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/uapi/asm-generic/signal.h | 93 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 include/uapi/asm-generic/signal.h (limited to 'include/uapi/asm-generic/signal.h') diff --git a/include/uapi/asm-generic/signal.h b/include/uapi/asm-generic/signal.h new file mode 100644 index 000000000..0eb69dc8e --- /dev/null +++ b/include/uapi/asm-generic/signal.h @@ -0,0 +1,93 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef _UAPI__ASM_GENERIC_SIGNAL_H +#define _UAPI__ASM_GENERIC_SIGNAL_H + +#include + +#define _NSIG 64 +#define _NSIG_BPW __BITS_PER_LONG +#define _NSIG_WORDS (_NSIG / _NSIG_BPW) + +#define SIGHUP 1 +#define SIGINT 2 +#define SIGQUIT 3 +#define SIGILL 4 +#define SIGTRAP 5 +#define SIGABRT 6 +#define SIGIOT 6 +#define SIGBUS 7 +#define SIGFPE 8 +#define SIGKILL 9 +#define SIGUSR1 10 +#define SIGSEGV 11 +#define SIGUSR2 12 +#define SIGPIPE 13 +#define SIGALRM 14 +#define SIGTERM 15 +#define SIGSTKFLT 16 +#define SIGCHLD 17 +#define SIGCONT 18 +#define SIGSTOP 19 +#define SIGTSTP 20 +#define SIGTTIN 21 +#define SIGTTOU 22 +#define SIGURG 23 +#define SIGXCPU 24 +#define SIGXFSZ 25 +#define SIGVTALRM 26 +#define SIGPROF 27 +#define SIGWINCH 28 +#define SIGIO 29 +#define SIGPOLL SIGIO +/* +#define SIGLOST 29 +*/ +#define SIGPWR 30 +#define SIGSYS 31 +#define SIGUNUSED 31 + +/* These should not be considered constants from userland. */ +#define SIGRTMIN 32 +#ifndef SIGRTMAX +#define SIGRTMAX _NSIG +#endif + +#if !defined MINSIGSTKSZ || !defined SIGSTKSZ +#define MINSIGSTKSZ 2048 +#define SIGSTKSZ 8192 +#endif + +#ifndef __ASSEMBLY__ +typedef struct { + unsigned long sig[_NSIG_WORDS]; +} sigset_t; + +/* not actually used, but required for linux/syscalls.h */ +typedef unsigned long old_sigset_t; + +#include + +#ifdef SA_RESTORER +#define __ARCH_HAS_SA_RESTORER +#endif + +#ifndef __KERNEL__ +struct sigaction { + __sighandler_t sa_handler; + unsigned long sa_flags; +#ifdef SA_RESTORER + __sigrestore_t sa_restorer; +#endif + sigset_t sa_mask; /* mask last for extensibility */ +}; +#endif + +typedef struct sigaltstack { + void __user *ss_sp; + int ss_flags; + __kernel_size_t ss_size; +} stack_t; + +#endif /* __ASSEMBLY__ */ + +#endif /* _UAPI__ASM_GENERIC_SIGNAL_H */ -- cgit v1.3.1