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, 279 insertions, 0 deletions

diff --git a/drivers/hwmon/ltc2990.c b/drivers/hwmon/ltc2990.c
new file mode 100644
index 000000000..a2725e4b2
--- /dev/null
+++ b/drivers/hwmon/ltc2990.c
@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for Linear Technology LTC2990 power monitor
+ *
+ * Copyright (C) 2014 Topic Embedded Products
+ * Author: Mike Looijmans <mike.looijmans@topic.nl>
+ */
+
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/property.h>
+
+#define LTC2990_STATUS	0x00
+#define LTC2990_CONTROL	0x01
+#define LTC2990_TRIGGER	0x02
+#define LTC2990_TINT_MSB	0x04
+#define LTC2990_V1_MSB	0x06
+#define LTC2990_V2_MSB	0x08
+#define LTC2990_V3_MSB	0x0A
+#define LTC2990_V4_MSB	0x0C
+#define LTC2990_VCC_MSB	0x0E
+
+#define LTC2990_IN0	BIT(0)
+#define LTC2990_IN1	BIT(1)
+#define LTC2990_IN2	BIT(2)
+#define LTC2990_IN3	BIT(3)
+#define LTC2990_IN4	BIT(4)
+#define LTC2990_CURR1	BIT(5)
+#define LTC2990_CURR2	BIT(6)
+#define LTC2990_TEMP1	BIT(7)
+#define LTC2990_TEMP2	BIT(8)
+#define LTC2990_TEMP3	BIT(9)
+#define LTC2990_NONE	0
+#define LTC2990_ALL	GENMASK(9, 0)
+
+#define LTC2990_MODE0_SHIFT	0
+#define LTC2990_MODE0_MASK	GENMASK(2, 0)
+#define LTC2990_MODE1_SHIFT	3
+#define LTC2990_MODE1_MASK	GENMASK(1, 0)
+
+/* Enabled measurements for mode bits 2..0 */
+static const int ltc2990_attrs_ena_0[] = {
+	LTC2990_IN1 | LTC2990_IN2 | LTC2990_TEMP3,
+	LTC2990_CURR1 | LTC2990_TEMP3,
+	LTC2990_CURR1 | LTC2990_IN3 | LTC2990_IN4,
+	LTC2990_TEMP2 | LTC2990_IN3 | LTC2990_IN4,
+	LTC2990_TEMP2 | LTC2990_CURR2,
+	LTC2990_TEMP2 | LTC2990_TEMP3,
+	LTC2990_CURR1 | LTC2990_CURR2,
+	LTC2990_IN1 | LTC2990_IN2 | LTC2990_IN3 | LTC2990_IN4
+};
+
+/* Enabled measurements for mode bits 4..3 */
+static const int ltc2990_attrs_ena_1[] = {
+	LTC2990_NONE,
+	LTC2990_TEMP2 | LTC2990_IN1 | LTC2990_CURR1,
+	LTC2990_TEMP3 | LTC2990_IN3 | LTC2990_CURR2,
+	LTC2990_ALL
+};
+
+struct ltc2990_data {
+	struct i2c_client *i2c;
+	u32 mode[2];
+};
+
+/* Return the converted value from the given register in uV or mC */
+static int ltc2990_get_value(struct i2c_client *i2c, int index, int *result)
+{
+	int val;
+	u8 reg;
+
+	switch (index) {
+	case LTC2990_IN0:
+		reg = LTC2990_VCC_MSB;
+		break;
+	case LTC2990_IN1:
+	case LTC2990_CURR1:
+	case LTC2990_TEMP2:
+		reg = LTC2990_V1_MSB;
+		break;
+	case LTC2990_IN2:
+		reg = LTC2990_V2_MSB;
+		break;
+	case LTC2990_IN3:
+	case LTC2990_CURR2:
+	case LTC2990_TEMP3:
+		reg = LTC2990_V3_MSB;
+		break;
+	case LTC2990_IN4:
+		reg = LTC2990_V4_MSB;
+		break;
+	case LTC2990_TEMP1:
+		reg = LTC2990_TINT_MSB;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	val = i2c_smbus_read_word_swapped(i2c, reg);
+	if (unlikely(val < 0))
+		return val;
+
+	switch (index) {
+	case LTC2990_TEMP1:
+	case LTC2990_TEMP2:
+	case LTC2990_TEMP3:
+		/* temp, 0.0625 degrees/LSB */
+		*result = sign_extend32(val, 12) * 1000 / 16;
+		break;
+	case LTC2990_CURR1:
+	case LTC2990_CURR2:
+		 /* Vx-Vy, 19.42uV/LSB */
+		*result = sign_extend32(val, 14) * 1942 / 100;
+		break;
+	case LTC2990_IN0:
+		/* Vcc, 305.18uV/LSB, 2.5V offset */
+		*result = sign_extend32(val, 14) * 30518 / (100 * 1000) + 2500;
+		break;
+	case LTC2990_IN1:
+	case LTC2990_IN2:
+	case LTC2990_IN3:
+	case LTC2990_IN4:
+		/* Vx, 305.18uV/LSB */
+		*result = sign_extend32(val, 14) * 30518 / (100 * 1000);
+		break;
+	default:
+		return -EINVAL; /* won't happen, keep compiler happy */
+	}
+
+	return 0;
+}
+
+static ssize_t ltc2990_value_show(struct device *dev,
+				  struct device_attribute *da, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+	struct ltc2990_data *data = dev_get_drvdata(dev);
+	int value;
+	int ret;
+
+	ret = ltc2990_get_value(data->i2c, attr->index, &value);
+	if (unlikely(ret < 0))
+		return ret;
+
+	return sysfs_emit(buf, "%d\n", value);
+}
+
+static umode_t ltc2990_attrs_visible(struct kobject *kobj,
+				     struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct ltc2990_data *data = dev_get_drvdata(dev);
+	struct device_attribute *da =
+			container_of(a, struct device_attribute, attr);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+
+	int attrs_mask = LTC2990_IN0 | LTC2990_TEMP1 |
+			 (ltc2990_attrs_ena_0[data->mode[0]] &
+			  ltc2990_attrs_ena_1[data->mode[1]]);
+
+	if (attr->index & attrs_mask)
+		return a->mode;
+
+	return 0;
+}
+
+static SENSOR_DEVICE_ATTR_RO(temp1_input, ltc2990_value, LTC2990_TEMP1);
+static SENSOR_DEVICE_ATTR_RO(temp2_input, ltc2990_value, LTC2990_TEMP2);
+static SENSOR_DEVICE_ATTR_RO(temp3_input, ltc2990_value, LTC2990_TEMP3);
+static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc2990_value, LTC2990_CURR1);
+static SENSOR_DEVICE_ATTR_RO(curr2_input, ltc2990_value, LTC2990_CURR2);
+static SENSOR_DEVICE_ATTR_RO(in0_input, ltc2990_value, LTC2990_IN0);
+static SENSOR_DEVICE_ATTR_RO(in1_input, ltc2990_value, LTC2990_IN1);
+static SENSOR_DEVICE_ATTR_RO(in2_input, ltc2990_value, LTC2990_IN2);
+static SENSOR_DEVICE_ATTR_RO(in3_input, ltc2990_value, LTC2990_IN3);
+static SENSOR_DEVICE_ATTR_RO(in4_input, ltc2990_value, LTC2990_IN4);
+
+static struct attribute *ltc2990_attrs[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp2_input.dev_attr.attr,
+	&sensor_dev_attr_temp3_input.dev_attr.attr,
+	&sensor_dev_attr_curr1_input.dev_attr.attr,
+	&sensor_dev_attr_curr2_input.dev_attr.attr,
+	&sensor_dev_attr_in0_input.dev_attr.attr,
+	&sensor_dev_attr_in1_input.dev_attr.attr,
+	&sensor_dev_attr_in2_input.dev_attr.attr,
+	&sensor_dev_attr_in3_input.dev_attr.attr,
+	&sensor_dev_attr_in4_input.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ltc2990_group = {
+	.attrs = ltc2990_attrs,
+	.is_visible = ltc2990_attrs_visible,
+};
+__ATTRIBUTE_GROUPS(ltc2990);
+
+static int ltc2990_i2c_probe(struct i2c_client *i2c)
+{
+	int ret;
+	struct device *hwmon_dev;
+	struct ltc2990_data *data;
+
+	if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+				     I2C_FUNC_SMBUS_WORD_DATA))
+		return -ENODEV;
+
+	data = devm_kzalloc(&i2c->dev, sizeof(struct ltc2990_data), GFP_KERNEL);
+	if (unlikely(!data))
+		return -ENOMEM;
+
+	data->i2c = i2c;
+
+	if (dev_fwnode(&i2c->dev)) {
+		ret = device_property_read_u32_array(&i2c->dev,
+						     "lltc,meas-mode",
+						     data->mode, 2);
+		if (ret < 0)
+			return ret;
+
+		if (data->mode[0] & ~LTC2990_MODE0_MASK ||
+		    data->mode[1] & ~LTC2990_MODE1_MASK)
+			return -EINVAL;
+	} else {
+		ret = i2c_smbus_read_byte_data(i2c, LTC2990_CONTROL);
+		if (ret < 0)
+			return ret;
+
+		data->mode[0] = ret >> LTC2990_MODE0_SHIFT & LTC2990_MODE0_MASK;
+		data->mode[1] = ret >> LTC2990_MODE1_SHIFT & LTC2990_MODE1_MASK;
+	}
+
+	/* Setup continuous mode */
+	ret = i2c_smbus_write_byte_data(i2c, LTC2990_CONTROL,
+					data->mode[0] << LTC2990_MODE0_SHIFT |
+					data->mode[1] << LTC2990_MODE1_SHIFT);
+	if (ret < 0) {
+		dev_err(&i2c->dev, "Error: Failed to set control mode.\n");
+		return ret;
+	}
+	/* Trigger once to start continuous conversion */
+	ret = i2c_smbus_write_byte_data(i2c, LTC2990_TRIGGER, 1);
+	if (ret < 0) {
+		dev_err(&i2c->dev, "Error: Failed to start acquisition.\n");
+		return ret;
+	}
+
+	hwmon_dev = devm_hwmon_device_register_with_groups(&i2c->dev,
+							   i2c->name,
+							   data,
+							   ltc2990_groups);
+
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id ltc2990_i2c_id[] = {
+	{ .name = "ltc2990" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ltc2990_i2c_id);
+
+static struct i2c_driver ltc2990_i2c_driver = {
+	.driver = {
+		.name = "ltc2990",
+	},
+	.probe = ltc2990_i2c_probe,
+	.id_table = ltc2990_i2c_id,
+};
+
+module_i2c_driver(ltc2990_i2c_driver);
+
+MODULE_DESCRIPTION("LTC2990 Sensor Driver");
+MODULE_AUTHOR("Topic Embedded Products");
+MODULE_LICENSE("GPL v2");