xref: /titanic_41/usr/src/cmd/sgs/rtld/sparc/sparc_a.out.c (revision 8e22821528b08c6dba4e8176351560f316f6d0de)
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 2007 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.
115 	 */
116 	sl.sl_name = name;
117 	sl.sl_cmap = lmp;
118 	sl.sl_imap = lml->lm_head;
119 	sl.sl_hash = 0;
120 	sl.sl_rsymndx = 0;
121 	sl.sl_flags = LKUP_DEFT;
122 
123 	if ((sym = aout_lookup_sym(&sl, &nlmp, &binfo)) == 0) {
124 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp),
125 		    demangle(name));
126 		rtldexit(lml, 1);
127 	}
128 
129 	symval = sym->st_value;
130 	if (!(FLAGS(nlmp) & FLG_RT_FIXED) &&
131 	    (sym->st_shndx != SHN_ABS))
132 		symval += (int)(ADDR(nlmp));
133 	if ((lmp != nlmp) && ((FLAGS1(nlmp) & FL1_RT_NOINIFIN) == 0)) {
134 		/*
135 		 * Record that this new link map is now bound to the caller.
136 		 */
137 		if (bind_one(lmp, nlmp, BND_REFER) == 0)
138 			rtldexit(lml, 1);
139 	}
140 
141 	/*
142 	 * Print binding information and rebuild PLT entry.
143 	 */
144 	DBG_CALL(Dbg_bind_global(lmp, (Addr)(ADDR(lmp) + rp->r_address),
145 	    (Off)rp->r_address, (Xword)(-1), PLT_T_NONE, nlmp,
146 	    (Addr)symval, sym->st_value, name, binfo));
147 
148 	if (!(rtld_flags & RT_FL_NOBIND))
149 		aout_plt_write((caddr_t)(ADDR(lmp) + rp->r_address), symval);
150 
151 	/*
152 	 * Complete any processing for newly loaded objects.  Note we don't
153 	 * know exactly where any new objects are loaded (we know the object
154 	 * that supplied the symbol, but others may have been loaded lazily as
155 	 * we searched for the symbol), so sorting starts from the last
156 	 * link-map know on entry to this routine.
157 	 */
158 	if (entry)
159 		load_completion(llmp);
160 
161 	/*
162 	 * If the object we've bound to is in the process of being initialized
163 	 * by another thread, determine whether we should block.
164 	 */
165 	is_dep_ready(nlmp, lmp, DBG_WAIT_SYMBOL);
166 
167 	/*
168 	 * Make sure the object to which we've bound has had it's .init fired.
169 	 * Cleanup before return to user code.
170 	 */
171 	if (entry) {
172 		is_dep_init(nlmp, lmp);
173 		leave(lml);
174 	}
175 
176 	return (symval);
177 }
178 
179 
180 #define	IS_PC_RELATIVE(X) (pc_rel_type[(X)] == 1)
181 
182 static const uchar_t pc_rel_type[] = {
183 	0,				/* RELOC_8 */
184 	0,				/* RELOC_16 */
185 	0,				/* RELOC_32 */
186 	1,				/* RELOC_DISP8 */
187 	1,				/* RELOC_DISP16 */
188 	1,				/* RELOC_DISP32 */
189 	1,				/* RELOC_WDISP30 */
190 	1,				/* RELOC_WDISP22 */
191 	0,				/* RELOC_HI22 */
192 	0,				/* RELOC_22 */
193 	0,				/* RELOC_13 */
194 	0,				/* RELOC_LO10 */
195 	0,				/* RELOC_SFA_BASE */
196 	0,				/* RELOC_SFA_OFF13 */
197 	0,				/* RELOC_BASE10 */
198 	0,				/* RELOC_BASE13 */
199 	0,				/* RELOC_BASE22 */
200 	0,				/* RELOC_PC10 */
201 	0,				/* RELOC_PC22 */
202 	0,				/* RELOC_JMP_TBL */
203 	0,				/* RELOC_SEGOFF16 */
204 	0,				/* RELOC_GLOB_DAT */
205 	0,				/* RELOC_JMP_SLOT */
206 	0				/* RELOC_RELATIVE */
207 };
208 
209 int
210 aout_reloc(Rt_map * lmp, uint_t plt)
211 {
212 	int		k;		/* loop temporary */
213 	int		nr;		/* number of relocations */
214 	char		*name;		/* symbol being searched for */
215 	long		*et;		/* cached _etext of object */
216 	long		value;		/* relocation temporary */
217 	long		*ra;		/* cached relocation address */
218 	struct relocation_info *rp;	/* current relocation */
219 	struct nlist	*sp;		/* symbol table of "symbol" */
220 	Rt_map *	_lmp;		/* lm which holds symbol definition */
221 	Sym *		sym;		/* symbol definition */
222 	int		textrel = 0, ret = 1;
223 	Alist		*bound = 0;
224 	Lm_list		*lml = LIST(lmp);
225 
226 	DBG_CALL(Dbg_reloc_run(lmp, SHT_RELA, plt, DBG_REL_START));
227 
228 	/*
229 	 * If we've been called upon to promote an RTLD_LAZY object to an
230 	 * RTLD_NOW don't bother to do anything - a.out's are bound as if
231 	 * RTLD_NOW regardless.
232 	 */
233 	if (plt)
234 		return (1);
235 
236 	rp = LM2LP(lmp)->lp_rp;
237 	et = (long *)ETEXT(lmp);
238 	nr = GETRELSZ(AOUTDYN(lmp)) / sizeof (struct relocation_info);
239 
240 	/*
241 	 * Initialize _PLT_, if any.
242 	 */
243 	if (AOUTDYN(lmp)->v2->ld_plt_sz)
244 		aout_plt_write((caddr_t)LM2LP(lmp)->lp_plt->jb_inst,
245 		    (ulong_t)aout_rtbndr);
246 
247 	/*
248 	 * Loop through relocations.
249 	 */
250 	for (k = 0; k < nr; k++, rp++) {
251 		/* LINTED */
252 		ra = (long *)&((char *)ADDR(lmp))[rp->r_address];
253 
254 		/*
255 		 * Check to see if we're relocating in the text segment
256 		 * and turn off the write protect if necessary.
257 		 */
258 		if ((ra < et) && (textrel == 0)) {
259 			if (aout_set_prot(lmp, PROT_WRITE) == 0) {
260 				ret = 0;
261 				break;
262 			}
263 			textrel = 1;
264 		}
265 
266 		/*
267 		 * Perform the relocation.
268 		 */
269 		if (rp->r_extern == 0) {
270 			name = (char *)0;
271 			value = ADDR(lmp);
272 		} else {
273 			Slookup		sl;
274 			uint_t		binfo;
275 
276 			if (rp->r_type == RELOC_JMP_SLOT)
277 				continue;
278 			sp = &LM2LP(lmp)->lp_symtab[rp->r_symbolnum];
279 			name = &LM2LP(lmp)->lp_symstr[sp->n_un.n_strx];
280 
281 			/*
282 			 * Locate symbol.
283 			 */
284 			sl.sl_name = name;
285 			sl.sl_cmap = lmp;
286 			sl.sl_imap = 0;
287 			sl.sl_hash = 0;
288 			sl.sl_rsymndx = 0;
289 			sl.sl_flags = (LKUP_DEFT | LKUP_ALLCNTLIST);
290 
291 			if ((sym = aout_lookup_sym(&sl, &_lmp, &binfo)) == 0) {
292 				if (lml->lm_flags & LML_FLG_TRC_WARN) {
293 					(void)
294 					    printf(MSG_INTL(MSG_LDD_SYM_NFOUND),
295 					    demangle(name), NAME(lmp));
296 					continue;
297 				} else {
298 					eprintf(lml, ERR_FATAL,
299 					    MSG_INTL(MSG_REL_NOSYM), NAME(lmp),
300 					    demangle(name));
301 					ret = 0;
302 					break;
303 				}
304 			}
305 
306 			/*
307 			 * If symbol was found in an object other than the
308 			 * referencing object then record the binding.
309 			 */
310 			if ((lmp != _lmp) &&
311 			    ((FLAGS1(_lmp) & FL1_RT_NOINIFIN) == 0)) {
312 				if (alist_test(&bound, _lmp, sizeof (Rt_map *),
313 				    AL_CNT_RELBIND) == 0) {
314 					ret = 0;
315 					break;
316 				}
317 			}
318 
319 			value = sym->st_value + rp->r_addend;
320 			if (!(FLAGS(_lmp) & FLG_RT_FIXED) &&
321 			    (sym->st_shndx != SHN_COMMON) &&
322 			    (sym->st_shndx != SHN_ABS))
323 				value += ADDR(_lmp);
324 
325 			if (IS_PC_RELATIVE(rp->r_type))
326 				value -= (long)ADDR(lmp);
327 
328 			DBG_CALL(Dbg_bind_global(lmp, (Addr)ra,
329 			    (Off)(ra - ADDR(lmp)), (Xword)(-1), PLT_T_NONE,
330 			    _lmp, (Addr)value, sym->st_value, name, binfo));
331 		}
332 
333 		/*
334 		 * Perform a specific relocation operation.
335 		 */
336 		switch (rp->r_type) {
337 		case RELOC_RELATIVE:
338 			value += *ra << (32-22);
339 			*(long *)ra = (*(long *)ra & ~S_MASK(22)) |
340 			    ((value >> (32 - 22)) & S_MASK(22));
341 			ra++;
342 			value += (*ra & S_MASK(10));
343 			*(long *)ra = (*(long *)ra & ~S_MASK(10)) |
344 			    (value & S_MASK(10));
345 			break;
346 		case RELOC_8:
347 		case RELOC_DISP8:
348 			value += *ra & S_MASK(8);
349 			if (!S_INRANGE(value, 8)) {
350 				eprintf(lml, ERR_FATAL,
351 				    MSG_INTL(MSG_REL_OVERFLOW), NAME(lmp),
352 				    (name ? demangle(name) :
353 				    MSG_INTL(MSG_STR_UNKNOWN)), (int)value, 8,
354 				    (uint_t)ra);
355 			}
356 			*ra = value;
357 			break;
358 		case RELOC_LO10:
359 		case RELOC_BASE10:
360 			value += *ra & S_MASK(10);
361 			*(long *)ra = (*(long *)ra & ~S_MASK(10)) |
362 			    (value & S_MASK(10));
363 			break;
364 		case RELOC_BASE13:
365 		case RELOC_13:
366 			value += *ra & S_MASK(13);
367 			*(long *)ra = (*(long *)ra & ~S_MASK(13)) |
368 			    (value & S_MASK(13));
369 			break;
370 		case RELOC_16:
371 		case RELOC_DISP16:
372 			value += *ra & S_MASK(16);
373 			if (!S_INRANGE(value, 16)) {
374 				eprintf(lml, ERR_FATAL,
375 				    MSG_INTL(MSG_REL_OVERFLOW), NAME(lmp),
376 				    (name ? demangle(name) :
377 				    MSG_INTL(MSG_STR_UNKNOWN)), (int)value, 16,
378 				    (uint_t)ra);
379 			}
380 			*(short *)ra = value;
381 			break;
382 		case RELOC_22:
383 		case RELOC_BASE22:
384 			value += *ra & S_MASK(22);
385 			if (!S_INRANGE(value, 22)) {
386 				eprintf(lml, ERR_FATAL,
387 				    MSG_INTL(MSG_REL_OVERFLOW), NAME(lmp),
388 				    (name ? demangle(name) :
389 				    MSG_INTL(MSG_STR_UNKNOWN)), (int)value, 22,
390 				    (uint_t)ra);
391 			}
392 			*(long *)ra = (*(long *)ra & ~S_MASK(22)) |
393 			    (value & S_MASK(22));
394 			break;
395 		case RELOC_HI22:
396 			value += (*ra & S_MASK(22)) << (32 - 22);
397 			*(long *)ra = (*(long *)ra & ~S_MASK(22)) |
398 			    ((value >> (32 - 22)) & S_MASK(22));
399 			break;
400 		case RELOC_WDISP22:
401 			value += *ra & S_MASK(22);
402 			value >>= 2;
403 			if (!S_INRANGE(value, 22)) {
404 				eprintf(lml, ERR_FATAL,
405 				    MSG_INTL(MSG_REL_OVERFLOW), NAME(lmp),
406 				    (name ? demangle(name) :
407 				    MSG_INTL(MSG_STR_UNKNOWN)), (int)value, 22,
408 				    (uint_t)ra);
409 			}
410 			*(long *)ra = (*(long *)ra & ~S_MASK(22)) |
411 			    (value & S_MASK(22));
412 			break;
413 		case RELOC_WDISP30:
414 			value += *ra & S_MASK(30);
415 			value >>= 2;
416 			*(long *)ra = (*(long *)ra & ~S_MASK(30)) |
417 			    (value & S_MASK(30));
418 			break;
419 		case RELOC_32:
420 		case RELOC_GLOB_DAT:
421 		case RELOC_DISP32:
422 			value += *ra;
423 			*(long *)ra = value;
424 			break;
425 		default:
426 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_UNIMPL),
427 			    NAME(lmp), (name ? demangle(name) :
428 			    MSG_INTL(MSG_STR_UNKNOWN)), rp->r_type);
429 			ret = 0;
430 			break;
431 		}
432 
433 		/*
434 		 * If this relocation is against a text segment we must make
435 		 * sure that the instruction cache is flushed.
436 		 */
437 		if (textrel) {
438 			if (rp->r_type == RELOC_RELATIVE)
439 				iflush_range((caddr_t)(ra - 1), 0x8);
440 			else
441 				iflush_range((caddr_t)ra, 0x4);
442 		}
443 	}
444 
445 	return (relocate_finish(lmp, bound, textrel, ret));
446 }
447