xref: /illumos-gate/usr/src/cmd/sgs/rtld/common/_a.out.h (revision 4870e0a7)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 #ifndef	_A_DOT_OUT_DOT_H
26 #define	_A_DOT_OUT_DOT_H
27 
28 #include <sys/types.h>
29 #include <sys/null.h>
30 #include <sys/mman.h>
31 #include <a.out.h>
32 #include <_rtld.h>
33 
34 #ifdef	__cplusplus
35 extern "C" {
36 #endif
37 
38 #define	max(a, b)	((a) < (b) ? (b) : (a))
39 
40 typedef struct link_dynamic	Link_dynamic;
41 
42 /*
43  * Extern functions for a.out format file class.
44  */
45 extern	ulong_t	aout_bndr(caddr_t);
46 extern	int	aout_get_mmap(Lm_list *, mmapobj_result_t *);
47 extern	int	aout_lookup_sym(Slookup *, Sresult *, uint_t *, int *);
48 extern	Rt_map	*aout_new_lmp(Lm_list *, Aliste, Fdesc *, Addr, size_t, void *,
49 		    Rt_map *, int *);
50 extern	void	aout_plt_write(caddr_t, ulong_t);
51 extern	int	aout_reloc(Rt_map *, uint_t, int *, APlist **);
52 extern	void	aout_rtbndr(caddr_t);
53 extern	Fct	*aout_verify(caddr_t, size_t, Fdesc *, const char *,
54 		    Rej_desc *);
55 
56 /*
57  * Private data for an a.out format file class.
58  */
59 typedef struct _rt_aout_private {
60 	struct link_dynamic	*lm_ld;		/* 4.x aout dynamic pointer */
61 	struct ld_private	*lm_lpd;	/* private aout object area */
62 } Rt_aoutp;
63 
64 /*
65  * Special defines for a.out format file class.
66  */
67 #define	N_UNDF	0x0		/* undefined */
68 #define	N_ABS	0x2		/* absolute */
69 #define	N_COMM	0x12		/* common (internal to ld) */
70 #define	N_EXT	01		/* external bit, or'ed in */
71 
72 /*
73  * Format of a symbol table entry.
74  */
75 struct	nlist {
76 	union {
77 		char	*n_name;		/* for use when in-core */
78 		long	n_strx;		/* index into file string table */
79 	} n_un;
80 	uchar_t 	n_type;		/* type flag (N_TEXT,..)  */
81 	char		n_other;	/* unused */
82 	short		n_desc;		/* see <stab.h> */
83 	ulong_t		n_value;	/* value of symbol (or sdb offset) */
84 };
85 
86 /*
87  * Link editor public definitions.
88  */
89 
90 #ifndef _link_h
91 #define	_link_h
92 
93 /*
94  * Structure describing logical name and requirements on an object
95  * which is to be loaded dynamically.
96  */
97 struct old_link_object {
98 	char	*lo_name;		/* name of object */
99 	int	lo_library : 1,		/* searched for by library rules */
100 		lo_unused : 31;
101 	short	lo_major;		/* major version number */
102 	short	lo_minor;		/* minor version number */
103 };
104 
105 struct link_object {
106 	long	lo_name;		/* name (often relative) */
107 	int	lo_library : 1,		/* searched for by library rules */
108 		lo_unused : 31;
109 	short	lo_major;		/* major version number */
110 	short	lo_minor;		/* minor version number */
111 	long	lo_next;		/* next one (often relative) */
112 };
113 typedef	struct	link_object Lnk_obj;
114 
115 /*
116  * Structure describing name and placement of dynamically loaded
117  * objects in a process' address space.
118  */
119 typedef struct a_link_map	A_link_map;
120 
121 struct a_link_map {
122 	caddr_t	lm_addr;		/* address at which object mapped */
123 	char	*lm_name;		/* full name of loaded object */
124 	struct	a_link_map *lm_next;	/* next object in map */
125 	struct	link_object *lm_lop;	/* link object that got us here */
126 	caddr_t lm_lob;			/* base address for said link object */
127 	int	lm_rwt : 1;		/* text is read/write */
128 	struct	link_dynamic *lm_ld;	/* dynamic structure */
129 	caddr_t	lm_lpd;			/* loader private data */
130 };
131 
132 /*
133  * Version 1 of dynamic linking information.  With the exception of
134  * ld_loaded (determined at execution time) and ld_stab_hash (a special
135  * case of relocation handled at execution time), the values in this
136  * structure reflect offsets from the containing link_dynamic structure.
137  */
138 struct link_dynamic_1 {
139 	struct	a_link_map *ld_loaded;	/* list of loaded objects */
140 	long	ld_need;		/* list of needed objects */
141 	long	ld_rules;		/* search rules for library objects */
142 	long	ld_got;			/* global offset table */
143 	long	ld_plt;			/* procedure linkage table */
144 	long	ld_rel;			/* relocation table */
145 	long	ld_hash;		/* symbol hash table */
146 	long	ld_stab;		/* symbol table itself */
147 	long	(*ld_stab_hash)();	/* "pointer" to symbol hash function */
148 	long	ld_buckets;		/* number of hash buckets */
149 	long	ld_symbols;		/* symbol strings */
150 	long	ld_symb_size;		/* size of symbol strings */
151 	long	ld_text;		/* size of text area */
152 };
153 
154 struct link_dynamic_2 {
155 	struct	a_link_map *ld_loaded;	/* list of loaded objects */
156 	long	ld_need;		/* list of needed objects */
157 	long	ld_rules;		/* search rules for library objects */
158 	long	ld_got;			/* global offset table */
159 	long	ld_plt;			/* procedure linkage table */
160 	long	ld_rel;			/* relocation table */
161 	long	ld_hash;		/* symbol hash table */
162 	long	ld_stab;		/* symbol table itself */
163 	long	(*ld_stab_hash)();	/* "pointer" to symbol hash function */
164 	long	ld_buckets;		/* number of hash buckets */
165 	long	ld_symbols;		/* symbol strings */
166 	long	ld_symb_size;		/* size of symbol strings */
167 	long	ld_text;		/* size of text area */
168 	long	ld_plt_sz;		/* size of procedure linkage table */
169 };
170 
171 /*
172  * Structure pointing to run time allocated common symbols and
173  * its string.
174  */
175 struct rtc_symb {
176 	struct	nlist *rtc_sp;		/* symbol for common */
177 	struct	rtc_symb *rtc_next;	/* next common */
178 };
179 
180 /*
181  * Debugger interface structure.
182  */
183 struct 	ld_debug {
184 	int	ldd_version;		/* version # of interface */
185 	int	ldd_in_debugger;	/* a debugger is running us */
186 	int	ldd_sym_loaded;		/* we loaded some symbols */
187 	char    *ldd_bp_addr;		/* place for ld-generated bpt */
188 	int	ldd_bp_inst;		/* instruction which was there */
189 	struct rtc_symb *ldd_cp;	/* commons we built */
190 };
191 
192 /*
193  * Structure associated with each object which may be or which requires
194  * execution-time link editing.  Used by the run-time linkage editor to
195  * identify needed objects and symbol definitions and references.
196  */
197 struct 	old_link_dynamic {
198 	int	ld_version;		/* version # of this structure */
199 	union {
200 		struct link_dynamic_1 ld_1;
201 	} ld_un;
202 
203 	int	in_debugging;
204 	int	sym_loaded;
205 	char    *bp_addr;
206 	int	bp_inst;
207 	struct rtc_symb *cp; 		/* pointer to an array of runtime */
208 					/* allocated common symbols. */
209 };
210 
211 struct	link_dynamic {
212 	int	ld_version;		/* version # of this structure */
213 	struct 	ld_debug *ldd;
214 	union {
215 		struct link_dynamic_1 *ld_1;
216 		struct link_dynamic_2 *ld_2;
217 	} ld_un;
218 };
219 
220 
221 /*
222  * Get size of relocations.
223  */
224 #define	GETGOTSZ(x)	(x->ld_version < 2 ?				\
225 			((struct old_link_dynamic *)x)->v1.ld_plt -	\
226 			((struct old_link_dynamic *)x)->v1.ld_got :	\
227 			(x)->v2->ld_plt - (x)->v2->ld_got)
228 
229 #define	GETPLTSZ(x)	(x->ld_version < 2 ?				\
230 			((struct old_link_dynamic *)x)->v1.ld_rel -	\
231 			((struct old_link_dynamic *)x)->v1.ld_plt :	\
232 			(x)->v2->ld_rel - (x)->v2->ld_plt)
233 
234 #define	GETRELSZ(x)	(x->ld_version < 2 ?				\
235 			((struct old_link_dynamic *)x)->v1.ld_hash -	\
236 			((struct old_link_dynamic *)x)->v1.ld_rel :	\
237 			(x)->v2->ld_hash - (x)->v2->ld_rel)
238 
239 #define	GETHASHSZ(x)	(x->ld_version < 2 ?				\
240 			((struct old_link_dynamic *)x)->v1.ld_stab -	\
241 			((struct old_link_dynamic *)x)->v1.ld_hash :	\
242 			(x)->v2->ld_stab - (x)->v2->ld_hash)
243 
244 #define	GETSTABSZ(x)	(x->ld_version < 2 ?				\
245 			((struct old_link_dynamic *)x)->v1.ld_symbols -\
246 			((struct old_link_dynamic *)x)->v1.ld_stab :	\
247 			(x)->v2->ld_symbols - (x)->v2->ld_stab)
248 
249 #undef v2
250 #undef v1
251 
252 #endif /* !_link_h */
253 
254 #define	MAIN_BASE 0x2000	/* base address of a.out in 4.x system */
255 
256 /*
257  * Macros for getting to linker a.out format private data.
258  */
259 #define	AOUTPRV(X)	((X)->rt_priv)
260 #define	AOUTDYN(X)	(((Rt_aoutp *)(X)->rt_priv)->lm_ld)
261 #define	LM2LP(X)	((struct ld_private *)((Rt_aoutp *) \
262 				(X)->rt_priv)->lm_lpd)
263 #define	TEXTBASE(X)	(LM2LP(X)->lp_textbase)
264 
265 /*
266  * Most of the above macros are used from AOUT specific routines, however there
267  * are a couple of instances where we need to ensure the file being processed
268  * is AOUT before dereferencing the macro.
269  */
270 #define	THIS_IS_AOUT(X)		(FCT(X) == &aout_fct)
271 
272 /*
273  * Code collapsing macros.
274  */
275 #define	v2 ld_un.ld_2
276 #define	v1 ld_un.ld_1
277 #define	JMPOFF(x)	(x)->v2->ld_plt
278 #define	RELOCOFF(x)	(x)->v2->ld_rel
279 #define	HASHOFF(x)	(x)->v2->ld_hash
280 #define	SYMOFF(x)	(x)->v2->ld_stab
281 #define	STROFF(x)	(x)->v2->ld_symbols
282 
283 struct jbind {
284 	int	jb_inst[3];	/* need 4 instructions for jump slot */
285 };
286 
287 struct fshash {
288 	int	fssymbno;	/* ordinal symbol number */
289 	int	next;		/* index to the hash array pointed by fs_hash */
290 };
291 
292 /*
293  * Sparc relocation types.
294  */
295 enum reloc_type
296 {
297 	RELOC_8,	RELOC_16,	RELOC_32,	/* simplest relocs */
298 	RELOC_DISP8,	RELOC_DISP16,	RELOC_DISP32,	/* Disp's (pc-rel) */
299 	RELOC_WDISP30,	RELOC_WDISP22,			/* SR word disp's */
300 	RELOC_HI22,	RELOC_22,			/* SR 22-bit relocs */
301 	RELOC_13,	RELOC_LO10,			/* SR 13&10-bit reloc */
302 	RELOC_SFA_BASE,	RELOC_SFA_OFF13,		/* SR S.F.A. relocs */
303 	RELOC_BASE10,	RELOC_BASE13,	RELOC_BASE22,	/* base_relative pic */
304 	RELOC_PC10,	RELOC_PC22,			/* special pc-rel pic */
305 	RELOC_JMP_TBL,					/* jmp_tbl_rel in pic */
306 	RELOC_SEGOFF16,					/* Shlib off-in-seg */
307 	RELOC_GLOB_DAT, RELOC_JMP_SLOT, RELOC_RELATIVE	/* rtld relocs */
308 };
309 
310 /*
311  * Format of a relocation datum.
312  */
313 #define	r_symbolnum 	r_index
314 
315 struct	relocation_info		/* used when header.a_machtype == M_SPARC */
316 {
317 	ulong_t		r_address;	/* relocation addr (offset in seg) */
318 	uint_t 		r_index   :24;	/* segment index or symbol index */
319 	uint_t 		r_extern  : 1;	/* if F, r_index==SEG#; if T, SYM idx */
320 	int			  : 2;	/* <unused> */
321 	enum reloc_type r_type    : 5;	/* type of relocation to perform */
322 	long		r_addend;	/* addend for relocation value */
323 };
324 
325 struct ld_private {
326 	struct	jbind *lp_plt;		/* procedure linkage table */
327 	struct	relocation_info *lp_rp;	/* relocation table */
328 	struct	fshash *lp_hash;	/* hash table */
329 	struct	nlist *lp_symtab;	/* symbol table */
330 	char	*lp_symstr;		/* symbol strings */
331 	caddr_t	lp_textbase;		/* base address for text addressing */
332 	struct	nlist *(*lp_interp)();	/* link map interpreter */
333 	long	lp_refcnt;		/* reference count of link map */
334 	struct 	dl_object *lp_dlp;	/* pointer to a dlopen object */
335 	caddr_t	lp_symbol_base;		/* base address for symbols */
336 };
337 
338 
339 /*
340  * Offsets of various sections of an object file.
341  */
342 #define	PAGSIZ		0x02000
343 #define	SEGSIZ		PAGSIZ
344 
345 #define	N_TXTOFF(x) \
346 	/* text segment */ \
347 	((x).a_magic == ZMAGIC ? 0 : sizeof (struct exec))
348 
349 #define	N_SYMOFF(x) \
350 	/* symbol table */ \
351 	(N_TXTOFF(x) + (x).a_text + (x).a_data + (x).a_trsize + (x).a_drsize)
352 
353 #define	SIZE(x) \
354 	/* round to segment size */ \
355 	(M_SROUND((x).a_text) + (x).a_data + (x).a_bss)
356 
357 #ifdef	__cplusplus
358 }
359 #endif
360 
361 #endif	/* _A_DOT_OUT_DOT_H */
362