG_R_STATUS1, &regval);
+		if (err < 0)
+			return err;
+		*val = regval;
+		err = regmap_read(data->regmap, LM83_REG_R_STATUS2, &regval);
+		if (err < 0)
+			return err;
+		*val |= regval << 8;
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int lm83_read(struct device *dev, enum hwmon_sensor_types type,
+		     u32 attr, int channel, long *val)
+{
+	switch (type) {
+	case hwmon_chip:
+		return lm83_chip_read(dev, attr, channel, val);
+	case hwmon_temp:
+		return lm83_temp_read(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int lm83_write(struct device *dev, enum hwmon_sensor_types type,
+		      u32 attr, int channel, long val)
+{
+	switch (type) {
+	case hwmon_temp:
+		return lm83_temp_write(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t lm83_is_visible(const void *_data, enum hwmon_sensor_types type,
+			       u32 attr, int channel)
+{
+	const struct lm83_data *data = _data;
+
+	/*
+	 * LM82 only supports a single external channel, modeled as channel 2.
+	 */
+	if (data->type == lm82 && (channel == 1 || channel == 3))
+		return 0;
+
+	switch (type) {
+	case hwmon_chip:
+		if (attr == hwmon_chip_alarms)
+			return 0444;
+		break;
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_input:
+		case hwmon_temp_max_alarm:
+		case hwmon_temp_crit_alarm:
+			return 0444;
+		case hwmon_temp_fault:
+			if (channel)
+				return 0444;
+			break;
+		case hwmon_temp_max:
+			return 0644;
+		case hwmon_temp_crit:
+			if (channel == 2)
+				return 0644;
+			return 0444;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static const struct hwmon_channel_info * const lm83_info[] = {
+	HWMON_CHANNEL_INFO(chip, HWMON_C_ALARMS),
+	HWMON_CHANNEL_INFO(temp,
+			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM,
+			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
+			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
+			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT
+			   ),
+	NULL
+};
+
+static const struct hwmon_ops lm83_hwmon_ops = {
+	.is_visible = lm83_is_visible,
+	.read = lm83_read,
+	.write = lm83_write,
+};
+
+static const struct hwmon_chip_info lm83_chip_info = {
+	.ops = &lm83_hwmon_ops,
+	.info = lm83_info,
+};
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int lm83_detect(struct i2c_client *client,
+		       struct i2c_board_info *info)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	const char *name;
+	u8 man_id, chip_id;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -ENODEV;
+
+	/* Detection */
+	if ((i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1) & 0xA8) ||
+	    (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2) & 0x48) ||
+	    (i2c_smbus_read_byte_data(client, LM83_REG_R_CONFIG) & 0x41)) {
+		dev_dbg(&adapter->dev, "LM83 detection failed at 0x%02x\n",
+			client->addr);
+		return -ENODEV;
+	}
+
+	/* Identification */
+	man_id = i2c_smbus_read_byte_data(client, LM83_REG_R_MAN_ID);
+	if (man_id != 0x01)	/* National Semiconductor */
+		return -ENODEV;
+
+	chip_id = i2c_smbus_read_byte_data(client, LM83_REG_R_CHIP_ID);
+	switch (chip_id) {
+	case 0x03:
+		/*
+		 * According to the LM82 datasheet dated March 2013, recent
+		 * revisions of LM82 have a die revision of 0x03. This was
+		 * confirmed with a real chip. Further details in this revision
+		 * of the LM82 datasheet strongly suggest that LM82 is just a
+		 * repackaged LM83. It is therefore impossible to distinguish
+		 * those chips from LM83, and they will be misdetected as LM83.
+		 */
+		name = "lm83";
+		break;
+	case 0x01:
+		name = "lm82";
+		break;
+	default:
+		/* identification failed */
+		dev_dbg(&adapter->dev,
+			"Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
+			man_id, chip_id);
+		return -ENODEV;
+	}
+
+	strscpy(info->type, name, I2C_NAME_SIZE);
+
+	return 0;
+}
+
+static int lm83_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct device *hwmon_dev;
+	struct lm83_data *data;
+
+	data = devm_kzalloc(dev, sizeof(struct lm83_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->regmap = devm_regmap_init(dev, NULL, client, &lm83_regmap_config);
+	if (IS_ERR(data->regmap))
+		return PTR_ERR(data->regmap);
+
+	data->type = (uintptr_t)i2c_get_match_data(client);
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
+							 data, &lm83_chip_info, NULL);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+/*
+ * Driver data (common to all clients)
+ */
+
+static const struct i2c_device_id lm83_id[] = {
+	{ .name = "lm83", .driver_data = lm83 },
+	{ .name = "lm82", .driver_data = lm82 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, lm83_id);
+
+static struct i2c_driver lm83_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "lm83",
+	},
+	.probe		= lm83_probe,
+	.id_table	= lm83_id,
+	.detect		= lm83_detect,
+	.address_list	= normal_i2c,
+};
+
+module_i2c_driver(lm83_driver);
+
+MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
+MODULE_DESCRIPTION("LM83 driver");
+MODULE_LICENSE("GPL");