rtld.h revision 1.10
1 /* $NetBSD: rtld.h,v 1.10 1999/04/18 19:40:06 ws 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 # define PAGESIZE 8192 /* NPBG is not constant! */ 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 unsigned char bool; 81 #define false 0 82 #define true 1 83 84 struct Struct_Obj_Entry; 85 86 typedef struct Struct_Needed_Entry { 87 struct Struct_Needed_Entry *next; 88 struct Struct_Obj_Entry *obj; 89 unsigned long name; /* Offset of name in string table */ 90 } Needed_Entry; 91 92 typedef struct _rtld_search_path_t { 93 struct _rtld_search_path_t *sp_next; 94 const char *sp_path; 95 size_t sp_pathlen; 96 } Search_Path; 97 98 /* 99 * Shared object descriptor. 100 * 101 * Items marked with "(%)" are dynamically allocated, and must be freed 102 * when the structure is destroyed. 103 */ 104 105 #define RTLD_MAGIC 0xd550b87a 106 #define RTLD_VERSION 1 107 108 typedef struct Struct_Obj_Entry { 109 Elf32_Word magic; /* Magic number (sanity check) */ 110 Elf32_Word version; /* Version number of struct format */ 111 112 struct Struct_Obj_Entry *next; 113 char *path; /* Pathname of underlying file (%) */ 114 int refcount; 115 int dl_refcount; /* Number of times loaded by dlopen */ 116 117 /* These items are computed by map_object() or by digest_phdr(). */ 118 caddr_t mapbase; /* Base address of mapped region */ 119 size_t mapsize; /* Size of mapped region in bytes */ 120 size_t textsize; /* Size of text segment in bytes */ 121 Elf_Addr vaddrbase; /* Base address in shared object file */ 122 caddr_t relocbase; /* Reloc const = mapbase - *vaddrbase */ 123 Elf_Dyn *dynamic; /* Dynamic section */ 124 caddr_t entry; /* Entry point */ 125 const Elf_Phdr *phdr; /* Program header if mapped, ow NULL */ 126 size_t phsize; /* Size of program header in bytes */ 127 128 /* Items from the dynamic section. */ 129 Elf_Addr *pltgot; /* PLTGOT table */ 130 const Elf_Rel *rel; /* Relocation entries */ 131 const Elf_Rel *rellim; /* Limit of Relocation entries */ 132 const Elf_RelA *rela; /* Relocation entries */ 133 const Elf_RelA *relalim; /* Limit of Relocation entries */ 134 const Elf_Rel *pltrel; /* PLT relocation entries */ 135 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 136 const Elf_RelA *pltrela; /* PLT relocation entries */ 137 const Elf_RelA *pltrelalim; /* Limit of PLT relocation entries */ 138 const Elf_Sym *symtab; /* Symbol table */ 139 const char *strtab; /* String table */ 140 unsigned long strsize; /* Size in bytes of string table */ 141 #if defined(__mips__) 142 Elf_Word local_gotno; /* Number of local GOT entries */ 143 Elf_Word symtabno; /* Number of dynamic symbols */ 144 Elf_Word gotsym; /* First dynamic symbol in GOT */ 145 #endif 146 147 const Elf_Word *buckets; /* Hash table buckets array */ 148 unsigned long nbuckets; /* Number of buckets */ 149 const Elf_Word *chains; /* Hash table chain array */ 150 unsigned long nchains; /* Number of chains */ 151 152 Search_Path *rpaths; /* Search path specified in object */ 153 Needed_Entry *needed; /* Shared objects needed by this (%) */ 154 155 void (*init) /* Initialization function to call */ 156 __P((void)); 157 void (*fini) /* Termination function to call */ 158 __P((void)); 159 160 /* Entry points for dlopen() and friends. */ 161 void *(*dlopen) __P((const char *, int)); 162 void *(*dlsym) __P((void *, const char *)); 163 char *(*dlerror) __P((void)); 164 int (*dlclose) __P((void *)); 165 166 int mainprog:1; /* True if this is the main program */ 167 int rtld:1; /* True if this is the dynamic linker */ 168 int textrel:1; /* True if there are relocations to 169 * text seg */ 170 int symbolic:1; /* True if generated with 171 * "-Bsymbolic" */ 172 int printed:1; /* True if ldd has printed it */ 173 174 struct link_map linkmap; /* for GDB */ 175 } Obj_Entry; 176 177 extern struct r_debug _rtld_debug; 178 extern Obj_Entry *_rtld_objlist; 179 extern Obj_Entry **_rtld_objtail; 180 extern Obj_Entry _rtld_objself; 181 extern Search_Path *_rtld_paths; 182 extern bool _rtld_trust; 183 extern const char *_rtld_error_message; 184 185 /* rtld_start.S */ 186 void _rtld_bind_start __P((void)); 187 188 /* rtld.c */ 189 void _rtld_error __P((const char *, ...)); 190 void _rtld_die __P((void)); 191 char *_rtld_dlerror __P((void)); 192 void *_rtld_dlopen __P((const char *, int)); 193 void *_rtld_dlsym __P((void *, const char *)); 194 int _rtld_dlclose __P((void *)); 195 void _rtld_debug_state __P((void)); 196 void _rtld_linkmap_add __P((Obj_Entry *)); 197 void _rtld_linkmap_delete __P((Obj_Entry *)); 198 199 /* headers.c */ 200 void _rtld_digest_dynamic __P((Obj_Entry *)); 201 Obj_Entry *_rtld_digest_phdr __P((const Elf_Phdr *, int, caddr_t)); 202 203 /* load.c */ 204 Obj_Entry *_rtld_load_object __P((char *, bool)); 205 int _rtld_load_needed_objects __P((Obj_Entry *)); 206 207 /* path.c */ 208 void _rtld_add_paths __P((Search_Path **, const char *, bool)); 209 210 /* reloc.c */ 211 int _rtld_do_copy_relocations __P((const Obj_Entry *, bool)); 212 caddr_t _rtld_bind __P((const Obj_Entry *, Elf_Word)); 213 int _rtld_relocate_objects __P((Obj_Entry *, bool, bool)); 214 int _rtld_relocate_nonplt_object __P((const Obj_Entry *, 215 const Elf_RelA *, bool)); 216 int _rtld_relocate_plt_object __P((const Obj_Entry *, const Elf_RelA *, 217 caddr_t *, bool, bool)); 218 219 /* search.c */ 220 char *_rtld_find_library __P((const char *, const Obj_Entry *)); 221 222 /* symbol.c */ 223 unsigned long _rtld_elf_hash __P((const char *)); 224 const Elf_Sym *_rtld_symlook_obj __P((const char *, unsigned long, 225 const Obj_Entry *, bool)); 226 const Elf_Sym *_rtld_find_symdef __P((const Obj_Entry *, Elf_Word, 227 const char *, const Obj_Entry *, const Obj_Entry **, bool)); 228 229 /* map_object.c */ 230 Obj_Entry *_rtld_map_object __P((const char *, int)); 231 232 #if defined(__mips__) 233 /* mips_reloc.c */ 234 void _rtld_relocate_mips_got __P((Obj_Entry *)); 235 caddr_t _rtld_bind_mips __P((Elf_Word, Elf_Addr, Elf_Addr, Elf_Addr)); 236 #endif 237 238 #if defined(__powerpc__) 239 /* ppc_reloc.c */ 240 caddr_t _rtld_bind_powerpc __P((const Obj_Entry *, Elf_Word)); 241 int _rtld_reloc_powerpc_plt __P((const Obj_Entry *, const Elf_RelA *, bool)); 242 void _rtld_setup_powerpc_plt __P((const Obj_Entry *)); 243 #endif 244 245 #endif 246
Indexes created Tue Sep 30 06:09:59 GMT 2025