Also fix a double free.
[dragonfly.git] / include / link.h
CommitLineData
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1/*
2 * Copyright (c) 1993 Paul Kranenburg
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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
18 *
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.
29 *
30 * $FreeBSD: src/include/link.h,v 1.20.2.2 2003/02/20 20:42:45 kan Exp $
7c4af8e1 31 * $DragonFly: src/include/link.h,v 1.3 2003/11/14 01:01:43 dillon Exp $
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32 */
33
34/*
35 * RRS section definitions.
36 *
37 * The layout of some data structures defined in this header file is
38 * such that we can provide compatibility with the SunOS 4.x shared
39 * library scheme.
40 */
41
42#ifndef _LINK_H_
43#define _LINK_H_
44
45#if (defined(FREEBSD_ELF) || defined(__ELF__)) && !defined(FREEBSD_AOUT)
46
47#include <sys/types.h>
48
49/*
50 * Flags that describe the origin of the entries in Dl_serinfo.
51 * SunOS has these in <sys/link.h>, we follow the suit.
52 */
53#define LA_SER_ORIG 0x01 /* original (needed) name */
54#define LA_SER_LIBPATH 0x02 /* LD_LIBRARY_PATH entry prepended */
55#define LA_SER_RUNPATH 0x04 /* runpath entry prepended */
56#define LA_SER_CONFIG 0x08 /* configuration entry prepended */
57#define LA_SER_DEFAULT 0x40 /* default path prepended */
58#define LA_SER_SECURE 0x80 /* default (secure) path prepended */
59
60typedef struct link_map {
61 caddr_t l_addr; /* Base Address of library */
62#ifdef __mips__
63 caddr_t l_offs; /* Load Offset of library */
64#endif
65 const char *l_name; /* Absolute Path to Library */
66 const void *l_ld; /* Pointer to .dynamic in memory */
67 struct link_map *l_next, *l_prev; /* linked list of of mapped libs */
68} Link_map;
69
70struct r_debug {
71 int r_version; /* not used */
72 struct link_map *r_map; /* list of loaded images */
73 void (*r_brk)(struct r_debug *, struct link_map *);
74 /* pointer to break point */
75 enum {
76 RT_CONSISTENT, /* things are stable */
77 RT_ADD, /* adding a shared library */
78 RT_DELETE /* removing a shared library */
79 } r_state;
80};
81
82#else /* !__ELF__ */
83
84struct dl_info;
85
86/*
87 * A `Shared Object Descriptor' describes a shared object that is needed
88 * to complete the link edit process of the object containing it.
89 * A list of such objects (chained through `sod_next') is pointed at
90 * by `sdt_sods' in the section_dispatch_table structure.
91 */
92
93struct sod { /* Shared Object Descriptor */
94 long sod_name; /* name (relative to load address) */
95 u_int sod_library : 1, /* Searched for by library rules */
96 sod_reserved : 31;
97 short sod_major; /* major version number */
98 short sod_minor; /* minor version number */
99 long sod_next; /* next sod */
100};
101
102/*
103 * `Shared Object Map's are used by the run-time link editor (ld.so) to
104 * keep track of all shared objects loaded into a process' address space.
105 * These structures are only used at run-time and do not occur within
106 * the text or data segment of an executable or shared library.
107 */
108struct so_map { /* Shared Object Map */
109 caddr_t som_addr; /* Address at which object mapped */
110 char *som_path; /* Path to mmap'ed file */
111 struct so_map *som_next; /* Next map in chain */
112 struct sod *som_sod; /* Sod responsible for this map */
113 caddr_t som_sodbase; /* Base address of this sod */
114 u_int som_write : 1; /* Text is currently writable */
115 struct _dynamic *som_dynamic; /* _dynamic structure */
116 caddr_t som_spd; /* Private data */
117};
118
119/*
120 * Symbol description with size. This is simply an `nlist' with
121 * one field (nz_size) added.
122 * Used to convey size information on items in the data segment
123 * of shared objects. An array of these live in the shared object's
124 * text segment and is addressed by the `sdt_nzlist' field.
125 */
126struct nzlist {
127 struct nlist nlist;
128 u_long nz_size;
129};
130
131#define nz_un nlist.n_un
132#define nz_strx nlist.n_un.n_strx
133#define nz_name nlist.n_un.n_name
134#define nz_type nlist.n_type
135#define nz_value nlist.n_value
136#define nz_desc nlist.n_desc
137#define nz_other nlist.n_other
138
139/*
140 * The `section_dispatch_table' structure contains offsets to various data
141 * structures needed to do run-time relocation.
142 */
143struct section_dispatch_table {
144 struct so_map *sdt_loaded; /* List of loaded objects */
145 long sdt_sods; /* List of shared objects descriptors */
146 long sdt_paths; /* Library search paths */
147 long sdt_got; /* Global offset table */
148 long sdt_plt; /* Procedure linkage table */
149 long sdt_rel; /* Relocation table */
150 long sdt_hash; /* Symbol hash table */
151 long sdt_nzlist; /* Symbol table itself */
152 long sdt_filler2; /* Unused (was: stab_hash) */
153 long sdt_buckets; /* Number of hash buckets */
154 long sdt_strings; /* Symbol strings */
155 long sdt_str_sz; /* Size of symbol strings */
156 long sdt_text_sz; /* Size of text area */
157 long sdt_plt_sz; /* Size of procedure linkage table */
158};
159
160/*
161 * RRS symbol hash table, addressed by `sdt_hash' in section_dispatch_table.
162 * Used to quickly lookup symbols of the shared object by hashing
163 * on the symbol's name. `rh_symbolnum' is the index of the symbol
164 * in the shared object's symbol list (`sdt_nzlist'), `rh_next' is
165 * the next symbol in the hash bucket (in case of collisions).
166 */
167struct rrs_hash {
168 int rh_symbolnum; /* Symbol number */
169 int rh_next; /* Next hash entry */
170};
171
172/*
173 * `rt_symbols' is used to keep track of run-time allocated commons
174 * and data items copied from shared objects.
175 */
176struct rt_symbol {
177 struct nzlist *rt_sp; /* The symbol */
178 struct rt_symbol *rt_next; /* Next in linear list */
179 struct rt_symbol *rt_link; /* Next in bucket */
180 caddr_t rt_srcaddr; /* Address of "master" copy */
181 struct so_map *rt_smp; /* Originating map */
182};
183
184/*
185 * Debugger interface structure.
186 */
187struct so_debug {
188 int dd_version; /* Version # of interface */
189 int dd_in_debugger; /* Set when run by debugger */
190 int dd_sym_loaded; /* Run-time linking brought more
191 symbols into scope */
192 char *dd_bpt_addr; /* Address of rtld-generated bpt */
193 int dd_bpt_shadow; /* Original contents of bpt */
194 struct rt_symbol *dd_cc; /* Allocated commons/copied data */
195};
196
197/*
198 * Version returned to crt0 from ld.so
199 */
200#define LDSO_VERSION_NONE 0 /* FreeBSD2.0, 2.0.5 */
201#define LDSO_VERSION_HAS_DLEXIT 1 /* includes dlexit in ld_entry */
202#define LDSO_VERSION_HAS_DLSYM3 2 /* includes 3-argument dlsym */
203#define LDSO_VERSION_HAS_DLADDR 3 /* includes dladdr in ld_entry */
204
205/*
206 * Entry points into ld.so - user interface to the run-time linker.
207 * Entries are valid for the given version numbers returned by ld.so
208 * to crt0.
209 */
210struct ld_entry {
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211 void *(*dlopen) (const char *, int); /* NONE */
212 int (*dlclose) (void *); /* NONE */
213 void *(*dlsym) (void *, const char *); /* NONE */
214 const char *(*dlerror) (void); /* NONE */
215 void (*dlexit) (void); /* HAS_DLEXIT */
216 void *(*dlsym3) (void *, const char *, void *); /* HAS_DLSYM3 */
217 int (*dladdr) (const void *,
218 struct dl_info *); /* HAS_DLADDR */
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219};
220
221/*
222 * This is the structure pointed at by the __DYNAMIC symbol if an
223 * executable requires the attention of the run-time link editor.
224 * __DYNAMIC is given the value zero if no run-time linking needs to
225 * be done (it is always present in shared objects).
226 * The union `d_un' provides for different versions of the dynamic
227 * linking mechanism (switched on by `d_version'). The last version
228 * used by Sun is 3. We leave some room here and go to version number
229 * 8 for NetBSD, the main difference lying in the support for the
230 * `nz_list' type of symbols.
231 */
232
233struct _dynamic {
234 int d_version; /* version # of this interface */
235 struct so_debug *d_debug;
236 union {
237 struct section_dispatch_table *d_sdt;
238 } d_un;
239 struct ld_entry *d_entry; /* XXX */
240};
241
242#define LD_VERSION_SUN (3)
243#define LD_VERSION_BSD (8)
244#define LD_VERSION_NZLIST_P(v) ((v) >= 8)
245
246#define LD_GOT(x) ((x)->d_un.d_sdt->sdt_got)
247#define LD_PLT(x) ((x)->d_un.d_sdt->sdt_plt)
248#define LD_REL(x) ((x)->d_un.d_sdt->sdt_rel)
249#define LD_SYMBOL(x) ((x)->d_un.d_sdt->sdt_nzlist)
250#define LD_HASH(x) ((x)->d_un.d_sdt->sdt_hash)
251#define LD_STRINGS(x) ((x)->d_un.d_sdt->sdt_strings)
252#define LD_NEED(x) ((x)->d_un.d_sdt->sdt_sods)
253#define LD_BUCKETS(x) ((x)->d_un.d_sdt->sdt_buckets)
254#define LD_PATHS(x) ((x)->d_un.d_sdt->sdt_paths)
255
256#define LD_GOTSZ(x) ((x)->d_un.d_sdt->sdt_plt - (x)->d_un.d_sdt->sdt_got)
257#define LD_RELSZ(x) ((x)->d_un.d_sdt->sdt_hash - (x)->d_un.d_sdt->sdt_rel)
258#define LD_HASHSZ(x) ((x)->d_un.d_sdt->sdt_nzlist - (x)->d_un.d_sdt->sdt_hash)
259#define LD_STABSZ(x) ((x)->d_un.d_sdt->sdt_strings - (x)->d_un.d_sdt->sdt_nzlist)
260#define LD_PLTSZ(x) ((x)->d_un.d_sdt->sdt_plt_sz)
261#define LD_STRSZ(x) ((x)->d_un.d_sdt->sdt_str_sz)
262#define LD_TEXTSZ(x) ((x)->d_un.d_sdt->sdt_text_sz)
263
264/*
265 * Interface to ld.so
266 */
267struct crt_ldso {
268 int crt_ba; /* Base address of ld.so */
269 int crt_dzfd; /* "/dev/zero" file descriptor (SunOS) */
270 int crt_ldfd; /* ld.so file descriptor */
271 struct _dynamic *crt_dp; /* Main's __DYNAMIC */
272 char **crt_ep; /* environment strings */
273 caddr_t crt_bp; /* Breakpoint if run from debugger */
274 char *crt_prog; /* Program name (v3) */
275 char *crt_ldso; /* Link editor name (v4) */
276 struct ld_entry *crt_ldentry; /* dl*() access (v4) */
277 char **crt_argv; /* argument strings (v5) */
278};
279
280/*
281 * Version passed from crt0 to ld.so (1st argument to _rtld()).
282 */
283#define CRT_VERSION_SUN 1
284#define CRT_VERSION_BSD_2 2
285#define CRT_VERSION_BSD_3 3
286#define CRT_VERSION_BSD_4 4
287#define CRT_VERSION_BSD_5 5
288
289/*
290 * Maximum number of recognized shared object version numbers.
291 */
292#define MAXDEWEY 8
293
294/*
295 * Header of the hints file.
296 */
297struct hints_header {
298 long hh_magic;
299#define HH_MAGIC 011421044151
300 long hh_version; /* Interface version number */
301#define LD_HINTS_VERSION_1 1
302#define LD_HINTS_VERSION_2 2
303 long hh_hashtab; /* Location of hash table */
304 long hh_nbucket; /* Number of buckets in hashtab */
305 long hh_strtab; /* Location of strings */
306 long hh_strtab_sz; /* Size of strings */
307 long hh_ehints; /* End of hints (max offset in file) */
308 long hh_dirlist; /* Colon-separated list of srch dirs */
309};
310
311#define HH_BADMAG(hdr) ((hdr).hh_magic != HH_MAGIC)
312
313/*
314 * Hash table element in hints file.
315 */
316struct hints_bucket {
317 /* namex and pathx are indices into the string table */
318 int hi_namex; /* Library name */
319 int hi_pathx; /* Full path */
320 int hi_dewey[MAXDEWEY]; /* The versions */
321 int hi_ndewey; /* Number of version numbers */
322#define hi_major hi_dewey[0]
323#define hi_minor hi_dewey[1]
324 int hi_next; /* Next in this bucket */
325};
326
327#define _PATH_LD_HINTS "/var/run/ld.so.hints"
328
329#endif /* !__ELF__ */
330
331#endif /* _LINK_H_ */