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) 1990, 1991 UNIX System Laboratories, Inc.
24 * Copyright (c) 1988 AT&T
25 * All Rights Reserved
26 *
27 * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
28 */
29
30 /* Get the x86 version of the relocation engine */
31 #define DO_RELOC_LIBLD_X86
32
33 #include <string.h>
34 #include <stdio.h>
35 #include <sys/elf_386.h>
36 #include <debug.h>
37 #include <reloc.h>
38 #include <i386/machdep_x86.h>
39 #include "msg.h"
40 #include "_libld.h"
41
42 /*
43 * Search the GOT index list for a GOT entry with a matching reference.
44 */
45 /* ARGSUSED3 */
46 static Gotndx *
ld_find_got_ndx(Alist * alp,Gotref gref,Ofl_desc * ofl,Rel_desc * rdesc)47 ld_find_got_ndx(Alist *alp, Gotref gref, Ofl_desc *ofl, Rel_desc *rdesc)
48 {
49 Aliste idx;
50 Gotndx *gnp;
51
52 if ((gref == GOT_REF_TLSLD) && ofl->ofl_tlsldgotndx)
53 return (ofl->ofl_tlsldgotndx);
54
55 for (ALIST_TRAVERSE(alp, idx, gnp)) {
56 if (gnp->gn_gotref == gref)
57 return (gnp);
58 }
59 return (NULL);
60 }
61
62 static Xword
ld_calc_got_offset(Rel_desc * rdesc,Ofl_desc * ofl)63 ld_calc_got_offset(Rel_desc *rdesc, Ofl_desc *ofl)
64 {
65 Os_desc *osp = ofl->ofl_osgot;
66 Sym_desc *sdp = rdesc->rel_sym;
67 Xword gotndx;
68 Gotref gref;
69 Gotndx *gnp;
70
71 if (rdesc->rel_flags & FLG_REL_DTLS)
72 gref = GOT_REF_TLSGD;
73 else if (rdesc->rel_flags & FLG_REL_MTLS)
74 gref = GOT_REF_TLSLD;
75 else if (rdesc->rel_flags & FLG_REL_STLS)
76 gref = GOT_REF_TLSIE;
77 else
78 gref = GOT_REF_GENERIC;
79
80 gnp = ld_find_got_ndx(sdp->sd_GOTndxs, gref, ofl, NULL);
81 assert(gnp);
82
83 gotndx = (Xword)gnp->gn_gotndx;
84
85 if ((rdesc->rel_flags & FLG_REL_DTLS) &&
86 (rdesc->rel_rtype == R_386_TLS_DTPOFF32))
87 gotndx++;
88
89 return ((Xword)(osp->os_shdr->sh_addr + (gotndx * M_GOT_ENTSIZE)));
90 }
91
92 static Word
ld_init_rel(Rel_desc * reld,Word * typedata,void * reloc)93 ld_init_rel(Rel_desc *reld, Word *typedata, void *reloc)
94 {
95 Rel *rel = (Rel *)reloc;
96
97 /* LINTED */
98 reld->rel_rtype = (Word)ELF_R_TYPE(rel->r_info, M_MACH);
99 reld->rel_roffset = rel->r_offset;
100 reld->rel_raddend = 0;
101 *typedata = 0;
102
103 return ((Word)ELF_R_SYM(rel->r_info));
104 }
105
106 static void
ld_mach_eflags(Ehdr * ehdr,Ofl_desc * ofl)107 ld_mach_eflags(Ehdr *ehdr, Ofl_desc *ofl)
108 {
109 ofl->ofl_dehdr->e_flags |= ehdr->e_flags;
110 }
111
112 static void
ld_mach_make_dynamic(Ofl_desc * ofl,size_t * cnt)113 ld_mach_make_dynamic(Ofl_desc *ofl, size_t *cnt)
114 {
115 if (!(ofl->ofl_flags & FLG_OF_RELOBJ)) {
116 /*
117 * Create this entry if we are going to create a PLT table.
118 */
119 if (ofl->ofl_pltcnt)
120 (*cnt)++; /* DT_PLTGOT */
121 }
122 }
123
124 static void
ld_mach_update_odynamic(Ofl_desc * ofl,Dyn ** dyn)125 ld_mach_update_odynamic(Ofl_desc *ofl, Dyn **dyn)
126 {
127 if (((ofl->ofl_flags & FLG_OF_RELOBJ) == 0) && ofl->ofl_pltcnt) {
128 (*dyn)->d_tag = DT_PLTGOT;
129 if (ofl->ofl_osgot)
130 (*dyn)->d_un.d_ptr = ofl->ofl_osgot->os_shdr->sh_addr;
131 else
132 (*dyn)->d_un.d_ptr = 0;
133 (*dyn)++;
134 }
135 }
136
137 static Xword
ld_calc_plt_addr(Sym_desc * sdp,Ofl_desc * ofl)138 ld_calc_plt_addr(Sym_desc *sdp, Ofl_desc *ofl)
139 {
140 Xword value;
141
142 value = (Xword)(ofl->ofl_osplt->os_shdr->sh_addr) +
143 M_PLT_RESERVSZ + ((sdp->sd_aux->sa_PLTndx - 1) * M_PLT_ENTSIZE);
144 return (value);
145 }
146
147 /*
148 * Build a single plt entry - code is:
149 * if (building a.out)
150 * JMP *got_off
151 * else
152 * JMP *got_off@GOT(%ebx)
153 * PUSHL &rel_off
154 * JMP -n(%pc) # -n is pcrel offset to first plt entry
155 *
156 * The got_off@GOT entry gets filled with the address of the PUSHL,
157 * so the first pass through the plt jumps back here, jumping
158 * in turn to the first plt entry, which jumps to the dynamic
159 * linker. The dynamic linker then patches the GOT, rerouting
160 * future plt calls to the proper destination.
161 */
162 static void
plt_entry(Ofl_desc * ofl,Word rel_off,Sym_desc * sdp)163 plt_entry(Ofl_desc * ofl, Word rel_off, Sym_desc * sdp)
164 {
165 uchar_t *pltent, *gotent;
166 Sword plt_off;
167 Word got_off;
168 int bswap = (ofl->ofl_flags1 & FLG_OF1_ENCDIFF) != 0;
169
170 got_off = sdp->sd_aux->sa_PLTGOTndx * M_GOT_ENTSIZE;
171 plt_off = M_PLT_RESERVSZ + ((sdp->sd_aux->sa_PLTndx - 1) *
172 M_PLT_ENTSIZE);
173 pltent = (uchar_t *)(ofl->ofl_osplt->os_outdata->d_buf) + plt_off;
174 gotent = (uchar_t *)(ofl->ofl_osgot->os_outdata->d_buf) + got_off;
175
176 /*
177 * Fill in the got entry with the address of the next instruction.
178 */
179 /* LINTED */
180 *(Word *)gotent = ofl->ofl_osplt->os_shdr->sh_addr + plt_off +
181 M_PLT_INSSIZE;
182 if (bswap)
183 /* LINTED */
184 *(Word *)gotent = ld_bswap_Word(*(Word *)gotent);
185
186 if (!(ofl->ofl_flags & FLG_OF_SHAROBJ)) {
187 pltent[0] = M_SPECIAL_INST;
188 pltent[1] = M_JMP_DISP_IND;
189 pltent += 2;
190 /* LINTED */
191 *(Word *)pltent = (Word)(ofl->ofl_osgot->os_shdr->sh_addr +
192 got_off);
193 } else {
194 pltent[0] = M_SPECIAL_INST;
195 pltent[1] = M_JMP_REG_DISP_IND;
196 pltent += 2;
197 /* LINTED */
198 *(Word *)pltent = (Word)got_off;
199 }
200 if (bswap)
201 /* LINTED */
202 *(Word *)pltent = ld_bswap_Word(*(Word *)pltent);
203 pltent += 4;
204
205 pltent[0] = M_INST_PUSHL;
206 pltent++;
207 /* LINTED */
208 *(Word *)pltent = (Word)rel_off;
209 if (bswap)
210 /* LINTED */
211 *(Word *)pltent = ld_bswap_Word(*(Word *)pltent);
212 pltent += 4;
213
214 plt_off = -(plt_off + 16); /* JMP, PUSHL, JMP take 16 bytes */
215 pltent[0] = M_INST_JMP;
216 pltent++;
217 /* LINTED */
218 *(Word *)pltent = (Word)plt_off;
219 if (bswap)
220 /* LINTED */
221 *(Word *)pltent = ld_bswap_Word(*(Word *)pltent);
222 }
223
224 static uintptr_t
ld_perform_outreloc(Rel_desc * orsp,Ofl_desc * ofl,Boolean * remain_seen)225 ld_perform_outreloc(Rel_desc * orsp, Ofl_desc * ofl, Boolean *remain_seen)
226 {
227 Os_desc * relosp, * osp = 0;
228 Word ndx, roffset, value;
229 Rel rea;
230 char *relbits;
231 Sym_desc * sdp, * psym = (Sym_desc *)0;
232 int sectmoved = 0;
233
234 sdp = orsp->rel_sym;
235
236 /*
237 * If the section this relocation is against has been discarded
238 * (-zignore), then also discard (skip) the relocation itself.
239 */
240 if (orsp->rel_isdesc && ((orsp->rel_flags &
241 (FLG_REL_GOT | FLG_REL_BSS | FLG_REL_PLT | FLG_REL_NOINFO)) == 0) &&
242 (orsp->rel_isdesc->is_flags & FLG_IS_DISCARD)) {
243 DBG_CALL(Dbg_reloc_discard(ofl->ofl_lml, M_MACH, orsp));
244 return (1);
245 }
246
247 /*
248 * If this is a relocation against a move table, or expanded move
249 * table, adjust the relocation entries.
250 */
251 if (RELAUX_GET_MOVE(orsp))
252 ld_adj_movereloc(ofl, orsp);
253
254 /*
255 * If this is a relocation against a section using a partial initialized
256 * symbol, adjust the embedded symbol info.
257 *
258 * The second argument of the am_I_partial() is the value stored at the
259 * target address relocation is going to be applied.
260 */
261 if (ELF_ST_TYPE(sdp->sd_sym->st_info) == STT_SECTION) {
262 if (ofl->ofl_parsyms &&
263 (sdp->sd_isc->is_flags & FLG_IS_RELUPD) &&
264 /* LINTED */
265 (psym = ld_am_I_partial(orsp, *(Xword *)
266 ((uchar_t *)(orsp->rel_isdesc->is_indata->d_buf) +
267 orsp->rel_roffset)))) {
268 DBG_CALL(Dbg_move_outsctadj(ofl->ofl_lml, psym));
269 sectmoved = 1;
270 }
271 }
272
273 value = sdp->sd_sym->st_value;
274
275 if (orsp->rel_flags & FLG_REL_GOT) {
276 osp = ofl->ofl_osgot;
277 roffset = (Word)ld_calc_got_offset(orsp, ofl);
278
279 } else if (orsp->rel_flags & FLG_REL_PLT) {
280 /*
281 * Note that relocations for PLT's actually
282 * cause a relocation againt the GOT.
283 */
284 osp = ofl->ofl_osplt;
285 roffset = (Word) (ofl->ofl_osgot->os_shdr->sh_addr) +
286 sdp->sd_aux->sa_PLTGOTndx * M_GOT_ENTSIZE;
287
288 plt_entry(ofl, osp->os_relosdesc->os_szoutrels, sdp);
289
290 } else if (orsp->rel_flags & FLG_REL_BSS) {
291 /*
292 * This must be a R_386_COPY. For these set the roffset to
293 * point to the new symbols location.
294 */
295 osp = ofl->ofl_isbss->is_osdesc;
296 roffset = (Word)value;
297 } else {
298 osp = RELAUX_GET_OSDESC(orsp);
299
300 /*
301 * Calculate virtual offset of reference point; equals offset
302 * into section + vaddr of section for loadable sections, or
303 * offset plus section displacement for nonloadable sections.
304 */
305 roffset = orsp->rel_roffset +
306 (Off)_elf_getxoff(orsp->rel_isdesc->is_indata);
307 if (!(ofl->ofl_flags & FLG_OF_RELOBJ))
308 roffset += orsp->rel_isdesc->is_osdesc->
309 os_shdr->sh_addr;
310 }
311
312 if ((osp == 0) || ((relosp = osp->os_relosdesc) == 0))
313 relosp = ofl->ofl_osrel;
314
315 /*
316 * Assign the symbols index for the output relocation. If the
317 * relocation refers to a SECTION symbol then it's index is based upon
318 * the output sections symbols index. Otherwise the index can be
319 * derived from the symbols index itself.
320 */
321 if (orsp->rel_rtype == R_386_RELATIVE)
322 ndx = STN_UNDEF;
323 else if ((orsp->rel_flags & FLG_REL_SCNNDX) ||
324 (ELF_ST_TYPE(sdp->sd_sym->st_info) == STT_SECTION)) {
325 if (sectmoved == 0) {
326 /*
327 * Check for a null input section. This can
328 * occur if this relocation references a symbol
329 * generated by sym_add_sym().
330 */
331 if (sdp->sd_isc && sdp->sd_isc->is_osdesc)
332 ndx = sdp->sd_isc->is_osdesc->os_identndx;
333 else
334 ndx = sdp->sd_shndx;
335 } else
336 ndx = ofl->ofl_parexpnndx;
337 } else
338 ndx = sdp->sd_symndx;
339
340 /*
341 * If we have a replacement value for the relocation
342 * target, put it in place now.
343 */
344 if (orsp->rel_flags & FLG_REL_NADDEND) {
345 Xword addend = orsp->rel_raddend;
346 uchar_t *addr;
347
348 /*
349 * Get the address of the data item we need to modify.
350 */
351 addr = (uchar_t *)((uintptr_t)orsp->rel_roffset +
352 (uintptr_t)_elf_getxoff(orsp->rel_isdesc->is_indata));
353 addr += (uintptr_t)RELAUX_GET_OSDESC(orsp)->os_outdata->d_buf;
354 if (ld_reloc_targval_set(ofl, orsp, addr, addend) == 0)
355 return (S_ERROR);
356 }
357
358 relbits = (char *)relosp->os_outdata->d_buf;
359
360 rea.r_info = ELF_R_INFO(ndx, orsp->rel_rtype);
361 rea.r_offset = roffset;
362 DBG_CALL(Dbg_reloc_out(ofl, ELF_DBG_LD, SHT_REL, &rea, relosp->os_name,
363 ld_reloc_sym_name(orsp)));
364
365 /*
366 * Assert we haven't walked off the end of our relocation table.
367 */
368 assert(relosp->os_szoutrels <= relosp->os_shdr->sh_size);
369
370 (void) memcpy((relbits + relosp->os_szoutrels),
371 (char *)&rea, sizeof (Rel));
372 relosp->os_szoutrels += sizeof (Rel);
373
374 /*
375 * Determine if this relocation is against a non-writable, allocatable
376 * section. If so we may need to provide a text relocation diagnostic.
377 * Note that relocations against the .plt (R_386_JMP_SLOT) actually
378 * result in modifications to the .got.
379 */
380 if (orsp->rel_rtype == R_386_JMP_SLOT)
381 osp = ofl->ofl_osgot;
382
383 ld_reloc_remain_entry(orsp, osp, ofl, remain_seen);
384 return (1);
385 }
386
387 /*
388 * i386 Instructions for TLS processing
389 */
390 static uchar_t tlsinstr_gd_ie[] = {
391 /*
392 * 0x00 movl %gs:0x0, %eax
393 */
394 0x65, 0xa1, 0x00, 0x00, 0x00, 0x00,
395 /*
396 * 0x06 addl x(%eax), %eax
397 * 0x0c ...
398 */
399 0x03, 0x80, 0x00, 0x00, 0x00, 0x00
400 };
401
402 static uchar_t tlsinstr_gd_le[] = {
403 /*
404 * 0x00 movl %gs:0x0, %eax
405 */
406 0x65, 0xa1, 0x00, 0x00, 0x00, 0x00,
407 /*
408 * 0x06 addl $0x0, %eax
409 */
410 0x05, 0x00, 0x00, 0x00, 0x00,
411 /*
412 * 0x0b nop
413 * 0x0c
414 */
415 0x90
416 };
417
418 static uchar_t tlsinstr_gd_ie_movgs[] = {
419 /*
420 * movl %gs:0x0,%eax
421 */
422 0x65, 0xa1, 0x00, 0x00, 0x00, 00
423 };
424
425 #define TLS_GD_IE_MOV 0x8b /* movl opcode */
426 #define TLS_GD_IE_POP 0x58 /* popl + reg */
427
428 #define TLS_GD_LE_MOVL 0xb8 /* movl + reg */
429
430 #define TLS_NOP 0x90 /* NOP instruction */
431
432 #define MODRM_MSK_MOD 0xc0
433 #define MODRM_MSK_RO 0x38
434 #define MODRM_MSK_RM 0x07
435
436 #define SIB_MSK_SS 0xc0
437 #define SIB_MSK_IND 0x38
438 #define SIB_MSK_BS 0x07
439
440 static Fixupret
tls_fixups(Ofl_desc * ofl,Rel_desc * arsp)441 tls_fixups(Ofl_desc *ofl, Rel_desc *arsp)
442 {
443 Sym_desc *sdp = arsp->rel_sym;
444 Word rtype = arsp->rel_rtype;
445 uchar_t *offset, r1, r2;
446
447 offset = (uchar_t *)((uintptr_t)arsp->rel_roffset +
448 (uintptr_t)_elf_getxoff(arsp->rel_isdesc->is_indata) +
449 (uintptr_t)RELAUX_GET_OSDESC(arsp)->os_outdata->d_buf);
450
451 if (sdp->sd_ref == REF_DYN_NEED) {
452 /*
453 * IE reference model
454 */
455 switch (rtype) {
456 case R_386_TLS_GD:
457 /*
458 * Transition:
459 * 0x0 leal x@tlsgd(,r1,1), %eax
460 * 0x7 call ___tls_get_addr
461 * 0xc
462 * To:
463 * 0x0 movl %gs:0, %eax
464 * 0x6 addl x@gotntpoff(r1), %eax
465 */
466 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
467 R_386_TLS_GOTIE, arsp, ld_reloc_sym_name));
468 arsp->rel_rtype = R_386_TLS_GOTIE;
469 arsp->rel_roffset += 5;
470
471 /*
472 * Adjust 'offset' to beginning of instruction
473 * sequence.
474 */
475 offset -= 3;
476 r1 = (offset[2] & SIB_MSK_IND) >> 3;
477 (void) memcpy(offset, tlsinstr_gd_ie,
478 sizeof (tlsinstr_gd_ie));
479
480 /*
481 * set register %r1 into the addl
482 * instruction.
483 */
484 offset[0x7] |= r1;
485 return (FIX_RELOC);
486
487 case R_386_TLS_GD_PLT:
488 /*
489 * Fixup done via the TLS_GD relocation
490 */
491 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
492 R_386_NONE, arsp, ld_reloc_sym_name));
493 return (FIX_DONE);
494 }
495 }
496
497 /*
498 * LE reference model
499 */
500 switch (rtype) {
501 case R_386_TLS_GD:
502 /*
503 * Transition:
504 * 0x0 leal x@tlsgd(,r1,1), %eax
505 * 0x7 call ___tls_get_addr
506 * 0xc
507 * To:
508 * 0x0 movl %gs:0, %eax
509 * 0x6 addl $x@ntpoff, %eax
510 * 0xb nop
511 * 0xc
512 */
513 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
514 R_386_TLS_LE, arsp, ld_reloc_sym_name));
515
516 arsp->rel_rtype = R_386_TLS_LE;
517 arsp->rel_roffset += 4;
518
519 /*
520 * Adjust 'offset' to beginning of instruction
521 * sequence.
522 */
523 offset -= 3;
524 (void) memcpy(offset, tlsinstr_gd_le,
525 sizeof (tlsinstr_gd_le));
526 return (FIX_RELOC);
527
528 case R_386_TLS_GD_PLT:
529 case R_386_PLT32:
530 /*
531 * Fixup done via the TLS_GD relocation
532 */
533 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
534 R_386_NONE, arsp, ld_reloc_sym_name));
535 return (FIX_DONE);
536
537 case R_386_TLS_LDM_PLT:
538 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
539 R_386_NONE, arsp, ld_reloc_sym_name));
540
541 /*
542 * Transition:
543 * call __tls_get_addr()
544 * to:
545 * nop
546 * nop
547 * nop
548 * nop
549 * nop
550 */
551 *(offset - 1) = TLS_NOP;
552 *(offset) = TLS_NOP;
553 *(offset + 1) = TLS_NOP;
554 *(offset + 2) = TLS_NOP;
555 *(offset + 3) = TLS_NOP;
556 return (FIX_DONE);
557
558 case R_386_TLS_LDM:
559 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
560 R_386_NONE, arsp, ld_reloc_sym_name));
561
562 /*
563 * Transition:
564 *
565 * 0x00 leal x1@tlsldm(%ebx), %eax
566 * 0x06 call ___tls_get_addr
567 *
568 * to:
569 *
570 * 0x00 movl %gs:0, %eax
571 */
572 (void) memcpy(offset - 2, tlsinstr_gd_ie_movgs,
573 sizeof (tlsinstr_gd_ie_movgs));
574 return (FIX_DONE);
575
576 case R_386_TLS_LDO_32:
577 /*
578 * Instructions:
579 *
580 * 0x10 leal x1@dtpoff(%eax), %edx R_386_TLS_LDO_32
581 * to
582 * 0x10 leal x1@ntpoff(%eax), %edx R_386_TLS_LE
583 *
584 */
585 offset -= 2;
586
587 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
588 R_386_TLS_LE, arsp, ld_reloc_sym_name));
589 arsp->rel_rtype = R_386_TLS_LE;
590 return (FIX_RELOC);
591
592 case R_386_TLS_GOTIE:
593 /*
594 * These transitions are a little different than the
595 * others, in that we could have multiple instructions
596 * pointed to by a single relocation. Depending upon the
597 * instruction, we perform a different code transition.
598 *
599 * Here's the known transitions:
600 *
601 * 1) movl foo@gotntpoff(%reg1), %reg2
602 * 0x8b, 0x80 | (reg2 << 3) | reg1, foo@gotntpoff
603 *
604 * 2) addl foo@gotntpoff(%reg1), %reg2
605 * 0x03, 0x80 | (reg2 << 3) | reg1, foo@gotntpoff
606 *
607 * Transitions IE -> LE
608 *
609 * 1) movl $foo@ntpoff, %reg2
610 * 0xc7, 0xc0 | reg2, foo@ntpoff
611 *
612 * 2) addl $foo@ntpoff, %reg2
613 * 0x81, 0xc0 | reg2, foo@ntpoff
614 *
615 * Note: reg1 != 4 (%esp)
616 */
617 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH,
618 R_386_TLS_LE, arsp, ld_reloc_sym_name));
619 arsp->rel_rtype = R_386_TLS_LE;
620
621 offset -= 2;
622 r2 = (offset[1] & MODRM_MSK_RO) >> 3;
623 if (offset[0] == 0x8b) {
624 /* case 1 above */
625 offset[0] = 0xc7; /* movl */
626 offset[1] = 0xc0 | r2;
627 return (FIX_RELOC);
628 }
629
630 if (offset[0] == 0x03) {
631 /* case 2 above */
632 assert(offset[0] == 0x03);
633 offset[0] = 0x81; /* addl */
634 offset[1] = 0xc0 | r2;
635 return (FIX_RELOC);
636 }
637
638 /*
639 * Unexpected instruction sequence - fatal error.
640 */
641 {
642 Conv_inv_buf_t inv_buf;
643
644 ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_REL_BADTLSINS),
645 conv_reloc_386_type(arsp->rel_rtype, 0, &inv_buf),
646 arsp->rel_isdesc->is_file->ifl_name,
647 ld_reloc_sym_name(arsp),
648 arsp->rel_isdesc->is_name,
649 EC_OFF(arsp->rel_roffset));
650 }
651 return (FIX_ERROR);
652
653 case R_386_TLS_IE:
654 /*
655 * These transitions are a little different than the
656 * others, in that we could have multiple instructions
657 * pointed to by a single relocation. Depending upon the
658 * instruction, we perform a different code transition.
659 *
660 * Here's the known transitions:
661 * 1) movl foo@indntpoff, %eax
662 * 0xa1, foo@indntpoff
663 *
664 * 2) movl foo@indntpoff, %eax
665 * 0x8b, 0x05 | (reg << 3), foo@gotntpoff
666 *
667 * 3) addl foo@indntpoff, %eax
668 * 0x03, 0x05 | (reg << 3), foo@gotntpoff
669 *
670 * Transitions IE -> LE
671 *
672 * 1) movl $foo@ntpoff, %eax
673 * 0xb8, foo@ntpoff
674 *
675 * 2) movl $foo@ntpoff, %reg
676 * 0xc7, 0xc0 | reg, foo@ntpoff
677 *
678 * 3) addl $foo@ntpoff, %reg
679 * 0x81, 0xc0 | reg, foo@ntpoff
680 */
681 arsp->rel_rtype = R_386_TLS_LE;
682 offset--;
683 if (offset[0] == 0xa1) {
684 /* case 1 above */
685 offset[0] = 0xb8; /* movl */
686 return (FIX_RELOC);
687 }
688
689 offset--;
690 if (offset[0] == 0x8b) {
691 /* case 2 above */
692 r2 = (offset[1] & MODRM_MSK_RO) >> 3;
693 offset[0] = 0xc7; /* movl */
694 offset[1] = 0xc0 | r2;
695 return (FIX_RELOC);
696 }
697 if (offset[0] == 0x03) {
698 /* case 3 above */
699 r2 = (offset[1] & MODRM_MSK_RO) >> 3;
700 offset[0] = 0x81; /* addl */
701 offset[1] = 0xc0 | r2;
702 return (FIX_RELOC);
703 }
704 /*
705 * Unexpected instruction sequence - fatal error.
706 */
707 {
708 Conv_inv_buf_t inv_buf;
709
710 ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_REL_BADTLSINS),
711 conv_reloc_386_type(arsp->rel_rtype, 0, &inv_buf),
712 arsp->rel_isdesc->is_file->ifl_name,
713 ld_reloc_sym_name(arsp),
714 arsp->rel_isdesc->is_name,
715 EC_OFF(arsp->rel_roffset));
716 }
717 return (FIX_ERROR);
718 }
719 return (FIX_RELOC);
720 }
721
722 static uintptr_t
ld_do_activerelocs(Ofl_desc * ofl)723 ld_do_activerelocs(Ofl_desc *ofl)
724 {
725 Rel_desc *arsp;
726 Rel_cachebuf *rcbp;
727 Aliste idx;
728 uintptr_t return_code = 1;
729 ofl_flag_t flags = ofl->ofl_flags;
730
731 if (aplist_nitems(ofl->ofl_actrels.rc_list) != 0)
732 DBG_CALL(Dbg_reloc_doact_title(ofl->ofl_lml));
733
734 /*
735 * Process active relocations.
736 */
737 REL_CACHE_TRAVERSE(&ofl->ofl_actrels, idx, rcbp, arsp) {
738 uchar_t *addr;
739 Xword value;
740 Sym_desc *sdp;
741 const char *ifl_name;
742 Xword refaddr;
743 int moved = 0;
744 Gotref gref;
745 Os_desc *osp;
746
747 /*
748 * If the section this relocation is against has been discarded
749 * (-zignore), then discard (skip) the relocation itself.
750 */
751 if ((arsp->rel_isdesc->is_flags & FLG_IS_DISCARD) &&
752 ((arsp->rel_flags & (FLG_REL_GOT | FLG_REL_BSS |
753 FLG_REL_PLT | FLG_REL_NOINFO)) == 0)) {
754 DBG_CALL(Dbg_reloc_discard(ofl->ofl_lml, M_MACH, arsp));
755 continue;
756 }
757
758 /*
759 * We determine what the 'got reference' model (if required)
760 * is at this point. This needs to be done before tls_fixup()
761 * since it may 'transition' our instructions.
762 *
763 * The got table entries have already been assigned,
764 * and we bind to those initial entries.
765 */
766 if (arsp->rel_flags & FLG_REL_DTLS)
767 gref = GOT_REF_TLSGD;
768 else if (arsp->rel_flags & FLG_REL_MTLS)
769 gref = GOT_REF_TLSLD;
770 else if (arsp->rel_flags & FLG_REL_STLS)
771 gref = GOT_REF_TLSIE;
772 else
773 gref = GOT_REF_GENERIC;
774
775 /*
776 * Perform any required TLS fixups.
777 */
778 if (arsp->rel_flags & FLG_REL_TLSFIX) {
779 Fixupret ret;
780
781 if ((ret = tls_fixups(ofl, arsp)) == FIX_ERROR)
782 return (S_ERROR);
783 if (ret == FIX_DONE)
784 continue;
785 }
786
787 /*
788 * If this is a relocation against a move table, or
789 * expanded move table, adjust the relocation entries.
790 */
791 if (RELAUX_GET_MOVE(arsp))
792 ld_adj_movereloc(ofl, arsp);
793
794 sdp = arsp->rel_sym;
795 refaddr = arsp->rel_roffset +
796 (Off)_elf_getxoff(arsp->rel_isdesc->is_indata);
797
798 if (arsp->rel_flags & FLG_REL_CLVAL)
799 value = 0;
800 else if (ELF_ST_TYPE(sdp->sd_sym->st_info) == STT_SECTION) {
801 /*
802 * The value for a symbol pointing to a SECTION
803 * is based off of that sections position.
804 */
805 if (sdp->sd_isc->is_flags & FLG_IS_RELUPD) {
806 Sym_desc *sym;
807 Xword radd;
808 uchar_t *raddr = (uchar_t *)
809 arsp->rel_isdesc->is_indata->d_buf +
810 arsp->rel_roffset;
811
812 /*
813 * This is a REL platform. Hence, the second
814 * argument of ld_am_I_partial() is the value
815 * stored at the target address where the
816 * relocation is going to be applied.
817 */
818 if (ld_reloc_targval_get(ofl, arsp, raddr,
819 &radd) == 0)
820 return (S_ERROR);
821 sym = ld_am_I_partial(arsp, radd);
822 if (sym) {
823 Sym *osym = sym->sd_osym;
824
825 /*
826 * The symbol was moved, so adjust the
827 * value relative to the new section.
828 */
829 value = sym->sd_sym->st_value;
830 moved = 1;
831
832 /*
833 * The original raddend covers the
834 * displacement from the section start
835 * to the desired address. The value
836 * computed above gets us from the
837 * section start to the start of the
838 * symbol range. Adjust the old raddend
839 * to remove the offset from section
840 * start to symbol start, leaving the
841 * displacement within the range of
842 * the symbol.
843 */
844 if (osym->st_value != 0) {
845 radd -= osym->st_value;
846 if (ld_reloc_targval_set(ofl,
847 arsp, raddr, radd) == 0)
848 return (S_ERROR);
849 }
850 }
851 }
852 if (!moved) {
853 value = _elf_getxoff(sdp->sd_isc->is_indata);
854 if (sdp->sd_isc->is_shdr->sh_flags & SHF_ALLOC)
855 value += sdp->sd_isc->
856 is_osdesc->os_shdr->sh_addr;
857 }
858 if (sdp->sd_isc->is_shdr->sh_flags & SHF_TLS)
859 value -= ofl->ofl_tlsphdr->p_vaddr;
860
861 } else if (IS_SIZE(arsp->rel_rtype)) {
862 /*
863 * Size relocations require the symbols size.
864 */
865 value = sdp->sd_sym->st_size;
866
867 } else if ((sdp->sd_flags & FLG_SY_CAP) &&
868 sdp->sd_aux && sdp->sd_aux->sa_PLTndx) {
869 /*
870 * If relocation is against a capabilities symbol, we
871 * need to jump to an associated PLT, so that at runtime
872 * ld.so.1 is involved to determine the best binding
873 * choice. Otherwise, the value is the symbols value.
874 */
875 value = ld_calc_plt_addr(sdp, ofl);
876
877 } else
878 value = sdp->sd_sym->st_value;
879
880 /*
881 * Relocation against the GLOBAL_OFFSET_TABLE.
882 */
883 if ((arsp->rel_flags & FLG_REL_GOT) &&
884 !ld_reloc_set_aux_osdesc(ofl, arsp, ofl->ofl_osgot))
885 return (S_ERROR);
886 osp = RELAUX_GET_OSDESC(arsp);
887
888 /*
889 * If loadable and not producing a relocatable object add the
890 * sections virtual address to the reference address.
891 */
892 if ((arsp->rel_flags & FLG_REL_LOAD) &&
893 ((flags & FLG_OF_RELOBJ) == 0))
894 refaddr +=
895 arsp->rel_isdesc->is_osdesc->os_shdr->sh_addr;
896
897 /*
898 * If this entry has a PLT assigned to it, its value is actually
899 * the address of the PLT (and not the address of the function).
900 */
901 if (IS_PLT(arsp->rel_rtype)) {
902 if (sdp->sd_aux && sdp->sd_aux->sa_PLTndx)
903 value = ld_calc_plt_addr(sdp, ofl);
904 }
905
906 /*
907 * Determine whether the value needs further adjustment. Filter
908 * through the attributes of the relocation to determine what
909 * adjustment is required. Note, many of the following cases
910 * are only applicable when a .got is present. As a .got is
911 * not generated when a relocatable object is being built,
912 * any adjustments that require a .got need to be skipped.
913 */
914 if ((arsp->rel_flags & FLG_REL_GOT) &&
915 ((flags & FLG_OF_RELOBJ) == 0)) {
916 Xword R1addr;
917 uintptr_t R2addr;
918 Word gotndx;
919 Gotndx *gnp;
920
921 /*
922 * Perform relocation against GOT table. Since this
923 * doesn't fit exactly into a relocation we place the
924 * appropriate byte in the GOT directly
925 *
926 * Calculate offset into GOT at which to apply
927 * the relocation.
928 */
929 gnp = ld_find_got_ndx(sdp->sd_GOTndxs, gref, ofl, NULL);
930 assert(gnp);
931
932 if (arsp->rel_rtype == R_386_TLS_DTPOFF32)
933 gotndx = gnp->gn_gotndx + 1;
934 else
935 gotndx = gnp->gn_gotndx;
936
937 R1addr = (Xword)(gotndx * M_GOT_ENTSIZE);
938
939 /*
940 * Add the GOTs data's offset.
941 */
942 R2addr = R1addr + (uintptr_t)osp->os_outdata->d_buf;
943
944 DBG_CALL(Dbg_reloc_doact(ofl->ofl_lml, ELF_DBG_LD_ACT,
945 M_MACH, SHT_REL, arsp, R1addr, value,
946 ld_reloc_sym_name));
947
948 /*
949 * And do it.
950 */
951 if (ofl->ofl_flags1 & FLG_OF1_ENCDIFF)
952 *(Xword *)R2addr = ld_bswap_Xword(value);
953 else
954 *(Xword *)R2addr = value;
955 continue;
956
957 } else if (IS_GOT_BASED(arsp->rel_rtype) &&
958 ((flags & FLG_OF_RELOBJ) == 0)) {
959 value -= ofl->ofl_osgot->os_shdr->sh_addr;
960
961 } else if (IS_GOT_PC(arsp->rel_rtype) &&
962 ((flags & FLG_OF_RELOBJ) == 0)) {
963 value = (Xword)(ofl->ofl_osgot->os_shdr->sh_addr) -
964 refaddr;
965
966 } else if ((IS_PC_RELATIVE(arsp->rel_rtype)) &&
967 (((flags & FLG_OF_RELOBJ) == 0) ||
968 (osp == sdp->sd_isc->is_osdesc))) {
969 value -= refaddr;
970
971 } else if (IS_TLS_INS(arsp->rel_rtype) &&
972 IS_GOT_RELATIVE(arsp->rel_rtype) &&
973 ((flags & FLG_OF_RELOBJ) == 0)) {
974 Gotndx *gnp;
975
976 gnp = ld_find_got_ndx(sdp->sd_GOTndxs, gref, ofl, NULL);
977 assert(gnp);
978 value = (Xword)gnp->gn_gotndx * M_GOT_ENTSIZE;
979 if (arsp->rel_rtype == R_386_TLS_IE) {
980 value += ofl->ofl_osgot->os_shdr->sh_addr;
981 }
982
983 } else if (IS_GOT_RELATIVE(arsp->rel_rtype) &&
984 ((flags & FLG_OF_RELOBJ) == 0)) {
985 Gotndx *gnp;
986
987 gnp = ld_find_got_ndx(sdp->sd_GOTndxs,
988 GOT_REF_GENERIC, ofl, NULL);
989 assert(gnp);
990 value = (Xword)gnp->gn_gotndx * M_GOT_ENTSIZE;
991
992 } else if ((arsp->rel_flags & FLG_REL_STLS) &&
993 ((flags & FLG_OF_RELOBJ) == 0)) {
994 Xword tlsstatsize;
995
996 /*
997 * This is the LE TLS reference model. Static
998 * offset is hard-coded.
999 */
1000 tlsstatsize = S_ROUND(ofl->ofl_tlsphdr->p_memsz,
1001 M_TLSSTATALIGN);
1002 value = tlsstatsize - value;
1003
1004 /*
1005 * Since this code is fixed up, it assumes a
1006 * negative offset that can be added to the
1007 * thread pointer.
1008 */
1009 if ((arsp->rel_rtype == R_386_TLS_LDO_32) ||
1010 (arsp->rel_rtype == R_386_TLS_LE))
1011 value = -value;
1012 }
1013
1014 if (arsp->rel_isdesc->is_file)
1015 ifl_name = arsp->rel_isdesc->is_file->ifl_name;
1016 else
1017 ifl_name = MSG_INTL(MSG_STR_NULL);
1018
1019 /*
1020 * Make sure we have data to relocate. Compiler and assembler
1021 * developers have been known to generate relocations against
1022 * invalid sections (normally .bss), so for their benefit give
1023 * them sufficient information to help analyze the problem.
1024 * End users should never see this.
1025 */
1026 if (arsp->rel_isdesc->is_indata->d_buf == 0) {
1027 Conv_inv_buf_t inv_buf;
1028
1029 ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_REL_EMPTYSEC),
1030 conv_reloc_386_type(arsp->rel_rtype, 0, &inv_buf),
1031 ifl_name, ld_reloc_sym_name(arsp),
1032 EC_WORD(arsp->rel_isdesc->is_scnndx),
1033 arsp->rel_isdesc->is_name);
1034 return (S_ERROR);
1035 }
1036
1037 /*
1038 * Get the address of the data item we need to modify.
1039 */
1040 addr = (uchar_t *)((uintptr_t)arsp->rel_roffset +
1041 (uintptr_t)_elf_getxoff(arsp->rel_isdesc->is_indata));
1042
1043 DBG_CALL(Dbg_reloc_doact(ofl->ofl_lml, ELF_DBG_LD_ACT,
1044 M_MACH, SHT_REL, arsp, EC_NATPTR(addr), value,
1045 ld_reloc_sym_name));
1046 addr += (uintptr_t)osp->os_outdata->d_buf;
1047
1048 if ((((uintptr_t)addr - (uintptr_t)ofl->ofl_nehdr) >
1049 ofl->ofl_size) || (arsp->rel_roffset >
1050 osp->os_shdr->sh_size)) {
1051 Conv_inv_buf_t inv_buf;
1052 int class;
1053
1054 if (((uintptr_t)addr - (uintptr_t)ofl->ofl_nehdr) >
1055 ofl->ofl_size)
1056 class = ERR_FATAL;
1057 else
1058 class = ERR_WARNING;
1059
1060 ld_eprintf(ofl, class, MSG_INTL(MSG_REL_INVALOFFSET),
1061 conv_reloc_386_type(arsp->rel_rtype, 0, &inv_buf),
1062 ifl_name, EC_WORD(arsp->rel_isdesc->is_scnndx),
1063 arsp->rel_isdesc->is_name, ld_reloc_sym_name(arsp),
1064 EC_ADDR((uintptr_t)addr -
1065 (uintptr_t)ofl->ofl_nehdr));
1066
1067 if (class == ERR_FATAL) {
1068 return_code = S_ERROR;
1069 continue;
1070 }
1071 }
1072
1073 /*
1074 * The relocation is additive. Ignore the previous symbol
1075 * value if this local partial symbol is expanded.
1076 */
1077 if (moved)
1078 value -= *addr;
1079
1080 /*
1081 * If we have a replacement value for the relocation
1082 * target, put it in place now.
1083 */
1084 if (arsp->rel_flags & FLG_REL_NADDEND) {
1085 Xword addend = arsp->rel_raddend;
1086
1087 if (ld_reloc_targval_set(ofl, arsp, addr, addend) == 0)
1088 return (S_ERROR);
1089 }
1090
1091 /*
1092 * If '-z noreloc' is specified - skip the do_reloc_ld stage.
1093 */
1094 if (OFL_DO_RELOC(ofl)) {
1095 if (do_reloc_ld(arsp, addr, &value, ld_reloc_sym_name,
1096 ifl_name, OFL_SWAP_RELOC_DATA(ofl, arsp),
1097 ofl->ofl_lml) == 0) {
1098 ofl->ofl_flags |= FLG_OF_FATAL;
1099 return_code = S_ERROR;
1100 }
1101 }
1102 }
1103 return (return_code);
1104 }
1105
1106 /*
1107 * Add an output relocation record.
1108 */
1109 static uintptr_t
ld_add_outrel(Word flags,Rel_desc * rsp,Ofl_desc * ofl)1110 ld_add_outrel(Word flags, Rel_desc *rsp, Ofl_desc *ofl)
1111 {
1112 Rel_desc *orsp;
1113 Sym_desc *sdp = rsp->rel_sym;
1114
1115 /*
1116 * Static executables *do not* want any relocations against them.
1117 * Since our engine still creates relocations against a WEAK UNDEFINED
1118 * symbol in a static executable, it's best to disable them here
1119 * instead of through out the relocation code.
1120 */
1121 if (OFL_IS_STATIC_EXEC(ofl))
1122 return (1);
1123
1124 /*
1125 * If we are adding a output relocation against a section
1126 * symbol (non-RELATIVE) then mark that section. These sections
1127 * will be added to the .dynsym symbol table.
1128 */
1129 if (sdp && (rsp->rel_rtype != M_R_RELATIVE) &&
1130 ((flags & FLG_REL_SCNNDX) ||
1131 (ELF_ST_TYPE(sdp->sd_sym->st_info) == STT_SECTION))) {
1132
1133 /*
1134 * If this is a COMMON symbol - no output section
1135 * exists yet - (it's created as part of sym_validate()).
1136 * So - we mark here that when it's created it should
1137 * be tagged with the FLG_OS_OUTREL flag.
1138 */
1139 if ((sdp->sd_flags & FLG_SY_SPECSEC) &&
1140 (sdp->sd_sym->st_shndx == SHN_COMMON)) {
1141 if (ELF_ST_TYPE(sdp->sd_sym->st_info) != STT_TLS)
1142 ofl->ofl_flags1 |= FLG_OF1_BSSOREL;
1143 else
1144 ofl->ofl_flags1 |= FLG_OF1_TLSOREL;
1145 } else {
1146 Os_desc *osp;
1147 Is_desc *isp = sdp->sd_isc;
1148
1149 if (isp && ((osp = isp->is_osdesc) != NULL) &&
1150 ((osp->os_flags & FLG_OS_OUTREL) == 0)) {
1151 ofl->ofl_dynshdrcnt++;
1152 osp->os_flags |= FLG_OS_OUTREL;
1153 }
1154 }
1155 }
1156
1157 /* Enter it into the output relocation cache */
1158 if ((orsp = ld_reloc_enter(ofl, &ofl->ofl_outrels, rsp, flags)) == NULL)
1159 return (S_ERROR);
1160
1161 if (flags & FLG_REL_GOT)
1162 ofl->ofl_relocgotsz += (Xword)sizeof (Rel);
1163 else if (flags & FLG_REL_PLT)
1164 ofl->ofl_relocpltsz += (Xword)sizeof (Rel);
1165 else if (flags & FLG_REL_BSS)
1166 ofl->ofl_relocbsssz += (Xword)sizeof (Rel);
1167 else if (flags & FLG_REL_NOINFO)
1168 ofl->ofl_relocrelsz += (Xword)sizeof (Rel);
1169 else
1170 RELAUX_GET_OSDESC(orsp)->os_szoutrels += (Xword)sizeof (Rel);
1171
1172 if (orsp->rel_rtype == M_R_RELATIVE)
1173 ofl->ofl_relocrelcnt++;
1174
1175 /*
1176 * We don't perform sorting on PLT relocations because
1177 * they have already been assigned a PLT index and if we
1178 * were to sort them we would have to re-assign the plt indexes.
1179 */
1180 if (!(flags & FLG_REL_PLT))
1181 ofl->ofl_reloccnt++;
1182
1183 /*
1184 * Insure a GLOBAL_OFFSET_TABLE is generated if required.
1185 */
1186 if (IS_GOT_REQUIRED(orsp->rel_rtype))
1187 ofl->ofl_flags |= FLG_OF_BLDGOT;
1188
1189 /*
1190 * Identify and possibly warn of a displacement relocation.
1191 */
1192 if (orsp->rel_flags & FLG_REL_DISP) {
1193 ofl->ofl_dtflags_1 |= DF_1_DISPRELPND;
1194
1195 if (ofl->ofl_flags & FLG_OF_VERBOSE)
1196 ld_disp_errmsg(MSG_INTL(MSG_REL_DISPREL4), orsp, ofl);
1197 }
1198 DBG_CALL(Dbg_reloc_ors_entry(ofl->ofl_lml, ELF_DBG_LD, SHT_REL,
1199 M_MACH, orsp));
1200 return (1);
1201 }
1202
1203 /*
1204 * process relocation for a LOCAL symbol
1205 */
1206 static uintptr_t
ld_reloc_local(Rel_desc * rsp,Ofl_desc * ofl)1207 ld_reloc_local(Rel_desc * rsp, Ofl_desc * ofl)
1208 {
1209 ofl_flag_t flags = ofl->ofl_flags;
1210 Sym_desc *sdp = rsp->rel_sym;
1211 Word shndx = sdp->sd_sym->st_shndx;
1212
1213 /*
1214 * if ((shared object) and (not pc relative relocation) and
1215 * (not against ABS symbol))
1216 * then
1217 * build R_386_RELATIVE
1218 * fi
1219 */
1220 if ((flags & FLG_OF_SHAROBJ) && (rsp->rel_flags & FLG_REL_LOAD) &&
1221 !(IS_PC_RELATIVE(rsp->rel_rtype)) && !(IS_SIZE(rsp->rel_rtype)) &&
1222 !(IS_GOT_BASED(rsp->rel_rtype)) &&
1223 !(rsp->rel_isdesc != NULL &&
1224 (rsp->rel_isdesc->is_shdr->sh_type == SHT_SUNW_dof)) &&
1225 (((sdp->sd_flags & FLG_SY_SPECSEC) == 0) ||
1226 (shndx != SHN_ABS) || (sdp->sd_aux && sdp->sd_aux->sa_symspec))) {
1227 Word ortype = rsp->rel_rtype;
1228
1229 rsp->rel_rtype = R_386_RELATIVE;
1230 if (ld_add_outrel(NULL, rsp, ofl) == S_ERROR)
1231 return (S_ERROR);
1232 rsp->rel_rtype = ortype;
1233 }
1234
1235 /*
1236 * If the relocation is against a 'non-allocatable' section
1237 * and we can not resolve it now - then give a warning
1238 * message.
1239 *
1240 * We can not resolve the symbol if either:
1241 * a) it's undefined
1242 * b) it's defined in a shared library and a
1243 * COPY relocation hasn't moved it to the executable
1244 *
1245 * Note: because we process all of the relocations against the
1246 * text segment before any others - we know whether
1247 * or not a copy relocation will be generated before
1248 * we get here (see reloc_init()->reloc_segments()).
1249 */
1250 if (!(rsp->rel_flags & FLG_REL_LOAD) &&
1251 ((shndx == SHN_UNDEF) ||
1252 ((sdp->sd_ref == REF_DYN_NEED) &&
1253 ((sdp->sd_flags & FLG_SY_MVTOCOMM) == 0)))) {
1254 Conv_inv_buf_t inv_buf;
1255 Os_desc *osp = RELAUX_GET_OSDESC(rsp);
1256
1257 /*
1258 * If the relocation is against a SHT_SUNW_ANNOTATE
1259 * section - then silently ignore that the relocation
1260 * can not be resolved.
1261 */
1262 if (osp && (osp->os_shdr->sh_type == SHT_SUNW_ANNOTATE))
1263 return (0);
1264 ld_eprintf(ofl, ERR_WARNING, MSG_INTL(MSG_REL_EXTERNSYM),
1265 conv_reloc_386_type(rsp->rel_rtype, 0, &inv_buf),
1266 rsp->rel_isdesc->is_file->ifl_name,
1267 ld_reloc_sym_name(rsp), osp->os_name);
1268 return (1);
1269 }
1270
1271 /*
1272 * Perform relocation.
1273 */
1274 return (ld_add_actrel(NULL, rsp, ofl));
1275 }
1276
1277 static uintptr_t
ld_reloc_TLS(Boolean local,Rel_desc * rsp,Ofl_desc * ofl)1278 ld_reloc_TLS(Boolean local, Rel_desc * rsp, Ofl_desc * ofl)
1279 {
1280 Word rtype = rsp->rel_rtype;
1281 Sym_desc *sdp = rsp->rel_sym;
1282 ofl_flag_t flags = ofl->ofl_flags;
1283 Gotndx *gnp;
1284
1285 /*
1286 * If we're building an executable - use either the IE or LE access
1287 * model. If we're building a shared object process any IE model.
1288 */
1289 if ((flags & FLG_OF_EXEC) || (IS_TLS_IE(rtype))) {
1290 /*
1291 * Set the DF_STATIC_TLS flag.
1292 */
1293 ofl->ofl_dtflags |= DF_STATIC_TLS;
1294
1295 if (!local || ((flags & FLG_OF_EXEC) == 0)) {
1296 /*
1297 * Assign a GOT entry for static TLS references.
1298 */
1299 if ((gnp = ld_find_got_ndx(sdp->sd_GOTndxs,
1300 GOT_REF_TLSIE, ofl, NULL)) == NULL) {
1301
1302 if (ld_assign_got_TLS(local, rsp, ofl, sdp,
1303 gnp, GOT_REF_TLSIE, FLG_REL_STLS,
1304 rtype, R_386_TLS_TPOFF, NULL) == S_ERROR)
1305 return (S_ERROR);
1306 }
1307
1308 /*
1309 * IE access model.
1310 */
1311 if (IS_TLS_IE(rtype)) {
1312 if (ld_add_actrel(FLG_REL_STLS,
1313 rsp, ofl) == S_ERROR)
1314 return (S_ERROR);
1315
1316 /*
1317 * A non-pic shared object needs to adjust the
1318 * active relocation (indntpoff).
1319 */
1320 if (((flags & FLG_OF_EXEC) == 0) &&
1321 (rtype == R_386_TLS_IE)) {
1322 rsp->rel_rtype = R_386_RELATIVE;
1323 return (ld_add_outrel(NULL, rsp, ofl));
1324 }
1325 return (1);
1326 }
1327
1328 /*
1329 * Fixups are required for other executable models.
1330 */
1331 return (ld_add_actrel((FLG_REL_TLSFIX | FLG_REL_STLS),
1332 rsp, ofl));
1333 }
1334
1335 /*
1336 * LE access model.
1337 */
1338 if (IS_TLS_LE(rtype) || (rtype == R_386_TLS_LDO_32))
1339 return (ld_add_actrel(FLG_REL_STLS, rsp, ofl));
1340
1341 return (ld_add_actrel((FLG_REL_TLSFIX | FLG_REL_STLS),
1342 rsp, ofl));
1343 }
1344
1345 /*
1346 * Building a shared object.
1347 *
1348 * Assign a GOT entry for a dynamic TLS reference.
1349 */
1350 if (IS_TLS_LD(rtype) && ((gnp = ld_find_got_ndx(sdp->sd_GOTndxs,
1351 GOT_REF_TLSLD, ofl, NULL)) == NULL)) {
1352
1353 if (ld_assign_got_TLS(local, rsp, ofl, sdp, gnp, GOT_REF_TLSLD,
1354 FLG_REL_MTLS, rtype, R_386_TLS_DTPMOD32, NULL) == S_ERROR)
1355 return (S_ERROR);
1356
1357 } else if (IS_TLS_GD(rtype) && ((gnp = ld_find_got_ndx(sdp->sd_GOTndxs,
1358 GOT_REF_TLSGD, ofl, NULL)) == NULL)) {
1359
1360 if (ld_assign_got_TLS(local, rsp, ofl, sdp, gnp, GOT_REF_TLSGD,
1361 FLG_REL_DTLS, rtype, R_386_TLS_DTPMOD32,
1362 R_386_TLS_DTPOFF32) == S_ERROR)
1363 return (S_ERROR);
1364 }
1365
1366 /*
1367 * For GD/LD TLS reference - TLS_{GD,LD}_CALL, this will eventually
1368 * cause a call to __tls_get_addr(). Convert this relocation to that
1369 * symbol now, and prepare for the PLT magic.
1370 */
1371 if ((rtype == R_386_TLS_GD_PLT) || (rtype == R_386_TLS_LDM_PLT)) {
1372 Sym_desc *tlsgetsym;
1373
1374 if ((tlsgetsym = ld_sym_add_u(MSG_ORIG(MSG_SYM_TLSGETADDR_UU),
1375 ofl, MSG_STR_TLSREL)) == (Sym_desc *)S_ERROR)
1376 return (S_ERROR);
1377
1378 rsp->rel_sym = tlsgetsym;
1379 rsp->rel_rtype = R_386_PLT32;
1380
1381 if (ld_reloc_plt(rsp, ofl) == S_ERROR)
1382 return (S_ERROR);
1383
1384 rsp->rel_sym = sdp;
1385 rsp->rel_rtype = rtype;
1386 return (1);
1387 }
1388
1389 if (IS_TLS_LD(rtype))
1390 return (ld_add_actrel(FLG_REL_MTLS, rsp, ofl));
1391
1392 return (ld_add_actrel(FLG_REL_DTLS, rsp, ofl));
1393 }
1394
1395 /* ARGSUSED4 */
1396 static uintptr_t
ld_assign_got_ndx(Alist ** alpp,Gotndx * pgnp,Gotref gref,Ofl_desc * ofl,Rel_desc * rsp,Sym_desc * sdp)1397 ld_assign_got_ndx(Alist **alpp, Gotndx *pgnp, Gotref gref, Ofl_desc *ofl,
1398 Rel_desc *rsp, Sym_desc *sdp)
1399 {
1400 Gotndx gn, *gnp;
1401 uint_t gotents;
1402
1403 if (pgnp)
1404 return (1);
1405
1406 if ((gref == GOT_REF_TLSGD) || (gref == GOT_REF_TLSLD))
1407 gotents = 2;
1408 else
1409 gotents = 1;
1410
1411 gn.gn_addend = 0;
1412 gn.gn_gotndx = ofl->ofl_gotcnt;
1413 gn.gn_gotref = gref;
1414
1415 ofl->ofl_gotcnt += gotents;
1416
1417 if (gref == GOT_REF_TLSLD) {
1418 if (ofl->ofl_tlsldgotndx == NULL) {
1419 if ((gnp = libld_malloc(sizeof (Gotndx))) == NULL)
1420 return (S_ERROR);
1421 (void) memcpy(gnp, &gn, sizeof (Gotndx));
1422 ofl->ofl_tlsldgotndx = gnp;
1423 }
1424 return (1);
1425 }
1426
1427 /*
1428 * GOT indexes are maintained on an Alist, where there is typically
1429 * only one index. The usage of this list is to scan the list to find
1430 * an index, and then apply that index immediately to a relocation.
1431 * Thus there are no external references to these GOT index structures
1432 * that can be compromised by the Alist being reallocated.
1433 */
1434 if (alist_append(alpp, &gn, sizeof (Gotndx), AL_CNT_SDP_GOT) == NULL)
1435 return (S_ERROR);
1436
1437 return (1);
1438 }
1439
1440 static void
ld_assign_plt_ndx(Sym_desc * sdp,Ofl_desc * ofl)1441 ld_assign_plt_ndx(Sym_desc * sdp, Ofl_desc *ofl)
1442 {
1443 sdp->sd_aux->sa_PLTndx = 1 + ofl->ofl_pltcnt++;
1444 sdp->sd_aux->sa_PLTGOTndx = ofl->ofl_gotcnt++;
1445 ofl->ofl_flags |= FLG_OF_BLDGOT;
1446 }
1447
1448 /*
1449 * Initializes .got[0] with the _DYNAMIC symbol value.
1450 */
1451 static uintptr_t
ld_fillin_gotplt(Ofl_desc * ofl)1452 ld_fillin_gotplt(Ofl_desc *ofl)
1453 {
1454 ofl_flag_t flags = ofl->ofl_flags;
1455 int bswap = (ofl->ofl_flags1 & FLG_OF1_ENCDIFF) != 0;
1456
1457 if (ofl->ofl_osgot) {
1458 Sym_desc *sdp;
1459
1460 if ((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_DYNAMIC_U),
1461 SYM_NOHASH, NULL, ofl)) != NULL) {
1462 uchar_t *genptr;
1463
1464 genptr = ((uchar_t *)ofl->ofl_osgot->os_outdata->d_buf +
1465 (M_GOT_XDYNAMIC * M_GOT_ENTSIZE));
1466 /* LINTED */
1467 *(Word *)genptr = (Word)sdp->sd_sym->st_value;
1468 if (bswap)
1469 /* LINTED */
1470 *(Word *)genptr =
1471 /* LINTED */
1472 ld_bswap_Word(*(Word *)genptr);
1473 }
1474 }
1475
1476 /*
1477 * Fill in the reserved slot in the procedure linkage table the first
1478 * entry is:
1479 * if (building a.out) {
1480 * PUSHL got[1] # the address of the link map entry
1481 * JMP * got[2] # the address of rtbinder
1482 * } else {
1483 * PUSHL got[1]@GOT(%ebx) # the address of the link map entry
1484 * JMP * got[2]@GOT(%ebx) # the address of rtbinder
1485 * }
1486 */
1487 if ((flags & FLG_OF_DYNAMIC) && ofl->ofl_osplt) {
1488 uchar_t *pltent;
1489
1490 pltent = (uchar_t *)ofl->ofl_osplt->os_outdata->d_buf;
1491 if (!(flags & FLG_OF_SHAROBJ)) {
1492 pltent[0] = M_SPECIAL_INST;
1493 pltent[1] = M_PUSHL_DISP;
1494 pltent += 2;
1495 /* LINTED */
1496 *(Word *)pltent = (Word)(ofl->ofl_osgot->os_shdr->
1497 sh_addr + M_GOT_XLINKMAP * M_GOT_ENTSIZE);
1498 if (bswap)
1499 /* LINTED */
1500 *(Word *)pltent =
1501 /* LINTED */
1502 ld_bswap_Word(*(Word *)pltent);
1503 pltent += 4;
1504 pltent[0] = M_SPECIAL_INST;
1505 pltent[1] = M_JMP_DISP_IND;
1506 pltent += 2;
1507 /* LINTED */
1508 *(Word *)pltent = (Word)(ofl->ofl_osgot->os_shdr->
1509 sh_addr + M_GOT_XRTLD * M_GOT_ENTSIZE);
1510 if (bswap)
1511 /* LINTED */
1512 *(Word *)pltent =
1513 /* LINTED */
1514 ld_bswap_Word(*(Word *)pltent);
1515 } else {
1516 pltent[0] = M_SPECIAL_INST;
1517 pltent[1] = M_PUSHL_REG_DISP;
1518 pltent += 2;
1519 /* LINTED */
1520 *(Word *)pltent = (Word)(M_GOT_XLINKMAP *
1521 M_GOT_ENTSIZE);
1522 if (bswap)
1523 /* LINTED */
1524 *(Word *)pltent =
1525 /* LINTED */
1526 ld_bswap_Word(*(Word *)pltent);
1527 pltent += 4;
1528 pltent[0] = M_SPECIAL_INST;
1529 pltent[1] = M_JMP_REG_DISP_IND;
1530 pltent += 2;
1531 /* LINTED */
1532 *(Word *)pltent = (Word)(M_GOT_XRTLD *
1533 M_GOT_ENTSIZE);
1534 if (bswap)
1535 /* LINTED */
1536 *(Word *)pltent =
1537 /* LINTED */
1538 ld_bswap_Word(*(Word *)pltent);
1539 }
1540 }
1541 return (1);
1542 }
1543
1544
1545
1546 /*
1547 * Template for generating "void (*)(void)" function
1548 */
1549 static const uchar_t nullfunc_tmpl[] = { /* IA32 */
1550 /* 0x00 */ 0xc3 /* ret */
1551 };
1552
1553
1554
1555 /*
1556 * Function used to provide fill padding in SHF_EXECINSTR sections
1557 *
1558 * entry:
1559 *
1560 * base - base address of section being filled
1561 * offset - starting offset for fill within memory referenced by base
1562 * cnt - # bytes to be filled
1563 *
1564 * exit:
1565 * The fill has been completed.
1566 */
1567 static void
execfill(void * base,off_t off,size_t cnt)1568 execfill(void *base, off_t off, size_t cnt)
1569 {
1570 /*
1571 * 0x90 is an X86 NOP instruction in both 32 and 64-bit worlds.
1572 * There are no alignment constraints.
1573 */
1574 (void) memset(off + (char *)base, 0x90, cnt);
1575 }
1576
1577
1578 /*
1579 * Return the ld_targ definition for this target.
1580 */
1581 const Target *
ld_targ_init_x86(void)1582 ld_targ_init_x86(void)
1583 {
1584 static const Target _ld_targ = {
1585 { /* Target_mach */
1586 M_MACH, /* m_mach */
1587 M_MACHPLUS, /* m_machplus */
1588 M_FLAGSPLUS, /* m_flagsplus */
1589 M_CLASS, /* m_class */
1590 M_DATA, /* m_data */
1591
1592 M_SEGM_ALIGN, /* m_segm_align */
1593 M_SEGM_ORIGIN, /* m_segm_origin */
1594 M_SEGM_AORIGIN, /* m_segm_aorigin */
1595 M_DATASEG_PERM, /* m_dataseg_perm */
1596 M_STACK_PERM, /* m_stack_perm */
1597 M_WORD_ALIGN, /* m_word_align */
1598 MSG_ORIG(MSG_PTH_RTLD), /* m_def_interp */
1599
1600 /* Relocation type codes */
1601 M_R_ARRAYADDR, /* m_r_arrayaddr */
1602 M_R_COPY, /* m_r_copy */
1603 M_R_GLOB_DAT, /* m_r_glob_dat */
1604 M_R_JMP_SLOT, /* m_r_jmp_slot */
1605 M_R_NUM, /* m_r_num */
1606 M_R_NONE, /* m_r_none */
1607 M_R_RELATIVE, /* m_r_relative */
1608 M_R_REGISTER, /* m_r_register */
1609
1610 /* Relocation related constants */
1611 M_REL_DT_COUNT, /* m_rel_dt_count */
1612 M_REL_DT_ENT, /* m_rel_dt_ent */
1613 M_REL_DT_SIZE, /* m_rel_dt_size */
1614 M_REL_DT_TYPE, /* m_rel_dt_type */
1615 M_REL_SHT_TYPE, /* m_rel_sht_type */
1616
1617 /* GOT related constants */
1618 M_GOT_ENTSIZE, /* m_got_entsize */
1619 M_GOT_XNumber, /* m_got_xnumber */
1620
1621 /* PLT related constants */
1622 M_PLT_ALIGN, /* m_plt_align */
1623 M_PLT_ENTSIZE, /* m_plt_entsize */
1624 M_PLT_RESERVSZ, /* m_plt_reservsz */
1625 M_PLT_SHF_FLAGS, /* m_plt_shf_flags */
1626
1627 /* Section type of .eh_frame/.eh_frame_hdr sections */
1628 SHT_PROGBITS, /* m_sht_unwind */
1629
1630 M_DT_REGISTER, /* m_dt_register */
1631 },
1632 { /* Target_machid */
1633 M_ID_ARRAY, /* id_array */
1634 M_ID_BSS, /* id_bss */
1635 M_ID_CAP, /* id_cap */
1636 M_ID_CAPINFO, /* id_capinfo */
1637 M_ID_CAPCHAIN, /* id_capchain */
1638 M_ID_DATA, /* id_data */
1639 M_ID_DYNAMIC, /* id_dynamic */
1640 M_ID_DYNSORT, /* id_dynsort */
1641 M_ID_DYNSTR, /* id_dynstr */
1642 M_ID_DYNSYM, /* id_dynsym */
1643 M_ID_DYNSYM_NDX, /* id_dynsym_ndx */
1644 M_ID_GOT, /* id_got */
1645 M_ID_UNKNOWN, /* id_gotdata (unused) */
1646 M_ID_HASH, /* id_hash */
1647 M_ID_INTERP, /* id_interp */
1648 M_ID_LBSS, /* id_lbss */
1649 M_ID_LDYNSYM, /* id_ldynsym */
1650 M_ID_NOTE, /* id_note */
1651 M_ID_NULL, /* id_null */
1652 M_ID_PLT, /* id_plt */
1653 M_ID_REL, /* id_rel */
1654 M_ID_STRTAB, /* id_strtab */
1655 M_ID_SYMINFO, /* id_syminfo */
1656 M_ID_SYMTAB, /* id_symtab */
1657 M_ID_SYMTAB_NDX, /* id_symtab_ndx */
1658 M_ID_TEXT, /* id_text */
1659 M_ID_TLS, /* id_tls */
1660 M_ID_TLSBSS, /* id_tlsbss */
1661 M_ID_UNKNOWN, /* id_unknown */
1662 M_ID_UNWIND, /* id_unwind */
1663 M_ID_UNWINDHDR, /* id_unwindhdr */
1664 M_ID_USER, /* id_user */
1665 M_ID_VERSION, /* id_version */
1666 },
1667 { /* Target_nullfunc */
1668 nullfunc_tmpl, /* nf_template */
1669 sizeof (nullfunc_tmpl), /* nf_size */
1670 },
1671 { /* Target_fillfunc */
1672 execfill /* ff_execfill */
1673 },
1674 { /* Target_machrel */
1675 reloc_table,
1676
1677 ld_init_rel, /* mr_init_rel */
1678 ld_mach_eflags, /* mr_mach_eflags */
1679 ld_mach_make_dynamic, /* mr_mach_make_dynamic */
1680 ld_mach_update_odynamic, /* mr_mach_update_odynamic */
1681 ld_calc_plt_addr, /* mr_calc_plt_addr */
1682 ld_perform_outreloc, /* mr_perform_outreloc */
1683 ld_do_activerelocs, /* mr_do_activerelocs */
1684 ld_add_outrel, /* mr_add_outrel */
1685 NULL, /* mr_reloc_register */
1686 ld_reloc_local, /* mr_reloc_local */
1687 NULL, /* mr_reloc_GOTOP */
1688 ld_reloc_TLS, /* mr_reloc_TLS */
1689 NULL, /* mr_assign_got */
1690 ld_find_got_ndx, /* mr_find_got_ndx */
1691 ld_calc_got_offset, /* mr_calc_got_offset */
1692 ld_assign_got_ndx, /* mr_assign_got_ndx */
1693 ld_assign_plt_ndx, /* mr_assign_plt_ndx */
1694 NULL, /* mr_allocate_got */
1695 ld_fillin_gotplt, /* mr_fillin_gotplt */
1696 },
1697 { /* Target_machsym */
1698 NULL, /* ms_reg_check */
1699 NULL, /* ms_mach_sym_typecheck */
1700 NULL, /* ms_is_regsym */
1701 NULL, /* ms_reg_find */
1702 NULL /* ms_reg_enter */
1703 }
1704 };
1705
1706 return (&_ld_targ);
1707 }
1708