i386_elf.c revision 4734:a4708faa3e85
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#pragma ident	"%Z%%M%	%I%	%E% SMI"
30
31/*
32 * x86 machine dependent and ELF file class dependent functions.
33 * Contains routines for performing function binding and symbol relocations.
34 */
35#include	"_synonyms.h"
36
37#include	<stdio.h>
38#include	<sys/elf.h>
39#include	<sys/elf_386.h>
40#include	<sys/mman.h>
41#include	<dlfcn.h>
42#include	<synch.h>
43#include	<string.h>
44#include	<debug.h>
45#include	<reloc.h>
46#include	<conv.h>
47#include	"_rtld.h"
48#include	"_audit.h"
49#include	"_elf.h"
50#include	"msg.h"
51
52
53extern void	elf_rtbndr(Rt_map *, ulong_t, caddr_t);
54
55int
56elf_mach_flags_check(Rej_desc *rej, Ehdr *ehdr)
57{
58	/*
59	 * Check machine type and flags.
60	 */
61	if (ehdr->e_flags != 0) {
62		rej->rej_type = SGS_REJ_BADFLAG;
63		rej->rej_info = (uint_t)ehdr->e_flags;
64		return (0);
65	}
66	return (1);
67}
68
69void
70ldso_plt_init(Rt_map * lmp)
71{
72	/*
73	 * There is no need to analyze ld.so because we don't map in any of
74	 * its dependencies.  However we may map these dependencies in later
75	 * (as if ld.so had dlopened them), so initialize the plt and the
76	 * permission information.
77	 */
78	if (PLTGOT(lmp))
79		elf_plt_init((PLTGOT(lmp)), (caddr_t)lmp);
80}
81
82static const uchar_t dyn_plt_template[] = {
83/* 0x00 */  0x55,				/* pushl %ebp */
84/* 0x01 */  0x8b, 0xec,				/* movl %esp, %ebp */
85/* 0x03 */  0x68, 0x00, 0x00, 0x00, 0x00,	/* pushl trace_fields */
86/* 0x08 */  0xe9, 0xfc, 0xff, 0xff, 0xff, 0xff	/* jmp  elf_plt_trace */
87};
88int	dyn_plt_ent_size = sizeof (dyn_plt_template);
89
90/*
91 * the dynamic plt entry is:
92 *
93 *	pushl	%ebp
94 *	movl	%esp, %ebp
95 *	pushl	tfp
96 *	jmp	elf_plt_trace
97 * dyn_data:
98 *	.align  4
99 *	uintptr_t	reflmp
100 *	uintptr_t	deflmp
101 *	uint_t		symndx
102 *	uint_t		sb_flags
103 *	Sym		symdef
104 */
105static caddr_t
106elf_plt_trace_write(uint_t roffset, Rt_map *rlmp, Rt_map *dlmp, Sym *sym,
107    uint_t symndx, uint_t pltndx, caddr_t to, uint_t sb_flags, int *fail)
108{
109	extern int	elf_plt_trace();
110	ulong_t		got_entry;
111	uchar_t		*dyn_plt;
112	uintptr_t	*dyndata;
113
114	/*
115	 * We only need to add the glue code if there is an auditing
116	 * library that is interested in this binding.
117	 */
118	dyn_plt = (uchar_t *)((uintptr_t)AUDINFO(rlmp)->ai_dynplts +
119	    (pltndx * dyn_plt_ent_size));
120
121	/*
122	 * Have we initialized this dynamic plt entry yet?  If we haven't do it
123	 * now.  Otherwise this function has been called before, but from a
124	 * different plt (ie. from another shared object).  In that case
125	 * we just set the plt to point to the new dyn_plt.
126	 */
127	if (*dyn_plt == 0) {
128		Sym	*symp;
129		Word	symvalue;
130		Lm_list	*lml = LIST(rlmp);
131
132		(void) memcpy((void *)dyn_plt, dyn_plt_template,
133		    sizeof (dyn_plt_template));
134		dyndata = (uintptr_t *)((uintptr_t)dyn_plt +
135		    ROUND(sizeof (dyn_plt_template), M_WORD_ALIGN));
136
137		/*
138		 * relocate:
139		 *	pushl	dyn_data
140		 */
141		symvalue = (Word)dyndata;
142		if (do_reloc(R_386_32, &dyn_plt[4], &symvalue,
143		    MSG_ORIG(MSG_SYM_LADYNDATA),
144		    MSG_ORIG(MSG_SPECFIL_DYNPLT), lml) == 0) {
145			*fail = 1;
146			return (0);
147		}
148
149		/*
150		 * jmps are relative, so I need to figure out the relative
151		 * address to elf_plt_trace.
152		 *
153		 * relocating:
154		 *	jmp	elf_plt_trace
155		 */
156		symvalue = (ulong_t)(elf_plt_trace) - (ulong_t)(dyn_plt + 9);
157		if (do_reloc(R_386_PC32, &dyn_plt[9], &symvalue,
158		    MSG_ORIG(MSG_SYM_ELFPLTTRACE),
159		    MSG_ORIG(MSG_SPECFIL_DYNPLT), lml) == 0) {
160			*fail = 1;
161			return (0);
162		}
163
164		*dyndata++ = (uintptr_t)rlmp;
165		*dyndata++ = (uintptr_t)dlmp;
166		*dyndata++ = (uint_t)symndx;
167		*dyndata++ = (uint_t)sb_flags;
168		symp = (Sym *)dyndata;
169		*symp = *sym;
170		symp->st_name += (Word)STRTAB(dlmp);
171		symp->st_value = (Addr)to;
172	}
173
174	got_entry = (ulong_t)roffset;
175	*(ulong_t *)got_entry = (ulong_t)dyn_plt;
176	return ((caddr_t)dyn_plt);
177}
178
179
180/*
181 * Function binding routine - invoked on the first call to a function through
182 * the procedure linkage table;
183 * passes first through an assembly language interface.
184 *
185 * Takes the offset into the relocation table of the associated
186 * relocation entry and the address of the link map (rt_private_map struct)
187 * for the entry.
188 *
189 * Returns the address of the function referenced after re-writing the PLT
190 * entry to invoke the function directly.
191 *
192 * On error, causes process to terminate with a signal.
193 */
194ulong_t
195elf_bndr(Rt_map *lmp, ulong_t reloff, caddr_t from)
196{
197	Rt_map		*nlmp, *llmp;
198	ulong_t		addr, symval, rsymndx;
199	char		*name;
200	Rel		*rptr;
201	Sym		*sym, *nsym;
202	uint_t		binfo, sb_flags = 0, dbg_class;
203	Slookup		sl;
204	int		entry, lmflags;
205	Lm_list		*lml;
206
207	/*
208	 * For compatibility with libthread (TI_VERSION 1) we track the entry
209	 * value.  A zero value indicates we have recursed into ld.so.1 to
210	 * further process a locking request.  Under this recursion we disable
211	 * tsort and cleanup activities.
212	 */
213	entry = enter();
214
215	lml = LIST(lmp);
216	if ((lmflags = lml->lm_flags) & LML_FLG_RTLDLM) {
217		dbg_class = dbg_desc->d_class;
218		dbg_desc->d_class = 0;
219	}
220
221	/*
222	 * Perform some basic sanity checks.  If we didn't get a load map or
223	 * the relocation offset is invalid then its possible someone has walked
224	 * over the .got entries or jumped to plt0 out of the blue.
225	 */
226	if (!lmp || ((reloff % sizeof (Rel)) != 0)) {
227		Conv_inv_buf_t inv_buf;
228
229		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_PLTREF),
230		    conv_reloc_386_type(R_386_JMP_SLOT, 0, &inv_buf),
231		    EC_NATPTR(lmp), EC_XWORD(reloff), EC_NATPTR(from));
232		rtldexit(lml, 1);
233	}
234
235	/*
236	 * Use relocation entry to get symbol table entry and symbol name.
237	 */
238	addr = (ulong_t)JMPREL(lmp);
239	rptr = (Rel *)(addr + reloff);
240	rsymndx = ELF_R_SYM(rptr->r_info);
241	sym = (Sym *)((ulong_t)SYMTAB(lmp) + (rsymndx * SYMENT(lmp)));
242	name = (char *)(STRTAB(lmp) + sym->st_name);
243
244	/*
245	 * Determine the last link-map of this list, this'll be the starting
246	 * point for any tsort() processing.
247	 */
248	llmp = lml->lm_tail;
249
250	/*
251	 * Find definition for symbol.
252	 */
253	sl.sl_name = name;
254	sl.sl_cmap = lmp;
255	sl.sl_imap = lml->lm_head;
256	sl.sl_hash = 0;
257	sl.sl_rsymndx = rsymndx;
258	sl.sl_flags = LKUP_DEFT;
259
260	if ((nsym = lookup_sym(&sl, &nlmp, &binfo)) == 0) {
261		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp),
262		    demangle(name));
263		rtldexit(lml, 1);
264	}
265
266	symval = nsym->st_value;
267	if (!(FLAGS(nlmp) & FLG_RT_FIXED) &&
268	    (nsym->st_shndx != SHN_ABS))
269		symval += ADDR(nlmp);
270	if ((lmp != nlmp) && ((FLAGS1(nlmp) & FL1_RT_NOINIFIN) == 0)) {
271		/*
272		 * Record that this new link map is now bound to the caller.
273		 */
274		if (bind_one(lmp, nlmp, BND_REFER) == 0)
275			rtldexit(lml, 1);
276	}
277
278	if ((lml->lm_tflags | FLAGS1(lmp)) & LML_TFLG_AUD_SYMBIND) {
279		uint_t	symndx = (((uintptr_t)nsym -
280		    (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp));
281		symval = audit_symbind(lmp, nlmp, nsym, symndx, symval,
282		    &sb_flags);
283	}
284
285	if (!(rtld_flags & RT_FL_NOBIND)) {
286		addr = rptr->r_offset;
287		if (!(FLAGS(lmp) & FLG_RT_FIXED))
288			addr += ADDR(lmp);
289		if (((lml->lm_tflags | FLAGS1(lmp)) &
290		    (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) &&
291		    AUDINFO(lmp)->ai_dynplts) {
292			int	fail = 0;
293			uint_t	pltndx = reloff / sizeof (Rel);
294			uint_t	symndx = (((uintptr_t)nsym -
295			    (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp));
296
297			symval = (ulong_t)elf_plt_trace_write(addr, lmp, nlmp,
298			    nsym, symndx, pltndx, (caddr_t)symval, sb_flags,
299			    &fail);
300			if (fail)
301				rtldexit(lml, 1);
302		} else {
303			/*
304			 * Write standard PLT entry to jump directly
305			 * to newly bound function.
306			 */
307			*(ulong_t *)addr = symval;
308		}
309	}
310
311	/*
312	 * Print binding information and rebuild PLT entry.
313	 */
314	DBG_CALL(Dbg_bind_global(lmp, (Addr)from, (Off)(from - ADDR(lmp)),
315	    (Xword)(reloff / sizeof (Rel)), PLT_T_FULL, nlmp, (Addr)symval,
316	    nsym->st_value, name, binfo));
317
318	/*
319	 * Complete any processing for newly loaded objects.  Note we don't
320	 * know exactly where any new objects are loaded (we know the object
321	 * that supplied the symbol, but others may have been loaded lazily as
322	 * we searched for the symbol), so sorting starts from the last
323	 * link-map know on entry to this routine.
324	 */
325	if (entry)
326		load_completion(llmp);
327
328	/*
329	 * Some operations like dldump() or dlopen()'ing a relocatable object
330	 * result in objects being loaded on rtld's link-map, make sure these
331	 * objects are initialized also.
332	 */
333	if ((LIST(nlmp)->lm_flags & LML_FLG_RTLDLM) && LIST(nlmp)->lm_init)
334		load_completion(nlmp);
335
336	/*
337	 * If the object we've bound to is in the process of being initialized
338	 * by another thread, determine whether we should block.
339	 */
340	is_dep_ready(nlmp, lmp, DBG_WAIT_SYMBOL);
341
342	/*
343	 * Make sure the object to which we've bound has had it's .init fired.
344	 * Cleanup before return to user code.
345	 */
346	if (entry) {
347		is_dep_init(nlmp, lmp);
348		leave(lml);
349	}
350
351	if (lmflags & LML_FLG_RTLDLM)
352		dbg_desc->d_class = dbg_class;
353
354	return (symval);
355}
356
357
358/*
359 * When the relocation loop realizes that it's dealing with relative
360 * relocations in a shared object, it breaks into this tighter loop
361 * as an optimization.
362 */
363ulong_t
364elf_reloc_relative(ulong_t relbgn, ulong_t relend, ulong_t relsiz,
365    ulong_t basebgn, ulong_t etext, ulong_t emap)
366{
367	ulong_t roffset = ((Rel *)relbgn)->r_offset;
368	char rtype;
369
370	do {
371		roffset += basebgn;
372
373		/*
374		 * If this relocation is against an address not mapped in,
375		 * then break out of the relative relocation loop, falling
376		 * back on the main relocation loop.
377		 */
378		if (roffset < etext || roffset > emap)
379			break;
380
381		/*
382		 * Perform the actual relocation.
383		 */
384		*((ulong_t *)roffset) += basebgn;
385
386		relbgn += relsiz;
387
388		if (relbgn >= relend)
389			break;
390
391		rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info);
392		roffset = ((Rel *)relbgn)->r_offset;
393
394	} while (rtype == R_386_RELATIVE);
395
396	return (relbgn);
397}
398
399/*
400 * This is the tightest loop for RELATIVE relocations for those
401 * objects built with the DT_RELACOUNT .dynamic entry.
402 */
403ulong_t
404elf_reloc_relacount(ulong_t relbgn, ulong_t relacount, ulong_t relsiz,
405    ulong_t basebgn)
406{
407	ulong_t roffset = ((Rel *) relbgn)->r_offset;
408
409	for (; relacount; relacount--) {
410		roffset += basebgn;
411
412		/*
413		 * Perform the actual relocation.
414		 */
415		*((ulong_t *)roffset) += basebgn;
416
417		relbgn += relsiz;
418
419		roffset = ((Rel *)relbgn)->r_offset;
420
421	}
422
423	return (relbgn);
424}
425
426/*
427 * Read and process the relocations for one link object, we assume all
428 * relocation sections for loadable segments are stored contiguously in
429 * the file.
430 */
431int
432elf_reloc(Rt_map *lmp, uint_t plt)
433{
434	ulong_t		relbgn, relend, relsiz, basebgn;
435	ulong_t		pltbgn, pltend, _pltbgn, _pltend;
436	ulong_t		roffset, rsymndx, psymndx = 0, etext  = ETEXT(lmp);
437	ulong_t		emap, dsymndx;
438	uchar_t		rtype;
439	long		value, pvalue;
440	Sym		*symref, *psymref, *symdef, *psymdef;
441	char		*name, *pname;
442	Rt_map		*_lmp, *plmp;
443	int		textrel = 0, ret = 1, noplt = 0;
444	int		relacount = RELACOUNT(lmp), plthint = 0;
445	Rel		*rel;
446	uint_t		binfo, pbinfo;
447	Alist		*bound = 0;
448
449	/*
450	 * Although only necessary for lazy binding, initialize the first
451	 * global offset entry to go to elf_rtbndr().  dbx(1) seems
452	 * to find this useful.
453	 */
454	if ((plt == 0) && PLTGOT(lmp)) {
455		if ((ulong_t)PLTGOT(lmp) < etext) {
456			if (elf_set_prot(lmp, PROT_WRITE) == 0)
457				return (0);
458			textrel = 1;
459		}
460		elf_plt_init(PLTGOT(lmp), (caddr_t)lmp);
461	}
462
463	/*
464	 * Initialize the plt start and end addresses.
465	 */
466	if ((pltbgn = (ulong_t)JMPREL(lmp)) != 0)
467		pltend = pltbgn + (ulong_t)(PLTRELSZ(lmp));
468
469
470	relsiz = (ulong_t)(RELENT(lmp));
471	basebgn = ADDR(lmp);
472	emap = ADDR(lmp) + MSIZE(lmp);
473
474	if (PLTRELSZ(lmp))
475		plthint = PLTRELSZ(lmp) / relsiz;
476
477	/*
478	 * If we've been called upon to promote an RTLD_LAZY object to an
479	 * RTLD_NOW then we're only interested in scaning the .plt table.
480	 * An uninitialized .plt is the case where the associated got entry
481	 * points back to the plt itself.  Determine the range of the real .plt
482	 * entries using the _PROCEDURE_LINKAGE_TABLE_ symbol.
483	 */
484	if (plt) {
485		Slookup	sl;
486
487		relbgn = pltbgn;
488		relend = pltend;
489		if (!relbgn || (relbgn == relend))
490			return (1);
491
492		sl.sl_name = MSG_ORIG(MSG_SYM_PLT);
493		sl.sl_cmap = lmp;
494		sl.sl_imap = lmp;
495		sl.sl_hash = elf_hash(MSG_ORIG(MSG_SYM_PLT));
496		sl.sl_rsymndx = 0;
497		sl.sl_flags = LKUP_DEFT;
498
499		if ((symdef = elf_find_sym(&sl, &_lmp, &binfo)) == 0)
500			return (1);
501
502		_pltbgn = symdef->st_value;
503		if (!(FLAGS(lmp) & FLG_RT_FIXED) &&
504		    (symdef->st_shndx != SHN_ABS))
505			_pltbgn += basebgn;
506		_pltend = _pltbgn + (((PLTRELSZ(lmp) / relsiz)) *
507		    M_PLT_ENTSIZE) + M_PLT_RESERVSZ;
508
509	} else {
510		/*
511		 * The relocation sections appear to the run-time linker as a
512		 * single table.  Determine the address of the beginning and end
513		 * of this table.  There are two different interpretations of
514		 * the ABI at this point:
515		 *
516		 *   o	The REL table and its associated RELSZ indicate the
517		 *	concatenation of *all* relocation sections (this is the
518		 *	model our link-editor constructs).
519		 *
520		 *   o	The REL table and its associated RELSZ indicate the
521		 *	concatenation of all *but* the .plt relocations.  These
522		 *	relocations are specified individually by the JMPREL and
523		 *	PLTRELSZ entries.
524		 *
525		 * Determine from our knowledege of the relocation range and
526		 * .plt range, the range of the total relocation table.  Note
527		 * that one other ABI assumption seems to be that the .plt
528		 * relocations always follow any other relocations, the
529		 * following range checking drops that assumption.
530		 */
531		relbgn = (ulong_t)(REL(lmp));
532		relend = relbgn + (ulong_t)(RELSZ(lmp));
533		if (pltbgn) {
534			if (!relbgn || (relbgn > pltbgn))
535				relbgn = pltbgn;
536			if (!relbgn || (relend < pltend))
537				relend = pltend;
538		}
539	}
540	if (!relbgn || (relbgn == relend)) {
541		DBG_CALL(Dbg_reloc_run(lmp, 0, plt, DBG_REL_NONE));
542		return (1);
543	}
544	DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, plt, DBG_REL_START));
545
546	/*
547	 * If we're processing a dynamic executable in lazy mode there is no
548	 * need to scan the .rel.plt table, however if we're processing a shared
549	 * object in lazy mode the .got addresses associated to each .plt must
550	 * be relocated to reflect the location of the shared object.
551	 */
552	if (pltbgn && ((MODE(lmp) & RTLD_NOW) == 0) &&
553	    (FLAGS(lmp) & FLG_RT_FIXED))
554		noplt = 1;
555
556	/*
557	 * Loop through relocations.
558	 */
559	while (relbgn < relend) {
560		uint_t	sb_flags = 0;
561
562		rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info);
563
564		/*
565		 * If this is a RELATIVE relocation in a shared object (the
566		 * common case), and if we are not debugging, then jump into a
567		 * tighter relocation loop (elf_reloc_relative).  Only make the
568		 * jump if we've been given a hint on the number of relocations.
569		 */
570		if ((rtype == R_386_RELATIVE) &&
571		    ((FLAGS(lmp) & FLG_RT_FIXED) == 0) && (DBG_ENABLED == 0)) {
572			/*
573			 * It's possible that the relative relocation block
574			 * has relocations against the text segment as well
575			 * as the data segment.  Since our optimized relocation
576			 * engine does not check which segment the relocation
577			 * is against - just mprotect it now if it's been
578			 * marked as containing TEXTREL's.
579			 */
580			if ((textrel == 0) && (FLAGS1(lmp) & FL1_RT_TEXTREL)) {
581				if (elf_set_prot(lmp, PROT_WRITE) == 0) {
582					ret = 0;
583					break;
584				}
585				textrel = 1;
586			}
587
588			if (relacount) {
589				relbgn = elf_reloc_relacount(relbgn, relacount,
590				    relsiz, basebgn);
591				relacount = 0;
592			} else {
593				relbgn = elf_reloc_relative(relbgn, relend,
594				    relsiz, basebgn, etext, emap);
595			}
596			if (relbgn >= relend)
597				break;
598			rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info);
599		}
600
601		roffset = ((Rel *)relbgn)->r_offset;
602
603		/*
604		 * If this is a shared object, add the base address to offset.
605		 */
606		if (!(FLAGS(lmp) & FLG_RT_FIXED)) {
607
608			/*
609			 * If we're processing lazy bindings, we have to step
610			 * through the plt entries and add the base address
611			 * to the corresponding got entry.
612			 */
613			if (plthint && (plt == 0) &&
614			    (rtype == R_386_JMP_SLOT) &&
615			    ((MODE(lmp) & RTLD_NOW) == 0)) {
616				relbgn = elf_reloc_relacount(relbgn,
617				    plthint, relsiz, basebgn);
618				plthint = 0;
619				continue;
620			}
621			roffset += basebgn;
622		}
623
624		rsymndx = ELF_R_SYM(((Rel *)relbgn)->r_info);
625		rel = (Rel *)relbgn;
626		relbgn += relsiz;
627
628		/*
629		 * Optimizations.
630		 */
631		if (rtype == R_386_NONE)
632			continue;
633		if (noplt && ((ulong_t)rel >= pltbgn) &&
634		    ((ulong_t)rel < pltend)) {
635			relbgn = pltend;
636			continue;
637		}
638
639		/*
640		 * If we're promoting plts determine if this one has already
641		 * been written.
642		 */
643		if (plt) {
644			if ((*(ulong_t *)roffset < _pltbgn) ||
645			    (*(ulong_t *)roffset > _pltend))
646				continue;
647		}
648
649		/*
650		 * If this relocation is not against part of the image
651		 * mapped into memory we skip it.
652		 */
653		if ((roffset < ADDR(lmp)) || (roffset > (ADDR(lmp) +
654		    MSIZE(lmp)))) {
655			elf_reloc_bad(lmp, (void *)rel, rtype, roffset,
656			    rsymndx);
657			continue;
658		}
659
660		binfo = 0;
661		/*
662		 * If a symbol index is specified then get the symbol table
663		 * entry, locate the symbol definition, and determine its
664		 * address.
665		 */
666		if (rsymndx) {
667			/*
668			 * Get the local symbol table entry.
669			 */
670			symref = (Sym *)((ulong_t)SYMTAB(lmp) +
671			    (rsymndx * SYMENT(lmp)));
672
673			/*
674			 * If this is a local symbol, just use the base address.
675			 * (we should have no local relocations in the
676			 * executable).
677			 */
678			if (ELF_ST_BIND(symref->st_info) == STB_LOCAL) {
679				value = basebgn;
680				name = (char *)0;
681
682				/*
683				 * Special case TLS relocations.
684				 */
685				if (rtype == R_386_TLS_DTPMOD32) {
686					/*
687					 * Use the TLS modid.
688					 */
689					value = TLSMODID(lmp);
690
691				} else if (rtype == R_386_TLS_TPOFF) {
692					if ((value = elf_static_tls(lmp, symref,
693					    rel, rtype, 0, roffset, 0)) == 0) {
694						ret = 0;
695						break;
696					}
697				}
698			} else {
699				/*
700				 * If the symbol index is equal to the previous
701				 * symbol index relocation we processed then
702				 * reuse the previous values. (Note that there
703				 * have been cases where a relocation exists
704				 * against a copy relocation symbol, our ld(1)
705				 * should optimize this away, but make sure we
706				 * don't use the same symbol information should
707				 * this case exist).
708				 */
709				if ((rsymndx == psymndx) &&
710				    (rtype != R_386_COPY)) {
711					/* LINTED */
712					if (psymdef == 0) {
713						DBG_CALL(Dbg_bind_weak(lmp,
714						    (Addr)roffset, (Addr)
715						    (roffset - basebgn), name));
716						continue;
717					}
718					/* LINTED */
719					value = pvalue;
720					/* LINTED */
721					name = pname;
722					/* LINTED */
723					symdef = psymdef;
724					/* LINTED */
725					symref = psymref;
726					/* LINTED */
727					_lmp = plmp;
728					/* LINTED */
729					binfo = pbinfo;
730
731					if ((LIST(_lmp)->lm_tflags |
732					    FLAGS1(_lmp)) &
733					    LML_TFLG_AUD_SYMBIND) {
734						value = audit_symbind(lmp, _lmp,
735						    /* LINTED */
736						    symdef, dsymndx, value,
737						    &sb_flags);
738					}
739				} else {
740					Slookup		sl;
741					uchar_t		bind;
742
743					/*
744					 * Lookup the symbol definition.
745					 */
746					name = (char *)(STRTAB(lmp) +
747					    symref->st_name);
748
749					sl.sl_name = name;
750					sl.sl_cmap = lmp;
751					sl.sl_imap = 0;
752					sl.sl_hash = 0;
753					sl.sl_rsymndx = rsymndx;
754
755					if (rtype == R_386_COPY)
756						sl.sl_flags = LKUP_COPY;
757					else
758						sl.sl_flags = LKUP_DEFT;
759
760					sl.sl_flags |= LKUP_ALLCNTLIST;
761
762					if (rtype != R_386_JMP_SLOT)
763						sl.sl_flags |= LKUP_SPEC;
764
765					bind = ELF_ST_BIND(symref->st_info);
766					if (bind == STB_WEAK)
767						sl.sl_flags |= LKUP_WEAK;
768
769					symdef = lookup_sym(&sl, &_lmp, &binfo);
770
771					/*
772					 * If the symbol is not found and the
773					 * reference was not to a weak symbol,
774					 * report an error.  Weak references
775					 * may be unresolved.
776					 * chkmsg: MSG_INTL(MSG_LDD_SYM_NFOUND)
777					 */
778					/* BEGIN CSTYLED */
779					if (symdef == 0) {
780					    Lm_list	*lml = LIST(lmp);
781
782					    if (bind != STB_WEAK) {
783						if (lml->lm_flags &
784						    LML_FLG_IGNRELERR) {
785						    continue;
786						} else if (lml->lm_flags &
787						    LML_FLG_TRC_WARN) {
788						    (void) printf(MSG_INTL(
789							MSG_LDD_SYM_NFOUND),
790							demangle(name),
791							NAME(lmp));
792						    continue;
793						} else {
794						    DBG_CALL(Dbg_reloc_in(lml,
795							ELF_DBG_RTLD, M_MACH,
796							M_REL_SHT_TYPE, rel,
797							NULL, name));
798						    eprintf(lml, ERR_FATAL,
799							MSG_INTL(MSG_REL_NOSYM),
800							NAME(lmp),
801							demangle(name));
802						    ret = 0;
803						    break;
804						}
805					    } else {
806						psymndx = rsymndx;
807						psymdef = 0;
808
809						DBG_CALL(Dbg_bind_weak(lmp,
810						    (Addr)roffset, (Addr)
811						    (roffset - basebgn), name));
812						continue;
813					    }
814					}
815					/* END CSTYLED */
816
817					/*
818					 * If symbol was found in an object
819					 * other than the referencing object
820					 * then record the binding.
821					 */
822					if ((lmp != _lmp) && ((FLAGS1(_lmp) &
823					    FL1_RT_NOINIFIN) == 0)) {
824						if (alist_test(&bound, _lmp,
825						    sizeof (Rt_map *),
826						    AL_CNT_RELBIND) == 0) {
827							ret = 0;
828							break;
829						}
830					}
831
832					/*
833					 * Calculate the location of definition;
834					 * symbol value plus base address of
835					 * containing shared object.
836					 */
837					if (IS_SIZE(rtype))
838						value = symdef->st_size;
839					else
840						value = symdef->st_value;
841
842					if (!(FLAGS(_lmp) & FLG_RT_FIXED) &&
843					    !(IS_SIZE(rtype)) &&
844					    (symdef->st_shndx != SHN_ABS) &&
845					    (ELF_ST_TYPE(symdef->st_info) !=
846					    STT_TLS))
847						value += ADDR(_lmp);
848
849					/*
850					 * Retain this symbol index and the
851					 * value in case it can be used for the
852					 * subsequent relocations.
853					 */
854					if (rtype != R_386_COPY) {
855						psymndx = rsymndx;
856						pvalue = value;
857						pname = name;
858						psymdef = symdef;
859						psymref = symref;
860						plmp = _lmp;
861						pbinfo = binfo;
862					}
863					if ((LIST(_lmp)->lm_tflags |
864					    FLAGS1(_lmp)) &
865					    LML_TFLG_AUD_SYMBIND) {
866						dsymndx = (((uintptr_t)symdef -
867						    (uintptr_t)SYMTAB(_lmp)) /
868						    SYMENT(_lmp));
869						value = audit_symbind(lmp, _lmp,
870						    symdef, dsymndx, value,
871						    &sb_flags);
872					}
873				}
874
875				/*
876				 * If relocation is PC-relative, subtract
877				 * offset address.
878				 */
879				if (IS_PC_RELATIVE(rtype))
880					value -= roffset;
881
882				/*
883				 * Special case TLS relocations.
884				 */
885				if (rtype == R_386_TLS_DTPMOD32) {
886					/*
887					 * Relocation value is the TLS modid.
888					 */
889					value = TLSMODID(_lmp);
890
891				} else if (rtype == R_386_TLS_TPOFF) {
892					if ((value = elf_static_tls(_lmp,
893					    symdef, rel, rtype, name, roffset,
894					    value)) == 0) {
895						ret = 0;
896						break;
897					}
898				}
899			}
900		} else {
901			/*
902			 * Special cases.
903			 */
904			if (rtype == R_386_TLS_DTPMOD32) {
905				/*
906				 * TLS relocation value is the TLS modid.
907				 */
908				value = TLSMODID(lmp);
909			} else
910				value = basebgn;
911			name = (char *)0;
912		}
913
914		DBG_CALL(Dbg_reloc_in(LIST(lmp), ELF_DBG_RTLD, M_MACH,
915		    M_REL_SHT_TYPE, rel, NULL, name));
916
917		/*
918		 * If this object has relocations in the text segment, turn
919		 * off the write protect.
920		 */
921		if ((roffset < etext) && (textrel == 0)) {
922			if (elf_set_prot(lmp, PROT_WRITE) == 0) {
923				ret = 0;
924				break;
925			}
926			textrel = 1;
927		}
928
929		/*
930		 * Call relocation routine to perform required relocation.
931		 */
932		switch (rtype) {
933		case R_386_COPY:
934			if (elf_copy_reloc(name, symref, lmp, (void *)roffset,
935			    symdef, _lmp, (const void *)value) == 0)
936				ret = 0;
937			break;
938		case R_386_JMP_SLOT:
939			if (((LIST(lmp)->lm_tflags | FLAGS1(lmp)) &
940			    (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) &&
941			    AUDINFO(lmp)->ai_dynplts) {
942				int	fail = 0;
943				int	pltndx = (((ulong_t)rel -
944				    (uintptr_t)JMPREL(lmp)) / relsiz);
945				int	symndx = (((uintptr_t)symdef -
946				    (uintptr_t)SYMTAB(_lmp)) / SYMENT(_lmp));
947
948				(void) elf_plt_trace_write(roffset, lmp, _lmp,
949				    symdef, symndx, pltndx, (caddr_t)value,
950				    sb_flags, &fail);
951				if (fail)
952					ret = 0;
953			} else {
954				/*
955				 * Write standard PLT entry to jump directly
956				 * to newly bound function.
957				 */
958				DBG_CALL(Dbg_reloc_apply_val(LIST(lmp),
959				    ELF_DBG_RTLD, (Xword)roffset,
960				    (Xword)value));
961				*(ulong_t *)roffset = value;
962			}
963			break;
964		default:
965			/*
966			 * Write the relocation out.
967			 */
968			if (do_reloc(rtype, (uchar_t *)roffset, (Word *)&value,
969			    name, NAME(lmp), LIST(lmp)) == 0)
970				ret = 0;
971
972			DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), ELF_DBG_RTLD,
973			    (Xword)roffset, (Xword)value));
974		}
975
976		if ((ret == 0) &&
977		    ((LIST(lmp)->lm_flags & LML_FLG_TRC_WARN) == 0))
978			break;
979
980		if (binfo) {
981			DBG_CALL(Dbg_bind_global(lmp, (Addr)roffset,
982			    (Off)(roffset - basebgn), (Xword)(-1), PLT_T_FULL,
983			    _lmp, (Addr)value, symdef->st_value, name, binfo));
984		}
985	}
986
987	return (relocate_finish(lmp, bound, textrel, ret));
988}
989
990/*
991 * Initialize the first few got entries so that function calls go to
992 * elf_rtbndr:
993 *
994 *	GOT[GOT_XLINKMAP] =	the address of the link map
995 *	GOT[GOT_XRTLD] =	the address of rtbinder
996 */
997void
998elf_plt_init(void *got, caddr_t l)
999{
1000	uint_t		*_got;
1001	/* LINTED */
1002	Rt_map		*lmp = (Rt_map *)l;
1003
1004	_got = (uint_t *)got + M_GOT_XLINKMAP;
1005	*_got = (uint_t)lmp;
1006	_got = (uint_t *)got + M_GOT_XRTLD;
1007	*_got = (uint_t)elf_rtbndr;
1008}
1009
1010/*
1011 * For SVR4 Intel compatability.  USL uses /usr/lib/libc.so.1 as the run-time
1012 * linker, so the interpreter's address will differ from /usr/lib/ld.so.1.
1013 * Further, USL has special _iob[] and _ctype[] processing that makes up for the
1014 * fact that these arrays do not have associated copy relocations.  So we try
1015 * and make up for that here.  Any relocations found will be added to the global
1016 * copy relocation list and will be processed in setup().
1017 */
1018static int
1019_elf_copy_reloc(const char *name, Rt_map *rlmp, Rt_map *dlmp)
1020{
1021	Sym		*symref, *symdef;
1022	caddr_t 	ref, def;
1023	Rt_map		*_lmp;
1024	Rel		rel;
1025	Slookup		sl;
1026	uint_t		binfo;
1027
1028	/*
1029	 * Determine if the special symbol exists as a reference in the dynamic
1030	 * executable, and that an associated definition exists in libc.so.1.
1031	 */
1032	sl.sl_name = name;
1033	sl.sl_cmap = rlmp;
1034	sl.sl_imap = rlmp;
1035	sl.sl_hash = 0;
1036	sl.sl_rsymndx = 0;
1037	sl.sl_flags = LKUP_FIRST;
1038
1039	if ((symref = lookup_sym(&sl, &_lmp, &binfo)) == 0)
1040		return (1);
1041
1042	sl.sl_imap = dlmp;
1043	sl.sl_flags = LKUP_DEFT;
1044
1045	if ((symdef = lookup_sym(&sl, &_lmp, &binfo)) == 0)
1046		return (1);
1047	if (strcmp(NAME(_lmp), MSG_ORIG(MSG_PTH_LIBC)))
1048		return (1);
1049
1050	/*
1051	 * Determine the reference and definition addresses.
1052	 */
1053	ref = (void *)(symref->st_value);
1054	if (!(FLAGS(rlmp) & FLG_RT_FIXED))
1055		ref += ADDR(rlmp);
1056	def = (void *)(symdef->st_value);
1057	if (!(FLAGS(_lmp) & FLG_RT_FIXED))
1058		def += ADDR(_lmp);
1059
1060	/*
1061	 * Set up a relocation entry for debugging and call the generic copy
1062	 * relocation function to provide symbol size error checking and to
1063	 * record the copy relocation that must be performed.
1064	 */
1065	rel.r_offset = (Addr)ref;
1066	rel.r_info = (Word)R_386_COPY;
1067	DBG_CALL(Dbg_reloc_in(LIST(rlmp), ELF_DBG_RTLD, M_MACH, M_REL_SHT_TYPE,
1068	    &rel, NULL, name));
1069
1070	return (elf_copy_reloc((char *)name, symref, rlmp, (void *)ref, symdef,
1071	    _lmp, (void *)def));
1072}
1073
1074int
1075elf_copy_gen(Rt_map *lmp)
1076{
1077	if (interp && ((ulong_t)interp->i_faddr !=
1078	    r_debug.rtd_rdebug.r_ldbase) &&
1079	    !(strcmp(interp->i_name, MSG_ORIG(MSG_PTH_LIBC)))) {
1080
1081		DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, 0,
1082		    DBG_REL_START));
1083
1084		if (_elf_copy_reloc(MSG_ORIG(MSG_SYM_CTYPE), lmp,
1085		    (Rt_map *)NEXT(lmp)) == 0)
1086			return (0);
1087		if (_elf_copy_reloc(MSG_ORIG(MSG_SYM_IOB), lmp,
1088		    (Rt_map *)NEXT(lmp)) == 0)
1089			return (0);
1090	}
1091	return (1);
1092}
1093
1094/*
1095 * Plt writing interface to allow debugging initialization to be generic.
1096 */
1097Pltbindtype
1098/* ARGSUSED1 */
1099elf_plt_write(uintptr_t addr, uintptr_t vaddr, void *rptr, uintptr_t symval,
1100	Xword pltndx)
1101{
1102	Rel		*rel = (Rel*)rptr;
1103	uintptr_t	pltaddr;
1104
1105	pltaddr = addr + rel->r_offset;
1106	*(ulong_t *)pltaddr = (ulong_t)symval;
1107	DBG_CALL(pltcntfull++);
1108	return (PLT_T_FULL);
1109}
1110
1111/*
1112 * Provide a machine specific interface to the conversion routine.  By calling
1113 * the machine specific version, rather than the generic version, we insure that
1114 * the data tables/strings for all known machine versions aren't dragged into
1115 * ld.so.1.
1116 */
1117const char *
1118_conv_reloc_type(uint_t rel)
1119{
1120	static Conv_inv_buf_t inv_buf;
1121
1122	return (conv_reloc_386_type(rel, 0, &inv_buf));
1123}
1124