From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions When using eBPF to probe CS CALL instructions within a function, a crash can be triggered. The eBPF tool probes offset 257 of the __hrtimer_run_queues() function: <__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1) <__hrtimer_run_queues+254>: mov %r14,%rdi <__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12> <__hrtimer_run_queues+263>: mov %eax,%r12d <__hrtimer_run_queues+266>: xchg %ax,%ax <__hrtimer_run_queues+268>: mov %r13,%rdi Which triggers this crash: BUG: unable to handle page fault for address: 00000000000f41c9 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P RIP: 0010:__hrtimer_run_queues+0x106/0x230 Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is at the 6th byte of the above CS CALL instruction. Since the CS CALL instruction occupies 6 bytes, the exception occurred in the middle of that call instruction. The root cause is that when using eBPF tools to probe in the middle of a function, a kprobe with INT3 is used as the underlying implementation. During single-step emulation of the original CALL instruction, int3_emulate_call() assumes that the probed CALL instruction is 5 bytes long. However, the actual CS-prefixed CALL instruction occupies 6 bytes, so it constructs an incorrect exception return address. When the CPU returns from the kprobe handler, the next instruction to be executed is at the address of the last byte of that CS CALL instruction. Coincidentally, starting from that address, the CPU fetches and decodes a completely different instruction, which ultimately triggers a kernel crash. Fix the issue by using the actual instruction length obtained from the instruction decoder when constructing the exception return address, rather than relying on the hardcoded CALL_INSN_SIZE macro. [ mingo: Refined the changelog ] Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step") Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- drivers/hid/hid-dr.c | 284 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 284 insertions(+) create mode 100644 drivers/hid/hid-dr.c (limited to 'drivers/hid/hid-dr.c') diff --git a/drivers/hid/hid-dr.c b/drivers/hid/hid-dr.c new file mode 100644 index 000000000..a1e10ee8d --- /dev/null +++ b/drivers/hid/hid-dr.c @@ -0,0 +1,284 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Force feedback support for DragonRise Inc. game controllers + * + * From what I have gathered, these devices are mass produced in China and are + * distributed under several vendors. They often share the same design as + * the original PlayStation DualShock controller. + * + * 0079:0006 "DragonRise Inc. Generic USB Joystick " + * - tested with a Tesun USB-703 game controller. + * + * Copyright (c) 2009 Richard Walmsley + */ + +/* + */ + +#include +#include +#include +#include + +#include "hid-ids.h" + +#ifdef CONFIG_DRAGONRISE_FF + +struct drff_device { + struct hid_report *report; +}; + +static int drff_play(struct input_dev *dev, void *data, + struct ff_effect *effect) +{ + struct hid_device *hid = input_get_drvdata(dev); + struct drff_device *drff = data; + int strong, weak; + + strong = effect->u.rumble.strong_magnitude; + weak = effect->u.rumble.weak_magnitude; + + dbg_hid("called with 0x%04x 0x%04x", strong, weak); + + if (strong || weak) { + strong = strong * 0xff / 0xffff; + weak = weak * 0xff / 0xffff; + + /* While reverse engineering this device, I found that when + this value is set, it causes the strong rumble to function + at a near maximum speed, so we'll bypass it. */ + if (weak == 0x0a) + weak = 0x0b; + + drff->report->field[0]->value[0] = 0x51; + drff->report->field[0]->value[1] = 0x00; + drff->report->field[0]->value[2] = weak; + drff->report->field[0]->value[4] = strong; + hid_hw_request(hid, drff->report, HID_REQ_SET_REPORT); + + drff->report->field[0]->value[0] = 0xfa; + drff->report->field[0]->value[1] = 0xfe; + } else { + drff->report->field[0]->value[0] = 0xf3; + drff->report->field[0]->value[1] = 0x00; + } + + drff->report->field[0]->value[2] = 0x00; + drff->report->field[0]->value[4] = 0x00; + dbg_hid("running with 0x%02x 0x%02x", strong, weak); + hid_hw_request(hid, drff->report, HID_REQ_SET_REPORT); + + return 0; +} + +static int dr_input_configured(struct hid_device *hid, struct hid_input *hidinput) +{ + struct drff_device *drff; + struct hid_report *report; + struct list_head *report_list = + &hid->report_enum[HID_OUTPUT_REPORT].report_list; + struct input_dev *dev = hidinput->input; + int error; + + if (!list_is_first(&hidinput->list, &hid->inputs)) + return 0; + + if (hid->product != 0x0006) + return 0; + + report = list_first_entry_or_null(report_list, struct hid_report, list); + if (!report) { + hid_err(hid, "no output reports found\n"); + return -ENODEV; + } + if (report->maxfield < 1) { + hid_err(hid, "no fields in the report\n"); + return -ENODEV; + } + + if (report->field[0]->report_count < 7) { + hid_err(hid, "not enough values in the field\n"); + return -ENODEV; + } + + drff = kzalloc_obj(struct drff_device); + if (!drff) + return -ENOMEM; + + drff->report = report; + set_bit(FF_RUMBLE, dev->ffbit); + + error = input_ff_create_memless(dev, drff, drff_play); + if (error) { + kfree(drff); + return error; + } + + drff->report->field[0]->value[0] = 0xf3; + drff->report->field[0]->value[1] = 0x00; + drff->report->field[0]->value[2] = 0x00; + drff->report->field[0]->value[3] = 0x00; + drff->report->field[0]->value[4] = 0x00; + drff->report->field[0]->value[5] = 0x00; + drff->report->field[0]->value[6] = 0x00; + hid_hw_request(hid, drff->report, HID_REQ_SET_REPORT); + + hid_info(hid, "Force Feedback for DragonRise Inc. " + "game controllers by Richard Walmsley \n"); + + return 0; +} +#else +static inline int dr_input_configured(struct hid_device *hid, + struct hid_input *hidinput) +{ + return 0; +} +#endif + +/* + * The original descriptor of joystick with PID 0x0011, represented by DVTech PC + * JS19. It seems both copied from another device and a result of confusion + * either about the specification or about the program used to create the + * descriptor. In any case, it's a wonder it works on Windows. + * + * Usage Page (Desktop), ; Generic desktop controls (01h) + * Usage (Joystick), ; Joystick (04h, application collection) + * Collection (Application), + * Collection (Logical), + * Report Size (8), + * Report Count (5), + * Logical Minimum (0), + * Logical Maximum (255), + * Physical Minimum (0), + * Physical Maximum (255), + * Usage (X), ; X (30h, dynamic value) + * Usage (X), ; X (30h, dynamic value) + * Usage (X), ; X (30h, dynamic value) + * Usage (X), ; X (30h, dynamic value) + * Usage (Y), ; Y (31h, dynamic value) + * Input (Variable), + * Report Size (4), + * Report Count (1), + * Logical Maximum (7), + * Physical Maximum (315), + * Unit (Degrees), + * Usage (00h), + * Input (Variable, Null State), + * Unit, + * Report Size (1), + * Report Count (10), + * Logical Maximum (1), + * Physical Maximum (1), + * Usage Page (Button), ; Button (09h) + * Usage Minimum (01h), + * Usage Maximum (0Ah), + * Input (Variable), + * Usage Page (FF00h), ; FF00h, vendor-defined + * Report Size (1), + * Report Count (10), + * Logical Maximum (1), + * Physical Maximum (1), + * Usage (01h), + * Input (Variable), + * End Collection, + * Collection (Logical), + * Report Size (8), + * Report Count (4), + * Physical Maximum (255), + * Logical Maximum (255), + * Usage (02h), + * Output (Variable), + * End Collection, + * End Collection + */ + +/* Size of the original descriptor of the PID 0x0011 joystick */ +#define PID0011_RDESC_ORIG_SIZE 101 + +/* Fixed report descriptor for PID 0x011 joystick */ +static const __u8 pid0011_rdesc_fixed[] = { + 0x05, 0x01, /* Usage Page (Desktop), */ + 0x09, 0x04, /* Usage (Joystick), */ + 0xA1, 0x01, /* Collection (Application), */ + 0xA1, 0x02, /* Collection (Logical), */ + 0x14, /* Logical Minimum (0), */ + 0x75, 0x08, /* Report Size (8), */ + 0x95, 0x03, /* Report Count (3), */ + 0x81, 0x01, /* Input (Constant), */ + 0x26, 0xFF, 0x00, /* Logical Maximum (255), */ + 0x95, 0x02, /* Report Count (2), */ + 0x09, 0x30, /* Usage (X), */ + 0x09, 0x31, /* Usage (Y), */ + 0x81, 0x02, /* Input (Variable), */ + 0x75, 0x01, /* Report Size (1), */ + 0x95, 0x04, /* Report Count (4), */ + 0x81, 0x01, /* Input (Constant), */ + 0x25, 0x01, /* Logical Maximum (1), */ + 0x95, 0x0A, /* Report Count (10), */ + 0x05, 0x09, /* Usage Page (Button), */ + 0x19, 0x01, /* Usage Minimum (01h), */ + 0x29, 0x0A, /* Usage Maximum (0Ah), */ + 0x81, 0x02, /* Input (Variable), */ + 0x95, 0x0A, /* Report Count (10), */ + 0x81, 0x01, /* Input (Constant), */ + 0xC0, /* End Collection, */ + 0xC0 /* End Collection */ +}; + +static const __u8 *dr_report_fixup(struct hid_device *hdev, __u8 *rdesc, + unsigned int *rsize) +{ + switch (hdev->product) { + case 0x0011: + if (*rsize == PID0011_RDESC_ORIG_SIZE) { + *rsize = sizeof(pid0011_rdesc_fixed); + return pid0011_rdesc_fixed; + } + break; + } + return rdesc; +} + +#define map_abs(c) hid_map_usage(hi, usage, bit, max, EV_ABS, (c)) +#define map_rel(c) hid_map_usage(hi, usage, bit, max, EV_REL, (c)) + +static int dr_input_mapping(struct hid_device *hdev, struct hid_input *hi, + struct hid_field *field, struct hid_usage *usage, + unsigned long **bit, int *max) +{ + switch (usage->hid) { + /* + * revert to the old hid-input behavior where axes + * can be randomly assigned when hid->usage is reused. + */ + case HID_GD_X: case HID_GD_Y: case HID_GD_Z: + case HID_GD_RX: case HID_GD_RY: case HID_GD_RZ: + if (field->flags & HID_MAIN_ITEM_RELATIVE) + map_rel(usage->hid & 0xf); + else + map_abs(usage->hid & 0xf); + return 1; + } + + return 0; +} + +static const struct hid_device_id dr_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, 0x0006), }, + { HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, 0x0011), }, + { } +}; +MODULE_DEVICE_TABLE(hid, dr_devices); + +static struct hid_driver dr_driver = { + .name = "dragonrise", + .id_table = dr_devices, + .report_fixup = dr_report_fixup, + .input_mapping = dr_input_mapping, + .input_configured = dr_input_configured, +}; +module_hid_driver(dr_driver); + +MODULE_DESCRIPTION("Force feedback support for DragonRise Inc. game controllers"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1