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 --- tools/perf/util/maps.h | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 tools/perf/util/maps.h (limited to 'tools/perf/util/maps.h') diff --git a/tools/perf/util/maps.h b/tools/perf/util/maps.h new file mode 100644 index 000000000..4ec9b7453 --- /dev/null +++ b/tools/perf/util/maps.h @@ -0,0 +1,88 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PERF_MAPS_H +#define __PERF_MAPS_H + +#include +#include +#include +#include + +struct ref_reloc_sym; +struct machine; +struct map; +struct maps; + +#define KMAP_NAME_LEN 256 + +struct kmap { + struct ref_reloc_sym *ref_reloc_sym; + struct maps *kmaps; + char name[KMAP_NAME_LEN]; +}; + +struct maps *maps__new(struct machine *machine); +bool maps__empty(struct maps *maps); +int maps__copy_from(struct maps *maps, struct maps *parent); + +struct maps *maps__get(struct maps *maps); +void maps__put(struct maps *maps); + +static inline void __maps__zput(struct maps **map) +{ + maps__put(*map); + *map = NULL; +} + +#define maps__zput(map) __maps__zput(&map) + +bool maps__equal(struct maps *a, struct maps *b); + +/* Iterate over map calling cb for each entry. */ +int maps__for_each_map(struct maps *maps, int (*cb)(struct map *map, void *data), void *data); +/* Iterate over map removing an entry if cb returns true. */ +void maps__remove_maps(struct maps *maps, bool (*cb)(struct map *map, void *data), void *data); + +struct machine *maps__machine(const struct maps *maps); +unsigned int maps__nr_maps(const struct maps *maps); /* Test only. */ +refcount_t *maps__refcnt(struct maps *maps); /* Test only. */ + +#ifdef HAVE_LIBUNWIND_SUPPORT +void *maps__addr_space(const struct maps *maps); +void maps__set_addr_space(struct maps *maps, void *addr_space); +uint16_t maps__e_machine(const struct maps *maps); +void maps__set_e_machine(struct maps *maps, uint16_t e_machine); +#endif +#ifdef HAVE_LIBDW_SUPPORT +void *maps__libdw_addr_space_dwfl(const struct maps *maps); +void maps__set_libdw_addr_space_dwfl(struct maps *maps, void *dwfl); +#endif + +size_t maps__fprintf(struct maps *maps, FILE *fp); + +int maps__load_maps(struct maps *maps); +int maps__insert(struct maps *maps, struct map *map); +void maps__remove(struct maps *maps, struct map *map); +int maps__mutate_mapping(struct maps *maps, struct map *map, + int (*mutate_cb)(struct map *map, void *data), void *data); + +struct map *maps__find(struct maps *maps, u64 addr); +struct symbol *maps__find_symbol(struct maps *maps, u64 addr, struct map **mapp); +struct symbol *maps__find_symbol_by_name(struct maps *maps, const char *name, struct map **mapp); + +struct addr_map_symbol; + +int maps__find_ams(struct maps *maps, struct addr_map_symbol *ams); + +int maps__fixup_overlap_and_insert(struct maps *maps, struct map *new); + +struct map *maps__find_by_name(struct maps *maps, const char *name); + +struct map *maps__find_next_entry(struct maps *maps, struct map *map); + +int maps__merge_in(struct maps *kmaps, struct map *new_map); + +void maps__fixup_end(struct maps *maps); + +void maps__load_first(struct maps *maps); + +#endif // __PERF_MAPS_H -- cgit v1.3.1