Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipgrafted

Pull futex fix from Ingo Molnar:

 - Also allocate a default private futex hash on vfork() as well, to
   avoid races with (private) futex waiters (Peter Zijlstra)

* tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Also allocate private hash on vfork()

1 files changed, 301 insertions, 0 deletions

diff --git a/drivers/acpi/ac.c b/drivers/acpi/ac.c
new file mode 100644
index 000000000..f19d6dd43
--- /dev/null
+++ b/drivers/acpi/ac.c
@@ -0,0 +1,301 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  acpi_ac.c - ACPI AC Adapter Driver (Revision: 27)
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ */
+
+#define pr_fmt(fmt) "ACPI: AC: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/dmi.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/string_choices.h>
+#include <linux/acpi.h>
+#include <acpi/battery.h>
+
+#define ACPI_AC_FILE_STATE		"state"
+#define ACPI_AC_NOTIFY_STATUS		0x80
+#define ACPI_AC_STATUS_OFFLINE		0x00
+#define ACPI_AC_STATUS_ONLINE		0x01
+#define ACPI_AC_STATUS_UNKNOWN		0xFF
+
+MODULE_AUTHOR("Paul Diefenbaugh");
+MODULE_DESCRIPTION("ACPI AC Adapter Driver");
+MODULE_LICENSE("GPL");
+
+static const struct acpi_device_id ac_device_ids[] = {
+	{"ACPI0003", 0},
+	{"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, ac_device_ids);
+
+static int ac_sleep_before_get_state_ms;
+static int ac_only;
+
+struct acpi_ac {
+	struct power_supply *charger;
+	struct power_supply_desc charger_desc;
+	struct acpi_device *device;
+	unsigned long long state;
+	struct notifier_block battery_nb;
+};
+
+#define to_acpi_ac(x) power_supply_get_drvdata(x)
+
+/* AC Adapter Management */
+static int acpi_ac_get_state(struct acpi_ac *ac)
+{
+	acpi_status status = AE_OK;
+
+	if (!ac)
+		return -EINVAL;
+
+	if (ac_only) {
+		ac->state = 1;
+		return 0;
+	}
+
+	status = acpi_evaluate_integer(ac->device->handle, "_PSR", NULL,
+				       &ac->state);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_info(ac->device->handle,
+				"Error reading AC Adapter state: %s\n",
+				acpi_format_exception(status));
+		ac->state = ACPI_AC_STATUS_UNKNOWN;
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+/* sysfs I/F */
+static int get_ac_property(struct power_supply *psy,
+			   enum power_supply_property psp,
+			   union power_supply_propval *val)
+{
+	struct acpi_ac *ac = to_acpi_ac(psy);
+
+	if (!ac)
+		return -ENODEV;
+
+	if (acpi_ac_get_state(ac))
+		return -ENODEV;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		val->intval = ac->state;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const enum power_supply_property ac_props[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+};
+
+/* Driver Model */
+static void acpi_ac_notify(acpi_handle handle, u32 event, void *data)
+{
+	struct acpi_ac *ac = data;
+	struct acpi_device *adev = ac->device;
+
+	switch (event) {
+	default:
+		acpi_handle_debug(adev->handle, "Unsupported event [0x%x]\n",
+				  event);
+		fallthrough;
+	case ACPI_AC_NOTIFY_STATUS:
+	case ACPI_NOTIFY_BUS_CHECK:
+	case ACPI_NOTIFY_DEVICE_CHECK:
+		/*
+		 * A buggy BIOS may notify AC first and then sleep for
+		 * a specific time before doing actual operations in the
+		 * EC event handler (_Qxx). This will cause the AC state
+		 * reported by the ACPI event to be incorrect, so wait for a
+		 * specific time for the EC event handler to make progress.
+		 */
+		if (ac_sleep_before_get_state_ms > 0)
+			msleep(ac_sleep_before_get_state_ms);
+
+		acpi_ac_get_state(ac);
+		acpi_bus_generate_netlink_event(ACPI_AC_CLASS,
+						dev_name(&adev->dev), event,
+						ac->state);
+		acpi_notifier_call_chain(ACPI_AC_CLASS, acpi_device_bid(adev),
+					 event, ac->state);
+		power_supply_changed(ac->charger);
+	}
+}
+
+static int acpi_ac_battery_notify(struct notifier_block *nb,
+				  unsigned long action, void *data)
+{
+	struct acpi_ac *ac = container_of(nb, struct acpi_ac, battery_nb);
+	struct acpi_bus_event *event = (struct acpi_bus_event *)data;
+
+	/*
+	 * On HP Pavilion dv6-6179er AC status notifications aren't triggered
+	 * when adapter is plugged/unplugged. However, battery status
+	 * notifications are triggered when battery starts charging or
+	 * discharging. Re-reading AC status triggers lost AC notifications,
+	 * if AC status has changed.
+	 */
+	if (strcmp(event->device_class, ACPI_BATTERY_CLASS) == 0 &&
+	    event->type == ACPI_BATTERY_NOTIFY_STATUS)
+		acpi_ac_get_state(ac);
+
+	return NOTIFY_OK;
+}
+
+static int __init thinkpad_e530_quirk(const struct dmi_system_id *d)
+{
+	ac_sleep_before_get_state_ms = 1000;
+	return 0;
+}
+
+static int __init ac_only_quirk(const struct dmi_system_id *d)
+{
+	ac_only = 1;
+	return 0;
+}
+
+/* Please keep this list alphabetically sorted */
+static const struct dmi_system_id ac_dmi_table[]  __initconst = {
+	{
+		/* Kodlix GK45 returning incorrect state */
+		.callback = ac_only_quirk,
+		.matches = {
+			DMI_MATCH(DMI_PRODUCT_NAME, "GK45"),
+		},
+	},
+	{
+		/* Lenovo Thinkpad e530, see comment in acpi_ac_notify() */
+		.callback = thinkpad_e530_quirk,
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "32597CG"),
+		},
+	},
+	{},
+};
+
+static int acpi_ac_probe(struct platform_device *pdev)
+{
+	struct power_supply_config psy_cfg = {};
+	struct device *dev = &pdev->dev;
+	struct acpi_device *adev;
+	struct acpi_ac *ac;
+	int result;
+
+	adev = ACPI_COMPANION(&pdev->dev);
+	if (!adev)
+		return -ENODEV;
+
+	ac = devm_kzalloc(dev, sizeof(*ac), GFP_KERNEL);
+	if (!ac)
+		return -ENOMEM;
+
+	ac->device = adev;
+
+	platform_set_drvdata(pdev, ac);
+
+	result = acpi_ac_get_state(ac);
+	if (result)
+		return result;
+
+	psy_cfg.drv_data = ac;
+
+	ac->charger_desc.name = acpi_device_bid(adev);
+	ac->charger_desc.type = POWER_SUPPLY_TYPE_MAINS;
+	ac->charger_desc.properties = ac_props;
+	ac->charger_desc.num_properties = ARRAY_SIZE(ac_props);
+	ac->charger_desc.get_property = get_ac_property;
+	ac->charger = devm_power_supply_register(dev, &ac->charger_desc, &psy_cfg);
+	if (IS_ERR(ac->charger))
+		return PTR_ERR(ac->charger);
+
+	pr_info("AC Adapter [%s] (%s-line)\n", acpi_device_bid(adev),
+		str_on_off(ac->state));
+
+	result = devm_acpi_install_notify_handler(dev, ACPI_ALL_NOTIFY,
+						  acpi_ac_notify, ac);
+	if (result)
+		return result;
+
+	ac->battery_nb.notifier_call = acpi_ac_battery_notify;
+	register_acpi_notifier(&ac->battery_nb);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int acpi_ac_resume(struct device *dev)
+{
+	struct acpi_ac *ac = dev_get_drvdata(dev);
+	unsigned int old_state;
+
+	old_state = ac->state;
+	if (acpi_ac_get_state(ac))
+		return 0;
+	if (old_state != ac->state)
+		power_supply_changed(ac->charger);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(acpi_ac_pm, NULL, acpi_ac_resume);
+
+static void acpi_ac_remove(struct platform_device *pdev)
+{
+	struct acpi_ac *ac = platform_get_drvdata(pdev);
+
+	unregister_acpi_notifier(&ac->battery_nb);
+}
+
+static struct platform_driver acpi_ac_driver = {
+	.probe = acpi_ac_probe,
+	.remove = acpi_ac_remove,
+	.driver = {
+		.name = "ac",
+		.acpi_match_table = ac_device_ids,
+		.pm = &acpi_ac_pm,
+	},
+};
+
+static int __init acpi_ac_init(void)
+{
+	int result;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	if (acpi_quirk_skip_acpi_ac_and_battery())
+		return -ENODEV;
+
+	dmi_check_system(ac_dmi_table);
+
+	result = platform_driver_register(&acpi_ac_driver);
+	if (result < 0)
+		return -ENODEV;
+
+	return 0;
+}
+
+static void __exit acpi_ac_exit(void)
+{
+	platform_driver_unregister(&acpi_ac_driver);
+}
+module_init(acpi_ac_init);
+module_exit(acpi_ac_exit);