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/usb/misc/ehset.c | 190 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 190 insertions(+) create mode 100644 drivers/usb/misc/ehset.c (limited to 'drivers/usb/misc/ehset.c') diff --git a/drivers/usb/misc/ehset.c b/drivers/usb/misc/ehset.c new file mode 100644 index 000000000..36b6e9fa7 --- /dev/null +++ b/drivers/usb/misc/ehset.c @@ -0,0 +1,190 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved. + */ + +#include +#include +#include +#include +#include +#include + +#define TEST_SE0_NAK_PID 0x0101 +#define TEST_J_PID 0x0102 +#define TEST_K_PID 0x0103 +#define TEST_PACKET_PID 0x0104 +#define TEST_HS_HOST_PORT_SUSPEND_RESUME 0x0106 +#define TEST_SINGLE_STEP_GET_DEV_DESC 0x0107 +#define TEST_SINGLE_STEP_SET_FEATURE 0x0108 + +extern const struct usb_device_id *usb_device_match_id(struct usb_device *udev, + const struct usb_device_id *id); + +/* + * A list of USB hubs which requires to disable the power + * to the port before starting the testing procedures. + */ +static const struct usb_device_id ehset_hub_list[] = { + { USB_DEVICE(0x0424, 0x4502) }, + { USB_DEVICE(0x0424, 0x4913) }, + { USB_DEVICE(0x0451, 0x8027) }, + { } +}; + +static int ehset_prepare_port_for_testing(struct usb_device *hub_udev, u16 portnum) +{ + int ret = 0; + + /* + * The USB2.0 spec chapter 11.24.2.13 says that the USB port which is + * going under test needs to be put in suspend before sending the + * test command. Most hubs don't enforce this precondition, but there + * are some hubs which needs to disable the power to the port before + * starting the test. + */ + if (usb_device_match_id(hub_udev, ehset_hub_list)) { + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_CLEAR_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_ENABLE, + portnum, NULL, 0, 1000, GFP_KERNEL); + /* + * Wait for the port to be disabled. It's an arbitrary value + * which worked every time. + */ + msleep(100); + } else { + /* + * For the hubs which are compliant with the spec, + * put the port in SUSPEND. + */ + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_SUSPEND, + portnum, NULL, 0, 1000, GFP_KERNEL); + } + return ret; +} + +static int ehset_probe(struct usb_interface *intf, + const struct usb_device_id *id) +{ + int ret = -EINVAL; + struct usb_device *dev = interface_to_usbdev(intf); + struct usb_device *hub_udev = dev->parent; + struct usb_device_descriptor buf; + u8 portnum = dev->portnum; + u16 test_pid = le16_to_cpu(dev->descriptor.idProduct); + + switch (test_pid) { + case TEST_SE0_NAK_PID: + ret = ehset_prepare_port_for_testing(hub_udev, portnum); + if (ret < 0) + break; + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_TEST, + (USB_TEST_SE0_NAK << 8) | portnum, + NULL, 0, 1000, GFP_KERNEL); + break; + case TEST_J_PID: + ret = ehset_prepare_port_for_testing(hub_udev, portnum); + if (ret < 0) + break; + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_TEST, + (USB_TEST_J << 8) | portnum, NULL, 0, + 1000, GFP_KERNEL); + break; + case TEST_K_PID: + ret = ehset_prepare_port_for_testing(hub_udev, portnum); + if (ret < 0) + break; + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_TEST, + (USB_TEST_K << 8) | portnum, NULL, 0, + 1000, GFP_KERNEL); + break; + case TEST_PACKET_PID: + ret = ehset_prepare_port_for_testing(hub_udev, portnum); + if (ret < 0) + break; + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_TEST, + (USB_TEST_PACKET << 8) | portnum, + NULL, 0, 1000, GFP_KERNEL); + break; + case TEST_HS_HOST_PORT_SUSPEND_RESUME: + /* Test: wait for 15secs -> suspend -> 15secs delay -> resume */ + msleep(15 * 1000); + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_SUSPEND, + portnum, NULL, 0, 1000, GFP_KERNEL); + if (ret < 0) + break; + + msleep(15 * 1000); + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_CLEAR_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_SUSPEND, + portnum, NULL, 0, 1000, GFP_KERNEL); + break; + case TEST_SINGLE_STEP_GET_DEV_DESC: + /* Test: wait for 15secs -> GetDescriptor request */ + msleep(15 * 1000); + + ret = usb_control_msg_recv(dev, 0, USB_REQ_GET_DESCRIPTOR, + USB_DIR_IN, USB_DT_DEVICE << 8, 0, + &buf, USB_DT_DEVICE_SIZE, + USB_CTRL_GET_TIMEOUT, GFP_KERNEL); + break; + case TEST_SINGLE_STEP_SET_FEATURE: + /* + * GetDescriptor SETUP request -> 15secs delay -> IN & STATUS + * + * Note, this test is only supported on root hubs since the + * SetPortFeature handling can only be done inside the HCD's + * hub_control callback function. + */ + if (hub_udev != dev->bus->root_hub) { + dev_err(&intf->dev, "SINGLE_STEP_SET_FEATURE test only supported on root hub\n"); + break; + } + + ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE, + USB_RT_PORT, USB_PORT_FEAT_TEST, + (6 << 8) | portnum, NULL, 0, + 60 * 1000, GFP_KERNEL); + + break; + default: + dev_err(&intf->dev, "%s: unsupported PID: 0x%x\n", + __func__, test_pid); + } + + return ret; +} + +static void ehset_disconnect(struct usb_interface *intf) +{ +} + +static const struct usb_device_id ehset_id_table[] = { + { USB_DEVICE(0x1a0a, TEST_SE0_NAK_PID) }, + { USB_DEVICE(0x1a0a, TEST_J_PID) }, + { USB_DEVICE(0x1a0a, TEST_K_PID) }, + { USB_DEVICE(0x1a0a, TEST_PACKET_PID) }, + { USB_DEVICE(0x1a0a, TEST_HS_HOST_PORT_SUSPEND_RESUME) }, + { USB_DEVICE(0x1a0a, TEST_SINGLE_STEP_GET_DEV_DESC) }, + { USB_DEVICE(0x1a0a, TEST_SINGLE_STEP_SET_FEATURE) }, + { } /* Terminating entry */ +}; +MODULE_DEVICE_TABLE(usb, ehset_id_table); + +static struct usb_driver ehset_driver = { + .name = "usb_ehset_test", + .probe = ehset_probe, + .disconnect = ehset_disconnect, + .id_table = ehset_id_table, +}; + +module_usb_driver(ehset_driver); + +MODULE_DESCRIPTION("USB Driver for EHSET Test Fixture"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1