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) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2012, Joyent, Inc. All rights reserved.
25 */
26
27 /*
28 * amd64 machine dependent and ELF file class dependent functions.
29 * Contains routines for performing function binding and symbol relocations.
30 */
31
32 #include <stdio.h>
33 #include <sys/elf.h>
34 #include <sys/elf_amd64.h>
35 #include <sys/mman.h>
36 #include <dlfcn.h>
37 #include <synch.h>
38 #include <string.h>
39 #include <debug.h>
40 #include <reloc.h>
41 #include <conv.h>
42 #include "_rtld.h"
43 #include "_audit.h"
44 #include "_elf.h"
45 #include "_inline_gen.h"
46 #include "_inline_reloc.h"
47 #include "msg.h"
48
49 extern void elf_rtbndr(Rt_map *, ulong_t, caddr_t);
50
51 int
52 elf_mach_flags_check(Rej_desc *rej, Ehdr *ehdr)
53 {
54 /*
55 * Check machine type and flags.
56 */
57 if (ehdr->e_flags != 0) {
58 rej->rej_type = SGS_REJ_BADFLAG;
59 rej->rej_info = (uint_t)ehdr->e_flags;
60 return (0);
61 }
62 return (1);
63 }
64
65 void
66 ldso_plt_init(Rt_map *lmp)
67 {
68 /*
69 * There is no need to analyze ld.so because we don't map in any of
70 * its dependencies. However we may map these dependencies in later
71 * (as if ld.so had dlopened them), so initialize the plt and the
72 * permission information.
73 */
74 if (PLTGOT(lmp))
75 elf_plt_init((PLTGOT(lmp)), (caddr_t)lmp);
76 }
77
78 static const uchar_t dyn_plt_template[] = {
79 /* 0x00 */ 0x55, /* pushq %rbp */
80 /* 0x01 */ 0x48, 0x89, 0xe5, /* movq %rsp, %rbp */
81 /* 0x04 */ 0x48, 0x83, 0xec, 0x10, /* subq $0x10, %rsp */
82 /* 0x08 */ 0x4c, 0x8d, 0x1d, 0x00, /* leaq trace_fields(%rip), %r11 */
83 0x00, 0x00, 0x00,
84 /* 0x0f */ 0x4c, 0x89, 0x5d, 0xf8, /* movq %r11, -0x8(%rbp) */
85 /* 0x13 */ 0x49, 0xbb, 0x00, 0x00, /* movq $elf_plt_trace, %r11 */
86 0x00, 0x00, 0x00,
87 0x00, 0x00, 0x00,
88 /* 0x1d */ 0x41, 0xff, 0xe3 /* jmp *%r11 */
89 /* 0x20 */
90 };
91
92 /*
93 * And the virutal outstanding relocations against the
94 * above block are:
95 *
96 * reloc offset Addend symbol
97 * R_AMD64_PC32 0x0b -4 trace_fields
98 * R_AMD64_64 0x15 0 elf_plt_trace
99 */
100
101 #define TRCREL1OFF 0x0b
102 #define TRCREL2OFF 0x15
103
104 int dyn_plt_ent_size = sizeof (dyn_plt_template);
105
106 /*
107 * the dynamic plt entry is:
108 *
109 * pushq %rbp
110 * movq %rsp, %rbp
111 * subq $0x10, %rsp
112 * leaq trace_fields(%rip), %r11
113 * movq %r11, -0x8(%rbp)
114 * movq $elf_plt_trace, %r11
115 * jmp *%r11
116 * dyn_data:
117 * .align 8
118 * uintptr_t reflmp
119 * uintptr_t deflmp
120 * uint_t symndx
121 * uint_t sb_flags
122 * Sym symdef
123 */
124 static caddr_t
125 elf_plt_trace_write(ulong_t roffset, Rt_map *rlmp, Rt_map *dlmp, Sym *sym,
126 uint_t symndx, uint_t pltndx, caddr_t to, uint_t sb_flags, int *fail)
127 {
128 extern int elf_plt_trace();
129 ulong_t got_entry;
130 uchar_t *dyn_plt;
131 uintptr_t *dyndata;
132
133 /*
134 * We only need to add the glue code if there is an auditing
135 * library that is interested in this binding.
136 */
137 dyn_plt = (uchar_t *)((uintptr_t)AUDINFO(rlmp)->ai_dynplts +
138 (pltndx * dyn_plt_ent_size));
139
140 /*
141 * Have we initialized this dynamic plt entry yet? If we haven't do it
142 * now. Otherwise this function has been called before, but from a
143 * different plt (ie. from another shared object). In that case
144 * we just set the plt to point to the new dyn_plt.
145 */
146 if (*dyn_plt == 0) {
147 Sym *symp;
148 Xword symvalue;
149 Lm_list *lml = LIST(rlmp);
150
151 (void) memcpy((void *)dyn_plt, dyn_plt_template,
152 sizeof (dyn_plt_template));
153 dyndata = (uintptr_t *)((uintptr_t)dyn_plt +
154 ROUND(sizeof (dyn_plt_template), M_WORD_ALIGN));
155
156 /*
157 * relocate:
158 * leaq trace_fields(%rip), %r11
159 * R_AMD64_PC32 0x0b -4 trace_fields
160 */
161 symvalue = (Xword)((uintptr_t)dyndata -
162 (uintptr_t)(&dyn_plt[TRCREL1OFF]) - 4);
163 if (do_reloc_rtld(R_AMD64_PC32, &dyn_plt[TRCREL1OFF],
164 &symvalue, MSG_ORIG(MSG_SYM_LADYNDATA),
165 MSG_ORIG(MSG_SPECFIL_DYNPLT), lml) == 0) {
166 *fail = 1;
167 return (0);
168 }
169
170 /*
171 * relocating:
172 * movq $elf_plt_trace, %r11
173 * R_AMD64_64 0x15 0 elf_plt_trace
174 */
175 symvalue = (Xword)elf_plt_trace;
176 if (do_reloc_rtld(R_AMD64_64, &dyn_plt[TRCREL2OFF],
177 &symvalue, MSG_ORIG(MSG_SYM_ELFPLTTRACE),
178 MSG_ORIG(MSG_SPECFIL_DYNPLT), lml) == 0) {
179 *fail = 1;
180 return (0);
181 }
182
183 *dyndata++ = (uintptr_t)rlmp;
184 *dyndata++ = (uintptr_t)dlmp;
185 *dyndata = (uintptr_t)(((uint64_t)sb_flags << 32) | symndx);
186 dyndata++;
187 symp = (Sym *)dyndata;
188 *symp = *sym;
189 symp->st_value = (Addr)to;
190 }
191
192 got_entry = (ulong_t)roffset;
193 *(ulong_t *)got_entry = (ulong_t)dyn_plt;
194 return ((caddr_t)dyn_plt);
195 }
196
197 /*
198 * Function binding routine - invoked on the first call to a function through
199 * the procedure linkage table;
200 * passes first through an assembly language interface.
201 *
202 * Takes the offset into the relocation table of the associated
203 * relocation entry and the address of the link map (rt_private_map struct)
204 * for the entry.
205 *
206 * Returns the address of the function referenced after re-writing the PLT
207 * entry to invoke the function directly.
208 *
209 * On error, causes process to terminate with a signal.
210 */
211 ulong_t
212 elf_bndr(Rt_map *lmp, ulong_t pltndx, caddr_t from)
213 {
214 Rt_map *nlmp, *llmp;
215 ulong_t addr, reloff, symval, rsymndx;
216 char *name;
217 Rela *rptr;
218 Sym *rsym, *nsym;
219 uint_t binfo, sb_flags = 0, dbg_class;
220 Slookup sl;
221 Sresult sr;
222 int entry, lmflags;
223 Lm_list *lml;
224
225 /*
226 * For compatibility with libthread (TI_VERSION 1) we track the entry
227 * value. A zero value indicates we have recursed into ld.so.1 to
228 * further process a locking request. Under this recursion we disable
229 * tsort and cleanup activities.
230 */
231 entry = enter(0);
232
233 lml = LIST(lmp);
234 if ((lmflags = lml->lm_flags) & LML_FLG_RTLDLM) {
235 dbg_class = dbg_desc->d_class;
236 dbg_desc->d_class = 0;
237 }
238
239 /*
240 * Perform some basic sanity checks. If the relocation offset is
241 * invalid then its possible someone has walked over the .got entries.
242 */
243 if (pltndx > (ulong_t)PLTRELSZ(lmp) / (ulong_t)RELENT(lmp)) {
244 Conv_inv_buf_t inv_buf;
245
246 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_PLTREF),
247 conv_reloc_amd64_type(R_AMD64_JUMP_SLOT, 0, &inv_buf),
248 EC_NATPTR(lmp), EC_XWORD(pltndx), EC_NATPTR(from));
249 rtldexit(lml, 1);
250 }
251 reloff = pltndx * (ulong_t)RELENT(lmp);
252
253 /*
254 * Use relocation entry to get symbol table entry and symbol name.
255 */
256 addr = (ulong_t)JMPREL(lmp);
257 rptr = (Rela *)(addr + reloff);
258 rsymndx = ELF_R_SYM(rptr->r_info);
259 rsym = (Sym *)((ulong_t)SYMTAB(lmp) + (rsymndx * SYMENT(lmp)));
260 name = (char *)(STRTAB(lmp) + rsym->st_name);
261
262 /*
263 * Determine the last link-map of this list, this'll be the starting
264 * point for any tsort() processing.
265 */
266 llmp = lml->lm_tail;
267
268 /*
269 * Find definition for symbol. Initialize the symbol lookup, and
270 * symbol result, data structures.
271 */
272 SLOOKUP_INIT(sl, name, lmp, lml->lm_head, ld_entry_cnt, 0,
273 rsymndx, rsym, 0, LKUP_DEFT);
274 SRESULT_INIT(sr, name);
275
276 if (lookup_sym(&sl, &sr, &binfo, NULL) == 0) {
277 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp),
278 demangle(name));
279 rtldexit(lml, 1);
280 }
281
282 name = (char *)sr.sr_name;
283 nlmp = sr.sr_dmap;
284 nsym = sr.sr_sym;
285
286 symval = nsym->st_value;
287
288 if (!(FLAGS(nlmp) & FLG_RT_FIXED) &&
289 (nsym->st_shndx != SHN_ABS))
290 symval += ADDR(nlmp);
291 if ((lmp != nlmp) && ((FLAGS1(nlmp) & FL1_RT_NOINIFIN) == 0)) {
292 /*
293 * Record that this new link map is now bound to the caller.
294 */
295 if (bind_one(lmp, nlmp, BND_REFER) == 0)
296 rtldexit(lml, 1);
297 }
298
299 if ((lml->lm_tflags | AFLAGS(lmp) | AFLAGS(nlmp)) &
300 LML_TFLG_AUD_SYMBIND) {
301 uint_t symndx = (((uintptr_t)nsym -
302 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp));
303 symval = audit_symbind(lmp, nlmp, nsym, symndx, symval,
304 &sb_flags);
305 }
306
307 if (!(rtld_flags & RT_FL_NOBIND)) {
308 addr = rptr->r_offset;
309 if (!(FLAGS(lmp) & FLG_RT_FIXED))
310 addr += ADDR(lmp);
311 if (((lml->lm_tflags | AFLAGS(lmp)) &
312 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) &&
313 AUDINFO(lmp)->ai_dynplts) {
314 int fail = 0;
315 uint_t pltndx = reloff / sizeof (Rela);
316 uint_t symndx = (((uintptr_t)nsym -
317 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp));
318
319 symval = (ulong_t)elf_plt_trace_write(addr, lmp, nlmp,
320 nsym, symndx, pltndx, (caddr_t)symval, sb_flags,
321 &fail);
322 if (fail)
323 rtldexit(lml, 1);
324 } else {
325 /*
326 * Write standard PLT entry to jump directly
327 * to newly bound function.
328 */
329 *(ulong_t *)addr = symval;
330 }
331 }
332
333 /*
334 * Print binding information and rebuild PLT entry.
335 */
336 DBG_CALL(Dbg_bind_global(lmp, (Addr)from, (Off)(from - ADDR(lmp)),
337 (Xword)(reloff / sizeof (Rela)), PLT_T_FULL, nlmp, (Addr)symval,
338 nsym->st_value, name, binfo));
339
340 /*
341 * Complete any processing for newly loaded objects. Note we don't
342 * know exactly where any new objects are loaded (we know the object
343 * that supplied the symbol, but others may have been loaded lazily as
344 * we searched for the symbol), so sorting starts from the last
345 * link-map know on entry to this routine.
346 */
347 if (entry)
348 load_completion(llmp);
349
350 /*
351 * Some operations like dldump() or dlopen()'ing a relocatable object
352 * result in objects being loaded on rtld's link-map, make sure these
353 * objects are initialized also.
354 */
355 if ((LIST(nlmp)->lm_flags & LML_FLG_RTLDLM) && LIST(nlmp)->lm_init)
356 load_completion(nlmp);
357
358 /*
359 * Make sure the object to which we've bound has had it's .init fired.
360 * Cleanup before return to user code.
361 */
362 if (entry) {
363 is_dep_init(nlmp, lmp);
364 leave(lml, 0);
365 }
366
367 if (lmflags & LML_FLG_RTLDLM)
368 dbg_desc->d_class = dbg_class;
369
370 return (symval);
371 }
372
373 /*
374 * Read and process the relocations for one link object, we assume all
375 * relocation sections for loadable segments are stored contiguously in
376 * the file.
377 */
378 int
379 elf_reloc(Rt_map *lmp, uint_t plt, int *in_nfavl, APlist **textrel)
380 {
381 ulong_t relbgn, relend, relsiz, basebgn;
382 ulong_t pltbgn, pltend, _pltbgn, _pltend;
383 ulong_t roffset, rsymndx, psymndx = 0;
384 ulong_t dsymndx;
385 uchar_t rtype;
386 long reladd, value, pvalue;
387 Sym *symref, *psymref, *symdef, *psymdef;
388 Syminfo *sip;
389 char *name, *pname;
390 Rt_map *_lmp, *plmp;
391 int ret = 1, noplt = 0;
392 int relacount = RELACOUNT(lmp), plthint = 0;
393 Rela *rel;
394 uint_t binfo, pbinfo;
395 APlist *bound = NULL;
396
397 /*
398 * Although only necessary for lazy binding, initialize the first
399 * global offset entry to go to elf_rtbndr(). dbx(1) seems
400 * to find this useful.
401 */
402 if ((plt == 0) && PLTGOT(lmp)) {
403 mmapobj_result_t *mpp;
404
405 /*
406 * Make sure the segment is writable.
407 */
408 if ((((mpp =
409 find_segment((caddr_t)PLTGOT(lmp), lmp)) != NULL) &&
410 ((mpp->mr_prot & PROT_WRITE) == 0)) &&
411 ((set_prot(lmp, mpp, 1) == 0) ||
412 (aplist_append(textrel, mpp, AL_CNT_TEXTREL) == NULL)))
413 return (0);
414
415 elf_plt_init(PLTGOT(lmp), (caddr_t)lmp);
416 }
417
418 /*
419 * Initialize the plt start and end addresses.
420 */
421 if ((pltbgn = (ulong_t)JMPREL(lmp)) != 0)
422 pltend = pltbgn + (ulong_t)(PLTRELSZ(lmp));
423
424 relsiz = (ulong_t)(RELENT(lmp));
425 basebgn = ADDR(lmp);
426
427 if (PLTRELSZ(lmp))
428 plthint = PLTRELSZ(lmp) / relsiz;
429
430 /*
431 * If we've been called upon to promote an RTLD_LAZY object to an
432 * RTLD_NOW then we're only interested in scaning the .plt table.
433 * An uninitialized .plt is the case where the associated got entry
434 * points back to the plt itself. Determine the range of the real .plt
435 * entries using the _PROCEDURE_LINKAGE_TABLE_ symbol.
436 */
437 if (plt) {
438 Slookup sl;
439 Sresult sr;
440
441 relbgn = pltbgn;
442 relend = pltend;
443 if (!relbgn || (relbgn == relend))
444 return (1);
445
446 /*
447 * Initialize the symbol lookup, and symbol result, data
448 * structures.
449 */
450 SLOOKUP_INIT(sl, MSG_ORIG(MSG_SYM_PLT), lmp, lmp, ld_entry_cnt,
451 elf_hash(MSG_ORIG(MSG_SYM_PLT)), 0, 0, 0, LKUP_DEFT);
452 SRESULT_INIT(sr, MSG_ORIG(MSG_SYM_PLT));
453
454 if (elf_find_sym(&sl, &sr, &binfo, NULL) == 0)
455 return (1);
456
457 symdef = sr.sr_sym;
458 _pltbgn = symdef->st_value;
459 if (!(FLAGS(lmp) & FLG_RT_FIXED) &&
460 (symdef->st_shndx != SHN_ABS))
461 _pltbgn += basebgn;
462 _pltend = _pltbgn + (((PLTRELSZ(lmp) / relsiz)) *
463 M_PLT_ENTSIZE) + M_PLT_RESERVSZ;
464
465 } else {
466 /*
467 * The relocation sections appear to the run-time linker as a
468 * single table. Determine the address of the beginning and end
469 * of this table. There are two different interpretations of
470 * the ABI at this point:
471 *
472 * o The REL table and its associated RELSZ indicate the
473 * concatenation of *all* relocation sections (this is the
474 * model our link-editor constructs).
475 *
476 * o The REL table and its associated RELSZ indicate the
477 * concatenation of all *but* the .plt relocations. These
478 * relocations are specified individually by the JMPREL and
479 * PLTRELSZ entries.
480 *
481 * Determine from our knowledege of the relocation range and
482 * .plt range, the range of the total relocation table. Note
483 * that one other ABI assumption seems to be that the .plt
484 * relocations always follow any other relocations, the
485 * following range checking drops that assumption.
486 */
487 relbgn = (ulong_t)(REL(lmp));
488 relend = relbgn + (ulong_t)(RELSZ(lmp));
489 if (pltbgn) {
490 if (!relbgn || (relbgn > pltbgn))
491 relbgn = pltbgn;
492 if (!relbgn || (relend < pltend))
493 relend = pltend;
494 }
495 }
496 if (!relbgn || (relbgn == relend)) {
497 DBG_CALL(Dbg_reloc_run(lmp, 0, plt, DBG_REL_NONE));
498 return (1);
499 }
500 DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, plt, DBG_REL_START));
501
502 /*
503 * If we're processing a dynamic executable in lazy mode there is no
504 * need to scan the .rel.plt table, however if we're processing a shared
505 * object in lazy mode the .got addresses associated to each .plt must
506 * be relocated to reflect the location of the shared object.
507 */
508 if (pltbgn && ((MODE(lmp) & RTLD_NOW) == 0) &&
509 (FLAGS(lmp) & FLG_RT_FIXED))
510 noplt = 1;
511
512 sip = SYMINFO(lmp);
513 /*
514 * Loop through relocations.
515 */
516 while (relbgn < relend) {
517 mmapobj_result_t *mpp;
518 uint_t sb_flags = 0;
519
520 rtype = ELF_R_TYPE(((Rela *)relbgn)->r_info, M_MACH);
521
522 /*
523 * If this is a RELATIVE relocation in a shared object (the
524 * common case), and if we are not debugging, then jump into a
525 * tighter relocation loop (elf_reloc_relative).
526 */
527 if ((rtype == R_AMD64_RELATIVE) &&
528 ((FLAGS(lmp) & FLG_RT_FIXED) == 0) && (DBG_ENABLED == 0)) {
529 if (relacount) {
530 relbgn = elf_reloc_relative_count(relbgn,
531 relacount, relsiz, basebgn, lmp,
532 textrel, 0);
533 relacount = 0;
534 } else {
535 relbgn = elf_reloc_relative(relbgn, relend,
536 relsiz, basebgn, lmp, textrel, 0);
537 }
538 if (relbgn >= relend)
539 break;
540 rtype = ELF_R_TYPE(((Rela *)relbgn)->r_info, M_MACH);
541 }
542
543 roffset = ((Rela *)relbgn)->r_offset;
544
545 /*
546 * If this is a shared object, add the base address to offset.
547 */
548 if (!(FLAGS(lmp) & FLG_RT_FIXED)) {
549 /*
550 * If we're processing lazy bindings, we have to step
551 * through the plt entries and add the base address
552 * to the corresponding got entry.
553 */
554 if (plthint && (plt == 0) &&
555 (rtype == R_AMD64_JUMP_SLOT) &&
556 ((MODE(lmp) & RTLD_NOW) == 0)) {
557 relbgn = elf_reloc_relative_count(relbgn,
558 plthint, relsiz, basebgn, lmp, textrel, 1);
559 plthint = 0;
560 continue;
561 }
562 roffset += basebgn;
563 }
564
565 reladd = (long)(((Rela *)relbgn)->r_addend);
566 rsymndx = ELF_R_SYM(((Rela *)relbgn)->r_info);
567 rel = (Rela *)relbgn;
568 relbgn += relsiz;
569
570 /*
571 * Optimizations.
572 */
573 if (rtype == R_AMD64_NONE)
574 continue;
575 if (noplt && ((ulong_t)rel >= pltbgn) &&
576 ((ulong_t)rel < pltend)) {
577 relbgn = pltend;
578 continue;
579 }
580
581 /*
582 * If we're promoting plts, determine if this one has already
583 * been written.
584 */
585 if (plt && ((*(ulong_t *)roffset < _pltbgn) ||
586 (*(ulong_t *)roffset > _pltend)))
587 continue;
588
589 /*
590 * If this relocation is not against part of the image
591 * mapped into memory we skip it.
592 */
593 if ((mpp = find_segment((caddr_t)roffset, lmp)) == NULL) {
594 elf_reloc_bad(lmp, (void *)rel, rtype, roffset,
595 rsymndx);
596 continue;
597 }
598
599 binfo = 0;
600 /*
601 * If a symbol index is specified then get the symbol table
602 * entry, locate the symbol definition, and determine its
603 * address.
604 */
605 if (rsymndx) {
606 /*
607 * If a Syminfo section is provided, determine if this
608 * symbol is deferred, and if so, skip this relocation.
609 */
610 if (sip && is_sym_deferred((ulong_t)rel, basebgn, lmp,
611 textrel, sip, rsymndx))
612 continue;
613
614 /*
615 * Get the local symbol table entry.
616 */
617 symref = (Sym *)((ulong_t)SYMTAB(lmp) +
618 (rsymndx * SYMENT(lmp)));
619
620 /*
621 * If this is a local symbol, just use the base address.
622 * (we should have no local relocations in the
623 * executable).
624 */
625 if (ELF_ST_BIND(symref->st_info) == STB_LOCAL) {
626 value = basebgn;
627 name = NULL;
628
629 /*
630 * Special case TLS relocations.
631 */
632 if (rtype == R_AMD64_DTPMOD64) {
633 /*
634 * Use the TLS modid.
635 */
636 value = TLSMODID(lmp);
637
638 } else if ((rtype == R_AMD64_TPOFF64) ||
639 (rtype == R_AMD64_TPOFF32)) {
640 if ((value = elf_static_tls(lmp, symref,
641 rel, rtype, 0, roffset, 0)) == 0) {
642 ret = 0;
643 break;
644 }
645 }
646 } else {
647 /*
648 * If the symbol index is equal to the previous
649 * symbol index relocation we processed then
650 * reuse the previous values. (Note that there
651 * have been cases where a relocation exists
652 * against a copy relocation symbol, our ld(1)
653 * should optimize this away, but make sure we
654 * don't use the same symbol information should
655 * this case exist).
656 */
657 if ((rsymndx == psymndx) &&
658 (rtype != R_AMD64_COPY)) {
659 /* LINTED */
660 if (psymdef == 0) {
661 DBG_CALL(Dbg_bind_weak(lmp,
662 (Addr)roffset, (Addr)
663 (roffset - basebgn), name));
664 continue;
665 }
666 /* LINTED */
667 value = pvalue;
668 /* LINTED */
669 name = pname;
670 /* LINTED */
671 symdef = psymdef;
672 /* LINTED */
673 symref = psymref;
674 /* LINTED */
675 _lmp = plmp;
676 /* LINTED */
677 binfo = pbinfo;
678
679 if ((LIST(_lmp)->lm_tflags |
680 AFLAGS(_lmp)) &
681 LML_TFLG_AUD_SYMBIND) {
682 value = audit_symbind(lmp, _lmp,
683 /* LINTED */
684 symdef, dsymndx, value,
685 &sb_flags);
686 }
687 } else {
688 Slookup sl;
689 Sresult sr;
690
691 /*
692 * Lookup the symbol definition.
693 * Initialize the symbol lookup, and
694 * symbol result, data structure.
695 */
696 name = (char *)(STRTAB(lmp) +
697 symref->st_name);
698
699 SLOOKUP_INIT(sl, name, lmp, 0,
700 ld_entry_cnt, 0, rsymndx, symref,
701 rtype, LKUP_STDRELOC);
702 SRESULT_INIT(sr, name);
703 symdef = NULL;
704
705 if (lookup_sym(&sl, &sr, &binfo,
706 in_nfavl)) {
707 name = (char *)sr.sr_name;
708 _lmp = sr.sr_dmap;
709 symdef = sr.sr_sym;
710 }
711
712 /*
713 * If the symbol is not found and the
714 * reference was not to a weak symbol,
715 * report an error. Weak references
716 * may be unresolved.
717 */
718 /* BEGIN CSTYLED */
719 if (symdef == 0) {
720 if (sl.sl_bind != STB_WEAK) {
721 if (elf_reloc_error(lmp, name,
722 rel, binfo))
723 continue;
724
725 ret = 0;
726 break;
727
728 } else {
729 psymndx = rsymndx;
730 psymdef = 0;
731
732 DBG_CALL(Dbg_bind_weak(lmp,
733 (Addr)roffset, (Addr)
734 (roffset - basebgn), name));
735 continue;
736 }
737 }
738 /* END CSTYLED */
739
740 /*
741 * If symbol was found in an object
742 * other than the referencing object
743 * then record the binding.
744 */
745 if ((lmp != _lmp) && ((FLAGS1(_lmp) &
746 FL1_RT_NOINIFIN) == 0)) {
747 if (aplist_test(&bound, _lmp,
748 AL_CNT_RELBIND) == 0) {
749 ret = 0;
750 break;
751 }
752 }
753
754 /*
755 * Calculate the location of definition;
756 * symbol value plus base address of
757 * containing shared object.
758 */
759 if (IS_SIZE(rtype))
760 value = symdef->st_size;
761 else
762 value = symdef->st_value;
763
764 if (!(FLAGS(_lmp) & FLG_RT_FIXED) &&
765 !(IS_SIZE(rtype)) &&
766 (symdef->st_shndx != SHN_ABS) &&
767 (ELF_ST_TYPE(symdef->st_info) !=
768 STT_TLS))
769 value += ADDR(_lmp);
770
771 /*
772 * Retain this symbol index and the
773 * value in case it can be used for the
774 * subsequent relocations.
775 */
776 if (rtype != R_AMD64_COPY) {
777 psymndx = rsymndx;
778 pvalue = value;
779 pname = name;
780 psymdef = symdef;
781 psymref = symref;
782 plmp = _lmp;
783 pbinfo = binfo;
784 }
785 if ((LIST(_lmp)->lm_tflags |
786 AFLAGS(_lmp)) &
787 LML_TFLG_AUD_SYMBIND) {
788 dsymndx = (((uintptr_t)symdef -
789 (uintptr_t)SYMTAB(_lmp)) /
790 SYMENT(_lmp));
791 value = audit_symbind(lmp, _lmp,
792 symdef, dsymndx, value,
793 &sb_flags);
794 }
795 }
796
797 /*
798 * If relocation is PC-relative, subtract
799 * offset address.
800 */
801 if (IS_PC_RELATIVE(rtype))
802 value -= roffset;
803
804 /*
805 * Special case TLS relocations.
806 */
807 if (rtype == R_AMD64_DTPMOD64) {
808 /*
809 * Relocation value is the TLS modid.
810 */
811 value = TLSMODID(_lmp);
812
813 } else if ((rtype == R_AMD64_TPOFF64) ||
814 (rtype == R_AMD64_TPOFF32)) {
815 if ((value = elf_static_tls(_lmp,
816 symdef, rel, rtype, name, roffset,
817 value)) == 0) {
818 ret = 0;
819 break;
820 }
821 }
822 }
823 } else {
824 /*
825 * Special cases.
826 */
827 if (rtype == R_AMD64_DTPMOD64) {
828 /*
829 * TLS relocation value is the TLS modid.
830 */
831 value = TLSMODID(lmp);
832 } else
833 value = basebgn;
834
835 name = NULL;
836 }
837
838 DBG_CALL(Dbg_reloc_in(LIST(lmp), ELF_DBG_RTLD, M_MACH,
839 M_REL_SHT_TYPE, rel, NULL, 0, name));
840
841 /*
842 * Make sure the segment is writable.
843 */
844 if (((mpp->mr_prot & PROT_WRITE) == 0) &&
845 ((set_prot(lmp, mpp, 1) == 0) ||
846 (aplist_append(textrel, mpp, AL_CNT_TEXTREL) == NULL))) {
847 ret = 0;
848 break;
849 }
850
851 /*
852 * Call relocation routine to perform required relocation.
853 */
854 switch (rtype) {
855 case R_AMD64_COPY:
856 if (elf_copy_reloc(name, symref, lmp, (void *)roffset,
857 symdef, _lmp, (const void *)value) == 0)
858 ret = 0;
859 break;
860 case R_AMD64_JUMP_SLOT:
861 if (((LIST(lmp)->lm_tflags | AFLAGS(lmp)) &
862 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) &&
863 AUDINFO(lmp)->ai_dynplts) {
864 int fail = 0;
865 int pltndx = (((ulong_t)rel -
866 (uintptr_t)JMPREL(lmp)) / relsiz);
867 int symndx = (((uintptr_t)symdef -
868 (uintptr_t)SYMTAB(_lmp)) / SYMENT(_lmp));
869
870 (void) elf_plt_trace_write(roffset, lmp, _lmp,
871 symdef, symndx, pltndx, (caddr_t)value,
872 sb_flags, &fail);
873 if (fail)
874 ret = 0;
875 } else {
876 /*
877 * Write standard PLT entry to jump directly
878 * to newly bound function.
879 */
880 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp),
881 ELF_DBG_RTLD, (Xword)roffset,
882 (Xword)value));
883 *(ulong_t *)roffset = value;
884 }
885 break;
886 default:
887 value += reladd;
888 /*
889 * Write the relocation out.
890 */
891 if (do_reloc_rtld(rtype, (uchar_t *)roffset,
892 (Xword *)&value, name, NAME(lmp), LIST(lmp)) == 0)
893 ret = 0;
894
895 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), ELF_DBG_RTLD,
896 (Xword)roffset, (Xword)value));
897 }
898
899 if ((ret == 0) &&
900 ((LIST(lmp)->lm_flags & LML_FLG_TRC_WARN) == 0))
901 break;
902
903 if (binfo) {
904 DBG_CALL(Dbg_bind_global(lmp, (Addr)roffset,
905 (Off)(roffset - basebgn), (Xword)(-1), PLT_T_FULL,
906 _lmp, (Addr)value, symdef->st_value, name, binfo));
907 }
908 }
909
910 return (relocate_finish(lmp, bound, ret));
911 }
912
913 /*
914 * Initialize the first few got entries so that function calls go to
915 * elf_rtbndr:
916 *
917 * GOT[GOT_XLINKMAP] = the address of the link map
918 * GOT[GOT_XRTLD] = the address of rtbinder
919 */
920 void
921 elf_plt_init(void *got, caddr_t l)
922 {
923 uint64_t *_got;
924 /* LINTED */
925 Rt_map *lmp = (Rt_map *)l;
926
927 _got = (uint64_t *)got + M_GOT_XLINKMAP;
928 *_got = (uint64_t)lmp;
929 _got = (uint64_t *)got + M_GOT_XRTLD;
930 *_got = (uint64_t)elf_rtbndr;
931 }
932
933 /*
934 * Plt writing interface to allow debugging initialization to be generic.
935 */
936 Pltbindtype
937 /* ARGSUSED1 */
938 elf_plt_write(uintptr_t addr, uintptr_t vaddr, void *rptr, uintptr_t symval,
939 Xword pltndx)
940 {
941 Rela *rel = (Rela*)rptr;
942 uintptr_t pltaddr;
943
944 pltaddr = addr + rel->r_offset;
945 *(ulong_t *)pltaddr = (ulong_t)symval + rel->r_addend;
946 DBG_CALL(pltcntfull++);
947 return (PLT_T_FULL);
948 }
949
950 /*
951 * Provide a machine specific interface to the conversion routine. By calling
952 * the machine specific version, rather than the generic version, we insure that
953 * the data tables/strings for all known machine versions aren't dragged into
954 * ld.so.1.
955 */
956 const char *
957 _conv_reloc_type(uint_t rel)
958 {
959 static Conv_inv_buf_t inv_buf;
960
961 return (conv_reloc_amd64_type(rel, 0, &inv_buf));
962 }