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 $
28 #ifndef RTLD_H /* { */
31 #include <machine/elf.h>
32 #include <sys/types.h>
33 #include <sys/queue.h>
35 #include <elf-hints.h>
39 #include "rtld_machdep.h"
41 #ifndef STANDARD_LIBRARY_PATH
42 #define STANDARD_LIBRARY_PATH "/usr/lib"
45 #define NEW(type) ((type *) xmalloc(sizeof(type)))
46 #define CNEW(type) ((type *) xcalloc(sizeof(type)))
48 /* We might as well do booleans like C++. */
49 typedef unsigned char bool;
53 extern size_t tls_last_offset;
54 extern size_t tls_last_size;
55 extern size_t tls_static_space;
56 extern int tls_dtv_generation;
57 extern int tls_max_index;
60 struct Struct_Obj_Entry;
62 /* Lists of shared objects */
63 typedef struct Struct_Objlist_Entry {
64 STAILQ_ENTRY(Struct_Objlist_Entry) link;
65 struct Struct_Obj_Entry *obj;
68 typedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist;
70 /* Types of init and fini functions */
71 typedef void (*InitFunc)(void);
73 /* Lists of shared object dependencies */
74 typedef struct Struct_Needed_Entry {
75 struct Struct_Needed_Entry *next;
76 struct Struct_Obj_Entry *obj;
77 unsigned long name; /* Offset of name in string table */
81 typedef struct Struct_LockInfo {
82 void *context; /* Client context for creating locks */
83 void *thelock; /* The one big lock */
85 volatile int rcount; /* Number of readers holding lock */
86 volatile int wcount; /* Number of writers holding lock */
88 void *(*lock_create)(void *context);
89 void (*rlock_acquire)(void *lock);
90 void (*wlock_acquire)(void *lock);
91 void (*rlock_release)(void *lock);
92 void (*wlock_release)(void *lock);
93 void (*lock_destroy)(void *lock);
94 void (*context_destroy)(void *context);
98 * Shared object descriptor.
100 * Items marked with "(%)" are dynamically allocated, and must be freed
101 * when the structure is destroyed.
103 * CAUTION: It appears that the JDK port peeks into these structures.
104 * It looks at "next" and "mapbase" at least. Don't add new members
105 * near the front, until this can be straightened out.
107 typedef struct Struct_Obj_Entry {
109 * These two items have to be set right for compatibility with the
110 * original ElfKit crt1.o.
112 Elf_Size magic; /* Magic number (sanity check) */
113 Elf_Size version; /* Version number of struct format */
115 struct Struct_Obj_Entry *next;
116 char *path; /* Pathname of underlying file (%) */
117 char *origin_path; /* Directory path of origin file */
119 int dl_refcount; /* Number of times loaded by dlopen */
121 /* These items are computed by map_object() or by digest_phdr(). */
122 caddr_t mapbase; /* Base address of mapped region */
123 size_t mapsize; /* Size of mapped region in bytes */
124 size_t textsize; /* Size of text segment in bytes */
125 Elf_Addr vaddrbase; /* Base address in shared object file */
126 caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */
127 const Elf_Dyn *dynamic; /* Dynamic section */
128 caddr_t entry; /* Entry point */
129 const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */
130 size_t phsize; /* Size of program header in bytes */
131 const char *interp; /* Pathname of the interpreter, if any */
133 /* TLS information */
134 int tlsindex; /* Index in DTV for this module */
135 void *tlsinit; /* Base address of TLS init block */
136 size_t tlsinitsize; /* Size of TLS init block for this module */
137 size_t tlssize; /* Size of TLS block for this module */
138 size_t tlsoffset; /* Offset of static TLS block for this module */
139 size_t tlsalign; /* Alignment of static TLS block */
141 /* Items from the dynamic section. */
142 Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */
143 const Elf_Rel *rel; /* Relocation entries */
144 unsigned long relsize; /* Size in bytes of relocation info */
145 const Elf_Rela *rela; /* Relocation entries with addend */
146 unsigned long relasize; /* Size in bytes of addend relocation info */
147 const Elf_Rel *pltrel; /* PLT relocation entries */
148 unsigned long pltrelsize; /* Size in bytes of PLT relocation info */
149 const Elf_Rela *pltrela; /* PLT relocation entries with addend */
150 unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */
151 const Elf_Sym *symtab; /* Symbol table */
152 const char *strtab; /* String table */
153 unsigned long strsize; /* Size in bytes of string table */
155 const Elf_Hashelt *buckets; /* Hash table buckets array */
156 unsigned long nbuckets; /* Number of buckets */
157 const Elf_Hashelt *chains; /* Hash table chain array */
158 unsigned long nchains; /* Number of chains */
160 const char *rpath; /* Search path specified in object */
161 Needed_Entry *needed; /* Shared objects needed by this one (%) */
163 InitFunc init; /* Initialization function to call */
164 InitFunc fini; /* Termination function to call */
166 bool mainprog; /* True if this is the main program */
167 bool rtld; /* True if this is the dynamic linker */
168 bool textrel; /* True if there are relocations to text seg */
169 bool symbolic; /* True if generated with "-Bsymbolic" */
170 bool bind_now; /* True if all relocations should be made first */
171 bool traced; /* Already printed in ldd trace output */
172 bool jmpslots_done; /* Already have relocated the jump slots */
173 bool init_done; /* Already have added object to init list */
174 bool tls_done; /* Already allocated offset for static TLS */
176 struct link_map linkmap; /* for GDB and dlinfo() */
177 Objlist dldags; /* Object belongs to these dlopened DAGs (%) */
178 Objlist dagmembers; /* DAG has these members (%) */
179 dev_t dev; /* Object's filesystem's device */
180 ino_t ino; /* Object's inode number */
181 void *priv; /* Platform-dependant */
184 #define RTLD_MAGIC 0xd550b87a
185 #define RTLD_VERSION 1
188 * Symbol cache entry used during relocation to avoid multiple lookups
189 * of the same symbol.
191 typedef struct Struct_SymCache {
192 const Elf_Sym *sym; /* Symbol table entry */
193 const Obj_Entry *obj; /* Shared object which defines it */
196 void _rtld_error(const char *, ...) __printflike(1, 2);
197 Obj_Entry *map_object(int, const char *, const struct stat *);
198 void *xcalloc(size_t);
199 void *xmalloc(size_t);
200 void *xrealloc(void *, size_t);
201 char *xstrdup(const char *);
203 void dump_relocations(Obj_Entry *);
204 void dump_obj_relocations(Obj_Entry *);
205 void dump_Elf_Rel(Obj_Entry *, const Elf_Rel *, u_long);
206 void dump_Elf_Rela(Obj_Entry *, const Elf_Rela *, u_long);
208 extern Elf_Addr _GLOBAL_OFFSET_TABLE_[];
211 * Function declarations.
213 const char *basename(const char *);
214 int do_copy_relocations(Obj_Entry *);
216 unsigned long elf_hash(const char *);
217 const Elf_Sym *find_symdef(unsigned long, const Obj_Entry *,
218 const Obj_Entry **, bool, SymCache *);
219 void init_pltgot(Obj_Entry *);
220 void lockdflt_init(LockInfo *);
221 void obj_free(Obj_Entry *);
222 Obj_Entry *obj_new(void);
223 int reloc_non_plt(Obj_Entry *, Obj_Entry *);
224 int reloc_plt(Obj_Entry *);
225 int reloc_jmpslots(Obj_Entry *);
226 void _rtld_bind_start(void);
227 const Elf_Sym *symlook_obj(const char *, unsigned long, const Obj_Entry *,
230 void *tls_get_addr_common(void **, int, size_t);
231 struct tls_tcb *allocate_tls(Obj_Entry *);
232 void free_tls(struct tls_tcb *);
233 void *allocate_module_tls(int);
234 bool allocate_tls_offset(Obj_Entry *);
235 void free_tls_offset(Obj_Entry *);
236 void allocate_initial_tls(Obj_Entry *);