diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-13 12:27:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-13 12:27:00 -0700 |
| commit | 22098763a10d9c1340827fcf6edab66f153b27f0 (patch) | |
| tree | 3962f95a34df034652ff93686cdd156c7197f2d9 /drivers/leds/trigger/ledtrig-pattern.c | |
| download | linux-stable-22098763a10d9c1340827fcf6edab66f153b27f0.tar.gz linux-stable-22098763a10d9c1340827fcf6edab66f153b27f0.zip | |
Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted
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
...
Diffstat (limited to 'drivers/leds/trigger/ledtrig-pattern.c')
| -rw-r--r-- | drivers/leds/trigger/ledtrig-pattern.c | 543 |
1 files changed, 543 insertions, 0 deletions
diff --git a/drivers/leds/trigger/ledtrig-pattern.c b/drivers/leds/trigger/ledtrig-pattern.c new file mode 100644 index 000000000..8f9cbe54e --- /dev/null +++ b/drivers/leds/trigger/ledtrig-pattern.c @@ -0,0 +1,543 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * LED pattern trigger + * + * Idea discussed with Pavel Machek. Raphael Teysseyre implemented + * the first version, Baolin Wang simplified and improved the approach. + */ + +#include <linux/kernel.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/timer.h> +#include <linux/hrtimer.h> + +#define MAX_PATTERNS 1024 +/* + * When doing gradual dimming, the led brightness will be updated + * every 50 milliseconds. + */ +#define UPDATE_INTERVAL 50 + +enum pattern_type { + PATTERN_TYPE_SW, /* Use standard timer for software pattern */ + PATTERN_TYPE_HR, /* Use hrtimer for software pattern */ + PATTERN_TYPE_HW, /* Hardware pattern */ +}; + +struct pattern_trig_data { + struct led_classdev *led_cdev; + struct led_pattern patterns[MAX_PATTERNS]; + struct led_pattern *curr; + struct led_pattern *next; + struct mutex lock; + u32 npatterns; + int repeat; + int last_repeat; + int delta_t; + bool is_indefinite; + enum pattern_type type; + struct timer_list timer; + struct hrtimer hrtimer; +}; + +static void pattern_trig_update_patterns(struct pattern_trig_data *data) +{ + data->curr = data->next; + if (!data->is_indefinite && data->curr == data->patterns) + data->repeat--; + + if (data->next == data->patterns + data->npatterns - 1) + data->next = data->patterns; + else + data->next++; + + data->delta_t = 0; +} + +static int pattern_trig_compute_brightness(struct pattern_trig_data *data) +{ + int step_brightness; + + /* + * If current tuple's duration is less than the dimming interval, + * we should treat it as a step change of brightness instead of + * doing gradual dimming. + */ + if (data->delta_t == 0 || data->curr->delta_t < UPDATE_INTERVAL) + return data->curr->brightness; + + step_brightness = abs(data->next->brightness - data->curr->brightness); + step_brightness = data->delta_t * step_brightness / data->curr->delta_t; + + if (data->next->brightness > data->curr->brightness) + return data->curr->brightness + step_brightness; + else + return data->curr->brightness - step_brightness; +} + +static void pattern_trig_timer_start(struct pattern_trig_data *data) +{ + if (data->type == PATTERN_TYPE_HR) { + hrtimer_start(&data->hrtimer, ns_to_ktime(0), HRTIMER_MODE_REL); + } else { + data->timer.expires = jiffies; + add_timer(&data->timer); + } +} + +static void pattern_trig_timer_cancel(struct pattern_trig_data *data) +{ + if (data->type == PATTERN_TYPE_HR) + hrtimer_cancel(&data->hrtimer); + else + timer_delete_sync(&data->timer); +} + +static void pattern_trig_timer_restart(struct pattern_trig_data *data, + unsigned long interval) +{ + if (data->type == PATTERN_TYPE_HR) + hrtimer_forward_now(&data->hrtimer, ms_to_ktime(interval)); + else + mod_timer(&data->timer, jiffies + msecs_to_jiffies(interval)); +} + +static void pattern_trig_timer_common_function(struct pattern_trig_data *data) +{ + for (;;) { + if (!data->is_indefinite && !data->repeat) + break; + + if (data->curr->brightness == data->next->brightness) { + /* Step change of brightness */ + led_set_brightness(data->led_cdev, + data->curr->brightness); + pattern_trig_timer_restart(data, data->curr->delta_t); + if (!data->next->delta_t) { + /* Skip the tuple with zero duration */ + pattern_trig_update_patterns(data); + } + /* Select next tuple */ + pattern_trig_update_patterns(data); + } else { + /* Gradual dimming */ + + /* + * If the accumulation time is larger than current + * tuple's duration, we should go next one and re-check + * if we repeated done. + */ + if (data->delta_t > data->curr->delta_t) { + pattern_trig_update_patterns(data); + continue; + } + + led_set_brightness(data->led_cdev, + pattern_trig_compute_brightness(data)); + pattern_trig_timer_restart(data, UPDATE_INTERVAL); + + /* Accumulate the gradual dimming time */ + data->delta_t += UPDATE_INTERVAL; + } + + break; + } +} + +static void pattern_trig_timer_function(struct timer_list *t) +{ + struct pattern_trig_data *data = timer_container_of(data, t, timer); + + return pattern_trig_timer_common_function(data); +} + +static enum hrtimer_restart pattern_trig_hrtimer_function(struct hrtimer *t) +{ + struct pattern_trig_data *data = + container_of(t, struct pattern_trig_data, hrtimer); + + pattern_trig_timer_common_function(data); + if (!data->is_indefinite && !data->repeat) + return HRTIMER_NORESTART; + + return HRTIMER_RESTART; +} + +static int pattern_trig_start_pattern(struct led_classdev *led_cdev) +{ + struct pattern_trig_data *data = led_cdev->trigger_data; + + if (!data->npatterns) + return 0; + + if (data->type == PATTERN_TYPE_HW) { + return led_cdev->pattern_set(led_cdev, data->patterns, + data->npatterns, data->repeat); + } + + /* At least 2 tuples for software pattern. */ + if (data->npatterns < 2) + return -EINVAL; + + data->delta_t = 0; + data->curr = data->patterns; + data->next = data->patterns + 1; + pattern_trig_timer_start(data); + + return 0; +} + +static ssize_t repeat_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct pattern_trig_data *data = led_cdev->trigger_data; + int repeat; + + mutex_lock(&data->lock); + + repeat = data->last_repeat; + + mutex_unlock(&data->lock); + + return sysfs_emit(buf, "%d\n", repeat); +} + +static ssize_t repeat_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct pattern_trig_data *data = led_cdev->trigger_data; + int err, res; + + err = kstrtos32(buf, 10, &res); + if (err) + return err; + + /* Number 0 and negative numbers except -1 are invalid. */ + if (res < -1 || res == 0) + return -EINVAL; + + mutex_lock(&data->lock); + + pattern_trig_timer_cancel(data); + + if (data->type == PATTERN_TYPE_HW) + led_cdev->pattern_clear(led_cdev); + + data->last_repeat = data->repeat = res; + /* -1 means repeat indefinitely */ + if (data->repeat == -1) + data->is_indefinite = true; + else + data->is_indefinite = false; + + err = pattern_trig_start_pattern(led_cdev); + + mutex_unlock(&data->lock); + return err < 0 ? err : count; +} + +static DEVICE_ATTR_RW(repeat); + +static ssize_t pattern_trig_show_patterns(struct pattern_trig_data *data, + char *buf, enum pattern_type type) +{ + ssize_t count = 0; + int i; + + mutex_lock(&data->lock); + + if (!data->npatterns || data->type != type) + goto out; + + for (i = 0; i < data->npatterns; i++) { + count += scnprintf(buf + count, PAGE_SIZE - count, + "%d %u ", + data->patterns[i].brightness, + data->patterns[i].delta_t); + } + + buf[count - 1] = '\n'; + +out: + mutex_unlock(&data->lock); + return count; +} + +static int pattern_trig_store_patterns_string(struct pattern_trig_data *data, + const char *buf, size_t count) +{ + int ccount, cr, offset = 0; + + while (offset < count - 1 && data->npatterns < MAX_PATTERNS) { + cr = 0; + ccount = sscanf(buf + offset, "%u %u %n", + &data->patterns[data->npatterns].brightness, + &data->patterns[data->npatterns].delta_t, &cr); + + if (ccount != 2 || + data->patterns[data->npatterns].brightness > data->led_cdev->max_brightness) { + data->npatterns = 0; + return -EINVAL; + } + + offset += cr; + data->npatterns++; + } + + return 0; +} + +static int pattern_trig_store_patterns_int(struct pattern_trig_data *data, + const u32 *buf, size_t count) +{ + unsigned int i; + + for (i = 0; i < count; i += 2) { + data->patterns[data->npatterns].brightness = buf[i]; + data->patterns[data->npatterns].delta_t = buf[i + 1]; + data->npatterns++; + } + + return 0; +} + +static ssize_t pattern_trig_store_patterns(struct led_classdev *led_cdev, + const char *buf, const u32 *buf_int, + size_t count, enum pattern_type type) +{ + struct pattern_trig_data *data = led_cdev->trigger_data; + int err = 0; + + mutex_lock(&data->lock); + + pattern_trig_timer_cancel(data); + + if (data->type == PATTERN_TYPE_HW) + led_cdev->pattern_clear(led_cdev); + + data->type = type; + data->npatterns = 0; + + if (buf) + err = pattern_trig_store_patterns_string(data, buf, count); + else + err = pattern_trig_store_patterns_int(data, buf_int, count); + if (err) + goto out; + + err = pattern_trig_start_pattern(led_cdev); + if (err) + data->npatterns = 0; + +out: + mutex_unlock(&data->lock); + return err < 0 ? err : count; +} + +static ssize_t pattern_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct pattern_trig_data *data = led_cdev->trigger_data; + + return pattern_trig_show_patterns(data, buf, PATTERN_TYPE_SW); +} + +static ssize_t pattern_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + + return pattern_trig_store_patterns(led_cdev, buf, NULL, count, + PATTERN_TYPE_SW); +} + +static DEVICE_ATTR_RW(pattern); + +static ssize_t hw_pattern_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct pattern_trig_data *data = led_cdev->trigger_data; + + return pattern_trig_show_patterns(data, buf, PATTERN_TYPE_HW); +} + +static ssize_t hw_pattern_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + + return pattern_trig_store_patterns(led_cdev, buf, NULL, count, + PATTERN_TYPE_HW); +} + +static DEVICE_ATTR_RW(hw_pattern); + +static ssize_t hr_pattern_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct pattern_trig_data *data = led_cdev->trigger_data; + + return pattern_trig_show_patterns(data, buf, PATTERN_TYPE_HR); +} + +static ssize_t hr_pattern_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + + return pattern_trig_store_patterns(led_cdev, buf, NULL, count, + PATTERN_TYPE_HR); +} + +static DEVICE_ATTR_RW(hr_pattern); + +static umode_t pattern_trig_attrs_mode(struct kobject *kobj, + struct attribute *attr, int index) +{ + struct device *dev = kobj_to_dev(kobj); + struct led_classdev *led_cdev = dev_get_drvdata(dev); + + if (attr == &dev_attr_repeat.attr || attr == &dev_attr_pattern.attr) + return attr->mode; + else if (attr == &dev_attr_hr_pattern.attr) + return attr->mode; + else if (attr == &dev_attr_hw_pattern.attr && led_cdev->pattern_set) + return attr->mode; + + return 0; +} + +static struct attribute *pattern_trig_attrs[] = { + &dev_attr_pattern.attr, + &dev_attr_hw_pattern.attr, + &dev_attr_hr_pattern.attr, + &dev_attr_repeat.attr, + NULL +}; + +static const struct attribute_group pattern_trig_group = { + .attrs = pattern_trig_attrs, + .is_visible = pattern_trig_attrs_mode, +}; + +static const struct attribute_group *pattern_trig_groups[] = { + &pattern_trig_group, + NULL, +}; + +static void pattern_init(struct led_classdev *led_cdev) +{ + unsigned int size = 0; + u32 *pattern; + int err; + + pattern = led_get_default_pattern(led_cdev, &size); + if (!pattern) + return; + + if (size % 2) { + dev_warn(led_cdev->dev, "Expected pattern of tuples\n"); + goto out; + } + + err = pattern_trig_store_patterns(led_cdev, NULL, pattern, size, + PATTERN_TYPE_SW); + if (err < 0) + dev_warn(led_cdev->dev, + "Pattern initialization failed with error %d\n", err); + +out: + kfree(pattern); +} + +static int pattern_trig_activate(struct led_classdev *led_cdev) +{ + struct pattern_trig_data *data; + + data = kzalloc_obj(*data); + if (!data) + return -ENOMEM; + + if (!!led_cdev->pattern_set ^ !!led_cdev->pattern_clear) { + dev_warn(led_cdev->dev, + "Hardware pattern ops validation failed\n"); + led_cdev->pattern_set = NULL; + led_cdev->pattern_clear = NULL; + } + + data->type = PATTERN_TYPE_SW; + data->is_indefinite = true; + data->last_repeat = -1; + mutex_init(&data->lock); + data->led_cdev = led_cdev; + led_set_trigger_data(led_cdev, data); + timer_setup(&data->timer, pattern_trig_timer_function, 0); + hrtimer_setup(&data->hrtimer, pattern_trig_hrtimer_function, CLOCK_MONOTONIC, + HRTIMER_MODE_REL); + led_cdev->activated = true; + + if (led_cdev->flags & LED_INIT_DEFAULT_TRIGGER) { + pattern_init(led_cdev); + /* + * Mark as initialized even on pattern_init() error because + * any consecutive call to it would produce the same error. + */ + led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER; + } + + return 0; +} + +static void pattern_trig_deactivate(struct led_classdev *led_cdev) +{ + struct pattern_trig_data *data = led_cdev->trigger_data; + + if (!led_cdev->activated) + return; + + if (led_cdev->pattern_clear) + led_cdev->pattern_clear(led_cdev); + + timer_shutdown_sync(&data->timer); + hrtimer_cancel(&data->hrtimer); + + led_set_brightness(led_cdev, LED_OFF); + kfree(data); + led_cdev->activated = false; +} + +static struct led_trigger pattern_led_trigger = { + .name = "pattern", + .activate = pattern_trig_activate, + .deactivate = pattern_trig_deactivate, + .groups = pattern_trig_groups, +}; + +static int __init pattern_trig_init(void) +{ + return led_trigger_register(&pattern_led_trigger); +} + +static void __exit pattern_trig_exit(void) +{ + led_trigger_unregister(&pattern_led_trigger); +} + +module_init(pattern_trig_init); +module_exit(pattern_trig_exit); + +MODULE_AUTHOR("Raphael Teysseyre <rteysseyre@gmail.com>"); +MODULE_AUTHOR("Baolin Wang <baolin.wang@linaro.org>"); +MODULE_DESCRIPTION("LED Pattern trigger"); +MODULE_LICENSE("GPL v2"); |
