1 | /* Completion of TCB initialization after TLS_INIT_TP. NPTL version. |
2 | Copyright (C) 2020-2024 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 | #include <kernel-features.h> |
20 | #include <ldsodefs.h> |
21 | #include <list.h> |
22 | #include <pthreadP.h> |
23 | #include <tls.h> |
24 | #include <rseq-internal.h> |
25 | #include <thread_pointer.h> |
26 | #include <dl-symbol-redir-ifunc.h> |
27 | |
28 | #define TUNABLE_NAMESPACE pthread |
29 | #include <dl-tunables.h> |
30 | |
31 | #ifndef __ASSUME_SET_ROBUST_LIST |
32 | bool __nptl_set_robust_list_avail; |
33 | rtld_hidden_data_def (__nptl_set_robust_list_avail) |
34 | #endif |
35 | |
36 | bool __nptl_initial_report_events; |
37 | rtld_hidden_def (__nptl_initial_report_events) |
38 | |
39 | #ifdef SHARED |
40 | /* Dummy implementation. See __rtld_mutex_init. */ |
41 | static int |
42 | rtld_mutex_dummy (pthread_mutex_t *lock) |
43 | { |
44 | return 0; |
45 | } |
46 | #endif |
47 | |
48 | const unsigned int __rseq_flags; |
49 | |
50 | void |
51 | __tls_pre_init_tp (void) |
52 | { |
53 | /* The list data structures are not consistent until |
54 | initialized. */ |
55 | INIT_LIST_HEAD (&GL (dl_stack_used)); |
56 | INIT_LIST_HEAD (&GL (dl_stack_user)); |
57 | INIT_LIST_HEAD (&GL (dl_stack_cache)); |
58 | |
59 | #ifdef SHARED |
60 | ___rtld_mutex_lock = rtld_mutex_dummy; |
61 | ___rtld_mutex_unlock = rtld_mutex_dummy; |
62 | #endif |
63 | } |
64 | |
65 | void |
66 | __tls_init_tp (void) |
67 | { |
68 | struct pthread *pd = THREAD_SELF; |
69 | |
70 | /* Set up thread stack list management. */ |
71 | list_add (newp: &pd->list, head: &GL (dl_stack_user)); |
72 | |
73 | /* Early initialization of the TCB. */ |
74 | pd->tid = INTERNAL_SYSCALL_CALL (set_tid_address, &pd->tid); |
75 | THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]); |
76 | THREAD_SETMEM (pd, user_stack, true); |
77 | |
78 | /* Before initializing GL (dl_stack_user), the debugger could not |
79 | find us and had to set __nptl_initial_report_events. Propagate |
80 | its setting. */ |
81 | THREAD_SETMEM (pd, report_events, __nptl_initial_report_events); |
82 | |
83 | /* Initialize the robust mutex data. */ |
84 | { |
85 | #if __PTHREAD_MUTEX_HAVE_PREV |
86 | pd->robust_prev = &pd->robust_head; |
87 | #endif |
88 | pd->robust_head.list = &pd->robust_head; |
89 | pd->robust_head.futex_offset = (offsetof (pthread_mutex_t, __data.__lock) |
90 | - offsetof (pthread_mutex_t, |
91 | __data.__list.__next)); |
92 | int res = INTERNAL_SYSCALL_CALL (set_robust_list, &pd->robust_head, |
93 | sizeof (struct robust_list_head)); |
94 | if (!INTERNAL_SYSCALL_ERROR_P (res)) |
95 | { |
96 | #ifndef __ASSUME_SET_ROBUST_LIST |
97 | __nptl_set_robust_list_avail = true; |
98 | #endif |
99 | } |
100 | } |
101 | |
102 | { |
103 | bool do_rseq = true; |
104 | do_rseq = TUNABLE_GET (rseq, int, NULL); |
105 | if (rseq_register_current_thread (self: pd, do_rseq)) |
106 | _rseq_size = RSEQ_AREA_SIZE_INITIAL_USED; |
107 | |
108 | #ifdef RSEQ_SIG |
109 | /* This should be a compile-time constant, but the current |
110 | infrastructure makes it difficult to determine its value. Not |
111 | all targets support __thread_pointer, so set __rseq_offset only |
112 | if the rseq registration may have happened because RSEQ_SIG is |
113 | defined. */ |
114 | _rseq_offset = (char *) &pd->rseq_area - (char *) __thread_pointer (); |
115 | #endif |
116 | } |
117 | |
118 | /* Set initial thread's stack block from 0 up to __libc_stack_end. |
119 | It will be bigger than it actually is, but for unwind.c/pt-longjmp.c |
120 | purposes this is good enough. */ |
121 | THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end); |
122 | } |
123 | |