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 --- io_uring/rw.h | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 io_uring/rw.h (limited to 'io_uring/rw.h') diff --git a/io_uring/rw.h b/io_uring/rw.h new file mode 100644 index 000000000..9bd7fbf70 --- /dev/null +++ b/io_uring/rw.h @@ -0,0 +1,52 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +struct io_meta_state { + u32 seed; + struct iov_iter_state iter_meta; +}; + +struct io_async_rw { + struct iou_vec vec; + size_t bytes_done; + + struct_group(clear, + struct iov_iter iter; + struct iov_iter_state iter_state; + struct iovec fast_iov; + unsigned buf_group; + + /* + * wpq is for buffered io, while meta fields are used with + * direct io + */ + union { + struct wait_page_queue wpq; + struct { + struct uio_meta meta; + struct io_meta_state meta_state; + }; + }; + ); +}; + +int io_prep_read_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_write_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_readv_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_writev_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_readv(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_writev(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_read(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_write(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_read(struct io_kiocb *req, unsigned int issue_flags); +int io_write(struct io_kiocb *req, unsigned int issue_flags); +int io_read_fixed(struct io_kiocb *req, unsigned int issue_flags); +int io_write_fixed(struct io_kiocb *req, unsigned int issue_flags); +void io_readv_writev_cleanup(struct io_kiocb *req); +void io_rw_fail(struct io_kiocb *req); +void io_req_rw_complete(struct io_tw_req tw_req, io_tw_token_t tw); +int io_read_mshot_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags); +void io_rw_cache_free(const void *entry); -- cgit v1.3.1