1 /* $NetBSD: ppc_reloc.c,v 1.10 2001/09/10 06:09:41 mycroft Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-2-Clause
5 *
6 * Copyright (C) 1998 Tsubai Masanari
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. The name of the author may not be used to endorse or promote products
18 * derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/param.h>
33 #include <sys/mman.h>
34
35 #include <errno.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <unistd.h>
40 #include <machine/cpu.h>
41 #include <machine/atomic.h>
42 #include <machine/md_var.h>
43
44 #include "debug.h"
45 #include "rtld.h"
46
47 #define _ppc_ha(x) ((((u_int32_t)(x) & 0x8000) ? \
48 ((u_int32_t)(x) + 0x10000) : (u_int32_t)(x)) >> 16)
49 #define _ppc_la(x) ((u_int32_t)(x) & 0xffff)
50
51 #define min(a,b) (((a) < (b)) ? (a) : (b))
52 #define max(a,b) (((a) > (b)) ? (a) : (b))
53
54 #define PLT_EXTENDED_BEGIN (1 << 13)
55 #define JMPTAB_BASE(N) (18 + N*2 + ((N > PLT_EXTENDED_BEGIN) ? \
56 (N - PLT_EXTENDED_BEGIN)*2 : 0))
57
58 void _rtld_bind_secureplt_start(void);
59
60 bool
arch_digest_dynamic(struct Struct_Obj_Entry * obj,const Elf_Dyn * dynp)61 arch_digest_dynamic(struct Struct_Obj_Entry *obj, const Elf_Dyn *dynp)
62 {
63 if (dynp->d_tag == DT_PPC_GOT) {
64 obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr);
65 return (true);
66 }
67
68 return (false);
69 }
70
71 /*
72 * Process the R_PPC_COPY relocations
73 */
74 int
do_copy_relocations(Obj_Entry * dstobj)75 do_copy_relocations(Obj_Entry *dstobj)
76 {
77 const Elf_Rela *relalim;
78 const Elf_Rela *rela;
79
80 /*
81 * COPY relocs are invalid outside of the main program
82 */
83 assert(dstobj->mainprog);
84
85 relalim = (const Elf_Rela *)((const char *) dstobj->rela +
86 dstobj->relasize);
87 for (rela = dstobj->rela; rela < relalim; rela++) {
88 void *dstaddr;
89 const Elf_Sym *dstsym;
90 const char *name;
91 size_t size;
92 const void *srcaddr;
93 const Elf_Sym *srcsym = NULL;
94 const Obj_Entry *srcobj, *defobj;
95 SymLook req;
96 int res;
97
98 if (ELF_R_TYPE(rela->r_info) != R_PPC_COPY) {
99 continue;
100 }
101
102 dstaddr = (void *)(dstobj->relocbase + rela->r_offset);
103 dstsym = dstobj->symtab + ELF_R_SYM(rela->r_info);
104 name = dstobj->strtab + dstsym->st_name;
105 size = dstsym->st_size;
106 symlook_init(&req, name);
107 req.ventry = fetch_ventry(dstobj, ELF_R_SYM(rela->r_info));
108 req.flags = SYMLOOK_EARLY;
109
110 for (srcobj = globallist_next(dstobj); srcobj != NULL;
111 srcobj = globallist_next(srcobj)) {
112 res = symlook_obj(&req, srcobj);
113 if (res == 0) {
114 srcsym = req.sym_out;
115 defobj = req.defobj_out;
116 break;
117 }
118 }
119
120 if (srcobj == NULL) {
121 _rtld_error("Undefined symbol \"%s\" "
122 " referenced from COPY"
123 " relocation in %s", name, dstobj->path);
124 return (-1);
125 }
126
127 srcaddr = (const void *)(defobj->relocbase+srcsym->st_value);
128 memcpy(dstaddr, srcaddr, size);
129 dbg("copy_reloc: src=%p,dst=%p,size=%d\n",srcaddr,dstaddr,size);
130 }
131
132 return (0);
133 }
134
135
136 /*
137 * Perform early relocation of the run-time linker image
138 */
139 void
reloc_non_plt_self(Elf_Dyn * dynp,Elf_Addr relocbase)140 reloc_non_plt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
141 {
142 const Elf_Rela *rela = NULL, *relalim;
143 Elf_Addr relasz = 0;
144 Elf_Addr *where;
145
146 /*
147 * Extract the rela/relasz values from the dynamic section
148 */
149 for (; dynp->d_tag != DT_NULL; dynp++) {
150 switch (dynp->d_tag) {
151 case DT_RELA:
152 rela = (const Elf_Rela *)(relocbase+dynp->d_un.d_ptr);
153 break;
154 case DT_RELASZ:
155 relasz = dynp->d_un.d_val;
156 break;
157 }
158 }
159
160 /*
161 * Relocate these values
162 */
163 relalim = (const Elf_Rela *)((const char *)rela + relasz);
164 for (; rela < relalim; rela++) {
165 where = (Elf_Addr *)(relocbase + rela->r_offset);
166 *where = (Elf_Addr)(relocbase + rela->r_addend);
167 }
168 }
169
170
171 /*
172 * Relocate a non-PLT object with addend.
173 */
174 static int
reloc_nonplt_object(Obj_Entry * obj_rtld __unused,Obj_Entry * obj,const Elf_Rela * rela,SymCache * cache,int flags,RtldLockState * lockstate)175 reloc_nonplt_object(Obj_Entry *obj_rtld __unused, Obj_Entry *obj,
176 const Elf_Rela *rela, SymCache *cache, int flags, RtldLockState *lockstate)
177 {
178 const Elf_Sym *def = NULL;
179 const Obj_Entry *defobj;
180 Elf_Addr *where, symval = 0;
181
182 /*
183 * First, resolve symbol for relocations which
184 * reference symbols.
185 */
186 switch (ELF_R_TYPE(rela->r_info)) {
187
188 case R_PPC_UADDR32: /* word32 S + A */
189 case R_PPC_ADDR32:
190 case R_PPC_GLOB_DAT: /* word32 S + A */
191 case R_PPC_DTPMOD32:
192 case R_PPC_TPREL32:
193 case R_PPC_DTPREL32:
194 def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
195 flags, cache, lockstate);
196 if (def == NULL) {
197 return (-1);
198 }
199
200 /*
201 * If symbol is IFUNC, only perform relocation
202 * when caller allowed it by passing
203 * SYMLOOK_IFUNC flag. Skip the relocations
204 * otherwise.
205 *
206 * Also error out in case IFUNC relocations
207 * are specified for TLS, which cannot be
208 * usefully interpreted.
209 */
210 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
211 switch (ELF_R_TYPE(rela->r_info)) {
212 case R_PPC_UADDR32:
213 case R_PPC_ADDR32:
214 case R_PPC_GLOB_DAT:
215 if ((flags & SYMLOOK_IFUNC) == 0) {
216 dbg("Non-PLT reference to IFUNC found!");
217 obj->non_plt_gnu_ifunc = true;
218 return (0);
219 }
220 symval = (Elf_Addr)rtld_resolve_ifunc(
221 defobj, def);
222 break;
223 default:
224 _rtld_error("%s: IFUNC for TLS reloc",
225 obj->path);
226 return (-1);
227 }
228 } else {
229 if ((flags & SYMLOOK_IFUNC) != 0)
230 return (0);
231 symval = (Elf_Addr)defobj->relocbase +
232 def->st_value;
233 }
234 break;
235 default:
236 if ((flags & SYMLOOK_IFUNC) != 0)
237 return (0);
238 }
239 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
240
241 switch (ELF_R_TYPE(rela->r_info)) {
242 case R_PPC_NONE:
243 break;
244 case R_PPC_UADDR32:
245 case R_PPC_ADDR32:
246 case R_PPC_GLOB_DAT:
247 /* Don't issue write if unnecessary; avoid COW page fault */
248 if (*where != symval + rela->r_addend) {
249 *where = symval + rela->r_addend;
250 }
251 break;
252 case R_PPC_DTPMOD32:
253 *where = (Elf_Addr) defobj->tlsindex;
254 break;
255 case R_PPC_TPREL32:
256 /*
257 * We lazily allocate offsets for static TLS as we
258 * see the first relocation that references the
259 * TLS block. This allows us to support (small
260 * amounts of) static TLS in dynamically loaded
261 * modules. If we run out of space, we generate an
262 * error.
263 */
264 if (!defobj->tls_static) {
265 if (!allocate_tls_offset(
266 __DECONST(Obj_Entry *, defobj))) {
267 _rtld_error("%s: No space available for static "
268 "Thread Local Storage", obj->path);
269 return (-1);
270 }
271 }
272
273 *(Elf_Addr **)where = *where * sizeof(Elf_Addr)
274 + (Elf_Addr *)(def->st_value + rela->r_addend
275 + defobj->tlsoffset - TLS_TP_OFFSET - TLS_TCB_SIZE);
276 break;
277 case R_PPC_DTPREL32:
278 *where += (Elf_Addr)(def->st_value + rela->r_addend
279 - TLS_DTV_OFFSET);
280 break;
281 case R_PPC_RELATIVE: /* word32 B + A */
282 symval = (Elf_Addr)(obj->relocbase + rela->r_addend);
283
284 /* As above, don't issue write unnecessarily */
285 if (*where != symval) {
286 *where = symval;
287 }
288 break;
289 case R_PPC_COPY:
290 /*
291 * These are deferred until all other relocations
292 * have been done. All we do here is make sure
293 * that the COPY relocation is not in a shared
294 * library. They are allowed only in executable
295 * files.
296 */
297 if (!obj->mainprog) {
298 _rtld_error("%s: Unexpected R_COPY "
299 " relocation in shared library",
300 obj->path);
301 return (-1);
302 }
303 break;
304 case R_PPC_IRELATIVE:
305 /*
306 * These will be handled by reloc_iresolve().
307 */
308 obj->irelative = true;
309 break;
310 case R_PPC_JMP_SLOT:
311 /*
312 * These will be handled by the plt/jmpslot routines
313 */
314 break;
315
316 default:
317 _rtld_error("%s: Unsupported relocation type %d"
318 " in non-PLT relocations\n", obj->path,
319 ELF_R_TYPE(rela->r_info));
320 return (-1);
321 }
322 return (0);
323 }
324
325
326 /*
327 * Process non-PLT relocations
328 */
329 int
reloc_non_plt(Obj_Entry * obj,Obj_Entry * obj_rtld,int flags,RtldLockState * lockstate)330 reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
331 RtldLockState *lockstate)
332 {
333 const Elf_Rela *relalim;
334 const Elf_Rela *rela;
335 const Elf_Phdr *phdr;
336 SymCache *cache;
337 int r = -1;
338
339 /*
340 * The dynamic loader may be called from a thread, we have
341 * limited amounts of stack available so we cannot use alloca().
342 */
343 if (obj != obj_rtld) {
344 cache = calloc(obj->dynsymcount, sizeof(SymCache));
345 /* No need to check for NULL here */
346 } else
347 cache = NULL;
348
349 /*
350 * From the SVR4 PPC ABI:
351 * "The PowerPC family uses only the Elf32_Rela relocation
352 * entries with explicit addends."
353 */
354 relalim = (const Elf_Rela *)((const char *)obj->rela + obj->relasize);
355 for (rela = obj->rela; rela < relalim; rela++) {
356 if (reloc_nonplt_object(obj_rtld, obj, rela, cache, flags,
357 lockstate) < 0)
358 goto done;
359 }
360 r = 0;
361 done:
362 if (cache != NULL)
363 free(cache);
364
365 /*
366 * Synchronize icache for executable segments in case we made
367 * any changes.
368 */
369 for (phdr = obj->phdr;
370 (const char *)phdr < (const char *)obj->phdr + obj->phsize;
371 phdr++) {
372 if (phdr->p_type == PT_LOAD && (phdr->p_flags & PF_X) != 0) {
373 __syncicache(obj->relocbase + phdr->p_vaddr,
374 phdr->p_memsz);
375 }
376 }
377
378 return (r);
379 }
380
381 /*
382 * Initialise a PLT slot to the resolving trampoline
383 */
384 static int
reloc_plt_object(Obj_Entry * obj,const Elf_Rela * rela)385 reloc_plt_object(Obj_Entry *obj, const Elf_Rela *rela)
386 {
387 Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset);
388 Elf_Addr *pltresolve, *pltlongresolve, *jmptab;
389 Elf_Addr distance;
390 int N = obj->pltrelasize / sizeof(Elf_Rela);
391 int reloff;
392
393 reloff = rela - obj->pltrela;
394
395 if (reloff < 0)
396 return (-1);
397
398 if (obj->gotptr != NULL) {
399 *where += (Elf_Addr)obj->relocbase;
400 return (0);
401 }
402
403 pltlongresolve = obj->pltgot + 5;
404 pltresolve = pltlongresolve + 5;
405
406 distance = (Elf_Addr)pltresolve - (Elf_Addr)(where + 1);
407
408 dbg(" reloc_plt_object: where=%p,pltres=%p,reloff=%x,distance=%x",
409 (void *)where, (void *)pltresolve, reloff, distance);
410
411 if (reloff < PLT_EXTENDED_BEGIN) {
412 /* li r11,reloff */
413 /* b pltresolve */
414 where[0] = 0x39600000 | reloff;
415 where[1] = 0x48000000 | (distance & 0x03fffffc);
416 } else {
417 jmptab = obj->pltgot + JMPTAB_BASE(N);
418 jmptab[reloff] = (u_int)pltlongresolve;
419
420 /* lis r11,jmptab[reloff]@ha */
421 /* lwzu r12,jmptab[reloff]@l(r11) */
422 /* mtctr r12 */
423 /* bctr */
424 where[0] = 0x3d600000 | _ppc_ha(&jmptab[reloff]);
425 where[1] = 0x858b0000 | _ppc_la(&jmptab[reloff]);
426 where[2] = 0x7d8903a6;
427 where[3] = 0x4e800420;
428 }
429
430
431 /*
432 * The icache will be sync'd in reloc_plt, which is called
433 * after all the slots have been updated
434 */
435
436 return (0);
437 }
438
439 /*
440 * Process the PLT relocations.
441 */
442 int
reloc_plt(Obj_Entry * obj,int flags __unused,RtldLockState * lockstate __unused)443 reloc_plt(Obj_Entry *obj, int flags __unused, RtldLockState *lockstate __unused)
444 {
445 const Elf_Rela *relalim;
446 const Elf_Rela *rela;
447 int N = obj->pltrelasize / sizeof(Elf_Rela);
448
449 if (obj->pltrelasize != 0) {
450
451 relalim = (const Elf_Rela *)((const char *)obj->pltrela +
452 obj->pltrelasize);
453 for (rela = obj->pltrela; rela < relalim; rela++) {
454 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) {
455 dbg("ABI violation - found IRELATIVE in the PLT.");
456 obj->irelative = true;
457 continue;
458 }
459
460 /*
461 * PowerPC(64) .rela.plt is composed of an array of
462 * R_PPC_JMP_SLOT relocations. Unlike other platforms,
463 * this is the ONLY relocation type that is valid here.
464 */
465 assert(ELF_R_TYPE(rela->r_info) == R_PPC_JMP_SLOT);
466
467 if (reloc_plt_object(obj, rela) < 0) {
468 return (-1);
469 }
470 }
471 }
472
473 /*
474 * Sync the icache for the byte range represented by the
475 * trampoline routines and call slots.
476 */
477 if (obj->pltgot != NULL && obj->gotptr == NULL)
478 __syncicache(obj->pltgot, JMPTAB_BASE(N)*4);
479
480 return (0);
481 }
482
483 /*
484 * LD_BIND_NOW was set - force relocation for all jump slots
485 */
486 int
reloc_jmpslots(Obj_Entry * obj,int flags,RtldLockState * lockstate)487 reloc_jmpslots(Obj_Entry *obj, int flags, RtldLockState *lockstate)
488 {
489 const Obj_Entry *defobj;
490 const Elf_Rela *relalim;
491 const Elf_Rela *rela;
492 const Elf_Sym *def;
493 Elf_Addr *where;
494 Elf_Addr target;
495
496 relalim = (const Elf_Rela *)((const char *)obj->pltrela +
497 obj->pltrelasize);
498 for (rela = obj->pltrela; rela < relalim; rela++) {
499 /* This isn't actually a jump slot, ignore it. */
500 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE)
501 continue;
502 assert(ELF_R_TYPE(rela->r_info) == R_PPC_JMP_SLOT);
503 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
504 def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
505 SYMLOOK_IN_PLT | flags, NULL, lockstate);
506 if (def == NULL) {
507 dbg("reloc_jmpslots: sym not found");
508 return (-1);
509 }
510
511 target = (Elf_Addr)(defobj->relocbase + def->st_value);
512
513 if (def == &sym_zero) {
514 /* Zero undefined weak symbols */
515 *where = 0;
516 } else {
517 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
518 /* LD_BIND_NOW, ifunc in shared lib.*/
519 obj->gnu_ifunc = true;
520 continue;
521 }
522 reloc_jmpslot(where, target, defobj, obj,
523 (const Elf_Rel *) rela);
524 }
525 }
526
527 obj->jmpslots_done = true;
528
529 return (0);
530 }
531
532
533 /*
534 * Update the value of a PLT jump slot.
535 */
536 Elf_Addr
reloc_jmpslot(Elf_Addr * wherep,Elf_Addr target,const Obj_Entry * defobj __unused,const Obj_Entry * obj,const Elf_Rel * rel)537 reloc_jmpslot(Elf_Addr *wherep, Elf_Addr target,
538 const Obj_Entry *defobj __unused, const Obj_Entry *obj, const Elf_Rel *rel)
539 {
540 Elf_Addr offset;
541 const Elf_Rela *rela = (const Elf_Rela *) rel;
542
543 dbg(" reloc_jmpslot: where=%p, target=%p",
544 (void *)wherep, (void *)target);
545
546 if (ld_bind_not)
547 goto out;
548
549
550 /*
551 * Process Secure-PLT.
552 */
553 if (obj->gotptr != NULL) {
554 assert(wherep >= (Elf_Word *)obj->pltgot);
555 assert(wherep <
556 (Elf_Word *)obj->pltgot + obj->pltrelasize);
557 if (*wherep != target)
558 *wherep = target;
559 goto out;
560 }
561
562 /*
563 * BSS-PLT optimization:
564 * Branch directly to the target if it is within +/- 32Mb,
565 * otherwise go indirectly via the pltcall trampoline call and
566 * jump table.
567 */
568 offset = target - (Elf_Addr)wherep;
569 if (abs((int)offset) < 32*1024*1024) { /* inside 32MB? */
570 /*
571 * At the PLT entry pointed at by `wherep', construct
572 * a direct transfer to the now fully resolved function
573 * address.
574 */
575 /* b value # branch directly */
576 *wherep = 0x48000000 | (offset & 0x03fffffc);
577 __syncicache(wherep, 4);
578 } else {
579 Elf_Addr *pltcall, *jmptab;
580 int distance;
581 int N = obj->pltrelasize / sizeof(Elf_Rela);
582 int reloff = rela - obj->pltrela;
583
584 if (reloff < 0)
585 return (-1);
586
587 pltcall = obj->pltgot;
588
589 dbg(" reloc_jmpslot: indir, reloff=%x, N=%x\n",
590 reloff, N);
591
592 jmptab = obj->pltgot + JMPTAB_BASE(N);
593 jmptab[reloff] = target;
594 mb(); /* Order jmptab update before next changes */
595
596 if (reloff < PLT_EXTENDED_BEGIN) {
597 /* for extended PLT entries, we keep the old code */
598
599 distance = (Elf_Addr)pltcall - (Elf_Addr)(wherep + 1);
600
601 /* li r11,reloff */
602 /* b pltcall # use indirect pltcall routine */
603
604 /* first instruction same as before */
605 wherep[1] = 0x48000000 | (distance & 0x03fffffc);
606 __syncicache(wherep, 8);
607 }
608 }
609
610 out:
611 return (target);
612 }
613
614 int
reloc_iresolve(Obj_Entry * obj,struct Struct_RtldLockState * lockstate)615 reloc_iresolve(Obj_Entry *obj,
616 struct Struct_RtldLockState *lockstate)
617 {
618 /*
619 * Since PLT slots on PowerPC are always R_PPC_JMP_SLOT,
620 * R_PPC_IRELATIVE is in RELA.
621 */
622 const Elf_Rela *relalim;
623 const Elf_Rela *rela;
624 Elf_Addr *where, target, *ptr;
625
626 if (!obj->irelative)
627 return (0);
628
629 relalim = (const Elf_Rela *)((const char *)obj->rela + obj->relasize);
630 for (rela = obj->rela; rela < relalim; rela++) {
631 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) {
632 ptr = (Elf_Addr *)(obj->relocbase + rela->r_addend);
633 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
634
635 lock_release(rtld_bind_lock, lockstate);
636 target = call_ifunc_resolver(ptr);
637 wlock_acquire(rtld_bind_lock, lockstate);
638
639 *where = target;
640 }
641 }
642 /*
643 * XXX Remove me when lld is fixed!
644 * LLD currently makes illegal relocations in the PLT.
645 */
646 relalim = (const Elf_Rela *)((const char *)obj->pltrela + obj->pltrelasize);
647 for (rela = obj->pltrela; rela < relalim; rela++) {
648 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) {
649 ptr = (Elf_Addr *)(obj->relocbase + rela->r_addend);
650 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
651
652 lock_release(rtld_bind_lock, lockstate);
653 target = call_ifunc_resolver(ptr);
654 wlock_acquire(rtld_bind_lock, lockstate);
655
656 *where = target;
657 }
658 }
659
660 obj->irelative = false;
661 return (0);
662 }
663
664 int
reloc_iresolve_nonplt(Obj_Entry * obj __unused,struct Struct_RtldLockState * lockstate __unused)665 reloc_iresolve_nonplt(Obj_Entry *obj __unused,
666 struct Struct_RtldLockState *lockstate __unused)
667 {
668 return (0);
669 }
670
671 int
reloc_gnu_ifunc(Obj_Entry * obj __unused,int flags __unused,struct Struct_RtldLockState * lockstate __unused)672 reloc_gnu_ifunc(Obj_Entry *obj __unused, int flags __unused,
673 struct Struct_RtldLockState *lockstate __unused)
674 {
675 const Elf_Rela *relalim;
676 const Elf_Rela *rela;
677 Elf_Addr *where, target;
678 const Elf_Sym *def;
679 const Obj_Entry *defobj;
680
681 if (!obj->gnu_ifunc)
682 return (0);
683 relalim = (const Elf_Rela *)((const char *)obj->pltrela + obj->pltrelasize);
684 for (rela = obj->pltrela; rela < relalim; rela++) {
685 if (ELF_R_TYPE(rela->r_info) == R_PPC_JMP_SLOT) {
686 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
687 def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
688 SYMLOOK_IN_PLT | flags, NULL, lockstate);
689 if (def == NULL)
690 return (-1);
691 if (ELF_ST_TYPE(def->st_info) != STT_GNU_IFUNC)
692 continue;
693 lock_release(rtld_bind_lock, lockstate);
694 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def);
695 wlock_acquire(rtld_bind_lock, lockstate);
696 reloc_jmpslot(where, target, defobj, obj,
697 (const Elf_Rel *)rela);
698 }
699 }
700 obj->gnu_ifunc = false;
701 return (0);
702 }
703
704 /*
705 * Setup the plt glue routines.
706 */
707 #define PLTCALL_SIZE 20
708 #define PLTLONGRESOLVE_SIZE 20
709 #define PLTRESOLVE_SIZE 24
710
711 void
init_pltgot(Obj_Entry * obj)712 init_pltgot(Obj_Entry *obj)
713 {
714 Elf_Word *pltcall, *pltresolve, *pltlongresolve;
715 Elf_Word *jmptab;
716 int N = obj->pltrelasize / sizeof(Elf_Rela);
717
718 pltcall = obj->pltgot;
719
720 if (pltcall == NULL) {
721 return;
722 }
723
724 /* Handle Secure-PLT first, if applicable. */
725 if (obj->gotptr != NULL) {
726 obj->gotptr[1] = (Elf_Addr)_rtld_bind_secureplt_start;
727 obj->gotptr[2] = (Elf_Addr)obj;
728 dbg("obj %s secure-plt gotptr=%p start=%p obj=%p",
729 obj->path, obj->gotptr,
730 (void *)obj->gotptr[1], (void *)obj->gotptr[2]);
731 return;
732 }
733
734 /*
735 * From the SVR4 PPC ABI:
736 *
737 * 'The first 18 words (72 bytes) of the PLT are reserved for
738 * use by the dynamic linker.
739 * ...
740 * 'If the executable or shared object requires N procedure
741 * linkage table entries, the link editor shall reserve 3*N
742 * words (12*N bytes) following the 18 reserved words. The
743 * first 2*N of these words are the procedure linkage table
744 * entries themselves. The static linker directs calls to bytes
745 * (72 + (i-1)*8), for i between 1 and N inclusive. The remaining
746 * N words (4*N bytes) are reserved for use by the dynamic linker.'
747 */
748
749 /*
750 * Copy the absolute-call assembler stub into the first part of
751 * the reserved PLT area.
752 */
753 memcpy(pltcall, _rtld_powerpc_pltcall, PLTCALL_SIZE);
754
755 /*
756 * Determine the address of the jumptable, which is the dyn-linker
757 * reserved area after the call cells. Write the absolute address
758 * of the jumptable into the absolute-call assembler code so it
759 * can determine this address.
760 */
761 jmptab = obj->pltgot + JMPTAB_BASE(N);
762 pltcall[1] |= _ppc_ha(jmptab); /* addis 11,11,jmptab@ha */
763 pltcall[2] |= _ppc_la(jmptab); /* lwz 11,jmptab@l(11) */
764
765 /*
766 * Skip down 20 bytes into the initial reserved area and copy
767 * in the standard resolving assembler call. Into this assembler,
768 * insert the absolute address of the _rtld_bind_start routine
769 * and the address of the relocation object.
770 *
771 * We place pltlongresolve first, so it can fix up its arguments
772 * and then fall through to the regular PLT resolver.
773 */
774 pltlongresolve = obj->pltgot + 5;
775
776 memcpy(pltlongresolve, _rtld_powerpc_pltlongresolve,
777 PLTLONGRESOLVE_SIZE);
778 pltlongresolve[0] |= _ppc_ha(jmptab); /* lis 12,jmptab@ha */
779 pltlongresolve[1] |= _ppc_la(jmptab); /* addi 12,12,jmptab@l */
780
781 pltresolve = pltlongresolve + PLTLONGRESOLVE_SIZE/sizeof(uint32_t);
782 memcpy(pltresolve, _rtld_powerpc_pltresolve, PLTRESOLVE_SIZE);
783 pltresolve[0] |= _ppc_ha(_rtld_bind_start);
784 pltresolve[1] |= _ppc_la(_rtld_bind_start);
785 pltresolve[3] |= _ppc_ha(obj);
786 pltresolve[4] |= _ppc_la(obj);
787
788 /*
789 * The icache will be sync'd in reloc_plt, which is called
790 * after all the slots have been updated
791 */
792 }
793
794 /*
795 * 32 bit cpu feature flag fields.
796 */
797 u_long cpu_features;
798 u_long cpu_features2;
799
800 void
powerpc_abi_variant_hook(Elf_Auxinfo ** aux_info)801 powerpc_abi_variant_hook(Elf_Auxinfo** aux_info)
802 {
803 /*
804 * Since aux_info[] is easier to work with than aux, go ahead and
805 * initialize cpu_features / cpu_features2.
806 */
807 cpu_features = -1UL;
808 cpu_features2 = -1UL;
809 if (aux_info[AT_HWCAP] != NULL)
810 cpu_features = aux_info[AT_HWCAP]->a_un.a_val;
811 if (aux_info[AT_HWCAP2] != NULL)
812 cpu_features2 = aux_info[AT_HWCAP2]->a_un.a_val;
813 }
814
815 void
ifunc_init(Elf_Auxinfo * aux_info[__min_size (AT_COUNT)]__unused)816 ifunc_init(Elf_Auxinfo *aux_info[__min_size(AT_COUNT)] __unused)
817 {
818
819 }
820
821 void
allocate_initial_tls(Obj_Entry * list)822 allocate_initial_tls(Obj_Entry *list)
823 {
824
825 /*
826 * Fix the size of the static TLS block by using the maximum
827 * offset allocated so far and adding a bit for dynamic modules to
828 * use.
829 */
830
831 tls_static_space = tls_last_offset + tls_last_size +
832 ld_static_tls_extra;
833
834 _tcb_set(allocate_tls(list, NULL, TLS_TCB_SIZE, TLS_TCB_ALIGN));
835 }
836
837 void*
__tls_get_addr(tls_index * ti)838 __tls_get_addr(tls_index* ti)
839 {
840 uintptr_t **dtvp;
841 char *p;
842
843 dtvp = &_tcb_get()->tcb_dtv;
844 p = tls_get_addr_common(dtvp, ti->ti_module, ti->ti_offset);
845
846 return (p + TLS_DTV_OFFSET);
847 }
848