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 (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
27 * Copyright (c) 2012, Joyent, Inc. All rights reserved.
28 */
29
30 /*
31 * x86 machine dependent and ELF file class dependent functions.
32 * Contains routines for performing function binding and symbol relocations.
33 */
34
35 #include <stdio.h>
36 #include <sys/elf.h>
37 #include <sys/elf_386.h>
38 #include <sys/mman.h>
39 #include <dlfcn.h>
40 #include <synch.h>
41 #include <string.h>
42 #include <debug.h>
43 #include <reloc.h>
44 #include <conv.h>
45 #include "_rtld.h"
46 #include "_audit.h"
47 #include "_elf.h"
48 #include "_inline_gen.h"
49 #include "_inline_reloc.h"
50 #include "msg.h"
51
52 extern void elf_rtbndr(Rt_map *, ulong_t, caddr_t);
53
54 int
55 elf_mach_flags_check(Rej_desc *rej, Ehdr *ehdr)
56 {
57 /*
58 * Check machine type and flags.
59 */
60 if (ehdr->e_flags != 0) {
61 rej->rej_type = SGS_REJ_BADFLAG;
62 rej->rej_info = (uint_t)ehdr->e_flags;
63 return (0);
64 }
65 return (1);
66 }
67
68 void
69 ldso_plt_init(Rt_map *lmp)
70 {
71 /*
72 * There is no need to analyze ld.so because we don't map in any of
73 * its dependencies. However we may map these dependencies in later
74 * (as if ld.so had dlopened them), so initialize the plt and the
75 * permission information.
76 */
77 if (PLTGOT(lmp))
78 elf_plt_init((PLTGOT(lmp)), (caddr_t)lmp);
79 }
80
81 static const uchar_t dyn_plt_template[] = {
82 /* 0x00 */ 0x55, /* pushl %ebp */
83 /* 0x01 */ 0x8b, 0xec, /* movl %esp, %ebp */
84 /* 0x03 */ 0x68, 0x00, 0x00, 0x00, 0x00, /* pushl trace_fields */
85 /* 0x08 */ 0xe9, 0xfc, 0xff, 0xff, 0xff, 0xff /* jmp elf_plt_trace */
86 };
87 int dyn_plt_ent_size = sizeof (dyn_plt_template);
88
89 /*
90 * the dynamic plt entry is:
91 *
92 * pushl %ebp
93 * movl %esp, %ebp
94 * pushl tfp
95 * jmp elf_plt_trace
96 * dyn_data:
97 * .align 4
98 * uintptr_t reflmp
99 * uintptr_t deflmp
100 * uint_t symndx
101 * uint_t sb_flags
102 * Sym symdef
103 */
104 static caddr_t
105 elf_plt_trace_write(uint_t roffset, Rt_map *rlmp, Rt_map *dlmp, Sym *sym,
106 uint_t symndx, uint_t pltndx, caddr_t to, uint_t sb_flags, int *fail)
107 {
108 extern int elf_plt_trace();
109 ulong_t got_entry;
110 uchar_t *dyn_plt;
111 uintptr_t *dyndata;
112
113 /*
114 * We only need to add the glue code if there is an auditing
115 * library that is interested in this binding.
116 */
117 dyn_plt = (uchar_t *)((uintptr_t)AUDINFO(rlmp)->ai_dynplts +
118 (pltndx * dyn_plt_ent_size));
119
120 /*
121 * Have we initialized this dynamic plt entry yet? If we haven't do it
122 * now. Otherwise this function has been called before, but from a
123 * different plt (ie. from another shared object). In that case
124 * we just set the plt to point to the new dyn_plt.
125 */
126 if (*dyn_plt == 0) {
127 Sym *symp;
128 Word symvalue;
129 Lm_list *lml = LIST(rlmp);
130
131 (void) memcpy((void *)dyn_plt, dyn_plt_template,
132 sizeof (dyn_plt_template));
133 dyndata = (uintptr_t *)((uintptr_t)dyn_plt +
134 ROUND(sizeof (dyn_plt_template), M_WORD_ALIGN));
135
136 /*
137 * relocate:
138 * pushl dyn_data
139 */
140 symvalue = (Word)dyndata;
141 if (do_reloc_rtld(R_386_32, &dyn_plt[4], &symvalue,
142 MSG_ORIG(MSG_SYM_LADYNDATA),
143 MSG_ORIG(MSG_SPECFIL_DYNPLT), lml) == 0) {
144 *fail = 1;
145 return (0);
146 }
147
148 /*
149 * jmps are relative, so I need to figure out the relative
150 * address to elf_plt_trace.
151 *
152 * relocating:
153 * jmp elf_plt_trace
154 */
155 symvalue = (ulong_t)(elf_plt_trace) - (ulong_t)(dyn_plt + 9);
156 if (do_reloc_rtld(R_386_PC32, &dyn_plt[9], &symvalue,
157 MSG_ORIG(MSG_SYM_ELFPLTTRACE),
158 MSG_ORIG(MSG_SPECFIL_DYNPLT), lml) == 0) {
159 *fail = 1;
160 return (0);
161 }
162
163 *dyndata++ = (uintptr_t)rlmp;
164 *dyndata++ = (uintptr_t)dlmp;
165 *dyndata++ = (uint_t)symndx;
166 *dyndata++ = (uint_t)sb_flags;
167 symp = (Sym *)dyndata;
168 *symp = *sym;
169 symp->st_name += (Word)STRTAB(dlmp);
170 symp->st_value = (Addr)to;
171 }
172
173 got_entry = (ulong_t)roffset;
174 *(ulong_t *)got_entry = (ulong_t)dyn_plt;
175 return ((caddr_t)dyn_plt);
176 }
177
178 /*
179 * Function binding routine - invoked on the first call to a function through
180 * the procedure linkage table;
181 * passes first through an assembly language interface.
182 *
183 * Takes the offset into the relocation table of the associated
184 * relocation entry and the address of the link map (rt_private_map struct)
185 * for the entry.
186 *
187 * Returns the address of the function referenced after re-writing the PLT
188 * entry to invoke the function directly.
189 *
190 * On error, causes process to terminate with a signal.
191 */
192 ulong_t
193 elf_bndr(Rt_map *lmp, ulong_t reloff, caddr_t from)
194 {
195 Rt_map *nlmp, *llmp;
196 ulong_t addr, symval, rsymndx;
197 char *name;
198 Rel *rptr;
199 Sym *rsym, *nsym;
200 uint_t binfo, sb_flags = 0, dbg_class;
201 Slookup sl;
202 Sresult sr;
203 int entry, lmflags;
204 Lm_list *lml;
205
206 /*
207 * For compatibility with libthread (TI_VERSION 1) we track the entry
208 * value. A zero value indicates we have recursed into ld.so.1 to
209 * further process a locking request. Under this recursion we disable
210 * tsort and cleanup activities.
211 */
212 entry = enter(0);
213
214 lml = LIST(lmp);
215 if ((lmflags = lml->lm_flags) & LML_FLG_RTLDLM) {
216 dbg_class = dbg_desc->d_class;
217 dbg_desc->d_class = 0;
218 }
219
220 /*
221 * Perform some basic sanity checks. If we didn't get a load map or
222 * the relocation offset is invalid then its possible someone has walked
223 * over the .got entries or jumped to plt0 out of the blue.
224 */
225 if (!lmp || ((reloff % sizeof (Rel)) != 0)) {
226 Conv_inv_buf_t inv_buf;
227
228 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_PLTREF),
229 conv_reloc_386_type(R_386_JMP_SLOT, 0, &inv_buf),
230 EC_NATPTR(lmp), EC_XWORD(reloff), EC_NATPTR(from));
231 rtldexit(lml, 1);
232 }
233
234 /*
235 * Use relocation entry to get symbol table entry and symbol name.
236 */
237 addr = (ulong_t)JMPREL(lmp);
238 rptr = (Rel *)(addr + reloff);
239 rsymndx = ELF_R_SYM(rptr->r_info);
240 rsym = (Sym *)((ulong_t)SYMTAB(lmp) + (rsymndx * SYMENT(lmp)));
241 name = (char *)(STRTAB(lmp) + rsym->st_name);
242
243 /*
244 * Determine the last link-map of this list, this'll be the starting
245 * point for any tsort() processing.
246 */
247 llmp = lml->lm_tail;
248
249 /*
250 * Find definition for symbol. Initialize the symbol lookup, and
251 * symbol result, data structures.
252 */
253 SLOOKUP_INIT(sl, name, lmp, lml->lm_head, ld_entry_cnt, 0,
254 rsymndx, rsym, 0, LKUP_DEFT);
255 SRESULT_INIT(sr, name);
256
257 if (lookup_sym(&sl, &sr, &binfo, NULL) == 0) {
258 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp),
259 demangle(name));
260 rtldexit(lml, 1);
261 }
262
263 name = (char *)sr.sr_name;
264 nlmp = sr.sr_dmap;
265 nsym = sr.sr_sym;
266
267 symval = nsym->st_value;
268
269 if (!(FLAGS(nlmp) & FLG_RT_FIXED) &&
270 (nsym->st_shndx != SHN_ABS))
271 symval += ADDR(nlmp);
272 if ((lmp != nlmp) && ((FLAGS1(nlmp) & FL1_RT_NOINIFIN) == 0)) {
273 /*
274 * Record that this new link map is now bound to the caller.
275 */
276 if (bind_one(lmp, nlmp, BND_REFER) == 0)
277 rtldexit(lml, 1);
278 }
279
280 if ((lml->lm_tflags | AFLAGS(lmp) | AFLAGS(nlmp)) &
281 LML_TFLG_AUD_SYMBIND) {
282 uint_t symndx = (((uintptr_t)nsym -
283 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp));
284 symval = audit_symbind(lmp, nlmp, nsym, symndx, symval,
285 &sb_flags);
286 }
287
288 if (!(rtld_flags & RT_FL_NOBIND)) {
289 addr = rptr->r_offset;
290 if (!(FLAGS(lmp) & FLG_RT_FIXED))
291 addr += ADDR(lmp);
292 if (((lml->lm_tflags | AFLAGS(lmp)) &
293 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) &&
294 AUDINFO(lmp)->ai_dynplts) {
295 int fail = 0;
296 uint_t pltndx = reloff / sizeof (Rel);
297 uint_t symndx = (((uintptr_t)nsym -
298 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp));
299
300 symval = (ulong_t)elf_plt_trace_write(addr, lmp, nlmp,
301 nsym, symndx, pltndx, (caddr_t)symval, sb_flags,
302 &fail);
303 if (fail)
304 rtldexit(lml, 1);
305 } else {
306 /*
307 * Write standard PLT entry to jump directly
308 * to newly bound function.
309 */
310 *(ulong_t *)addr = symval;
311 }
312 }
313
314 /*
315 * Print binding information and rebuild PLT entry.
316 */
317 DBG_CALL(Dbg_bind_global(lmp, (Addr)from, (Off)(from - ADDR(lmp)),
318 (Xword)(reloff / sizeof (Rel)), PLT_T_FULL, nlmp, (Addr)symval,
319 nsym->st_value, name, binfo));
320
321 /*
322 * Complete any processing for newly loaded objects. Note we don't
323 * know exactly where any new objects are loaded (we know the object
324 * that supplied the symbol, but others may have been loaded lazily as
325 * we searched for the symbol), so sorting starts from the last
326 * link-map know on entry to this routine.
327 */
328 if (entry)
329 load_completion(llmp);
330
331 /*
332 * Some operations like dldump() or dlopen()'ing a relocatable object
333 * result in objects being loaded on rtld's link-map, make sure these
334 * objects are initialized also.
335 */
336 if ((LIST(nlmp)->lm_flags & LML_FLG_RTLDLM) && LIST(nlmp)->lm_init)
337 load_completion(nlmp);
338
339 /*
340 * Make sure the object to which we've bound has had it's .init fired.
341 * Cleanup before return to user code.
342 */
343 if (entry) {
344 is_dep_init(nlmp, lmp);
345 leave(lml, 0);
346 }
347
348 if (lmflags & LML_FLG_RTLDLM)
349 dbg_desc->d_class = dbg_class;
350
351 return (symval);
352 }
353
354 /*
355 * Read and process the relocations for one link object, we assume all
356 * relocation sections for loadable segments are stored contiguously in
357 * the file.
358 */
359 int
360 elf_reloc(Rt_map *lmp, uint_t plt, int *in_nfavl, APlist **textrel)
361 {
362 ulong_t relbgn, relend, relsiz, basebgn, pltbgn, pltend;
363 ulong_t _pltbgn, _pltend;
364 ulong_t dsymndx, roffset, rsymndx, psymndx = 0;
365 uchar_t rtype;
366 long value, pvalue;
367 Sym *symref, *psymref, *symdef, *psymdef;
368 Syminfo *sip;
369 char *name, *pname;
370 Rt_map *_lmp, *plmp;
371 int ret = 1, noplt = 0;
372 int relacount = RELACOUNT(lmp), plthint = 0;
373 Rel *rel;
374 uint_t binfo, pbinfo;
375 APlist *bound = NULL;
376
377 /*
378 * Although only necessary for lazy binding, initialize the first
379 * global offset entry to go to elf_rtbndr(). dbx(1) seems
380 * to find this useful.
381 */
382 if ((plt == 0) && PLTGOT(lmp)) {
383 mmapobj_result_t *mpp;
384
385 /*
386 * Make sure the segment is writable.
387 */
388 if ((((mpp =
389 find_segment((caddr_t)PLTGOT(lmp), lmp)) != NULL) &&
390 ((mpp->mr_prot & PROT_WRITE) == 0)) &&
391 ((set_prot(lmp, mpp, 1) == 0) ||
392 (aplist_append(textrel, mpp, AL_CNT_TEXTREL) == NULL)))
393 return (0);
394
395 elf_plt_init(PLTGOT(lmp), (caddr_t)lmp);
396 }
397
398 /*
399 * Initialize the plt start and end addresses.
400 */
401 if ((pltbgn = (ulong_t)JMPREL(lmp)) != 0)
402 pltend = pltbgn + (ulong_t)(PLTRELSZ(lmp));
403
404 relsiz = (ulong_t)(RELENT(lmp));
405 basebgn = ADDR(lmp);
406
407 if (PLTRELSZ(lmp))
408 plthint = PLTRELSZ(lmp) / relsiz;
409
410 /*
411 * If we've been called upon to promote an RTLD_LAZY object to an
412 * RTLD_NOW then we're only interested in scaning the .plt table.
413 * An uninitialized .plt is the case where the associated got entry
414 * points back to the plt itself. Determine the range of the real .plt
415 * entries using the _PROCEDURE_LINKAGE_TABLE_ symbol.
416 */
417 if (plt) {
418 Slookup sl;
419 Sresult sr;
420
421 relbgn = pltbgn;
422 relend = pltend;
423 if (!relbgn || (relbgn == relend))
424 return (1);
425
426 /*
427 * Initialize the symbol lookup, and symbol result, data
428 * structures.
429 */
430 SLOOKUP_INIT(sl, MSG_ORIG(MSG_SYM_PLT), lmp, lmp, ld_entry_cnt,
431 elf_hash(MSG_ORIG(MSG_SYM_PLT)), 0, 0, 0, LKUP_DEFT);
432 SRESULT_INIT(sr, MSG_ORIG(MSG_SYM_PLT));
433
434 if (elf_find_sym(&sl, &sr, &binfo, NULL) == 0)
435 return (1);
436
437 symdef = sr.sr_sym;
438 _pltbgn = symdef->st_value;
439 if (!(FLAGS(lmp) & FLG_RT_FIXED) &&
440 (symdef->st_shndx != SHN_ABS))
441 _pltbgn += basebgn;
442 _pltend = _pltbgn + (((PLTRELSZ(lmp) / relsiz)) *
443 M_PLT_ENTSIZE) + M_PLT_RESERVSZ;
444
445 } else {
446 /*
447 * The relocation sections appear to the run-time linker as a
448 * single table. Determine the address of the beginning and end
449 * of this table. There are two different interpretations of
450 * the ABI at this point:
451 *
452 * o The REL table and its associated RELSZ indicate the
453 * concatenation of *all* relocation sections (this is the
454 * model our link-editor constructs).
455 *
456 * o The REL table and its associated RELSZ indicate the
457 * concatenation of all *but* the .plt relocations. These
458 * relocations are specified individually by the JMPREL and
459 * PLTRELSZ entries.
460 *
461 * Determine from our knowledege of the relocation range and
462 * .plt range, the range of the total relocation table. Note
463 * that one other ABI assumption seems to be that the .plt
464 * relocations always follow any other relocations, the
465 * following range checking drops that assumption.
466 */
467 relbgn = (ulong_t)(REL(lmp));
468 relend = relbgn + (ulong_t)(RELSZ(lmp));
469 if (pltbgn) {
470 if (!relbgn || (relbgn > pltbgn))
471 relbgn = pltbgn;
472 if (!relbgn || (relend < pltend))
473 relend = pltend;
474 }
475 }
476 if (!relbgn || (relbgn == relend)) {
477 DBG_CALL(Dbg_reloc_run(lmp, 0, plt, DBG_REL_NONE));
478 return (1);
479 }
480 DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, plt, DBG_REL_START));
481
482 /*
483 * If we're processing a dynamic executable in lazy mode there is no
484 * need to scan the .rel.plt table, however if we're processing a shared
485 * object in lazy mode the .got addresses associated to each .plt must
486 * be relocated to reflect the location of the shared object.
487 */
488 if (pltbgn && ((MODE(lmp) & RTLD_NOW) == 0) &&
489 (FLAGS(lmp) & FLG_RT_FIXED))
490 noplt = 1;
491
492 sip = SYMINFO(lmp);
493 /*
494 * Loop through relocations.
495 */
496 while (relbgn < relend) {
497 mmapobj_result_t *mpp;
498 uint_t sb_flags = 0;
499
500 rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info, M_MACH);
501
502 /*
503 * If this is a RELATIVE relocation in a shared object (the
504 * common case), and if we are not debugging, then jump into a
505 * tighter relocation loop (elf_reloc_relative).
506 */
507 if ((rtype == R_386_RELATIVE) &&
508 ((FLAGS(lmp) & FLG_RT_FIXED) == 0) && (DBG_ENABLED == 0)) {
509 if (relacount) {
510 relbgn = elf_reloc_relative_count(relbgn,
511 relacount, relsiz, basebgn, lmp,
512 textrel, 0);
513 relacount = 0;
514 } else {
515 relbgn = elf_reloc_relative(relbgn, relend,
516 relsiz, basebgn, lmp, textrel, 0);
517 }
518 if (relbgn >= relend)
519 break;
520 rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info, M_MACH);
521 }
522
523 roffset = ((Rel *)relbgn)->r_offset;
524
525 /*
526 * If this is a shared object, add the base address to offset.
527 */
528 if (!(FLAGS(lmp) & FLG_RT_FIXED)) {
529 /*
530 * If we're processing lazy bindings, we have to step
531 * through the plt entries and add the base address
532 * to the corresponding got entry.
533 */
534 if (plthint && (plt == 0) &&
535 (rtype == R_386_JMP_SLOT) &&
536 ((MODE(lmp) & RTLD_NOW) == 0)) {
537 relbgn = elf_reloc_relative_count(relbgn,
538 plthint, relsiz, basebgn, lmp, textrel, 0);
539 plthint = 0;
540 continue;
541 }
542 roffset += basebgn;
543 }
544
545 rsymndx = ELF_R_SYM(((Rel *)relbgn)->r_info);
546 rel = (Rel *)relbgn;
547 relbgn += relsiz;
548
549 /*
550 * Optimizations.
551 */
552 if (rtype == R_386_NONE)
553 continue;
554 if (noplt && ((ulong_t)rel >= pltbgn) &&
555 ((ulong_t)rel < pltend)) {
556 relbgn = pltend;
557 continue;
558 }
559
560 /*
561 * If we're promoting plts, determine if this one has already
562 * been written.
563 */
564 if (plt && ((*(ulong_t *)roffset < _pltbgn) ||
565 (*(ulong_t *)roffset > _pltend)))
566 continue;
567
568 /*
569 * If this relocation is not against part of the image
570 * mapped into memory we skip it.
571 */
572 if ((mpp = find_segment((caddr_t)roffset, lmp)) == NULL) {
573 elf_reloc_bad(lmp, (void *)rel, rtype, roffset,
574 rsymndx);
575 continue;
576 }
577
578 binfo = 0;
579 /*
580 * If a symbol index is specified then get the symbol table
581 * entry, locate the symbol definition, and determine its
582 * address.
583 */
584 if (rsymndx) {
585 /*
586 * If a Syminfo section is provided, determine if this
587 * symbol is deferred, and if so, skip this relocation.
588 */
589 if (sip && is_sym_deferred((ulong_t)rel, basebgn, lmp,
590 textrel, sip, rsymndx))
591 continue;
592
593 /*
594 * Get the local symbol table entry.
595 */
596 symref = (Sym *)((ulong_t)SYMTAB(lmp) +
597 (rsymndx * SYMENT(lmp)));
598
599 /*
600 * If this is a local symbol, just use the base address.
601 * (we should have no local relocations in the
602 * executable).
603 */
604 if (ELF_ST_BIND(symref->st_info) == STB_LOCAL) {
605 value = basebgn;
606 name = NULL;
607
608 /*
609 * Special case TLS relocations.
610 */
611 if (rtype == R_386_TLS_DTPMOD32) {
612 /*
613 * Use the TLS modid.
614 */
615 value = TLSMODID(lmp);
616
617 } else if (rtype == R_386_TLS_TPOFF) {
618 if ((value = elf_static_tls(lmp, symref,
619 rel, rtype, 0, roffset, 0)) == 0) {
620 ret = 0;
621 break;
622 }
623 }
624 } else {
625 /*
626 * If the symbol index is equal to the previous
627 * symbol index relocation we processed then
628 * reuse the previous values. (Note that there
629 * have been cases where a relocation exists
630 * against a copy relocation symbol, our ld(1)
631 * should optimize this away, but make sure we
632 * don't use the same symbol information should
633 * this case exist).
634 */
635 if ((rsymndx == psymndx) &&
636 (rtype != R_386_COPY)) {
637 /* LINTED */
638 if (psymdef == 0) {
639 DBG_CALL(Dbg_bind_weak(lmp,
640 (Addr)roffset, (Addr)
641 (roffset - basebgn), name));
642 continue;
643 }
644 /* LINTED */
645 value = pvalue;
646 /* LINTED */
647 name = pname;
648 /* LINTED */
649 symdef = psymdef;
650 /* LINTED */
651 symref = psymref;
652 /* LINTED */
653 _lmp = plmp;
654 /* LINTED */
655 binfo = pbinfo;
656
657 if ((LIST(_lmp)->lm_tflags |
658 AFLAGS(_lmp)) &
659 LML_TFLG_AUD_SYMBIND) {
660 value = audit_symbind(lmp, _lmp,
661 /* LINTED */
662 symdef, dsymndx, value,
663 &sb_flags);
664 }
665 } else {
666 Slookup sl;
667 Sresult sr;
668
669 /*
670 * Lookup the symbol definition.
671 * Initialize the symbol lookup, and
672 * symbol result, data structures.
673 */
674 name = (char *)(STRTAB(lmp) +
675 symref->st_name);
676
677 SLOOKUP_INIT(sl, name, lmp, 0,
678 ld_entry_cnt, 0, rsymndx, symref,
679 rtype, LKUP_STDRELOC);
680 SRESULT_INIT(sr, name);
681 symdef = NULL;
682
683 if (lookup_sym(&sl, &sr, &binfo,
684 in_nfavl)) {
685 name = (char *)sr.sr_name;
686 _lmp = sr.sr_dmap;
687 symdef = sr.sr_sym;
688 }
689
690 /*
691 * If the symbol is not found and the
692 * reference was not to a weak symbol,
693 * report an error. Weak references
694 * may be unresolved.
695 */
696 /* BEGIN CSTYLED */
697 if (symdef == 0) {
698 if (sl.sl_bind != STB_WEAK) {
699 if (elf_reloc_error(lmp, name,
700 rel, binfo))
701 continue;
702
703 ret = 0;
704 break;
705
706 } else {
707 psymndx = rsymndx;
708 psymdef = 0;
709
710 DBG_CALL(Dbg_bind_weak(lmp,
711 (Addr)roffset, (Addr)
712 (roffset - basebgn), name));
713 continue;
714 }
715 }
716 /* END CSTYLED */
717
718 /*
719 * If symbol was found in an object
720 * other than the referencing object
721 * then record the binding.
722 */
723 if ((lmp != _lmp) && ((FLAGS1(_lmp) &
724 FL1_RT_NOINIFIN) == 0)) {
725 if (aplist_test(&bound, _lmp,
726 AL_CNT_RELBIND) == 0) {
727 ret = 0;
728 break;
729 }
730 }
731
732 /*
733 * Calculate the location of definition;
734 * symbol value plus base address of
735 * containing shared object.
736 */
737 if (IS_SIZE(rtype))
738 value = symdef->st_size;
739 else
740 value = symdef->st_value;
741
742 if (!(FLAGS(_lmp) & FLG_RT_FIXED) &&
743 !(IS_SIZE(rtype)) &&
744 (symdef->st_shndx != SHN_ABS) &&
745 (ELF_ST_TYPE(symdef->st_info) !=
746 STT_TLS))
747 value += ADDR(_lmp);
748
749 /*
750 * Retain this symbol index and the
751 * value in case it can be used for the
752 * subsequent relocations.
753 */
754 if (rtype != R_386_COPY) {
755 psymndx = rsymndx;
756 pvalue = value;
757 pname = name;
758 psymdef = symdef;
759 psymref = symref;
760 plmp = _lmp;
761 pbinfo = binfo;
762 }
763 if ((LIST(_lmp)->lm_tflags |
764 AFLAGS(_lmp)) &
765 LML_TFLG_AUD_SYMBIND) {
766 dsymndx = (((uintptr_t)symdef -
767 (uintptr_t)SYMTAB(_lmp)) /
768 SYMENT(_lmp));
769 value = audit_symbind(lmp, _lmp,
770 symdef, dsymndx, value,
771 &sb_flags);
772 }
773 }
774
775 /*
776 * If relocation is PC-relative, subtract
777 * offset address.
778 */
779 if (IS_PC_RELATIVE(rtype))
780 value -= roffset;
781
782 /*
783 * Special case TLS relocations.
784 */
785 if (rtype == R_386_TLS_DTPMOD32) {
786 /*
787 * Relocation value is the TLS modid.
788 */
789 value = TLSMODID(_lmp);
790
791 } else if (rtype == R_386_TLS_TPOFF) {
792 if ((value = elf_static_tls(_lmp,
793 symdef, rel, rtype, name, roffset,
794 value)) == 0) {
795 ret = 0;
796 break;
797 }
798 }
799 }
800 } else {
801 /*
802 * Special cases.
803 */
804 if (rtype == R_386_TLS_DTPMOD32) {
805 /*
806 * TLS relocation value is the TLS modid.
807 */
808 value = TLSMODID(lmp);
809 } else
810 value = basebgn;
811
812 name = NULL;
813 }
814
815 DBG_CALL(Dbg_reloc_in(LIST(lmp), ELF_DBG_RTLD, M_MACH,
816 M_REL_SHT_TYPE, rel, NULL, 0, name));
817
818 /*
819 * Make sure the segment is writable.
820 */
821 if (((mpp->mr_prot & PROT_WRITE) == 0) &&
822 ((set_prot(lmp, mpp, 1) == 0) ||
823 (aplist_append(textrel, mpp, AL_CNT_TEXTREL) == NULL))) {
824 ret = 0;
825 break;
826 }
827
828 /*
829 * Call relocation routine to perform required relocation.
830 */
831 switch (rtype) {
832 case R_386_COPY:
833 if (elf_copy_reloc(name, symref, lmp, (void *)roffset,
834 symdef, _lmp, (const void *)value) == 0)
835 ret = 0;
836 break;
837 case R_386_JMP_SLOT:
838 if (((LIST(lmp)->lm_tflags | AFLAGS(lmp)) &
839 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) &&
840 AUDINFO(lmp)->ai_dynplts) {
841 int fail = 0;
842 int pltndx = (((ulong_t)rel -
843 (uintptr_t)JMPREL(lmp)) / relsiz);
844 int symndx = (((uintptr_t)symdef -
845 (uintptr_t)SYMTAB(_lmp)) / SYMENT(_lmp));
846
847 (void) elf_plt_trace_write(roffset, lmp, _lmp,
848 symdef, symndx, pltndx, (caddr_t)value,
849 sb_flags, &fail);
850 if (fail)
851 ret = 0;
852 } else {
853 /*
854 * Write standard PLT entry to jump directly
855 * to newly bound function.
856 */
857 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp),
858 ELF_DBG_RTLD, (Xword)roffset,
859 (Xword)value));
860 *(ulong_t *)roffset = value;
861 }
862 break;
863 default:
864 /*
865 * Write the relocation out.
866 */
867 if (do_reloc_rtld(rtype, (uchar_t *)roffset,
868 (Word *)&value, name, NAME(lmp), LIST(lmp)) == 0)
869 ret = 0;
870
871 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), ELF_DBG_RTLD,
872 (Xword)roffset, (Xword)value));
873 }
874
875 if ((ret == 0) &&
876 ((LIST(lmp)->lm_flags & LML_FLG_TRC_WARN) == 0))
877 break;
878
879 if (binfo) {
880 DBG_CALL(Dbg_bind_global(lmp, (Addr)roffset,
881 (Off)(roffset - basebgn), (Xword)(-1), PLT_T_FULL,
882 _lmp, (Addr)value, symdef->st_value, name, binfo));
883 }
884 }
885
886 return (relocate_finish(lmp, bound, ret));
887 }
888
889 /*
890 * Initialize the first few got entries so that function calls go to
891 * elf_rtbndr:
892 *
893 * GOT[GOT_XLINKMAP] = the address of the link map
894 * GOT[GOT_XRTLD] = the address of rtbinder
895 */
896 void
897 elf_plt_init(void *got, caddr_t l)
898 {
899 uint_t *_got;
900 /* LINTED */
901 Rt_map *lmp = (Rt_map *)l;
902
903 _got = (uint_t *)got + M_GOT_XLINKMAP;
904 *_got = (uint_t)lmp;
905 _got = (uint_t *)got + M_GOT_XRTLD;
906 *_got = (uint_t)elf_rtbndr;
907 }
908
909 /*
910 * For SVR4 Intel compatability. USL uses /usr/lib/libc.so.1 as the run-time
911 * linker, so the interpreter's address will differ from /usr/lib/ld.so.1.
912 * Further, USL has special _iob[] and _ctype[] processing that makes up for the
913 * fact that these arrays do not have associated copy relocations. So we try
914 * and make up for that here. Any relocations found will be added to the global
915 * copy relocation list and will be processed in setup().
916 */
917 static int
918 _elf_copy_reloc(const char *name, Rt_map *rlmp, Rt_map *dlmp)
919 {
920 Sym *symref, *symdef;
921 caddr_t ref, def;
922 Rt_map *_lmp;
923 Rel rel;
924 Slookup sl;
925 Sresult sr;
926 uint_t binfo;
927
928 /*
929 * Determine if the special symbol exists as a reference in the dynamic
930 * executable, and that an associated definition exists in libc.so.1.
931 *
932 * Initialize the symbol lookup, and symbol result, data structures.
933 */
934 SLOOKUP_INIT(sl, name, rlmp, rlmp, ld_entry_cnt, 0, 0, 0, 0,
935 LKUP_FIRST);
936 SRESULT_INIT(sr, name);
937
938 if (lookup_sym(&sl, &sr, &binfo, NULL) == 0)
939 return (1);
940 symref = sr.sr_sym;
941
942 SLOOKUP_INIT(sl, name, rlmp, dlmp, ld_entry_cnt, 0, 0, 0, 0,
943 LKUP_DEFT);
944 SRESULT_INIT(sr, name);
945
946 if (lookup_sym(&sl, &sr, &binfo, NULL) == 0)
947 return (1);
948
949 _lmp = sr.sr_dmap;
950 symdef = sr.sr_sym;
951
952 if (strcmp(NAME(sr.sr_dmap), MSG_ORIG(MSG_PTH_LIBC)))
953 return (1);
954
955 /*
956 * Determine the reference and definition addresses.
957 */
958 ref = (void *)(symref->st_value);
959 if (!(FLAGS(rlmp) & FLG_RT_FIXED))
960 ref += ADDR(rlmp);
961 def = (void *)(symdef->st_value);
962 if (!(FLAGS(sr.sr_dmap) & FLG_RT_FIXED))
963 def += ADDR(_lmp);
964
965 /*
966 * Set up a relocation entry for debugging and call the generic copy
967 * relocation function to provide symbol size error checking and to
968 * record the copy relocation that must be performed.
969 */
970 rel.r_offset = (Addr)ref;
971 rel.r_info = (Word)R_386_COPY;
972 DBG_CALL(Dbg_reloc_in(LIST(rlmp), ELF_DBG_RTLD, M_MACH, M_REL_SHT_TYPE,
973 &rel, NULL, 0, name));
974
975 return (elf_copy_reloc((char *)name, symref, rlmp, (void *)ref, symdef,
976 _lmp, (void *)def));
977 }
978
979 int
980 elf_copy_gen(Rt_map *lmp)
981 {
982 if (interp && ((ulong_t)interp->i_faddr !=
983 r_debug.rtd_rdebug.r_ldbase) &&
984 !(strcmp(interp->i_name, MSG_ORIG(MSG_PTH_LIBC)))) {
985
986 DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, 0,
987 DBG_REL_START));
988
989 if (_elf_copy_reloc(MSG_ORIG(MSG_SYM_CTYPE), lmp,
990 (Rt_map *)NEXT(lmp)) == 0)
991 return (0);
992 if (_elf_copy_reloc(MSG_ORIG(MSG_SYM_IOB), lmp,
993 (Rt_map *)NEXT(lmp)) == 0)
994 return (0);
995 }
996 return (1);
997 }
998
999 /*
1000 * Plt writing interface to allow debugging initialization to be generic.
1001 */
1002 Pltbindtype
1003 /* ARGSUSED1 */
1004 elf_plt_write(uintptr_t addr, uintptr_t vaddr, void *rptr, uintptr_t symval,
1005 Xword pltndx)
1006 {
1007 Rel *rel = (Rel*)rptr;
1008 uintptr_t pltaddr;
1009
1010 pltaddr = addr + rel->r_offset;
1011 *(ulong_t *)pltaddr = (ulong_t)symval;
1012 DBG_CALL(pltcntfull++);
1013 return (PLT_T_FULL);
1014 }
1015
1016 /*
1017 * Provide a machine specific interface to the conversion routine. By calling
1018 * the machine specific version, rather than the generic version, we insure that
1019 * the data tables/strings for all known machine versions aren't dragged into
1020 * ld.so.1.
1021 */
1022 const char *
1023 _conv_reloc_type(uint_t rel)
1024 {
1025 static Conv_inv_buf_t inv_buf;
1026
1027 return (conv_reloc_386_type(rel, 0, &inv_buf));
1028 }