RISC-V: Delete zero-size .tdata.dyn section.
[deliverable/binutils-gdb.git] / bfd / elfnn-riscv.c
1 /* RISC-V-specific support for NN-bit ELF.
2 Copyright (C) 2011-2018 Free Software Foundation, Inc.
3
4 Contributed by Andrew Waterman (andrew@sifive.com).
5 Based on TILE-Gx and MIPS targets.
6
7 This file is part of BFD, the Binary File Descriptor library.
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program; see the file COPYING3. If not,
21 see <http://www.gnu.org/licenses/>. */
22
23 /* This file handles RISC-V ELF targets. */
24
25 #include "sysdep.h"
26 #include "bfd.h"
27 #include "libbfd.h"
28 #include "bfdlink.h"
29 #include "genlink.h"
30 #include "elf-bfd.h"
31 #include "elfxx-riscv.h"
32 #include "elf/riscv.h"
33 #include "opcode/riscv.h"
34
35 /* Internal relocations used exclusively by the relaxation pass. */
36 #define R_RISCV_DELETE (R_RISCV_max + 1)
37
38 #define ARCH_SIZE NN
39
40 #define MINUS_ONE ((bfd_vma)0 - 1)
41
42 #define RISCV_ELF_LOG_WORD_BYTES (ARCH_SIZE == 32 ? 2 : 3)
43
44 #define RISCV_ELF_WORD_BYTES (1 << RISCV_ELF_LOG_WORD_BYTES)
45
46 /* The name of the dynamic interpreter. This is put in the .interp
47 section. */
48
49 #define ELF64_DYNAMIC_INTERPRETER "/lib/ld.so.1"
50 #define ELF32_DYNAMIC_INTERPRETER "/lib32/ld.so.1"
51
52 #define ELF_ARCH bfd_arch_riscv
53 #define ELF_TARGET_ID RISCV_ELF_DATA
54 #define ELF_MACHINE_CODE EM_RISCV
55 #define ELF_MAXPAGESIZE 0x1000
56 #define ELF_COMMONPAGESIZE 0x1000
57
58 /* RISC-V ELF linker hash entry. */
59
60 struct riscv_elf_link_hash_entry
61 {
62 struct elf_link_hash_entry elf;
63
64 /* Track dynamic relocs copied for this symbol. */
65 struct elf_dyn_relocs *dyn_relocs;
66
67 #define GOT_UNKNOWN 0
68 #define GOT_NORMAL 1
69 #define GOT_TLS_GD 2
70 #define GOT_TLS_IE 4
71 #define GOT_TLS_LE 8
72 char tls_type;
73 };
74
75 #define riscv_elf_hash_entry(ent) \
76 ((struct riscv_elf_link_hash_entry *)(ent))
77
78 struct _bfd_riscv_elf_obj_tdata
79 {
80 struct elf_obj_tdata root;
81
82 /* tls_type for each local got entry. */
83 char *local_got_tls_type;
84 };
85
86 #define _bfd_riscv_elf_tdata(abfd) \
87 ((struct _bfd_riscv_elf_obj_tdata *) (abfd)->tdata.any)
88
89 #define _bfd_riscv_elf_local_got_tls_type(abfd) \
90 (_bfd_riscv_elf_tdata (abfd)->local_got_tls_type)
91
92 #define _bfd_riscv_elf_tls_type(abfd, h, symndx) \
93 (*((h) != NULL ? &riscv_elf_hash_entry (h)->tls_type \
94 : &_bfd_riscv_elf_local_got_tls_type (abfd) [symndx]))
95
96 #define is_riscv_elf(bfd) \
97 (bfd_get_flavour (bfd) == bfd_target_elf_flavour \
98 && elf_tdata (bfd) != NULL \
99 && elf_object_id (bfd) == RISCV_ELF_DATA)
100
101 #include "elf/common.h"
102 #include "elf/internal.h"
103
104 struct riscv_elf_link_hash_table
105 {
106 struct elf_link_hash_table elf;
107
108 /* Short-cuts to get to dynamic linker sections. */
109 asection *sdyntdata;
110
111 /* Small local sym to section mapping cache. */
112 struct sym_cache sym_cache;
113
114 /* The max alignment of output sections. */
115 bfd_vma max_alignment;
116 };
117
118
119 /* Get the RISC-V ELF linker hash table from a link_info structure. */
120 #define riscv_elf_hash_table(p) \
121 (elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) \
122 == RISCV_ELF_DATA ? ((struct riscv_elf_link_hash_table *) ((p)->hash)) : NULL)
123
124 static bfd_boolean
125 riscv_info_to_howto_rela (bfd *abfd,
126 arelent *cache_ptr,
127 Elf_Internal_Rela *dst)
128 {
129 cache_ptr->howto = riscv_elf_rtype_to_howto (abfd, ELFNN_R_TYPE (dst->r_info));
130 return cache_ptr->howto != NULL;
131 }
132
133 static void
134 riscv_elf_append_rela (bfd *abfd, asection *s, Elf_Internal_Rela *rel)
135 {
136 const struct elf_backend_data *bed;
137 bfd_byte *loc;
138
139 bed = get_elf_backend_data (abfd);
140 loc = s->contents + (s->reloc_count++ * bed->s->sizeof_rela);
141 bed->s->swap_reloca_out (abfd, rel, loc);
142 }
143
144 /* PLT/GOT stuff. */
145
146 #define PLT_HEADER_INSNS 8
147 #define PLT_ENTRY_INSNS 4
148 #define PLT_HEADER_SIZE (PLT_HEADER_INSNS * 4)
149 #define PLT_ENTRY_SIZE (PLT_ENTRY_INSNS * 4)
150
151 #define GOT_ENTRY_SIZE RISCV_ELF_WORD_BYTES
152
153 #define GOTPLT_HEADER_SIZE (2 * GOT_ENTRY_SIZE)
154
155 #define sec_addr(sec) ((sec)->output_section->vma + (sec)->output_offset)
156
157 static bfd_vma
158 riscv_elf_got_plt_val (bfd_vma plt_index, struct bfd_link_info *info)
159 {
160 return sec_addr (riscv_elf_hash_table (info)->elf.sgotplt)
161 + GOTPLT_HEADER_SIZE + (plt_index * GOT_ENTRY_SIZE);
162 }
163
164 #if ARCH_SIZE == 32
165 # define MATCH_LREG MATCH_LW
166 #else
167 # define MATCH_LREG MATCH_LD
168 #endif
169
170 /* Generate a PLT header. */
171
172 static bfd_boolean
173 riscv_make_plt_header (bfd *output_bfd, bfd_vma gotplt_addr, bfd_vma addr,
174 uint32_t *entry)
175 {
176 bfd_vma gotplt_offset_high = RISCV_PCREL_HIGH_PART (gotplt_addr, addr);
177 bfd_vma gotplt_offset_low = RISCV_PCREL_LOW_PART (gotplt_addr, addr);
178
179 /* RVE has no t3 register, so this won't work, and is not supported. */
180 if (elf_elfheader (output_bfd)->e_flags & EF_RISCV_RVE)
181 {
182 _bfd_error_handler (_("%pB: warning: RVE PLT generation not supported"),
183 output_bfd);
184 return FALSE;
185 }
186
187 /* auipc t2, %hi(.got.plt)
188 sub t1, t1, t3 # shifted .got.plt offset + hdr size + 12
189 l[w|d] t3, %lo(.got.plt)(t2) # _dl_runtime_resolve
190 addi t1, t1, -(hdr size + 12) # shifted .got.plt offset
191 addi t0, t2, %lo(.got.plt) # &.got.plt
192 srli t1, t1, log2(16/PTRSIZE) # .got.plt offset
193 l[w|d] t0, PTRSIZE(t0) # link map
194 jr t3 */
195
196 entry[0] = RISCV_UTYPE (AUIPC, X_T2, gotplt_offset_high);
197 entry[1] = RISCV_RTYPE (SUB, X_T1, X_T1, X_T3);
198 entry[2] = RISCV_ITYPE (LREG, X_T3, X_T2, gotplt_offset_low);
199 entry[3] = RISCV_ITYPE (ADDI, X_T1, X_T1, -(PLT_HEADER_SIZE + 12));
200 entry[4] = RISCV_ITYPE (ADDI, X_T0, X_T2, gotplt_offset_low);
201 entry[5] = RISCV_ITYPE (SRLI, X_T1, X_T1, 4 - RISCV_ELF_LOG_WORD_BYTES);
202 entry[6] = RISCV_ITYPE (LREG, X_T0, X_T0, RISCV_ELF_WORD_BYTES);
203 entry[7] = RISCV_ITYPE (JALR, 0, X_T3, 0);
204
205 return TRUE;
206 }
207
208 /* Generate a PLT entry. */
209
210 static bfd_boolean
211 riscv_make_plt_entry (bfd *output_bfd, bfd_vma got, bfd_vma addr,
212 uint32_t *entry)
213 {
214 /* RVE has no t3 register, so this won't work, and is not supported. */
215 if (elf_elfheader (output_bfd)->e_flags & EF_RISCV_RVE)
216 {
217 _bfd_error_handler (_("%pB: warning: RVE PLT generation not supported"),
218 output_bfd);
219 return FALSE;
220 }
221
222 /* auipc t3, %hi(.got.plt entry)
223 l[w|d] t3, %lo(.got.plt entry)(t3)
224 jalr t1, t3
225 nop */
226
227 entry[0] = RISCV_UTYPE (AUIPC, X_T3, RISCV_PCREL_HIGH_PART (got, addr));
228 entry[1] = RISCV_ITYPE (LREG, X_T3, X_T3, RISCV_PCREL_LOW_PART (got, addr));
229 entry[2] = RISCV_ITYPE (JALR, X_T1, X_T3, 0);
230 entry[3] = RISCV_NOP;
231
232 return TRUE;
233 }
234
235 /* Create an entry in an RISC-V ELF linker hash table. */
236
237 static struct bfd_hash_entry *
238 link_hash_newfunc (struct bfd_hash_entry *entry,
239 struct bfd_hash_table *table, const char *string)
240 {
241 /* Allocate the structure if it has not already been allocated by a
242 subclass. */
243 if (entry == NULL)
244 {
245 entry =
246 bfd_hash_allocate (table,
247 sizeof (struct riscv_elf_link_hash_entry));
248 if (entry == NULL)
249 return entry;
250 }
251
252 /* Call the allocation method of the superclass. */
253 entry = _bfd_elf_link_hash_newfunc (entry, table, string);
254 if (entry != NULL)
255 {
256 struct riscv_elf_link_hash_entry *eh;
257
258 eh = (struct riscv_elf_link_hash_entry *) entry;
259 eh->dyn_relocs = NULL;
260 eh->tls_type = GOT_UNKNOWN;
261 }
262
263 return entry;
264 }
265
266 /* Create a RISC-V ELF linker hash table. */
267
268 static struct bfd_link_hash_table *
269 riscv_elf_link_hash_table_create (bfd *abfd)
270 {
271 struct riscv_elf_link_hash_table *ret;
272 bfd_size_type amt = sizeof (struct riscv_elf_link_hash_table);
273
274 ret = (struct riscv_elf_link_hash_table *) bfd_zmalloc (amt);
275 if (ret == NULL)
276 return NULL;
277
278 if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd, link_hash_newfunc,
279 sizeof (struct riscv_elf_link_hash_entry),
280 RISCV_ELF_DATA))
281 {
282 free (ret);
283 return NULL;
284 }
285
286 ret->max_alignment = (bfd_vma) -1;
287 return &ret->elf.root;
288 }
289
290 /* Create the .got section. */
291
292 static bfd_boolean
293 riscv_elf_create_got_section (bfd *abfd, struct bfd_link_info *info)
294 {
295 flagword flags;
296 asection *s, *s_got;
297 struct elf_link_hash_entry *h;
298 const struct elf_backend_data *bed = get_elf_backend_data (abfd);
299 struct elf_link_hash_table *htab = elf_hash_table (info);
300
301 /* This function may be called more than once. */
302 if (htab->sgot != NULL)
303 return TRUE;
304
305 flags = bed->dynamic_sec_flags;
306
307 s = bfd_make_section_anyway_with_flags (abfd,
308 (bed->rela_plts_and_copies_p
309 ? ".rela.got" : ".rel.got"),
310 (bed->dynamic_sec_flags
311 | SEC_READONLY));
312 if (s == NULL
313 || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
314 return FALSE;
315 htab->srelgot = s;
316
317 s = s_got = bfd_make_section_anyway_with_flags (abfd, ".got", flags);
318 if (s == NULL
319 || !bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
320 return FALSE;
321 htab->sgot = s;
322
323 /* The first bit of the global offset table is the header. */
324 s->size += bed->got_header_size;
325
326 if (bed->want_got_plt)
327 {
328 s = bfd_make_section_anyway_with_flags (abfd, ".got.plt", flags);
329 if (s == NULL
330 || !bfd_set_section_alignment (abfd, s,
331 bed->s->log_file_align))
332 return FALSE;
333 htab->sgotplt = s;
334
335 /* Reserve room for the header. */
336 s->size += GOTPLT_HEADER_SIZE;
337 }
338
339 if (bed->want_got_sym)
340 {
341 /* Define the symbol _GLOBAL_OFFSET_TABLE_ at the start of the .got
342 section. We don't do this in the linker script because we don't want
343 to define the symbol if we are not creating a global offset
344 table. */
345 h = _bfd_elf_define_linkage_sym (abfd, info, s_got,
346 "_GLOBAL_OFFSET_TABLE_");
347 elf_hash_table (info)->hgot = h;
348 if (h == NULL)
349 return FALSE;
350 }
351
352 return TRUE;
353 }
354
355 /* Create .plt, .rela.plt, .got, .got.plt, .rela.got, .dynbss, and
356 .rela.bss sections in DYNOBJ, and set up shortcuts to them in our
357 hash table. */
358
359 static bfd_boolean
360 riscv_elf_create_dynamic_sections (bfd *dynobj,
361 struct bfd_link_info *info)
362 {
363 struct riscv_elf_link_hash_table *htab;
364
365 htab = riscv_elf_hash_table (info);
366 BFD_ASSERT (htab != NULL);
367
368 if (!riscv_elf_create_got_section (dynobj, info))
369 return FALSE;
370
371 if (!_bfd_elf_create_dynamic_sections (dynobj, info))
372 return FALSE;
373
374 if (!bfd_link_pic (info))
375 {
376 htab->sdyntdata =
377 bfd_make_section_anyway_with_flags (dynobj, ".tdata.dyn",
378 (SEC_ALLOC | SEC_THREAD_LOCAL
379 | SEC_LINKER_CREATED));
380 }
381
382 if (!htab->elf.splt || !htab->elf.srelplt || !htab->elf.sdynbss
383 || (!bfd_link_pic (info) && (!htab->elf.srelbss || !htab->sdyntdata)))
384 abort ();
385
386 return TRUE;
387 }
388
389 /* Copy the extra info we tack onto an elf_link_hash_entry. */
390
391 static void
392 riscv_elf_copy_indirect_symbol (struct bfd_link_info *info,
393 struct elf_link_hash_entry *dir,
394 struct elf_link_hash_entry *ind)
395 {
396 struct riscv_elf_link_hash_entry *edir, *eind;
397
398 edir = (struct riscv_elf_link_hash_entry *) dir;
399 eind = (struct riscv_elf_link_hash_entry *) ind;
400
401 if (eind->dyn_relocs != NULL)
402 {
403 if (edir->dyn_relocs != NULL)
404 {
405 struct elf_dyn_relocs **pp;
406 struct elf_dyn_relocs *p;
407
408 /* Add reloc counts against the indirect sym to the direct sym
409 list. Merge any entries against the same section. */
410 for (pp = &eind->dyn_relocs; (p = *pp) != NULL; )
411 {
412 struct elf_dyn_relocs *q;
413
414 for (q = edir->dyn_relocs; q != NULL; q = q->next)
415 if (q->sec == p->sec)
416 {
417 q->pc_count += p->pc_count;
418 q->count += p->count;
419 *pp = p->next;
420 break;
421 }
422 if (q == NULL)
423 pp = &p->next;
424 }
425 *pp = edir->dyn_relocs;
426 }
427
428 edir->dyn_relocs = eind->dyn_relocs;
429 eind->dyn_relocs = NULL;
430 }
431
432 if (ind->root.type == bfd_link_hash_indirect
433 && dir->got.refcount <= 0)
434 {
435 edir->tls_type = eind->tls_type;
436 eind->tls_type = GOT_UNKNOWN;
437 }
438 _bfd_elf_link_hash_copy_indirect (info, dir, ind);
439 }
440
441 static bfd_boolean
442 riscv_elf_record_tls_type (bfd *abfd, struct elf_link_hash_entry *h,
443 unsigned long symndx, char tls_type)
444 {
445 char *new_tls_type = &_bfd_riscv_elf_tls_type (abfd, h, symndx);
446
447 *new_tls_type |= tls_type;
448 if ((*new_tls_type & GOT_NORMAL) && (*new_tls_type & ~GOT_NORMAL))
449 {
450 (*_bfd_error_handler)
451 (_("%pB: `%s' accessed both as normal and thread local symbol"),
452 abfd, h ? h->root.root.string : "<local>");
453 return FALSE;
454 }
455 return TRUE;
456 }
457
458 static bfd_boolean
459 riscv_elf_record_got_reference (bfd *abfd, struct bfd_link_info *info,
460 struct elf_link_hash_entry *h, long symndx)
461 {
462 struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
463 Elf_Internal_Shdr *symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
464
465 if (htab->elf.sgot == NULL)
466 {
467 if (!riscv_elf_create_got_section (htab->elf.dynobj, info))
468 return FALSE;
469 }
470
471 if (h != NULL)
472 {
473 h->got.refcount += 1;
474 return TRUE;
475 }
476
477 /* This is a global offset table entry for a local symbol. */
478 if (elf_local_got_refcounts (abfd) == NULL)
479 {
480 bfd_size_type size = symtab_hdr->sh_info * (sizeof (bfd_vma) + 1);
481 if (!(elf_local_got_refcounts (abfd) = bfd_zalloc (abfd, size)))
482 return FALSE;
483 _bfd_riscv_elf_local_got_tls_type (abfd)
484 = (char *) (elf_local_got_refcounts (abfd) + symtab_hdr->sh_info);
485 }
486 elf_local_got_refcounts (abfd) [symndx] += 1;
487
488 return TRUE;
489 }
490
491 static bfd_boolean
492 bad_static_reloc (bfd *abfd, unsigned r_type, struct elf_link_hash_entry *h)
493 {
494 reloc_howto_type * r = riscv_elf_rtype_to_howto (abfd, r_type);
495
496 (*_bfd_error_handler)
497 (_("%pB: relocation %s against `%s' can not be used when making a shared "
498 "object; recompile with -fPIC"),
499 abfd, r ? r->name : _("<unknown>"),
500 h != NULL ? h->root.root.string : "a local symbol");
501 bfd_set_error (bfd_error_bad_value);
502 return FALSE;
503 }
504 /* Look through the relocs for a section during the first phase, and
505 allocate space in the global offset table or procedure linkage
506 table. */
507
508 static bfd_boolean
509 riscv_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
510 asection *sec, const Elf_Internal_Rela *relocs)
511 {
512 struct riscv_elf_link_hash_table *htab;
513 Elf_Internal_Shdr *symtab_hdr;
514 struct elf_link_hash_entry **sym_hashes;
515 const Elf_Internal_Rela *rel;
516 asection *sreloc = NULL;
517
518 if (bfd_link_relocatable (info))
519 return TRUE;
520
521 htab = riscv_elf_hash_table (info);
522 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
523 sym_hashes = elf_sym_hashes (abfd);
524
525 if (htab->elf.dynobj == NULL)
526 htab->elf.dynobj = abfd;
527
528 for (rel = relocs; rel < relocs + sec->reloc_count; rel++)
529 {
530 unsigned int r_type;
531 unsigned int r_symndx;
532 struct elf_link_hash_entry *h;
533
534 r_symndx = ELFNN_R_SYM (rel->r_info);
535 r_type = ELFNN_R_TYPE (rel->r_info);
536
537 if (r_symndx >= NUM_SHDR_ENTRIES (symtab_hdr))
538 {
539 (*_bfd_error_handler) (_("%pB: bad symbol index: %d"),
540 abfd, r_symndx);
541 return FALSE;
542 }
543
544 if (r_symndx < symtab_hdr->sh_info)
545 h = NULL;
546 else
547 {
548 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
549 while (h->root.type == bfd_link_hash_indirect
550 || h->root.type == bfd_link_hash_warning)
551 h = (struct elf_link_hash_entry *) h->root.u.i.link;
552 }
553
554 switch (r_type)
555 {
556 case R_RISCV_TLS_GD_HI20:
557 if (!riscv_elf_record_got_reference (abfd, info, h, r_symndx)
558 || !riscv_elf_record_tls_type (abfd, h, r_symndx, GOT_TLS_GD))
559 return FALSE;
560 break;
561
562 case R_RISCV_TLS_GOT_HI20:
563 if (bfd_link_pic (info))
564 info->flags |= DF_STATIC_TLS;
565 if (!riscv_elf_record_got_reference (abfd, info, h, r_symndx)
566 || !riscv_elf_record_tls_type (abfd, h, r_symndx, GOT_TLS_IE))
567 return FALSE;
568 break;
569
570 case R_RISCV_GOT_HI20:
571 if (!riscv_elf_record_got_reference (abfd, info, h, r_symndx)
572 || !riscv_elf_record_tls_type (abfd, h, r_symndx, GOT_NORMAL))
573 return FALSE;
574 break;
575
576 case R_RISCV_CALL_PLT:
577 /* This symbol requires a procedure linkage table entry. We
578 actually build the entry in adjust_dynamic_symbol,
579 because this might be a case of linking PIC code without
580 linking in any dynamic objects, in which case we don't
581 need to generate a procedure linkage table after all. */
582
583 if (h != NULL)
584 {
585 h->needs_plt = 1;
586 h->plt.refcount += 1;
587 }
588 break;
589
590 case R_RISCV_CALL:
591 case R_RISCV_JAL:
592 case R_RISCV_BRANCH:
593 case R_RISCV_RVC_BRANCH:
594 case R_RISCV_RVC_JUMP:
595 case R_RISCV_PCREL_HI20:
596 /* In shared libraries, these relocs are known to bind locally. */
597 if (bfd_link_pic (info))
598 break;
599 goto static_reloc;
600
601 case R_RISCV_TPREL_HI20:
602 if (!bfd_link_executable (info))
603 return bad_static_reloc (abfd, r_type, h);
604 if (h != NULL)
605 riscv_elf_record_tls_type (abfd, h, r_symndx, GOT_TLS_LE);
606 goto static_reloc;
607
608 case R_RISCV_HI20:
609 if (bfd_link_pic (info))
610 return bad_static_reloc (abfd, r_type, h);
611 /* Fall through. */
612
613 case R_RISCV_COPY:
614 case R_RISCV_JUMP_SLOT:
615 case R_RISCV_RELATIVE:
616 case R_RISCV_64:
617 case R_RISCV_32:
618 /* Fall through. */
619
620 static_reloc:
621 /* This reloc might not bind locally. */
622 if (h != NULL)
623 h->non_got_ref = 1;
624
625 if (h != NULL && !bfd_link_pic (info))
626 {
627 /* We may need a .plt entry if the function this reloc
628 refers to is in a shared lib. */
629 h->plt.refcount += 1;
630 }
631
632 /* If we are creating a shared library, and this is a reloc
633 against a global symbol, or a non PC relative reloc
634 against a local symbol, then we need to copy the reloc
635 into the shared library. However, if we are linking with
636 -Bsymbolic, we do not need to copy a reloc against a
637 global symbol which is defined in an object we are
638 including in the link (i.e., DEF_REGULAR is set). At
639 this point we have not seen all the input files, so it is
640 possible that DEF_REGULAR is not set now but will be set
641 later (it is never cleared). In case of a weak definition,
642 DEF_REGULAR may be cleared later by a strong definition in
643 a shared library. We account for that possibility below by
644 storing information in the relocs_copied field of the hash
645 table entry. A similar situation occurs when creating
646 shared libraries and symbol visibility changes render the
647 symbol local.
648
649 If on the other hand, we are creating an executable, we
650 may need to keep relocations for symbols satisfied by a
651 dynamic library if we manage to avoid copy relocs for the
652 symbol. */
653 reloc_howto_type * r = riscv_elf_rtype_to_howto (abfd, r_type);
654
655 if ((bfd_link_pic (info)
656 && (sec->flags & SEC_ALLOC) != 0
657 && ((r != NULL && ! r->pc_relative)
658 || (h != NULL
659 && (! info->symbolic
660 || h->root.type == bfd_link_hash_defweak
661 || !h->def_regular))))
662 || (!bfd_link_pic (info)
663 && (sec->flags & SEC_ALLOC) != 0
664 && h != NULL
665 && (h->root.type == bfd_link_hash_defweak
666 || !h->def_regular)))
667 {
668 struct elf_dyn_relocs *p;
669 struct elf_dyn_relocs **head;
670
671 /* When creating a shared object, we must copy these
672 relocs into the output file. We create a reloc
673 section in dynobj and make room for the reloc. */
674 if (sreloc == NULL)
675 {
676 sreloc = _bfd_elf_make_dynamic_reloc_section
677 (sec, htab->elf.dynobj, RISCV_ELF_LOG_WORD_BYTES,
678 abfd, /*rela?*/ TRUE);
679
680 if (sreloc == NULL)
681 return FALSE;
682 }
683
684 /* If this is a global symbol, we count the number of
685 relocations we need for this symbol. */
686 if (h != NULL)
687 head = &((struct riscv_elf_link_hash_entry *) h)->dyn_relocs;
688 else
689 {
690 /* Track dynamic relocs needed for local syms too.
691 We really need local syms available to do this
692 easily. Oh well. */
693
694 asection *s;
695 void *vpp;
696 Elf_Internal_Sym *isym;
697
698 isym = bfd_sym_from_r_symndx (&htab->sym_cache,
699 abfd, r_symndx);
700 if (isym == NULL)
701 return FALSE;
702
703 s = bfd_section_from_elf_index (abfd, isym->st_shndx);
704 if (s == NULL)
705 s = sec;
706
707 vpp = &elf_section_data (s)->local_dynrel;
708 head = (struct elf_dyn_relocs **) vpp;
709 }
710
711 p = *head;
712 if (p == NULL || p->sec != sec)
713 {
714 bfd_size_type amt = sizeof *p;
715 p = ((struct elf_dyn_relocs *)
716 bfd_alloc (htab->elf.dynobj, amt));
717 if (p == NULL)
718 return FALSE;
719 p->next = *head;
720 *head = p;
721 p->sec = sec;
722 p->count = 0;
723 p->pc_count = 0;
724 }
725
726 p->count += 1;
727 p->pc_count += r == NULL ? 0 : r->pc_relative;
728 }
729
730 break;
731
732 case R_RISCV_GNU_VTINHERIT:
733 if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
734 return FALSE;
735 break;
736
737 case R_RISCV_GNU_VTENTRY:
738 if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))
739 return FALSE;
740 break;
741
742 default:
743 break;
744 }
745 }
746
747 return TRUE;
748 }
749
750 static asection *
751 riscv_elf_gc_mark_hook (asection *sec,
752 struct bfd_link_info *info,
753 Elf_Internal_Rela *rel,
754 struct elf_link_hash_entry *h,
755 Elf_Internal_Sym *sym)
756 {
757 if (h != NULL)
758 switch (ELFNN_R_TYPE (rel->r_info))
759 {
760 case R_RISCV_GNU_VTINHERIT:
761 case R_RISCV_GNU_VTENTRY:
762 return NULL;
763 }
764
765 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
766 }
767
768 /* Find dynamic relocs for H that apply to read-only sections. */
769
770 static asection *
771 readonly_dynrelocs (struct elf_link_hash_entry *h)
772 {
773 struct elf_dyn_relocs *p;
774
775 for (p = riscv_elf_hash_entry (h)->dyn_relocs; p != NULL; p = p->next)
776 {
777 asection *s = p->sec->output_section;
778
779 if (s != NULL && (s->flags & SEC_READONLY) != 0)
780 return p->sec;
781 }
782 return NULL;
783 }
784
785 /* Adjust a symbol defined by a dynamic object and referenced by a
786 regular object. The current definition is in some section of the
787 dynamic object, but we're not including those sections. We have to
788 change the definition to something the rest of the link can
789 understand. */
790
791 static bfd_boolean
792 riscv_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
793 struct elf_link_hash_entry *h)
794 {
795 struct riscv_elf_link_hash_table *htab;
796 struct riscv_elf_link_hash_entry * eh;
797 bfd *dynobj;
798 asection *s, *srel;
799
800 htab = riscv_elf_hash_table (info);
801 BFD_ASSERT (htab != NULL);
802
803 dynobj = htab->elf.dynobj;
804
805 /* Make sure we know what is going on here. */
806 BFD_ASSERT (dynobj != NULL
807 && (h->needs_plt
808 || h->type == STT_GNU_IFUNC
809 || h->is_weakalias
810 || (h->def_dynamic
811 && h->ref_regular
812 && !h->def_regular)));
813
814 /* If this is a function, put it in the procedure linkage table. We
815 will fill in the contents of the procedure linkage table later
816 (although we could actually do it here). */
817 if (h->type == STT_FUNC || h->type == STT_GNU_IFUNC || h->needs_plt)
818 {
819 if (h->plt.refcount <= 0
820 || SYMBOL_CALLS_LOCAL (info, h)
821 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
822 && h->root.type == bfd_link_hash_undefweak))
823 {
824 /* This case can occur if we saw a R_RISCV_CALL_PLT reloc in an
825 input file, but the symbol was never referred to by a dynamic
826 object, or if all references were garbage collected. In such
827 a case, we don't actually need to build a PLT entry. */
828 h->plt.offset = (bfd_vma) -1;
829 h->needs_plt = 0;
830 }
831
832 return TRUE;
833 }
834 else
835 h->plt.offset = (bfd_vma) -1;
836
837 /* If this is a weak symbol, and there is a real definition, the
838 processor independent code will have arranged for us to see the
839 real definition first, and we can just use the same value. */
840 if (h->is_weakalias)
841 {
842 struct elf_link_hash_entry *def = weakdef (h);
843 BFD_ASSERT (def->root.type == bfd_link_hash_defined);
844 h->root.u.def.section = def->root.u.def.section;
845 h->root.u.def.value = def->root.u.def.value;
846 return TRUE;
847 }
848
849 /* This is a reference to a symbol defined by a dynamic object which
850 is not a function. */
851
852 /* If we are creating a shared library, we must presume that the
853 only references to the symbol are via the global offset table.
854 For such cases we need not do anything here; the relocations will
855 be handled correctly by relocate_section. */
856 if (bfd_link_pic (info))
857 return TRUE;
858
859 /* If there are no references to this symbol that do not use the
860 GOT, we don't need to generate a copy reloc. */
861 if (!h->non_got_ref)
862 return TRUE;
863
864 /* If -z nocopyreloc was given, we won't generate them either. */
865 if (info->nocopyreloc)
866 {
867 h->non_got_ref = 0;
868 return TRUE;
869 }
870
871 /* If we don't find any dynamic relocs in read-only sections, then
872 we'll be keeping the dynamic relocs and avoiding the copy reloc. */
873 if (!readonly_dynrelocs (h))
874 {
875 h->non_got_ref = 0;
876 return TRUE;
877 }
878
879 /* We must allocate the symbol in our .dynbss section, which will
880 become part of the .bss section of the executable. There will be
881 an entry for this symbol in the .dynsym section. The dynamic
882 object will contain position independent code, so all references
883 from the dynamic object to this symbol will go through the global
884 offset table. The dynamic linker will use the .dynsym entry to
885 determine the address it must put in the global offset table, so
886 both the dynamic object and the regular object will refer to the
887 same memory location for the variable. */
888
889 /* We must generate a R_RISCV_COPY reloc to tell the dynamic linker
890 to copy the initial value out of the dynamic object and into the
891 runtime process image. We need to remember the offset into the
892 .rel.bss section we are going to use. */
893 eh = (struct riscv_elf_link_hash_entry *) h;
894 if (eh->tls_type & ~GOT_NORMAL)
895 {
896 s = htab->sdyntdata;
897 srel = htab->elf.srelbss;
898 }
899 else if ((h->root.u.def.section->flags & SEC_READONLY) != 0)
900 {
901 s = htab->elf.sdynrelro;
902 srel = htab->elf.sreldynrelro;
903 }
904 else
905 {
906 s = htab->elf.sdynbss;
907 srel = htab->elf.srelbss;
908 }
909 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0)
910 {
911 srel->size += sizeof (ElfNN_External_Rela);
912 h->needs_copy = 1;
913 }
914
915 return _bfd_elf_adjust_dynamic_copy (info, h, s);
916 }
917
918 /* Allocate space in .plt, .got and associated reloc sections for
919 dynamic relocs. */
920
921 static bfd_boolean
922 allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
923 {
924 struct bfd_link_info *info;
925 struct riscv_elf_link_hash_table *htab;
926 struct riscv_elf_link_hash_entry *eh;
927 struct elf_dyn_relocs *p;
928
929 if (h->root.type == bfd_link_hash_indirect)
930 return TRUE;
931
932 info = (struct bfd_link_info *) inf;
933 htab = riscv_elf_hash_table (info);
934 BFD_ASSERT (htab != NULL);
935
936 if (htab->elf.dynamic_sections_created
937 && h->plt.refcount > 0)
938 {
939 /* Make sure this symbol is output as a dynamic symbol.
940 Undefined weak syms won't yet be marked as dynamic. */
941 if (h->dynindx == -1
942 && !h->forced_local)
943 {
944 if (! bfd_elf_link_record_dynamic_symbol (info, h))
945 return FALSE;
946 }
947
948 if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, bfd_link_pic (info), h))
949 {
950 asection *s = htab->elf.splt;
951
952 if (s->size == 0)
953 s->size = PLT_HEADER_SIZE;
954
955 h->plt.offset = s->size;
956
957 /* Make room for this entry. */
958 s->size += PLT_ENTRY_SIZE;
959
960 /* We also need to make an entry in the .got.plt section. */
961 htab->elf.sgotplt->size += GOT_ENTRY_SIZE;
962
963 /* We also need to make an entry in the .rela.plt section. */
964 htab->elf.srelplt->size += sizeof (ElfNN_External_Rela);
965
966 /* If this symbol is not defined in a regular file, and we are
967 not generating a shared library, then set the symbol to this
968 location in the .plt. This is required to make function
969 pointers compare as equal between the normal executable and
970 the shared library. */
971 if (! bfd_link_pic (info)
972 && !h->def_regular)
973 {
974 h->root.u.def.section = s;
975 h->root.u.def.value = h->plt.offset;
976 }
977 }
978 else
979 {
980 h->plt.offset = (bfd_vma) -1;
981 h->needs_plt = 0;
982 }
983 }
984 else
985 {
986 h->plt.offset = (bfd_vma) -1;
987 h->needs_plt = 0;
988 }
989
990 if (h->got.refcount > 0)
991 {
992 asection *s;
993 bfd_boolean dyn;
994 int tls_type = riscv_elf_hash_entry (h)->tls_type;
995
996 /* Make sure this symbol is output as a dynamic symbol.
997 Undefined weak syms won't yet be marked as dynamic. */
998 if (h->dynindx == -1
999 && !h->forced_local)
1000 {
1001 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1002 return FALSE;
1003 }
1004
1005 s = htab->elf.sgot;
1006 h->got.offset = s->size;
1007 dyn = htab->elf.dynamic_sections_created;
1008 if (tls_type & (GOT_TLS_GD | GOT_TLS_IE))
1009 {
1010 /* TLS_GD needs two dynamic relocs and two GOT slots. */
1011 if (tls_type & GOT_TLS_GD)
1012 {
1013 s->size += 2 * RISCV_ELF_WORD_BYTES;
1014 htab->elf.srelgot->size += 2 * sizeof (ElfNN_External_Rela);
1015 }
1016
1017 /* TLS_IE needs one dynamic reloc and one GOT slot. */
1018 if (tls_type & GOT_TLS_IE)
1019 {
1020 s->size += RISCV_ELF_WORD_BYTES;
1021 htab->elf.srelgot->size += sizeof (ElfNN_External_Rela);
1022 }
1023 }
1024 else
1025 {
1026 s->size += RISCV_ELF_WORD_BYTES;
1027 if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, bfd_link_pic (info), h)
1028 && ! UNDEFWEAK_NO_DYNAMIC_RELOC (info, h))
1029 htab->elf.srelgot->size += sizeof (ElfNN_External_Rela);
1030 }
1031 }
1032 else
1033 h->got.offset = (bfd_vma) -1;
1034
1035 eh = (struct riscv_elf_link_hash_entry *) h;
1036 if (eh->dyn_relocs == NULL)
1037 return TRUE;
1038
1039 /* In the shared -Bsymbolic case, discard space allocated for
1040 dynamic pc-relative relocs against symbols which turn out to be
1041 defined in regular objects. For the normal shared case, discard
1042 space for pc-relative relocs that have become local due to symbol
1043 visibility changes. */
1044
1045 if (bfd_link_pic (info))
1046 {
1047 if (SYMBOL_CALLS_LOCAL (info, h))
1048 {
1049 struct elf_dyn_relocs **pp;
1050
1051 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
1052 {
1053 p->count -= p->pc_count;
1054 p->pc_count = 0;
1055 if (p->count == 0)
1056 *pp = p->next;
1057 else
1058 pp = &p->next;
1059 }
1060 }
1061
1062 /* Also discard relocs on undefined weak syms with non-default
1063 visibility. */
1064 if (eh->dyn_relocs != NULL
1065 && h->root.type == bfd_link_hash_undefweak)
1066 {
1067 if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1068 || UNDEFWEAK_NO_DYNAMIC_RELOC (info, h))
1069 eh->dyn_relocs = NULL;
1070
1071 /* Make sure undefined weak symbols are output as a dynamic
1072 symbol in PIEs. */
1073 else if (h->dynindx == -1
1074 && !h->forced_local)
1075 {
1076 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1077 return FALSE;
1078 }
1079 }
1080 }
1081 else
1082 {
1083 /* For the non-shared case, discard space for relocs against
1084 symbols which turn out to need copy relocs or are not
1085 dynamic. */
1086
1087 if (!h->non_got_ref
1088 && ((h->def_dynamic
1089 && !h->def_regular)
1090 || (htab->elf.dynamic_sections_created
1091 && (h->root.type == bfd_link_hash_undefweak
1092 || h->root.type == bfd_link_hash_undefined))))
1093 {
1094 /* Make sure this symbol is output as a dynamic symbol.
1095 Undefined weak syms won't yet be marked as dynamic. */
1096 if (h->dynindx == -1
1097 && !h->forced_local)
1098 {
1099 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1100 return FALSE;
1101 }
1102
1103 /* If that succeeded, we know we'll be keeping all the
1104 relocs. */
1105 if (h->dynindx != -1)
1106 goto keep;
1107 }
1108
1109 eh->dyn_relocs = NULL;
1110
1111 keep: ;
1112 }
1113
1114 /* Finally, allocate space. */
1115 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1116 {
1117 asection *sreloc = elf_section_data (p->sec)->sreloc;
1118 sreloc->size += p->count * sizeof (ElfNN_External_Rela);
1119 }
1120
1121 return TRUE;
1122 }
1123
1124 /* Set DF_TEXTREL if we find any dynamic relocs that apply to
1125 read-only sections. */
1126
1127 static bfd_boolean
1128 maybe_set_textrel (struct elf_link_hash_entry *h, void *info_p)
1129 {
1130 asection *sec;
1131
1132 if (h->root.type == bfd_link_hash_indirect)
1133 return TRUE;
1134
1135 sec = readonly_dynrelocs (h);
1136 if (sec != NULL)
1137 {
1138 struct bfd_link_info *info = (struct bfd_link_info *) info_p;
1139
1140 info->flags |= DF_TEXTREL;
1141 info->callbacks->minfo
1142 (_("%pB: dynamic relocation against `%pT' in read-only section `%pA'\n"),
1143 sec->owner, h->root.root.string, sec);
1144
1145 /* Not an error, just cut short the traversal. */
1146 return FALSE;
1147 }
1148 return TRUE;
1149 }
1150
1151 static bfd_boolean
1152 riscv_elf_size_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info)
1153 {
1154 struct riscv_elf_link_hash_table *htab;
1155 bfd *dynobj;
1156 asection *s;
1157 bfd *ibfd;
1158
1159 htab = riscv_elf_hash_table (info);
1160 BFD_ASSERT (htab != NULL);
1161 dynobj = htab->elf.dynobj;
1162 BFD_ASSERT (dynobj != NULL);
1163
1164 if (elf_hash_table (info)->dynamic_sections_created)
1165 {
1166 /* Set the contents of the .interp section to the interpreter. */
1167 if (bfd_link_executable (info) && !info->nointerp)
1168 {
1169 s = bfd_get_linker_section (dynobj, ".interp");
1170 BFD_ASSERT (s != NULL);
1171 s->size = strlen (ELFNN_DYNAMIC_INTERPRETER) + 1;
1172 s->contents = (unsigned char *) ELFNN_DYNAMIC_INTERPRETER;
1173 }
1174 }
1175
1176 /* Set up .got offsets for local syms, and space for local dynamic
1177 relocs. */
1178 for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
1179 {
1180 bfd_signed_vma *local_got;
1181 bfd_signed_vma *end_local_got;
1182 char *local_tls_type;
1183 bfd_size_type locsymcount;
1184 Elf_Internal_Shdr *symtab_hdr;
1185 asection *srel;
1186
1187 if (! is_riscv_elf (ibfd))
1188 continue;
1189
1190 for (s = ibfd->sections; s != NULL; s = s->next)
1191 {
1192 struct elf_dyn_relocs *p;
1193
1194 for (p = elf_section_data (s)->local_dynrel; p != NULL; p = p->next)
1195 {
1196 if (!bfd_is_abs_section (p->sec)
1197 && bfd_is_abs_section (p->sec->output_section))
1198 {
1199 /* Input section has been discarded, either because
1200 it is a copy of a linkonce section or due to
1201 linker script /DISCARD/, so we'll be discarding
1202 the relocs too. */
1203 }
1204 else if (p->count != 0)
1205 {
1206 srel = elf_section_data (p->sec)->sreloc;
1207 srel->size += p->count * sizeof (ElfNN_External_Rela);
1208 if ((p->sec->output_section->flags & SEC_READONLY) != 0)
1209 info->flags |= DF_TEXTREL;
1210 }
1211 }
1212 }
1213
1214 local_got = elf_local_got_refcounts (ibfd);
1215 if (!local_got)
1216 continue;
1217
1218 symtab_hdr = &elf_symtab_hdr (ibfd);
1219 locsymcount = symtab_hdr->sh_info;
1220 end_local_got = local_got + locsymcount;
1221 local_tls_type = _bfd_riscv_elf_local_got_tls_type (ibfd);
1222 s = htab->elf.sgot;
1223 srel = htab->elf.srelgot;
1224 for (; local_got < end_local_got; ++local_got, ++local_tls_type)
1225 {
1226 if (*local_got > 0)
1227 {
1228 *local_got = s->size;
1229 s->size += RISCV_ELF_WORD_BYTES;
1230 if (*local_tls_type & GOT_TLS_GD)
1231 s->size += RISCV_ELF_WORD_BYTES;
1232 if (bfd_link_pic (info)
1233 || (*local_tls_type & (GOT_TLS_GD | GOT_TLS_IE)))
1234 srel->size += sizeof (ElfNN_External_Rela);
1235 }
1236 else
1237 *local_got = (bfd_vma) -1;
1238 }
1239 }
1240
1241 /* Allocate global sym .plt and .got entries, and space for global
1242 sym dynamic relocs. */
1243 elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, info);
1244
1245 if (htab->elf.sgotplt)
1246 {
1247 struct elf_link_hash_entry *got;
1248 got = elf_link_hash_lookup (elf_hash_table (info),
1249 "_GLOBAL_OFFSET_TABLE_",
1250 FALSE, FALSE, FALSE);
1251
1252 /* Don't allocate .got.plt section if there are no GOT nor PLT
1253 entries and there is no refeence to _GLOBAL_OFFSET_TABLE_. */
1254 if ((got == NULL
1255 || !got->ref_regular_nonweak)
1256 && (htab->elf.sgotplt->size == GOTPLT_HEADER_SIZE)
1257 && (htab->elf.splt == NULL
1258 || htab->elf.splt->size == 0)
1259 && (htab->elf.sgot == NULL
1260 || (htab->elf.sgot->size
1261 == get_elf_backend_data (output_bfd)->got_header_size)))
1262 htab->elf.sgotplt->size = 0;
1263 }
1264
1265 /* The check_relocs and adjust_dynamic_symbol entry points have
1266 determined the sizes of the various dynamic sections. Allocate
1267 memory for them. */
1268 for (s = dynobj->sections; s != NULL; s = s->next)
1269 {
1270 if ((s->flags & SEC_LINKER_CREATED) == 0)
1271 continue;
1272
1273 if (s == htab->elf.splt
1274 || s == htab->elf.sgot
1275 || s == htab->elf.sgotplt
1276 || s == htab->elf.sdynbss
1277 || s == htab->elf.sdynrelro
1278 || s == htab->sdyntdata)
1279 {
1280 /* Strip this section if we don't need it; see the
1281 comment below. */
1282 }
1283 else if (strncmp (s->name, ".rela", 5) == 0)
1284 {
1285 if (s->size != 0)
1286 {
1287 /* We use the reloc_count field as a counter if we need
1288 to copy relocs into the output file. */
1289 s->reloc_count = 0;
1290 }
1291 }
1292 else
1293 {
1294 /* It's not one of our sections. */
1295 continue;
1296 }
1297
1298 if (s->size == 0)
1299 {
1300 /* If we don't need this section, strip it from the
1301 output file. This is mostly to handle .rela.bss and
1302 .rela.plt. We must create both sections in
1303 create_dynamic_sections, because they must be created
1304 before the linker maps input sections to output
1305 sections. The linker does that before
1306 adjust_dynamic_symbol is called, and it is that
1307 function which decides whether anything needs to go
1308 into these sections. */
1309 s->flags |= SEC_EXCLUDE;
1310 continue;
1311 }
1312
1313 if ((s->flags & SEC_HAS_CONTENTS) == 0)
1314 continue;
1315
1316 /* Allocate memory for the section contents. Zero the memory
1317 for the benefit of .rela.plt, which has 4 unused entries
1318 at the beginning, and we don't want garbage. */
1319 s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->size);
1320 if (s->contents == NULL)
1321 return FALSE;
1322 }
1323
1324 if (elf_hash_table (info)->dynamic_sections_created)
1325 {
1326 /* Add some entries to the .dynamic section. We fill in the
1327 values later, in riscv_elf_finish_dynamic_sections, but we
1328 must add the entries now so that we get the correct size for
1329 the .dynamic section. The DT_DEBUG entry is filled in by the
1330 dynamic linker and used by the debugger. */
1331 #define add_dynamic_entry(TAG, VAL) \
1332 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
1333
1334 if (bfd_link_executable (info))
1335 {
1336 if (!add_dynamic_entry (DT_DEBUG, 0))
1337 return FALSE;
1338 }
1339
1340 if (htab->elf.srelplt->size != 0)
1341 {
1342 if (!add_dynamic_entry (DT_PLTGOT, 0)
1343 || !add_dynamic_entry (DT_PLTRELSZ, 0)
1344 || !add_dynamic_entry (DT_PLTREL, DT_RELA)
1345 || !add_dynamic_entry (DT_JMPREL, 0))
1346 return FALSE;
1347 }
1348
1349 if (!add_dynamic_entry (DT_RELA, 0)
1350 || !add_dynamic_entry (DT_RELASZ, 0)
1351 || !add_dynamic_entry (DT_RELAENT, sizeof (ElfNN_External_Rela)))
1352 return FALSE;
1353
1354 /* If any dynamic relocs apply to a read-only section,
1355 then we need a DT_TEXTREL entry. */
1356 if ((info->flags & DF_TEXTREL) == 0)
1357 elf_link_hash_traverse (&htab->elf, maybe_set_textrel, info);
1358
1359 if (info->flags & DF_TEXTREL)
1360 {
1361 if (!add_dynamic_entry (DT_TEXTREL, 0))
1362 return FALSE;
1363 }
1364 }
1365 #undef add_dynamic_entry
1366
1367 return TRUE;
1368 }
1369
1370 #define TP_OFFSET 0
1371 #define DTP_OFFSET 0x800
1372
1373 /* Return the relocation value for a TLS dtp-relative reloc. */
1374
1375 static bfd_vma
1376 dtpoff (struct bfd_link_info *info, bfd_vma address)
1377 {
1378 /* If tls_sec is NULL, we should have signalled an error already. */
1379 if (elf_hash_table (info)->tls_sec == NULL)
1380 return 0;
1381 return address - elf_hash_table (info)->tls_sec->vma - DTP_OFFSET;
1382 }
1383
1384 /* Return the relocation value for a static TLS tp-relative relocation. */
1385
1386 static bfd_vma
1387 tpoff (struct bfd_link_info *info, bfd_vma address)
1388 {
1389 /* If tls_sec is NULL, we should have signalled an error already. */
1390 if (elf_hash_table (info)->tls_sec == NULL)
1391 return 0;
1392 return address - elf_hash_table (info)->tls_sec->vma - TP_OFFSET;
1393 }
1394
1395 /* Return the global pointer's value, or 0 if it is not in use. */
1396
1397 static bfd_vma
1398 riscv_global_pointer_value (struct bfd_link_info *info)
1399 {
1400 struct bfd_link_hash_entry *h;
1401
1402 h = bfd_link_hash_lookup (info->hash, RISCV_GP_SYMBOL, FALSE, FALSE, TRUE);
1403 if (h == NULL || h->type != bfd_link_hash_defined)
1404 return 0;
1405
1406 return h->u.def.value + sec_addr (h->u.def.section);
1407 }
1408
1409 /* Emplace a static relocation. */
1410
1411 static bfd_reloc_status_type
1412 perform_relocation (const reloc_howto_type *howto,
1413 const Elf_Internal_Rela *rel,
1414 bfd_vma value,
1415 asection *input_section,
1416 bfd *input_bfd,
1417 bfd_byte *contents)
1418 {
1419 if (howto->pc_relative)
1420 value -= sec_addr (input_section) + rel->r_offset;
1421 value += rel->r_addend;
1422
1423 switch (ELFNN_R_TYPE (rel->r_info))
1424 {
1425 case R_RISCV_HI20:
1426 case R_RISCV_TPREL_HI20:
1427 case R_RISCV_PCREL_HI20:
1428 case R_RISCV_GOT_HI20:
1429 case R_RISCV_TLS_GOT_HI20:
1430 case R_RISCV_TLS_GD_HI20:
1431 if (ARCH_SIZE > 32 && !VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (value)))
1432 return bfd_reloc_overflow;
1433 value = ENCODE_UTYPE_IMM (RISCV_CONST_HIGH_PART (value));
1434 break;
1435
1436 case R_RISCV_LO12_I:
1437 case R_RISCV_GPREL_I:
1438 case R_RISCV_TPREL_LO12_I:
1439 case R_RISCV_TPREL_I:
1440 case R_RISCV_PCREL_LO12_I:
1441 value = ENCODE_ITYPE_IMM (value);
1442 break;
1443
1444 case R_RISCV_LO12_S:
1445 case R_RISCV_GPREL_S:
1446 case R_RISCV_TPREL_LO12_S:
1447 case R_RISCV_TPREL_S:
1448 case R_RISCV_PCREL_LO12_S:
1449 value = ENCODE_STYPE_IMM (value);
1450 break;
1451
1452 case R_RISCV_CALL:
1453 case R_RISCV_CALL_PLT:
1454 if (ARCH_SIZE > 32 && !VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (value)))
1455 return bfd_reloc_overflow;
1456 value = ENCODE_UTYPE_IMM (RISCV_CONST_HIGH_PART (value))
1457 | (ENCODE_ITYPE_IMM (value) << 32);
1458 break;
1459
1460 case R_RISCV_JAL:
1461 if (!VALID_UJTYPE_IMM (value))
1462 return bfd_reloc_overflow;
1463 value = ENCODE_UJTYPE_IMM (value);
1464 break;
1465
1466 case R_RISCV_BRANCH:
1467 if (!VALID_SBTYPE_IMM (value))
1468 return bfd_reloc_overflow;
1469 value = ENCODE_SBTYPE_IMM (value);
1470 break;
1471
1472 case R_RISCV_RVC_BRANCH:
1473 if (!VALID_RVC_B_IMM (value))
1474 return bfd_reloc_overflow;
1475 value = ENCODE_RVC_B_IMM (value);
1476 break;
1477
1478 case R_RISCV_RVC_JUMP:
1479 if (!VALID_RVC_J_IMM (value))
1480 return bfd_reloc_overflow;
1481 value = ENCODE_RVC_J_IMM (value);
1482 break;
1483
1484 case R_RISCV_RVC_LUI:
1485 if (!VALID_RVC_LUI_IMM (RISCV_CONST_HIGH_PART (value)))
1486 return bfd_reloc_overflow;
1487 value = ENCODE_RVC_LUI_IMM (RISCV_CONST_HIGH_PART (value));
1488 break;
1489
1490 case R_RISCV_32:
1491 case R_RISCV_64:
1492 case R_RISCV_ADD8:
1493 case R_RISCV_ADD16:
1494 case R_RISCV_ADD32:
1495 case R_RISCV_ADD64:
1496 case R_RISCV_SUB6:
1497 case R_RISCV_SUB8:
1498 case R_RISCV_SUB16:
1499 case R_RISCV_SUB32:
1500 case R_RISCV_SUB64:
1501 case R_RISCV_SET6:
1502 case R_RISCV_SET8:
1503 case R_RISCV_SET16:
1504 case R_RISCV_SET32:
1505 case R_RISCV_32_PCREL:
1506 case R_RISCV_TLS_DTPREL32:
1507 case R_RISCV_TLS_DTPREL64:
1508 break;
1509
1510 case R_RISCV_DELETE:
1511 return bfd_reloc_ok;
1512
1513 default:
1514 return bfd_reloc_notsupported;
1515 }
1516
1517 bfd_vma word = bfd_get (howto->bitsize, input_bfd, contents + rel->r_offset);
1518 word = (word & ~howto->dst_mask) | (value & howto->dst_mask);
1519 bfd_put (howto->bitsize, input_bfd, word, contents + rel->r_offset);
1520
1521 return bfd_reloc_ok;
1522 }
1523
1524 /* Remember all PC-relative high-part relocs we've encountered to help us
1525 later resolve the corresponding low-part relocs. */
1526
1527 typedef struct
1528 {
1529 bfd_vma address;
1530 bfd_vma value;
1531 } riscv_pcrel_hi_reloc;
1532
1533 typedef struct riscv_pcrel_lo_reloc
1534 {
1535 asection * input_section;
1536 struct bfd_link_info * info;
1537 reloc_howto_type * howto;
1538 const Elf_Internal_Rela * reloc;
1539 bfd_vma addr;
1540 const char * name;
1541 bfd_byte * contents;
1542 struct riscv_pcrel_lo_reloc * next;
1543 } riscv_pcrel_lo_reloc;
1544
1545 typedef struct
1546 {
1547 htab_t hi_relocs;
1548 riscv_pcrel_lo_reloc *lo_relocs;
1549 } riscv_pcrel_relocs;
1550
1551 static hashval_t
1552 riscv_pcrel_reloc_hash (const void *entry)
1553 {
1554 const riscv_pcrel_hi_reloc *e = entry;
1555 return (hashval_t)(e->address >> 2);
1556 }
1557
1558 static bfd_boolean
1559 riscv_pcrel_reloc_eq (const void *entry1, const void *entry2)
1560 {
1561 const riscv_pcrel_hi_reloc *e1 = entry1, *e2 = entry2;
1562 return e1->address == e2->address;
1563 }
1564
1565 static bfd_boolean
1566 riscv_init_pcrel_relocs (riscv_pcrel_relocs *p)
1567 {
1568
1569 p->lo_relocs = NULL;
1570 p->hi_relocs = htab_create (1024, riscv_pcrel_reloc_hash,
1571 riscv_pcrel_reloc_eq, free);
1572 return p->hi_relocs != NULL;
1573 }
1574
1575 static void
1576 riscv_free_pcrel_relocs (riscv_pcrel_relocs *p)
1577 {
1578 riscv_pcrel_lo_reloc *cur = p->lo_relocs;
1579
1580 while (cur != NULL)
1581 {
1582 riscv_pcrel_lo_reloc *next = cur->next;
1583 free (cur);
1584 cur = next;
1585 }
1586
1587 htab_delete (p->hi_relocs);
1588 }
1589
1590 static bfd_boolean
1591 riscv_zero_pcrel_hi_reloc (Elf_Internal_Rela *rel,
1592 struct bfd_link_info *info,
1593 bfd_vma pc,
1594 bfd_vma addr,
1595 bfd_byte *contents,
1596 const reloc_howto_type *howto,
1597 bfd *input_bfd)
1598 {
1599 /* We may need to reference low addreses in PC-relative modes even when the
1600 * PC is far away from these addresses. For example, undefweak references
1601 * need to produce the address 0 when linked. As 0 is far from the arbitrary
1602 * addresses that we can link PC-relative programs at, the linker can't
1603 * actually relocate references to those symbols. In order to allow these
1604 * programs to work we simply convert the PC-relative auipc sequences to
1605 * 0-relative lui sequences. */
1606 if (bfd_link_pic (info))
1607 return FALSE;
1608
1609 /* If it's possible to reference the symbol using auipc we do so, as that's
1610 * more in the spirit of the PC-relative relocations we're processing. */
1611 bfd_vma offset = addr - pc;
1612 if (ARCH_SIZE == 32 || VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (offset)))
1613 return FALSE;
1614
1615 /* If it's impossible to reference this with a LUI-based offset then don't
1616 * bother to convert it at all so users still see the PC-relative relocation
1617 * in the truncation message. */
1618 if (ARCH_SIZE > 32 && !VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (addr)))
1619 return FALSE;
1620
1621 rel->r_info = ELFNN_R_INFO(addr, R_RISCV_HI20);
1622
1623 bfd_vma insn = bfd_get(howto->bitsize, input_bfd, contents + rel->r_offset);
1624 insn = (insn & ~MASK_AUIPC) | MATCH_LUI;
1625 bfd_put(howto->bitsize, input_bfd, insn, contents + rel->r_offset);
1626 return TRUE;
1627 }
1628
1629 static bfd_boolean
1630 riscv_record_pcrel_hi_reloc (riscv_pcrel_relocs *p, bfd_vma addr,
1631 bfd_vma value, bfd_boolean absolute)
1632 {
1633 bfd_vma offset = absolute ? value : value - addr;
1634 riscv_pcrel_hi_reloc entry = {addr, offset};
1635 riscv_pcrel_hi_reloc **slot =
1636 (riscv_pcrel_hi_reloc **) htab_find_slot (p->hi_relocs, &entry, INSERT);
1637
1638 BFD_ASSERT (*slot == NULL);
1639 *slot = (riscv_pcrel_hi_reloc *) bfd_malloc (sizeof (riscv_pcrel_hi_reloc));
1640 if (*slot == NULL)
1641 return FALSE;
1642 **slot = entry;
1643 return TRUE;
1644 }
1645
1646 static bfd_boolean
1647 riscv_record_pcrel_lo_reloc (riscv_pcrel_relocs *p,
1648 asection *input_section,
1649 struct bfd_link_info *info,
1650 reloc_howto_type *howto,
1651 const Elf_Internal_Rela *reloc,
1652 bfd_vma addr,
1653 const char *name,
1654 bfd_byte *contents)
1655 {
1656 riscv_pcrel_lo_reloc *entry;
1657 entry = (riscv_pcrel_lo_reloc *) bfd_malloc (sizeof (riscv_pcrel_lo_reloc));
1658 if (entry == NULL)
1659 return FALSE;
1660 *entry = (riscv_pcrel_lo_reloc) {input_section, info, howto, reloc, addr,
1661 name, contents, p->lo_relocs};
1662 p->lo_relocs = entry;
1663 return TRUE;
1664 }
1665
1666 static bfd_boolean
1667 riscv_resolve_pcrel_lo_relocs (riscv_pcrel_relocs *p)
1668 {
1669 riscv_pcrel_lo_reloc *r;
1670
1671 for (r = p->lo_relocs; r != NULL; r = r->next)
1672 {
1673 bfd *input_bfd = r->input_section->owner;
1674
1675 riscv_pcrel_hi_reloc search = {r->addr, 0};
1676 riscv_pcrel_hi_reloc *entry = htab_find (p->hi_relocs, &search);
1677 if (entry == NULL
1678 /* Check for overflow into bit 11 when adding reloc addend. */
1679 || (! (entry->value & 0x800)
1680 && ((entry->value + r->reloc->r_addend) & 0x800)))
1681 {
1682 char *string = (entry == NULL
1683 ? "%pcrel_lo missing matching %pcrel_hi"
1684 : "%pcrel_lo overflow with an addend");
1685 (*r->info->callbacks->reloc_dangerous)
1686 (r->info, string, input_bfd, r->input_section, r->reloc->r_offset);
1687 return TRUE;
1688 }
1689
1690 perform_relocation (r->howto, r->reloc, entry->value, r->input_section,
1691 input_bfd, r->contents);
1692 }
1693
1694 return TRUE;
1695 }
1696
1697 /* Relocate a RISC-V ELF section.
1698
1699 The RELOCATE_SECTION function is called by the new ELF backend linker
1700 to handle the relocations for a section.
1701
1702 The relocs are always passed as Rela structures.
1703
1704 This function is responsible for adjusting the section contents as
1705 necessary, and (if generating a relocatable output file) adjusting
1706 the reloc addend as necessary.
1707
1708 This function does not have to worry about setting the reloc
1709 address or the reloc symbol index.
1710
1711 LOCAL_SYMS is a pointer to the swapped in local symbols.
1712
1713 LOCAL_SECTIONS is an array giving the section in the input file
1714 corresponding to the st_shndx field of each local symbol.
1715
1716 The global hash table entry for the global symbols can be found
1717 via elf_sym_hashes (input_bfd).
1718
1719 When generating relocatable output, this function must handle
1720 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
1721 going to be the section symbol corresponding to the output
1722 section, which means that the addend must be adjusted
1723 accordingly. */
1724
1725 static bfd_boolean
1726 riscv_elf_relocate_section (bfd *output_bfd,
1727 struct bfd_link_info *info,
1728 bfd *input_bfd,
1729 asection *input_section,
1730 bfd_byte *contents,
1731 Elf_Internal_Rela *relocs,
1732 Elf_Internal_Sym *local_syms,
1733 asection **local_sections)
1734 {
1735 Elf_Internal_Rela *rel;
1736 Elf_Internal_Rela *relend;
1737 riscv_pcrel_relocs pcrel_relocs;
1738 bfd_boolean ret = FALSE;
1739 asection *sreloc = elf_section_data (input_section)->sreloc;
1740 struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
1741 Elf_Internal_Shdr *symtab_hdr = &elf_symtab_hdr (input_bfd);
1742 struct elf_link_hash_entry **sym_hashes = elf_sym_hashes (input_bfd);
1743 bfd_vma *local_got_offsets = elf_local_got_offsets (input_bfd);
1744 bfd_boolean absolute;
1745
1746 if (!riscv_init_pcrel_relocs (&pcrel_relocs))
1747 return FALSE;
1748
1749 relend = relocs + input_section->reloc_count;
1750 for (rel = relocs; rel < relend; rel++)
1751 {
1752 unsigned long r_symndx;
1753 struct elf_link_hash_entry *h;
1754 Elf_Internal_Sym *sym;
1755 asection *sec;
1756 bfd_vma relocation;
1757 bfd_reloc_status_type r = bfd_reloc_ok;
1758 const char *name;
1759 bfd_vma off, ie_off;
1760 bfd_boolean unresolved_reloc, is_ie = FALSE;
1761 bfd_vma pc = sec_addr (input_section) + rel->r_offset;
1762 int r_type = ELFNN_R_TYPE (rel->r_info), tls_type;
1763 reloc_howto_type *howto = riscv_elf_rtype_to_howto (input_bfd, r_type);
1764 const char *msg = NULL;
1765 bfd_boolean resolved_to_zero;
1766
1767 if (howto == NULL
1768 || r_type == R_RISCV_GNU_VTINHERIT || r_type == R_RISCV_GNU_VTENTRY)
1769 continue;
1770
1771 /* This is a final link. */
1772 r_symndx = ELFNN_R_SYM (rel->r_info);
1773 h = NULL;
1774 sym = NULL;
1775 sec = NULL;
1776 unresolved_reloc = FALSE;
1777 if (r_symndx < symtab_hdr->sh_info)
1778 {
1779 sym = local_syms + r_symndx;
1780 sec = local_sections[r_symndx];
1781 relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
1782 }
1783 else
1784 {
1785 bfd_boolean warned, ignored;
1786
1787 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
1788 r_symndx, symtab_hdr, sym_hashes,
1789 h, sec, relocation,
1790 unresolved_reloc, warned, ignored);
1791 if (warned)
1792 {
1793 /* To avoid generating warning messages about truncated
1794 relocations, set the relocation's address to be the same as
1795 the start of this section. */
1796 if (input_section->output_section != NULL)
1797 relocation = input_section->output_section->vma;
1798 else
1799 relocation = 0;
1800 }
1801 }
1802
1803 if (sec != NULL && discarded_section (sec))
1804 RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
1805 rel, 1, relend, howto, 0, contents);
1806
1807 if (bfd_link_relocatable (info))
1808 continue;
1809
1810 if (h != NULL)
1811 name = h->root.root.string;
1812 else
1813 {
1814 name = (bfd_elf_string_from_elf_section
1815 (input_bfd, symtab_hdr->sh_link, sym->st_name));
1816 if (name == NULL || *name == '\0')
1817 name = bfd_section_name (input_bfd, sec);
1818 }
1819
1820 resolved_to_zero = (h != NULL
1821 && UNDEFWEAK_NO_DYNAMIC_RELOC (info, h));
1822
1823 switch (r_type)
1824 {
1825 case R_RISCV_NONE:
1826 case R_RISCV_RELAX:
1827 case R_RISCV_TPREL_ADD:
1828 case R_RISCV_COPY:
1829 case R_RISCV_JUMP_SLOT:
1830 case R_RISCV_RELATIVE:
1831 /* These require nothing of us at all. */
1832 continue;
1833
1834 case R_RISCV_HI20:
1835 case R_RISCV_BRANCH:
1836 case R_RISCV_RVC_BRANCH:
1837 case R_RISCV_RVC_LUI:
1838 case R_RISCV_LO12_I:
1839 case R_RISCV_LO12_S:
1840 case R_RISCV_SET6:
1841 case R_RISCV_SET8:
1842 case R_RISCV_SET16:
1843 case R_RISCV_SET32:
1844 case R_RISCV_32_PCREL:
1845 case R_RISCV_DELETE:
1846 /* These require no special handling beyond perform_relocation. */
1847 break;
1848
1849 case R_RISCV_GOT_HI20:
1850 if (h != NULL)
1851 {
1852 bfd_boolean dyn, pic;
1853
1854 off = h->got.offset;
1855 BFD_ASSERT (off != (bfd_vma) -1);
1856 dyn = elf_hash_table (info)->dynamic_sections_created;
1857 pic = bfd_link_pic (info);
1858
1859 if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, pic, h)
1860 || (pic && SYMBOL_REFERENCES_LOCAL (info, h)))
1861 {
1862 /* This is actually a static link, or it is a
1863 -Bsymbolic link and the symbol is defined
1864 locally, or the symbol was forced to be local
1865 because of a version file. We must initialize
1866 this entry in the global offset table. Since the
1867 offset must always be a multiple of the word size,
1868 we use the least significant bit to record whether
1869 we have initialized it already.
1870
1871 When doing a dynamic link, we create a .rela.got
1872 relocation entry to initialize the value. This
1873 is done in the finish_dynamic_symbol routine. */
1874 if ((off & 1) != 0)
1875 off &= ~1;
1876 else
1877 {
1878 bfd_put_NN (output_bfd, relocation,
1879 htab->elf.sgot->contents + off);
1880 h->got.offset |= 1;
1881 }
1882 }
1883 else
1884 unresolved_reloc = FALSE;
1885 }
1886 else
1887 {
1888 BFD_ASSERT (local_got_offsets != NULL
1889 && local_got_offsets[r_symndx] != (bfd_vma) -1);
1890
1891 off = local_got_offsets[r_symndx];
1892
1893 /* The offset must always be a multiple of the word size.
1894 So, we can use the least significant bit to record
1895 whether we have already processed this entry. */
1896 if ((off & 1) != 0)
1897 off &= ~1;
1898 else
1899 {
1900 if (bfd_link_pic (info))
1901 {
1902 asection *s;
1903 Elf_Internal_Rela outrel;
1904
1905 /* We need to generate a R_RISCV_RELATIVE reloc
1906 for the dynamic linker. */
1907 s = htab->elf.srelgot;
1908 BFD_ASSERT (s != NULL);
1909
1910 outrel.r_offset = sec_addr (htab->elf.sgot) + off;
1911 outrel.r_info =
1912 ELFNN_R_INFO (0, R_RISCV_RELATIVE);
1913 outrel.r_addend = relocation;
1914 relocation = 0;
1915 riscv_elf_append_rela (output_bfd, s, &outrel);
1916 }
1917
1918 bfd_put_NN (output_bfd, relocation,
1919 htab->elf.sgot->contents + off);
1920 local_got_offsets[r_symndx] |= 1;
1921 }
1922 }
1923 relocation = sec_addr (htab->elf.sgot) + off;
1924 absolute = riscv_zero_pcrel_hi_reloc (rel,
1925 info,
1926 pc,
1927 relocation,
1928 contents,
1929 howto,
1930 input_bfd);
1931 r_type = ELFNN_R_TYPE (rel->r_info);
1932 howto = riscv_elf_rtype_to_howto (input_bfd, r_type);
1933 if (howto == NULL)
1934 r = bfd_reloc_notsupported;
1935 else if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc,
1936 relocation, absolute))
1937 r = bfd_reloc_overflow;
1938 break;
1939
1940 case R_RISCV_ADD8:
1941 case R_RISCV_ADD16:
1942 case R_RISCV_ADD32:
1943 case R_RISCV_ADD64:
1944 {
1945 bfd_vma old_value = bfd_get (howto->bitsize, input_bfd,
1946 contents + rel->r_offset);
1947 relocation = old_value + relocation;
1948 }
1949 break;
1950
1951 case R_RISCV_SUB6:
1952 case R_RISCV_SUB8:
1953 case R_RISCV_SUB16:
1954 case R_RISCV_SUB32:
1955 case R_RISCV_SUB64:
1956 {
1957 bfd_vma old_value = bfd_get (howto->bitsize, input_bfd,
1958 contents + rel->r_offset);
1959 relocation = old_value - relocation;
1960 }
1961 break;
1962
1963 case R_RISCV_CALL:
1964 /* Handle a call to an undefined weak function. This won't be
1965 relaxed, so we have to handle it here. */
1966 if (h != NULL && h->root.type == bfd_link_hash_undefweak
1967 && h->plt.offset == MINUS_ONE)
1968 {
1969 /* We can use x0 as the base register. */
1970 bfd_vma insn = bfd_get_32 (input_bfd,
1971 contents + rel->r_offset + 4);
1972 insn &= ~(OP_MASK_RS1 << OP_SH_RS1);
1973 bfd_put_32 (input_bfd, insn, contents + rel->r_offset + 4);
1974 /* Set the relocation value so that we get 0 after the pc
1975 relative adjustment. */
1976 relocation = sec_addr (input_section) + rel->r_offset;
1977 }
1978 /* Fall through. */
1979
1980 case R_RISCV_CALL_PLT:
1981 case R_RISCV_JAL:
1982 case R_RISCV_RVC_JUMP:
1983 if (bfd_link_pic (info) && h != NULL && h->plt.offset != MINUS_ONE)
1984 {
1985 /* Refer to the PLT entry. */
1986 relocation = sec_addr (htab->elf.splt) + h->plt.offset;
1987 unresolved_reloc = FALSE;
1988 }
1989 break;
1990
1991 case R_RISCV_TPREL_HI20:
1992 relocation = tpoff (info, relocation);
1993 break;
1994
1995 case R_RISCV_TPREL_LO12_I:
1996 case R_RISCV_TPREL_LO12_S:
1997 relocation = tpoff (info, relocation);
1998 break;
1999
2000 case R_RISCV_TPREL_I:
2001 case R_RISCV_TPREL_S:
2002 relocation = tpoff (info, relocation);
2003 if (VALID_ITYPE_IMM (relocation + rel->r_addend))
2004 {
2005 /* We can use tp as the base register. */
2006 bfd_vma insn = bfd_get_32 (input_bfd, contents + rel->r_offset);
2007 insn &= ~(OP_MASK_RS1 << OP_SH_RS1);
2008 insn |= X_TP << OP_SH_RS1;
2009 bfd_put_32 (input_bfd, insn, contents + rel->r_offset);
2010 }
2011 else
2012 r = bfd_reloc_overflow;
2013 break;
2014
2015 case R_RISCV_GPREL_I:
2016 case R_RISCV_GPREL_S:
2017 {
2018 bfd_vma gp = riscv_global_pointer_value (info);
2019 bfd_boolean x0_base = VALID_ITYPE_IMM (relocation + rel->r_addend);
2020 if (x0_base || VALID_ITYPE_IMM (relocation + rel->r_addend - gp))
2021 {
2022 /* We can use x0 or gp as the base register. */
2023 bfd_vma insn = bfd_get_32 (input_bfd, contents + rel->r_offset);
2024 insn &= ~(OP_MASK_RS1 << OP_SH_RS1);
2025 if (!x0_base)
2026 {
2027 rel->r_addend -= gp;
2028 insn |= X_GP << OP_SH_RS1;
2029 }
2030 bfd_put_32 (input_bfd, insn, contents + rel->r_offset);
2031 }
2032 else
2033 r = bfd_reloc_overflow;
2034 break;
2035 }
2036
2037 case R_RISCV_PCREL_HI20:
2038 absolute = riscv_zero_pcrel_hi_reloc (rel,
2039 info,
2040 pc,
2041 relocation,
2042 contents,
2043 howto,
2044 input_bfd);
2045 r_type = ELFNN_R_TYPE (rel->r_info);
2046 howto = riscv_elf_rtype_to_howto (input_bfd, r_type);
2047 if (howto == NULL)
2048 r = bfd_reloc_notsupported;
2049 else if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc,
2050 relocation + rel->r_addend,
2051 absolute))
2052 r = bfd_reloc_overflow;
2053 break;
2054
2055 case R_RISCV_PCREL_LO12_I:
2056 case R_RISCV_PCREL_LO12_S:
2057 /* We don't allow section symbols plus addends as the auipc address,
2058 because then riscv_relax_delete_bytes would have to search through
2059 all relocs to update these addends. This is also ambiguous, as
2060 we do allow offsets to be added to the target address, which are
2061 not to be used to find the auipc address. */
2062 if ((ELF_ST_TYPE (sym->st_info) == STT_SECTION) && rel->r_addend)
2063 {
2064 r = bfd_reloc_dangerous;
2065 break;
2066 }
2067
2068 if (riscv_record_pcrel_lo_reloc (&pcrel_relocs, input_section, info,
2069 howto, rel, relocation, name,
2070 contents))
2071 continue;
2072 r = bfd_reloc_overflow;
2073 break;
2074
2075 case R_RISCV_TLS_DTPREL32:
2076 case R_RISCV_TLS_DTPREL64:
2077 relocation = dtpoff (info, relocation);
2078 break;
2079
2080 case R_RISCV_32:
2081 case R_RISCV_64:
2082 if ((input_section->flags & SEC_ALLOC) == 0)
2083 break;
2084
2085 if ((bfd_link_pic (info)
2086 && (h == NULL
2087 || (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
2088 && !resolved_to_zero)
2089 || h->root.type != bfd_link_hash_undefweak)
2090 && (! howto->pc_relative
2091 || !SYMBOL_CALLS_LOCAL (info, h)))
2092 || (!bfd_link_pic (info)
2093 && h != NULL
2094 && h->dynindx != -1
2095 && !h->non_got_ref
2096 && ((h->def_dynamic
2097 && !h->def_regular)
2098 || h->root.type == bfd_link_hash_undefweak
2099 || h->root.type == bfd_link_hash_undefined)))
2100 {
2101 Elf_Internal_Rela outrel;
2102 bfd_boolean skip_static_relocation, skip_dynamic_relocation;
2103
2104 /* When generating a shared object, these relocations
2105 are copied into the output file to be resolved at run
2106 time. */
2107
2108 outrel.r_offset =
2109 _bfd_elf_section_offset (output_bfd, info, input_section,
2110 rel->r_offset);
2111 skip_static_relocation = outrel.r_offset != (bfd_vma) -2;
2112 skip_dynamic_relocation = outrel.r_offset >= (bfd_vma) -2;
2113 outrel.r_offset += sec_addr (input_section);
2114
2115 if (skip_dynamic_relocation)
2116 memset (&outrel, 0, sizeof outrel);
2117 else if (h != NULL && h->dynindx != -1
2118 && !(bfd_link_pic (info)
2119 && SYMBOLIC_BIND (info, h)
2120 && h->def_regular))
2121 {
2122 outrel.r_info = ELFNN_R_INFO (h->dynindx, r_type);
2123 outrel.r_addend = rel->r_addend;
2124 }
2125 else
2126 {
2127 outrel.r_info = ELFNN_R_INFO (0, R_RISCV_RELATIVE);
2128 outrel.r_addend = relocation + rel->r_addend;
2129 }
2130
2131 riscv_elf_append_rela (output_bfd, sreloc, &outrel);
2132 if (skip_static_relocation)
2133 continue;
2134 }
2135 break;
2136
2137 case R_RISCV_TLS_GOT_HI20:
2138 is_ie = TRUE;
2139 /* Fall through. */
2140
2141 case R_RISCV_TLS_GD_HI20:
2142 if (h != NULL)
2143 {
2144 off = h->got.offset;
2145 h->got.offset |= 1;
2146 }
2147 else
2148 {
2149 off = local_got_offsets[r_symndx];
2150 local_got_offsets[r_symndx] |= 1;
2151 }
2152
2153 tls_type = _bfd_riscv_elf_tls_type (input_bfd, h, r_symndx);
2154 BFD_ASSERT (tls_type & (GOT_TLS_IE | GOT_TLS_GD));
2155 /* If this symbol is referenced by both GD and IE TLS, the IE
2156 reference's GOT slot follows the GD reference's slots. */
2157 ie_off = 0;
2158 if ((tls_type & GOT_TLS_GD) && (tls_type & GOT_TLS_IE))
2159 ie_off = 2 * GOT_ENTRY_SIZE;
2160
2161 if ((off & 1) != 0)
2162 off &= ~1;
2163 else
2164 {
2165 Elf_Internal_Rela outrel;
2166 int indx = 0;
2167 bfd_boolean need_relocs = FALSE;
2168
2169 if (htab->elf.srelgot == NULL)
2170 abort ();
2171
2172 if (h != NULL)
2173 {
2174 bfd_boolean dyn, pic;
2175 dyn = htab->elf.dynamic_sections_created;
2176 pic = bfd_link_pic (info);
2177
2178 if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, pic, h)
2179 && (!pic || !SYMBOL_REFERENCES_LOCAL (info, h)))
2180 indx = h->dynindx;
2181 }
2182
2183 /* The GOT entries have not been initialized yet. Do it
2184 now, and emit any relocations. */
2185 if ((bfd_link_pic (info) || indx != 0)
2186 && (h == NULL
2187 || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
2188 || h->root.type != bfd_link_hash_undefweak))
2189 need_relocs = TRUE;
2190
2191 if (tls_type & GOT_TLS_GD)
2192 {
2193 if (need_relocs)
2194 {
2195 outrel.r_offset = sec_addr (htab->elf.sgot) + off;
2196 outrel.r_addend = 0;
2197 outrel.r_info = ELFNN_R_INFO (indx, R_RISCV_TLS_DTPMODNN);
2198 bfd_put_NN (output_bfd, 0,
2199 htab->elf.sgot->contents + off);
2200 riscv_elf_append_rela (output_bfd, htab->elf.srelgot, &outrel);
2201 if (indx == 0)
2202 {
2203 BFD_ASSERT (! unresolved_reloc);
2204 bfd_put_NN (output_bfd,
2205 dtpoff (info, relocation),
2206 (htab->elf.sgot->contents + off +
2207 RISCV_ELF_WORD_BYTES));
2208 }
2209 else
2210 {
2211 bfd_put_NN (output_bfd, 0,
2212 (htab->elf.sgot->contents + off +
2213 RISCV_ELF_WORD_BYTES));
2214 outrel.r_info = ELFNN_R_INFO (indx, R_RISCV_TLS_DTPRELNN);
2215 outrel.r_offset += RISCV_ELF_WORD_BYTES;
2216 riscv_elf_append_rela (output_bfd, htab->elf.srelgot, &outrel);
2217 }
2218 }
2219 else
2220 {
2221 /* If we are not emitting relocations for a
2222 general dynamic reference, then we must be in a
2223 static link or an executable link with the
2224 symbol binding locally. Mark it as belonging
2225 to module 1, the executable. */
2226 bfd_put_NN (output_bfd, 1,
2227 htab->elf.sgot->contents + off);
2228 bfd_put_NN (output_bfd,
2229 dtpoff (info, relocation),
2230 (htab->elf.sgot->contents + off +
2231 RISCV_ELF_WORD_BYTES));
2232 }
2233 }
2234
2235 if (tls_type & GOT_TLS_IE)
2236 {
2237 if (need_relocs)
2238 {
2239 bfd_put_NN (output_bfd, 0,
2240 htab->elf.sgot->contents + off + ie_off);
2241 outrel.r_offset = sec_addr (htab->elf.sgot)
2242 + off + ie_off;
2243 outrel.r_addend = 0;
2244 if (indx == 0)
2245 outrel.r_addend = tpoff (info, relocation);
2246 outrel.r_info = ELFNN_R_INFO (indx, R_RISCV_TLS_TPRELNN);
2247 riscv_elf_append_rela (output_bfd, htab->elf.srelgot, &outrel);
2248 }
2249 else
2250 {
2251 bfd_put_NN (output_bfd, tpoff (info, relocation),
2252 htab->elf.sgot->contents + off + ie_off);
2253 }
2254 }
2255 }
2256
2257 BFD_ASSERT (off < (bfd_vma) -2);
2258 relocation = sec_addr (htab->elf.sgot) + off + (is_ie ? ie_off : 0);
2259 if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc,
2260 relocation, FALSE))
2261 r = bfd_reloc_overflow;
2262 unresolved_reloc = FALSE;
2263 break;
2264
2265 default:
2266 r = bfd_reloc_notsupported;
2267 }
2268
2269 /* Dynamic relocs are not propagated for SEC_DEBUGGING sections
2270 because such sections are not SEC_ALLOC and thus ld.so will
2271 not process them. */
2272 if (unresolved_reloc
2273 && !((input_section->flags & SEC_DEBUGGING) != 0
2274 && h->def_dynamic)
2275 && _bfd_elf_section_offset (output_bfd, info, input_section,
2276 rel->r_offset) != (bfd_vma) -1)
2277 {
2278 (*_bfd_error_handler)
2279 (_("%pB(%pA+%#" PRIx64 "): "
2280 "unresolvable %s relocation against symbol `%s'"),
2281 input_bfd,
2282 input_section,
2283 (uint64_t) rel->r_offset,
2284 howto->name,
2285 h->root.root.string);
2286 continue;
2287 }
2288
2289 if (r == bfd_reloc_ok)
2290 r = perform_relocation (howto, rel, relocation, input_section,
2291 input_bfd, contents);
2292
2293 switch (r)
2294 {
2295 case bfd_reloc_ok:
2296 continue;
2297
2298 case bfd_reloc_overflow:
2299 info->callbacks->reloc_overflow
2300 (info, (h ? &h->root : NULL), name, howto->name,
2301 (bfd_vma) 0, input_bfd, input_section, rel->r_offset);
2302 break;
2303
2304 case bfd_reloc_undefined:
2305 info->callbacks->undefined_symbol
2306 (info, name, input_bfd, input_section, rel->r_offset,
2307 TRUE);
2308 break;
2309
2310 case bfd_reloc_outofrange:
2311 msg = _("%X%P: internal error: out of range error\n");
2312 break;
2313
2314 case bfd_reloc_notsupported:
2315 msg = _("%X%P: internal error: unsupported relocation error\n");
2316 break;
2317
2318 case bfd_reloc_dangerous:
2319 info->callbacks->reloc_dangerous
2320 (info, "%pcrel_lo section symbol with an addend", input_bfd,
2321 input_section, rel->r_offset);
2322 break;
2323
2324 default:
2325 msg = _("%X%P: internal error: unknown error\n");
2326 break;
2327 }
2328
2329 if (msg)
2330 info->callbacks->einfo (msg);
2331
2332 /* We already reported the error via a callback, so don't try to report
2333 it again by returning false. That leads to spurious errors. */
2334 ret = TRUE;
2335 goto out;
2336 }
2337
2338 ret = riscv_resolve_pcrel_lo_relocs (&pcrel_relocs);
2339 out:
2340 riscv_free_pcrel_relocs (&pcrel_relocs);
2341 return ret;
2342 }
2343
2344 /* Finish up dynamic symbol handling. We set the contents of various
2345 dynamic sections here. */
2346
2347 static bfd_boolean
2348 riscv_elf_finish_dynamic_symbol (bfd *output_bfd,
2349 struct bfd_link_info *info,
2350 struct elf_link_hash_entry *h,
2351 Elf_Internal_Sym *sym)
2352 {
2353 struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
2354 const struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
2355
2356 if (h->plt.offset != (bfd_vma) -1)
2357 {
2358 /* We've decided to create a PLT entry for this symbol. */
2359 bfd_byte *loc;
2360 bfd_vma i, header_address, plt_idx, got_address;
2361 uint32_t plt_entry[PLT_ENTRY_INSNS];
2362 Elf_Internal_Rela rela;
2363
2364 BFD_ASSERT (h->dynindx != -1);
2365
2366 /* Calculate the address of the PLT header. */
2367 header_address = sec_addr (htab->elf.splt);
2368
2369 /* Calculate the index of the entry. */
2370 plt_idx = (h->plt.offset - PLT_HEADER_SIZE) / PLT_ENTRY_SIZE;
2371
2372 /* Calculate the address of the .got.plt entry. */
2373 got_address = riscv_elf_got_plt_val (plt_idx, info);
2374
2375 /* Find out where the .plt entry should go. */
2376 loc = htab->elf.splt->contents + h->plt.offset;
2377
2378 /* Fill in the PLT entry itself. */
2379 if (! riscv_make_plt_entry (output_bfd, got_address,
2380 header_address + h->plt.offset,
2381 plt_entry))
2382 return FALSE;
2383
2384 for (i = 0; i < PLT_ENTRY_INSNS; i++)
2385 bfd_put_32 (output_bfd, plt_entry[i], loc + 4*i);
2386
2387 /* Fill in the initial value of the .got.plt entry. */
2388 loc = htab->elf.sgotplt->contents
2389 + (got_address - sec_addr (htab->elf.sgotplt));
2390 bfd_put_NN (output_bfd, sec_addr (htab->elf.splt), loc);
2391
2392 /* Fill in the entry in the .rela.plt section. */
2393 rela.r_offset = got_address;
2394 rela.r_addend = 0;
2395 rela.r_info = ELFNN_R_INFO (h->dynindx, R_RISCV_JUMP_SLOT);
2396
2397 loc = htab->elf.srelplt->contents + plt_idx * sizeof (ElfNN_External_Rela);
2398 bed->s->swap_reloca_out (output_bfd, &rela, loc);
2399
2400 if (!h->def_regular)
2401 {
2402 /* Mark the symbol as undefined, rather than as defined in
2403 the .plt section. Leave the value alone. */
2404 sym->st_shndx = SHN_UNDEF;
2405 /* If the symbol is weak, we do need to clear the value.
2406 Otherwise, the PLT entry would provide a definition for
2407 the symbol even if the symbol wasn't defined anywhere,
2408 and so the symbol would never be NULL. */
2409 if (!h->ref_regular_nonweak)
2410 sym->st_value = 0;
2411 }
2412 }
2413
2414 if (h->got.offset != (bfd_vma) -1
2415 && !(riscv_elf_hash_entry (h)->tls_type & (GOT_TLS_GD | GOT_TLS_IE))
2416 && !UNDEFWEAK_NO_DYNAMIC_RELOC (info, h))
2417 {
2418 asection *sgot;
2419 asection *srela;
2420 Elf_Internal_Rela rela;
2421
2422 /* This symbol has an entry in the GOT. Set it up. */
2423
2424 sgot = htab->elf.sgot;
2425 srela = htab->elf.srelgot;
2426 BFD_ASSERT (sgot != NULL && srela != NULL);
2427
2428 rela.r_offset = sec_addr (sgot) + (h->got.offset &~ (bfd_vma) 1);
2429
2430 /* If this is a local symbol reference, we just want to emit a RELATIVE
2431 reloc. This can happen if it is a -Bsymbolic link, or a pie link, or
2432 the symbol was forced to be local because of a version file.
2433 The entry in the global offset table will already have been
2434 initialized in the relocate_section function. */
2435 if (bfd_link_pic (info)
2436 && SYMBOL_REFERENCES_LOCAL (info, h))
2437 {
2438 BFD_ASSERT((h->got.offset & 1) != 0);
2439 asection *sec = h->root.u.def.section;
2440 rela.r_info = ELFNN_R_INFO (0, R_RISCV_RELATIVE);
2441 rela.r_addend = (h->root.u.def.value
2442 + sec->output_section->vma
2443 + sec->output_offset);
2444 }
2445 else
2446 {
2447 BFD_ASSERT((h->got.offset & 1) == 0);
2448 BFD_ASSERT (h->dynindx != -1);
2449 rela.r_info = ELFNN_R_INFO (h->dynindx, R_RISCV_NN);
2450 rela.r_addend = 0;
2451 }
2452
2453 bfd_put_NN (output_bfd, 0,
2454 sgot->contents + (h->got.offset & ~(bfd_vma) 1));
2455 riscv_elf_append_rela (output_bfd, srela, &rela);
2456 }
2457
2458 if (h->needs_copy)
2459 {
2460 Elf_Internal_Rela rela;
2461 asection *s;
2462
2463 /* This symbols needs a copy reloc. Set it up. */
2464 BFD_ASSERT (h->dynindx != -1);
2465
2466 rela.r_offset = sec_addr (h->root.u.def.section) + h->root.u.def.value;
2467 rela.r_info = ELFNN_R_INFO (h->dynindx, R_RISCV_COPY);
2468 rela.r_addend = 0;
2469 if (h->root.u.def.section == htab->elf.sdynrelro)
2470 s = htab->elf.sreldynrelro;
2471 else
2472 s = htab->elf.srelbss;
2473 riscv_elf_append_rela (output_bfd, s, &rela);
2474 }
2475
2476 /* Mark some specially defined symbols as absolute. */
2477 if (h == htab->elf.hdynamic
2478 || (h == htab->elf.hgot || h == htab->elf.hplt))
2479 sym->st_shndx = SHN_ABS;
2480
2481 return TRUE;
2482 }
2483
2484 /* Finish up the dynamic sections. */
2485
2486 static bfd_boolean
2487 riscv_finish_dyn (bfd *output_bfd, struct bfd_link_info *info,
2488 bfd *dynobj, asection *sdyn)
2489 {
2490 struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
2491 const struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
2492 size_t dynsize = bed->s->sizeof_dyn;
2493 bfd_byte *dyncon, *dynconend;
2494
2495 dynconend = sdyn->contents + sdyn->size;
2496 for (dyncon = sdyn->contents; dyncon < dynconend; dyncon += dynsize)
2497 {
2498 Elf_Internal_Dyn dyn;
2499 asection *s;
2500
2501 bed->s->swap_dyn_in (dynobj, dyncon, &dyn);
2502
2503 switch (dyn.d_tag)
2504 {
2505 case DT_PLTGOT:
2506 s = htab->elf.sgotplt;
2507 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
2508 break;
2509 case DT_JMPREL:
2510 s = htab->elf.srelplt;
2511 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
2512 break;
2513 case DT_PLTRELSZ:
2514 s = htab->elf.srelplt;
2515 dyn.d_un.d_val = s->size;
2516 break;
2517 default:
2518 continue;
2519 }
2520
2521 bed->s->swap_dyn_out (output_bfd, &dyn, dyncon);
2522 }
2523 return TRUE;
2524 }
2525
2526 static bfd_boolean
2527 riscv_elf_finish_dynamic_sections (bfd *output_bfd,
2528 struct bfd_link_info *info)
2529 {
2530 bfd *dynobj;
2531 asection *sdyn;
2532 struct riscv_elf_link_hash_table *htab;
2533
2534 htab = riscv_elf_hash_table (info);
2535 BFD_ASSERT (htab != NULL);
2536 dynobj = htab->elf.dynobj;
2537
2538 sdyn = bfd_get_linker_section (dynobj, ".dynamic");
2539
2540 if (elf_hash_table (info)->dynamic_sections_created)
2541 {
2542 asection *splt;
2543 bfd_boolean ret;
2544
2545 splt = htab->elf.splt;
2546 BFD_ASSERT (splt != NULL && sdyn != NULL);
2547
2548 ret = riscv_finish_dyn (output_bfd, info, dynobj, sdyn);
2549
2550 if (!ret)
2551 return ret;
2552
2553 /* Fill in the head and tail entries in the procedure linkage table. */
2554 if (splt->size > 0)
2555 {
2556 int i;
2557 uint32_t plt_header[PLT_HEADER_INSNS];
2558 ret = riscv_make_plt_header (output_bfd,
2559 sec_addr (htab->elf.sgotplt),
2560 sec_addr (splt), plt_header);
2561 if (!ret)
2562 return ret;
2563
2564 for (i = 0; i < PLT_HEADER_INSNS; i++)
2565 bfd_put_32 (output_bfd, plt_header[i], splt->contents + 4*i);
2566
2567 elf_section_data (splt->output_section)->this_hdr.sh_entsize
2568 = PLT_ENTRY_SIZE;
2569 }
2570 }
2571
2572 if (htab->elf.sgotplt)
2573 {
2574 asection *output_section = htab->elf.sgotplt->output_section;
2575
2576 if (bfd_is_abs_section (output_section))
2577 {
2578 (*_bfd_error_handler)
2579 (_("discarded output section: `%pA'"), htab->elf.sgotplt);
2580 return FALSE;
2581 }
2582
2583 if (htab->elf.sgotplt->size > 0)
2584 {
2585 /* Write the first two entries in .got.plt, needed for the dynamic
2586 linker. */
2587 bfd_put_NN (output_bfd, (bfd_vma) -1, htab->elf.sgotplt->contents);
2588 bfd_put_NN (output_bfd, (bfd_vma) 0,
2589 htab->elf.sgotplt->contents + GOT_ENTRY_SIZE);
2590 }
2591
2592 elf_section_data (output_section)->this_hdr.sh_entsize = GOT_ENTRY_SIZE;
2593 }
2594
2595 if (htab->elf.sgot)
2596 {
2597 asection *output_section = htab->elf.sgot->output_section;
2598
2599 if (htab->elf.sgot->size > 0)
2600 {
2601 /* Set the first entry in the global offset table to the address of
2602 the dynamic section. */
2603 bfd_vma val = sdyn ? sec_addr (sdyn) : 0;
2604 bfd_put_NN (output_bfd, val, htab->elf.sgot->contents);
2605 }
2606
2607 elf_section_data (output_section)->this_hdr.sh_entsize = GOT_ENTRY_SIZE;
2608 }
2609
2610 return TRUE;
2611 }
2612
2613 /* Return address for Ith PLT stub in section PLT, for relocation REL
2614 or (bfd_vma) -1 if it should not be included. */
2615
2616 static bfd_vma
2617 riscv_elf_plt_sym_val (bfd_vma i, const asection *plt,
2618 const arelent *rel ATTRIBUTE_UNUSED)
2619 {
2620 return plt->vma + PLT_HEADER_SIZE + i * PLT_ENTRY_SIZE;
2621 }
2622
2623 static enum elf_reloc_type_class
2624 riscv_reloc_type_class (const struct bfd_link_info *info ATTRIBUTE_UNUSED,
2625 const asection *rel_sec ATTRIBUTE_UNUSED,
2626 const Elf_Internal_Rela *rela)
2627 {
2628 switch (ELFNN_R_TYPE (rela->r_info))
2629 {
2630 case R_RISCV_RELATIVE:
2631 return reloc_class_relative;
2632 case R_RISCV_JUMP_SLOT:
2633 return reloc_class_plt;
2634 case R_RISCV_COPY:
2635 return reloc_class_copy;
2636 default:
2637 return reloc_class_normal;
2638 }
2639 }
2640
2641 /* Merge backend specific data from an object file to the output
2642 object file when linking. */
2643
2644 static bfd_boolean
2645 _bfd_riscv_elf_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
2646 {
2647 bfd *obfd = info->output_bfd;
2648 flagword new_flags = elf_elfheader (ibfd)->e_flags;
2649 flagword old_flags = elf_elfheader (obfd)->e_flags;
2650
2651 if (!is_riscv_elf (ibfd) || !is_riscv_elf (obfd))
2652 return TRUE;
2653
2654 if (strcmp (bfd_get_target (ibfd), bfd_get_target (obfd)) != 0)
2655 {
2656 (*_bfd_error_handler)
2657 (_("%pB: ABI is incompatible with that of the selected emulation:\n"
2658 " target emulation `%s' does not match `%s'"),
2659 ibfd, bfd_get_target (ibfd), bfd_get_target (obfd));
2660 return FALSE;
2661 }
2662
2663 if (!_bfd_elf_merge_object_attributes (ibfd, info))
2664 return FALSE;
2665
2666 if (! elf_flags_init (obfd))
2667 {
2668 elf_flags_init (obfd) = TRUE;
2669 elf_elfheader (obfd)->e_flags = new_flags;
2670 return TRUE;
2671 }
2672
2673 /* Disallow linking different float ABIs. */
2674 if ((old_flags ^ new_flags) & EF_RISCV_FLOAT_ABI)
2675 {
2676 (*_bfd_error_handler)
2677 (_("%pB: can't link hard-float modules with soft-float modules"), ibfd);
2678 goto fail;
2679 }
2680
2681 /* Disallow linking RVE and non-RVE. */
2682 if ((old_flags ^ new_flags) & EF_RISCV_RVE)
2683 {
2684 (*_bfd_error_handler)
2685 (_("%pB: can't link RVE with other target"), ibfd);
2686 goto fail;
2687 }
2688
2689 /* Allow linking RVC and non-RVC, and keep the RVC flag. */
2690 elf_elfheader (obfd)->e_flags |= new_flags & EF_RISCV_RVC;
2691
2692 return TRUE;
2693
2694 fail:
2695 bfd_set_error (bfd_error_bad_value);
2696 return FALSE;
2697 }
2698
2699 /* Delete some bytes from a section while relaxing. */
2700
2701 static bfd_boolean
2702 riscv_relax_delete_bytes (bfd *abfd, asection *sec, bfd_vma addr, size_t count,
2703 struct bfd_link_info *link_info)
2704 {
2705 unsigned int i, symcount;
2706 bfd_vma toaddr = sec->size;
2707 struct elf_link_hash_entry **sym_hashes = elf_sym_hashes (abfd);
2708 Elf_Internal_Shdr *symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
2709 unsigned int sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec);
2710 struct bfd_elf_section_data *data = elf_section_data (sec);
2711 bfd_byte *contents = data->this_hdr.contents;
2712
2713 /* Actually delete the bytes. */
2714 sec->size -= count;
2715 memmove (contents + addr, contents + addr + count, toaddr - addr - count);
2716
2717 /* Adjust the location of all of the relocs. Note that we need not
2718 adjust the addends, since all PC-relative references must be against
2719 symbols, which we will adjust below. */
2720 for (i = 0; i < sec->reloc_count; i++)
2721 if (data->relocs[i].r_offset > addr && data->relocs[i].r_offset < toaddr)
2722 data->relocs[i].r_offset -= count;
2723
2724 /* Adjust the local symbols defined in this section. */
2725 for (i = 0; i < symtab_hdr->sh_info; i++)
2726 {
2727 Elf_Internal_Sym *sym = (Elf_Internal_Sym *) symtab_hdr->contents + i;
2728 if (sym->st_shndx == sec_shndx)
2729 {
2730 /* If the symbol is in the range of memory we just moved, we
2731 have to adjust its value. */
2732 if (sym->st_value > addr && sym->st_value <= toaddr)
2733 sym->st_value -= count;
2734
2735 /* If the symbol *spans* the bytes we just deleted (i.e. its
2736 *end* is in the moved bytes but its *start* isn't), then we
2737 must adjust its size.
2738
2739 This test needs to use the original value of st_value, otherwise
2740 we might accidentally decrease size when deleting bytes right
2741 before the symbol. But since deleted relocs can't span across
2742 symbols, we can't have both a st_value and a st_size decrease,
2743 so it is simpler to just use an else. */
2744 else if (sym->st_value <= addr
2745 && sym->st_value + sym->st_size > addr
2746 && sym->st_value + sym->st_size <= toaddr)
2747 sym->st_size -= count;
2748 }
2749 }
2750
2751 /* Now adjust the global symbols defined in this section. */
2752 symcount = ((symtab_hdr->sh_size / sizeof (ElfNN_External_Sym))
2753 - symtab_hdr->sh_info);
2754
2755 for (i = 0; i < symcount; i++)
2756 {
2757 struct elf_link_hash_entry *sym_hash = sym_hashes[i];
2758
2759 /* The '--wrap SYMBOL' option is causing a pain when the object file,
2760 containing the definition of __wrap_SYMBOL, includes a direct
2761 call to SYMBOL as well. Since both __wrap_SYMBOL and SYMBOL reference
2762 the same symbol (which is __wrap_SYMBOL), but still exist as two
2763 different symbols in 'sym_hashes', we don't want to adjust
2764 the global symbol __wrap_SYMBOL twice. */
2765 /* The same problem occurs with symbols that are versioned_hidden, as
2766 foo becomes an alias for foo@BAR, and hence they need the same
2767 treatment. */
2768 if (link_info->wrap_hash != NULL
2769 || sym_hash->versioned == versioned_hidden)
2770 {
2771 struct elf_link_hash_entry **cur_sym_hashes;
2772
2773 /* Loop only over the symbols which have already been checked. */
2774 for (cur_sym_hashes = sym_hashes; cur_sym_hashes < &sym_hashes[i];
2775 cur_sym_hashes++)
2776 {
2777 /* If the current symbol is identical to 'sym_hash', that means
2778 the symbol was already adjusted (or at least checked). */
2779 if (*cur_sym_hashes == sym_hash)
2780 break;
2781 }
2782 /* Don't adjust the symbol again. */
2783 if (cur_sym_hashes < &sym_hashes[i])
2784 continue;
2785 }
2786
2787 if ((sym_hash->root.type == bfd_link_hash_defined
2788 || sym_hash->root.type == bfd_link_hash_defweak)
2789 && sym_hash->root.u.def.section == sec)
2790 {
2791 /* As above, adjust the value if needed. */
2792 if (sym_hash->root.u.def.value > addr
2793 && sym_hash->root.u.def.value <= toaddr)
2794 sym_hash->root.u.def.value -= count;
2795
2796 /* As above, adjust the size if needed. */
2797 else if (sym_hash->root.u.def.value <= addr
2798 && sym_hash->root.u.def.value + sym_hash->size > addr
2799 && sym_hash->root.u.def.value + sym_hash->size <= toaddr)
2800 sym_hash->size -= count;
2801 }
2802 }
2803
2804 return TRUE;
2805 }
2806
2807 /* A second format for recording PC-relative hi relocations. This stores the
2808 information required to relax them to GP-relative addresses. */
2809
2810 typedef struct riscv_pcgp_hi_reloc riscv_pcgp_hi_reloc;
2811 struct riscv_pcgp_hi_reloc
2812 {
2813 bfd_vma hi_sec_off;
2814 bfd_vma hi_addend;
2815 bfd_vma hi_addr;
2816 unsigned hi_sym;
2817 asection *sym_sec;
2818 riscv_pcgp_hi_reloc *next;
2819 };
2820
2821 typedef struct riscv_pcgp_lo_reloc riscv_pcgp_lo_reloc;
2822 struct riscv_pcgp_lo_reloc
2823 {
2824 bfd_vma hi_sec_off;
2825 riscv_pcgp_lo_reloc *next;
2826 };
2827
2828 typedef struct
2829 {
2830 riscv_pcgp_hi_reloc *hi;
2831 riscv_pcgp_lo_reloc *lo;
2832 } riscv_pcgp_relocs;
2833
2834 /* Initialize the pcgp reloc info in P. */
2835
2836 static bfd_boolean
2837 riscv_init_pcgp_relocs (riscv_pcgp_relocs *p)
2838 {
2839 p->hi = NULL;
2840 p->lo = NULL;
2841 return TRUE;
2842 }
2843
2844 /* Free the pcgp reloc info in P. */
2845
2846 static void
2847 riscv_free_pcgp_relocs (riscv_pcgp_relocs *p,
2848 bfd *abfd ATTRIBUTE_UNUSED,
2849 asection *sec ATTRIBUTE_UNUSED)
2850 {
2851 riscv_pcgp_hi_reloc *c;
2852 riscv_pcgp_lo_reloc *l;
2853
2854 for (c = p->hi; c != NULL;)
2855 {
2856 riscv_pcgp_hi_reloc *next = c->next;
2857 free (c);
2858 c = next;
2859 }
2860
2861 for (l = p->lo; l != NULL;)
2862 {
2863 riscv_pcgp_lo_reloc *next = l->next;
2864 free (l);
2865 l = next;
2866 }
2867 }
2868
2869 /* Record pcgp hi part reloc info in P, using HI_SEC_OFF as the lookup index.
2870 The HI_ADDEND, HI_ADDR, HI_SYM, and SYM_SEC args contain info required to
2871 relax the corresponding lo part reloc. */
2872
2873 static bfd_boolean
2874 riscv_record_pcgp_hi_reloc (riscv_pcgp_relocs *p, bfd_vma hi_sec_off,
2875 bfd_vma hi_addend, bfd_vma hi_addr,
2876 unsigned hi_sym, asection *sym_sec)
2877 {
2878 riscv_pcgp_hi_reloc *new = bfd_malloc (sizeof(*new));
2879 if (!new)
2880 return FALSE;
2881 new->hi_sec_off = hi_sec_off;
2882 new->hi_addend = hi_addend;
2883 new->hi_addr = hi_addr;
2884 new->hi_sym = hi_sym;
2885 new->sym_sec = sym_sec;
2886 new->next = p->hi;
2887 p->hi = new;
2888 return TRUE;
2889 }
2890
2891 /* Look up hi part pcgp reloc info in P, using HI_SEC_OFF as the lookup index.
2892 This is used by a lo part reloc to find the corresponding hi part reloc. */
2893
2894 static riscv_pcgp_hi_reloc *
2895 riscv_find_pcgp_hi_reloc(riscv_pcgp_relocs *p, bfd_vma hi_sec_off)
2896 {
2897 riscv_pcgp_hi_reloc *c;
2898
2899 for (c = p->hi; c != NULL; c = c->next)
2900 if (c->hi_sec_off == hi_sec_off)
2901 return c;
2902 return NULL;
2903 }
2904
2905 /* Record pcgp lo part reloc info in P, using HI_SEC_OFF as the lookup info.
2906 This is used to record relocs that can't be relaxed. */
2907
2908 static bfd_boolean
2909 riscv_record_pcgp_lo_reloc (riscv_pcgp_relocs *p, bfd_vma hi_sec_off)
2910 {
2911 riscv_pcgp_lo_reloc *new = bfd_malloc (sizeof(*new));
2912 if (!new)
2913 return FALSE;
2914 new->hi_sec_off = hi_sec_off;
2915 new->next = p->lo;
2916 p->lo = new;
2917 return TRUE;
2918 }
2919
2920 /* Look up lo part pcgp reloc info in P, using HI_SEC_OFF as the lookup index.
2921 This is used by a hi part reloc to find the corresponding lo part reloc. */
2922
2923 static bfd_boolean
2924 riscv_find_pcgp_lo_reloc (riscv_pcgp_relocs *p, bfd_vma hi_sec_off)
2925 {
2926 riscv_pcgp_lo_reloc *c;
2927
2928 for (c = p->lo; c != NULL; c = c->next)
2929 if (c->hi_sec_off == hi_sec_off)
2930 return TRUE;
2931 return FALSE;
2932 }
2933
2934 typedef bfd_boolean (*relax_func_t) (bfd *, asection *, asection *,
2935 struct bfd_link_info *,
2936 Elf_Internal_Rela *,
2937 bfd_vma, bfd_vma, bfd_vma, bfd_boolean *,
2938 riscv_pcgp_relocs *);
2939
2940 /* Relax AUIPC + JALR into JAL. */
2941
2942 static bfd_boolean
2943 _bfd_riscv_relax_call (bfd *abfd, asection *sec, asection *sym_sec,
2944 struct bfd_link_info *link_info,
2945 Elf_Internal_Rela *rel,
2946 bfd_vma symval,
2947 bfd_vma max_alignment,
2948 bfd_vma reserve_size ATTRIBUTE_UNUSED,
2949 bfd_boolean *again,
2950 riscv_pcgp_relocs *pcgp_relocs ATTRIBUTE_UNUSED)
2951 {
2952 bfd_byte *contents = elf_section_data (sec)->this_hdr.contents;
2953 bfd_signed_vma foff = symval - (sec_addr (sec) + rel->r_offset);
2954 bfd_boolean near_zero = (symval + RISCV_IMM_REACH/2) < RISCV_IMM_REACH;
2955 bfd_vma auipc, jalr;
2956 int rd, r_type, len = 4, rvc = elf_elfheader (abfd)->e_flags & EF_RISCV_RVC;
2957
2958 /* If the call crosses section boundaries, an alignment directive could
2959 cause the PC-relative offset to later increase. */
2960 if (VALID_UJTYPE_IMM (foff) && sym_sec->output_section != sec->output_section)
2961 foff += (foff < 0 ? -max_alignment : max_alignment);
2962
2963 /* See if this function call can be shortened. */
2964 if (!VALID_UJTYPE_IMM (foff) && !(!bfd_link_pic (link_info) && near_zero))
2965 return TRUE;
2966
2967 /* Shorten the function call. */
2968 BFD_ASSERT (rel->r_offset + 8 <= sec->size);
2969
2970 auipc = bfd_get_32 (abfd, contents + rel->r_offset);
2971 jalr = bfd_get_32 (abfd, contents + rel->r_offset + 4);
2972 rd = (jalr >> OP_SH_RD) & OP_MASK_RD;
2973 rvc = rvc && VALID_RVC_J_IMM (foff) && ARCH_SIZE == 32;
2974
2975 if (rvc && (rd == 0 || rd == X_RA))
2976 {
2977 /* Relax to C.J[AL] rd, addr. */
2978 r_type = R_RISCV_RVC_JUMP;
2979 auipc = rd == 0 ? MATCH_C_J : MATCH_C_JAL;
2980 len = 2;
2981 }
2982 else if (VALID_UJTYPE_IMM (foff))
2983 {
2984 /* Relax to JAL rd, addr. */
2985 r_type = R_RISCV_JAL;
2986 auipc = MATCH_JAL | (rd << OP_SH_RD);
2987 }
2988 else /* near_zero */
2989 {
2990 /* Relax to JALR rd, x0, addr. */
2991 r_type = R_RISCV_LO12_I;
2992 auipc = MATCH_JALR | (rd << OP_SH_RD);
2993 }
2994
2995 /* Replace the R_RISCV_CALL reloc. */
2996 rel->r_info = ELFNN_R_INFO (ELFNN_R_SYM (rel->r_info), r_type);
2997 /* Replace the AUIPC. */
2998 bfd_put (8 * len, abfd, auipc, contents + rel->r_offset);
2999
3000 /* Delete unnecessary JALR. */
3001 *again = TRUE;
3002 return riscv_relax_delete_bytes (abfd, sec, rel->r_offset + len, 8 - len,
3003 link_info);
3004 }
3005
3006 /* Traverse all output sections and return the max alignment. */
3007
3008 static bfd_vma
3009 _bfd_riscv_get_max_alignment (asection *sec)
3010 {
3011 unsigned int max_alignment_power = 0;
3012 asection *o;
3013
3014 for (o = sec->output_section->owner->sections; o != NULL; o = o->next)
3015 {
3016 if (o->alignment_power > max_alignment_power)
3017 max_alignment_power = o->alignment_power;
3018 }
3019
3020 return (bfd_vma) 1 << max_alignment_power;
3021 }
3022
3023 /* Relax non-PIC global variable references. */
3024
3025 static bfd_boolean
3026 _bfd_riscv_relax_lui (bfd *abfd,
3027 asection *sec,
3028 asection *sym_sec,
3029 struct bfd_link_info *link_info,
3030 Elf_Internal_Rela *rel,
3031 bfd_vma symval,
3032 bfd_vma max_alignment,
3033 bfd_vma reserve_size,
3034 bfd_boolean *again,
3035 riscv_pcgp_relocs *pcgp_relocs ATTRIBUTE_UNUSED)
3036 {
3037 bfd_byte *contents = elf_section_data (sec)->this_hdr.contents;
3038 bfd_vma gp = riscv_global_pointer_value (link_info);
3039 int use_rvc = elf_elfheader (abfd)->e_flags & EF_RISCV_RVC;
3040
3041 /* Mergeable symbols and code might later move out of range. */
3042 if (sym_sec->flags & (SEC_MERGE | SEC_CODE))
3043 return TRUE;
3044
3045 BFD_ASSERT (rel->r_offset + 4 <= sec->size);
3046
3047 if (gp)
3048 {
3049 /* If gp and the symbol are in the same output section, then
3050 consider only that section's alignment. */
3051 struct bfd_link_hash_entry *h =
3052 bfd_link_hash_lookup (link_info->hash, RISCV_GP_SYMBOL, FALSE, FALSE,
3053 TRUE);
3054 if (h->u.def.section->output_section == sym_sec->output_section)
3055 max_alignment = (bfd_vma) 1 << sym_sec->output_section->alignment_power;
3056 }
3057
3058 /* Is the reference in range of x0 or gp?
3059 Valid gp range conservatively because of alignment issue. */
3060 if (VALID_ITYPE_IMM (symval)
3061 || (symval >= gp
3062 && VALID_ITYPE_IMM (symval - gp + max_alignment + reserve_size))
3063 || (symval < gp
3064 && VALID_ITYPE_IMM (symval - gp - max_alignment - reserve_size)))
3065 {
3066 unsigned sym = ELFNN_R_SYM (rel->r_info);
3067 switch (ELFNN_R_TYPE (rel->r_info))
3068 {
3069 case R_RISCV_LO12_I:
3070 rel->r_info = ELFNN_R_INFO (sym, R_RISCV_GPREL_I);
3071 return TRUE;
3072
3073 case R_RISCV_LO12_S:
3074 rel->r_info = ELFNN_R_INFO (sym, R_RISCV_GPREL_S);
3075 return TRUE;
3076
3077 case R_RISCV_HI20:
3078 /* We can delete the unnecessary LUI and reloc. */
3079 rel->r_info = ELFNN_R_INFO (0, R_RISCV_NONE);
3080 *again = TRUE;
3081 return riscv_relax_delete_bytes (abfd, sec, rel->r_offset, 4,
3082 link_info);
3083
3084 default:
3085 abort ();
3086 }
3087 }
3088
3089 /* Can we relax LUI to C.LUI? Alignment might move the section forward;
3090 account for this assuming page alignment at worst. */
3091 if (use_rvc
3092 && ELFNN_R_TYPE (rel->r_info) == R_RISCV_HI20
3093 && VALID_RVC_LUI_IMM (RISCV_CONST_HIGH_PART (symval))
3094 && VALID_RVC_LUI_IMM (RISCV_CONST_HIGH_PART (symval + ELF_MAXPAGESIZE)))
3095 {
3096 /* Replace LUI with C.LUI if legal (i.e., rd != x0 and rd != x2/sp). */
3097 bfd_vma lui = bfd_get_32 (abfd, contents + rel->r_offset);
3098 unsigned rd = ((unsigned)lui >> OP_SH_RD) & OP_MASK_RD;
3099 if (rd == 0 || rd == X_SP)
3100 return TRUE;
3101
3102 lui = (lui & (OP_MASK_RD << OP_SH_RD)) | MATCH_C_LUI;
3103 bfd_put_32 (abfd, lui, contents + rel->r_offset);
3104
3105 /* Replace the R_RISCV_HI20 reloc. */
3106 rel->r_info = ELFNN_R_INFO (ELFNN_R_SYM (rel->r_info), R_RISCV_RVC_LUI);
3107
3108 *again = TRUE;
3109 return riscv_relax_delete_bytes (abfd, sec, rel->r_offset + 2, 2,
3110 link_info);
3111 }
3112
3113 return TRUE;
3114 }
3115
3116 /* Relax non-PIC TLS references. */
3117
3118 static bfd_boolean
3119 _bfd_riscv_relax_tls_le (bfd *abfd,
3120 asection *sec,
3121 asection *sym_sec ATTRIBUTE_UNUSED,
3122 struct bfd_link_info *link_info,
3123 Elf_Internal_Rela *rel,
3124 bfd_vma symval,
3125 bfd_vma max_alignment ATTRIBUTE_UNUSED,
3126 bfd_vma reserve_size ATTRIBUTE_UNUSED,
3127 bfd_boolean *again,
3128 riscv_pcgp_relocs *prcel_relocs ATTRIBUTE_UNUSED)
3129 {
3130 /* See if this symbol is in range of tp. */
3131 if (RISCV_CONST_HIGH_PART (tpoff (link_info, symval)) != 0)
3132 return TRUE;
3133
3134 BFD_ASSERT (rel->r_offset + 4 <= sec->size);
3135 switch (ELFNN_R_TYPE (rel->r_info))
3136 {
3137 case R_RISCV_TPREL_LO12_I:
3138 rel->r_info = ELFNN_R_INFO (ELFNN_R_SYM (rel->r_info), R_RISCV_TPREL_I);
3139 return TRUE;
3140
3141 case R_RISCV_TPREL_LO12_S:
3142 rel->r_info = ELFNN_R_INFO (ELFNN_R_SYM (rel->r_info), R_RISCV_TPREL_S);
3143 return TRUE;
3144
3145 case R_RISCV_TPREL_HI20:
3146 case R_RISCV_TPREL_ADD:
3147 /* We can delete the unnecessary instruction and reloc. */
3148 rel->r_info = ELFNN_R_INFO (0, R_RISCV_NONE);
3149 *again = TRUE;
3150 return riscv_relax_delete_bytes (abfd, sec, rel->r_offset, 4, link_info);
3151
3152 default:
3153 abort ();
3154 }
3155 }
3156
3157 /* Implement R_RISCV_ALIGN by deleting excess alignment NOPs. */
3158
3159 static bfd_boolean
3160 _bfd_riscv_relax_align (bfd *abfd, asection *sec,
3161 asection *sym_sec,
3162 struct bfd_link_info *link_info,
3163 Elf_Internal_Rela *rel,
3164 bfd_vma symval,
3165 bfd_vma max_alignment ATTRIBUTE_UNUSED,
3166 bfd_vma reserve_size ATTRIBUTE_UNUSED,
3167 bfd_boolean *again ATTRIBUTE_UNUSED,
3168 riscv_pcgp_relocs *pcrel_relocs ATTRIBUTE_UNUSED)
3169 {
3170 bfd_byte *contents = elf_section_data (sec)->this_hdr.contents;
3171 bfd_vma alignment = 1, pos;
3172 while (alignment <= rel->r_addend)
3173 alignment *= 2;
3174
3175 symval -= rel->r_addend;
3176 bfd_vma aligned_addr = ((symval - 1) & ~(alignment - 1)) + alignment;
3177 bfd_vma nop_bytes = aligned_addr - symval;
3178
3179 /* Once we've handled an R_RISCV_ALIGN, we can't relax anything else. */
3180 sec->sec_flg0 = TRUE;
3181
3182 /* Make sure there are enough NOPs to actually achieve the alignment. */
3183 if (rel->r_addend < nop_bytes)
3184 {
3185 _bfd_error_handler
3186 (_("%pB(%pA+%#" PRIx64 "): %" PRId64 " bytes required for alignment "
3187 "to %" PRId64 "-byte boundary, but only %" PRId64 " present"),
3188 abfd, sym_sec, (uint64_t) rel->r_offset,
3189 (int64_t) nop_bytes, (int64_t) alignment, (int64_t) rel->r_addend);
3190 bfd_set_error (bfd_error_bad_value);
3191 return FALSE;
3192 }
3193
3194 /* Delete the reloc. */
3195 rel->r_info = ELFNN_R_INFO (0, R_RISCV_NONE);
3196
3197 /* If the number of NOPs is already correct, there's nothing to do. */
3198 if (nop_bytes == rel->r_addend)
3199 return TRUE;
3200
3201 /* Write as many RISC-V NOPs as we need. */
3202 for (pos = 0; pos < (nop_bytes & -4); pos += 4)
3203 bfd_put_32 (abfd, RISCV_NOP, contents + rel->r_offset + pos);
3204
3205 /* Write a final RVC NOP if need be. */
3206 if (nop_bytes % 4 != 0)
3207 bfd_put_16 (abfd, RVC_NOP, contents + rel->r_offset + pos);
3208
3209 /* Delete the excess bytes. */
3210 return riscv_relax_delete_bytes (abfd, sec, rel->r_offset + nop_bytes,
3211 rel->r_addend - nop_bytes, link_info);
3212 }
3213
3214 /* Relax PC-relative references to GP-relative references. */
3215
3216 static bfd_boolean
3217 _bfd_riscv_relax_pc (bfd *abfd ATTRIBUTE_UNUSED,
3218 asection *sec,
3219 asection *sym_sec,
3220 struct bfd_link_info *link_info,
3221 Elf_Internal_Rela *rel,
3222 bfd_vma symval,
3223 bfd_vma max_alignment,
3224 bfd_vma reserve_size,
3225 bfd_boolean *again ATTRIBUTE_UNUSED,
3226 riscv_pcgp_relocs *pcgp_relocs)
3227 {
3228 bfd_vma gp = riscv_global_pointer_value (link_info);
3229
3230 BFD_ASSERT (rel->r_offset + 4 <= sec->size);
3231
3232 /* Chain the _LO relocs to their cooresponding _HI reloc to compute the
3233 * actual target address. */
3234 riscv_pcgp_hi_reloc hi_reloc;
3235 memset (&hi_reloc, 0, sizeof (hi_reloc));
3236 switch (ELFNN_R_TYPE (rel->r_info))
3237 {
3238 case R_RISCV_PCREL_LO12_I:
3239 case R_RISCV_PCREL_LO12_S:
3240 {
3241 /* If the %lo has an addend, it isn't for the label pointing at the
3242 hi part instruction, but rather for the symbol pointed at by the
3243 hi part instruction. So we must subtract it here for the lookup.
3244 It is still used below in the final symbol address. */
3245 bfd_vma hi_sec_off = symval - sec_addr (sym_sec) - rel->r_addend;
3246 riscv_pcgp_hi_reloc *hi = riscv_find_pcgp_hi_reloc (pcgp_relocs,
3247 hi_sec_off);
3248 if (hi == NULL)
3249 {
3250 riscv_record_pcgp_lo_reloc (pcgp_relocs, hi_sec_off);
3251 return TRUE;
3252 }
3253
3254 hi_reloc = *hi;
3255 symval = hi_reloc.hi_addr;
3256 sym_sec = hi_reloc.sym_sec;
3257 }
3258 break;
3259
3260 case R_RISCV_PCREL_HI20:
3261 /* Mergeable symbols and code might later move out of range. */
3262 if (sym_sec->flags & (SEC_MERGE | SEC_CODE))
3263 return TRUE;
3264
3265 /* If the cooresponding lo relocation has already been seen then it's not
3266 * safe to relax this relocation. */
3267 if (riscv_find_pcgp_lo_reloc (pcgp_relocs, rel->r_offset))
3268 return TRUE;
3269
3270 break;
3271
3272 default:
3273 abort ();
3274 }
3275
3276 if (gp)
3277 {
3278 /* If gp and the symbol are in the same output section, then
3279 consider only that section's alignment. */
3280 struct bfd_link_hash_entry *h =
3281 bfd_link_hash_lookup (link_info->hash, RISCV_GP_SYMBOL, FALSE, FALSE, TRUE);
3282 if (h->u.def.section->output_section == sym_sec->output_section)
3283 max_alignment = (bfd_vma) 1 << sym_sec->output_section->alignment_power;
3284 }
3285
3286 /* Is the reference in range of x0 or gp?
3287 Valid gp range conservatively because of alignment issue. */
3288 if (VALID_ITYPE_IMM (symval)
3289 || (symval >= gp
3290 && VALID_ITYPE_IMM (symval - gp + max_alignment + reserve_size))
3291 || (symval < gp
3292 && VALID_ITYPE_IMM (symval - gp - max_alignment - reserve_size)))
3293 {
3294 unsigned sym = hi_reloc.hi_sym;
3295 switch (ELFNN_R_TYPE (rel->r_info))
3296 {
3297 case R_RISCV_PCREL_LO12_I:
3298 rel->r_info = ELFNN_R_INFO (sym, R_RISCV_GPREL_I);
3299 rel->r_addend += hi_reloc.hi_addend;
3300 return TRUE;
3301
3302 case R_RISCV_PCREL_LO12_S:
3303 rel->r_info = ELFNN_R_INFO (sym, R_RISCV_GPREL_S);
3304 rel->r_addend += hi_reloc.hi_addend;
3305 return TRUE;
3306
3307 case R_RISCV_PCREL_HI20:
3308 riscv_record_pcgp_hi_reloc (pcgp_relocs,
3309 rel->r_offset,
3310 rel->r_addend,
3311 symval,
3312 ELFNN_R_SYM(rel->r_info),
3313 sym_sec);
3314 /* We can delete the unnecessary AUIPC and reloc. */
3315 rel->r_info = ELFNN_R_INFO (0, R_RISCV_DELETE);
3316 rel->r_addend = 4;
3317 return TRUE;
3318
3319 default:
3320 abort ();
3321 }
3322 }
3323
3324 return TRUE;
3325 }
3326
3327 /* Relax PC-relative references to GP-relative references. */
3328
3329 static bfd_boolean
3330 _bfd_riscv_relax_delete (bfd *abfd,
3331 asection *sec,
3332 asection *sym_sec ATTRIBUTE_UNUSED,
3333 struct bfd_link_info *link_info,
3334 Elf_Internal_Rela *rel,
3335 bfd_vma symval ATTRIBUTE_UNUSED,
3336 bfd_vma max_alignment ATTRIBUTE_UNUSED,
3337 bfd_vma reserve_size ATTRIBUTE_UNUSED,
3338 bfd_boolean *again ATTRIBUTE_UNUSED,
3339 riscv_pcgp_relocs *pcgp_relocs ATTRIBUTE_UNUSED)
3340 {
3341 if (!riscv_relax_delete_bytes(abfd, sec, rel->r_offset, rel->r_addend,
3342 link_info))
3343 return FALSE;
3344 rel->r_info = ELFNN_R_INFO(0, R_RISCV_NONE);
3345 return TRUE;
3346 }
3347
3348 /* Relax a section. Pass 0 shortens code sequences unless disabled. Pass 1
3349 deletes the bytes that pass 0 made obselete. Pass 2, which cannot be
3350 disabled, handles code alignment directives. */
3351
3352 static bfd_boolean
3353 _bfd_riscv_relax_section (bfd *abfd, asection *sec,
3354 struct bfd_link_info *info,
3355 bfd_boolean *again)
3356 {
3357 Elf_Internal_Shdr *symtab_hdr = &elf_symtab_hdr (abfd);
3358 struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
3359 struct bfd_elf_section_data *data = elf_section_data (sec);
3360 Elf_Internal_Rela *relocs;
3361 bfd_boolean ret = FALSE;
3362 unsigned int i;
3363 bfd_vma max_alignment, reserve_size = 0;
3364 riscv_pcgp_relocs pcgp_relocs;
3365
3366 *again = FALSE;
3367
3368 if (bfd_link_relocatable (info)
3369 || sec->sec_flg0
3370 || (sec->flags & SEC_RELOC) == 0
3371 || sec->reloc_count == 0
3372 || (info->disable_target_specific_optimizations
3373 && info->relax_pass == 0))
3374 return TRUE;
3375
3376 riscv_init_pcgp_relocs (&pcgp_relocs);
3377
3378 /* Read this BFD's relocs if we haven't done so already. */
3379 if (data->relocs)
3380 relocs = data->relocs;
3381 else if (!(relocs = _bfd_elf_link_read_relocs (abfd, sec, NULL, NULL,
3382 info->keep_memory)))
3383 goto fail;
3384
3385 if (htab)
3386 {
3387 max_alignment = htab->max_alignment;
3388 if (max_alignment == (bfd_vma) -1)
3389 {
3390 max_alignment = _bfd_riscv_get_max_alignment (sec);
3391 htab->max_alignment = max_alignment;
3392 }
3393 }
3394 else
3395 max_alignment = _bfd_riscv_get_max_alignment (sec);
3396
3397 /* Examine and consider relaxing each reloc. */
3398 for (i = 0; i < sec->reloc_count; i++)
3399 {
3400 asection *sym_sec;
3401 Elf_Internal_Rela *rel = relocs + i;
3402 relax_func_t relax_func;
3403 int type = ELFNN_R_TYPE (rel->r_info);
3404 bfd_vma symval;
3405
3406 relax_func = NULL;
3407 if (info->relax_pass == 0)
3408 {
3409 if (type == R_RISCV_CALL || type == R_RISCV_CALL_PLT)
3410 relax_func = _bfd_riscv_relax_call;
3411 else if (type == R_RISCV_HI20
3412 || type == R_RISCV_LO12_I
3413 || type == R_RISCV_LO12_S)
3414 relax_func = _bfd_riscv_relax_lui;
3415 else if (!bfd_link_pic(info)
3416 && (type == R_RISCV_PCREL_HI20
3417 || type == R_RISCV_PCREL_LO12_I
3418 || type == R_RISCV_PCREL_LO12_S))
3419 relax_func = _bfd_riscv_relax_pc;
3420 else if (type == R_RISCV_TPREL_HI20
3421 || type == R_RISCV_TPREL_ADD
3422 || type == R_RISCV_TPREL_LO12_I
3423 || type == R_RISCV_TPREL_LO12_S)
3424 relax_func = _bfd_riscv_relax_tls_le;
3425 else
3426 continue;
3427
3428 /* Only relax this reloc if it is paired with R_RISCV_RELAX. */
3429 if (i == sec->reloc_count - 1
3430 || ELFNN_R_TYPE ((rel + 1)->r_info) != R_RISCV_RELAX
3431 || rel->r_offset != (rel + 1)->r_offset)
3432 continue;
3433
3434 /* Skip over the R_RISCV_RELAX. */
3435 i++;
3436 }
3437 else if (info->relax_pass == 1 && type == R_RISCV_DELETE)
3438 relax_func = _bfd_riscv_relax_delete;
3439 else if (info->relax_pass == 2 && type == R_RISCV_ALIGN)
3440 relax_func = _bfd_riscv_relax_align;
3441 else
3442 continue;
3443
3444 data->relocs = relocs;
3445
3446 /* Read this BFD's contents if we haven't done so already. */
3447 if (!data->this_hdr.contents
3448 && !bfd_malloc_and_get_section (abfd, sec, &data->this_hdr.contents))
3449 goto fail;
3450
3451 /* Read this BFD's symbols if we haven't done so already. */
3452 if (symtab_hdr->sh_info != 0
3453 && !symtab_hdr->contents
3454 && !(symtab_hdr->contents =
3455 (unsigned char *) bfd_elf_get_elf_syms (abfd, symtab_hdr,
3456 symtab_hdr->sh_info,
3457 0, NULL, NULL, NULL)))
3458 goto fail;
3459
3460 /* Get the value of the symbol referred to by the reloc. */
3461 if (ELFNN_R_SYM (rel->r_info) < symtab_hdr->sh_info)
3462 {
3463 /* A local symbol. */
3464 Elf_Internal_Sym *isym = ((Elf_Internal_Sym *) symtab_hdr->contents
3465 + ELFNN_R_SYM (rel->r_info));
3466 reserve_size = (isym->st_size - rel->r_addend) > isym->st_size
3467 ? 0 : isym->st_size - rel->r_addend;
3468
3469 if (isym->st_shndx == SHN_UNDEF)
3470 sym_sec = sec, symval = sec_addr (sec) + rel->r_offset;
3471 else
3472 {
3473 BFD_ASSERT (isym->st_shndx < elf_numsections (abfd));
3474 sym_sec = elf_elfsections (abfd)[isym->st_shndx]->bfd_section;
3475 #if 0
3476 /* The purpose of this code is unknown. It breaks linker scripts
3477 for embedded development that place sections at address zero.
3478 This code is believed to be unnecessary. Disabling it but not
3479 yet removing it, in case something breaks. */
3480 if (sec_addr (sym_sec) == 0)
3481 continue;
3482 #endif
3483 symval = sec_addr (sym_sec) + isym->st_value;
3484 }
3485 }
3486 else
3487 {
3488 unsigned long indx;
3489 struct elf_link_hash_entry *h;
3490
3491 indx = ELFNN_R_SYM (rel->r_info) - symtab_hdr->sh_info;
3492 h = elf_sym_hashes (abfd)[indx];
3493
3494 while (h->root.type == bfd_link_hash_indirect
3495 || h->root.type == bfd_link_hash_warning)
3496 h = (struct elf_link_hash_entry *) h->root.u.i.link;
3497
3498 if (h->plt.offset != MINUS_ONE)
3499 symval = sec_addr (htab->elf.splt) + h->plt.offset;
3500 else if (h->root.u.def.section->output_section == NULL
3501 || (h->root.type != bfd_link_hash_defined
3502 && h->root.type != bfd_link_hash_defweak))
3503 continue;
3504 else
3505 symval = sec_addr (h->root.u.def.section) + h->root.u.def.value;
3506
3507 if (h->type != STT_FUNC)
3508 reserve_size =
3509 (h->size - rel->r_addend) > h->size ? 0 : h->size - rel->r_addend;
3510 sym_sec = h->root.u.def.section;
3511 }
3512
3513 symval += rel->r_addend;
3514
3515 if (!relax_func (abfd, sec, sym_sec, info, rel, symval,
3516 max_alignment, reserve_size, again,
3517 &pcgp_relocs))
3518 goto fail;
3519 }
3520
3521 ret = TRUE;
3522
3523 fail:
3524 if (relocs != data->relocs)
3525 free (relocs);
3526 riscv_free_pcgp_relocs(&pcgp_relocs, abfd, sec);
3527
3528 return ret;
3529 }
3530
3531 #if ARCH_SIZE == 32
3532 # define PRSTATUS_SIZE 0 /* FIXME */
3533 # define PRSTATUS_OFFSET_PR_CURSIG 12
3534 # define PRSTATUS_OFFSET_PR_PID 24
3535 # define PRSTATUS_OFFSET_PR_REG 72
3536 # define ELF_GREGSET_T_SIZE 128
3537 # define PRPSINFO_SIZE 128
3538 # define PRPSINFO_OFFSET_PR_PID 16
3539 # define PRPSINFO_OFFSET_PR_FNAME 32
3540 # define PRPSINFO_OFFSET_PR_PSARGS 48
3541 #else
3542 # define PRSTATUS_SIZE 376
3543 # define PRSTATUS_OFFSET_PR_CURSIG 12
3544 # define PRSTATUS_OFFSET_PR_PID 32
3545 # define PRSTATUS_OFFSET_PR_REG 112
3546 # define ELF_GREGSET_T_SIZE 256
3547 # define PRPSINFO_SIZE 136
3548 # define PRPSINFO_OFFSET_PR_PID 24
3549 # define PRPSINFO_OFFSET_PR_FNAME 40
3550 # define PRPSINFO_OFFSET_PR_PSARGS 56
3551 #endif
3552
3553 /* Support for core dump NOTE sections. */
3554
3555 static bfd_boolean
3556 riscv_elf_grok_prstatus (bfd *abfd, Elf_Internal_Note *note)
3557 {
3558 switch (note->descsz)
3559 {
3560 default:
3561 return FALSE;
3562
3563 case PRSTATUS_SIZE: /* sizeof(struct elf_prstatus) on Linux/RISC-V. */
3564 /* pr_cursig */
3565 elf_tdata (abfd)->core->signal
3566 = bfd_get_16 (abfd, note->descdata + PRSTATUS_OFFSET_PR_CURSIG);
3567
3568 /* pr_pid */
3569 elf_tdata (abfd)->core->lwpid
3570 = bfd_get_32 (abfd, note->descdata + PRSTATUS_OFFSET_PR_PID);
3571 break;
3572 }
3573
3574 /* Make a ".reg/999" section. */
3575 return _bfd_elfcore_make_pseudosection (abfd, ".reg", ELF_GREGSET_T_SIZE,
3576 note->descpos + PRSTATUS_OFFSET_PR_REG);
3577 }
3578
3579 static bfd_boolean
3580 riscv_elf_grok_psinfo (bfd *abfd, Elf_Internal_Note *note)
3581 {
3582 switch (note->descsz)
3583 {
3584 default:
3585 return FALSE;
3586
3587 case PRPSINFO_SIZE: /* sizeof(struct elf_prpsinfo) on Linux/RISC-V. */
3588 /* pr_pid */
3589 elf_tdata (abfd)->core->pid
3590 = bfd_get_32 (abfd, note->descdata + PRPSINFO_OFFSET_PR_PID);
3591
3592 /* pr_fname */
3593 elf_tdata (abfd)->core->program = _bfd_elfcore_strndup
3594 (abfd, note->descdata + PRPSINFO_OFFSET_PR_FNAME, 16);
3595
3596 /* pr_psargs */
3597 elf_tdata (abfd)->core->command = _bfd_elfcore_strndup
3598 (abfd, note->descdata + PRPSINFO_OFFSET_PR_PSARGS, 80);
3599 break;
3600 }
3601
3602 /* Note that for some reason, a spurious space is tacked
3603 onto the end of the args in some (at least one anyway)
3604 implementations, so strip it off if it exists. */
3605
3606 {
3607 char *command = elf_tdata (abfd)->core->command;
3608 int n = strlen (command);
3609
3610 if (0 < n && command[n - 1] == ' ')
3611 command[n - 1] = '\0';
3612 }
3613
3614 return TRUE;
3615 }
3616
3617 /* Set the right mach type. */
3618 static bfd_boolean
3619 riscv_elf_object_p (bfd *abfd)
3620 {
3621 /* There are only two mach types in RISCV currently. */
3622 if (strcmp (abfd->xvec->name, "elf32-littleriscv") == 0)
3623 bfd_default_set_arch_mach (abfd, bfd_arch_riscv, bfd_mach_riscv32);
3624 else
3625 bfd_default_set_arch_mach (abfd, bfd_arch_riscv, bfd_mach_riscv64);
3626
3627 return TRUE;
3628 }
3629
3630
3631 #define TARGET_LITTLE_SYM riscv_elfNN_vec
3632 #define TARGET_LITTLE_NAME "elfNN-littleriscv"
3633
3634 #define elf_backend_reloc_type_class riscv_reloc_type_class
3635
3636 #define bfd_elfNN_bfd_reloc_name_lookup riscv_reloc_name_lookup
3637 #define bfd_elfNN_bfd_link_hash_table_create riscv_elf_link_hash_table_create
3638 #define bfd_elfNN_bfd_reloc_type_lookup riscv_reloc_type_lookup
3639 #define bfd_elfNN_bfd_merge_private_bfd_data \
3640 _bfd_riscv_elf_merge_private_bfd_data
3641
3642 #define elf_backend_copy_indirect_symbol riscv_elf_copy_indirect_symbol
3643 #define elf_backend_create_dynamic_sections riscv_elf_create_dynamic_sections
3644 #define elf_backend_check_relocs riscv_elf_check_relocs
3645 #define elf_backend_adjust_dynamic_symbol riscv_elf_adjust_dynamic_symbol
3646 #define elf_backend_size_dynamic_sections riscv_elf_size_dynamic_sections
3647 #define elf_backend_relocate_section riscv_elf_relocate_section
3648 #define elf_backend_finish_dynamic_symbol riscv_elf_finish_dynamic_symbol
3649 #define elf_backend_finish_dynamic_sections riscv_elf_finish_dynamic_sections
3650 #define elf_backend_gc_mark_hook riscv_elf_gc_mark_hook
3651 #define elf_backend_plt_sym_val riscv_elf_plt_sym_val
3652 #define elf_backend_grok_prstatus riscv_elf_grok_prstatus
3653 #define elf_backend_grok_psinfo riscv_elf_grok_psinfo
3654 #define elf_backend_object_p riscv_elf_object_p
3655 #define elf_info_to_howto_rel NULL
3656 #define elf_info_to_howto riscv_info_to_howto_rela
3657 #define bfd_elfNN_bfd_relax_section _bfd_riscv_relax_section
3658
3659 #define elf_backend_init_index_section _bfd_elf_init_1_index_section
3660
3661 #define elf_backend_can_gc_sections 1
3662 #define elf_backend_can_refcount 1
3663 #define elf_backend_want_got_plt 1
3664 #define elf_backend_plt_readonly 1
3665 #define elf_backend_plt_alignment 4
3666 #define elf_backend_want_plt_sym 1
3667 #define elf_backend_got_header_size (ARCH_SIZE / 8)
3668 #define elf_backend_want_dynrelro 1
3669 #define elf_backend_rela_normal 1
3670 #define elf_backend_default_execstack 0
3671
3672 #include "elfNN-target.h"
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