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, 472 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-m48t59.c b/drivers/rtc/rtc-m48t59.c
new file mode 100644
index 000000000..4e608bc8b
--- /dev/null
+++ b/drivers/rtc/rtc-m48t59.c
@@ -0,0 +1,472 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ST M48T59 RTC driver
+ *
+ * Copyright (c) 2007 Wind River Systems, Inc.
+ *
+ * Author: Mark Zhan <rongkai.zhan@windriver.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/rtc/m48t59.h>
+#include <linux/bcd.h>
+#include <linux/slab.h>
+
+#ifndef NO_IRQ
+#define NO_IRQ	(-1)
+#endif
+
+#define M48T59_READ(reg) (pdata->read_byte(dev, pdata->offset + reg))
+#define M48T59_WRITE(val, reg) \
+	(pdata->write_byte(dev, pdata->offset + reg, val))
+
+#define M48T59_SET_BITS(mask, reg)	\
+	M48T59_WRITE((M48T59_READ(reg) | (mask)), (reg))
+#define M48T59_CLEAR_BITS(mask, reg)	\
+	M48T59_WRITE((M48T59_READ(reg) & ~(mask)), (reg))
+
+struct m48t59_private {
+	void __iomem *ioaddr;
+	int irq;
+	struct rtc_device *rtc;
+	spinlock_t lock; /* serialize the NVRAM and RTC access */
+};
+
+/*
+ * This is the generic access method when the chip is memory-mapped
+ */
+static void
+m48t59_mem_writeb(struct device *dev, u32 ofs, u8 val)
+{
+	struct m48t59_private *m48t59 = dev_get_drvdata(dev);
+
+	writeb(val, m48t59->ioaddr+ofs);
+}
+
+static u8
+m48t59_mem_readb(struct device *dev, u32 ofs)
+{
+	struct m48t59_private *m48t59 = dev_get_drvdata(dev);
+
+	return readb(m48t59->ioaddr+ofs);
+}
+
+/*
+ * NOTE: M48T59 only uses BCD mode
+ */
+static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct m48t59_plat_data *pdata = dev_get_platdata(dev);
+	struct m48t59_private *m48t59 = dev_get_drvdata(dev);
+	unsigned long flags;
+	u8 val;
+
+	spin_lock_irqsave(&m48t59->lock, flags);
+	/* Issue the READ command */
+	M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
+
+	tm->tm_year	= bcd2bin(M48T59_READ(M48T59_YEAR)) + pdata->yy_offset;
+	/* tm_mon is 0-11 */
+	tm->tm_mon	= bcd2bin(M48T59_READ(M48T59_MONTH)) - 1;
+	tm->tm_mday	= bcd2bin(M48T59_READ(M48T59_MDAY));
+
+	val = M48T59_READ(M48T59_WDAY);
+	if ((pdata->type == M48T59RTC_TYPE_M48T59) &&
+	    (val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) {
+		dev_dbg(dev, "Century bit is enabled\n");
+		tm->tm_year += 100;	/* one century */
+	}
+
+	tm->tm_wday	= bcd2bin(val & 0x07);
+	tm->tm_hour	= bcd2bin(M48T59_READ(M48T59_HOUR) & 0x3F);
+	tm->tm_min	= bcd2bin(M48T59_READ(M48T59_MIN) & 0x7F);
+	tm->tm_sec	= bcd2bin(M48T59_READ(M48T59_SEC) & 0x7F);
+
+	/* Clear the READ bit */
+	M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
+	spin_unlock_irqrestore(&m48t59->lock, flags);
+
+	dev_dbg(dev, "RTC read time %ptR\n", tm);
+	return 0;
+}
+
+static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct m48t59_plat_data *pdata = dev_get_platdata(dev);
+	struct m48t59_private *m48t59 = dev_get_drvdata(dev);
+	unsigned long flags;
+	u8 val = 0;
+	int year = tm->tm_year - pdata->yy_offset;
+
+	dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n",
+		year + 1900, tm->tm_mon, tm->tm_mday,
+		tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+	if (year < 0)
+		return -EINVAL;
+
+	spin_lock_irqsave(&m48t59->lock, flags);
+	/* Issue the WRITE command */
+	M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
+
+	M48T59_WRITE((bin2bcd(tm->tm_sec) & 0x7F), M48T59_SEC);
+	M48T59_WRITE((bin2bcd(tm->tm_min) & 0x7F), M48T59_MIN);
+	M48T59_WRITE((bin2bcd(tm->tm_hour) & 0x3F), M48T59_HOUR);
+	M48T59_WRITE((bin2bcd(tm->tm_mday) & 0x3F), M48T59_MDAY);
+	/* tm_mon is 0-11 */
+	M48T59_WRITE((bin2bcd(tm->tm_mon + 1) & 0x1F), M48T59_MONTH);
+	M48T59_WRITE(bin2bcd(year % 100), M48T59_YEAR);
+
+	if (pdata->type == M48T59RTC_TYPE_M48T59 && (year >= 100))
+		val = (M48T59_WDAY_CEB | M48T59_WDAY_CB);
+	val |= (bin2bcd(tm->tm_wday) & 0x07);
+	M48T59_WRITE(val, M48T59_WDAY);
+
+	/* Clear the WRITE bit */
+	M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
+	spin_unlock_irqrestore(&m48t59->lock, flags);
+	return 0;
+}
+
+/*
+ * Read alarm time and date in RTC
+ */
+static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct m48t59_plat_data *pdata = dev_get_platdata(dev);
+	struct m48t59_private *m48t59 = dev_get_drvdata(dev);
+	struct rtc_time *tm = &alrm->time;
+	unsigned long flags;
+	u8 val;
+
+	/* If no irq, we don't support ALARM */
+	if (m48t59->irq == NO_IRQ)
+		return -EIO;
+
+	spin_lock_irqsave(&m48t59->lock, flags);
+	/* Issue the READ command */
+	M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
+
+	tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR)) + pdata->yy_offset;
+	/* tm_mon is 0-11 */
+	tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1;
+
+	val = M48T59_READ(M48T59_WDAY);
+	if ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB))
+		tm->tm_year += 100;	/* one century */
+
+	tm->tm_mday = bcd2bin(M48T59_READ(M48T59_ALARM_DATE));
+	tm->tm_hour = bcd2bin(M48T59_READ(M48T59_ALARM_HOUR));
+	tm->tm_min = bcd2bin(M48T59_READ(M48T59_ALARM_MIN));
+	tm->tm_sec = bcd2bin(M48T59_READ(M48T59_ALARM_SEC));
+
+	/* Clear the READ bit */
+	M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
+	spin_unlock_irqrestore(&m48t59->lock, flags);
+
+	dev_dbg(dev, "RTC read alarm time %ptR\n", tm);
+	return rtc_valid_tm(tm);
+}
+
+/*
+ * Set alarm time and date in RTC
+ */
+static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct m48t59_plat_data *pdata = dev_get_platdata(dev);
+	struct m48t59_private *m48t59 = dev_get_drvdata(dev);
+	struct rtc_time *tm = &alrm->time;
+	u8 mday, hour, min, sec;
+	unsigned long flags;
+	int year = tm->tm_year - pdata->yy_offset;
+
+	/* If no irq, we don't support ALARM */
+	if (m48t59->irq == NO_IRQ)
+		return -EIO;
+
+	if (year < 0)
+		return -EINVAL;
+
+	/*
+	 * 0xff means "always match"
+	 */
+	mday = tm->tm_mday;
+	mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
+	if (mday == 0xff)
+		mday = M48T59_READ(M48T59_MDAY);
+
+	hour = tm->tm_hour;
+	hour = (hour < 24) ? bin2bcd(hour) : 0x00;
+
+	min = tm->tm_min;
+	min = (min < 60) ? bin2bcd(min) : 0x00;
+
+	sec = tm->tm_sec;
+	sec = (sec < 60) ? bin2bcd(sec) : 0x00;
+
+	spin_lock_irqsave(&m48t59->lock, flags);
+	/* Issue the WRITE command */
+	M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
+
+	M48T59_WRITE(mday, M48T59_ALARM_DATE);
+	M48T59_WRITE(hour, M48T59_ALARM_HOUR);
+	M48T59_WRITE(min, M48T59_ALARM_MIN);
+	M48T59_WRITE(sec, M48T59_ALARM_SEC);
+
+	/* Clear the WRITE bit */
+	M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
+	spin_unlock_irqrestore(&m48t59->lock, flags);
+
+	dev_dbg(dev, "RTC set alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
+		year + 1900, tm->tm_mon, tm->tm_mday,
+		tm->tm_hour, tm->tm_min, tm->tm_sec);
+	return 0;
+}
+
+/*
+ * Handle commands from user-space
+ */
+static int m48t59_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct m48t59_plat_data *pdata = dev_get_platdata(dev);
+	struct m48t59_private *m48t59 = dev_get_drvdata(dev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&m48t59->lock, flags);
+	if (enabled)
+		M48T59_WRITE(M48T59_INTR_AFE, M48T59_INTR);
+	else
+		M48T59_WRITE(0x00, M48T59_INTR);
+	spin_unlock_irqrestore(&m48t59->lock, flags);
+
+	return 0;
+}
+
+static int m48t59_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+	struct m48t59_plat_data *pdata = dev_get_platdata(dev);
+	struct m48t59_private *m48t59 = dev_get_drvdata(dev);
+	unsigned long flags;
+	u8 val;
+
+	spin_lock_irqsave(&m48t59->lock, flags);
+	val = M48T59_READ(M48T59_FLAGS);
+	spin_unlock_irqrestore(&m48t59->lock, flags);
+
+	seq_printf(seq, "battery\t\t: %s\n",
+		 (val & M48T59_FLAGS_BF) ? "low" : "normal");
+	return 0;
+}
+
+/*
+ * IRQ handler for the RTC
+ */
+static irqreturn_t m48t59_rtc_interrupt(int irq, void *dev_id)
+{
+	struct device *dev = (struct device *)dev_id;
+	struct m48t59_plat_data *pdata = dev_get_platdata(dev);
+	struct m48t59_private *m48t59 = dev_get_drvdata(dev);
+	u8 event;
+
+	spin_lock(&m48t59->lock);
+	event = M48T59_READ(M48T59_FLAGS);
+	spin_unlock(&m48t59->lock);
+
+	if (event & M48T59_FLAGS_AF) {
+		rtc_update_irq(m48t59->rtc, 1, (RTC_AF | RTC_IRQF));
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static const struct rtc_class_ops m48t59_rtc_ops = {
+	.read_time	= m48t59_rtc_read_time,
+	.set_time	= m48t59_rtc_set_time,
+	.read_alarm	= m48t59_rtc_readalarm,
+	.set_alarm	= m48t59_rtc_setalarm,
+	.proc		= m48t59_rtc_proc,
+	.alarm_irq_enable = m48t59_rtc_alarm_irq_enable,
+};
+
+static int m48t59_nvram_read(void *priv, unsigned int offset, void *val,
+			     size_t size)
+{
+	struct platform_device *pdev = priv;
+	struct device *dev = &pdev->dev;
+	struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev);
+	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
+	ssize_t cnt = 0;
+	unsigned long flags;
+	u8 *buf = val;
+
+	spin_lock_irqsave(&m48t59->lock, flags);
+
+	for (; cnt < size; cnt++)
+		*buf++ = M48T59_READ(cnt);
+
+	spin_unlock_irqrestore(&m48t59->lock, flags);
+
+	return 0;
+}
+
+static int m48t59_nvram_write(void *priv, unsigned int offset, void *val,
+			      size_t size)
+{
+	struct platform_device *pdev = priv;
+	struct device *dev = &pdev->dev;
+	struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev);
+	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
+	ssize_t cnt = 0;
+	unsigned long flags;
+	u8 *buf = val;
+
+	spin_lock_irqsave(&m48t59->lock, flags);
+
+	for (; cnt < size; cnt++)
+		M48T59_WRITE(*buf++, cnt);
+
+	spin_unlock_irqrestore(&m48t59->lock, flags);
+
+	return 0;
+}
+
+static int m48t59_rtc_probe(struct platform_device *pdev)
+{
+	struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev);
+	struct m48t59_private *m48t59 = NULL;
+	struct resource *res;
+	int ret = -ENOMEM;
+	struct nvmem_config nvmem_cfg = {
+		.name = "m48t59-",
+		.word_size = 1,
+		.stride = 1,
+		.reg_read = m48t59_nvram_read,
+		.reg_write = m48t59_nvram_write,
+		.priv = pdev,
+	};
+
+	/* This chip could be memory-mapped or I/O-mapped */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+		if (!res)
+			return -EINVAL;
+	}
+
+	if (res->flags & IORESOURCE_IO) {
+		/* If we are I/O-mapped, the platform should provide
+		 * the operations accessing chip registers.
+		 */
+		if (!pdata || !pdata->write_byte || !pdata->read_byte)
+			return -EINVAL;
+	} else if (res->flags & IORESOURCE_MEM) {
+		/* we are memory-mapped */
+		if (!pdata) {
+			pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata),
+						GFP_KERNEL);
+			if (!pdata)
+				return -ENOMEM;
+			/* Ensure we only kmalloc platform data once */
+			pdev->dev.platform_data = pdata;
+		}
+		if (!pdata->type)
+			pdata->type = M48T59RTC_TYPE_M48T59;
+
+		/* Try to use the generic memory read/write ops */
+		if (!pdata->write_byte)
+			pdata->write_byte = m48t59_mem_writeb;
+		if (!pdata->read_byte)
+			pdata->read_byte = m48t59_mem_readb;
+	}
+
+	m48t59 = devm_kzalloc(&pdev->dev, sizeof(*m48t59), GFP_KERNEL);
+	if (!m48t59)
+		return -ENOMEM;
+
+	m48t59->ioaddr = pdata->ioaddr;
+
+	if (!m48t59->ioaddr) {
+		/* ioaddr not mapped externally */
+		m48t59->ioaddr = devm_ioremap(&pdev->dev, res->start,
+						resource_size(res));
+		if (!m48t59->ioaddr)
+			return ret;
+	}
+
+	/* Try to get irq number. We also can work in
+	 * the mode without IRQ.
+	 */
+	m48t59->irq = platform_get_irq_optional(pdev, 0);
+	if (m48t59->irq <= 0)
+		m48t59->irq = NO_IRQ;
+
+	if (m48t59->irq != NO_IRQ) {
+		ret = devm_request_irq(&pdev->dev, m48t59->irq,
+				m48t59_rtc_interrupt, IRQF_SHARED,
+				"rtc-m48t59", &pdev->dev);
+		if (ret)
+			return ret;
+	}
+
+	m48t59->rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(m48t59->rtc))
+		return PTR_ERR(m48t59->rtc);
+
+	switch (pdata->type) {
+	case M48T59RTC_TYPE_M48T59:
+		pdata->offset = 0x1ff0;
+		break;
+	case M48T59RTC_TYPE_M48T02:
+		clear_bit(RTC_FEATURE_ALARM, m48t59->rtc->features);
+		pdata->offset = 0x7f0;
+		break;
+	case M48T59RTC_TYPE_M48T08:
+		clear_bit(RTC_FEATURE_ALARM, m48t59->rtc->features);
+		pdata->offset = 0x1ff0;
+		break;
+	default:
+		dev_err(&pdev->dev, "Unknown RTC type\n");
+		return -ENODEV;
+	}
+
+	spin_lock_init(&m48t59->lock);
+	platform_set_drvdata(pdev, m48t59);
+
+	m48t59->rtc->ops = &m48t59_rtc_ops;
+	m48t59->rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
+	m48t59->rtc->range_max = RTC_TIMESTAMP_END_2099;
+
+	nvmem_cfg.size = pdata->offset;
+	ret = devm_rtc_nvmem_register(m48t59->rtc, &nvmem_cfg);
+	if (ret)
+		return ret;
+
+	ret = devm_rtc_register_device(m48t59->rtc);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:rtc-m48t59");
+
+static struct platform_driver m48t59_rtc_driver = {
+	.driver		= {
+		.name	= "rtc-m48t59",
+	},
+	.probe		= m48t59_rtc_probe,
+};
+
+module_platform_driver(m48t59_rtc_driver);
+
+MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>");
+MODULE_DESCRIPTION("M48T59/M48T02/M48T08 RTC driver");
+MODULE_LICENSE("GPL");