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, 511 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-rx6110.c b/drivers/rtc/rtc-rx6110.c
new file mode 100644
index 000000000..1eacd470a
--- /dev/null
+++ b/drivers/rtc/rtc-rx6110.c
@@ -0,0 +1,511 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for the Epson RTC module RX-6110 SA
+ *
+ * Copyright(C) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de>
+ * Copyright(C) SEIKO EPSON CORPORATION 2013. All rights reserved.
+ */
+
+#include <linux/bcd.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/of.h>
+#include <linux/spi/spi.h>
+#include <linux/i2c.h>
+
+/* RX-6110 Register definitions */
+#define RX6110_REG_SEC		0x10
+#define RX6110_REG_MIN		0x11
+#define RX6110_REG_HOUR		0x12
+#define RX6110_REG_WDAY		0x13
+#define RX6110_REG_MDAY		0x14
+#define RX6110_REG_MONTH	0x15
+#define RX6110_REG_YEAR		0x16
+#define RX6110_REG_RES1		0x17
+#define RX6110_REG_ALMIN	0x18
+#define RX6110_REG_ALHOUR	0x19
+#define RX6110_REG_ALWDAY	0x1A
+#define RX6110_REG_TCOUNT0	0x1B
+#define RX6110_REG_TCOUNT1	0x1C
+#define RX6110_REG_EXT		0x1D
+#define RX6110_REG_FLAG		0x1E
+#define RX6110_REG_CTRL		0x1F
+#define RX6110_REG_USER0	0x20
+#define RX6110_REG_USER1	0x21
+#define RX6110_REG_USER2	0x22
+#define RX6110_REG_USER3	0x23
+#define RX6110_REG_USER4	0x24
+#define RX6110_REG_USER5	0x25
+#define RX6110_REG_USER6	0x26
+#define RX6110_REG_USER7	0x27
+#define RX6110_REG_USER8	0x28
+#define RX6110_REG_USER9	0x29
+#define RX6110_REG_USERA	0x2A
+#define RX6110_REG_USERB	0x2B
+#define RX6110_REG_USERC	0x2C
+#define RX6110_REG_USERD	0x2D
+#define RX6110_REG_USERE	0x2E
+#define RX6110_REG_USERF	0x2F
+#define RX6110_REG_RES2		0x30
+#define RX6110_REG_RES3		0x31
+#define RX6110_REG_IRQ		0x32
+
+#define RX6110_BIT_ALARM_EN		BIT(7)
+
+/* Extension Register (1Dh) bit positions */
+#define RX6110_BIT_EXT_TSEL0		BIT(0)
+#define RX6110_BIT_EXT_TSEL1		BIT(1)
+#define RX6110_BIT_EXT_TSEL2		BIT(2)
+#define RX6110_BIT_EXT_WADA		BIT(3)
+#define RX6110_BIT_EXT_TE		BIT(4)
+#define RX6110_BIT_EXT_USEL		BIT(5)
+#define RX6110_BIT_EXT_FSEL0		BIT(6)
+#define RX6110_BIT_EXT_FSEL1		BIT(7)
+
+/* Flag Register (1Eh) bit positions */
+#define RX6110_BIT_FLAG_VLF		BIT(1)
+#define RX6110_BIT_FLAG_AF		BIT(3)
+#define RX6110_BIT_FLAG_TF		BIT(4)
+#define RX6110_BIT_FLAG_UF		BIT(5)
+
+/* Control Register (1Fh) bit positions */
+#define RX6110_BIT_CTRL_TBKE		BIT(0)
+#define RX6110_BIT_CTRL_TBKON		BIT(1)
+#define RX6110_BIT_CTRL_TSTP		BIT(2)
+#define RX6110_BIT_CTRL_AIE		BIT(3)
+#define RX6110_BIT_CTRL_TIE		BIT(4)
+#define RX6110_BIT_CTRL_UIE		BIT(5)
+#define RX6110_BIT_CTRL_STOP		BIT(6)
+#define RX6110_BIT_CTRL_TEST		BIT(7)
+
+enum {
+	RTC_SEC = 0,
+	RTC_MIN,
+	RTC_HOUR,
+	RTC_WDAY,
+	RTC_MDAY,
+	RTC_MONTH,
+	RTC_YEAR,
+	RTC_NR_TIME
+};
+
+#define RX6110_DRIVER_NAME		"rx6110"
+
+struct rx6110_data {
+	struct rtc_device *rtc;
+	struct regmap *regmap;
+};
+
+/**
+ * rx6110_rtc_tm_to_data - convert rtc_time to native time encoding
+ *
+ * @tm: holds date and time
+ * @data: holds the encoding in rx6110 native form
+ */
+static int rx6110_rtc_tm_to_data(struct rtc_time *tm, u8 *data)
+{
+	pr_debug("%s: date %ptRr\n", __func__, tm);
+
+	/*
+	 * The year in the RTC is a value between 0 and 99.
+	 * Assume that this represents the current century
+	 * and disregard all other values.
+	 */
+	if (tm->tm_year < 100 || tm->tm_year >= 200)
+		return -EINVAL;
+
+	data[RTC_SEC] = bin2bcd(tm->tm_sec);
+	data[RTC_MIN] = bin2bcd(tm->tm_min);
+	data[RTC_HOUR] = bin2bcd(tm->tm_hour);
+	data[RTC_WDAY] = BIT(bin2bcd(tm->tm_wday));
+	data[RTC_MDAY] = bin2bcd(tm->tm_mday);
+	data[RTC_MONTH] = bin2bcd(tm->tm_mon + 1);
+	data[RTC_YEAR] = bin2bcd(tm->tm_year % 100);
+
+	return 0;
+}
+
+/**
+ * rx6110_data_to_rtc_tm - convert native time encoding to rtc_time
+ *
+ * @data: holds the encoding in rx6110 native form
+ * @tm: holds date and time
+ */
+static int rx6110_data_to_rtc_tm(u8 *data, struct rtc_time *tm)
+{
+	tm->tm_sec = bcd2bin(data[RTC_SEC] & 0x7f);
+	tm->tm_min = bcd2bin(data[RTC_MIN] & 0x7f);
+	/* only 24-hour clock */
+	tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);
+	tm->tm_wday = ffs(data[RTC_WDAY] & 0x7f);
+	tm->tm_mday = bcd2bin(data[RTC_MDAY] & 0x3f);
+	tm->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1f) - 1;
+	tm->tm_year = bcd2bin(data[RTC_YEAR]) + 100;
+
+	pr_debug("%s: date %ptRr\n", __func__, tm);
+
+	/*
+	 * The year in the RTC is a value between 0 and 99.
+	 * Assume that this represents the current century
+	 * and disregard all other values.
+	 */
+	if (tm->tm_year < 100 || tm->tm_year >= 200)
+		return -EINVAL;
+
+	return 0;
+}
+
+/**
+ * rx6110_set_time - set the current time in the rx6110 registers
+ *
+ * @dev: the rtc device in use
+ * @tm: holds date and time
+ *
+ * BUG: The HW assumes every year that is a multiple of 4 to be a leap
+ * year. Next time this is wrong is 2100, which will not be a leap year
+ *
+ * Note: If STOP is not set/cleared, the clock will start when the seconds
+ *       register is written
+ *
+ */
+static int rx6110_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rx6110_data *rx6110 = dev_get_drvdata(dev);
+	u8 data[RTC_NR_TIME];
+	int ret;
+
+	ret = rx6110_rtc_tm_to_data(tm, data);
+	if (ret < 0)
+		return ret;
+
+	/* set STOP bit before changing clock/calendar */
+	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,
+				 RX6110_BIT_CTRL_STOP, RX6110_BIT_CTRL_STOP);
+	if (ret)
+		return ret;
+
+	ret = regmap_bulk_write(rx6110->regmap, RX6110_REG_SEC, data,
+				RTC_NR_TIME);
+	if (ret)
+		return ret;
+
+	/* The time in the RTC is valid. Be sure to have VLF cleared. */
+	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,
+				 RX6110_BIT_FLAG_VLF, 0);
+	if (ret)
+		return ret;
+
+	/* clear STOP bit after changing clock/calendar */
+	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,
+				 RX6110_BIT_CTRL_STOP, 0);
+
+	return ret;
+}
+
+/**
+ * rx6110_get_time - get the current time from the rx6110 registers
+ * @dev: the rtc device in use
+ * @tm: holds date and time
+ */
+static int rx6110_get_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rx6110_data *rx6110 = dev_get_drvdata(dev);
+	u8 data[RTC_NR_TIME];
+	int flags;
+	int ret;
+
+	ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);
+	if (ret)
+		return -EINVAL;
+
+	/* check for VLF Flag (set at power-on) */
+	if ((flags & RX6110_BIT_FLAG_VLF)) {
+		dev_warn(dev, "Voltage low, data is invalid.\n");
+		return -EINVAL;
+	}
+
+	/* read registers to date */
+	ret = regmap_bulk_read(rx6110->regmap, RX6110_REG_SEC, data,
+			       RTC_NR_TIME);
+	if (ret)
+		return ret;
+
+	ret = rx6110_data_to_rtc_tm(data, tm);
+	if (ret)
+		return ret;
+
+	dev_dbg(dev, "%s: date %ptRr\n", __func__, tm);
+
+	return 0;
+}
+
+static const struct reg_sequence rx6110_default_regs[] = {
+	{ RX6110_REG_RES1,   0xB8 },
+	{ RX6110_REG_RES2,   0x00 },
+	{ RX6110_REG_RES3,   0x10 },
+	{ RX6110_REG_IRQ,    0x00 },
+	{ RX6110_REG_ALMIN,  0x00 },
+	{ RX6110_REG_ALHOUR, 0x00 },
+	{ RX6110_REG_ALWDAY, 0x00 },
+};
+
+/**
+ * rx6110_init - initialize the rx6110 registers
+ *
+ * @rx6110: pointer to the rx6110 struct in use
+ *
+ */
+static int rx6110_init(struct rx6110_data *rx6110)
+{
+	struct rtc_device *rtc = rx6110->rtc;
+	int flags;
+	int ret;
+
+	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_EXT,
+				 RX6110_BIT_EXT_TE, 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_register_patch(rx6110->regmap, rx6110_default_regs,
+				    ARRAY_SIZE(rx6110_default_regs));
+	if (ret)
+		return ret;
+
+	ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);
+	if (ret)
+		return ret;
+
+	/* check for VLF Flag (set at power-on) */
+	if ((flags & RX6110_BIT_FLAG_VLF))
+		dev_warn(&rtc->dev, "Voltage low, data loss detected.\n");
+
+	/* check for Alarm Flag */
+	if (flags & RX6110_BIT_FLAG_AF)
+		dev_warn(&rtc->dev, "An alarm may have been missed.\n");
+
+	/* check for Periodic Timer Flag */
+	if (flags & RX6110_BIT_FLAG_TF)
+		dev_warn(&rtc->dev, "Periodic timer was detected\n");
+
+	/* check for Update Timer Flag */
+	if (flags & RX6110_BIT_FLAG_UF)
+		dev_warn(&rtc->dev, "Update timer was detected\n");
+
+	/* clear all flags BUT VLF */
+	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,
+				 RX6110_BIT_FLAG_AF |
+				 RX6110_BIT_FLAG_UF |
+				 RX6110_BIT_FLAG_TF,
+				 0);
+
+	return ret;
+}
+
+static const struct rtc_class_ops rx6110_rtc_ops = {
+	.read_time = rx6110_get_time,
+	.set_time = rx6110_set_time,
+};
+
+static int rx6110_probe(struct rx6110_data *rx6110, struct device *dev)
+{
+	int err;
+
+	rx6110->rtc = devm_rtc_device_register(dev,
+					       RX6110_DRIVER_NAME,
+					       &rx6110_rtc_ops, THIS_MODULE);
+
+	if (IS_ERR(rx6110->rtc))
+		return PTR_ERR(rx6110->rtc);
+
+	err = rx6110_init(rx6110);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+#if IS_ENABLED(CONFIG_SPI_MASTER)
+static const struct regmap_config regmap_spi_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = RX6110_REG_IRQ,
+	.read_flag_mask = 0x80,
+};
+
+/**
+ * rx6110_spi_probe - initialize rtc driver
+ * @spi: pointer to spi device
+ */
+static int rx6110_spi_probe(struct spi_device *spi)
+{
+	struct rx6110_data *rx6110;
+
+	if ((spi->bits_per_word && spi->bits_per_word != 8) ||
+	    (spi->max_speed_hz > 2000000) ||
+	    (spi->mode != (SPI_CS_HIGH | SPI_CPOL | SPI_CPHA))) {
+		dev_warn(&spi->dev, "SPI settings: bits_per_word: %d, max_speed_hz: %d, mode: %xh\n",
+			 spi->bits_per_word, spi->max_speed_hz, spi->mode);
+		dev_warn(&spi->dev, "driving device in an unsupported mode");
+	}
+
+	rx6110 = devm_kzalloc(&spi->dev, sizeof(*rx6110), GFP_KERNEL);
+	if (!rx6110)
+		return -ENOMEM;
+
+	rx6110->regmap = devm_regmap_init_spi(spi, &regmap_spi_config);
+	if (IS_ERR(rx6110->regmap)) {
+		dev_err(&spi->dev, "regmap init failed for rtc rx6110\n");
+		return PTR_ERR(rx6110->regmap);
+	}
+
+	spi_set_drvdata(spi, rx6110);
+
+	return rx6110_probe(rx6110, &spi->dev);
+}
+
+static const struct spi_device_id rx6110_spi_id[] = {
+	{ "rx6110", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, rx6110_spi_id);
+
+static const __maybe_unused struct of_device_id rx6110_spi_of_match[] = {
+	{ .compatible = "epson,rx6110" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, rx6110_spi_of_match);
+
+static struct spi_driver rx6110_spi_driver = {
+	.driver = {
+		.name = RX6110_DRIVER_NAME,
+		.of_match_table = of_match_ptr(rx6110_spi_of_match),
+	},
+	.probe		= rx6110_spi_probe,
+	.id_table	= rx6110_spi_id,
+};
+
+static int rx6110_spi_register(void)
+{
+	return spi_register_driver(&rx6110_spi_driver);
+}
+
+static void rx6110_spi_unregister(void)
+{
+	spi_unregister_driver(&rx6110_spi_driver);
+}
+#else
+static int rx6110_spi_register(void)
+{
+	return 0;
+}
+
+static void rx6110_spi_unregister(void)
+{
+}
+#endif /* CONFIG_SPI_MASTER */
+
+#if IS_ENABLED(CONFIG_I2C)
+static const struct regmap_config regmap_i2c_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = RX6110_REG_IRQ,
+	.read_flag_mask = 0x80,
+};
+
+static int rx6110_i2c_probe(struct i2c_client *client)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	struct rx6110_data *rx6110;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
+				| I2C_FUNC_SMBUS_I2C_BLOCK)) {
+		dev_err(&adapter->dev,
+			"doesn't support required functionality\n");
+		return -EIO;
+	}
+
+	rx6110 = devm_kzalloc(&client->dev, sizeof(*rx6110), GFP_KERNEL);
+	if (!rx6110)
+		return -ENOMEM;
+
+	rx6110->regmap = devm_regmap_init_i2c(client, &regmap_i2c_config);
+	if (IS_ERR(rx6110->regmap)) {
+		dev_err(&client->dev, "regmap init failed for rtc rx6110\n");
+		return PTR_ERR(rx6110->regmap);
+	}
+
+	i2c_set_clientdata(client, rx6110);
+
+	return rx6110_probe(rx6110, &client->dev);
+}
+
+static const struct acpi_device_id rx6110_i2c_acpi_match[] = {
+	{ "SECC6110" },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, rx6110_i2c_acpi_match);
+
+static const struct i2c_device_id rx6110_i2c_id[] = {
+	{ .name = "rx6110" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, rx6110_i2c_id);
+
+static struct i2c_driver rx6110_i2c_driver = {
+	.driver = {
+		.name = RX6110_DRIVER_NAME,
+		.acpi_match_table = rx6110_i2c_acpi_match,
+	},
+	.probe		= rx6110_i2c_probe,
+	.id_table	= rx6110_i2c_id,
+};
+
+static int rx6110_i2c_register(void)
+{
+	return i2c_add_driver(&rx6110_i2c_driver);
+}
+
+static void rx6110_i2c_unregister(void)
+{
+	i2c_del_driver(&rx6110_i2c_driver);
+}
+#else
+static int rx6110_i2c_register(void)
+{
+	return 0;
+}
+
+static void rx6110_i2c_unregister(void)
+{
+}
+#endif /* CONFIG_I2C */
+
+static int __init rx6110_module_init(void)
+{
+	int ret;
+
+	ret = rx6110_spi_register();
+	if (ret)
+		return ret;
+
+	ret = rx6110_i2c_register();
+	if (ret)
+		rx6110_spi_unregister();
+
+	return ret;
+}
+module_init(rx6110_module_init);
+
+static void __exit rx6110_module_exit(void)
+{
+	rx6110_spi_unregister();
+	rx6110_i2c_unregister();
+}
+module_exit(rx6110_module_exit);
+
+MODULE_AUTHOR("Val Krutov <val.krutov@erd.epson.com>");
+MODULE_DESCRIPTION("RX-6110 SA RTC driver");
+MODULE_LICENSE("GPL");