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, 495 insertions, 0 deletions

diff --git a/drivers/hwmon/max6620.c b/drivers/hwmon/max6620.c
new file mode 100644
index 000000000..100acf357
--- /dev/null
+++ b/drivers/hwmon/max6620.c
@@ -0,0 +1,495 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Hardware monitoring driver for Maxim MAX6620
+ *
+ * Originally from L. Grunenberg.
+ * (C) 2012 by L. Grunenberg <contact@lgrunenberg.de>
+ *
+ * Copyright (c) 2021 Dell Inc. or its subsidiaries. All Rights Reserved.
+ *
+ * based on code written by :
+ * 2007 by Hans J. Koch <hjk@hansjkoch.de>
+ * John Morris <john.morris@spirentcom.com>
+ * Copyright (c) 2003 Spirent Communications
+ * and Claus Gindhart <claus.gindhart@kontron.com>
+ *
+ * This module has only been tested with the MAX6620 chip.
+ *
+ * The datasheet was last seen at:
+ *
+ *        http://pdfserv.maxim-ic.com/en/ds/MAX6620.pdf
+ *
+ */
+
+#include <linux/bits.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+/*
+ * MAX 6620 registers
+ */
+
+#define MAX6620_REG_CONFIG	0x00
+#define MAX6620_REG_FAULT	0x01
+#define MAX6620_REG_CONF_FAN0	0x02
+#define MAX6620_REG_CONF_FAN1	0x03
+#define MAX6620_REG_CONF_FAN2	0x04
+#define MAX6620_REG_CONF_FAN3	0x05
+#define MAX6620_REG_DYN_FAN0	0x06
+#define MAX6620_REG_DYN_FAN1	0x07
+#define MAX6620_REG_DYN_FAN2	0x08
+#define MAX6620_REG_DYN_FAN3	0x09
+#define MAX6620_REG_TACH0	0x10
+#define MAX6620_REG_TACH1	0x12
+#define MAX6620_REG_TACH2	0x14
+#define MAX6620_REG_TACH3	0x16
+#define MAX6620_REG_VOLT0	0x18
+#define MAX6620_REG_VOLT1	0x1A
+#define MAX6620_REG_VOLT2	0x1C
+#define MAX6620_REG_VOLT3	0x1E
+#define MAX6620_REG_TAR0	0x20
+#define MAX6620_REG_TAR1	0x22
+#define MAX6620_REG_TAR2	0x24
+#define MAX6620_REG_TAR3	0x26
+#define MAX6620_REG_DAC0	0x28
+#define MAX6620_REG_DAC1	0x2A
+#define MAX6620_REG_DAC2	0x2C
+#define MAX6620_REG_DAC3	0x2E
+
+/*
+ * Config register bits
+ */
+
+#define MAX6620_CFG_RUN		BIT(7)
+#define MAX6620_CFG_POR		BIT(6)
+#define MAX6620_CFG_TIMEOUT	BIT(5)
+#define MAX6620_CFG_FULLFAN	BIT(4)
+#define MAX6620_CFG_OSC		BIT(3)
+#define MAX6620_CFG_WD_MASK	(BIT(2) | BIT(1))
+#define MAX6620_CFG_WD_2	BIT(1)
+#define MAX6620_CFG_WD_6	BIT(2)
+#define MAX6620_CFG_WD10	(BIT(2) | BIT(1))
+#define MAX6620_CFG_WD		BIT(0)
+
+/*
+ * Failure status register bits
+ */
+
+#define MAX6620_FAIL_TACH0	BIT(4)
+#define MAX6620_FAIL_TACH1	BIT(5)
+#define MAX6620_FAIL_TACH2	BIT(6)
+#define MAX6620_FAIL_TACH3	BIT(7)
+#define MAX6620_FAIL_MASK0	BIT(0)
+#define MAX6620_FAIL_MASK1	BIT(1)
+#define MAX6620_FAIL_MASK2	BIT(2)
+#define MAX6620_FAIL_MASK3	BIT(3)
+
+#define MAX6620_CLOCK_FREQ	8192 /* Clock frequency in Hz */
+#define MAX6620_PULSE_PER_REV	2 /* Tachometer pulses per revolution */
+
+/* Minimum and maximum values of the FAN-RPM */
+#define FAN_RPM_MIN	240
+#define FAN_RPM_MAX	30000
+
+static const u8 config_reg[] = {
+	MAX6620_REG_CONF_FAN0,
+	MAX6620_REG_CONF_FAN1,
+	MAX6620_REG_CONF_FAN2,
+	MAX6620_REG_CONF_FAN3,
+};
+
+static const u8 dyn_reg[] = {
+	MAX6620_REG_DYN_FAN0,
+	MAX6620_REG_DYN_FAN1,
+	MAX6620_REG_DYN_FAN2,
+	MAX6620_REG_DYN_FAN3,
+};
+
+static const u8 tach_reg[] = {
+	MAX6620_REG_TACH0,
+	MAX6620_REG_TACH1,
+	MAX6620_REG_TACH2,
+	MAX6620_REG_TACH3,
+};
+
+static const u8 target_reg[] = {
+	MAX6620_REG_TAR0,
+	MAX6620_REG_TAR1,
+	MAX6620_REG_TAR2,
+	MAX6620_REG_TAR3,
+};
+
+/*
+ * Client data (each client gets its own)
+ */
+
+struct max6620_data {
+	struct i2c_client *client;
+	bool valid; /* false until following fields are valid */
+	unsigned long last_updated; /* in jiffies */
+
+	/* register values */
+	u8 fancfg[4];
+	u8 fandyn[4];
+	u8 fault;
+	u16 tach[4];
+	u16 target[4];
+};
+
+static u8 max6620_fan_div_from_reg(u8 val)
+{
+	return BIT((val & 0xE0) >> 5);
+}
+
+static u16 max6620_fan_rpm_to_tach(u8 div, int rpm)
+{
+	return (60 * div * MAX6620_CLOCK_FREQ) / (rpm * MAX6620_PULSE_PER_REV);
+}
+
+static int max6620_fan_tach_to_rpm(u8 div, u16 tach)
+{
+	return (60 * div * MAX6620_CLOCK_FREQ) / (tach * MAX6620_PULSE_PER_REV);
+}
+
+static int max6620_update_device(struct device *dev)
+{
+	struct max6620_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	int i, ret;
+
+	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
+		for (i = 0; i < 4; i++) {
+			ret = i2c_smbus_read_byte_data(client, config_reg[i]);
+			if (ret < 0)
+				return ret;
+			data->fancfg[i] = ret;
+
+			ret = i2c_smbus_read_byte_data(client, dyn_reg[i]);
+			if (ret < 0)
+				return ret;
+			data->fandyn[i] = ret;
+
+			ret = i2c_smbus_read_byte_data(client, tach_reg[i]);
+			if (ret < 0)
+				return ret;
+			data->tach[i] = (ret << 3) & 0x7f8;
+			ret = i2c_smbus_read_byte_data(client, tach_reg[i] + 1);
+			if (ret < 0)
+				return ret;
+			data->tach[i] |= (ret >> 5) & 0x7;
+
+			ret = i2c_smbus_read_byte_data(client, target_reg[i]);
+			if (ret < 0)
+				return ret;
+			data->target[i] = (ret << 3) & 0x7f8;
+			ret = i2c_smbus_read_byte_data(client, target_reg[i] + 1);
+			if (ret < 0)
+				return ret;
+			data->target[i] |= (ret >> 5) & 0x7;
+		}
+
+		/*
+		 * Alarms are cleared on read in case the condition that
+		 * caused the alarm is removed. Keep the value latched here
+		 * for providing the register through different alarm files.
+		 */
+		ret = i2c_smbus_read_byte_data(client, MAX6620_REG_FAULT);
+		if (ret < 0)
+			return ret;
+		data->fault |= (ret >> 4) & (ret & 0x0F);
+
+		data->last_updated = jiffies;
+		data->valid = true;
+	}
+	return 0;
+}
+
+static umode_t
+max6620_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
+		   int channel)
+{
+	switch (type) {
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_alarm:
+		case hwmon_fan_input:
+			return 0444;
+		case hwmon_fan_div:
+		case hwmon_fan_target:
+			return 0644;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int
+max6620_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+	     int channel, long *val)
+{
+	struct max6620_data *data;
+	struct i2c_client *client;
+	int ret;
+	u8 div;
+	u8 val1;
+	u8 val2;
+
+	ret = max6620_update_device(dev);
+	if (ret < 0)
+		return ret;
+	data = dev_get_drvdata(dev);
+	client = data->client;
+
+	switch (type) {
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_alarm:
+			*val = !!(data->fault & BIT(channel));
+
+			/* Setting TACH count to re-enable fan fault detection */
+			if (*val == 1) {
+				val1 = (data->target[channel] >> 3) & 0xff;
+				val2 = (data->target[channel] << 5) & 0xe0;
+				ret = i2c_smbus_write_byte_data(client,
+								target_reg[channel], val1);
+				if (ret < 0)
+					return ret;
+				ret = i2c_smbus_write_byte_data(client,
+								target_reg[channel] + 1, val2);
+				if (ret < 0)
+					return ret;
+
+				data->fault &= ~BIT(channel);
+			}
+			break;
+		case hwmon_fan_div:
+			*val = max6620_fan_div_from_reg(data->fandyn[channel]);
+			break;
+		case hwmon_fan_input:
+			if (data->tach[channel] == 0) {
+				*val = 0;
+			} else {
+				div = max6620_fan_div_from_reg(data->fandyn[channel]);
+				*val = max6620_fan_tach_to_rpm(div, data->tach[channel]);
+			}
+			break;
+		case hwmon_fan_target:
+			if (data->target[channel] == 0) {
+				*val = 0;
+			} else {
+				div = max6620_fan_div_from_reg(data->fandyn[channel]);
+				*val = max6620_fan_tach_to_rpm(div, data->target[channel]);
+			}
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+		break;
+
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int
+max6620_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+	      int channel, long val)
+{
+	struct max6620_data *data;
+	struct i2c_client *client;
+	int ret;
+	u8 div;
+	u16 tach;
+	u8 val1;
+	u8 val2;
+
+	ret = max6620_update_device(dev);
+	if (ret < 0)
+		return ret;
+	data = dev_get_drvdata(dev);
+	client = data->client;
+
+	switch (type) {
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_div:
+			switch (val) {
+			case 1:
+				div = 0;
+				break;
+			case 2:
+				div = 1;
+				break;
+			case 4:
+				div = 2;
+				break;
+			case 8:
+				div = 3;
+				break;
+			case 16:
+				div = 4;
+				break;
+			case 32:
+				div = 5;
+				break;
+			default:
+				return -EINVAL;
+			}
+			data->fandyn[channel] &= 0x1F;
+			data->fandyn[channel] |= div << 5;
+			ret = i2c_smbus_write_byte_data(client, dyn_reg[channel],
+							data->fandyn[channel]);
+			break;
+		case hwmon_fan_target:
+			val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX);
+			div = max6620_fan_div_from_reg(data->fandyn[channel]);
+			tach = max6620_fan_rpm_to_tach(div, val);
+			val1 = (tach >> 3) & 0xff;
+			val2 = (tach << 5) & 0xe0;
+			ret = i2c_smbus_write_byte_data(client, target_reg[channel], val1);
+			if (ret < 0)
+				break;
+			ret = i2c_smbus_write_byte_data(client, target_reg[channel] + 1, val2);
+			if (ret < 0)
+				break;
+
+			/* Setting TACH count re-enables fan fault detection */
+			data->fault &= ~BIT(channel);
+
+			break;
+		default:
+			ret = -EOPNOTSUPP;
+			break;
+		}
+		break;
+
+	default:
+		ret = -EOPNOTSUPP;
+		break;
+	}
+
+	return ret;
+}
+
+static const struct hwmon_channel_info * const max6620_info[] = {
+	HWMON_CHANNEL_INFO(fan,
+			   HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM,
+			   HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM,
+			   HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM,
+			   HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM),
+	NULL
+};
+
+static const struct hwmon_ops max6620_hwmon_ops = {
+	.read = max6620_read,
+	.write = max6620_write,
+	.is_visible = max6620_is_visible,
+};
+
+static const struct hwmon_chip_info max6620_chip_info = {
+	.ops = &max6620_hwmon_ops,
+	.info = max6620_info,
+};
+
+static int max6620_init_client(struct max6620_data *data)
+{
+	struct i2c_client *client = data->client;
+	int config;
+	int err;
+	int i;
+	int reg;
+
+	config = i2c_smbus_read_byte_data(client, MAX6620_REG_CONFIG);
+	if (config < 0) {
+		dev_err(&client->dev, "Error reading config, aborting.\n");
+		return config;
+	}
+
+	/*
+	 * Set bit 4, disable other fans from going full speed on a fail
+	 * failure.
+	 */
+	err = i2c_smbus_write_byte_data(client, MAX6620_REG_CONFIG, config | 0x10);
+	if (err < 0) {
+		dev_err(&client->dev, "Config write error, aborting.\n");
+		return err;
+	}
+
+	for (i = 0; i < 4; i++) {
+		reg = i2c_smbus_read_byte_data(client, config_reg[i]);
+		if (reg < 0)
+			return reg;
+		data->fancfg[i] = reg;
+
+		/* Enable RPM mode */
+		data->fancfg[i] |= 0xa8;
+		err = i2c_smbus_write_byte_data(client, config_reg[i], data->fancfg[i]);
+		if (err < 0)
+			return err;
+
+		/* 2 counts (001) and Rate change 100 (0.125 secs) */
+		data->fandyn[i] = 0x30;
+		err = i2c_smbus_write_byte_data(client, dyn_reg[i], data->fandyn[i]);
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}
+
+static int max6620_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct max6620_data *data;
+	struct device *hwmon_dev;
+	int err;
+
+	data = devm_kzalloc(dev, sizeof(struct max6620_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = client;
+
+	err = max6620_init_client(data);
+	if (err)
+		return err;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
+							 data,
+							 &max6620_chip_info,
+							 NULL);
+
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id max6620_id[] = {
+	{ .name = "max6620" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max6620_id);
+
+static struct i2c_driver max6620_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "max6620",
+	},
+	.probe		= max6620_probe,
+	.id_table	= max6620_id,
+};
+
+module_i2c_driver(max6620_driver);
+
+MODULE_AUTHOR("Lucas Grunenberg");
+MODULE_DESCRIPTION("MAX6620 sensor driver");
+MODULE_LICENSE("GPL");