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-qcom-spmi-misc.c | 218 +++++++++++++++++++++++++++++++++ 1 file changed, 218 insertions(+) create mode 100644 drivers/extcon/extcon-qcom-spmi-misc.c (limited to 'drivers/extcon/extcon-qcom-spmi-misc.c') diff --git a/drivers/extcon/extcon-qcom-spmi-misc.c b/drivers/extcon/extcon-qcom-spmi-misc.c new file mode 100644 index 000000000..3c522c9c9 --- /dev/null +++ b/drivers/extcon/extcon-qcom-spmi-misc.c @@ -0,0 +1,218 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * extcon-qcom-spmi-misc.c - Qualcomm USB extcon driver to support USB ID + * and VBUS detection based on extcon-usb-gpio.c. + * + * Copyright (C) 2016 Linaro, Ltd. + * Stephen Boyd + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define USB_ID_DEBOUNCE_MS 5 /* ms */ + +struct qcom_usb_extcon_info { + struct extcon_dev *edev; + int id_irq; + int vbus_irq; + struct delayed_work wq_detcable; + unsigned long debounce_jiffies; +}; + +static const unsigned int qcom_usb_extcon_cable[] = { + EXTCON_USB, + EXTCON_USB_HOST, + EXTCON_NONE, +}; + +static void qcom_usb_extcon_detect_cable(struct work_struct *work) +{ + bool state = false; + int ret; + union extcon_property_value val; + struct qcom_usb_extcon_info *info = container_of(to_delayed_work(work), + struct qcom_usb_extcon_info, + wq_detcable); + + if (info->id_irq > 0) { + /* check ID and update cable state */ + ret = irq_get_irqchip_state(info->id_irq, + IRQCHIP_STATE_LINE_LEVEL, &state); + if (ret) + return; + + if (!state) { + val.intval = true; + extcon_set_property(info->edev, EXTCON_USB_HOST, + EXTCON_PROP_USB_SS, val); + } + extcon_set_state_sync(info->edev, EXTCON_USB_HOST, !state); + } + + if (info->vbus_irq > 0) { + /* check VBUS and update cable state */ + ret = irq_get_irqchip_state(info->vbus_irq, + IRQCHIP_STATE_LINE_LEVEL, &state); + if (ret) + return; + + if (state) { + val.intval = true; + extcon_set_property(info->edev, EXTCON_USB, + EXTCON_PROP_USB_SS, val); + } + extcon_set_state_sync(info->edev, EXTCON_USB, state); + } +} + +static irqreturn_t qcom_usb_irq_handler(int irq, void *dev_id) +{ + struct qcom_usb_extcon_info *info = dev_id; + + queue_delayed_work(system_power_efficient_wq, &info->wq_detcable, + info->debounce_jiffies); + + return IRQ_HANDLED; +} + +static int qcom_usb_extcon_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct qcom_usb_extcon_info *info; + int ret; + + info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + + info->edev = devm_extcon_dev_allocate(dev, qcom_usb_extcon_cable); + if (IS_ERR(info->edev)) { + dev_err(dev, "failed to allocate extcon device\n"); + return -ENOMEM; + } + + ret = devm_extcon_dev_register(dev, info->edev); + if (ret < 0) { + dev_err(dev, "failed to register extcon device\n"); + return ret; + } + + ret = extcon_set_property_capability(info->edev, + EXTCON_USB, EXTCON_PROP_USB_SS); + ret |= extcon_set_property_capability(info->edev, + EXTCON_USB_HOST, EXTCON_PROP_USB_SS); + if (ret) { + dev_err(dev, "failed to register extcon props rc=%d\n", + ret); + return ret; + } + + info->debounce_jiffies = msecs_to_jiffies(USB_ID_DEBOUNCE_MS); + + ret = devm_delayed_work_autocancel(dev, &info->wq_detcable, + qcom_usb_extcon_detect_cable); + if (ret) + return ret; + + info->id_irq = platform_get_irq_byname_optional(pdev, "usb_id"); + if (info->id_irq > 0) { + ret = devm_request_threaded_irq(dev, info->id_irq, NULL, + qcom_usb_irq_handler, + IRQF_TRIGGER_RISING | + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + pdev->name, info); + if (ret < 0) { + dev_err(dev, "failed to request handler for ID IRQ\n"); + return ret; + } + } + + info->vbus_irq = platform_get_irq_byname_optional(pdev, "usb_vbus"); + if (info->vbus_irq > 0) { + ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL, + qcom_usb_irq_handler, + IRQF_TRIGGER_RISING | + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + pdev->name, info); + if (ret < 0) { + dev_err(dev, "failed to request handler for VBUS IRQ\n"); + return ret; + } + } + + if (info->id_irq < 0 && info->vbus_irq < 0) { + dev_err(dev, "ID and VBUS IRQ not found\n"); + return -EINVAL; + } + + platform_set_drvdata(pdev, info); + devm_device_init_wakeup(dev); + + /* Perform initial detection */ + qcom_usb_extcon_detect_cable(&info->wq_detcable.work); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int qcom_usb_extcon_suspend(struct device *dev) +{ + struct qcom_usb_extcon_info *info = dev_get_drvdata(dev); + int ret = 0; + + if (device_may_wakeup(dev)) { + if (info->id_irq > 0) + ret = enable_irq_wake(info->id_irq); + if (info->vbus_irq > 0) + ret = enable_irq_wake(info->vbus_irq); + } + + return ret; +} + +static int qcom_usb_extcon_resume(struct device *dev) +{ + struct qcom_usb_extcon_info *info = dev_get_drvdata(dev); + int ret = 0; + + if (device_may_wakeup(dev)) { + if (info->id_irq > 0) + ret = disable_irq_wake(info->id_irq); + if (info->vbus_irq > 0) + ret = disable_irq_wake(info->vbus_irq); + } + + return ret; +} +#endif + +static SIMPLE_DEV_PM_OPS(qcom_usb_extcon_pm_ops, + qcom_usb_extcon_suspend, qcom_usb_extcon_resume); + +static const struct of_device_id qcom_usb_extcon_dt_match[] = { + { .compatible = "qcom,pm8941-misc", }, + { } +}; +MODULE_DEVICE_TABLE(of, qcom_usb_extcon_dt_match); + +static struct platform_driver qcom_usb_extcon_driver = { + .probe = qcom_usb_extcon_probe, + .driver = { + .name = "extcon-pm8941-misc", + .pm = &qcom_usb_extcon_pm_ops, + .of_match_table = qcom_usb_extcon_dt_match, + }, +}; +module_platform_driver(qcom_usb_extcon_driver); + +MODULE_DESCRIPTION("QCOM USB ID extcon driver"); +MODULE_AUTHOR("Stephen Boyd "); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1