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 */
25
26 /* Get the x86 version of the relocation engine */
27 #define DO_RELOC_LIBLD_X86
28
29 #include <string.h>
30 #include <stdio.h>
31 #include <strings.h>
32 #include <sys/elf_amd64.h>
33 #include <debug.h>
34 #include <reloc.h>
35 #include <i386/machdep_x86.h>
36 #include "msg.h"
37 #include "_libld.h"
38
39 /*
40 * This module uses do_reloc_ld() to execute several synthesized relocations.
41 * That function expects to be passed two things that we need to construct
42 * here:
43 *
44 * 1) A Rel_desc descriptor for each relocation type, from which the
45 * rel_rtype field, and nothing else, is obtained. This is easily
46 * handled by constructing the necessary descriptors.
47 *
48 * 2) A function, which called with the Rel_desc descriptor, returns
49 * a string representing the name of the symbol associated with
50 * the descriptor. The usual function for this is ld_reloc_sym_name().
51 * However, that function will not work in this case, as these synthetic
52 * relocations do not have an associated symbol. We supply the
53 * syn_rdesc_sym_name() function to simply return the fixed name.
54 */
55 static Rel_desc rdesc_r_amd64_gotpcrel = {
56 NULL, NULL, NULL, 0, 0, 0, R_AMD64_GOTPCREL };
57 static Rel_desc rdesc_r_amd64_32 = {
58 NULL, NULL, NULL, 0, 0, 0, R_AMD64_32 };
59 static Rel_desc rdesc_r_amd64_pc32 = {
60 NULL, NULL, NULL, 0, 0, 0, R_AMD64_PC32 };
61
62 /*ARGSUSED*/
63 static const char *
syn_rdesc_sym_name(Rel_desc * rdesc)64 syn_rdesc_sym_name(Rel_desc *rdesc)
65 {
66 return (MSG_ORIG(MSG_SYM_PLTENT));
67 }
68
69 /*
70 * Search the GOT index list for a GOT entry with a matching reference and the
71 * proper addend.
72 */
73 static Gotndx *
ld_find_got_ndx(Alist * alp,Gotref gref,Ofl_desc * ofl,Rel_desc * rdesc)74 ld_find_got_ndx(Alist *alp, Gotref gref, Ofl_desc *ofl, Rel_desc *rdesc)
75 {
76 Aliste idx;
77 Gotndx *gnp;
78
79 assert(rdesc != 0);
80
81 if ((gref == GOT_REF_TLSLD) && ofl->ofl_tlsldgotndx)
82 return (ofl->ofl_tlsldgotndx);
83
84 for (ALIST_TRAVERSE(alp, idx, gnp)) {
85 if ((rdesc->rel_raddend == gnp->gn_addend) &&
86 (gnp->gn_gotref == gref)) {
87 return (gnp);
88 }
89 }
90 return (NULL);
91 }
92
93 static Xword
ld_calc_got_offset(Rel_desc * rdesc,Ofl_desc * ofl)94 ld_calc_got_offset(Rel_desc *rdesc, Ofl_desc *ofl)
95 {
96 Os_desc *osp = ofl->ofl_osgot;
97 Sym_desc *sdp = rdesc->rel_sym;
98 Xword gotndx;
99 Gotref gref;
100 Gotndx *gnp;
101
102 if (rdesc->rel_flags & FLG_REL_DTLS)
103 gref = GOT_REF_TLSGD;
104 else if (rdesc->rel_flags & FLG_REL_MTLS)
105 gref = GOT_REF_TLSLD;
106 else if (rdesc->rel_flags & FLG_REL_STLS)
107 gref = GOT_REF_TLSIE;
108 else
109 gref = GOT_REF_GENERIC;
110
111 gnp = ld_find_got_ndx(sdp->sd_GOTndxs, gref, ofl, rdesc);
112 assert(gnp);
113
114 gotndx = (Xword)gnp->gn_gotndx;
115
116 if ((rdesc->rel_flags & FLG_REL_DTLS) &&
117 (rdesc->rel_rtype == R_AMD64_DTPOFF64))
118 gotndx++;
119
120 return ((Xword)(osp->os_shdr->sh_addr + (gotndx * M_GOT_ENTSIZE)));
121 }
122
123 static Word
ld_init_rel(Rel_desc * reld,Word * typedata,void * reloc)124 ld_init_rel(Rel_desc *reld, Word *typedata, void *reloc)
125 {
126 Rela *rel = (Rela *)reloc;
127
128 /* LINTED */
129 reld->rel_rtype = (Word)ELF_R_TYPE(rel->r_info, M_MACH);
130 reld->rel_roffset = rel->r_offset;
131 reld->rel_raddend = rel->r_addend;
132 *typedata = 0;
133
134 reld->rel_flags |= FLG_REL_RELA;
135
136 return ((Word)ELF_R_SYM(rel->r_info));
137 }
138
139 static void
ld_mach_eflags(Ehdr * ehdr,Ofl_desc * ofl)140 ld_mach_eflags(Ehdr *ehdr, Ofl_desc *ofl)
141 {
142 ofl->ofl_dehdr->e_flags |= ehdr->e_flags;
143 }
144
145 static void
ld_mach_make_dynamic(Ofl_desc * ofl,size_t * cnt)146 ld_mach_make_dynamic(Ofl_desc *ofl, size_t *cnt)
147 {
148 if (!(ofl->ofl_flags & FLG_OF_RELOBJ)) {
149 /*
150 * Create this entry if we are going to create a PLT table.
151 */
152 if (ofl->ofl_pltcnt)
153 (*cnt)++; /* DT_PLTGOT */
154 }
155 }
156
157 static void
ld_mach_update_odynamic(Ofl_desc * ofl,Dyn ** dyn)158 ld_mach_update_odynamic(Ofl_desc *ofl, Dyn **dyn)
159 {
160 if (((ofl->ofl_flags & FLG_OF_RELOBJ) == 0) && ofl->ofl_pltcnt) {
161 (*dyn)->d_tag = DT_PLTGOT;
162 if (ofl->ofl_osgot)
163 (*dyn)->d_un.d_ptr = ofl->ofl_osgot->os_shdr->sh_addr;
164 else
165 (*dyn)->d_un.d_ptr = 0;
166 (*dyn)++;
167 }
168 }
169
170 static Xword
ld_calc_plt_addr(Sym_desc * sdp,Ofl_desc * ofl)171 ld_calc_plt_addr(Sym_desc *sdp, Ofl_desc *ofl)
172 {
173 Xword value;
174
175 value = (Xword)(ofl->ofl_osplt->os_shdr->sh_addr) +
176 M_PLT_RESERVSZ + ((sdp->sd_aux->sa_PLTndx - 1) * M_PLT_ENTSIZE);
177 return (value);
178 }
179
180 /*
181 * Build a single plt entry - code is:
182 * JMP *name1@GOTPCREL(%rip)
183 * PUSHL $index
184 * JMP .PLT0
185 */
186 static uchar_t pltn_entry[M_PLT_ENTSIZE] = {
187 /* 0x00 jmpq *name1@GOTPCREL(%rip) */ 0xff, 0x25, 0x00, 0x00, 0x00, 0x00,
188 /* 0x06 pushq $index */ 0x68, 0x00, 0x00, 0x00, 0x00,
189 /* 0x0b jmpq .plt0(%rip) */ 0xe9, 0x00, 0x00, 0x00, 0x00
190 /* 0x10 */
191 };
192
193 static uintptr_t
plt_entry(Ofl_desc * ofl,Sym_desc * sdp)194 plt_entry(Ofl_desc * ofl, Sym_desc * sdp)
195 {
196 uchar_t *plt0, *pltent, *gotent;
197 Sword plt_off;
198 Word got_off;
199 Xword val1;
200 int bswap = (ofl->ofl_flags1 & FLG_OF1_ENCDIFF) != 0;
201
202 got_off = sdp->sd_aux->sa_PLTGOTndx * M_GOT_ENTSIZE;
203 plt_off = M_PLT_RESERVSZ + ((sdp->sd_aux->sa_PLTndx - 1) *
204 M_PLT_ENTSIZE);
205 plt0 = (uchar_t *)(ofl->ofl_osplt->os_outdata->d_buf);
206 pltent = plt0 + plt_off;
207 gotent = (uchar_t *)(ofl->ofl_osgot->os_outdata->d_buf) + got_off;
208
209 bcopy(pltn_entry, pltent, sizeof (pltn_entry));
210 /*
211 * Fill in the got entry with the address of the next instruction.
212 */
213 /* LINTED */
214 *(Word *)gotent = ofl->ofl_osplt->os_shdr->sh_addr + plt_off +
215 M_PLT_INSSIZE;
216 if (bswap)
217 /* LINTED */
218 *(Word *)gotent = ld_bswap_Word(*(Word *)gotent);
219
220 /*
221 * If '-z noreloc' is specified - skip the do_reloc_ld
222 * stage.
223 */
224 if (!OFL_DO_RELOC(ofl))
225 return (1);
226
227 /*
228 * patchup:
229 * jmpq *name1@gotpcrel(%rip)
230 *
231 * NOTE: 0x06 represents next instruction.
232 */
233 val1 = (ofl->ofl_osgot->os_shdr->sh_addr + got_off) -
234 (ofl->ofl_osplt->os_shdr->sh_addr + plt_off) - 0x06;
235
236 if (do_reloc_ld(&rdesc_r_amd64_gotpcrel, &pltent[0x02], &val1,
237 syn_rdesc_sym_name, MSG_ORIG(MSG_SPECFIL_PLTENT), bswap,
238 ofl->ofl_lml) == 0) {
239 ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_PLT_PLTNFAIL),
240 sdp->sd_aux->sa_PLTndx, demangle(sdp->sd_name));
241 return (S_ERROR);
242 }
243
244 /*
245 * patchup:
246 * pushq $pltndx
247 */
248 val1 = (Xword)(sdp->sd_aux->sa_PLTndx - 1);
249
250 if (do_reloc_ld(&rdesc_r_amd64_32, &pltent[0x07], &val1,
251 syn_rdesc_sym_name, MSG_ORIG(MSG_SPECFIL_PLTENT), bswap,
252 ofl->ofl_lml) == 0) {
253 ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_PLT_PLTNFAIL),
254 sdp->sd_aux->sa_PLTndx, demangle(sdp->sd_name));
255 return (S_ERROR);
256 }
257
258 /*
259 * patchup:
260 * jmpq .plt0(%rip)
261 * NOTE: 0x10 represents next instruction. The rather complex
262 * series of casts is necessary to sign extend an offset into
263 * a 64-bit value while satisfying various compiler error
264 * checks. Handle with care.
265 */
266 val1 = (Xword)((intptr_t)((uintptr_t)plt0 -
267 (uintptr_t)(&pltent[0x10])));
268
269 if (do_reloc_ld(&rdesc_r_amd64_pc32, &pltent[0x0c], &val1,
270 syn_rdesc_sym_name, MSG_ORIG(MSG_SPECFIL_PLTENT), bswap,
271 ofl->ofl_lml) == 0) {
272 ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_PLT_PLTNFAIL),
273 sdp->sd_aux->sa_PLTndx, demangle(sdp->sd_name));
274 return (S_ERROR);
275 }
276
277 return (1);
278 }
279
280 static uintptr_t
ld_perform_outreloc(Rel_desc * orsp,Ofl_desc * ofl,Boolean * remain_seen)281 ld_perform_outreloc(Rel_desc * orsp, Ofl_desc * ofl, Boolean *remain_seen)
282 {
283 Os_desc * relosp, * osp = 0;
284 Word ndx;
285 Xword roffset, value;
286 Sxword raddend;
287 Rela rea;
288 char *relbits;
289 Sym_desc * sdp, * psym = (Sym_desc *)0;
290 int sectmoved = 0;
291
292 raddend = orsp->rel_raddend;
293 sdp = orsp->rel_sym;
294
295 /*
296 * If the section this relocation is against has been discarded
297 * (-zignore), then also discard (skip) the relocation itself.
298 */
299 if (orsp->rel_isdesc && ((orsp->rel_flags &
300 (FLG_REL_GOT | FLG_REL_BSS | FLG_REL_PLT | FLG_REL_NOINFO)) == 0) &&
301 (orsp->rel_isdesc->is_flags & FLG_IS_DISCARD)) {
302 DBG_CALL(Dbg_reloc_discard(ofl->ofl_lml, M_MACH, orsp));
303 return (1);
304 }
305
306 /*
307 * If this is a relocation against a move table, or expanded move
308 * table, adjust the relocation entries.
309 */
310 if (RELAUX_GET_MOVE(orsp))
311 ld_adj_movereloc(ofl, orsp);
312
313 /*
314 * If this is a relocation against a section then we need to adjust the
315 * raddend field to compensate for the new position of the input section
316 * within the new output section.
317 */
318 if (ELF_ST_TYPE(sdp->sd_sym->st_info) == STT_SECTION) {
319 if (ofl->ofl_parsyms &&
320 (sdp->sd_isc->is_flags & FLG_IS_RELUPD) &&
321 /* LINTED */
322 (psym = ld_am_I_partial(orsp, orsp->rel_raddend))) {
323 DBG_CALL(Dbg_move_outsctadj(ofl->ofl_lml, psym));
324 sectmoved = 1;
325 if (ofl->ofl_flags & FLG_OF_RELOBJ)
326 raddend = psym->sd_sym->st_value;
327 else
328 raddend = psym->sd_sym->st_value -
329 psym->sd_isc->is_osdesc->os_shdr->sh_addr;
330 /* LINTED */
331 raddend += (Off)_elf_getxoff(psym->sd_isc->is_indata);
332 if (psym->sd_isc->is_shdr->sh_flags & SHF_ALLOC)
333 raddend +=
334 psym->sd_isc->is_osdesc->os_shdr->sh_addr;
335 } else {
336 /* LINTED */
337 raddend += (Off)_elf_getxoff(sdp->sd_isc->is_indata);
338 if (sdp->sd_isc->is_shdr->sh_flags & SHF_ALLOC)
339 raddend +=
340 sdp->sd_isc->is_osdesc->os_shdr->sh_addr;
341 }
342 }
343
344 value = sdp->sd_sym->st_value;
345
346 if (orsp->rel_flags & FLG_REL_GOT) {
347 /*
348 * Note: for GOT relative relocations on amd64
349 * we discard the addend. It was relevant
350 * to the reference - not to the data item
351 * being referenced (ie: that -4 thing).
352 */
353 raddend = 0;
354 osp = ofl->ofl_osgot;
355 roffset = ld_calc_got_offset(orsp, ofl);
356
357 } else if (orsp->rel_flags & FLG_REL_PLT) {
358 /*
359 * Note that relocations for PLT's actually
360 * cause a relocation againt the GOT.
361 */
362 osp = ofl->ofl_osplt;
363 roffset = (ofl->ofl_osgot->os_shdr->sh_addr) +
364 sdp->sd_aux->sa_PLTGOTndx * M_GOT_ENTSIZE;
365 raddend = 0;
366 if (plt_entry(ofl, sdp) == S_ERROR)
367 return (S_ERROR);
368
369 } else if (orsp->rel_flags & FLG_REL_BSS) {
370 /*
371 * This must be a R_AMD64_COPY. For these set the roffset to
372 * point to the new symbols location.
373 */
374 osp = ofl->ofl_isbss->is_osdesc;
375 roffset = value;
376
377 /*
378 * The raddend doesn't mean anything in a R_SPARC_COPY
379 * relocation. Null it out because it can confuse people.
380 */
381 raddend = 0;
382 } else {
383 osp = RELAUX_GET_OSDESC(orsp);
384
385 /*
386 * Calculate virtual offset of reference point; equals offset
387 * into section + vaddr of section for loadable sections, or
388 * offset plus section displacement for nonloadable sections.
389 */
390 roffset = orsp->rel_roffset +
391 (Off)_elf_getxoff(orsp->rel_isdesc->is_indata);
392 if (!(ofl->ofl_flags & FLG_OF_RELOBJ))
393 roffset += orsp->rel_isdesc->is_osdesc->
394 os_shdr->sh_addr;
395 }
396
397 if ((osp == 0) || ((relosp = osp->os_relosdesc) == 0))
398 relosp = ofl->ofl_osrel;
399
400 /*
401 * Assign the symbols index for the output relocation. If the
402 * relocation refers to a SECTION symbol then it's index is based upon
403 * the output sections symbols index. Otherwise the index can be
404 * derived from the symbols index itself.
405 */
406 if (orsp->rel_rtype == R_AMD64_RELATIVE)
407 ndx = STN_UNDEF;
408 else if ((orsp->rel_flags & FLG_REL_SCNNDX) ||
409 (ELF_ST_TYPE(sdp->sd_sym->st_info) == STT_SECTION)) {
410 if (sectmoved == 0) {
411 /*
412 * Check for a null input section. This can
413 * occur if this relocation references a symbol
414 * generated by sym_add_sym().
415 */
416 if (sdp->sd_isc && sdp->sd_isc->is_osdesc)
417 ndx = sdp->sd_isc->is_osdesc->os_identndx;
418 else
419 ndx = sdp->sd_shndx;
420 } else
421 ndx = ofl->ofl_parexpnndx;
422 } else
423 ndx = sdp->sd_symndx;
424
425 /*
426 * Add the symbols 'value' to the addend field.
427 */
428 if (orsp->rel_flags & FLG_REL_ADVAL)
429 raddend += value;
430
431 /*
432 * The addend field for R_AMD64_DTPMOD64 means nothing. The addend
433 * is propagated in the corresponding R_AMD64_DTPOFF64 relocation.
434 */
435 if (orsp->rel_rtype == R_AMD64_DTPMOD64)
436 raddend = 0;
437
438 relbits = (char *)relosp->os_outdata->d_buf;
439
440 rea.r_info = ELF_R_INFO(ndx, orsp->rel_rtype);
441 rea.r_offset = roffset;
442 rea.r_addend = raddend;
443 DBG_CALL(Dbg_reloc_out(ofl, ELF_DBG_LD, SHT_RELA, &rea, relosp->os_name,
444 ld_reloc_sym_name(orsp)));
445
446 /*
447 * Assert we haven't walked off the end of our relocation table.
448 */
449 assert(relosp->os_szoutrels <= relosp->os_shdr->sh_size);
450
451 (void) memcpy((relbits + relosp->os_szoutrels),
452 (char *)&rea, sizeof (Rela));
453 relosp->os_szoutrels += (Xword)sizeof (Rela);
454
455 /*
456 * Determine if this relocation is against a non-writable, allocatable
457 * section. If so we may need to provide a text relocation diagnostic.
458 * Note that relocations against the .plt (R_AMD64_JUMP_SLOT) actually
459 * result in modifications to the .got.
460 */
461 if (orsp->rel_rtype == R_AMD64_JUMP_SLOT)
462 osp = ofl->ofl_osgot;
463
464 ld_reloc_remain_entry(orsp, osp, ofl, remain_seen);
465 return (1);
466 }
467
468 /*
469 * amd64 Instructions for TLS processing
470 */
471 static uchar_t tlsinstr_gd_ie[] = {
472 /*
473 * 0x00 movq %fs:0, %rax
474 */
475 0x64, 0x48, 0x8b, 0x04, 0x25,
476 0x00, 0x00, 0x00, 0x00,
477 /*
478 * 0x09 addq x@gottpoff(%rip), %rax
479 */
480 0x48, 0x03, 0x05, 0x00, 0x00,
481 0x00, 0x00
482 };
483
484 static uchar_t tlsinstr_gd_le[] = {
485 /*
486 * 0x00 movq %fs:0, %rax
487 */
488 0x64, 0x48, 0x8b, 0x04, 0x25,
489 0x00, 0x00, 0x00, 0x00,
490 /*
491 * 0x09 leaq x@gottpoff(%rip), %rax
492 */
493 0x48, 0x8d, 0x80, 0x00, 0x00,
494 0x00, 0x00
495 };
496
497 static uchar_t tlsinstr_ld_le[] = {
498 /*
499 * .byte 0x66
500 */
501 0x66,
502 /*
503 * .byte 0x66
504 */
505 0x66,
506 /*
507 * .byte 0x66
508 */
509 0x66,
510 /*
511 * movq %fs:0, %rax
512 */
513 0x64, 0x48, 0x8b, 0x04, 0x25,
514 0x00, 0x00, 0x00, 0x00
515 };
516
517
518 static Fixupret
tls_fixups(Ofl_desc * ofl,Rel_desc * arsp)519 tls_fixups(Ofl_desc *ofl, Rel_desc *arsp)
520 {
521 Sym_desc *sdp = arsp->rel_sym;
522 Word rtype = arsp->rel_rtype;
523 uchar_t *offset;
524
525 offset = (uchar_t *)((uintptr_t)arsp->rel_roffset +
526 (uintptr_t)_elf_getxoff(arsp->rel_isdesc->is_indata) +
527 (uintptr_t)RELAUX_GET_OSDESC(arsp)->os_outdata->d_buf);
528
529 if (sdp->sd_ref == REF_DYN_NEED) {
530 /*
531 * IE reference model
532 */
533 switch (rtype) {
534 case R_AMD64_TLSGD:
535 /*
536 * GD -> IE
537 *
538 * Transition:
539 * 0x00 .byte 0x66
540 * 0x01 leaq x@tlsgd(%rip), %rdi
541 * 0x08 .word 0x6666
542 * 0x0a rex64
543 * 0x0b call __tls_get_addr@plt
544 * 0x10
545 * To:
546 * 0x00 movq %fs:0, %rax
547 * 0x09 addq x@gottpoff(%rip), %rax
548 * 0x10
549 */
550 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
551 R_AMD64_GOTTPOFF, arsp, ld_reloc_sym_name));
552 arsp->rel_rtype = R_AMD64_GOTTPOFF;
553 arsp->rel_roffset += 8;
554 arsp->rel_raddend = (Sxword)-4;
555
556 /*
557 * Adjust 'offset' to beginning of instruction
558 * sequence.
559 */
560 offset -= 4;
561 (void) memcpy(offset, tlsinstr_gd_ie,
562 sizeof (tlsinstr_gd_ie));
563 return (FIX_RELOC);
564
565 case R_AMD64_PLT32:
566 /*
567 * Fixup done via the TLS_GD relocation.
568 */
569 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
570 R_AMD64_NONE, arsp, ld_reloc_sym_name));
571 return (FIX_DONE);
572 }
573 }
574
575 /*
576 * LE reference model
577 */
578 switch (rtype) {
579 case R_AMD64_TLSGD:
580 /*
581 * GD -> LE
582 *
583 * Transition:
584 * 0x00 .byte 0x66
585 * 0x01 leaq x@tlsgd(%rip), %rdi
586 * 0x08 .word 0x6666
587 * 0x0a rex64
588 * 0x0b call __tls_get_addr@plt
589 * 0x10
590 * To:
591 * 0x00 movq %fs:0, %rax
592 * 0x09 leaq x@tpoff(%rax), %rax
593 * 0x10
594 */
595 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
596 R_AMD64_TPOFF32, arsp, ld_reloc_sym_name));
597 arsp->rel_rtype = R_AMD64_TPOFF32;
598 arsp->rel_roffset += 8;
599 arsp->rel_raddend = 0;
600
601 /*
602 * Adjust 'offset' to beginning of instruction sequence.
603 */
604 offset -= 4;
605 (void) memcpy(offset, tlsinstr_gd_le, sizeof (tlsinstr_gd_le));
606 return (FIX_RELOC);
607
608 case R_AMD64_GOTTPOFF:
609 /*
610 * IE -> LE
611 *
612 * Transition:
613 * 0x00 movq %fs:0, %rax
614 * 0x09 addq x@gottopoff(%rip), %rax
615 * 0x10
616 * To:
617 * 0x00 movq %fs:0, %rax
618 * 0x09 leaq x@tpoff(%rax), %rax
619 * 0x10
620 */
621 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
622 R_AMD64_TPOFF32, arsp, ld_reloc_sym_name));
623 arsp->rel_rtype = R_AMD64_TPOFF32;
624 arsp->rel_raddend = 0;
625
626 /*
627 * Adjust 'offset' to beginning of instruction sequence.
628 */
629 offset -= 12;
630
631 /*
632 * Same code sequence used in the GD -> LE transition.
633 */
634 (void) memcpy(offset, tlsinstr_gd_le, sizeof (tlsinstr_gd_le));
635 return (FIX_RELOC);
636
637 case R_AMD64_TLSLD:
638 /*
639 * LD -> LE
640 *
641 * Transition
642 * 0x00 leaq x1@tlsgd(%rip), %rdi
643 * 0x07 call __tls_get_addr@plt
644 * 0x0c
645 * To:
646 * 0x00 .byte 0x66
647 * 0x01 .byte 0x66
648 * 0x02 .byte 0x66
649 * 0x03 movq %fs:0, %rax
650 */
651 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
652 R_AMD64_NONE, arsp, ld_reloc_sym_name));
653 offset -= 3;
654 (void) memcpy(offset, tlsinstr_ld_le, sizeof (tlsinstr_ld_le));
655 return (FIX_DONE);
656
657 case R_AMD64_DTPOFF32:
658 /*
659 * LD->LE
660 *
661 * Transition:
662 * 0x00 leaq x1@dtpoff(%rax), %rcx
663 * To:
664 * 0x00 leaq x1@tpoff(%rax), %rcx
665 */
666 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
667 R_AMD64_TPOFF32, arsp, ld_reloc_sym_name));
668 arsp->rel_rtype = R_AMD64_TPOFF32;
669 arsp->rel_raddend = 0;
670 return (FIX_RELOC);
671 }
672
673 return (FIX_RELOC);
674 }
675
676 static uintptr_t
ld_do_activerelocs(Ofl_desc * ofl)677 ld_do_activerelocs(Ofl_desc *ofl)
678 {
679 Rel_desc *arsp;
680 Rel_cachebuf *rcbp;
681 Aliste idx;
682 uintptr_t return_code = 1;
683 ofl_flag_t flags = ofl->ofl_flags;
684
685 if (aplist_nitems(ofl->ofl_actrels.rc_list) != 0)
686 DBG_CALL(Dbg_reloc_doact_title(ofl->ofl_lml));
687
688 /*
689 * Process active relocations.
690 */
691 REL_CACHE_TRAVERSE(&ofl->ofl_actrels, idx, rcbp, arsp) {
692 uchar_t *addr;
693 Xword value;
694 Sym_desc *sdp;
695 const char *ifl_name;
696 Xword refaddr;
697 int moved = 0;
698 Gotref gref;
699 Os_desc *osp;
700
701 /*
702 * If the section this relocation is against has been discarded
703 * (-zignore), then discard (skip) the relocation itself.
704 */
705 if ((arsp->rel_isdesc->is_flags & FLG_IS_DISCARD) &&
706 ((arsp->rel_flags & (FLG_REL_GOT | FLG_REL_BSS |
707 FLG_REL_PLT | FLG_REL_NOINFO)) == 0)) {
708 DBG_CALL(Dbg_reloc_discard(ofl->ofl_lml, M_MACH, arsp));
709 continue;
710 }
711
712 /*
713 * We determine what the 'got reference' model (if required)
714 * is at this point. This needs to be done before tls_fixup()
715 * since it may 'transition' our instructions.
716 *
717 * The got table entries have already been assigned,
718 * and we bind to those initial entries.
719 */
720 if (arsp->rel_flags & FLG_REL_DTLS)
721 gref = GOT_REF_TLSGD;
722 else if (arsp->rel_flags & FLG_REL_MTLS)
723 gref = GOT_REF_TLSLD;
724 else if (arsp->rel_flags & FLG_REL_STLS)
725 gref = GOT_REF_TLSIE;
726 else
727 gref = GOT_REF_GENERIC;
728
729 /*
730 * Perform any required TLS fixups.
731 */
732 if (arsp->rel_flags & FLG_REL_TLSFIX) {
733 Fixupret ret;
734
735 if ((ret = tls_fixups(ofl, arsp)) == FIX_ERROR)
736 return (S_ERROR);
737 if (ret == FIX_DONE)
738 continue;
739 }
740
741 /*
742 * If this is a relocation against a move table, or
743 * expanded move table, adjust the relocation entries.
744 */
745 if (RELAUX_GET_MOVE(arsp))
746 ld_adj_movereloc(ofl, arsp);
747
748 sdp = arsp->rel_sym;
749 refaddr = arsp->rel_roffset +
750 (Off)_elf_getxoff(arsp->rel_isdesc->is_indata);
751
752 if ((arsp->rel_flags & FLG_REL_CLVAL) ||
753 (arsp->rel_flags & FLG_REL_GOTCL))
754 value = 0;
755 else if (ELF_ST_TYPE(sdp->sd_sym->st_info) == STT_SECTION) {
756 Sym_desc *sym;
757
758 /*
759 * The value for a symbol pointing to a SECTION
760 * is based off of that sections position.
761 */
762 if ((sdp->sd_isc->is_flags & FLG_IS_RELUPD) &&
763 /* LINTED */
764 (sym = ld_am_I_partial(arsp, arsp->rel_raddend))) {
765 /*
766 * The symbol was moved, so adjust the value
767 * relative to the new section.
768 */
769 value = sym->sd_sym->st_value;
770 moved = 1;
771
772 /*
773 * The original raddend covers the displacement
774 * from the section start to the desired
775 * address. The value computed above gets us
776 * from the section start to the start of the
777 * symbol range. Adjust the old raddend to
778 * remove the offset from section start to
779 * symbol start, leaving the displacement
780 * within the range of the symbol.
781 */
782 arsp->rel_raddend -= sym->sd_osym->st_value;
783 } else {
784 value = _elf_getxoff(sdp->sd_isc->is_indata);
785 if (sdp->sd_isc->is_shdr->sh_flags & SHF_ALLOC)
786 value += sdp->sd_isc->is_osdesc->
787 os_shdr->sh_addr;
788 }
789 if (sdp->sd_isc->is_shdr->sh_flags & SHF_TLS)
790 value -= ofl->ofl_tlsphdr->p_vaddr;
791
792 } else if (IS_SIZE(arsp->rel_rtype)) {
793 /*
794 * Size relocations require the symbols size.
795 */
796 value = sdp->sd_sym->st_size;
797
798 } else if ((sdp->sd_flags & FLG_SY_CAP) &&
799 sdp->sd_aux && sdp->sd_aux->sa_PLTndx) {
800 /*
801 * If relocation is against a capabilities symbol, we
802 * need to jump to an associated PLT, so that at runtime
803 * ld.so.1 is involved to determine the best binding
804 * choice. Otherwise, the value is the symbols value.
805 */
806 value = ld_calc_plt_addr(sdp, ofl);
807 } else
808 value = sdp->sd_sym->st_value;
809
810 /*
811 * Relocation against the GLOBAL_OFFSET_TABLE.
812 */
813 if ((arsp->rel_flags & FLG_REL_GOT) &&
814 !ld_reloc_set_aux_osdesc(ofl, arsp, ofl->ofl_osgot))
815 return (S_ERROR);
816 osp = RELAUX_GET_OSDESC(arsp);
817
818 /*
819 * If loadable and not producing a relocatable object add the
820 * sections virtual address to the reference address.
821 */
822 if ((arsp->rel_flags & FLG_REL_LOAD) &&
823 ((flags & FLG_OF_RELOBJ) == 0))
824 refaddr += arsp->rel_isdesc->is_osdesc->
825 os_shdr->sh_addr;
826
827 /*
828 * If this entry has a PLT assigned to it, its value is actually
829 * the address of the PLT (and not the address of the function).
830 */
831 if (IS_PLT(arsp->rel_rtype)) {
832 if (sdp->sd_aux && sdp->sd_aux->sa_PLTndx)
833 value = ld_calc_plt_addr(sdp, ofl);
834 }
835
836 /*
837 * Add relocations addend to value. Add extra
838 * relocation addend if needed.
839 *
840 * Note: For GOT relative relocations on amd64 we discard the
841 * addend. It was relevant to the reference - not to the
842 * data item being referenced (ie: that -4 thing).
843 */
844 if ((arsp->rel_flags & FLG_REL_GOT) == 0)
845 value += arsp->rel_raddend;
846
847 /*
848 * Determine whether the value needs further adjustment. Filter
849 * through the attributes of the relocation to determine what
850 * adjustment is required. Note, many of the following cases
851 * are only applicable when a .got is present. As a .got is
852 * not generated when a relocatable object is being built,
853 * any adjustments that require a .got need to be skipped.
854 */
855 if ((arsp->rel_flags & FLG_REL_GOT) &&
856 ((flags & FLG_OF_RELOBJ) == 0)) {
857 Xword R1addr;
858 uintptr_t R2addr;
859 Word gotndx;
860 Gotndx *gnp;
861
862 /*
863 * Perform relocation against GOT table. Since this
864 * doesn't fit exactly into a relocation we place the
865 * appropriate byte in the GOT directly
866 *
867 * Calculate offset into GOT at which to apply
868 * the relocation.
869 */
870 gnp = ld_find_got_ndx(sdp->sd_GOTndxs, gref, ofl, arsp);
871 assert(gnp);
872
873 if (arsp->rel_rtype == R_AMD64_DTPOFF64)
874 gotndx = gnp->gn_gotndx + 1;
875 else
876 gotndx = gnp->gn_gotndx;
877
878 R1addr = (Xword)(gotndx * M_GOT_ENTSIZE);
879
880 /*
881 * Add the GOTs data's offset.
882 */
883 R2addr = R1addr + (uintptr_t)osp->os_outdata->d_buf;
884
885 DBG_CALL(Dbg_reloc_doact(ofl->ofl_lml, ELF_DBG_LD_ACT,
886 M_MACH, SHT_RELA, arsp, R1addr, value,
887 ld_reloc_sym_name));
888
889 /*
890 * And do it.
891 */
892 if (ofl->ofl_flags1 & FLG_OF1_ENCDIFF)
893 *(Xword *)R2addr = ld_bswap_Xword(value);
894 else
895 *(Xword *)R2addr = value;
896 continue;
897
898 } else if (IS_GOT_BASED(arsp->rel_rtype) &&
899 ((flags & FLG_OF_RELOBJ) == 0)) {
900 value -= ofl->ofl_osgot->os_shdr->sh_addr;
901
902 } else if (IS_GOTPCREL(arsp->rel_rtype) &&
903 ((flags & FLG_OF_RELOBJ) == 0)) {
904 Gotndx *gnp;
905
906 /*
907 * Calculation:
908 * G + GOT + A - P
909 */
910 gnp = ld_find_got_ndx(sdp->sd_GOTndxs, gref, ofl, arsp);
911 assert(gnp);
912 value = (Xword)(ofl->ofl_osgot->os_shdr-> sh_addr) +
913 ((Xword)gnp->gn_gotndx * M_GOT_ENTSIZE) +
914 arsp->rel_raddend - refaddr;
915
916 } else if (IS_GOT_PC(arsp->rel_rtype) &&
917 ((flags & FLG_OF_RELOBJ) == 0)) {
918 value = (Xword)(ofl->ofl_osgot->os_shdr->
919 sh_addr) - refaddr + arsp->rel_raddend;
920
921 } else if ((IS_PC_RELATIVE(arsp->rel_rtype)) &&
922 (((flags & FLG_OF_RELOBJ) == 0) ||
923 (osp == sdp->sd_isc->is_osdesc))) {
924 value -= refaddr;
925
926 } else if (IS_TLS_INS(arsp->rel_rtype) &&
927 IS_GOT_RELATIVE(arsp->rel_rtype) &&
928 ((flags & FLG_OF_RELOBJ) == 0)) {
929 Gotndx *gnp;
930
931 gnp = ld_find_got_ndx(sdp->sd_GOTndxs, gref, ofl, arsp);
932 assert(gnp);
933 value = (Xword)gnp->gn_gotndx * M_GOT_ENTSIZE;
934
935 } else if (IS_GOT_RELATIVE(arsp->rel_rtype) &&
936 ((flags & FLG_OF_RELOBJ) == 0)) {
937 Gotndx *gnp;
938
939 gnp = ld_find_got_ndx(sdp->sd_GOTndxs, gref, ofl, arsp);
940 assert(gnp);
941 value = (Xword)gnp->gn_gotndx * M_GOT_ENTSIZE;
942
943 } else if ((arsp->rel_flags & FLG_REL_STLS) &&
944 ((flags & FLG_OF_RELOBJ) == 0)) {
945 Xword tlsstatsize;
946
947 /*
948 * This is the LE TLS reference model. Static
949 * offset is hard-coded.
950 */
951 tlsstatsize = S_ROUND(ofl->ofl_tlsphdr->p_memsz,
952 M_TLSSTATALIGN);
953 value = tlsstatsize - value;
954
955 /*
956 * Since this code is fixed up, it assumes a negative
957 * offset that can be added to the thread pointer.
958 */
959 if (arsp->rel_rtype == R_AMD64_TPOFF32)
960 value = -value;
961 }
962
963 if (arsp->rel_isdesc->is_file)
964 ifl_name = arsp->rel_isdesc->is_file->ifl_name;
965 else
966 ifl_name = MSG_INTL(MSG_STR_NULL);
967
968 /*
969 * Make sure we have data to relocate. Compiler and assembler
970 * developers have been known to generate relocations against
971 * invalid sections (normally .bss), so for their benefit give
972 * them sufficient information to help analyze the problem.
973 * End users should never see this.
974 */
975 if (arsp->rel_isdesc->is_indata->d_buf == 0) {
976 Conv_inv_buf_t inv_buf;
977
978 ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_REL_EMPTYSEC),
979 conv_reloc_amd64_type(arsp->rel_rtype, 0, &inv_buf),
980 ifl_name, ld_reloc_sym_name(arsp),
981 EC_WORD(arsp->rel_isdesc->is_scnndx),
982 arsp->rel_isdesc->is_name);
983 return (S_ERROR);
984 }
985
986 /*
987 * Get the address of the data item we need to modify.
988 */
989 addr = (uchar_t *)((uintptr_t)arsp->rel_roffset +
990 (uintptr_t)_elf_getxoff(arsp->rel_isdesc->is_indata));
991
992 DBG_CALL(Dbg_reloc_doact(ofl->ofl_lml, ELF_DBG_LD_ACT,
993 M_MACH, SHT_RELA, arsp, EC_NATPTR(addr), value,
994 ld_reloc_sym_name));
995 addr += (uintptr_t)osp->os_outdata->d_buf;
996
997 if ((((uintptr_t)addr - (uintptr_t)ofl->ofl_nehdr) >
998 ofl->ofl_size) || (arsp->rel_roffset >
999 osp->os_shdr->sh_size)) {
1000 int class;
1001 Conv_inv_buf_t inv_buf;
1002
1003 if (((uintptr_t)addr - (uintptr_t)ofl->ofl_nehdr) >
1004 ofl->ofl_size)
1005 class = ERR_FATAL;
1006 else
1007 class = ERR_WARNING;
1008
1009 ld_eprintf(ofl, class, MSG_INTL(MSG_REL_INVALOFFSET),
1010 conv_reloc_amd64_type(arsp->rel_rtype, 0, &inv_buf),
1011 ifl_name, EC_WORD(arsp->rel_isdesc->is_scnndx),
1012 arsp->rel_isdesc->is_name, ld_reloc_sym_name(arsp),
1013 EC_ADDR((uintptr_t)addr -
1014 (uintptr_t)ofl->ofl_nehdr));
1015
1016 if (class == ERR_FATAL) {
1017 return_code = S_ERROR;
1018 continue;
1019 }
1020 }
1021
1022 /*
1023 * The relocation is additive. Ignore the previous symbol
1024 * value if this local partial symbol is expanded.
1025 */
1026 if (moved)
1027 value -= *addr;
1028
1029 /*
1030 * If '-z noreloc' is specified - skip the do_reloc_ld stage.
1031 */
1032 if (OFL_DO_RELOC(ofl)) {
1033 /*
1034 * If this is a PROGBITS section and the running linker
1035 * has a different byte order than the target host,
1036 * tell do_reloc_ld() to swap bytes.
1037 */
1038 if (do_reloc_ld(arsp, addr, &value, ld_reloc_sym_name,
1039 ifl_name, OFL_SWAP_RELOC_DATA(ofl, arsp),
1040 ofl->ofl_lml) == 0) {
1041 ofl->ofl_flags |= FLG_OF_FATAL;
1042 return_code = S_ERROR;
1043 }
1044 }
1045 }
1046 return (return_code);
1047 }
1048
1049 static uintptr_t
ld_add_outrel(Word flags,Rel_desc * rsp,Ofl_desc * ofl)1050 ld_add_outrel(Word flags, Rel_desc *rsp, Ofl_desc *ofl)
1051 {
1052 Rel_desc *orsp;
1053 Sym_desc *sdp = rsp->rel_sym;
1054
1055 /*
1056 * Static executables *do not* want any relocations against them.
1057 * Since our engine still creates relocations against a WEAK UNDEFINED
1058 * symbol in a static executable, it's best to disable them here
1059 * instead of through out the relocation code.
1060 */
1061 if (OFL_IS_STATIC_EXEC(ofl))
1062 return (1);
1063
1064 /*
1065 * If we are adding a output relocation against a section
1066 * symbol (non-RELATIVE) then mark that section. These sections
1067 * will be added to the .dynsym symbol table.
1068 */
1069 if (sdp && (rsp->rel_rtype != M_R_RELATIVE) &&
1070 ((flags & FLG_REL_SCNNDX) ||
1071 (ELF_ST_TYPE(sdp->sd_sym->st_info) == STT_SECTION))) {
1072
1073 /*
1074 * If this is a COMMON symbol - no output section
1075 * exists yet - (it's created as part of sym_validate()).
1076 * So - we mark here that when it's created it should
1077 * be tagged with the FLG_OS_OUTREL flag.
1078 */
1079 if ((sdp->sd_flags & FLG_SY_SPECSEC) &&
1080 (sdp->sd_sym->st_shndx == SHN_COMMON)) {
1081 if (ELF_ST_TYPE(sdp->sd_sym->st_info) != STT_TLS)
1082 ofl->ofl_flags1 |= FLG_OF1_BSSOREL;
1083 else
1084 ofl->ofl_flags1 |= FLG_OF1_TLSOREL;
1085 } else {
1086 Os_desc *osp;
1087 Is_desc *isp = sdp->sd_isc;
1088
1089 if (isp && ((osp = isp->is_osdesc) != NULL) &&
1090 ((osp->os_flags & FLG_OS_OUTREL) == 0)) {
1091 ofl->ofl_dynshdrcnt++;
1092 osp->os_flags |= FLG_OS_OUTREL;
1093 }
1094 }
1095 }
1096
1097 /* Enter it into the output relocation cache */
1098 if ((orsp = ld_reloc_enter(ofl, &ofl->ofl_outrels, rsp, flags)) == NULL)
1099 return (S_ERROR);
1100
1101 if (flags & FLG_REL_GOT)
1102 ofl->ofl_relocgotsz += (Xword)sizeof (Rela);
1103 else if (flags & FLG_REL_PLT)
1104 ofl->ofl_relocpltsz += (Xword)sizeof (Rela);
1105 else if (flags & FLG_REL_BSS)
1106 ofl->ofl_relocbsssz += (Xword)sizeof (Rela);
1107 else if (flags & FLG_REL_NOINFO)
1108 ofl->ofl_relocrelsz += (Xword)sizeof (Rela);
1109 else
1110 RELAUX_GET_OSDESC(orsp)->os_szoutrels += (Xword)sizeof (Rela);
1111
1112 if (orsp->rel_rtype == M_R_RELATIVE)
1113 ofl->ofl_relocrelcnt++;
1114
1115 /*
1116 * We don't perform sorting on PLT relocations because
1117 * they have already been assigned a PLT index and if we
1118 * were to sort them we would have to re-assign the plt indexes.
1119 */
1120 if (!(flags & FLG_REL_PLT))
1121 ofl->ofl_reloccnt++;
1122
1123 /*
1124 * Insure a GLOBAL_OFFSET_TABLE is generated if required.
1125 */
1126 if (IS_GOT_REQUIRED(orsp->rel_rtype))
1127 ofl->ofl_flags |= FLG_OF_BLDGOT;
1128
1129 /*
1130 * Identify and possibly warn of a displacement relocation.
1131 */
1132 if (orsp->rel_flags & FLG_REL_DISP) {
1133 ofl->ofl_dtflags_1 |= DF_1_DISPRELPND;
1134
1135 if (ofl->ofl_flags & FLG_OF_VERBOSE)
1136 ld_disp_errmsg(MSG_INTL(MSG_REL_DISPREL4), orsp, ofl);
1137 }
1138 DBG_CALL(Dbg_reloc_ors_entry(ofl->ofl_lml, ELF_DBG_LD, SHT_RELA,
1139 M_MACH, orsp));
1140 return (1);
1141 }
1142
1143 /*
1144 * process relocation for a LOCAL symbol
1145 */
1146 static uintptr_t
ld_reloc_local(Rel_desc * rsp,Ofl_desc * ofl)1147 ld_reloc_local(Rel_desc * rsp, Ofl_desc * ofl)
1148 {
1149 ofl_flag_t flags = ofl->ofl_flags;
1150 Sym_desc *sdp = rsp->rel_sym;
1151 Word shndx = sdp->sd_sym->st_shndx;
1152 Word ortype = rsp->rel_rtype;
1153
1154 /*
1155 * if ((shared object) and (not pc relative relocation) and
1156 * (not against ABS symbol))
1157 * then
1158 * build R_AMD64_RELATIVE
1159 * fi
1160 */
1161 if ((flags & FLG_OF_SHAROBJ) && (rsp->rel_flags & FLG_REL_LOAD) &&
1162 !(IS_PC_RELATIVE(rsp->rel_rtype)) && !(IS_SIZE(rsp->rel_rtype)) &&
1163 !(IS_GOT_BASED(rsp->rel_rtype)) &&
1164 !(rsp->rel_isdesc != NULL &&
1165 (rsp->rel_isdesc->is_shdr->sh_type == SHT_SUNW_dof)) &&
1166 (((sdp->sd_flags & FLG_SY_SPECSEC) == 0) ||
1167 (shndx != SHN_ABS) || (sdp->sd_aux && sdp->sd_aux->sa_symspec))) {
1168
1169 /*
1170 * R_AMD64_RELATIVE updates a 64bit address, if this
1171 * relocation isn't a 64bit binding then we can not
1172 * simplify it to a RELATIVE relocation.
1173 */
1174 if (reloc_table[ortype].re_fsize != sizeof (Addr)) {
1175 return (ld_add_outrel(0, rsp, ofl));
1176 }
1177
1178 rsp->rel_rtype = R_AMD64_RELATIVE;
1179 if (ld_add_outrel(FLG_REL_ADVAL, rsp, ofl) == S_ERROR)
1180 return (S_ERROR);
1181 rsp->rel_rtype = ortype;
1182 return (1);
1183 }
1184
1185 /*
1186 * If the relocation is against a 'non-allocatable' section
1187 * and we can not resolve it now - then give a warning
1188 * message.
1189 *
1190 * We can not resolve the symbol if either:
1191 * a) it's undefined
1192 * b) it's defined in a shared library and a
1193 * COPY relocation hasn't moved it to the executable
1194 *
1195 * Note: because we process all of the relocations against the
1196 * text segment before any others - we know whether
1197 * or not a copy relocation will be generated before
1198 * we get here (see reloc_init()->reloc_segments()).
1199 */
1200 if (!(rsp->rel_flags & FLG_REL_LOAD) &&
1201 ((shndx == SHN_UNDEF) ||
1202 ((sdp->sd_ref == REF_DYN_NEED) &&
1203 ((sdp->sd_flags & FLG_SY_MVTOCOMM) == 0)))) {
1204 Conv_inv_buf_t inv_buf;
1205 Os_desc *osp = RELAUX_GET_OSDESC(rsp);
1206
1207 /*
1208 * If the relocation is against a SHT_SUNW_ANNOTATE
1209 * section - then silently ignore that the relocation
1210 * can not be resolved.
1211 */
1212 if (osp && (osp->os_shdr->sh_type == SHT_SUNW_ANNOTATE))
1213 return (0);
1214 ld_eprintf(ofl, ERR_WARNING, MSG_INTL(MSG_REL_EXTERNSYM),
1215 conv_reloc_amd64_type(rsp->rel_rtype, 0, &inv_buf),
1216 rsp->rel_isdesc->is_file->ifl_name,
1217 ld_reloc_sym_name(rsp), osp->os_name);
1218 return (1);
1219 }
1220
1221 /*
1222 * Perform relocation.
1223 */
1224 return (ld_add_actrel(NULL, rsp, ofl));
1225 }
1226
1227
1228 static uintptr_t
ld_reloc_TLS(Boolean local,Rel_desc * rsp,Ofl_desc * ofl)1229 ld_reloc_TLS(Boolean local, Rel_desc * rsp, Ofl_desc * ofl)
1230 {
1231 Word rtype = rsp->rel_rtype;
1232 Sym_desc *sdp = rsp->rel_sym;
1233 ofl_flag_t flags = ofl->ofl_flags;
1234 Gotndx *gnp;
1235
1236 /*
1237 * If we're building an executable - use either the IE or LE access
1238 * model. If we're building a shared object process any IE model.
1239 */
1240 if ((flags & FLG_OF_EXEC) || (IS_TLS_IE(rtype))) {
1241 /*
1242 * Set the DF_STATIC_TLS flag.
1243 */
1244 ofl->ofl_dtflags |= DF_STATIC_TLS;
1245
1246 if (!local || ((flags & FLG_OF_EXEC) == 0)) {
1247 /*
1248 * Assign a GOT entry for static TLS references.
1249 */
1250 if ((gnp = ld_find_got_ndx(sdp->sd_GOTndxs,
1251 GOT_REF_TLSIE, ofl, rsp)) == NULL) {
1252
1253 if (ld_assign_got_TLS(local, rsp, ofl, sdp,
1254 gnp, GOT_REF_TLSIE, FLG_REL_STLS,
1255 rtype, R_AMD64_TPOFF64, 0) == S_ERROR)
1256 return (S_ERROR);
1257 }
1258
1259 /*
1260 * IE access model.
1261 */
1262 if (IS_TLS_IE(rtype))
1263 return (ld_add_actrel(FLG_REL_STLS, rsp, ofl));
1264
1265 /*
1266 * Fixups are required for other executable models.
1267 */
1268 return (ld_add_actrel((FLG_REL_TLSFIX | FLG_REL_STLS),
1269 rsp, ofl));
1270 }
1271
1272 /*
1273 * LE access model.
1274 */
1275 if (IS_TLS_LE(rtype))
1276 return (ld_add_actrel(FLG_REL_STLS, rsp, ofl));
1277
1278 return (ld_add_actrel((FLG_REL_TLSFIX | FLG_REL_STLS),
1279 rsp, ofl));
1280 }
1281
1282 /*
1283 * Building a shared object.
1284 *
1285 * Assign a GOT entry for a dynamic TLS reference.
1286 */
1287 if (IS_TLS_LD(rtype) && ((gnp = ld_find_got_ndx(sdp->sd_GOTndxs,
1288 GOT_REF_TLSLD, ofl, rsp)) == NULL)) {
1289
1290 if (ld_assign_got_TLS(local, rsp, ofl, sdp, gnp, GOT_REF_TLSLD,
1291 FLG_REL_MTLS, rtype, R_AMD64_DTPMOD64, NULL) == S_ERROR)
1292 return (S_ERROR);
1293
1294 } else if (IS_TLS_GD(rtype) &&
1295 ((gnp = ld_find_got_ndx(sdp->sd_GOTndxs, GOT_REF_TLSGD,
1296 ofl, rsp)) == NULL)) {
1297
1298 if (ld_assign_got_TLS(local, rsp, ofl, sdp, gnp, GOT_REF_TLSGD,
1299 FLG_REL_DTLS, rtype, R_AMD64_DTPMOD64,
1300 R_AMD64_DTPOFF64) == S_ERROR)
1301 return (S_ERROR);
1302 }
1303
1304 if (IS_TLS_LD(rtype))
1305 return (ld_add_actrel(FLG_REL_MTLS, rsp, ofl));
1306
1307 return (ld_add_actrel(FLG_REL_DTLS, rsp, ofl));
1308 }
1309
1310 /* ARGSUSED5 */
1311 static uintptr_t
ld_assign_got_ndx(Alist ** alpp,Gotndx * pgnp,Gotref gref,Ofl_desc * ofl,Rel_desc * rsp,Sym_desc * sdp)1312 ld_assign_got_ndx(Alist **alpp, Gotndx *pgnp, Gotref gref, Ofl_desc *ofl,
1313 Rel_desc *rsp, Sym_desc *sdp)
1314 {
1315 Xword raddend;
1316 Gotndx gn, *gnp;
1317 Aliste idx;
1318 uint_t gotents;
1319
1320 raddend = rsp->rel_raddend;
1321 if (pgnp && (pgnp->gn_addend == raddend) && (pgnp->gn_gotref == gref))
1322 return (1);
1323
1324 if ((gref == GOT_REF_TLSGD) || (gref == GOT_REF_TLSLD))
1325 gotents = 2;
1326 else
1327 gotents = 1;
1328
1329 gn.gn_addend = raddend;
1330 gn.gn_gotndx = ofl->ofl_gotcnt;
1331 gn.gn_gotref = gref;
1332
1333 ofl->ofl_gotcnt += gotents;
1334
1335 if (gref == GOT_REF_TLSLD) {
1336 if (ofl->ofl_tlsldgotndx == NULL) {
1337 if ((gnp = libld_malloc(sizeof (Gotndx))) == NULL)
1338 return (S_ERROR);
1339 (void) memcpy(gnp, &gn, sizeof (Gotndx));
1340 ofl->ofl_tlsldgotndx = gnp;
1341 }
1342 return (1);
1343 }
1344
1345 idx = 0;
1346 for (ALIST_TRAVERSE(*alpp, idx, gnp)) {
1347 if (gnp->gn_addend > raddend)
1348 break;
1349 }
1350
1351 /*
1352 * GOT indexes are maintained on an Alist, where there is typically
1353 * only one index. The usage of this list is to scan the list to find
1354 * an index, and then apply that index immediately to a relocation.
1355 * Thus there are no external references to these GOT index structures
1356 * that can be compromised by the Alist being reallocated.
1357 */
1358 if (alist_insert(alpp, &gn, sizeof (Gotndx),
1359 AL_CNT_SDP_GOT, idx) == NULL)
1360 return (S_ERROR);
1361
1362 return (1);
1363 }
1364
1365 static void
ld_assign_plt_ndx(Sym_desc * sdp,Ofl_desc * ofl)1366 ld_assign_plt_ndx(Sym_desc * sdp, Ofl_desc *ofl)
1367 {
1368 sdp->sd_aux->sa_PLTndx = 1 + ofl->ofl_pltcnt++;
1369 sdp->sd_aux->sa_PLTGOTndx = ofl->ofl_gotcnt++;
1370 ofl->ofl_flags |= FLG_OF_BLDGOT;
1371 }
1372
1373 static uchar_t plt0_template[M_PLT_ENTSIZE] = {
1374 /* 0x00 PUSHQ GOT+8(%rip) */ 0xff, 0x35, 0x00, 0x00, 0x00, 0x00,
1375 /* 0x06 JMP *GOT+16(%rip) */ 0xff, 0x25, 0x00, 0x00, 0x00, 0x00,
1376 /* 0x0c NOP */ 0x90,
1377 /* 0x0d NOP */ 0x90,
1378 /* 0x0e NOP */ 0x90,
1379 /* 0x0f NOP */ 0x90
1380 };
1381
1382 /*
1383 * Initializes .got[0] with the _DYNAMIC symbol value.
1384 */
1385 static uintptr_t
ld_fillin_gotplt(Ofl_desc * ofl)1386 ld_fillin_gotplt(Ofl_desc *ofl)
1387 {
1388 int bswap = (ofl->ofl_flags1 & FLG_OF1_ENCDIFF) != 0;
1389
1390 if (ofl->ofl_osgot) {
1391 Sym_desc *sdp;
1392
1393 if ((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_DYNAMIC_U),
1394 SYM_NOHASH, NULL, ofl)) != NULL) {
1395 uchar_t *genptr;
1396
1397 genptr = ((uchar_t *)ofl->ofl_osgot->os_outdata->d_buf +
1398 (M_GOT_XDYNAMIC * M_GOT_ENTSIZE));
1399 /* LINTED */
1400 *(Xword *)genptr = sdp->sd_sym->st_value;
1401 if (bswap)
1402 /* LINTED */
1403 *(Xword *)genptr =
1404 /* LINTED */
1405 ld_bswap_Xword(*(Xword *)genptr);
1406 }
1407 }
1408
1409 /*
1410 * Fill in the reserved slot in the procedure linkage table the first
1411 * entry is:
1412 * 0x00 PUSHQ GOT+8(%rip) # GOT[1]
1413 * 0x06 JMP *GOT+16(%rip) # GOT[2]
1414 * 0x0c NOP
1415 * 0x0d NOP
1416 * 0x0e NOP
1417 * 0x0f NOP
1418 */
1419 if ((ofl->ofl_flags & FLG_OF_DYNAMIC) && ofl->ofl_osplt) {
1420 uchar_t *pltent;
1421 Xword val1;
1422
1423 pltent = (uchar_t *)ofl->ofl_osplt->os_outdata->d_buf;
1424 bcopy(plt0_template, pltent, sizeof (plt0_template));
1425
1426 /*
1427 * If '-z noreloc' is specified - skip the do_reloc_ld
1428 * stage.
1429 */
1430 if (!OFL_DO_RELOC(ofl))
1431 return (1);
1432
1433 /*
1434 * filin:
1435 * PUSHQ GOT + 8(%rip)
1436 *
1437 * Note: 0x06 below represents the offset to the
1438 * next instruction - which is what %rip will
1439 * be pointing at.
1440 */
1441 val1 = (ofl->ofl_osgot->os_shdr->sh_addr) +
1442 (M_GOT_XLINKMAP * M_GOT_ENTSIZE) -
1443 ofl->ofl_osplt->os_shdr->sh_addr - 0x06;
1444
1445 if (do_reloc_ld(&rdesc_r_amd64_gotpcrel, &pltent[0x02],
1446 &val1, syn_rdesc_sym_name, MSG_ORIG(MSG_SPECFIL_PLTENT),
1447 bswap, ofl->ofl_lml) == 0) {
1448 ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_PLT_PLT0FAIL));
1449 return (S_ERROR);
1450 }
1451
1452 /*
1453 * filin:
1454 * JMP *GOT+16(%rip)
1455 */
1456 val1 = (ofl->ofl_osgot->os_shdr->sh_addr) +
1457 (M_GOT_XRTLD * M_GOT_ENTSIZE) -
1458 ofl->ofl_osplt->os_shdr->sh_addr - 0x0c;
1459
1460 if (do_reloc_ld(&rdesc_r_amd64_gotpcrel, &pltent[0x08],
1461 &val1, syn_rdesc_sym_name, MSG_ORIG(MSG_SPECFIL_PLTENT),
1462 bswap, ofl->ofl_lml) == 0) {
1463 ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_PLT_PLT0FAIL));
1464 return (S_ERROR);
1465 }
1466 }
1467
1468 return (1);
1469 }
1470
1471
1472
1473 /*
1474 * Template for generating "void (*)(void)" function
1475 */
1476 static const uchar_t nullfunc_tmpl[] = { /* amd64 */
1477 /* 0x00 */ 0x55, /* pushq %rbp */
1478 /* 0x01 */ 0x48, 0x8b, 0xec, /* movq %rsp,%rbp */
1479 /* 0x04 */ 0x48, 0x8b, 0xe5, /* movq %rbp,%rsp */
1480 /* 0x07 */ 0x5d, /* popq %rbp */
1481 /* 0x08 */ 0xc3 /* ret */
1482 };
1483
1484
1485 /*
1486 * Function used to provide fill padding in SHF_EXECINSTR sections
1487 *
1488 * entry:
1489 *
1490 * base - base address of section being filled
1491 * offset - starting offset for fill within memory referenced by base
1492 * cnt - # bytes to be filled
1493 *
1494 * exit:
1495 * The fill has been completed.
1496 */
1497 static void
execfill(void * base,off_t off,size_t cnt)1498 execfill(void *base, off_t off, size_t cnt)
1499 {
1500 /*
1501 * 0x90 is an X86 NOP instruction in both 32 and 64-bit worlds.
1502 * There are no alignment constraints.
1503 */
1504 (void) memset(off + (char *)base, 0x90, cnt);
1505 }
1506
1507
1508 /*
1509 * Return the ld_targ definition for this target.
1510 */
1511 const Target *
ld_targ_init_x86(void)1512 ld_targ_init_x86(void)
1513 {
1514 static const Target _ld_targ = {
1515 { /* Target_mach */
1516 M_MACH, /* m_mach */
1517 M_MACHPLUS, /* m_machplus */
1518 M_FLAGSPLUS, /* m_flagsplus */
1519 M_CLASS, /* m_class */
1520 M_DATA, /* m_data */
1521
1522 M_SEGM_ALIGN, /* m_segm_align */
1523 M_SEGM_ORIGIN, /* m_segm_origin */
1524 M_SEGM_AORIGIN, /* m_segm_aorigin */
1525 M_DATASEG_PERM, /* m_dataseg_perm */
1526 M_STACK_PERM, /* m_stack_perm */
1527 M_WORD_ALIGN, /* m_word_align */
1528 MSG_ORIG(MSG_PTH_RTLD_AMD64), /* m_def_interp */
1529
1530 /* Relocation type codes */
1531 M_R_ARRAYADDR, /* m_r_arrayaddr */
1532 M_R_COPY, /* m_r_copy */
1533 M_R_GLOB_DAT, /* m_r_glob_dat */
1534 M_R_JMP_SLOT, /* m_r_jmp_slot */
1535 M_R_NUM, /* m_r_num */
1536 M_R_NONE, /* m_r_none */
1537 M_R_RELATIVE, /* m_r_relative */
1538 M_R_REGISTER, /* m_r_register */
1539
1540 /* Relocation related constants */
1541 M_REL_DT_COUNT, /* m_rel_dt_count */
1542 M_REL_DT_ENT, /* m_rel_dt_ent */
1543 M_REL_DT_SIZE, /* m_rel_dt_size */
1544 M_REL_DT_TYPE, /* m_rel_dt_type */
1545 M_REL_SHT_TYPE, /* m_rel_sht_type */
1546
1547 /* GOT related constants */
1548 M_GOT_ENTSIZE, /* m_got_entsize */
1549 M_GOT_XNumber, /* m_got_xnumber */
1550
1551 /* PLT related constants */
1552 M_PLT_ALIGN, /* m_plt_align */
1553 M_PLT_ENTSIZE, /* m_plt_entsize */
1554 M_PLT_RESERVSZ, /* m_plt_reservsz */
1555 M_PLT_SHF_FLAGS, /* m_plt_shf_flags */
1556
1557 /* Section type of .eh_frame/.eh_frame_hdr sections */
1558 SHT_AMD64_UNWIND, /* m_sht_unwind */
1559
1560 M_DT_REGISTER, /* m_dt_register */
1561 },
1562 { /* Target_machid */
1563 M_ID_ARRAY, /* id_array */
1564 M_ID_BSS, /* id_bss */
1565 M_ID_CAP, /* id_cap */
1566 M_ID_CAPINFO, /* id_capinfo */
1567 M_ID_CAPCHAIN, /* id_capchain */
1568 M_ID_DATA, /* id_data */
1569 M_ID_DYNAMIC, /* id_dynamic */
1570 M_ID_DYNSORT, /* id_dynsort */
1571 M_ID_DYNSTR, /* id_dynstr */
1572 M_ID_DYNSYM, /* id_dynsym */
1573 M_ID_DYNSYM_NDX, /* id_dynsym_ndx */
1574 M_ID_GOT, /* id_got */
1575 M_ID_UNKNOWN, /* id_gotdata (unused) */
1576 M_ID_HASH, /* id_hash */
1577 M_ID_INTERP, /* id_interp */
1578 M_ID_LBSS, /* id_lbss */
1579 M_ID_LDYNSYM, /* id_ldynsym */
1580 M_ID_NOTE, /* id_note */
1581 M_ID_NULL, /* id_null */
1582 M_ID_PLT, /* id_plt */
1583 M_ID_REL, /* id_rel */
1584 M_ID_STRTAB, /* id_strtab */
1585 M_ID_SYMINFO, /* id_syminfo */
1586 M_ID_SYMTAB, /* id_symtab */
1587 M_ID_SYMTAB_NDX, /* id_symtab_ndx */
1588 M_ID_TEXT, /* id_text */
1589 M_ID_TLS, /* id_tls */
1590 M_ID_TLSBSS, /* id_tlsbss */
1591 M_ID_UNKNOWN, /* id_unknown */
1592 M_ID_UNWIND, /* id_unwind */
1593 M_ID_UNWINDHDR, /* id_unwindhdr */
1594 M_ID_USER, /* id_user */
1595 M_ID_VERSION, /* id_version */
1596 },
1597 { /* Target_nullfunc */
1598 nullfunc_tmpl, /* nf_template */
1599 sizeof (nullfunc_tmpl), /* nf_size */
1600 },
1601 { /* Target_fillfunc */
1602 execfill /* ff_execfill */
1603 },
1604 { /* Target_machrel */
1605 reloc_table,
1606
1607 ld_init_rel, /* mr_init_rel */
1608 ld_mach_eflags, /* mr_mach_eflags */
1609 ld_mach_make_dynamic, /* mr_mach_make_dynamic */
1610 ld_mach_update_odynamic, /* mr_mach_update_odynamic */
1611 ld_calc_plt_addr, /* mr_calc_plt_addr */
1612 ld_perform_outreloc, /* mr_perform_outreloc */
1613 ld_do_activerelocs, /* mr_do_activerelocs */
1614 ld_add_outrel, /* mr_add_outrel */
1615 NULL, /* mr_reloc_register */
1616 ld_reloc_local, /* mr_reloc_local */
1617 NULL, /* mr_reloc_GOTOP */
1618 ld_reloc_TLS, /* mr_reloc_TLS */
1619 NULL, /* mr_assign_got */
1620 ld_find_got_ndx, /* mr_find_got_ndx */
1621 ld_calc_got_offset, /* mr_calc_got_offset */
1622 ld_assign_got_ndx, /* mr_assign_got_ndx */
1623 ld_assign_plt_ndx, /* mr_assign_plt_ndx */
1624 NULL, /* mr_allocate_got */
1625 ld_fillin_gotplt, /* mr_fillin_gotplt */
1626 },
1627 { /* Target_machsym */
1628 NULL, /* ms_reg_check */
1629 NULL, /* ms_mach_sym_typecheck */
1630 NULL, /* ms_is_regsym */
1631 NULL, /* ms_reg_find */
1632 NULL /* ms_reg_enter */
1633 }
1634 };
1635
1636 return (&_ld_targ);
1637 }
1638