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/cvisionppc.h | 51 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 include/video/cvisionppc.h (limited to 'include/video/cvisionppc.h') diff --git a/include/video/cvisionppc.h b/include/video/cvisionppc.h new file mode 100644 index 000000000..11250eee9 --- /dev/null +++ b/include/video/cvisionppc.h @@ -0,0 +1,51 @@ +/* + * Phase5 CybervisionPPC (TVP4020) definitions for the Permedia2 framebuffer + * driver. + * + * Copyright (c) 1998-1999 Ilario Nardinocchi (nardinoc@CS.UniBO.IT) + * -------------------------------------------------------------------------- + * $Id: cvisionppc.h,v 1.8 1999/01/28 13:18:07 illo Exp $ + * -------------------------------------------------------------------------- + * 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 CVISIONPPC_H +#define CVISIONPPC_H + +#ifndef PM2FB_H +#include "pm2fb.h" +#endif + +struct cvppc_par { + unsigned char* pci_config; + unsigned char* pci_bridge; + u32 user_flags; +}; + +#define CSPPC_PCI_BRIDGE 0xfffe0000 +#define CSPPC_BRIDGE_ENDIAN 0x0000 +#define CSPPC_BRIDGE_INT 0x0010 + +#define CVPPC_PCI_CONFIG 0xfffc0000 +#define CVPPC_ROM_ADDRESS 0xe2000001 +#define CVPPC_REGS_REGION 0xef000000 +#define CVPPC_FB_APERTURE_ONE 0xe0000000 +#define CVPPC_FB_APERTURE_TWO 0xe1000000 +#define CVPPC_FB_SIZE 0x00800000 +#define CVPPC_MEM_CONFIG_OLD 0xed61fcaa /* FIXME Fujitsu?? */ +#define CVPPC_MEM_CONFIG_NEW 0xed41c532 /* FIXME USA?? */ +#define CVPPC_MEMCLOCK 83000 /* in KHz */ + +/* CVPPC_BRIDGE_ENDIAN */ +#define CSPPCF_BRIDGE_BIG_ENDIAN 0x02 + +/* CVPPC_BRIDGE_INT */ +#define CSPPCF_BRIDGE_ACTIVE_INT2 0x01 + +#endif /* CVISIONPPC_H */ + +/***************************************************************************** + * That's all folks! + *****************************************************************************/ -- cgit v1.3.1