1/*
2 * Copyright (C) 2008 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#ifndef _LINKER_H_
30#define _LINKER_H_
31
32#include <unistd.h>
33#include <sys/types.h>
34#include <elf.h>
35#include <sys/exec_elf.h>
36
37#undef PAGE_MASK
38#undef PAGE_SIZE
39#define PAGE_SIZE 4096
40#define PAGE_MASK 4095
41
42void debugger_init();
43const char *addr_to_name(unsigned addr);
44
45/* magic shared structures that GDB knows about */
46
47struct link_map
48{
49    uintptr_t l_addr;
50    char * l_name;
51    uintptr_t l_ld;
52    struct link_map * l_next;
53    struct link_map * l_prev;
54};
55
56/* needed for dl_iterate_phdr to be passed to the callbacks provided */
57struct dl_phdr_info
58{
59    Elf32_Addr dlpi_addr;
60    const char *dlpi_name;
61    const Elf32_Phdr *dlpi_phdr;
62    Elf32_Half dlpi_phnum;
63};
64
65
66// Values for r_debug->state
67enum {
68    RT_CONSISTENT,
69    RT_ADD,
70    RT_DELETE
71};
72
73struct r_debug
74{
75    int32_t r_version;
76    struct link_map * r_map;
77    void (*r_brk)(void);
78    int32_t r_state;
79    uintptr_t r_ldbase;
80};
81
82typedef struct soinfo soinfo;
83
84#define FLAG_LINKED     0x00000001
85#define FLAG_ERROR      0x00000002
86#define FLAG_EXE        0x00000004 // The main executable
87#define FLAG_LINKER     0x00000010 // The linker itself
88
89#define SOINFO_NAME_LEN 128
90
91struct soinfo
92{
93    const char name[SOINFO_NAME_LEN];
94    Elf32_Phdr *phdr;
95    int phnum;
96    unsigned entry;
97    unsigned base;
98    unsigned size;
99
100    int unused;  // DO NOT USE, maintained for compatibility.
101
102    unsigned *dynamic;
103
104    unsigned wrprotect_start;
105    unsigned wrprotect_end;
106
107    soinfo *next;
108    unsigned flags;
109
110    const char *strtab;
111    Elf32_Sym *symtab;
112
113    unsigned nbucket;
114    unsigned nchain;
115    unsigned *bucket;
116    unsigned *chain;
117
118    unsigned *plt_got;
119
120    Elf32_Rel *plt_rel;
121    unsigned plt_rel_count;
122
123    Elf32_Rel *rel;
124    unsigned rel_count;
125
126    unsigned *preinit_array;
127    unsigned preinit_array_count;
128
129    unsigned *init_array;
130    unsigned init_array_count;
131    unsigned *fini_array;
132    unsigned fini_array_count;
133
134    void (*init_func)(void);
135    void (*fini_func)(void);
136
137#ifdef ANDROID_ARM_LINKER
138    /* ARM EABI section used for stack unwinding. */
139    unsigned *ARM_exidx;
140    unsigned ARM_exidx_count;
141#endif
142
143    unsigned refcount;
144    struct link_map linkmap;
145
146    int constructors_called;
147
148    Elf32_Addr gnu_relro_start;
149    unsigned gnu_relro_len;
150
151};
152
153
154extern soinfo libdl_info;
155
156#ifdef ANDROID_ARM_LINKER
157
158#define R_ARM_COPY       20
159#define R_ARM_GLOB_DAT   21
160#define R_ARM_JUMP_SLOT  22
161#define R_ARM_RELATIVE   23
162
163/* According to the AAPCS specification, we only
164 * need the above relocations. However, in practice,
165 * the following ones turn up from time to time.
166 */
167#define R_ARM_ABS32      2
168#define R_ARM_REL32      3
169
170#elif defined(ANDROID_X86_LINKER)
171
172#define R_386_32         1
173#define R_386_PC32       2
174#define R_386_GLOB_DAT   6
175#define R_386_JUMP_SLOT  7
176#define R_386_RELATIVE   8
177
178#endif
179
180#ifndef DT_INIT_ARRAY
181#define DT_INIT_ARRAY      25
182#endif
183
184#ifndef DT_FINI_ARRAY
185#define DT_FINI_ARRAY      26
186#endif
187
188#ifndef DT_INIT_ARRAYSZ
189#define DT_INIT_ARRAYSZ    27
190#endif
191
192#ifndef DT_FINI_ARRAYSZ
193#define DT_FINI_ARRAYSZ    28
194#endif
195
196#ifndef DT_PREINIT_ARRAY
197#define DT_PREINIT_ARRAY   32
198#endif
199
200#ifndef DT_PREINIT_ARRAYSZ
201#define DT_PREINIT_ARRAYSZ 33
202#endif
203
204soinfo *find_library(const char *name);
205unsigned unload_library(soinfo *si);
206Elf32_Sym *lookup_in_library(soinfo *si, const char *name);
207Elf32_Sym *lookup(const char *name, soinfo **found, soinfo *start);
208soinfo *find_containing_library(const void *addr);
209Elf32_Sym *find_containing_symbol(const void *addr, soinfo *si);
210const char *linker_get_error(void);
211void call_constructors_recursive(soinfo *si);
212
213#ifdef ANDROID_ARM_LINKER
214typedef long unsigned int *_Unwind_Ptr;
215_Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int *pcount);
216#elif defined(ANDROID_X86_LINKER)
217int dl_iterate_phdr(int (*cb)(struct dl_phdr_info *, size_t, void *), void *);
218#endif
219
220#endif
221