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, 390 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-mxc_v2.c b/drivers/rtc/rtc-mxc_v2.c
new file mode 100644
index 000000000..a07acbbcf
--- /dev/null
+++ b/drivers/rtc/rtc-mxc_v2.c
@@ -0,0 +1,390 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Real Time Clock (RTC) Driver for i.MX53
+ * Copyright (c) 2004-2011 Freescale Semiconductor, Inc.
+ * Copyright (c) 2017 Beckhoff Automation GmbH & Co. KG
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/rtc.h>
+
+#define SRTC_LPPDR_INIT       0x41736166	/* init for glitch detect */
+
+#define SRTC_LPCR_EN_LP       BIT(3)	/* lp enable */
+#define SRTC_LPCR_WAE         BIT(4)	/* lp wakeup alarm enable */
+#define SRTC_LPCR_ALP         BIT(7)	/* lp alarm flag */
+#define SRTC_LPCR_NSA         BIT(11)	/* lp non secure access */
+#define SRTC_LPCR_NVE         BIT(14)	/* lp non valid state exit bit */
+#define SRTC_LPCR_IE          BIT(15)	/* lp init state exit bit */
+
+#define SRTC_LPSR_ALP         BIT(3)	/* lp alarm flag */
+#define SRTC_LPSR_NVES        BIT(14)	/* lp non-valid state exit status */
+#define SRTC_LPSR_IES         BIT(15)	/* lp init state exit status */
+
+#define SRTC_LPSCMR	0x00	/* LP Secure Counter MSB Reg */
+#define SRTC_LPSCLR	0x04	/* LP Secure Counter LSB Reg */
+#define SRTC_LPSAR	0x08	/* LP Secure Alarm Reg */
+#define SRTC_LPCR	0x10	/* LP Control Reg */
+#define SRTC_LPSR	0x14	/* LP Status Reg */
+#define SRTC_LPPDR	0x18	/* LP Power Supply Glitch Detector Reg */
+
+/* max. number of retries to read registers, 120 was max during test */
+#define REG_READ_TIMEOUT 2000
+
+struct mxc_rtc_data {
+	struct rtc_device *rtc;
+	void __iomem *ioaddr;
+	struct clk *clk;
+	spinlock_t lock; /* protects register access */
+	int irq;
+};
+
+/*
+ * This function does write synchronization for writes to the lp srtc block.
+ * To take care of the asynchronous CKIL clock, all writes from the IP domain
+ * will be synchronized to the CKIL domain.
+ * The caller should hold the pdata->lock
+ */
+static void mxc_rtc_sync_lp_locked(struct device *dev, void __iomem *ioaddr)
+{
+	unsigned int i;
+
+	/* Wait for 3 CKIL cycles */
+	for (i = 0; i < 3; i++) {
+		const u32 count = readl(ioaddr + SRTC_LPSCLR);
+		unsigned int timeout = REG_READ_TIMEOUT;
+
+		while ((readl(ioaddr + SRTC_LPSCLR)) == count) {
+			if (!--timeout) {
+				dev_err_once(dev, "SRTC_LPSCLR stuck! Check your hw.\n");
+				return;
+			}
+		}
+	}
+}
+
+/* This function is the RTC interrupt service routine. */
+static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
+{
+	struct device *dev = dev_id;
+	struct mxc_rtc_data *pdata = dev_get_drvdata(dev);
+	void __iomem *ioaddr = pdata->ioaddr;
+	u32 lp_status;
+	u32 lp_cr;
+
+	spin_lock(&pdata->lock);
+	if (clk_enable(pdata->clk)) {
+		spin_unlock(&pdata->lock);
+		return IRQ_NONE;
+	}
+
+	lp_status = readl(ioaddr + SRTC_LPSR);
+	lp_cr = readl(ioaddr + SRTC_LPCR);
+
+	/* update irq data & counter */
+	if (lp_status & SRTC_LPSR_ALP) {
+		if (lp_cr & SRTC_LPCR_ALP)
+			rtc_update_irq(pdata->rtc, 1, RTC_AF | RTC_IRQF);
+
+		/* disable further lp alarm interrupts */
+		lp_cr &= ~(SRTC_LPCR_ALP | SRTC_LPCR_WAE);
+	}
+
+	/* Update interrupt enables */
+	writel(lp_cr, ioaddr + SRTC_LPCR);
+
+	/* clear interrupt status */
+	writel(lp_status, ioaddr + SRTC_LPSR);
+
+	mxc_rtc_sync_lp_locked(dev, ioaddr);
+	clk_disable(pdata->clk);
+	spin_unlock(&pdata->lock);
+	return IRQ_HANDLED;
+}
+
+/*
+ * Enable clk and aquire spinlock
+ * @return  0 if successful; non-zero otherwise.
+ */
+static int mxc_rtc_lock(struct mxc_rtc_data *const pdata)
+{
+	int ret;
+
+	spin_lock_irq(&pdata->lock);
+	ret = clk_enable(pdata->clk);
+	if (ret) {
+		spin_unlock_irq(&pdata->lock);
+		return ret;
+	}
+	return 0;
+}
+
+static int mxc_rtc_unlock(struct mxc_rtc_data *const pdata)
+{
+	clk_disable(pdata->clk);
+	spin_unlock_irq(&pdata->lock);
+	return 0;
+}
+
+/*
+ * This function reads the current RTC time into tm in Gregorian date.
+ *
+ * @param  tm           contains the RTC time value upon return
+ *
+ * @return  0 if successful; non-zero otherwise.
+ */
+static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct mxc_rtc_data *pdata = dev_get_drvdata(dev);
+	const int clk_failed = clk_enable(pdata->clk);
+
+	if (!clk_failed) {
+		const time64_t now = readl(pdata->ioaddr + SRTC_LPSCMR);
+
+		rtc_time64_to_tm(now, tm);
+		clk_disable(pdata->clk);
+		return 0;
+	}
+	return clk_failed;
+}
+
+/*
+ * This function sets the internal RTC time based on tm in Gregorian date.
+ *
+ * @param  tm           the time value to be set in the RTC
+ *
+ * @return  0 if successful; non-zero otherwise.
+ */
+static int mxc_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct mxc_rtc_data *pdata = dev_get_drvdata(dev);
+	time64_t time = rtc_tm_to_time64(tm);
+	int ret;
+
+	ret = mxc_rtc_lock(pdata);
+	if (ret)
+		return ret;
+
+	writel(time, pdata->ioaddr + SRTC_LPSCMR);
+	mxc_rtc_sync_lp_locked(dev, pdata->ioaddr);
+	return mxc_rtc_unlock(pdata);
+}
+
+/*
+ * This function reads the current alarm value into the passed in \b alrm
+ * argument. It updates the \b alrm's pending field value based on the whether
+ * an alarm interrupt occurs or not.
+ *
+ * @param  alrm         contains the RTC alarm value upon return
+ *
+ * @return  0 if successful; non-zero otherwise.
+ */
+static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct mxc_rtc_data *pdata = dev_get_drvdata(dev);
+	void __iomem *ioaddr = pdata->ioaddr;
+	int ret;
+
+	ret = mxc_rtc_lock(pdata);
+	if (ret)
+		return ret;
+
+	rtc_time64_to_tm(readl(ioaddr + SRTC_LPSAR), &alrm->time);
+	alrm->pending = !!(readl(ioaddr + SRTC_LPSR) & SRTC_LPSR_ALP);
+	return mxc_rtc_unlock(pdata);
+}
+
+/*
+ * Enable/Disable alarm interrupt
+ * The caller should hold the pdata->lock
+ */
+static void mxc_rtc_alarm_irq_enable_locked(struct mxc_rtc_data *pdata,
+					    unsigned int enable)
+{
+	u32 lp_cr = readl(pdata->ioaddr + SRTC_LPCR);
+
+	if (enable)
+		lp_cr |= (SRTC_LPCR_ALP | SRTC_LPCR_WAE);
+	else
+		lp_cr &= ~(SRTC_LPCR_ALP | SRTC_LPCR_WAE);
+
+	writel(lp_cr, pdata->ioaddr + SRTC_LPCR);
+}
+
+static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
+{
+	struct mxc_rtc_data *pdata = dev_get_drvdata(dev);
+	int ret = mxc_rtc_lock(pdata);
+
+	if (ret)
+		return ret;
+
+	mxc_rtc_alarm_irq_enable_locked(pdata, enable);
+	return mxc_rtc_unlock(pdata);
+}
+
+/*
+ * This function sets the RTC alarm based on passed in alrm.
+ *
+ * @param  alrm         the alarm value to be set in the RTC
+ *
+ * @return  0 if successful; non-zero otherwise.
+ */
+static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	const time64_t time = rtc_tm_to_time64(&alrm->time);
+	struct mxc_rtc_data *pdata = dev_get_drvdata(dev);
+	int ret = mxc_rtc_lock(pdata);
+
+	if (ret)
+		return ret;
+
+	writel((u32)time, pdata->ioaddr + SRTC_LPSAR);
+
+	/* clear alarm interrupt status bit */
+	writel(SRTC_LPSR_ALP, pdata->ioaddr + SRTC_LPSR);
+	mxc_rtc_sync_lp_locked(dev, pdata->ioaddr);
+
+	mxc_rtc_alarm_irq_enable_locked(pdata, alrm->enabled);
+	mxc_rtc_sync_lp_locked(dev, pdata->ioaddr);
+	mxc_rtc_unlock(pdata);
+	return ret;
+}
+
+static const struct rtc_class_ops mxc_rtc_ops = {
+	.read_time = mxc_rtc_read_time,
+	.set_time = mxc_rtc_set_time,
+	.read_alarm = mxc_rtc_read_alarm,
+	.set_alarm = mxc_rtc_set_alarm,
+	.alarm_irq_enable = mxc_rtc_alarm_irq_enable,
+};
+
+static int mxc_rtc_wait_for_flag(void __iomem *ioaddr, int flag)
+{
+	unsigned int timeout = REG_READ_TIMEOUT;
+
+	while (!(readl(ioaddr) & flag)) {
+		if (!--timeout)
+			return -EBUSY;
+	}
+	return 0;
+}
+
+static int mxc_rtc_probe(struct platform_device *pdev)
+{
+	struct mxc_rtc_data *pdata;
+	void __iomem *ioaddr;
+	int ret = 0;
+
+	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(pdata->ioaddr))
+		return PTR_ERR(pdata->ioaddr);
+
+	ioaddr = pdata->ioaddr;
+
+	pdata->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(pdata->clk)) {
+		dev_err(&pdev->dev, "unable to get rtc clock!\n");
+		return PTR_ERR(pdata->clk);
+	}
+
+	spin_lock_init(&pdata->lock);
+	pdata->irq = platform_get_irq(pdev, 0);
+	if (pdata->irq < 0)
+		return pdata->irq;
+
+	device_init_wakeup(&pdev->dev, true);
+	ret = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
+	if (ret)
+		dev_err(&pdev->dev, "failed to enable irq wake\n");
+
+	ret = clk_prepare_enable(pdata->clk);
+	if (ret)
+		return ret;
+	/* initialize glitch detect */
+	writel(SRTC_LPPDR_INIT, ioaddr + SRTC_LPPDR);
+
+	/* clear lp interrupt status */
+	writel(0xFFFFFFFF, ioaddr + SRTC_LPSR);
+
+	/* move out of init state */
+	writel((SRTC_LPCR_IE | SRTC_LPCR_NSA), ioaddr + SRTC_LPCR);
+	ret = mxc_rtc_wait_for_flag(ioaddr + SRTC_LPSR, SRTC_LPSR_IES);
+	if (ret) {
+		dev_err(&pdev->dev, "Timeout waiting for SRTC_LPSR_IES\n");
+		clk_disable_unprepare(pdata->clk);
+		return ret;
+	}
+
+	/* move out of non-valid state */
+	writel((SRTC_LPCR_IE | SRTC_LPCR_NVE | SRTC_LPCR_NSA |
+		SRTC_LPCR_EN_LP), ioaddr + SRTC_LPCR);
+	ret = mxc_rtc_wait_for_flag(ioaddr + SRTC_LPSR, SRTC_LPSR_NVES);
+	if (ret) {
+		dev_err(&pdev->dev, "Timeout waiting for SRTC_LPSR_NVES\n");
+		clk_disable_unprepare(pdata->clk);
+		return ret;
+	}
+
+	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(pdata->rtc)) {
+		clk_disable_unprepare(pdata->clk);
+		return PTR_ERR(pdata->rtc);
+	}
+
+	pdata->rtc->ops = &mxc_rtc_ops;
+	pdata->rtc->range_max = U32_MAX;
+
+	clk_disable(pdata->clk);
+	platform_set_drvdata(pdev, pdata);
+	ret =
+	    devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt, 0,
+			     pdev->name, &pdev->dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "interrupt not available.\n");
+		clk_unprepare(pdata->clk);
+		return ret;
+	}
+
+	ret = devm_rtc_register_device(pdata->rtc);
+	if (ret < 0)
+		clk_unprepare(pdata->clk);
+
+	return ret;
+}
+
+static void mxc_rtc_remove(struct platform_device *pdev)
+{
+	struct mxc_rtc_data *pdata = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(pdata->clk);
+}
+
+static const struct of_device_id mxc_ids[] = {
+	{ .compatible = "fsl,imx53-rtc", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, mxc_ids);
+
+static struct platform_driver mxc_rtc_driver = {
+	.driver = {
+		.name = "mxc_rtc_v2",
+		.of_match_table = mxc_ids,
+	},
+	.probe = mxc_rtc_probe,
+	.remove = mxc_rtc_remove,
+};
+
+module_platform_driver(mxc_rtc_driver);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("Real Time Clock (RTC) Driver for i.MX53");
+MODULE_LICENSE("GPL");