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, 358 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-ds1286.c b/drivers/rtc/rtc-ds1286.c
new file mode 100644
index 000000000..7acf849d4
--- /dev/null
+++ b/drivers/rtc/rtc-ds1286.c
@@ -0,0 +1,358 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * DS1286 Real Time Clock interface for Linux
+ *
+ * Copyright (C) 1998, 1999, 2000 Ralf Baechle
+ * Copyright (C) 2008 Thomas Bogendoerfer
+ *
+ * Based on code written by Paul Gortmaker.
+ */
+
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/bcd.h>
+#include <linux/rtc/ds1286.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+struct ds1286_priv {
+	struct rtc_device *rtc;
+	u32 __iomem *rtcregs;
+	spinlock_t lock;
+};
+
+static inline u8 ds1286_rtc_read(struct ds1286_priv *priv, int reg)
+{
+	return __raw_readl(&priv->rtcregs[reg]) & 0xff;
+}
+
+static inline void ds1286_rtc_write(struct ds1286_priv *priv, u8 data, int reg)
+{
+	__raw_writel(data, &priv->rtcregs[reg]);
+}
+
+
+static int ds1286_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct ds1286_priv *priv = dev_get_drvdata(dev);
+	unsigned long flags;
+	unsigned char val;
+
+	/* Allow or mask alarm interrupts */
+	spin_lock_irqsave(&priv->lock, flags);
+	val = ds1286_rtc_read(priv, RTC_CMD);
+	if (enabled)
+		val &=  ~RTC_TDM;
+	else
+		val |=  RTC_TDM;
+	ds1286_rtc_write(priv, val, RTC_CMD);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
+#ifdef CONFIG_RTC_INTF_DEV
+
+static int ds1286_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+	struct ds1286_priv *priv = dev_get_drvdata(dev);
+	unsigned long flags;
+	unsigned char val;
+
+	switch (cmd) {
+	case RTC_WIE_OFF:
+		/* Mask watchdog int. enab. bit	*/
+		spin_lock_irqsave(&priv->lock, flags);
+		val = ds1286_rtc_read(priv, RTC_CMD);
+		val |= RTC_WAM;
+		ds1286_rtc_write(priv, val, RTC_CMD);
+		spin_unlock_irqrestore(&priv->lock, flags);
+		break;
+	case RTC_WIE_ON:
+		/* Allow watchdog interrupts.	*/
+		spin_lock_irqsave(&priv->lock, flags);
+		val = ds1286_rtc_read(priv, RTC_CMD);
+		val &= ~RTC_WAM;
+		ds1286_rtc_write(priv, val, RTC_CMD);
+		spin_unlock_irqrestore(&priv->lock, flags);
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+	return 0;
+}
+
+#else
+#define ds1286_ioctl    NULL
+#endif
+
+#ifdef CONFIG_PROC_FS
+
+static int ds1286_proc(struct device *dev, struct seq_file *seq)
+{
+	struct ds1286_priv *priv = dev_get_drvdata(dev);
+	unsigned char month, cmd, amode;
+	const char *s;
+
+	month = ds1286_rtc_read(priv, RTC_MONTH);
+	seq_printf(seq,
+		   "oscillator\t: %s\n"
+		   "square_wave\t: %s\n",
+		   (month & RTC_EOSC) ? "disabled" : "enabled",
+		   (month & RTC_ESQW) ? "disabled" : "enabled");
+
+	amode = ((ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x80) >> 5) |
+		((ds1286_rtc_read(priv, RTC_HOURS_ALARM) & 0x80) >> 6) |
+		((ds1286_rtc_read(priv, RTC_DAY_ALARM) & 0x80) >> 7);
+	switch (amode) {
+	case 7:
+		s = "each minute";
+		break;
+	case 3:
+		s = "minutes match";
+		break;
+	case 1:
+		s = "hours and minutes match";
+		break;
+	case 0:
+		s = "days, hours and minutes match";
+		break;
+	default:
+		s = "invalid";
+		break;
+	}
+	seq_printf(seq, "alarm_mode\t: %s\n", s);
+
+	cmd = ds1286_rtc_read(priv, RTC_CMD);
+	seq_printf(seq,
+		   "alarm_enable\t: %s\n"
+		   "wdog_alarm\t: %s\n"
+		   "alarm_mask\t: %s\n"
+		   "wdog_alarm_mask\t: %s\n"
+		   "interrupt_mode\t: %s\n"
+		   "INTB_mode\t: %s_active\n"
+		   "interrupt_pins\t: %s\n",
+		   (cmd & RTC_TDF) ? "yes" : "no",
+		   (cmd & RTC_WAF) ? "yes" : "no",
+		   (cmd & RTC_TDM) ? "disabled" : "enabled",
+		   (cmd & RTC_WAM) ? "disabled" : "enabled",
+		   (cmd & RTC_PU_LVL) ? "pulse" : "level",
+		   (cmd & RTC_IBH_LO) ? "low" : "high",
+		   (cmd & RTC_IPSW) ? "unswapped" : "swapped");
+	return 0;
+}
+
+#else
+#define ds1286_proc     NULL
+#endif
+
+static int ds1286_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct ds1286_priv *priv = dev_get_drvdata(dev);
+	unsigned char save_control;
+	unsigned long flags;
+	unsigned long uip_watchdog = jiffies;
+
+	/*
+	 * read RTC once any update in progress is done. The update
+	 * can take just over 2ms. We wait 10 to 20ms. There is no need to
+	 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
+	 * If you need to know *exactly* when a second has started, enable
+	 * periodic update complete interrupts, (via ioctl) and then
+	 * immediately read /dev/rtc which will block until you get the IRQ.
+	 * Once the read clears, read the RTC time (again via ioctl). Easy.
+	 */
+
+	if (ds1286_rtc_read(priv, RTC_CMD) & RTC_TE)
+		while (time_before(jiffies, uip_watchdog + 2*HZ/100))
+			barrier();
+
+	/*
+	 * Only the values that we read from the RTC are set. We leave
+	 * tm_wday, tm_yday and tm_isdst untouched. Even though the
+	 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
+	 * by the RTC when initially set to a non-zero value.
+	 */
+	spin_lock_irqsave(&priv->lock, flags);
+	save_control = ds1286_rtc_read(priv, RTC_CMD);
+	ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD);
+
+	tm->tm_sec = ds1286_rtc_read(priv, RTC_SECONDS);
+	tm->tm_min = ds1286_rtc_read(priv, RTC_MINUTES);
+	tm->tm_hour = ds1286_rtc_read(priv, RTC_HOURS) & 0x3f;
+	tm->tm_mday = ds1286_rtc_read(priv, RTC_DATE);
+	tm->tm_mon = ds1286_rtc_read(priv, RTC_MONTH) & 0x1f;
+	tm->tm_year = ds1286_rtc_read(priv, RTC_YEAR);
+
+	ds1286_rtc_write(priv, save_control, RTC_CMD);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	tm->tm_sec = bcd2bin(tm->tm_sec);
+	tm->tm_min = bcd2bin(tm->tm_min);
+	tm->tm_hour = bcd2bin(tm->tm_hour);
+	tm->tm_mday = bcd2bin(tm->tm_mday);
+	tm->tm_mon = bcd2bin(tm->tm_mon);
+	tm->tm_year = bcd2bin(tm->tm_year);
+
+	/*
+	 * Account for differences between how the RTC uses the values
+	 * and how they are defined in a struct rtc_time;
+	 */
+	if (tm->tm_year < 45)
+		tm->tm_year += 30;
+	tm->tm_year += 40;
+	if (tm->tm_year < 70)
+		tm->tm_year += 100;
+
+	tm->tm_mon--;
+
+	return 0;
+}
+
+static int ds1286_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct ds1286_priv *priv = dev_get_drvdata(dev);
+	unsigned char mon, day, hrs, min, sec;
+	unsigned char save_control;
+	unsigned int yrs;
+	unsigned long flags;
+
+	yrs = tm->tm_year + 1900;
+	mon = tm->tm_mon + 1;   /* tm_mon starts at zero */
+	day = tm->tm_mday;
+	hrs = tm->tm_hour;
+	min = tm->tm_min;
+	sec = tm->tm_sec;
+
+	if (yrs < 1970)
+		return -EINVAL;
+
+	yrs -= 1940;
+	if (yrs > 255)    /* They are unsigned */
+		return -EINVAL;
+
+	if (yrs >= 100)
+		yrs -= 100;
+
+	sec = bin2bcd(sec);
+	min = bin2bcd(min);
+	hrs = bin2bcd(hrs);
+	day = bin2bcd(day);
+	mon = bin2bcd(mon);
+	yrs = bin2bcd(yrs);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	save_control = ds1286_rtc_read(priv, RTC_CMD);
+	ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD);
+
+	ds1286_rtc_write(priv, yrs, RTC_YEAR);
+	ds1286_rtc_write(priv, mon, RTC_MONTH);
+	ds1286_rtc_write(priv, day, RTC_DATE);
+	ds1286_rtc_write(priv, hrs, RTC_HOURS);
+	ds1286_rtc_write(priv, min, RTC_MINUTES);
+	ds1286_rtc_write(priv, sec, RTC_SECONDS);
+	ds1286_rtc_write(priv, 0, RTC_HUNDREDTH_SECOND);
+
+	ds1286_rtc_write(priv, save_control, RTC_CMD);
+	spin_unlock_irqrestore(&priv->lock, flags);
+	return 0;
+}
+
+static int ds1286_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	struct ds1286_priv *priv = dev_get_drvdata(dev);
+	unsigned long flags;
+
+	/*
+	 * Only the values that we read from the RTC are set. That
+	 * means only tm_wday, tm_hour, tm_min.
+	 */
+	spin_lock_irqsave(&priv->lock, flags);
+	alm->time.tm_min = ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x7f;
+	alm->time.tm_hour = ds1286_rtc_read(priv, RTC_HOURS_ALARM)  & 0x1f;
+	alm->time.tm_wday = ds1286_rtc_read(priv, RTC_DAY_ALARM)    & 0x07;
+	ds1286_rtc_read(priv, RTC_CMD);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	alm->time.tm_min = bcd2bin(alm->time.tm_min);
+	alm->time.tm_hour = bcd2bin(alm->time.tm_hour);
+	alm->time.tm_sec = 0;
+	return 0;
+}
+
+static int ds1286_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	struct ds1286_priv *priv = dev_get_drvdata(dev);
+	unsigned char hrs, min, sec;
+
+	hrs = alm->time.tm_hour;
+	min = alm->time.tm_min;
+	sec = alm->time.tm_sec;
+
+	if (hrs >= 24)
+		hrs = 0xff;
+
+	if (min >= 60)
+		min = 0xff;
+
+	if (sec != 0)
+		return -EINVAL;
+
+	min = bin2bcd(min);
+	hrs = bin2bcd(hrs);
+
+	spin_lock(&priv->lock);
+	ds1286_rtc_write(priv, hrs, RTC_HOURS_ALARM);
+	ds1286_rtc_write(priv, min, RTC_MINUTES_ALARM);
+	spin_unlock(&priv->lock);
+
+	return 0;
+}
+
+static const struct rtc_class_ops ds1286_ops = {
+	.ioctl		= ds1286_ioctl,
+	.proc		= ds1286_proc,
+	.read_time	= ds1286_read_time,
+	.set_time	= ds1286_set_time,
+	.read_alarm	= ds1286_read_alarm,
+	.set_alarm	= ds1286_set_alarm,
+	.alarm_irq_enable = ds1286_alarm_irq_enable,
+};
+
+static int ds1286_probe(struct platform_device *pdev)
+{
+	struct rtc_device *rtc;
+	struct ds1286_priv *priv;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(struct ds1286_priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->rtcregs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->rtcregs))
+		return PTR_ERR(priv->rtcregs);
+
+	spin_lock_init(&priv->lock);
+	platform_set_drvdata(pdev, priv);
+	rtc = devm_rtc_device_register(&pdev->dev, "ds1286", &ds1286_ops,
+					THIS_MODULE);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+	priv->rtc = rtc;
+	return 0;
+}
+
+static struct platform_driver ds1286_platform_driver = {
+	.driver		= {
+		.name	= "rtc-ds1286",
+	},
+	.probe		= ds1286_probe,
+};
+
+module_platform_driver(ds1286_platform_driver);
+
+MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
+MODULE_DESCRIPTION("DS1286 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:rtc-ds1286");