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, 363 insertions, 0 deletions

diff --git a/drivers/clocksource/em_sti.c b/drivers/clocksource/em_sti.c
new file mode 100644
index 000000000..73a3357d1
--- /dev/null
+++ b/drivers/clocksource/em_sti.c
@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Emma Mobile Timer Support - STI
+ *
+ *  Copyright (C) 2012 Magnus Damm
+ */
+
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/irq.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+enum { USER_CLOCKSOURCE, USER_CLOCKEVENT, USER_NR };
+
+struct em_sti_priv {
+	void __iomem *base;
+	struct clk *clk;
+	struct platform_device *pdev;
+	unsigned int active[USER_NR];
+	unsigned long rate;
+	raw_spinlock_t lock;
+	struct clock_event_device ced;
+	struct clocksource cs;
+};
+
+#define STI_CONTROL 0x00
+#define STI_COMPA_H 0x10
+#define STI_COMPA_L 0x14
+#define STI_COMPB_H 0x18
+#define STI_COMPB_L 0x1c
+#define STI_COUNT_H 0x20
+#define STI_COUNT_L 0x24
+#define STI_COUNT_RAW_H 0x28
+#define STI_COUNT_RAW_L 0x2c
+#define STI_SET_H 0x30
+#define STI_SET_L 0x34
+#define STI_INTSTATUS 0x40
+#define STI_INTRAWSTATUS 0x44
+#define STI_INTENSET 0x48
+#define STI_INTENCLR 0x4c
+#define STI_INTFFCLR 0x50
+
+static inline unsigned long em_sti_read(struct em_sti_priv *p, int offs)
+{
+	return ioread32(p->base + offs);
+}
+
+static inline void em_sti_write(struct em_sti_priv *p, int offs,
+				unsigned long value)
+{
+	iowrite32(value, p->base + offs);
+}
+
+static int em_sti_enable(struct em_sti_priv *p)
+{
+	int ret;
+
+	/* enable clock */
+	ret = clk_enable(p->clk);
+	if (ret) {
+		dev_err(&p->pdev->dev, "cannot enable clock\n");
+		return ret;
+	}
+
+	/* reset the counter */
+	em_sti_write(p, STI_SET_H, 0x40000000);
+	em_sti_write(p, STI_SET_L, 0x00000000);
+
+	/* mask and clear pending interrupts */
+	em_sti_write(p, STI_INTENCLR, 3);
+	em_sti_write(p, STI_INTFFCLR, 3);
+
+	/* enable updates of counter registers */
+	em_sti_write(p, STI_CONTROL, 1);
+
+	return 0;
+}
+
+static void em_sti_disable(struct em_sti_priv *p)
+{
+	/* mask interrupts */
+	em_sti_write(p, STI_INTENCLR, 3);
+
+	/* stop clock */
+	clk_disable(p->clk);
+}
+
+static u64 em_sti_count(struct em_sti_priv *p)
+{
+	u64 ticks;
+	unsigned long flags;
+
+	/* the STI hardware buffers the 48-bit count, but to
+	 * break it out into two 32-bit access the registers
+	 * must be accessed in a certain order.
+	 * Always read STI_COUNT_H before STI_COUNT_L.
+	 */
+	raw_spin_lock_irqsave(&p->lock, flags);
+	ticks = (u64)(em_sti_read(p, STI_COUNT_H) & 0xffff) << 32;
+	ticks |= em_sti_read(p, STI_COUNT_L);
+	raw_spin_unlock_irqrestore(&p->lock, flags);
+
+	return ticks;
+}
+
+static u64 em_sti_set_next(struct em_sti_priv *p, u64 next)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&p->lock, flags);
+
+	/* mask compare A interrupt */
+	em_sti_write(p, STI_INTENCLR, 1);
+
+	/* update compare A value */
+	em_sti_write(p, STI_COMPA_H, next >> 32);
+	em_sti_write(p, STI_COMPA_L, next & 0xffffffff);
+
+	/* clear compare A interrupt source */
+	em_sti_write(p, STI_INTFFCLR, 1);
+
+	/* unmask compare A interrupt */
+	em_sti_write(p, STI_INTENSET, 1);
+
+	raw_spin_unlock_irqrestore(&p->lock, flags);
+
+	return next;
+}
+
+static irqreturn_t em_sti_interrupt(int irq, void *dev_id)
+{
+	struct em_sti_priv *p = dev_id;
+
+	p->ced.event_handler(&p->ced);
+	return IRQ_HANDLED;
+}
+
+static int em_sti_start(struct em_sti_priv *p, unsigned int user)
+{
+	unsigned long flags;
+	int used_before;
+	int ret = 0;
+
+	raw_spin_lock_irqsave(&p->lock, flags);
+	used_before = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
+	if (!used_before)
+		ret = em_sti_enable(p);
+
+	if (!ret)
+		p->active[user] = 1;
+	raw_spin_unlock_irqrestore(&p->lock, flags);
+
+	return ret;
+}
+
+static void em_sti_stop(struct em_sti_priv *p, unsigned int user)
+{
+	unsigned long flags;
+	int used_before, used_after;
+
+	raw_spin_lock_irqsave(&p->lock, flags);
+	used_before = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
+	p->active[user] = 0;
+	used_after = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
+
+	if (used_before && !used_after)
+		em_sti_disable(p);
+	raw_spin_unlock_irqrestore(&p->lock, flags);
+}
+
+static struct em_sti_priv *cs_to_em_sti(struct clocksource *cs)
+{
+	return container_of(cs, struct em_sti_priv, cs);
+}
+
+static u64 em_sti_clocksource_read(struct clocksource *cs)
+{
+	return em_sti_count(cs_to_em_sti(cs));
+}
+
+static int em_sti_clocksource_enable(struct clocksource *cs)
+{
+	struct em_sti_priv *p = cs_to_em_sti(cs);
+
+	return em_sti_start(p, USER_CLOCKSOURCE);
+}
+
+static void em_sti_clocksource_disable(struct clocksource *cs)
+{
+	em_sti_stop(cs_to_em_sti(cs), USER_CLOCKSOURCE);
+}
+
+static void em_sti_clocksource_resume(struct clocksource *cs)
+{
+	em_sti_clocksource_enable(cs);
+}
+
+static int em_sti_register_clocksource(struct em_sti_priv *p)
+{
+	struct clocksource *cs = &p->cs;
+
+	cs->name = dev_name(&p->pdev->dev);
+	cs->rating = 200;
+	cs->read = em_sti_clocksource_read;
+	cs->enable = em_sti_clocksource_enable;
+	cs->disable = em_sti_clocksource_disable;
+	cs->suspend = em_sti_clocksource_disable;
+	cs->resume = em_sti_clocksource_resume;
+	cs->mask = CLOCKSOURCE_MASK(48);
+	cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
+
+	dev_info(&p->pdev->dev, "used as clock source\n");
+
+	clocksource_register_hz(cs, p->rate);
+	return 0;
+}
+
+static struct em_sti_priv *ced_to_em_sti(struct clock_event_device *ced)
+{
+	return container_of(ced, struct em_sti_priv, ced);
+}
+
+static int em_sti_clock_event_shutdown(struct clock_event_device *ced)
+{
+	struct em_sti_priv *p = ced_to_em_sti(ced);
+	em_sti_stop(p, USER_CLOCKEVENT);
+	return 0;
+}
+
+static int em_sti_clock_event_set_oneshot(struct clock_event_device *ced)
+{
+	struct em_sti_priv *p = ced_to_em_sti(ced);
+
+	dev_info(&p->pdev->dev, "used for oneshot clock events\n");
+	em_sti_start(p, USER_CLOCKEVENT);
+	return 0;
+}
+
+static int em_sti_clock_event_next(unsigned long delta,
+				   struct clock_event_device *ced)
+{
+	struct em_sti_priv *p = ced_to_em_sti(ced);
+	u64 next;
+	int safe;
+
+	next = em_sti_set_next(p, em_sti_count(p) + delta);
+	safe = em_sti_count(p) < (next - 1);
+
+	return !safe;
+}
+
+static void em_sti_register_clockevent(struct em_sti_priv *p)
+{
+	struct clock_event_device *ced = &p->ced;
+
+	ced->name = dev_name(&p->pdev->dev);
+	ced->features = CLOCK_EVT_FEAT_ONESHOT;
+	ced->rating = 200;
+	ced->cpumask = cpu_possible_mask;
+	ced->set_next_event = em_sti_clock_event_next;
+	ced->set_state_shutdown = em_sti_clock_event_shutdown;
+	ced->set_state_oneshot = em_sti_clock_event_set_oneshot;
+
+	dev_info(&p->pdev->dev, "used for clock events\n");
+
+	clockevents_config_and_register(ced, p->rate, 2, 0xffffffff);
+}
+
+static int em_sti_probe(struct platform_device *pdev)
+{
+	struct em_sti_priv *p;
+	int irq, ret;
+
+	p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
+	if (p == NULL)
+		return -ENOMEM;
+
+	p->pdev = pdev;
+	platform_set_drvdata(pdev, p);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	/* map memory, let base point to the STI instance */
+	p->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(p->base))
+		return PTR_ERR(p->base);
+
+	ret = devm_request_irq(&pdev->dev, irq, em_sti_interrupt,
+			       IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
+			       dev_name(&pdev->dev), p);
+	if (ret)
+		return ret;
+
+	/* get hold of clock */
+	p->clk = devm_clk_get(&pdev->dev, "sclk");
+	if (IS_ERR(p->clk)) {
+		dev_err(&pdev->dev, "cannot get clock\n");
+		return PTR_ERR(p->clk);
+	}
+
+	ret = clk_prepare(p->clk);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "cannot prepare clock\n");
+		return ret;
+	}
+
+	ret = clk_enable(p->clk);
+	if (ret < 0) {
+		dev_err(&p->pdev->dev, "cannot enable clock\n");
+		clk_unprepare(p->clk);
+		return ret;
+	}
+	p->rate = clk_get_rate(p->clk);
+	clk_disable(p->clk);
+
+	raw_spin_lock_init(&p->lock);
+	em_sti_register_clockevent(p);
+	em_sti_register_clocksource(p);
+	return 0;
+}
+
+static const struct of_device_id em_sti_dt_ids[] = {
+	{ .compatible = "renesas,em-sti", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, em_sti_dt_ids);
+
+static struct platform_driver em_sti_device_driver = {
+	.probe		= em_sti_probe,
+	.driver		= {
+		.name	= "em_sti",
+		.of_match_table = em_sti_dt_ids,
+		.suppress_bind_attrs = true,
+	}
+};
+
+static int __init em_sti_init(void)
+{
+	return platform_driver_register(&em_sti_device_driver);
+}
+
+static void __exit em_sti_exit(void)
+{
+	platform_driver_unregister(&em_sti_device_driver);
+}
+
+subsys_initcall(em_sti_init);
+module_exit(em_sti_exit);
+
+MODULE_AUTHOR("Magnus Damm");
+MODULE_DESCRIPTION("Renesas Emma Mobile STI Timer Driver");