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, 331 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-ds1553.c b/drivers/rtc/rtc-ds1553.c
new file mode 100644
index 000000000..dbff5b621
--- /dev/null
+++ b/drivers/rtc/rtc-ds1553.c
@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * An rtc driver for the Dallas DS1553
+ *
+ * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
+ */
+
+#include <linux/bcd.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/gfp.h>
+#include <linux/delay.h>
+#include <linux/jiffies.h>
+#include <linux/interrupt.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+
+#define RTC_REG_SIZE		0x2000
+#define RTC_OFFSET		0x1ff0
+
+#define RTC_FLAGS		(RTC_OFFSET + 0)
+#define RTC_SECONDS_ALARM	(RTC_OFFSET + 2)
+#define RTC_MINUTES_ALARM	(RTC_OFFSET + 3)
+#define RTC_HOURS_ALARM		(RTC_OFFSET + 4)
+#define RTC_DATE_ALARM		(RTC_OFFSET + 5)
+#define RTC_INTERRUPTS		(RTC_OFFSET + 6)
+#define RTC_WATCHDOG		(RTC_OFFSET + 7)
+#define RTC_CONTROL		(RTC_OFFSET + 8)
+#define RTC_CENTURY		(RTC_OFFSET + 8)
+#define RTC_SECONDS		(RTC_OFFSET + 9)
+#define RTC_MINUTES		(RTC_OFFSET + 10)
+#define RTC_HOURS		(RTC_OFFSET + 11)
+#define RTC_DAY			(RTC_OFFSET + 12)
+#define RTC_DATE		(RTC_OFFSET + 13)
+#define RTC_MONTH		(RTC_OFFSET + 14)
+#define RTC_YEAR		(RTC_OFFSET + 15)
+
+#define RTC_CENTURY_MASK	0x3f
+#define RTC_SECONDS_MASK	0x7f
+#define RTC_DAY_MASK		0x07
+
+/* Bits in the Control/Century register */
+#define RTC_WRITE		0x80
+#define RTC_READ		0x40
+
+/* Bits in the Seconds register */
+#define RTC_STOP		0x80
+
+/* Bits in the Flags register */
+#define RTC_FLAGS_AF		0x40
+#define RTC_FLAGS_BLF		0x10
+
+/* Bits in the Interrupts register */
+#define RTC_INTS_AE		0x80
+
+struct rtc_plat_data {
+	struct rtc_device *rtc;
+	void __iomem *ioaddr;
+	unsigned long last_jiffies;
+	int irq;
+	unsigned int irqen;
+	int alrm_sec;
+	int alrm_min;
+	int alrm_hour;
+	int alrm_mday;
+	spinlock_t lock;
+};
+
+static int ds1553_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+	void __iomem *ioaddr = pdata->ioaddr;
+	u8 century;
+
+	century = bin2bcd((tm->tm_year + 1900) / 100);
+
+	writeb(RTC_WRITE, pdata->ioaddr + RTC_CONTROL);
+
+	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
+	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
+	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
+	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
+	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
+	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
+	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
+
+	/* RTC_CENTURY and RTC_CONTROL share same register */
+	writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
+	writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
+	return 0;
+}
+
+static int ds1553_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+	void __iomem *ioaddr = pdata->ioaddr;
+	unsigned int year, month, day, hour, minute, second, week;
+	unsigned int century;
+
+	/* give enough time to update RTC in case of continuous read */
+	if (pdata->last_jiffies == jiffies)
+		msleep(1);
+	pdata->last_jiffies = jiffies;
+	writeb(RTC_READ, ioaddr + RTC_CONTROL);
+	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
+	minute = readb(ioaddr + RTC_MINUTES);
+	hour = readb(ioaddr + RTC_HOURS);
+	day = readb(ioaddr + RTC_DATE);
+	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
+	month = readb(ioaddr + RTC_MONTH);
+	year = readb(ioaddr + RTC_YEAR);
+	century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
+	writeb(0, ioaddr + RTC_CONTROL);
+	tm->tm_sec = bcd2bin(second);
+	tm->tm_min = bcd2bin(minute);
+	tm->tm_hour = bcd2bin(hour);
+	tm->tm_mday = bcd2bin(day);
+	tm->tm_wday = bcd2bin(week);
+	tm->tm_mon = bcd2bin(month) - 1;
+	/* year is 1900 + tm->tm_year */
+	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
+
+	return 0;
+}
+
+static void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata)
+{
+	void __iomem *ioaddr = pdata->ioaddr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pdata->lock, flags);
+	writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
+	       0x80 : bin2bcd(pdata->alrm_mday),
+	       ioaddr + RTC_DATE_ALARM);
+	writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
+	       0x80 : bin2bcd(pdata->alrm_hour),
+	       ioaddr + RTC_HOURS_ALARM);
+	writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
+	       0x80 : bin2bcd(pdata->alrm_min),
+	       ioaddr + RTC_MINUTES_ALARM);
+	writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
+	       0x80 : bin2bcd(pdata->alrm_sec),
+	       ioaddr + RTC_SECONDS_ALARM);
+	writeb(pdata->irqen ? RTC_INTS_AE : 0, ioaddr + RTC_INTERRUPTS);
+	readb(ioaddr + RTC_FLAGS);	/* clear interrupts */
+	spin_unlock_irqrestore(&pdata->lock, flags);
+}
+
+static int ds1553_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+
+	if (pdata->irq <= 0)
+		return -EINVAL;
+	pdata->alrm_mday = alrm->time.tm_mday;
+	pdata->alrm_hour = alrm->time.tm_hour;
+	pdata->alrm_min = alrm->time.tm_min;
+	pdata->alrm_sec = alrm->time.tm_sec;
+	if (alrm->enabled)
+		pdata->irqen |= RTC_AF;
+	ds1553_rtc_update_alarm(pdata);
+	return 0;
+}
+
+static int ds1553_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+
+	if (pdata->irq <= 0)
+		return -EINVAL;
+	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
+	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
+	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
+	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
+	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
+	return 0;
+}
+
+static irqreturn_t ds1553_rtc_interrupt(int irq, void *dev_id)
+{
+	struct platform_device *pdev = dev_id;
+	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+	void __iomem *ioaddr = pdata->ioaddr;
+	unsigned long events = 0;
+
+	spin_lock(&pdata->lock);
+	/* read and clear interrupt */
+	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
+		events = RTC_IRQF;
+		if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
+			events |= RTC_UF;
+		else
+			events |= RTC_AF;
+		rtc_update_irq(pdata->rtc, 1, events);
+	}
+	spin_unlock(&pdata->lock);
+	return events ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int ds1553_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+
+	if (pdata->irq <= 0)
+		return -EINVAL;
+	if (enabled)
+		pdata->irqen |= RTC_AF;
+	else
+		pdata->irqen &= ~RTC_AF;
+	ds1553_rtc_update_alarm(pdata);
+	return 0;
+}
+
+static const struct rtc_class_ops ds1553_rtc_ops = {
+	.read_time		= ds1553_rtc_read_time,
+	.set_time		= ds1553_rtc_set_time,
+	.read_alarm		= ds1553_rtc_read_alarm,
+	.set_alarm		= ds1553_rtc_set_alarm,
+	.alarm_irq_enable	= ds1553_rtc_alarm_irq_enable,
+};
+
+static int ds1553_nvram_read(void *priv, unsigned int pos, void *val,
+			     size_t bytes)
+{
+	struct platform_device *pdev = priv;
+	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+	void __iomem *ioaddr = pdata->ioaddr;
+	u8 *buf = val;
+
+	for (; bytes; bytes--)
+		*buf++ = readb(ioaddr + pos++);
+	return 0;
+}
+
+static int ds1553_nvram_write(void *priv, unsigned int pos, void *val,
+			      size_t bytes)
+{
+	struct platform_device *pdev = priv;
+	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+	void __iomem *ioaddr = pdata->ioaddr;
+	u8 *buf = val;
+
+	for (; bytes; bytes--)
+		writeb(*buf++, ioaddr + pos++);
+	return 0;
+}
+
+static int ds1553_rtc_probe(struct platform_device *pdev)
+{
+	unsigned int cen, sec;
+	struct rtc_plat_data *pdata;
+	void __iomem *ioaddr;
+	int ret = 0;
+	struct nvmem_config nvmem_cfg = {
+		.name = "ds1553_nvram",
+		.word_size = 1,
+		.stride = 1,
+		.size = RTC_OFFSET,
+		.reg_read = ds1553_nvram_read,
+		.reg_write = ds1553_nvram_write,
+		.priv = pdev,
+	};
+
+	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	ioaddr = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ioaddr))
+		return PTR_ERR(ioaddr);
+	pdata->ioaddr = ioaddr;
+	pdata->irq = platform_get_irq(pdev, 0);
+
+	/* turn RTC on if it was not on */
+	sec = readb(ioaddr + RTC_SECONDS);
+	if (sec & RTC_STOP) {
+		sec &= RTC_SECONDS_MASK;
+		cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
+		writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
+		writeb(sec, ioaddr + RTC_SECONDS);
+		writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
+	}
+	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_BLF)
+		dev_warn(&pdev->dev, "voltage-low detected.\n");
+
+	spin_lock_init(&pdata->lock);
+	pdata->last_jiffies = jiffies;
+	platform_set_drvdata(pdev, pdata);
+
+	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(pdata->rtc))
+		return PTR_ERR(pdata->rtc);
+
+	pdata->rtc->ops = &ds1553_rtc_ops;
+
+	ret = devm_rtc_register_device(pdata->rtc);
+	if (ret)
+		return ret;
+
+	if (pdata->irq > 0) {
+		writeb(0, ioaddr + RTC_INTERRUPTS);
+		if (devm_request_irq(&pdev->dev, pdata->irq,
+				ds1553_rtc_interrupt,
+				0, pdev->name, pdev) < 0) {
+			dev_warn(&pdev->dev, "interrupt not available.\n");
+			pdata->irq = 0;
+		}
+	}
+
+	devm_rtc_nvmem_register(pdata->rtc, &nvmem_cfg);
+
+	return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:rtc-ds1553");
+
+static struct platform_driver ds1553_rtc_driver = {
+	.probe		= ds1553_rtc_probe,
+	.driver		= {
+		.name	= "rtc-ds1553",
+	},
+};
+
+module_platform_driver(ds1553_rtc_driver);
+
+MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
+MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
+MODULE_LICENSE("GPL");