From 22098763a10d9c1340827fcf6edab66f153b27f0 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 13 Sep 2026 12:27:00 -0700 Subject: Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Don't destroy user event fields when removal fails User event fields are destroyed before the event is removed from visibility. But that can fail leaving the still visible event with no fields. Move the destroying of the fields to after the event is successfully removed from visibility. - Initialize function graph state is fork before calling copy_exec_state() For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, ftrace_graph_exit_task() will free the tasks ret_stack pointer. Since that pointer is still using the parent's ret_stack, it mistakenly frees the parent's pointer too. Call ftrace_graph_init() on the task first which will NULL out the new tasks's ret_stack and if the copy fails, it will not free anything. - Remove FGRAPH_MAX_INDEX The macro FGRAPH_MAX_INDEX was added but never used. Remove it. - Save ent_size in function graph printing of nested functions The function graph tracer needs to look at the next event to see if the next event is the return of the current function entry. If it is, it prints a single line: ktime_get(); Otherwise it prints it like a nested function: tick_nohz_irq_exit() { ktime_get(); kcpustat_irq_exit(); } In order to look at the next event, it must save the current event so that it has the information to print from it. It saves the event in the iterator descriptor called "ent". What it doesn't save is the ent_size of the event which is now used to know if the function graph arguments are to be printed. The peek doesn't save the size so the size used happens to be that of the size of the last event that was seen. Save the entry event size in the iterator descriptor so that the correct size is used. - Fix several errors with freeing data in the histogram code The histogram code had a lot of leaked or or incorrect accounting when failures happen. Correct them. - Fix histogram regression of .percent and .graph modifiers Up until 6.3 histogram values could have "percent" or "graph" modifiers that changed how they were printed. But a change that added restricting histograms values from being strings, stack traces and other modifiers inadvertently prevented them from using the percent and graph modifiers, which were legal use cases for values. Put back the percent and graph modifiers. - Fix various typos in the comments - Set the trace_clock before initializing a histogram with clock argument The histogram API allows the user to specific which trace clock to use via a "clock=" string. The histogram is set up first before the clock is checked. If the passed in clock is not valid, it exits without fully fixing up the histogram leaving it on the list and a use-after-free can trigger. Update the clock argument first and if it fails then exit gracefully before the histogram trigger is placed on any lists. - Restore :mod: trailer after parsing in ftrace_set_clr_event The function ftrace_set_clr_event() modifies the parse string and needs to put it back to what was passed in. It searches for ":mod:" via a strsep() but fails to put back the first ':' in the string. Add back the ':' in the passed in string. - Take trace_array reference when opening a tracer options file The options files are dynamically created and some tracers add their own options. When a tracer adds their own list of options, the trace_array holding them has an array to hold the list of options for each tracer. This array increases in size via a krealloc(), and the new entry gets a newly allocated array to hold the options of the new tracer being added. The element in each entry of the tracer's option array holds a pointer back to the trace_array, a pointer to the tracer it is associated to, a pointer to the flags of the option. The issue is that these arrays are freed when the trace_array is freed when its instance it represents is removed from the instances directory. There's a race that an open of one of these options files can happen when the instance is being removed. Add a new helper function to be called by the open function of the options file to iterate all existing trace_arrays under a lock and find the one that has the given option element in one of it's tracer arrays. If found, then update the associated trace_array's reference counter to keep it from being freed. If not found, have the open call return -ENODEV. - Disable interrupts when acquiring the lock in rb_wake_up_waiters() The function rb_wake_up_waiters() assumes it will be called in interrupt context and does not disable irqs when taking cpu_buffer->reader_lock, which can be called in hard interrupt context. The issue is in PREEMPT_RT, this function is called in thread context leaving this lock open to a deadlock. Take the lock with interrupts disabled. - Use rcu_assign_pointer() for tmp_ops filter hash The tmp_ops used in update_ftrace_direct_mod() assigns its filter_hash field directly, but that field is annotated as __rcu and sparse complains. Assign it with rcu_assign_pointer() - Fix use-after-free in enable_trigger_private_data_free() The trace_event_call is accessed through the event_trigger_data's trace_event_file pointer to put the trace_event_call on freeing. The issue is that the trace_event_file data may have been freed already causing a use-after-free. Add a field to the event_trigger_data that points directly to the trace_event_call so that it can decrement its reference directly without needing to go through the trace_event_file. - Fix accounting of buffer data remote headers trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the number of pages is needed for the asked for size as it doesn't take into account the meta data on each page. Add a helper function to do the calculation properly and use that in these functions. - Catch nr_page_va overflow in ring_buffer_desc sizing The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. - Do not resize the subbuf order if any per_cpu buffer is disabled The mmapping of ring buffers disables resizing the subbuffers, but it is done per-cpu whereas the subbuf size change is done for all the per_cpu buffers under the buffer->mutex. It could change the size of some while the mapping is happening on others. Have the resize of the subbuf order check all the per_cpu buffers under the lock to see if any of them is disabled before starting and causing an inconsistency between buffers that are being mapped. * tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits) ring-buffer: Check resize_disabled before publishing the new subbuf order tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing tracing/remotes: Account for ring buffer page header in size calculation tracing: Don't dereference trace_event_file in deferred trigger free ftrace: Use rcu_assign_pointer() for tmp_ops filter hash ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters() tracing: Take trace_array reference when opening a tracer options file tracing: Fix ring_buffer_read_page_size() kernel-doc tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event() tracing: Fix memory corruption from a "STACKTRACE" histogram key tracing: Fix memory corruption from the histogram stacktrace modifier tracing: Undo the registration when enabling the histogram trigger fails tracing: Take the reference before publishing the named histogram trigger tracing: Set the trace clock before registering the histogram trigger tracing: Fix typo "preceeded" in comment tracing: Fix typo "availabe" in comment tracing: Let histogram values keep the percent and graph modifiers tracing: Keep the entry count when the histogram stats allocation fails tracing: Free histogram the field rejected for a bad modifier tracing: Free histogram the var ref when its initialization fails ... --- drivers/input/input-mt.c | 534 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 534 insertions(+) create mode 100644 drivers/input/input-mt.c (limited to 'drivers/input/input-mt.c') 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 +#include +#include +#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); -- cgit v1.3.1