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/rds/stats.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 155 insertions(+) create mode 100644 net/rds/stats.c (limited to 'net/rds/stats.c') diff --git a/net/rds/stats.c b/net/rds/stats.c new file mode 100644 index 000000000..24ee22d09 --- /dev/null +++ b/net/rds/stats.c @@ -0,0 +1,155 @@ +/* + * Copyright (c) 2006 Oracle. All rights reserved. + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the + * OpenIB.org BSD license below: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + * + */ +#include +#include +#include +#include + +#include "rds.h" + +DEFINE_PER_CPU_SHARED_ALIGNED(struct rds_statistics, rds_stats); +EXPORT_PER_CPU_SYMBOL_GPL(rds_stats); + +/* :.,$s/unsigned long\>.*\= sizeof(ctr.name)); + strscpy_pad(ctr.name, names[i]); + ctr.value = values[i]; + + rds_info_copy(iter, &ctr, sizeof(ctr)); + } +} +EXPORT_SYMBOL_GPL(rds_stats_info_copy); + +/* + * This gives global counters across all the transports. The strings + * are copied in so that the tool doesn't need knowledge of the specific + * stats that we're exporting. Some are pretty implementation dependent + * and may change over time. That doesn't stop them from being useful. + * + * This is the only function in the chain that knows about the byte granular + * length in userspace. It converts it to number of stat entries that the + * rest of the functions operate in. + */ +static void rds_stats_info(struct socket *sock, unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens) +{ + struct rds_statistics stats = {0, }; + uint64_t *src; + uint64_t *sum; + size_t i; + int cpu; + unsigned int avail; + + avail = len / sizeof(struct rds_info_counter); + + if (avail < ARRAY_SIZE(rds_stat_names)) { + avail = 0; + goto trans; + } + + for_each_online_cpu(cpu) { + src = (uint64_t *)&(per_cpu(rds_stats, cpu)); + sum = (uint64_t *)&stats; + for (i = 0; i < sizeof(stats) / sizeof(uint64_t); i++) + *(sum++) += *(src++); + } + + rds_stats_info_copy(iter, (uint64_t *)&stats, rds_stat_names, + ARRAY_SIZE(rds_stat_names)); + avail -= ARRAY_SIZE(rds_stat_names); + +trans: + lens->each = sizeof(struct rds_info_counter); + lens->nr = rds_trans_stats_info_copy(iter, avail) + + ARRAY_SIZE(rds_stat_names); +} + +void rds_stats_exit(void) +{ + rds_info_deregister_func(RDS_INFO_COUNTERS, rds_stats_info); +} + +int rds_stats_init(void) +{ + rds_info_register_func(RDS_INFO_COUNTERS, rds_stats_info); + return 0; +} -- cgit v1.3.1