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/comedi/comedi_usb.c | 139 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 139 insertions(+) create mode 100644 drivers/comedi/comedi_usb.c (limited to 'drivers/comedi/comedi_usb.c') diff --git a/drivers/comedi/comedi_usb.c b/drivers/comedi/comedi_usb.c new file mode 100644 index 000000000..75d65171c --- /dev/null +++ b/drivers/comedi/comedi_usb.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * comedi_usb.c + * Comedi USB driver specific functions. + * + * COMEDI - Linux Control and Measurement Device Interface + * Copyright (C) 1997-2000 David A. Schleef + */ + +#include +#include + +/** + * comedi_to_usb_interface() - Return USB interface attached to COMEDI device + * @dev: COMEDI device. + * + * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a + * a &struct device embedded in a &struct usb_interface. + * + * Return: Attached USB interface if @dev->hw_dev is non-%NULL. + * Return %NULL if @dev->hw_dev is %NULL. + */ +struct usb_interface *comedi_to_usb_interface(struct comedi_device *dev) +{ + return dev->hw_dev ? to_usb_interface(dev->hw_dev) : NULL; +} +EXPORT_SYMBOL_GPL(comedi_to_usb_interface); + +/** + * comedi_to_usb_dev() - Return USB device attached to COMEDI device + * @dev: COMEDI device. + * + * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a + * a &struct device embedded in a &struct usb_interface. + * + * Return: USB device to which the USB interface belongs if @dev->hw_dev is + * non-%NULL. Return %NULL if @dev->hw_dev is %NULL. + */ +struct usb_device *comedi_to_usb_dev(struct comedi_device *dev) +{ + struct usb_interface *intf = comedi_to_usb_interface(dev); + + return intf ? interface_to_usbdev(intf) : NULL; +} +EXPORT_SYMBOL_GPL(comedi_to_usb_dev); + +/** + * comedi_usb_auto_config() - Configure/probe a USB COMEDI driver + * @intf: USB interface. + * @driver: Registered COMEDI driver. + * @context: Driver specific data, passed to comedi_auto_config(). + * + * Typically called from the usb_driver (*probe) function. Auto-configure a + * COMEDI device, using a pointer to the &struct device embedded in *@intf as + * the hardware device. The @context value gets passed through to @driver's + * "auto_attach" handler. The "auto_attach" handler may call + * comedi_to_usb_interface() on the passed in COMEDI device to recover @intf. + * + * Return: The result of calling comedi_auto_config() (%0 on success, or + * a negative error number on failure). + */ +int comedi_usb_auto_config(struct usb_interface *intf, + struct comedi_driver *driver, + unsigned long context) +{ + return comedi_auto_config(&intf->dev, driver, context); +} +EXPORT_SYMBOL_GPL(comedi_usb_auto_config); + +/** + * comedi_usb_auto_unconfig() - Unconfigure/disconnect a USB COMEDI device + * @intf: USB interface. + * + * Typically called from the usb_driver (*disconnect) function. + * Auto-unconfigure a COMEDI device attached to this USB interface, using a + * pointer to the &struct device embedded in *@intf as the hardware device. + * The COMEDI driver's "detach" handler will be called during unconfiguration + * of the COMEDI device. + * + * Note that the COMEDI device may have already been unconfigured using the + * %COMEDI_DEVCONFIG ioctl, in which case this attempt to unconfigure it + * again should be ignored. + */ +void comedi_usb_auto_unconfig(struct usb_interface *intf) +{ + comedi_auto_unconfig(&intf->dev); +} +EXPORT_SYMBOL_GPL(comedi_usb_auto_unconfig); + +/** + * comedi_usb_driver_register() - Register a USB COMEDI driver + * @comedi_driver: COMEDI driver to be registered. + * @usb_driver: USB driver to be registered. + * + * This function is called from the module_init() of USB COMEDI driver modules + * to register the COMEDI driver and the USB driver. Do not call it directly, + * use the module_comedi_usb_driver() helper macro instead. + * + * Return: %0 on success, or a negative error number on failure. + */ +int comedi_usb_driver_register(struct comedi_driver *comedi_driver, + struct usb_driver *usb_driver) +{ + int ret; + + ret = comedi_driver_register(comedi_driver); + if (ret < 0) + return ret; + + ret = usb_register(usb_driver); + if (ret < 0) { + comedi_driver_unregister(comedi_driver); + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(comedi_usb_driver_register); + +/** + * comedi_usb_driver_unregister() - Unregister a USB COMEDI driver + * @comedi_driver: COMEDI driver to be registered. + * @usb_driver: USB driver to be registered. + * + * This function is called from the module_exit() of USB COMEDI driver modules + * to unregister the USB driver and the COMEDI driver. Do not call it + * directly, use the module_comedi_usb_driver() helper macro instead. + */ +void comedi_usb_driver_unregister(struct comedi_driver *comedi_driver, + struct usb_driver *usb_driver) +{ + usb_deregister(usb_driver); + comedi_driver_unregister(comedi_driver); +} +EXPORT_SYMBOL_GPL(comedi_usb_driver_unregister); + +MODULE_AUTHOR("https://www.comedi.org"); +MODULE_DESCRIPTION("Comedi USB interface module"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1