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, 354 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-sa1100.c b/drivers/rtc/rtc-sa1100.c
new file mode 100644
index 000000000..26b2f4184
--- /dev/null
+++ b/drivers/rtc/rtc-sa1100.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Real Time Clock interface for StrongARM SA1x00 and XScale PXA2xx
+ *
+ * Copyright (c) 2000 Nils Faerber
+ *
+ * Based on rtc.c by Paul Gortmaker
+ *
+ * Original Driver by Nils Faerber <nils@kernelconcepts.de>
+ *
+ * Modifications from:
+ *   CIH <cih@coventive.com>
+ *   Nicolas Pitre <nico@fluxnic.net>
+ *   Andrew Christian <andrew.christian@hp.com>
+ *
+ * Converted to the RTC subsystem and Driver Model
+ *   by Richard Purdie <rpurdie@rpsys.net>
+ */
+
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+
+#define RTSR_HZE		BIT(3)	/* HZ interrupt enable */
+#define RTSR_ALE		BIT(2)	/* RTC alarm interrupt enable */
+#define RTSR_HZ			BIT(1)	/* HZ rising-edge detected */
+#define RTSR_AL			BIT(0)	/* RTC alarm detected */
+
+#include "rtc-sa1100.h"
+
+#define RTC_DEF_DIVIDER		(32768 - 1)
+#define RTC_DEF_TRIM		0
+
+static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id)
+{
+	struct sa1100_rtc *info = dev_get_drvdata(dev_id);
+	struct rtc_device *rtc = info->rtc;
+	unsigned int rtsr;
+	unsigned long events = 0;
+
+	spin_lock(&info->lock);
+
+	rtsr = readl_relaxed(info->rtsr);
+	/* clear interrupt sources */
+	writel_relaxed(0, info->rtsr);
+	/* Fix for a nasty initialization problem the in SA11xx RTSR register.
+	 * See also the comments in sa1100_rtc_probe(). */
+	if (rtsr & (RTSR_ALE | RTSR_HZE)) {
+		/* This is the original code, before there was the if test
+		 * above. This code does not clear interrupts that were not
+		 * enabled. */
+		writel_relaxed((RTSR_AL | RTSR_HZ) & (rtsr >> 2), info->rtsr);
+	} else {
+		/* For some reason, it is possible to enter this routine
+		 * without interruptions enabled, it has been tested with
+		 * several units (Bug in SA11xx chip?).
+		 *
+		 * This situation leads to an infinite "loop" of interrupt
+		 * routine calling and as a result the processor seems to
+		 * lock on its first call to open(). */
+		writel_relaxed(RTSR_AL | RTSR_HZ, info->rtsr);
+	}
+
+	/* clear alarm interrupt if it has occurred */
+	if (rtsr & RTSR_AL)
+		rtsr &= ~RTSR_ALE;
+	writel_relaxed(rtsr & (RTSR_ALE | RTSR_HZE), info->rtsr);
+
+	/* update irq data & counter */
+	if (rtsr & RTSR_AL)
+		events |= RTC_AF | RTC_IRQF;
+	if (rtsr & RTSR_HZ)
+		events |= RTC_UF | RTC_IRQF;
+
+	rtc_update_irq(rtc, 1, events);
+
+	spin_unlock(&info->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int sa1100_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	u32 rtsr;
+	struct sa1100_rtc *info = dev_get_drvdata(dev);
+
+	spin_lock_irq(&info->lock);
+	rtsr = readl_relaxed(info->rtsr);
+	if (enabled)
+		rtsr |= RTSR_ALE;
+	else
+		rtsr &= ~RTSR_ALE;
+	writel_relaxed(rtsr, info->rtsr);
+	spin_unlock_irq(&info->lock);
+	return 0;
+}
+
+static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct sa1100_rtc *info = dev_get_drvdata(dev);
+
+	rtc_time64_to_tm(readl_relaxed(info->rcnr), tm);
+	return 0;
+}
+
+static int sa1100_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct sa1100_rtc *info = dev_get_drvdata(dev);
+
+	writel_relaxed(rtc_tm_to_time64(tm), info->rcnr);
+
+	return 0;
+}
+
+static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	u32	rtsr;
+	struct sa1100_rtc *info = dev_get_drvdata(dev);
+
+	rtsr = readl_relaxed(info->rtsr);
+	alrm->enabled = (rtsr & RTSR_ALE) ? 1 : 0;
+	alrm->pending = (rtsr & RTSR_AL) ? 1 : 0;
+	return 0;
+}
+
+static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct sa1100_rtc *info = dev_get_drvdata(dev);
+
+	spin_lock_irq(&info->lock);
+	writel_relaxed(readl_relaxed(info->rtsr) &
+		(RTSR_HZE | RTSR_ALE | RTSR_AL), info->rtsr);
+	writel_relaxed(rtc_tm_to_time64(&alrm->time), info->rtar);
+	if (alrm->enabled)
+		writel_relaxed(readl_relaxed(info->rtsr) | RTSR_ALE, info->rtsr);
+	else
+		writel_relaxed(readl_relaxed(info->rtsr) & ~RTSR_ALE, info->rtsr);
+	spin_unlock_irq(&info->lock);
+
+	return 0;
+}
+
+static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+	struct sa1100_rtc *info = dev_get_drvdata(dev);
+
+	seq_printf(seq, "trim/divider\t\t: 0x%08x\n", readl_relaxed(info->rttr));
+	seq_printf(seq, "RTSR\t\t\t: 0x%08x\n", readl_relaxed(info->rtsr));
+
+	return 0;
+}
+
+static const struct rtc_class_ops sa1100_rtc_ops = {
+	.read_time = sa1100_rtc_read_time,
+	.set_time = sa1100_rtc_set_time,
+	.read_alarm = sa1100_rtc_read_alarm,
+	.set_alarm = sa1100_rtc_set_alarm,
+	.proc = sa1100_rtc_proc,
+	.alarm_irq_enable = sa1100_rtc_alarm_irq_enable,
+};
+
+int sa1100_rtc_init(struct platform_device *pdev, struct sa1100_rtc *info)
+{
+	int ret;
+
+	spin_lock_init(&info->lock);
+
+	info->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(info->clk)) {
+		dev_err(&pdev->dev, "failed to find rtc clock source\n");
+		return PTR_ERR(info->clk);
+	}
+
+	ret = clk_prepare_enable(info->clk);
+	if (ret)
+		return ret;
+	/*
+	 * According to the manual we should be able to let RTTR be zero
+	 * and then a default diviser for a 32.768KHz clock is used.
+	 * Apparently this doesn't work, at least for my SA1110 rev 5.
+	 * If the clock divider is uninitialized then reset it to the
+	 * default value to get the 1Hz clock.
+	 */
+	if (readl_relaxed(info->rttr) == 0) {
+		writel_relaxed(RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16), info->rttr);
+		dev_warn(&pdev->dev, "warning: "
+			"initializing default clock divider/trim value\n");
+		/* The current RTC value probably doesn't make sense either */
+		writel_relaxed(0, info->rcnr);
+	}
+
+	info->rtc->ops = &sa1100_rtc_ops;
+	info->rtc->range_max = U32_MAX;
+
+	ret = devm_rtc_register_device(info->rtc);
+	if (ret) {
+		clk_disable_unprepare(info->clk);
+		return ret;
+	}
+
+	/* Fix for a nasty initialization problem the in SA11xx RTSR register.
+	 * See also the comments in sa1100_rtc_interrupt().
+	 *
+	 * Sometimes bit 1 of the RTSR (RTSR_HZ) will wake up 1, which means an
+	 * interrupt pending, even though interrupts were never enabled.
+	 * In this case, this bit it must be reset before enabling
+	 * interruptions to avoid a nonexistent interrupt to occur.
+	 *
+	 * In principle, the same problem would apply to bit 0, although it has
+	 * never been observed to happen.
+	 *
+	 * This issue is addressed both here and in sa1100_rtc_interrupt().
+	 * If the issue is not addressed here, in the times when the processor
+	 * wakes up with the bit set there will be one spurious interrupt.
+	 *
+	 * The issue is also dealt with in sa1100_rtc_interrupt() to be on the
+	 * safe side, once the condition that lead to this strange
+	 * initialization is unknown and could in principle happen during
+	 * normal processing.
+	 *
+	 * Notice that clearing bit 1 and 0 is accomplished by writting ONES to
+	 * the corresponding bits in RTSR. */
+	writel_relaxed(RTSR_AL | RTSR_HZ, info->rtsr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(sa1100_rtc_init);
+
+static int sa1100_rtc_probe(struct platform_device *pdev)
+{
+	struct sa1100_rtc *info;
+	void __iomem *base;
+	int irq_1hz, irq_alarm;
+	int ret;
+
+	irq_1hz = platform_get_irq_byname(pdev, "rtc 1Hz");
+	irq_alarm = platform_get_irq_byname(pdev, "rtc alarm");
+	if (irq_1hz < 0 || irq_alarm < 0)
+		return -ENODEV;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(struct sa1100_rtc), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+	info->irq_1hz = irq_1hz;
+	info->irq_alarm = irq_alarm;
+
+	info->rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(info->rtc))
+		return PTR_ERR(info->rtc);
+
+	ret = devm_request_irq(&pdev->dev, irq_1hz, sa1100_rtc_interrupt, 0,
+			       "rtc 1Hz", &pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "IRQ %d already in use.\n", irq_1hz);
+		return ret;
+	}
+	ret = devm_request_irq(&pdev->dev, irq_alarm, sa1100_rtc_interrupt, 0,
+			       "rtc Alrm", &pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "IRQ %d already in use.\n", irq_alarm);
+		return ret;
+	}
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	if (IS_ENABLED(CONFIG_ARCH_SA1100) ||
+	    of_device_is_compatible(pdev->dev.of_node, "mrvl,sa1100-rtc")) {
+		info->rcnr = base + 0x04;
+		info->rtsr = base + 0x10;
+		info->rtar = base + 0x00;
+		info->rttr = base + 0x08;
+	} else {
+		info->rcnr = base + 0x0;
+		info->rtsr = base + 0x8;
+		info->rtar = base + 0x4;
+		info->rttr = base + 0xc;
+	}
+
+	platform_set_drvdata(pdev, info);
+	device_init_wakeup(&pdev->dev, true);
+
+	return sa1100_rtc_init(pdev, info);
+}
+
+static void sa1100_rtc_remove(struct platform_device *pdev)
+{
+	struct sa1100_rtc *info = platform_get_drvdata(pdev);
+
+	if (info) {
+		spin_lock_irq(&info->lock);
+		writel_relaxed(0, info->rtsr);
+		spin_unlock_irq(&info->lock);
+		clk_disable_unprepare(info->clk);
+	}
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int sa1100_rtc_suspend(struct device *dev)
+{
+	struct sa1100_rtc *info = dev_get_drvdata(dev);
+	if (device_may_wakeup(dev))
+		enable_irq_wake(info->irq_alarm);
+	return 0;
+}
+
+static int sa1100_rtc_resume(struct device *dev)
+{
+	struct sa1100_rtc *info = dev_get_drvdata(dev);
+	if (device_may_wakeup(dev))
+		disable_irq_wake(info->irq_alarm);
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(sa1100_rtc_pm_ops, sa1100_rtc_suspend,
+			sa1100_rtc_resume);
+
+#ifdef CONFIG_OF
+static const struct of_device_id sa1100_rtc_dt_ids[] = {
+	{ .compatible = "mrvl,sa1100-rtc", },
+	{ .compatible = "mrvl,mmp-rtc", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sa1100_rtc_dt_ids);
+#endif
+
+static struct platform_driver sa1100_rtc_driver = {
+	.probe		= sa1100_rtc_probe,
+	.remove		= sa1100_rtc_remove,
+	.driver		= {
+		.name	= "sa1100-rtc",
+		.pm	= &sa1100_rtc_pm_ops,
+		.of_match_table = of_match_ptr(sa1100_rtc_dt_ids),
+	},
+};
+
+module_platform_driver(sa1100_rtc_driver);
+
+MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
+MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:sa1100-rtc");