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/maxinefb.h | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 include/video/maxinefb.h (limited to 'include/video/maxinefb.h') diff --git a/include/video/maxinefb.h b/include/video/maxinefb.h new file mode 100644 index 000000000..6aeb4acca --- /dev/null +++ b/include/video/maxinefb.h @@ -0,0 +1,38 @@ +/* + * linux/drivers/video/maxinefb.h + * + * DECstation 5000/xx onboard framebuffer support, Copyright (C) 1999 by + * Michael Engel and Karsten Merker + * 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. + */ + +#include + +/* + * IMS332 video controller register base address + */ +#define MAXINEFB_IMS332_ADDRESS KSEG1ADDR(0x1c140000) + +/* + * Begin of DECstation 5000/xx onboard framebuffer memory, default resolution + * is 1024x768x8 + */ +#define DS5000_xx_ONBOARD_FBMEM_START KSEG1ADDR(0x0a000000) + +/* + * The IMS 332 video controller used in the DECstation 5000/xx series + * uses 32 bits wide registers; the following defines declare the + * register numbers, to get the real offset, these have to be multiplied + * by four. + */ + +#define IMS332_REG_CURSOR_RAM 0x200 /* hardware cursor bitmap */ + +/* + * The color palette entries have the form 0x00BBGGRR + */ +#define IMS332_REG_COLOR_PALETTE 0x100 /* color palette, 256 entries */ +#define IMS332_REG_CURSOR_COLOR_PALETTE 0x0a1 /* cursor color palette, */ + /* 3 entries */ -- cgit v1.3.1