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 * $DragonFly: src/libexec/rtld-elf/rtld.h,v 1.11 2005/05/11 19:47:06 dillon Exp $ 27 */ 28 29 #ifndef RTLD_H /* { */ 30 #define RTLD_H 1 31 32 #include <machine/elf.h> 33 #include <sys/types.h> 34 #include <sys/queue.h> 35 36 #include <elf-hints.h> 37 #include <link.h> 38 #include <stddef.h> 39 40 #include "rtld_machdep.h" 41 42 #ifndef STANDARD_LIBRARY_PATH 43 #define STANDARD_LIBRARY_PATH "/usr/lib" 44 #endif 45 46 #define NEW(type) ((type *) xmalloc(sizeof(type))) 47 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 48 49 /* We might as well do booleans like C++. */ 50 typedef unsigned char bool; 51 #define false 0 52 #define true 1 53 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; 59 60 extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; 61 62 struct stat; 63 struct Struct_Obj_Entry; 64 65 /* Lists of shared objects */ 66 typedef struct Struct_Objlist_Entry { 67 STAILQ_ENTRY(Struct_Objlist_Entry) link; 68 struct Struct_Obj_Entry *obj; 69 } Objlist_Entry; 70 71 typedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; 72 73 /* Types of init and fini functions */ 74 typedef void (*InitFunc)(void); 75 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 */ 81 } Needed_Entry; 82 83 /* Lock object */ 84 typedef struct Struct_LockInfo { 85 void *context; /* Client context for creating locks */ 86 void *thelock; /* The one big lock */ 87 /* Debugging aids. */ 88 volatile int rcount; /* Number of readers holding lock */ 89 volatile int wcount; /* Number of writers holding lock */ 90 /* Methods */ 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); 98 } LockInfo; 99 100 /* 101 * Shared object descriptor. 102 * 103 * Items marked with "(%)" are dynamically allocated, and must be freed 104 * when the structure is destroyed. 105 * 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. 109 */ 110 typedef struct Struct_Obj_Entry { 111 /* 112 * These two items have to be set right for compatibility with the 113 * original ElfKit crt1.o. 114 */ 115 Elf_Word magic; /* Magic number (sanity check) */ 116 Elf_Word version; /* Version number of struct format */ 117 118 struct Struct_Obj_Entry *next; 119 char *path; /* Pathname of underlying file (%) */ 120 char *origin_path; /* Directory path of origin file */ 121 int refcount; 122 int dl_refcount; /* Number of times loaded by dlopen */ 123 124 /* 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 */ 135 136 /* 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 */ 143 144 /* 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 */ 157 158 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 */ 162 163 const char *rpath; /* Search path specified in object */ 164 Needed_Entry *needed; /* Shared objects needed by this one (%) */ 165 166 InitFunc init; /* Initialization function to call */ 167 InitFunc fini; /* Termination function to call */ 168 169 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 */ 178 179 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 */ 184 } Obj_Entry; 185 186 #define RTLD_MAGIC 0xd550b87a 187 #define RTLD_VERSION 1 188 189 /* 190 * Symbol cache entry used during relocation to avoid multiple lookups 191 * of the same symbol. 192 */ 193 typedef struct Struct_SymCache { 194 const Elf_Sym *sym; /* Symbol table entry */ 195 const Obj_Entry *obj; /* Shared object which defines it */ 196 } SymCache; 197 198 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 *); 204 205 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); 209 210 /* 211 * Function declarations. 212 */ 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 *, 227 bool); 228 229 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 *); 236 #endif /* } */ 237