xref: /titanic_51/usr/src/cmd/sgs/rtld/sparc/sparc_a.out.c (revision 60c45ed01d4f99571d468c42f609d11a099fab1e)
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) 1988 AT&T
24  *	All Rights Reserved
25  *
26  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  * SPARC machine dependent and a.out format file class dependent functions.
34  * Contains routines for performing function binding and symbol relocations.
35  */
36 #include	"_synonyms.h"
37 
38 #include	<stdio.h>
39 #include	<sys/types.h>
40 #include	<sys/mman.h>
41 #include	<synch.h>
42 #include	<dlfcn.h>
43 #include	<debug.h>
44 #include	"_a.out.h"
45 #include	"_rtld.h"
46 #include	"_audit.h"
47 #include	"msg.h"
48 
49 extern void	iflush_range(caddr_t, size_t);
50 
51 /*
52  * Function binding routine - invoked on the first call to a function through
53  * the procedure linkage table;
54  * passes first through an assembly language interface.
55  *
56  * Takes the address of the PLT entry where the call originated,
57  * the offset into the relocation table of the associated
58  * relocation entry and the address of the link map (rt_private_map struct)
59  * for the entry.
60  *
61  * Returns the address of the function referenced after re-writing the PLT
62  * entry to invoke the function directly.
63  *
64  * On error, causes process to terminate with a signal.
65  */
66 ulong_t
67 aout_bndr(caddr_t pc)
68 {
69 	Rt_map		*lmp, *nlmp, *llmp;
70 	struct relocation_info *rp;
71 	struct nlist	*sp;
72 	Sym		*sym;
73 	char		*name;
74 	int 		rndx, entry;
75 	ulong_t		symval;
76 	Slookup		sl;
77 	uint_t		binfo;
78 	Lm_list		*lml;
79 
80 	/*
81 	 * For compatibility with libthread (TI_VERSION 1) we track the entry
82 	 * value.  A zero value indicates we have recursed into ld.so.1 to
83 	 * further process a locking request (see comments in completion()).
84 	 * Under this recursion we disable tsort and cleanup activities.
85 	 */
86 	entry = enter();
87 
88 	for (lmp = lml_main.lm_head; lmp; lmp = (Rt_map *)NEXT(lmp)) {
89 		if (FCT(lmp) == &aout_fct) {
90 			if (pc > (caddr_t)(LM2LP(lmp)->lp_plt) &&
91 			    pc < (caddr_t)((int)LM2LP(lmp)->lp_plt +
92 			    AOUTDYN(lmp)->v2->ld_plt_sz))  {
93 				break;
94 			}
95 		}
96 	}
97 
98 #define	LAST22BITS	0x3fffff
99 
100 	/* LINTED */
101 	rndx = *(int *)(pc + (sizeof (ulong_t *) * 2)) & LAST22BITS;
102 	rp = &LM2LP(lmp)->lp_rp[rndx];
103 	sp = &LM2LP(lmp)->lp_symtab[rp->r_symbolnum];
104 	name = &LM2LP(lmp)->lp_symstr[sp->n_un.n_strx];
105 
106 	/*
107 	 * Determine the last link-map of this list, this'll be the starting
108 	 * point for any tsort() processing.
109 	 */
110 	lml = LIST(lmp);
111 	llmp = lml->lm_tail;
112 
113 	/*
114 	 * Find definition for symbol.  Initialize the symbol lookup data
115 	 * structure.
116 	 */
117 	SLOOKUP_INIT(sl, name, lmp, lml->lm_head, ld_entry_cnt, 0, 0, 0, 0,
118 	    LKUP_DEFT);
119 
120 	if ((sym = aout_lookup_sym(&sl, &nlmp, &binfo, NULL)) == 0) {
121 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp),
122 		    demangle(name));
123 		rtldexit(lml, 1);
124 	}
125 
126 	symval = sym->st_value;
127 	if (!(FLAGS(nlmp) & FLG_RT_FIXED) &&
128 	    (sym->st_shndx != SHN_ABS))
129 		symval += (int)(ADDR(nlmp));
130 	if ((lmp != nlmp) && ((FLAGS1(nlmp) & FL1_RT_NOINIFIN) == 0)) {
131 		/*
132 		 * Record that this new link map is now bound to the caller.
133 		 */
134 		if (bind_one(lmp, nlmp, BND_REFER) == 0)
135 			rtldexit(lml, 1);
136 	}
137 
138 	/*
139 	 * Print binding information and rebuild PLT entry.
140 	 */
141 	DBG_CALL(Dbg_bind_global(lmp, (Addr)(ADDR(lmp) + rp->r_address),
142 	    (Off)rp->r_address, (Xword)(-1), PLT_T_NONE, nlmp,
143 	    (Addr)symval, sym->st_value, name, binfo));
144 
145 	if (!(rtld_flags & RT_FL_NOBIND))
146 		aout_plt_write((caddr_t)(ADDR(lmp) + rp->r_address), symval);
147 
148 	/*
149 	 * Complete any processing for newly loaded objects.  Note we don't
150 	 * know exactly where any new objects are loaded (we know the object
151 	 * that supplied the symbol, but others may have been loaded lazily as
152 	 * we searched for the symbol), so sorting starts from the last
153 	 * link-map know on entry to this routine.
154 	 */
155 	if (entry)
156 		load_completion(llmp);
157 
158 	/*
159 	 * If the object we've bound to is in the process of being initialized
160 	 * by another thread, determine whether we should block.
161 	 */
162 	is_dep_ready(nlmp, lmp, DBG_WAIT_SYMBOL);
163 
164 	/*
165 	 * Make sure the object to which we've bound has had it's .init fired.
166 	 * Cleanup before return to user code.
167 	 */
168 	if (entry) {
169 		is_dep_init(nlmp, lmp);
170 		leave(lml);
171 	}
172 
173 	return (symval);
174 }
175 
176 
177 #define	IS_PC_RELATIVE(X) (pc_rel_type[(X)] == 1)
178 
179 static const uchar_t pc_rel_type[] = {
180 	0,				/* RELOC_8 */
181 	0,				/* RELOC_16 */
182 	0,				/* RELOC_32 */
183 	1,				/* RELOC_DISP8 */
184 	1,				/* RELOC_DISP16 */
185 	1,				/* RELOC_DISP32 */
186 	1,				/* RELOC_WDISP30 */
187 	1,				/* RELOC_WDISP22 */
188 	0,				/* RELOC_HI22 */
189 	0,				/* RELOC_22 */
190 	0,				/* RELOC_13 */
191 	0,				/* RELOC_LO10 */
192 	0,				/* RELOC_SFA_BASE */
193 	0,				/* RELOC_SFA_OFF13 */
194 	0,				/* RELOC_BASE10 */
195 	0,				/* RELOC_BASE13 */
196 	0,				/* RELOC_BASE22 */
197 	0,				/* RELOC_PC10 */
198 	0,				/* RELOC_PC22 */
199 	0,				/* RELOC_JMP_TBL */
200 	0,				/* RELOC_SEGOFF16 */
201 	0,				/* RELOC_GLOB_DAT */
202 	0,				/* RELOC_JMP_SLOT */
203 	0				/* RELOC_RELATIVE */
204 };
205 
206 int
207 aout_reloc(Rt_map * lmp, uint_t plt, int *in_nfavl)
208 {
209 	int		k;		/* loop temporary */
210 	int		nr;		/* number of relocations */
211 	char		*name;		/* symbol being searched for */
212 	long		*et;		/* cached _etext of object */
213 	long		value;		/* relocation temporary */
214 	long		*ra;		/* cached relocation address */
215 	struct relocation_info *rp;	/* current relocation */
216 	struct nlist	*sp;		/* symbol table of "symbol" */
217 	Rt_map *	_lmp;		/* lm which holds symbol definition */
218 	Sym *		sym;		/* symbol definition */
219 	int		textrel = 0, ret = 1;
220 	APlist		*bound = NULL;
221 	Lm_list		*lml = LIST(lmp);
222 
223 	DBG_CALL(Dbg_reloc_run(lmp, SHT_RELA, plt, DBG_REL_START));
224 
225 	/*
226 	 * If we've been called upon to promote an RTLD_LAZY object to an
227 	 * RTLD_NOW don't bother to do anything - a.out's are bound as if
228 	 * RTLD_NOW regardless.
229 	 */
230 	if (plt)
231 		return (1);
232 
233 	rp = LM2LP(lmp)->lp_rp;
234 	et = (long *)ETEXT(lmp);
235 	nr = GETRELSZ(AOUTDYN(lmp)) / sizeof (struct relocation_info);
236 
237 	/*
238 	 * Initialize _PLT_, if any.
239 	 */
240 	if (AOUTDYN(lmp)->v2->ld_plt_sz)
241 		aout_plt_write((caddr_t)LM2LP(lmp)->lp_plt->jb_inst,
242 		    (ulong_t)aout_rtbndr);
243 
244 	/*
245 	 * Loop through relocations.
246 	 */
247 	for (k = 0; k < nr; k++, rp++) {
248 		/* LINTED */
249 		ra = (long *)&((char *)ADDR(lmp))[rp->r_address];
250 
251 		/*
252 		 * Check to see if we're relocating in the text segment
253 		 * and turn off the write protect if necessary.
254 		 */
255 		if ((ra < et) && (textrel == 0)) {
256 			if (aout_set_prot(lmp, PROT_WRITE) == 0) {
257 				ret = 0;
258 				break;
259 			}
260 			textrel = 1;
261 		}
262 
263 		/*
264 		 * Perform the relocation.
265 		 */
266 		if (rp->r_extern == 0) {
267 			name = (char *)0;
268 			value = ADDR(lmp);
269 		} else {
270 			Slookup		sl;
271 			uint_t		binfo;
272 
273 			if (rp->r_type == RELOC_JMP_SLOT)
274 				continue;
275 			sp = &LM2LP(lmp)->lp_symtab[rp->r_symbolnum];
276 			name = &LM2LP(lmp)->lp_symstr[sp->n_un.n_strx];
277 
278 			/*
279 			 * Locate symbol.  Initialize the symbol lookup data
280 			 * structure.
281 			 */
282 			SLOOKUP_INIT(sl, name, lmp, 0, ld_entry_cnt, 0, 0, 0, 0,
283 			    LKUP_STDRELOC);
284 
285 			if ((sym = aout_lookup_sym(&sl, &_lmp,
286 			    &binfo, in_nfavl)) == 0) {
287 				if (lml->lm_flags & LML_FLG_TRC_WARN) {
288 					(void)
289 					    printf(MSG_INTL(MSG_LDD_SYM_NFOUND),
290 					    demangle(name), NAME(lmp));
291 					continue;
292 				} else {
293 					eprintf(lml, ERR_FATAL,
294 					    MSG_INTL(MSG_REL_NOSYM), NAME(lmp),
295 					    demangle(name));
296 					ret = 0;
297 					break;
298 				}
299 			}
300 
301 			/*
302 			 * If symbol was found in an object other than the
303 			 * referencing object then record the binding.
304 			 */
305 			if ((lmp != _lmp) &&
306 			    ((FLAGS1(_lmp) & FL1_RT_NOINIFIN) == 0)) {
307 				if (aplist_test(&bound, _lmp,
308 				    AL_CNT_RELBIND) == 0) {
309 					ret = 0;
310 					break;
311 				}
312 			}
313 
314 			value = sym->st_value + rp->r_addend;
315 			if (!(FLAGS(_lmp) & FLG_RT_FIXED) &&
316 			    (sym->st_shndx != SHN_COMMON) &&
317 			    (sym->st_shndx != SHN_ABS))
318 				value += ADDR(_lmp);
319 
320 			if (IS_PC_RELATIVE(rp->r_type))
321 				value -= (long)ADDR(lmp);
322 
323 			DBG_CALL(Dbg_bind_global(lmp, (Addr)ra,
324 			    (Off)(ra - ADDR(lmp)), (Xword)(-1), PLT_T_NONE,
325 			    _lmp, (Addr)value, sym->st_value, name, binfo));
326 		}
327 
328 		/*
329 		 * Perform a specific relocation operation.
330 		 */
331 		switch (rp->r_type) {
332 		case RELOC_RELATIVE:
333 			value += *ra << (32-22);
334 			*(long *)ra = (*(long *)ra & ~S_MASK(22)) |
335 			    ((value >> (32 - 22)) & S_MASK(22));
336 			ra++;
337 			value += (*ra & S_MASK(10));
338 			*(long *)ra = (*(long *)ra & ~S_MASK(10)) |
339 			    (value & S_MASK(10));
340 			break;
341 		case RELOC_8:
342 		case RELOC_DISP8:
343 			value += *ra & S_MASK(8);
344 			if (!S_INRANGE(value, 8)) {
345 				eprintf(lml, ERR_FATAL,
346 				    MSG_INTL(MSG_REL_OVERFLOW), NAME(lmp),
347 				    (name ? demangle(name) :
348 				    MSG_INTL(MSG_STR_UNKNOWN)), (int)value, 8,
349 				    (uint_t)ra);
350 			}
351 			*ra = value;
352 			break;
353 		case RELOC_LO10:
354 		case RELOC_BASE10:
355 			value += *ra & S_MASK(10);
356 			*(long *)ra = (*(long *)ra & ~S_MASK(10)) |
357 			    (value & S_MASK(10));
358 			break;
359 		case RELOC_BASE13:
360 		case RELOC_13:
361 			value += *ra & S_MASK(13);
362 			*(long *)ra = (*(long *)ra & ~S_MASK(13)) |
363 			    (value & S_MASK(13));
364 			break;
365 		case RELOC_16:
366 		case RELOC_DISP16:
367 			value += *ra & S_MASK(16);
368 			if (!S_INRANGE(value, 16)) {
369 				eprintf(lml, ERR_FATAL,
370 				    MSG_INTL(MSG_REL_OVERFLOW), NAME(lmp),
371 				    (name ? demangle(name) :
372 				    MSG_INTL(MSG_STR_UNKNOWN)), (int)value, 16,
373 				    (uint_t)ra);
374 			}
375 			*(short *)ra = value;
376 			break;
377 		case RELOC_22:
378 		case RELOC_BASE22:
379 			value += *ra & S_MASK(22);
380 			if (!S_INRANGE(value, 22)) {
381 				eprintf(lml, ERR_FATAL,
382 				    MSG_INTL(MSG_REL_OVERFLOW), NAME(lmp),
383 				    (name ? demangle(name) :
384 				    MSG_INTL(MSG_STR_UNKNOWN)), (int)value, 22,
385 				    (uint_t)ra);
386 			}
387 			*(long *)ra = (*(long *)ra & ~S_MASK(22)) |
388 			    (value & S_MASK(22));
389 			break;
390 		case RELOC_HI22:
391 			value += (*ra & S_MASK(22)) << (32 - 22);
392 			*(long *)ra = (*(long *)ra & ~S_MASK(22)) |
393 			    ((value >> (32 - 22)) & S_MASK(22));
394 			break;
395 		case RELOC_WDISP22:
396 			value += *ra & S_MASK(22);
397 			value >>= 2;
398 			if (!S_INRANGE(value, 22)) {
399 				eprintf(lml, ERR_FATAL,
400 				    MSG_INTL(MSG_REL_OVERFLOW), NAME(lmp),
401 				    (name ? demangle(name) :
402 				    MSG_INTL(MSG_STR_UNKNOWN)), (int)value, 22,
403 				    (uint_t)ra);
404 			}
405 			*(long *)ra = (*(long *)ra & ~S_MASK(22)) |
406 			    (value & S_MASK(22));
407 			break;
408 		case RELOC_WDISP30:
409 			value += *ra & S_MASK(30);
410 			value >>= 2;
411 			*(long *)ra = (*(long *)ra & ~S_MASK(30)) |
412 			    (value & S_MASK(30));
413 			break;
414 		case RELOC_32:
415 		case RELOC_GLOB_DAT:
416 		case RELOC_DISP32:
417 			value += *ra;
418 			*(long *)ra = value;
419 			break;
420 		default:
421 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_UNIMPL),
422 			    NAME(lmp), (name ? demangle(name) :
423 			    MSG_INTL(MSG_STR_UNKNOWN)), rp->r_type);
424 			ret = 0;
425 			break;
426 		}
427 
428 		/*
429 		 * If this relocation is against a text segment we must make
430 		 * sure that the instruction cache is flushed.
431 		 */
432 		if (textrel) {
433 			if (rp->r_type == RELOC_RELATIVE)
434 				iflush_range((caddr_t)(ra - 1), 0x8);
435 			else
436 				iflush_range((caddr_t)ra, 0x4);
437 		}
438 	}
439 
440 	return (relocate_finish(lmp, bound, textrel, ret));
441 }
442