Initial import from FreeBSD RELENG_4:
[dragonfly.git] / libexec / rtld-elf / rtld.h
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MD
1/*-
2 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
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 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
25 * $FreeBSD: src/libexec/rtld-elf/rtld.h,v 1.15.2.6 2003/02/20 20:42:46 kan Exp $
26 */
27
28#ifndef RTLD_H /* { */
29#define RTLD_H 1
30
31#include <machine/elf.h>
32#include <sys/types.h>
33#include <sys/queue.h>
34
35#include <elf-hints.h>
36#include <link.h>
37#include <stddef.h>
38
39#include "rtld_machdep.h"
40
41#ifndef STANDARD_LIBRARY_PATH
42#define STANDARD_LIBRARY_PATH "/usr/lib"
43#endif
44
45#define NEW(type) ((type *) xmalloc(sizeof(type)))
46#define CNEW(type) ((type *) xcalloc(sizeof(type)))
47
48/* We might as well do booleans like C++. */
49typedef unsigned char bool;
50#define false 0
51#define true 1
52
53struct stat;
54struct Struct_Obj_Entry;
55
56/* Lists of shared objects */
57typedef struct Struct_Objlist_Entry {
58 STAILQ_ENTRY(Struct_Objlist_Entry) link;
59 struct Struct_Obj_Entry *obj;
60} Objlist_Entry;
61
62typedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist;
63
64/* Types of init and fini functions */
65typedef void (*InitFunc)(void);
66
67/* Lists of shared object dependencies */
68typedef struct Struct_Needed_Entry {
69 struct Struct_Needed_Entry *next;
70 struct Struct_Obj_Entry *obj;
71 unsigned long name; /* Offset of name in string table */
72} Needed_Entry;
73
74/* Lock object */
75typedef struct Struct_LockInfo {
76 void *context; /* Client context for creating locks */
77 void *thelock; /* The one big lock */
78 /* Debugging aids. */
79 volatile int rcount; /* Number of readers holding lock */
80 volatile int wcount; /* Number of writers holding lock */
81 /* Methods */
82 void *(*lock_create)(void *context);
83 void (*rlock_acquire)(void *lock);
84 void (*wlock_acquire)(void *lock);
85 void (*rlock_release)(void *lock);
86 void (*wlock_release)(void *lock);
87 void (*lock_destroy)(void *lock);
88 void (*context_destroy)(void *context);
89} LockInfo;
90
91/*
92 * Shared object descriptor.
93 *
94 * Items marked with "(%)" are dynamically allocated, and must be freed
95 * when the structure is destroyed.
96 *
97 * CAUTION: It appears that the JDK port peeks into these structures.
98 * It looks at "next" and "mapbase" at least. Don't add new members
99 * near the front, until this can be straightened out.
100 */
101typedef struct Struct_Obj_Entry {
102 /*
103 * These two items have to be set right for compatibility with the
104 * original ElfKit crt1.o.
105 */
106 Elf_Word magic; /* Magic number (sanity check) */
107 Elf_Word version; /* Version number of struct format */
108
109 struct Struct_Obj_Entry *next;
110 char *path; /* Pathname of underlying file (%) */
111 int refcount;
112 int dl_refcount; /* Number of times loaded by dlopen */
113
114 /* These items are computed by map_object() or by digest_phdr(). */
115 caddr_t mapbase; /* Base address of mapped region */
116 size_t mapsize; /* Size of mapped region in bytes */
117 size_t textsize; /* Size of text segment in bytes */
118 Elf_Addr vaddrbase; /* Base address in shared object file */
119 caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */
120 const Elf_Dyn *dynamic; /* Dynamic section */
121 caddr_t entry; /* Entry point */
122 const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */
123 size_t phsize; /* Size of program header in bytes */
124 const char *interp; /* Pathname of the interpreter, if any */
125
126 /* Items from the dynamic section. */
127 Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */
128 const Elf_Rel *rel; /* Relocation entries */
129 unsigned long relsize; /* Size in bytes of relocation info */
130 const Elf_Rela *rela; /* Relocation entries with addend */
131 unsigned long relasize; /* Size in bytes of addend relocation info */
132 const Elf_Rel *pltrel; /* PLT relocation entries */
133 unsigned long pltrelsize; /* Size in bytes of PLT relocation info */
134 const Elf_Rela *pltrela; /* PLT relocation entries with addend */
135 unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */
136 const Elf_Sym *symtab; /* Symbol table */
137 const char *strtab; /* String table */
138 unsigned long strsize; /* Size in bytes of string table */
139
140 const Elf_Addr *buckets; /* Hash table buckets array */
141 unsigned long nbuckets; /* Number of buckets */
142 const Elf_Addr *chains; /* Hash table chain array */
143 unsigned long nchains; /* Number of chains */
144
145 const char *rpath; /* Search path specified in object */
146 Needed_Entry *needed; /* Shared objects needed by this one (%) */
147
148 InitFunc init; /* Initialization function to call */
149 InitFunc fini; /* Termination function to call */
150
151 bool mainprog; /* True if this is the main program */
152 bool rtld; /* True if this is the dynamic linker */
153 bool textrel; /* True if there are relocations to text seg */
154 bool symbolic; /* True if generated with "-Bsymbolic" */
155 bool traced; /* Already printed in ldd trace output */
156 bool jmpslots_done; /* Already have relocated the jump slots */
157 bool init_done; /* Already have added object to init list */
158
159 struct link_map linkmap; /* for GDB and dlinfo() */
160 Objlist dldags; /* Object belongs to these dlopened DAGs (%) */
161 Objlist dagmembers; /* DAG has these members (%) */
162 dev_t dev; /* Object's filesystem's device */
163 ino_t ino; /* Object's inode number */
164} Obj_Entry;
165
166#define RTLD_MAGIC 0xd550b87a
167#define RTLD_VERSION 1
168
169/*
170 * Symbol cache entry used during relocation to avoid multiple lookups
171 * of the same symbol.
172 */
173typedef struct Struct_SymCache {
174 const Elf_Sym *sym; /* Symbol table entry */
175 const Obj_Entry *obj; /* Shared object which defines it */
176} SymCache;
177
178extern void _rtld_error(const char *, ...) __printflike(1, 2);
179extern Obj_Entry *map_object(int, const char *, const struct stat *);
180extern void *xcalloc(size_t);
181extern void *xmalloc(size_t);
182extern char *xstrdup(const char *);
183extern Elf_Addr _GLOBAL_OFFSET_TABLE_[];
184
185/*
186 * Function declarations.
187 */
188int do_copy_relocations(Obj_Entry *);
189unsigned long elf_hash(const char *);
190const Elf_Sym *find_symdef(unsigned long, const Obj_Entry *,
191 const Obj_Entry **, bool, SymCache *);
192void init_pltgot(Obj_Entry *);
193void lockdflt_init(LockInfo *);
194void obj_free(Obj_Entry *);
195Obj_Entry *obj_new(void);
196int reloc_non_plt(Obj_Entry *, Obj_Entry *);
197int reloc_plt(Obj_Entry *);
198int reloc_jmpslots(Obj_Entry *);
199void _rtld_bind_start(void);
200const Elf_Sym *symlook_obj(const char *, unsigned long,
201 const Obj_Entry *, bool);
202
203#endif /* } */