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, 434 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
new file mode 100644
index 000000000..ce3954132
--- /dev/null
+++ b/drivers/rtc/rtc-rx8010.c
@@ -0,0 +1,434 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for the Epson RTC module RX-8010 SJ
+ *
+ * Copyright(C) Timesys Corporation 2015
+ * Copyright(C) General Electric Company 2015
+ */
+
+#include <linux/bcd.h>
+#include <linux/bitops.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+
+#define RX8010_SEC		0x10
+#define RX8010_MIN		0x11
+#define RX8010_HOUR		0x12
+#define RX8010_WDAY		0x13
+#define RX8010_MDAY		0x14
+#define RX8010_MONTH		0x15
+#define RX8010_YEAR		0x16
+#define RX8010_RESV17		0x17
+#define RX8010_ALMIN		0x18
+#define RX8010_ALHOUR		0x19
+#define RX8010_ALWDAY		0x1A
+#define RX8010_TCOUNT0		0x1B
+#define RX8010_TCOUNT1		0x1C
+#define RX8010_EXT		0x1D
+#define RX8010_FLAG		0x1E
+#define RX8010_CTRL		0x1F
+/* 0x20 to 0x2F are user registers */
+#define RX8010_RESV30		0x30
+#define RX8010_RESV31		0x31
+#define RX8010_IRQ		0x32
+
+#define RX8010_EXT_WADA		BIT(3)
+
+#define RX8010_FLAG_VLF		BIT(1)
+#define RX8010_FLAG_AF		BIT(3)
+#define RX8010_FLAG_TF		BIT(4)
+#define RX8010_FLAG_UF		BIT(5)
+
+#define RX8010_CTRL_AIE		BIT(3)
+#define RX8010_CTRL_UIE		BIT(5)
+#define RX8010_CTRL_STOP	BIT(6)
+#define RX8010_CTRL_TEST	BIT(7)
+
+#define RX8010_ALARM_AE		BIT(7)
+
+static const struct i2c_device_id rx8010_id[] = {
+	{ .name = "rx8010" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, rx8010_id);
+
+static const __maybe_unused struct of_device_id rx8010_of_match[] = {
+	{ .compatible = "epson,rx8010" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, rx8010_of_match);
+
+struct rx8010_data {
+	struct regmap *regs;
+	struct rtc_device *rtc;
+	u8 ctrlreg;
+};
+
+static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
+{
+	struct i2c_client *client = dev_id;
+	struct rx8010_data *rx8010 = i2c_get_clientdata(client);
+	int flagreg, err;
+
+	rtc_lock(rx8010->rtc);
+
+	err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
+	if (err) {
+		rtc_unlock(rx8010->rtc);
+		return IRQ_NONE;
+	}
+
+	if (flagreg & RX8010_FLAG_VLF)
+		dev_warn(&client->dev, "Frequency stop detected\n");
+
+	if (flagreg & RX8010_FLAG_TF) {
+		flagreg &= ~RX8010_FLAG_TF;
+		rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);
+	}
+
+	if (flagreg & RX8010_FLAG_AF) {
+		flagreg &= ~RX8010_FLAG_AF;
+		rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);
+	}
+
+	if (flagreg & RX8010_FLAG_UF) {
+		flagreg &= ~RX8010_FLAG_UF;
+		rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);
+	}
+
+	err = regmap_write(rx8010->regs, RX8010_FLAG, flagreg);
+	rtc_unlock(rx8010->rtc);
+	return err ? IRQ_NONE : IRQ_HANDLED;
+}
+
+static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
+{
+	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+	u8 date[RX8010_YEAR - RX8010_SEC + 1];
+	int flagreg, err;
+
+	err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
+	if (err)
+		return err;
+
+	if (flagreg & RX8010_FLAG_VLF) {
+		dev_warn(dev, "Frequency stop detected\n");
+		return -EINVAL;
+	}
+
+	err = regmap_bulk_read(rx8010->regs, RX8010_SEC, date, sizeof(date));
+	if (err)
+		return err;
+
+	dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);
+	dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f);
+	dt->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f);
+	dt->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f);
+	dt->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f) - 1;
+	dt->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 100;
+	dt->tm_wday = ffs(date[RX8010_WDAY - RX8010_SEC] & 0x7f);
+
+	return 0;
+}
+
+static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
+{
+	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+	u8 date[RX8010_YEAR - RX8010_SEC + 1];
+	int err;
+
+	/* set STOP bit before changing clock/calendar */
+	err = regmap_set_bits(rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP);
+	if (err)
+		return err;
+
+	date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec);
+	date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min);
+	date[RX8010_HOUR - RX8010_SEC] = bin2bcd(dt->tm_hour);
+	date[RX8010_MDAY - RX8010_SEC] = bin2bcd(dt->tm_mday);
+	date[RX8010_MONTH - RX8010_SEC] = bin2bcd(dt->tm_mon + 1);
+	date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100);
+	date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday);
+
+	err = regmap_bulk_write(rx8010->regs, RX8010_SEC, date, sizeof(date));
+	if (err)
+		return err;
+
+	/* clear STOP bit after changing clock/calendar */
+	err = regmap_clear_bits(rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP);
+	if (err)
+		return err;
+
+	err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_VLF);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int rx8010_init(struct device *dev)
+{
+	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+	u8 ctrl[2];
+	int need_clear = 0, err;
+
+	/* Initialize reserved registers as specified in datasheet */
+	err = regmap_write(rx8010->regs, RX8010_RESV17, 0xD8);
+	if (err)
+		return err;
+
+	err = regmap_write(rx8010->regs, RX8010_RESV30, 0x00);
+	if (err)
+		return err;
+
+	err = regmap_write(rx8010->regs, RX8010_RESV31, 0x08);
+	if (err)
+		return err;
+
+	err = regmap_write(rx8010->regs, RX8010_IRQ, 0x00);
+	if (err)
+		return err;
+
+	err = regmap_bulk_read(rx8010->regs, RX8010_FLAG, ctrl, 2);
+	if (err)
+		return err;
+
+	if (ctrl[0] & RX8010_FLAG_VLF)
+		dev_warn(dev, "Frequency stop was detected\n");
+
+	if (ctrl[0] & RX8010_FLAG_AF) {
+		dev_warn(dev, "Alarm was detected\n");
+		need_clear = 1;
+	}
+
+	if (ctrl[0] & RX8010_FLAG_TF)
+		need_clear = 1;
+
+	if (ctrl[0] & RX8010_FLAG_UF)
+		need_clear = 1;
+
+	if (need_clear) {
+		ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF);
+		err = regmap_write(rx8010->regs, RX8010_FLAG, ctrl[0]);
+		if (err)
+			return err;
+	}
+
+	rx8010->ctrlreg = (ctrl[1] & ~RX8010_CTRL_TEST);
+
+	return 0;
+}
+
+static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+	u8 alarmvals[3];
+	int flagreg, err;
+
+	err = regmap_bulk_read(rx8010->regs, RX8010_ALMIN, alarmvals, 3);
+	if (err)
+		return err;
+
+	err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
+	if (err)
+		return err;
+
+	t->time.tm_sec = 0;
+	t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
+	t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
+
+	if (!(alarmvals[2] & RX8010_ALARM_AE))
+		t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f);
+
+	t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE);
+	t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled;
+
+	return 0;
+}
+
+static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+	u8 alarmvals[3];
+	int err;
+
+	if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {
+		rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
+		err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
+		if (err)
+			return err;
+	}
+
+	err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF);
+	if (err)
+		return err;
+
+	alarmvals[0] = bin2bcd(t->time.tm_min);
+	alarmvals[1] = bin2bcd(t->time.tm_hour);
+	alarmvals[2] = bin2bcd(t->time.tm_mday);
+
+	err = regmap_bulk_write(rx8010->regs, RX8010_ALMIN, alarmvals, 2);
+	if (err)
+		return err;
+
+	err = regmap_clear_bits(rx8010->regs, RX8010_EXT, RX8010_EXT_WADA);
+	if (err)
+		return err;
+
+	if (alarmvals[2] == 0)
+		alarmvals[2] |= RX8010_ALARM_AE;
+
+	err = regmap_write(rx8010->regs, RX8010_ALWDAY, alarmvals[2]);
+	if (err)
+		return err;
+
+	if (t->enabled) {
+		if (rx8010->rtc->uie_rtctimer.enabled)
+			rx8010->ctrlreg |= RX8010_CTRL_UIE;
+		if (rx8010->rtc->aie_timer.enabled)
+			rx8010->ctrlreg |=
+				(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
+
+		err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static int rx8010_alarm_irq_enable(struct device *dev,
+				   unsigned int enabled)
+{
+	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+	int err;
+	u8 ctrl;
+
+	ctrl = rx8010->ctrlreg;
+
+	if (enabled) {
+		if (rx8010->rtc->uie_rtctimer.enabled)
+			ctrl |= RX8010_CTRL_UIE;
+		if (rx8010->rtc->aie_timer.enabled)
+			ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
+	} else {
+		if (!rx8010->rtc->uie_rtctimer.enabled)
+			ctrl &= ~RX8010_CTRL_UIE;
+		if (!rx8010->rtc->aie_timer.enabled)
+			ctrl &= ~RX8010_CTRL_AIE;
+	}
+
+	err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF);
+	if (err)
+		return err;
+
+	if (ctrl != rx8010->ctrlreg) {
+		rx8010->ctrlreg = ctrl;
+		err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+	int tmp, flagreg, err;
+
+	switch (cmd) {
+	case RTC_VL_READ:
+		err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
+		if (err)
+			return err;
+
+		tmp = flagreg & RX8010_FLAG_VLF ? RTC_VL_DATA_INVALID : 0;
+		return put_user(tmp, (unsigned int __user *)arg);
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+static const struct rtc_class_ops rx8010_rtc_ops = {
+	.read_time = rx8010_get_time,
+	.set_time = rx8010_set_time,
+	.ioctl = rx8010_ioctl,
+	.read_alarm = rx8010_read_alarm,
+	.set_alarm = rx8010_set_alarm,
+	.alarm_irq_enable = rx8010_alarm_irq_enable,
+};
+
+static const struct regmap_config rx8010_regmap_config = {
+	.name = "rx8010-rtc",
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int rx8010_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct rx8010_data *rx8010;
+	int err = 0;
+
+	rx8010 = devm_kzalloc(dev, sizeof(*rx8010), GFP_KERNEL);
+	if (!rx8010)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, rx8010);
+
+	rx8010->regs = devm_regmap_init_i2c(client, &rx8010_regmap_config);
+	if (IS_ERR(rx8010->regs))
+		return PTR_ERR(rx8010->regs);
+
+	err = rx8010_init(dev);
+	if (err)
+		return err;
+
+	rx8010->rtc = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rx8010->rtc))
+		return PTR_ERR(rx8010->rtc);
+
+	if (client->irq > 0) {
+		unsigned long irqflags = IRQF_TRIGGER_LOW;
+
+		if (dev_fwnode(&client->dev))
+			irqflags = 0;
+
+		err = devm_request_threaded_irq(dev, client->irq, NULL,
+						rx8010_irq_1_handler,
+						irqflags | IRQF_ONESHOT,
+						"rx8010", client);
+		if (err) {
+			dev_err(dev, "unable to request IRQ\n");
+			return err;
+		}
+	} else {
+		clear_bit(RTC_FEATURE_ALARM, rx8010->rtc->features);
+	}
+
+	rx8010->rtc->ops = &rx8010_rtc_ops;
+	rx8010->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rx8010->rtc->range_max = RTC_TIMESTAMP_END_2099;
+
+	return devm_rtc_register_device(rx8010->rtc);
+}
+
+static struct i2c_driver rx8010_driver = {
+	.driver = {
+		.name = "rtc-rx8010",
+		.of_match_table = of_match_ptr(rx8010_of_match),
+	},
+	.probe		= rx8010_probe,
+	.id_table	= rx8010_id,
+};
+
+module_i2c_driver(rx8010_driver);
+
+MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");
+MODULE_DESCRIPTION("Epson RX8010SJ RTC driver");
+MODULE_LICENSE("GPL v2");