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/acpi/container.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 drivers/acpi/container.c (limited to 'drivers/acpi/container.c') diff --git a/drivers/acpi/container.c b/drivers/acpi/container.c new file mode 100644 index 000000000..f138a4335 --- /dev/null +++ b/drivers/acpi/container.c @@ -0,0 +1,117 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * container.c - ACPI Generic Container Driver + * + * Copyright (C) 2004 Anil S Keshavamurthy (anil.s.keshavamurthy@intel.com) + * Copyright (C) 2004 Keiichiro Tokunaga (tokunaga.keiich@jp.fujitsu.com) + * Copyright (C) 2004 Motoyuki Ito (motoyuki@soft.fujitsu.com) + * Copyright (C) 2004 FUJITSU LIMITED + * Copyright (C) 2004, 2013 Intel Corp. + * Author: Rafael J. Wysocki + */ +#include +#include + +#include "internal.h" + +static const struct acpi_device_id container_device_ids[] = { + {"ACPI0004", 0}, + {"PNP0A05", 0}, + {"PNP0A06", 0}, + {"", 0}, +}; + +#ifdef CONFIG_ACPI_CONTAINER + +static int check_offline(struct acpi_device *adev, void *not_used) +{ + if (acpi_scan_is_offline(adev, false)) + return 0; + + return -EBUSY; +} + +static int acpi_container_offline(struct container_dev *cdev) +{ + /* Check all of the dependent devices' physical companions. */ + return acpi_dev_for_each_child(ACPI_COMPANION(&cdev->dev), check_offline, NULL); +} + +static void acpi_container_release(struct device *dev) +{ + kfree(to_container_dev(dev)); +} + +static int container_device_attach(struct acpi_device *adev, + const struct acpi_device_id *not_used) +{ + struct container_dev *cdev; + struct device *dev; + int ret; + + if (adev->flags.is_dock_station) + return 0; + + cdev = kzalloc_obj(*cdev); + if (!cdev) + return -ENOMEM; + + cdev->offline = acpi_container_offline; + dev = &cdev->dev; + dev->bus = &container_subsys; + dev_set_name(dev, "%s", dev_name(&adev->dev)); + ACPI_COMPANION_SET(dev, adev); + dev->release = acpi_container_release; + ret = device_register(dev); + if (ret) { + put_device(dev); + return ret; + } + adev->driver_data = dev; + return 1; +} + +static void container_device_detach(struct acpi_device *adev) +{ + struct device *dev = acpi_driver_data(adev); + + adev->driver_data = NULL; + if (dev) + device_unregister(dev); +} + +static void container_device_online(struct acpi_device *adev) +{ + struct device *dev = acpi_driver_data(adev); + + kobject_uevent(&dev->kobj, KOBJ_ONLINE); +} + +static struct acpi_scan_handler container_handler = { + .ids = container_device_ids, + .attach = container_device_attach, + .detach = container_device_detach, + .hotplug = { + .enabled = true, + .demand_offline = true, + .notify_online = container_device_online, + }, +}; + +void __init acpi_container_init(void) +{ + acpi_scan_add_handler(&container_handler); +} + +#else + +static struct acpi_scan_handler container_handler = { + .ids = container_device_ids, +}; + +void __init acpi_container_init(void) +{ + acpi_scan_add_handler_with_hotplug(&container_handler, "container"); +} + +#endif /* CONFIG_ACPI_CONTAINER */ -- cgit v1.3.1