1/* pthread initialization called from __libc_early_init. NPTL version.
2 Copyright (C) 2021-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#ifndef _PTHREAD_EARLY_INIT_H
20#define _PTHREAD_EARLY_INIT_H 1
21
22#include <nptl/nptl-stack.h>
23#include <pthreadP.h>
24#include <pthread_mutex_conf.h>
25#include <sys/resource.h>
26
27static inline void
28__pthread_early_init (void)
29{
30 /* Determine the default allowed stack size. This is the size used
31 in case the user does not specify one. */
32 struct rlimit limit;
33 if (__getrlimit (RLIMIT_STACK, &limit) != 0
34 || limit.rlim_cur == RLIM_INFINITY)
35 /* The system limit is not usable. Use an architecture-specific
36 default. */
37 limit.rlim_cur = ARCH_STACK_DEFAULT_SIZE;
38 else if (limit.rlim_cur < PTHREAD_STACK_MIN)
39 /* The system limit is unusably small.
40 Use the minimal size acceptable. */
41 limit.rlim_cur = PTHREAD_STACK_MIN;
42
43 /* Make sure it meets the minimum size that allocate_stack
44 (allocatestack.c) will demand, which depends on the page size. */
45 const uintptr_t pagesz = GLRO(dl_pagesize);
46 const size_t minstack = (pagesz + __nptl_tls_static_size_for_stack ()
47 + MINIMAL_REST_STACK);
48 if (limit.rlim_cur < minstack)
49 limit.rlim_cur = minstack;
50
51 /* Round the resource limit up to page size. */
52 limit.rlim_cur = ALIGN_UP (limit.rlim_cur, pagesz);
53 __default_pthread_attr.internal.stacksize = limit.rlim_cur;
54 __default_pthread_attr.internal.guardsize = GLRO (dl_pagesize);
55
56#if HAVE_TUNABLES
57 __pthread_tunables_init ();
58#endif
59}
60
61#endif /* _PTHREAD_EARLY_INIT_H */
62