From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/extcon/extcon-adc-jack.c | 213 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 213 insertions(+) create mode 100644 drivers/extcon/extcon-adc-jack.c (limited to 'drivers/extcon/extcon-adc-jack.c') diff --git a/drivers/extcon/extcon-adc-jack.c b/drivers/extcon/extcon-adc-jack.c new file mode 100644 index 000000000..e735f43dc --- /dev/null +++ b/drivers/extcon/extcon-adc-jack.c @@ -0,0 +1,213 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * drivers/extcon/extcon-adc-jack.c + * + * Analog Jack extcon driver with ADC-based detection capability. + * + * Copyright (C) 2016 Samsung Electronics + * Chanwoo Choi + * + * Copyright (C) 2012 Samsung Electronics + * MyungJoo Ham + * + * Modified for calling to IIO to get adc by + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/** + * struct adc_jack_data - internal data for adc_jack device driver + * @dev: The device structure associated with the adc_jack. + * @edev: extcon device. + * @cable_names: list of supported cables. + * @adc_conditions: list of adc value conditions. + * @num_conditions: size of adc_conditions. + * @irq: irq number of attach/detach event (0 if not exist). + * @handling_delay: interrupt handler will schedule extcon event + * handling at handling_delay jiffies. + * @handler: extcon event handler called by interrupt handler. + * @chan: iio channel being queried. + * @wakeup_source: Indicates if the device can wake up the system. + */ +struct adc_jack_data { + struct device *dev; + struct extcon_dev *edev; + + const unsigned int **cable_names; + struct adc_jack_cond *adc_conditions; + int num_conditions; + + int irq; + unsigned long handling_delay; /* in jiffies */ + struct delayed_work handler; + + struct iio_channel *chan; + bool wakeup_source; +}; + +static void adc_jack_handler(struct work_struct *work) +{ + struct adc_jack_data *data = container_of(to_delayed_work(work), + struct adc_jack_data, + handler); + struct adc_jack_cond *def; + int ret, adc_val; + int i; + + ret = iio_read_channel_raw(data->chan, &adc_val); + if (ret < 0) { + dev_err(data->dev, "read channel() error: %d\n", ret); + return; + } + + /* Get state from adc value with adc_conditions */ + for (i = 0; i < data->num_conditions; i++) { + def = &data->adc_conditions[i]; + if (def->min_adc <= adc_val && def->max_adc >= adc_val) { + extcon_set_state_sync(data->edev, def->id, true); + return; + } + } + + /* Set the detached state if adc value is not included in the range */ + for (i = 0; i < data->num_conditions; i++) { + def = &data->adc_conditions[i]; + extcon_set_state_sync(data->edev, def->id, false); + } +} + +static irqreturn_t adc_jack_irq_thread(int irq, void *_data) +{ + struct adc_jack_data *data = _data; + + queue_delayed_work(system_power_efficient_wq, + &data->handler, data->handling_delay); + return IRQ_HANDLED; +} + +static int adc_jack_probe(struct platform_device *pdev) +{ + struct adc_jack_data *data; + struct adc_jack_pdata *pdata = dev_get_platdata(&pdev->dev); + int i, err = 0; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + if (!pdata->cable_names) { + dev_err(&pdev->dev, "error: cable_names not defined.\n"); + return -EINVAL; + } + + data->dev = &pdev->dev; + data->edev = devm_extcon_dev_allocate(&pdev->dev, pdata->cable_names); + if (IS_ERR(data->edev)) { + dev_err(&pdev->dev, "failed to allocate extcon device\n"); + return -ENOMEM; + } + + if (!pdata->adc_conditions) { + dev_err(&pdev->dev, "error: adc_conditions not defined.\n"); + return -EINVAL; + } + data->adc_conditions = pdata->adc_conditions; + + /* Check the length of array and set num_conditions */ + for (i = 0; data->adc_conditions[i].id != EXTCON_NONE; i++); + data->num_conditions = i; + + data->chan = devm_iio_channel_get(&pdev->dev, pdata->consumer_channel); + if (IS_ERR(data->chan)) + return PTR_ERR(data->chan); + + data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms); + data->wakeup_source = pdata->wakeup_source; + + INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler); + + platform_set_drvdata(pdev, data); + + err = devm_extcon_dev_register(&pdev->dev, data->edev); + if (err) + return err; + + data->irq = platform_get_irq(pdev, 0); + if (data->irq < 0) + return -ENODEV; + + err = request_any_context_irq(data->irq, adc_jack_irq_thread, + pdata->irq_flags, pdata->name, data); + + if (err < 0) { + dev_err(&pdev->dev, "error: irq %d\n", data->irq); + return err; + } + + if (data->wakeup_source) + device_init_wakeup(&pdev->dev, 1); + + adc_jack_handler(&data->handler.work); + return 0; +} + +static void adc_jack_remove(struct platform_device *pdev) +{ + struct adc_jack_data *data = platform_get_drvdata(pdev); + + if (data->wakeup_source) + device_init_wakeup(&pdev->dev, false); + free_irq(data->irq, data); + cancel_work_sync(&data->handler.work); +} + +#ifdef CONFIG_PM_SLEEP +static int adc_jack_suspend(struct device *dev) +{ + struct adc_jack_data *data = dev_get_drvdata(dev); + + cancel_delayed_work_sync(&data->handler); + if (device_may_wakeup(data->dev)) + enable_irq_wake(data->irq); + + return 0; +} + +static int adc_jack_resume(struct device *dev) +{ + struct adc_jack_data *data = dev_get_drvdata(dev); + + if (device_may_wakeup(data->dev)) + disable_irq_wake(data->irq); + + return 0; +} +#endif /* CONFIG_PM_SLEEP */ + +static SIMPLE_DEV_PM_OPS(adc_jack_pm_ops, + adc_jack_suspend, adc_jack_resume); + +static struct platform_driver adc_jack_driver = { + .probe = adc_jack_probe, + .remove = adc_jack_remove, + .driver = { + .name = "adc-jack", + .pm = &adc_jack_pm_ops, + }, +}; + +module_platform_driver(adc_jack_driver); + +MODULE_AUTHOR("MyungJoo Ham "); +MODULE_DESCRIPTION("ADC Jack extcon driver"); +MODULE_LICENSE("GPL v2"); +MODULE_IMPORT_NS("IIO_CONSUMER"); -- cgit v1.3.1