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 --- drivers/net/wireguard/allowedips.h | 63 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 drivers/net/wireguard/allowedips.h (limited to 'drivers/net/wireguard/allowedips.h') diff --git a/drivers/net/wireguard/allowedips.h b/drivers/net/wireguard/allowedips.h new file mode 100644 index 000000000..931958cb6 --- /dev/null +++ b/drivers/net/wireguard/allowedips.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2015-2019 Jason A. Donenfeld . All Rights Reserved. + */ + +#ifndef _WG_ALLOWEDIPS_H +#define _WG_ALLOWEDIPS_H + +#include +#include +#include + +struct wg_peer; + +struct allowedips_node { + struct wg_peer __rcu *peer; + struct allowedips_node __rcu *bit[2]; + u8 cidr, bit_at_a, bit_at_b, bitlen; + u8 bits[16] __aligned(__alignof(u64)); + + /* Keep rarely used members at bottom to be beyond cache line. */ + unsigned long parent_bit_packed; + union { + struct list_head peer_list; + struct rcu_head rcu; + }; +}; + +struct allowedips { + struct allowedips_node __rcu *root4; + struct allowedips_node __rcu *root6; + u64 seq; +} __aligned(4); /* We pack the lower 2 bits of &root, but m68k only gives 16-bit alignment. */ + +void wg_allowedips_init(struct allowedips *table); +void wg_allowedips_free(struct allowedips *table, struct mutex *mutex); +int wg_allowedips_insert_v4(struct allowedips *table, const struct in_addr *ip, + u8 cidr, struct wg_peer *peer, struct mutex *lock); +int wg_allowedips_insert_v6(struct allowedips *table, const struct in6_addr *ip, + u8 cidr, struct wg_peer *peer, struct mutex *lock); +int wg_allowedips_remove_v4(struct allowedips *table, const struct in_addr *ip, + u8 cidr, struct wg_peer *peer, struct mutex *lock); +int wg_allowedips_remove_v6(struct allowedips *table, const struct in6_addr *ip, + u8 cidr, struct wg_peer *peer, struct mutex *lock); +void wg_allowedips_remove_by_peer(struct allowedips *table, + struct wg_peer *peer, struct mutex *lock); +/* The ip input pointer should be __aligned(__alignof(u64))) */ +int wg_allowedips_read_node(struct allowedips_node *node, u8 ip[16], u8 *cidr); + +/* These return a strong reference to a peer: */ +struct wg_peer *wg_allowedips_lookup_dst(struct allowedips *table, + struct sk_buff *skb); +struct wg_peer *wg_allowedips_lookup_src(struct allowedips *table, + struct sk_buff *skb); + +#ifdef DEBUG +bool wg_allowedips_selftest(void); +#endif + +int wg_allowedips_slab_init(void); +void wg_allowedips_slab_uninit(void); + +#endif /* _WG_ALLOWEDIPS_H */ -- cgit v1.3.1