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 --- include/video/hecubafb.h | 51 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 include/video/hecubafb.h (limited to 'include/video/hecubafb.h') diff --git a/include/video/hecubafb.h b/include/video/hecubafb.h new file mode 100644 index 000000000..7b9952339 --- /dev/null +++ b/include/video/hecubafb.h @@ -0,0 +1,51 @@ +/* + * hecubafb.h - definitions for the hecuba framebuffer driver + * + * Copyright (C) 2008 by Jaya Kumar + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive for + * more details. + * + */ + +#ifndef _LINUX_HECUBAFB_H_ +#define _LINUX_HECUBAFB_H_ + +/* Apollo controller specific defines */ +#define APOLLO_START_NEW_IMG 0xA0 +#define APOLLO_STOP_IMG_DATA 0xA1 +#define APOLLO_DISPLAY_IMG 0xA2 +#define APOLLO_ERASE_DISPLAY 0xA3 +#define APOLLO_INIT_DISPLAY 0xA4 + +/* Hecuba interface specific defines */ +#define HCB_WUP_BIT 0x01 +#define HCB_DS_BIT 0x02 +#define HCB_RW_BIT 0x04 +#define HCB_CD_BIT 0x08 +#define HCB_ACK_BIT 0x80 + +/* struct used by hecuba. board specific stuff comes from *board */ +struct hecubafb_par { + struct fb_info *info; + struct hecuba_board *board; + void (*send_command)(struct hecubafb_par *, unsigned char); + void (*send_data)(struct hecubafb_par *, unsigned char); +}; + +/* board specific routines +board drivers can implement wait_for_ack with interrupts if desired. if +wait_for_ack is called with clear=0, then go to sleep and return when ack +goes hi or if wait_for_ack with clear=1, then return when ack goes lo */ +struct hecuba_board { + struct module *owner; + void (*remove)(struct hecubafb_par *); + void (*set_ctl)(struct hecubafb_par *, unsigned char, unsigned char); + void (*set_data)(struct hecubafb_par *, unsigned char); + void (*wait_for_ack)(struct hecubafb_par *, int); + int (*init)(struct hecubafb_par *); +}; + + +#endif -- cgit v1.3.1