1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1993 Paul Kranenburg 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Paul Kranenburg. 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 * 32 * $FreeBSD$ 33 */ 34 35 /* 36 * RRS section definitions. 37 * 38 * The layout of some data structures defined in this header file is 39 * such that we can provide compatibility with the SunOS 4.x shared 40 * library scheme. 41 */ 42 43 #ifndef _SYS_LINK_AOUT_H_ 44 #define _SYS_LINK_AOUT_H_ 45 46 struct dl_info; 47 48 /* 49 * A `Shared Object Descriptor' describes a shared object that is needed 50 * to complete the link edit process of the object containing it. 51 * A list of such objects (chained through `sod_next') is pointed at 52 * by `sdt_sods' in the section_dispatch_table structure. 53 */ 54 55 struct sod { /* Shared Object Descriptor */ 56 long sod_name; /* name (relative to load address) */ 57 u_int sod_library : 1, /* Searched for by library rules */ 58 sod_reserved : 31; 59 short sod_major; /* major version number */ 60 short sod_minor; /* minor version number */ 61 long sod_next; /* next sod */ 62 }; 63 64 /* 65 * `Shared Object Map's are used by the run-time link editor (ld.so) to 66 * keep track of all shared objects loaded into a process' address space. 67 * These structures are only used at run-time and do not occur within 68 * the text or data segment of an executable or shared library. 69 */ 70 struct so_map { /* Shared Object Map */ 71 caddr_t som_addr; /* Address at which object mapped */ 72 char *som_path; /* Path to mmap'ed file */ 73 struct so_map *som_next; /* Next map in chain */ 74 struct sod *som_sod; /* Sod responsible for this map */ 75 caddr_t som_sodbase; /* Base address of this sod */ 76 u_int som_write : 1; /* Text is currently writable */ 77 struct _dynamic *som_dynamic; /* _dynamic structure */ 78 caddr_t som_spd; /* Private data */ 79 }; 80 81 /* 82 * Symbol description with size. This is simply an `nlist' with 83 * one field (nz_size) added. 84 * Used to convey size information on items in the data segment 85 * of shared objects. An array of these live in the shared object's 86 * text segment and is addressed by the `sdt_nzlist' field. 87 */ 88 struct nzlist { 89 struct nlist nlist; 90 u_long nz_size; 91 }; 92 93 #define nz_un nlist.n_un 94 #define nz_strx nlist.n_un.n_strx 95 #define nz_name nlist.n_un.n_name 96 #define nz_type nlist.n_type 97 #define nz_value nlist.n_value 98 #define nz_desc nlist.n_desc 99 #define nz_other nlist.n_other 100 101 /* 102 * The `section_dispatch_table' structure contains offsets to various data 103 * structures needed to do run-time relocation. 104 */ 105 struct section_dispatch_table { 106 struct so_map *sdt_loaded; /* List of loaded objects */ 107 long sdt_sods; /* List of shared objects descriptors */ 108 long sdt_paths; /* Library search paths */ 109 long sdt_got; /* Global offset table */ 110 long sdt_plt; /* Procedure linkage table */ 111 long sdt_rel; /* Relocation table */ 112 long sdt_hash; /* Symbol hash table */ 113 long sdt_nzlist; /* Symbol table itself */ 114 long sdt_filler2; /* Unused (was: stab_hash) */ 115 long sdt_buckets; /* Number of hash buckets */ 116 long sdt_strings; /* Symbol strings */ 117 long sdt_str_sz; /* Size of symbol strings */ 118 long sdt_text_sz; /* Size of text area */ 119 long sdt_plt_sz; /* Size of procedure linkage table */ 120 }; 121 122 /* 123 * RRS symbol hash table, addressed by `sdt_hash' in section_dispatch_table. 124 * Used to quickly lookup symbols of the shared object by hashing 125 * on the symbol's name. `rh_symbolnum' is the index of the symbol 126 * in the shared object's symbol list (`sdt_nzlist'), `rh_next' is 127 * the next symbol in the hash bucket (in case of collisions). 128 */ 129 struct rrs_hash { 130 int rh_symbolnum; /* Symbol number */ 131 int rh_next; /* Next hash entry */ 132 }; 133 134 /* 135 * `rt_symbols' is used to keep track of run-time allocated commons 136 * and data items copied from shared objects. 137 */ 138 struct rt_symbol { 139 struct nzlist *rt_sp; /* The symbol */ 140 struct rt_symbol *rt_next; /* Next in linear list */ 141 struct rt_symbol *rt_link; /* Next in bucket */ 142 caddr_t rt_srcaddr; /* Address of "master" copy */ 143 struct so_map *rt_smp; /* Originating map */ 144 }; 145 146 /* 147 * Debugger interface structure. 148 */ 149 struct so_debug { 150 int dd_version; /* Version # of interface */ 151 int dd_in_debugger; /* Set when run by debugger */ 152 int dd_sym_loaded; /* Run-time linking brought more 153 symbols into scope */ 154 char *dd_bpt_addr; /* Address of rtld-generated bpt */ 155 int dd_bpt_shadow; /* Original contents of bpt */ 156 struct rt_symbol *dd_cc; /* Allocated commons/copied data */ 157 }; 158 159 /* 160 * Version returned to crt0 from ld.so 161 */ 162 #define LDSO_VERSION_NONE 0 /* FreeBSD2.0, 2.0.5 */ 163 #define LDSO_VERSION_HAS_DLEXIT 1 /* includes dlexit in ld_entry */ 164 #define LDSO_VERSION_HAS_DLSYM3 2 /* includes 3-argument dlsym */ 165 #define LDSO_VERSION_HAS_DLADDR 3 /* includes dladdr in ld_entry */ 166 167 /* 168 * Entry points into ld.so - user interface to the run-time linker. 169 * Entries are valid for the given version numbers returned by ld.so 170 * to crt0. 171 */ 172 struct ld_entry { 173 void *(*dlopen)(const char *, int); /* NONE */ 174 int (*dlclose)(void *); /* NONE */ 175 void *(*dlsym)(void *, const char *); /* NONE */ 176 const char *(*dlerror)(void); /* NONE */ 177 void (*dlexit)(void); /* HAS_DLEXIT */ 178 void *(*dlsym3)(void *, const char *, void *); /* HAS_DLSYM3 */ 179 int (*dladdr)(const void *, struct dl_info *); /* HAS_DLADDR */ 180 }; 181 182 /* 183 * This is the structure pointed at by the __DYNAMIC symbol if an 184 * executable requires the attention of the run-time link editor. 185 * __DYNAMIC is given the value zero if no run-time linking needs to 186 * be done (it is always present in shared objects). 187 * The union `d_un' provides for different versions of the dynamic 188 * linking mechanism (switched on by `d_version'). The last version 189 * used by Sun is 3. We leave some room here and go to version number 190 * 8 for NetBSD, the main difference lying in the support for the 191 * `nz_list' type of symbols. 192 */ 193 194 struct _dynamic { 195 int d_version; /* version # of this interface */ 196 struct so_debug *d_debug; 197 union { 198 struct section_dispatch_table *d_sdt; 199 } d_un; 200 struct ld_entry *d_entry; /* XXX */ 201 }; 202 203 #define LD_VERSION_SUN (3) 204 #define LD_VERSION_BSD (8) 205 #define LD_VERSION_NZLIST_P(v) ((v) >= 8) 206 207 #define LD_GOT(x) ((x)->d_un.d_sdt->sdt_got) 208 #define LD_PLT(x) ((x)->d_un.d_sdt->sdt_plt) 209 #define LD_REL(x) ((x)->d_un.d_sdt->sdt_rel) 210 #define LD_SYMBOL(x) ((x)->d_un.d_sdt->sdt_nzlist) 211 #define LD_HASH(x) ((x)->d_un.d_sdt->sdt_hash) 212 #define LD_STRINGS(x) ((x)->d_un.d_sdt->sdt_strings) 213 #define LD_NEED(x) ((x)->d_un.d_sdt->sdt_sods) 214 #define LD_BUCKETS(x) ((x)->d_un.d_sdt->sdt_buckets) 215 #define LD_PATHS(x) ((x)->d_un.d_sdt->sdt_paths) 216 217 #define LD_GOTSZ(x) ((x)->d_un.d_sdt->sdt_plt - (x)->d_un.d_sdt->sdt_got) 218 #define LD_RELSZ(x) ((x)->d_un.d_sdt->sdt_hash - (x)->d_un.d_sdt->sdt_rel) 219 #define LD_HASHSZ(x) ((x)->d_un.d_sdt->sdt_nzlist - (x)->d_un.d_sdt->sdt_hash) 220 #define LD_STABSZ(x) ((x)->d_un.d_sdt->sdt_strings - (x)->d_un.d_sdt->sdt_nzlist) 221 #define LD_PLTSZ(x) ((x)->d_un.d_sdt->sdt_plt_sz) 222 #define LD_STRSZ(x) ((x)->d_un.d_sdt->sdt_str_sz) 223 #define LD_TEXTSZ(x) ((x)->d_un.d_sdt->sdt_text_sz) 224 225 /* 226 * Interface to ld.so 227 */ 228 struct crt_ldso { 229 int crt_ba; /* Base address of ld.so */ 230 int crt_dzfd; /* "/dev/zero" file descriptor (SunOS) */ 231 int crt_ldfd; /* ld.so file descriptor */ 232 struct _dynamic *crt_dp; /* Main's __DYNAMIC */ 233 char **crt_ep; /* environment strings */ 234 caddr_t crt_bp; /* Breakpoint if run from debugger */ 235 char *crt_prog; /* Program name (v3) */ 236 char *crt_ldso; /* Link editor name (v4) */ 237 struct ld_entry *crt_ldentry; /* dl*() access (v4) */ 238 char **crt_argv; /* argument strings (v5) */ 239 }; 240 241 /* 242 * Version passed from crt0 to ld.so (1st argument to _rtld()). 243 */ 244 #define CRT_VERSION_SUN 1 245 #define CRT_VERSION_BSD_2 2 246 #define CRT_VERSION_BSD_3 3 247 #define CRT_VERSION_BSD_4 4 248 #define CRT_VERSION_BSD_5 5 249 250 /* 251 * Maximum number of recognized shared object version numbers. 252 */ 253 #define MAXDEWEY 8 254 255 /* 256 * Header of the hints file. 257 */ 258 struct hints_header { 259 long hh_magic; 260 #define HH_MAGIC 011421044151 261 long hh_version; /* Interface version number */ 262 #define LD_HINTS_VERSION_1 1 263 #define LD_HINTS_VERSION_2 2 264 long hh_hashtab; /* Location of hash table */ 265 long hh_nbucket; /* Number of buckets in hashtab */ 266 long hh_strtab; /* Location of strings */ 267 long hh_strtab_sz; /* Size of strings */ 268 long hh_ehints; /* End of hints (max offset in file) */ 269 long hh_dirlist; /* Colon-separated list of srch dirs */ 270 }; 271 272 #define HH_BADMAG(hdr) ((hdr).hh_magic != HH_MAGIC) 273 274 /* 275 * Hash table element in hints file. 276 */ 277 struct hints_bucket { 278 /* namex and pathx are indices into the string table */ 279 int hi_namex; /* Library name */ 280 int hi_pathx; /* Full path */ 281 int hi_dewey[MAXDEWEY]; /* The versions */ 282 int hi_ndewey; /* Number of version numbers */ 283 #define hi_major hi_dewey[0] 284 #define hi_minor hi_dewey[1] 285 int hi_next; /* Next in this bucket */ 286 }; 287 288 #define _PATH_LD_HINTS "/var/run/ld.so.hints" 289 290 #endif /* _SYS_LINK_AOUT_H_ */ 291