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, 319 insertions, 0 deletions

diff --git a/drivers/hwmon/max1668.c b/drivers/hwmon/max1668.c
new file mode 100644
index 000000000..32548f564
--- /dev/null
+++ b/drivers/hwmon/max1668.c
@@ -0,0 +1,319 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2011 David George <david.george@ska.ac.za>
+ *
+ * based on adm1021.c
+ * some credit to Christoph Scheurer, but largely a rewrite
+ */
+
+#include <linux/bitops.h>
+#include <linux/bits.h>
+#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>
+
+/* Addresses to scan */
+static const unsigned short max1668_addr_list[] = {
+	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
+
+/* max1668 registers */
+
+#define MAX1668_REG_TEMP(nr)	(nr)
+#define MAX1668_REG_STAT1	0x05
+#define MAX1668_REG_STAT2	0x06
+#define MAX1668_REG_MAN_ID	0xfe
+#define MAX1668_REG_DEV_ID	0xff
+
+/* limits */
+
+/* high limits */
+#define MAX1668_REG_LIMH(nr)	(0x08 + 2 * (nr))
+/* read low limits */
+#define MAX1668_REG_LIML(nr)	(0x09 + 2 * (nr))
+
+/* manufacturer and device ID Constants */
+#define MAN_ID_MAXIM		0x4d
+#define DEV_ID_MAX1668		0x3
+#define DEV_ID_MAX1805		0x5
+#define DEV_ID_MAX1989		0xb
+
+/* read only mode module parameter */
+static bool read_only;
+module_param(read_only, bool, 0);
+MODULE_PARM_DESC(read_only, "Don't set any values, read only mode");
+
+struct max1668_data {
+	struct regmap *regmap;
+	int channels;
+};
+
+static int max1668_read(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long *val)
+{
+	struct max1668_data *data = dev_get_drvdata(dev);
+	struct regmap *regmap = data->regmap;
+	u32 regs[2] = { MAX1668_REG_STAT1, MAX1668_REG_TEMP(channel) };
+	u8 regvals[2];
+	u32 regval;
+	int ret;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		ret = regmap_read(regmap, MAX1668_REG_TEMP(channel), &regval);
+		if (ret)
+			return ret;
+		*val = sign_extend32(regval, 7) * 1000;
+		break;
+	case hwmon_temp_min:
+		ret = regmap_read(regmap, MAX1668_REG_LIML(channel), &regval);
+		if (ret)
+			return ret;
+		*val = sign_extend32(regval, 7) * 1000;
+		break;
+	case hwmon_temp_max:
+		ret = regmap_read(regmap, MAX1668_REG_LIMH(channel), &regval);
+		if (ret)
+			return ret;
+		*val = sign_extend32(regval, 7) * 1000;
+		break;
+	case hwmon_temp_min_alarm:
+		ret = regmap_read(regmap,
+				  channel ? MAX1668_REG_STAT2 : MAX1668_REG_STAT1,
+				  &regval);
+		if (ret)
+			return ret;
+		if (channel)
+			*val = !!(regval & BIT(9 - channel * 2));
+		else
+			*val = !!(regval & BIT(5));
+		break;
+	case hwmon_temp_max_alarm:
+		ret = regmap_read(regmap,
+				  channel ? MAX1668_REG_STAT2 : MAX1668_REG_STAT1,
+				  &regval);
+		if (ret)
+			return ret;
+		if (channel)
+			*val = !!(regval & BIT(8 - channel * 2));
+		else
+			*val = !!(regval & BIT(6));
+		break;
+	case hwmon_temp_fault:
+		ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
+		if (ret)
+			return ret;
+		*val = !!((regvals[0] & BIT(4)) && regvals[1] == 127);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int max1668_write(struct device *dev, enum hwmon_sensor_types type,
+			 u32 attr, int channel, long val)
+{
+	struct max1668_data *data = dev_get_drvdata(dev);
+	struct regmap *regmap = data->regmap;
+
+	val = clamp_val(val / 1000, -128, 127);
+
+	switch (attr) {
+	case hwmon_temp_min:
+		return regmap_write(regmap, MAX1668_REG_LIML(channel), val);
+	case hwmon_temp_max:
+		return regmap_write(regmap, MAX1668_REG_LIMH(channel), val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t max1668_is_visible(const void *_data, enum hwmon_sensor_types type,
+				  u32 attr, int channel)
+{
+	const struct max1668_data *data = _data;
+
+	if (channel >= data->channels)
+		return 0;
+
+	switch (attr) {
+	case hwmon_temp_min:
+	case hwmon_temp_max:
+		return read_only ? 0444 : 0644;
+	case hwmon_temp_input:
+	case hwmon_temp_min_alarm:
+	case hwmon_temp_max_alarm:
+		return 0444;
+	case hwmon_temp_fault:
+		if (channel)
+			return 0444;
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static const struct hwmon_channel_info * const max1668_info[] = {
+	HWMON_CHANNEL_INFO(temp,
+			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM,
+			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
+			   HWMON_T_FAULT,
+			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
+			   HWMON_T_FAULT,
+			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
+			   HWMON_T_FAULT,
+			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
+			   HWMON_T_FAULT),
+	NULL
+};
+
+static const struct hwmon_ops max1668_hwmon_ops = {
+	.is_visible = max1668_is_visible,
+	.read = max1668_read,
+	.write = max1668_write,
+};
+
+static const struct hwmon_chip_info max1668_chip_info = {
+	.ops = &max1668_hwmon_ops,
+	.info = max1668_info,
+};
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int max1668_detect(struct i2c_client *client,
+			  struct i2c_board_info *info)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	const char *type_name;
+	int man_id, dev_id;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -ENODEV;
+
+	/* Check for unsupported part */
+	man_id = i2c_smbus_read_byte_data(client, MAX1668_REG_MAN_ID);
+	if (man_id != MAN_ID_MAXIM)
+		return -ENODEV;
+
+	dev_id = i2c_smbus_read_byte_data(client, MAX1668_REG_DEV_ID);
+	if (dev_id < 0)
+		return -ENODEV;
+
+	type_name = NULL;
+	if (dev_id == DEV_ID_MAX1668)
+		type_name = "max1668";
+	else if (dev_id == DEV_ID_MAX1805)
+		type_name = "max1805";
+	else if (dev_id == DEV_ID_MAX1989)
+		type_name = "max1989";
+
+	if (!type_name)
+		return -ENODEV;
+
+	strscpy(info->type, type_name, I2C_NAME_SIZE);
+
+	return 0;
+}
+
+/* regmap */
+
+static int max1668_reg_read(void *context, unsigned int reg, unsigned int *val)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(context, reg);
+	if (ret < 0)
+		return ret;
+
+	*val = ret;
+	return 0;
+}
+
+static int max1668_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+	return i2c_smbus_write_byte_data(context, reg + 11, val);
+}
+
+static bool max1668_regmap_is_volatile(struct device *dev, unsigned int reg)
+{
+	return reg <= MAX1668_REG_STAT2;
+}
+
+static bool max1668_regmap_is_writeable(struct device *dev, unsigned int reg)
+{
+	return reg > MAX1668_REG_STAT2 && reg <= MAX1668_REG_LIML(4);
+}
+
+static const struct regmap_config max1668_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.cache_type = REGCACHE_MAPLE,
+	.volatile_reg = max1668_regmap_is_volatile,
+	.writeable_reg = max1668_regmap_is_writeable,
+};
+
+static const struct regmap_bus max1668_regmap_bus = {
+	.reg_write = max1668_reg_write,
+	.reg_read = max1668_reg_read,
+};
+
+static int max1668_probe(struct i2c_client *client)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	struct device *dev = &client->dev;
+	struct device *hwmon_dev;
+	struct max1668_data *data;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -ENODEV;
+
+	data = devm_kzalloc(dev, sizeof(struct max1668_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->regmap = devm_regmap_init(dev, &max1668_regmap_bus, client,
+					&max1668_regmap_config);
+	if (IS_ERR(data->regmap))
+		return PTR_ERR(data->regmap);
+
+	data->channels = (uintptr_t)i2c_get_match_data(client);
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data,
+							 &max1668_chip_info, NULL);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id max1668_id[] = {
+	{ .name = "max1668", .driver_data = 5 },
+	{ .name = "max1805", .driver_data = 3 },
+	{ .name = "max1989", .driver_data = 5 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max1668_id);
+
+/* This is the driver that will be inserted */
+static struct i2c_driver max1668_driver = {
+	.class = I2C_CLASS_HWMON,
+	.driver = {
+		  .name	= "max1668",
+		  },
+	.probe = max1668_probe,
+	.id_table = max1668_id,
+	.detect	= max1668_detect,
+	.address_list = max1668_addr_list,
+};
+
+module_i2c_driver(max1668_driver);
+
+MODULE_AUTHOR("David George <david.george@ska.ac.za>");
+MODULE_DESCRIPTION("MAX1668 remote temperature sensor driver");
+MODULE_LICENSE("GPL");