Fix debug section compression so that it is only performed if it would make the secti...
[deliverable/binutils-gdb.git] / bfd / elfxx-aarch64.c
1 /* AArch64-specific support for ELF.
2 Copyright (C) 2009-2015 Free Software Foundation, Inc.
3 Contributed by ARM Ltd.
4
5 This file is part of BFD, the Binary File Descriptor library.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program; see the file COPYING3. If not,
19 see <http://www.gnu.org/licenses/>. */
20
21 #include "sysdep.h"
22 #include "elfxx-aarch64.h"
23 #include <stdarg.h>
24 #include <string.h>
25
26 #define MASK(n) ((1u << (n)) - 1)
27
28 /* Reencode the imm field of add immediate. */
29 static inline uint32_t
30 reencode_add_imm (uint32_t insn, uint32_t imm)
31 {
32 return (insn & ~(MASK (12) << 10)) | ((imm & MASK (12)) << 10);
33 }
34
35 /* Reencode the imm field of adr. */
36 static inline uint32_t
37 reencode_adr_imm (uint32_t insn, uint32_t imm)
38 {
39 return (insn & ~((MASK (2) << 29) | (MASK (19) << 5)))
40 | ((imm & MASK (2)) << 29) | ((imm & (MASK (19) << 2)) << 3);
41 }
42
43 /* Reencode the imm field of ld/st pos immediate. */
44 static inline uint32_t
45 reencode_ldst_pos_imm (uint32_t insn, uint32_t imm)
46 {
47 return (insn & ~(MASK (12) << 10)) | ((imm & MASK (12)) << 10);
48 }
49
50 /* Encode the 26-bit offset of unconditional branch. */
51 static inline uint32_t
52 reencode_branch_ofs_26 (uint32_t insn, uint32_t ofs)
53 {
54 return (insn & ~MASK (26)) | (ofs & MASK (26));
55 }
56
57 /* Encode the 19-bit offset of conditional branch and compare & branch. */
58 static inline uint32_t
59 reencode_cond_branch_ofs_19 (uint32_t insn, uint32_t ofs)
60 {
61 return (insn & ~(MASK (19) << 5)) | ((ofs & MASK (19)) << 5);
62 }
63
64 /* Decode the 19-bit offset of load literal. */
65 static inline uint32_t
66 reencode_ld_lit_ofs_19 (uint32_t insn, uint32_t ofs)
67 {
68 return (insn & ~(MASK (19) << 5)) | ((ofs & MASK (19)) << 5);
69 }
70
71 /* Encode the 14-bit offset of test & branch. */
72 static inline uint32_t
73 reencode_tst_branch_ofs_14 (uint32_t insn, uint32_t ofs)
74 {
75 return (insn & ~(MASK (14) << 5)) | ((ofs & MASK (14)) << 5);
76 }
77
78 /* Reencode the imm field of move wide. */
79 static inline uint32_t
80 reencode_movw_imm (uint32_t insn, uint32_t imm)
81 {
82 return (insn & ~(MASK (16) << 5)) | ((imm & MASK (16)) << 5);
83 }
84
85 /* Reencode mov[zn] to movz. */
86 static inline uint32_t
87 reencode_movzn_to_movz (uint32_t opcode)
88 {
89 return opcode | (1 << 30);
90 }
91
92 /* Reencode mov[zn] to movn. */
93 static inline uint32_t
94 reencode_movzn_to_movn (uint32_t opcode)
95 {
96 return opcode & ~(1 << 30);
97 }
98
99 /* Return non-zero if the indicated VALUE has overflowed the maximum
100 range expressible by a unsigned number with the indicated number of
101 BITS. */
102
103 static bfd_reloc_status_type
104 aarch64_unsigned_overflow (bfd_vma value, unsigned int bits)
105 {
106 bfd_vma lim;
107 if (bits >= sizeof (bfd_vma) * 8)
108 return bfd_reloc_ok;
109 lim = (bfd_vma) 1 << bits;
110 if (value >= lim)
111 return bfd_reloc_overflow;
112 return bfd_reloc_ok;
113 }
114
115 /* Return non-zero if the indicated VALUE has overflowed the maximum
116 range expressible by an signed number with the indicated number of
117 BITS. */
118
119 static bfd_reloc_status_type
120 aarch64_signed_overflow (bfd_vma value, unsigned int bits)
121 {
122 bfd_signed_vma svalue = (bfd_signed_vma) value;
123 bfd_signed_vma lim;
124
125 if (bits >= sizeof (bfd_vma) * 8)
126 return bfd_reloc_ok;
127 lim = (bfd_signed_vma) 1 << (bits - 1);
128 if (svalue < -lim || svalue >= lim)
129 return bfd_reloc_overflow;
130 return bfd_reloc_ok;
131 }
132
133 /* Insert the addend/value into the instruction or data object being
134 relocated. */
135 bfd_reloc_status_type
136 _bfd_aarch64_elf_put_addend (bfd *abfd,
137 bfd_byte *address, bfd_reloc_code_real_type r_type,
138 reloc_howto_type *howto, bfd_signed_vma addend)
139 {
140 bfd_reloc_status_type status = bfd_reloc_ok;
141 bfd_signed_vma old_addend = addend;
142 bfd_vma contents;
143 int size;
144
145 size = bfd_get_reloc_size (howto);
146 switch (size)
147 {
148 case 0:
149 return status;
150 case 2:
151 contents = bfd_get_16 (abfd, address);
152 break;
153 case 4:
154 if (howto->src_mask != 0xffffffff)
155 /* Must be 32-bit instruction, always little-endian. */
156 contents = bfd_getl32 (address);
157 else
158 /* Must be 32-bit data (endianness dependent). */
159 contents = bfd_get_32 (abfd, address);
160 break;
161 case 8:
162 contents = bfd_get_64 (abfd, address);
163 break;
164 default:
165 abort ();
166 }
167
168 switch (howto->complain_on_overflow)
169 {
170 case complain_overflow_dont:
171 break;
172 case complain_overflow_signed:
173 status = aarch64_signed_overflow (addend,
174 howto->bitsize + howto->rightshift);
175 break;
176 case complain_overflow_unsigned:
177 status = aarch64_unsigned_overflow (addend,
178 howto->bitsize + howto->rightshift);
179 break;
180 case complain_overflow_bitfield:
181 default:
182 abort ();
183 }
184
185 addend >>= howto->rightshift;
186
187 switch (r_type)
188 {
189 case BFD_RELOC_AARCH64_JUMP26:
190 case BFD_RELOC_AARCH64_CALL26:
191 contents = reencode_branch_ofs_26 (contents, addend);
192 break;
193
194 case BFD_RELOC_AARCH64_BRANCH19:
195 contents = reencode_cond_branch_ofs_19 (contents, addend);
196 break;
197
198 case BFD_RELOC_AARCH64_TSTBR14:
199 contents = reencode_tst_branch_ofs_14 (contents, addend);
200 break;
201
202 case BFD_RELOC_AARCH64_TLSDESC_LD_PREL19:
203 case BFD_RELOC_AARCH64_LD_LO19_PCREL:
204 case BFD_RELOC_AARCH64_GOT_LD_PREL19:
205 case BFD_RELOC_AARCH64_TLSIE_LD_GOTTPREL_PREL19:
206 if (old_addend & ((1 << howto->rightshift) - 1))
207 return bfd_reloc_overflow;
208 contents = reencode_ld_lit_ofs_19 (contents, addend);
209 break;
210
211 case BFD_RELOC_AARCH64_TLSDESC_CALL:
212 break;
213
214 case BFD_RELOC_AARCH64_TLSDESC_ADR_PREL21:
215 case BFD_RELOC_AARCH64_TLSGD_ADR_PREL21:
216 case BFD_RELOC_AARCH64_TLSGD_ADR_PAGE21:
217 case BFD_RELOC_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
218 case BFD_RELOC_AARCH64_TLSDESC_ADR_PAGE21:
219 case BFD_RELOC_AARCH64_ADR_GOT_PAGE:
220 case BFD_RELOC_AARCH64_ADR_LO21_PCREL:
221 case BFD_RELOC_AARCH64_ADR_HI21_PCREL:
222 case BFD_RELOC_AARCH64_ADR_HI21_NC_PCREL:
223 contents = reencode_adr_imm (contents, addend);
224 break;
225
226 case BFD_RELOC_AARCH64_TLSGD_ADD_LO12_NC:
227 case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_LO12:
228 case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_HI12:
229 case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_LO12_NC:
230 case BFD_RELOC_AARCH64_TLSDESC_ADD_LO12_NC:
231 case BFD_RELOC_AARCH64_ADD_LO12:
232 /* Corresponds to: add rd, rn, #uimm12 to provide the low order
233 12 bits of the page offset following
234 BFD_RELOC_AARCH64_ADR_HI21_PCREL which computes the
235 (pc-relative) page base. */
236 contents = reencode_add_imm (contents, addend);
237 break;
238
239 case BFD_RELOC_AARCH64_LDST8_LO12:
240 case BFD_RELOC_AARCH64_LDST16_LO12:
241 case BFD_RELOC_AARCH64_LDST32_LO12:
242 case BFD_RELOC_AARCH64_LDST64_LO12:
243 case BFD_RELOC_AARCH64_LDST128_LO12:
244 case BFD_RELOC_AARCH64_TLSDESC_LD64_LO12_NC:
245 case BFD_RELOC_AARCH64_TLSDESC_LD32_LO12_NC:
246 case BFD_RELOC_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
247 case BFD_RELOC_AARCH64_TLSIE_LD32_GOTTPREL_LO12_NC:
248 case BFD_RELOC_AARCH64_LD64_GOT_LO12_NC:
249 case BFD_RELOC_AARCH64_LD32_GOT_LO12_NC:
250 if (old_addend & ((1 << howto->rightshift) - 1))
251 return bfd_reloc_overflow;
252 /* Used for ldr*|str* rt, [rn, #uimm12] to provide the low order
253 12 bits of the page offset following BFD_RELOC_AARCH64_ADR_HI21_PCREL
254 which computes the (pc-relative) page base. */
255 contents = reencode_ldst_pos_imm (contents, addend);
256 break;
257
258 /* Group relocations to create high bits of a 16, 32, 48 or 64
259 bit signed data or abs address inline. Will change
260 instruction to MOVN or MOVZ depending on sign of calculated
261 value. */
262
263 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G2:
264 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G1:
265 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G0:
266 case BFD_RELOC_AARCH64_MOVW_G0_S:
267 case BFD_RELOC_AARCH64_MOVW_G1_S:
268 case BFD_RELOC_AARCH64_MOVW_G2_S:
269 /* NOTE: We can only come here with movz or movn. */
270 if (addend < 0)
271 {
272 /* Force use of MOVN. */
273 addend = ~addend;
274 contents = reencode_movzn_to_movn (contents);
275 }
276 else
277 {
278 /* Force use of MOVZ. */
279 contents = reencode_movzn_to_movz (contents);
280 }
281 /* fall through */
282
283 /* Group relocations to create a 16, 32, 48 or 64 bit unsigned
284 data or abs address inline. */
285
286 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G0_NC:
287 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G1_NC:
288 case BFD_RELOC_AARCH64_MOVW_G0:
289 case BFD_RELOC_AARCH64_MOVW_G0_NC:
290 case BFD_RELOC_AARCH64_MOVW_G1:
291 case BFD_RELOC_AARCH64_MOVW_G1_NC:
292 case BFD_RELOC_AARCH64_MOVW_G2:
293 case BFD_RELOC_AARCH64_MOVW_G2_NC:
294 case BFD_RELOC_AARCH64_MOVW_G3:
295 contents = reencode_movw_imm (contents, addend);
296 break;
297
298 default:
299 /* Repack simple data */
300 if (howto->dst_mask & (howto->dst_mask + 1))
301 return bfd_reloc_notsupported;
302
303 contents = ((contents & ~howto->dst_mask) | (addend & howto->dst_mask));
304 break;
305 }
306
307 switch (size)
308 {
309 case 2:
310 bfd_put_16 (abfd, contents, address);
311 break;
312 case 4:
313 if (howto->dst_mask != 0xffffffff)
314 /* must be 32-bit instruction, always little-endian */
315 bfd_putl32 (contents, address);
316 else
317 /* must be 32-bit data (endianness dependent) */
318 bfd_put_32 (abfd, contents, address);
319 break;
320 case 8:
321 bfd_put_64 (abfd, contents, address);
322 break;
323 default:
324 abort ();
325 }
326
327 return status;
328 }
329
330 bfd_vma
331 _bfd_aarch64_elf_resolve_relocation (bfd_reloc_code_real_type r_type,
332 bfd_vma place, bfd_vma value,
333 bfd_vma addend, bfd_boolean weak_undef_p)
334 {
335 switch (r_type)
336 {
337 case BFD_RELOC_AARCH64_TLSDESC_CALL:
338 case BFD_RELOC_AARCH64_NONE:
339 break;
340
341 case BFD_RELOC_AARCH64_TLSDESC_ADR_PREL21:
342 case BFD_RELOC_AARCH64_TLSDESC_LD_PREL19:
343 case BFD_RELOC_AARCH64_TLSGD_ADR_PREL21:
344 case BFD_RELOC_AARCH64_TLSIE_LD_GOTTPREL_PREL19:
345 case BFD_RELOC_AARCH64_ADR_LO21_PCREL:
346 case BFD_RELOC_AARCH64_BRANCH19:
347 case BFD_RELOC_AARCH64_LD_LO19_PCREL:
348 case BFD_RELOC_AARCH64_16_PCREL:
349 case BFD_RELOC_AARCH64_32_PCREL:
350 case BFD_RELOC_AARCH64_64_PCREL:
351 case BFD_RELOC_AARCH64_TSTBR14:
352 if (weak_undef_p)
353 value = place;
354 value = value + addend - place;
355 break;
356
357 case BFD_RELOC_AARCH64_CALL26:
358 case BFD_RELOC_AARCH64_JUMP26:
359 value = value + addend - place;
360 break;
361
362 case BFD_RELOC_AARCH64_16:
363 case BFD_RELOC_AARCH64_32:
364 case BFD_RELOC_AARCH64_MOVW_G0_S:
365 case BFD_RELOC_AARCH64_MOVW_G1_S:
366 case BFD_RELOC_AARCH64_MOVW_G2_S:
367 case BFD_RELOC_AARCH64_MOVW_G0:
368 case BFD_RELOC_AARCH64_MOVW_G0_NC:
369 case BFD_RELOC_AARCH64_MOVW_G1:
370 case BFD_RELOC_AARCH64_MOVW_G1_NC:
371 case BFD_RELOC_AARCH64_MOVW_G2:
372 case BFD_RELOC_AARCH64_MOVW_G2_NC:
373 case BFD_RELOC_AARCH64_MOVW_G3:
374 value = value + addend;
375 break;
376
377 case BFD_RELOC_AARCH64_ADR_HI21_PCREL:
378 case BFD_RELOC_AARCH64_ADR_HI21_NC_PCREL:
379 if (weak_undef_p)
380 value = PG (place);
381 value = PG (value + addend) - PG (place);
382 break;
383
384 case BFD_RELOC_AARCH64_GOT_LD_PREL19:
385 value = value + addend - place;
386 break;
387
388 case BFD_RELOC_AARCH64_ADR_GOT_PAGE:
389 case BFD_RELOC_AARCH64_TLSDESC_ADR_PAGE21:
390 case BFD_RELOC_AARCH64_TLSGD_ADR_PAGE21:
391 case BFD_RELOC_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
392 value = PG (value + addend) - PG (place);
393 break;
394
395 case BFD_RELOC_AARCH64_ADD_LO12:
396 case BFD_RELOC_AARCH64_LD64_GOT_LO12_NC:
397 case BFD_RELOC_AARCH64_LD32_GOT_LO12_NC:
398 case BFD_RELOC_AARCH64_LDST8_LO12:
399 case BFD_RELOC_AARCH64_LDST16_LO12:
400 case BFD_RELOC_AARCH64_LDST32_LO12:
401 case BFD_RELOC_AARCH64_LDST64_LO12:
402 case BFD_RELOC_AARCH64_LDST128_LO12:
403 case BFD_RELOC_AARCH64_TLSDESC_ADD_LO12_NC:
404 case BFD_RELOC_AARCH64_TLSDESC_ADD:
405 case BFD_RELOC_AARCH64_TLSDESC_LD64_LO12_NC:
406 case BFD_RELOC_AARCH64_TLSDESC_LD32_LO12_NC:
407 case BFD_RELOC_AARCH64_TLSDESC_LDR:
408 case BFD_RELOC_AARCH64_TLSGD_ADD_LO12_NC:
409 case BFD_RELOC_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
410 case BFD_RELOC_AARCH64_TLSIE_LD32_GOTTPREL_LO12_NC:
411 case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_LO12:
412 case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_LO12_NC:
413 value = PG_OFFSET (value + addend);
414 break;
415
416 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G1:
417 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G1_NC:
418 value = (value + addend) & (bfd_vma) 0xffff0000;
419 break;
420 case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_HI12:
421 /* Mask off low 12bits, keep all other high bits, so that the later
422 generic code could check whehter there is overflow. */
423 value = (value + addend) & ~(bfd_vma) 0xfff;
424 break;
425
426 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G0:
427 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G0_NC:
428 value = (value + addend) & (bfd_vma) 0xffff;
429 break;
430
431 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G2:
432 value = (value + addend) & ~(bfd_vma) 0xffffffff;
433 value -= place & ~(bfd_vma) 0xffffffff;
434 break;
435
436 default:
437 break;
438 }
439
440 return value;
441 }
442
443 /* Hook called by the linker routine which adds symbols from an object
444 file. */
445
446 bfd_boolean
447 _bfd_aarch64_elf_add_symbol_hook (bfd *abfd, struct bfd_link_info *info,
448 Elf_Internal_Sym *sym,
449 const char **namep ATTRIBUTE_UNUSED,
450 flagword *flagsp ATTRIBUTE_UNUSED,
451 asection **secp ATTRIBUTE_UNUSED,
452 bfd_vma *valp ATTRIBUTE_UNUSED)
453 {
454 if ((ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC
455 || ELF_ST_BIND (sym->st_info) == STB_GNU_UNIQUE)
456 && (abfd->flags & DYNAMIC) == 0
457 && bfd_get_flavour (info->output_bfd) == bfd_target_elf_flavour)
458 elf_tdata (info->output_bfd)->has_gnu_symbols = TRUE;
459
460 return TRUE;
461 }
462
463 /* Support for core dump NOTE sections. */
464
465 bfd_boolean
466 _bfd_aarch64_elf_grok_prstatus (bfd *abfd, Elf_Internal_Note *note)
467 {
468 int offset;
469 size_t size;
470
471 switch (note->descsz)
472 {
473 default:
474 return FALSE;
475
476 case 392: /* sizeof(struct elf_prstatus) on Linux/arm64. */
477 /* pr_cursig */
478 elf_tdata (abfd)->core->signal
479 = bfd_get_16 (abfd, note->descdata + 12);
480
481 /* pr_pid */
482 elf_tdata (abfd)->core->lwpid
483 = bfd_get_32 (abfd, note->descdata + 32);
484
485 /* pr_reg */
486 offset = 112;
487 size = 272;
488
489 break;
490 }
491
492 /* Make a ".reg/999" section. */
493 return _bfd_elfcore_make_pseudosection (abfd, ".reg",
494 size, note->descpos + offset);
495 }
496
497 bfd_boolean
498 _bfd_aarch64_elf_grok_psinfo (bfd *abfd, Elf_Internal_Note *note)
499 {
500 switch (note->descsz)
501 {
502 default:
503 return FALSE;
504
505 case 136: /* This is sizeof(struct elf_prpsinfo) on Linux/aarch64. */
506 elf_tdata (abfd)->core->pid = bfd_get_32 (abfd, note->descdata + 24);
507 elf_tdata (abfd)->core->program
508 = _bfd_elfcore_strndup (abfd, note->descdata + 40, 16);
509 elf_tdata (abfd)->core->command
510 = _bfd_elfcore_strndup (abfd, note->descdata + 56, 80);
511 }
512
513 /* Note that for some reason, a spurious space is tacked
514 onto the end of the args in some (at least one anyway)
515 implementations, so strip it off if it exists. */
516
517 {
518 char *command = elf_tdata (abfd)->core->command;
519 int n = strlen (command);
520
521 if (0 < n && command[n - 1] == ' ')
522 command[n - 1] = '\0';
523 }
524
525 return TRUE;
526 }
527
528 char *
529 _bfd_aarch64_elf_write_core_note (bfd *abfd, char *buf, int *bufsiz, int note_type,
530 ...)
531 {
532 switch (note_type)
533 {
534 default:
535 return NULL;
536
537 case NT_PRPSINFO:
538 {
539 char data[136];
540 va_list ap;
541
542 va_start (ap, note_type);
543 memset (data, 0, sizeof (data));
544 strncpy (data + 40, va_arg (ap, const char *), 16);
545 strncpy (data + 56, va_arg (ap, const char *), 80);
546 va_end (ap);
547
548 return elfcore_write_note (abfd, buf, bufsiz, "CORE",
549 note_type, data, sizeof (data));
550 }
551
552 case NT_PRSTATUS:
553 {
554 char data[392];
555 va_list ap;
556 long pid;
557 int cursig;
558 const void *greg;
559
560 va_start (ap, note_type);
561 memset (data, 0, sizeof (data));
562 pid = va_arg (ap, long);
563 bfd_put_32 (abfd, pid, data + 32);
564 cursig = va_arg (ap, int);
565 bfd_put_16 (abfd, cursig, data + 12);
566 greg = va_arg (ap, const void *);
567 memcpy (data + 112, greg, 272);
568 va_end (ap);
569
570 return elfcore_write_note (abfd, buf, bufsiz, "CORE",
571 note_type, data, sizeof (data));
572 }
573 }
574 }
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