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, 430 insertions, 0 deletions

diff --git a/drivers/hwmon/ltc2991.c b/drivers/hwmon/ltc2991.c
new file mode 100644
index 000000000..bc8d803e8
--- /dev/null
+++ b/drivers/hwmon/ltc2991.c
@@ -0,0 +1,430 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 Analog Devices, Inc.
+ * Author: Antoniu Miclaus <antoniu.miclaus@analog.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+#define LTC2991_STATUS_LOW		0x00
+#define LTC2991_CH_EN_TRIGGER		0x01
+#define LTC2991_V1_V4_CTRL		0x06
+#define LTC2991_V5_V8_CTRL		0x07
+#define LTC2991_PWM_TH_LSB_T_INT	0x08
+#define LTC2991_PWM_TH_MSB		0x09
+#define LTC2991_CHANNEL_V_MSB(x)	(0x0A + ((x) * 2))
+#define LTC2991_CHANNEL_T_MSB(x)	(0x0A + ((x) * 4))
+#define LTC2991_CHANNEL_C_MSB(x)	(0x0C + ((x) * 4))
+#define LTC2991_T_INT_MSB		0x1A
+#define LTC2991_VCC_MSB			0x1C
+
+#define LTC2991_V7_V8_EN		BIT(7)
+#define LTC2991_V5_V6_EN		BIT(6)
+#define LTC2991_V3_V4_EN		BIT(5)
+#define LTC2991_V1_V2_EN		BIT(4)
+#define LTC2991_T_INT_VCC_EN		BIT(3)
+
+#define LTC2991_V3_V4_FILT_EN		BIT(7)
+#define LTC2991_V3_V4_TEMP_EN		BIT(5)
+#define LTC2991_V3_V4_DIFF_EN		BIT(4)
+#define LTC2991_V1_V2_FILT_EN		BIT(3)
+#define LTC2991_V1_V2_TEMP_EN		BIT(1)
+#define LTC2991_V1_V2_DIFF_EN		BIT(0)
+
+#define LTC2991_V7_V8_FILT_EN		BIT(7)
+#define LTC2991_V7_V8_TEMP_EN		BIT(5)
+#define LTC2991_V7_V8_DIFF_EN		BIT(4)
+#define LTC2991_V5_V6_FILT_EN		BIT(3)
+#define LTC2991_V5_V6_TEMP_EN		BIT(1)
+#define LTC2991_V5_V6_DIFF_EN		BIT(0)
+
+#define LTC2991_REPEAT_ACQ_EN		BIT(4)
+#define LTC2991_T_INT_FILT_EN		BIT(3)
+
+#define LTC2991_MAX_CHANNEL		4
+#define LTC2991_T_INT_CH_NR		4
+#define LTC2991_VCC_CH_NR		0
+
+struct ltc2991_state {
+	struct regmap		*regmap;
+	u32			r_sense_uohm[LTC2991_MAX_CHANNEL];
+	bool			temp_en[LTC2991_MAX_CHANNEL];
+};
+
+static int ltc2991_read_reg(struct ltc2991_state *st, u8 addr, u8 reg_len,
+			    int *val)
+{
+	__be16 regvals;
+	int ret;
+
+	if (reg_len < 2)
+		return regmap_read(st->regmap, addr, val);
+
+	ret = regmap_bulk_read(st->regmap, addr, &regvals, reg_len);
+	if (ret)
+		return ret;
+
+	*val = be16_to_cpu(regvals);
+
+	return 0;
+}
+
+static int ltc2991_get_voltage(struct ltc2991_state *st, u32 reg, long *val)
+{
+	int reg_val, ret, offset = 0;
+
+	ret = ltc2991_read_reg(st, reg, 2, &reg_val);
+	if (ret)
+		return ret;
+
+	if (reg == LTC2991_VCC_MSB)
+		/* Vcc 2.5V offset */
+		offset = 2500;
+
+	/* Vx, 305.18uV/LSB */
+	*val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 14) * 30518,
+				 1000 * 100) + offset;
+
+	return 0;
+}
+
+static int ltc2991_read_in(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct ltc2991_state *st = dev_get_drvdata(dev);
+	u32 reg;
+
+	switch (attr) {
+	case hwmon_in_input:
+		if (channel == LTC2991_VCC_CH_NR)
+			reg = LTC2991_VCC_MSB;
+		else
+			reg = LTC2991_CHANNEL_V_MSB(channel - 1);
+
+		return ltc2991_get_voltage(st, reg, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ltc2991_get_curr(struct ltc2991_state *st, u32 reg, int channel,
+			    long *val)
+{
+	int reg_val, ret;
+
+	ret = ltc2991_read_reg(st, reg, 2, &reg_val);
+	if (ret)
+		return ret;
+
+	/* Vx-Vy, 19.075uV/LSB */
+	*val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 14) * 19075,
+				 (s32)st->r_sense_uohm[channel]);
+
+	return 0;
+}
+
+static int ltc2991_read_curr(struct device *dev, u32 attr, int channel,
+			     long *val)
+{
+	struct ltc2991_state *st = dev_get_drvdata(dev);
+	u32 reg;
+
+	switch (attr) {
+	case hwmon_curr_input:
+		reg = LTC2991_CHANNEL_C_MSB(channel);
+		return ltc2991_get_curr(st, reg, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ltc2991_get_temp(struct ltc2991_state *st, u32 reg, int channel,
+			    long *val)
+{
+	int reg_val, ret;
+
+	ret = ltc2991_read_reg(st, reg, 2, &reg_val);
+	if (ret)
+		return ret;
+
+	/* Temp LSB = 0.0625 Degrees */
+	*val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 12) * 1000, 16);
+
+	return 0;
+}
+
+static int ltc2991_read_temp(struct device *dev, u32 attr, int channel,
+			     long *val)
+{
+	struct ltc2991_state *st = dev_get_drvdata(dev);
+	u32 reg;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		if (channel == LTC2991_T_INT_CH_NR)
+			reg = LTC2991_T_INT_MSB;
+		else
+			reg = LTC2991_CHANNEL_T_MSB(channel);
+
+		return ltc2991_get_temp(st, reg, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ltc2991_read(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long *val)
+{
+	switch (type) {
+	case hwmon_in:
+		return ltc2991_read_in(dev, attr, channel, val);
+	case hwmon_curr:
+		return ltc2991_read_curr(dev, attr, channel, val);
+	case hwmon_temp:
+		return ltc2991_read_temp(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t ltc2991_is_visible(const void *data,
+				  enum hwmon_sensor_types type, u32 attr,
+				  int channel)
+{
+	const struct ltc2991_state *st = data;
+
+	switch (type) {
+	case hwmon_in:
+		switch (attr) {
+		case hwmon_in_input:
+			if (channel == LTC2991_VCC_CH_NR)
+				return 0444;
+			if (st->temp_en[(channel - 1) / 2])
+				break;
+			if (channel % 2)
+				return 0444;
+			if (!st->r_sense_uohm[(channel - 1) / 2])
+				return 0444;
+		}
+		break;
+	case hwmon_curr:
+		switch (attr) {
+		case hwmon_curr_input:
+			if (st->r_sense_uohm[channel])
+				return 0444;
+			break;
+		}
+		break;
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_input:
+			if (channel == LTC2991_T_INT_CH_NR ||
+			    st->temp_en[channel])
+				return 0444;
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static const struct hwmon_ops ltc2991_hwmon_ops = {
+	.is_visible = ltc2991_is_visible,
+	.read = ltc2991_read,
+};
+
+static const struct hwmon_channel_info *ltc2991_info[] = {
+	HWMON_CHANNEL_INFO(temp,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT
+			   ),
+	HWMON_CHANNEL_INFO(curr,
+			   HWMON_C_INPUT,
+			   HWMON_C_INPUT,
+			   HWMON_C_INPUT,
+			   HWMON_C_INPUT
+			   ),
+	HWMON_CHANNEL_INFO(in,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT
+			   ),
+	NULL
+};
+
+static const struct hwmon_chip_info ltc2991_chip_info = {
+	.ops = &ltc2991_hwmon_ops,
+	.info = ltc2991_info,
+};
+
+static const struct regmap_config ltc2991_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x1D,
+};
+
+static int ltc2991_init(struct ltc2991_state *st, struct device *dev)
+{
+	int ret;
+	u32 val, addr;
+	u8 v5_v8_reg_data = 0, v1_v4_reg_data = 0;
+
+	ret = devm_regulator_get_enable(dev, "vcc");
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "failed to enable regulator\n");
+
+	device_for_each_child_node_scoped(dev, child) {
+		ret = fwnode_property_read_u32(child, "reg", &addr);
+		if (ret < 0)
+			return ret;
+
+		if (addr > 3)
+			return -EINVAL;
+
+		ret = fwnode_property_read_u32(child,
+					       "shunt-resistor-micro-ohms",
+					       &val);
+		if (!ret) {
+			if (!val)
+				return dev_err_probe(dev, -EINVAL,
+						     "shunt resistor value cannot be zero\n");
+
+			st->r_sense_uohm[addr] = val;
+
+			switch (addr) {
+			case 0:
+				v1_v4_reg_data |= LTC2991_V1_V2_DIFF_EN;
+				break;
+			case 1:
+				v1_v4_reg_data |= LTC2991_V3_V4_DIFF_EN;
+				break;
+			case 2:
+				v5_v8_reg_data |= LTC2991_V5_V6_DIFF_EN;
+				break;
+			case 3:
+				v5_v8_reg_data |= LTC2991_V7_V8_DIFF_EN;
+				break;
+			default:
+				break;
+			}
+		}
+
+		ret = fwnode_property_read_bool(child,
+						"adi,temperature-enable");
+		if (ret) {
+			st->temp_en[addr] = ret;
+
+			switch (addr) {
+			case 0:
+				v1_v4_reg_data |= LTC2991_V1_V2_TEMP_EN;
+				break;
+			case 1:
+				v1_v4_reg_data |= LTC2991_V3_V4_TEMP_EN;
+				break;
+			case 2:
+				v5_v8_reg_data |= LTC2991_V5_V6_TEMP_EN;
+				break;
+			case 3:
+				v5_v8_reg_data |= LTC2991_V7_V8_TEMP_EN;
+				break;
+			default:
+				break;
+			}
+		}
+	}
+
+	ret = regmap_write(st->regmap, LTC2991_V5_V8_CTRL, v5_v8_reg_data);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Error: Failed to set V5-V8 CTRL reg.\n");
+
+	ret = regmap_write(st->regmap, LTC2991_V1_V4_CTRL, v1_v4_reg_data);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Error: Failed to set V1-V4 CTRL reg.\n");
+
+	ret = regmap_write(st->regmap, LTC2991_PWM_TH_LSB_T_INT,
+			   LTC2991_REPEAT_ACQ_EN);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Error: Failed to set continuous mode.\n");
+
+	/* Enable all channels and trigger conversions */
+	return regmap_write(st->regmap, LTC2991_CH_EN_TRIGGER,
+			    LTC2991_V7_V8_EN | LTC2991_V5_V6_EN |
+			    LTC2991_V3_V4_EN | LTC2991_V1_V2_EN |
+			    LTC2991_T_INT_VCC_EN);
+}
+
+static int ltc2991_i2c_probe(struct i2c_client *client)
+{
+	int ret;
+	struct device *hwmon_dev;
+	struct ltc2991_state *st;
+
+	st = devm_kzalloc(&client->dev, sizeof(*st), GFP_KERNEL);
+	if (!st)
+		return -ENOMEM;
+
+	st->regmap = devm_regmap_init_i2c(client, &ltc2991_regmap_config);
+	if (IS_ERR(st->regmap))
+		return PTR_ERR(st->regmap);
+
+	ret = ltc2991_init(st, &client->dev);
+	if (ret)
+		return ret;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
+							 client->name, st,
+							 &ltc2991_chip_info,
+							 NULL);
+
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct of_device_id ltc2991_of_match[] = {
+	{ .compatible = "adi,ltc2991" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ltc2991_of_match);
+
+static const struct i2c_device_id ltc2991_i2c_id[] = {
+	{ .name = "ltc2991" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ltc2991_i2c_id);
+
+static struct i2c_driver ltc2991_i2c_driver = {
+	.driver = {
+		.name = "ltc2991",
+		.of_match_table = ltc2991_of_match,
+	},
+	.probe = ltc2991_i2c_probe,
+	.id_table = ltc2991_i2c_id,
+};
+
+module_i2c_driver(ltc2991_i2c_driver);
+
+MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com>");
+MODULE_DESCRIPTION("Analog Devices LTC2991 HWMON Driver");
+MODULE_LICENSE("GPL");