From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- drivers/hid/hid-elecom.c | 173 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 173 insertions(+) create mode 100644 drivers/hid/hid-elecom.c (limited to 'drivers/hid/hid-elecom.c') diff --git a/drivers/hid/hid-elecom.c b/drivers/hid/hid-elecom.c new file mode 100644 index 000000000..37d88ce57 --- /dev/null +++ b/drivers/hid/hid-elecom.c @@ -0,0 +1,173 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * HID driver for ELECOM devices: + * - BM084 Bluetooth Mouse + * - EX-G Trackballs (M-XT3DRBK, M-XT3URBK, M-XT4DRBK) + * - DEFT Trackballs (M-DT1DRBK, M-DT1URBK, M-DT2DRBK, M-DT2URBK) + * - HUGE Trackballs (M-HT1DRBK, M-HT1URBK) + * - HUGE Plus Trackball (M-HT1MRBK) + * + * Copyright (c) 2010 Richard Nauber + * Copyright (c) 2016 Yuxuan Shui + * Copyright (c) 2017 Diego Elio Pettenò + * Copyright (c) 2017 Alex Manoussakis + * Copyright (c) 2017 Tomasz Kramkowski + * Copyright (c) 2020 YOSHIOKA Takuma + * Copyright (c) 2022 Takahiro Fujii + */ + +/* + */ + +#include +#include +#include + +#include "hid-ids.h" + +/* + * Certain ELECOM mice misreport their button count meaning that they only work + * correctly with the ELECOM mouse assistant software which is unavailable for + * Linux. A four extra INPUT reports and a FEATURE report are described by the + * report descriptor but it does not appear that these enable software to + * control what the extra buttons map to. The only simple and straightforward + * solution seems to involve fixing up the report descriptor. + */ +#define MOUSE_BUTTONS_MAX 8 +static void mouse_button_fixup(struct hid_device *hdev, + __u8 *rdesc, unsigned int rsize, + unsigned int button_bit_count, + unsigned int padding_bit, + unsigned int button_report_size, + unsigned int button_usage_maximum, + int nbuttons) +{ + if (rsize < 32 || rdesc[button_bit_count] != 0x95 || + rdesc[button_report_size] != 0x75 || + rdesc[button_report_size + 1] != 0x01 || + rdesc[button_usage_maximum] != 0x29 || rdesc[padding_bit] != 0x75) + return; + hid_info(hdev, "Fixing up Elecom mouse button count\n"); + nbuttons = clamp(nbuttons, 0, MOUSE_BUTTONS_MAX); + rdesc[button_bit_count + 1] = nbuttons; + rdesc[button_usage_maximum + 1] = nbuttons; + rdesc[padding_bit + 1] = MOUSE_BUTTONS_MAX - nbuttons; +} + +static const __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc, + unsigned int *rsize) +{ + switch (hdev->product) { + case USB_DEVICE_ID_ELECOM_BM084: + /* The BM084 Bluetooth mouse includes a non-existing horizontal + * wheel in the HID descriptor. */ + if (*rsize >= 48 && rdesc[46] == 0x05 && rdesc[47] == 0x0c) { + hid_info(hdev, "Fixing up Elecom BM084 report descriptor\n"); + rdesc[47] = 0x00; + } + break; + case USB_DEVICE_ID_ELECOM_M_XGL20DLBK: + /* + * Report descriptor format: + * 20: button bit count + * 28: padding bit count + * 22: button report size + * 14: button usage maximum + */ + mouse_button_fixup(hdev, rdesc, *rsize, 20, 28, 22, 14, 8); + break; + case USB_DEVICE_ID_ELECOM_M_XT3URBK_00FB: + case USB_DEVICE_ID_ELECOM_M_XT3URBK_018F: + case USB_DEVICE_ID_ELECOM_M_XT3DRBK_00FC: + case USB_DEVICE_ID_ELECOM_M_XT4DRBK: + /* + * Report descriptor format: + * 12: button bit count + * 30: padding bit count + * 14: button report size + * 20: button usage maximum + */ + mouse_button_fixup(hdev, rdesc, *rsize, 12, 30, 14, 20, 6); + break; + case USB_DEVICE_ID_ELECOM_M_DT1URBK: + case USB_DEVICE_ID_ELECOM_M_DT1DRBK: + case USB_DEVICE_ID_ELECOM_M_HT1URBK_010C: + case USB_DEVICE_ID_ELECOM_M_HT1URBK_019B: + case USB_DEVICE_ID_ELECOM_M_HT1DRBK_010D: + /* + * Report descriptor format: + * 12: button bit count + * 30: padding bit count + * 14: button report size + * 20: button usage maximum + */ + mouse_button_fixup(hdev, rdesc, *rsize, 12, 30, 14, 20, 8); + break; + case USB_DEVICE_ID_ELECOM_M_XT3DRBK_018C: + /* + * Report descriptor format: + * 22: button bit count + * 30: padding bit count + * 24: button report size + * 16: button usage maximum + */ + mouse_button_fixup(hdev, rdesc, *rsize, 22, 30, 24, 16, 6); + break; + case USB_DEVICE_ID_ELECOM_M_DT2DRBK: + case USB_DEVICE_ID_ELECOM_M_HT1DRBK_011C: + /* + * Report descriptor format: + * 22: button bit count + * 30: padding bit count + * 24: button report size + * 16: button usage maximum + */ + mouse_button_fixup(hdev, rdesc, *rsize, 22, 30, 24, 16, 8); + break; + case USB_DEVICE_ID_ELECOM_M_HT1MRBK: + case USB_DEVICE_ID_ELECOM_M_HT1MRBK_01AB: + case USB_DEVICE_ID_ELECOM_M_HT1MRBK_01AC: + /* + * Report descriptor format: + * 24: button bit count + * 28: padding bit count + * 22: button report size + * 16: button usage maximum + */ + mouse_button_fixup(hdev, rdesc, *rsize, 24, 28, 22, 16, 8); + break; + } + return rdesc; +} + +static const struct hid_device_id elecom_devices[] = { + { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) }, + { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1MRBK_01AC) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XGL20DLBK) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK_00FB) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK_018F) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3DRBK_00FC) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3DRBK_018C) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT4DRBK) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1URBK) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1DRBK) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT2DRBK) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1URBK_010C) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1URBK_019B) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1DRBK_010D) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1DRBK_011C) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1MRBK) }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1MRBK_01AB) }, + { } +}; +MODULE_DEVICE_TABLE(hid, elecom_devices); + +static struct hid_driver elecom_driver = { + .name = "elecom", + .id_table = elecom_devices, + .report_fixup = elecom_report_fixup +}; +module_hid_driver(elecom_driver); + +MODULE_DESCRIPTION("HID driver for ELECOM devices"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1