rtld.h revision 1.20
1 /* $NetBSD: rtld.h,v 1.20 1999/12/05 18:36:25 fredb Exp $ */ 2 3 /* 4 * Copyright 1996 John D. Polstra. 5 * Copyright 1996 Matt Thomas <matt (at) 3am-software.com> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by John Polstra. 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #ifndef RTLD_H 35 #define RTLD_H 36 37 #include <dlfcn.h> 38 #include <stddef.h> 39 #include <sys/param.h> 40 #include <sys/types.h> 41 #include <sys/queue.h> 42 #include <sys/exec_elf.h> 43 #include "rtldenv.h" 44 #include "link.h" 45 46 #if defined(_RTLD_SOURCE) 47 48 #define RTLD_DEFAULT_LIBRARY_PATH "/usr/lib" 49 #define _PATH_LD_HINTS "/etc/ld.so.conf" 50 51 #if 0 52 #define SVR4_LIBDIR "/usr/lib" 53 #endif 54 55 #define LIBDIRLEN (sizeof LIBDIR - 1) 56 #define SVR4_LIBDIRLEN (sizeof SVR4_LIBDIR - 1) 57 58 #ifndef PAGESIZE 59 # ifdef VARPSZ 60 extern int _rtld_pagesz; 61 # ifdef RTLD_DEBUG 62 # define PAGESIZE (assert(_rtld_pagesz), _rtld_pagesz) 63 # else 64 # define PAGESIZE _rtld_pagesz 65 # endif 66 # else 67 # ifndef __sparc__ 68 # define PAGESIZE NBPG 69 # else 70 #error "Sparc has a variable page size" 71 # endif 72 # endif 73 #endif 74 75 #define round_down(x) ((x) & ~(PAGESIZE-1)) 76 #define round_up(x) round_down((x) + PAGESIZE - 1) 77 78 #define NEW(type) ((type *) xmalloc(sizeof(type))) 79 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 80 81 #endif /* _RTLD_SOURCE */ 82 83 /* 84 * C++ has mandated the use of the following keywords for its new boolean 85 * type. We might as well follow their lead. 86 */ 87 typedef enum { 88 false = 0, 89 true = 1 90 } bool; 91 92 struct Struct_Obj_Entry; 93 94 typedef struct Struct_Objlist_Entry { 95 SIMPLEQ_ENTRY(Struct_Objlist_Entry) link; 96 struct Struct_Obj_Entry *obj; 97 } Objlist_Entry; 98 99 typedef SIMPLEQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; 100 101 typedef struct Struct_Needed_Entry { 102 struct Struct_Needed_Entry *next; 103 struct Struct_Obj_Entry *obj; 104 unsigned long name; /* Offset of name in string table */ 105 } Needed_Entry; 106 107 typedef struct _rtld_search_path_t { 108 struct _rtld_search_path_t *sp_next; 109 const char *sp_path; 110 size_t sp_pathlen; 111 } Search_Path; 112 113 /* 114 * Shared object descriptor. 115 * 116 * Items marked with "(%)" are dynamically allocated, and must be freed 117 * when the structure is destroyed. 118 */ 119 120 #define RTLD_MAGIC 0xd550b87a 121 #define RTLD_VERSION 1 122 123 typedef struct Struct_Obj_Entry { 124 Elf32_Word magic; /* Magic number (sanity check) */ 125 Elf32_Word version; /* Version number of struct format */ 126 127 struct Struct_Obj_Entry *next; 128 char *path; /* Pathname of underlying file (%) */ 129 int refcount; 130 int dl_refcount; /* Number of times loaded by dlopen */ 131 132 /* These items are computed by map_object() or by digest_phdr(). */ 133 caddr_t mapbase; /* Base address of mapped region */ 134 size_t mapsize; /* Size of mapped region in bytes */ 135 size_t textsize; /* Size of text segment in bytes */ 136 Elf_Addr vaddrbase; /* Base address in shared object file */ 137 caddr_t relocbase; /* Reloc const = mapbase - *vaddrbase */ 138 Elf_Dyn *dynamic; /* Dynamic section */ 139 caddr_t entry; /* Entry point */ 140 const Elf_Phdr *phdr; /* Program header if mapped, ow NULL */ 141 size_t phsize; /* Size of program header in bytes */ 142 143 /* Items from the dynamic section. */ 144 Elf_Addr *pltgot; /* PLTGOT table */ 145 const Elf_Rel *rel; /* Relocation entries */ 146 const Elf_Rel *rellim; /* Limit of Relocation entries */ 147 const Elf_RelA *rela; /* Relocation entries */ 148 const Elf_RelA *relalim; /* Limit of Relocation entries */ 149 const Elf_Rel *pltrel; /* PLT relocation entries */ 150 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 151 const Elf_RelA *pltrela; /* PLT relocation entries */ 152 const Elf_RelA *pltrelalim; /* Limit of PLT relocation entries */ 153 const Elf_Sym *symtab; /* Symbol table */ 154 const char *strtab; /* String table */ 155 unsigned long strsize; /* Size in bytes of string table */ 156 #if defined(__mips__) 157 Elf_Word local_gotno; /* Number of local GOT entries */ 158 Elf_Word symtabno; /* Number of dynamic symbols */ 159 Elf_Word gotsym; /* First dynamic symbol in GOT */ 160 #endif 161 162 const Elf_Word *buckets; /* Hash table buckets array */ 163 unsigned long nbuckets; /* Number of buckets */ 164 const Elf_Word *chains; /* Hash table chain array */ 165 unsigned long nchains; /* Number of chains */ 166 167 Search_Path *rpaths; /* Search path specified in object */ 168 Needed_Entry *needed; /* Shared objects needed by this (%) */ 169 170 void (*init) /* Initialization function to call */ 171 __P((void)); 172 void (*fini) /* Termination function to call */ 173 __P((void)); 174 175 /* Entry points for dlopen() and friends. */ 176 void *(*dlopen) __P((const char *, int)); 177 void *(*dlsym) __P((void *, const char *)); 178 char *(*dlerror) __P((void)); 179 int (*dlclose) __P((void *)); 180 181 int mainprog:1; /* True if this is the main program */ 182 int rtld:1; /* True if this is the dynamic linker */ 183 int textrel:1; /* True if there are relocations to 184 * text seg */ 185 int symbolic:1; /* True if generated with 186 * "-Bsymbolic" */ 187 int printed:1; /* True if ldd has printed it */ 188 189 struct link_map linkmap; /* for GDB */ 190 191 /* These items are computed by map_object() or by digest_phdr(). */ 192 const char *interp; /* Pathname of the interpreter, if any */ 193 Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ 194 Objlist dagmembers; /* DAG has these members (%) */ 195 dev_t dev; /* Object's filesystem's device */ 196 ino_t ino; /* Object's inode number */ 197 unsigned long mark; /* Set to "_rtld_curmark" to avoid 198 repeat visits */ 199 } Obj_Entry; 200 201 #if defined(_RTLD_SOURCE) 202 203 extern struct r_debug _rtld_debug; 204 extern Search_Path *_rtld_default_paths; 205 extern Obj_Entry *_rtld_objlist; 206 extern Obj_Entry **_rtld_objtail; 207 extern Obj_Entry *_rtld_objmain; 208 extern Obj_Entry _rtld_objself; 209 extern Search_Path *_rtld_paths; 210 extern bool _rtld_trust; 211 extern const char *_rtld_error_message; 212 extern unsigned long _rtld_curmark; 213 extern Objlist _rtld_list_global; 214 extern Objlist _rtld_list_main; 215 extern Elf_Sym _rtld_sym_zero; 216 217 /* rtld_start.S */ 218 void _rtld_bind_start __P((void)); 219 220 /* rtld.c */ 221 void _rtld_error __P((const char *, ...)); 222 void _rtld_die __P((void)); 223 char *_rtld_dlerror __P((void)); 224 void *_rtld_dlopen __P((const char *, int)); 225 void *_rtld_dlsym __P((void *, const char *)); 226 int _rtld_dlclose __P((void *)); 227 int _rtld_dladdr __P((const void *, Dl_info *)); 228 void _rtld_debug_state __P((void)); 229 void _rtld_linkmap_add __P((Obj_Entry *)); 230 void _rtld_linkmap_delete __P((Obj_Entry *)); 231 232 /* headers.c */ 233 void _rtld_digest_dynamic __P((Obj_Entry *)); 234 Obj_Entry *_rtld_digest_phdr __P((const Elf_Phdr *, int, caddr_t)); 235 236 /* load.c */ 237 Obj_Entry *_rtld_load_object __P((char *, bool)); 238 int _rtld_load_needed_objects __P((Obj_Entry *)); 239 int _rtld_preload __P((const char *, bool)); 240 241 /* path.c */ 242 void _rtld_add_paths __P((Search_Path **, const char *, bool)); 243 void _rtld_process_hints __P((Search_Path **, const char *, bool)); 244 245 /* reloc.c */ 246 int _rtld_do_copy_relocations __P((const Obj_Entry *, bool)); 247 caddr_t _rtld_bind __P((Obj_Entry *, Elf_Word)); 248 int _rtld_relocate_objects __P((Obj_Entry *, bool, bool)); 249 int _rtld_relocate_nonplt_object __P((Obj_Entry *, 250 const Elf_RelA *, bool)); 251 int _rtld_relocate_plt_object __P((Obj_Entry *, const Elf_RelA *, 252 caddr_t *, bool, bool)); 253 254 /* search.c */ 255 char *_rtld_find_library __P((const char *, const Obj_Entry *)); 256 257 /* symbol.c */ 258 unsigned long _rtld_elf_hash __P((const char *)); 259 const Elf_Sym *_rtld_symlook_obj __P((const char *, unsigned long, 260 const Obj_Entry *, bool)); 261 const Elf_Sym *_rtld_find_symdef __P((const Obj_Entry *, Elf_Word, 262 const char *, Obj_Entry *, const Obj_Entry **, bool)); 263 const Elf_Sym *_rtld_symlook_list(const char *, unsigned long, 264 Objlist *, const Obj_Entry **, bool in_plt); 265 266 /* map_object.c */ 267 Obj_Entry *_rtld_map_object __P((const char *, int, const struct stat *)); 268 void _rtld_obj_free(Obj_Entry *); 269 Obj_Entry *_rtld_obj_new(void); 270 271 #if defined(__mips__) 272 /* mips_reloc.c */ 273 void _rtld_relocate_mips_got __P((Obj_Entry *)); 274 caddr_t _rtld_bind_mips __P((Elf_Word, Elf_Addr, Elf_Addr, Elf_Addr)); 275 #endif 276 277 #if defined(__powerpc__) 278 /* ppc_reloc.c */ 279 caddr_t _rtld_bind_powerpc __P((Obj_Entry *, Elf_Word)); 280 int _rtld_reloc_powerpc_plt __P((Obj_Entry *, const Elf_RelA *, bool)); 281 void _rtld_setup_powerpc_plt __P((const Obj_Entry *)); 282 #endif 283 284 #endif /* _RTLD_SOURCE */ 285 286 #endif /* RTLD_H */ 287
Indexes created Tue Sep 30 07:10:03 GMT 2025