From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 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 --- drivers/input/touch-overlay.c | 278 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 278 insertions(+) create mode 100644 drivers/input/touch-overlay.c (limited to 'drivers/input/touch-overlay.c') diff --git a/drivers/input/touch-overlay.c b/drivers/input/touch-overlay.c new file mode 100644 index 000000000..b9fd82c48 --- /dev/null +++ b/drivers/input/touch-overlay.c @@ -0,0 +1,278 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Helper functions for overlay objects on touchscreens + * + * Copyright (c) 2023 Javier Carrasco + */ + +#include +#include +#include +#include +#include +#include +#include + +struct touch_overlay_segment { + struct list_head list; + u32 x_origin; + u32 y_origin; + u32 x_size; + u32 y_size; + u32 key; + bool pressed; + int slot; +}; + +static int touch_overlay_get_segment(struct fwnode_handle *segment_node, + struct touch_overlay_segment *segment, + struct input_dev *input) +{ + int error; + + error = fwnode_property_read_u32(segment_node, "x-origin", + &segment->x_origin); + if (error) + return error; + + error = fwnode_property_read_u32(segment_node, "y-origin", + &segment->y_origin); + if (error) + return error; + + error = fwnode_property_read_u32(segment_node, "x-size", + &segment->x_size); + if (error) + return error; + + error = fwnode_property_read_u32(segment_node, "y-size", + &segment->y_size); + if (error) + return error; + + error = fwnode_property_read_u32(segment_node, "linux,code", + &segment->key); + if (!error) + input_set_capability(input, EV_KEY, segment->key); + else if (error != -EINVAL) + return error; + + return 0; +} + +/** + * touch_overlay_map - map overlay objects from the device tree and set + * key capabilities if buttons are defined. + * @list: pointer to the list that will hold the segments + * @input: pointer to the already allocated input_dev + * + * Returns 0 on success and error number otherwise. + * + * If buttons are defined, key capabilities are set accordingly. + */ +int touch_overlay_map(struct list_head *list, struct input_dev *input) +{ + struct fwnode_handle *fw_segment; + struct device *dev = input->dev.parent; + struct touch_overlay_segment *segment; + int error; + + struct fwnode_handle *overlay __free(fwnode_handle) = + device_get_named_child_node(dev, "touch-overlay"); + if (!overlay) + return 0; + + fwnode_for_each_available_child_node(overlay, fw_segment) { + segment = devm_kzalloc(dev, sizeof(*segment), GFP_KERNEL); + if (!segment) { + fwnode_handle_put(fw_segment); + return -ENOMEM; + } + error = touch_overlay_get_segment(fw_segment, segment, input); + if (error) { + fwnode_handle_put(fw_segment); + return error; + } + list_add_tail(&segment->list, list); + } + + return 0; +} +EXPORT_SYMBOL(touch_overlay_map); + +/** + * touch_overlay_get_touchscreen_abs - get abs size from the touchscreen area. + * @list: pointer to the list that holds the segments + * @x: horizontal abs + * @y: vertical abs + */ +void touch_overlay_get_touchscreen_abs(struct list_head *list, u16 *x, u16 *y) +{ + struct touch_overlay_segment *segment; + struct list_head *ptr; + + list_for_each(ptr, list) { + segment = list_entry(ptr, struct touch_overlay_segment, list); + if (!segment->key) { + *x = segment->x_size - 1; + *y = segment->y_size - 1; + break; + } + } +} +EXPORT_SYMBOL(touch_overlay_get_touchscreen_abs); + +static bool touch_overlay_segment_event(struct touch_overlay_segment *seg, + struct input_mt_pos *pos) +{ + if (pos->x >= seg->x_origin && pos->x < (seg->x_origin + seg->x_size) && + pos->y >= seg->y_origin && pos->y < (seg->y_origin + seg->y_size)) + return true; + + return false; +} + +/** + * touch_overlay_mapped_touchscreen - check if a touchscreen area is mapped + * @list: pointer to the list that holds the segments + * + * Returns true if a touchscreen area is mapped or false otherwise. + */ +bool touch_overlay_mapped_touchscreen(struct list_head *list) +{ + struct touch_overlay_segment *segment; + struct list_head *ptr; + + list_for_each(ptr, list) { + segment = list_entry(ptr, struct touch_overlay_segment, list); + if (!segment->key) + return true; + } + + return false; +} +EXPORT_SYMBOL(touch_overlay_mapped_touchscreen); + +static bool touch_overlay_event_on_ts(struct list_head *list, + struct input_mt_pos *pos) +{ + struct touch_overlay_segment *segment; + struct list_head *ptr; + + list_for_each(ptr, list) { + segment = list_entry(ptr, struct touch_overlay_segment, list); + if (segment->key) + continue; + + if (touch_overlay_segment_event(segment, pos)) { + pos->x -= segment->x_origin; + pos->y -= segment->y_origin; + return true; + } + /* ignore touch events outside the defined area */ + return false; + } + + return true; +} + +static bool touch_overlay_button_event(struct input_dev *input, + struct touch_overlay_segment *segment, + struct input_mt_pos *pos, int slot) +{ + struct input_mt *mt = input->mt; + struct input_mt_slot *s = &mt->slots[slot]; + bool button_contact = touch_overlay_segment_event(segment, pos); + + if (segment->slot == slot && segment->pressed) { + /* sliding out of the button releases it */ + if (!button_contact) { + input_report_key(input, segment->key, false); + segment->pressed = false; + /* keep available for a possible touch event */ + return false; + } + /* ignore sliding on the button while pressed */ + s->frame = mt->frame; + return true; + } else if (button_contact) { + input_report_key(input, segment->key, true); + s->frame = mt->frame; + segment->slot = slot; + segment->pressed = true; + return true; + } + + return false; +} + +/** + * touch_overlay_sync_frame - update the status of the segments and report + * buttons whose tracked slot is unused. + * @list: pointer to the list that holds the segments + * @input: pointer to the input device associated to the contact + */ +void touch_overlay_sync_frame(struct list_head *list, struct input_dev *input) +{ + struct touch_overlay_segment *segment; + struct input_mt *mt = input->mt; + struct input_mt_slot *s; + struct list_head *ptr; + + list_for_each(ptr, list) { + segment = list_entry(ptr, struct touch_overlay_segment, list); + if (!segment->key) + continue; + + s = &mt->slots[segment->slot]; + if (!input_mt_is_used(mt, s) && segment->pressed) { + input_report_key(input, segment->key, false); + segment->pressed = false; + } + } +} +EXPORT_SYMBOL(touch_overlay_sync_frame); + +/** + * touch_overlay_process_contact - process contacts according to the overlay + * mapping. This function acts as a filter to release the calling driver + * from the contacts that are either related to overlay buttons or out of the + * overlay touchscreen area, if defined. + * @list: pointer to the list that holds the segments + * @input: pointer to the input device associated to the contact + * @pos: pointer to the contact position + * @slot: slot associated to the contact (0 if multitouch is not supported) + * + * Returns true if the contact was processed (reported for valid key events + * and dropped for contacts outside the overlay touchscreen area) or false + * if the contact must be processed by the caller. In that case this function + * shifts the (x,y) coordinates to the overlay touchscreen axis if required. + */ +bool touch_overlay_process_contact(struct list_head *list, + struct input_dev *input, + struct input_mt_pos *pos, int slot) +{ + struct touch_overlay_segment *segment; + struct list_head *ptr; + + /* + * buttons must be prioritized over overlay touchscreens to account for + * overlappings e.g. a button inside the touchscreen area. + */ + list_for_each(ptr, list) { + segment = list_entry(ptr, struct touch_overlay_segment, list); + if (segment->key && + touch_overlay_button_event(input, segment, pos, slot)) + return true; + } + + /* + * valid contacts on the overlay touchscreen are left for the client + * to be processed/reported according to its (possibly) unique features. + */ + return !touch_overlay_event_on_ts(list, pos); +} +EXPORT_SYMBOL(touch_overlay_process_contact); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Helper functions for overlay objects on touch devices"); -- cgit v1.3.1