2 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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.
25 * $FreeBSD: src/libexec/rtld-elf/rtld.h,v 1.15.2.6 2003/02/20 20:42:46 kan Exp $
26 * $DragonFly: src/libexec/rtld-elf/rtld.h,v 1.11 2005/05/11 19:47:06 dillon Exp $
29 #ifndef RTLD_H /* { */
32 #include <machine/elf.h>
33 #include <sys/types.h>
34 #include <sys/queue.h>
36 #include <elf-hints.h>
40 #include "rtld_machdep.h"
42 #ifndef STANDARD_LIBRARY_PATH
43 #define STANDARD_LIBRARY_PATH "/usr/lib"
46 #define NEW(type) ((type *) xmalloc(sizeof(type)))
47 #define CNEW(type) ((type *) xcalloc(sizeof(type)))
49 /* We might as well do booleans like C++. */
50 typedef unsigned char bool;
54 extern size_t tls_last_offset
;
55 extern size_t tls_last_size
;
56 extern size_t tls_static_space
;
57 extern int tls_dtv_generation
;
58 extern int tls_max_index
;
60 extern Elf_Addr _GLOBAL_OFFSET_TABLE_
[];
63 struct Struct_Obj_Entry
;
65 /* Lists of shared objects */
66 typedef struct Struct_Objlist_Entry
{
67 STAILQ_ENTRY(Struct_Objlist_Entry
) link
;
68 struct Struct_Obj_Entry
*obj
;
71 typedef STAILQ_HEAD(Struct_Objlist
, Struct_Objlist_Entry
) Objlist
;
73 /* Types of init and fini functions */
74 typedef void (*InitFunc
)(void);
76 /* Lists of shared object dependencies */
77 typedef struct Struct_Needed_Entry
{
78 struct Struct_Needed_Entry
*next
;
79 struct Struct_Obj_Entry
*obj
;
80 unsigned long name
; /* Offset of name in string table */
84 typedef struct Struct_LockInfo
{
85 void *context
; /* Client context for creating locks */
86 void *thelock
; /* The one big lock */
88 volatile int rcount
; /* Number of readers holding lock */
89 volatile int wcount
; /* Number of writers holding lock */
91 void *(*lock_create
)(void *context
);
92 void (*rlock_acquire
)(void *lock
);
93 void (*wlock_acquire
)(void *lock
);
94 void (*rlock_release
)(void *lock
);
95 void (*wlock_release
)(void *lock
);
96 void (*lock_destroy
)(void *lock
);
97 void (*context_destroy
)(void *context
);
101 * Shared object descriptor.
103 * Items marked with "(%)" are dynamically allocated, and must be freed
104 * when the structure is destroyed.
106 * CAUTION: It appears that the JDK port peeks into these structures.
107 * It looks at "next" and "mapbase" at least. Don't add new members
108 * near the front, until this can be straightened out.
110 typedef struct Struct_Obj_Entry
{
112 * These two items have to be set right for compatibility with the
113 * original ElfKit crt1.o.
115 Elf_Word magic
; /* Magic number (sanity check) */
116 Elf_Word version
; /* Version number of struct format */
118 struct Struct_Obj_Entry
*next
;
119 char *path
; /* Pathname of underlying file (%) */
120 char *origin_path
; /* Directory path of origin file */
122 int dl_refcount
; /* Number of times loaded by dlopen */
124 /* These items are computed by map_object() or by digest_phdr(). */
125 caddr_t mapbase
; /* Base address of mapped region */
126 size_t mapsize
; /* Size of mapped region in bytes */
127 size_t textsize
; /* Size of text segment in bytes */
128 Elf_Addr vaddrbase
; /* Base address in shared object file */
129 caddr_t relocbase
; /* Relocation constant = mapbase - vaddrbase */
130 const Elf_Dyn
*dynamic
; /* Dynamic section */
131 caddr_t entry
; /* Entry point */
132 const Elf_Phdr
*phdr
; /* Program header if it is mapped, else NULL */
133 size_t phsize
; /* Size of program header in bytes */
134 const char *interp
; /* Pathname of the interpreter, if any */
136 /* TLS information */
137 int tlsindex
; /* Index in DTV for this module */
138 void *tlsinit
; /* Base address of TLS init block */
139 size_t tlsinitsize
; /* Size of TLS init block for this module */
140 size_t tlssize
; /* Size of TLS block for this module */
141 size_t tlsoffset
; /* Offset of static TLS block for this module */
142 size_t tlsalign
; /* Alignment of static TLS block */
144 /* Items from the dynamic section. */
145 Elf_Addr
*pltgot
; /* PLT or GOT, depending on architecture */
146 const Elf_Rel
*rel
; /* Relocation entries */
147 unsigned long relsize
; /* Size in bytes of relocation info */
148 const Elf_Rela
*rela
; /* Relocation entries with addend */
149 unsigned long relasize
; /* Size in bytes of addend relocation info */
150 const Elf_Rel
*pltrel
; /* PLT relocation entries */
151 unsigned long pltrelsize
; /* Size in bytes of PLT relocation info */
152 const Elf_Rela
*pltrela
; /* PLT relocation entries with addend */
153 unsigned long pltrelasize
; /* Size in bytes of PLT addend reloc info */
154 const Elf_Sym
*symtab
; /* Symbol table */
155 const char *strtab
; /* String table */
156 unsigned long strsize
; /* Size in bytes of string table */
158 const Elf_Addr
*buckets
; /* Hash table buckets array */
159 unsigned long nbuckets
; /* Number of buckets */
160 const Elf_Addr
*chains
; /* Hash table chain array */
161 unsigned long nchains
; /* Number of chains */
163 const char *rpath
; /* Search path specified in object */
164 Needed_Entry
*needed
; /* Shared objects needed by this one (%) */
166 InitFunc init
; /* Initialization function to call */
167 InitFunc fini
; /* Termination function to call */
169 bool mainprog
; /* True if this is the main program */
170 bool rtld
; /* True if this is the dynamic linker */
171 bool textrel
; /* True if there are relocations to text seg */
172 bool symbolic
; /* True if generated with "-Bsymbolic" */
173 bool bind_now
; /* True if all relocations should be made first */
174 bool traced
; /* Already printed in ldd trace output */
175 bool jmpslots_done
; /* Already have relocated the jump slots */
176 bool init_done
; /* Already have added object to init list */
177 bool tls_done
; /* Already allocated offset for static TLS */
179 struct link_map linkmap
; /* for GDB and dlinfo() */
180 Objlist dldags
; /* Object belongs to these dlopened DAGs (%) */
181 Objlist dagmembers
; /* DAG has these members (%) */
182 dev_t dev
; /* Object's filesystem's device */
183 ino_t ino
; /* Object's inode number */
186 #define RTLD_MAGIC 0xd550b87a
187 #define RTLD_VERSION 1
190 * Symbol cache entry used during relocation to avoid multiple lookups
191 * of the same symbol.
193 typedef struct Struct_SymCache
{
194 const Elf_Sym
*sym
; /* Symbol table entry */
195 const Obj_Entry
*obj
; /* Shared object which defines it */
198 void _rtld_error(const char *, ...) __printflike(1, 2);
199 Obj_Entry
*map_object(int, const char *, const struct stat
*);
200 void *xcalloc(size_t);
201 void *xmalloc(size_t);
202 void *xrealloc(void *, size_t);
203 char *xstrdup(const char *);
205 void dump_relocations(Obj_Entry
*);
206 void dump_obj_relocations(Obj_Entry
*);
207 void dump_Elf_Rel(Obj_Entry
*, const Elf_Rel
*, u_long
);
208 void dump_Elf_Rela(Obj_Entry
*, const Elf_Rela
*, u_long
);
211 * Function declarations.
213 const char *basename(const char *);
214 int do_copy_relocations(Obj_Entry
*);
215 unsigned long elf_hash(const char *);
216 const Elf_Sym
*find_symdef(unsigned long, const Obj_Entry
*,
217 const Obj_Entry
**, bool, SymCache
*);
218 void init_pltgot(Obj_Entry
*);
219 void lockdflt_init(LockInfo
*);
220 void obj_free(Obj_Entry
*);
221 Obj_Entry
*obj_new(void);
222 int reloc_non_plt(Obj_Entry
*, Obj_Entry
*);
223 int reloc_plt(Obj_Entry
*);
224 int reloc_jmpslots(Obj_Entry
*);
225 void _rtld_bind_start(void);
226 const Elf_Sym
*symlook_obj(const char *, unsigned long, const Obj_Entry
*,
229 void *tls_get_addr_common(void **, int, size_t);
230 struct tls_tcb
*allocate_tls(Obj_Entry
*);
231 void free_tls(struct tls_tcb
*);
232 void *allocate_module_tls(int);
233 bool allocate_tls_offset(Obj_Entry
*);
234 void free_tls_offset(Obj_Entry
*);
235 void allocate_initial_tls(Obj_Entry
*);