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/sa1100fb.h | 63 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 include/video/sa1100fb.h (limited to 'include/video/sa1100fb.h') diff --git a/include/video/sa1100fb.h b/include/video/sa1100fb.h new file mode 100644 index 000000000..4ab409653 --- /dev/null +++ b/include/video/sa1100fb.h @@ -0,0 +1,63 @@ +/* + * StrongARM 1100 LCD Controller Frame Buffer Device + * + * Copyright (C) 1999 Eric A. Thomas + * Based on acornfb.c Copyright (C) Russell King. + * + * 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 _VIDEO_SA1100FB_H +#define _VIDEO_SA1100FB_H + +#include +#include + +#define RGB_4 0 +#define RGB_8 1 +#define RGB_16 2 +#define NR_RGB 3 + +/* These are the bitfields for each display depth that we support. */ +struct sa1100fb_rgb { + struct fb_bitfield red; + struct fb_bitfield green; + struct fb_bitfield blue; + struct fb_bitfield transp; +}; + +/* This structure describes the machine which we are running on. */ +struct sa1100fb_mach_info { + u_long pixclock; + + u_short xres; + u_short yres; + + u_char bpp; + u_char hsync_len; + u_char left_margin; + u_char right_margin; + + u_char vsync_len; + u_char upper_margin; + u_char lower_margin; + u_char sync; + + u_int cmap_greyscale:1, + cmap_inverse:1, + cmap_static:1, + unused:29; + + u_int lccr0; + u_int lccr3; + + /* Overrides for the default RGB maps */ + const struct sa1100fb_rgb *rgb[NR_RGB]; + + void (*backlight_power)(int); + void (*lcd_power)(int); + void (*set_visual)(u32); +}; + +#endif -- cgit v1.3.1