rtld.h revision 1.7
1 /* $NetBSD: rtld.h,v 1.7 1999/02/24 18:31:00 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 1 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 #define round_down(x) ((x) & ~(PAGESIZE-1)) 61 #define round_up(x) round_down((x) + PAGESIZE - 1) 62 63 #define NEW(type) ((type *) xmalloc(sizeof(type))) 64 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 65 66 /* 67 * C++ has mandated the use of the following keywords for its new boolean 68 * type. We might as well follow their lead. 69 */ 70 typedef unsigned char bool; 71 #define false 0 72 #define true 1 73 74 struct Struct_Obj_Entry; 75 76 typedef struct Struct_Needed_Entry { 77 struct Struct_Needed_Entry *next; 78 struct Struct_Obj_Entry *obj; 79 unsigned long name; /* Offset of name in string table */ 80 } Needed_Entry; 81 82 typedef struct _rtld_search_path_t { 83 struct _rtld_search_path_t *sp_next; 84 const char *sp_path; 85 size_t sp_pathlen; 86 } Search_Path; 87 88 /* 89 * Shared object descriptor. 90 * 91 * Items marked with "(%)" are dynamically allocated, and must be freed 92 * when the structure is destroyed. 93 */ 94 95 #define RTLD_MAGIC 0xd550b87a 96 #define RTLD_VERSION 1 97 98 typedef struct Struct_Obj_Entry { 99 Elf32_Word magic; /* Magic number (sanity check) */ 100 Elf32_Word version; /* Version number of struct format */ 101 102 struct Struct_Obj_Entry *next; 103 char *path; /* Pathname of underlying file (%) */ 104 int refcount; 105 int dl_refcount; /* Number of times loaded by dlopen */ 106 107 /* These items are computed by map_object() or by digest_phdr(). */ 108 caddr_t mapbase; /* Base address of mapped region */ 109 size_t mapsize; /* Size of mapped region in bytes */ 110 size_t textsize; /* Size of text segment in bytes */ 111 Elf_Addr vaddrbase; /* Base address in shared object file */ 112 caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ 113 Elf_Dyn *dynamic; /* Dynamic section */ 114 caddr_t entry; /* Entry point */ 115 const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ 116 size_t phsize; /* Size of program header in bytes */ 117 118 /* Items from the dynamic section. */ 119 Elf_Addr *pltgot; /* PLTGOT table */ 120 const Elf_Rel *rel; /* Relocation entries */ 121 const Elf_Rel *rellim; /* Limit of Relocation entries */ 122 const Elf_RelA *rela; /* Relocation entries */ 123 const Elf_RelA *relalim; /* Limit of Relocation entries */ 124 const Elf_Rel *pltrel; /* PLT relocation entries */ 125 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 126 const Elf_RelA *pltrela; /* PLT relocation entries */ 127 const Elf_RelA *pltrelalim; /* Limit of PLT relocation entries */ 128 const Elf_Sym *symtab; /* Symbol table */ 129 const char *strtab; /* String table */ 130 unsigned long strsize; /* Size in bytes of string table */ 131 #if defined(__mips__) 132 Elf_Word local_gotno; /* Number of local GOT entries */ 133 Elf_Word symtabno; /* Number of dynamic symbols */ 134 Elf_Word gotsym; /* First dynamic symbol in GOT */ 135 #endif 136 137 const Elf_Word *buckets; /* Hash table buckets array */ 138 unsigned long nbuckets; /* Number of buckets */ 139 const Elf_Word *chains; /* Hash table chain array */ 140 unsigned long nchains; /* Number of chains */ 141 142 Search_Path *rpaths; /* Search path specified in object */ 143 Needed_Entry *needed; /* Shared objects needed by this one (%) */ 144 145 void (*init)(void); /* Initialization function to call */ 146 void (*fini)(void); /* Termination function to call */ 147 148 /* Entry points for dlopen() and friends. */ 149 void *(*dlopen)(const char *, int); 150 void *(*dlsym)(void *, const char *); 151 char *(*dlerror)(void); 152 int (*dlclose)(void *); 153 154 int mainprog : 1; /* True if this is the main program */ 155 int rtld : 1; /* True if this is the dynamic linker */ 156 int textrel : 1; /* True if there are relocations to text seg */ 157 int symbolic : 1; /* True if generated with "-Bsymbolic" */ 158 int printed : 1; /* True if ldd has printed it */ 159 160 struct link_map linkmap; /* for GDB */ 161 } Obj_Entry; 162 163 extern struct r_debug _rtld_debug; 164 extern Obj_Entry *_rtld_objlist; 165 extern Obj_Entry **_rtld_objtail; 166 extern Obj_Entry _rtld_objself; 167 extern Search_Path *_rtld_paths; 168 extern bool _rtld_trust; 169 extern const char *_rtld_error_message; 170 171 /* rtld_start.S */ 172 extern void _rtld_bind_start(void); 173 174 /* rtld.c */ 175 176 extern void _rtld_error(const char *, ...); 177 extern void _rtld_die(void); 178 179 extern char *_rtld_dlerror(void); 180 extern void *_rtld_dlopen(const char *, int); 181 extern void *_rtld_dlsym(void *, const char *); 182 extern int _rtld_dlclose(void *); 183 184 extern void _rtld_debug_state(void); 185 186 extern void _rtld_linkmap_add(Obj_Entry *); 187 extern void _rtld_linkmap_delete(Obj_Entry *); 188 189 /* headers.c */ 190 191 extern void _rtld_digest_dynamic(Obj_Entry *); 192 extern Obj_Entry *_rtld_digest_phdr(const Elf_Phdr *, int, caddr_t); 193 194 /* load.c */ 195 196 extern Obj_Entry *_rtld_load_object(char *path, bool); 197 extern int _rtld_load_needed_objects(Obj_Entry *); 198 199 /* path.c */ 200 201 extern void _rtld_add_paths(Search_Path **, const char *, bool); 202 203 /* reloc.c */ 204 extern int _rtld_do_copy_relocations(const Obj_Entry *, bool); 205 extern caddr_t _rtld_bind(const Obj_Entry *, Elf_Word); 206 extern int _rtld_relocate_objects(Obj_Entry *, bool, bool); 207 extern int _rtld_relocate_nonplt_object(const Obj_Entry *, const Elf_RelA *, 208 bool); 209 extern int _rtld_relocate_plt_object(const Obj_Entry *, const Elf_RelA *, 210 caddr_t *, bool, bool); 211 212 /* search.c */ 213 214 extern char *_rtld_find_library(const char *, const Obj_Entry *); 215 216 /* symbol.c */ 217 extern unsigned long _rtld_elf_hash(const char *); 218 extern const Elf_Sym *_rtld_symlook_obj(const char *, unsigned long, 219 const Obj_Entry *, bool); 220 extern const Elf_Sym *_rtld_find_symdef(const Obj_Entry *, Elf_Word, 221 const char *, const Obj_Entry *, const Obj_Entry **, bool); 222 223 /* map_object.c */ 224 extern Obj_Entry *_rtld_map_object(const char *, int); 225 226 #if defined(__mips__) 227 /* mips_reloc.c */ 228 extern void _rtld_relocate_mips_got(Obj_Entry *); 229 extern caddr_t _rtld_bind_mips (Elf_Word, Elf_Addr, Elf_Addr, Elf_Addr); 230 #endif 231 232 #if defined(__powerpc__) 233 /* ppc_reloc.c */ 234 extern caddr_t _rtld_bind_powerpc(const Obj_Entry *, Elf_Word); 235 extern int _rtld_reloc_powerpc_plt(const Obj_Entry *, const Elf_RelA *, bool); 236 extern void _rtld_setup_powerpc_plt(const Obj_Entry *); 237 #endif 238 239 #endif /* } */ 240
Indexes created Tue Sep 30 06:09:59 GMT 2025