1 /* Restartable Sequences tests header.
2 Copyright (C) 2021-2022 Free Software Foundation, Inc.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <errno.h>
19 #include <error.h>
20 #include <stdbool.h>
21 #include <stdint.h>
22 #include <support/check.h>
23 #include <syscall.h>
24 #include <sys/rseq.h>
25 #include <tls.h>
26
27 static inline bool
rseq_thread_registered(void)28 rseq_thread_registered (void)
29 {
30 return THREAD_GETMEM_VOLATILE (THREAD_SELF, rseq_area.cpu_id) >= 0;
31 }
32
33 static inline int
sys_rseq(struct rseq * rseq_abi,uint32_t rseq_len,int flags,uint32_t sig)34 sys_rseq (struct rseq *rseq_abi, uint32_t rseq_len, int flags, uint32_t sig)
35 {
36 return syscall (__NR_rseq, rseq_abi, rseq_len, flags, sig);
37 }
38
39 static inline bool
rseq_available(void)40 rseq_available (void)
41 {
42 int rc;
43
44 rc = sys_rseq (NULL, 0, 0, 0);
45 if (rc != -1)
46 FAIL_EXIT1 ("Unexpected rseq return value %d", rc);
47 switch (errno)
48 {
49 case ENOSYS:
50 return false;
51 case EINVAL:
52 /* rseq is implemented, but detected an invalid rseq_len parameter. */
53 return true;
54 default:
55 FAIL_EXIT1 ("Unexpected rseq error %s", strerror (errno));
56 }
57 }
58