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 --- fs/sysfs/sysfs.h | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 fs/sysfs/sysfs.h (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h new file mode 100644 index 000000000..f4583dcaf --- /dev/null +++ b/fs/sysfs/sysfs.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * fs/sysfs/sysfs.h - sysfs internal header file + * + * Copyright (c) 2001-3 Patrick Mochel + * Copyright (c) 2007 SUSE Linux Products GmbH + * Copyright (c) 2007 Tejun Heo + */ + +#ifndef __SYSFS_INTERNAL_H +#define __SYSFS_INTERNAL_H + +#include + +/* + * mount.c + */ +extern struct kernfs_node *sysfs_root_kn; + +/* + * dir.c + */ +extern spinlock_t sysfs_symlink_target_lock; + +void sysfs_warn_dup(struct kernfs_node *parent, const char *name); + +/* + * file.c + */ +int sysfs_add_file_mode_ns(struct kernfs_node *parent, + const struct attribute *attr, umode_t amode, kuid_t uid, + kgid_t gid, const struct ns_common *ns); +int sysfs_add_bin_file_mode_ns(struct kernfs_node *parent, + const struct bin_attribute *battr, umode_t mode, size_t size, + kuid_t uid, kgid_t gid, const struct ns_common *ns); + +/* + * symlink.c + */ +int sysfs_create_link_sd(struct kernfs_node *kn, struct kobject *target, + const char *name); + +#endif /* __SYSFS_INTERNAL_H */ -- cgit v1.3.1