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 --- scripts/dtc/srcpos.h | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 scripts/dtc/srcpos.h (limited to 'scripts/dtc/srcpos.h') diff --git a/scripts/dtc/srcpos.h b/scripts/dtc/srcpos.h new file mode 100644 index 000000000..4d60b50e3 --- /dev/null +++ b/scripts/dtc/srcpos.h @@ -0,0 +1,104 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright 2007 Jon Loeliger, Freescale Semiconductor, Inc. + */ + +#ifndef SRCPOS_H +#define SRCPOS_H + +#include +#include +#include "util.h" + +struct srcfile_state { + FILE *f; + char *name; + char *dir; + int lineno, colno; + struct srcfile_state *prev; +}; + +extern FILE *depfile; /* = NULL */ +extern struct srcfile_state *current_srcfile; /* = NULL */ + +/** + * Open a source file. + * + * If the source file is a relative pathname, then it is searched for in the + * current directory (the directory of the last source file read) and after + * that in the search path. + * + * We work through the search path in order from the first path specified to + * the last. + * + * If the file is not found, then this function does not return, but calls + * die(). + * + * @param fname Filename to search + * @param fullnamep If non-NULL, it is set to the allocated filename of the + * file that was opened. The caller is then responsible + * for freeing the pointer. + * @return pointer to opened FILE + */ +FILE *srcfile_relative_open(const char *fname, char **fullnamep); + +void srcfile_push(const char *fname); +bool srcfile_pop(void); + +/** + * Add a new directory to the search path for input files + * + * The new path is added at the end of the list. + * + * @param dirname Directory to add + */ +void srcfile_add_search_path(const char *dirname); + +struct srcpos { + int first_line; + int first_column; + int last_line; + int last_column; + struct srcfile_state *file; + struct srcpos *next; +}; + +#define YYLTYPE struct srcpos + +#define YYLLOC_DEFAULT(Current, Rhs, N) \ + do { \ + if (N) { \ + (Current).first_line = YYRHSLOC(Rhs, 1).first_line; \ + (Current).first_column = YYRHSLOC(Rhs, 1).first_column; \ + (Current).last_line = YYRHSLOC(Rhs, N).last_line; \ + (Current).last_column = YYRHSLOC (Rhs, N).last_column; \ + (Current).file = YYRHSLOC(Rhs, N).file; \ + } else { \ + (Current).first_line = (Current).last_line = \ + YYRHSLOC(Rhs, 0).last_line; \ + (Current).first_column = (Current).last_column = \ + YYRHSLOC(Rhs, 0).last_column; \ + (Current).file = YYRHSLOC (Rhs, 0).file; \ + } \ + (Current).next = NULL; \ + } while (0) + + +extern void srcpos_update(struct srcpos *pos, const char *text, int len); +extern struct srcpos *srcpos_copy(struct srcpos *pos); +extern struct srcpos *srcpos_extend(struct srcpos *new_srcpos, + struct srcpos *old_srcpos); +extern void srcpos_free(struct srcpos *pos); +extern char *srcpos_string(struct srcpos *pos); +extern char *srcpos_string_first(struct srcpos *pos, int level); +extern char *srcpos_string_last(struct srcpos *pos, int level); + + +extern void PRINTF(3, 0) srcpos_verror(struct srcpos *pos, const char *prefix, + const char *fmt, va_list va); +extern void PRINTF(3, 4) srcpos_error(struct srcpos *pos, const char *prefix, + const char *fmt, ...); + +extern void srcpos_set_line(char *f, int l); + +#endif /* SRCPOS_H */ -- cgit v1.3.1