1 // SPDX-License-Identifier: LGPL-2.1
5 * Copyright (C) 2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; only
10 * version 2.1 of the License.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
31 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
33 __attribute__((tls_model("initial-exec"))) __thread
34 volatile struct rseq __rseq_abi = {
35 .cpu_id = RSEQ_CPU_ID_UNINITIALIZED,
38 static __attribute__((tls_model("initial-exec"))) __thread
39 volatile int refcount;
41 static void signal_off_save(sigset_t *oldset)
47 ret = pthread_sigmask(SIG_BLOCK, &set, oldset);
52 static void signal_restore(sigset_t oldset)
56 ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL);
61 static int sys_rseq(volatile struct rseq *rseq_abi, uint32_t rseq_len,
62 int flags, uint32_t sig)
64 return syscall(__NR_rseq, rseq_abi, rseq_len, flags, sig);
67 int rseq_register_current_thread(void)
72 signal_off_save(&oldset);
75 rc = sys_rseq(&__rseq_abi, sizeof(struct rseq), 0, RSEQ_SIG);
77 assert(rseq_current_cpu_raw() >= 0);
81 __rseq_abi.cpu_id = -2;
85 signal_restore(oldset);
89 int rseq_unregister_current_thread(void)
94 signal_off_save(&oldset);
97 rc = sys_rseq(&__rseq_abi, sizeof(struct rseq),
98 RSEQ_FLAG_UNREGISTER, RSEQ_SIG);
103 signal_restore(oldset);
107 int32_t rseq_fallback_current_cpu(void)
111 cpu = sched_getcpu();
113 perror("sched_getcpu()");