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, 563 insertions, 0 deletions

diff --git a/drivers/input/ff-memless.c b/drivers/input/ff-memless.c
new file mode 100644
index 000000000..d1fefd1df
--- /dev/null
+++ b/drivers/input/ff-memless.c
@@ -0,0 +1,563 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Force feedback support for memoryless devices
+ *
+ *  Copyright (c) 2006 Anssi Hannula <anssi.hannula@gmail.com>
+ *  Copyright (c) 2006 Dmitry Torokhov <dtor@mail.ru>
+ */
+
+/* #define DEBUG */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/jiffies.h>
+#include <linux/fixp-arith.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Anssi Hannula <anssi.hannula@gmail.com>");
+MODULE_DESCRIPTION("Force feedback support for memoryless devices");
+
+/* Number of effects handled with memoryless devices */
+#define FF_MEMLESS_EFFECTS	16
+
+/* Envelope update interval in ms */
+#define FF_ENVELOPE_INTERVAL	50
+
+#define FF_EFFECT_STARTED	0
+#define FF_EFFECT_PLAYING	1
+#define FF_EFFECT_ABORTING	2
+
+struct ml_effect_state {
+	struct ff_effect *effect;
+	unsigned long flags;	/* effect state (STARTED, PLAYING, etc) */
+	int count;		/* loop count of the effect */
+	unsigned long play_at;	/* start time */
+	unsigned long stop_at;	/* stop time */
+	unsigned long adj_at;	/* last time the effect was sent */
+};
+
+struct ml_device {
+	void *private;
+	struct ml_effect_state states[FF_MEMLESS_EFFECTS];
+	int gain;
+	struct timer_list timer;
+	struct input_dev *dev;
+
+	int (*play_effect)(struct input_dev *dev, void *data,
+			   struct ff_effect *effect);
+};
+
+static const struct ff_envelope *get_envelope(const struct ff_effect *effect)
+{
+	static const struct ff_envelope empty_envelope;
+
+	switch (effect->type) {
+	case FF_PERIODIC:
+		return &effect->u.periodic.envelope;
+
+	case FF_CONSTANT:
+		return &effect->u.constant.envelope;
+
+	default:
+		return &empty_envelope;
+	}
+}
+
+/*
+ * Check for the next time envelope requires an update on memoryless devices
+ */
+static unsigned long calculate_next_time(struct ml_effect_state *state)
+{
+	const struct ff_envelope *envelope = get_envelope(state->effect);
+	unsigned long attack_stop, fade_start, next_fade;
+
+	if (envelope->attack_length) {
+		attack_stop = state->play_at +
+			msecs_to_jiffies(envelope->attack_length);
+		if (time_before(state->adj_at, attack_stop))
+			return state->adj_at +
+					msecs_to_jiffies(FF_ENVELOPE_INTERVAL);
+	}
+
+	if (state->effect->replay.length) {
+		if (envelope->fade_length) {
+			/* check when fading should start */
+			fade_start = state->stop_at -
+					msecs_to_jiffies(envelope->fade_length);
+
+			if (time_before(state->adj_at, fade_start))
+				return fade_start;
+
+			/* already fading, advance to next checkpoint */
+			next_fade = state->adj_at +
+					msecs_to_jiffies(FF_ENVELOPE_INTERVAL);
+			if (time_before(next_fade, state->stop_at))
+				return next_fade;
+		}
+
+		return state->stop_at;
+	}
+
+	return state->play_at;
+}
+
+static void ml_schedule_timer(struct ml_device *ml)
+{
+	struct ml_effect_state *state;
+	unsigned long now = jiffies;
+	unsigned long earliest = 0;
+	unsigned long next_at;
+	int events = 0;
+	int i;
+
+	pr_debug("calculating next timer\n");
+
+	for (i = 0; i < FF_MEMLESS_EFFECTS; i++) {
+
+		state = &ml->states[i];
+
+		if (!test_bit(FF_EFFECT_STARTED, &state->flags))
+			continue;
+
+		if (test_bit(FF_EFFECT_PLAYING, &state->flags))
+			next_at = calculate_next_time(state);
+		else
+			next_at = state->play_at;
+
+		if (time_before_eq(now, next_at) &&
+		    (++events == 1 || time_before(next_at, earliest)))
+			earliest = next_at;
+	}
+
+	if (!events) {
+		pr_debug("no actions\n");
+		timer_delete(&ml->timer);
+	} else {
+		pr_debug("timer set\n");
+		mod_timer(&ml->timer, earliest);
+	}
+}
+
+/*
+ * Apply an envelope to a value
+ */
+static int apply_envelope(struct ml_effect_state *state, int value,
+			  struct ff_envelope *envelope)
+{
+	struct ff_effect *effect = state->effect;
+	unsigned long now = jiffies;
+	int time_from_level;
+	int time_of_envelope;
+	int envelope_level;
+	int difference;
+
+	if (envelope->attack_length &&
+	    time_before(now,
+			state->play_at + msecs_to_jiffies(envelope->attack_length))) {
+		pr_debug("value = 0x%x, attack_level = 0x%x\n",
+			 value, envelope->attack_level);
+		time_from_level = jiffies_to_msecs(now - state->play_at);
+		time_of_envelope = envelope->attack_length;
+		envelope_level = min_t(u16, envelope->attack_level, 0x7fff);
+
+	} else if (envelope->fade_length && effect->replay.length &&
+		   time_after(now,
+			      state->stop_at - msecs_to_jiffies(envelope->fade_length)) &&
+		   time_before(now, state->stop_at)) {
+		time_from_level = jiffies_to_msecs(state->stop_at - now);
+		time_of_envelope = envelope->fade_length;
+		envelope_level = min_t(u16, envelope->fade_level, 0x7fff);
+	} else
+		return value;
+
+	difference = abs(value) - envelope_level;
+
+	pr_debug("difference = %d\n", difference);
+	pr_debug("time_from_level = 0x%x\n", time_from_level);
+	pr_debug("time_of_envelope = 0x%x\n", time_of_envelope);
+
+	difference = difference * time_from_level / time_of_envelope;
+
+	pr_debug("difference = %d\n", difference);
+
+	return value < 0 ?
+		-(difference + envelope_level) : (difference + envelope_level);
+}
+
+/*
+ * Return the type the effect has to be converted into (memless devices)
+ */
+static int get_compatible_type(struct ff_device *ff, int effect_type)
+{
+
+	if (test_bit(effect_type, ff->ffbit))
+		return effect_type;
+
+	if (effect_type == FF_PERIODIC && test_bit(FF_RUMBLE, ff->ffbit))
+		return FF_RUMBLE;
+
+	pr_err("invalid type in get_compatible_type()\n");
+
+	return 0;
+}
+
+/*
+ * Only left/right direction should be used (under/over 0x8000) for
+ * forward/reverse motor direction (to keep calculation fast & simple).
+ */
+static u16 ml_calculate_direction(u16 direction, u16 force,
+				  u16 new_direction, u16 new_force)
+{
+	if (!force)
+		return new_direction;
+	if (!new_force)
+		return direction;
+	return (((u32)(direction >> 1) * force +
+		 (new_direction >> 1) * new_force) /
+		(force + new_force)) << 1;
+}
+
+#define FRAC_N 8
+static inline s16 fixp_new16(s16 a)
+{
+	return ((s32)a) >> (16 - FRAC_N);
+}
+
+static inline s16 fixp_mult(s16 a, s16 b)
+{
+	a = ((s32)a * 0x100) / 0x7fff;
+	return ((s32)(a * b)) >> FRAC_N;
+}
+
+/*
+ * Combine two effects and apply gain.
+ */
+static void ml_combine_effects(struct ff_effect *effect,
+			       struct ml_effect_state *state,
+			       int gain)
+{
+	struct ff_effect *new = state->effect;
+	unsigned int strong, weak, i;
+	int x, y;
+	s16 level;
+
+	switch (new->type) {
+	case FF_CONSTANT:
+		i = new->direction * 360 / 0xffff;
+		level = fixp_new16(apply_envelope(state,
+					new->u.constant.level,
+					&new->u.constant.envelope));
+		x = fixp_mult(fixp_sin16(i), level) * gain / 0xffff;
+		y = fixp_mult(-fixp_cos16(i), level) * gain / 0xffff;
+		/*
+		 * here we abuse ff_ramp to hold x and y of constant force
+		 * If in future any driver wants something else than x and y
+		 * in s8, this should be changed to something more generic
+		 */
+		effect->u.ramp.start_level =
+			clamp_val(effect->u.ramp.start_level + x, -0x80, 0x7f);
+		effect->u.ramp.end_level =
+			clamp_val(effect->u.ramp.end_level + y, -0x80, 0x7f);
+		break;
+
+	case FF_RUMBLE:
+		strong = (u32)new->u.rumble.strong_magnitude * gain / 0xffff;
+		weak = (u32)new->u.rumble.weak_magnitude * gain / 0xffff;
+
+		if (effect->u.rumble.strong_magnitude + strong)
+			effect->direction = ml_calculate_direction(
+				effect->direction,
+				effect->u.rumble.strong_magnitude,
+				new->direction, strong);
+		else if (effect->u.rumble.weak_magnitude + weak)
+			effect->direction = ml_calculate_direction(
+				effect->direction,
+				effect->u.rumble.weak_magnitude,
+				new->direction, weak);
+		else
+			effect->direction = 0;
+		effect->u.rumble.strong_magnitude =
+			min(strong + effect->u.rumble.strong_magnitude,
+			    0xffffU);
+		effect->u.rumble.weak_magnitude =
+			min(weak + effect->u.rumble.weak_magnitude, 0xffffU);
+		break;
+
+	case FF_PERIODIC:
+		i = apply_envelope(state, abs(new->u.periodic.magnitude),
+				   &new->u.periodic.envelope);
+
+		/* here we also scale it 0x7fff => 0xffff */
+		i = i * gain / 0x7fff;
+
+		if (effect->u.rumble.strong_magnitude + i)
+			effect->direction = ml_calculate_direction(
+				effect->direction,
+				effect->u.rumble.strong_magnitude,
+				new->direction, i);
+		else
+			effect->direction = 0;
+		effect->u.rumble.strong_magnitude =
+			min(i + effect->u.rumble.strong_magnitude, 0xffffU);
+		effect->u.rumble.weak_magnitude =
+			min(i + effect->u.rumble.weak_magnitude, 0xffffU);
+		break;
+
+	default:
+		pr_err("invalid type in ml_combine_effects()\n");
+		break;
+	}
+
+}
+
+
+/*
+ * Because memoryless devices have only one effect per effect type active
+ * at one time we have to combine multiple effects into one
+ */
+static int ml_get_combo_effect(struct ml_device *ml,
+			       unsigned long *effect_handled,
+			       struct ff_effect *combo_effect)
+{
+	struct ff_effect *effect;
+	struct ml_effect_state *state;
+	int effect_type;
+	int i;
+
+	memset(combo_effect, 0, sizeof(struct ff_effect));
+
+	for (i = 0; i < FF_MEMLESS_EFFECTS; i++) {
+		if (__test_and_set_bit(i, effect_handled))
+			continue;
+
+		state = &ml->states[i];
+		effect = state->effect;
+
+		if (!test_bit(FF_EFFECT_STARTED, &state->flags))
+			continue;
+
+		if (time_before(jiffies, state->play_at))
+			continue;
+
+		/*
+		 * here we have started effects that are either
+		 * currently playing (and may need be aborted)
+		 * or need to start playing.
+		 */
+		effect_type = get_compatible_type(ml->dev->ff, effect->type);
+		if (combo_effect->type != effect_type) {
+			if (combo_effect->type != 0) {
+				__clear_bit(i, effect_handled);
+				continue;
+			}
+			combo_effect->type = effect_type;
+		}
+
+		if (__test_and_clear_bit(FF_EFFECT_ABORTING, &state->flags)) {
+			__clear_bit(FF_EFFECT_PLAYING, &state->flags);
+			__clear_bit(FF_EFFECT_STARTED, &state->flags);
+		} else if (effect->replay.length &&
+			   time_after_eq(jiffies, state->stop_at)) {
+
+			__clear_bit(FF_EFFECT_PLAYING, &state->flags);
+
+			if (--state->count <= 0) {
+				__clear_bit(FF_EFFECT_STARTED, &state->flags);
+			} else {
+				state->play_at = jiffies +
+					msecs_to_jiffies(effect->replay.delay);
+				state->stop_at = state->play_at +
+					msecs_to_jiffies(effect->replay.length);
+			}
+		} else {
+			__set_bit(FF_EFFECT_PLAYING, &state->flags);
+			state->adj_at = jiffies;
+			ml_combine_effects(combo_effect, state, ml->gain);
+		}
+	}
+
+	return combo_effect->type != 0;
+}
+
+static void ml_play_effects(struct ml_device *ml)
+{
+	struct ff_effect effect;
+	DECLARE_BITMAP(handled_bm, FF_MEMLESS_EFFECTS);
+
+	memset(handled_bm, 0, sizeof(handled_bm));
+
+	while (ml_get_combo_effect(ml, handled_bm, &effect))
+		ml->play_effect(ml->dev, ml->private, &effect);
+
+	ml_schedule_timer(ml);
+}
+
+static void ml_effect_timer(struct timer_list *t)
+{
+	struct ml_device *ml = timer_container_of(ml, t, timer);
+	struct input_dev *dev = ml->dev;
+
+	pr_debug("timer: updating effects\n");
+
+	guard(spinlock_irqsave)(&dev->event_lock);
+	ml_play_effects(ml);
+}
+
+/*
+ * Sets requested gain for FF effects. Called with dev->event_lock held.
+ */
+static void ml_ff_set_gain(struct input_dev *dev, u16 gain)
+{
+	struct ml_device *ml = dev->ff->private;
+	int i;
+
+	ml->gain = gain;
+
+	for (i = 0; i < FF_MEMLESS_EFFECTS; i++)
+		__clear_bit(FF_EFFECT_PLAYING, &ml->states[i].flags);
+
+	ml_play_effects(ml);
+}
+
+/*
+ * Start/stop specified FF effect. Called with dev->event_lock held.
+ */
+static int ml_ff_playback(struct input_dev *dev, int effect_id, int value)
+{
+	struct ml_device *ml = dev->ff->private;
+	struct ml_effect_state *state = &ml->states[effect_id];
+
+	if (value > 0) {
+		pr_debug("initiated play\n");
+
+		__set_bit(FF_EFFECT_STARTED, &state->flags);
+		state->count = value;
+		state->play_at = jiffies +
+				 msecs_to_jiffies(state->effect->replay.delay);
+		state->stop_at = state->play_at +
+				 msecs_to_jiffies(state->effect->replay.length);
+		state->adj_at = state->play_at;
+
+	} else {
+		pr_debug("initiated stop\n");
+
+		if (test_bit(FF_EFFECT_PLAYING, &state->flags))
+			__set_bit(FF_EFFECT_ABORTING, &state->flags);
+		else
+			__clear_bit(FF_EFFECT_STARTED, &state->flags);
+	}
+
+	ml_play_effects(ml);
+
+	return 0;
+}
+
+static int ml_ff_upload(struct input_dev *dev,
+			struct ff_effect *effect, struct ff_effect *old)
+{
+	struct ml_device *ml = dev->ff->private;
+	struct ml_effect_state *state = &ml->states[effect->id];
+
+	guard(spinlock_irq)(&dev->event_lock);
+
+	if (test_bit(FF_EFFECT_STARTED, &state->flags)) {
+		__clear_bit(FF_EFFECT_PLAYING, &state->flags);
+		state->play_at = jiffies +
+				 msecs_to_jiffies(state->effect->replay.delay);
+		state->stop_at = state->play_at +
+				 msecs_to_jiffies(state->effect->replay.length);
+		state->adj_at = state->play_at;
+		ml_schedule_timer(ml);
+	}
+
+	return 0;
+}
+
+static void ml_ff_destroy(struct ff_device *ff)
+{
+	struct ml_device *ml = ff->private;
+
+	/*
+	 * The timer is normally shut down in ml_ff_stop() when the device
+	 * is unregistered. However, we still shut it down here as a safety
+	 * net and for cases where the device was never registered (e.g.
+	 * error paths during probe).
+	 */
+	timer_shutdown_sync(&ml->timer);
+
+	kfree(ml->private);
+}
+
+static void ml_ff_stop(struct ff_device *ff)
+{
+	struct ml_device *ml = ff->private;
+
+	/*
+	 * Even though we stop all playing effects when tearing down an
+	 * input device (by the way of evdev calling input_flush_device()
+	 * that calls into input_ff_flush() that stops and erases all
+	 * effects), we do not actually shutdown the timer, and therefore
+	 * we should do it here to prevent it firing after the input
+	 * device is unregistered and its associated resources are freed.
+	 */
+	timer_shutdown_sync(&ml->timer);
+}
+
+/**
+ * input_ff_create_memless() - create memoryless force-feedback device
+ * @dev: input device supporting force-feedback
+ * @data: driver-specific data to be passed into @play_effect
+ * @play_effect: driver-specific method for playing FF effect
+ */
+int input_ff_create_memless(struct input_dev *dev, void *data,
+		int (*play_effect)(struct input_dev *, void *, struct ff_effect *))
+{
+	struct ff_device *ff;
+	int error;
+	int i;
+
+	struct ml_device *ml __free(kfree) = kzalloc_obj(*ml);
+	if (!ml)
+		return -ENOMEM;
+
+	ml->dev = dev;
+	ml->private = data;
+	ml->play_effect = play_effect;
+	ml->gain = 0xffff;
+	timer_setup(&ml->timer, ml_effect_timer, 0);
+
+	set_bit(FF_GAIN, dev->ffbit);
+
+	error = input_ff_create(dev, FF_MEMLESS_EFFECTS);
+	if (error)
+		return error;
+
+	ff = dev->ff;
+	ff->upload = ml_ff_upload;
+	ff->playback = ml_ff_playback;
+	ff->set_gain = ml_ff_set_gain;
+	ff->destroy = ml_ff_destroy;
+	ff->stop = ml_ff_stop;
+
+	/* we can emulate periodic effects with RUMBLE */
+	if (test_bit(FF_RUMBLE, ff->ffbit)) {
+		set_bit(FF_PERIODIC, dev->ffbit);
+		set_bit(FF_SINE, dev->ffbit);
+		set_bit(FF_TRIANGLE, dev->ffbit);
+		set_bit(FF_SQUARE, dev->ffbit);
+	}
+
+	for (i = 0; i < FF_MEMLESS_EFFECTS; i++)
+		ml->states[i].effect = &ff->effects[i];
+
+	ff->private = no_free_ptr(ml);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(input_ff_create_memless);