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, 405 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-ab8500.c b/drivers/rtc/rtc-ab8500.c
new file mode 100644
index 000000000..0978bd0a3
--- /dev/null
+++ b/drivers/rtc/rtc-ab8500.c
@@ -0,0 +1,405 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
+ *
+ * RTC clock driver for the RTC part of the AB8500 Power management chip.
+ * Based on RTC clock driver for the AB3100 Analog Baseband Chip by
+ * Linus Walleij <linus.walleij@stericsson.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/mfd/abx500.h>
+#include <linux/mfd/abx500/ab8500.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/pm_wakeirq.h>
+
+#define AB8500_RTC_SOFF_STAT_REG	0x00
+#define AB8500_RTC_CC_CONF_REG		0x01
+#define AB8500_RTC_READ_REQ_REG		0x02
+#define AB8500_RTC_WATCH_TSECMID_REG	0x03
+#define AB8500_RTC_WATCH_TSECHI_REG	0x04
+#define AB8500_RTC_WATCH_TMIN_LOW_REG	0x05
+#define AB8500_RTC_WATCH_TMIN_MID_REG	0x06
+#define AB8500_RTC_WATCH_TMIN_HI_REG	0x07
+#define AB8500_RTC_ALRM_MIN_LOW_REG	0x08
+#define AB8500_RTC_ALRM_MIN_MID_REG	0x09
+#define AB8500_RTC_ALRM_MIN_HI_REG	0x0A
+#define AB8500_RTC_STAT_REG		0x0B
+#define AB8500_RTC_BKUP_CHG_REG		0x0C
+#define AB8500_RTC_FORCE_BKUP_REG	0x0D
+#define AB8500_RTC_CALIB_REG		0x0E
+#define AB8500_RTC_SWITCH_STAT_REG	0x0F
+
+/* RtcReadRequest bits */
+#define RTC_READ_REQUEST		0x01
+#define RTC_WRITE_REQUEST		0x02
+
+/* RtcCtrl bits */
+#define RTC_ALARM_ENA			0x04
+#define RTC_STATUS_DATA			0x01
+
+#define COUNTS_PER_SEC			(0xF000 / 60)
+
+static const u8 ab8500_rtc_time_regs[] = {
+	AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
+	AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
+	AB8500_RTC_WATCH_TSECMID_REG
+};
+
+static const u8 ab8500_rtc_alarm_regs[] = {
+	AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
+	AB8500_RTC_ALRM_MIN_LOW_REG
+};
+
+static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	unsigned long timeout = jiffies + HZ;
+	int retval, i;
+	unsigned long mins, secs;
+	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
+	u8 value;
+
+	/* Request a data read */
+	retval = abx500_set_register_interruptible(dev,
+		AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
+	if (retval < 0)
+		return retval;
+
+	/* Wait for some cycles after enabling the rtc read in ab8500 */
+	while (time_before(jiffies, timeout)) {
+		retval = abx500_get_register_interruptible(dev,
+			AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
+		if (retval < 0)
+			return retval;
+
+		if (!(value & RTC_READ_REQUEST))
+			break;
+
+		usleep_range(1000, 5000);
+	}
+
+	/* Read the Watchtime registers */
+	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
+		retval = abx500_get_register_interruptible(dev,
+			AB8500_RTC, ab8500_rtc_time_regs[i], &value);
+		if (retval < 0)
+			return retval;
+		buf[i] = value;
+	}
+
+	mins = (buf[0] << 16) | (buf[1] << 8) | buf[2];
+
+	secs =	(buf[3] << 8) | buf[4];
+	secs =	secs / COUNTS_PER_SEC;
+	secs =	secs + (mins * 60);
+
+	rtc_time64_to_tm(secs, tm);
+	return 0;
+}
+
+static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	int retval, i;
+	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
+	unsigned long no_secs, no_mins, secs = 0;
+
+	secs = rtc_tm_to_time64(tm);
+
+	no_mins = secs / 60;
+
+	no_secs = secs % 60;
+	/* Make the seconds count as per the RTC resolution */
+	no_secs = no_secs * COUNTS_PER_SEC;
+
+	buf[4] = no_secs & 0xFF;
+	buf[3] = (no_secs >> 8) & 0xFF;
+
+	buf[2] = no_mins & 0xFF;
+	buf[1] = (no_mins >> 8) & 0xFF;
+	buf[0] = (no_mins >> 16) & 0xFF;
+
+	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
+		retval = abx500_set_register_interruptible(dev, AB8500_RTC,
+			ab8500_rtc_time_regs[i], buf[i]);
+		if (retval < 0)
+			return retval;
+	}
+
+	/* Request a data write */
+	return abx500_set_register_interruptible(dev, AB8500_RTC,
+		AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
+}
+
+static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	int retval, i;
+	u8 rtc_ctrl, value;
+	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
+	unsigned long secs, mins;
+
+	/* Check if the alarm is enabled or not */
+	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
+		AB8500_RTC_STAT_REG, &rtc_ctrl);
+	if (retval < 0)
+		return retval;
+
+	if (rtc_ctrl & RTC_ALARM_ENA)
+		alarm->enabled = 1;
+	else
+		alarm->enabled = 0;
+
+	alarm->pending = 0;
+
+	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
+		retval = abx500_get_register_interruptible(dev, AB8500_RTC,
+			ab8500_rtc_alarm_regs[i], &value);
+		if (retval < 0)
+			return retval;
+		buf[i] = value;
+	}
+
+	mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);
+	secs = mins * 60;
+
+	rtc_time64_to_tm(secs, &alarm->time);
+
+	return 0;
+}
+
+static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
+{
+	return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
+		AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
+		enabled ? RTC_ALARM_ENA : 0);
+}
+
+static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	int retval, i;
+	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
+	unsigned long mins;
+
+	mins = (unsigned long)rtc_tm_to_time64(&alarm->time) / 60;
+
+	buf[2] = mins & 0xFF;
+	buf[1] = (mins >> 8) & 0xFF;
+	buf[0] = (mins >> 16) & 0xFF;
+
+	/* Set the alarm time */
+	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
+		retval = abx500_set_register_interruptible(dev, AB8500_RTC,
+			ab8500_rtc_alarm_regs[i], buf[i]);
+		if (retval < 0)
+			return retval;
+	}
+
+	return ab8500_rtc_irq_enable(dev, alarm->enabled);
+}
+
+static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
+{
+	int retval;
+	u8  rtccal = 0;
+
+	/*
+	 * Check that the calibration value (which is in units of 0.5
+	 * parts-per-million) is in the AB8500's range for RtcCalibration
+	 * register. -128 (0x80) is not permitted because the AB8500 uses
+	 * a sign-bit rather than two's complement, so 0x80 is just another
+	 * representation of zero.
+	 */
+	if ((calibration < -127) || (calibration > 127)) {
+		dev_err(dev, "RtcCalibration value outside permitted range\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
+	 * so need to convert to this sort of representation before writing
+	 * into RtcCalibration register...
+	 */
+	if (calibration >= 0)
+		rtccal = 0x7F & calibration;
+	else
+		rtccal = ~(calibration - 1) | 0x80;
+
+	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
+			AB8500_RTC_CALIB_REG, rtccal);
+
+	return retval;
+}
+
+static int ab8500_rtc_get_calibration(struct device *dev, int *calibration)
+{
+	int retval;
+	u8  rtccal = 0;
+
+	retval =  abx500_get_register_interruptible(dev, AB8500_RTC,
+			AB8500_RTC_CALIB_REG, &rtccal);
+	if (retval >= 0) {
+		/*
+		 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
+		 * so need to convert value from RtcCalibration register into
+		 * a two's complement signed value...
+		 */
+		if (rtccal & 0x80)
+			*calibration = 0 - (rtccal & 0x7F);
+		else
+			*calibration = 0x7F & rtccal;
+	}
+
+	return retval;
+}
+
+static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	int retval;
+	int calibration = 0;
+
+	if (sscanf(buf, " %i ", &calibration) != 1) {
+		dev_err(dev, "Failed to store RTC calibration attribute\n");
+		return -EINVAL;
+	}
+
+	retval = ab8500_rtc_set_calibration(dev, calibration);
+
+	return retval ? retval : count;
+}
+
+static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	int  retval = 0;
+	int  calibration = 0;
+
+	retval = ab8500_rtc_get_calibration(dev, &calibration);
+	if (retval < 0) {
+		dev_err(dev, "Failed to read RTC calibration attribute\n");
+		return retval;
+	}
+
+	return sysfs_emit(buf, "%d\n", calibration);
+}
+
+static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR,
+		   ab8500_sysfs_show_rtc_calibration,
+		   ab8500_sysfs_store_rtc_calibration);
+
+static struct attribute *ab8500_rtc_attrs[] = {
+	&dev_attr_rtc_calibration.attr,
+	NULL
+};
+
+static const struct attribute_group ab8500_rtc_sysfs_files = {
+	.attrs	= ab8500_rtc_attrs,
+};
+
+static irqreturn_t rtc_alarm_handler(int irq, void *data)
+{
+	struct rtc_device *rtc = data;
+	unsigned long events = RTC_IRQF | RTC_AF;
+
+	dev_dbg(&rtc->dev, "%s\n", __func__);
+	rtc_update_irq(rtc, 1, events);
+
+	return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops ab8500_rtc_ops = {
+	.read_time		= ab8500_rtc_read_time,
+	.set_time		= ab8500_rtc_set_time,
+	.read_alarm		= ab8500_rtc_read_alarm,
+	.set_alarm		= ab8500_rtc_set_alarm,
+	.alarm_irq_enable	= ab8500_rtc_irq_enable,
+};
+
+static const struct platform_device_id ab85xx_rtc_ids[] = {
+	{ .name = "ab8500-rtc" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, ab85xx_rtc_ids);
+
+static int ab8500_rtc_probe(struct platform_device *pdev)
+{
+	int err;
+	struct rtc_device *rtc;
+	u8 rtc_ctrl;
+	int irq;
+
+	irq = platform_get_irq_byname(pdev, "ALARM");
+	if (irq < 0)
+		return irq;
+
+	/* For RTC supply test */
+	err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
+		AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
+	if (err < 0)
+		return err;
+
+	/* Wait for reset by the PorRtc */
+	usleep_range(1000, 5000);
+
+	err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
+		AB8500_RTC_STAT_REG, &rtc_ctrl);
+	if (err < 0)
+		return err;
+
+	/* Check if the RTC Supply fails */
+	if (!(rtc_ctrl & RTC_STATUS_DATA)) {
+		dev_err(&pdev->dev, "RTC supply failure\n");
+		return -ENODEV;
+	}
+
+	devm_device_init_wakeup(&pdev->dev);
+
+	rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	rtc->ops = &ab8500_rtc_ops;
+
+	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+			rtc_alarm_handler, IRQF_ONESHOT,
+			"ab8500-rtc", rtc);
+	if (err < 0)
+		return err;
+
+	devm_pm_set_wake_irq(&pdev->dev, irq);
+	platform_set_drvdata(pdev, rtc);
+
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
+
+	rtc->range_max = (1ULL << 24) * 60 - 1; // 24-bit minutes + 59 secs
+	rtc->start_secs = RTC_TIMESTAMP_BEGIN_2000;
+	rtc->set_start_time = true;
+
+	err = rtc_add_group(rtc, &ab8500_rtc_sysfs_files);
+	if (err)
+		return err;
+
+	return devm_rtc_register_device(rtc);
+}
+
+static struct platform_driver ab8500_rtc_driver = {
+	.driver = {
+		.name = "ab8500-rtc",
+	},
+	.probe	= ab8500_rtc_probe,
+	.id_table = ab85xx_rtc_ids,
+};
+
+module_platform_driver(ab8500_rtc_driver);
+
+MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
+MODULE_DESCRIPTION("AB8500 RTC Driver");
+MODULE_LICENSE("GPL v2");