rtld.h revision 1.8
1 /* $NetBSD: rtld.h,v 1.8 1999/03/01 16:40:07 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:/usr/local/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 # ifndef __sparc__ 55 # define PAGESIZE CLBYTES 56 # else 57 # define PAGESIZE 8192 /* NPBG is not constant! */ 58 # endif 59 #endif 60 61 #define round_down(x) ((x) & ~(PAGESIZE-1)) 62 #define round_up(x) round_down((x) + PAGESIZE - 1) 63 64 #define NEW(type) ((type *) xmalloc(sizeof(type))) 65 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 66 67 /* 68 * C++ has mandated the use of the following keywords for its new boolean 69 * type. We might as well follow their lead. 70 */ 71 typedef unsigned char bool; 72 #define false 0 73 #define true 1 74 75 struct Struct_Obj_Entry; 76 77 typedef struct Struct_Needed_Entry { 78 struct Struct_Needed_Entry *next; 79 struct Struct_Obj_Entry *obj; 80 unsigned long name; /* Offset of name in string table */ 81 } Needed_Entry; 82 83 typedef struct _rtld_search_path_t { 84 struct _rtld_search_path_t *sp_next; 85 const char *sp_path; 86 size_t sp_pathlen; 87 } Search_Path; 88 89 /* 90 * Shared object descriptor. 91 * 92 * Items marked with "(%)" are dynamically allocated, and must be freed 93 * when the structure is destroyed. 94 */ 95 96 #define RTLD_MAGIC 0xd550b87a 97 #define RTLD_VERSION 1 98 99 typedef struct Struct_Obj_Entry { 100 Elf32_Word magic; /* Magic number (sanity check) */ 101 Elf32_Word version; /* Version number of struct format */ 102 103 struct Struct_Obj_Entry *next; 104 char *path; /* Pathname of underlying file (%) */ 105 int refcount; 106 int dl_refcount; /* Number of times loaded by dlopen */ 107 108 /* These items are computed by map_object() or by digest_phdr(). */ 109 caddr_t mapbase; /* Base address of mapped region */ 110 size_t mapsize; /* Size of mapped region in bytes */ 111 size_t textsize; /* Size of text segment in bytes */ 112 Elf_Addr vaddrbase; /* Base address in shared object file */ 113 caddr_t relocbase; /* Reloc const = mapbase - *vaddrbase */ 114 Elf_Dyn *dynamic; /* Dynamic section */ 115 caddr_t entry; /* Entry point */ 116 const Elf_Phdr *phdr; /* Program header if mapped, ow NULL */ 117 size_t phsize; /* Size of program header in bytes */ 118 119 /* Items from the dynamic section. */ 120 Elf_Addr *pltgot; /* PLTGOT table */ 121 const Elf_Rel *rel; /* Relocation entries */ 122 const Elf_Rel *rellim; /* Limit of Relocation entries */ 123 const Elf_RelA *rela; /* Relocation entries */ 124 const Elf_RelA *relalim; /* Limit of Relocation entries */ 125 const Elf_Rel *pltrel; /* PLT relocation entries */ 126 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 127 const Elf_RelA *pltrela; /* PLT relocation entries */ 128 const Elf_RelA *pltrelalim; /* Limit of PLT relocation entries */ 129 const Elf_Sym *symtab; /* Symbol table */ 130 const char *strtab; /* String table */ 131 unsigned long strsize; /* Size in bytes of string table */ 132 #if defined(__mips__) 133 Elf_Word local_gotno; /* Number of local GOT entries */ 134 Elf_Word symtabno; /* Number of dynamic symbols */ 135 Elf_Word gotsym; /* First dynamic symbol in GOT */ 136 #endif 137 138 const Elf_Word *buckets; /* Hash table buckets array */ 139 unsigned long nbuckets; /* Number of buckets */ 140 const Elf_Word *chains; /* Hash table chain array */ 141 unsigned long nchains; /* Number of chains */ 142 143 Search_Path *rpaths; /* Search path specified in object */ 144 Needed_Entry *needed; /* Shared objects needed by this (%) */ 145 146 void (*init) /* Initialization function to call */ 147 __P((void)); 148 void (*fini) /* Termination function to call */ 149 __P((void)); 150 151 /* Entry points for dlopen() and friends. */ 152 void *(*dlopen) __P((const char *, int)); 153 void *(*dlsym) __P((void *, const char *)); 154 char *(*dlerror) __P((void)); 155 int (*dlclose) __P((void *)); 156 157 int mainprog:1; /* True if this is the main program */ 158 int rtld:1; /* True if this is the dynamic linker */ 159 int textrel:1; /* True if there are relocations to 160 * text seg */ 161 int symbolic:1; /* True if generated with 162 * "-Bsymbolic" */ 163 int printed:1; /* True if ldd has printed it */ 164 165 struct link_map linkmap; /* for GDB */ 166 } Obj_Entry; 167 168 extern struct r_debug _rtld_debug; 169 extern Obj_Entry *_rtld_objlist; 170 extern Obj_Entry **_rtld_objtail; 171 extern Obj_Entry _rtld_objself; 172 extern Search_Path *_rtld_paths; 173 extern bool _rtld_trust; 174 extern const char *_rtld_error_message; 175 176 /* rtld_start.S */ 177 void _rtld_bind_start __P((void)); 178 179 /* rtld.c */ 180 void _rtld_error __P((const char *, ...)); 181 void _rtld_die __P((void)); 182 char *_rtld_dlerror __P((void)); 183 void *_rtld_dlopen __P((const char *, int)); 184 void *_rtld_dlsym __P((void *, const char *)); 185 int _rtld_dlclose __P((void *)); 186 void _rtld_debug_state __P((void)); 187 void _rtld_linkmap_add __P((Obj_Entry *)); 188 void _rtld_linkmap_delete __P((Obj_Entry *)); 189 190 /* headers.c */ 191 void _rtld_digest_dynamic __P((Obj_Entry *)); 192 Obj_Entry *_rtld_digest_phdr __P((const Elf_Phdr *, int, caddr_t)); 193 194 /* load.c */ 195 Obj_Entry *_rtld_load_object __P((char *, bool)); 196 int _rtld_load_needed_objects __P((Obj_Entry *)); 197 198 /* path.c */ 199 void _rtld_add_paths __P((Search_Path **, const char *, bool)); 200 201 /* reloc.c */ 202 int _rtld_do_copy_relocations __P((const Obj_Entry *, bool)); 203 caddr_t _rtld_bind __P((const Obj_Entry *, Elf_Word)); 204 int _rtld_relocate_objects __P((Obj_Entry *, bool, bool)); 205 int _rtld_relocate_nonplt_object __P((const Obj_Entry *, 206 const Elf_RelA *, bool)); 207 int _rtld_relocate_plt_object __P((const Obj_Entry *, const Elf_RelA *, 208 caddr_t *, bool, bool)); 209 210 /* search.c */ 211 char *_rtld_find_library __P((const char *, const Obj_Entry *)); 212 213 /* symbol.c */ 214 unsigned long _rtld_elf_hash __P((const char *)); 215 const Elf_Sym *_rtld_symlook_obj __P((const char *, unsigned long, 216 const Obj_Entry *, bool)); 217 const Elf_Sym *_rtld_find_symdef __P((const Obj_Entry *, Elf_Word, 218 const char *, const Obj_Entry *, const Obj_Entry **, bool)); 219 220 /* map_object.c */ 221 Obj_Entry *_rtld_map_object __P((const char *, int)); 222 223 #if defined(__mips__) 224 /* mips_reloc.c */ 225 void _rtld_relocate_mips_got __P((Obj_Entry *)); 226 caddr_t _rtld_bind_mips __P((Elf_Word, Elf_Addr, Elf_Addr, Elf_Addr)); 227 #endif 228 229 #if defined(__powerpc__) 230 /* ppc_reloc.c */ 231 caddr_t _rtld_bind_powerpc __P((const Obj_Entry *, Elf_Word)); 232 int _rtld_reloc_powerpc_plt __P((const Obj_Entry *, const Elf_RelA *, bool)); 233 void _rtld_setup_powerpc_plt __P((const Obj_Entry *)); 234 #endif 235 236 #endif 237
Indexes created Mon Sep 29 21:09:56 GMT 2025