2 * Copyright (c) 1993 Paul Kranenburg
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by Paul Kranenburg.
16 * 4. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 * $Id: link.h,v 1.18 1998/02/06 16:46:44 jdp Exp $
34 * RRS section definitions.
36 * The layout of some data structures defined in this header file is
37 * such that we can provide compatibility with the SunOS 4.x shared
44 #if (defined(FREEBSD_ELF) || defined(__ELF__)) && !defined(FREEBSD_AOUT)
46 #include <sys/types.h>
49 caddr_t l_addr; /* Base Address of library */
51 caddr_t l_offs; /* Load Offset of library */
53 const char *l_name; /* Absolute Path to Library */
54 const void *l_ld; /* Pointer to .dynamic in memory */
55 struct link_map *l_next, *l_prev; /* linked list of of mapped libs */
59 int r_version; /* not used */
60 struct link_map *r_map; /* list of loaded images */
61 void (*r_brk)(void); /* pointer to break point */
63 RT_CONSISTENT, /* things are stable */
64 RT_ADD, /* adding a shared library */
65 RT_DELETE /* removing a shared library */
74 * A `Shared Object Descriptor' describes a shared object that is needed
75 * to complete the link edit process of the object containing it.
76 * A list of such objects (chained through `sod_next') is pointed at
77 * by `sdt_sods' in the section_dispatch_table structure.
80 struct sod { /* Shared Object Descriptor */
81 long sod_name; /* name (relative to load address) */
82 u_int sod_library : 1, /* Searched for by library rules */
84 short sod_major; /* major version number */
85 short sod_minor; /* minor version number */
86 long sod_next; /* next sod */
90 * `Shared Object Map's are used by the run-time link editor (ld.so) to
91 * keep track of all shared objects loaded into a process' address space.
92 * These structures are only used at run-time and do not occur within
93 * the text or data segment of an executable or shared library.
95 struct so_map { /* Shared Object Map */
96 caddr_t som_addr; /* Address at which object mapped */
97 char *som_path; /* Path to mmap'ed file */
98 struct so_map *som_next; /* Next map in chain */
99 struct sod *som_sod; /* Sod responsible for this map */
100 caddr_t som_sodbase; /* Base address of this sod */
101 u_int som_write : 1; /* Text is currently writable */
102 struct _dynamic *som_dynamic; /* _dynamic structure */
103 caddr_t som_spd; /* Private data */
107 * Symbol description with size. This is simply an `nlist' with
108 * one field (nz_size) added.
109 * Used to convey size information on items in the data segment
110 * of shared objects. An array of these live in the shared object's
111 * text segment and is addressed by the `sdt_nzlist' field.
118 #define nz_un nlist.n_un
119 #define nz_strx nlist.n_un.n_strx
120 #define nz_name nlist.n_un.n_name
121 #define nz_type nlist.n_type
122 #define nz_value nlist.n_value
123 #define nz_desc nlist.n_desc
124 #define nz_other nlist.n_other
127 * The `section_dispatch_table' structure contains offsets to various data
128 * structures needed to do run-time relocation.
130 struct section_dispatch_table {
131 struct so_map *sdt_loaded; /* List of loaded objects */
132 long sdt_sods; /* List of shared objects descriptors */
133 long sdt_paths; /* Library search paths */
134 long sdt_got; /* Global offset table */
135 long sdt_plt; /* Procedure linkage table */
136 long sdt_rel; /* Relocation table */
137 long sdt_hash; /* Symbol hash table */
138 long sdt_nzlist; /* Symbol table itself */
139 long sdt_filler2; /* Unused (was: stab_hash) */
140 long sdt_buckets; /* Number of hash buckets */
141 long sdt_strings; /* Symbol strings */
142 long sdt_str_sz; /* Size of symbol strings */
143 long sdt_text_sz; /* Size of text area */
144 long sdt_plt_sz; /* Size of procedure linkage table */
148 * RRS symbol hash table, addressed by `sdt_hash' in section_dispatch_table.
149 * Used to quickly lookup symbols of the shared object by hashing
150 * on the symbol's name. `rh_symbolnum' is the index of the symbol
151 * in the shared object's symbol list (`sdt_nzlist'), `rh_next' is
152 * the next symbol in the hash bucket (in case of collisions).
155 int rh_symbolnum; /* Symbol number */
156 int rh_next; /* Next hash entry */
160 * `rt_symbols' is used to keep track of run-time allocated commons
161 * and data items copied from shared objects.
164 struct nzlist *rt_sp; /* The symbol */
165 struct rt_symbol *rt_next; /* Next in linear list */
166 struct rt_symbol *rt_link; /* Next in bucket */
167 caddr_t rt_srcaddr; /* Address of "master" copy */
168 struct so_map *rt_smp; /* Originating map */
172 * Debugger interface structure.
175 int dd_version; /* Version # of interface */
176 int dd_in_debugger; /* Set when run by debugger */
177 int dd_sym_loaded; /* Run-time linking brought more
178 symbols into scope */
179 char *dd_bpt_addr; /* Address of rtld-generated bpt */
180 int dd_bpt_shadow; /* Original contents of bpt */
181 struct rt_symbol *dd_cc; /* Allocated commons/copied data */
185 * Version returned to crt0 from ld.so
187 #define LDSO_VERSION_NONE 0 /* FreeBSD2.0, 2.0.5 */
188 #define LDSO_VERSION_HAS_DLEXIT 1 /* includes dlexit in ld_entry */
189 #define LDSO_VERSION_HAS_DLSYM3 2 /* includes 3-argument dlsym */
190 #define LDSO_VERSION_HAS_DLADDR 3 /* includes dladdr in ld_entry */
193 * Entry points into ld.so - user interface to the run-time linker.
194 * Entries are valid for the given version numbers returned by ld.so
198 void *(*dlopen) __P((const char *, int)); /* NONE */
199 int (*dlclose) __P((void *)); /* NONE */
200 void *(*dlsym) __P((void *, const char *)); /* NONE */
201 const char *(*dlerror) __P((void)); /* NONE */
202 void (*dlexit) __P((void)); /* HAS_DLEXIT */
203 void *(*dlsym3) __P((void *, const char *, void *)); /* HAS_DLSYM3 */
204 int (*dladdr) __P((const void *,
205 struct dl_info *)); /* HAS_DLADDR */
209 * This is the structure pointed at by the __DYNAMIC symbol if an
210 * executable requires the attention of the run-time link editor.
211 * __DYNAMIC is given the value zero if no run-time linking needs to
212 * be done (it is always present in shared objects).
213 * The union `d_un' provides for different versions of the dynamic
214 * linking mechanism (switched on by `d_version'). The last version
215 * used by Sun is 3. We leave some room here and go to version number
216 * 8 for NetBSD, the main difference lying in the support for the
217 * `nz_list' type of symbols.
221 int d_version; /* version # of this interface */
222 struct so_debug *d_debug;
224 struct section_dispatch_table *d_sdt;
226 struct ld_entry *d_entry; /* XXX */
229 #define LD_VERSION_SUN (3)
230 #define LD_VERSION_BSD (8)
231 #define LD_VERSION_NZLIST_P(v) ((v) >= 8)
233 #define LD_GOT(x) ((x)->d_un.d_sdt->sdt_got)
234 #define LD_PLT(x) ((x)->d_un.d_sdt->sdt_plt)
235 #define LD_REL(x) ((x)->d_un.d_sdt->sdt_rel)
236 #define LD_SYMBOL(x) ((x)->d_un.d_sdt->sdt_nzlist)
237 #define LD_HASH(x) ((x)->d_un.d_sdt->sdt_hash)
238 #define LD_STRINGS(x) ((x)->d_un.d_sdt->sdt_strings)
239 #define LD_NEED(x) ((x)->d_un.d_sdt->sdt_sods)
240 #define LD_BUCKETS(x) ((x)->d_un.d_sdt->sdt_buckets)
241 #define LD_PATHS(x) ((x)->d_un.d_sdt->sdt_paths)
243 #define LD_GOTSZ(x) ((x)->d_un.d_sdt->sdt_plt - (x)->d_un.d_sdt->sdt_got)
244 #define LD_RELSZ(x) ((x)->d_un.d_sdt->sdt_hash - (x)->d_un.d_sdt->sdt_rel)
245 #define LD_HASHSZ(x) ((x)->d_un.d_sdt->sdt_nzlist - (x)->d_un.d_sdt->sdt_hash)
246 #define LD_STABSZ(x) ((x)->d_un.d_sdt->sdt_strings - (x)->d_un.d_sdt->sdt_nzlist)
247 #define LD_PLTSZ(x) ((x)->d_un.d_sdt->sdt_plt_sz)
248 #define LD_STRSZ(x) ((x)->d_un.d_sdt->sdt_str_sz)
249 #define LD_TEXTSZ(x) ((x)->d_un.d_sdt->sdt_text_sz)
255 int crt_ba; /* Base address of ld.so */
256 int crt_dzfd; /* "/dev/zero" file descriptor (SunOS) */
257 int crt_ldfd; /* ld.so file descriptor */
258 struct _dynamic *crt_dp; /* Main's __DYNAMIC */
259 char **crt_ep; /* environment strings */
260 caddr_t crt_bp; /* Breakpoint if run from debugger */
261 char *crt_prog; /* Program name (v3) */
262 char *crt_ldso; /* Link editor name (v4) */
263 struct ld_entry *crt_ldentry; /* dl*() access (v4) */
264 char **crt_argv; /* argument strings (v5) */
268 * Version passed from crt0 to ld.so (1st argument to _rtld()).
270 #define CRT_VERSION_SUN 1
271 #define CRT_VERSION_BSD_2 2
272 #define CRT_VERSION_BSD_3 3
273 #define CRT_VERSION_BSD_4 4
274 #define CRT_VERSION_BSD_5 5
277 * Maximum number of recognized shared object version numbers.
282 * Header of the hints file.
284 struct hints_header {
286 #define HH_MAGIC 011421044151
287 long hh_version; /* Interface version number */
288 #define LD_HINTS_VERSION_1 1
289 #define LD_HINTS_VERSION_2 2
290 long hh_hashtab; /* Location of hash table */
291 long hh_nbucket; /* Number of buckets in hashtab */
292 long hh_strtab; /* Location of strings */
293 long hh_strtab_sz; /* Size of strings */
294 long hh_ehints; /* End of hints (max offset in file) */
295 long hh_dirlist; /* Colon-separated list of srch dirs */
298 #define HH_BADMAG(hdr) ((hdr).hh_magic != HH_MAGIC)
301 * Hash table element in hints file.
303 struct hints_bucket {
304 /* namex and pathx are indices into the string table */
305 int hi_namex; /* Library name */
306 int hi_pathx; /* Full path */
307 int hi_dewey[MAXDEWEY]; /* The versions */
308 int hi_ndewey; /* Number of version numbers */
309 #define hi_major hi_dewey[0]
310 #define hi_minor hi_dewey[1]
311 int hi_next; /* Next in this bucket */
314 #define _PATH_LD_HINTS "/var/run/ld.so.hints"
316 #endif /* !__ELF__ */
318 #endif /* _LINK_H_ */