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8893239d | 1 | /* TLS emulation. |
a945c346 | 2 | Copyright (C) 2006-2024 Free Software Foundation, Inc. |
8893239d RH |
3 | Contributed by Jakub Jelinek <jakub@redhat.com>. |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
748086b7 | 9 | Software Foundation; either version 3, or (at your option) any later |
8893239d RH |
10 | version. |
11 | ||
8893239d RH |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
748086b7 JJ |
17 | Under Section 7 of GPL version 3, you are granted additional |
18 | permissions described in the GCC Runtime Library Exception, version | |
19 | 3.1, as published by the Free Software Foundation. | |
20 | ||
21 | You should have received a copy of the GNU General Public License and | |
22 | a copy of the GCC Runtime Library Exception along with this program; | |
23 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
24 | <http://www.gnu.org/licenses/>. */ | |
8893239d RH |
25 | |
26 | #include "tconfig.h" | |
27 | #include "tsystem.h" | |
28 | #include "coretypes.h" | |
29 | #include "tm.h" | |
852b75ed | 30 | #include "libgcc_tm.h" |
8893239d RH |
31 | #include "gthr.h" |
32 | ||
33 | typedef unsigned int word __attribute__((mode(word))); | |
34 | typedef unsigned int pointer __attribute__((mode(pointer))); | |
35 | ||
36 | struct __emutls_object | |
37 | { | |
38 | word size; | |
39 | word align; | |
40 | union { | |
41 | pointer offset; | |
42 | void *ptr; | |
43 | } loc; | |
44 | void *templ; | |
45 | }; | |
46 | ||
5b77de89 RH |
47 | struct __emutls_array |
48 | { | |
49 | pointer size; | |
50 | void **data[]; | |
51 | }; | |
52 | ||
b9873b4e IS |
53 | /* EMUTLS_ATTR is provided to allow targets to build the emulated tls |
54 | routines as weak definitions, for example. | |
55 | If there is no definition, fall back to the default. */ | |
56 | #ifndef EMUTLS_ATTR | |
57 | # define EMUTLS_ATTR | |
58 | #endif | |
59 | ||
d7ceffab JJ |
60 | /* __emutls_get_address and __emutls_register_common are registered as |
61 | builtins, but the compiler struct __emutls_object doesn't have | |
62 | a union in there and is only created when actually needed for | |
63 | the calls to the builtins, so the builtins are created with void * | |
64 | arguments rather than struct __emutls_object *. Avoid | |
65 | -Wbuiltin-declaration-mismatch warnings. */ | |
66 | #pragma GCC diagnostic ignored "-Wbuiltin-declaration-mismatch" | |
67 | ||
b9873b4e | 68 | EMUTLS_ATTR |
c6c2b18d | 69 | void *__emutls_get_address (struct __emutls_object *); |
b9873b4e | 70 | EMUTLS_ATTR |
c6c2b18d BE |
71 | void __emutls_register_common (struct __emutls_object *, word, word, void *); |
72 | ||
8893239d RH |
73 | #ifdef __GTHREADS |
74 | #ifdef __GTHREAD_MUTEX_INIT | |
75 | static __gthread_mutex_t emutls_mutex = __GTHREAD_MUTEX_INIT; | |
76 | #else | |
77 | static __gthread_mutex_t emutls_mutex; | |
78 | #endif | |
79 | static __gthread_key_t emutls_key; | |
80 | static pointer emutls_size; | |
81 | ||
82 | static void | |
83 | emutls_destroy (void *ptr) | |
84 | { | |
5b77de89 RH |
85 | struct __emutls_array *arr = ptr; |
86 | pointer size = arr->size; | |
87 | pointer i; | |
88 | ||
89 | for (i = 0; i < size; ++i) | |
8893239d | 90 | { |
5b77de89 RH |
91 | if (arr->data[i]) |
92 | free (arr->data[i][-1]); | |
8893239d | 93 | } |
5b77de89 | 94 | |
8893239d RH |
95 | free (ptr); |
96 | } | |
97 | ||
98 | static void | |
99 | emutls_init (void) | |
100 | { | |
101 | #ifndef __GTHREAD_MUTEX_INIT | |
102 | __GTHREAD_MUTEX_INIT_FUNCTION (&emutls_mutex); | |
103 | #endif | |
104 | if (__gthread_key_create (&emutls_key, emutls_destroy) != 0) | |
105 | abort (); | |
106 | } | |
107 | #endif | |
108 | ||
109 | static void * | |
110 | emutls_alloc (struct __emutls_object *obj) | |
111 | { | |
112 | void *ptr; | |
113 | void *ret; | |
114 | ||
115 | /* We could use here posix_memalign if available and adjust | |
116 | emutls_destroy accordingly. */ | |
117 | if (obj->align <= sizeof (void *)) | |
118 | { | |
119 | ptr = malloc (obj->size + sizeof (void *)); | |
120 | if (ptr == NULL) | |
121 | abort (); | |
122 | ((void **) ptr)[0] = ptr; | |
123 | ret = ptr + sizeof (void *); | |
124 | } | |
125 | else | |
126 | { | |
127 | ptr = malloc (obj->size + sizeof (void *) + obj->align - 1); | |
128 | if (ptr == NULL) | |
129 | abort (); | |
130 | ret = (void *) (((pointer) (ptr + sizeof (void *) + obj->align - 1)) | |
131 | & ~(pointer)(obj->align - 1)); | |
132 | ((void **) ret)[-1] = ptr; | |
133 | } | |
134 | ||
135 | if (obj->templ) | |
136 | memcpy (ret, obj->templ, obj->size); | |
137 | else | |
138 | memset (ret, 0, obj->size); | |
139 | ||
140 | return ret; | |
141 | } | |
142 | ||
b9873b4e IS |
143 | /* Despite applying the attribute to the declaration, in this case the mis- |
144 | match between the builtin's declaration [void * (*)(void *)] and the | |
145 | implementation here, causes the decl. attributes to be discarded. */ | |
146 | ||
147 | EMUTLS_ATTR void * | |
8893239d RH |
148 | __emutls_get_address (struct __emutls_object *obj) |
149 | { | |
150 | if (! __gthread_active_p ()) | |
151 | { | |
152 | if (__builtin_expect (obj->loc.ptr == NULL, 0)) | |
153 | obj->loc.ptr = emutls_alloc (obj); | |
154 | return obj->loc.ptr; | |
155 | } | |
156 | ||
157 | #ifndef __GTHREADS | |
158 | abort (); | |
159 | #else | |
f4919e4a | 160 | pointer offset = __atomic_load_n (&obj->loc.offset, __ATOMIC_ACQUIRE); |
8893239d | 161 | |
5b77de89 | 162 | if (__builtin_expect (offset == 0, 0)) |
8893239d RH |
163 | { |
164 | static __gthread_once_t once = __GTHREAD_ONCE_INIT; | |
165 | __gthread_once (&once, emutls_init); | |
166 | __gthread_mutex_lock (&emutls_mutex); | |
b6b561e4 JDA |
167 | offset = obj->loc.offset; |
168 | if (offset == 0) | |
169 | { | |
170 | offset = ++emutls_size; | |
f4919e4a | 171 | __atomic_store_n (&obj->loc.offset, offset, __ATOMIC_RELEASE); |
b6b561e4 | 172 | } |
8893239d RH |
173 | __gthread_mutex_unlock (&emutls_mutex); |
174 | } | |
8893239d | 175 | |
5b77de89 | 176 | struct __emutls_array *arr = __gthread_getspecific (emutls_key); |
8893239d RH |
177 | if (__builtin_expect (arr == NULL, 0)) |
178 | { | |
179 | pointer size = offset + 32; | |
df0026a7 | 180 | arr = calloc (size + 1, sizeof (void *)); |
8893239d RH |
181 | if (arr == NULL) |
182 | abort (); | |
5b77de89 | 183 | arr->size = size; |
8893239d RH |
184 | __gthread_setspecific (emutls_key, (void *) arr); |
185 | } | |
df0026a7 | 186 | else if (__builtin_expect (offset > arr->size, 0)) |
8893239d | 187 | { |
5b77de89 | 188 | pointer orig_size = arr->size; |
8893239d | 189 | pointer size = orig_size * 2; |
df0026a7 | 190 | if (offset > size) |
8893239d | 191 | size = offset + 32; |
df0026a7 | 192 | arr = realloc (arr, (size + 1) * sizeof (void *)); |
8893239d RH |
193 | if (arr == NULL) |
194 | abort (); | |
5b77de89 | 195 | arr->size = size; |
df0026a7 | 196 | memset (arr->data + orig_size, 0, |
5b77de89 | 197 | (size - orig_size) * sizeof (void *)); |
8893239d RH |
198 | __gthread_setspecific (emutls_key, (void *) arr); |
199 | } | |
200 | ||
5b77de89 | 201 | void *ret = arr->data[offset - 1]; |
8893239d RH |
202 | if (__builtin_expect (ret == NULL, 0)) |
203 | { | |
204 | ret = emutls_alloc (obj); | |
5b77de89 | 205 | arr->data[offset - 1] = ret; |
8893239d RH |
206 | } |
207 | return ret; | |
208 | #endif | |
209 | } | |
210 | ||
b9873b4e | 211 | EMUTLS_ATTR void |
8893239d RH |
212 | __emutls_register_common (struct __emutls_object *obj, |
213 | word size, word align, void *templ) | |
214 | { | |
215 | if (obj->size < size) | |
216 | { | |
217 | obj->size = size; | |
218 | obj->templ = NULL; | |
219 | } | |
220 | if (obj->align < align) | |
221 | obj->align = align; | |
222 | if (templ && size == obj->size) | |
223 | obj->templ = templ; | |
224 | } |