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 --- tools/perf/util/cputopo.h | 78 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 tools/perf/util/cputopo.h (limited to 'tools/perf/util/cputopo.h') diff --git a/tools/perf/util/cputopo.h b/tools/perf/util/cputopo.h new file mode 100644 index 000000000..8d42f6102 --- /dev/null +++ b/tools/perf/util/cputopo.h @@ -0,0 +1,78 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PERF_CPUTOPO_H +#define __PERF_CPUTOPO_H + +#include + +struct cpu_topology { + /* The number of unique package_cpus_lists below. */ + u32 package_cpus_lists; + /* The number of unique die_cpu_lists below. */ + u32 die_cpus_lists; + /* The number of unique core_cpu_lists below. */ + u32 core_cpus_lists; + /* + * An array of strings where each string is unique and read from + * /sys/devices/system/cpu/cpuX/topology/package_cpus_list. From the ABI + * each of these is a human-readable list of CPUs sharing the same + * physical_package_id. The format is like 0-3, 8-11, 14,17. + */ + const char **package_cpus_list; + /* + * An array of string where each string is unique and from + * /sys/devices/system/cpu/cpuX/topology/die_cpus_list. From the ABI + * each of these is a human-readable list of CPUs within the same die. + * The format is like 0-3, 8-11, 14,17. + */ + const char **die_cpus_list; + /* + * An array of string where each string is unique and from + * /sys/devices/system/cpu/cpuX/topology/core_cpus_list. From the ABI + * each of these is a human-readable list of CPUs within the same + * core. The format is like 0-3, 8-11, 14,17. + */ + const char **core_cpus_list; +}; + +struct numa_topology_node { + char *cpus; + u32 node; + u64 mem_total; + u64 mem_free; +}; + +struct numa_topology { + u32 nr; + struct numa_topology_node nodes[]; +}; + +struct hybrid_topology_node { + char *pmu_name; + char *cpus; +}; + +struct hybrid_topology { + u32 nr; + struct hybrid_topology_node nodes[]; +}; + +/* + * The topology for online CPUs, lazily created. + */ +const struct cpu_topology *online_topology(void); + +struct cpu_topology *cpu_topology__new(void); +void cpu_topology__delete(struct cpu_topology *tp); +/* Determine from the core list whether SMT was enabled. */ +bool cpu_topology__smt_on(const struct cpu_topology *topology); +/* Are the sets of SMT siblings all enabled or all disabled in user_requested_cpus. */ +bool cpu_topology__core_wide(const struct cpu_topology *topology, + const char *user_requested_cpu_list); + +struct numa_topology *numa_topology__new(void); +void numa_topology__delete(struct numa_topology *tp); + +struct hybrid_topology *hybrid_topology__new(void); +void hybrid_topology__delete(struct hybrid_topology *tp); + +#endif /* __PERF_CPUTOPO_H */ -- cgit v1.3.1