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, 409 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-cros-ec.c b/drivers/rtc/rtc-cros-ec.c
new file mode 100644
index 000000000..f56650899
--- /dev/null
+++ b/drivers/rtc/rtc-cros-ec.c
@@ -0,0 +1,409 @@
+// SPDX-License-Identifier: GPL-2.0
+// RTC driver for ChromeOS Embedded Controller.
+//
+// Copyright (C) 2017 Google, Inc.
+// Author: Stephen Barber <smbarber@chromium.org>
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+#define DRV_NAME	"cros-ec-rtc"
+
+#define SECS_PER_DAY	(24 * 60 * 60)
+
+/**
+ * struct cros_ec_rtc - Driver data for EC RTC
+ *
+ * @cros_ec: Pointer to EC device
+ * @rtc: Pointer to RTC device
+ * @notifier: Notifier info for responding to EC events
+ * @saved_alarm: Alarm to restore when interrupts are reenabled
+ */
+struct cros_ec_rtc {
+	struct cros_ec_device *cros_ec;
+	struct rtc_device *rtc;
+	struct notifier_block notifier;
+	u32 saved_alarm;
+};
+
+static int cros_ec_rtc_get(struct cros_ec_device *cros_ec, u32 command,
+			   u32 *response)
+{
+	DEFINE_RAW_FLEX(struct cros_ec_command, msg, data,
+			sizeof(struct ec_response_rtc));
+	int ret;
+
+	msg->command = command;
+	msg->insize = sizeof(struct ec_response_rtc);
+
+	ret = cros_ec_cmd_xfer_status(cros_ec, msg);
+	if (ret < 0)
+		return ret;
+
+	*response = ((struct ec_response_rtc *)msg->data)->time;
+
+	return 0;
+}
+
+static int cros_ec_rtc_set(struct cros_ec_device *cros_ec, u32 command,
+			   u32 param)
+{
+	DEFINE_RAW_FLEX(struct cros_ec_command, msg, data,
+			sizeof(struct ec_response_rtc));
+	int ret;
+
+	msg->command = command;
+	msg->outsize = sizeof(struct ec_response_rtc);
+	((struct ec_response_rtc *)msg->data)->time = param;
+
+	ret = cros_ec_cmd_xfer_status(cros_ec, msg);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+/* Read the current time from the EC. */
+static int cros_ec_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(dev);
+	struct cros_ec_device *cros_ec = cros_ec_rtc->cros_ec;
+	int ret;
+	u32 time;
+
+	ret = cros_ec_rtc_get(cros_ec, EC_CMD_RTC_GET_VALUE, &time);
+	if (ret) {
+		dev_err(dev, "error getting time: %d\n", ret);
+		return ret;
+	}
+
+	rtc_time64_to_tm(time, tm);
+
+	return 0;
+}
+
+/* Set the current EC time. */
+static int cros_ec_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(dev);
+	struct cros_ec_device *cros_ec = cros_ec_rtc->cros_ec;
+	int ret;
+	time64_t time = rtc_tm_to_time64(tm);
+
+	ret = cros_ec_rtc_set(cros_ec, EC_CMD_RTC_SET_VALUE, (u32)time);
+	if (ret < 0) {
+		dev_err(dev, "error setting time: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+/* Read alarm time from RTC. */
+static int cros_ec_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(dev);
+	struct cros_ec_device *cros_ec = cros_ec_rtc->cros_ec;
+	int ret;
+	u32 current_time, alarm_offset;
+
+	/*
+	 * The EC host command for getting the alarm is relative (i.e. 5
+	 * seconds from now) whereas rtc_wkalrm is absolute. Get the current
+	 * RTC time first so we can calculate the relative time.
+	 */
+	ret = cros_ec_rtc_get(cros_ec, EC_CMD_RTC_GET_VALUE, &current_time);
+	if (ret < 0) {
+		dev_err(dev, "error getting time: %d\n", ret);
+		return ret;
+	}
+
+	ret = cros_ec_rtc_get(cros_ec, EC_CMD_RTC_GET_ALARM, &alarm_offset);
+	if (ret < 0) {
+		dev_err(dev, "error getting alarm: %d\n", ret);
+		return ret;
+	}
+
+	rtc_time64_to_tm(current_time + alarm_offset, &alrm->time);
+
+	return 0;
+}
+
+/* Set the EC's RTC alarm. */
+static int cros_ec_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(dev);
+	struct cros_ec_device *cros_ec = cros_ec_rtc->cros_ec;
+	int ret;
+	time64_t alarm_time;
+	u32 current_time, alarm_offset;
+
+	/*
+	 * The EC host command for setting the alarm is relative
+	 * (i.e. 5 seconds from now) whereas rtc_wkalrm is absolute.
+	 * Get the current RTC time first so we can calculate the
+	 * relative time.
+	 */
+	ret = cros_ec_rtc_get(cros_ec, EC_CMD_RTC_GET_VALUE, &current_time);
+	if (ret < 0) {
+		dev_err(dev, "error getting time: %d\n", ret);
+		return ret;
+	}
+
+	alarm_time = rtc_tm_to_time64(&alrm->time);
+
+	if (alarm_time < 0 || alarm_time > U32_MAX)
+		return -EINVAL;
+
+	if (!alrm->enabled) {
+		/*
+		 * If the alarm is being disabled, send an alarm
+		 * clear command.
+		 */
+		alarm_offset = EC_RTC_ALARM_CLEAR;
+		cros_ec_rtc->saved_alarm = (u32)alarm_time;
+	} else {
+		/* Don't set an alarm in the past. */
+		if ((u32)alarm_time <= current_time)
+			return -ETIME;
+
+		alarm_offset = (u32)alarm_time - current_time;
+	}
+
+	ret = cros_ec_rtc_set(cros_ec, EC_CMD_RTC_SET_ALARM, alarm_offset);
+	if (ret < 0) {
+		dev_err(dev, "error setting alarm in %u seconds: %d\n",
+			alarm_offset, ret);
+		/*
+		 * The EC code returns -EINVAL if the alarm time is too
+		 * far in the future. Convert it to the expected error code.
+		 */
+		if (ret == -EINVAL)
+			ret = -ERANGE;
+		return ret;
+	}
+
+	return 0;
+}
+
+static int cros_ec_rtc_alarm_irq_enable(struct device *dev,
+					unsigned int enabled)
+{
+	struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(dev);
+	struct cros_ec_device *cros_ec = cros_ec_rtc->cros_ec;
+	int ret;
+	u32 current_time, alarm_offset, alarm_value;
+
+	ret = cros_ec_rtc_get(cros_ec, EC_CMD_RTC_GET_VALUE, &current_time);
+	if (ret < 0) {
+		dev_err(dev, "error getting time: %d\n", ret);
+		return ret;
+	}
+
+	if (enabled) {
+		/* Restore saved alarm if it's still in the future. */
+		if (cros_ec_rtc->saved_alarm < current_time)
+			alarm_offset = EC_RTC_ALARM_CLEAR;
+		else
+			alarm_offset = cros_ec_rtc->saved_alarm - current_time;
+
+		ret = cros_ec_rtc_set(cros_ec, EC_CMD_RTC_SET_ALARM,
+				      alarm_offset);
+		if (ret < 0) {
+			dev_err(dev, "error restoring alarm: %d\n", ret);
+			return ret;
+		}
+	} else {
+		/* Disable alarm, saving the old alarm value. */
+		ret = cros_ec_rtc_get(cros_ec, EC_CMD_RTC_GET_ALARM,
+				      &alarm_offset);
+		if (ret < 0) {
+			dev_err(dev, "error saving alarm: %d\n", ret);
+			return ret;
+		}
+
+		alarm_value = current_time + alarm_offset;
+
+		/*
+		 * If the current EC alarm is already past, we don't want
+		 * to set an alarm when we go through the alarm irq enable
+		 * path.
+		 */
+		if (alarm_value < current_time)
+			cros_ec_rtc->saved_alarm = EC_RTC_ALARM_CLEAR;
+		else
+			cros_ec_rtc->saved_alarm = alarm_value;
+
+		alarm_offset = EC_RTC_ALARM_CLEAR;
+		ret = cros_ec_rtc_set(cros_ec, EC_CMD_RTC_SET_ALARM,
+				      alarm_offset);
+		if (ret < 0) {
+			dev_err(dev, "error disabling alarm: %d\n", ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int cros_ec_rtc_event(struct notifier_block *nb,
+			     unsigned long queued_during_suspend,
+			     void *_notify)
+{
+	struct cros_ec_rtc *cros_ec_rtc;
+	struct rtc_device *rtc;
+	struct cros_ec_device *cros_ec;
+	u32 host_event;
+
+	cros_ec_rtc = container_of(nb, struct cros_ec_rtc, notifier);
+	rtc = cros_ec_rtc->rtc;
+	cros_ec = cros_ec_rtc->cros_ec;
+
+	host_event = cros_ec_get_host_event(cros_ec);
+	if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_RTC)) {
+		rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
+		return NOTIFY_OK;
+	} else {
+		return NOTIFY_DONE;
+	}
+}
+
+static const struct rtc_class_ops cros_ec_rtc_ops = {
+	.read_time = cros_ec_rtc_read_time,
+	.set_time = cros_ec_rtc_set_time,
+	.read_alarm = cros_ec_rtc_read_alarm,
+	.set_alarm = cros_ec_rtc_set_alarm,
+	.alarm_irq_enable = cros_ec_rtc_alarm_irq_enable,
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int cros_ec_rtc_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(&pdev->dev);
+
+	if (device_may_wakeup(dev))
+		return enable_irq_wake(cros_ec_rtc->cros_ec->irq);
+
+	return 0;
+}
+
+static int cros_ec_rtc_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(&pdev->dev);
+
+	if (device_may_wakeup(dev))
+		return disable_irq_wake(cros_ec_rtc->cros_ec->irq);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(cros_ec_rtc_pm_ops, cros_ec_rtc_suspend,
+			 cros_ec_rtc_resume);
+
+static int cros_ec_rtc_probe(struct platform_device *pdev)
+{
+	struct cros_ec_dev *ec_dev = dev_get_drvdata(pdev->dev.parent);
+	struct cros_ec_device *cros_ec = ec_dev->ec_dev;
+	struct cros_ec_rtc *cros_ec_rtc;
+	struct rtc_time tm;
+	int ret;
+
+	cros_ec_rtc = devm_kzalloc(&pdev->dev, sizeof(*cros_ec_rtc),
+				   GFP_KERNEL);
+	if (!cros_ec_rtc)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, cros_ec_rtc);
+	cros_ec_rtc->cros_ec = cros_ec;
+
+	/* Get initial time */
+	ret = cros_ec_rtc_read_time(&pdev->dev, &tm);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to read RTC time\n");
+		return ret;
+	}
+
+	ret = device_init_wakeup(&pdev->dev, true);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to initialize wakeup\n");
+		return ret;
+	}
+
+	cros_ec_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(cros_ec_rtc->rtc))
+		return PTR_ERR(cros_ec_rtc->rtc);
+
+	cros_ec_rtc->rtc->ops = &cros_ec_rtc_ops;
+	cros_ec_rtc->rtc->range_max = U32_MAX;
+
+	/*
+	 * The RTC on some older Chromebooks can only handle alarms less than
+	 * 24 hours in the future. The only way to find out is to try to set an
+	 * alarm further in the future. If that fails, assume that the RTC
+	 * connected to the EC can only handle less than 24 hours of alarm
+	 * window.
+	 */
+	ret = cros_ec_rtc_set(cros_ec, EC_CMD_RTC_SET_ALARM, SECS_PER_DAY * 2);
+	if (ret == -EINVAL)
+		cros_ec_rtc->rtc->alarm_offset_max = SECS_PER_DAY - 1;
+
+	(void)cros_ec_rtc_set(cros_ec, EC_CMD_RTC_SET_ALARM,
+			      EC_RTC_ALARM_CLEAR);
+
+	ret = devm_rtc_register_device(cros_ec_rtc->rtc);
+	if (ret)
+		return ret;
+
+	/* Get RTC events from the EC. */
+	cros_ec_rtc->notifier.notifier_call = cros_ec_rtc_event;
+	ret = blocking_notifier_chain_register(&cros_ec->event_notifier,
+					       &cros_ec_rtc->notifier);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register notifier\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static void cros_ec_rtc_remove(struct platform_device *pdev)
+{
+	struct cros_ec_rtc *cros_ec_rtc = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	ret = blocking_notifier_chain_unregister(
+				&cros_ec_rtc->cros_ec->event_notifier,
+				&cros_ec_rtc->notifier);
+	if (ret)
+		dev_err(dev, "failed to unregister notifier\n");
+}
+
+static const struct platform_device_id cros_ec_rtc_id[] = {
+	{ .name = DRV_NAME },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, cros_ec_rtc_id);
+
+static struct platform_driver cros_ec_rtc_driver = {
+	.probe = cros_ec_rtc_probe,
+	.remove = cros_ec_rtc_remove,
+	.driver = {
+		.name = DRV_NAME,
+		.pm = &cros_ec_rtc_pm_ops,
+	},
+	.id_table = cros_ec_rtc_id,
+};
+
+module_platform_driver(cros_ec_rtc_driver);
+
+MODULE_DESCRIPTION("RTC driver for Chrome OS ECs");
+MODULE_AUTHOR("Stephen Barber <smbarber@chromium.org>");
+MODULE_LICENSE("GPL v2");