rtld.h revision 127250
1219820Sjeff/*- 2219820Sjeff * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 3219820Sjeff * All rights reserved. 4219820Sjeff * 5219820Sjeff * Redistribution and use in source and binary forms, with or without 6219820Sjeff * modification, are permitted provided that the following conditions 7219820Sjeff * are met: 8219820Sjeff * 1. Redistributions of source code must retain the above copyright 9219820Sjeff * notice, this list of conditions and the following disclaimer. 10219820Sjeff * 2. Redistributions in binary form must reproduce the above copyright 11219820Sjeff * notice, this list of conditions and the following disclaimer in the 12219820Sjeff * documentation and/or other materials provided with the distribution. 13219820Sjeff * 14219820Sjeff * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15219820Sjeff * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16219820Sjeff * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17219820Sjeff * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18219820Sjeff * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19219820Sjeff * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20219820Sjeff * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21219820Sjeff * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22219820Sjeff * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23219820Sjeff * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24219820Sjeff * 25219820Sjeff * $FreeBSD: head/libexec/rtld-elf/rtld.h 127250 2004-03-21 01:21:26Z peter $ 26219820Sjeff */ 27219820Sjeff 28219820Sjeff#ifndef RTLD_H /* { */ 29219820Sjeff#define RTLD_H 1 30219820Sjeff 31219820Sjeff#include <machine/elf.h> 32219820Sjeff#include <sys/types.h> 33219820Sjeff#include <sys/queue.h> 34219820Sjeff 35219820Sjeff#include <elf-hints.h> 36219820Sjeff#include <link.h> 37219820Sjeff#include <stddef.h> 38219820Sjeff 39219820Sjeff#include "rtld_lock.h" 40219820Sjeff#include "rtld_machdep.h" 41219820Sjeff 42219820Sjeff#ifdef COMPAT_32BIT 43219820Sjeff#undef STANDARD_LIBRARY_PATH 44219820Sjeff#undef _PATH_ELF_HINTS 45219820Sjeff#define _PATH_ELF_HINTS "/var/run/ld-elf32.so.hints" 46219820Sjeff/* For running 32 bit binaries */ 47219820Sjeff#define STANDARD_LIBRARY_PATH "/lib32:/usr/lib32" 48219820Sjeff#define LD_ "LD_32_" 49219820Sjeff#endif 50219820Sjeff 51219820Sjeff#ifndef STANDARD_LIBRARY_PATH 52219820Sjeff#define STANDARD_LIBRARY_PATH "/lib:/usr/lib" 53219820Sjeff#endif 54219820Sjeff#ifndef LD_ 55219820Sjeff#define LD_ "LD_" 56219820Sjeff#endif 57219820Sjeff 58219820Sjeff#define NEW(type) ((type *) xmalloc(sizeof(type))) 59219820Sjeff#define CNEW(type) ((type *) xcalloc(sizeof(type))) 60219820Sjeff 61219820Sjeff/* We might as well do booleans like C++. */ 62219820Sjefftypedef unsigned char bool; 63219820Sjeff#define false 0 64219820Sjeff#define true 1 65219820Sjeff 66219820Sjeffstruct stat; 67219820Sjeffstruct Struct_Obj_Entry; 68219820Sjeff 69219820Sjeff/* Lists of shared objects */ 70219820Sjefftypedef struct Struct_Objlist_Entry { 71219820Sjeff STAILQ_ENTRY(Struct_Objlist_Entry) link; 72219820Sjeff struct Struct_Obj_Entry *obj; 73219820Sjeff} Objlist_Entry; 74219820Sjeff 75219820Sjefftypedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; 76219820Sjeff 77219820Sjeff/* Types of init and fini functions */ 78219820Sjefftypedef void (*InitFunc)(void); 79219820Sjeff 80219820Sjeff/* Lists of shared object dependencies */ 81219820Sjefftypedef struct Struct_Needed_Entry { 82219820Sjeff struct Struct_Needed_Entry *next; 83219820Sjeff struct Struct_Obj_Entry *obj; 84219820Sjeff unsigned long name; /* Offset of name in string table */ 85219820Sjeff} Needed_Entry; 86219820Sjeff 87219820Sjeff/* Lock object */ 88219820Sjefftypedef struct Struct_LockInfo { 89219820Sjeff void *context; /* Client context for creating locks */ 90219820Sjeff void *thelock; /* The one big lock */ 91219820Sjeff /* Debugging aids. */ 92219820Sjeff volatile int rcount; /* Number of readers holding lock */ 93219820Sjeff volatile int wcount; /* Number of writers holding lock */ 94219820Sjeff /* Methods */ 95219820Sjeff void *(*lock_create)(void *context); 96219820Sjeff void (*rlock_acquire)(void *lock); 97219820Sjeff void (*wlock_acquire)(void *lock); 98219820Sjeff void (*rlock_release)(void *lock); 99219820Sjeff void (*wlock_release)(void *lock); 100219820Sjeff void (*lock_destroy)(void *lock); 101219820Sjeff 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 */ 114typedef 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 */ 189typedef struct Struct_SymCache { 190 const Elf_Sym *sym; /* Symbol table entry */ 191 const Obj_Entry *obj; /* Shared object which defines it */ 192} SymCache; 193 194extern void _rtld_error(const char *, ...) __printflike(1, 2); 195extern Obj_Entry *map_object(int, const char *, const struct stat *); 196extern void *xcalloc(size_t); 197extern void *xmalloc(size_t); 198extern char *xstrdup(const char *); 199extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; 200 201extern void dump_relocations (Obj_Entry *); 202extern void dump_obj_relocations (Obj_Entry *); 203extern void dump_Elf_Rel (Obj_Entry *, const Elf_Rel *, u_long); 204extern void dump_Elf_Rela (Obj_Entry *, const Elf_Rela *, u_long); 205 206/* 207 * Function declarations. 208 */ 209unsigned long elf_hash(const char *); 210const Elf_Sym *find_symdef(unsigned long, const Obj_Entry *, 211 const Obj_Entry **, bool, SymCache *); 212void init_pltgot(Obj_Entry *); 213void lockdflt_init(void); 214void obj_free(Obj_Entry *); 215Obj_Entry *obj_new(void); 216void _rtld_bind_start(void); 217const Elf_Sym *symlook_obj(const char *, unsigned long, 218 const Obj_Entry *, bool); 219 220/* 221 * MD function declarations. 222 */ 223int do_copy_relocations(Obj_Entry *); 224int reloc_non_plt(Obj_Entry *, Obj_Entry *); 225int reloc_plt(Obj_Entry *); 226int reloc_jmpslots(Obj_Entry *); 227 228#endif /* } */ 229