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, 446 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c
new file mode 100644
index 000000000..d82acf1af
--- /dev/null
+++ b/drivers/rtc/rtc-snvs.c
@@ -0,0 +1,446 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Copyright (C) 2011-2012 Freescale Semiconductor, Inc.
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/rtc.h>
+#include <linux/clk.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#define SNVS_LPREGISTER_OFFSET	0x34
+
+/* These register offsets are relative to LP (Low Power) range */
+#define SNVS_LPCR		0x04
+#define SNVS_LPSR		0x18
+#define SNVS_LPSRTCMR		0x1c
+#define SNVS_LPSRTCLR		0x20
+#define SNVS_LPTAR		0x24
+#define SNVS_LPPGDR		0x30
+
+#define SNVS_LPCR_SRTC_ENV	(1 << 0)
+#define SNVS_LPCR_LPTA_EN	(1 << 1)
+#define SNVS_LPCR_LPWUI_EN	(1 << 3)
+#define SNVS_LPSR_LPTA		(1 << 0)
+
+#define SNVS_LPPGDR_INIT	0x41736166
+#define CNTR_TO_SECS_SH		15
+
+/* The maximum RTC clock cycles that are allowed to pass between two
+ * consecutive clock counter register reads. If the values are corrupted a
+ * bigger difference is expected. The RTC frequency is 32kHz. With 320 cycles
+ * we end at 10ms which should be enough for most cases. If it once takes
+ * longer than expected we do a retry.
+ */
+#define MAX_RTC_READ_DIFF_CYCLES	320
+
+struct snvs_rtc_data {
+	struct rtc_device *rtc;
+	struct regmap *regmap;
+	int offset;
+	int irq;
+	struct clk *clk;
+};
+
+/* Read 64 bit timer register, which could be in inconsistent state */
+static u64 rtc_read_lpsrt(struct snvs_rtc_data *data)
+{
+	u32 msb, lsb;
+
+	regmap_read(data->regmap, data->offset + SNVS_LPSRTCMR, &msb);
+	regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &lsb);
+	return (u64)msb << 32 | lsb;
+}
+
+/* Read the secure real time counter, taking care to deal with the cases of the
+ * counter updating while being read.
+ */
+static u32 rtc_read_lp_counter(struct snvs_rtc_data *data)
+{
+	u64 read1, read2;
+	s64 diff;
+	unsigned int timeout = 100;
+
+	/* As expected, the registers might update between the read of the LSB
+	 * reg and the MSB reg.  It's also possible that one register might be
+	 * in partially modified state as well.
+	 */
+	read1 = rtc_read_lpsrt(data);
+	do {
+		read2 = read1;
+		read1 = rtc_read_lpsrt(data);
+		diff = read1 - read2;
+	} while (((diff < 0) || (diff > MAX_RTC_READ_DIFF_CYCLES)) && --timeout);
+	if (!timeout)
+		dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
+
+	/* Convert 47-bit counter to 32-bit raw second count */
+	return (u32) (read1 >> CNTR_TO_SECS_SH);
+}
+
+/* Just read the lsb from the counter, dealing with inconsistent state */
+static int rtc_read_lp_counter_lsb(struct snvs_rtc_data *data, u32 *lsb)
+{
+	u32 count1, count2;
+	s32 diff;
+	unsigned int timeout = 100;
+
+	regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
+	do {
+		count2 = count1;
+		regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
+		diff = count1 - count2;
+	} while (((diff < 0) || (diff > MAX_RTC_READ_DIFF_CYCLES)) && --timeout);
+	if (!timeout) {
+		dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
+		return -ETIMEDOUT;
+	}
+
+	*lsb = count1;
+	return 0;
+}
+
+static int rtc_write_sync_lp(struct snvs_rtc_data *data)
+{
+	u32 count1, count2;
+	u32 elapsed;
+	unsigned int timeout = 1000;
+	int ret;
+
+	ret = rtc_read_lp_counter_lsb(data, &count1);
+	if (ret)
+		return ret;
+
+	/* Wait for 3 CKIL cycles, about 61.0-91.5 µs */
+	do {
+		ret = rtc_read_lp_counter_lsb(data, &count2);
+		if (ret)
+			return ret;
+		elapsed = count2 - count1; /* wrap around _is_ handled! */
+	} while (elapsed < 3 && --timeout);
+	if (!timeout) {
+		dev_err(&data->rtc->dev, "Timeout waiting for LPSRT Counter to change\n");
+		return -ETIMEDOUT;
+	}
+	return 0;
+}
+
+static int snvs_rtc_enable(struct snvs_rtc_data *data, bool enable)
+{
+	int timeout = 1000;
+	u32 lpcr;
+
+	regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_SRTC_ENV,
+			   enable ? SNVS_LPCR_SRTC_ENV : 0);
+
+	while (--timeout) {
+		regmap_read(data->regmap, data->offset + SNVS_LPCR, &lpcr);
+
+		if (enable) {
+			if (lpcr & SNVS_LPCR_SRTC_ENV)
+				break;
+		} else {
+			if (!(lpcr & SNVS_LPCR_SRTC_ENV))
+				break;
+		}
+	}
+
+	if (!timeout)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static int snvs_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct snvs_rtc_data *data = dev_get_drvdata(dev);
+	unsigned long time;
+	int ret;
+
+	ret = clk_enable(data->clk);
+	if (ret)
+		return ret;
+
+	time = rtc_read_lp_counter(data);
+	rtc_time64_to_tm(time, tm);
+
+	clk_disable(data->clk);
+
+	return 0;
+}
+
+static int snvs_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct snvs_rtc_data *data = dev_get_drvdata(dev);
+	unsigned long time = rtc_tm_to_time64(tm);
+	int ret;
+
+	ret = clk_enable(data->clk);
+	if (ret)
+		return ret;
+
+	/* Disable RTC first */
+	ret = snvs_rtc_enable(data, false);
+	if (ret)
+		return ret;
+
+	/* Write 32-bit time to 47-bit timer, leaving 15 LSBs blank */
+	regmap_write(data->regmap, data->offset + SNVS_LPSRTCLR, time << CNTR_TO_SECS_SH);
+	regmap_write(data->regmap, data->offset + SNVS_LPSRTCMR, time >> (32 - CNTR_TO_SECS_SH));
+
+	/* Enable RTC again */
+	ret = snvs_rtc_enable(data, true);
+
+	clk_disable(data->clk);
+
+	return ret;
+}
+
+static int snvs_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct snvs_rtc_data *data = dev_get_drvdata(dev);
+	u32 lptar, lpsr;
+	int ret;
+
+	ret = clk_enable(data->clk);
+	if (ret)
+		return ret;
+
+	regmap_read(data->regmap, data->offset + SNVS_LPTAR, &lptar);
+	rtc_time64_to_tm(lptar, &alrm->time);
+
+	regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);
+	alrm->pending = (lpsr & SNVS_LPSR_LPTA) ? 1 : 0;
+
+	clk_disable(data->clk);
+
+	return 0;
+}
+
+static int snvs_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
+{
+	struct snvs_rtc_data *data = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_enable(data->clk);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(data->regmap, data->offset + SNVS_LPCR,
+			   (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN),
+			   enable ? (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN) : 0);
+
+	ret = rtc_write_sync_lp(data);
+
+	clk_disable(data->clk);
+
+	return ret;
+}
+
+static int snvs_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct snvs_rtc_data *data = dev_get_drvdata(dev);
+	unsigned long time = rtc_tm_to_time64(&alrm->time);
+	int ret;
+
+	ret = clk_enable(data->clk);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_LPTA_EN, 0);
+	ret = rtc_write_sync_lp(data);
+	if (ret)
+		return ret;
+	regmap_write(data->regmap, data->offset + SNVS_LPTAR, time);
+
+	/* Clear alarm interrupt status bit */
+	regmap_write(data->regmap, data->offset + SNVS_LPSR, SNVS_LPSR_LPTA);
+
+	clk_disable(data->clk);
+
+	return snvs_rtc_alarm_irq_enable(dev, alrm->enabled);
+}
+
+static const struct rtc_class_ops snvs_rtc_ops = {
+	.read_time = snvs_rtc_read_time,
+	.set_time = snvs_rtc_set_time,
+	.read_alarm = snvs_rtc_read_alarm,
+	.set_alarm = snvs_rtc_set_alarm,
+	.alarm_irq_enable = snvs_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t snvs_rtc_irq_handler(int irq, void *dev_id)
+{
+	struct device *dev = dev_id;
+	struct snvs_rtc_data *data = dev_get_drvdata(dev);
+	u32 lpsr;
+	u32 events = 0;
+
+	clk_enable(data->clk);
+
+	regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);
+
+	if (lpsr & SNVS_LPSR_LPTA) {
+		events |= (RTC_AF | RTC_IRQF);
+
+		/* RTC alarm should be one-shot */
+		snvs_rtc_alarm_irq_enable(dev, 0);
+
+		rtc_update_irq(data->rtc, 1, events);
+	}
+
+	/* clear interrupt status */
+	regmap_write(data->regmap, data->offset + SNVS_LPSR, lpsr);
+
+	clk_disable(data->clk);
+
+	return events ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static const struct regmap_config snvs_rtc_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static void snvs_rtc_action(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static int snvs_rtc_probe(struct platform_device *pdev)
+{
+	struct snvs_rtc_data *data;
+	int ret;
+	void __iomem *mmio;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(data->rtc))
+		return PTR_ERR(data->rtc);
+
+	data->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap");
+
+	if (IS_ERR(data->regmap)) {
+		dev_warn(&pdev->dev, "snvs rtc: you use old dts file, please update it\n");
+
+		mmio = devm_platform_ioremap_resource(pdev, 0);
+		if (IS_ERR(mmio))
+			return PTR_ERR(mmio);
+
+		data->regmap = devm_regmap_init_mmio(&pdev->dev, mmio, &snvs_rtc_config);
+	} else {
+		data->offset = SNVS_LPREGISTER_OFFSET;
+		of_property_read_u32(pdev->dev.of_node, "offset", &data->offset);
+	}
+
+	if (IS_ERR(data->regmap)) {
+		dev_err(&pdev->dev, "Can't find snvs syscon\n");
+		return -ENODEV;
+	}
+
+	data->irq = platform_get_irq(pdev, 0);
+	if (data->irq < 0)
+		return data->irq;
+
+	data->clk = devm_clk_get(&pdev->dev, "snvs-rtc");
+	if (IS_ERR(data->clk)) {
+		data->clk = NULL;
+	} else {
+		ret = clk_prepare_enable(data->clk);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"Could not prepare or enable the snvs clock\n");
+			return ret;
+		}
+	}
+
+	ret = devm_add_action_or_reset(&pdev->dev, snvs_rtc_action, data->clk);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, data);
+
+	/* Initialize glitch detect */
+	regmap_write(data->regmap, data->offset + SNVS_LPPGDR, SNVS_LPPGDR_INIT);
+
+	/* Clear interrupt status */
+	regmap_write(data->regmap, data->offset + SNVS_LPSR, 0xffffffff);
+
+	/* Enable RTC */
+	ret = snvs_rtc_enable(data, true);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable rtc %d\n", ret);
+		return ret;
+	}
+
+	device_init_wakeup(&pdev->dev, true);
+	ret = dev_pm_set_wake_irq(&pdev->dev, data->irq);
+	if (ret)
+		dev_err(&pdev->dev, "failed to enable irq wake\n");
+
+	ret = devm_request_irq(&pdev->dev, data->irq, snvs_rtc_irq_handler,
+			       IRQF_SHARED, "rtc alarm", &pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to request irq %d: %d\n",
+			data->irq, ret);
+		return ret;
+	}
+
+	data->rtc->ops = &snvs_rtc_ops;
+	data->rtc->range_max = U32_MAX;
+
+	return devm_rtc_register_device(data->rtc);
+}
+
+static int __maybe_unused snvs_rtc_suspend_noirq(struct device *dev)
+{
+	struct snvs_rtc_data *data = dev_get_drvdata(dev);
+
+	clk_disable(data->clk);
+
+	return 0;
+}
+
+static int __maybe_unused snvs_rtc_resume_noirq(struct device *dev)
+{
+	struct snvs_rtc_data *data = dev_get_drvdata(dev);
+
+	if (data->clk)
+		return clk_enable(data->clk);
+
+	return 0;
+}
+
+static const struct dev_pm_ops snvs_rtc_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(snvs_rtc_suspend_noirq, snvs_rtc_resume_noirq)
+};
+
+static const struct of_device_id snvs_dt_ids[] = {
+	{ .compatible = "fsl,sec-v4.0-mon-rtc-lp", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, snvs_dt_ids);
+
+static struct platform_driver snvs_rtc_driver = {
+	.driver = {
+		.name	= "snvs_rtc",
+		.pm	= &snvs_rtc_pm_ops,
+		.of_match_table = snvs_dt_ids,
+	},
+	.probe		= snvs_rtc_probe,
+};
+module_platform_driver(snvs_rtc_driver);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("Freescale SNVS RTC Driver");
+MODULE_LICENSE("GPL");