1 | /* Restartable Sequences tests header. |
2 | Copyright (C) 2021-2024 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 |
28 | rseq_thread_registered (void) |
29 | { |
30 | return THREAD_GETMEM_VOLATILE (THREAD_SELF, rseq_area.cpu_id) >= 0; |
31 | } |
32 | |
33 | static inline int |
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 |
40 | rseq_available (void) |
41 | { |
42 | int rc; |
43 | |
44 | rc = sys_rseq (NULL, rseq_len: 0, flags: 0, sig: 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 | |