xref: /titanic_41/usr/src/cmd/sgs/rtld/sparc/sparc_a.out.c (revision 26fd77009b17f8c8fb32eb362584cfd635e87ad9)
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 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  *	Copyright (c) 1988 AT&T
29  *	All Rights Reserved
30  */
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 
37 #include	<stdio.h>
38 #include	<sys/types.h>
39 #include	<sys/mman.h>
40 #include	<synch.h>
41 #include	<dlfcn.h>
42 #include	<debug.h>
43 #include	"_a.out.h"
44 #include	"_rtld.h"
45 #include	"_audit.h"
46 #include	"_inline.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(0);
87 
88 	for (lmp = lml_main.lm_head; lmp; lmp = NEXT_RT_MAP(lmp)) {
89 		if (THIS_IS_AOUT(lmp)) {
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 	 * Make sure the object to which we've bound has had it's .init fired.
160 	 * Cleanup before return to user code.
161 	 */
162 	if (entry) {
163 		is_dep_init(nlmp, lmp);
164 		leave(lml, 0);
165 	}
166 
167 	return (symval);
168 }
169 
170 
171 #define	IS_PC_RELATIVE(X) (pc_rel_type[(X)] == 1)
172 
173 static const uchar_t pc_rel_type[] = {
174 	0,				/* RELOC_8 */
175 	0,				/* RELOC_16 */
176 	0,				/* RELOC_32 */
177 	1,				/* RELOC_DISP8 */
178 	1,				/* RELOC_DISP16 */
179 	1,				/* RELOC_DISP32 */
180 	1,				/* RELOC_WDISP30 */
181 	1,				/* RELOC_WDISP22 */
182 	0,				/* RELOC_HI22 */
183 	0,				/* RELOC_22 */
184 	0,				/* RELOC_13 */
185 	0,				/* RELOC_LO10 */
186 	0,				/* RELOC_SFA_BASE */
187 	0,				/* RELOC_SFA_OFF13 */
188 	0,				/* RELOC_BASE10 */
189 	0,				/* RELOC_BASE13 */
190 	0,				/* RELOC_BASE22 */
191 	0,				/* RELOC_PC10 */
192 	0,				/* RELOC_PC22 */
193 	0,				/* RELOC_JMP_TBL */
194 	0,				/* RELOC_SEGOFF16 */
195 	0,				/* RELOC_GLOB_DAT */
196 	0,				/* RELOC_JMP_SLOT */
197 	0				/* RELOC_RELATIVE */
198 };
199 
200 int
201 aout_reloc(Rt_map *lmp, uint_t plt, int *in_nfavl, APlist **textrel)
202 {
203 	int		k;		/* loop temporary */
204 	int		nr;		/* number of relocations */
205 	char		*name;		/* symbol being searched for */
206 	long		value;		/* relocation temporary */
207 	long		*ra;		/* cached relocation address */
208 	struct relocation_info *rp;	/* current relocation */
209 	struct nlist	*sp;		/* symbol table of "symbol" */
210 	Rt_map *	_lmp;		/* lm which holds symbol definition */
211 	Sym *		sym;		/* symbol definition */
212 	int		ret = 1;
213 	APlist		*bound = NULL;
214 	Lm_list		*lml = LIST(lmp);
215 
216 	DBG_CALL(Dbg_reloc_run(lmp, SHT_RELA, plt, DBG_REL_START));
217 
218 	/*
219 	 * If we've been called upon to promote an RTLD_LAZY object to an
220 	 * RTLD_NOW don't bother to do anything - a.out's are bound as if
221 	 * RTLD_NOW regardless.
222 	 */
223 	if (plt)
224 		return (1);
225 
226 	rp = LM2LP(lmp)->lp_rp;
227 	nr = GETRELSZ(AOUTDYN(lmp)) / sizeof (struct relocation_info);
228 
229 	/*
230 	 * Initialize _PLT_, if any.
231 	 */
232 	if (AOUTDYN(lmp)->v2->ld_plt_sz)
233 		aout_plt_write((caddr_t)LM2LP(lmp)->lp_plt->jb_inst,
234 		    (ulong_t)aout_rtbndr);
235 
236 	/*
237 	 * Loop through relocations.
238 	 */
239 	for (k = 0; k < nr; k++, rp++) {
240 		mmapobj_result_t	*mpp;
241 
242 		/* LINTED */
243 		ra = (long *)&((char *)ADDR(lmp))[rp->r_address];
244 
245 		/*
246 		 * Make sure the segment is writable.
247 		 */
248 		if (((mpp = find_segment((caddr_t)ra, lmp)) != NULL) &&
249 		    ((mpp->mr_prot & PROT_WRITE) == 0)) {
250 			if ((set_prot(lmp, mpp, 1) == 0) ||
251 			    (aplist_append(textrel, mpp,
252 			    AL_CNT_TEXTREL) == NULL)) {
253 				ret = 0;
254 				break;
255 			}
256 		}
257 
258 		/*
259 		 * Perform the relocation.
260 		 */
261 		if (rp->r_extern == 0) {
262 			name = (char *)0;
263 			value = ADDR(lmp);
264 		} else {
265 			Slookup		sl;
266 			uint_t		binfo;
267 
268 			if (rp->r_type == RELOC_JMP_SLOT)
269 				continue;
270 			sp = &LM2LP(lmp)->lp_symtab[rp->r_symbolnum];
271 			name = &LM2LP(lmp)->lp_symstr[sp->n_un.n_strx];
272 
273 			/*
274 			 * Locate symbol.  Initialize the symbol lookup data
275 			 * structure.
276 			 */
277 			SLOOKUP_INIT(sl, name, lmp, 0, ld_entry_cnt,
278 			    0, 0, 0, 0, LKUP_STDRELOC);
279 
280 			if ((sym = aout_lookup_sym(&sl, &_lmp,
281 			    &binfo, in_nfavl)) == 0) {
282 				if (lml->lm_flags & LML_FLG_TRC_WARN) {
283 					(void)
284 					    printf(MSG_INTL(MSG_LDD_SYM_NFOUND),
285 					    demangle(name), NAME(lmp));
286 					continue;
287 				} else {
288 					eprintf(lml, ERR_FATAL,
289 					    MSG_INTL(MSG_REL_NOSYM), NAME(lmp),
290 					    demangle(name));
291 					ret = 0;
292 					break;
293 				}
294 			}
295 
296 			/*
297 			 * If symbol was found in an object other than the
298 			 * referencing object then record the binding.
299 			 */
300 			if ((lmp != _lmp) &&
301 			    ((FLAGS1(_lmp) & FL1_RT_NOINIFIN) == 0)) {
302 				if (aplist_test(&bound, _lmp,
303 				    AL_CNT_RELBIND) == 0) {
304 					ret = 0;
305 					break;
306 				}
307 			}
308 
309 			value = sym->st_value + rp->r_addend;
310 			if (!(FLAGS(_lmp) & FLG_RT_FIXED) &&
311 			    (sym->st_shndx != SHN_COMMON) &&
312 			    (sym->st_shndx != SHN_ABS))
313 				value += ADDR(_lmp);
314 
315 			if (IS_PC_RELATIVE(rp->r_type))
316 				value -= (long)ADDR(lmp);
317 
318 			DBG_CALL(Dbg_bind_global(lmp, (Addr)ra,
319 			    (Off)(ra - ADDR(lmp)), (Xword)(-1), PLT_T_NONE,
320 			    _lmp, (Addr)value, sym->st_value, name, binfo));
321 		}
322 
323 		/*
324 		 * Perform a specific relocation operation.
325 		 */
326 		switch (rp->r_type) {
327 		case RELOC_RELATIVE:
328 			value += *ra << (32-22);
329 			*(long *)ra = (*(long *)ra & ~S_MASK(22)) |
330 			    ((value >> (32 - 22)) & S_MASK(22));
331 			ra++;
332 			value += (*ra & S_MASK(10));
333 			*(long *)ra = (*(long *)ra & ~S_MASK(10)) |
334 			    (value & S_MASK(10));
335 			break;
336 		case RELOC_8:
337 		case RELOC_DISP8:
338 			value += *ra & S_MASK(8);
339 			if (!S_INRANGE(value, 8)) {
340 				eprintf(lml, ERR_FATAL,
341 				    MSG_INTL(MSG_REL_OVERFLOW), NAME(lmp),
342 				    (name ? demangle(name) :
343 				    MSG_INTL(MSG_STR_UNKNOWN)), (int)value, 8,
344 				    (uint_t)ra);
345 			}
346 			*ra = value;
347 			break;
348 		case RELOC_LO10:
349 		case RELOC_BASE10:
350 			value += *ra & S_MASK(10);
351 			*(long *)ra = (*(long *)ra & ~S_MASK(10)) |
352 			    (value & S_MASK(10));
353 			break;
354 		case RELOC_BASE13:
355 		case RELOC_13:
356 			value += *ra & S_MASK(13);
357 			*(long *)ra = (*(long *)ra & ~S_MASK(13)) |
358 			    (value & S_MASK(13));
359 			break;
360 		case RELOC_16:
361 		case RELOC_DISP16:
362 			value += *ra & S_MASK(16);
363 			if (!S_INRANGE(value, 16)) {
364 				eprintf(lml, ERR_FATAL,
365 				    MSG_INTL(MSG_REL_OVERFLOW), NAME(lmp),
366 				    (name ? demangle(name) :
367 				    MSG_INTL(MSG_STR_UNKNOWN)), (int)value, 16,
368 				    (uint_t)ra);
369 			}
370 			*(short *)ra = value;
371 			break;
372 		case RELOC_22:
373 		case RELOC_BASE22:
374 			value += *ra & S_MASK(22);
375 			if (!S_INRANGE(value, 22)) {
376 				eprintf(lml, ERR_FATAL,
377 				    MSG_INTL(MSG_REL_OVERFLOW), NAME(lmp),
378 				    (name ? demangle(name) :
379 				    MSG_INTL(MSG_STR_UNKNOWN)), (int)value, 22,
380 				    (uint_t)ra);
381 			}
382 			*(long *)ra = (*(long *)ra & ~S_MASK(22)) |
383 			    (value & S_MASK(22));
384 			break;
385 		case RELOC_HI22:
386 			value += (*ra & S_MASK(22)) << (32 - 22);
387 			*(long *)ra = (*(long *)ra & ~S_MASK(22)) |
388 			    ((value >> (32 - 22)) & S_MASK(22));
389 			break;
390 		case RELOC_WDISP22:
391 			value += *ra & S_MASK(22);
392 			value >>= 2;
393 			if (!S_INRANGE(value, 22)) {
394 				eprintf(lml, ERR_FATAL,
395 				    MSG_INTL(MSG_REL_OVERFLOW), NAME(lmp),
396 				    (name ? demangle(name) :
397 				    MSG_INTL(MSG_STR_UNKNOWN)), (int)value, 22,
398 				    (uint_t)ra);
399 			}
400 			*(long *)ra = (*(long *)ra & ~S_MASK(22)) |
401 			    (value & S_MASK(22));
402 			break;
403 		case RELOC_WDISP30:
404 			value += *ra & S_MASK(30);
405 			value >>= 2;
406 			*(long *)ra = (*(long *)ra & ~S_MASK(30)) |
407 			    (value & S_MASK(30));
408 			break;
409 		case RELOC_32:
410 		case RELOC_GLOB_DAT:
411 		case RELOC_DISP32:
412 			value += *ra;
413 			*(long *)ra = value;
414 			break;
415 		default:
416 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_UNIMPL),
417 			    NAME(lmp), (name ? demangle(name) :
418 			    MSG_INTL(MSG_STR_UNKNOWN)), rp->r_type);
419 			ret = 0;
420 			break;
421 		}
422 
423 		/*
424 		 * If this relocation is against a text segment we must make
425 		 * sure that the instruction cache is flushed.
426 		 */
427 		if (textrel) {
428 			if (rp->r_type == RELOC_RELATIVE)
429 				iflush_range((caddr_t)(ra - 1), 0x8);
430 			else
431 				iflush_range((caddr_t)ra, 0x4);
432 		}
433 	}
434 
435 	return (relocate_finish(lmp, bound, ret));
436 }
437