rtld.h revision 1.16
1 /* $NetBSD: rtld.h,v 1.16 1999/08/19 23:42:15 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 #if defined(_RTLD_SOURCE) 45 46 #define RTLD_DEFAULT_LIBRARY_PATH "/usr/lib" 47 #define _PATH_LD_HINTS "/etc/ld.so.conf" 48 49 #if 0 50 #define SVR4_LIBDIR "/usr/lib" 51 #endif 52 53 #define LIBDIRLEN (sizeof LIBDIR - 1) 54 #define SVR4_LIBDIRLEN (sizeof SVR4_LIBDIR - 1) 55 56 #ifndef PAGESIZE 57 # ifdef VARPSZ 58 extern int _rtld_pagesz; 59 # ifdef RTLD_DEBUG 60 # define PAGESIZE (assert(_rtld_pagesz), _rtld_pagesz) 61 # else 62 # define PAGESIZE _rtld_pagesz 63 # endif 64 # else 65 # ifndef __sparc__ 66 # define PAGESIZE CLBYTES 67 # else 68 #error "Sparc has a variable page size" 69 # endif 70 # endif 71 #endif 72 73 #define round_down(x) ((x) & ~(PAGESIZE-1)) 74 #define round_up(x) round_down((x) + PAGESIZE - 1) 75 76 #define NEW(type) ((type *) xmalloc(sizeof(type))) 77 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 78 79 #endif /* _RTLD_SOURCE */ 80 81 /* 82 * C++ has mandated the use of the following keywords for its new boolean 83 * type. We might as well follow their lead. 84 */ 85 typedef enum { 86 false = 0, 87 true = 1 88 } bool; 89 90 struct Struct_Obj_Entry; 91 92 typedef struct Struct_Needed_Entry { 93 struct Struct_Needed_Entry *next; 94 struct Struct_Obj_Entry *obj; 95 unsigned long name; /* Offset of name in string table */ 96 } Needed_Entry; 97 98 typedef struct _rtld_search_path_t { 99 struct _rtld_search_path_t *sp_next; 100 const char *sp_path; 101 size_t sp_pathlen; 102 } Search_Path; 103 104 /* 105 * Shared object descriptor. 106 * 107 * Items marked with "(%)" are dynamically allocated, and must be freed 108 * when the structure is destroyed. 109 */ 110 111 #define RTLD_MAGIC 0xd550b87a 112 #define RTLD_VERSION 1 113 114 typedef struct Struct_Obj_Entry { 115 Elf32_Word magic; /* Magic number (sanity check) */ 116 Elf32_Word version; /* Version number of struct format */ 117 118 struct Struct_Obj_Entry *next; 119 char *path; /* Pathname of underlying file (%) */ 120 int refcount; 121 int dl_refcount; /* Number of times loaded by dlopen */ 122 123 /* These items are computed by map_object() or by digest_phdr(). */ 124 caddr_t mapbase; /* Base address of mapped region */ 125 size_t mapsize; /* Size of mapped region in bytes */ 126 size_t textsize; /* Size of text segment in bytes */ 127 Elf_Addr vaddrbase; /* Base address in shared object file */ 128 caddr_t relocbase; /* Reloc const = mapbase - *vaddrbase */ 129 Elf_Dyn *dynamic; /* Dynamic section */ 130 caddr_t entry; /* Entry point */ 131 const Elf_Phdr *phdr; /* Program header if mapped, ow NULL */ 132 size_t phsize; /* Size of program header in bytes */ 133 134 /* Items from the dynamic section. */ 135 Elf_Addr *pltgot; /* PLTGOT table */ 136 const Elf_Rel *rel; /* Relocation entries */ 137 const Elf_Rel *rellim; /* Limit of Relocation entries */ 138 const Elf_RelA *rela; /* Relocation entries */ 139 const Elf_RelA *relalim; /* Limit of Relocation entries */ 140 const Elf_Rel *pltrel; /* PLT relocation entries */ 141 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 142 const Elf_RelA *pltrela; /* PLT relocation entries */ 143 const Elf_RelA *pltrelalim; /* Limit of PLT relocation entries */ 144 const Elf_Sym *symtab; /* Symbol table */ 145 const char *strtab; /* String table */ 146 unsigned long strsize; /* Size in bytes of string table */ 147 #if defined(__mips__) 148 Elf_Word local_gotno; /* Number of local GOT entries */ 149 Elf_Word symtabno; /* Number of dynamic symbols */ 150 Elf_Word gotsym; /* First dynamic symbol in GOT */ 151 #endif 152 153 const Elf_Word *buckets; /* Hash table buckets array */ 154 unsigned long nbuckets; /* Number of buckets */ 155 const Elf_Word *chains; /* Hash table chain array */ 156 unsigned long nchains; /* Number of chains */ 157 158 Search_Path *rpaths; /* Search path specified in object */ 159 Needed_Entry *needed; /* Shared objects needed by this (%) */ 160 161 void (*init) /* Initialization function to call */ 162 __P((void)); 163 void (*fini) /* Termination function to call */ 164 __P((void)); 165 166 /* Entry points for dlopen() and friends. */ 167 void *(*dlopen) __P((const char *, int)); 168 void *(*dlsym) __P((void *, const char *)); 169 char *(*dlerror) __P((void)); 170 int (*dlclose) __P((void *)); 171 172 int mainprog:1; /* True if this is the main program */ 173 int rtld:1; /* True if this is the dynamic linker */ 174 int textrel:1; /* True if there are relocations to 175 * text seg */ 176 int symbolic:1; /* True if generated with 177 * "-Bsymbolic" */ 178 int printed:1; /* True if ldd has printed it */ 179 180 struct link_map linkmap; /* for GDB */ 181 } Obj_Entry; 182 183 #if defined(_RTLD_SOURCE) 184 185 extern struct r_debug _rtld_debug; 186 extern Search_Path *_rtld_default_paths; 187 extern Obj_Entry *_rtld_objlist; 188 extern Obj_Entry **_rtld_objtail; 189 extern Obj_Entry _rtld_objself; 190 extern Search_Path *_rtld_paths; 191 extern bool _rtld_trust; 192 extern const char *_rtld_error_message; 193 194 /* rtld_start.S */ 195 void _rtld_bind_start __P((void)); 196 197 /* rtld.c */ 198 void _rtld_error __P((const char *, ...)); 199 void _rtld_die __P((void)); 200 char *_rtld_dlerror __P((void)); 201 void *_rtld_dlopen __P((const char *, int)); 202 void *_rtld_dlsym __P((void *, const char *)); 203 int _rtld_dlclose __P((void *)); 204 void _rtld_debug_state __P((void)); 205 void _rtld_linkmap_add __P((Obj_Entry *)); 206 void _rtld_linkmap_delete __P((Obj_Entry *)); 207 208 /* headers.c */ 209 void _rtld_digest_dynamic __P((Obj_Entry *)); 210 Obj_Entry *_rtld_digest_phdr __P((const Elf_Phdr *, int, caddr_t)); 211 212 /* load.c */ 213 Obj_Entry *_rtld_load_object __P((char *, bool)); 214 int _rtld_load_needed_objects __P((Obj_Entry *)); 215 int _rtld_preload __P((const char *, bool)); 216 217 /* path.c */ 218 void _rtld_add_paths __P((Search_Path **, const char *, bool)); 219 void _rtld_process_hints __P((Search_Path **, const char *, bool)); 220 221 /* reloc.c */ 222 int _rtld_do_copy_relocations __P((const Obj_Entry *, bool)); 223 caddr_t _rtld_bind __P((const Obj_Entry *, Elf_Word)); 224 int _rtld_relocate_objects __P((Obj_Entry *, bool, bool)); 225 int _rtld_relocate_nonplt_object __P((const Obj_Entry *, 226 const Elf_RelA *, bool)); 227 int _rtld_relocate_plt_object __P((const Obj_Entry *, const Elf_RelA *, 228 caddr_t *, bool, bool)); 229 230 /* search.c */ 231 char *_rtld_find_library __P((const char *, const Obj_Entry *)); 232 233 /* symbol.c */ 234 unsigned long _rtld_elf_hash __P((const char *)); 235 const Elf_Sym *_rtld_symlook_obj __P((const char *, unsigned long, 236 const Obj_Entry *, bool)); 237 const Elf_Sym *_rtld_find_symdef __P((const Obj_Entry *, Elf_Word, 238 const char *, const Obj_Entry *, const Obj_Entry **, bool)); 239 240 /* map_object.c */ 241 Obj_Entry *_rtld_map_object __P((const char *, int)); 242 243 #if defined(__mips__) 244 /* mips_reloc.c */ 245 void _rtld_relocate_mips_got __P((Obj_Entry *)); 246 caddr_t _rtld_bind_mips __P((Elf_Word, Elf_Addr, Elf_Addr, Elf_Addr)); 247 #endif 248 249 #if defined(__powerpc__) 250 /* ppc_reloc.c */ 251 caddr_t _rtld_bind_powerpc __P((const Obj_Entry *, Elf_Word)); 252 int _rtld_reloc_powerpc_plt __P((const Obj_Entry *, const Elf_RelA *, bool)); 253 void _rtld_setup_powerpc_plt __P((const Obj_Entry *)); 254 #endif 255 256 #endif /* _RTLD_SOURCE */ 257 258 #endif /* RTLD_H */ 259
Indexes created Tue Sep 30 20:09:53 GMT 2025