rtld.h revision 1.13
1 /* $NetBSD: rtld.h,v 1.13 1999/06/22 16:28:22 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 <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 #define RTLD_DEFAULT_LIBRARY_PATH "/usr/lib" 45 46 #if 0 47 #define SVR4_LIBDIR "/usr/lib" 48 #endif 49 50 #define LIBDIRLEN (sizeof LIBDIR - 1) 51 #define SVR4_LIBDIRLEN (sizeof SVR4_LIBDIR - 1) 52 53 #ifndef PAGESIZE 54 # ifdef VARPSZ 55 extern int _rtld_pagesz; 56 # ifdef RTLD_DEBUG 57 # define PAGESIZE (assert(_rtld_pagesz), _rtld_pagesz) 58 # else 59 # define PAGESIZE _rtld_pagesz 60 # endif 61 # else 62 # ifndef __sparc__ 63 # define PAGESIZE CLBYTES 64 # else 65 #error "Sparc has a variable page size" 66 # endif 67 # endif 68 #endif 69 70 #define round_down(x) ((x) & ~(PAGESIZE-1)) 71 #define round_up(x) round_down((x) + PAGESIZE - 1) 72 73 #define NEW(type) ((type *) xmalloc(sizeof(type))) 74 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 75 76 /* 77 * C++ has mandated the use of the following keywords for its new boolean 78 * type. We might as well follow their lead. 79 */ 80 typedef enum { 81 false = 0, 82 true = 1 83 } bool; 84 85 struct Struct_Obj_Entry; 86 87 typedef struct Struct_Needed_Entry { 88 struct Struct_Needed_Entry *next; 89 struct Struct_Obj_Entry *obj; 90 unsigned long name; /* Offset of name in string table */ 91 } Needed_Entry; 92 93 typedef struct _rtld_search_path_t { 94 struct _rtld_search_path_t *sp_next; 95 const char *sp_path; 96 size_t sp_pathlen; 97 } Search_Path; 98 99 /* 100 * Shared object descriptor. 101 * 102 * Items marked with "(%)" are dynamically allocated, and must be freed 103 * when the structure is destroyed. 104 */ 105 106 #define RTLD_MAGIC 0xd550b87a 107 #define RTLD_VERSION 1 108 109 typedef struct Struct_Obj_Entry { 110 Elf32_Word magic; /* Magic number (sanity check) */ 111 Elf32_Word version; /* Version number of struct format */ 112 113 struct Struct_Obj_Entry *next; 114 char *path; /* Pathname of underlying file (%) */ 115 int refcount; 116 int dl_refcount; /* Number of times loaded by dlopen */ 117 118 /* These items are computed by map_object() or by digest_phdr(). */ 119 caddr_t mapbase; /* Base address of mapped region */ 120 size_t mapsize; /* Size of mapped region in bytes */ 121 size_t textsize; /* Size of text segment in bytes */ 122 Elf_Addr vaddrbase; /* Base address in shared object file */ 123 caddr_t relocbase; /* Reloc const = mapbase - *vaddrbase */ 124 Elf_Dyn *dynamic; /* Dynamic section */ 125 caddr_t entry; /* Entry point */ 126 const Elf_Phdr *phdr; /* Program header if mapped, ow NULL */ 127 size_t phsize; /* Size of program header in bytes */ 128 129 /* Items from the dynamic section. */ 130 Elf_Addr *pltgot; /* PLTGOT table */ 131 const Elf_Rel *rel; /* Relocation entries */ 132 const Elf_Rel *rellim; /* Limit of Relocation entries */ 133 const Elf_RelA *rela; /* Relocation entries */ 134 const Elf_RelA *relalim; /* Limit of Relocation entries */ 135 const Elf_Rel *pltrel; /* PLT relocation entries */ 136 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 137 const Elf_RelA *pltrela; /* PLT relocation entries */ 138 const Elf_RelA *pltrelalim; /* Limit of PLT relocation entries */ 139 const Elf_Sym *symtab; /* Symbol table */ 140 const char *strtab; /* String table */ 141 unsigned long strsize; /* Size in bytes of string table */ 142 #if defined(__mips__) 143 Elf_Word local_gotno; /* Number of local GOT entries */ 144 Elf_Word symtabno; /* Number of dynamic symbols */ 145 Elf_Word gotsym; /* First dynamic symbol in GOT */ 146 #endif 147 148 const Elf_Word *buckets; /* Hash table buckets array */ 149 unsigned long nbuckets; /* Number of buckets */ 150 const Elf_Word *chains; /* Hash table chain array */ 151 unsigned long nchains; /* Number of chains */ 152 153 Search_Path *rpaths; /* Search path specified in object */ 154 Needed_Entry *needed; /* Shared objects needed by this (%) */ 155 156 void (*init) /* Initialization function to call */ 157 __P((void)); 158 void (*fini) /* Termination function to call */ 159 __P((void)); 160 161 /* Entry points for dlopen() and friends. */ 162 void *(*dlopen) __P((const char *, int)); 163 void *(*dlsym) __P((void *, const char *)); 164 char *(*dlerror) __P((void)); 165 int (*dlclose) __P((void *)); 166 167 int mainprog:1; /* True if this is the main program */ 168 int rtld:1; /* True if this is the dynamic linker */ 169 int textrel:1; /* True if there are relocations to 170 * text seg */ 171 int symbolic:1; /* True if generated with 172 * "-Bsymbolic" */ 173 int printed:1; /* True if ldd has printed it */ 174 175 struct link_map linkmap; /* for GDB */ 176 } Obj_Entry; 177 178 extern struct r_debug _rtld_debug; 179 extern Obj_Entry *_rtld_objlist; 180 extern Obj_Entry **_rtld_objtail; 181 extern Obj_Entry _rtld_objself; 182 extern Search_Path *_rtld_paths; 183 extern bool _rtld_trust; 184 extern const char *_rtld_error_message; 185 186 /* rtld_start.S */ 187 void _rtld_bind_start __P((void)); 188 189 /* rtld.c */ 190 void _rtld_error __P((const char *, ...)); 191 void _rtld_die __P((void)); 192 char *_rtld_dlerror __P((void)); 193 void *_rtld_dlopen __P((const char *, int)); 194 void *_rtld_dlsym __P((void *, const char *)); 195 int _rtld_dlclose __P((void *)); 196 void _rtld_debug_state __P((void)); 197 void _rtld_linkmap_add __P((Obj_Entry *)); 198 void _rtld_linkmap_delete __P((Obj_Entry *)); 199 200 /* headers.c */ 201 void _rtld_digest_dynamic __P((Obj_Entry *)); 202 Obj_Entry *_rtld_digest_phdr __P((const Elf_Phdr *, int, caddr_t)); 203 204 /* load.c */ 205 Obj_Entry *_rtld_load_object __P((char *, bool)); 206 int _rtld_load_needed_objects __P((Obj_Entry *)); 207 int _rtld_preload __P((const char *, bool)); 208 209 /* path.c */ 210 void _rtld_add_paths __P((Search_Path **, const char *, bool)); 211 212 /* reloc.c */ 213 int _rtld_do_copy_relocations __P((const Obj_Entry *, bool)); 214 caddr_t _rtld_bind __P((const Obj_Entry *, Elf_Word)); 215 int _rtld_relocate_objects __P((Obj_Entry *, bool, bool)); 216 int _rtld_relocate_nonplt_object __P((const Obj_Entry *, 217 const Elf_RelA *, bool)); 218 int _rtld_relocate_plt_object __P((const Obj_Entry *, const Elf_RelA *, 219 caddr_t *, bool, bool)); 220 221 /* search.c */ 222 char *_rtld_find_library __P((const char *, const Obj_Entry *)); 223 224 /* symbol.c */ 225 unsigned long _rtld_elf_hash __P((const char *)); 226 const Elf_Sym *_rtld_symlook_obj __P((const char *, unsigned long, 227 const Obj_Entry *, bool)); 228 const Elf_Sym *_rtld_find_symdef __P((const Obj_Entry *, Elf_Word, 229 const char *, const Obj_Entry *, const Obj_Entry **, bool)); 230 231 /* map_object.c */ 232 Obj_Entry *_rtld_map_object __P((const char *, int)); 233 234 #if defined(__mips__) 235 /* mips_reloc.c */ 236 void _rtld_relocate_mips_got __P((Obj_Entry *)); 237 caddr_t _rtld_bind_mips __P((Elf_Word, Elf_Addr, Elf_Addr, Elf_Addr)); 238 #endif 239 240 #if defined(__powerpc__) 241 /* ppc_reloc.c */ 242 caddr_t _rtld_bind_powerpc __P((const Obj_Entry *, Elf_Word)); 243 int _rtld_reloc_powerpc_plt __P((const Obj_Entry *, const Elf_RelA *, bool)); 244 void _rtld_setup_powerpc_plt __P((const Obj_Entry *)); 245 #endif 246 247 #endif 248
Indexes created Mon Sep 29 21:09:56 GMT 2025