1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 typedef struct
30 {
31 void (**preinit_array)(void);
32 void (**init_array)(void);
33 void (**fini_array)(void);
34 void (**ctor_list)(void);
35 } structors_array_t;
36
37 extern int main(int argc, char **argv, char **env);
38
39 extern void __libc_init(
40 unsigned int *elfdata,
41 void (*onexit)(void),
42 int (*slingshot)(int, char**, char**),
43 structors_array_t const * const structors
44 );
45
46 __attribute__ ((section (".preinit_array")))
47 void (*__PREINIT_ARRAY__)(void) = (void (*)(void)) -1;
48
49 __attribute__ ((section (".init_array")))
50 void (*__INIT_ARRAY__)(void) = (void (*)(void)) -1;
51
52 __attribute__ ((section (".fini_array")))
53 void (*__FINI_ARRAY__)(void) = (void (*)(void)) -1;
54
55 __attribute__ ((section (".ctors")))
56 void (*__CTOR_LIST__)(void) = (void (*)(void)) -1;
57
58 /*
59 * This is the small startup code that is first run when any executable runs.
60 *
61 * Its purpose is to call __libc_init with appropriate arguments, which are:
62 *
63 * - The address of the raw data block setup by the Linux kernel ELF loader.
64 *
65 * - The address of an "onexit" function, not used on any platform supported by
66 * Bionic.
67 *
68 * - The address of the "main" function of the program.
69 *
70 * - The address of the constructor list.
71 */
72 __attribute__((visibility("hidden")))
_start()73 void _start() {
74 structors_array_t array;
75 void *elfdata;
76
77 array.preinit_array = &__PREINIT_ARRAY__;
78 array.init_array = &__INIT_ARRAY__;
79 array.fini_array = &__FINI_ARRAY__;
80 array.ctor_list = &__CTOR_LIST__;
81
82 elfdata = __builtin_frame_address(0) + sizeof(void *);
83 __libc_init(elfdata, (void *) 0, &main, &array);
84 }
85
86 #include "__dso_handle.h"
87 #include "atexit.h"
88