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, 470 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
new file mode 100644
index 000000000..eab39dfa4
--- /dev/null
+++ b/drivers/rtc/rtc-pl031.c
@@ -0,0 +1,470 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * drivers/rtc/rtc-pl031.c
+ *
+ * Real Time Clock interface for ARM AMBA PrimeCell 031 RTC
+ *
+ * Author: Deepak Saxena <dsaxena@plexity.net>
+ *
+ * Copyright 2006 (c) MontaVista Software, Inc.
+ *
+ * Author: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
+ * Copyright 2010 (c) ST-Ericsson AB
+ */
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/amba/bus.h>
+#include <linux/io.h>
+#include <linux/bcd.h>
+#include <linux/delay.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/slab.h>
+
+/*
+ * Register definitions
+ */
+#define	RTC_DR		0x00	/* Data read register */
+#define	RTC_MR		0x04	/* Match register */
+#define	RTC_LR		0x08	/* Data load register */
+#define	RTC_CR		0x0c	/* Control register */
+#define	RTC_IMSC	0x10	/* Interrupt mask and set register */
+#define	RTC_RIS		0x14	/* Raw interrupt status register */
+#define	RTC_MIS		0x18	/* Masked interrupt status register */
+#define	RTC_ICR		0x1c	/* Interrupt clear register */
+/* ST variants have additional timer functionality */
+#define RTC_TDR		0x20	/* Timer data read register */
+#define RTC_TLR		0x24	/* Timer data load register */
+#define RTC_TCR		0x28	/* Timer control register */
+#define RTC_YDR		0x30	/* Year data read register */
+#define RTC_YMR		0x34	/* Year match register */
+#define RTC_YLR		0x38	/* Year data load register */
+
+#define RTC_CR_EN	(1 << 0)	/* counter enable bit */
+#define RTC_CR_CWEN	(1 << 26)	/* Clockwatch enable bit */
+
+#define RTC_TCR_EN	(1 << 1) /* Periodic timer enable bit */
+
+/* Common bit definitions for Interrupt status and control registers */
+#define RTC_BIT_AI	(1 << 0) /* Alarm interrupt bit */
+#define RTC_BIT_PI	(1 << 1) /* Periodic interrupt bit. ST variants only. */
+
+/* Common bit definations for ST v2 for reading/writing time */
+#define RTC_SEC_SHIFT 0
+#define RTC_SEC_MASK (0x3F << RTC_SEC_SHIFT) /* Second [0-59] */
+#define RTC_MIN_SHIFT 6
+#define RTC_MIN_MASK (0x3F << RTC_MIN_SHIFT) /* Minute [0-59] */
+#define RTC_HOUR_SHIFT 12
+#define RTC_HOUR_MASK (0x1F << RTC_HOUR_SHIFT) /* Hour [0-23] */
+#define RTC_WDAY_SHIFT 17
+#define RTC_WDAY_MASK (0x7 << RTC_WDAY_SHIFT) /* Day of Week [1-7] 1=Sunday */
+#define RTC_MDAY_SHIFT 20
+#define RTC_MDAY_MASK (0x1F << RTC_MDAY_SHIFT) /* Day of Month [1-31] */
+#define RTC_MON_SHIFT 25
+#define RTC_MON_MASK (0xF << RTC_MON_SHIFT) /* Month [1-12] 1=January */
+
+#define RTC_TIMER_FREQ 32768
+
+/**
+ * struct pl031_vendor_data - per-vendor variations
+ * @ops: the vendor-specific operations used on this silicon version
+ * @clockwatch: if this is an ST Microelectronics silicon version with a
+ *	clockwatch function
+ * @st_weekday: if this is an ST Microelectronics silicon version that need
+ *	the weekday fix
+ * @irqflags: special IRQ flags per variant
+ * @range_min: minimum date/time supported by the RTC
+ * @range_max: maximum date/time supported by the RTC
+ */
+struct pl031_vendor_data {
+	struct rtc_class_ops ops;
+	bool clockwatch;
+	bool st_weekday;
+	unsigned long irqflags;
+	time64_t range_min;
+	timeu64_t range_max;
+};
+
+struct pl031_local {
+	struct pl031_vendor_data *vendor;
+	struct rtc_device *rtc;
+	void __iomem *base;
+};
+
+static int pl031_alarm_irq_enable(struct device *dev,
+	unsigned int enabled)
+{
+	struct pl031_local *ldata = dev_get_drvdata(dev);
+	unsigned long imsc;
+
+	/* Clear any pending alarm interrupts. */
+	writel(RTC_BIT_AI, ldata->base + RTC_ICR);
+
+	imsc = readl(ldata->base + RTC_IMSC);
+
+	if (enabled == 1)
+		writel(imsc | RTC_BIT_AI, ldata->base + RTC_IMSC);
+	else
+		writel(imsc & ~RTC_BIT_AI, ldata->base + RTC_IMSC);
+
+	return 0;
+}
+
+/*
+ * Convert Gregorian date to ST v2 RTC format.
+ */
+static int pl031_stv2_tm_to_time(struct device *dev,
+				 struct rtc_time *tm, unsigned long *st_time,
+	unsigned long *bcd_year)
+{
+	int year = tm->tm_year + 1900;
+	int wday = tm->tm_wday;
+
+	/* wday masking is not working in hardware so wday must be valid */
+	if (wday < -1 || wday > 6) {
+		dev_err(dev, "invalid wday value %d\n", tm->tm_wday);
+		return -EINVAL;
+	} else if (wday == -1) {
+		/* wday is not provided, calculate it here */
+		struct rtc_time calc_tm;
+
+		rtc_time64_to_tm(rtc_tm_to_time64(tm), &calc_tm);
+		wday = calc_tm.tm_wday;
+	}
+
+	*bcd_year = (bin2bcd(year % 100) | bin2bcd(year / 100) << 8);
+
+	*st_time = ((tm->tm_mon + 1) << RTC_MON_SHIFT)
+			|	(tm->tm_mday << RTC_MDAY_SHIFT)
+			|	((wday + 1) << RTC_WDAY_SHIFT)
+			|	(tm->tm_hour << RTC_HOUR_SHIFT)
+			|	(tm->tm_min << RTC_MIN_SHIFT)
+			|	(tm->tm_sec << RTC_SEC_SHIFT);
+
+	return 0;
+}
+
+/*
+ * Convert ST v2 RTC format to Gregorian date.
+ */
+static int pl031_stv2_time_to_tm(unsigned long st_time, unsigned long bcd_year,
+	struct rtc_time *tm)
+{
+	tm->tm_year = bcd2bin(bcd_year) + (bcd2bin(bcd_year >> 8) * 100);
+	tm->tm_mon  = ((st_time & RTC_MON_MASK) >> RTC_MON_SHIFT) - 1;
+	tm->tm_mday = ((st_time & RTC_MDAY_MASK) >> RTC_MDAY_SHIFT);
+	tm->tm_wday = ((st_time & RTC_WDAY_MASK) >> RTC_WDAY_SHIFT) - 1;
+	tm->tm_hour = ((st_time & RTC_HOUR_MASK) >> RTC_HOUR_SHIFT);
+	tm->tm_min  = ((st_time & RTC_MIN_MASK) >> RTC_MIN_SHIFT);
+	tm->tm_sec  = ((st_time & RTC_SEC_MASK) >> RTC_SEC_SHIFT);
+
+	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
+	tm->tm_year -= 1900;
+
+	return 0;
+}
+
+static int pl031_stv2_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct pl031_local *ldata = dev_get_drvdata(dev);
+
+	pl031_stv2_time_to_tm(readl(ldata->base + RTC_DR),
+			readl(ldata->base + RTC_YDR), tm);
+
+	return 0;
+}
+
+static int pl031_stv2_set_time(struct device *dev, struct rtc_time *tm)
+{
+	unsigned long time;
+	unsigned long bcd_year;
+	struct pl031_local *ldata = dev_get_drvdata(dev);
+	int ret;
+
+	ret = pl031_stv2_tm_to_time(dev, tm, &time, &bcd_year);
+	if (ret == 0) {
+		writel(bcd_year, ldata->base + RTC_YLR);
+		writel(time, ldata->base + RTC_LR);
+	}
+
+	return ret;
+}
+
+static int pl031_stv2_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct pl031_local *ldata = dev_get_drvdata(dev);
+	int ret;
+
+	ret = pl031_stv2_time_to_tm(readl(ldata->base + RTC_MR),
+			readl(ldata->base + RTC_YMR), &alarm->time);
+
+	alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI;
+	alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI;
+
+	return ret;
+}
+
+static int pl031_stv2_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct pl031_local *ldata = dev_get_drvdata(dev);
+	unsigned long time;
+	unsigned long bcd_year;
+	int ret;
+
+	ret = pl031_stv2_tm_to_time(dev, &alarm->time,
+				    &time, &bcd_year);
+	if (ret == 0) {
+		writel(bcd_year, ldata->base + RTC_YMR);
+		writel(time, ldata->base + RTC_MR);
+
+		pl031_alarm_irq_enable(dev, alarm->enabled);
+	}
+
+	return ret;
+}
+
+static irqreturn_t pl031_interrupt(int irq, void *dev_id)
+{
+	struct pl031_local *ldata = dev_id;
+	unsigned long rtcmis;
+	unsigned long events = 0;
+
+	rtcmis = readl(ldata->base + RTC_MIS);
+	if (rtcmis & RTC_BIT_AI) {
+		writel(RTC_BIT_AI, ldata->base + RTC_ICR);
+		events |= (RTC_AF | RTC_IRQF);
+		rtc_update_irq(ldata->rtc, 1, events);
+
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static int pl031_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct pl031_local *ldata = dev_get_drvdata(dev);
+
+	rtc_time64_to_tm(readl(ldata->base + RTC_DR), tm);
+
+	return 0;
+}
+
+static int pl031_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct pl031_local *ldata = dev_get_drvdata(dev);
+
+	writel(rtc_tm_to_time64(tm), ldata->base + RTC_LR);
+
+	return 0;
+}
+
+static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct pl031_local *ldata = dev_get_drvdata(dev);
+
+	rtc_time64_to_tm(readl(ldata->base + RTC_MR), &alarm->time);
+
+	alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI;
+	alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI;
+
+	return 0;
+}
+
+static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct pl031_local *ldata = dev_get_drvdata(dev);
+
+	writel(rtc_tm_to_time64(&alarm->time), ldata->base + RTC_MR);
+	pl031_alarm_irq_enable(dev, alarm->enabled);
+
+	return 0;
+}
+
+static void pl031_remove(struct amba_device *adev)
+{
+	struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
+
+	if (adev->irq[0])
+		free_irq(adev->irq[0], ldata);
+	amba_release_regions(adev);
+}
+
+static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	int ret;
+	struct pl031_local *ldata;
+	struct pl031_vendor_data *vendor = id->data;
+	struct rtc_class_ops *ops;
+	unsigned long time, data;
+
+	ret = amba_request_regions(adev, NULL);
+	if (ret)
+		goto err_req;
+
+	ldata = devm_kzalloc(&adev->dev, sizeof(struct pl031_local),
+			     GFP_KERNEL);
+	ops = devm_kmemdup(&adev->dev, &vendor->ops, sizeof(vendor->ops),
+			   GFP_KERNEL);
+	if (!ldata || !ops) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ldata->vendor = vendor;
+	ldata->base = devm_ioremap(&adev->dev, adev->res.start,
+				   resource_size(&adev->res));
+	if (!ldata->base) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	amba_set_drvdata(adev, ldata);
+
+	dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev));
+	dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev));
+
+	data = readl(ldata->base + RTC_CR);
+	/* Enable the clockwatch on ST Variants */
+	if (vendor->clockwatch)
+		data |= RTC_CR_CWEN;
+	else
+		data |= RTC_CR_EN;
+	writel(data, ldata->base + RTC_CR);
+
+	/*
+	 * On ST PL031 variants, the RTC reset value does not provide correct
+	 * weekday for 2000-01-01. Correct the erroneous sunday to saturday.
+	 */
+	if (vendor->st_weekday) {
+		if (readl(ldata->base + RTC_YDR) == 0x2000) {
+			time = readl(ldata->base + RTC_DR);
+			if ((time &
+			     (RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK))
+			    == 0x02120000) {
+				time = time | (0x7 << RTC_WDAY_SHIFT);
+				writel(0x2000, ldata->base + RTC_YLR);
+				writel(time, ldata->base + RTC_LR);
+			}
+		}
+	}
+
+	devm_device_init_wakeup(&adev->dev);
+	ldata->rtc = devm_rtc_allocate_device(&adev->dev);
+	if (IS_ERR(ldata->rtc)) {
+		ret = PTR_ERR(ldata->rtc);
+		goto out;
+	}
+
+	if (!adev->irq[0])
+		clear_bit(RTC_FEATURE_ALARM, ldata->rtc->features);
+
+	ldata->rtc->ops = ops;
+	ldata->rtc->range_min = vendor->range_min;
+	ldata->rtc->range_max = vendor->range_max;
+
+	ret = devm_rtc_register_device(ldata->rtc);
+	if (ret)
+		goto out;
+
+	if (adev->irq[0]) {
+		ret = request_irq(adev->irq[0], pl031_interrupt,
+				  vendor->irqflags, "rtc-pl031", ldata);
+		if (ret)
+			goto out;
+		devm_pm_set_wake_irq(&adev->dev, adev->irq[0]);
+	}
+	return 0;
+
+out:
+	amba_release_regions(adev);
+err_req:
+
+	return ret;
+}
+
+/* Operations for the original ARM version */
+static struct pl031_vendor_data arm_pl031 = {
+	.ops = {
+		.read_time = pl031_read_time,
+		.set_time = pl031_set_time,
+		.read_alarm = pl031_read_alarm,
+		.set_alarm = pl031_set_alarm,
+		.alarm_irq_enable = pl031_alarm_irq_enable,
+	},
+	.range_max = U32_MAX,
+};
+
+/* The First ST derivative */
+static struct pl031_vendor_data stv1_pl031 = {
+	.ops = {
+		.read_time = pl031_read_time,
+		.set_time = pl031_set_time,
+		.read_alarm = pl031_read_alarm,
+		.set_alarm = pl031_set_alarm,
+		.alarm_irq_enable = pl031_alarm_irq_enable,
+	},
+	.clockwatch = true,
+	.st_weekday = true,
+	.range_max = U32_MAX,
+};
+
+/* And the second ST derivative */
+static struct pl031_vendor_data stv2_pl031 = {
+	.ops = {
+		.read_time = pl031_stv2_read_time,
+		.set_time = pl031_stv2_set_time,
+		.read_alarm = pl031_stv2_read_alarm,
+		.set_alarm = pl031_stv2_set_alarm,
+		.alarm_irq_enable = pl031_alarm_irq_enable,
+	},
+	.clockwatch = true,
+	.st_weekday = true,
+	/*
+	 * This variant shares the IRQ with another block and must not
+	 * suspend that IRQ line.
+	 * TODO check if it shares with IRQF_NO_SUSPEND user, else we can
+	 * remove IRQF_COND_SUSPEND
+	 */
+	.irqflags = IRQF_SHARED | IRQF_COND_SUSPEND,
+	.range_min = RTC_TIMESTAMP_BEGIN_0000,
+	.range_max = RTC_TIMESTAMP_END_9999,
+};
+
+static const struct amba_id pl031_ids[] = {
+	{
+		.id = 0x00041031,
+		.mask = 0x000fffff,
+		.data = &arm_pl031,
+	},
+	/* ST Micro variants */
+	{
+		.id = 0x00180031,
+		.mask = 0x00ffffff,
+		.data = &stv1_pl031,
+	},
+	{
+		.id = 0x00280031,
+		.mask = 0x00ffffff,
+		.data = &stv2_pl031,
+	},
+	{0, 0},
+};
+
+MODULE_DEVICE_TABLE(amba, pl031_ids);
+
+static struct amba_driver pl031_driver = {
+	.drv = {
+		.name = "rtc-pl031",
+	},
+	.id_table = pl031_ids,
+	.probe = pl031_probe,
+	.remove = pl031_remove,
+};
+
+module_amba_driver(pl031_driver);
+
+MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
+MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver");
+MODULE_LICENSE("GPL");