1/* Copyright (C) 2007-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
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 <sched.h>
20#include <sysdep.h>
21#include <sysdep-vdso.h>
22
23static int
24vsyscall_sched_getcpu (void)
25{
26 unsigned int cpu;
27 int r = -1;
28#ifdef HAVE_GETCPU_VSYSCALL
29 r = INLINE_VSYSCALL (getcpu, 3, &cpu, NULL, NULL);
30#else
31 r = INLINE_SYSCALL_CALL (getcpu, &cpu, NULL, NULL);
32#endif
33 return r == -1 ? r : cpu;
34}
35
36#ifdef RSEQ_SIG
37int
38sched_getcpu (void)
39{
40 int cpu_id = THREAD_GETMEM_VOLATILE (THREAD_SELF, rseq_area.cpu_id);
41 return __glibc_likely (cpu_id >= 0) ? cpu_id : vsyscall_sched_getcpu ();
42}
43#else /* RSEQ_SIG */
44int
45sched_getcpu (void)
46{
47 return vsyscall_sched_getcpu ();
48}
49#endif /* RSEQ_SIG */
50