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, 321 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-max8998.c b/drivers/rtc/rtc-max8998.c
new file mode 100644
index 000000000..a2c946edc
--- /dev/null
+++ b/drivers/rtc/rtc-max8998.c
@@ -0,0 +1,321 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// RTC driver for Maxim MAX8998
+//
+// Copyright (C) 2010 Samsung Electronics Co.Ltd
+// Author: Minkyu Kang <mk7.kang@samsung.com>
+// Author: Joonyoung Shim <jy0922.shim@samsung.com>
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/bcd.h>
+#include <linux/irqdomain.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/max8998.h>
+#include <linux/mfd/max8998-private.h>
+#include <linux/delay.h>
+
+#define MAX8998_RTC_SEC			0x00
+#define MAX8998_RTC_MIN			0x01
+#define MAX8998_RTC_HOUR		0x02
+#define MAX8998_RTC_WEEKDAY		0x03
+#define MAX8998_RTC_DATE		0x04
+#define MAX8998_RTC_MONTH		0x05
+#define MAX8998_RTC_YEAR1		0x06
+#define MAX8998_RTC_YEAR2		0x07
+#define MAX8998_ALARM0_SEC		0x08
+#define MAX8998_ALARM0_MIN		0x09
+#define MAX8998_ALARM0_HOUR		0x0a
+#define MAX8998_ALARM0_WEEKDAY		0x0b
+#define MAX8998_ALARM0_DATE		0x0c
+#define MAX8998_ALARM0_MONTH		0x0d
+#define MAX8998_ALARM0_YEAR1		0x0e
+#define MAX8998_ALARM0_YEAR2		0x0f
+#define MAX8998_ALARM1_SEC		0x10
+#define MAX8998_ALARM1_MIN		0x11
+#define MAX8998_ALARM1_HOUR		0x12
+#define MAX8998_ALARM1_WEEKDAY		0x13
+#define MAX8998_ALARM1_DATE		0x14
+#define MAX8998_ALARM1_MONTH		0x15
+#define MAX8998_ALARM1_YEAR1		0x16
+#define MAX8998_ALARM1_YEAR2		0x17
+#define MAX8998_ALARM0_CONF		0x18
+#define MAX8998_ALARM1_CONF		0x19
+#define MAX8998_RTC_STATUS		0x1a
+#define MAX8998_WTSR_SMPL_CNTL		0x1b
+#define MAX8998_TEST			0x1f
+
+#define HOUR_12				(1 << 7)
+#define HOUR_PM				(1 << 5)
+#define ALARM0_STATUS			(1 << 1)
+#define ALARM1_STATUS			(1 << 2)
+
+enum {
+	RTC_SEC = 0,
+	RTC_MIN,
+	RTC_HOUR,
+	RTC_WEEKDAY,
+	RTC_DATE,
+	RTC_MONTH,
+	RTC_YEAR1,
+	RTC_YEAR2,
+};
+
+struct max8998_rtc_info {
+	struct device		*dev;
+	struct max8998_dev	*max8998;
+	struct i2c_client	*rtc;
+	struct rtc_device	*rtc_dev;
+	int irq;
+	bool lp3974_bug_workaround;
+};
+
+static void max8998_data_to_tm(u8 *data, struct rtc_time *tm)
+{
+	tm->tm_sec = bcd2bin(data[RTC_SEC]);
+	tm->tm_min = bcd2bin(data[RTC_MIN]);
+	if (data[RTC_HOUR] & HOUR_12) {
+		tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x1f);
+		if (data[RTC_HOUR] & HOUR_PM)
+			tm->tm_hour += 12;
+	} else
+		tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);
+
+	tm->tm_wday = data[RTC_WEEKDAY] & 0x07;
+	tm->tm_mday = bcd2bin(data[RTC_DATE]);
+	tm->tm_mon = bcd2bin(data[RTC_MONTH]);
+	tm->tm_year = bcd2bin(data[RTC_YEAR1]) + bcd2bin(data[RTC_YEAR2]) * 100;
+	tm->tm_year -= 1900;
+}
+
+static void max8998_tm_to_data(struct rtc_time *tm, u8 *data)
+{
+	data[RTC_SEC] = bin2bcd(tm->tm_sec);
+	data[RTC_MIN] = bin2bcd(tm->tm_min);
+	data[RTC_HOUR] = bin2bcd(tm->tm_hour);
+	data[RTC_WEEKDAY] = tm->tm_wday;
+	data[RTC_DATE] = bin2bcd(tm->tm_mday);
+	data[RTC_MONTH] = bin2bcd(tm->tm_mon);
+	data[RTC_YEAR1] = bin2bcd(tm->tm_year % 100);
+	data[RTC_YEAR2] = bin2bcd((tm->tm_year + 1900) / 100);
+}
+
+static int max8998_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct max8998_rtc_info *info = dev_get_drvdata(dev);
+	u8 data[8];
+	int ret;
+
+	ret = max8998_bulk_read(info->rtc, MAX8998_RTC_SEC, 8, data);
+	if (ret < 0)
+		return ret;
+
+	max8998_data_to_tm(data, tm);
+
+	return 0;
+}
+
+static int max8998_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct max8998_rtc_info *info = dev_get_drvdata(dev);
+	u8 data[8];
+	int ret;
+
+	max8998_tm_to_data(tm, data);
+
+	ret = max8998_bulk_write(info->rtc, MAX8998_RTC_SEC, 8, data);
+
+	if (info->lp3974_bug_workaround)
+		msleep(2000);
+
+	return ret;
+}
+
+static int max8998_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct max8998_rtc_info *info = dev_get_drvdata(dev);
+	u8 data[8];
+	u8 val;
+	int ret;
+
+	ret = max8998_bulk_read(info->rtc, MAX8998_ALARM0_SEC, 8, data);
+	if (ret < 0)
+		return ret;
+
+	max8998_data_to_tm(data, &alrm->time);
+
+	ret = max8998_read_reg(info->rtc, MAX8998_ALARM0_CONF, &val);
+	if (ret < 0)
+		return ret;
+
+	alrm->enabled = !!val;
+
+	ret = max8998_read_reg(info->rtc, MAX8998_RTC_STATUS, &val);
+	if (ret < 0)
+		return ret;
+
+	if (val & ALARM0_STATUS)
+		alrm->pending = 1;
+	else
+		alrm->pending = 0;
+
+	return 0;
+}
+
+static int max8998_rtc_stop_alarm(struct max8998_rtc_info *info)
+{
+	int ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0);
+
+	if (info->lp3974_bug_workaround)
+		msleep(2000);
+
+	return ret;
+}
+
+static int max8998_rtc_start_alarm(struct max8998_rtc_info *info)
+{
+	int ret;
+	u8 alarm0_conf = 0x77;
+
+	/* LP3974 with delay bug chips has rtc alarm bugs with "MONTH" field */
+	if (info->lp3974_bug_workaround)
+		alarm0_conf = 0x57;
+
+	ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, alarm0_conf);
+
+	if (info->lp3974_bug_workaround)
+		msleep(2000);
+
+	return ret;
+}
+
+static int max8998_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct max8998_rtc_info *info = dev_get_drvdata(dev);
+	u8 data[8];
+	int ret;
+
+	max8998_tm_to_data(&alrm->time, data);
+
+	ret = max8998_rtc_stop_alarm(info);
+	if (ret < 0)
+		return ret;
+
+	ret = max8998_bulk_write(info->rtc, MAX8998_ALARM0_SEC, 8, data);
+	if (ret < 0)
+		return ret;
+
+	if (info->lp3974_bug_workaround)
+		msleep(2000);
+
+	if (alrm->enabled)
+		ret = max8998_rtc_start_alarm(info);
+
+	return ret;
+}
+
+static int max8998_rtc_alarm_irq_enable(struct device *dev,
+					unsigned int enabled)
+{
+	struct max8998_rtc_info *info = dev_get_drvdata(dev);
+
+	if (enabled)
+		return max8998_rtc_start_alarm(info);
+	else
+		return max8998_rtc_stop_alarm(info);
+}
+
+static irqreturn_t max8998_rtc_alarm_irq(int irq, void *data)
+{
+	struct max8998_rtc_info *info = data;
+
+	rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
+
+	return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops max8998_rtc_ops = {
+	.read_time = max8998_rtc_read_time,
+	.set_time = max8998_rtc_set_time,
+	.read_alarm = max8998_rtc_read_alarm,
+	.set_alarm = max8998_rtc_set_alarm,
+	.alarm_irq_enable = max8998_rtc_alarm_irq_enable,
+};
+
+static int max8998_rtc_probe(struct platform_device *pdev)
+{
+	struct max8998_dev *max8998 = dev_get_drvdata(pdev->dev.parent);
+	struct max8998_platform_data *pdata = max8998->pdata;
+	struct max8998_rtc_info *info;
+	int ret;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(struct max8998_rtc_info),
+			GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->dev = &pdev->dev;
+	info->max8998 = max8998;
+	info->rtc = max8998->rtc;
+
+	platform_set_drvdata(pdev, info);
+
+	info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8998-rtc",
+			&max8998_rtc_ops, THIS_MODULE);
+
+	if (IS_ERR(info->rtc_dev)) {
+		ret = PTR_ERR(info->rtc_dev);
+		dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
+		return ret;
+	}
+
+	if (!max8998->irq_domain)
+		goto no_irq;
+
+	info->irq = irq_create_mapping(max8998->irq_domain, MAX8998_IRQ_ALARM0);
+	if (!info->irq) {
+		dev_warn(&pdev->dev, "Failed to map alarm IRQ\n");
+		goto no_irq;
+	}
+
+	ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
+				max8998_rtc_alarm_irq, 0, "rtc-alarm0", info);
+
+	if (ret < 0)
+		dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
+			info->irq, ret);
+
+no_irq:
+	dev_info(&pdev->dev, "RTC CHIP NAME: %s\n", pdev->id_entry->name);
+	if (pdata && pdata->rtc_delay) {
+		info->lp3974_bug_workaround = true;
+		dev_warn(&pdev->dev, "LP3974 with RTC REGERR option."
+				" RTC updates will be extremely slow.\n");
+	}
+
+	return 0;
+}
+
+static const struct platform_device_id max8998_rtc_id[] = {
+	{ .name = "max8998-rtc", .driver_data = TYPE_MAX8998 },
+	{ .name = "lp3974-rtc", .driver_data = TYPE_LP3974 },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, max8998_rtc_id);
+
+static struct platform_driver max8998_rtc_driver = {
+	.driver		= {
+		.name	= "max8998-rtc",
+	},
+	.probe		= max8998_rtc_probe,
+	.id_table	= max8998_rtc_id,
+};
+
+module_platform_driver(max8998_rtc_driver);
+
+MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
+MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
+MODULE_DESCRIPTION("Maxim MAX8998 RTC driver");
+MODULE_LICENSE("GPL");