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/dax/bus.h | 79 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 drivers/dax/bus.h (limited to 'drivers/dax/bus.h') diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h new file mode 100644 index 000000000..5909171a4 --- /dev/null +++ b/drivers/dax/bus.h @@ -0,0 +1,79 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */ +#ifndef __DAX_BUS_H__ +#define __DAX_BUS_H__ +#include +#include +#include +#include + +struct dev_dax; +struct resource; +struct dax_device; +struct dax_region; + +/* dax bus specific ioresource flags */ +#define IORESOURCE_DAX_STATIC BIT(0) +#define IORESOURCE_DAX_KMEM BIT(1) + +struct dax_region *alloc_dax_region(struct device *parent, int region_id, + struct range *range, int target_node, unsigned int align, + unsigned long flags); + +struct dev_dax_data { + struct dax_region *dax_region; + struct dev_pagemap *pgmap; + resource_size_t size; + int id; + bool memmap_on_memory; +}; + +struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data); + +enum dax_driver_type { + DAXDRV_KMEM_TYPE, + DAXDRV_DEVICE_TYPE, + DAXDRV_FSDEV_TYPE, +}; + +struct dax_device_driver { + struct device_driver drv; + struct list_head ids; + enum dax_driver_type type; + int (*probe)(struct dev_dax *dev); + void (*remove)(struct dev_dax *dev); +}; + +#define to_dax_drv(__drv) container_of_const(__drv, struct dax_device_driver, drv) + +int __dax_driver_register(struct dax_device_driver *dax_drv, + struct module *module, const char *mod_name); +#define dax_driver_register(driver) \ + __dax_driver_register(driver, THIS_MODULE, KBUILD_MODNAME) +void dax_driver_unregister(struct dax_device_driver *dax_drv); +void kill_dev_dax(struct dev_dax *dev_dax); +bool static_dev_dax(struct dev_dax *dev_dax); + +struct hmem_platform_device { + struct platform_device pdev; + struct work_struct work; + bool did_probe; +}; + +static inline struct hmem_platform_device * +to_hmem_platform_device(struct platform_device *pdev) +{ + return container_of(pdev, struct hmem_platform_device, pdev); +} + +#if IS_ENABLED(CONFIG_DEV_DAX_HMEM) +void dax_hmem_flush_work(void); +#else +static inline void dax_hmem_flush_work(void) { } +#endif + +#define MODULE_ALIAS_DAX_DEVICE(type) \ + MODULE_ALIAS("dax:t" __stringify(type) "*") +#define DAX_DEVICE_MODALIAS_FMT "dax:t%d" + +#endif /* __DAX_BUS_H__ */ -- cgit v1.3.1