rtld.h revision 1.22
1 /* $NetBSD: rtld.h,v 1.22 1999/12/15 05:22:37 christos 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 #define RTLD_MAX_ENTRY 10 115 #define RTLD_MAX_LIBRARY 4 116 #define RTLD_MAX_CTL 2 117 typedef struct _rtld_library_xform_t { 118 struct _rtld_library_xform_t *next; 119 char *name; 120 int ctl[RTLD_MAX_CTL]; 121 int ctltype[RTLD_MAX_CTL]; 122 int ctlmax; 123 struct { 124 char *value; 125 char *library[RTLD_MAX_LIBRARY]; 126 } entry[RTLD_MAX_ENTRY]; 127 } Library_Xform; 128 129 /* 130 * Shared object descriptor. 131 * 132 * Items marked with "(%)" are dynamically allocated, and must be freed 133 * when the structure is destroyed. 134 */ 135 136 #define RTLD_MAGIC 0xd550b87a 137 #define RTLD_VERSION 1 138 139 typedef struct Struct_Obj_Entry { 140 Elf32_Word magic; /* Magic number (sanity check) */ 141 Elf32_Word version; /* Version number of struct format */ 142 143 struct Struct_Obj_Entry *next; 144 char *path; /* Pathname of underlying file (%) */ 145 int refcount; 146 int dl_refcount; /* Number of times loaded by dlopen */ 147 148 /* These items are computed by map_object() or by digest_phdr(). */ 149 caddr_t mapbase; /* Base address of mapped region */ 150 size_t mapsize; /* Size of mapped region in bytes */ 151 size_t textsize; /* Size of text segment in bytes */ 152 Elf_Addr vaddrbase; /* Base address in shared object file */ 153 caddr_t relocbase; /* Reloc const = mapbase - *vaddrbase */ 154 Elf_Dyn *dynamic; /* Dynamic section */ 155 caddr_t entry; /* Entry point */ 156 const Elf_Phdr *phdr; /* Program header if mapped, ow NULL */ 157 size_t phsize; /* Size of program header in bytes */ 158 159 /* Items from the dynamic section. */ 160 Elf_Addr *pltgot; /* PLTGOT table */ 161 const Elf_Rel *rel; /* Relocation entries */ 162 const Elf_Rel *rellim; /* Limit of Relocation entries */ 163 const Elf_RelA *rela; /* Relocation entries */ 164 const Elf_RelA *relalim; /* Limit of Relocation entries */ 165 const Elf_Rel *pltrel; /* PLT relocation entries */ 166 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 167 const Elf_RelA *pltrela; /* PLT relocation entries */ 168 const Elf_RelA *pltrelalim; /* Limit of PLT relocation entries */ 169 const Elf_Sym *symtab; /* Symbol table */ 170 const char *strtab; /* String table */ 171 unsigned long strsize; /* Size in bytes of string table */ 172 #if defined(__mips__) 173 Elf_Word local_gotno; /* Number of local GOT entries */ 174 Elf_Word symtabno; /* Number of dynamic symbols */ 175 Elf_Word gotsym; /* First dynamic symbol in GOT */ 176 #endif 177 178 const Elf_Word *buckets; /* Hash table buckets array */ 179 unsigned long nbuckets; /* Number of buckets */ 180 const Elf_Word *chains; /* Hash table chain array */ 181 unsigned long nchains; /* Number of chains */ 182 183 Search_Path *rpaths; /* Search path specified in object */ 184 Needed_Entry *needed; /* Shared objects needed by this (%) */ 185 186 void (*init) /* Initialization function to call */ 187 __P((void)); 188 void (*fini) /* Termination function to call */ 189 __P((void)); 190 191 /* Entry points for dlopen() and friends. */ 192 void *(*dlopen) __P((const char *, int)); 193 void *(*dlsym) __P((void *, const char *)); 194 char *(*dlerror) __P((void)); 195 int (*dlclose) __P((void *)); 196 197 int mainprog:1; /* True if this is the main program */ 198 int rtld:1; /* True if this is the dynamic linker */ 199 int textrel:1; /* True if there are relocations to 200 * text seg */ 201 int symbolic:1; /* True if generated with 202 * "-Bsymbolic" */ 203 int printed:1; /* True if ldd has printed it */ 204 205 struct link_map linkmap; /* for GDB */ 206 207 /* These items are computed by map_object() or by digest_phdr(). */ 208 const char *interp; /* Pathname of the interpreter, if any */ 209 Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ 210 Objlist dagmembers; /* DAG has these members (%) */ 211 dev_t dev; /* Object's filesystem's device */ 212 ino_t ino; /* Object's inode number */ 213 unsigned long mark; /* Set to "_rtld_curmark" to avoid 214 repeat visits */ 215 } Obj_Entry; 216 217 #if defined(_RTLD_SOURCE) 218 219 extern struct r_debug _rtld_debug; 220 extern Search_Path *_rtld_default_paths; 221 extern Obj_Entry *_rtld_objlist; 222 extern Obj_Entry **_rtld_objtail; 223 extern Obj_Entry *_rtld_objmain; 224 extern Obj_Entry _rtld_objself; 225 extern Search_Path *_rtld_paths; 226 extern Library_Xform *_rtld_xforms; 227 extern bool _rtld_trust; 228 extern const char *_rtld_error_message; 229 extern unsigned long _rtld_curmark; 230 extern Objlist _rtld_list_global; 231 extern Objlist _rtld_list_main; 232 extern Elf_Sym _rtld_sym_zero; 233 234 /* rtld_start.S */ 235 void _rtld_bind_start __P((void)); 236 237 /* rtld.c */ 238 void _rtld_error __P((const char *, ...)); 239 void _rtld_die __P((void)); 240 char *_rtld_dlerror __P((void)); 241 void *_rtld_dlopen __P((const char *, int)); 242 void *_rtld_dlsym __P((void *, const char *)); 243 int _rtld_dlclose __P((void *)); 244 int _rtld_dladdr __P((const void *, Dl_info *)); 245 void _rtld_debug_state __P((void)); 246 void _rtld_linkmap_add __P((Obj_Entry *)); 247 void _rtld_linkmap_delete __P((Obj_Entry *)); 248 249 /* headers.c */ 250 void _rtld_digest_dynamic __P((Obj_Entry *)); 251 Obj_Entry *_rtld_digest_phdr __P((const Elf_Phdr *, int, caddr_t)); 252 253 /* load.c */ 254 Obj_Entry *_rtld_load_object __P((char *, bool)); 255 int _rtld_load_needed_objects __P((Obj_Entry *, bool)); 256 int _rtld_preload __P((const char *, bool)); 257 258 /* path.c */ 259 void _rtld_add_paths __P((Search_Path **, const char *, bool)); 260 void _rtld_process_hints __P((Search_Path **, Library_Xform **, const char *, 261 bool)); 262 263 /* reloc.c */ 264 int _rtld_do_copy_relocations __P((const Obj_Entry *, bool)); 265 caddr_t _rtld_bind __P((Obj_Entry *, Elf_Word)); 266 int _rtld_relocate_objects __P((Obj_Entry *, bool, bool)); 267 int _rtld_relocate_nonplt_object __P((Obj_Entry *, 268 const Elf_RelA *, bool)); 269 int _rtld_relocate_plt_object __P((Obj_Entry *, const Elf_RelA *, 270 caddr_t *, bool, bool)); 271 272 /* search.c */ 273 char *_rtld_find_library __P((const char *, const Obj_Entry *)); 274 275 /* symbol.c */ 276 unsigned long _rtld_elf_hash __P((const char *)); 277 const Elf_Sym *_rtld_symlook_obj __P((const char *, unsigned long, 278 const Obj_Entry *, bool)); 279 const Elf_Sym *_rtld_find_symdef __P((const Obj_Entry *, Elf_Word, 280 const char *, Obj_Entry *, const Obj_Entry **, bool)); 281 const Elf_Sym *_rtld_symlook_list(const char *, unsigned long, 282 Objlist *, const Obj_Entry **, bool in_plt); 283 284 /* map_object.c */ 285 Obj_Entry *_rtld_map_object __P((const char *, int, const struct stat *)); 286 void _rtld_obj_free(Obj_Entry *); 287 Obj_Entry *_rtld_obj_new(void); 288 289 #if defined(__mips__) 290 /* mips_reloc.c */ 291 void _rtld_relocate_mips_got __P((Obj_Entry *)); 292 caddr_t _rtld_bind_mips __P((Elf_Word, Elf_Addr, Elf_Addr, Elf_Addr)); 293 #endif 294 295 #if defined(__powerpc__) 296 /* ppc_reloc.c */ 297 caddr_t _rtld_bind_powerpc __P((Obj_Entry *, Elf_Word)); 298 int _rtld_reloc_powerpc_plt __P((Obj_Entry *, const Elf_RelA *, bool)); 299 void _rtld_setup_powerpc_plt __P((const Obj_Entry *)); 300 #endif 301 302 #endif /* _RTLD_SOURCE */ 303 304 #endif /* RTLD_H */ 305
Indexes created Tue Sep 30 11:09:46 GMT 2025