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, 523 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-pcf8523.c b/drivers/rtc/rtc-pcf8523.c
new file mode 100644
index 000000000..e83549538
--- /dev/null
+++ b/drivers/rtc/rtc-pcf8523.c
@@ -0,0 +1,523 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012 Avionic Design GmbH
+ */
+
+#include <linux/bcd.h>
+#include <linux/bitfield.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/of.h>
+#include <linux/pm_wakeirq.h>
+
+#define PCF8523_REG_CONTROL1 0x00
+#define PCF8523_CONTROL1_CAP_SEL BIT(7)
+#define PCF8523_CONTROL1_STOP    BIT(5)
+#define PCF8523_CONTROL1_AIE    BIT(1)
+
+#define PCF8523_REG_CONTROL2 0x01
+#define PCF8523_CONTROL2_AF BIT(3)
+
+#define PCF8523_REG_CONTROL3 0x02
+#define PCF8523_CONTROL3_PM  GENMASK(7, 5)
+#define PCF8523_PM_STANDBY   0x7
+#define PCF8523_CONTROL3_BLF BIT(2) /* battery low bit, read-only */
+#define PCF8523_CONTROL3_BSF BIT(3)
+
+#define PCF8523_REG_SECONDS  0x03
+#define PCF8523_SECONDS_OS BIT(7)
+
+#define PCF8523_REG_MINUTES  0x04
+#define PCF8523_REG_HOURS    0x05
+#define PCF8523_REG_DAYS     0x06
+#define PCF8523_REG_WEEKDAYS 0x07
+#define PCF8523_REG_MONTHS   0x08
+#define PCF8523_REG_YEARS    0x09
+
+#define PCF8523_REG_MINUTE_ALARM	0x0a
+#define PCF8523_REG_HOUR_ALARM		0x0b
+#define PCF8523_REG_DAY_ALARM		0x0c
+#define PCF8523_REG_WEEKDAY_ALARM	0x0d
+#define ALARM_DIS BIT(7)
+
+#define PCF8523_REG_OFFSET   0x0e
+#define PCF8523_OFFSET_MODE BIT(7)
+
+#define PCF8523_TMR_CLKOUT_CTRL 0x0f
+
+struct pcf8523 {
+	struct rtc_device *rtc;
+	struct regmap *regmap;
+};
+
+static int pcf8523_load_capacitance(struct pcf8523 *pcf8523, struct device_node *node)
+{
+	u32 load, value = 0;
+
+	load = 12500;
+	of_property_read_u32(node, "quartz-load-femtofarads", &load);
+
+	switch (load) {
+	default:
+		dev_warn(&pcf8523->rtc->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 12500",
+			 load);
+		fallthrough;
+	case 12500:
+		value = PCF8523_CONTROL1_CAP_SEL;
+		break;
+	case 7000:
+		break;
+	}
+
+	return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				  PCF8523_CONTROL1_CAP_SEL, value);
+}
+
+static irqreturn_t pcf8523_irq(int irq, void *dev_id)
+{
+	struct pcf8523 *pcf8523 = dev_id;
+	u32 value;
+	int err;
+
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL2, &value);
+	if (err < 0)
+		return IRQ_HANDLED;
+
+	if (value & PCF8523_CONTROL2_AF) {
+		value &= ~PCF8523_CONTROL2_AF;
+		regmap_write(pcf8523->regmap, PCF8523_REG_CONTROL2, value);
+		rtc_update_irq(pcf8523->rtc, 1, RTC_IRQF | RTC_AF);
+
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static int pcf8523_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 regs[10];
+	int err;
+
+	err = regmap_bulk_read(pcf8523->regmap, PCF8523_REG_CONTROL1, regs,
+			       sizeof(regs));
+	if (err < 0)
+		return err;
+
+	if ((regs[0] & PCF8523_CONTROL1_STOP) || (regs[3] & PCF8523_SECONDS_OS))
+		return -EINVAL;
+
+	tm->tm_sec = bcd2bin(regs[3] & 0x7f);
+	tm->tm_min = bcd2bin(regs[4] & 0x7f);
+	tm->tm_hour = bcd2bin(regs[5] & 0x3f);
+	tm->tm_mday = bcd2bin(regs[6] & 0x3f);
+	tm->tm_wday = regs[7] & 0x7;
+	tm->tm_mon = bcd2bin(regs[8] & 0x1f) - 1;
+	tm->tm_year = bcd2bin(regs[9]) + 100;
+
+	return 0;
+}
+
+static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 regs[7];
+	int err;
+
+	err = regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				 PCF8523_CONTROL1_STOP, PCF8523_CONTROL1_STOP);
+	if (err < 0)
+		return err;
+
+	/* This will purposely overwrite PCF8523_SECONDS_OS */
+	regs[0] = bin2bcd(tm->tm_sec);
+	regs[1] = bin2bcd(tm->tm_min);
+	regs[2] = bin2bcd(tm->tm_hour);
+	regs[3] = bin2bcd(tm->tm_mday);
+	regs[4] = tm->tm_wday;
+	regs[5] = bin2bcd(tm->tm_mon + 1);
+	regs[6] = bin2bcd(tm->tm_year - 100);
+
+	err = regmap_bulk_write(pcf8523->regmap, PCF8523_REG_SECONDS, regs,
+				sizeof(regs));
+	if (err < 0) {
+		/*
+		 * If the time cannot be set, restart the RTC anyway. Note
+		 * that errors are ignored if the RTC cannot be started so
+		 * that we have a chance to propagate the original error.
+		 */
+		regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				   PCF8523_CONTROL1_STOP, 0);
+		return err;
+	}
+
+	return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				 PCF8523_CONTROL1_STOP, 0);
+}
+
+static int pcf8523_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 regs[4];
+	u32 value;
+	int err;
+
+	err = regmap_bulk_read(pcf8523->regmap, PCF8523_REG_MINUTE_ALARM, regs,
+			       sizeof(regs));
+	if (err < 0)
+		return err;
+
+	tm->time.tm_sec = 0;
+	tm->time.tm_min = bcd2bin(regs[0] & 0x7F);
+	tm->time.tm_hour = bcd2bin(regs[1] & 0x3F);
+	tm->time.tm_mday = bcd2bin(regs[2] & 0x3F);
+	tm->time.tm_wday = bcd2bin(regs[3] & 0x7);
+
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL1, &value);
+	if (err < 0)
+		return err;
+	tm->enabled = !!(value & PCF8523_CONTROL1_AIE);
+
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL2, &value);
+	if (err < 0)
+		return err;
+	tm->pending = !!(value & PCF8523_CONTROL2_AF);
+
+	return 0;
+}
+
+static int pcf8523_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+
+	return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				  PCF8523_CONTROL1_AIE, enabled ?
+				  PCF8523_CONTROL1_AIE : 0);
+}
+
+static int pcf8523_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 regs[5];
+	int err;
+
+	err = pcf8523_irq_enable(dev, 0);
+	if (err)
+		return err;
+
+	err = regmap_write(pcf8523->regmap, PCF8523_REG_CONTROL2, 0);
+	if (err < 0)
+		return err;
+
+	regs[0] = bin2bcd(tm->time.tm_min);
+	regs[1] = bin2bcd(tm->time.tm_hour);
+	regs[2] = bin2bcd(tm->time.tm_mday);
+	regs[3] = ALARM_DIS;
+
+	err = regmap_bulk_write(pcf8523->regmap, PCF8523_REG_MINUTE_ALARM, regs,
+				sizeof(regs));
+	if (err < 0)
+		return err;
+
+	if (tm->enabled)
+		return pcf8523_irq_enable(dev, tm->enabled);
+
+	return 0;
+}
+
+static int pcf8523_param_get(struct device *dev, struct rtc_param *param)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	int ret;
+	u32 value;
+
+	switch (param->param) {
+	case RTC_PARAM_BACKUP_SWITCH_MODE:
+		ret = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
+		if (ret < 0)
+			return ret;
+
+		value = FIELD_GET(PCF8523_CONTROL3_PM, value);
+
+		switch (value) {
+		case 0x0:
+		case 0x4:
+			param->uvalue = RTC_BSM_LEVEL;
+			break;
+		case 0x1:
+		case 0x5:
+			param->uvalue = RTC_BSM_DIRECT;
+			break;
+		case PCF8523_PM_STANDBY:
+			param->uvalue = RTC_BSM_STANDBY;
+			break;
+		default:
+			param->uvalue = RTC_BSM_DISABLED;
+		}
+
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int pcf8523_param_set(struct device *dev, struct rtc_param *param)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 mode;
+
+	switch (param->param) {
+	case RTC_PARAM_BACKUP_SWITCH_MODE:
+		switch (param->uvalue) {
+		case RTC_BSM_DISABLED:
+			mode = 0x2;
+			break;
+		case RTC_BSM_DIRECT:
+			mode = 0x1;
+			break;
+		case RTC_BSM_LEVEL:
+			mode = 0x0;
+			break;
+		case RTC_BSM_STANDBY:
+			mode = PCF8523_PM_STANDBY;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL3,
+					  PCF8523_CONTROL3_PM,
+					  FIELD_PREP(PCF8523_CONTROL3_PM, mode));
+
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int pcf8523_rtc_ioctl(struct device *dev, unsigned int cmd,
+			     unsigned long arg)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	unsigned int flags = 0;
+	u32 value;
+	int ret;
+
+	switch (cmd) {
+	case RTC_VL_READ:
+		ret = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
+		if (ret < 0)
+			return ret;
+
+		if (value & PCF8523_CONTROL3_BLF)
+			flags |= RTC_VL_BACKUP_LOW;
+
+		ret = regmap_read(pcf8523->regmap, PCF8523_REG_SECONDS, &value);
+		if (ret < 0)
+			return ret;
+
+		if (value & PCF8523_SECONDS_OS)
+			flags |= RTC_VL_DATA_INVALID;
+
+		return put_user(flags, (unsigned int __user *)arg);
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+static int pcf8523_rtc_read_offset(struct device *dev, long *offset)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	int err;
+	u32 value;
+	s8 val;
+
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_OFFSET, &value);
+	if (err < 0)
+		return err;
+
+	/* sign extend the 7-bit offset value */
+	val = value << 1;
+	*offset = (value & PCF8523_OFFSET_MODE ? 4069 : 4340) * (val >> 1);
+
+	return 0;
+}
+
+static int pcf8523_rtc_set_offset(struct device *dev, long offset)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	long reg_m0, reg_m1;
+	u32 value;
+
+	reg_m0 = clamp(DIV_ROUND_CLOSEST(offset, 4340), -64L, 63L);
+	reg_m1 = clamp(DIV_ROUND_CLOSEST(offset, 4069), -64L, 63L);
+
+	if (abs(reg_m0 * 4340 - offset) < abs(reg_m1 * 4069 - offset))
+		value = reg_m0 & 0x7f;
+	else
+		value = (reg_m1 & 0x7f) | PCF8523_OFFSET_MODE;
+
+	return regmap_write(pcf8523->regmap, PCF8523_REG_OFFSET, value);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int pcf8523_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	if (client->irq > 0 && device_may_wakeup(dev))
+		enable_irq_wake(client->irq);
+
+	return 0;
+}
+
+static int pcf8523_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	if (client->irq > 0 && device_may_wakeup(dev))
+		disable_irq_wake(client->irq);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(pcf8523_pm, pcf8523_suspend, pcf8523_resume);
+
+static const struct rtc_class_ops pcf8523_rtc_ops = {
+	.read_time = pcf8523_rtc_read_time,
+	.set_time = pcf8523_rtc_set_time,
+	.read_alarm = pcf8523_rtc_read_alarm,
+	.set_alarm = pcf8523_rtc_set_alarm,
+	.alarm_irq_enable = pcf8523_irq_enable,
+	.ioctl = pcf8523_rtc_ioctl,
+	.read_offset = pcf8523_rtc_read_offset,
+	.set_offset = pcf8523_rtc_set_offset,
+	.param_get = pcf8523_param_get,
+	.param_set = pcf8523_param_set,
+};
+
+static const struct regmap_config regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x13,
+};
+
+static int pcf8523_probe(struct i2c_client *client)
+{
+	struct pcf8523 *pcf8523;
+	struct rtc_device *rtc;
+	bool wakeup_source = false;
+	u32 value;
+	int err;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		return -ENODEV;
+
+	pcf8523 = devm_kzalloc(&client->dev, sizeof(struct pcf8523), GFP_KERNEL);
+	if (!pcf8523)
+		return -ENOMEM;
+
+	pcf8523->regmap = devm_regmap_init_i2c(client, &regmap_config);
+	if (IS_ERR(pcf8523->regmap))
+		return PTR_ERR(pcf8523->regmap);
+
+	i2c_set_clientdata(client, pcf8523);
+
+	rtc = devm_rtc_allocate_device(&client->dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+	pcf8523->rtc = rtc;
+
+	err = pcf8523_load_capacitance(pcf8523, client->dev.of_node);
+	if (err < 0)
+		dev_warn(&client->dev, "failed to set xtal load capacitance: %d",
+			 err);
+
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_SECONDS, &value);
+	if (err < 0)
+		return err;
+
+	if (value & PCF8523_SECONDS_OS) {
+		err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
+		if (err < 0)
+			return err;
+
+		if (FIELD_GET(PCF8523_CONTROL3_PM, value) == PCF8523_PM_STANDBY) {
+			err = regmap_write(pcf8523->regmap, PCF8523_REG_CONTROL3,
+					   value & ~PCF8523_CONTROL3_PM);
+			if (err < 0)
+				return err;
+		}
+	}
+
+	rtc->ops = &pcf8523_rtc_ops;
+	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rtc->range_max = RTC_TIMESTAMP_END_2099;
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
+
+	if (client->irq > 0) {
+		unsigned long irqflags = IRQF_TRIGGER_LOW;
+
+		if (dev_fwnode(&client->dev))
+			irqflags = 0;
+
+		err = regmap_write(pcf8523->regmap, PCF8523_TMR_CLKOUT_CTRL, 0x38);
+		if (err < 0)
+			return err;
+
+		err = devm_request_threaded_irq(&client->dev, client->irq,
+						NULL, pcf8523_irq,
+						IRQF_SHARED | IRQF_ONESHOT | irqflags,
+						dev_name(&rtc->dev), pcf8523);
+		if (err)
+			return err;
+
+		dev_pm_set_wake_irq(&client->dev, client->irq);
+	}
+
+	wakeup_source = of_property_read_bool(client->dev.of_node, "wakeup-source");
+	if (client->irq > 0 || wakeup_source)
+		device_init_wakeup(&client->dev, true);
+
+	return devm_rtc_register_device(rtc);
+}
+
+static const struct i2c_device_id pcf8523_id[] = {
+	{ .name = "pcf8523" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, pcf8523_id);
+
+static const struct of_device_id pcf8523_of_match[] = {
+	{ .compatible = "nxp,pcf8523" },
+	{ .compatible = "microcrystal,rv8523" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, pcf8523_of_match);
+
+static struct i2c_driver pcf8523_driver = {
+	.driver = {
+		.name = "rtc-pcf8523",
+		.of_match_table = pcf8523_of_match,
+		.pm = &pcf8523_pm,
+	},
+	.probe = pcf8523_probe,
+	.id_table = pcf8523_id,
+};
+module_i2c_driver(pcf8523_driver);
+
+MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
+MODULE_DESCRIPTION("NXP PCF8523 RTC driver");
+MODULE_LICENSE("GPL v2");