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, 534 insertions, 0 deletions

diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
new file mode 100644
index 000000000..c06e98fbd
--- /dev/null
+++ b/drivers/input/input-mt.c
@@ -0,0 +1,534 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Input Multitouch Library
+ *
+ * Copyright (c) 2008-2010 Henrik Rydberg
+ */
+
+#include <linux/input/mt.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include "input-core-private.h"
+
+#define TRKID_SGN	((TRKID_MAX + 1) >> 1)
+
+static void copy_abs(struct input_dev *dev, unsigned int dst, unsigned int src)
+{
+	if (dev->absinfo && test_bit(src, dev->absbit)) {
+		dev->absinfo[dst] = dev->absinfo[src];
+		dev->absinfo[dst].fuzz = 0;
+		__set_bit(dst, dev->absbit);
+	}
+}
+
+/**
+ * input_mt_init_slots() - initialize MT input slots
+ * @dev: input device supporting MT events and finger tracking
+ * @num_slots: number of slots used by the device
+ * @flags: mt tasks to handle in core
+ *
+ * This function allocates all necessary memory for MT slot handling
+ * in the input device, prepares the ABS_MT_SLOT and
+ * ABS_MT_TRACKING_ID events for use and sets up appropriate buffers.
+ * Depending on the flags set, it also performs pointer emulation and
+ * frame synchronization.
+ *
+ * May be called repeatedly. Returns -EINVAL if attempting to
+ * reinitialize with a different number of slots.
+ */
+int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,
+			unsigned int flags)
+{
+	if (!num_slots)
+		return 0;
+
+	if (dev->mt)
+		return dev->mt->num_slots != num_slots ? -EINVAL : 0;
+
+	/* Arbitrary limit for avoiding too large memory allocation. */
+	if (num_slots > 1024)
+		return -EINVAL;
+
+	struct input_mt *mt __free(kfree) =
+			kzalloc_flex(*mt, slots, num_slots);
+	if (!mt)
+		return -ENOMEM;
+
+	mt->num_slots = num_slots;
+	mt->flags = flags;
+	input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0);
+	input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0);
+
+	if (flags & (INPUT_MT_POINTER | INPUT_MT_DIRECT)) {
+		__set_bit(EV_KEY, dev->evbit);
+		__set_bit(BTN_TOUCH, dev->keybit);
+
+		copy_abs(dev, ABS_X, ABS_MT_POSITION_X);
+		copy_abs(dev, ABS_Y, ABS_MT_POSITION_Y);
+		copy_abs(dev, ABS_PRESSURE, ABS_MT_PRESSURE);
+	}
+	if (flags & INPUT_MT_POINTER) {
+		__set_bit(BTN_TOOL_FINGER, dev->keybit);
+		__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
+		if (num_slots >= 3)
+			__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
+		if (num_slots >= 4)
+			__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
+		if (num_slots >= 5)
+			__set_bit(BTN_TOOL_QUINTTAP, dev->keybit);
+		__set_bit(INPUT_PROP_POINTER, dev->propbit);
+	}
+	if (flags & INPUT_MT_DIRECT)
+		__set_bit(INPUT_PROP_DIRECT, dev->propbit);
+	if (flags & INPUT_MT_SEMI_MT)
+		__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
+	if (flags & INPUT_MT_TRACK) {
+		unsigned int n2 = num_slots * num_slots;
+		mt->red = kzalloc_objs(*mt->red, n2);
+		if (!mt->red)
+			return -ENOMEM;
+	}
+
+	/* Mark slots as 'inactive' */
+	for (unsigned int i = 0; i < num_slots; i++)
+		input_mt_set_value(&mt->slots[i], ABS_MT_TRACKING_ID, -1);
+
+	/* Mark slots as 'unused' */
+	mt->frame = 1;
+
+	dev->mt = no_free_ptr(mt);
+	return 0;
+}
+EXPORT_SYMBOL(input_mt_init_slots);
+
+/**
+ * input_mt_destroy_slots() - frees the MT slots of the input device
+ * @dev: input device with allocated MT slots
+ *
+ * This function is only needed in error path as the input core will
+ * automatically free the MT slots when the device is destroyed.
+ */
+void input_mt_destroy_slots(struct input_dev *dev)
+{
+	if (dev->mt) {
+		kfree(dev->mt->red);
+		kfree(dev->mt);
+	}
+	dev->mt = NULL;
+}
+EXPORT_SYMBOL(input_mt_destroy_slots);
+
+/**
+ * input_mt_report_slot_state() - report contact state
+ * @dev: input device with allocated MT slots
+ * @tool_type: the tool type to use in this slot
+ * @active: true if contact is active, false otherwise
+ *
+ * Reports a contact via ABS_MT_TRACKING_ID, and optionally
+ * ABS_MT_TOOL_TYPE. If active is true and the slot is currently
+ * inactive, or if the tool type is changed, a new tracking id is
+ * assigned to the slot. The tool type is only reported if the
+ * corresponding absbit field is set.
+ *
+ * Returns true if contact is active.
+ */
+bool input_mt_report_slot_state(struct input_dev *dev,
+				unsigned int tool_type, bool active)
+{
+	struct input_mt *mt = dev->mt;
+	struct input_mt_slot *slot;
+	int id;
+
+	if (!mt)
+		return false;
+
+	slot = &mt->slots[mt->slot];
+	slot->frame = mt->frame;
+
+	if (!active) {
+		input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
+		return false;
+	}
+
+	id = input_mt_get_value(slot, ABS_MT_TRACKING_ID);
+	if (id < 0)
+		id = input_mt_new_trkid(mt);
+
+	input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id);
+	input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type);
+
+	return true;
+}
+EXPORT_SYMBOL(input_mt_report_slot_state);
+
+/**
+ * input_mt_report_finger_count() - report contact count
+ * @dev: input device with allocated MT slots
+ * @count: the number of contacts
+ *
+ * Reports the contact count via BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP,
+ * BTN_TOOL_TRIPLETAP and BTN_TOOL_QUADTAP.
+ *
+ * The input core ensures only the KEY events already setup for
+ * this device will produce output.
+ */
+void input_mt_report_finger_count(struct input_dev *dev, int count)
+{
+	input_event(dev, EV_KEY, BTN_TOOL_FINGER, count == 1);
+	input_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, count == 2);
+	input_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, count == 3);
+	input_event(dev, EV_KEY, BTN_TOOL_QUADTAP, count == 4);
+	input_event(dev, EV_KEY, BTN_TOOL_QUINTTAP, count == 5);
+}
+EXPORT_SYMBOL(input_mt_report_finger_count);
+
+/**
+ * input_mt_report_pointer_emulation() - common pointer emulation
+ * @dev: input device with allocated MT slots
+ * @use_count: report number of active contacts as finger count
+ *
+ * Performs legacy pointer emulation via BTN_TOUCH, ABS_X, ABS_Y and
+ * ABS_PRESSURE. Touchpad finger count is emulated if use_count is true.
+ *
+ * The input core ensures only the KEY and ABS axes already setup for
+ * this device will produce output.
+ */
+void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count)
+{
+	struct input_mt *mt = dev->mt;
+	struct input_mt_slot *oldest;
+	int oldid, count, i;
+	int p, reported_p = 0;
+
+	if (!mt)
+		return;
+
+	oldest = NULL;
+	oldid = mt->trkid;
+	count = 0;
+
+	for (i = 0; i < mt->num_slots; ++i) {
+		struct input_mt_slot *ps = &mt->slots[i];
+		int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID);
+
+		if (id < 0)
+			continue;
+		if ((id - oldid) & TRKID_SGN) {
+			oldest = ps;
+			oldid = id;
+		}
+		if (test_bit(ABS_MT_PRESSURE, dev->absbit)) {
+			p = input_mt_get_value(ps, ABS_MT_PRESSURE);
+			if (mt->flags & INPUT_MT_TOTAL_FORCE)
+				reported_p += p;
+			else if (oldid == id)
+				reported_p = p;
+		}
+		count++;
+	}
+
+	input_event(dev, EV_KEY, BTN_TOUCH, count > 0);
+
+	if (use_count) {
+		if (count == 0 &&
+		    !test_bit(ABS_MT_DISTANCE, dev->absbit) &&
+		    test_bit(ABS_DISTANCE, dev->absbit) &&
+		    input_abs_get_val(dev, ABS_DISTANCE) != 0) {
+			/*
+			 * Force reporting BTN_TOOL_FINGER for devices that
+			 * only report general hover (and not per-contact
+			 * distance) when contact is in proximity but not
+			 * on the surface.
+			 */
+			count = 1;
+		}
+
+		input_mt_report_finger_count(dev, count);
+	}
+
+	if (oldest) {
+		int x = input_mt_get_value(oldest, ABS_MT_POSITION_X);
+		int y = input_mt_get_value(oldest, ABS_MT_POSITION_Y);
+
+		input_event(dev, EV_ABS, ABS_X, x);
+		input_event(dev, EV_ABS, ABS_Y, y);
+
+		if (test_bit(ABS_MT_PRESSURE, dev->absbit))
+			input_event(dev, EV_ABS, ABS_PRESSURE, reported_p);
+	} else {
+		if (test_bit(ABS_MT_PRESSURE, dev->absbit))
+			input_event(dev, EV_ABS, ABS_PRESSURE, 0);
+	}
+}
+EXPORT_SYMBOL(input_mt_report_pointer_emulation);
+
+static void __input_mt_drop_unused(struct input_dev *dev, struct input_mt *mt)
+{
+	int i;
+
+	lockdep_assert_held(&dev->event_lock);
+
+	for (i = 0; i < mt->num_slots; i++) {
+		if (input_mt_is_active(&mt->slots[i]) &&
+		    !input_mt_is_used(mt, &mt->slots[i])) {
+			input_handle_event(dev, EV_ABS, ABS_MT_SLOT, i);
+			input_handle_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
+		}
+	}
+}
+
+/**
+ * input_mt_drop_unused() - Inactivate slots not seen in this frame
+ * @dev: input device with allocated MT slots
+ *
+ * Lift all slots not seen since the last call to this function.
+ */
+void input_mt_drop_unused(struct input_dev *dev)
+{
+	struct input_mt *mt = dev->mt;
+
+	if (mt) {
+		guard(spinlock_irqsave)(&dev->event_lock);
+
+		__input_mt_drop_unused(dev, mt);
+		mt->frame++;
+	}
+}
+EXPORT_SYMBOL(input_mt_drop_unused);
+
+/**
+ * input_mt_release_slots() - Deactivate all slots
+ * @dev: input device with allocated MT slots
+ *
+ * Lift all active slots.
+ */
+void input_mt_release_slots(struct input_dev *dev)
+{
+	struct input_mt *mt = dev->mt;
+
+	lockdep_assert_held(&dev->event_lock);
+
+	if (mt) {
+		/* This will effectively mark all slots unused. */
+		mt->frame++;
+
+		__input_mt_drop_unused(dev, mt);
+
+		if (test_bit(ABS_PRESSURE, dev->absbit))
+			input_handle_event(dev, EV_ABS, ABS_PRESSURE, 0);
+
+		mt->frame++;
+	}
+}
+
+/**
+ * input_mt_sync_frame() - synchronize mt frame
+ * @dev: input device with allocated MT slots
+ *
+ * Close the frame and prepare the internal state for a new one.
+ * Depending on the flags, marks unused slots as inactive and performs
+ * pointer emulation.
+ */
+void input_mt_sync_frame(struct input_dev *dev)
+{
+	struct input_mt *mt = dev->mt;
+	bool use_count = false;
+
+	if (!mt)
+		return;
+
+	if (mt->flags & INPUT_MT_DROP_UNUSED) {
+		guard(spinlock_irqsave)(&dev->event_lock);
+		__input_mt_drop_unused(dev, mt);
+	}
+
+	if ((mt->flags & INPUT_MT_POINTER) && !(mt->flags & INPUT_MT_SEMI_MT))
+		use_count = true;
+
+	input_mt_report_pointer_emulation(dev, use_count);
+
+	mt->frame++;
+}
+EXPORT_SYMBOL(input_mt_sync_frame);
+
+static int adjust_dual(int *begin, int step, int *end, int eq, int mu)
+{
+	int f, *p, s, c;
+
+	if (begin == end)
+		return 0;
+
+	f = *begin;
+	p = begin + step;
+	s = p == end ? f + 1 : *p;
+
+	for (; p != end; p += step) {
+		if (*p < f) {
+			s = f;
+			f = *p;
+		} else if (*p < s) {
+			s = *p;
+		}
+	}
+
+	c = (f + s + 1) / 2;
+	if (c == 0 || (c > mu && (!eq || mu > 0)))
+		return 0;
+	/* Improve convergence for positive matrices by penalizing overcovers */
+	if (s < 0 && mu <= 0)
+		c *= 2;
+
+	for (p = begin; p != end; p += step)
+		*p -= c;
+
+	return (c < s && s <= 0) || (f >= 0 && f < c);
+}
+
+static void find_reduced_matrix(int *w, int nr, int nc, int nrc, int mu)
+{
+	int i, k, sum;
+
+	for (k = 0; k < nrc; k++) {
+		for (i = 0; i < nr; i++)
+			adjust_dual(w + i, nr, w + i + nrc, nr <= nc, mu);
+		sum = 0;
+		for (i = 0; i < nrc; i += nr)
+			sum += adjust_dual(w + i, 1, w + i + nr, nc <= nr, mu);
+		if (!sum)
+			break;
+	}
+}
+
+static int input_mt_set_matrix(struct input_mt *mt,
+			       const struct input_mt_pos *pos, int num_pos,
+			       int mu)
+{
+	const struct input_mt_pos *p;
+	struct input_mt_slot *s;
+	int *w = mt->red;
+	int x, y;
+
+	for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
+		if (!input_mt_is_active(s))
+			continue;
+		x = input_mt_get_value(s, ABS_MT_POSITION_X);
+		y = input_mt_get_value(s, ABS_MT_POSITION_Y);
+		for (p = pos; p != pos + num_pos; p++) {
+			int dx = x - p->x, dy = y - p->y;
+			*w++ = dx * dx + dy * dy - mu;
+		}
+	}
+
+	return w - mt->red;
+}
+
+static void input_mt_set_slots(struct input_mt *mt,
+			       int *slots, int num_pos)
+{
+	struct input_mt_slot *s;
+	int *w = mt->red, j;
+
+	for (j = 0; j != num_pos; j++)
+		slots[j] = -1;
+
+	for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
+		if (!input_mt_is_active(s))
+			continue;
+
+		for (j = 0; j != num_pos; j++) {
+			if (w[j] < 0) {
+				slots[j] = s - mt->slots;
+				break;
+			}
+		}
+
+		w += num_pos;
+	}
+
+	for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
+		if (input_mt_is_active(s))
+			continue;
+
+		for (j = 0; j != num_pos; j++) {
+			if (slots[j] < 0) {
+				slots[j] = s - mt->slots;
+				break;
+			}
+		}
+	}
+}
+
+/**
+ * input_mt_assign_slots() - perform a best-match assignment
+ * @dev: input device with allocated MT slots
+ * @slots: the slot assignment to be filled
+ * @pos: the position array to match
+ * @num_pos: number of positions
+ * @dmax: maximum ABS_MT_POSITION displacement (zero for infinite)
+ *
+ * Performs a best match against the current contacts and returns
+ * the slot assignment list. New contacts are assigned to unused
+ * slots.
+ *
+ * The assignments are balanced so that all coordinate displacements are
+ * below the euclidian distance dmax. If no such assignment can be found,
+ * some contacts are assigned to unused slots.
+ *
+ * Returns zero on success, or negative error in case of failure.
+ */
+int input_mt_assign_slots(struct input_dev *dev, int *slots,
+			  const struct input_mt_pos *pos, int num_pos,
+			  int dmax)
+{
+	struct input_mt *mt = dev->mt;
+	int mu = 2 * dmax * dmax;
+	int nrc;
+
+	if (!mt || !mt->red)
+		return -ENXIO;
+	if (num_pos > mt->num_slots)
+		return -EINVAL;
+	if (num_pos < 1)
+		return 0;
+
+	nrc = input_mt_set_matrix(mt, pos, num_pos, mu);
+	find_reduced_matrix(mt->red, num_pos, nrc / num_pos, nrc, mu);
+	input_mt_set_slots(mt, slots, num_pos);
+
+	return 0;
+}
+EXPORT_SYMBOL(input_mt_assign_slots);
+
+/**
+ * input_mt_get_slot_by_key() - return slot matching key
+ * @dev: input device with allocated MT slots
+ * @key: the key of the sought slot
+ *
+ * Returns the slot of the given key, if it exists, otherwise
+ * set the key on the first unused slot and return.
+ *
+ * If no available slot can be found, -1 is returned.
+ * Note that for this function to work properly, input_mt_sync_frame() has
+ * to be called at each frame.
+ */
+int input_mt_get_slot_by_key(struct input_dev *dev, int key)
+{
+	struct input_mt *mt = dev->mt;
+	struct input_mt_slot *s;
+
+	if (!mt)
+		return -1;
+
+	for (s = mt->slots; s != mt->slots + mt->num_slots; s++)
+		if (input_mt_is_active(s) && s->key == key)
+			return s - mt->slots;
+
+	for (s = mt->slots; s != mt->slots + mt->num_slots; s++)
+		if (!input_mt_is_active(s) && !input_mt_is_used(mt, s)) {
+			s->key = key;
+			return s - mt->slots;
+		}
+
+	return -1;
+}
+EXPORT_SYMBOL(input_mt_get_slot_by_key);