1 /* MMIX-specific support for 64-bit ELF.
2 Copyright (C) 2001-2024 Free Software Foundation, Inc.
3 Contributed by Hans-Peter Nilsson <hp@bitrange.com>
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; if not, write to the Free Software
19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
20 MA 02110-1301, USA. */
21
22
23 /* No specific ABI or "processor-specific supplement" defined. */
24
25 /* TODO:
26 - "Traditional" linker relaxation (shrinking whole sections).
27 - Merge reloc stubs jumping to same location.
28 - GETA stub relaxation (call a stub for out of range new
29 R_MMIX_GETA_STUBBABLE). */
30
31 #include "sysdep.h"
32 #include "bfd.h"
33 #include "libbfd.h"
34 #include "elf-bfd.h"
35 #include "elf/mmix.h"
36 #include "opcode/mmix.h"
37
38 #define MINUS_ONE (((bfd_vma) 0) - 1)
39
40 #define MAX_PUSHJ_STUB_SIZE (5 * 4)
41
42 /* Put these everywhere in new code. */
43 #define FATAL_DEBUG \
44 _bfd_abort (__FILE__, __LINE__, \
45 "Internal: Non-debugged code (test-case missing)")
46
47 #define BAD_CASE(x) \
48 _bfd_abort (__FILE__, __LINE__, \
49 "bad case for " #x)
50
51 struct _mmix_elf_section_data
52 {
53 struct bfd_elf_section_data elf;
54 union
55 {
56 struct bpo_reloc_section_info *reloc;
57 struct bpo_greg_section_info *greg;
58 } bpo;
59
60 struct pushj_stub_info
61 {
62 /* Maximum number of stubs needed for this section. */
63 bfd_size_type n_pushj_relocs;
64
65 /* Size of stubs after a mmix_elf_relax_section round. */
66 bfd_size_type stubs_size_sum;
67
68 /* Per-reloc stubs_size_sum information. The stubs_size_sum member is the sum
69 of these. Allocated in mmix_elf_check_common_relocs. */
70 bfd_size_type *stub_size;
71
72 /* Offset of next stub during relocation. Somewhat redundant with the
73 above: error coverage is easier and we don't have to reset the
74 stubs_size_sum for relocation. */
75 bfd_size_type stub_offset;
76 } pjs;
77
78 /* Whether there has been a warning that this section could not be
79 linked due to a specific cause. FIXME: a way to access the
80 linker info or output section, then stuff the limiter guard
81 there. */
82 bool has_warned_bpo;
83 bool has_warned_pushj;
84 };
85
86 #define mmix_elf_section_data(sec) \
87 ((struct _mmix_elf_section_data *) elf_section_data (sec))
88
89 /* For each section containing a base-plus-offset (BPO) reloc, we attach
90 this struct as mmix_elf_section_data (section)->bpo, which is otherwise
91 NULL. */
92 struct bpo_reloc_section_info
93 {
94 /* The base is 1; this is the first number in this section. */
95 size_t first_base_plus_offset_reloc;
96
97 /* Number of BPO-relocs in this section. */
98 size_t n_bpo_relocs_this_section;
99
100 /* Running index, used at relocation time. */
101 size_t bpo_index;
102
103 /* We don't have access to the bfd_link_info struct in
104 mmix_final_link_relocate. What we really want to get at is the
105 global single struct greg_relocation, so we stash it here. */
106 asection *bpo_greg_section;
107 };
108
109 /* Helper struct (in global context) for the one below.
110 There's one of these created for every BPO reloc. */
111 struct bpo_reloc_request
112 {
113 bfd_vma value;
114
115 /* Valid after relaxation. The base is 0; the first register number
116 must be added. The offset is in range 0..255. */
117 size_t regindex;
118 size_t offset;
119
120 /* The order number for this BPO reloc, corresponding to the order in
121 which BPO relocs were found. Used to create an index after reloc
122 requests are sorted. */
123 size_t bpo_reloc_no;
124
125 /* Set when the value is computed. Better than coding "guard values"
126 into the other members. Is FALSE only for BPO relocs in a GC:ed
127 section. */
128 bool valid;
129 };
130
131 /* We attach this as mmix_elf_section_data (sec)->bpo in the linker-allocated
132 greg contents section (MMIX_LD_ALLOCATED_REG_CONTENTS_SECTION_NAME),
133 which is linked into the register contents section
134 (MMIX_REG_CONTENTS_SECTION_NAME). This section is created by the
135 linker; using the same hook as for usual with BPO relocs does not
136 collide. */
137 struct bpo_greg_section_info
138 {
139 /* After GC, this reflects the number of remaining, non-excluded
140 BPO-relocs. */
141 size_t n_bpo_relocs;
142
143 /* This is the number of allocated bpo_reloc_requests; the size of
144 sorted_indexes. Valid after the check.*relocs functions are called
145 for all incoming sections. It includes the number of BPO relocs in
146 sections that were GC:ed. */
147 size_t n_max_bpo_relocs;
148
149 /* A counter used to find out when to fold the BPO gregs, since we
150 don't have a single "after-relaxation" hook. */
151 size_t n_remaining_bpo_relocs_this_relaxation_round;
152
153 /* The number of linker-allocated GREGs resulting from BPO relocs.
154 This is an approximation after _bfd_mmix_before_linker_allocation
155 and supposedly accurate after mmix_elf_relax_section is called for
156 all incoming non-collected sections. */
157 size_t n_allocated_bpo_gregs;
158
159 /* Index into reloc_request[], sorted on increasing "value", secondary
160 by increasing index for strict sorting order. */
161 size_t *bpo_reloc_indexes;
162
163 /* An array of all relocations, with the "value" member filled in by
164 the relaxation function. */
165 struct bpo_reloc_request *reloc_request;
166 };
167
168
169 extern bool mmix_elf_final_link (bfd *, struct bfd_link_info *);
170
171 extern void mmix_elf_symbol_processing (bfd *, asymbol *);
172
173 /* Only intended to be called from a debugger. */
174 extern void mmix_dump_bpo_gregs
175 (struct bfd_link_info *, void (*) (const char *, ...));
176
177 static void
178 mmix_set_relaxable_size (bfd *, asection *, void *);
179 static bfd_reloc_status_type
180 mmix_elf_reloc (bfd *, arelent *, asymbol *, void *,
181 asection *, bfd *, char **);
182 static bfd_reloc_status_type
183 mmix_final_link_relocate (reloc_howto_type *, asection *, bfd_byte *, bfd_vma,
184 bfd_signed_vma, bfd_vma, const char *, asection *,
185 char **);
186
187
188 /* Watch out: this currently needs to have elements with the same index as
189 their R_MMIX_ number. */
190 static reloc_howto_type elf_mmix_howto_table[] =
191 {
192 /* This reloc does nothing. */
193 HOWTO (R_MMIX_NONE, /* type */
194 0, /* rightshift */
195 0, /* size */
196 0, /* bitsize */
197 false, /* pc_relative */
198 0, /* bitpos */
199 complain_overflow_dont, /* complain_on_overflow */
200 bfd_elf_generic_reloc, /* special_function */
201 "R_MMIX_NONE", /* name */
202 false, /* partial_inplace */
203 0, /* src_mask */
204 0, /* dst_mask */
205 false), /* pcrel_offset */
206
207 /* An 8 bit absolute relocation. */
208 HOWTO (R_MMIX_8, /* type */
209 0, /* rightshift */
210 1, /* size */
211 8, /* bitsize */
212 false, /* pc_relative */
213 0, /* bitpos */
214 complain_overflow_bitfield, /* complain_on_overflow */
215 bfd_elf_generic_reloc, /* special_function */
216 "R_MMIX_8", /* name */
217 false, /* partial_inplace */
218 0, /* src_mask */
219 0xff, /* dst_mask */
220 false), /* pcrel_offset */
221
222 /* An 16 bit absolute relocation. */
223 HOWTO (R_MMIX_16, /* type */
224 0, /* rightshift */
225 2, /* size */
226 16, /* bitsize */
227 false, /* pc_relative */
228 0, /* bitpos */
229 complain_overflow_bitfield, /* complain_on_overflow */
230 bfd_elf_generic_reloc, /* special_function */
231 "R_MMIX_16", /* name */
232 false, /* partial_inplace */
233 0, /* src_mask */
234 0xffff, /* dst_mask */
235 false), /* pcrel_offset */
236
237 /* An 24 bit absolute relocation. */
238 HOWTO (R_MMIX_24, /* type */
239 0, /* rightshift */
240 4, /* size */
241 24, /* bitsize */
242 false, /* pc_relative */
243 0, /* bitpos */
244 complain_overflow_bitfield, /* complain_on_overflow */
245 bfd_elf_generic_reloc, /* special_function */
246 "R_MMIX_24", /* name */
247 false, /* partial_inplace */
248 ~0xffffff, /* src_mask */
249 0xffffff, /* dst_mask */
250 false), /* pcrel_offset */
251
252 /* A 32 bit absolute relocation. */
253 HOWTO (R_MMIX_32, /* type */
254 0, /* rightshift */
255 4, /* size */
256 32, /* bitsize */
257 false, /* pc_relative */
258 0, /* bitpos */
259 complain_overflow_bitfield, /* complain_on_overflow */
260 bfd_elf_generic_reloc, /* special_function */
261 "R_MMIX_32", /* name */
262 false, /* partial_inplace */
263 0, /* src_mask */
264 0xffffffff, /* dst_mask */
265 false), /* pcrel_offset */
266
267 /* 64 bit relocation. */
268 HOWTO (R_MMIX_64, /* type */
269 0, /* rightshift */
270 8, /* size */
271 64, /* bitsize */
272 false, /* pc_relative */
273 0, /* bitpos */
274 complain_overflow_bitfield, /* complain_on_overflow */
275 bfd_elf_generic_reloc, /* special_function */
276 "R_MMIX_64", /* name */
277 false, /* partial_inplace */
278 0, /* src_mask */
279 MINUS_ONE, /* dst_mask */
280 false), /* pcrel_offset */
281
282 /* An 8 bit PC-relative relocation. */
283 HOWTO (R_MMIX_PC_8, /* type */
284 0, /* rightshift */
285 1, /* size */
286 8, /* bitsize */
287 true, /* pc_relative */
288 0, /* bitpos */
289 complain_overflow_bitfield, /* complain_on_overflow */
290 bfd_elf_generic_reloc, /* special_function */
291 "R_MMIX_PC_8", /* name */
292 false, /* partial_inplace */
293 0, /* src_mask */
294 0xff, /* dst_mask */
295 true), /* pcrel_offset */
296
297 /* An 16 bit PC-relative relocation. */
298 HOWTO (R_MMIX_PC_16, /* type */
299 0, /* rightshift */
300 2, /* size */
301 16, /* bitsize */
302 true, /* pc_relative */
303 0, /* bitpos */
304 complain_overflow_bitfield, /* complain_on_overflow */
305 bfd_elf_generic_reloc, /* special_function */
306 "R_MMIX_PC_16", /* name */
307 false, /* partial_inplace */
308 0, /* src_mask */
309 0xffff, /* dst_mask */
310 true), /* pcrel_offset */
311
312 /* An 24 bit PC-relative relocation. */
313 HOWTO (R_MMIX_PC_24, /* type */
314 0, /* rightshift */
315 4, /* size */
316 24, /* bitsize */
317 true, /* pc_relative */
318 0, /* bitpos */
319 complain_overflow_bitfield, /* complain_on_overflow */
320 bfd_elf_generic_reloc, /* special_function */
321 "R_MMIX_PC_24", /* name */
322 false, /* partial_inplace */
323 ~0xffffff, /* src_mask */
324 0xffffff, /* dst_mask */
325 true), /* pcrel_offset */
326
327 /* A 32 bit absolute PC-relative relocation. */
328 HOWTO (R_MMIX_PC_32, /* type */
329 0, /* rightshift */
330 4, /* size */
331 32, /* bitsize */
332 true, /* pc_relative */
333 0, /* bitpos */
334 complain_overflow_bitfield, /* complain_on_overflow */
335 bfd_elf_generic_reloc, /* special_function */
336 "R_MMIX_PC_32", /* name */
337 false, /* partial_inplace */
338 0, /* src_mask */
339 0xffffffff, /* dst_mask */
340 true), /* pcrel_offset */
341
342 /* 64 bit PC-relative relocation. */
343 HOWTO (R_MMIX_PC_64, /* type */
344 0, /* rightshift */
345 8, /* size */
346 64, /* bitsize */
347 true, /* pc_relative */
348 0, /* bitpos */
349 complain_overflow_bitfield, /* complain_on_overflow */
350 bfd_elf_generic_reloc, /* special_function */
351 "R_MMIX_PC_64", /* name */
352 false, /* partial_inplace */
353 0, /* src_mask */
354 MINUS_ONE, /* dst_mask */
355 true), /* pcrel_offset */
356
357 /* GNU extension to record C++ vtable hierarchy. */
358 HOWTO (R_MMIX_GNU_VTINHERIT, /* type */
359 0, /* rightshift */
360 0, /* size */
361 0, /* bitsize */
362 false, /* pc_relative */
363 0, /* bitpos */
364 complain_overflow_dont, /* complain_on_overflow */
365 NULL, /* special_function */
366 "R_MMIX_GNU_VTINHERIT", /* name */
367 false, /* partial_inplace */
368 0, /* src_mask */
369 0, /* dst_mask */
370 true), /* pcrel_offset */
371
372 /* GNU extension to record C++ vtable member usage. */
373 HOWTO (R_MMIX_GNU_VTENTRY, /* type */
374 0, /* rightshift */
375 0, /* size */
376 0, /* bitsize */
377 false, /* pc_relative */
378 0, /* bitpos */
379 complain_overflow_dont, /* complain_on_overflow */
380 _bfd_elf_rel_vtable_reloc_fn, /* special_function */
381 "R_MMIX_GNU_VTENTRY", /* name */
382 false, /* partial_inplace */
383 0, /* src_mask */
384 0, /* dst_mask */
385 false), /* pcrel_offset */
386
387 /* The GETA relocation is supposed to get any address that could
388 possibly be reached by the GETA instruction. It can silently expand
389 to get a 64-bit operand, but will complain if any of the two least
390 significant bits are set. The howto members reflect a simple GETA. */
391 HOWTO (R_MMIX_GETA, /* type */
392 2, /* rightshift */
393 4, /* size */
394 19, /* bitsize */
395 true, /* pc_relative */
396 0, /* bitpos */
397 complain_overflow_signed, /* complain_on_overflow */
398 mmix_elf_reloc, /* special_function */
399 "R_MMIX_GETA", /* name */
400 false, /* partial_inplace */
401 ~0x0100ffff, /* src_mask */
402 0x0100ffff, /* dst_mask */
403 true), /* pcrel_offset */
404
405 HOWTO (R_MMIX_GETA_1, /* type */
406 2, /* rightshift */
407 4, /* size */
408 19, /* bitsize */
409 true, /* pc_relative */
410 0, /* bitpos */
411 complain_overflow_signed, /* complain_on_overflow */
412 mmix_elf_reloc, /* special_function */
413 "R_MMIX_GETA_1", /* name */
414 false, /* partial_inplace */
415 ~0x0100ffff, /* src_mask */
416 0x0100ffff, /* dst_mask */
417 true), /* pcrel_offset */
418
419 HOWTO (R_MMIX_GETA_2, /* type */
420 2, /* rightshift */
421 4, /* size */
422 19, /* bitsize */
423 true, /* pc_relative */
424 0, /* bitpos */
425 complain_overflow_signed, /* complain_on_overflow */
426 mmix_elf_reloc, /* special_function */
427 "R_MMIX_GETA_2", /* name */
428 false, /* partial_inplace */
429 ~0x0100ffff, /* src_mask */
430 0x0100ffff, /* dst_mask */
431 true), /* pcrel_offset */
432
433 HOWTO (R_MMIX_GETA_3, /* type */
434 2, /* rightshift */
435 4, /* size */
436 19, /* bitsize */
437 true, /* pc_relative */
438 0, /* bitpos */
439 complain_overflow_signed, /* complain_on_overflow */
440 mmix_elf_reloc, /* special_function */
441 "R_MMIX_GETA_3", /* name */
442 false, /* partial_inplace */
443 ~0x0100ffff, /* src_mask */
444 0x0100ffff, /* dst_mask */
445 true), /* pcrel_offset */
446
447 /* The conditional branches are supposed to reach any (code) address.
448 It can silently expand to a 64-bit operand, but will emit an error if
449 any of the two least significant bits are set. The howto members
450 reflect a simple branch. */
451 HOWTO (R_MMIX_CBRANCH, /* type */
452 2, /* rightshift */
453 4, /* size */
454 19, /* bitsize */
455 true, /* pc_relative */
456 0, /* bitpos */
457 complain_overflow_signed, /* complain_on_overflow */
458 mmix_elf_reloc, /* special_function */
459 "R_MMIX_CBRANCH", /* name */
460 false, /* partial_inplace */
461 ~0x0100ffff, /* src_mask */
462 0x0100ffff, /* dst_mask */
463 true), /* pcrel_offset */
464
465 HOWTO (R_MMIX_CBRANCH_J, /* type */
466 2, /* rightshift */
467 4, /* size */
468 19, /* bitsize */
469 true, /* pc_relative */
470 0, /* bitpos */
471 complain_overflow_signed, /* complain_on_overflow */
472 mmix_elf_reloc, /* special_function */
473 "R_MMIX_CBRANCH_J", /* name */
474 false, /* partial_inplace */
475 ~0x0100ffff, /* src_mask */
476 0x0100ffff, /* dst_mask */
477 true), /* pcrel_offset */
478
479 HOWTO (R_MMIX_CBRANCH_1, /* type */
480 2, /* rightshift */
481 4, /* size */
482 19, /* bitsize */
483 true, /* pc_relative */
484 0, /* bitpos */
485 complain_overflow_signed, /* complain_on_overflow */
486 mmix_elf_reloc, /* special_function */
487 "R_MMIX_CBRANCH_1", /* name */
488 false, /* partial_inplace */
489 ~0x0100ffff, /* src_mask */
490 0x0100ffff, /* dst_mask */
491 true), /* pcrel_offset */
492
493 HOWTO (R_MMIX_CBRANCH_2, /* type */
494 2, /* rightshift */
495 4, /* size */
496 19, /* bitsize */
497 true, /* pc_relative */
498 0, /* bitpos */
499 complain_overflow_signed, /* complain_on_overflow */
500 mmix_elf_reloc, /* special_function */
501 "R_MMIX_CBRANCH_2", /* name */
502 false, /* partial_inplace */
503 ~0x0100ffff, /* src_mask */
504 0x0100ffff, /* dst_mask */
505 true), /* pcrel_offset */
506
507 HOWTO (R_MMIX_CBRANCH_3, /* type */
508 2, /* rightshift */
509 4, /* size */
510 19, /* bitsize */
511 true, /* pc_relative */
512 0, /* bitpos */
513 complain_overflow_signed, /* complain_on_overflow */
514 mmix_elf_reloc, /* special_function */
515 "R_MMIX_CBRANCH_3", /* name */
516 false, /* partial_inplace */
517 ~0x0100ffff, /* src_mask */
518 0x0100ffff, /* dst_mask */
519 true), /* pcrel_offset */
520
521 /* The PUSHJ instruction can reach any (code) address, as long as it's
522 the beginning of a function (no usable restriction). It can silently
523 expand to a 64-bit operand, but will emit an error if any of the two
524 least significant bits are set. It can also expand into a call to a
525 stub; see R_MMIX_PUSHJ_STUBBABLE. The howto members reflect a simple
526 PUSHJ. */
527 HOWTO (R_MMIX_PUSHJ, /* type */
528 2, /* rightshift */
529 4, /* size */
530 19, /* bitsize */
531 true, /* pc_relative */
532 0, /* bitpos */
533 complain_overflow_signed, /* complain_on_overflow */
534 mmix_elf_reloc, /* special_function */
535 "R_MMIX_PUSHJ", /* name */
536 false, /* partial_inplace */
537 ~0x0100ffff, /* src_mask */
538 0x0100ffff, /* dst_mask */
539 true), /* pcrel_offset */
540
541 HOWTO (R_MMIX_PUSHJ_1, /* type */
542 2, /* rightshift */
543 4, /* size */
544 19, /* bitsize */
545 true, /* pc_relative */
546 0, /* bitpos */
547 complain_overflow_signed, /* complain_on_overflow */
548 mmix_elf_reloc, /* special_function */
549 "R_MMIX_PUSHJ_1", /* name */
550 false, /* partial_inplace */
551 ~0x0100ffff, /* src_mask */
552 0x0100ffff, /* dst_mask */
553 true), /* pcrel_offset */
554
555 HOWTO (R_MMIX_PUSHJ_2, /* type */
556 2, /* rightshift */
557 4, /* size */
558 19, /* bitsize */
559 true, /* pc_relative */
560 0, /* bitpos */
561 complain_overflow_signed, /* complain_on_overflow */
562 mmix_elf_reloc, /* special_function */
563 "R_MMIX_PUSHJ_2", /* name */
564 false, /* partial_inplace */
565 ~0x0100ffff, /* src_mask */
566 0x0100ffff, /* dst_mask */
567 true), /* pcrel_offset */
568
569 HOWTO (R_MMIX_PUSHJ_3, /* type */
570 2, /* rightshift */
571 4, /* size */
572 19, /* bitsize */
573 true, /* pc_relative */
574 0, /* bitpos */
575 complain_overflow_signed, /* complain_on_overflow */
576 mmix_elf_reloc, /* special_function */
577 "R_MMIX_PUSHJ_3", /* name */
578 false, /* partial_inplace */
579 ~0x0100ffff, /* src_mask */
580 0x0100ffff, /* dst_mask */
581 true), /* pcrel_offset */
582
583 /* A JMP is supposed to reach any (code) address. By itself, it can
584 reach +-64M; the expansion can reach all 64 bits. Note that the 64M
585 limit is soon reached if you link the program in wildly different
586 memory segments. The howto members reflect a trivial JMP. */
587 HOWTO (R_MMIX_JMP, /* type */
588 2, /* rightshift */
589 4, /* size */
590 27, /* bitsize */
591 true, /* pc_relative */
592 0, /* bitpos */
593 complain_overflow_signed, /* complain_on_overflow */
594 mmix_elf_reloc, /* special_function */
595 "R_MMIX_JMP", /* name */
596 false, /* partial_inplace */
597 ~0x1ffffff, /* src_mask */
598 0x1ffffff, /* dst_mask */
599 true), /* pcrel_offset */
600
601 HOWTO (R_MMIX_JMP_1, /* type */
602 2, /* rightshift */
603 4, /* size */
604 27, /* bitsize */
605 true, /* pc_relative */
606 0, /* bitpos */
607 complain_overflow_signed, /* complain_on_overflow */
608 mmix_elf_reloc, /* special_function */
609 "R_MMIX_JMP_1", /* name */
610 false, /* partial_inplace */
611 ~0x1ffffff, /* src_mask */
612 0x1ffffff, /* dst_mask */
613 true), /* pcrel_offset */
614
615 HOWTO (R_MMIX_JMP_2, /* type */
616 2, /* rightshift */
617 4, /* size */
618 27, /* bitsize */
619 true, /* pc_relative */
620 0, /* bitpos */
621 complain_overflow_signed, /* complain_on_overflow */
622 mmix_elf_reloc, /* special_function */
623 "R_MMIX_JMP_2", /* name */
624 false, /* partial_inplace */
625 ~0x1ffffff, /* src_mask */
626 0x1ffffff, /* dst_mask */
627 true), /* pcrel_offset */
628
629 HOWTO (R_MMIX_JMP_3, /* type */
630 2, /* rightshift */
631 4, /* size */
632 27, /* bitsize */
633 true, /* pc_relative */
634 0, /* bitpos */
635 complain_overflow_signed, /* complain_on_overflow */
636 mmix_elf_reloc, /* special_function */
637 "R_MMIX_JMP_3", /* name */
638 false, /* partial_inplace */
639 ~0x1ffffff, /* src_mask */
640 0x1ffffff, /* dst_mask */
641 true), /* pcrel_offset */
642
643 /* When we don't emit link-time-relaxable code from the assembler, or
644 when relaxation has done all it can do, these relocs are used. For
645 GETA/PUSHJ/branches. */
646 HOWTO (R_MMIX_ADDR19, /* type */
647 2, /* rightshift */
648 4, /* size */
649 19, /* bitsize */
650 true, /* pc_relative */
651 0, /* bitpos */
652 complain_overflow_signed, /* complain_on_overflow */
653 mmix_elf_reloc, /* special_function */
654 "R_MMIX_ADDR19", /* name */
655 false, /* partial_inplace */
656 ~0x0100ffff, /* src_mask */
657 0x0100ffff, /* dst_mask */
658 true), /* pcrel_offset */
659
660 /* For JMP. */
661 HOWTO (R_MMIX_ADDR27, /* type */
662 2, /* rightshift */
663 4, /* size */
664 27, /* bitsize */
665 true, /* pc_relative */
666 0, /* bitpos */
667 complain_overflow_signed, /* complain_on_overflow */
668 mmix_elf_reloc, /* special_function */
669 "R_MMIX_ADDR27", /* name */
670 false, /* partial_inplace */
671 ~0x1ffffff, /* src_mask */
672 0x1ffffff, /* dst_mask */
673 true), /* pcrel_offset */
674
675 /* A general register or the value 0..255. If a value, then the
676 instruction (offset -3) needs adjusting. */
677 HOWTO (R_MMIX_REG_OR_BYTE, /* type */
678 0, /* rightshift */
679 2, /* size */
680 8, /* bitsize */
681 false, /* pc_relative */
682 0, /* bitpos */
683 complain_overflow_bitfield, /* complain_on_overflow */
684 mmix_elf_reloc, /* special_function */
685 "R_MMIX_REG_OR_BYTE", /* name */
686 false, /* partial_inplace */
687 0, /* src_mask */
688 0xff, /* dst_mask */
689 false), /* pcrel_offset */
690
691 /* A general register. */
692 HOWTO (R_MMIX_REG, /* type */
693 0, /* rightshift */
694 2, /* size */
695 8, /* bitsize */
696 false, /* pc_relative */
697 0, /* bitpos */
698 complain_overflow_bitfield, /* complain_on_overflow */
699 mmix_elf_reloc, /* special_function */
700 "R_MMIX_REG", /* name */
701 false, /* partial_inplace */
702 0, /* src_mask */
703 0xff, /* dst_mask */
704 false), /* pcrel_offset */
705
706 /* A register plus an index, corresponding to the relocation expression.
707 The sizes must correspond to the valid range of the expression, while
708 the bitmasks correspond to what we store in the image. */
709 HOWTO (R_MMIX_BASE_PLUS_OFFSET, /* type */
710 0, /* rightshift */
711 8, /* size */
712 64, /* bitsize */
713 false, /* pc_relative */
714 0, /* bitpos */
715 complain_overflow_bitfield, /* complain_on_overflow */
716 mmix_elf_reloc, /* special_function */
717 "R_MMIX_BASE_PLUS_OFFSET", /* name */
718 false, /* partial_inplace */
719 0, /* src_mask */
720 0xffff, /* dst_mask */
721 false), /* pcrel_offset */
722
723 /* A "magic" relocation for a LOCAL expression, asserting that the
724 expression is less than the number of global registers. No actual
725 modification of the contents is done. Implementing this as a
726 relocation was less intrusive than e.g. putting such expressions in a
727 section to discard *after* relocation. */
728 HOWTO (R_MMIX_LOCAL, /* type */
729 0, /* rightshift */
730 0, /* size */
731 0, /* bitsize */
732 false, /* pc_relative */
733 0, /* bitpos */
734 complain_overflow_dont, /* complain_on_overflow */
735 mmix_elf_reloc, /* special_function */
736 "R_MMIX_LOCAL", /* name */
737 false, /* partial_inplace */
738 0, /* src_mask */
739 0, /* dst_mask */
740 false), /* pcrel_offset */
741
742 HOWTO (R_MMIX_PUSHJ_STUBBABLE, /* type */
743 2, /* rightshift */
744 4, /* size */
745 19, /* bitsize */
746 true, /* pc_relative */
747 0, /* bitpos */
748 complain_overflow_signed, /* complain_on_overflow */
749 mmix_elf_reloc, /* special_function */
750 "R_MMIX_PUSHJ_STUBBABLE", /* name */
751 false, /* partial_inplace */
752 ~0x0100ffff, /* src_mask */
753 0x0100ffff, /* dst_mask */
754 true) /* pcrel_offset */
755 };
756
757
758 /* Map BFD reloc types to MMIX ELF reloc types. */
759
760 struct mmix_reloc_map
761 {
762 bfd_reloc_code_real_type bfd_reloc_val;
763 enum elf_mmix_reloc_type elf_reloc_val;
764 };
765
766
767 static const struct mmix_reloc_map mmix_reloc_map[] =
768 {
769 {BFD_RELOC_NONE, R_MMIX_NONE},
770 {BFD_RELOC_8, R_MMIX_8},
771 {BFD_RELOC_16, R_MMIX_16},
772 {BFD_RELOC_24, R_MMIX_24},
773 {BFD_RELOC_32, R_MMIX_32},
774 {BFD_RELOC_64, R_MMIX_64},
775 {BFD_RELOC_8_PCREL, R_MMIX_PC_8},
776 {BFD_RELOC_16_PCREL, R_MMIX_PC_16},
777 {BFD_RELOC_24_PCREL, R_MMIX_PC_24},
778 {BFD_RELOC_32_PCREL, R_MMIX_PC_32},
779 {BFD_RELOC_64_PCREL, R_MMIX_PC_64},
780 {BFD_RELOC_VTABLE_INHERIT, R_MMIX_GNU_VTINHERIT},
781 {BFD_RELOC_VTABLE_ENTRY, R_MMIX_GNU_VTENTRY},
782 {BFD_RELOC_MMIX_GETA, R_MMIX_GETA},
783 {BFD_RELOC_MMIX_CBRANCH, R_MMIX_CBRANCH},
784 {BFD_RELOC_MMIX_PUSHJ, R_MMIX_PUSHJ},
785 {BFD_RELOC_MMIX_JMP, R_MMIX_JMP},
786 {BFD_RELOC_MMIX_ADDR19, R_MMIX_ADDR19},
787 {BFD_RELOC_MMIX_ADDR27, R_MMIX_ADDR27},
788 {BFD_RELOC_MMIX_REG_OR_BYTE, R_MMIX_REG_OR_BYTE},
789 {BFD_RELOC_MMIX_REG, R_MMIX_REG},
790 {BFD_RELOC_MMIX_BASE_PLUS_OFFSET, R_MMIX_BASE_PLUS_OFFSET},
791 {BFD_RELOC_MMIX_LOCAL, R_MMIX_LOCAL},
792 {BFD_RELOC_MMIX_PUSHJ_STUBBABLE, R_MMIX_PUSHJ_STUBBABLE}
793 };
794
795 static reloc_howto_type *
bfd_elf64_bfd_reloc_type_lookup(bfd * abfd ATTRIBUTE_UNUSED,bfd_reloc_code_real_type code)796 bfd_elf64_bfd_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
797 bfd_reloc_code_real_type code)
798 {
799 unsigned int i;
800
801 for (i = 0;
802 i < sizeof (mmix_reloc_map) / sizeof (mmix_reloc_map[0]);
803 i++)
804 {
805 if (mmix_reloc_map[i].bfd_reloc_val == code)
806 return &elf_mmix_howto_table[mmix_reloc_map[i].elf_reloc_val];
807 }
808
809 return NULL;
810 }
811
812 static reloc_howto_type *
bfd_elf64_bfd_reloc_name_lookup(bfd * abfd ATTRIBUTE_UNUSED,const char * r_name)813 bfd_elf64_bfd_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
814 const char *r_name)
815 {
816 unsigned int i;
817
818 for (i = 0;
819 i < sizeof (elf_mmix_howto_table) / sizeof (elf_mmix_howto_table[0]);
820 i++)
821 if (elf_mmix_howto_table[i].name != NULL
822 && strcasecmp (elf_mmix_howto_table[i].name, r_name) == 0)
823 return &elf_mmix_howto_table[i];
824
825 return NULL;
826 }
827
828 static bool
mmix_elf_new_section_hook(bfd * abfd,asection * sec)829 mmix_elf_new_section_hook (bfd *abfd, asection *sec)
830 {
831 if (!sec->used_by_bfd)
832 {
833 struct _mmix_elf_section_data *sdata;
834 size_t amt = sizeof (*sdata);
835
836 sdata = bfd_zalloc (abfd, amt);
837 if (sdata == NULL)
838 return false;
839 sec->used_by_bfd = sdata;
840 }
841
842 return _bfd_elf_new_section_hook (abfd, sec);
843 }
844
845
846 /* This function performs the actual bitfiddling and sanity check for a
847 final relocation. Each relocation gets its *worst*-case expansion
848 in size when it arrives here; any reduction in size should have been
849 caught in linker relaxation earlier. When we get here, the relocation
850 looks like the smallest instruction with SWYM:s (nop:s) appended to the
851 max size. We fill in those nop:s.
852
853 R_MMIX_GETA: (FIXME: Relaxation should break this up in 1, 2, 3 tetra)
854 GETA $N,foo
855 ->
856 SETL $N,foo & 0xffff
857 INCML $N,(foo >> 16) & 0xffff
858 INCMH $N,(foo >> 32) & 0xffff
859 INCH $N,(foo >> 48) & 0xffff
860
861 R_MMIX_CBRANCH: (FIXME: Relaxation should break this up, but
862 condbranches needing relaxation might be rare enough to not be
863 worthwhile.)
864 [P]Bcc $N,foo
865 ->
866 [~P]B~cc $N,.+20
867 SETL $255,foo & ...
868 INCML ...
869 INCMH ...
870 INCH ...
871 GO $255,$255,0
872
873 R_MMIX_PUSHJ: (FIXME: Relaxation...)
874 PUSHJ $N,foo
875 ->
876 SETL $255,foo & ...
877 INCML ...
878 INCMH ...
879 INCH ...
880 PUSHGO $N,$255,0
881
882 R_MMIX_JMP: (FIXME: Relaxation...)
883 JMP foo
884 ->
885 SETL $255,foo & ...
886 INCML ...
887 INCMH ...
888 INCH ...
889 GO $255,$255,0
890
891 R_MMIX_ADDR19 and R_MMIX_ADDR27 are just filled in. */
892
893 static bfd_reloc_status_type
mmix_elf_perform_relocation(asection * isec,reloc_howto_type * howto,void * datap,bfd_vma addr,bfd_vma value,char ** error_message)894 mmix_elf_perform_relocation (asection *isec, reloc_howto_type *howto,
895 void *datap, bfd_vma addr, bfd_vma value,
896 char **error_message)
897 {
898 bfd *abfd = isec->owner;
899 bfd_reloc_status_type flag = bfd_reloc_ok;
900 bfd_reloc_status_type r;
901 int offs = 0;
902 int reg = 255;
903
904 /* The worst case bits are all similar SETL/INCML/INCMH/INCH sequences.
905 We handle the differences here and the common sequence later. */
906 switch (howto->type)
907 {
908 case R_MMIX_GETA:
909 offs = 0;
910 reg = bfd_get_8 (abfd, (bfd_byte *) datap + 1);
911
912 /* We change to an absolute value. */
913 value += addr;
914 break;
915
916 case R_MMIX_CBRANCH:
917 {
918 int in1 = bfd_get_16 (abfd, (bfd_byte *) datap) << 16;
919
920 /* Invert the condition and prediction bit, and set the offset
921 to five instructions ahead.
922
923 We *can* do better if we want to. If the branch is found to be
924 within limits, we could leave the branch as is; there'll just
925 be a bunch of NOP:s after it. But we shouldn't see this
926 sequence often enough that it's worth doing it. */
927
928 bfd_put_32 (abfd,
929 (((in1 ^ ((PRED_INV_BIT | COND_INV_BIT) << 24)) & ~0xffff)
930 | (24/4)),
931 (bfd_byte *) datap);
932
933 /* Put a "GO $255,$255,0" after the common sequence. */
934 bfd_put_32 (abfd,
935 ((GO_INSN_BYTE | IMM_OFFSET_BIT) << 24) | 0xffff00,
936 (bfd_byte *) datap + 20);
937
938 /* Common sequence starts at offset 4. */
939 offs = 4;
940
941 /* We change to an absolute value. */
942 value += addr;
943 }
944 break;
945
946 case R_MMIX_PUSHJ_STUBBABLE:
947 /* If the address fits, we're fine. */
948 if ((value & 3) == 0
949 /* Note rightshift 0; see R_MMIX_JMP case below. */
950 && (r = bfd_check_overflow (complain_overflow_signed,
951 howto->bitsize,
952 0,
953 bfd_arch_bits_per_address (abfd),
954 value)) == bfd_reloc_ok)
955 goto pcrel_mmix_reloc_fits;
956 else
957 {
958 bfd_size_type size = isec->rawsize ? isec->rawsize : isec->size;
959
960 /* We have the bytes at the PUSHJ insn and need to get the
961 position for the stub. There's supposed to be room allocated
962 for the stub. */
963 bfd_byte *stubcontents
964 = ((bfd_byte *) datap
965 - (addr - (isec->output_section->vma + isec->output_offset))
966 + size
967 + mmix_elf_section_data (isec)->pjs.stub_offset);
968 bfd_vma stubaddr;
969
970 if (mmix_elf_section_data (isec)->pjs.n_pushj_relocs == 0)
971 {
972 /* This shouldn't happen when linking to ELF or mmo, so
973 this is an attempt to link to "binary", right? We
974 can't access the output bfd, so we can't verify that
975 assumption. We only know that the critical
976 mmix_elf_check_common_relocs has not been called,
977 which happens when the output format is different
978 from the input format (and is not mmo). */
979 if (! mmix_elf_section_data (isec)->has_warned_pushj)
980 {
981 /* For the first such error per input section, produce
982 a verbose message. */
983 *error_message
984 = _("invalid input relocation when producing"
985 " non-ELF, non-mmo format output;"
986 " please use the objcopy program to convert from"
987 " ELF or mmo,"
988 " or assemble using"
989 " \"-no-expand\" (for gcc, \"-Wa,-no-expand\"");
990 mmix_elf_section_data (isec)->has_warned_pushj = true;
991 return bfd_reloc_dangerous;
992 }
993
994 /* For subsequent errors, return this one, which is
995 rate-limited but looks a little bit different,
996 hopefully without affecting user-friendliness. */
997 return bfd_reloc_overflow;
998 }
999
1000 /* The address doesn't fit, so redirect the PUSHJ to the
1001 location of the stub. */
1002 r = mmix_elf_perform_relocation (isec,
1003 &elf_mmix_howto_table
1004 [R_MMIX_ADDR19],
1005 datap,
1006 addr,
1007 isec->output_section->vma
1008 + isec->output_offset
1009 + size
1010 + (mmix_elf_section_data (isec)
1011 ->pjs.stub_offset)
1012 - addr,
1013 error_message);
1014 if (r != bfd_reloc_ok)
1015 return r;
1016
1017 stubaddr
1018 = (isec->output_section->vma
1019 + isec->output_offset
1020 + size
1021 + mmix_elf_section_data (isec)->pjs.stub_offset);
1022
1023 /* We generate a simple JMP if that suffices, else the whole 5
1024 insn stub. */
1025 if (bfd_check_overflow (complain_overflow_signed,
1026 elf_mmix_howto_table[R_MMIX_ADDR27].bitsize,
1027 0,
1028 bfd_arch_bits_per_address (abfd),
1029 addr + value - stubaddr) == bfd_reloc_ok)
1030 {
1031 bfd_put_32 (abfd, JMP_INSN_BYTE << 24, stubcontents);
1032 r = mmix_elf_perform_relocation (isec,
1033 &elf_mmix_howto_table
1034 [R_MMIX_ADDR27],
1035 stubcontents,
1036 stubaddr,
1037 value + addr - stubaddr,
1038 error_message);
1039 mmix_elf_section_data (isec)->pjs.stub_offset += 4;
1040
1041 if (size + mmix_elf_section_data (isec)->pjs.stub_offset
1042 > isec->size)
1043 abort ();
1044
1045 return r;
1046 }
1047 else
1048 {
1049 /* Put a "GO $255,0" after the common sequence. */
1050 bfd_put_32 (abfd,
1051 ((GO_INSN_BYTE | IMM_OFFSET_BIT) << 24)
1052 | 0xff00, (bfd_byte *) stubcontents + 16);
1053
1054 /* Prepare for the general code to set the first part of the
1055 linker stub, and */
1056 value += addr;
1057 datap = stubcontents;
1058 mmix_elf_section_data (isec)->pjs.stub_offset
1059 += MAX_PUSHJ_STUB_SIZE;
1060 }
1061 }
1062 break;
1063
1064 case R_MMIX_PUSHJ:
1065 {
1066 int inreg = bfd_get_8 (abfd, (bfd_byte *) datap + 1);
1067
1068 /* Put a "PUSHGO $N,$255,0" after the common sequence. */
1069 bfd_put_32 (abfd,
1070 ((PUSHGO_INSN_BYTE | IMM_OFFSET_BIT) << 24)
1071 | (inreg << 16)
1072 | 0xff00,
1073 (bfd_byte *) datap + 16);
1074
1075 /* We change to an absolute value. */
1076 value += addr;
1077 }
1078 break;
1079
1080 case R_MMIX_JMP:
1081 /* This one is a little special. If we get here on a non-relaxing
1082 link, and the destination is actually in range, we don't need to
1083 execute the nops.
1084 If so, we fall through to the bit-fiddling relocs.
1085
1086 FIXME: bfd_check_overflow seems broken; the relocation is
1087 rightshifted before testing, so supply a zero rightshift. */
1088
1089 if (! ((value & 3) == 0
1090 && (r = bfd_check_overflow (complain_overflow_signed,
1091 howto->bitsize,
1092 0,
1093 bfd_arch_bits_per_address (abfd),
1094 value)) == bfd_reloc_ok))
1095 {
1096 /* If the relocation doesn't fit in a JMP, we let the NOP:s be
1097 modified below, and put a "GO $255,$255,0" after the
1098 address-loading sequence. */
1099 bfd_put_32 (abfd,
1100 ((GO_INSN_BYTE | IMM_OFFSET_BIT) << 24)
1101 | 0xffff00,
1102 (bfd_byte *) datap + 16);
1103
1104 /* We change to an absolute value. */
1105 value += addr;
1106 break;
1107 }
1108 /* FALLTHROUGH. */
1109 case R_MMIX_ADDR19:
1110 case R_MMIX_ADDR27:
1111 pcrel_mmix_reloc_fits:
1112 /* These must be in range, or else we emit an error. */
1113 if ((value & 3) == 0
1114 /* Note rightshift 0; see above. */
1115 && (r = bfd_check_overflow (complain_overflow_signed,
1116 howto->bitsize,
1117 0,
1118 bfd_arch_bits_per_address (abfd),
1119 value)) == bfd_reloc_ok)
1120 {
1121 bfd_vma in1
1122 = bfd_get_32 (abfd, (bfd_byte *) datap);
1123 bfd_vma highbit;
1124
1125 if ((bfd_signed_vma) value < 0)
1126 {
1127 highbit = 1 << 24;
1128 value += (1 << (howto->bitsize - 1));
1129 }
1130 else
1131 highbit = 0;
1132
1133 value >>= 2;
1134
1135 bfd_put_32 (abfd,
1136 (in1 & howto->src_mask)
1137 | highbit
1138 | (value & howto->dst_mask),
1139 (bfd_byte *) datap);
1140
1141 return bfd_reloc_ok;
1142 }
1143 else
1144 return bfd_reloc_overflow;
1145
1146 case R_MMIX_BASE_PLUS_OFFSET:
1147 {
1148 struct bpo_reloc_section_info *bpodata
1149 = mmix_elf_section_data (isec)->bpo.reloc;
1150 asection *bpo_greg_section;
1151 struct bpo_greg_section_info *gregdata;
1152 size_t bpo_index;
1153
1154 if (bpodata == NULL)
1155 {
1156 /* This shouldn't happen when linking to ELF or mmo, so
1157 this is an attempt to link to "binary", right? We
1158 can't access the output bfd, so we can't verify that
1159 assumption. We only know that the critical
1160 mmix_elf_check_common_relocs has not been called, which
1161 happens when the output format is different from the
1162 input format (and is not mmo). */
1163 if (! mmix_elf_section_data (isec)->has_warned_bpo)
1164 {
1165 /* For the first such error per input section, produce
1166 a verbose message. */
1167 *error_message
1168 = _("invalid input relocation when producing"
1169 " non-ELF, non-mmo format output;"
1170 " please use the objcopy program to convert from"
1171 " ELF or mmo,"
1172 " or compile using the gcc-option"
1173 " \"-mno-base-addresses\".");
1174 mmix_elf_section_data (isec)->has_warned_bpo = true;
1175 return bfd_reloc_dangerous;
1176 }
1177
1178 /* For subsequent errors, return this one, which is
1179 rate-limited but looks a little bit different,
1180 hopefully without affecting user-friendliness. */
1181 return bfd_reloc_overflow;
1182 }
1183
1184 bpo_greg_section = bpodata->bpo_greg_section;
1185 gregdata = mmix_elf_section_data (bpo_greg_section)->bpo.greg;
1186 bpo_index = gregdata->bpo_reloc_indexes[bpodata->bpo_index++];
1187
1188 /* A consistency check: The value we now have in "relocation" must
1189 be the same as the value we stored for that relocation. It
1190 doesn't cost much, so can be left in at all times. */
1191 if (value != gregdata->reloc_request[bpo_index].value)
1192 {
1193 _bfd_error_handler
1194 /* xgettext:c-format */
1195 (_("%pB: Internal inconsistency error for value for\n\
1196 linker-allocated global register: linked: %#" PRIx64 " != relaxed: %#" PRIx64 ""),
1197 isec->owner,
1198 (uint64_t) value,
1199 (uint64_t) gregdata->reloc_request[bpo_index].value);
1200 bfd_set_error (bfd_error_bad_value);
1201 return bfd_reloc_overflow;
1202 }
1203
1204 /* Then store the register number and offset for that register
1205 into datap and datap + 1 respectively. */
1206 bfd_put_8 (abfd,
1207 gregdata->reloc_request[bpo_index].regindex
1208 + bpo_greg_section->output_section->vma / 8,
1209 datap);
1210 bfd_put_8 (abfd,
1211 gregdata->reloc_request[bpo_index].offset,
1212 ((unsigned char *) datap) + 1);
1213 return bfd_reloc_ok;
1214 }
1215
1216 case R_MMIX_REG_OR_BYTE:
1217 case R_MMIX_REG:
1218 if (value > 255)
1219 return bfd_reloc_overflow;
1220 bfd_put_8 (abfd, value, datap);
1221 return bfd_reloc_ok;
1222
1223 default:
1224 BAD_CASE (howto->type);
1225 }
1226
1227 /* This code adds the common SETL/INCML/INCMH/INCH worst-case
1228 sequence. */
1229
1230 /* Lowest two bits must be 0. We return bfd_reloc_overflow for
1231 everything that looks strange. */
1232 if (value & 3)
1233 flag = bfd_reloc_overflow;
1234
1235 bfd_put_32 (abfd,
1236 (SETL_INSN_BYTE << 24) | (value & 0xffff) | (reg << 16),
1237 (bfd_byte *) datap + offs);
1238 bfd_put_32 (abfd,
1239 (INCML_INSN_BYTE << 24) | ((value >> 16) & 0xffff) | (reg << 16),
1240 (bfd_byte *) datap + offs + 4);
1241 bfd_put_32 (abfd,
1242 (INCMH_INSN_BYTE << 24) | ((value >> 32) & 0xffff) | (reg << 16),
1243 (bfd_byte *) datap + offs + 8);
1244 bfd_put_32 (abfd,
1245 (INCH_INSN_BYTE << 24) | ((value >> 48) & 0xffff) | (reg << 16),
1246 (bfd_byte *) datap + offs + 12);
1247
1248 return flag;
1249 }
1250
1251 /* Set the howto pointer for an MMIX ELF reloc (type RELA). */
1252
1253 static bool
mmix_info_to_howto_rela(bfd * abfd,arelent * cache_ptr,Elf_Internal_Rela * dst)1254 mmix_info_to_howto_rela (bfd *abfd,
1255 arelent *cache_ptr,
1256 Elf_Internal_Rela *dst)
1257 {
1258 unsigned int r_type;
1259
1260 r_type = ELF64_R_TYPE (dst->r_info);
1261 if (r_type >= (unsigned int) R_MMIX_max)
1262 {
1263 /* xgettext:c-format */
1264 _bfd_error_handler (_("%pB: unsupported relocation type %#x"),
1265 abfd, r_type);
1266 bfd_set_error (bfd_error_bad_value);
1267 return false;
1268 }
1269 cache_ptr->howto = &elf_mmix_howto_table[r_type];
1270 return true;
1271 }
1272
1273 /* Any MMIX-specific relocation gets here at assembly time or when linking
1274 to other formats (such as mmo); this is the relocation function from
1275 the reloc_table. We don't get here for final pure ELF linking. */
1276
1277 static bfd_reloc_status_type
mmix_elf_reloc(bfd * abfd,arelent * reloc_entry,asymbol * symbol,void * data,asection * input_section,bfd * output_bfd,char ** error_message)1278 mmix_elf_reloc (bfd *abfd,
1279 arelent *reloc_entry,
1280 asymbol *symbol,
1281 void * data,
1282 asection *input_section,
1283 bfd *output_bfd,
1284 char **error_message)
1285 {
1286 bfd_vma relocation;
1287 bfd_reloc_status_type r;
1288 asection *reloc_target_output_section;
1289 bfd_reloc_status_type flag = bfd_reloc_ok;
1290 bfd_vma output_base = 0;
1291
1292 r = bfd_elf_generic_reloc (abfd, reloc_entry, symbol, data,
1293 input_section, output_bfd, error_message);
1294
1295 /* If that was all that was needed (i.e. this isn't a final link, only
1296 some segment adjustments), we're done. */
1297 if (r != bfd_reloc_continue)
1298 return r;
1299
1300 if (bfd_is_und_section (symbol->section)
1301 && (symbol->flags & BSF_WEAK) == 0
1302 && output_bfd == (bfd *) NULL)
1303 return bfd_reloc_undefined;
1304
1305 /* Is the address of the relocation really within the section? */
1306 if (reloc_entry->address > bfd_get_section_limit (abfd, input_section))
1307 return bfd_reloc_outofrange;
1308
1309 /* Work out which section the relocation is targeted at and the
1310 initial relocation command value. */
1311
1312 /* Get symbol value. (Common symbols are special.) */
1313 if (bfd_is_com_section (symbol->section))
1314 relocation = 0;
1315 else
1316 relocation = symbol->value;
1317
1318 reloc_target_output_section = bfd_asymbol_section (symbol)->output_section;
1319
1320 /* Here the variable relocation holds the final address of the symbol we
1321 are relocating against, plus any addend. */
1322 if (output_bfd)
1323 output_base = 0;
1324 else
1325 output_base = reloc_target_output_section->vma;
1326
1327 relocation += output_base + symbol->section->output_offset;
1328
1329 if (output_bfd != (bfd *) NULL)
1330 {
1331 /* Add in supplied addend. */
1332 relocation += reloc_entry->addend;
1333
1334 /* This is a partial relocation, and we want to apply the
1335 relocation to the reloc entry rather than the raw data.
1336 Modify the reloc inplace to reflect what we now know. */
1337 reloc_entry->addend = relocation;
1338 reloc_entry->address += input_section->output_offset;
1339 return flag;
1340 }
1341
1342 return mmix_final_link_relocate (reloc_entry->howto, input_section,
1343 data, reloc_entry->address,
1344 reloc_entry->addend, relocation,
1345 bfd_asymbol_name (symbol),
1346 reloc_target_output_section,
1347 error_message);
1348 }
1349
1350 /* Relocate an MMIX ELF section. Modified from elf32-fr30.c; look to it
1351 for guidance if you're thinking of copying this. */
1352
1353 static int
mmix_elf_relocate_section(bfd * output_bfd ATTRIBUTE_UNUSED,struct bfd_link_info * info,bfd * input_bfd,asection * input_section,bfd_byte * contents,Elf_Internal_Rela * relocs,Elf_Internal_Sym * local_syms,asection ** local_sections)1354 mmix_elf_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED,
1355 struct bfd_link_info *info,
1356 bfd *input_bfd,
1357 asection *input_section,
1358 bfd_byte *contents,
1359 Elf_Internal_Rela *relocs,
1360 Elf_Internal_Sym *local_syms,
1361 asection **local_sections)
1362 {
1363 Elf_Internal_Shdr *symtab_hdr;
1364 struct elf_link_hash_entry **sym_hashes;
1365 Elf_Internal_Rela *rel;
1366 Elf_Internal_Rela *relend;
1367 bfd_size_type size;
1368 size_t pjsno = 0;
1369
1370 size = input_section->rawsize ? input_section->rawsize : input_section->size;
1371 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
1372 sym_hashes = elf_sym_hashes (input_bfd);
1373 relend = relocs + input_section->reloc_count;
1374
1375 /* Zero the stub area before we start. */
1376 if (input_section->rawsize != 0
1377 && input_section->size > input_section->rawsize)
1378 memset (contents + input_section->rawsize, 0,
1379 input_section->size - input_section->rawsize);
1380
1381 for (rel = relocs; rel < relend; rel ++)
1382 {
1383 reloc_howto_type *howto;
1384 unsigned long r_symndx;
1385 Elf_Internal_Sym *sym;
1386 asection *sec;
1387 struct elf_link_hash_entry *h;
1388 bfd_vma relocation;
1389 bfd_reloc_status_type r;
1390 const char *name = NULL;
1391 int r_type;
1392 bool undefined_signalled = false;
1393
1394 r_type = ELF64_R_TYPE (rel->r_info);
1395
1396 if (r_type == R_MMIX_GNU_VTINHERIT
1397 || r_type == R_MMIX_GNU_VTENTRY)
1398 continue;
1399
1400 r_symndx = ELF64_R_SYM (rel->r_info);
1401
1402 howto = elf_mmix_howto_table + ELF64_R_TYPE (rel->r_info);
1403 h = NULL;
1404 sym = NULL;
1405 sec = NULL;
1406
1407 if (r_symndx < symtab_hdr->sh_info)
1408 {
1409 sym = local_syms + r_symndx;
1410 sec = local_sections [r_symndx];
1411 relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
1412
1413 name = bfd_elf_string_from_elf_section (input_bfd,
1414 symtab_hdr->sh_link,
1415 sym->st_name);
1416 if (name == NULL)
1417 name = bfd_section_name (sec);
1418 }
1419 else
1420 {
1421 bool unresolved_reloc, ignored;
1422
1423 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
1424 r_symndx, symtab_hdr, sym_hashes,
1425 h, sec, relocation,
1426 unresolved_reloc, undefined_signalled,
1427 ignored);
1428 name = h->root.root.string;
1429 }
1430
1431 if (sec != NULL && discarded_section (sec))
1432 RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
1433 rel, 1, relend, howto, 0, contents);
1434
1435 if (bfd_link_relocatable (info))
1436 {
1437 /* This is a relocatable link. For most relocs we don't have to
1438 change anything, unless the reloc is against a section
1439 symbol, in which case we have to adjust according to where
1440 the section symbol winds up in the output section. */
1441 if (sym != NULL && ELF_ST_TYPE (sym->st_info) == STT_SECTION)
1442 rel->r_addend += sec->output_offset;
1443
1444 /* For PUSHJ stub relocs however, we may need to change the
1445 reloc and the section contents, if the reloc doesn't reach
1446 beyond the end of the output section and previous stubs.
1447 Then we change the section contents to be a PUSHJ to the end
1448 of the input section plus stubs (we can do that without using
1449 a reloc), and then we change the reloc to be a R_MMIX_PUSHJ
1450 at the stub location. */
1451 if (r_type == R_MMIX_PUSHJ_STUBBABLE)
1452 {
1453 /* We've already checked whether we need a stub; use that
1454 knowledge. */
1455 if (mmix_elf_section_data (input_section)->pjs.stub_size[pjsno]
1456 != 0)
1457 {
1458 Elf_Internal_Rela relcpy;
1459
1460 if (mmix_elf_section_data (input_section)
1461 ->pjs.stub_size[pjsno] != MAX_PUSHJ_STUB_SIZE)
1462 abort ();
1463
1464 /* There's already a PUSHJ insn there, so just fill in
1465 the offset bits to the stub. */
1466 if (mmix_final_link_relocate (elf_mmix_howto_table
1467 + R_MMIX_ADDR19,
1468 input_section,
1469 contents,
1470 rel->r_offset,
1471 0,
1472 input_section
1473 ->output_section->vma
1474 + input_section->output_offset
1475 + size
1476 + mmix_elf_section_data (input_section)
1477 ->pjs.stub_offset,
1478 NULL, NULL, NULL) != bfd_reloc_ok)
1479 return false;
1480
1481 /* Put a JMP insn at the stub; it goes with the
1482 R_MMIX_JMP reloc. */
1483 bfd_put_32 (output_bfd, JMP_INSN_BYTE << 24,
1484 contents
1485 + size
1486 + mmix_elf_section_data (input_section)
1487 ->pjs.stub_offset);
1488
1489 /* Change the reloc to be at the stub, and to a full
1490 R_MMIX_JMP reloc. */
1491 rel->r_info = ELF64_R_INFO (r_symndx, R_MMIX_JMP);
1492 rel->r_offset
1493 = (size
1494 + mmix_elf_section_data (input_section)
1495 ->pjs.stub_offset);
1496
1497 mmix_elf_section_data (input_section)->pjs.stub_offset
1498 += MAX_PUSHJ_STUB_SIZE;
1499
1500 /* Shift this reloc to the end of the relocs to maintain
1501 the r_offset sorted reloc order. */
1502 relcpy = *rel;
1503 memmove (rel, rel + 1, (char *) relend - (char *) rel);
1504 relend[-1] = relcpy;
1505
1506 /* Back up one reloc, or else we'd skip the next reloc
1507 in turn. */
1508 rel--;
1509 }
1510
1511 pjsno++;
1512 }
1513 continue;
1514 }
1515
1516 r = mmix_final_link_relocate (howto, input_section,
1517 contents, rel->r_offset,
1518 rel->r_addend, relocation, name, sec, NULL);
1519
1520 if (r != bfd_reloc_ok)
1521 {
1522 const char * msg = (const char *) NULL;
1523
1524 switch (r)
1525 {
1526 case bfd_reloc_overflow:
1527 info->callbacks->reloc_overflow
1528 (info, (h ? &h->root : NULL), name, howto->name,
1529 (bfd_vma) 0, input_bfd, input_section, rel->r_offset);
1530 break;
1531
1532 case bfd_reloc_undefined:
1533 /* We may have sent this message above. */
1534 if (! undefined_signalled)
1535 info->callbacks->undefined_symbol
1536 (info, name, input_bfd, input_section, rel->r_offset, true);
1537 undefined_signalled = true;
1538 break;
1539
1540 case bfd_reloc_outofrange:
1541 msg = _("internal error: out of range error");
1542 break;
1543
1544 case bfd_reloc_notsupported:
1545 msg = _("internal error: unsupported relocation error");
1546 break;
1547
1548 case bfd_reloc_dangerous:
1549 msg = _("internal error: dangerous relocation");
1550 break;
1551
1552 default:
1553 msg = _("internal error: unknown error");
1554 break;
1555 }
1556
1557 if (msg)
1558 (*info->callbacks->warning) (info, msg, name, input_bfd,
1559 input_section, rel->r_offset);
1560 }
1561 }
1562
1563 return true;
1564 }
1565
1566 /* Perform a single relocation. By default we use the standard BFD
1567 routines. A few relocs we have to do ourselves. */
1568
1569 static bfd_reloc_status_type
mmix_final_link_relocate(reloc_howto_type * howto,asection * input_section,bfd_byte * contents,bfd_vma r_offset,bfd_signed_vma r_addend,bfd_vma relocation,const char * symname,asection * symsec,char ** error_message)1570 mmix_final_link_relocate (reloc_howto_type *howto, asection *input_section,
1571 bfd_byte *contents, bfd_vma r_offset,
1572 bfd_signed_vma r_addend, bfd_vma relocation,
1573 const char *symname, asection *symsec,
1574 char **error_message)
1575 {
1576 bfd_reloc_status_type r = bfd_reloc_ok;
1577 bfd_vma addr
1578 = (input_section->output_section->vma
1579 + input_section->output_offset
1580 + r_offset);
1581 bfd_signed_vma srel
1582 = (bfd_signed_vma) relocation + r_addend;
1583
1584 switch (howto->type)
1585 {
1586 /* All these are PC-relative. */
1587 case R_MMIX_PUSHJ_STUBBABLE:
1588 case R_MMIX_PUSHJ:
1589 case R_MMIX_CBRANCH:
1590 case R_MMIX_ADDR19:
1591 case R_MMIX_GETA:
1592 case R_MMIX_ADDR27:
1593 case R_MMIX_JMP:
1594 contents += r_offset;
1595
1596 srel -= (input_section->output_section->vma
1597 + input_section->output_offset
1598 + r_offset);
1599
1600 r = mmix_elf_perform_relocation (input_section, howto, contents,
1601 addr, srel, error_message);
1602 break;
1603
1604 case R_MMIX_BASE_PLUS_OFFSET:
1605 if (symsec == NULL)
1606 return bfd_reloc_undefined;
1607
1608 /* Check that we're not relocating against a register symbol. */
1609 if (strcmp (bfd_section_name (symsec),
1610 MMIX_REG_CONTENTS_SECTION_NAME) == 0
1611 || strcmp (bfd_section_name (symsec),
1612 MMIX_REG_SECTION_NAME) == 0)
1613 {
1614 /* Note: This is separated out into two messages in order
1615 to ease the translation into other languages. */
1616 if (symname == NULL || *symname == 0)
1617 _bfd_error_handler
1618 /* xgettext:c-format */
1619 (_("%pB: base-plus-offset relocation against register symbol:"
1620 " (unknown) in %pA"),
1621 input_section->owner, symsec);
1622 else
1623 _bfd_error_handler
1624 /* xgettext:c-format */
1625 (_("%pB: base-plus-offset relocation against register symbol:"
1626 " %s in %pA"),
1627 input_section->owner, symname, symsec);
1628 return bfd_reloc_overflow;
1629 }
1630 goto do_mmix_reloc;
1631
1632 case R_MMIX_REG_OR_BYTE:
1633 case R_MMIX_REG:
1634 /* For now, we handle these alike. They must refer to an register
1635 symbol, which is either relative to the register section and in
1636 the range 0..255, or is in the register contents section with vma
1637 regno * 8. */
1638
1639 /* FIXME: A better way to check for reg contents section?
1640 FIXME: Postpone section->scaling to mmix_elf_perform_relocation? */
1641 if (symsec == NULL)
1642 return bfd_reloc_undefined;
1643
1644 if (strcmp (bfd_section_name (symsec),
1645 MMIX_REG_CONTENTS_SECTION_NAME) == 0)
1646 {
1647 if ((srel & 7) != 0 || srel < 32*8 || srel > 255*8)
1648 {
1649 /* The bfd_reloc_outofrange return value, though intuitively
1650 a better value, will not get us an error. */
1651 return bfd_reloc_overflow;
1652 }
1653 srel /= 8;
1654 }
1655 else if (strcmp (bfd_section_name (symsec),
1656 MMIX_REG_SECTION_NAME) == 0)
1657 {
1658 if (srel < 0 || srel > 255)
1659 /* The bfd_reloc_outofrange return value, though intuitively a
1660 better value, will not get us an error. */
1661 return bfd_reloc_overflow;
1662 }
1663 else
1664 {
1665 /* Note: This is separated out into two messages in order
1666 to ease the translation into other languages. */
1667 if (symname == NULL || *symname == 0)
1668 _bfd_error_handler
1669 /* xgettext:c-format */
1670 (_("%pB: register relocation against non-register symbol:"
1671 " (unknown) in %pA"),
1672 input_section->owner, symsec);
1673 else
1674 _bfd_error_handler
1675 /* xgettext:c-format */
1676 (_("%pB: register relocation against non-register symbol:"
1677 " %s in %pA"),
1678 input_section->owner, symname, symsec);
1679
1680 /* The bfd_reloc_outofrange return value, though intuitively a
1681 better value, will not get us an error. */
1682 return bfd_reloc_overflow;
1683 }
1684 do_mmix_reloc:
1685 contents += r_offset;
1686 r = mmix_elf_perform_relocation (input_section, howto, contents,
1687 addr, srel, error_message);
1688 break;
1689
1690 case R_MMIX_LOCAL:
1691 /* This isn't a real relocation, it's just an assertion that the
1692 final relocation value corresponds to a local register. We
1693 ignore the actual relocation; nothing is changed. */
1694 {
1695 asection *regsec
1696 = bfd_get_section_by_name (input_section->output_section->owner,
1697 MMIX_REG_CONTENTS_SECTION_NAME);
1698 bfd_vma first_global;
1699
1700 /* Check that this is an absolute value, or a reference to the
1701 register contents section or the register (symbol) section.
1702 Absolute numbers can get here as undefined section. Undefined
1703 symbols are signalled elsewhere, so there's no conflict in us
1704 accidentally handling it. */
1705 if (!bfd_is_abs_section (symsec)
1706 && !bfd_is_und_section (symsec)
1707 && strcmp (bfd_section_name (symsec),
1708 MMIX_REG_CONTENTS_SECTION_NAME) != 0
1709 && strcmp (bfd_section_name (symsec),
1710 MMIX_REG_SECTION_NAME) != 0)
1711 {
1712 _bfd_error_handler
1713 (_("%pB: directive LOCAL valid only with a register or absolute value"),
1714 input_section->owner);
1715
1716 return bfd_reloc_overflow;
1717 }
1718
1719 /* If we don't have a register contents section, then $255 is the
1720 first global register. */
1721 if (regsec == NULL)
1722 first_global = 255;
1723 else
1724 {
1725 first_global = bfd_section_vma (regsec) / 8;
1726 if (strcmp (bfd_section_name (symsec),
1727 MMIX_REG_CONTENTS_SECTION_NAME) == 0)
1728 {
1729 if ((srel & 7) != 0 || srel < 32*8 || srel > 255*8)
1730 /* The bfd_reloc_outofrange return value, though
1731 intuitively a better value, will not get us an error. */
1732 return bfd_reloc_overflow;
1733 srel /= 8;
1734 }
1735 }
1736
1737 if ((bfd_vma) srel >= first_global)
1738 {
1739 /* FIXME: Better error message. */
1740 _bfd_error_handler
1741 /* xgettext:c-format */
1742 (_("%pB: LOCAL directive: "
1743 "register $%" PRId64 " is not a local register;"
1744 " first global register is $%" PRId64),
1745 input_section->owner, (int64_t) srel, (int64_t) first_global);
1746
1747 return bfd_reloc_overflow;
1748 }
1749 }
1750 r = bfd_reloc_ok;
1751 break;
1752
1753 default:
1754 r = _bfd_final_link_relocate (howto, input_section->owner, input_section,
1755 contents, r_offset,
1756 relocation, r_addend);
1757 }
1758
1759 return r;
1760 }
1761
1762 /* Return the section that should be marked against GC for a given
1763 relocation. */
1764
1765 static asection *
mmix_elf_gc_mark_hook(asection * sec,struct bfd_link_info * info,Elf_Internal_Rela * rel,struct elf_link_hash_entry * h,Elf_Internal_Sym * sym)1766 mmix_elf_gc_mark_hook (asection *sec,
1767 struct bfd_link_info *info,
1768 Elf_Internal_Rela *rel,
1769 struct elf_link_hash_entry *h,
1770 Elf_Internal_Sym *sym)
1771 {
1772 if (h != NULL)
1773 switch (ELF64_R_TYPE (rel->r_info))
1774 {
1775 case R_MMIX_GNU_VTINHERIT:
1776 case R_MMIX_GNU_VTENTRY:
1777 return NULL;
1778 }
1779
1780 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
1781 }
1782
1783 /* Sort register relocs to come before expanding relocs. */
1784
1785 static int
mmix_elf_sort_relocs(const void * p1,const void * p2)1786 mmix_elf_sort_relocs (const void * p1, const void * p2)
1787 {
1788 const Elf_Internal_Rela *r1 = (const Elf_Internal_Rela *) p1;
1789 const Elf_Internal_Rela *r2 = (const Elf_Internal_Rela *) p2;
1790 int r1_is_reg, r2_is_reg;
1791
1792 /* Sort primarily on r_offset & ~3, so relocs are done to consecutive
1793 insns. */
1794 if ((r1->r_offset & ~(bfd_vma) 3) > (r2->r_offset & ~(bfd_vma) 3))
1795 return 1;
1796 else if ((r1->r_offset & ~(bfd_vma) 3) < (r2->r_offset & ~(bfd_vma) 3))
1797 return -1;
1798
1799 r1_is_reg
1800 = (ELF64_R_TYPE (r1->r_info) == R_MMIX_REG_OR_BYTE
1801 || ELF64_R_TYPE (r1->r_info) == R_MMIX_REG);
1802 r2_is_reg
1803 = (ELF64_R_TYPE (r2->r_info) == R_MMIX_REG_OR_BYTE
1804 || ELF64_R_TYPE (r2->r_info) == R_MMIX_REG);
1805 if (r1_is_reg != r2_is_reg)
1806 return r2_is_reg - r1_is_reg;
1807
1808 /* Neither or both are register relocs. Then sort on full offset. */
1809 if (r1->r_offset > r2->r_offset)
1810 return 1;
1811 else if (r1->r_offset < r2->r_offset)
1812 return -1;
1813 return 0;
1814 }
1815
1816 /* Subset of mmix_elf_check_relocs, common to ELF and mmo linking. */
1817
1818 static bool
mmix_elf_check_common_relocs(bfd * abfd,struct bfd_link_info * info,asection * sec,const Elf_Internal_Rela * relocs)1819 mmix_elf_check_common_relocs (bfd *abfd,
1820 struct bfd_link_info *info,
1821 asection *sec,
1822 const Elf_Internal_Rela *relocs)
1823 {
1824 bfd *bpo_greg_owner = NULL;
1825 asection *allocated_gregs_section = NULL;
1826 struct bpo_greg_section_info *gregdata = NULL;
1827 struct bpo_reloc_section_info *bpodata = NULL;
1828 const Elf_Internal_Rela *rel;
1829 const Elf_Internal_Rela *rel_end;
1830
1831 /* We currently have to abuse this COFF-specific member, since there's
1832 no target-machine-dedicated member. There's no alternative outside
1833 the bfd_link_info struct; we can't specialize a hash-table since
1834 they're different between ELF and mmo. */
1835 bpo_greg_owner = (bfd *) info->base_file;
1836
1837 rel_end = relocs + sec->reloc_count;
1838 for (rel = relocs; rel < rel_end; rel++)
1839 {
1840 switch (ELF64_R_TYPE (rel->r_info))
1841 {
1842 /* This relocation causes a GREG allocation. We need to count
1843 them, and we need to create a section for them, so we need an
1844 object to fake as the owner of that section. We can't use
1845 the ELF dynobj for this, since the ELF bits assume lots of
1846 DSO-related stuff if that member is non-NULL. */
1847 case R_MMIX_BASE_PLUS_OFFSET:
1848 /* We don't do anything with this reloc for a relocatable link. */
1849 if (bfd_link_relocatable (info))
1850 break;
1851
1852 if (bpo_greg_owner == NULL)
1853 {
1854 bpo_greg_owner = abfd;
1855 info->base_file = bpo_greg_owner;
1856 }
1857
1858 if (allocated_gregs_section == NULL)
1859 allocated_gregs_section
1860 = bfd_get_section_by_name (bpo_greg_owner,
1861 MMIX_LD_ALLOCATED_REG_CONTENTS_SECTION_NAME);
1862
1863 if (allocated_gregs_section == NULL)
1864 {
1865 allocated_gregs_section
1866 = bfd_make_section_with_flags (bpo_greg_owner,
1867 MMIX_LD_ALLOCATED_REG_CONTENTS_SECTION_NAME,
1868 (SEC_HAS_CONTENTS
1869 | SEC_IN_MEMORY
1870 | SEC_LINKER_CREATED));
1871 /* Setting both SEC_ALLOC and SEC_LOAD means the section is
1872 treated like any other section, and we'd get errors for
1873 address overlap with the text section. Let's set none of
1874 those flags, as that is what currently happens for usual
1875 GREG allocations, and that works. */
1876 if (allocated_gregs_section == NULL
1877 || !bfd_set_section_alignment (allocated_gregs_section, 3))
1878 return false;
1879
1880 gregdata = (struct bpo_greg_section_info *)
1881 bfd_zalloc (bpo_greg_owner, sizeof (struct bpo_greg_section_info));
1882 if (gregdata == NULL)
1883 return false;
1884 mmix_elf_section_data (allocated_gregs_section)->bpo.greg
1885 = gregdata;
1886 }
1887 else if (gregdata == NULL)
1888 gregdata
1889 = mmix_elf_section_data (allocated_gregs_section)->bpo.greg;
1890
1891 /* Get ourselves some auxiliary info for the BPO-relocs. */
1892 if (bpodata == NULL)
1893 {
1894 /* No use doing a separate iteration pass to find the upper
1895 limit - just use the number of relocs. */
1896 bpodata = (struct bpo_reloc_section_info *)
1897 bfd_alloc (bpo_greg_owner,
1898 sizeof (struct bpo_reloc_section_info)
1899 * (sec->reloc_count + 1));
1900 if (bpodata == NULL)
1901 return false;
1902 mmix_elf_section_data (sec)->bpo.reloc = bpodata;
1903 bpodata->first_base_plus_offset_reloc
1904 = bpodata->bpo_index
1905 = gregdata->n_max_bpo_relocs;
1906 bpodata->bpo_greg_section
1907 = allocated_gregs_section;
1908 bpodata->n_bpo_relocs_this_section = 0;
1909 }
1910
1911 bpodata->n_bpo_relocs_this_section++;
1912 gregdata->n_max_bpo_relocs++;
1913
1914 /* We don't get another chance to set this before GC; we've not
1915 set up any hook that runs before GC. */
1916 gregdata->n_bpo_relocs
1917 = gregdata->n_max_bpo_relocs;
1918 break;
1919
1920 case R_MMIX_PUSHJ_STUBBABLE:
1921 mmix_elf_section_data (sec)->pjs.n_pushj_relocs++;
1922 break;
1923 }
1924 }
1925
1926 /* Allocate per-reloc stub storage and initialize it to the max stub
1927 size. */
1928 if (mmix_elf_section_data (sec)->pjs.n_pushj_relocs != 0)
1929 {
1930 size_t i;
1931
1932 mmix_elf_section_data (sec)->pjs.stub_size
1933 = bfd_alloc (abfd, mmix_elf_section_data (sec)->pjs.n_pushj_relocs
1934 * sizeof (mmix_elf_section_data (sec)
1935 ->pjs.stub_size[0]));
1936 if (mmix_elf_section_data (sec)->pjs.stub_size == NULL)
1937 return false;
1938
1939 for (i = 0; i < mmix_elf_section_data (sec)->pjs.n_pushj_relocs; i++)
1940 mmix_elf_section_data (sec)->pjs.stub_size[i] = MAX_PUSHJ_STUB_SIZE;
1941 }
1942
1943 return true;
1944 }
1945
1946 /* Look through the relocs for a section during the first phase. */
1947
1948 static bool
mmix_elf_check_relocs(bfd * abfd,struct bfd_link_info * info,asection * sec,const Elf_Internal_Rela * relocs)1949 mmix_elf_check_relocs (bfd *abfd,
1950 struct bfd_link_info *info,
1951 asection *sec,
1952 const Elf_Internal_Rela *relocs)
1953 {
1954 Elf_Internal_Shdr *symtab_hdr;
1955 struct elf_link_hash_entry **sym_hashes;
1956 const Elf_Internal_Rela *rel;
1957 const Elf_Internal_Rela *rel_end;
1958
1959 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1960 sym_hashes = elf_sym_hashes (abfd);
1961
1962 /* First we sort the relocs so that any register relocs come before
1963 expansion-relocs to the same insn. FIXME: Not done for mmo. */
1964 qsort ((void *) relocs, sec->reloc_count, sizeof (Elf_Internal_Rela),
1965 mmix_elf_sort_relocs);
1966
1967 /* Do the common part. */
1968 if (!mmix_elf_check_common_relocs (abfd, info, sec, relocs))
1969 return false;
1970
1971 if (bfd_link_relocatable (info))
1972 return true;
1973
1974 rel_end = relocs + sec->reloc_count;
1975 for (rel = relocs; rel < rel_end; rel++)
1976 {
1977 struct elf_link_hash_entry *h;
1978 unsigned long r_symndx;
1979
1980 r_symndx = ELF64_R_SYM (rel->r_info);
1981 if (r_symndx < symtab_hdr->sh_info)
1982 h = NULL;
1983 else
1984 {
1985 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
1986 while (h->root.type == bfd_link_hash_indirect
1987 || h->root.type == bfd_link_hash_warning)
1988 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1989 }
1990
1991 switch (ELF64_R_TYPE (rel->r_info))
1992 {
1993 /* This relocation describes the C++ object vtable hierarchy.
1994 Reconstruct it for later use during GC. */
1995 case R_MMIX_GNU_VTINHERIT:
1996 if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
1997 return false;
1998 break;
1999
2000 /* This relocation describes which C++ vtable entries are actually
2001 used. Record for later use during GC. */
2002 case R_MMIX_GNU_VTENTRY:
2003 if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))
2004 return false;
2005 break;
2006 }
2007 }
2008
2009 return true;
2010 }
2011
2012 /* Wrapper for mmix_elf_check_common_relocs, called when linking to mmo.
2013 Copied from elf_link_add_object_symbols. */
2014
2015 bool
_bfd_mmix_check_all_relocs(bfd * abfd,struct bfd_link_info * info)2016 _bfd_mmix_check_all_relocs (bfd *abfd, struct bfd_link_info *info)
2017 {
2018 asection *o;
2019
2020 for (o = abfd->sections; o != NULL; o = o->next)
2021 {
2022 Elf_Internal_Rela *internal_relocs;
2023 bool ok;
2024
2025 if ((o->flags & SEC_RELOC) == 0
2026 || o->reloc_count == 0
2027 || ((info->strip == strip_all || info->strip == strip_debugger)
2028 && (o->flags & SEC_DEBUGGING) != 0)
2029 || bfd_is_abs_section (o->output_section))
2030 continue;
2031
2032 internal_relocs
2033 = _bfd_elf_link_read_relocs (abfd, o, NULL,
2034 (Elf_Internal_Rela *) NULL,
2035 info->keep_memory);
2036 if (internal_relocs == NULL)
2037 return false;
2038
2039 ok = mmix_elf_check_common_relocs (abfd, info, o, internal_relocs);
2040
2041 if (! info->keep_memory)
2042 free (internal_relocs);
2043
2044 if (! ok)
2045 return false;
2046 }
2047
2048 return true;
2049 }
2050
2051 /* Change symbols relative to the reg contents section to instead be to
2052 the register section, and scale them down to correspond to the register
2053 number. */
2054
2055 static int
mmix_elf_link_output_symbol_hook(struct bfd_link_info * info ATTRIBUTE_UNUSED,const char * name ATTRIBUTE_UNUSED,Elf_Internal_Sym * sym,asection * input_sec,struct elf_link_hash_entry * h ATTRIBUTE_UNUSED)2056 mmix_elf_link_output_symbol_hook (struct bfd_link_info *info ATTRIBUTE_UNUSED,
2057 const char *name ATTRIBUTE_UNUSED,
2058 Elf_Internal_Sym *sym,
2059 asection *input_sec,
2060 struct elf_link_hash_entry *h ATTRIBUTE_UNUSED)
2061 {
2062 if (input_sec != NULL
2063 && input_sec->name != NULL
2064 && ELF_ST_TYPE (sym->st_info) != STT_SECTION
2065 && strcmp (input_sec->name, MMIX_REG_CONTENTS_SECTION_NAME) == 0)
2066 {
2067 sym->st_value /= 8;
2068 sym->st_shndx = SHN_REGISTER;
2069 }
2070
2071 return 1;
2072 }
2073
2074 /* We fake a register section that holds values that are register numbers.
2075 Having a SHN_REGISTER and register section translates better to other
2076 formats (e.g. mmo) than for example a STT_REGISTER attribute.
2077 This section faking is based on a construct in elf32-mips.c. */
2078 static asection mmix_elf_reg_section;
2079 static const asymbol mmix_elf_reg_section_symbol =
2080 GLOBAL_SYM_INIT (MMIX_REG_SECTION_NAME, &mmix_elf_reg_section);
2081 static asection mmix_elf_reg_section =
2082 BFD_FAKE_SECTION (mmix_elf_reg_section, &mmix_elf_reg_section_symbol,
2083 MMIX_REG_SECTION_NAME, 0, SEC_NO_FLAGS);
2084
2085 /* Handle the special section numbers that a symbol may use. */
2086
2087 void
mmix_elf_symbol_processing(bfd * abfd ATTRIBUTE_UNUSED,asymbol * asym)2088 mmix_elf_symbol_processing (bfd *abfd ATTRIBUTE_UNUSED, asymbol *asym)
2089 {
2090 elf_symbol_type *elfsym;
2091
2092 elfsym = (elf_symbol_type *) asym;
2093 switch (elfsym->internal_elf_sym.st_shndx)
2094 {
2095 case SHN_REGISTER:
2096 asym->section = &mmix_elf_reg_section;
2097 break;
2098
2099 default:
2100 break;
2101 }
2102 }
2103
2104 /* Given a BFD section, try to locate the corresponding ELF section
2105 index. */
2106
2107 static bool
mmix_elf_section_from_bfd_section(bfd * abfd ATTRIBUTE_UNUSED,asection * sec,int * retval)2108 mmix_elf_section_from_bfd_section (bfd * abfd ATTRIBUTE_UNUSED,
2109 asection * sec,
2110 int * retval)
2111 {
2112 if (strcmp (bfd_section_name (sec), MMIX_REG_SECTION_NAME) == 0)
2113 *retval = SHN_REGISTER;
2114 else
2115 return false;
2116
2117 return true;
2118 }
2119
2120 /* Hook called by the linker routine which adds symbols from an object
2121 file. We must handle the special SHN_REGISTER section number here.
2122
2123 We also check that we only have *one* each of the section-start
2124 symbols, since otherwise having two with the same value would cause
2125 them to be "merged", but with the contents serialized. */
2126
2127 static bool
mmix_elf_add_symbol_hook(bfd * abfd,struct bfd_link_info * info ATTRIBUTE_UNUSED,Elf_Internal_Sym * sym,const char ** namep ATTRIBUTE_UNUSED,flagword * flagsp ATTRIBUTE_UNUSED,asection ** secp,bfd_vma * valp ATTRIBUTE_UNUSED)2128 mmix_elf_add_symbol_hook (bfd *abfd,
2129 struct bfd_link_info *info ATTRIBUTE_UNUSED,
2130 Elf_Internal_Sym *sym,
2131 const char **namep ATTRIBUTE_UNUSED,
2132 flagword *flagsp ATTRIBUTE_UNUSED,
2133 asection **secp,
2134 bfd_vma *valp ATTRIBUTE_UNUSED)
2135 {
2136 if (sym->st_shndx == SHN_REGISTER)
2137 {
2138 *secp = bfd_make_section_old_way (abfd, MMIX_REG_SECTION_NAME);
2139 (*secp)->flags |= SEC_LINKER_CREATED;
2140 }
2141 else if ((*namep)[0] == '_' && (*namep)[1] == '_' && (*namep)[2] == '.'
2142 && startswith (*namep, MMIX_LOC_SECTION_START_SYMBOL_PREFIX))
2143 {
2144 /* See if we have another one. */
2145 struct bfd_link_hash_entry *h = bfd_link_hash_lookup (info->hash,
2146 *namep,
2147 false,
2148 false,
2149 false);
2150
2151 if (h != NULL && h->type != bfd_link_hash_undefined)
2152 {
2153 /* How do we get the asymbol (or really: the filename) from h?
2154 h->u.def.section->owner is NULL. */
2155 _bfd_error_handler
2156 /* xgettext:c-format */
2157 (_("%pB: error: multiple definition of `%s'; start of %s "
2158 "is set in a earlier linked file"),
2159 abfd, *namep,
2160 *namep + strlen (MMIX_LOC_SECTION_START_SYMBOL_PREFIX));
2161 bfd_set_error (bfd_error_bad_value);
2162 return false;
2163 }
2164 }
2165
2166 return true;
2167 }
2168
2169 /* We consider symbols matching "L.*:[0-9]+" to be local symbols. */
2170
2171 static bool
mmix_elf_is_local_label_name(bfd * abfd,const char * name)2172 mmix_elf_is_local_label_name (bfd *abfd, const char *name)
2173 {
2174 const char *colpos;
2175 int digits;
2176
2177 /* Also include the default local-label definition. */
2178 if (_bfd_elf_is_local_label_name (abfd, name))
2179 return true;
2180
2181 if (*name != 'L')
2182 return false;
2183
2184 /* If there's no ":", or more than one, it's not a local symbol. */
2185 colpos = strchr (name, ':');
2186 if (colpos == NULL || strchr (colpos + 1, ':') != NULL)
2187 return false;
2188
2189 /* Check that there are remaining characters and that they are digits. */
2190 if (colpos[1] == 0)
2191 return false;
2192
2193 digits = strspn (colpos + 1, "0123456789");
2194 return digits != 0 && colpos[1 + digits] == 0;
2195 }
2196
2197 /* We get rid of the register section here. */
2198
2199 bool
mmix_elf_final_link(bfd * abfd,struct bfd_link_info * info)2200 mmix_elf_final_link (bfd *abfd, struct bfd_link_info *info)
2201 {
2202 /* We never output a register section, though we create one for
2203 temporary measures. Check that nobody entered contents into it. */
2204 asection *reg_section;
2205
2206 reg_section = bfd_get_section_by_name (abfd, MMIX_REG_SECTION_NAME);
2207
2208 if (reg_section != NULL)
2209 {
2210 /* FIXME: Pass error state gracefully. */
2211 if (bfd_section_flags (reg_section) & SEC_HAS_CONTENTS)
2212 _bfd_abort (__FILE__, __LINE__, _("register section has contents\n"));
2213
2214 /* Really remove the section, if it hasn't already been done. */
2215 if (!bfd_section_removed_from_list (abfd, reg_section))
2216 {
2217 bfd_section_list_remove (abfd, reg_section);
2218 --abfd->section_count;
2219 }
2220 }
2221
2222 if (! bfd_elf_final_link (abfd, info))
2223 return false;
2224
2225 /* Since this section is marked SEC_LINKER_CREATED, it isn't output by
2226 the regular linker machinery. We do it here, like other targets with
2227 special sections. */
2228 if (info->base_file != NULL)
2229 {
2230 asection *greg_section
2231 = bfd_get_section_by_name ((bfd *) info->base_file,
2232 MMIX_LD_ALLOCATED_REG_CONTENTS_SECTION_NAME);
2233 if (!bfd_set_section_contents (abfd,
2234 greg_section->output_section,
2235 greg_section->contents,
2236 (file_ptr) greg_section->output_offset,
2237 greg_section->size))
2238 return false;
2239 }
2240 return true;
2241 }
2242
2243 /* We need to include the maximum size of PUSHJ-stubs in the initial
2244 section size. This is expected to shrink during linker relaxation. */
2245
2246 static void
mmix_set_relaxable_size(bfd * abfd ATTRIBUTE_UNUSED,asection * sec,void * ptr)2247 mmix_set_relaxable_size (bfd *abfd ATTRIBUTE_UNUSED,
2248 asection *sec,
2249 void *ptr)
2250 {
2251 struct bfd_link_info *info = ptr;
2252
2253 /* Make sure we only do this for section where we know we want this,
2254 otherwise we might end up resetting the size of COMMONs. */
2255 if (mmix_elf_section_data (sec)->pjs.n_pushj_relocs == 0)
2256 return;
2257
2258 sec->rawsize = sec->size;
2259 sec->size += (mmix_elf_section_data (sec)->pjs.n_pushj_relocs
2260 * MAX_PUSHJ_STUB_SIZE);
2261
2262 /* For use in relocatable link, we start with a max stubs size. See
2263 mmix_elf_relax_section. */
2264 if (bfd_link_relocatable (info) && sec->output_section)
2265 mmix_elf_section_data (sec->output_section)->pjs.stubs_size_sum
2266 += (mmix_elf_section_data (sec)->pjs.n_pushj_relocs
2267 * MAX_PUSHJ_STUB_SIZE);
2268 }
2269
2270 /* Initialize stuff for the linker-generated GREGs to match
2271 R_MMIX_BASE_PLUS_OFFSET relocs seen by the linker. */
2272
2273 bool
_bfd_mmix_before_linker_allocation(bfd * abfd ATTRIBUTE_UNUSED,struct bfd_link_info * info)2274 _bfd_mmix_before_linker_allocation (bfd *abfd ATTRIBUTE_UNUSED,
2275 struct bfd_link_info *info)
2276 {
2277 asection *bpo_gregs_section;
2278 bfd *bpo_greg_owner;
2279 struct bpo_greg_section_info *gregdata;
2280 size_t n_gregs;
2281 bfd_vma gregs_size;
2282 size_t i;
2283 size_t *bpo_reloc_indexes;
2284 bfd *ibfd;
2285
2286 /* Set the initial size of sections. */
2287 for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
2288 bfd_map_over_sections (ibfd, mmix_set_relaxable_size, info);
2289
2290 /* The bpo_greg_owner bfd is supposed to have been set by
2291 mmix_elf_check_relocs when the first R_MMIX_BASE_PLUS_OFFSET is seen.
2292 If there is no such object, there was no R_MMIX_BASE_PLUS_OFFSET. */
2293 bpo_greg_owner = (bfd *) info->base_file;
2294 if (bpo_greg_owner == NULL)
2295 return true;
2296
2297 bpo_gregs_section
2298 = bfd_get_section_by_name (bpo_greg_owner,
2299 MMIX_LD_ALLOCATED_REG_CONTENTS_SECTION_NAME);
2300
2301 if (bpo_gregs_section == NULL)
2302 return true;
2303
2304 /* We use the target-data handle in the ELF section data. */
2305 gregdata = mmix_elf_section_data (bpo_gregs_section)->bpo.greg;
2306 if (gregdata == NULL)
2307 return false;
2308
2309 n_gregs = gregdata->n_bpo_relocs;
2310 gregdata->n_allocated_bpo_gregs = n_gregs;
2311
2312 /* When this reaches zero during relaxation, all entries have been
2313 filled in and the size of the linker gregs can be calculated. */
2314 gregdata->n_remaining_bpo_relocs_this_relaxation_round = n_gregs;
2315
2316 /* Set the zeroth-order estimate for the GREGs size. */
2317 gregs_size = n_gregs * 8;
2318
2319 if (!bfd_set_section_size (bpo_gregs_section, gregs_size))
2320 return false;
2321
2322 /* Allocate and set up the GREG arrays. They're filled in at relaxation
2323 time. Note that we must use the max number ever noted for the array,
2324 since the index numbers were created before GC. */
2325 gregdata->reloc_request
2326 = bfd_zalloc (bpo_greg_owner,
2327 sizeof (struct bpo_reloc_request)
2328 * gregdata->n_max_bpo_relocs);
2329
2330 gregdata->bpo_reloc_indexes
2331 = bpo_reloc_indexes
2332 = bfd_alloc (bpo_greg_owner,
2333 gregdata->n_max_bpo_relocs
2334 * sizeof (size_t));
2335 if (bpo_reloc_indexes == NULL)
2336 return false;
2337
2338 /* The default order is an identity mapping. */
2339 for (i = 0; i < gregdata->n_max_bpo_relocs; i++)
2340 {
2341 bpo_reloc_indexes[i] = i;
2342 gregdata->reloc_request[i].bpo_reloc_no = i;
2343 }
2344
2345 return true;
2346 }
2347
2348 /* Fill in contents in the linker allocated gregs. Everything is
2349 calculated at this point; we just move the contents into place here. */
2350
2351 bool
_bfd_mmix_after_linker_allocation(bfd * abfd ATTRIBUTE_UNUSED,struct bfd_link_info * link_info)2352 _bfd_mmix_after_linker_allocation (bfd *abfd ATTRIBUTE_UNUSED,
2353 struct bfd_link_info *link_info)
2354 {
2355 asection *bpo_gregs_section;
2356 bfd *bpo_greg_owner;
2357 struct bpo_greg_section_info *gregdata;
2358 size_t n_gregs;
2359 size_t i, j;
2360 size_t lastreg;
2361 bfd_byte *contents;
2362
2363 /* The bpo_greg_owner bfd is supposed to have been set by mmix_elf_check_relocs
2364 when the first R_MMIX_BASE_PLUS_OFFSET is seen. If there is no such
2365 object, there was no R_MMIX_BASE_PLUS_OFFSET. */
2366 bpo_greg_owner = (bfd *) link_info->base_file;
2367 if (bpo_greg_owner == NULL)
2368 return true;
2369
2370 bpo_gregs_section
2371 = bfd_get_section_by_name (bpo_greg_owner,
2372 MMIX_LD_ALLOCATED_REG_CONTENTS_SECTION_NAME);
2373
2374 /* This can't happen without DSO handling. When DSOs are handled
2375 without any R_MMIX_BASE_PLUS_OFFSET seen, there will be no such
2376 section. */
2377 if (bpo_gregs_section == NULL)
2378 return true;
2379
2380 /* We use the target-data handle in the ELF section data. */
2381
2382 gregdata = mmix_elf_section_data (bpo_gregs_section)->bpo.greg;
2383 if (gregdata == NULL)
2384 return false;
2385
2386 n_gregs = gregdata->n_allocated_bpo_gregs;
2387
2388 bpo_gregs_section->contents
2389 = contents = bfd_alloc (bpo_greg_owner, bpo_gregs_section->size);
2390 if (contents == NULL)
2391 return false;
2392
2393 /* Sanity check: If these numbers mismatch, some relocation has not been
2394 accounted for and the rest of gregdata is probably inconsistent.
2395 It's a bug, but it's more helpful to identify it than segfaulting
2396 below. */
2397 if (gregdata->n_remaining_bpo_relocs_this_relaxation_round
2398 != gregdata->n_bpo_relocs)
2399 {
2400 _bfd_error_handler
2401 /* xgettext:c-format */
2402 (_("internal inconsistency: remaining %lu != max %lu;"
2403 " please report this bug"),
2404 (unsigned long) gregdata->n_remaining_bpo_relocs_this_relaxation_round,
2405 (unsigned long) gregdata->n_bpo_relocs);
2406 return false;
2407 }
2408
2409 for (lastreg = 255, i = 0, j = 0; j < n_gregs; i++)
2410 if (gregdata->reloc_request[i].regindex != lastreg)
2411 {
2412 bfd_put_64 (bpo_greg_owner, gregdata->reloc_request[i].value,
2413 contents + j * 8);
2414 lastreg = gregdata->reloc_request[i].regindex;
2415 j++;
2416 }
2417
2418 return true;
2419 }
2420
2421 /* Sort valid relocs to come before non-valid relocs, then on increasing
2422 value. */
2423
2424 static int
bpo_reloc_request_sort_fn(const void * p1,const void * p2)2425 bpo_reloc_request_sort_fn (const void * p1, const void * p2)
2426 {
2427 const struct bpo_reloc_request *r1 = (const struct bpo_reloc_request *) p1;
2428 const struct bpo_reloc_request *r2 = (const struct bpo_reloc_request *) p2;
2429
2430 /* Primary function is validity; non-valid relocs sorted after valid
2431 ones. */
2432 if (r1->valid != r2->valid)
2433 return r2->valid - r1->valid;
2434
2435 /* Then sort on value. Don't simplify and return just the difference of
2436 the values: the upper bits of the 64-bit value would be truncated on
2437 a host with 32-bit ints. */
2438 if (r1->value != r2->value)
2439 return r1->value > r2->value ? 1 : -1;
2440
2441 /* As a last re-sort, use the relocation number, so we get a stable
2442 sort. The *addresses* aren't stable since items are swapped during
2443 sorting. It depends on the qsort implementation if this actually
2444 happens. */
2445 return r1->bpo_reloc_no > r2->bpo_reloc_no
2446 ? 1 : (r1->bpo_reloc_no < r2->bpo_reloc_no ? -1 : 0);
2447 }
2448
2449 /* For debug use only. Dumps the global register allocations resulting
2450 from base-plus-offset relocs. */
2451
2452 void
mmix_dump_bpo_gregs(struct bfd_link_info * link_info,void (* pf)(const char * fmt,...))2453 mmix_dump_bpo_gregs (struct bfd_link_info *link_info,
2454 void (*pf) (const char *fmt, ...))
2455 {
2456 bfd *bpo_greg_owner;
2457 asection *bpo_gregs_section;
2458 struct bpo_greg_section_info *gregdata;
2459 unsigned int i;
2460
2461 if (link_info == NULL || link_info->base_file == NULL)
2462 return;
2463
2464 bpo_greg_owner = (bfd *) link_info->base_file;
2465
2466 bpo_gregs_section
2467 = bfd_get_section_by_name (bpo_greg_owner,
2468 MMIX_LD_ALLOCATED_REG_CONTENTS_SECTION_NAME);
2469
2470 if (bpo_gregs_section == NULL)
2471 return;
2472
2473 gregdata = mmix_elf_section_data (bpo_gregs_section)->bpo.greg;
2474 if (gregdata == NULL)
2475 return;
2476
2477 if (pf == NULL)
2478 pf = _bfd_error_handler;
2479
2480 /* These format strings are not translated. They are for debug purposes
2481 only and never displayed to an end user. Should they escape, we
2482 surely want them in original. */
2483 (*pf) (" n_bpo_relocs: %u\n n_max_bpo_relocs: %u\n n_remain...round: %u\n\
2484 n_allocated_bpo_gregs: %u\n", gregdata->n_bpo_relocs,
2485 gregdata->n_max_bpo_relocs,
2486 gregdata->n_remaining_bpo_relocs_this_relaxation_round,
2487 gregdata->n_allocated_bpo_gregs);
2488
2489 if (gregdata->reloc_request)
2490 for (i = 0; i < gregdata->n_max_bpo_relocs; i++)
2491 (*pf) ("%4u (%4u)/%4u#%u: 0x%08lx%08lx r: %3u o: %3u\n",
2492 i,
2493 (gregdata->bpo_reloc_indexes != NULL
2494 ? gregdata->bpo_reloc_indexes[i] : (size_t) -1),
2495 gregdata->reloc_request[i].bpo_reloc_no,
2496 gregdata->reloc_request[i].valid,
2497
2498 (unsigned long) (gregdata->reloc_request[i].value >> 32),
2499 (unsigned long) gregdata->reloc_request[i].value,
2500 gregdata->reloc_request[i].regindex,
2501 gregdata->reloc_request[i].offset);
2502 }
2503
2504 /* This links all R_MMIX_BASE_PLUS_OFFSET relocs into a special array, and
2505 when the last such reloc is done, an index-array is sorted according to
2506 the values and iterated over to produce register numbers (indexed by 0
2507 from the first allocated register number) and offsets for use in real
2508 relocation. (N.B.: Relocatable runs are handled, not just punted.)
2509
2510 PUSHJ stub accounting is also done here.
2511
2512 Symbol- and reloc-reading infrastructure copied from elf-m10200.c. */
2513
2514 static bool
mmix_elf_relax_section(bfd * abfd,asection * sec,struct bfd_link_info * link_info,bool * again)2515 mmix_elf_relax_section (bfd *abfd,
2516 asection *sec,
2517 struct bfd_link_info *link_info,
2518 bool *again)
2519 {
2520 Elf_Internal_Shdr *symtab_hdr;
2521 Elf_Internal_Rela *internal_relocs;
2522 Elf_Internal_Rela *irel, *irelend;
2523 asection *bpo_gregs_section = NULL;
2524 struct bpo_greg_section_info *gregdata;
2525 struct bpo_reloc_section_info *bpodata
2526 = mmix_elf_section_data (sec)->bpo.reloc;
2527 /* The initialization is to quiet compiler warnings. The value is to
2528 spot a missing actual initialization. */
2529 size_t bpono = (size_t) -1;
2530 size_t pjsno = 0;
2531 size_t pjsno_undefs = 0;
2532 Elf_Internal_Sym *isymbuf = NULL;
2533 bfd_size_type size = sec->rawsize ? sec->rawsize : sec->size;
2534
2535 mmix_elf_section_data (sec)->pjs.stubs_size_sum = 0;
2536
2537 /* Assume nothing changes. */
2538 *again = false;
2539
2540 /* We don't have to do anything if this section does not have relocs, or
2541 if this is not a code section. */
2542 if ((sec->flags & SEC_RELOC) == 0
2543 || sec->reloc_count == 0
2544 || (sec->flags & SEC_CODE) == 0
2545 || (sec->flags & SEC_LINKER_CREATED) != 0
2546 /* If no R_MMIX_BASE_PLUS_OFFSET relocs and no PUSHJ-stub relocs,
2547 then nothing to do. */
2548 || (bpodata == NULL
2549 && mmix_elf_section_data (sec)->pjs.n_pushj_relocs == 0))
2550 return true;
2551
2552 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
2553
2554 if (bpodata != NULL)
2555 {
2556 bpo_gregs_section = bpodata->bpo_greg_section;
2557 gregdata = mmix_elf_section_data (bpo_gregs_section)->bpo.greg;
2558 bpono = bpodata->first_base_plus_offset_reloc;
2559 }
2560 else
2561 gregdata = NULL;
2562
2563 /* Get a copy of the native relocations. */
2564 internal_relocs
2565 = _bfd_elf_link_read_relocs (abfd, sec, NULL,
2566 (Elf_Internal_Rela *) NULL,
2567 link_info->keep_memory);
2568 if (internal_relocs == NULL)
2569 goto error_return;
2570
2571 /* Walk through them looking for relaxing opportunities. */
2572 irelend = internal_relocs + sec->reloc_count;
2573 for (irel = internal_relocs; irel < irelend; irel++)
2574 {
2575 bfd_vma symval;
2576 struct elf_link_hash_entry *h = NULL;
2577
2578 /* We only process two relocs. */
2579 if (ELF64_R_TYPE (irel->r_info) != (int) R_MMIX_BASE_PLUS_OFFSET
2580 && ELF64_R_TYPE (irel->r_info) != (int) R_MMIX_PUSHJ_STUBBABLE)
2581 continue;
2582
2583 /* We process relocs in a distinctly different way when this is a
2584 relocatable link (for one, we don't look at symbols), so we avoid
2585 mixing its code with that for the "normal" relaxation. */
2586 if (bfd_link_relocatable (link_info))
2587 {
2588 /* The only transformation in a relocatable link is to generate
2589 a full stub at the location of the stub calculated for the
2590 input section, if the relocated stub location, the end of the
2591 output section plus earlier stubs, cannot be reached. Thus
2592 relocatable linking can only lead to worse code, but it still
2593 works. */
2594 if (ELF64_R_TYPE (irel->r_info) == R_MMIX_PUSHJ_STUBBABLE)
2595 {
2596 /* If we can reach the end of the output-section and beyond
2597 any current stubs, then we don't need a stub for this
2598 reloc. The relaxed order of output stub allocation may
2599 not exactly match the straightforward order, so we always
2600 assume presence of output stubs, which will allow
2601 relaxation only on relocations indifferent to the
2602 presence of output stub allocations for other relocations
2603 and thus the order of output stub allocation. */
2604 if (bfd_check_overflow (complain_overflow_signed,
2605 19,
2606 0,
2607 bfd_arch_bits_per_address (abfd),
2608 /* Output-stub location. */
2609 sec->output_section->rawsize
2610 + (mmix_elf_section_data (sec
2611 ->output_section)
2612 ->pjs.stubs_size_sum)
2613 /* Location of this PUSHJ reloc. */
2614 - (sec->output_offset + irel->r_offset)
2615 /* Don't count *this* stub twice. */
2616 - (mmix_elf_section_data (sec)
2617 ->pjs.stub_size[pjsno]
2618 + MAX_PUSHJ_STUB_SIZE))
2619 == bfd_reloc_ok)
2620 mmix_elf_section_data (sec)->pjs.stub_size[pjsno] = 0;
2621
2622 mmix_elf_section_data (sec)->pjs.stubs_size_sum
2623 += mmix_elf_section_data (sec)->pjs.stub_size[pjsno];
2624
2625 pjsno++;
2626 }
2627
2628 continue;
2629 }
2630
2631 /* Get the value of the symbol referred to by the reloc. */
2632 if (ELF64_R_SYM (irel->r_info) < symtab_hdr->sh_info)
2633 {
2634 /* A local symbol. */
2635 Elf_Internal_Sym *isym;
2636 asection *sym_sec;
2637
2638 /* Read this BFD's local symbols if we haven't already. */
2639 if (isymbuf == NULL)
2640 {
2641 isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
2642 if (isymbuf == NULL)
2643 isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr,
2644 symtab_hdr->sh_info, 0,
2645 NULL, NULL, NULL);
2646 if (isymbuf == 0)
2647 goto error_return;
2648 }
2649
2650 isym = isymbuf + ELF64_R_SYM (irel->r_info);
2651 if (isym->st_shndx == SHN_UNDEF)
2652 sym_sec = bfd_und_section_ptr;
2653 else if (isym->st_shndx == SHN_ABS)
2654 sym_sec = bfd_abs_section_ptr;
2655 else if (isym->st_shndx == SHN_COMMON)
2656 sym_sec = bfd_com_section_ptr;
2657 else
2658 sym_sec = bfd_section_from_elf_index (abfd, isym->st_shndx);
2659 symval = (isym->st_value
2660 + sym_sec->output_section->vma
2661 + sym_sec->output_offset);
2662 }
2663 else
2664 {
2665 unsigned long indx;
2666
2667 /* An external symbol. */
2668 indx = ELF64_R_SYM (irel->r_info) - symtab_hdr->sh_info;
2669 h = elf_sym_hashes (abfd)[indx];
2670 BFD_ASSERT (h != NULL);
2671 if (h->root.type == bfd_link_hash_undefweak)
2672 /* FIXME: for R_MMIX_PUSHJ_STUBBABLE, there are alternatives to
2673 the canonical value 0 for an unresolved weak symbol to
2674 consider: as the debug-friendly approach, resolve to "abort"
2675 (or a port-specific function), or as the space-friendly
2676 approach resolve to the next instruction (like some other
2677 ports, notably ARM and AArch64). These alternatives require
2678 matching code in mmix_elf_perform_relocation or its caller. */
2679 symval = 0;
2680 else if (h->root.type == bfd_link_hash_defined
2681 || h->root.type == bfd_link_hash_defweak)
2682 symval = (h->root.u.def.value
2683 + h->root.u.def.section->output_section->vma
2684 + h->root.u.def.section->output_offset);
2685 else
2686 {
2687 /* This appears to be a reference to an undefined symbol. Just
2688 ignore it--it will be caught by the regular reloc processing.
2689 We need to keep BPO reloc accounting consistent, though
2690 else we'll abort instead of emitting an error message. */
2691 if (ELF64_R_TYPE (irel->r_info) == R_MMIX_BASE_PLUS_OFFSET
2692 && gregdata != NULL)
2693 {
2694 gregdata->n_remaining_bpo_relocs_this_relaxation_round--;
2695 bpono++;
2696 }
2697
2698 /* Similarly, keep accounting consistent for PUSHJ
2699 referring to an undefined symbol. */
2700 if (ELF64_R_TYPE (irel->r_info) == R_MMIX_PUSHJ_STUBBABLE)
2701 pjsno_undefs++;
2702 continue;
2703 }
2704 }
2705
2706 if (ELF64_R_TYPE (irel->r_info) == (int) R_MMIX_PUSHJ_STUBBABLE)
2707 {
2708 bfd_vma value = symval + irel->r_addend;
2709 bfd_vma dot
2710 = (sec->output_section->vma
2711 + sec->output_offset
2712 + irel->r_offset);
2713 bfd_vma stubaddr
2714 = (sec->output_section->vma
2715 + sec->output_offset
2716 + size
2717 + mmix_elf_section_data (sec)->pjs.stubs_size_sum);
2718
2719 if ((value & 3) == 0
2720 && bfd_check_overflow (complain_overflow_signed,
2721 19,
2722 0,
2723 bfd_arch_bits_per_address (abfd),
2724 value - dot
2725 - (value > dot
2726 ? mmix_elf_section_data (sec)
2727 ->pjs.stub_size[pjsno]
2728 : 0))
2729 == bfd_reloc_ok)
2730 /* If the reloc fits, no stub is needed. */
2731 mmix_elf_section_data (sec)->pjs.stub_size[pjsno] = 0;
2732 else
2733 /* Maybe we can get away with just a JMP insn? */
2734 if ((value & 3) == 0
2735 && bfd_check_overflow (complain_overflow_signed,
2736 27,
2737 0,
2738 bfd_arch_bits_per_address (abfd),
2739 value - stubaddr
2740 - (value > dot
2741 ? mmix_elf_section_data (sec)
2742 ->pjs.stub_size[pjsno] - 4
2743 : 0))
2744 == bfd_reloc_ok)
2745 /* Yep, account for a stub consisting of a single JMP insn. */
2746 mmix_elf_section_data (sec)->pjs.stub_size[pjsno] = 4;
2747 else
2748 /* Nope, go for the full insn stub. It doesn't seem useful to
2749 emit the intermediate sizes; those will only be useful for
2750 a >64M program assuming contiguous code. */
2751 mmix_elf_section_data (sec)->pjs.stub_size[pjsno]
2752 = MAX_PUSHJ_STUB_SIZE;
2753
2754 mmix_elf_section_data (sec)->pjs.stubs_size_sum
2755 += mmix_elf_section_data (sec)->pjs.stub_size[pjsno];
2756 pjsno++;
2757 continue;
2758 }
2759
2760 /* We're looking at a R_MMIX_BASE_PLUS_OFFSET reloc. */
2761
2762 gregdata->reloc_request[gregdata->bpo_reloc_indexes[bpono]].value
2763 = symval + irel->r_addend;
2764 gregdata->reloc_request[gregdata->bpo_reloc_indexes[bpono++]].valid = true;
2765 gregdata->n_remaining_bpo_relocs_this_relaxation_round--;
2766 }
2767
2768 /* Check if that was the last BPO-reloc. If so, sort the values and
2769 calculate how many registers we need to cover them. Set the size of
2770 the linker gregs, and if the number of registers changed, indicate
2771 that we need to relax some more because we have more work to do. */
2772 if (gregdata != NULL
2773 && gregdata->n_remaining_bpo_relocs_this_relaxation_round == 0)
2774 {
2775 size_t i;
2776 bfd_vma prev_base;
2777 size_t regindex;
2778
2779 /* First, reset the remaining relocs for the next round. */
2780 gregdata->n_remaining_bpo_relocs_this_relaxation_round
2781 = gregdata->n_bpo_relocs;
2782
2783 qsort (gregdata->reloc_request,
2784 gregdata->n_max_bpo_relocs,
2785 sizeof (struct bpo_reloc_request),
2786 bpo_reloc_request_sort_fn);
2787
2788 /* Recalculate indexes. When we find a change (however unlikely
2789 after the initial iteration), we know we need to relax again,
2790 since items in the GREG-array are sorted by increasing value and
2791 stored in the relaxation phase. */
2792 for (i = 0; i < gregdata->n_max_bpo_relocs; i++)
2793 if (gregdata->bpo_reloc_indexes[gregdata->reloc_request[i].bpo_reloc_no]
2794 != i)
2795 {
2796 gregdata->bpo_reloc_indexes[gregdata->reloc_request[i].bpo_reloc_no]
2797 = i;
2798 *again = true;
2799 }
2800
2801 /* Allocate register numbers (indexing from 0). Stop at the first
2802 non-valid reloc. */
2803 for (i = 0, regindex = 0, prev_base = gregdata->reloc_request[0].value;
2804 i < gregdata->n_bpo_relocs;
2805 i++)
2806 {
2807 if (gregdata->reloc_request[i].value > prev_base + 255)
2808 {
2809 regindex++;
2810 prev_base = gregdata->reloc_request[i].value;
2811 }
2812 gregdata->reloc_request[i].regindex = regindex;
2813 gregdata->reloc_request[i].offset
2814 = gregdata->reloc_request[i].value - prev_base;
2815 }
2816
2817 /* If it's not the same as the last time, we need to relax again,
2818 because the size of the section has changed. I'm not sure we
2819 actually need to do any adjustments since the shrinking happens
2820 at the start of this section, but better safe than sorry. */
2821 if (gregdata->n_allocated_bpo_gregs != regindex + 1)
2822 {
2823 gregdata->n_allocated_bpo_gregs = regindex + 1;
2824 *again = true;
2825 }
2826
2827 bpo_gregs_section->size = (regindex + 1) * 8;
2828 }
2829
2830 if (isymbuf != NULL && (unsigned char *) isymbuf != symtab_hdr->contents)
2831 {
2832 if (! link_info->keep_memory)
2833 free (isymbuf);
2834 else
2835 {
2836 /* Cache the symbols for elf_link_input_bfd. */
2837 symtab_hdr->contents = (unsigned char *) isymbuf;
2838 }
2839 }
2840
2841 BFD_ASSERT(pjsno + pjsno_undefs
2842 == mmix_elf_section_data (sec)->pjs.n_pushj_relocs);
2843
2844 if (elf_section_data (sec)->relocs != internal_relocs)
2845 free (internal_relocs);
2846
2847 if (sec->size < size + mmix_elf_section_data (sec)->pjs.stubs_size_sum)
2848 abort ();
2849
2850 if (sec->size > size + mmix_elf_section_data (sec)->pjs.stubs_size_sum)
2851 {
2852 sec->size = size + mmix_elf_section_data (sec)->pjs.stubs_size_sum;
2853 *again = true;
2854 }
2855
2856 return true;
2857
2858 error_return:
2859 if ((unsigned char *) isymbuf != symtab_hdr->contents)
2860 free (isymbuf);
2861 if (elf_section_data (sec)->relocs != internal_relocs)
2862 free (internal_relocs);
2863 return false;
2864 }
2865
2866 #define ELF_ARCH bfd_arch_mmix
2867 #define ELF_MACHINE_CODE EM_MMIX
2868
2869 /* According to mmix-doc page 36 (paragraph 45), this should be (1LL << 48LL).
2870 However, that's too much for something somewhere in the linker part of
2871 BFD; perhaps the start-address has to be a non-zero multiple of this
2872 number, or larger than this number. The symptom is that the linker
2873 complains: "warning: allocated section `.text' not in segment". We
2874 settle for 64k; the page-size used in examples is 8k.
2875 #define ELF_MAXPAGESIZE 0x10000
2876
2877 Unfortunately, this causes excessive padding in the supposedly small
2878 for-education programs that are the expected usage (where people would
2879 inspect output). We stick to 256 bytes just to have *some* default
2880 alignment. */
2881 #define ELF_MAXPAGESIZE 0x100
2882
2883 #define TARGET_BIG_SYM mmix_elf64_vec
2884 #define TARGET_BIG_NAME "elf64-mmix"
2885
2886 #define elf_info_to_howto_rel NULL
2887 #define elf_info_to_howto mmix_info_to_howto_rela
2888 #define elf_backend_relocate_section mmix_elf_relocate_section
2889 #define elf_backend_gc_mark_hook mmix_elf_gc_mark_hook
2890
2891 #define elf_backend_link_output_symbol_hook \
2892 mmix_elf_link_output_symbol_hook
2893 #define elf_backend_add_symbol_hook mmix_elf_add_symbol_hook
2894
2895 #define elf_backend_check_relocs mmix_elf_check_relocs
2896 #define elf_backend_symbol_processing mmix_elf_symbol_processing
2897 #define elf_backend_omit_section_dynsym _bfd_elf_omit_section_dynsym_all
2898
2899 #define bfd_elf64_bfd_copy_link_hash_symbol_type \
2900 _bfd_generic_copy_link_hash_symbol_type
2901
2902 #define bfd_elf64_bfd_is_local_label_name \
2903 mmix_elf_is_local_label_name
2904
2905 #define elf_backend_may_use_rel_p 0
2906 #define elf_backend_may_use_rela_p 1
2907 #define elf_backend_default_use_rela_p 1
2908
2909 #define elf_backend_can_gc_sections 1
2910 #define elf_backend_section_from_bfd_section \
2911 mmix_elf_section_from_bfd_section
2912
2913 #define bfd_elf64_new_section_hook mmix_elf_new_section_hook
2914 #define bfd_elf64_bfd_final_link mmix_elf_final_link
2915 #define bfd_elf64_bfd_relax_section mmix_elf_relax_section
2916
2917 #include "elf64-target.h"
2918