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 --- net/mptcp/token_test.c | 151 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 151 insertions(+) create mode 100644 net/mptcp/token_test.c (limited to 'net/mptcp/token_test.c') diff --git a/net/mptcp/token_test.c b/net/mptcp/token_test.c new file mode 100644 index 000000000..4fc39fa2e --- /dev/null +++ b/net/mptcp/token_test.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0 +#include + +#include "protocol.h" + +static struct mptcp_subflow_request_sock *build_req_sock(struct kunit *test) +{ + struct mptcp_subflow_request_sock *req; + + req = kunit_kzalloc(test, sizeof(struct mptcp_subflow_request_sock), + GFP_USER); + KUNIT_EXPECT_NOT_ERR_OR_NULL(test, req); + mptcp_token_init_request((struct request_sock *)req); + sock_net_set((struct sock *)req, &init_net); + return req; +} + +static void mptcp_token_test_req_basic(struct kunit *test) +{ + struct mptcp_subflow_request_sock *req = build_req_sock(test); + struct mptcp_sock *null_msk = NULL; + + KUNIT_ASSERT_EQ(test, 0, + mptcp_token_new_request((struct request_sock *)req)); + KUNIT_EXPECT_NE(test, 0, (int)req->token); + KUNIT_EXPECT_PTR_EQ(test, null_msk, mptcp_token_get_sock(&init_net, req->token)); + + /* cleanup */ + mptcp_token_destroy_request((struct request_sock *)req); +} + +static struct inet_connection_sock *build_icsk(struct kunit *test) +{ + struct inet_connection_sock *icsk; + + icsk = kunit_kzalloc(test, sizeof(struct inet_connection_sock), + GFP_USER); + KUNIT_EXPECT_NOT_ERR_OR_NULL(test, icsk); + return icsk; +} + +static struct mptcp_subflow_context *build_ctx(struct kunit *test) +{ + struct mptcp_subflow_context *ctx; + + ctx = kunit_kzalloc(test, sizeof(struct mptcp_subflow_context), + GFP_USER); + KUNIT_EXPECT_NOT_ERR_OR_NULL(test, ctx); + return ctx; +} + +static struct mptcp_sock *build_msk(struct kunit *test) +{ + struct mptcp_sock *msk; + struct sock *sk; + + msk = kunit_kzalloc(test, sizeof(struct mptcp_sock), GFP_USER); + KUNIT_EXPECT_NOT_ERR_OR_NULL(test, msk); + refcount_set(&((struct sock *)msk)->sk_refcnt, 1); + sock_net_set((struct sock *)msk, &init_net); + + sk = (struct sock *)msk; + + /* be sure the token helpers can dereference sk->sk_prot */ + sk->sk_prot = &tcp_prot; + sk->sk_protocol = IPPROTO_MPTCP; + + return msk; +} + +static void mptcp_token_test_msk_basic(struct kunit *test) +{ + struct inet_connection_sock *icsk = build_icsk(test); + struct mptcp_subflow_context *ctx = build_ctx(test); + struct mptcp_sock *msk = build_msk(test); + struct mptcp_sock *null_msk = NULL; + struct sock *sk; + + rcu_assign_pointer(icsk->icsk_ulp_data, ctx); + ctx->conn = (struct sock *)msk; + sk = (struct sock *)msk; + + KUNIT_ASSERT_EQ(test, 0, + mptcp_token_new_connect((struct sock *)icsk)); + KUNIT_EXPECT_NE(test, 0, (int)ctx->token); + KUNIT_EXPECT_EQ(test, ctx->token, msk->token); + KUNIT_EXPECT_PTR_EQ(test, msk, mptcp_token_get_sock(&init_net, ctx->token)); + KUNIT_EXPECT_EQ(test, 2, (int)refcount_read(&sk->sk_refcnt)); + + mptcp_token_destroy(msk); + KUNIT_EXPECT_PTR_EQ(test, null_msk, mptcp_token_get_sock(&init_net, ctx->token)); +} + +static void mptcp_token_test_accept(struct kunit *test) +{ + struct mptcp_subflow_request_sock *req = build_req_sock(test); + struct mptcp_sock *msk = build_msk(test); + + KUNIT_ASSERT_EQ(test, 0, + mptcp_token_new_request((struct request_sock *)req)); + msk->token = req->token; + mptcp_token_accept(req, msk); + KUNIT_EXPECT_PTR_EQ(test, msk, mptcp_token_get_sock(&init_net, msk->token)); + + /* this is now a no-op */ + mptcp_token_destroy_request((struct request_sock *)req); + KUNIT_EXPECT_PTR_EQ(test, msk, mptcp_token_get_sock(&init_net, msk->token)); + + /* cleanup */ + mptcp_token_destroy(msk); +} + +static void mptcp_token_test_destroyed(struct kunit *test) +{ + struct mptcp_subflow_request_sock *req = build_req_sock(test); + struct mptcp_sock *msk = build_msk(test); + struct mptcp_sock *null_msk = NULL; + struct sock *sk; + + sk = (struct sock *)msk; + + KUNIT_ASSERT_EQ(test, 0, + mptcp_token_new_request((struct request_sock *)req)); + msk->token = req->token; + mptcp_token_accept(req, msk); + + /* simulate race on removal */ + refcount_set(&sk->sk_refcnt, 0); + KUNIT_EXPECT_PTR_EQ(test, null_msk, mptcp_token_get_sock(&init_net, msk->token)); + + /* cleanup */ + mptcp_token_destroy(msk); +} + +static struct kunit_case mptcp_token_test_cases[] = { + KUNIT_CASE(mptcp_token_test_req_basic), + KUNIT_CASE(mptcp_token_test_msk_basic), + KUNIT_CASE(mptcp_token_test_accept), + KUNIT_CASE(mptcp_token_test_destroyed), + {} +}; + +static struct kunit_suite mptcp_token_suite = { + .name = "mptcp-token", + .test_cases = mptcp_token_test_cases, +}; + +kunit_test_suite(mptcp_token_suite); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("KUnit tests for MPTCP Token"); -- cgit v1.3.1