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, 322 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-rx8581.c b/drivers/rtc/rtc-rx8581.c
new file mode 100644
index 000000000..cf4dab94c
--- /dev/null
+++ b/drivers/rtc/rtc-rx8581.c
@@ -0,0 +1,322 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * An I2C driver for the Epson RX8581 RTC
+ *
+ * Author: Martyn Welch <martyn.welch@ge.com>
+ * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.
+ *
+ * Based on: rtc-pcf8563.c (An I2C driver for the Philips PCF8563 RTC)
+ * Copyright 2005-06 Tower Technologies
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/bcd.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/log2.h>
+
+#define RX8581_REG_SC		0x00 /* Second in BCD */
+#define RX8581_REG_MN		0x01 /* Minute in BCD */
+#define RX8581_REG_HR		0x02 /* Hour in BCD */
+#define RX8581_REG_DW		0x03 /* Day of Week */
+#define RX8581_REG_DM		0x04 /* Day of Month in BCD */
+#define RX8581_REG_MO		0x05 /* Month in BCD */
+#define RX8581_REG_YR		0x06 /* Year in BCD */
+#define RX8581_REG_RAM		0x07 /* RAM */
+#define RX8581_REG_AMN		0x08 /* Alarm Min in BCD*/
+#define RX8581_REG_AHR		0x09 /* Alarm Hour in BCD */
+#define RX8581_REG_ADM		0x0A
+#define RX8581_REG_ADW		0x0A
+#define RX8581_REG_TMR0		0x0B
+#define RX8581_REG_TMR1		0x0C
+#define RX8581_REG_EXT		0x0D /* Extension Register */
+#define RX8581_REG_FLAG		0x0E /* Flag Register */
+#define RX8581_REG_CTRL		0x0F /* Control Register */
+
+
+/* Flag Register bit definitions */
+#define RX8581_FLAG_UF		0x20 /* Update */
+#define RX8581_FLAG_TF		0x10 /* Timer */
+#define RX8581_FLAG_AF		0x08 /* Alarm */
+#define RX8581_FLAG_VLF		0x02 /* Voltage Low */
+
+/* Control Register bit definitions */
+#define RX8581_CTRL_UIE		0x20 /* Update Interrupt Enable */
+#define RX8581_CTRL_TIE		0x10 /* Timer Interrupt Enable */
+#define RX8581_CTRL_AIE		0x08 /* Alarm Interrupt Enable */
+#define RX8581_CTRL_STOP	0x02 /* STOP bit */
+#define RX8581_CTRL_RESET	0x01 /* RESET bit */
+
+#define RX8571_USER_RAM		0x10
+#define RX8571_NVRAM_SIZE	0x10
+
+struct rx85x1_config {
+	struct regmap_config regmap;
+	unsigned int num_nvram;
+};
+
+/*
+ * In the routines that deal directly with the rx8581 hardware, we use
+ * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
+ */
+static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	unsigned char date[7];
+	unsigned int data;
+	int err;
+	struct regmap *regmap = i2c_get_clientdata(client);
+
+	/* First we ensure that the "update flag" is not set, we read the
+	 * time and date then re-read the "update flag". If the update flag
+	 * has been set, we know that the time has changed during the read so
+	 * we repeat the whole process again.
+	 */
+	err = regmap_read(regmap, RX8581_REG_FLAG, &data);
+	if (err < 0)
+		return err;
+
+	if (data & RX8581_FLAG_VLF) {
+		dev_warn(dev,
+			 "low voltage detected, date/time is not reliable.\n");
+		return -EINVAL;
+	}
+
+	do {
+		/* If update flag set, clear it */
+		if (data & RX8581_FLAG_UF) {
+			err = regmap_write(regmap, RX8581_REG_FLAG,
+					   data & ~RX8581_FLAG_UF);
+			if (err < 0)
+				return err;
+		}
+
+		/* Now read time and date */
+		err = regmap_bulk_read(regmap, RX8581_REG_SC, date,
+				       sizeof(date));
+		if (err < 0)
+			return err;
+
+		/* Check flag register */
+		err = regmap_read(regmap, RX8581_REG_FLAG, &data);
+		if (err < 0)
+			return err;
+	} while (data & RX8581_FLAG_UF);
+
+	dev_dbg(dev, "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
+		"wday=%02x, mday=%02x, mon=%02x, year=%02x\n",
+		__func__,
+		date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
+
+	tm->tm_sec = bcd2bin(date[RX8581_REG_SC] & 0x7F);
+	tm->tm_min = bcd2bin(date[RX8581_REG_MN] & 0x7F);
+	tm->tm_hour = bcd2bin(date[RX8581_REG_HR] & 0x3F); /* rtc hr 0-23 */
+	tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F);
+	tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F);
+	tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
+	tm->tm_year = bcd2bin(date[RX8581_REG_YR]) + 100;
+
+	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
+		"mday=%d, mon=%d, year=%d, wday=%d\n",
+		__func__,
+		tm->tm_sec, tm->tm_min, tm->tm_hour,
+		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
+
+	return 0;
+}
+
+static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	int err;
+	unsigned char buf[7];
+	struct regmap *regmap = i2c_get_clientdata(client);
+
+	dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, "
+		"mday=%d, mon=%d, year=%d, wday=%d\n",
+		__func__,
+		tm->tm_sec, tm->tm_min, tm->tm_hour,
+		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
+
+	/* hours, minutes and seconds */
+	buf[RX8581_REG_SC] = bin2bcd(tm->tm_sec);
+	buf[RX8581_REG_MN] = bin2bcd(tm->tm_min);
+	buf[RX8581_REG_HR] = bin2bcd(tm->tm_hour);
+
+	buf[RX8581_REG_DM] = bin2bcd(tm->tm_mday);
+
+	/* month, 1 - 12 */
+	buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1);
+
+	/* year and century */
+	buf[RX8581_REG_YR] = bin2bcd(tm->tm_year - 100);
+	buf[RX8581_REG_DW] = (0x1 << tm->tm_wday);
+
+	/* Stop the clock */
+	err = regmap_update_bits(regmap, RX8581_REG_CTRL,
+				 RX8581_CTRL_STOP, RX8581_CTRL_STOP);
+	if (err < 0)
+		return err;
+
+	/* write register's data */
+	err = regmap_bulk_write(regmap, RX8581_REG_SC, buf, sizeof(buf));
+	if (err < 0)
+		return err;
+
+	/* get VLF and clear it */
+	err = regmap_update_bits(regmap, RX8581_REG_FLAG, RX8581_FLAG_VLF, 0);
+	if (err < 0)
+		return err;
+
+	/* Restart the clock */
+	return regmap_update_bits(regmap, RX8581_REG_CTRL,
+				 RX8581_CTRL_STOP, 0);
+}
+
+static const struct rtc_class_ops rx8581_rtc_ops = {
+	.read_time	= rx8581_rtc_read_time,
+	.set_time	= rx8581_rtc_set_time,
+};
+
+static int rx8571_nvram_read(void *priv, unsigned int offset, void *val,
+			     size_t bytes)
+{
+	struct regmap *regmap = priv;
+
+	return regmap_bulk_read(regmap, RX8571_USER_RAM + offset, val, bytes);
+}
+
+static int rx8571_nvram_write(void *priv, unsigned int offset, void *val,
+			      size_t bytes)
+{
+	struct regmap *regmap = priv;
+
+	return regmap_bulk_write(regmap, RX8571_USER_RAM + offset, val, bytes);
+}
+
+static int rx85x1_nvram_read(void *priv, unsigned int offset, void *val,
+			     size_t bytes)
+{
+	struct regmap *regmap = priv;
+	unsigned int tmp_val;
+	int ret;
+
+	ret = regmap_read(regmap, RX8581_REG_RAM, &tmp_val);
+	(*(unsigned char *)val) = (unsigned char) tmp_val;
+
+	return ret;
+}
+
+static int rx85x1_nvram_write(void *priv, unsigned int offset, void *val,
+			      size_t bytes)
+{
+	struct regmap *regmap = priv;
+	unsigned char tmp_val;
+
+	tmp_val = *((unsigned char *)val);
+	return regmap_write(regmap, RX8581_REG_RAM, (unsigned int)tmp_val);
+}
+
+static const struct rx85x1_config rx8581_config = {
+	.regmap = {
+		.reg_bits = 8,
+		.val_bits = 8,
+		.max_register = 0xf,
+	},
+	.num_nvram = 1
+};
+
+static const struct rx85x1_config rx8571_config = {
+	.regmap = {
+		.reg_bits = 8,
+		.val_bits = 8,
+		.max_register = 0x1f,
+	},
+	.num_nvram = 2
+};
+
+static int rx8581_probe(struct i2c_client *client)
+{
+	struct regmap *regmap;
+	const struct rx85x1_config *config = &rx8581_config;
+	const void *data = of_device_get_match_data(&client->dev);
+	struct rtc_device *rtc;
+	static struct nvmem_config nvmem_cfg[] = {
+		{
+			.name = "rx85x1-",
+			.word_size = 1,
+			.stride = 1,
+			.size = 1,
+			.reg_read = rx85x1_nvram_read,
+			.reg_write = rx85x1_nvram_write,
+		}, {
+			.name = "rx8571-",
+			.word_size = 1,
+			.stride = 1,
+			.size = RX8571_NVRAM_SIZE,
+			.reg_read = rx8571_nvram_read,
+			.reg_write = rx8571_nvram_write,
+		},
+	};
+	int ret, i;
+
+	dev_dbg(&client->dev, "%s\n", __func__);
+
+	if (data)
+		config = data;
+
+	regmap = devm_regmap_init_i2c(client, &config->regmap);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	i2c_set_clientdata(client, regmap);
+
+	rtc = devm_rtc_allocate_device(&client->dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	rtc->ops = &rx8581_rtc_ops;
+	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rtc->range_max = RTC_TIMESTAMP_END_2099;
+	rtc->start_secs = 0;
+	rtc->set_start_time = true;
+
+	ret = devm_rtc_register_device(rtc);
+
+	for (i = 0; i < config->num_nvram; i++) {
+		nvmem_cfg[i].priv = regmap;
+		devm_rtc_nvmem_register(rtc, &nvmem_cfg[i]);
+	}
+
+	return ret;
+}
+
+static const struct i2c_device_id rx8581_id[] = {
+	{ .name = "rx8581" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, rx8581_id);
+
+static const __maybe_unused struct of_device_id rx8581_of_match[] = {
+	{ .compatible = "epson,rx8571", .data = &rx8571_config },
+	{ .compatible = "epson,rx8581", .data = &rx8581_config },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rx8581_of_match);
+
+static struct i2c_driver rx8581_driver = {
+	.driver		= {
+		.name	= "rtc-rx8581",
+		.of_match_table = of_match_ptr(rx8581_of_match),
+	},
+	.probe		= rx8581_probe,
+	.id_table	= rx8581_id,
+};
+
+module_i2c_driver(rx8581_driver);
+
+MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>");
+MODULE_DESCRIPTION("Epson RX-8571/RX-8581 RTC driver");
+MODULE_LICENSE("GPL");