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, 479 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-r7301.c b/drivers/rtc/rtc-r7301.c
new file mode 100644
index 000000000..6323b7771
--- /dev/null
+++ b/drivers/rtc/rtc-r7301.c
@@ -0,0 +1,479 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * EPSON TOYOCOM RTC-7301SF/DG Driver
+ *
+ * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>
+ *
+ * Based on rtc-rp5c01.c
+ *
+ * Datasheet: http://www5.epsondevice.com/en/products/parallel/rtc7301sf.html
+ */
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+#define DRV_NAME "rtc-r7301"
+
+#define RTC7301_1_SEC		0x0	/* Bank 0 and Band 1 */
+#define RTC7301_10_SEC		0x1	/* Bank 0 and Band 1 */
+#define RTC7301_AE		BIT(3)
+#define RTC7301_1_MIN		0x2	/* Bank 0 and Band 1 */
+#define RTC7301_10_MIN		0x3	/* Bank 0 and Band 1 */
+#define RTC7301_1_HOUR		0x4	/* Bank 0 and Band 1 */
+#define RTC7301_10_HOUR		0x5	/* Bank 0 and Band 1 */
+#define RTC7301_DAY_OF_WEEK	0x6	/* Bank 0 and Band 1 */
+#define RTC7301_1_DAY		0x7	/* Bank 0 and Band 1 */
+#define RTC7301_10_DAY		0x8	/* Bank 0 and Band 1 */
+#define RTC7301_1_MONTH		0x9	/* Bank 0 */
+#define RTC7301_10_MONTH	0xa	/* Bank 0 */
+#define RTC7301_1_YEAR		0xb	/* Bank 0 */
+#define RTC7301_10_YEAR		0xc	/* Bank 0 */
+#define RTC7301_100_YEAR	0xd	/* Bank 0 */
+#define RTC7301_1000_YEAR	0xe	/* Bank 0 */
+#define RTC7301_ALARM_CONTROL	0xe	/* Bank 1 */
+#define RTC7301_ALARM_CONTROL_AIE	BIT(0)
+#define RTC7301_ALARM_CONTROL_AF	BIT(1)
+#define RTC7301_TIMER_CONTROL	0xe	/* Bank 2 */
+#define RTC7301_TIMER_CONTROL_TIE	BIT(0)
+#define RTC7301_TIMER_CONTROL_TF	BIT(1)
+#define RTC7301_CONTROL		0xf	/* All banks */
+#define RTC7301_CONTROL_BUSY		BIT(0)
+#define RTC7301_CONTROL_STOP		BIT(1)
+#define RTC7301_CONTROL_BANK_SEL_0	BIT(2)
+#define RTC7301_CONTROL_BANK_SEL_1	BIT(3)
+
+struct rtc7301_priv {
+	struct regmap *regmap;
+	int irq;
+	spinlock_t lock;
+	u8 bank;
+};
+
+/*
+ * When the device is memory-mapped, some platforms pack the registers into
+ * 32-bit access using the lower 8 bits at each 4-byte stride, while others
+ * expose them as simply consecutive bytes.
+ */
+static const struct regmap_config rtc7301_regmap_32_config = {
+	.reg_bits = 32,
+	.val_bits = 8,
+	.reg_stride = 4,
+};
+
+static const struct regmap_config rtc7301_regmap_8_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.reg_stride = 1,
+};
+
+static u8 rtc7301_read(struct rtc7301_priv *priv, unsigned int reg)
+{
+	int reg_stride = regmap_get_reg_stride(priv->regmap);
+	unsigned int val;
+
+	regmap_read(priv->regmap, reg_stride * reg, &val);
+
+	return val & 0xf;
+}
+
+static void rtc7301_write(struct rtc7301_priv *priv, u8 val, unsigned int reg)
+{
+	int reg_stride = regmap_get_reg_stride(priv->regmap);
+
+	regmap_write(priv->regmap, reg_stride * reg, val);
+}
+
+static void rtc7301_update_bits(struct rtc7301_priv *priv, unsigned int reg,
+				u8 mask, u8 val)
+{
+	int reg_stride = regmap_get_reg_stride(priv->regmap);
+
+	regmap_update_bits(priv->regmap, reg_stride * reg, mask, val);
+}
+
+static int rtc7301_wait_while_busy(struct rtc7301_priv *priv)
+{
+	int retries = 100;
+
+	while (retries-- > 0) {
+		u8 val;
+
+		val = rtc7301_read(priv, RTC7301_CONTROL);
+		if (!(val & RTC7301_CONTROL_BUSY))
+			return 0;
+
+		udelay(300);
+	}
+
+	return -ETIMEDOUT;
+}
+
+static void rtc7301_stop(struct rtc7301_priv *priv)
+{
+	rtc7301_update_bits(priv, RTC7301_CONTROL, RTC7301_CONTROL_STOP,
+			    RTC7301_CONTROL_STOP);
+}
+
+static void rtc7301_start(struct rtc7301_priv *priv)
+{
+	rtc7301_update_bits(priv, RTC7301_CONTROL, RTC7301_CONTROL_STOP, 0);
+}
+
+static void rtc7301_select_bank(struct rtc7301_priv *priv, u8 bank)
+{
+	u8 val = 0;
+
+	if (bank == priv->bank)
+		return;
+
+	if (bank & BIT(0))
+		val |= RTC7301_CONTROL_BANK_SEL_0;
+	if (bank & BIT(1))
+		val |= RTC7301_CONTROL_BANK_SEL_1;
+
+	rtc7301_update_bits(priv, RTC7301_CONTROL,
+			    RTC7301_CONTROL_BANK_SEL_0 |
+			    RTC7301_CONTROL_BANK_SEL_1, val);
+
+	priv->bank = bank;
+}
+
+static void rtc7301_get_time(struct rtc7301_priv *priv, struct rtc_time *tm,
+			     bool alarm)
+{
+	int year;
+
+	tm->tm_sec = rtc7301_read(priv, RTC7301_1_SEC);
+	tm->tm_sec += (rtc7301_read(priv, RTC7301_10_SEC) & ~RTC7301_AE) * 10;
+	tm->tm_min = rtc7301_read(priv, RTC7301_1_MIN);
+	tm->tm_min += (rtc7301_read(priv, RTC7301_10_MIN) & ~RTC7301_AE) * 10;
+	tm->tm_hour = rtc7301_read(priv, RTC7301_1_HOUR);
+	tm->tm_hour += (rtc7301_read(priv, RTC7301_10_HOUR) & ~RTC7301_AE) * 10;
+	tm->tm_mday = rtc7301_read(priv, RTC7301_1_DAY);
+	tm->tm_mday += (rtc7301_read(priv, RTC7301_10_DAY) & ~RTC7301_AE) * 10;
+
+	if (alarm) {
+		tm->tm_wday = -1;
+		tm->tm_mon = -1;
+		tm->tm_year = -1;
+		tm->tm_yday = -1;
+		tm->tm_isdst = -1;
+		return;
+	}
+
+	tm->tm_wday = (rtc7301_read(priv, RTC7301_DAY_OF_WEEK) & ~RTC7301_AE);
+	tm->tm_mon = rtc7301_read(priv, RTC7301_10_MONTH) * 10 +
+		     rtc7301_read(priv, RTC7301_1_MONTH) - 1;
+	year = rtc7301_read(priv, RTC7301_1000_YEAR) * 1000 +
+	       rtc7301_read(priv, RTC7301_100_YEAR) * 100 +
+	       rtc7301_read(priv, RTC7301_10_YEAR) * 10 +
+	       rtc7301_read(priv, RTC7301_1_YEAR);
+
+	tm->tm_year = year - 1900;
+}
+
+static void rtc7301_write_time(struct rtc7301_priv *priv, struct rtc_time *tm,
+			       bool alarm)
+{
+	int year;
+
+	rtc7301_write(priv, tm->tm_sec % 10, RTC7301_1_SEC);
+	rtc7301_write(priv, tm->tm_sec / 10, RTC7301_10_SEC);
+
+	rtc7301_write(priv, tm->tm_min % 10, RTC7301_1_MIN);
+	rtc7301_write(priv, tm->tm_min / 10, RTC7301_10_MIN);
+
+	rtc7301_write(priv, tm->tm_hour % 10, RTC7301_1_HOUR);
+	rtc7301_write(priv, tm->tm_hour / 10, RTC7301_10_HOUR);
+
+	rtc7301_write(priv, tm->tm_mday % 10, RTC7301_1_DAY);
+	rtc7301_write(priv, tm->tm_mday / 10, RTC7301_10_DAY);
+
+	/* Don't care for alarm register */
+	rtc7301_write(priv, alarm ? RTC7301_AE : tm->tm_wday,
+		      RTC7301_DAY_OF_WEEK);
+
+	if (alarm)
+		return;
+
+	rtc7301_write(priv, (tm->tm_mon + 1) % 10, RTC7301_1_MONTH);
+	rtc7301_write(priv, (tm->tm_mon + 1) / 10, RTC7301_10_MONTH);
+
+	year = tm->tm_year + 1900;
+
+	rtc7301_write(priv, year % 10, RTC7301_1_YEAR);
+	rtc7301_write(priv, (year / 10) % 10, RTC7301_10_YEAR);
+	rtc7301_write(priv, (year / 100) % 10, RTC7301_100_YEAR);
+	rtc7301_write(priv, year / 1000, RTC7301_1000_YEAR);
+}
+
+static void rtc7301_alarm_irq(struct rtc7301_priv *priv, unsigned int enabled)
+{
+	rtc7301_update_bits(priv, RTC7301_ALARM_CONTROL,
+			    RTC7301_ALARM_CONTROL_AF |
+			    RTC7301_ALARM_CONTROL_AIE,
+			    enabled ? RTC7301_ALARM_CONTROL_AIE : 0);
+}
+
+static int rtc7301_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rtc7301_priv *priv = dev_get_drvdata(dev);
+	unsigned long flags;
+	int err;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	rtc7301_select_bank(priv, 0);
+
+	err = rtc7301_wait_while_busy(priv);
+	if (!err)
+		rtc7301_get_time(priv, tm, false);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return err;
+}
+
+static int rtc7301_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rtc7301_priv *priv = dev_get_drvdata(dev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	rtc7301_stop(priv);
+	udelay(300);
+	rtc7301_select_bank(priv, 0);
+	rtc7301_write_time(priv, tm, false);
+	rtc7301_start(priv);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
+static int rtc7301_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct rtc7301_priv *priv = dev_get_drvdata(dev);
+	unsigned long flags;
+	u8 alrm_ctrl;
+
+	if (priv->irq <= 0)
+		return -EINVAL;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	rtc7301_select_bank(priv, 1);
+	rtc7301_get_time(priv, &alarm->time, true);
+
+	alrm_ctrl = rtc7301_read(priv, RTC7301_ALARM_CONTROL);
+
+	alarm->enabled = !!(alrm_ctrl & RTC7301_ALARM_CONTROL_AIE);
+	alarm->pending = !!(alrm_ctrl & RTC7301_ALARM_CONTROL_AF);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
+static int rtc7301_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct rtc7301_priv *priv = dev_get_drvdata(dev);
+	unsigned long flags;
+
+	if (priv->irq <= 0)
+		return -EINVAL;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	rtc7301_select_bank(priv, 1);
+	rtc7301_write_time(priv, &alarm->time, true);
+	rtc7301_alarm_irq(priv, alarm->enabled);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
+static int rtc7301_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct rtc7301_priv *priv = dev_get_drvdata(dev);
+	unsigned long flags;
+
+	if (priv->irq <= 0)
+		return -EINVAL;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	rtc7301_select_bank(priv, 1);
+	rtc7301_alarm_irq(priv, enabled);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
+static const struct rtc_class_ops rtc7301_rtc_ops = {
+	.read_time	= rtc7301_read_time,
+	.set_time	= rtc7301_set_time,
+	.read_alarm	= rtc7301_read_alarm,
+	.set_alarm	= rtc7301_set_alarm,
+	.alarm_irq_enable = rtc7301_alarm_irq_enable,
+};
+
+static irqreturn_t rtc7301_irq_handler(int irq, void *dev_id)
+{
+	struct rtc_device *rtc = dev_id;
+	struct rtc7301_priv *priv = dev_get_drvdata(rtc->dev.parent);
+	irqreturn_t ret = IRQ_NONE;
+	u8 alrm_ctrl;
+
+	spin_lock(&priv->lock);
+
+	rtc7301_select_bank(priv, 1);
+
+	alrm_ctrl = rtc7301_read(priv, RTC7301_ALARM_CONTROL);
+	if (alrm_ctrl & RTC7301_ALARM_CONTROL_AF) {
+		ret = IRQ_HANDLED;
+		rtc7301_alarm_irq(priv, false);
+		rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
+	}
+
+	spin_unlock(&priv->lock);
+
+	return ret;
+}
+
+static void rtc7301_init(struct rtc7301_priv *priv)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	rtc7301_select_bank(priv, 2);
+	rtc7301_write(priv, 0, RTC7301_TIMER_CONTROL);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static int __init rtc7301_rtc_probe(struct platform_device *dev)
+{
+	void __iomem *regs;
+	struct rtc7301_priv *priv;
+	struct rtc_device *rtc;
+	static const struct regmap_config *mapconf;
+	int ret;
+	u32 val;
+
+	priv = devm_kzalloc(&dev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	regs = devm_platform_ioremap_resource(dev, 0);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	ret = device_property_read_u32(&dev->dev, "reg-io-width", &val);
+	if (ret)
+		/* Default to 32bit accesses */
+		val = 4;
+
+	switch (val) {
+	case 1:
+		mapconf = &rtc7301_regmap_8_config;
+		break;
+	case 4:
+		mapconf = &rtc7301_regmap_32_config;
+		break;
+	default:
+		dev_err(&dev->dev, "invalid reg-io-width %d\n", val);
+		return -EINVAL;
+	}
+
+	priv->regmap = devm_regmap_init_mmio(&dev->dev, regs,
+					     mapconf);
+	if (IS_ERR(priv->regmap))
+		return PTR_ERR(priv->regmap);
+
+	priv->irq = platform_get_irq(dev, 0);
+
+	spin_lock_init(&priv->lock);
+	priv->bank = -1;
+
+	rtc7301_init(priv);
+
+	platform_set_drvdata(dev, priv);
+
+	rtc = devm_rtc_device_register(&dev->dev, DRV_NAME, &rtc7301_rtc_ops,
+				       THIS_MODULE);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	if (priv->irq > 0) {
+		ret = devm_request_irq(&dev->dev, priv->irq,
+				       rtc7301_irq_handler, IRQF_SHARED,
+				       dev_name(&dev->dev), rtc);
+		if (ret) {
+			priv->irq = 0;
+			dev_err(&dev->dev, "unable to request IRQ\n");
+		} else {
+			device_set_wakeup_capable(&dev->dev, true);
+		}
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int rtc7301_suspend(struct device *dev)
+{
+	struct rtc7301_priv *priv = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(priv->irq);
+
+	return 0;
+}
+
+static int rtc7301_resume(struct device *dev)
+{
+	struct rtc7301_priv *priv = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(priv->irq);
+
+	return 0;
+}
+
+#endif
+
+static SIMPLE_DEV_PM_OPS(rtc7301_pm_ops, rtc7301_suspend, rtc7301_resume);
+
+static const struct of_device_id rtc7301_dt_match[] = {
+	{ .compatible = "epson,rtc7301sf" },
+	{ .compatible = "epson,rtc7301dg" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, rtc7301_dt_match);
+
+static struct platform_driver rtc7301_rtc_driver = {
+	.driver	= {
+		.name = DRV_NAME,
+		.of_match_table = rtc7301_dt_match,
+		.pm = &rtc7301_pm_ops,
+	},
+};
+
+module_platform_driver_probe(rtc7301_rtc_driver, rtc7301_rtc_probe);
+
+MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("EPSON TOYOCOM RTC-7301SF/DG Driver");
+MODULE_ALIAS("platform:rtc-r7301");