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, 368 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-rx8111.c b/drivers/rtc/rtc-rx8111.c
new file mode 100644
index 000000000..8450d9f0b
--- /dev/null
+++ b/drivers/rtc/rtc-rx8111.c
@@ -0,0 +1,368 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for Epson RX8111 RTC.
+ *
+ * Copyright (C) 2023 Axis Communications AB
+ */
+
+#include <linux/bcd.h>
+#include <linux/bitfield.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include <linux/rtc.h>
+
+#define RX8111_REG_SEC			0x10	/* Second counter. */
+#define RX8111_REG_MIN			0x11	/* Minute counter */
+#define RX8111_REG_HOUR			0x12	/* Hour counter. */
+#define RX8111_REG_WEEK			0x13	/* Week day counter. */
+#define RX8111_REG_DAY			0x14	/* Month day counter. */
+#define RX8111_REG_MONTH		0x15	/* Month counter. */
+#define RX8111_REG_YEAR			0x16	/* Year counter. */
+
+#define RX8111_REG_ALARM_MIN		0x17	/* Alarm minute. */
+#define RX8111_REG_ALARM_HOUR		0x18	/* Alarm hour. */
+#define RX8111_REG_ALARM_WEEK_DAY	0x19	/* Alarm week or month day. */
+
+#define RX8111_REG_TIMER_COUNTER0	0x1a	/* Timer counter LSB. */
+#define RX8111_REG_TIMER_COUNTER1	0x1b	/* Timer counter. */
+#define RX8111_REG_TIMER_COUNTER2	0x1c	/* Timer counter MSB. */
+
+#define RX8111_REG_EXT			0x1d	/* Extension register. */
+#define RX8111_REG_FLAG			0x1e	/* Flag register. */
+#define RX8111_REG_CTRL			0x1f	/* Control register. */
+
+#define RX8111_REG_TS_1_1000_SEC	0x20	/* Timestamp 256 or 512 Hz . */
+#define RX8111_REG_TS_1_100_SEC		0x21	/* Timestamp 1 - 128 Hz. */
+#define RX8111_REG_TS_SEC		0x22	/* Timestamp second. */
+#define RX8111_REG_TS_MIN		0x23	/* Timestamp minute. */
+#define RX8111_REG_TS_HOUR		0x24	/* Timestamp hour. */
+#define RX8111_REG_TS_WEEK		0x25	/* Timestamp week day. */
+#define RX8111_REG_TS_DAY		0x26	/* Timestamp month day. */
+#define RX8111_REG_TS_MONTH		0x27	/* Timestamp month. */
+#define RX8111_REG_TS_YEAR		0x28	/* Timestamp year. */
+#define RX8111_REG_TS_STATUS		0x29	/* Timestamp status. */
+
+#define RX8111_REG_EVIN_SETTING		0x2b	/* Timestamp trigger setting. */
+#define RX8111_REG_ALARM_SEC		0x2c	/* Alarm second. */
+#define RX8111_REG_TIMER_CTRL		0x2d	/* Timer control. */
+#define RX8111_REG_TS_CTRL0		0x2e	/* Timestamp control 0. */
+#define RX8111_REG_CMD_TRIGGER		0x2f	/* Timestamp trigger. */
+#define RX8111_REG_PWR_SWITCH_CTRL	0x32	/* Power switch control. */
+#define RX8111_REG_STATUS_MON		0x33	/* Status monitor. */
+#define RX8111_REG_TS_CTRL1		0x34	/* Timestamp control 1. */
+#define RX8111_REG_TS_CTRL2		0x35	/* Timestamp control 2. */
+#define RX8111_REG_TS_CTRL3		0x36	/* Timestamp control 3. */
+
+#define RX8111_FLAG_XST_BIT BIT(0)
+#define RX8111_FLAG_VLF_BIT BIT(1)
+
+#define RX8111_TIME_BUF_SZ (RX8111_REG_YEAR - RX8111_REG_SEC + 1)
+
+enum rx8111_regfield {
+	/* RX8111_REG_EXT. */
+	RX8111_REGF_TSEL0,
+	RX8111_REGF_TSEL1,
+	RX8111_REGF_ETS,
+	RX8111_REGF_WADA,
+	RX8111_REGF_TE,
+	RX8111_REGF_USEL,
+	RX8111_REGF_FSEL0,
+	RX8111_REGF_FSEL1,
+
+	/* RX8111_REG_FLAG. */
+	RX8111_REGF_XST,
+	RX8111_REGF_VLF,
+	RX8111_REGF_EVF,
+	RX8111_REGF_AF,
+	RX8111_REGF_TF,
+	RX8111_REGF_UF,
+	RX8111_REGF_POR,
+
+	/* RX8111_REG_CTRL. */
+	RX8111_REGF_STOP,
+	RX8111_REGF_EIE,
+	RX8111_REGF_AIE,
+	RX8111_REGF_TIE,
+	RX8111_REGF_UIE,
+
+	/* RX8111_REG_PWR_SWITCH_CTRL. */
+	RX8111_REGF_SMPT0,
+	RX8111_REGF_SMPT1,
+	RX8111_REGF_SWSEL0,
+	RX8111_REGF_SWSEL1,
+	RX8111_REGF_INIEN,
+	RX8111_REGF_CHGEN,
+
+	/* RX8111_REG_STATUS_MON. */
+	RX8111_REGF_VLOW,
+
+	/* Sentinel value. */
+	RX8111_REGF_MAX
+};
+
+static const struct reg_field rx8111_regfields[] = {
+	[RX8111_REGF_TSEL0] = REG_FIELD(RX8111_REG_EXT, 0, 0),
+	[RX8111_REGF_TSEL1] = REG_FIELD(RX8111_REG_EXT, 1, 1),
+	[RX8111_REGF_ETS]   = REG_FIELD(RX8111_REG_EXT, 2, 2),
+	[RX8111_REGF_WADA]  = REG_FIELD(RX8111_REG_EXT, 3, 3),
+	[RX8111_REGF_TE]    = REG_FIELD(RX8111_REG_EXT, 4, 4),
+	[RX8111_REGF_USEL]  = REG_FIELD(RX8111_REG_EXT, 5, 5),
+	[RX8111_REGF_FSEL0] = REG_FIELD(RX8111_REG_EXT, 6, 6),
+	[RX8111_REGF_FSEL1] = REG_FIELD(RX8111_REG_EXT, 7, 7),
+
+	[RX8111_REGF_XST] = REG_FIELD(RX8111_REG_FLAG, 0, 0),
+	[RX8111_REGF_VLF] = REG_FIELD(RX8111_REG_FLAG, 1, 1),
+	[RX8111_REGF_EVF] = REG_FIELD(RX8111_REG_FLAG, 2, 2),
+	[RX8111_REGF_AF]  = REG_FIELD(RX8111_REG_FLAG, 3, 3),
+	[RX8111_REGF_TF]  = REG_FIELD(RX8111_REG_FLAG, 4, 4),
+	[RX8111_REGF_UF]  = REG_FIELD(RX8111_REG_FLAG, 5, 5),
+	[RX8111_REGF_POR] = REG_FIELD(RX8111_REG_FLAG, 7, 7),
+
+	[RX8111_REGF_STOP] = REG_FIELD(RX8111_REG_CTRL, 0, 0),
+	[RX8111_REGF_EIE]  = REG_FIELD(RX8111_REG_CTRL, 2, 2),
+	[RX8111_REGF_AIE]  = REG_FIELD(RX8111_REG_CTRL, 3, 3),
+	[RX8111_REGF_TIE]  = REG_FIELD(RX8111_REG_CTRL, 4, 4),
+	[RX8111_REGF_UIE]  = REG_FIELD(RX8111_REG_CTRL, 5, 5),
+
+	[RX8111_REGF_SMPT0]  = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 0, 0),
+	[RX8111_REGF_SMPT1]  = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 1, 1),
+	[RX8111_REGF_SWSEL0] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 2, 2),
+	[RX8111_REGF_SWSEL1] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 3, 3),
+	[RX8111_REGF_INIEN]  = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 6, 6),
+	[RX8111_REGF_CHGEN]  = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 7, 7),
+
+	[RX8111_REGF_VLOW]  = REG_FIELD(RX8111_REG_STATUS_MON, 1, 1),
+};
+
+static const struct regmap_config rx8111_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = RX8111_REG_TS_CTRL3,
+};
+
+struct rx8111_data {
+	struct regmap *regmap;
+	struct regmap_field *regfields[RX8111_REGF_MAX];
+	struct device *dev;
+	struct rtc_device *rtc;
+};
+
+static int rx8111_read_vl_flag(struct rx8111_data *data, unsigned int *vlval)
+{
+	int ret;
+
+	ret = regmap_field_read(data->regfields[RX8111_REGF_VLF], vlval);
+	if (ret)
+		dev_dbg(data->dev, "Could not read VL flag (%d)", ret);
+
+	return ret;
+}
+
+static int rx8111_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rx8111_data *data = dev_get_drvdata(dev);
+	u8 buf[RX8111_TIME_BUF_SZ];
+	unsigned int regval;
+	int ret;
+
+	/* Check status. */
+	ret = regmap_read(data->regmap, RX8111_REG_FLAG, &regval);
+	if (ret) {
+		dev_dbg(data->dev, "Could not read flag register (%d)\n", ret);
+		return ret;
+	}
+
+	if (FIELD_GET(RX8111_FLAG_XST_BIT, regval)) {
+		dev_dbg(data->dev,
+			"Crystal oscillation stopped, time is not reliable\n");
+		return -EINVAL;
+	}
+
+	if (FIELD_GET(RX8111_FLAG_VLF_BIT, regval)) {
+		dev_dbg(data->dev,
+			"Low voltage detected, time is not reliable\n");
+		return -EINVAL;
+	}
+
+	ret = regmap_field_read(data->regfields[RX8111_REGF_STOP], &regval);
+	if (ret) {
+		dev_dbg(data->dev, "Could not read clock status (%d)\n", ret);
+		return ret;
+	}
+
+	if (regval) {
+		dev_dbg(data->dev, "Clock stopped, time is not reliable\n");
+		return -EINVAL;
+	}
+
+	/* Read time. */
+	ret = regmap_bulk_read(data->regmap, RX8111_REG_SEC, buf,
+			       ARRAY_SIZE(buf));
+	if (ret) {
+		dev_dbg(data->dev, "Could not bulk read time (%d)\n", ret);
+		return ret;
+	}
+
+	tm->tm_sec = bcd2bin(buf[0]);
+	tm->tm_min = bcd2bin(buf[1]);
+	tm->tm_hour = bcd2bin(buf[2]);
+	tm->tm_wday = ffs(buf[3]) - 1;
+	tm->tm_mday = bcd2bin(buf[4]);
+	tm->tm_mon = bcd2bin(buf[5]) - 1;
+	tm->tm_year = bcd2bin(buf[6]) + 100;
+
+	return 0;
+}
+
+static int rx8111_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rx8111_data *data = dev_get_drvdata(dev);
+	u8 buf[RX8111_TIME_BUF_SZ];
+	int ret;
+
+	buf[0] = bin2bcd(tm->tm_sec);
+	buf[1] = bin2bcd(tm->tm_min);
+	buf[2] = bin2bcd(tm->tm_hour);
+	buf[3] = BIT(tm->tm_wday);
+	buf[4] = bin2bcd(tm->tm_mday);
+	buf[5] = bin2bcd(tm->tm_mon + 1);
+	buf[6] = bin2bcd(tm->tm_year - 100);
+
+	ret = regmap_clear_bits(data->regmap, RX8111_REG_FLAG,
+				RX8111_FLAG_XST_BIT | RX8111_FLAG_VLF_BIT);
+	if (ret)
+		return ret;
+
+	/* Stop the clock. */
+	ret = regmap_field_write(data->regfields[RX8111_REGF_STOP], 1);
+	if (ret) {
+		dev_dbg(data->dev, "Could not stop the clock (%d)\n", ret);
+		return ret;
+	}
+
+	/* Set the time. */
+	ret = regmap_bulk_write(data->regmap, RX8111_REG_SEC, buf,
+				ARRAY_SIZE(buf));
+	if (ret) {
+		dev_dbg(data->dev, "Could not bulk write time (%d)\n", ret);
+
+		/*
+		 * We don't bother with trying to start the clock again. We
+		 * check for this in rx8111_read_time() (and thus force user to
+		 * call rx8111_set_time() to try again).
+		 */
+		return ret;
+	}
+
+	/* Start the clock. */
+	ret = regmap_field_write(data->regfields[RX8111_REGF_STOP], 0);
+	if (ret) {
+		dev_dbg(data->dev, "Could not start the clock (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int rx8111_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+	struct rx8111_data *data = dev_get_drvdata(dev);
+	unsigned int regval;
+	unsigned int vlval;
+	int ret;
+
+	switch (cmd) {
+	case RTC_VL_READ:
+		ret = rx8111_read_vl_flag(data, &regval);
+		if (ret)
+			return ret;
+
+		vlval = regval ? RTC_VL_DATA_INVALID : 0;
+
+		ret = regmap_field_read(data->regfields[RX8111_REGF_VLOW],
+					&regval);
+		if (ret)
+			return ret;
+
+		vlval |= regval ? RTC_VL_BACKUP_LOW : 0;
+
+		return put_user(vlval, (typeof(vlval) __user *)arg);
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+static const struct rtc_class_ops rx8111_rtc_ops = {
+	.read_time = rx8111_read_time,
+	.set_time = rx8111_set_time,
+	.ioctl = rx8111_ioctl,
+};
+
+static int rx8111_probe(struct i2c_client *client)
+{
+	struct rx8111_data *data;
+	struct rtc_device *rtc;
+	size_t i;
+
+	data = devm_kmalloc(&client->dev, sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		dev_dbg(&client->dev, "Could not allocate device data\n");
+		return -ENOMEM;
+	}
+
+	data->dev = &client->dev;
+	dev_set_drvdata(data->dev, data);
+
+	data->regmap = devm_regmap_init_i2c(client, &rx8111_regmap_config);
+	if (IS_ERR(data->regmap)) {
+		dev_dbg(data->dev, "Could not initialize regmap\n");
+		return PTR_ERR(data->regmap);
+	}
+
+	for (i = 0; i < RX8111_REGF_MAX; ++i) {
+		data->regfields[i] = devm_regmap_field_alloc(
+			data->dev, data->regmap, rx8111_regfields[i]);
+		if (IS_ERR(data->regfields[i])) {
+			dev_dbg(data->dev,
+				"Could not allocate register field %zu\n", i);
+			return PTR_ERR(data->regfields[i]);
+		}
+	}
+
+	rtc = devm_rtc_allocate_device(data->dev);
+	if (IS_ERR(rtc)) {
+		dev_dbg(data->dev, "Could not allocate rtc device\n");
+		return PTR_ERR(rtc);
+	}
+
+	rtc->ops = &rx8111_rtc_ops;
+	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rtc->range_max = RTC_TIMESTAMP_END_2099;
+
+	clear_bit(RTC_FEATURE_ALARM, rtc->features);
+
+	return devm_rtc_register_device(rtc);
+}
+
+static const struct of_device_id rx8111_of_match[] = {
+	{
+		.compatible = "epson,rx8111",
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, rx8111_of_match);
+
+static struct i2c_driver rx8111_driver = {
+	.driver = {
+		.name = "rtc-rx8111",
+		.of_match_table = rx8111_of_match,
+	},
+	.probe = rx8111_probe,
+};
+module_i2c_driver(rx8111_driver);
+
+MODULE_AUTHOR("Waqar Hameed <waqar.hameed@axis.com>");
+MODULE_DESCRIPTION("Epson RX8111 RTC driver");
+MODULE_LICENSE("GPL");