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, 361 insertions, 0 deletions

diff --git a/drivers/hwmon/lm77.c b/drivers/hwmon/lm77.c
new file mode 100644
index 000000000..96c5c2584
--- /dev/null
+++ b/drivers/hwmon/lm77.c
@@ -0,0 +1,361 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * lm77.c - Part of lm_sensors, Linux kernel modules for hardware
+ *	    monitoring
+ *
+ * Copyright (c) 2004  Andras BALI <drewie@freemail.hu>
+ *
+ * Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>.  The LM77
+ * is a temperature sensor and thermal window comparator with 0.5 deg
+ * resolution made by National Semiconductor.  Complete datasheet can be
+ * obtained at their site:
+ *	http://www.national.com/pf/LM/LM77.html
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+
+/* Addresses to scan */
+static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
+						I2C_CLIENT_END };
+
+/* The LM77 registers */
+#define LM77_REG_TEMP		0x00
+#define LM77_REG_CONF		0x01
+#define LM77_REG_TEMP_HYST	0x02
+#define LM77_REG_TEMP_CRIT	0x03
+#define LM77_REG_TEMP_MIN	0x04
+#define LM77_REG_TEMP_MAX	0x05
+
+enum temp_index {
+	t_input = 0,
+	t_crit,
+	t_min,
+	t_max,
+	t_hyst,
+	t_num_temp
+};
+
+static const u8 temp_regs[t_num_temp] = {
+	[t_input] = LM77_REG_TEMP,
+	[t_min] = LM77_REG_TEMP_MIN,
+	[t_max] = LM77_REG_TEMP_MAX,
+	[t_crit] = LM77_REG_TEMP_CRIT,
+	[t_hyst] = LM77_REG_TEMP_HYST,
+};
+
+/* Each client has this additional data */
+struct lm77_data {
+	struct i2c_client	*client;
+	struct mutex		update_lock;
+	bool			valid;
+	unsigned long		last_updated;	/* In jiffies */
+	int			temp[t_num_temp]; /* index using temp_index */
+	u8			alarms;
+};
+
+/* straight from the datasheet */
+#define LM77_TEMP_MIN (-55000)
+#define LM77_TEMP_MAX 125000
+
+/*
+ * In the temperature registers, the low 3 bits are not part of the
+ * temperature values; they are the status bits.
+ */
+static inline s16 LM77_TEMP_TO_REG(int temp)
+{
+	return (temp / 500) * 8;
+}
+
+static inline int LM77_TEMP_FROM_REG(s16 reg)
+{
+	return (reg / 8) * 500;
+}
+
+/*
+ * All registers are word-sized, except for the configuration register.
+ * The LM77 uses the high-byte first convention.
+ */
+static u16 lm77_read_value(struct i2c_client *client, u8 reg)
+{
+	if (reg == LM77_REG_CONF)
+		return i2c_smbus_read_byte_data(client, reg);
+	else
+		return i2c_smbus_read_word_swapped(client, reg);
+}
+
+static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
+{
+	if (reg == LM77_REG_CONF)
+		return i2c_smbus_write_byte_data(client, reg, value);
+	else
+		return i2c_smbus_write_word_swapped(client, reg, value);
+}
+
+static struct lm77_data *lm77_update_device(struct device *dev)
+{
+	struct lm77_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	int i;
+
+	mutex_lock(&data->update_lock);
+
+	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
+	    || !data->valid) {
+		dev_dbg(&client->dev, "Starting lm77 update\n");
+		for (i = 0; i < t_num_temp; i++) {
+			data->temp[i] =
+			  LM77_TEMP_FROM_REG(lm77_read_value(client,
+							     temp_regs[i]));
+		}
+		data->alarms =
+			lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
+		data->last_updated = jiffies;
+		data->valid = true;
+	}
+
+	mutex_unlock(&data->update_lock);
+
+	return data;
+}
+
+/* sysfs stuff */
+
+static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
+			 char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct lm77_data *data = lm77_update_device(dev);
+
+	return sprintf(buf, "%d\n", data->temp[attr->index]);
+}
+
+static ssize_t temp_hyst_show(struct device *dev,
+			      struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct lm77_data *data = lm77_update_device(dev);
+	int nr = attr->index;
+	int temp;
+
+	temp = nr == t_min ? data->temp[nr] + data->temp[t_hyst] :
+			     data->temp[nr] - data->temp[t_hyst];
+
+	return sprintf(buf, "%d\n", temp);
+}
+
+static ssize_t temp_store(struct device *dev,
+			  struct device_attribute *devattr, const char *buf,
+			  size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct lm77_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	int nr = attr->index;
+	long val;
+	int err;
+
+	err = kstrtol(buf, 10, &val);
+	if (err)
+		return err;
+
+	val = clamp_val(val, LM77_TEMP_MIN, LM77_TEMP_MAX);
+	mutex_lock(&data->update_lock);
+	data->temp[nr] = val;
+	lm77_write_value(client, temp_regs[nr], LM77_TEMP_TO_REG(val));
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+/*
+ * hysteresis is stored as a relative value on the chip, so it has to be
+ * converted first.
+ */
+static ssize_t temp_hyst_store(struct device *dev,
+			       struct device_attribute *devattr,
+			       const char *buf, size_t count)
+{
+	struct lm77_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	long val;
+	int err;
+
+	err = kstrtol(buf, 10, &val);
+	if (err)
+		return err;
+
+	mutex_lock(&data->update_lock);
+	val = clamp_val(data->temp[t_crit] - val, LM77_TEMP_MIN, LM77_TEMP_MAX);
+	data->temp[t_hyst] = val;
+	lm77_write_value(client, LM77_REG_TEMP_HYST,
+			 LM77_TEMP_TO_REG(data->temp[t_hyst]));
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static ssize_t alarm_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	int bitnr = to_sensor_dev_attr(attr)->index;
+	struct lm77_data *data = lm77_update_device(dev);
+	return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
+}
+
+static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, t_input);
+static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp, t_crit);
+static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, t_min);
+static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, t_max);
+
+static SENSOR_DEVICE_ATTR_RW(temp1_crit_hyst, temp_hyst, t_crit);
+static SENSOR_DEVICE_ATTR_RO(temp1_min_hyst, temp_hyst, t_min);
+static SENSOR_DEVICE_ATTR_RO(temp1_max_hyst, temp_hyst, t_max);
+
+static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 2);
+static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, 0);
+static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 1);
+
+static struct attribute *lm77_attrs[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit.dev_attr.attr,
+	&sensor_dev_attr_temp1_min.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(lm77);
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	int i, cur, conf, hyst, crit, min, max;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+				     I2C_FUNC_SMBUS_WORD_DATA))
+		return -ENODEV;
+
+	/*
+	 * Here comes the remaining detection.  Since the LM77 has no
+	 * register dedicated to identification, we have to rely on the
+	 * following tricks:
+	 *
+	 * 1. the high 4 bits represent the sign and thus they should
+	 *    always be the same
+	 * 2. the high 3 bits are unused in the configuration register
+	 * 3. addresses 0x06 and 0x07 return the last read value
+	 * 4. registers cycling over 8-address boundaries
+	 *
+	 * Word-sized registers are high-byte first.
+	 */
+
+	/* addresses cycling */
+	cur = i2c_smbus_read_word_data(client, 0);
+	conf = i2c_smbus_read_byte_data(client, 1);
+	hyst = i2c_smbus_read_word_data(client, 2);
+	crit = i2c_smbus_read_word_data(client, 3);
+	min = i2c_smbus_read_word_data(client, 4);
+	max = i2c_smbus_read_word_data(client, 5);
+	for (i = 8; i <= 0xff; i += 8) {
+		if (i2c_smbus_read_byte_data(client, i + 1) != conf
+		 || i2c_smbus_read_word_data(client, i + 2) != hyst
+		 || i2c_smbus_read_word_data(client, i + 3) != crit
+		 || i2c_smbus_read_word_data(client, i + 4) != min
+		 || i2c_smbus_read_word_data(client, i + 5) != max)
+			return -ENODEV;
+	}
+
+	/* sign bits */
+	if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
+	 || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
+	 || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
+	 || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
+	 || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
+		return -ENODEV;
+
+	/* unused bits */
+	if (conf & 0xe0)
+		return -ENODEV;
+
+	/* 0x06 and 0x07 return the last read value */
+	cur = i2c_smbus_read_word_data(client, 0);
+	if (i2c_smbus_read_word_data(client, 6) != cur
+	 || i2c_smbus_read_word_data(client, 7) != cur)
+		return -ENODEV;
+	hyst = i2c_smbus_read_word_data(client, 2);
+	if (i2c_smbus_read_word_data(client, 6) != hyst
+	 || i2c_smbus_read_word_data(client, 7) != hyst)
+		return -ENODEV;
+	min = i2c_smbus_read_word_data(client, 4);
+	if (i2c_smbus_read_word_data(client, 6) != min
+	 || i2c_smbus_read_word_data(client, 7) != min)
+		return -ENODEV;
+
+	strscpy(info->type, "lm77", I2C_NAME_SIZE);
+
+	return 0;
+}
+
+static void lm77_init_client(struct i2c_client *client)
+{
+	/* Initialize the LM77 chip - turn off shutdown mode */
+	int conf = lm77_read_value(client, LM77_REG_CONF);
+	if (conf & 1)
+		lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
+}
+
+static int lm77_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct device *hwmon_dev;
+	struct lm77_data *data;
+
+	data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = client;
+	mutex_init(&data->update_lock);
+
+	/* Initialize the LM77 chip */
+	lm77_init_client(client);
+
+	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
+							   data, lm77_groups);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id lm77_id[] = {
+	{ .name = "lm77" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, lm77_id);
+
+/* This is the driver that will be inserted */
+static struct i2c_driver lm77_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "lm77",
+	},
+	.probe		= lm77_probe,
+	.id_table	= lm77_id,
+	.detect		= lm77_detect,
+	.address_list	= normal_i2c,
+};
+
+module_i2c_driver(lm77_driver);
+
+MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
+MODULE_DESCRIPTION("LM77 driver");
+MODULE_LICENSE("GPL");