rtld.h revision 1.14
1 /* $NetBSD: rtld.h,v 1.14 1999/07/05 17:55:34 thorpej 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 <stddef.h> 38 #include <sys/param.h> 39 #include <sys/types.h> 40 #include <sys/exec_elf.h> 41 #include "rtldenv.h" 42 #include "link.h" 43 44 #if defined(_RTLD_SOURCE) 45 46 #define RTLD_DEFAULT_LIBRARY_PATH "/usr/lib" 47 48 #if 0 49 #define SVR4_LIBDIR "/usr/lib" 50 #endif 51 52 #define LIBDIRLEN (sizeof LIBDIR - 1) 53 #define SVR4_LIBDIRLEN (sizeof SVR4_LIBDIR - 1) 54 55 #ifndef PAGESIZE 56 # ifdef VARPSZ 57 extern int _rtld_pagesz; 58 # ifdef RTLD_DEBUG 59 # define PAGESIZE (assert(_rtld_pagesz), _rtld_pagesz) 60 # else 61 # define PAGESIZE _rtld_pagesz 62 # endif 63 # else 64 # ifndef __sparc__ 65 # define PAGESIZE CLBYTES 66 # else 67 #error "Sparc has a variable page size" 68 # endif 69 # endif 70 #endif 71 72 #define round_down(x) ((x) & ~(PAGESIZE-1)) 73 #define round_up(x) round_down((x) + PAGESIZE - 1) 74 75 #define NEW(type) ((type *) xmalloc(sizeof(type))) 76 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 77 78 #endif /* _RTLD_SOURCE */ 79 80 /* 81 * C++ has mandated the use of the following keywords for its new boolean 82 * type. We might as well follow their lead. 83 */ 84 typedef enum { 85 false = 0, 86 true = 1 87 } bool; 88 89 struct Struct_Obj_Entry; 90 91 typedef struct Struct_Needed_Entry { 92 struct Struct_Needed_Entry *next; 93 struct Struct_Obj_Entry *obj; 94 unsigned long name; /* Offset of name in string table */ 95 } Needed_Entry; 96 97 typedef struct _rtld_search_path_t { 98 struct _rtld_search_path_t *sp_next; 99 const char *sp_path; 100 size_t sp_pathlen; 101 } Search_Path; 102 103 /* 104 * Shared object descriptor. 105 * 106 * Items marked with "(%)" are dynamically allocated, and must be freed 107 * when the structure is destroyed. 108 */ 109 110 #define RTLD_MAGIC 0xd550b87a 111 #define RTLD_VERSION 1 112 113 typedef struct Struct_Obj_Entry { 114 Elf32_Word magic; /* Magic number (sanity check) */ 115 Elf32_Word version; /* Version number of struct format */ 116 117 struct Struct_Obj_Entry *next; 118 char *path; /* Pathname of underlying file (%) */ 119 int refcount; 120 int dl_refcount; /* Number of times loaded by dlopen */ 121 122 /* These items are computed by map_object() or by digest_phdr(). */ 123 caddr_t mapbase; /* Base address of mapped region */ 124 size_t mapsize; /* Size of mapped region in bytes */ 125 size_t textsize; /* Size of text segment in bytes */ 126 Elf_Addr vaddrbase; /* Base address in shared object file */ 127 caddr_t relocbase; /* Reloc const = mapbase - *vaddrbase */ 128 Elf_Dyn *dynamic; /* Dynamic section */ 129 caddr_t entry; /* Entry point */ 130 const Elf_Phdr *phdr; /* Program header if mapped, ow NULL */ 131 size_t phsize; /* Size of program header in bytes */ 132 133 /* Items from the dynamic section. */ 134 Elf_Addr *pltgot; /* PLTGOT table */ 135 const Elf_Rel *rel; /* Relocation entries */ 136 const Elf_Rel *rellim; /* Limit of Relocation entries */ 137 const Elf_RelA *rela; /* Relocation entries */ 138 const Elf_RelA *relalim; /* Limit of Relocation entries */ 139 const Elf_Rel *pltrel; /* PLT relocation entries */ 140 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 141 const Elf_RelA *pltrela; /* PLT relocation entries */ 142 const Elf_RelA *pltrelalim; /* Limit of PLT relocation entries */ 143 const Elf_Sym *symtab; /* Symbol table */ 144 const char *strtab; /* String table */ 145 unsigned long strsize; /* Size in bytes of string table */ 146 #if defined(__mips__) 147 Elf_Word local_gotno; /* Number of local GOT entries */ 148 Elf_Word symtabno; /* Number of dynamic symbols */ 149 Elf_Word gotsym; /* First dynamic symbol in GOT */ 150 #endif 151 152 const Elf_Word *buckets; /* Hash table buckets array */ 153 unsigned long nbuckets; /* Number of buckets */ 154 const Elf_Word *chains; /* Hash table chain array */ 155 unsigned long nchains; /* Number of chains */ 156 157 Search_Path *rpaths; /* Search path specified in object */ 158 Needed_Entry *needed; /* Shared objects needed by this (%) */ 159 160 void (*init) /* Initialization function to call */ 161 __P((void)); 162 void (*fini) /* Termination function to call */ 163 __P((void)); 164 165 /* Entry points for dlopen() and friends. */ 166 void *(*dlopen) __P((const char *, int)); 167 void *(*dlsym) __P((void *, const char *)); 168 char *(*dlerror) __P((void)); 169 int (*dlclose) __P((void *)); 170 171 int mainprog:1; /* True if this is the main program */ 172 int rtld:1; /* True if this is the dynamic linker */ 173 int textrel:1; /* True if there are relocations to 174 * text seg */ 175 int symbolic:1; /* True if generated with 176 * "-Bsymbolic" */ 177 int printed:1; /* True if ldd has printed it */ 178 179 struct link_map linkmap; /* for GDB */ 180 } Obj_Entry; 181 182 #if defined(_RTLD_SOURCE) 183 184 extern struct r_debug _rtld_debug; 185 extern Obj_Entry *_rtld_objlist; 186 extern Obj_Entry **_rtld_objtail; 187 extern Obj_Entry _rtld_objself; 188 extern Search_Path *_rtld_paths; 189 extern bool _rtld_trust; 190 extern const char *_rtld_error_message; 191 192 /* rtld_start.S */ 193 void _rtld_bind_start __P((void)); 194 195 /* rtld.c */ 196 void _rtld_error __P((const char *, ...)); 197 void _rtld_die __P((void)); 198 char *_rtld_dlerror __P((void)); 199 void *_rtld_dlopen __P((const char *, int)); 200 void *_rtld_dlsym __P((void *, const char *)); 201 int _rtld_dlclose __P((void *)); 202 void _rtld_debug_state __P((void)); 203 void _rtld_linkmap_add __P((Obj_Entry *)); 204 void _rtld_linkmap_delete __P((Obj_Entry *)); 205 206 /* headers.c */ 207 void _rtld_digest_dynamic __P((Obj_Entry *)); 208 Obj_Entry *_rtld_digest_phdr __P((const Elf_Phdr *, int, caddr_t)); 209 210 /* load.c */ 211 Obj_Entry *_rtld_load_object __P((char *, bool)); 212 int _rtld_load_needed_objects __P((Obj_Entry *)); 213 int _rtld_preload __P((const char *, bool)); 214 215 /* path.c */ 216 void _rtld_add_paths __P((Search_Path **, const char *, bool)); 217 218 /* reloc.c */ 219 int _rtld_do_copy_relocations __P((const Obj_Entry *, bool)); 220 caddr_t _rtld_bind __P((const Obj_Entry *, Elf_Word)); 221 int _rtld_relocate_objects __P((Obj_Entry *, bool, bool)); 222 int _rtld_relocate_nonplt_object __P((const Obj_Entry *, 223 const Elf_RelA *, bool)); 224 int _rtld_relocate_plt_object __P((const Obj_Entry *, const Elf_RelA *, 225 caddr_t *, bool, bool)); 226 227 /* search.c */ 228 char *_rtld_find_library __P((const char *, const Obj_Entry *)); 229 230 /* symbol.c */ 231 unsigned long _rtld_elf_hash __P((const char *)); 232 const Elf_Sym *_rtld_symlook_obj __P((const char *, unsigned long, 233 const Obj_Entry *, bool)); 234 const Elf_Sym *_rtld_find_symdef __P((const Obj_Entry *, Elf_Word, 235 const char *, const Obj_Entry *, const Obj_Entry **, bool)); 236 237 /* map_object.c */ 238 Obj_Entry *_rtld_map_object __P((const char *, int)); 239 240 #if defined(__mips__) 241 /* mips_reloc.c */ 242 void _rtld_relocate_mips_got __P((Obj_Entry *)); 243 caddr_t _rtld_bind_mips __P((Elf_Word, Elf_Addr, Elf_Addr, Elf_Addr)); 244 #endif 245 246 #if defined(__powerpc__) 247 /* ppc_reloc.c */ 248 caddr_t _rtld_bind_powerpc __P((const Obj_Entry *, Elf_Word)); 249 int _rtld_reloc_powerpc_plt __P((const Obj_Entry *, const Elf_RelA *, bool)); 250 void _rtld_setup_powerpc_plt __P((const Obj_Entry *)); 251 #endif 252 253 #endif /* _RTLD_SOURCE */ 254 255 #endif /* RTLD_H */ 256
Indexes created Mon Sep 29 21:09:56 GMT 2025