2 * SPDX-License-Identifier: BSD-4-Clause
4 * Copyright (c) 1993 Paul Kranenburg
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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
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.
36 * RRS section definitions.
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
43 #ifndef _SYS_LINK_AOUT_H_
44 #define _SYS_LINK_AOUT_H_
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.
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 */
59 short sod_major; /* major version number */
60 short sod_minor; /* minor version number */
61 long sod_next; /* next sod */
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.
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 */
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.
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
102 * The `section_dispatch_table' structure contains offsets to various data
103 * structures needed to do run-time relocation.
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 */
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).
130 int rh_symbolnum; /* Symbol number */
131 int rh_next; /* Next hash entry */
135 * `rt_symbols' is used to keep track of run-time allocated commons
136 * and data items copied from shared objects.
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 */
147 * Debugger interface structure.
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 */
160 * Version returned to crt0 from ld.so
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 */
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
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 */
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.
195 int d_version; /* version # of this interface */
196 struct so_debug *d_debug;
198 struct section_dispatch_table *d_sdt;
200 struct ld_entry *d_entry; /* XXX */
203 #define LD_VERSION_SUN (3)
204 #define LD_VERSION_BSD (8)
205 #define LD_VERSION_NZLIST_P(v) ((v) >= 8)
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)
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)
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) */
242 * Version passed from crt0 to ld.so (1st argument to _rtld()).
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
251 * Maximum number of recognized shared object version numbers.
256 * Header of the hints file.
258 struct hints_header {
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 */
272 #define HH_BADMAG(hdr) ((hdr).hh_magic != HH_MAGIC)
275 * Hash table element in hints file.
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 */
288 #define _PATH_LD_HINTS "/var/run/ld.so.hints"
290 #endif /* _SYS_LINK_AOUT_H_ */