rtld.h revision 1.55
1 /* $NetBSD: rtld.h,v 1.55 2002/09/24 09:45:59 junyoung 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 extern int _rtld_pagesz; 61 62 #define round_down(x) ((x) & ~(_rtld_pagesz - 1)) 63 #define round_up(x) round_down((x) + _rtld_pagesz - 1) 64 65 #define NEW(type) ((type *) xmalloc(sizeof(type))) 66 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 67 68 #endif /* _RTLD_SOURCE */ 69 70 /* 71 * C++ has mandated the use of the following keywords for its new boolean 72 * type. We might as well follow their lead. 73 */ 74 typedef enum { 75 false = 0, 76 true = 1 77 } bool; 78 79 struct Struct_Obj_Entry; 80 81 typedef struct Struct_Objlist_Entry { 82 SIMPLEQ_ENTRY(Struct_Objlist_Entry) link; 83 struct Struct_Obj_Entry *obj; 84 } Objlist_Entry; 85 86 typedef SIMPLEQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; 87 88 typedef struct Struct_Needed_Entry { 89 struct Struct_Needed_Entry *next; 90 struct Struct_Obj_Entry *obj; 91 unsigned long name; /* Offset of name in string table */ 92 } Needed_Entry; 93 94 typedef struct _rtld_search_path_t { 95 struct _rtld_search_path_t *sp_next; 96 const char *sp_path; 97 size_t sp_pathlen; 98 } Search_Path; 99 100 101 #define RTLD_MAX_ENTRY 10 102 #define RTLD_MAX_LIBRARY 4 103 #define RTLD_MAX_CTL 2 104 typedef struct _rtld_library_xform_t { 105 struct _rtld_library_xform_t *next; 106 char *name; 107 int ctl[RTLD_MAX_CTL]; 108 int ctltype[RTLD_MAX_CTL]; 109 int ctlmax; 110 struct { 111 char *value; 112 char *library[RTLD_MAX_LIBRARY]; 113 } entry[RTLD_MAX_ENTRY]; 114 } Library_Xform; 115 116 /* 117 * Shared object descriptor. 118 * 119 * Items marked with "(%)" are dynamically allocated, and must be freed 120 * when the structure is destroyed. 121 */ 122 123 #define RTLD_MAGIC 0xd550b87a 124 #define RTLD_VERSION 1 125 126 typedef struct Struct_Obj_Entry { 127 Elf32_Word magic; /* Magic number (sanity check) */ 128 Elf32_Word version; /* Version number of struct format */ 129 130 struct Struct_Obj_Entry *next; 131 char *path; /* Pathname of underlying file (%) */ 132 int refcount; 133 int dl_refcount; /* Number of times loaded by dlopen */ 134 135 /* These items are computed by map_object() or by digest_phdr(). */ 136 caddr_t mapbase; /* Base address of mapped region */ 137 size_t mapsize; /* Size of mapped region in bytes */ 138 size_t textsize; /* Size of text segment in bytes */ 139 Elf_Addr vaddrbase; /* Base address in shared object file */ 140 caddr_t relocbase; /* Reloc const = mapbase - *vaddrbase */ 141 Elf_Dyn *dynamic; /* Dynamic section */ 142 caddr_t entry; /* Entry point */ 143 const Elf_Phdr *phdr; /* Program header if mapped, ow NULL */ 144 size_t phsize; /* Size of program header in bytes */ 145 146 /* Items from the dynamic section. */ 147 Elf_Addr *pltgot; /* PLTGOT table */ 148 const Elf_Rel *rel; /* Relocation entries */ 149 const Elf_Rel *rellim; /* Limit of Relocation entries */ 150 const Elf_Rela *rela; /* Relocation entries */ 151 const Elf_Rela *relalim; /* Limit of Relocation entries */ 152 const Elf_Rel *pltrel; /* PLT relocation entries */ 153 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 154 const Elf_Rela *pltrela; /* PLT relocation entries */ 155 const Elf_Rela *pltrelalim; /* Limit of PLT relocation entries */ 156 const Elf_Sym *symtab; /* Symbol table */ 157 const char *strtab; /* String table */ 158 unsigned long strsize; /* Size in bytes of string table */ 159 #if defined(__mips__) 160 Elf_Word local_gotno; /* Number of local GOT entries */ 161 Elf_Word symtabno; /* Number of dynamic symbols */ 162 Elf_Word gotsym; /* First dynamic symbol in GOT */ 163 #endif 164 165 const Elf_Word *buckets; /* Hash table buckets array */ 166 unsigned long nbuckets; /* Number of buckets */ 167 const Elf_Word *chains; /* Hash table chain array */ 168 unsigned long nchains; /* Number of chains */ 169 170 Search_Path *rpaths; /* Search path specified in object */ 171 Needed_Entry *needed; /* Shared objects needed by this (%) */ 172 173 void (*init) /* Initialization function to call */ 174 __P((void)); 175 void (*fini) /* Termination function to call */ 176 __P((void)); 177 178 /* Entry points for dlopen() and friends. */ 179 void *(*dlopen) __P((const char *, int)); 180 void *(*dlsym) __P((void *, const char *)); 181 char *(*dlerror) __P((void)); 182 int (*dlclose) __P((void *)); 183 int (*dladdr) __P((const void *, Dl_info *)); 184 185 u_int32_t mainprog:1, /* True if this is the main program */ 186 rtld:1, /* True if this is the dynamic linker */ 187 textrel:1, /* True if there are relocations to 188 * text seg */ 189 symbolic:1, /* True if generated with 190 * "-Bsymbolic" */ 191 printed:1, /* True if ldd has printed it */ 192 isdynamic:1; /* True if this is a pure PIC object */ 193 194 struct link_map linkmap; /* for GDB */ 195 196 /* These items are computed by map_object() or by digest_phdr(). */ 197 const char *interp; /* Pathname of the interpreter, if any */ 198 Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ 199 Objlist dagmembers; /* DAG has these members (%) */ 200 dev_t dev; /* Object's filesystem's device */ 201 ino_t ino; /* Object's inode number */ 202 } Obj_Entry; 203 204 #if defined(_RTLD_SOURCE) 205 206 extern struct r_debug _rtld_debug; 207 extern Search_Path *_rtld_default_paths; 208 extern Obj_Entry *_rtld_objlist; 209 extern Obj_Entry **_rtld_objtail; 210 extern Obj_Entry *_rtld_objmain; 211 extern Obj_Entry _rtld_objself; 212 extern Search_Path *_rtld_paths; 213 extern Library_Xform *_rtld_xforms; 214 extern bool _rtld_trust; 215 extern const char *_rtld_error_message; 216 extern Objlist _rtld_list_global; 217 extern Objlist _rtld_list_main; 218 extern Elf_Sym _rtld_sym_zero; 219 220 /* rtld.c */ 221 void _rtld_error __P((const char *, ...)) 222 __attribute__((__format__(__printf__,1,2))); 223 void _rtld_die __P((void)); 224 char *_rtld_dlerror __P((void)); 225 void *_rtld_dlopen __P((const char *, int)); 226 void *_rtld_objmain_sym __P((const char *)); 227 void *_rtld_dlsym __P((void *, const char *)); 228 int _rtld_dlclose __P((void *)); 229 int _rtld_dladdr __P((const void *, Dl_info *)); 230 void _rtld_debug_state __P((void)); 231 void _rtld_linkmap_add __P((Obj_Entry *)); 232 void _rtld_linkmap_delete __P((Obj_Entry *)); 233 void _rtld_objlist_add __P((Objlist *, Obj_Entry *)); 234 Objlist_Entry *_rtld_objlist_find __P((Objlist *, const Obj_Entry *)); 235 236 /* headers.c */ 237 void _rtld_digest_dynamic __P((Obj_Entry *)); 238 Obj_Entry *_rtld_digest_phdr __P((const Elf_Phdr *, int, caddr_t)); 239 240 /* load.c */ 241 Obj_Entry *_rtld_load_object __P((char *, int)); 242 int _rtld_load_needed_objects __P((Obj_Entry *, int)); 243 int _rtld_preload __P((const char *)); 244 245 /* path.c */ 246 void _rtld_add_paths __P((Search_Path **, const char *)); 247 void _rtld_process_hints __P((Search_Path **, Library_Xform **, const char *)); 248 249 /* reloc.c */ 250 int _rtld_do_copy_relocations __P((const Obj_Entry *)); 251 caddr_t _rtld_bind __P((const Obj_Entry *, Elf_Word)); 252 int _rtld_relocate_objects __P((Obj_Entry *, bool, bool)); 253 int _rtld_relocate_nonplt_objects __P((const Obj_Entry *, bool)); 254 int _rtld_relocate_plt_lazy __P((const Obj_Entry *)); 255 int _rtld_relocate_plt_object __P((const Obj_Entry *, const Elf_Rela *, 256 caddr_t *)); 257 int _rtld_relocate_plt_objects __P((const Obj_Entry *)); 258 void _rtld_setup_pltgot __P((const Obj_Entry *)); 259 260 /* search.c */ 261 Obj_Entry *_rtld_load_library __P((const char *, const Obj_Entry *, int)); 262 263 /* symbol.c */ 264 unsigned long _rtld_elf_hash __P((const char *)); 265 const Elf_Sym *_rtld_symlook_obj __P((const char *, unsigned long, 266 const Obj_Entry *)); 267 const Elf_Sym *_rtld_find_symdef __P((unsigned long, const Obj_Entry *, 268 const Obj_Entry **, bool)); 269 const Elf_Sym *_rtld_symlook_list(const char *, unsigned long, 270 Objlist *, const Obj_Entry **); 271 272 /* map_object.c */ 273 Obj_Entry *_rtld_map_object __P((char *, int, const struct stat *)); 274 void _rtld_obj_free(Obj_Entry *); 275 Obj_Entry *_rtld_obj_new(void); 276 277 /* function descriptors */ 278 #ifdef __HAVE_FUNCTION_DESCRIPTORS 279 Elf_Addr _rtld_function_descriptor_alloc __P((const Obj_Entry *, 280 const Elf_Sym *, Elf_Addr)); 281 const void *_rtld_function_descriptor_function __P((const void *)); 282 #endif /* __HAVE_FUNCTION_DESCRIPTORS */ 283 284 #endif /* _RTLD_SOURCE */ 285 286 #endif /* RTLD_H */ 287
Indexes created Mon Sep 29 21:09:56 GMT 2025