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 * $FreeBSD$ 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_lock.h" 40 #include "rtld_machdep.h" 41 42 #ifdef COMPAT_32BIT 43 #undef STANDARD_LIBRARY_PATH 44 #undef _PATH_ELF_HINTS 45 #define _PATH_ELF_HINTS "/var/run/ld-elf32.so.hints" 46 /* For running 32 bit binaries */ 47 #define STANDARD_LIBRARY_PATH "/lib32:/usr/lib32" 48 #define LD_ "LD_32_" 49 #endif 50 51 #ifndef STANDARD_LIBRARY_PATH 52 #define STANDARD_LIBRARY_PATH "/lib:/usr/lib" 53 #endif 54 #ifndef LD_ 55 #define LD_ "LD_" 56 #endif 57 58 #define NEW(type) ((type *) xmalloc(sizeof(type))) 59 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 60 61 /* We might as well do booleans like C++. */ 62 typedef unsigned char bool; 63 #define false 0 64 #define true 1 65 66 struct stat; 67 struct Struct_Obj_Entry; 68 69 /* Lists of shared objects */ 70 typedef struct Struct_Objlist_Entry { 71 STAILQ_ENTRY(Struct_Objlist_Entry) link; 72 struct Struct_Obj_Entry *obj; 73 } Objlist_Entry; 74 75 typedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; 76 77 /* Types of init and fini functions */ 78 typedef void (*InitFunc)(void); 79 80 /* Lists of shared object dependencies */ 81 typedef struct Struct_Needed_Entry { 82 struct Struct_Needed_Entry *next; 83 struct Struct_Obj_Entry *obj; 84 unsigned long name; /* Offset of name in string table */ 85 } Needed_Entry; 86 87 /* Lock object */ 88 typedef struct Struct_LockInfo { 89 void *context; /* Client context for creating locks */ 90 void *thelock; /* The one big lock */ 91 /* Debugging aids. */ 92 volatile int rcount; /* Number of readers holding lock */ 93 volatile int wcount; /* Number of writers holding lock */ 94 /* Methods */ 95 void *(*lock_create)(void *context); 96 void (*rlock_acquire)(void *lock); 97 void (*wlock_acquire)(void *lock); 98 void (*rlock_release)(void *lock); 99 void (*wlock_release)(void *lock); 100 void (*lock_destroy)(void *lock); 101 void (*context_destroy)(void *context); 102 } LockInfo; 103 104 /* 105 * Shared object descriptor. 106 * 107 * Items marked with "(%)" are dynamically allocated, and must be freed 108 * when the structure is destroyed. 109 * 110 * CAUTION: It appears that the JDK port peeks into these structures. 111 * It looks at "next" and "mapbase" at least. Don't add new members 112 * near the front, until this can be straightened out. 113 */ 114 typedef struct Struct_Obj_Entry { 115 /* 116 * These two items have to be set right for compatibility with the 117 * original ElfKit crt1.o. 118 */ 119 Elf_Word magic; /* Magic number (sanity check) */ 120 Elf_Word version; /* Version number of struct format */ 121 122 struct Struct_Obj_Entry *next; 123 char *path; /* Pathname of underlying file (%) */ 124 char *origin_path; /* Directory path of origin file */ 125 int refcount; 126 int dl_refcount; /* Number of times loaded by dlopen */ 127 128 /* These items are computed by map_object() or by digest_phdr(). */ 129 caddr_t mapbase; /* Base address of mapped region */ 130 size_t mapsize; /* Size of mapped region in bytes */ 131 size_t textsize; /* Size of text segment in bytes */ 132 Elf_Addr vaddrbase; /* Base address in shared object file */ 133 caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ 134 const Elf_Dyn *dynamic; /* Dynamic section */ 135 caddr_t entry; /* Entry point */ 136 const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ 137 size_t phsize; /* Size of program header in bytes */ 138 const char *interp; /* Pathname of the interpreter, if any */ 139 140 /* Items from the dynamic section. */ 141 Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ 142 const Elf_Rel *rel; /* Relocation entries */ 143 unsigned long relsize; /* Size in bytes of relocation info */ 144 const Elf_Rela *rela; /* Relocation entries with addend */ 145 unsigned long relasize; /* Size in bytes of addend relocation info */ 146 const Elf_Rel *pltrel; /* PLT relocation entries */ 147 unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ 148 const Elf_Rela *pltrela; /* PLT relocation entries with addend */ 149 unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */ 150 const Elf_Sym *symtab; /* Symbol table */ 151 const char *strtab; /* String table */ 152 unsigned long strsize; /* Size in bytes of string table */ 153 154 const Elf_Hashelt *buckets; /* Hash table buckets array */ 155 unsigned long nbuckets; /* Number of buckets */ 156 const Elf_Hashelt *chains; /* Hash table chain array */ 157 unsigned long nchains; /* Number of chains */ 158 159 const char *rpath; /* Search path specified in object */ 160 Needed_Entry *needed; /* Shared objects needed by this one (%) */ 161 162 Elf_Addr init; /* Initialization function to call */ 163 Elf_Addr fini; /* Termination function to call */ 164 165 bool mainprog; /* True if this is the main program */ 166 bool rtld; /* True if this is the dynamic linker */ 167 bool textrel; /* True if there are relocations to text seg */ 168 bool symbolic; /* True if generated with "-Bsymbolic" */ 169 bool bind_now; /* True if all relocations should be made first */ 170 bool traced; /* Already printed in ldd trace output */ 171 bool jmpslots_done; /* Already have relocated the jump slots */ 172 bool init_done; /* Already have added object to init list */ 173 174 struct link_map linkmap; /* for GDB and dlinfo() */ 175 Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ 176 Objlist dagmembers; /* DAG has these members (%) */ 177 dev_t dev; /* Object's filesystem's device */ 178 ino_t ino; /* Object's inode number */ 179 void *priv; /* Platform-dependant */ 180 } Obj_Entry; 181 182 #define RTLD_MAGIC 0xd550b87a 183 #define RTLD_VERSION 1 184 185 /* 186 * Symbol cache entry used during relocation to avoid multiple lookups 187 * of the same symbol. 188 */ 189 typedef struct Struct_SymCache { 190 const Elf_Sym *sym; /* Symbol table entry */ 191 const Obj_Entry *obj; /* Shared object which defines it */ 192 } SymCache; 193 194 extern void _rtld_error(const char *, ...) __printflike(1, 2); 195 extern Obj_Entry *map_object(int, const char *, const struct stat *); 196 extern void *xcalloc(size_t); 197 extern void *xmalloc(size_t); 198 extern char *xstrdup(const char *); 199 extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; 200 201 extern void dump_relocations (Obj_Entry *); 202 extern void dump_obj_relocations (Obj_Entry *); 203 extern void dump_Elf_Rel (Obj_Entry *, const Elf_Rel *, u_long); 204 extern void dump_Elf_Rela (Obj_Entry *, const Elf_Rela *, u_long); 205 206 /* 207 * Function declarations. 208 */ 209 unsigned long elf_hash(const char *); 210 const Elf_Sym *find_symdef(unsigned long, const Obj_Entry *, 211 const Obj_Entry **, bool, SymCache *); 212 void init_pltgot(Obj_Entry *); 213 void lockdflt_init(void); 214 void obj_free(Obj_Entry *); 215 Obj_Entry *obj_new(void); 216 void _rtld_bind_start(void); 217 const Elf_Sym *symlook_obj(const char *, unsigned long, 218 const Obj_Entry *, bool); 219 220 /* 221 * MD function declarations. 222 */ 223 int do_copy_relocations(Obj_Entry *); 224 int reloc_non_plt(Obj_Entry *, Obj_Entry *); 225 int reloc_plt(Obj_Entry *); 226 int reloc_jmpslots(Obj_Entry *); 227 228 #endif /* } */ 229