rtld.h revision 1.35
1 /* $NetBSD: rtld.h,v 1.35 2002/09/05 15:38:22 mycroft 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 #ifndef RTLD_DEFAULT_LIBRARY_PATH 49 #define RTLD_DEFAULT_LIBRARY_PATH "/usr/lib" 50 #endif 51 #define _PATH_LD_HINTS "/etc/ld.so.conf" 52 53 #if 0 54 #define SVR4_LIBDIR "/usr/lib" 55 #endif 56 57 #define LIBDIRLEN (sizeof LIBDIR - 1) 58 #define SVR4_LIBDIRLEN (sizeof SVR4_LIBDIR - 1) 59 60 #ifndef PAGESIZE 61 # ifdef VARPSZ 62 extern int _rtld_pagesz; 63 # ifdef RTLD_DEBUG 64 # define PAGESIZE (assert(_rtld_pagesz), _rtld_pagesz) 65 # else 66 # define PAGESIZE _rtld_pagesz 67 # endif 68 # else 69 # ifndef __sparc__ 70 # define PAGESIZE NBPG 71 # else 72 #error "Sparc has a variable page size" 73 # endif 74 # endif 75 #endif 76 77 #define round_down(x) ((x) & ~(PAGESIZE-1)) 78 #define round_up(x) round_down((x) + PAGESIZE - 1) 79 80 #define NEW(type) ((type *) xmalloc(sizeof(type))) 81 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 82 83 #endif /* _RTLD_SOURCE */ 84 85 /* 86 * C++ has mandated the use of the following keywords for its new boolean 87 * type. We might as well follow their lead. 88 */ 89 typedef enum { 90 false = 0, 91 true = 1 92 } bool; 93 94 struct Struct_Obj_Entry; 95 96 typedef struct Struct_Objlist_Entry { 97 SIMPLEQ_ENTRY(Struct_Objlist_Entry) link; 98 struct Struct_Obj_Entry *obj; 99 } Objlist_Entry; 100 101 typedef SIMPLEQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; 102 103 typedef struct Struct_Needed_Entry { 104 struct Struct_Needed_Entry *next; 105 struct Struct_Obj_Entry *obj; 106 unsigned long name; /* Offset of name in string table */ 107 } Needed_Entry; 108 109 typedef struct _rtld_search_path_t { 110 struct _rtld_search_path_t *sp_next; 111 const char *sp_path; 112 size_t sp_pathlen; 113 } Search_Path; 114 115 116 #define RTLD_MAX_ENTRY 10 117 #define RTLD_MAX_LIBRARY 4 118 #define RTLD_MAX_CTL 2 119 typedef struct _rtld_library_xform_t { 120 struct _rtld_library_xform_t *next; 121 char *name; 122 int ctl[RTLD_MAX_CTL]; 123 int ctltype[RTLD_MAX_CTL]; 124 int ctlmax; 125 struct { 126 char *value; 127 char *library[RTLD_MAX_LIBRARY]; 128 } entry[RTLD_MAX_ENTRY]; 129 } Library_Xform; 130 131 /* 132 * Shared object descriptor. 133 * 134 * Items marked with "(%)" are dynamically allocated, and must be freed 135 * when the structure is destroyed. 136 */ 137 138 #define RTLD_MAGIC 0xd550b87a 139 #define RTLD_VERSION 1 140 141 typedef struct Struct_Obj_Entry { 142 Elf32_Word magic; /* Magic number (sanity check) */ 143 Elf32_Word version; /* Version number of struct format */ 144 145 struct Struct_Obj_Entry *next; 146 char *path; /* Pathname of underlying file (%) */ 147 int refcount; 148 int dl_refcount; /* Number of times loaded by dlopen */ 149 150 /* These items are computed by map_object() or by digest_phdr(). */ 151 caddr_t mapbase; /* Base address of mapped region */ 152 size_t mapsize; /* Size of mapped region in bytes */ 153 size_t textsize; /* Size of text segment in bytes */ 154 Elf_Addr vaddrbase; /* Base address in shared object file */ 155 caddr_t relocbase; /* Reloc const = mapbase - *vaddrbase */ 156 Elf_Dyn *dynamic; /* Dynamic section */ 157 caddr_t entry; /* Entry point */ 158 const Elf_Phdr *phdr; /* Program header if mapped, ow NULL */ 159 size_t phsize; /* Size of program header in bytes */ 160 161 /* Items from the dynamic section. */ 162 Elf_Addr *pltgot; /* PLTGOT table */ 163 const Elf_Rel *rel; /* Relocation entries */ 164 const Elf_Rel *rellim; /* Limit of Relocation entries */ 165 const Elf_Rela *rela; /* Relocation entries */ 166 const Elf_Rela *relalim; /* Limit of Relocation entries */ 167 const Elf_Rel *pltrel; /* PLT relocation entries */ 168 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 169 const Elf_Rela *pltrela; /* PLT relocation entries */ 170 const Elf_Rela *pltrelalim; /* Limit of PLT relocation entries */ 171 const Elf_Sym *symtab; /* Symbol table */ 172 const char *strtab; /* String table */ 173 unsigned long strsize; /* Size in bytes of string table */ 174 #if defined(__mips__) 175 Elf_Word local_gotno; /* Number of local GOT entries */ 176 Elf_Word symtabno; /* Number of dynamic symbols */ 177 Elf_Word gotsym; /* First dynamic symbol in GOT */ 178 #endif 179 180 const Elf_Word *buckets; /* Hash table buckets array */ 181 unsigned long nbuckets; /* Number of buckets */ 182 const Elf_Word *chains; /* Hash table chain array */ 183 unsigned long nchains; /* Number of chains */ 184 185 Search_Path *rpaths; /* Search path specified in object */ 186 Needed_Entry *needed; /* Shared objects needed by this (%) */ 187 188 void (*init) /* Initialization function to call */ 189 __P((void)); 190 void (*fini) /* Termination function to call */ 191 __P((void)); 192 193 /* Entry points for dlopen() and friends. */ 194 void *(*dlopen) __P((const char *, int)); 195 void *(*dlsym) __P((void *, const char *)); 196 char *(*dlerror) __P((void)); 197 int (*dlclose) __P((void *)); 198 int (*dladdr) __P((const void *, Dl_info *)); 199 200 u_int32_t mainprog:1, /* True if this is the main program */ 201 rtld:1, /* True if this is the dynamic linker */ 202 textrel:1, /* True if there are relocations to 203 * text seg */ 204 symbolic:1, /* True if generated with 205 * "-Bsymbolic" */ 206 printed:1; /* True if ldd has printed it */ 207 208 struct link_map linkmap; /* for GDB */ 209 210 /* These items are computed by map_object() or by digest_phdr(). */ 211 const char *interp; /* Pathname of the interpreter, if any */ 212 Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ 213 Objlist dagmembers; /* DAG has these members (%) */ 214 dev_t dev; /* Object's filesystem's device */ 215 ino_t ino; /* Object's inode number */ 216 unsigned long mark; /* Set to "_rtld_curmark" to avoid 217 repeat visits */ 218 } Obj_Entry; 219 220 #if defined(_RTLD_SOURCE) 221 222 extern struct r_debug _rtld_debug; 223 extern Search_Path *_rtld_default_paths; 224 extern Obj_Entry *_rtld_objlist; 225 extern Obj_Entry **_rtld_objtail; 226 extern Obj_Entry *_rtld_objmain; 227 extern Obj_Entry _rtld_objself; 228 extern Search_Path *_rtld_paths; 229 extern Library_Xform *_rtld_xforms; 230 extern bool _rtld_trust; 231 extern const char *_rtld_error_message; 232 extern unsigned long _rtld_curmark; 233 extern Objlist _rtld_list_global; 234 extern Objlist _rtld_list_main; 235 extern Elf_Sym _rtld_sym_zero; 236 237 /* rtld_start.S */ 238 void _rtld_bind_start __P((void)); 239 240 /* rtld.c */ 241 void _rtld_error __P((const char *, ...)) 242 __attribute__((__format__(__printf__,1,2))); 243 void _rtld_die __P((void)); 244 char *_rtld_dlerror __P((void)); 245 void *_rtld_dlopen __P((const char *, int)); 246 void *_rtld_objmain_sym __P((const char *)); 247 void *_rtld_dlsym __P((void *, const char *)); 248 int _rtld_dlclose __P((void *)); 249 int _rtld_dladdr __P((const void *, Dl_info *)); 250 void _rtld_debug_state __P((void)); 251 void _rtld_linkmap_add __P((Obj_Entry *)); 252 void _rtld_linkmap_delete __P((Obj_Entry *)); 253 void _rtld_objlist_add __P((Objlist *, Obj_Entry *)); 254 Objlist_Entry *_rtld_objlist_find __P((Objlist *, const Obj_Entry *)); 255 256 /* headers.c */ 257 void _rtld_digest_dynamic __P((Obj_Entry *)); 258 Obj_Entry *_rtld_digest_phdr __P((const Elf_Phdr *, int, caddr_t)); 259 260 /* load.c */ 261 Obj_Entry *_rtld_load_object __P((char *, int, bool)); 262 int _rtld_load_needed_objects __P((Obj_Entry *, int, bool)); 263 int _rtld_preload __P((const char *, bool)); 264 265 /* path.c */ 266 void _rtld_add_paths __P((Search_Path **, const char *, bool)); 267 void _rtld_process_hints __P((Search_Path **, Library_Xform **, const char *, 268 bool)); 269 270 /* reloc.c */ 271 int _rtld_do_copy_relocations __P((const Obj_Entry *, bool)); 272 caddr_t _rtld_bind __P((Obj_Entry *, Elf_Word)); 273 int _rtld_relocate_objects __P((Obj_Entry *, bool, bool)); 274 int _rtld_relocate_nonplt_object __P((Obj_Entry *, 275 const Elf_Rela *, bool)); 276 int _rtld_relocate_plt_object __P((Obj_Entry *, const Elf_Rela *, 277 caddr_t *, bool, bool)); 278 279 /* search.c */ 280 char *_rtld_find_library __P((const char *, const Obj_Entry *)); 281 282 /* symbol.c */ 283 unsigned long _rtld_elf_hash __P((const char *)); 284 const Elf_Sym *_rtld_symlook_obj __P((const char *, unsigned long, 285 const Obj_Entry *, bool)); 286 const Elf_Sym *_rtld_find_symdef __P((const Obj_Entry *, Elf_Addr, 287 const char *, Obj_Entry *, const Obj_Entry **, bool)); 288 const Elf_Sym *_rtld_symlook_list(const char *, unsigned long, 289 Objlist *, const Obj_Entry **, bool in_plt); 290 291 /* map_object.c */ 292 Obj_Entry *_rtld_map_object __P((const char *, int, const struct stat *)); 293 void _rtld_obj_free(Obj_Entry *); 294 Obj_Entry *_rtld_obj_new(void); 295 296 /* function descriptors */ 297 #ifdef __HAVE_FUNCTION_DESCRIPTORS 298 Elf_Addr _rtld_function_descriptor_alloc __P((const Obj_Entry *, 299 const Elf_Sym *, Elf_Addr)); 300 const void *_rtld_function_descriptor_function __P((const void *)); 301 #endif /* __HAVE_FUNCTION_DESCRIPTORS */ 302 303 void _rtld_setup_pltgot __P((const Obj_Entry *)); 304 305 #if defined(__alpha__) 306 /* rtld_start.S */ 307 void _rtld_bind_start_old __P((void)); 308 #endif 309 310 #if defined(__hppa__) 311 /* hppa_reloc.c */ 312 void _rtld_bootstrap_hppa_got __P((Elf_Dyn *, Elf_Addr, Elf_Addr, Elf_Addr)); 313 314 /* rtld_start.S */ 315 void __rtld_setup_hppa_pltgot __P((const Obj_Entry *, Elf_Addr *)); 316 #endif 317 318 #if defined(__powerpc__) 319 /* ppc_reloc.c */ 320 caddr_t _rtld_bind_powerpc __P((Obj_Entry *, Elf_Word)); 321 int _rtld_reloc_powerpc_plt __P((Obj_Entry *, const Elf_Rela *, bool)); 322 #endif 323 324 #endif /* _RTLD_SOURCE */ 325 326 #endif /* RTLD_H */ 327
Indexes created Tue Sep 30 11:09:46 GMT 2025