xref: /titanic_51/usr/src/cmd/sgs/libld/common/resolve.c (revision 005d3feb53a9a10272d4a24b03991575d6a9bcb3)
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 2010 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 /*
31  * Symbol table resolution
32  */
33 #define	ELF_TARGET_AMD64
34 
35 #include	<stdio.h>
36 #include	<debug.h>
37 #include	"msg.h"
38 #include	"_libld.h"
39 
40 
41 /*
42  * Categorize the symbol types that are applicable to the resolution process.
43  */
44 typedef	enum {
45 	SYM_DEFINED,		/* Defined symbol (SHN_ABS or shndx != 0) */
46 	SYM_UNDEFINED,		/* Undefined symbol (SHN_UNDEF) */
47 	SYM_TENTATIVE,		/* Tentative symbol (SHN_COMMON) */
48 	SYM_NUM			/* the number of symbol types */
49 } Symtype;
50 
51 /*
52  * Do nothing.
53  */
54 /* ARGSUSED0 */
55 static void
56 sym_null(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl,
57     int ndx, Word nshndx, sd_flag_t nsdflags)
58 {
59 }
60 
61 static void
62 sym_visibility_diag(Error err, Sym_desc *sdp, Sym *osym, Sym *nsym,
63     Ifl_desc *ifl, Ofl_desc *ofl)
64 {
65 	Conv_inv_buf_t	inv_obuf, inv_nbuf;
66 
67 	eprintf(ofl->ofl_lml, err, MSG_INTL(MSG_SYM_CONFVIS),
68 	    demangle(sdp->sd_name));
69 	eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(MSG_SYM_VISTYPES),
70 	    sdp->sd_file->ifl_name, conv_sym_other(osym->st_other, &inv_obuf),
71 	    ifl->ifl_name, conv_sym_other(nsym->st_other, &inv_nbuf));
72 
73 	if (err == ERR_FATAL)
74 		ofl->ofl_flags |= FLG_OF_FATAL;
75 	else
76 		eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(MSG_SYM_DEFTAKEN),
77 		    ifl->ifl_name);
78 }
79 
80 /*
81  * STV_VISIBILITY rules for STV_DEFAULT/INTERNAL/HIDDEN/PROTECTED say that the
82  * most restrictive visibility value should be taken.  The precedence is:
83  *
84  *    (most restrictive) INTERNAL -> HIDDEN -> PROTECTED -> DEFAULT  (least)
85  *
86  * The STV_EXPORT and STV_SINGLETON visibilities are slightly different, in that
87  * the visibility must remain global and can not be reduced in any way.
88  *
89  * Resolution of different visibilities between two relocatable objects can
90  * take the following actions:
91  *
92  *  i.     if applicable, the most restrictive action is silently taken.
93  *  ii.    if a mapfile visibility definition competes with a more restrictive
94  *         relocatable object definition, then a warning is generated, but the
95  *         the more restrictive visibility is taken.
96  *  iii.   in the case of conflicts with an EXPORTED or SINGLETON symbol with
97  *	   any type of visibility between relocatable objects, the combination
98  *	   is deemed fatal.
99  *
100  *                                  new visibility
101  *                    D        I         H         P         X         S
102  *                 ------------------------------------------------------------
103  *              D |   D        I(mw)     H(mw)     P         X         S
104  *   original   I |   I        I         I         I         X(mw/of)  S(mw/of)
105  *  visibility  H |   H        I(mw)     H         H         X(mw/of)  S(mw/of)
106  *              P |   P        I(mw)     H(mw)     P         X(mw/of)  S(mw/of)
107  *              X |   X        I(mw/of)  H(mw/of)  P(mw/of)  X         S
108  *              S |   S        I(mw/of)  H(mw/of)  P(mw/of)  S         S
109  * where:
110  *
111  *  mw -  mapfile warning: if the original symbol originates from a mapfile
112  *        then warn the user that their scope definition is being overridden.
113  *  of -  object definitions are fatal: any combination of relocatable object
114  *        visibilities that conflict with a SINGLETON and EXPORTED are fatal.
115  *
116  * Note, an eliminate symbol (STV_ELIMINATE) is treated as hidden (STV_HIDDEN)
117  * for processing through this state table.
118  */
119 static Half
120 sym_visibility(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl)
121 {
122 	Sym	*osym = sdp->sd_sym;
123 	uchar_t	wovis, ovis;
124 	uchar_t	wnvis, nvis;
125 
126 	wovis = ovis = ELF_ST_VISIBILITY(osym->st_other);
127 	wnvis = nvis = ELF_ST_VISIBILITY(nsym->st_other);
128 
129 	/*
130 	 * If the original visibilities are eliminate, assign them hidden for
131 	 * the state table processing.  The original visibility, rather than
132 	 * the working visibility, will be returned to the caller.
133 	 */
134 	if (wovis == STV_ELIMINATE)
135 		wovis = STV_HIDDEN;
136 	if (wnvis == STV_ELIMINATE)
137 		wnvis = STV_HIDDEN;
138 
139 	/*
140 	 * The most complex visibility resolution is between two relocatable
141 	 * objects.  However, in the case of SINGLETONS we also want to catch
142 	 * any singleton definitions within shared objects.  Relocatable objects
143 	 * that bind to these symbols inherit the singleton visibility as this
144 	 * efficiently triggers ld.so.1 into carrying out the appropriate
145 	 * runtime symbol search.  Any other resolution between a relocatable
146 	 * object and a shared object will retain the relocatable objects
147 	 * visibility.
148 	 */
149 	if ((sdp->sd_ref == REF_REL_NEED) &&
150 	    (ifl->ifl_ehdr->e_type == ET_DYN)) {
151 		if ((sdp->sd_sym->st_shndx == SHN_UNDEF) &&
152 		    (nsym->st_shndx != SHN_UNDEF) && (wnvis == STV_SINGLETON))
153 			return (STV_SINGLETON);
154 		else
155 			return (ovis);
156 	}
157 	if ((sdp->sd_ref != REF_REL_NEED) &&
158 	    (ifl->ifl_ehdr->e_type == ET_REL)) {
159 		if ((sdp->sd_sym->st_shndx != SHN_UNDEF) &&
160 		    (nsym->st_shndx == SHN_UNDEF) && (wovis == STV_SINGLETON))
161 			return (STV_SINGLETON);
162 		else
163 			return (nvis);
164 	}
165 
166 	/*
167 	 * If the visibilities are the same, we're done.  If the working
168 	 * visibilities differ from the original, then one must have been
169 	 * STV_HIDDEN and the other STV_ELIMINATE.
170 	 */
171 	if (wovis == wnvis) {
172 		if (ovis == nvis)
173 			return (nvis);
174 		else
175 			return (STV_ELIMINATE);
176 	}
177 
178 	/*
179 	 * An EXPORTED symbol or SINGLETON symbol can not be demoted, any
180 	 * conflicting visibility from another object is fatal.  A conflicting
181 	 * visibility from a mapfile produces a warning, as the mapfile
182 	 * definition can be overridden.
183 	 */
184 	if ((wnvis == STV_EXPORTED) || (wnvis == STV_SINGLETON)) {
185 		if ((wovis != STV_DEFAULT) && (wovis != STV_EXPORTED) &&
186 		    (wovis != STV_SINGLETON)) {
187 			if (sdp->sd_flags & FLG_SY_MAPFILE) {
188 				sym_visibility_diag(ERR_WARNING, sdp, osym,
189 				    nsym, ifl, ofl);
190 			} else {
191 				sym_visibility_diag(ERR_FATAL, sdp, osym,
192 				    nsym, ifl, ofl);
193 			}
194 		}
195 		return (nvis);
196 	}
197 	if (wovis == STV_SINGLETON) {
198 		if ((wnvis == STV_EXPORTED) || (wnvis == STV_DEFAULT))
199 			return (STV_SINGLETON);
200 		if (sdp->sd_flags & FLG_SY_MAPFILE) {
201 			sym_visibility_diag(ERR_WARNING, sdp, osym,
202 			    nsym, ifl, ofl);
203 		} else {
204 			sym_visibility_diag(ERR_FATAL, sdp, osym,
205 			    nsym, ifl, ofl);
206 		}
207 		return (nvis);
208 	}
209 	if (wovis == STV_EXPORTED) {
210 		if (wnvis == STV_SINGLETON)
211 			return (STV_SINGLETON);
212 		if (wnvis == STV_DEFAULT)
213 			return (STV_EXPORTED);
214 		if (sdp->sd_flags & FLG_SY_MAPFILE) {
215 			sym_visibility_diag(ERR_WARNING, sdp, osym,
216 			    nsym, ifl, ofl);
217 		} else {
218 			sym_visibility_diag(ERR_FATAL, sdp, osym,
219 			    nsym, ifl, ofl);
220 		}
221 		return (nvis);
222 	}
223 
224 	/*
225 	 * Now that symbols with the same visibility, and all instances of
226 	 * SINGLETON's have been dealt with, we're left with visibilities that
227 	 * differ, but can be dealt with in the order of how restrictive the
228 	 * visibilities are.  When a differing visibility originates from a
229 	 * mapfile definition, produces a warning, as the mapfile definition
230 	 * can be overridden by the relocatable object.
231 	 */
232 	if ((wnvis == STV_INTERNAL) || (wovis == STV_INTERNAL)) {
233 		if ((wnvis == STV_INTERNAL) &&
234 		    (sdp->sd_flags & FLG_SY_MAPFILE)) {
235 			sym_visibility_diag(ERR_WARNING, sdp, osym, nsym,
236 			    ifl, ofl);
237 		}
238 		return (STV_INTERNAL);
239 
240 	} else if ((wnvis == STV_HIDDEN) || (wovis == STV_HIDDEN)) {
241 		if ((wnvis == STV_HIDDEN) &&
242 		    (sdp->sd_flags & FLG_SY_MAPFILE)) {
243 			sym_visibility_diag(ERR_WARNING, sdp, osym, nsym,
244 			    ifl, ofl);
245 		}
246 
247 		/*
248 		 * In the case of STV_ELIMINATE and STV_HIDDEN, the working
249 		 * visibility can differ from the original visibility, so make
250 		 * sure to return the original visibility.
251 		 */
252 		if ((ovis == STV_ELIMINATE) || (nvis == STV_ELIMINATE))
253 			return (STV_ELIMINATE);
254 		else
255 			return (STV_HIDDEN);
256 
257 	} else if ((wnvis == STV_PROTECTED) || (wovis == STV_PROTECTED))
258 		return (STV_PROTECTED);
259 
260 	return (STV_DEFAULT);
261 }
262 
263 /*
264  * Check if two symbols types are compatible
265  */
266 /*ARGSUSED4*/
267 static void
268 sym_typecheck(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl,
269     int ndx, Word nshndx, sd_flag_t nsdflags)
270 {
271 	uchar_t		otype = ELF_ST_TYPE(sdp->sd_sym->st_info);
272 	uchar_t		ntype = ELF_ST_TYPE(nsym->st_info);
273 	Conv_inv_buf_t	inv_buf1, inv_buf2;
274 
275 	/*
276 	 * Perform any machine specific type checking.
277 	 */
278 	if ((ld_targ.t_ms.ms_mach_sym_typecheck != NULL) &&
279 	    (*ld_targ.t_ms.ms_mach_sym_typecheck)(sdp, nsym, ifl, ofl))
280 		return;
281 
282 	/*
283 	 * NOTYPE's can be combined with other types, only give an error if
284 	 * combining two differing types without NOTYPE.
285 	 */
286 	if ((otype == ntype) || (otype == STT_NOTYPE) || (ntype == STT_NOTYPE))
287 		return;
288 
289 	eprintf(ofl->ofl_lml, ERR_WARNING, MSG_INTL(MSG_SYM_DIFFTYPE),
290 	    demangle(sdp->sd_name));
291 	eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(MSG_SYM_FILETYPES),
292 	    sdp->sd_file->ifl_name,
293 	    conv_sym_info_type(ofl->ofl_dehdr->e_machine, otype, 0, &inv_buf1),
294 	    ifl->ifl_name,
295 	    conv_sym_info_type(ofl->ofl_dehdr->e_machine, ntype, 0, &inv_buf2));
296 }
297 
298 /*ARGSUSED4*/
299 static void
300 sym_mach_check(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl,
301     int ndx, Word nshndx, sd_flag_t nsdflags)
302 {
303 	/*
304 	 * Perform any machine specific type checking.
305 	 */
306 	if (ld_targ.t_ms.ms_mach_sym_typecheck != NULL)
307 		(void) (*ld_targ.t_ms.ms_mach_sym_typecheck)(sdp, nsym,
308 		    ifl, ofl);
309 }
310 
311 /*
312  * Promote the symbols reference.
313  */
314 static void
315 /* ARGSUSED4 */
316 sym_promote(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl,
317     int ndx, Word nshndx, sd_flag_t nsdflags)
318 {
319 	Word	shndx = nsym->st_shndx;
320 
321 	sym_typecheck(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags);
322 
323 	/*
324 	 * If the old symbol is from a shared object and the new symbol is a
325 	 * reference from a relocatable object, promote the old symbols
326 	 * reference.
327 	 */
328 	if ((sdp->sd_ref == REF_DYN_SEEN) &&
329 	    (ifl->ifl_ehdr->e_type == ET_REL)) {
330 		sdp->sd_ref = REF_DYN_NEED;
331 
332 		/*
333 		 * If this is an undefined symbol it must be a relocatable
334 		 * object overriding a shared object.  In this case also
335 		 * override the reference name so that any undefined symbol
336 		 * diagnostics will refer to the relocatable object name.
337 		 */
338 		if (shndx == SHN_UNDEF)
339 			sdp->sd_aux->sa_rfile = ifl->ifl_name;
340 
341 		/*
342 		 * If this symbol is an undefined, or common, determine whether
343 		 * it is a global or weak reference (see build_osym(), where
344 		 * REF_DYN_NEED definitions are returned back to undefines).
345 		 */
346 		if (((shndx == SHN_UNDEF) || ((nsdflags & FLG_SY_SPECSEC) &&
347 		    (shndx == SHN_COMMON))) &&
348 		    (ELF_ST_BIND(nsym->st_info) == STB_GLOBAL))
349 			sdp->sd_flags |= FLG_SY_GLOBREF;
350 
351 	}
352 }
353 
354 /*
355  * Override a symbol.
356  */
357 static void
358 sym_override(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl,
359     int ndx, Word nshndx, sd_flag_t nsdflags)
360 {
361 	Sym	*osym = sdp->sd_sym;
362 	Word	link;
363 
364 	/*
365 	 * In the case of a WEAK UNDEF symbol don't let a symbol from an
366 	 * unavailable object override the symbol definition.  This is because
367 	 * this symbol *may* not be present in a future object and by promoting
368 	 * this symbol we are actually causing bindings (PLTS) to be formed
369 	 * to this symbol.  Instead let the 'generic' weak binding take place.
370 	 */
371 	if ((ELF_ST_BIND(osym->st_info) == STB_WEAK) &&
372 	    (sdp->sd_sym->st_shndx == SHN_UNDEF) &&
373 	    ((ifl->ifl_flags & FLG_IF_NEEDED) == 0))
374 		return;
375 
376 	sym_typecheck(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags);
377 
378 	/*
379 	 * This symbol has already been compared to an SO definition,
380 	 * as per the runtime behavior, ignore extra definitions.
381 	 */
382 	if ((sdp->sd_flags & FLG_SY_SOFOUND) &&
383 	    (ifl->ifl_ehdr->e_type == ET_DYN))
384 		return;
385 
386 	/*
387 	 * Mark the symbol as available and copy the new symbols contents.
388 	 */
389 	sdp->sd_flags &= ~FLG_SY_NOTAVAIL;
390 	*osym = *nsym;
391 	sdp->sd_shndx = nshndx;
392 	sdp->sd_flags &= ~FLG_SY_SPECSEC;
393 	sdp->sd_flags |= (nsdflags & (FLG_SY_SPECSEC | FLG_SY_TENTSYM));
394 
395 	/*
396 	 * If the new symbol has PROTECTED visibility, mark it.  If a PROTECTED
397 	 * symbol is copy relocated, a warning message will be printed.  See
398 	 * reloc_exec().
399 	 */
400 	if (ELF_ST_VISIBILITY(nsym->st_other) == STV_PROTECTED)
401 		sdp->sd_flags |= FLG_SY_PROT;
402 	else
403 		sdp->sd_flags &= ~FLG_SY_PROT;
404 
405 	/*
406 	 * Establish the symbols reference.  If the new symbol originates from a
407 	 * relocatable object then this reference becomes needed, otherwise
408 	 * the new symbol must be from a shared object.  In this case only
409 	 * promote the symbol to needed if we presently have a reference from a
410 	 * relocatable object.
411 	 */
412 	if (ifl->ifl_ehdr->e_type == ET_REL) {
413 		sdp->sd_ref = REF_REL_NEED;
414 
415 		if (nsym->st_shndx == SHN_UNDEF) {
416 			/*
417 			 * If this is an undefined symbol, then we can only be
418 			 * attempting to override an existing undefined symbol.
419 			 * The original symbol is either:
420 			 *
421 			 *  -	a mapfile definition
422 			 *  -	a previous relocatable object whose visibility
423 			 *	or type should be overridden by this new symbol
424 			 *  -	a previous shared object
425 			 *
426 			 * If the original undefined symbol stems from a mapfile
427 			 * then don't alter the reference file name.  Should we
428 			 * end up with some form of 'undefined' symbol error,
429 			 * the characteristics of that error are most likely to
430 			 * have originated from a mapfile.
431 			 *
432 			 * Otherwise, update the reference file name to indicate
433 			 * this symbol.
434 			 */
435 			if ((sdp->sd_flags & FLG_SY_MAPREF) == 0)
436 				sdp->sd_aux->sa_rfile = ifl->ifl_name;
437 		} else {
438 			/*
439 			 * Under -Bnodirect, all exported interfaces that have
440 			 * not explicitly been defined protected or directly
441 			 * bound to, are tagged to prevent direct binding.
442 			 */
443 			if ((ofl->ofl_flags1 & FLG_OF1_ALNODIR) &&
444 			    ((sdp->sd_flags &
445 			    (FLG_SY_PROTECT | FLG_SY_DIR)) == 0))
446 				sdp->sd_flags |= FLG_SY_NDIR;
447 		}
448 
449 		/*
450 		 * If this symbol is an undefined, or common, determine whether
451 		 * it is a global or weak reference (see build_osym(), where
452 		 * REF_DYN_NEED definitions are returned back to undefines).
453 		 */
454 		if (((nsym->st_shndx == SHN_UNDEF) ||
455 		    ((nsdflags & FLG_SY_SPECSEC) &&
456 		    (nsym->st_shndx == SHN_COMMON))) &&
457 		    (ELF_ST_BIND(nsym->st_info) == STB_GLOBAL))
458 			sdp->sd_flags |= FLG_SY_GLOBREF;
459 		else
460 			sdp->sd_flags &= ~FLG_SY_GLOBREF;
461 	} else {
462 		if (sdp->sd_ref == REF_REL_NEED)
463 			sdp->sd_ref = REF_DYN_NEED;
464 
465 		/*
466 		 * Determine the symbols availability.  A symbol is determined
467 		 * to be unavailable if it belongs to a version of a shared
468 		 * object that this user does not wish to use, or if it belongs
469 		 * to an implicit shared object.
470 		 */
471 		if (ifl->ifl_vercnt) {
472 			Ver_index	*vip;
473 			Half		vndx = ifl->ifl_versym[ndx];
474 
475 			sdp->sd_aux->sa_dverndx = vndx;
476 			vip = &ifl->ifl_verndx[vndx];
477 			if (!(vip->vi_flags & FLG_VER_AVAIL)) {
478 				sdp->sd_flags |= FLG_SY_NOTAVAIL;
479 				/*
480 				 * If this is the first occurrence of an
481 				 * unavailable symbol record it for possible
482 				 * use in later error diagnostics
483 				 * (see sym_undef).
484 				 */
485 				if (!(sdp->sd_aux->sa_vfile))
486 					sdp->sd_aux->sa_vfile = ifl->ifl_name;
487 			}
488 		}
489 		if (!(ifl->ifl_flags & FLG_IF_NEEDED))
490 			sdp->sd_flags |= FLG_SY_NOTAVAIL;
491 	}
492 
493 	/*
494 	 * Make sure any symbol association maintained by the original symbol
495 	 * is cleared and then update the symbols file reference.
496 	 */
497 	if ((link = sdp->sd_aux->sa_linkndx) != 0) {
498 		Sym_desc *	_sdp;
499 
500 		_sdp = sdp->sd_file->ifl_oldndx[link];
501 		_sdp->sd_aux->sa_linkndx = 0;
502 		sdp->sd_aux->sa_linkndx = 0;
503 	}
504 	sdp->sd_file = ifl;
505 
506 	/*
507 	 * Update the input section descriptor to that of the new input file
508 	 */
509 	if (((nsdflags & FLG_SY_SPECSEC) == 0) &&
510 	    (nsym->st_shndx != SHN_UNDEF)) {
511 		if ((sdp->sd_isc = ifl->ifl_isdesc[nshndx]) == 0) {
512 			eprintf(ofl->ofl_lml, ERR_FATAL,
513 			    MSG_INTL(MSG_SYM_NOSECDEF), demangle(sdp->sd_name),
514 			    ifl->ifl_name);
515 			ofl->ofl_flags |= FLG_OF_FATAL;
516 		}
517 	}
518 }
519 
520 /*
521  * Resolve two undefines (only called for two relocatable objects).
522  */
523 static void
524 sym_twoundefs(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl,
525     int ndx, Word nshndx, sd_flag_t nsdflags)
526 {
527 	Sym	*osym = sdp->sd_sym;
528 	uchar_t	obind = ELF_ST_BIND(osym->st_info);
529 	uchar_t	otype = ELF_ST_TYPE(osym->st_info);
530 	uchar_t	nbind = ELF_ST_BIND(nsym->st_info);
531 	uchar_t	ntype = ELF_ST_TYPE(nsym->st_info);
532 
533 	/*
534 	 * If two relocatable objects define a weak and non-weak undefined
535 	 * reference, take the non-weak definition.
536 	 *
537 	 *		-- or --
538 	 *
539 	 * If two relocatable objects define a NOTYPE & another, then
540 	 * take the other.
541 	 */
542 	if (((obind == STB_WEAK) && (nbind != STB_WEAK)) ||
543 	    (otype == STT_NOTYPE) && (ntype != STT_NOTYPE)) {
544 		sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags);
545 		return;
546 	}
547 	sym_typecheck(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags);
548 }
549 
550 /*
551  * Resolve two real definitions.
552  */
553 static void
554 sym_tworeals(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl,
555     int ndx, Word nshndx, sd_flag_t nsdflags)
556 {
557 	Conv_inv_buf_t inv_buf1, inv_buf2;
558 	Sym	*osym = sdp->sd_sym;
559 	uchar_t	otype = ELF_ST_TYPE(osym->st_info);
560 	uchar_t	obind = ELF_ST_BIND(osym->st_info);
561 	uchar_t	ntype = ELF_ST_TYPE(nsym->st_info);
562 	uchar_t	nbind = ELF_ST_BIND(nsym->st_info);
563 	Half	ofile = sdp->sd_file->ifl_ehdr->e_type;
564 	Half	nfile = ifl->ifl_ehdr->e_type;
565 	int	warn = 0;
566 
567 	/*
568 	 * If both definitions are from relocatable objects, and have non-weak
569 	 * binding then this is a fatal condition.
570 	 */
571 	if ((ofile == ET_REL) && (nfile == ET_REL) && (obind != STB_WEAK) &&
572 	    (nbind != STB_WEAK) && (!(ofl->ofl_flags & FLG_OF_MULDEFS))) {
573 		eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_SYM_MULDEF),
574 		    demangle(sdp->sd_name));
575 		eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(MSG_SYM_FILETYPES),
576 		    sdp->sd_file->ifl_name,
577 		    conv_sym_info_type(ofl->ofl_dehdr->e_machine, otype,
578 		    0, &inv_buf1), ifl->ifl_name,
579 		    conv_sym_info_type(ofl->ofl_dehdr->e_machine, ntype,
580 		    0, &inv_buf2));
581 		ofl->ofl_flags |= FLG_OF_FATAL;
582 		return;
583 	}
584 
585 	/*
586 	 * Perform any machine specific type checking.
587 	 */
588 	if ((ld_targ.t_ms.ms_mach_sym_typecheck != NULL) &&
589 	    (*ld_targ.t_ms.ms_mach_sym_typecheck)(sdp, nsym, ifl, ofl))
590 		return;
591 
592 	/*
593 	 * Check the symbols type and size.
594 	 */
595 	if (otype != ntype) {
596 		eprintf(ofl->ofl_lml, ERR_WARNING, MSG_INTL(MSG_SYM_DIFFTYPE),
597 		    demangle(sdp->sd_name));
598 		eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(MSG_SYM_FILETYPES),
599 		    sdp->sd_file->ifl_name,
600 		    conv_sym_info_type(ofl->ofl_dehdr->e_machine, otype,
601 		    0, &inv_buf1), ifl->ifl_name,
602 		    conv_sym_info_type(ofl->ofl_dehdr->e_machine, ntype,
603 		    0, &inv_buf2));
604 		warn++;
605 	} else if ((otype == STT_OBJECT) && (osym->st_size != nsym->st_size)) {
606 		if (!(ofl->ofl_flags & FLG_OF_NOWARN)) {
607 			eprintf(ofl->ofl_lml, ERR_WARNING,
608 			    MSG_INTL(MSG_SYM_DIFFATTR), demangle(sdp->sd_name),
609 			    MSG_INTL(MSG_STR_SIZES), sdp->sd_file->ifl_name,
610 			    EC_XWORD(osym->st_size), ifl->ifl_name,
611 			    EC_XWORD(nsym->st_size));
612 			warn++;
613 		}
614 	}
615 
616 	/*
617 	 * Having provided the user with any necessary warnings, take the
618 	 * appropriate symbol:
619 	 *
620 	 *  -	if one symbol is from a shared object and the other is from a
621 	 *	relocatable object, take the relocatable objects symbol (the
622 	 *	run-time linker is always going to find the relocatable object
623 	 *	symbol regardless of the binding), else
624 	 *
625 	 *  -	if both symbols are from relocatable objects and one symbol is
626 	 *	weak take the non-weak symbol (two non-weak symbols would have
627 	 *	generated the fatal error condition above unless -z muldefs is
628 	 *	in effect), else
629 	 *
630 	 *  -	take the first symbol definition encountered.
631 	 */
632 	if ((sdp->sd_flags & FLG_SY_SOFOUND) && (nfile == ET_DYN)) {
633 		if (warn)
634 			eprintf(ofl->ofl_lml, ERR_NONE,
635 			    MSG_INTL(MSG_SYM_DEFTAKEN), sdp->sd_file->ifl_name);
636 		return;
637 	} else if ((nfile == ET_REL) && ((ofile == ET_DYN) ||
638 	    ((obind == STB_WEAK) && (nbind != STB_WEAK)))) {
639 		if (warn)
640 			eprintf(ofl->ofl_lml, ERR_NONE,
641 			    MSG_INTL(MSG_SYM_DEFTAKEN), ifl->ifl_name);
642 		sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags);
643 		return;
644 	} else {
645 		if (warn)
646 			eprintf(ofl->ofl_lml, ERR_NONE,
647 			    MSG_INTL(MSG_SYM_DEFTAKEN), sdp->sd_file->ifl_name);
648 		sym_promote(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags);
649 		return;
650 	}
651 }
652 
653 /*
654  * Resolve a real and tentative definition.
655  */
656 static void
657 sym_realtent(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl,
658     int ndx, Word nshndx, sd_flag_t nsdflags)
659 {
660 	Conv_inv_buf_t inv_buf1, inv_buf2;
661 	Sym	*osym = sdp->sd_sym;
662 	uchar_t otype = ELF_ST_TYPE(osym->st_info);
663 	uchar_t obind = ELF_ST_BIND(osym->st_info);
664 	uchar_t ntype = ELF_ST_TYPE(nsym->st_info);
665 	uchar_t nbind = ELF_ST_BIND(nsym->st_info);
666 	Boolean	otent = FALSE, ntent = FALSE;
667 	Half	ofile = sdp->sd_file->ifl_ehdr->e_type;
668 	Half	nfile = ifl->ifl_ehdr->e_type;
669 	int	warn = 0;
670 	uchar_t	ovis = ELF_ST_VISIBILITY(osym->st_other);
671 	uchar_t	nvis = ELF_ST_VISIBILITY(nsym->st_other);
672 
673 	/*
674 	 * Special rules for functions.
675 	 *
676 	 *  -	If both definitions are from relocatable objects, have the same
677 	 *	binding (ie. two weaks or two non-weaks), and the real
678 	 *	definition is a function (the other must be tentative), treat
679 	 *	this as a multiply defined symbol error, else
680 	 *
681 	 *  -	if the real symbol definition is a function within a shared
682 	 *	library and the tentative symbol is a relocatable object, and
683 	 *	the tentative is not weak and the function real, then retain the
684 	 *	tentative definition.
685 	 */
686 	if ((ofile == ET_REL) && (nfile == ET_REL) && (obind == nbind) &&
687 	    ((otype == STT_FUNC) || (ntype == STT_FUNC))) {
688 		if (ofl->ofl_flags & FLG_OF_MULDEFS) {
689 			eprintf(ofl->ofl_lml, ERR_WARNING,
690 			    MSG_INTL(MSG_SYM_DIFFTYPE), demangle(sdp->sd_name));
691 			sym_promote(sdp, nsym, ifl, ofl, ndx,
692 			    nshndx, nsdflags);
693 		} else {
694 			eprintf(ofl->ofl_lml, ERR_FATAL,
695 			    MSG_INTL(MSG_SYM_MULDEF), demangle(sdp->sd_name));
696 			ofl->ofl_flags |= FLG_OF_FATAL;
697 		}
698 		eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(MSG_SYM_FILETYPES),
699 		    sdp->sd_file->ifl_name,
700 		    conv_sym_info_type(ofl->ofl_dehdr->e_machine, otype,
701 		    0, &inv_buf1), ifl->ifl_name,
702 		    conv_sym_info_type(ofl->ofl_dehdr->e_machine, ntype,
703 		    0, &inv_buf2));
704 		return;
705 	} else if (ofile != nfile) {
706 
707 
708 		if ((ofile == ET_DYN) && (otype == STT_FUNC)) {
709 			if ((otype != STB_WEAK) && (ntype == STB_WEAK))
710 				return;
711 			else {
712 				sym_override(sdp, nsym, ifl, ofl, ndx,
713 				    nshndx, nsdflags);
714 				return;
715 			}
716 		}
717 		if ((nfile == ET_DYN) && (ntype == STT_FUNC)) {
718 			if ((ntype != STB_WEAK) && (otype == STB_WEAK)) {
719 				sym_override(sdp, nsym, ifl, ofl, ndx,
720 				    nshndx, nsdflags);
721 				return;
722 			} else
723 				return;
724 		}
725 	}
726 
727 	if (sdp->sd_flags & FLG_SY_TENTSYM)
728 		otent = TRUE;
729 	if (nsdflags & FLG_SY_TENTSYM)
730 		ntent = TRUE;
731 
732 
733 	/*
734 	 * Check the symbols type and size.
735 	 */
736 	if (otype != ntype) {
737 		eprintf(ofl->ofl_lml, ERR_WARNING, MSG_INTL(MSG_SYM_DIFFTYPE),
738 		    demangle(sdp->sd_name));
739 		eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(MSG_SYM_FILETYPES),
740 		    sdp->sd_file->ifl_name,
741 		    conv_sym_info_type(ofl->ofl_dehdr->e_machine, otype,
742 		    0, &inv_buf1), ifl->ifl_name,
743 		    conv_sym_info_type(ofl->ofl_dehdr->e_machine, ntype,
744 		    0, &inv_buf2));
745 		warn++;
746 	} else if (osym->st_size != nsym->st_size) {
747 		/*
748 		 * If both definitions are from relocatable objects we have a
749 		 * potential fatal error condition.  If the tentative is larger
750 		 * than the real definition treat this as a multiple definition.
751 		 * Note that if only one symbol is weak, the non-weak will be
752 		 * taken.
753 		 */
754 		if (((ofile == ET_REL) && (nfile == ET_REL) &&
755 		    (obind == nbind)) &&
756 		    ((otent && (osym->st_size > nsym->st_size)) ||
757 		    (ntent && (osym->st_size < nsym->st_size)))) {
758 			eprintf(ofl->ofl_lml, ERR_FATAL,
759 			    MSG_INTL(MSG_SYM_DIFFATTR), demangle(sdp->sd_name),
760 			    MSG_INTL(MSG_STR_SIZES), sdp->sd_file->ifl_name,
761 			    EC_XWORD(osym->st_size), ifl->ifl_name,
762 			    EC_XWORD(nsym->st_size));
763 			eprintf(ofl->ofl_lml, ERR_NONE,
764 			    MSG_INTL(MSG_SYM_TENTERR));
765 			ofl->ofl_flags |= FLG_OF_FATAL;
766 		} else {
767 			if (!(ofl->ofl_flags & FLG_OF_NOWARN)) {
768 				eprintf(ofl->ofl_lml, ERR_WARNING,
769 				    MSG_INTL(MSG_SYM_DIFFATTR),
770 				    demangle(sdp->sd_name),
771 				    MSG_INTL(MSG_STR_SIZES),
772 				    sdp->sd_file->ifl_name,
773 				    EC_XWORD(osym->st_size),
774 				    ifl->ifl_name, EC_XWORD(nsym->st_size));
775 				warn++;
776 			}
777 		}
778 	}
779 
780 	/*
781 	 * Having provided the user with any necessary warnings, take the
782 	 * appropriate symbol:
783 	 *
784 	 *  -	if the original symbol is from relocatable file and it is
785 	 *	a protected tentative symbol, take the original one.
786 	 *
787 	 *  -	if the original symbol is from shared object and the new
788 	 *	symbol is a protected tentative symbol from a relocatable file,
789 	 *	take the new one.
790 	 *
791 	 *  -	if the original symbol is tentative, and providing the original
792 	 *	symbol isn't strong and the new symbol weak, take the real
793 	 *	symbol, else
794 	 *
795 	 *  -	if the original symbol is weak and the new tentative symbol is
796 	 *	strong take the new symbol.
797 	 *
798 	 * Refer to the System V ABI Page 4-27 for a description of the binding
799 	 * requirements of tentative and weak symbols.
800 	 */
801 	if ((ofile == ET_REL) && (nfile == ET_DYN) && (otent == TRUE) &&
802 	    (ovis == STV_PROTECTED)) {
803 		return;
804 	}
805 
806 	if ((ofile == ET_DYN) && (nfile == ET_REL) && (ntent == TRUE) &&
807 	    (nvis == STV_PROTECTED)) {
808 		sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags);
809 		return;
810 	}
811 
812 	if ((sdp->sd_flags & FLG_SY_SOFOUND) && (nfile == ET_DYN)) {
813 		if (warn)
814 			eprintf(ofl->ofl_lml, ERR_NONE,
815 			    MSG_INTL(MSG_SYM_DEFTAKEN), sdp->sd_file->ifl_name);
816 		return;
817 	}
818 
819 	if (((otent) && (!((obind != STB_WEAK) && (nbind == STB_WEAK)))) ||
820 	    ((obind == STB_WEAK) && (nbind != STB_WEAK))) {
821 		if (warn)
822 			eprintf(ofl->ofl_lml, ERR_NONE,
823 			    MSG_INTL(MSG_SYM_DEFTAKEN), ifl->ifl_name);
824 		sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags);
825 		return;
826 	} else {
827 		if (warn)
828 			eprintf(ofl->ofl_lml, ERR_NONE,
829 			    MSG_INTL(MSG_SYM_DEFTAKEN), sdp->sd_file->ifl_name);
830 		sym_promote(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags);
831 		return;
832 	}
833 }
834 
835 /*
836  * Resolve two tentative symbols.
837  */
838 static void
839 sym_twotent(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl,
840     int ndx, Word nshndx, sd_flag_t nsdflags)
841 {
842 	Sym	*osym = sdp->sd_sym;
843 	uchar_t	obind = ELF_ST_BIND(osym->st_info);
844 	uchar_t	nbind = ELF_ST_BIND(nsym->st_info);
845 	Half	ofile = sdp->sd_file->ifl_ehdr->e_type;
846 	Half	nfile = ifl->ifl_ehdr->e_type;
847 	size_t	size = 0;
848 	Xword	value = 0;
849 
850 #if	defined(_ELF64)
851 	if (ld_targ.t_m.m_mach == EM_AMD64) {
852 		/*
853 		 * If the original and new symbols are both COMMON, but of
854 		 * a different size model, take the small one.
855 		 */
856 		if ((sdp->sd_sym->st_shndx == SHN_COMMON) &&
857 		    (nsym->st_shndx == SHN_X86_64_LCOMMON)) {
858 			/*
859 			 * Take the original symbol.
860 			 */
861 			return;
862 
863 		} else if ((sdp->sd_sym->st_shndx == SHN_X86_64_LCOMMON) &&
864 		    (nsym->st_shndx == SHN_COMMON)) {
865 			/*
866 			 * Take the new symbol.
867 			 */
868 			sym_override(sdp, nsym, ifl, ofl, ndx, nshndx,
869 			    nsdflags);
870 			return;
871 		}
872 	}
873 #endif
874 
875 	/*
876 	 * Check the alignment of the symbols.  This can only be tested for if
877 	 * the symbols are not real definitions to a SHT_NOBITS section (ie.
878 	 * they were originally tentative), as in this case the symbol would
879 	 * have a displacement value rather than an alignment.  In other words
880 	 * we can only test this for two relocatable objects.
881 	 */
882 	/* BEGIN CSTYLED */
883 	if ((osym->st_value != nsym->st_value) &&
884 	    ((sdp->sd_flags & FLG_SY_SPECSEC) &&
885 	    (sdp->sd_sym->st_shndx == SHN_COMMON) &&
886 	    (nsdflags & FLG_SY_SPECSEC) &&
887 #if	defined(_ELF64)
888 	    (nsym->st_shndx == SHN_COMMON)) ||
889 	    ((ld_targ.t_m.m_mach == EM_AMD64) &&
890 	    (sdp->sd_flags & FLG_SY_SPECSEC) &&
891 	    (sdp->sd_sym->st_shndx == SHN_X86_64_LCOMMON) &&
892 	    (nsdflags & FLG_SY_SPECSEC) &&
893 	    (nsym->st_shndx == SHN_X86_64_LCOMMON))) {
894 #else
895 	    (nsym->st_shndx == SHN_COMMON))) {
896 #endif
897 	/* END CSTYLED */
898 
899 		const char	*emsg = MSG_INTL(MSG_SYM_DEFTAKEN);
900 		const char	*file;
901 		Xword		salign;
902 		Xword		balign;
903 		uint_t		alignscompliment;
904 
905 		if (osym->st_value < nsym->st_value) {
906 			salign = osym->st_value;
907 			balign = nsym->st_value;
908 		} else {
909 			salign = nsym->st_value;
910 			balign = osym->st_value;
911 		}
912 
913 		/*
914 		 * If the smaller alignment fits smoothly into the
915 		 * larger alignment - we take it with no warning.
916 		 */
917 		if (S_ALIGN(balign, salign) == balign)
918 			alignscompliment = 1;
919 		else
920 			alignscompliment = 0;
921 
922 		if (!(ofl->ofl_flags & FLG_OF_NOWARN) && !alignscompliment)
923 			eprintf(ofl->ofl_lml, ERR_WARNING,
924 			    MSG_INTL(MSG_SYM_DIFFATTR), demangle(sdp->sd_name),
925 			    MSG_INTL(MSG_STR_ALIGNMENTS),
926 			    sdp->sd_file->ifl_name, EC_XWORD(osym->st_value),
927 			    ifl->ifl_name, EC_XWORD(nsym->st_value));
928 
929 		/*
930 		 * Having provided the necessary warning indicate which
931 		 * relocatable object we are going to take.
932 		 *
933 		 *  -	if one symbol is weak and the other is non-weak
934 		 *	take the non-weak symbol, else
935 		 *
936 		 *  -	take the largest alignment (as we still have to check
937 		 *	the symbols size simply save the largest value for
938 		 *	updating later).
939 		 */
940 		if ((obind == STB_WEAK) && (nbind != STB_WEAK))
941 			file = ifl->ifl_name;
942 		else if (obind != nbind)
943 			file = sdp->sd_file->ifl_name;
944 		else {
945 			emsg = MSG_INTL(MSG_SYM_LARGER);
946 			value = balign;
947 		}
948 		if (!(ofl->ofl_flags & FLG_OF_NOWARN) && !alignscompliment)
949 			eprintf(ofl->ofl_lml, ERR_NONE, emsg, file);
950 	}
951 
952 	/*
953 	 * Check the size of the symbols.
954 	 */
955 	if (osym->st_size != nsym->st_size) {
956 		const char	*emsg = MSG_INTL(MSG_SYM_DEFTAKEN);
957 		const char	*file;
958 
959 		if (!(ofl->ofl_flags & FLG_OF_NOWARN))
960 			eprintf(ofl->ofl_lml, ERR_WARNING,
961 			    MSG_INTL(MSG_SYM_DIFFATTR), demangle(sdp->sd_name),
962 			    MSG_INTL(MSG_STR_SIZES), sdp->sd_file->ifl_name,
963 			    EC_XWORD(osym->st_size), ifl->ifl_name,
964 			    EC_XWORD(nsym->st_size));
965 
966 
967 		/*
968 		 * This symbol has already been compared to an SO definition,
969 		 * as per the runtime behavior, ignore extra definitions.
970 		 */
971 		if ((sdp->sd_flags & FLG_SY_SOFOUND) && (nfile == ET_DYN)) {
972 			if (!(ofl->ofl_flags & FLG_OF_NOWARN))
973 				eprintf(ofl->ofl_lml, ERR_NONE, emsg,
974 				    sdp->sd_file->ifl_name);
975 			return;
976 		}
977 
978 		/*
979 		 * Having provided the necessary warning indicate what course
980 		 * of action we are going to take.
981 		 *
982 		 *  -	if the file types differ, take the relocatable object
983 		 *	and apply the largest symbol size, else
984 		 *  -	if one symbol is weak and the other is non-weak, take
985 		 *	the non-weak symbol, else
986 		 *  -	simply take the largest symbol reference.
987 		 */
988 		if (nfile != ofile) {
989 			if (nfile == ET_REL) {
990 				file = ifl->ifl_name;
991 				if (osym->st_size > nsym->st_size) {
992 					size = (size_t)osym->st_size;
993 					emsg = MSG_INTL(MSG_SYM_DEFUPDATE);
994 				}
995 				sym_override(sdp, nsym, ifl, ofl, ndx,
996 				    nshndx, nsdflags);
997 			} else {
998 				file = sdp->sd_file->ifl_name;
999 				if (osym->st_size < nsym->st_size) {
1000 					size = (size_t)nsym->st_size;
1001 					emsg = MSG_INTL(MSG_SYM_DEFUPDATE);
1002 				}
1003 				sym_promote(sdp, nsym, ifl, ofl, ndx,
1004 				    nshndx, nsdflags);
1005 			}
1006 		} else if (obind != nbind) {
1007 			if ((obind == STB_WEAK) && (nbind != STB_WEAK)) {
1008 				sym_override(sdp, nsym, ifl, ofl, ndx,
1009 				    nshndx, nsdflags);
1010 				file = ifl->ifl_name;
1011 			} else
1012 				file = sdp->sd_file->ifl_name;
1013 		} else {
1014 			if (osym->st_size < nsym->st_size) {
1015 				sym_override(sdp, nsym, ifl, ofl, ndx,
1016 				    nshndx, nsdflags);
1017 				file = ifl->ifl_name;
1018 			} else
1019 				file = sdp->sd_file->ifl_name;
1020 		}
1021 		if (!(ofl->ofl_flags & FLG_OF_NOWARN))
1022 			eprintf(ofl->ofl_lml, ERR_NONE, emsg, file);
1023 		if (size)
1024 			sdp->sd_sym->st_size = (Xword)size;
1025 	} else {
1026 		/*
1027 		 * If the sizes are the same
1028 		 *
1029 		 *  -	if the file types differ, take the relocatable object,
1030 		 *	else
1031 		 *
1032 		 *  -	if one symbol is weak and the other is non-weak, take
1033 		 *	the non-weak symbol, else
1034 		 *
1035 		 *  -	take the first reference.
1036 		 */
1037 		if ((sdp->sd_flags & FLG_SY_SOFOUND) && (nfile == ET_DYN))
1038 			return;
1039 		else if (((ofile != nfile) && (nfile == ET_REL)) ||
1040 		    (((obind == STB_WEAK) && (nbind != STB_WEAK)) &&
1041 		    (!((ofile != nfile) && (ofile == ET_REL)))))
1042 			sym_override(sdp, nsym, ifl, ofl, ndx,
1043 			    nshndx, nsdflags);
1044 		else
1045 			sym_promote(sdp, nsym, ifl, ofl, ndx,
1046 			    nshndx, nsdflags);
1047 	}
1048 
1049 	/*
1050 	 * Enforce the largest alignment if necessary.
1051 	 */
1052 	if (value)
1053 		sdp->sd_sym->st_value = value;
1054 }
1055 
1056 /*
1057  * Symbol resolution state table.  `Action' describes the required
1058  * procedure to be called (if any).
1059  */
1060 static void (*Action[REF_NUM * SYM_NUM * 2][SYM_NUM])(Sym_desc *,
1061     Sym *, Ifl_desc *, Ofl_desc *, int, Word, sd_flag_t) = {
1062 
1063 /*				defined		undef		tent	*/
1064 /*				ET_REL		ET_REL		ET_REL	*/
1065 
1066 /*  0 defined REF_DYN_SEEN */	sym_tworeals,	sym_promote,	sym_realtent,
1067 /*  1   undef REF_DYN_SEEN */	sym_override,	sym_override,	sym_override,
1068 /*  2    tent REF_DYN_SEEN */	sym_realtent,	sym_promote,	sym_twotent,
1069 /*  3 defined REF_DYN_NEED */	sym_tworeals,	sym_typecheck,	sym_realtent,
1070 /*  4   undef REF_DYN_NEED */	sym_override,	sym_override,	sym_override,
1071 /*  5    tent REF_DYN_NEED */	sym_realtent,	sym_typecheck,	sym_twotent,
1072 /*  6 defined REF_REL_NEED */	sym_tworeals,	sym_typecheck,	sym_realtent,
1073 /*  7   undef REF_REL_NEED */	sym_override,	sym_twoundefs,	sym_override,
1074 /*  8    tent REF_REL_NEED */	sym_realtent,	sym_null,	sym_twotent,
1075 
1076 /*				defined		undef		tent	*/
1077 /*				ET_DYN		ET_DYN		ET_DYN	*/
1078 
1079 /*  9 defined REF_DYN_SEEN */	sym_tworeals,	sym_null,	sym_realtent,
1080 /* 10   undef REF_DYN_SEEN */	sym_override,	sym_mach_check,	sym_override,
1081 /* 11    tent REF_DYN_SEEN */	sym_realtent,	sym_null,	sym_twotent,
1082 /* 12 defined REF_DYN_NEED */	sym_tworeals,	sym_null,	sym_realtent,
1083 /* 13   undef REF_DYN_NEED */	sym_override,	sym_null,	sym_override,
1084 /* 14    tent REF_DYN_NEED */	sym_realtent,	sym_null,	sym_twotent,
1085 /* 15 defined REF_REL_NEED */	sym_tworeals,	sym_null,	sym_realtent,
1086 /* 16   undef REF_REL_NEED */	sym_override,	sym_mach_check,	sym_override,
1087 /* 17    tent REF_REL_NEED */	sym_realtent,	sym_null,	sym_twotent
1088 
1089 };
1090 
1091 uintptr_t
1092 ld_sym_resolve(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl, int ndx,
1093     Word nshndx, sd_flag_t nsdflags)
1094 {
1095 	int		row, column;		/* State table coordinates */
1096 	Sym		*osym = sdp->sd_sym;
1097 	sd_flag_t	osdflags = sdp->sd_flags;
1098 	Is_desc		*isp;
1099 	Half		vis = 0, nfile = ifl->ifl_ehdr->e_type;
1100 	Half		oref = sdp->sd_ref;
1101 
1102 	/*
1103 	 * Determine the original symbols definition (defines row in Action[]).
1104 	 */
1105 	if (osdflags & FLG_SY_TENTSYM)
1106 		row = SYM_TENTATIVE;
1107 	else if ((sdp->sd_sym->st_shndx == SHN_UNDEF) ||
1108 	    (sdp->sd_sym->st_shndx == SHN_SUNW_IGNORE))
1109 		row = SYM_UNDEFINED;
1110 	else
1111 		row = SYM_DEFINED;
1112 
1113 	/*
1114 	 * If the input file is an implicit shared object then we don't need
1115 	 * to bind to any symbols within it other than to verify that any
1116 	 * undefined references will be closed (implicit shared objects are only
1117 	 * processed when no undefined symbols are required as a result of the
1118 	 * link-edit (see process_dynamic())).
1119 	 */
1120 	if ((nfile == ET_DYN) && !(ifl->ifl_flags & FLG_IF_NEEDED) &&
1121 	    (row != SYM_UNDEFINED))
1122 		return (1);
1123 
1124 	/*
1125 	 * Finish computing the Action[] row by applying the symbols reference
1126 	 * together with the input files type.
1127 	 */
1128 	row = row + (REF_NUM * sdp->sd_ref);
1129 	if (nfile == ET_DYN)
1130 		row += (REF_NUM * SYM_NUM);
1131 
1132 	/*
1133 	 * If either the original or new symbol originates from a relocatable
1134 	 * object, determine the appropriate visibility for the resolved symbol.
1135 	 */
1136 	if ((oref == REF_REL_NEED) || (nfile == ET_REL))
1137 		vis = sym_visibility(sdp, nsym, ifl, ofl);
1138 
1139 	/*
1140 	 * Determine the new symbols definition (defines column in Action[]).
1141 	 */
1142 	if ((nsdflags & FLG_SY_SPECSEC) &&
1143 	    (nsym->st_shndx == SHN_COMMON)) {
1144 		column = SYM_TENTATIVE;
1145 		nsdflags |= FLG_SY_TENTSYM;
1146 #if	defined(_ELF64)
1147 	} else if ((ld_targ.t_m.m_mach == EM_AMD64) &&
1148 	    (nsdflags & FLG_SY_SPECSEC) &&
1149 	    (nsym->st_shndx == SHN_X86_64_LCOMMON)) {
1150 		column = SYM_TENTATIVE;
1151 		nsdflags |= FLG_SY_TENTSYM;
1152 #endif
1153 	} else if ((nsym->st_shndx == SHN_UNDEF) ||
1154 	    (nsym->st_shndx == SHN_SUNW_IGNORE)) {
1155 		column = SYM_UNDEFINED;
1156 		nshndx = SHN_UNDEF;
1157 	} else {
1158 		column = SYM_DEFINED;
1159 		/*
1160 		 * If the new symbol is from a shared library and it is
1161 		 * associated with a SHT_NOBITS section then this symbol
1162 		 * originated from a tentative symbol.
1163 		 */
1164 		if (((nsdflags & FLG_SY_SPECSEC) == 0) && (nfile == ET_DYN)) {
1165 			isp = ifl->ifl_isdesc[nshndx];
1166 			if (isp && (isp->is_shdr->sh_type == SHT_NOBITS)) {
1167 				column = SYM_TENTATIVE;
1168 				nsdflags |= FLG_SY_TENTSYM;
1169 			}
1170 		}
1171 	}
1172 
1173 	DBG_CALL(Dbg_syms_resolving(ofl, ndx, sdp->sd_name, row, column,
1174 	    osym, nsym, sdp, ifl));
1175 
1176 	/*
1177 	 * Record the input filename on the defined files list for possible
1178 	 * later diagnostics.  The `sa_dfiles' list is used to maintain the list
1179 	 * of shared objects that define the same symbol.  This list is only
1180 	 * generated when the -m option is in effect and is used to list
1181 	 * multiple (interposed) definitions of a symbol (refer to ldmap_out()).
1182 	 */
1183 	if ((ofl->ofl_flags & FLG_OF_GENMAP) && (nsym->st_shndx != SHN_UNDEF) &&
1184 	    ((nsdflags & FLG_SY_SPECSEC) == 0))
1185 		if (aplist_append(&sdp->sd_aux->sa_dfiles, ifl->ifl_name,
1186 		    AL_CNT_SDP_DFILES) == NULL)
1187 			return (S_ERROR);
1188 
1189 	/*
1190 	 * Perform the required resolution.
1191 	 */
1192 	Action[row][column](sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags);
1193 
1194 	/*
1195 	 * Apply any visibility requirements.  If a SINGLETON has been
1196 	 * established, make sure no symbol reduction indicators remain
1197 	 * associated with the symbol, and indicate that the symbol can not
1198 	 * be directly bound to.
1199 	 */
1200 	if ((oref == REF_REL_NEED) || (nfile == ET_REL)) {
1201 		if ((vis == STV_EXPORTED) || (vis == STV_SINGLETON)) {
1202 			sdp->sd_flags &= ~MSK_SY_LOCAL;
1203 
1204 			if (vis == STV_EXPORTED)
1205 				sdp->sd_flags |= FLG_SY_EXPORT;
1206 			else {
1207 				sdp->sd_flags |= (FLG_SY_NDIR | FLG_SY_SINGLE);
1208 
1209 				if (sdp->sd_ref == REF_REL_NEED) {
1210 					ofl->ofl_flags1 |=
1211 					    (FLG_OF1_NDIRECT | FLG_OF1_NGLBDIR);
1212 				}
1213 			}
1214 		} else if (vis == STV_PROTECTED) {
1215 			sdp->sd_flags |= FLG_SY_PROTECT;
1216 		} else if ((vis == STV_INTERNAL) || (vis == STV_HIDDEN)) {
1217 			sdp->sd_flags |= FLG_SY_HIDDEN;
1218 		} else if (vis == STV_ELIMINATE) {
1219 			sdp->sd_flags |= (FLG_SY_HIDDEN | FLG_SY_ELIM);
1220 		}
1221 
1222 		sdp->sd_sym->st_other =
1223 		    (sdp->sd_sym->st_other & ~MSK_SYM_VISIBILITY) | vis;
1224 	}
1225 
1226 	/*
1227 	 * If the symbol has been resolved to the new input file, and this is
1228 	 * a versioned relocatable object, then the version information of the
1229 	 * new symbol must be promoted to the versioning of the output file.
1230 	 */
1231 	if ((sdp->sd_file == ifl) && (nfile == ET_REL) && (ifl->ifl_versym) &&
1232 	    (nsym->st_shndx != SHN_UNDEF))
1233 		ld_vers_promote(sdp, ndx, ifl, ofl);
1234 
1235 	/*
1236 	 * Determine whether a mapfile reference has been satisfied.  Mapfile
1237 	 * symbol references augment symbols that should be contributed from
1238 	 * the relocatable objects used to build the output image.  If a
1239 	 * relocatable object doesn't provide one of the mapfile symbol
1240 	 * references then somethings amiss, and will be flagged during symbol
1241 	 * validation.
1242 	 */
1243 	if ((nfile == ET_REL) && ((sdp->sd_flags &
1244 	    (FLG_SY_MAPREF | FLG_SY_MAPUSED)) == FLG_SY_MAPREF)) {
1245 		/*
1246 		 * Extern and parent references are satisfied by references from
1247 		 * a relocatable object.  Note that we let *any* symbol type
1248 		 * satisfy this reference, to be as flexible as possible with
1249 		 * user written mapfiles.  It could be questionable, for
1250 		 * example, if what a user expects to be an extern reference is
1251 		 * actually found to be a definition in a relocatable object.
1252 		 *
1253 		 * Any other mapfile reference (typically for versioning
1254 		 * information) simply augments a relocatables definition.
1255 		 */
1256 		if ((sdp->sd_flags & (FLG_SY_EXTERN | FLG_SY_PARENT)) ||
1257 		    ((sdp->sd_sym->st_shndx != SHN_UNDEF) &&
1258 		    (sdp->sd_ref == REF_REL_NEED)))
1259 			sdp->sd_flags |= FLG_SY_MAPUSED;
1260 	}
1261 
1262 	/*
1263 	 * Make sure any special symbol requirements are carried over.
1264 	 */
1265 	if ((osdflags & FLG_SY_CAP) || (nsdflags & FLG_SY_CAP))
1266 		sdp->sd_flags |= FLG_SY_CAP;
1267 
1268 	DBG_CALL(Dbg_syms_resolved(ofl, sdp));
1269 
1270 	return (1);
1271 }
1272