| blob | 4eb0153dfba3fff4d56568a8f6ea25bb16622f75 |
1 /* PowerPC64-specific support for 64-bit ELF.
2 Copyright (C) 1999-2019 Free Software Foundation, Inc.
3 Written by Linus Nordberg, Swox AB <info@swox.com>,
4 based on elf32-ppc.c by Ian Lance Taylor.
5 Largely rewritten by Alan Modra.
7 This file is part of BFD, the Binary File Descriptor library.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License along
20 with this program; if not, write to the Free Software Foundation, Inc.,
21 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
24 /* The 64-bit PowerPC ELF ABI may be found at
25 http://www.linuxbase.org/spec/ELF/ppc64/PPC-elf64abi.txt, and
26 http://www.linuxbase.org/spec/ELF/ppc64/spec/book1.html */
29 #include <stdarg.h>
38 static bfd_reloc_status_type ppc64_elf_ha_reloc
40 static bfd_reloc_status_type ppc64_elf_branch_reloc
42 static bfd_reloc_status_type ppc64_elf_brtaken_reloc
44 static bfd_reloc_status_type ppc64_elf_sectoff_reloc
46 static bfd_reloc_status_type ppc64_elf_sectoff_ha_reloc
48 static bfd_reloc_status_type ppc64_elf_toc_reloc
50 static bfd_reloc_status_type ppc64_elf_toc_ha_reloc
52 static bfd_reloc_status_type ppc64_elf_toc64_reloc
54 static bfd_reloc_status_type ppc64_elf_unhandled_reloc
56 static bfd_vma opd_entry_value
59 #define TARGET_LITTLE_SYM powerpc_elf64_le_vec
61 #define TARGET_BIG_SYM powerpc_elf64_vec
63 #define ELF_ARCH bfd_arch_powerpc
64 #define ELF_TARGET_ID PPC64_ELF_DATA
65 #define ELF_MACHINE_CODE EM_PPC64
66 #define ELF_MAXPAGESIZE 0x10000
67 #define ELF_COMMONPAGESIZE 0x1000
68 #define ELF_RELROPAGESIZE ELF_MAXPAGESIZE
69 #define elf_info_to_howto ppc64_elf_info_to_howto
71 #define elf_backend_want_got_sym 0
72 #define elf_backend_want_plt_sym 0
73 #define elf_backend_plt_alignment 3
74 #define elf_backend_plt_not_loaded 1
75 #define elf_backend_got_header_size 8
76 #define elf_backend_want_dynrelro 1
77 #define elf_backend_can_gc_sections 1
78 #define elf_backend_can_refcount 1
79 #define elf_backend_rela_normal 1
80 #define elf_backend_dtrel_excludes_plt 1
81 #define elf_backend_default_execstack 0
83 #define bfd_elf64_mkobject ppc64_elf_mkobject
84 #define bfd_elf64_bfd_reloc_type_lookup ppc64_elf_reloc_type_lookup
85 #define bfd_elf64_bfd_reloc_name_lookup ppc64_elf_reloc_name_lookup
86 #define bfd_elf64_bfd_merge_private_bfd_data ppc64_elf_merge_private_bfd_data
87 #define bfd_elf64_bfd_print_private_bfd_data ppc64_elf_print_private_bfd_data
88 #define bfd_elf64_new_section_hook ppc64_elf_new_section_hook
89 #define bfd_elf64_bfd_link_hash_table_create ppc64_elf_link_hash_table_create
90 #define bfd_elf64_get_synthetic_symtab ppc64_elf_get_synthetic_symtab
91 #define bfd_elf64_bfd_link_just_syms ppc64_elf_link_just_syms
92 #define bfd_elf64_bfd_gc_sections ppc64_elf_gc_sections
94 #define elf_backend_object_p ppc64_elf_object_p
95 #define elf_backend_grok_prstatus ppc64_elf_grok_prstatus
96 #define elf_backend_grok_psinfo ppc64_elf_grok_psinfo
97 #define elf_backend_write_core_note ppc64_elf_write_core_note
98 #define elf_backend_create_dynamic_sections _bfd_elf_create_dynamic_sections
99 #define elf_backend_copy_indirect_symbol ppc64_elf_copy_indirect_symbol
100 #define elf_backend_add_symbol_hook ppc64_elf_add_symbol_hook
101 #define elf_backend_check_directives ppc64_elf_before_check_relocs
102 #define elf_backend_notice_as_needed ppc64_elf_notice_as_needed
103 #define elf_backend_archive_symbol_lookup ppc64_elf_archive_symbol_lookup
104 #define elf_backend_check_relocs ppc64_elf_check_relocs
105 #define elf_backend_relocs_compatible _bfd_elf_relocs_compatible
106 #define elf_backend_gc_keep ppc64_elf_gc_keep
107 #define elf_backend_gc_mark_dynamic_ref ppc64_elf_gc_mark_dynamic_ref
108 #define elf_backend_gc_mark_hook ppc64_elf_gc_mark_hook
109 #define elf_backend_adjust_dynamic_symbol ppc64_elf_adjust_dynamic_symbol
110 #define elf_backend_hide_symbol ppc64_elf_hide_symbol
111 #define elf_backend_maybe_function_sym ppc64_elf_maybe_function_sym
112 #define elf_backend_always_size_sections ppc64_elf_func_desc_adjust
113 #define elf_backend_size_dynamic_sections ppc64_elf_size_dynamic_sections
114 #define elf_backend_hash_symbol ppc64_elf_hash_symbol
115 #define elf_backend_init_index_section _bfd_elf_init_2_index_sections
116 #define elf_backend_action_discarded ppc64_elf_action_discarded
117 #define elf_backend_relocate_section ppc64_elf_relocate_section
118 #define elf_backend_finish_dynamic_symbol ppc64_elf_finish_dynamic_symbol
119 #define elf_backend_reloc_type_class ppc64_elf_reloc_type_class
120 #define elf_backend_finish_dynamic_sections ppc64_elf_finish_dynamic_sections
121 #define elf_backend_link_output_symbol_hook ppc64_elf_output_symbol_hook
122 #define elf_backend_special_sections ppc64_elf_special_sections
123 #define elf_backend_merge_symbol_attribute ppc64_elf_merge_symbol_attribute
124 #define elf_backend_merge_symbol ppc64_elf_merge_symbol
125 #define elf_backend_get_reloc_section bfd_get_section_by_name
127 /* The name of the dynamic interpreter. This is put in the .interp
128 section. */
131 /* The size in bytes of an entry in the procedure linkage table. */
132 #define PLT_ENTRY_SIZE(htab) (htab->opd_abi ? 24 : 8)
133 #define LOCAL_PLT_ENTRY_SIZE(htab) (htab->opd_abi ? 16 : 8)
135 /* The initial size of the plt reserved for the dynamic linker. */
136 #define PLT_INITIAL_ENTRY_SIZE(htab) (htab->opd_abi ? 24 : 16)
138 /* Offsets to some stack save slots. */
139 #define STK_LR 16
140 #define STK_TOC(htab) (htab->opd_abi ? 40 : 24)
141 /* This one is dodgy. ELFv2 does not have a linker word, so use the
142 CR save slot. Used only by optimised __tls_get_addr call stub,
143 relying on __tls_get_addr_opt not saving CR.. */
144 #define STK_LINKER(htab) (htab->opd_abi ? 32 : 8)
146 /* TOC base pointers offset from start of TOC. */
147 #define TOC_BASE_OFF 0x8000
148 /* TOC base alignment. */
149 #define TOC_BASE_ALIGN 256
151 /* Offset of tp and dtp pointers from start of TLS block. */
152 #define TP_OFFSET 0x7000
153 #define DTP_OFFSET 0x8000
155 /* .plt call stub instructions. The normal stub is like this, but
156 sometimes the .plt entry crosses a 64k boundary and we need to
157 insert an addi to adjust r11. */
201 /* __glink_PLTresolve stub instructions. We enter with the index in R0. */
202 #define GLINK_PLTRESOLVE_SIZE(htab) \
203 (8u + (htab->opd_abi ? 11 * 4 : 14 * 4))
204 /* 0: */
205 /* .quad plt0-1f */
206 /* __glink: */
209 /* 1: */
211 /* ld %2,(0b-1b)(%11) */
214 /* ld %12,0(%11) */
215 /* ld %2,8(%11) */
216 /* mtctr %12 */
217 /* ld %11,16(%11) */
218 /* bctr */
225 /* Pad with this. */
226 #define NOP 0x60000000
228 /* Some other nops. */
229 #define CROR_151515 0x4def7b82
230 #define CROR_313131 0x4ffffb82
232 /* .glink entries for the first 32k functions are two instructions. */
236 /* After that, we need two instructions to load the index, followed by
237 a branch. */
241 /* Instructions used by the save and restore reg functions. */
254 /* Since .opd is an array of descriptors and each entry will end up
255 with identical R_PPC64_RELATIVE relocs, there is really no need to
256 propagate .opd relocs; The dynamic linker should be taught to
257 relocate .opd without reloc entries. */
258 #ifndef NO_OPD_RELOCS
259 #define NO_OPD_RELOCS 0
260 #endif
262 #ifndef ARRAY_SIZE
263 #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
264 #endif
268 {
270 }
274 {
277 }
278 \f
279 /* Relocation HOWTO's. */
280 /* Like other ELF RELA targets that don't apply multiple
281 field-altering relocations to the same localation, src_mask is
282 always zero and pcrel_offset is the same as pc_relative.
283 PowerPC can always use a zero bitpos, even when the field is not at
284 the LSB. For example, a REL24 could use rightshift=2, bisize=24
285 and bitpos=2 which matches the ABI description, or as we do here,
286 rightshift=0, bitsize=26 and bitpos=0. */
287 #define HOW(type, size, bitsize, mask, rightshift, pc_relative, \
288 complain, special_func) \
289 HOWTO (type, rightshift, size, bitsize, pc_relative, 0, \
290 complain_overflow_ ## complain, special_func, \
291 #type, FALSE, 0, mask, pc_relative)
296 {
297 /* This reloc does nothing. */
299 bfd_elf_generic_reloc),
301 /* A standard 32 bit relocation. */
303 bfd_elf_generic_reloc),
305 /* An absolute 26 bit branch; the lower two bits must be zero.
306 FIXME: we don't check that, we just clear them. */
308 bfd_elf_generic_reloc),
310 /* A standard 16 bit relocation. */
312 bfd_elf_generic_reloc),
314 /* A 16 bit relocation without overflow. */
316 bfd_elf_generic_reloc),
318 /* Bits 16-31 of an address. */
320 bfd_elf_generic_reloc),
322 /* Bits 16-31 of an address, plus 1 if the contents of the low 16
323 bits, treated as a signed number, is negative. */
325 ppc64_elf_ha_reloc),
327 /* An absolute 16 bit branch; the lower two bits must be zero.
328 FIXME: we don't check that, we just clear them. */
330 ppc64_elf_branch_reloc),
332 /* An absolute 16 bit branch, for which bit 10 should be set to
333 indicate that the branch is expected to be taken. The lower two
334 bits must be zero. */
336 ppc64_elf_brtaken_reloc),
338 /* An absolute 16 bit branch, for which bit 10 should be set to
339 indicate that the branch is not expected to be taken. The lower
340 two bits must be zero. */
342 ppc64_elf_brtaken_reloc),
344 /* A relative 26 bit branch; the lower two bits must be zero. */
346 ppc64_elf_branch_reloc),
348 /* A variant of R_PPC64_REL24, used when r2 is not the toc pointer. */
350 ppc64_elf_branch_reloc),
352 /* A relative 16 bit branch; the lower two bits must be zero. */
354 ppc64_elf_branch_reloc),
356 /* A relative 16 bit branch. Bit 10 should be set to indicate that
357 the branch is expected to be taken. The lower two bits must be
358 zero. */
360 ppc64_elf_brtaken_reloc),
362 /* A relative 16 bit branch. Bit 10 should be set to indicate that
363 the branch is not expected to be taken. The lower two bits must
364 be zero. */
366 ppc64_elf_brtaken_reloc),
368 /* Like R_PPC64_ADDR16, but referring to the GOT table entry for the
369 symbol. */
371 ppc64_elf_unhandled_reloc),
373 /* Like R_PPC64_ADDR16_LO, but referring to the GOT table entry for
374 the symbol. */
376 ppc64_elf_unhandled_reloc),
378 /* Like R_PPC64_ADDR16_HI, but referring to the GOT table entry for
379 the symbol. */
381 ppc64_elf_unhandled_reloc),
383 /* Like R_PPC64_ADDR16_HA, but referring to the GOT table entry for
384 the symbol. */
386 ppc64_elf_unhandled_reloc),
388 /* This is used only by the dynamic linker. The symbol should exist
389 both in the object being run and in some shared library. The
390 dynamic linker copies the data addressed by the symbol from the
391 shared library into the object, because the object being
392 run has to have the data at some particular address. */
394 ppc64_elf_unhandled_reloc),
396 /* Like R_PPC64_ADDR64, but used when setting global offset table
397 entries. */
399 ppc64_elf_unhandled_reloc),
401 /* Created by the link editor. Marks a procedure linkage table
402 entry for a symbol. */
404 ppc64_elf_unhandled_reloc),
406 /* Used only by the dynamic linker. When the object is run, this
407 doubleword64 is set to the load address of the object, plus the
408 addend. */
410 bfd_elf_generic_reloc),
412 /* Like R_PPC64_ADDR32, but may be unaligned. */
414 bfd_elf_generic_reloc),
416 /* Like R_PPC64_ADDR16, but may be unaligned. */
418 bfd_elf_generic_reloc),
420 /* 32-bit PC relative. */
422 bfd_elf_generic_reloc),
424 /* 32-bit relocation to the symbol's procedure linkage table. */
426 ppc64_elf_unhandled_reloc),
428 /* 32-bit PC relative relocation to the symbol's procedure linkage table.
429 FIXME: R_PPC64_PLTREL32 not supported. */
431 ppc64_elf_unhandled_reloc),
433 /* Like R_PPC64_ADDR16_LO, but referring to the PLT table entry for
434 the symbol. */
436 ppc64_elf_unhandled_reloc),
438 /* Like R_PPC64_ADDR16_HI, but referring to the PLT table entry for
439 the symbol. */
441 ppc64_elf_unhandled_reloc),
443 /* Like R_PPC64_ADDR16_HA, but referring to the PLT table entry for
444 the symbol. */
446 ppc64_elf_unhandled_reloc),
448 /* 16-bit section relative relocation. */
450 ppc64_elf_sectoff_reloc),
452 /* Like R_PPC64_SECTOFF, but no overflow warning. */
454 ppc64_elf_sectoff_reloc),
456 /* 16-bit upper half section relative relocation. */
458 ppc64_elf_sectoff_reloc),
460 /* 16-bit upper half adjusted section relative relocation. */
462 ppc64_elf_sectoff_ha_reloc),
464 /* Like R_PPC64_REL24 without touching the two least significant bits. */
466 bfd_elf_generic_reloc),
468 /* Relocs in the 64-bit PowerPC ELF ABI, not in the 32-bit ABI. */
470 /* A standard 64-bit relocation. */
472 bfd_elf_generic_reloc),
474 /* The bits 32-47 of an address. */
476 bfd_elf_generic_reloc),
478 /* The bits 32-47 of an address, plus 1 if the contents of the low
479 16 bits, treated as a signed number, is negative. */
481 ppc64_elf_ha_reloc),
483 /* The bits 48-63 of an address. */
485 bfd_elf_generic_reloc),
487 /* The bits 48-63 of an address, plus 1 if the contents of the low
488 16 bits, treated as a signed number, is negative. */
490 ppc64_elf_ha_reloc),
492 /* Like ADDR64, but may be unaligned. */
494 bfd_elf_generic_reloc),
496 /* 64-bit relative relocation. */
498 bfd_elf_generic_reloc),
500 /* 64-bit relocation to the symbol's procedure linkage table. */
502 ppc64_elf_unhandled_reloc),
504 /* 64-bit PC relative relocation to the symbol's procedure linkage
505 table. */
506 /* FIXME: R_PPC64_PLTREL64 not supported. */
508 ppc64_elf_unhandled_reloc),
510 /* 16 bit TOC-relative relocation. */
511 /* R_PPC64_TOC16 47 half16* S + A - .TOC. */
513 ppc64_elf_toc_reloc),
515 /* 16 bit TOC-relative relocation without overflow. */
516 /* R_PPC64_TOC16_LO 48 half16 #lo (S + A - .TOC.) */
518 ppc64_elf_toc_reloc),
520 /* 16 bit TOC-relative relocation, high 16 bits. */
521 /* R_PPC64_TOC16_HI 49 half16 #hi (S + A - .TOC.) */
523 ppc64_elf_toc_reloc),
525 /* 16 bit TOC-relative relocation, high 16 bits, plus 1 if the
526 contents of the low 16 bits, treated as a signed number, is
527 negative. */
528 /* R_PPC64_TOC16_HA 50 half16 #ha (S + A - .TOC.) */
530 ppc64_elf_toc_ha_reloc),
532 /* 64-bit relocation; insert value of TOC base (.TOC.). */
533 /* R_PPC64_TOC 51 doubleword64 .TOC. */
535 ppc64_elf_toc64_reloc),
537 /* Like R_PPC64_GOT16, but also informs the link editor that the
538 value to relocate may (!) refer to a PLT entry which the link
539 editor (a) may replace with the symbol value. If the link editor
540 is unable to fully resolve the symbol, it may (b) create a PLT
541 entry and store the address to the new PLT entry in the GOT.
542 This permits lazy resolution of function symbols at run time.
543 The link editor may also skip all of this and just (c) emit a
544 R_PPC64_GLOB_DAT to tie the symbol to the GOT entry. */
545 /* FIXME: R_PPC64_PLTGOT16 not implemented. */
547 ppc64_elf_unhandled_reloc),
549 /* Like R_PPC64_PLTGOT16, but without overflow. */
550 /* FIXME: R_PPC64_PLTGOT16_LO not implemented. */
552 ppc64_elf_unhandled_reloc),
554 /* Like R_PPC64_PLT_GOT16, but using bits 16-31 of the address. */
555 /* FIXME: R_PPC64_PLTGOT16_HI not implemented. */
557 ppc64_elf_unhandled_reloc),
559 /* Like R_PPC64_PLT_GOT16, but using bits 16-31 of the address, plus
560 1 if the contents of the low 16 bits, treated as a signed number,
561 is negative. */
562 /* FIXME: R_PPC64_PLTGOT16_HA not implemented. */
564 ppc64_elf_unhandled_reloc),
566 /* Like R_PPC64_ADDR16, but for instructions with a DS field. */
568 bfd_elf_generic_reloc),
570 /* Like R_PPC64_ADDR16_LO, but for instructions with a DS field. */
572 bfd_elf_generic_reloc),
574 /* Like R_PPC64_GOT16, but for instructions with a DS field. */
576 ppc64_elf_unhandled_reloc),
578 /* Like R_PPC64_GOT16_LO, but for instructions with a DS field. */
580 ppc64_elf_unhandled_reloc),
582 /* Like R_PPC64_PLT16_LO, but for instructions with a DS field. */
584 ppc64_elf_unhandled_reloc),
586 /* Like R_PPC64_SECTOFF, but for instructions with a DS field. */
588 ppc64_elf_sectoff_reloc),
590 /* Like R_PPC64_SECTOFF_LO, but for instructions with a DS field. */
592 ppc64_elf_sectoff_reloc),
594 /* Like R_PPC64_TOC16, but for instructions with a DS field. */
596 ppc64_elf_toc_reloc),
598 /* Like R_PPC64_TOC16_LO, but for instructions with a DS field. */
600 ppc64_elf_toc_reloc),
602 /* Like R_PPC64_PLTGOT16, but for instructions with a DS field. */
603 /* FIXME: R_PPC64_PLTGOT16_DS not implemented. */
605 ppc64_elf_unhandled_reloc),
607 /* Like R_PPC64_PLTGOT16_LO, but for instructions with a DS field. */
608 /* FIXME: R_PPC64_PLTGOT16_LO not implemented. */
610 ppc64_elf_unhandled_reloc),
612 /* Marker relocs for TLS. */
614 bfd_elf_generic_reloc),
617 bfd_elf_generic_reloc),
620 bfd_elf_generic_reloc),
622 /* Marker reloc for optimizing r2 save in prologue rather than on
623 each plt call stub. */
625 bfd_elf_generic_reloc),
627 /* Marker relocs on inline plt call instructions. */
629 bfd_elf_generic_reloc),
632 bfd_elf_generic_reloc),
634 /* Computes the load module index of the load module that contains the
635 definition of its TLS sym. */
637 ppc64_elf_unhandled_reloc),
639 /* Computes a dtv-relative displacement, the difference between the value
640 of sym+add and the base address of the thread-local storage block that
641 contains the definition of sym, minus 0x8000. */
643 ppc64_elf_unhandled_reloc),
645 /* A 16 bit dtprel reloc. */
647 ppc64_elf_unhandled_reloc),
649 /* Like DTPREL16, but no overflow. */
651 ppc64_elf_unhandled_reloc),
653 /* Like DTPREL16_LO, but next higher group of 16 bits. */
655 ppc64_elf_unhandled_reloc),
657 /* Like DTPREL16_HI, but adjust for low 16 bits. */
659 ppc64_elf_unhandled_reloc),
661 /* Like DTPREL16_HI, but next higher group of 16 bits. */
663 ppc64_elf_unhandled_reloc),
665 /* Like DTPREL16_HIGHER, but adjust for low 16 bits. */
667 ppc64_elf_unhandled_reloc),
669 /* Like DTPREL16_HIGHER, but next higher group of 16 bits. */
671 ppc64_elf_unhandled_reloc),
673 /* Like DTPREL16_HIGHEST, but adjust for low 16 bits. */
675 ppc64_elf_unhandled_reloc),
677 /* Like DTPREL16, but for insns with a DS field. */
679 ppc64_elf_unhandled_reloc),
681 /* Like DTPREL16_DS, but no overflow. */
683 ppc64_elf_unhandled_reloc),
685 /* Computes a tp-relative displacement, the difference between the value of
686 sym+add and the value of the thread pointer (r13). */
688 ppc64_elf_unhandled_reloc),
690 /* A 16 bit tprel reloc. */
692 ppc64_elf_unhandled_reloc),
694 /* Like TPREL16, but no overflow. */
696 ppc64_elf_unhandled_reloc),
698 /* Like TPREL16_LO, but next higher group of 16 bits. */
700 ppc64_elf_unhandled_reloc),
702 /* Like TPREL16_HI, but adjust for low 16 bits. */
704 ppc64_elf_unhandled_reloc),
706 /* Like TPREL16_HI, but next higher group of 16 bits. */
708 ppc64_elf_unhandled_reloc),
710 /* Like TPREL16_HIGHER, but adjust for low 16 bits. */
712 ppc64_elf_unhandled_reloc),
714 /* Like TPREL16_HIGHER, but next higher group of 16 bits. */
716 ppc64_elf_unhandled_reloc),
718 /* Like TPREL16_HIGHEST, but adjust for low 16 bits. */
720 ppc64_elf_unhandled_reloc),
722 /* Like TPREL16, but for insns with a DS field. */
724 ppc64_elf_unhandled_reloc),
726 /* Like TPREL16_DS, but no overflow. */
728 ppc64_elf_unhandled_reloc),
730 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
731 with values (sym+add)@dtpmod and (sym+add)@dtprel, and computes the offset
732 to the first entry relative to the TOC base (r2). */
734 ppc64_elf_unhandled_reloc),
736 /* Like GOT_TLSGD16, but no overflow. */
738 ppc64_elf_unhandled_reloc),
740 /* Like GOT_TLSGD16_LO, but next higher group of 16 bits. */
742 ppc64_elf_unhandled_reloc),
744 /* Like GOT_TLSGD16_HI, but adjust for low 16 bits. */
746 ppc64_elf_unhandled_reloc),
748 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
749 with values (sym+add)@dtpmod and zero, and computes the offset to the
750 first entry relative to the TOC base (r2). */
752 ppc64_elf_unhandled_reloc),
754 /* Like GOT_TLSLD16, but no overflow. */
756 ppc64_elf_unhandled_reloc),
758 /* Like GOT_TLSLD16_LO, but next higher group of 16 bits. */
760 ppc64_elf_unhandled_reloc),
762 /* Like GOT_TLSLD16_HI, but adjust for low 16 bits. */
764 ppc64_elf_unhandled_reloc),
766 /* Allocates an entry in the GOT with value (sym+add)@dtprel, and computes
767 the offset to the entry relative to the TOC base (r2). */
769 ppc64_elf_unhandled_reloc),
771 /* Like GOT_DTPREL16_DS, but no overflow. */
773 ppc64_elf_unhandled_reloc),
775 /* Like GOT_DTPREL16_LO_DS, but next higher group of 16 bits. */
777 ppc64_elf_unhandled_reloc),
779 /* Like GOT_DTPREL16_HI, but adjust for low 16 bits. */
781 ppc64_elf_unhandled_reloc),
783 /* Allocates an entry in the GOT with value (sym+add)@tprel, and computes the
784 offset to the entry relative to the TOC base (r2). */
786 ppc64_elf_unhandled_reloc),
788 /* Like GOT_TPREL16_DS, but no overflow. */
790 ppc64_elf_unhandled_reloc),
792 /* Like GOT_TPREL16_LO_DS, but next higher group of 16 bits. */
794 ppc64_elf_unhandled_reloc),
796 /* Like GOT_TPREL16_HI, but adjust for low 16 bits. */
798 ppc64_elf_unhandled_reloc),
801 ppc64_elf_unhandled_reloc),
804 bfd_elf_generic_reloc),
806 /* A 16 bit relative relocation. */
808 bfd_elf_generic_reloc),
810 /* A 16 bit relative relocation without overflow. */
812 bfd_elf_generic_reloc),
814 /* The high order 16 bits of a relative address. */
816 bfd_elf_generic_reloc),
818 /* The high order 16 bits of a relative address, plus 1 if the contents of
819 the low 16 bits, treated as a signed number, is negative. */
821 ppc64_elf_ha_reloc),
824 bfd_elf_generic_reloc),
827 ppc64_elf_ha_reloc),
830 bfd_elf_generic_reloc),
833 ppc64_elf_ha_reloc),
836 bfd_elf_generic_reloc),
839 ppc64_elf_ha_reloc),
841 /* Like R_PPC64_REL16_HA but for split field in addpcis. */
843 ppc64_elf_ha_reloc),
845 /* A split-field reloc for addpcis, non-relative (gas internal use only). */
847 ppc64_elf_ha_reloc),
849 /* Like R_PPC64_ADDR16_HI, but no overflow. */
851 bfd_elf_generic_reloc),
853 /* Like R_PPC64_ADDR16_HA, but no overflow. */
855 ppc64_elf_ha_reloc),
857 /* Like R_PPC64_DTPREL16_HI, but no overflow. */
859 ppc64_elf_unhandled_reloc),
861 /* Like R_PPC64_DTPREL16_HA, but no overflow. */
863 ppc64_elf_unhandled_reloc),
865 /* Like R_PPC64_TPREL16_HI, but no overflow. */
867 ppc64_elf_unhandled_reloc),
869 /* Like R_PPC64_TPREL16_HA, but no overflow. */
871 ppc64_elf_unhandled_reloc),
873 /* Marker reloc on ELFv2 large-model function entry. */
875 bfd_elf_generic_reloc),
877 /* Like ADDR64, but use local entry point of function. */
879 bfd_elf_generic_reloc),
881 /* GNU extension to record C++ vtable hierarchy. */
883 NULL),
885 /* GNU extension to record C++ vtable member usage. */
887 NULL),
888 };
890 \f
891 /* Initialize the ppc64_elf_howto_table, so that linear accesses can
892 be done. */
894 static void
896 {
900 {
904 }
905 }
909 bfd_reloc_code_real_type code)
910 {
914 /* Initialize howto table if needed. */
918 {
920 /* xgettext:c-format */
1174 }
1177 };
1182 {
1191 }
1193 /* Set the howto pointer for a PowerPC ELF reloc. */
1195 static bfd_boolean
1198 {
1201 /* Initialize howto table if needed. */
1207 {
1208 /* xgettext:c-format */
1213 }
1216 {
1217 /* xgettext:c-format */
1222 }
1225 }
1227 /* Handle the R_PPC64_ADDR16_HA and similar relocs. */
1229 static bfd_reloc_status_type
1233 {
1236 bfd_size_type octets;
1237 bfd_vma value;
1239 /* If this is a relocatable link (output_bfd test tells us), just
1240 call the generic function. Any adjustment will be done at final
1241 link time. */
1246 /* Adjust the addend for sign extension of the low 16 bits.
1247 We won't actually be using the low 16 bits, so trashing them
1248 doesn't matter. */
1273 }
1275 static bfd_reloc_status_type
1279 {
1286 {
1294 }
1295 else
1296 {
1302 {
1306 {
1310 {
1313 }
1314 }
1315 }
1316 reloc_entry->addend
1318 }
1320 }
1322 static bfd_reloc_status_type
1326 {
1329 bfd_size_type octets;
1330 /* Assume 'at' branch hints. */
1333 /* If this is a relocatable link (output_bfd test tells us), just
1334 call the generic function. Any adjustment will be done at final
1335 link time. */
1349 {
1350 /* Set 'a' bit. This is 0b00010 in BO field for branch
1351 on CR(BI) insns (BO == 001at or 011at), and 0b01000
1352 for branch on CTR insns (BO == 1a00t or 1a01t). */
1357 else
1359 }
1360 else
1361 {
1363 bfd_vma from;
1375 /* Invert 'y' bit if not the default. */
1378 }
1380 out:
1383 }
1385 static bfd_reloc_status_type
1389 {
1390 /* If this is a relocatable link (output_bfd test tells us), just
1391 call the generic function. Any adjustment will be done at final
1392 link time. */
1397 /* Subtract the symbol section base address. */
1400 }
1402 static bfd_reloc_status_type
1406 {
1407 /* If this is a relocatable link (output_bfd test tells us), just
1408 call the generic function. Any adjustment will be done at final
1409 link time. */
1414 /* Subtract the symbol section base address. */
1417 /* Adjust the addend for sign extension of the low 16 bits. */
1420 }
1422 static bfd_reloc_status_type
1426 {
1427 bfd_vma TOCstart;
1429 /* If this is a relocatable link (output_bfd test tells us), just
1430 call the generic function. Any adjustment will be done at final
1431 link time. */
1440 /* Subtract the TOC base address. */
1443 }
1445 static bfd_reloc_status_type
1449 {
1450 bfd_vma TOCstart;
1452 /* If this is a relocatable link (output_bfd test tells us), just
1453 call the generic function. Any adjustment will be done at final
1454 link time. */
1463 /* Subtract the TOC base address. */
1466 /* Adjust the addend for sign extension of the low 16 bits. */
1469 }
1471 static bfd_reloc_status_type
1475 {
1476 bfd_vma TOCstart;
1477 bfd_size_type octets;
1479 /* If this is a relocatable link (output_bfd test tells us), just
1480 call the generic function. Any adjustment will be done at final
1481 link time. */
1493 }
1495 static bfd_reloc_status_type
1499 {
1500 /* If this is a relocatable link (output_bfd test tells us), just
1501 call the generic function. Any adjustment will be done at final
1502 link time. */
1508 {
1513 }
1515 }
1517 /* Track GOT entries needed for a given symbol. We might need more
1518 than one got entry per symbol. */
1519 struct got_entry
1520 {
1523 /* The symbol addend that we'll be placing in the GOT. */
1524 bfd_vma addend;
1526 /* Unlike other ELF targets, we use separate GOT entries for the same
1527 symbol referenced from different input files. This is to support
1528 automatic multiple TOC/GOT sections, where the TOC base can vary
1529 from one input file to another. After partitioning into TOC groups
1530 we merge entries within the group.
1532 Point to the BFD owning this GOT entry. */
1535 /* Zero for non-tls entries, or TLS_TLS and one of TLS_GD, TLS_LD,
1536 TLS_TPREL or TLS_DTPREL for tls entries. */
1539 /* Non-zero if got.ent points to real entry. */
1542 /* Reference count until size_dynamic_sections, GOT offset thereafter. */
1543 union
1544 {
1545 bfd_signed_vma refcount;
1546 bfd_vma offset;
1549 };
1551 /* The same for PLT. */
1552 struct plt_entry
1553 {
1556 bfd_vma addend;
1558 union
1559 {
1560 bfd_signed_vma refcount;
1561 bfd_vma offset;
1563 };
1565 struct ppc64_elf_obj_tdata
1566 {
1569 /* Shortcuts to dynamic linker sections. */
1573 /* Used during garbage collection. We attach global symbols defined
1574 on removed .opd entries to this section so that the sym is removed. */
1577 /* TLS local dynamic got entry handling. Support for multiple GOT
1578 sections means we potentially need one of these for each input bfd. */
1581 union
1582 {
1583 /* A copy of relocs before they are modified for --emit-relocs. */
1586 /* Section contents. */
1590 /* Nonzero if this bfd has small toc/got relocs, ie. that expect
1591 the reloc to be in the range -32768 to 32767. */
1594 /* Set if toc/got ha relocs detected not using r2, or lo reloc
1595 instruction not one we handle. */
1598 /* Set if got relocs that can be optimised are present in this file. */
1600 };
1602 #define ppc64_elf_tdata(bfd) \
1603 ((struct ppc64_elf_obj_tdata *) (bfd)->tdata.any)
1605 #define ppc64_tlsld_got(bfd) \
1606 (&ppc64_elf_tdata (bfd)->tlsld_got)
1608 #define is_ppc64_elf(bfd) \
1609 (bfd_get_flavour (bfd) == bfd_target_elf_flavour \
1610 && elf_object_id (bfd) == PPC64_ELF_DATA)
1612 /* Override the generic function because we store some extras. */
1614 static bfd_boolean
1616 {
1618 PPC64_ELF_DATA);
1619 }
1621 /* Fix bad default arch selected for a 64 bit input bfd when the
1622 default is 32 bit. Also select arch based on apuinfo. */
1624 static bfd_boolean
1626 {
1631 {
1635 {
1636 /* Relies on arch after 32 bit default being 64 bit default. */
1639 }
1640 }
1642 }
1644 /* Support for core dump NOTE sections. */
1646 static bfd_boolean
1648 {
1654 /* pr_cursig */
1657 /* pr_pid */
1660 /* pr_reg */
1664 /* Make a ".reg/999" section. */
1667 }
1669 static bfd_boolean
1671 {
1683 }
1687 ...)
1688 {
1690 {
1695 {
1702 #if GCC_VERSION == 8000 || GCC_VERSION == 8001
1703 DIAGNOSTIC_PUSH;
1704 /* GCC 8.0 and 8.1 warn about 80 equals destination size with
1705 -Wstringop-truncation:
1706 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85643
1707 */
1708 DIAGNOSTIC_IGNORE_STRINGOP_TRUNCATION;
1709 #endif
1711 #if GCC_VERSION == 8000 || GCC_VERSION == 8001
1712 DIAGNOSTIC_POP;
1713 #endif
1717 }
1720 {
1739 }
1740 }
1741 }
1743 /* Add extra PPC sections. */
1746 {
1754 };
1760 };
1762 struct _ppc64_elf_section_data
1763 {
1766 union
1767 {
1768 /* An array with one entry for each opd function descriptor,
1769 and some spares since opd entries may be either 16 or 24 bytes. */
1770 #define OPD_NDX(OFF) ((OFF) >> 4)
1771 struct _opd_sec_data
1772 {
1773 /* Points to the function code section for local opd entries. */
1776 /* After editing .opd, adjust references to opd local syms. */
1780 /* An array for toc sections, indexed by offset/8. */
1781 struct _toc_sec_data
1782 {
1783 /* Specifies the relocation symbol index used at a given toc offset. */
1786 /* And the relocation addend. */
1793 /* Flag set when small branches are detected. Used to
1794 select suitable defaults for the stub group size. */
1797 /* Flag set when PLTCALL relocs are detected. */
1800 /* Flag set when section has GOT relocations that can be optimised. */
1802 };
1804 #define ppc64_elf_section_data(sec) \
1805 ((struct _ppc64_elf_section_data *) elf_section_data (sec))
1807 static bfd_boolean
1809 {
1811 {
1819 }
1822 }
1826 {
1832 }
1833 \f
1834 /* Parameters for the qsort hook. */
1838 /* qsort comparison function for ppc64_elf_get_synthetic_symtab. */
1840 static int
1842 {
1846 /* Section symbols first. */
1852 /* then .opd symbols. */
1854 {
1861 }
1863 /* then other code symbols. */
1877 {
1883 }
1891 /* For syms with the same value, prefer strong dynamic global function
1892 syms over other syms. */
1918 }
1920 /* Search SYMS for a symbol of the given VALUE. */
1924 {
1928 {
1930 {
1936 else
1938 }
1939 }
1940 else
1941 {
1943 {
1953 else
1955 }
1956 }
1958 }
1960 static bfd_boolean
1962 {
1967 }
1969 /* Create synthetic symbols, effectively restoring "dot-symbol" function
1970 entry syms. Also generate @plt symbols for the glink branch table.
1971 Returns count of synthetic symbols in RET or -1 on error. */
1973 static long
1978 {
1991 {
1995 }
2004 {
2016 {
2017 /* Use both symbol tables. */
2021 }
2024 else
2027 /* Trim uninteresting symbols. Interesting symbols are section,
2028 function, and notype symbols. */
2040 {
2041 /* Trim duplicate syms, since we may have merged the normal
2042 and dynamic symbols. Actually, we only care about syms
2043 that have different values, so trim any with the same
2044 value. Don't consider ifunc and ifunc resolver symbols
2045 duplicates however, because GDB wants to know whether a
2046 text symbol is an ifunc resolver. */
2048 {
2057 }
2059 }
2062 /* Note that here and in compare_symbols we can't compare opd and
2063 sym->section directly. With separate debug info files, the
2064 symbols will be extracted from the debug file while abfd passed
2065 to this function is the real binary. */
2094 }
2098 {
2113 {
2116 }
2120 {
2139 {
2143 }
2144 }
2150 {
2153 }
2158 {
2177 {
2189 /* Have udata.p point back to the original symbol this
2190 synthetic symbol was derived from. */
2192 s++;
2193 }
2194 }
2195 }
2196 else
2197 {
2207 {
2208 free_contents_and_exit_err:
2210 free_contents_and_exit:
2214 }
2218 {
2219 bfd_vma ent;
2221 /* Ignore bogus symbols. */
2227 {
2231 }
2232 }
2234 /* Get start of .glink stubs from DT_PPC64_GLINK. */
2237 {
2251 {
2252 Elf_Internal_Dyn dyn;
2259 {
2260 /* The first glink stub starts at DT_PPC64_GLINK plus 32.
2261 See comment in ppc64_elf_finish_dynamic_sections. */
2263 /* The .glink section usually does not survive the final
2264 link; search for the section (usually .text) where the
2265 glink stubs now reside. */
2269 }
2270 }
2273 }
2276 {
2277 /* Determine __glink trampoline by reading the relative branch
2278 from the first glink stub. */
2284 {
2288 {
2289 resolv_vma
2292 }
2296 }
2303 {
2313 {
2317 }
2318 }
2319 }
2330 {
2331 bfd_vma ent;
2338 {
2347 {
2353 else
2354 {
2357 }
2358 }
2364 {
2367 /* SEC_LOAD may not be set if SEC is from a separate debug
2368 info file. */
2373 }
2381 /* Have udata.p point back to the original symbol this
2382 synthetic symbol was derived from. */
2384 s++;
2385 }
2386 }
2390 {
2392 {
2393 /* Add a symbol for the main glink trampoline. */
2403 s++;
2404 count++;
2405 }
2407 /* FIXME: It would be very much nicer to put sym@plt on the
2408 stub rather than on the glink branch table entry. The
2409 objdump disassembler would then use a sensible symbol
2410 name on plt calls. The difficulty in doing so is
2411 a) finding the stubs, and,
2412 b) matching stubs against plt entries, and,
2413 c) there can be multiple stubs for a given plt entry.
2415 Solving (a) could be done by code scanning, but older
2416 ppc64 binaries used different stubs to current code.
2417 (b) is the tricky one since you need to known the toc
2418 pointer for at least one function that uses a pic stub to
2419 be able to calculate the plt address referenced.
2420 (c) means gdb would need to set multiple breakpoints (or
2421 find the glink branch itself) when setting breakpoints
2422 for pending shared library loads. */
2425 {
2429 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL set. Since
2430 we are defining a symbol, ensure one of them is set. */
2442 {
2447 }
2450 s++;
2452 {
2456 }
2457 else
2459 }
2461 }
2462 }
2464 done:
2467 }
2468 \f
2469 /* The following functions are specific to the ELF linker, while
2470 functions above are used generally. Those named ppc64_elf_* are
2471 called by the main ELF linker code. They appear in this file more
2472 or less in the order in which they are called. eg.
2473 ppc64_elf_check_relocs is called early in the link process,
2474 ppc64_elf_finish_dynamic_sections is one of the last functions
2475 called.
2477 PowerPC64-ELF uses a similar scheme to PowerPC64-XCOFF in that
2478 functions have both a function code symbol and a function descriptor
2479 symbol. A call to foo in a relocatable object file looks like:
2481 . .text
2482 . x:
2483 . bl .foo
2484 . nop
2486 The function definition in another object file might be:
2488 . .section .opd
2489 . foo: .quad .foo
2490 . .quad .TOC.@tocbase
2491 . .quad 0
2492 .
2493 . .text
2494 . .foo: blr
2496 When the linker resolves the call during a static link, the branch
2497 unsurprisingly just goes to .foo and the .opd information is unused.
2498 If the function definition is in a shared library, things are a little
2499 different: The call goes via a plt call stub, the opd information gets
2500 copied to the plt, and the linker patches the nop.
2502 . x:
2503 . bl .foo_stub
2504 . ld 2,40(1)
2505 .
2506 .
2507 . .foo_stub:
2508 . std 2,40(1) # in practice, the call stub
2509 . addis 11,2,Lfoo@toc@ha # is slightly optimized, but
2510 . addi 11,11,Lfoo@toc@l # this is the general idea
2511 . ld 12,0(11)
2512 . ld 2,8(11)
2513 . mtctr 12
2514 . ld 11,16(11)
2515 . bctr
2516 .
2517 . .section .plt
2518 . Lfoo: reloc (R_PPC64_JMP_SLOT, foo)
2520 The "reloc ()" notation is supposed to indicate that the linker emits
2521 an R_PPC64_JMP_SLOT reloc against foo. The dynamic linker does the opd
2522 copying.
2524 What are the difficulties here? Well, firstly, the relocations
2525 examined by the linker in check_relocs are against the function code
2526 sym .foo, while the dynamic relocation in the plt is emitted against
2527 the function descriptor symbol, foo. Somewhere along the line, we need
2528 to carefully copy dynamic link information from one symbol to the other.
2529 Secondly, the generic part of the elf linker will make .foo a dynamic
2530 symbol as is normal for most other backends. We need foo dynamic
2531 instead, at least for an application final link. However, when
2532 creating a shared library containing foo, we need to have both symbols
2533 dynamic so that references to .foo are satisfied during the early
2534 stages of linking. Otherwise the linker might decide to pull in a
2535 definition from some other object, eg. a static library.
2537 Update: As of August 2004, we support a new convention. Function
2538 calls may use the function descriptor symbol, ie. "bl foo". This
2539 behaves exactly as "bl .foo". */
2541 /* Of those relocs that might be copied as dynamic relocs, this
2542 function selects those that must be copied when linking a shared
2543 library or PIE, even when the symbol is local. */
2545 static int
2548 {
2550 {
2552 /* Only relative relocs can be resolved when the object load
2553 address isn't fixed. DTPREL64 is excluded because the
2554 dynamic linker needs to differentiate global dynamic from
2555 local dynamic __tls_index pairs when PPC64_OPT_TLS is set. */
2576 /* These relocations are relative but in a shared library the
2577 linker doesn't know the thread pointer base. */
2579 }
2580 }
2582 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
2583 copying dynamic variables from a shared lib into an app's dynbss
2584 section, and instead use a dynamic relocation to point into the
2585 shared lib. With code that gcc generates, it's vital that this be
2586 enabled; In the PowerPC64 ABI, the address of a function is actually
2587 the address of a function descriptor, which resides in the .opd
2588 section. gcc uses the descriptor directly rather than going via the
2589 GOT as some other ABI's do, which means that initialized function
2590 pointers must reference the descriptor. Thus, a function pointer
2591 initialized to the address of a function in a shared library will
2592 either require a copy reloc, or a dynamic reloc. Using a copy reloc
2593 redefines the function descriptor symbol to point to the copy. This
2594 presents a problem as a plt entry for that function is also
2595 initialized from the function descriptor symbol and the copy reloc
2596 may not be initialized first. */
2597 #define ELIMINATE_COPY_RELOCS 1
2599 /* Section name for stubs is the associated section name plus this
2600 string. */
2603 /* Linker stubs.
2604 ppc_stub_long_branch:
2605 Used when a 14 bit branch (or even a 24 bit branch) can't reach its
2606 destination, but a 24 bit branch in a stub section will reach.
2607 . b dest
2609 ppc_stub_plt_branch:
2610 Similar to the above, but a 24 bit branch in the stub section won't
2611 reach its destination.
2612 . addis %r11,%r2,xxx@toc@ha
2613 . ld %r12,xxx@toc@l(%r11)
2614 . mtctr %r12
2615 . bctr
2617 ppc_stub_plt_call:
2618 Used to call a function in a shared library. If it so happens that
2619 the plt entry referenced crosses a 64k boundary, then an extra
2620 "addi %r11,%r11,xxx@toc@l" will be inserted before the "mtctr".
2621 ppc_stub_plt_call_r2save starts with "std %r2,40(%r1)".
2622 . addis %r11,%r2,xxx@toc@ha
2623 . ld %r12,xxx+0@toc@l(%r11)
2624 . mtctr %r12
2625 . ld %r2,xxx+8@toc@l(%r11)
2626 . ld %r11,xxx+16@toc@l(%r11)
2627 . bctr
2629 ppc_stub_long_branch and ppc_stub_plt_branch may also have additional
2630 code to adjust the value and save r2 to support multiple toc sections.
2631 A ppc_stub_long_branch with an r2 offset looks like:
2632 . std %r2,40(%r1)
2633 . addis %r2,%r2,off@ha
2634 . addi %r2,%r2,off@l
2635 . b dest
2637 A ppc_stub_plt_branch with an r2 offset looks like:
2638 . std %r2,40(%r1)
2639 . addis %r11,%r2,xxx@toc@ha
2640 . ld %r12,xxx@toc@l(%r11)
2641 . addis %r2,%r2,off@ha
2642 . addi %r2,%r2,off@l
2643 . mtctr %r12
2644 . bctr
2646 All of the above stubs are shown as their ELFv1 variants. ELFv2
2647 variants exist too, simpler for plt calls since a new toc pointer
2648 and static chain are not loaded by the stub. In addition, ELFv2
2649 has some more complex stubs to handle calls marked with NOTOC
2650 relocs from functions where r2 is not a valid toc pointer. These
2651 come in two flavours, the ones shown below, and _both variants that
2652 start with "std %r2,24(%r1)" to save r2 in the unlikely event that
2653 one call is from a function where r2 is used as the toc pointer but
2654 needs a toc adjusting stub for small-model multi-toc, and another
2655 call is from a function where r2 is not valid.
2656 ppc_stub_long_branch_notoc:
2657 . mflr %r12
2658 . bcl 20,31,1f
2659 . 1:
2660 . mflr %r11
2661 . mtlr %r12
2662 . addis %r12,%r11,dest-1b@ha
2663 . addi %r12,%r12,dest-1b@l
2664 . b dest
2666 ppc_stub_plt_branch_notoc:
2667 . mflr %r12
2668 . bcl 20,31,1f
2669 . 1:
2670 . mflr %r11
2671 . mtlr %r12
2672 . lis %r12,xxx-1b@highest
2673 . ori %r12,%r12,xxx-1b@higher
2674 . sldi %r12,%r12,32
2675 . oris %r12,%r12,xxx-1b@high
2676 . ori %r12,%r12,xxx-1b@l
2677 . add %r12,%r11,%r12
2678 . mtctr %r12
2679 . bctr
2681 ppc_stub_plt_call_notoc:
2682 . mflr %r12
2683 . bcl 20,31,1f
2684 . 1:
2685 . mflr %r11
2686 . mtlr %r12
2687 . lis %r12,xxx-1b@highest
2688 . ori %r12,%r12,xxx-1b@higher
2689 . sldi %r12,%r12,32
2690 . oris %r12,%r12,xxx-1b@high
2691 . ori %r12,%r12,xxx-1b@l
2692 . ldx %r12,%r11,%r12
2693 . mtctr %r12
2694 . bctr
2696 In cases where the high instructions would add zero, they are
2697 omitted and following instructions modified in some cases.
2699 For a given stub group (a set of sections all using the same toc
2700 pointer value) there will be just one stub type used for any
2701 particular function symbol. For example, if printf is called from
2702 code with the tocsave optimization (ie. r2 saved in function
2703 prologue) and therefore calls use a ppc_stub_plt_call linkage stub,
2704 and from other code without the tocsave optimization requiring a
2705 ppc_stub_plt_call_r2save linkage stub, a single stub of the latter
2706 type will be created. Calls with the tocsave optimization will
2707 enter this stub after the instruction saving r2. A similar
2708 situation exists when calls are marked with R_PPC64_REL24_NOTOC
2709 relocations. These require a ppc_stub_plt_call_notoc linkage stub
2710 to call an external function like printf. If other calls to printf
2711 require a ppc_stub_plt_call linkage stub then a single
2712 ppc_stub_plt_call_notoc linkage stub will be used for both types of
2713 call. If other calls to printf require a ppc_stub_plt_call_r2save
2714 linkage stub then a single ppc_stub_plt_call_both linkage stub will
2715 be created and calls not requiring r2 to be saved will enter the
2716 stub after the r2 save instruction. There is an analogous
2717 hierarchy of long branch and plt branch stubs for local call
2718 linkage. */
2720 enum ppc_stub_type
2721 {
2722 ppc_stub_none,
2723 ppc_stub_long_branch,
2724 ppc_stub_long_branch_r2off,
2725 ppc_stub_long_branch_notoc,
2727 ppc_stub_plt_branch,
2728 ppc_stub_plt_branch_r2off,
2729 ppc_stub_plt_branch_notoc,
2730 ppc_stub_plt_branch_both,
2731 ppc_stub_plt_call,
2732 ppc_stub_plt_call_r2save,
2733 ppc_stub_plt_call_notoc,
2734 ppc_stub_plt_call_both,
2735 ppc_stub_global_entry,
2736 ppc_stub_save_res
2737 };
2739 /* Information on stub grouping. */
2740 struct map_stub
2741 {
2742 /* The stub section. */
2744 /* This is the section to which stubs in the group will be attached. */
2746 /* Next group. */
2748 /* Whether to emit a copy of register save/restore functions in this
2749 group. */
2751 /* Current offset within stubs after the insn restoring lr in a
2752 _notoc or _both stub using bcl for pc-relative addressing, or
2753 after the insn restoring lr in a __tls_get_addr_opt plt stub. */
2755 /* Accumulated size of EH info emitted to describe return address
2756 if stubs modify lr. Does not include 17 byte FDE header. */
2758 /* Offset in glink_eh_frame to the start of EH info for this group. */
2760 };
2762 struct ppc_stub_hash_entry
2763 {
2764 /* Base hash table entry structure. */
2769 /* Group information. */
2772 /* Offset within stub_sec of the beginning of this stub. */
2773 bfd_vma stub_offset;
2775 /* Given the symbol's value and its section we can determine its final
2776 value when building the stubs (so the stub knows where to jump. */
2777 bfd_vma target_value;
2780 /* The symbol table entry, if any, that this was derived from. */
2784 /* Symbol type. */
2787 /* Symbol st_other. */
2789 };
2791 struct ppc_branch_hash_entry
2792 {
2793 /* Base hash table entry structure. */
2796 /* Offset within branch lookup table. */
2799 /* Generation marker. */
2801 };
2803 /* Used to track dynamic relocations for local symbols. */
2804 struct ppc_dyn_relocs
2805 {
2808 /* The input section of the reloc. */
2811 /* Total number of relocs copied for the input section. */
2814 /* Whether this entry is for STT_GNU_IFUNC symbols. */
2816 };
2818 struct ppc_link_hash_entry
2819 {
2822 union
2823 {
2824 /* A pointer to the most recently used stub hash entry against this
2825 symbol. */
2828 /* A pointer to the next symbol starting with a '.' */
2832 /* Track dynamic relocs copied for this symbol. */
2835 /* Link between function code and descriptor symbols. */
2838 /* Flag function code and descriptor symbols. */
2843 /* Whether global opd/toc sym has been adjusted or not.
2844 After ppc64_elf_edit_opd/ppc64_elf_edit_toc has run, this flag
2845 should be set for all globals defined in any opd/toc section. */
2848 /* Set if this is an out-of-line register save/restore function,
2849 with non-standard calling convention. */
2852 /* Set if a duplicate symbol with non-zero localentry is detected,
2853 even when the duplicate symbol does not provide a definition. */
2856 /* Contexts in which symbol is used in the GOT (or TOC).
2857 Bits are or'd into the mask as the corresponding relocs are
2858 encountered during check_relocs, with TLS_TLS being set when any
2859 of the other TLS bits are set. tls_optimize clears bits when
2860 optimizing to indicate the corresponding GOT entry type is not
2861 needed. If set, TLS_TLS is never cleared. tls_optimize may also
2862 set TLS_TPRELGD when a GD reloc turns into a TPREL one. We use a
2863 separate flag rather than setting TPREL just for convenience in
2864 distinguishing the two cases.
2865 These flags are also kept for local symbols. */
2876 /* The above field is also used to mark function symbols. In which
2877 case TLS_TLS will be 0. */
2881 };
2883 /* ppc64 ELF linker hash table. */
2885 struct ppc_link_hash_table
2886 {
2889 /* The stub hash table. */
2892 /* Another hash table for plt_branch stubs. */
2895 /* Hash table for function prologue tocsave. */
2896 htab_t tocsave_htab;
2898 /* Various options and other info passed from the linker. */
2901 /* The size of sec_info below. */
2904 /* Per-section array of extra section info. Done this way rather
2905 than as part of ppc64_elf_section_data so we have the info for
2906 non-ppc64 sections. */
2907 struct
2908 {
2909 /* Along with elf_gp, specifies the TOC pointer used by this section. */
2910 bfd_vma toc_off;
2912 union
2913 {
2914 /* The section group that this section belongs to. */
2916 /* A temp section list pointer. */
2921 /* Linked list of groups. */
2924 /* Temp used when calculating TOC pointers. */
2925 bfd_vma toc_curr;
2929 /* Used when adding symbols. */
2932 /* Shortcuts to get to dynamic linker sections. */
2942 /* Shortcut to .__tls_get_addr and __tls_get_addr. */
2946 /* The size of reliplt used by got entry relocs. */
2947 bfd_size_type got_reli_size;
2949 /* Statistics. */
2952 /* Number of stubs against global syms. */
2955 /* Set if we're linking code with function descriptors. */
2958 /* Support for multiple toc sections. */
2964 /* Set if tls optimization is enabled. */
2967 /* Set if inline plt calls should be converted to direct calls. */
2970 /* Set on error. */
2973 /* Whether func_desc_adjust needs to be run over symbols. */
2976 /* Whether there exist local gnu indirect function resolvers,
2977 referenced by dynamic relocations. */
2981 /* Whether plt calls for ELFv2 localentry:0 funcs have been optimized. */
2984 /* Incremented every time we size stubs. */
2987 /* Small local sym cache. */
2989 };
2991 /* Rename some of the generic section flags to better document how they
2992 are used here. */
2994 /* Nonzero if this section has TLS related relocations. */
2995 #define has_tls_reloc sec_flg0
2997 /* Nonzero if this section has an old-style call to __tls_get_addr. */
2998 #define has_tls_get_addr_call sec_flg1
3000 /* Nonzero if this section has any toc or got relocs. */
3001 #define has_toc_reloc sec_flg2
3003 /* Nonzero if this section has a call to another section that uses
3004 the toc or got. */
3005 #define makes_toc_func_call sec_flg3
3007 /* Recursion protection when determining above flag. */
3008 #define call_check_in_progress sec_flg4
3009 #define call_check_done sec_flg5
3011 /* Get the ppc64 ELF linker hash table from a link_info structure. */
3013 #define ppc_hash_table(p) \
3014 (elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) \
3015 == PPC64_ELF_DATA ? ((struct ppc_link_hash_table *) ((p)->hash)) : NULL)
3017 #define ppc_stub_hash_lookup(table, string, create, copy) \
3018 ((struct ppc_stub_hash_entry *) \
3019 bfd_hash_lookup ((table), (string), (create), (copy)))
3021 #define ppc_branch_hash_lookup(table, string, create, copy) \
3022 ((struct ppc_branch_hash_entry *) \
3023 bfd_hash_lookup ((table), (string), (create), (copy)))
3025 /* Create an entry in the stub hash table. */
3031 {
3032 /* Allocate the structure if it has not already been allocated by a
3033 subclass. */
3035 {
3039 }
3041 /* Call the allocation method of the superclass. */
3044 {
3047 /* Initialize the local fields. */
3057 }
3060 }
3062 /* Create an entry in the branch hash table. */
3068 {
3069 /* Allocate the structure if it has not already been allocated by a
3070 subclass. */
3072 {
3076 }
3078 /* Call the allocation method of the superclass. */
3081 {
3084 /* Initialize the local fields. */
3088 }
3091 }
3093 /* Create an entry in a ppc64 ELF linker hash table. */
3099 {
3100 /* Allocate the structure if it has not already been allocated by a
3101 subclass. */
3103 {
3107 }
3109 /* Call the allocation method of the superclass. */
3112 {
3119 /* When making function calls, old ABI code references function entry
3120 points (dot symbols), while new ABI code references the function
3121 descriptor symbol. We need to make any combination of reference and
3122 definition work together, without breaking archive linking.
3124 For a defined function "foo" and an undefined call to "bar":
3125 An old object defines "foo" and ".foo", references ".bar" (possibly
3126 "bar" too).
3127 A new object defines "foo" and references "bar".
3129 A new object thus has no problem with its undefined symbols being
3130 satisfied by definitions in an old object. On the other hand, the
3131 old object won't have ".bar" satisfied by a new object.
3133 Keep a list of newly added dot-symbols. */
3136 {
3142 }
3143 }
3146 }
3148 struct tocsave_entry
3149 {
3151 bfd_vma offset;
3152 };
3154 static hashval_t
3156 {
3159 }
3161 static int
3163 {
3167 }
3169 /* Destroy a ppc64 ELF linker hash table. */
3171 static void
3173 {
3182 }
3184 /* Create a ppc64 ELF linker hash table. */
3188 {
3198 PPC64_ELF_DATA))
3199 {
3202 }
3204 /* Init the stub hash table too. */
3207 {
3210 }
3212 /* And the branch hash table. */
3215 {
3219 }
3222 tocsave_htab_hash,
3223 tocsave_htab_eq,
3224 NULL);
3226 {
3229 }
3232 /* Initializing two fields of the union is just cosmetic. We really
3233 only care about glist, but when compiled on a 32-bit host the
3234 bfd_vma fields are larger. Setting the bfd_vma to zero makes
3235 debugger inspection of these fields look nicer. */
3246 }
3248 /* Create sections for linker generated code. */
3250 static bfd_boolean
3252 {
3254 flagword flags;
3261 {
3262 /* Create .sfpr for code to save and restore fp regs. */
3264 flags);
3268 }
3273 /* Create .glink for lazy dynamic linking support. */
3275 flags);
3280 /* The part of .glink used by global entry stubs, separate so that
3281 it can be aligned appropriately without affecting htab->glink. */
3283 flags);
3289 {
3294 flags);
3298 }
3314 /* Create branch lookup table for plt_branch stubs. */
3318 flags);
3323 /* Local plt entries, put in .branch_lt but a separate section for
3324 convenience. */
3326 flags);
3336 htab->relbrlt
3342 htab->relpltlocal
3349 }
3351 /* Satisfy the ELF linker by filling in some fields in our fake bfd. */
3353 bfd_boolean
3356 {
3361 /* Always hook our dynamic sections into the first bfd, which is the
3362 linker created stub bfd. This ensures that the GOT header is at
3363 the start of the output TOC section. */
3369 }
3371 /* Build a name for an entry in the stub hash table. */
3378 {
3380 ssize_t len;
3382 /* rel->r_addend is actually 64 bit, but who uses more than +/- 2^31
3383 offsets from a sym as a branch target? In fact, we could
3384 probably assume the addend is always zero. */
3388 {
3398 }
3399 else
3400 {
3411 }
3415 }
3417 /* Look up an entry in the stub hash. Stub entries are cached because
3418 creating the stub name takes a bit of time. */
3426 {
3430 /* If this input section is part of a group of sections sharing one
3431 stub section, then use the id of the first section in the group.
3432 Stub names need to include a section id, as there may well be
3433 more than one stub used to reach say, printf, and we need to
3434 distinguish between them. */
3442 {
3444 }
3445 else
3446 {
3459 }
3462 }
3464 /* Add a new stub entry to the stub hash. Not all fields of the new
3465 stub entry are initialised. */
3471 {
3482 {
3484 bfd_size_type len;
3499 }
3501 /* Enter this entry into the linker stub hash table. */
3505 {
3506 /* xgettext:c-format */
3510 }
3515 }
3517 /* Create .got and .rela.got sections in ABFD, and .got in dynobj if
3518 not already done. */
3520 static bfd_boolean
3522 {
3524 flagword flags;
3553 }
3555 /* Follow indirect and warning symbol links. */
3559 {
3564 }
3568 {
3570 }
3574 {
3576 }
3578 /* Merge PLT info on FROM with that on TO. */
3580 static void
3583 {
3585 {
3587 {
3592 {
3597 {
3601 }
3604 }
3606 }
3610 }
3611 }
3613 /* Copy the extra info we tack onto an elf_link_hash_entry. */
3615 static void
3619 {
3639 /* If we were called to copy over info for a weak sym, don't copy
3640 dyn_relocs, plt/got info, or dynindx. We used to copy dyn_relocs
3641 in order to simplify readonly_dynrelocs and save a field in the
3642 symbol hash entry, but that means dyn_relocs can't be used in any
3643 tests about a specific symbol, or affect other symbol flags which
3644 are then tested. */
3648 /* Copy over any dynamic relocs we may have on the indirect sym. */
3650 {
3652 {
3656 /* Add reloc counts against the indirect sym to the direct sym
3657 list. Merge any entries against the same section. */
3659 {
3664 {
3669 }
3672 }
3674 }
3678 }
3680 /* Copy over got entries that we may have already seen to the
3681 symbol which just became indirect. */
3683 {
3685 {
3690 {
3697 {
3701 }
3704 }
3706 }
3710 }
3712 /* And plt entries. */
3716 {
3724 }
3725 }
3727 /* Find the function descriptor hash entry from the given function code
3728 hash entry FH. Link the entries via their OH fields. */
3732 {
3736 {
3748 }
3754 }
3756 /* Make a fake function descriptor sym for the undefined code sym FH. */
3761 {
3766 ? BSF_WEAK
3783 }
3785 /* Fix function descriptor symbols defined in .opd sections to be
3786 function type. */
3788 static bfd_boolean
3796 {
3799 {
3806 /* If the symbol is a function defined in .opd, and the function
3807 code is in a discarded group, let it appear to be undefined. */
3813 {
3816 }
3817 }
3821 {
3825 }
3828 {
3832 {
3837 }
3838 }
3841 }
3843 /* Merge non-visibility st_other attributes: local entry point. */
3845 static void
3848 bfd_boolean definition,
3849 bfd_boolean dynamic)
3850 {
3854 }
3856 /* Hook called on merging a symbol. We use this to clear "fake" since
3857 we now have a real symbol. */
3859 static bfd_boolean
3863 bfd_boolean newdef ATTRIBUTE_UNUSED,
3864 bfd_boolean olddef ATTRIBUTE_UNUSED,
3867 {
3872 }
3874 /* This function makes an old ABI object reference to ".bar" cause the
3875 inclusion of a new ABI object archive that defines "bar".
3876 NAME is a symbol defined in an archive. Return a symbol in the hash
3877 table that might be satisfied by the archive symbols. */
3883 {
3890 /* Don't return this sym if it is a fake function descriptor
3891 created by add_symbol_adjust. */
3907 }
3909 /* This function satisfies all old ABI object references to ".bar" if a
3910 new ABI object defines "bar". Well, at least, undefined dot symbols
3911 are made weak. This stops later archive searches from including an
3912 object if we already have a function descriptor definition. It also
3913 prevents the linker complaining about undefined symbols.
3914 We also check and correct mismatched symbol visibility here. The
3915 most restrictive visibility of the function descriptor and the
3916 function entry symbol is used. */
3918 static bfd_boolean
3920 {
3943 {
3944 /* Make an undefined function descriptor sym, in order to
3945 pull in an --as-needed shared lib. Archives are handled
3946 elsewhere. */
3950 }
3953 {
3957 /* Make both descriptor and entry symbol have the most
3958 constraining visibility of either symbol. */
3964 /* Propagate reference flags from entry symbol to function
3965 descriptor symbol. */
3979 {
3982 }
3983 }
3986 }
3988 /* Set up opd section info and abiversion for IBFD, and process list
3989 of dot-symbols we made in link_hash_newfunc. */
3991 static bfd_boolean
3993 {
3999 {
4006 {
4007 /* xgettext:c-format */
4012 }
4013 }
4016 {
4017 /* For input files without an explicit abiversion in e_flags
4018 we should have flagged any with symbol st_other bits set
4019 as ELFv1 and above flagged those with .opd as ELFv2.
4020 Set the output abiversion if not yet set, and for any input
4021 still ambiguous, take its abiversion from the output.
4022 Differences in ABI are reported later. */
4027 }
4039 {
4040 /* Garbage collection needs some extra help with .opd sections.
4041 We don't want to necessarily keep everything referenced by
4042 relocs in .opd, as that would keep all functions. Instead,
4043 if we reference an .opd symbol (a function descriptor), we
4044 want to keep the function code symbol's section. This is
4045 easy for global symbols, but for local syms we need to keep
4046 information about the associated function section. */
4047 bfd_size_type amt;
4064 {
4071 {
4077 {
4081 }
4086 }
4087 }
4090 }
4094 {
4097 ;
4102 {
4106 }
4108 }
4110 }
4112 /* Undo hash table changes when an --as-needed input file is determined
4113 not to be needed. */
4115 static bfd_boolean
4119 {
4121 {
4128 }
4130 }
4132 /* If --just-symbols against a final linked binary, then assume we need
4133 toc adjusting stubs when calling functions defined there. */
4135 static void
4137 {
4141 {
4145 }
4147 }
4152 {
4158 {
4168 }
4171 {
4180 {
4192 }
4194 }
4201 }
4203 static bfd_boolean
4205 {
4212 {
4221 }
4224 }
4226 static bfd_boolean
4228 {
4239 }
4241 /* Relocs on inline plt call sequence insns prior to the call. */
4243 static bfd_boolean
4245 {
4251 }
4253 /* Look through the relocs for a section during the first phase, and
4254 calculate needed space in the global offset table, procedure
4255 linkage table, and dynamic reloc sections. */
4257 static bfd_boolean
4260 {
4268 bfd_boolean is_opd;
4273 /* Don't do anything special with non-loaded, non-alloced sections.
4274 In particular, any relocs in such sections should not affect GOT
4275 and PLT reference counting (ie. we don't allow them to create GOT
4276 or PLT entries), there's no possibility or desire to optimize TLS
4277 relocs, and there's not much point in propagating relocs to shared
4278 libs that the dynamic linker won't relocate. */
4298 {
4309 else
4310 {
4316 }
4321 {
4323 {
4326 }
4327 }
4328 else
4329 {
4336 {
4342 }
4343 }
4347 {
4350 /* These special tls relocs tie a call to __tls_get_addr with
4351 its parameter symbol. */
4354 else
4390 dogottls:
4399 /* Fall through. */
4404 dogot:
4405 /* This symbol requires a global offset table entry. */
4413 {
4416 }
4423 {
4434 {
4446 }
4449 }
4450 else
4451 /* This is a global offset table entry for a local symbol. */
4456 /* We may also need a plt entry if the symbol turns out to be
4457 an ifunc. */
4459 {
4462 }
4471 /* This symbol requires a procedure linkage table entry. */
4474 {
4481 }
4490 /* The following relocations don't need to propagate the
4491 relocation if linking a shared object since they are
4492 section relative. */
4513 /* Nor do these. */
4527 /* Not supported as a dynamic relocation. */
4530 {
4533 /* xgettext:c-format */
4540 }
4547 /* Fall through. */
4555 /* Marker reloc. */
4559 /* This relocation describes the C++ object vtable hierarchy.
4560 Reconstruct it for later use during GC. */
4566 /* This relocation describes which C++ vtable entries are actually
4567 used. Record for later use during GC. */
4576 {
4579 /* Heuristic: If jumping outside our section, chances are
4580 we are going to need a stub. */
4582 {
4583 /* If the sym is weak it may be overridden later, so
4584 don't assume we know where a weak sym lives. */
4587 }
4588 else
4589 {
4598 }
4602 }
4607 /* Fall through. */
4611 rel24:
4614 {
4621 {
4626 /* We have a new-style __tls_get_addr call with
4627 a marker reloc. */
4628 ;
4629 else
4630 /* Mark this section as having an old-style call. */
4632 }
4634 }
4636 /* We may need a .plt entry if the function this reloc
4637 refers to is in a shared lib. */
4660 else
4669 /* This is the second reloc of a dtpmod, dtprel pair.
4670 Don't mark with TLS_DTPREL. */
4673 dotlstoc:
4676 {
4680 }
4681 else
4688 {
4689 bfd_size_type amt;
4691 /* One extra to simplify get_tls_mask. */
4702 }
4707 /* Mark the second slot of a GD or LD entry.
4708 -1 to indicate GD and -2 to indicate LD. */
4735 {
4738 }
4739 /* Fall through. */
4755 {
4756 /* We may need a .plt entry if this reloc refers to a
4757 function in a shared lib. */
4761 }
4762 /* Fall through. */
4773 /* We may need a copy reloc. */
4776 /* Don't propagate .opd relocs. */
4780 /* If we are creating a shared library, and this is a reloc
4781 against a global symbol, or a non PC relative reloc
4782 against a local symbol, then we need to copy the reloc
4783 into the shared library. However, if we are linking with
4784 -Bsymbolic, we do not need to copy a reloc against a
4785 global symbol which is defined in an object we are
4786 including in the link (i.e., DEF_REGULAR is set). At
4787 this point we have not seen all the input files, so it is
4788 possible that DEF_REGULAR is not set now but will be set
4789 later (it is never cleared). In case of a weak definition,
4790 DEF_REGULAR may be cleared later by a strong definition in
4791 a shared library. We account for that possibility below by
4792 storing information in the dyn_relocs field of the hash
4793 table entry. A similar situation occurs when creating
4794 shared libraries and symbol visibility changes render the
4795 symbol local.
4797 If on the other hand, we are creating an executable, we
4798 may need to keep relocations for symbols satisfied by a
4799 dynamic library if we manage to avoid copy relocs for the
4800 symbol. */
4801 dodyn:
4808 || (ELIMINATE_COPY_RELOCS
4815 {
4816 /* We must copy these reloc types into the output file.
4817 Create a reloc section in dynobj and make room for
4818 this reloc. */
4820 {
4821 sreloc = _bfd_elf_make_dynamic_reloc_section
4826 }
4828 /* If this is a global symbol, we count the number of
4829 relocations we need for this symbol. */
4831 {
4838 {
4847 }
4851 }
4852 else
4853 {
4854 /* Track dynamic relocs needed for local syms too.
4855 We really need local syms available to do this
4856 easily. Oh well. */
4859 bfd_boolean is_ifunc;
4880 {
4889 }
4891 }
4892 }
4897 }
4898 }
4901 }
4903 /* Merge backend specific data from an object file to the output
4904 object file when linking. */
4906 static bfd_boolean
4908 {
4925 {
4926 _bfd_error_handler
4927 /* xgettext:c-format */
4931 }
4933 {
4934 _bfd_error_handler
4935 /* xgettext:c-format */
4940 }
4945 /* Merge Tag_compatibility attributes and any common GNU ones. */
4947 }
4949 static bfd_boolean
4951 {
4952 /* Print normal ELF private data. */
4956 {
4966 }
4969 }
4971 /* OFFSET in OPD_SEC specifies a function descriptor. Return the address
4972 of the code entry point, and its section, which must be in the same
4973 object as OPD_SEC. Returns (bfd_vma) -1 on error. */
4975 static bfd_vma
4977 bfd_vma offset,
4980 bfd_boolean in_code_sec)
4981 {
4985 bfd_vma val;
4987 /* No relocs implies we are linking a --just-symbols object, or looking
4988 at a final linked executable with addr2line or somesuch. */
4990 {
4994 {
4998 }
5000 /* PR 17512: file: 64b9dfbb. */
5006 {
5010 {
5015 else
5017 }
5018 else
5025 {
5029 }
5030 }
5032 }
5039 /* PR 17512: file: df8e1fd6. */
5043 /* Go find the opd reloc at the sym address. */
5048 {
5054 else
5055 {
5060 {
5066 {
5073 {
5079 {
5082 }
5083 }
5084 }
5087 {
5091 {
5094 {
5102 }
5104 }
5105 else
5106 {
5112 }
5118 }
5124 {
5127 else
5129 }
5132 }
5134 }
5135 }
5138 }
5140 /* If the ELF symbol SYM might be a function in SEC, return the
5141 function size and set *CODE_OFF to the function's entry point,
5142 otherwise return zero. */
5144 static bfd_size_type
5147 {
5148 bfd_size_type size;
5159 {
5166 {
5167 /* opd_entry_value will use cached relocs that have been
5168 adjusted, but with raw symbols. That means both local
5169 and global symbols need adjusting. */
5174 }
5179 /* An old ABI binary with dot-syms has a size of 24 on the .opd
5180 symbol. This size has nothing to do with the code size of the
5181 function, which is what we're supposed to return, but the
5182 code size isn't available without looking up the dot-sym.
5183 However, doing that would be a waste of time particularly
5184 since elf_find_function will look at the dot-sym anyway.
5185 Now, elf_find_function will keep the largest size of any
5186 function sym found at the code address of interest, so return
5187 1 here to avoid it incorrectly caching a larger function size
5188 for a small function. This does mean we return the wrong
5189 size for a new-ABI function of size 24, but all that does is
5190 disable caching for such functions. */
5193 }
5194 else
5195 {
5199 }
5203 }
5205 /* Return true if symbol is a strong function defined in an ELFv2
5206 object with st_other localentry bits of zero, ie. its local entry
5207 point coincides with its global entry point. */
5209 static bfd_boolean
5211 {
5219 }
5221 /* Return true if symbol is defined in a regular object file. */
5223 static bfd_boolean
5225 {
5230 }
5232 /* If FDH is a function descriptor symbol, return the associated code
5233 entry symbol if it is defined. Return NULL otherwise. */
5237 {
5239 {
5244 }
5246 }
5248 /* If FH is a function code entry symbol, return the associated
5249 function descriptor symbol if it is defined. Return NULL otherwise. */
5253 {
5256 {
5261 }
5263 }
5267 /* Garbage collect sections, after first dealing with dot-symbols. */
5269 static bfd_boolean
5271 {
5275 {
5278 }
5280 }
5282 /* Mark all our entry sym sections, both opd and code section. */
5284 static void
5286 {
5294 {
5308 {
5311 }
5320 }
5321 }
5323 /* Mark sections containing dynamically referenced symbols. When
5324 building shared libraries, we must assume that any visible symbol is
5325 referenced. */
5327 static bfd_boolean
5329 {
5335 /* Dynamic linking info is on the func descriptor sym. */
5356 {
5362 /* Function descriptor syms cause the associated
5363 function code sym section to be marked. */
5366 {
5369 }
5375 }
5378 }
5380 /* Return the section that should be marked against GC for a given
5381 relocation. */
5389 {
5392 /* Syms return NULL if we're marking .opd, so we avoid marking all
5393 function sections, as all functions are referenced in .opd. */
5399 {
5405 {
5412 {
5418 {
5419 /* -mcall-aixdesc code references the dot-symbol on
5420 a call reloc. Mark the function descriptor too
5421 against garbage collection. */
5426 }
5428 /* Function descriptor syms cause the associated
5429 function code sym section to be marked. */
5432 {
5433 /* They also mark their opd section. */
5437 }
5443 else
5453 }
5454 }
5455 }
5456 else
5457 {
5463 {
5467 }
5468 }
5471 }
5473 /* The maximum size of .sfpr. */
5474 #define SFPR_MAX (218*4)
5476 struct sfpr_def_parms
5477 {
5482 };
5484 /* Auto-generate _save*, _rest* functions in .sfpr.
5485 If STUB_SEC is non-null, define alias symbols in STUB_SEC
5486 instead. */
5488 static bfd_boolean
5492 {
5506 {
5514 {
5518 {
5528 {
5539 }
5540 }
5542 }
5544 {
5547 {
5557 {
5562 }
5563 }
5564 }
5566 {
5570 else
5573 }
5574 }
5577 }
5581 {
5584 }
5588 {
5594 }
5598 {
5601 }
5605 {
5612 {
5615 }
5618 }
5622 {
5625 }
5629 {
5633 }
5637 {
5640 }
5644 {
5648 }
5652 {
5655 }
5659 {
5665 }
5669 {
5672 }
5676 {
5683 {
5686 }
5689 }
5693 {
5697 }
5701 {
5705 }
5709 {
5714 }
5718 {
5722 }
5726 {
5731 }
5735 {
5739 }
5741 /* Called via elf_link_hash_traverse to transfer dynamic linking
5742 information on function code symbol entries to their corresponding
5743 function descriptor symbol entries. */
5745 static bfd_boolean
5747 {
5752 bfd_boolean force_local;
5770 /* Find the corresponding function descriptor symbol. */
5773 /* Resolve undefined references to dot-symbols as the value
5774 in the function descriptor, if we have one in a regular object.
5775 This is to satisfy cases like ".quad .foo". Calls to functions
5776 in dynamic objects are handled elsewhere. */
5786 {
5791 }
5794 {
5802 }
5804 /* Create a descriptor as undefined if necessary. */
5809 {
5813 }
5815 /* We can't support overriding of symbols on a fake descriptor. */
5822 /* Transfer dynamic linking information to the function descriptor. */
5824 {
5839 }
5841 /* Now that the info is on the function descriptor, clear the
5842 function code sym info. Any function code syms for which we
5843 don't have a definition in a regular file, we force local.
5844 This prevents a shared library from exporting syms that have
5845 been imported from another library. Function code syms that
5846 are really in the library we must leave global to prevent the
5847 linker dragging in a definition from a static library. */
5855 }
5858 {
5871 };
5873 /* Called near the start of bfd_elf_size_dynamic_sections. We use
5874 this hook to a) provide some gcc support functions, and b) transfer
5875 dynamic linking information gathered so far on function code symbol
5876 entries, to their corresponding function descriptor symbol entries. */
5878 static bfd_boolean
5881 {
5888 /* Provide any missing _save* and _rest* functions. */
5890 {
5899 }
5905 {
5907 /* Make .TOC. defined so as to prevent it being made dynamic.
5908 The wrong value here is fixed later in ppc64_elf_set_toc. */
5911 {
5917 }
5921 }
5924 {
5927 }
5930 }
5932 /* Find dynamic relocs for H that apply to read-only sections. */
5936 {
5942 {
5947 }
5949 }
5951 /* Return true if we have dynamic relocs against H or any of its weak
5952 aliases, that apply to read-only sections. Cannot be used after
5953 size_dynamic_sections. */
5955 static bfd_boolean
5957 {
5961 do
5962 {
5966 }
5970 }
5972 /* Return whether EH has pc-relative dynamic relocs. */
5974 static bfd_boolean
5976 {
5983 }
5985 /* Return true if a global entry stub will be created for H. Valid
5986 for ELFv2 before plt entries have been allocated. */
5988 static bfd_boolean
5990 {
6003 }
6005 /* Adjust a symbol defined by a dynamic object and referenced by a
6006 regular object. The current definition is in some section of the
6007 dynamic object, but we're not including those sections. We have to
6008 change the definition to something the rest of the link can
6009 understand. */
6011 static bfd_boolean
6014 {
6022 /* Deal with function syms. */
6026 {
6030 /* Discard dyn_relocs when non-pic if we've decided that a
6031 function symbol is local and not an ifunc. We keep dynamic
6032 relocs for ifuncs when local rather than always emitting a
6033 plt call stub for them and defining the symbol on the call
6034 stub. We can't do that for ELFv1 anyway (a function symbol
6035 is defined on a descriptor, not code) and it can be faster at
6036 run-time due to not needing to bounce through a stub. The
6037 dyn_relocs for ifuncs will be applied even in a static
6038 executable. */
6044 /* Clear procedure linkage table information for any symbol that
6045 won't need a .plt entry. */
6052 && local
6056 {
6060 }
6062 {
6063 /* Taking a function's address in a read/write section
6064 doesn't require us to define the function symbol in the
6065 executable on a global entry stub. A dynamic reloc can
6066 be used instead. The reason we prefer a few more dynamic
6067 relocs is that calling via a global entry stub costs a
6068 few more instructions, and pointer_equality_needed causes
6069 extra work in ld.so when resolving these symbols. */
6071 {
6073 {
6075 /* If we haven't seen a branch reloc and the symbol
6076 isn't an ifunc then we don't need a plt entry. */
6079 }
6081 /* We are going to be defining the function symbol on the
6082 plt stub, so no dyn_relocs needed when non-pic. */
6084 }
6086 /* ELFv2 function symbols can't have copy relocs. */
6088 }
6091 {
6092 /* If we haven't seen a branch reloc and the symbol isn't an
6093 ifunc then we don't need a plt entry. */
6097 }
6098 }
6099 else
6102 /* If this is a weak symbol, and there is a real definition, the
6103 processor independent code will have arranged for us to see the
6104 real definition first, and we can just use the same value. */
6106 {
6115 }
6117 /* If we are creating a shared library, we must presume that the
6118 only references to the symbol are via the global offset table.
6119 For such cases we need not do anything here; the relocations will
6120 be handled correctly by relocate_section. */
6124 /* If there are no references to this symbol that do not use the
6125 GOT, we don't need to generate a copy reloc. */
6129 /* Don't generate a copy reloc for symbols defined in the executable. */
6132 /* If -z nocopyreloc was given, don't generate them either. */
6135 /* If we don't find any dynamic relocs in read-only sections, then
6136 we'll be keeping the dynamic relocs and avoiding the copy reloc. */
6139 /* Protected variables do not work with .dynbss. The copy in
6140 .dynbss won't be used by the shared library with the protected
6141 definition for the variable. Text relocations are preferable
6142 to an incorrect program. */
6147 {
6148 /* We should never get here, but unfortunately there are versions
6149 of gcc out there that improperly (for this ABI) put initialized
6150 function pointers, vtable refs and suchlike in read-only
6151 sections. Allow them to proceed, but warn that this might
6152 break at runtime. */
6157 }
6159 /* This is a reference to a symbol defined by a dynamic object which
6160 is not a function. */
6162 /* We must allocate the symbol in our .dynbss section, which will
6163 become part of the .bss section of the executable. There will be
6164 an entry for this symbol in the .dynsym section. The dynamic
6165 object will contain position independent code, so all references
6166 from the dynamic object to this symbol will go through the global
6167 offset table. The dynamic linker will use the .dynsym entry to
6168 determine the address it must put in the global offset table, so
6169 both the dynamic object and the regular object will refer to the
6170 same memory location for the variable. */
6172 {
6175 }
6176 else
6177 {
6180 }
6182 {
6183 /* We must generate a R_PPC64_COPY reloc to tell the dynamic
6184 linker to copy the initial value out of the dynamic object
6185 and into the runtime process image. */
6188 }
6190 /* We no longer want dyn_relocs. */
6193 }
6195 /* If given a function descriptor symbol, hide both the function code
6196 sym and the descriptor. */
6197 static void
6200 bfd_boolean force_local)
6201 {
6210 {
6214 {
6219 /* We aren't supposed to use alloca in BFD because on
6220 systems which do not have alloca the version in libiberty
6221 calls xmalloc, which might cause the program to crash
6222 when it runs out of memory. This function doesn't have a
6223 return status, so there's no way to gracefully return an
6224 error. So cheat. We know that string[-1] can be safely
6225 accessed; It's either a string in an ELF string table,
6226 or allocated in an objalloc structure. */
6235 /* Unfortunately, if it so happens that the string we were
6236 looking for was allocated immediately before this string,
6237 then we overwrote the string terminator. That's the only
6238 reason the lookup should fail. */
6240 {
6247 }
6249 {
6252 }
6253 }
6256 }
6257 }
6259 static bfd_boolean
6267 {
6271 {
6285 {
6291 }
6294 {
6299 }
6300 }
6301 else
6302 {
6307 {
6316 }
6329 {
6336 {
6342 }
6344 }
6345 }
6347 }
6349 /* Returns TLS_MASKP for the given REL symbol. Function return is 0 on
6350 error, 2 on a toc GD type suitable for optimization, 3 on a toc LD
6351 type suitable for optimization, and 1 otherwise. */
6353 static int
6360 {
6366 bfd_vma off;
6380 /* Look inside a TOC section too. */
6382 {
6385 }
6386 else
6402 }
6404 /* Find (or create) an entry in the tocsave hash table. */
6412 {
6417 hashval_t hash;
6424 {
6425 _bfd_error_handler
6428 }
6432 else
6443 {
6449 }
6451 }
6453 /* Adjust all global syms defined in opd sections. In gcc generated
6454 code for the old ABI, these will already have been done. */
6456 static bfd_boolean
6458 {
6477 {
6480 {
6481 /* This entry has been deleted. */
6484 {
6487 {
6490 }
6491 }
6494 }
6495 else
6498 }
6500 }
6502 /* Handles decrementing dynamic reloc counts for the reloc specified by
6503 R_INFO in section SEC. If LOCAL_SYMS is NULL, then H and SYM
6504 have already been determined. */
6506 static bfd_boolean
6513 {
6517 /* Can this reloc be dynamic? This switch, and later tests here
6518 should be kept in sync with the code in check_relocs. */
6521 {
6566 }
6569 {
6576 }
6584 || (ELIMINATE_COPY_RELOCS
6589 ;
6590 else
6594 {
6599 /* elf_gc_sweep may have already removed all dyn relocs associated
6600 with local syms for a given section. Also, symbol flags are
6601 changed by elf_gc_sweep_symbol, confusing the test above. Don't
6602 report a dynreloc miscount. */
6607 {
6609 {
6616 }
6618 }
6619 }
6620 else
6621 {
6625 bfd_boolean is_ifunc;
6640 {
6642 {
6647 }
6649 }
6650 }
6652 /* xgettext:c-format */
6657 }
6659 /* Remove unused Official Procedure Descriptor entries. Currently we
6660 only remove those associated with functions in discarded link-once
6661 sections, or weakly defined functions that have been overridden. It
6662 would be possible to remove many more entries for statically linked
6663 applications. */
6665 bfd_boolean
6667 {
6678 {
6700 /* Look through the section relocs. */
6707 /* Read the relocations. */
6713 /* First run through the relocs to check they are sane, and to
6714 determine whether we need to edit this opd section. */
6720 {
6726 bfd_vma offset;
6728 /* .opd contains an array of 16 or 24 byte entries. We're
6729 only interested in the reloc pointing to a function entry
6730 point. */
6734 {
6735 /* If someone messes with .opd alignment then after a
6736 "ld -r" we might have padding in the middle of .opd.
6737 Also, there's nothing to prevent someone putting
6738 something silly in .opd with the assembler. No .opd
6739 optimization for them! */
6740 broken_opd:
6741 _bfd_error_handler
6745 }
6749 {
6750 _bfd_error_handler
6751 /* xgettext:c-format */
6756 }
6764 {
6768 else
6770 sym_sec);
6772 _bfd_error_handler
6773 /* xgettext:c-format */
6778 }
6780 /* opd entries are always for functions defined in the
6781 current input bfd. If the symbol isn't defined in the
6782 input bfd, then we won't be using the function in this
6783 bfd; It must be defined in a linkonce section in another
6784 bfd, or is weak. It's also possible that we are
6785 discarding the function due to a linker script /DISCARD/,
6786 which we test for via the output_section. */
6798 {
6800 {
6803 }
6805 {
6806 cnt_16b++;
6808 }
6810 }
6814 {
6816 cnt_16b++;
6819 }
6820 else
6822 }
6827 {
6832 bfd_size_type amt;
6841 /* This seems a waste of time as input .opd sections are all
6842 zeros as generated by gcc, but I suppose there's no reason
6843 this will always be so. We might start putting something in
6844 the third word of .opd entries. */
6846 {
6849 {
6852 error_ret:
6859 }
6862 }
6868 {
6873 }
6878 {
6886 bfd_boolean skip;
6899 /* See if the .opd entry is full 24 byte or
6900 16 byte (with fd_aux entry overlapped with next
6901 fd_func). */
6904 {
6907 }
6913 {
6916 {
6921 }
6922 }
6927 {
6929 {
6930 /* Arrange for the function descriptor sym
6931 to be dropped. */
6934 }
6939 else
6941 {
6953 }
6954 }
6955 else
6956 {
6957 /* We'll be keeping this opd entry. */
6961 {
6962 /* Redefine the function descriptor symbol to
6963 this location in the opd section. It is
6964 necessary to update the value here rather
6965 than using an array of adjustments as we do
6966 for local symbols, because various places
6967 in the generic ELF code use the value
6968 stored in u.def.value. */
6971 }
6973 /* Local syms are a bit tricky. We could
6974 tweak them as they can be cached, but
6975 we'd need to look through the local syms
6976 for the function descriptor sym which we
6977 don't have at the moment. So keep an
6978 array of adjustments. */
6986 {
6989 }
6991 /* We need to adjust any reloc offsets to point to the
6992 new opd entries. */
6994 {
6999 }
7000 }
7003 }
7008 {
7011 }
7013 /* Fudge the header size too, as this is used later in
7014 elf_bfd_final_link if we are emitting relocs. */
7018 }
7024 {
7027 else
7029 }
7030 }
7035 /* If we are doing a final link and the last .opd entry is just 16 byte
7036 long, add a 8 byte padding after it. */
7038 {
7042 {
7055 }
7056 else
7057 {
7063 }
7067 }
7070 }
7072 /* Analyze inline PLT call relocations to see whether calls to locally
7073 defined functions can be converted to direct calls. */
7075 bfd_boolean
7077 {
7087 /* A bl insn can reach -0x2000000 to 0x1fffffc. The limit is
7088 reduced somewhat to cater for possible stubs that might be added
7089 between the call and its destination. */
7091 {
7095 }
7096 else
7097 {
7101 }
7107 {
7112 }
7114 /* If a "bl" can reach anywhere in local code sections, then we can
7115 convert all inline PLT sequences to direct calls when the symbol
7116 is local. */
7118 {
7121 }
7123 /* Otherwise, go looking through relocs for cases where a direct
7124 call won't reach. Mark the symbol on any such reloc to disable
7125 the optimization and keep the PLT entry as it seems likely that
7126 this will be better than creating trampolines. Note that this
7127 will disable the optimization for all inline PLT calls to a
7128 particular symbol, not just those that won't reach. The
7129 difficulty in doing a more precise optimization is that the
7130 linker needs to make a decision depending on whether a
7131 particular R_PPC64_PLTCALL insn can be turned into a direct
7132 call, for each of the R_PPC64_PLTSEQ and R_PPC64_PLT16* insns in
7133 the sequence, and there is nothing that ties those relocs
7134 together except their symbol. */
7137 {
7150 {
7153 /* Read the relocations. */
7161 {
7176 {
7183 }
7186 {
7190 else
7200 }
7201 }
7204 }
7208 {
7211 else
7213 }
7214 }
7217 }
7219 /* Set htab->tls_get_addr and call the generic ELF tls_setup function. */
7221 asection *
7223 {
7238 /* Default to --no-plt-localentry, as this option can cause problems
7239 with symbol interposition. For example, glibc libpthread.so and
7240 libc.so duplicate many pthread symbols, with a fallback
7241 implementation in libc.so. In some cases the fallback does more
7242 work than the pthread implementation. __pthread_condattr_destroy
7243 is one such symbol: the libpthread.so implementation is
7244 localentry:0 while the libc.so implementation is localentry:8.
7245 An app that "cleverly" uses dlopen to only load necessary
7246 libraries at runtime may omit loading libpthread.so when not
7247 running multi-threaded, which then results in the libc.so
7248 fallback symbols being used and ld.so complaining. Now there
7249 are workarounds in ld (see non_zero_localentry) to detect the
7250 pthread situation, but that may not be the only case where
7251 --plt-localentry can cause trouble. */
7257 _bfd_error_handler
7264 /* Move dynamic linking info to the function descriptor sym. */
7271 {
7283 {
7284 /* If glibc supports an optimized __tls_get_addr call stub,
7285 signalled by the presence of __tls_get_addr_opt, and we'll
7286 be calling __tls_get_addr via a plt call stub, then
7287 make __tls_get_addr point to __tls_get_addr_opt. */
7295 {
7302 {
7308 {
7309 /* Use __tls_get_addr_opt in dynamic relocations. */
7315 }
7316 htab->tls_get_addr_fd
7320 {
7328 }
7332 {
7335 }
7336 }
7337 }
7338 }
7341 }
7343 }
7345 /* Return TRUE iff REL is a branch reloc with a global symbol matching
7346 HASH1 or HASH2. */
7348 static bfd_boolean
7353 {
7359 {
7367 }
7369 }
7371 /* Run through all the TLS relocs looking for optimization
7372 opportunities. The linker has been hacked (see ppc64elf.em) to do
7373 a preliminary section layout so that we know the TLS segment
7374 offsets. We can't optimize earlier because some optimizations need
7375 to know the tp offset, and we need to optimize before allocating
7376 dynamic relocations. */
7378 bfd_boolean
7380 {
7394 /* Make two passes over the relocs. On the first pass, mark toc
7395 entries involved with tls relocs, and check that tls relocs
7396 involved in setting up a tls_get_addr call are indeed followed by
7397 such a call. If they are not, we can't do any tls optimization.
7398 On the second pass twiddle tls_mask flags to notify
7399 relocate_section that optimization can be done, and adjust got
7400 and plt refcounts. */
7404 {
7410 {
7414 /* Read the relocations. */
7418 {
7421 }
7425 {
7433 bfd_vma value;
7442 {
7443 err_free_rel:
7453 }
7456 {
7462 else
7463 {
7466 }
7467 }
7468 else
7469 /* Symbols referenced by TLS relocs must be of type
7470 STT_TLS. So no need for .opd local sym adjust. */
7477 {
7484 {
7490 }
7491 }
7494 /* If this section has old-style __tls_get_addr calls
7495 without marker relocs, then check that each
7496 __tls_get_addr call reloc is preceded by a reloc
7497 that conceivably belongs to the __tls_get_addr arg
7498 setup insn. If we don't find matching arg setup
7499 relocs, don't do any tls optimization. */
7505 && !found_tls_get_addr_arg
7507 {
7513 }
7517 {
7522 /* Fall through. */
7526 /* These relocs should never be against a symbol
7527 defined in a shared lib. Leave them alone if
7528 that turns out to be the case. */
7532 /* LD -> LE */
7542 /* Fall through. */
7547 /* GD -> LE */
7549 else
7550 /* GD -> IE */
7561 {
7562 /* IE -> LE */
7567 }
7574 {
7578 {
7584 {
7596 }
7597 }
7599 }
7601 /* Fall through. */
7609 /* Mark this toc entry as referenced by a TLS
7610 code sequence. We can do that now in the
7611 case of R_PPC64_TLS, and after checking for
7612 tls_get_addr for the TOC16 relocs. */
7614 toc_ref
7621 else
7632 {
7635 }
7652 {
7653 /* IE -> LE */
7657 }
7670 {
7672 /* GD -> LE */
7674 else
7675 /* GD -> IE */
7678 }
7679 else
7680 {
7684 /* LD -> LE */
7687 }
7692 }
7695 {
7704 {
7706 {
7707 /* Check for toc tls entries. */
7717 {
7723 }
7724 }
7726 }
7728 /* Uh oh, we didn't find the expected call. We
7729 could just mark this symbol to exclude it
7730 from tls optimization but it's safer to skip
7731 the entire optimization. */
7732 /* xgettext:c-format */
7738 }
7740 /* If we don't have old-style __tls_get_addr calls
7741 without TLSGD/TLSLD marker relocs, and we haven't
7742 found a new-style __tls_get_addr call with a
7743 marker for this symbol, then we either have a
7744 broken object file or an -mlongcall style
7745 indirect call to __tls_get_addr without a marker.
7746 Disable optimization in this case. */
7755 {
7775 }
7781 {
7784 /* Adjust got entry for this reloc. */
7787 else
7799 {
7800 /* We managed to get rid of a got entry. */
7803 }
7804 }
7805 else
7806 {
7807 /* If we got rid of a DTPMOD/DTPREL reloc pair then
7808 we'll lose one or two dyn relocs. */
7814 {
7818 }
7819 }
7823 }
7827 }
7831 {
7834 else
7836 }
7837 }
7843 }
7845 /* Called via elf_link_hash_traverse from ppc64_elf_edit_toc to adjust
7846 the values of any global symbols in a toc section that has been
7847 edited. Globals in toc sections should be a rarity, so this function
7848 sets a flag if any are found in toc sections other than the one just
7849 edited, so that further hash table traversals can be avoided. */
7851 struct adjust_toc_info
7852 {
7855 bfd_boolean global_toc_syms;
7856 };
7860 static bfd_boolean
7862 {
7876 {
7879 else
7883 {
7884 _bfd_error_handler
7886 do
7890 }
7894 }
7899 }
7901 /* Return TRUE iff INSN with a relocation of R_TYPE is one we expect
7902 on a _LO variety toc/got reloc. */
7904 static bfd_boolean
7906 {
7924 /* Exclude lfqu by testing reloc. If relocs are ever
7925 defined for the reduced D field in psq_lu then those
7926 will need testing too. */
7932 /* Exclude stfqu. psq_stu as above for psq_lu. */
7936 }
7938 /* Examine all relocs referencing .toc sections in order to remove
7939 unused .toc entries. */
7941 bfd_boolean
7943 {
7951 {
7974 /* Look at sections dropped from the final link. */
7978 {
7990 /* Run through the relocs to see which toc entries might be
7991 unused. */
7993 {
7999 bfd_vma val;
8003 {
8014 }
8026 else
8033 /* Anything in the toc ought to be aligned to 8 bytes.
8034 If not, don't mark as unused. */
8039 {
8043 }
8046 }
8050 }
8052 /* For largetoc loads of address constants, we can convert
8053 . addis rx,2,addr@got@ha
8054 . ld ry,addr@got@l(rx)
8055 to
8056 . addis rx,2,addr@toc@ha
8057 . addi ry,rx,addr@toc@l
8058 when addr is within 2G of the toc pointer. This then means
8059 that the word storing "addr" in the toc is no longer needed. */
8064 {
8065 /* Read toc relocs. */
8072 {
8098 {
8102 }
8103 else
8104 {
8108 }
8112 /* We don't yet know the exact toc pointer value, but we
8113 know it will be somewhere in the toc section. Don't
8114 optimize if the difference from any possible toc
8115 pointer is outside [ff..f80008000, 7fff7fff]. */
8125 {
8129 }
8133 }
8134 }
8141 {
8142 error_ret:
8156 }
8158 /* Now check all kept sections that might reference the toc.
8159 Check the toc itself last. */
8167 {
8180 {
8183 }
8185 /* Mark toc entries referenced as used. */
8186 do
8187 {
8190 {
8196 bfd_vma val;
8201 {
8225 }
8228 {
8234 {
8237 }
8243 {
8249 /* xgettext:c-format */
8253 }
8254 }
8257 {
8264 /* In case we're taking addresses of toc entries. */
8270 }
8275 {
8278 }
8285 else
8293 {
8294 bfd_vma off;
8298 {
8307 {
8310 }
8313 /* Fall through. */
8316 /* Wrong sort of reloc, or not a ld. We may
8317 as well clear ref_from_discarded too. */
8319 }
8320 }
8324 /* For the toc section, we only mark as used if this
8325 entry itself isn't unused. */
8329 {
8330 /* Do all the relocs again, to catch reference
8331 chains. */
8334 }
8335 }
8336 }
8341 }
8343 /* Merge the used and skip arrays. Assume that TOC
8344 doublewords not appearing as either used or unused belong
8345 to an entry more than one doubleword in size. */
8349 {
8351 {
8356 }
8358 {
8361 }
8362 else
8364 }
8369 {
8375 /* Shuffle the toc contents, and at the same time convert the
8376 skip array from booleans into offsets. */
8385 {
8389 {
8392 }
8393 }
8398 /* Adjust addends for relocs against the toc section sym,
8399 and optimize any accesses we can. */
8401 {
8412 {
8417 bfd_vma val;
8421 {
8433 }
8445 else
8446 {
8450 }
8459 {
8460 Elf_Internal_Rela *tocrel
8465 {
8478 /* xgettext:c-format */
8485 }
8489 }
8496 }
8500 }
8502 /* We shouldn't have local or global symbols defined in the TOC,
8503 but handle them anyway. */
8510 {
8515 else
8519 {
8521 _bfd_error_handler
8524 do
8528 }
8532 }
8534 /* Adjust any global syms defined in this toc input section. */
8536 {
8542 }
8545 {
8548 bfd_size_type sz;
8550 /* Remove unused toc relocs, and adjust those we keep. */
8561 {
8566 }
8576 }
8577 }
8584 {
8587 else
8589 }
8591 }
8593 /* Look for cases where we can change an indirect GOT access to
8594 a GOT relative access, possibly reducing the number of GOT
8595 entries. */
8597 {
8602 bfd_vma got;
8617 {
8626 {
8627 got_error_ret:
8636 }
8639 {
8646 bfd_vma val;
8652 {
8660 }
8672 else
8678 {
8716 }
8720 else
8721 {
8724 }
8732 }
8736 }
8740 {
8743 else
8745 }
8746 }
8749 }
8751 /* Return true iff input section I references the TOC using
8752 instructions limited to +/-32k offsets. */
8754 bfd_boolean
8756 {
8759 }
8761 /* Allocate space for one GOT entry. */
8763 static void
8767 {
8780 {
8783 }
8792 {
8795 }
8796 }
8798 /* This function merges got entries in the same toc group. */
8800 static void
8802 {
8812 {
8815 }
8816 }
8818 /* If H is undefined, make it dynamic if that makes sense. */
8820 static bfd_boolean
8823 {
8835 }
8837 /* Allocate space in .plt, .got and associated reloc sections for
8838 dynamic relocs. */
8840 static bfd_boolean
8842 {
8858 /* Run through the TLS GD got entries first if we're changing them
8859 to TPREL. */
8864 {
8865 /* This was a GD entry that has been converted to TPREL. If
8866 there happens to be a TPREL entry we can use that one. */
8873 {
8876 }
8878 /* If not, then we'll be using our own TPREL entry. */
8881 }
8883 /* Remove any list entry that won't generate a word in the GOT before
8884 we call merge_got_entries. Otherwise we risk merging to empty
8885 entries. */
8889 {
8892 {
8895 }
8896 else
8898 }
8899 else
8907 {
8908 /* Make sure this symbol is output as a dynamic symbol. */
8916 }
8918 /* If no dynamic sections we can't have dynamic relocs, except for
8919 IFUNCs which are handled even in static executables. */
8924 /* Discard relocs on undefined symbols that must be local. */
8929 /* Also discard relocs on undefined weak syms with non-default
8930 visibility, or when dynamic_undefined_weak says so. */
8935 {
8938 /* In the shared -Bsymbolic case, discard space allocated for
8939 dynamic pc-relative relocs against symbols which turn out to
8940 be defined in regular objects. For the normal shared case,
8941 discard space for relocs that have become local due to symbol
8942 visibility changes. */
8945 {
8946 /* Relocs that use pc_count are those that appear on a call
8947 insn, or certain REL relocs (see must_be_dyn_reloc) that
8948 can be generated via assembly. We want calls to
8949 protected symbols to resolve directly to the function
8950 rather than going via the plt. If people want function
8951 pointer comparisons to work as expected then they should
8952 avoid writing weird assembly. */
8954 {
8956 {
8961 else
8963 }
8964 }
8967 {
8968 /* Make sure this symbol is output as a dynamic symbol. */
8971 }
8972 }
8974 {
8975 /* For the non-pic case, discard space for relocs against
8976 symbols which turn out to need copy relocs or are not
8977 dynamic. */
8981 {
8982 /* Make sure this symbol is output as a dynamic symbol. */
8988 }
8989 else
8991 }
8993 /* Finally, allocate space. */
8995 {
9000 }
9001 }
9003 /* We might need a PLT entry when the symbol
9004 a) is dynamic, or
9005 b) is an ifunc, or
9006 c) has plt16 relocs and has been processed by adjust_dynamic_symbol, or
9007 d) has plt16 relocs and we are linking statically. */
9017 {
9022 {
9025 {
9027 {
9032 }
9033 else
9034 {
9039 }
9040 }
9041 else
9042 {
9043 /* If this is the first .plt entry, make room for the special
9044 first entry. */
9051 /* Make room for this entry. */
9054 /* Make room for the .glink code. */
9059 {
9060 /* We need bigger stubs past index 32767. */
9064 }
9065 else
9068 /* We also need to make an entry in the .rela.plt section. */
9070 }
9074 }
9075 else
9078 {
9081 }
9082 }
9083 else
9084 {
9087 }
9090 }
9092 #define PPC_LO(v) ((v) & 0xffff)
9093 #define PPC_HI(v) (((v) >> 16) & 0xffff)
9094 #define PPC_HA(v) PPC_HI ((v) + 0x8000)
9096 /* Called via elf_link_hash_traverse from ppc64_elf_size_dynamic_sections
9097 to set up space for global entry stubs. These are put in glink,
9098 after the branch table. */
9100 static bfd_boolean
9102 {
9127 {
9128 /* For ELFv2, if this symbol is not defined in a regular file
9129 and we are not generating a shared library or pie, then we
9130 need to define the symbol in the executable on a call stub.
9131 This is to avoid text relocations. */
9139 else
9141 /* Setting section alignment is delayed until we know it is
9142 non-empty. Otherwise the .text output section will be
9143 aligned at least to plt_stub_align even when no global
9144 entry stubs are needed. */
9155 /* Note that for --plt-stub-align negative we have a possible
9156 dependency between stub offset and size. Break that
9157 dependency by assuming the max stub size when calculating
9158 the stub offset. */
9166 }
9168 }
9170 /* Set DF_TEXTREL if we find any dynamic relocs that apply to
9171 read-only sections. */
9173 static bfd_boolean
9175 {
9183 {
9191 /* Not an error, just cut short the traversal. */
9193 }
9195 }
9197 /* Set the sizes of the dynamic sections. */
9199 static bfd_boolean
9202 {
9206 bfd_boolean relocs;
9219 {
9220 /* Set the contents of the .interp section to the interpreter. */
9222 {
9228 }
9229 }
9231 /* Set up .got offsets for local syms, and space for local dynamic
9232 relocs. */
9234 {
9240 bfd_size_type locsymcount;
9247 {
9251 {
9254 {
9255 /* Input section has been discarded, either because
9256 it is a copy of a linkonce section or due to
9257 linker script /DISCARD/, so we'll be discarding
9258 the relocs too. */
9259 }
9261 {
9268 }
9269 }
9270 }
9284 {
9290 {
9292 {
9295 }
9296 else
9297 {
9303 {
9306 }
9309 {
9312 }
9316 {
9319 }
9321 }
9322 }
9323 else
9325 }
9327 /* Allocate space for plt calls to local syms. */
9330 {
9335 {
9337 {
9342 }
9346 else
9347 {
9353 }
9354 }
9355 else
9357 }
9358 }
9360 /* Allocate global sym .plt and .got entries, and space for global
9361 sym dynamic relocs. */
9369 {
9377 {
9379 {
9382 }
9383 else
9384 {
9392 {
9395 }
9396 }
9397 }
9398 else
9400 }
9402 /* We now have determined the sizes of the various dynamic sections.
9403 Allocate memory for them. */
9406 {
9411 /* These haven't been allocated yet; don't strip. */
9421 {
9422 /* Strip this section if we don't need it; see the
9423 comment below. */
9424 }
9426 {
9428 /* Not sized yet. */
9430 }
9432 {
9434 {
9438 /* We use the reloc_count field as a counter if we need
9439 to copy relocs into the output file. */
9441 }
9442 }
9443 else
9444 {
9445 /* It's not one of our sections, so don't allocate space. */
9447 }
9450 {
9451 /* If we don't need this section, strip it from the
9452 output file. This is mostly to handle .rela.bss and
9453 .rela.plt. We must create both sections in
9454 create_dynamic_sections, because they must be created
9455 before the linker maps input sections to output
9456 sections. The linker does that before
9457 adjust_dynamic_symbol is called, and it is that
9458 function which decides whether anything needs to go
9459 into these sections. */
9462 }
9471 /* Allocate memory for the section contents. We use bfd_zalloc
9472 here in case unused entries are not reclaimed before the
9473 section's contents are written out. This should not happen,
9474 but this way if it does we get a R_PPC64_NONE reloc in .rela
9475 sections instead of garbage.
9476 We also rely on the section contents being zero when writing
9477 the GOT and .dynrelro. */
9481 }
9484 {
9490 {
9493 else
9494 {
9498 }
9499 }
9502 {
9505 else
9506 {
9512 }
9513 }
9514 }
9517 {
9518 bfd_boolean tls_opt;
9520 /* Add some entries to the .dynamic section. We fill in the
9521 values later, in ppc64_elf_finish_dynamic_sections, but we
9522 must add the entries now so that we get the correct size for
9523 the .dynamic section. The DT_DEBUG entry is filled in by the
9524 dynamic linker and used by the debugger. */
9525 #define add_dynamic_entry(TAG, VAL) \
9526 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
9529 {
9532 }
9535 {
9542 }
9545 {
9549 }
9555 {
9558 }
9561 {
9567 /* If any dynamic relocs apply to a read-only section,
9568 then we need a DT_TEXTREL entry. */
9573 {
9576 }
9577 }
9578 }
9579 #undef add_dynamic_entry
9582 }
9584 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
9586 static bfd_boolean
9588 {
9595 }
9597 /* Determine the type of stub needed, if any, for a call. */
9604 bfd_vma destination,
9606 {
9608 bfd_vma location;
9609 bfd_vma branch_offset;
9610 bfd_vma max_branch_offset;
9614 {
9619 {
9622 }
9627 {
9630 }
9632 /* Here, we know we don't have a plt entry. If we don't have a
9633 either a defined function descriptor or a defined entry symbol
9634 in a regular object file, then it is pointless trying to make
9635 any other type of stub. */
9639 }
9641 {
9648 {
9654 {
9657 }
9658 }
9659 }
9661 /* Determine where the call point is. */
9669 /* Determine if a long branch stub is needed. */
9677 /* We need a stub. Figure out whether a long_branch or plt_branch
9678 is needed later. */
9682 }
9684 /* Gets the address of a label (1:) in r11 and builds an offset in r12,
9685 then adds it to r11 (LOAD false) or loads r12 from r11+r12 (LOAD true).
9686 . mflr %r12
9687 . bcl 20,31,1f
9688 .1: mflr %r11
9689 . mtlr %r12
9690 . lis %r12,xxx-1b@highest
9691 . ori %r12,%r12,xxx-1b@higher
9692 . sldi %r12,%r12,32
9693 . oris %r12,%r12,xxx-1b@high
9694 . ori %r12,%r12,xxx-1b@l
9695 . add/ldx %r12,%r11,%r12 */
9699 {
9709 {
9712 else
9715 }
9717 {
9722 else
9725 }
9726 else
9727 {
9729 {
9732 }
9733 else
9734 {
9738 {
9741 }
9742 }
9744 {
9747 }
9749 {
9752 }
9754 {
9757 }
9760 else
9763 }
9765 }
9767 static unsigned int
9769 {
9775 else
9776 {
9779 else
9780 {
9784 }
9792 }
9794 }
9796 static unsigned int
9798 {
9804 else
9805 {
9814 }
9816 }
9821 {
9830 {
9837 }
9838 else
9839 {
9842 else
9843 {
9846 {
9852 }
9853 }
9857 {
9863 }
9865 {
9871 }
9872 }
9874 }
9876 /* Emit .eh_frame opcode to advance pc by DELTA. */
9880 {
9885 {
9888 }
9890 {
9894 }
9895 else
9896 {
9900 }
9902 }
9904 /* Size of required .eh_frame opcode to advance pc by DELTA. */
9906 static unsigned int
9908 {
9910 /* DW_CFA_advance_loc+[1..63]. */
9913 /* DW_CFA_advance_loc1, byte. */
9916 /* DW_CFA_advance_loc2, 2 bytes. */
9918 /* DW_CFA_advance_loc4, 4 bytes. */
9920 }
9922 /* With power7 weakly ordered memory model, it is possible for ld.so
9923 to update a plt entry in one thread and have another thread see a
9924 stale zero toc entry. To avoid this we need some sort of acquire
9925 barrier in the call stub. One solution is to make the load of the
9926 toc word seem to appear to depend on the load of the function entry
9927 word. Another solution is to test for r2 being zero, and branch to
9928 the appropriate glink entry if so.
9930 . fake dep barrier compare
9931 . ld 12,xxx(2) ld 12,xxx(2)
9932 . mtctr 12 mtctr 12
9933 . xor 11,12,12 ld 2,xxx+8(2)
9934 . add 2,2,11 cmpldi 2,0
9935 . ld 2,xxx+8(2) bnectr+
9936 . bctr b <glink_entry>
9938 The solution involving the compare turns out to be faster, so
9939 that's what we use unless the branch won't reach. */
9941 #define ALWAYS_USE_FAKE_DEP 0
9942 #define ALWAYS_EMIT_R2SAVE 0
9947 bfd_vma off)
9948 {
9952 {
9957 }
9966 {
9977 }
9982 {
9986 }
9988 }
9990 /* Depending on the sign of plt_stub_align:
9991 If positive, return the padding to align to a 2**plt_stub_align
9992 boundary.
9993 If negative, if this stub would cross fewer 2**plt_stub_align
9994 boundaries if we align, then return the padding needed to do so. */
9999 bfd_vma plt_off)
10000 {
10006 {
10011 }
10019 }
10021 /* Build a .plt call stub. */
10027 {
10039 && plt_load_toc
10040 && plt_thread_safe
10044 {
10053 to = (glinkoff
10068 }
10071 {
10073 {
10082 {
10084 {
10088 }
10089 else
10090 {
10095 {
10099 }
10100 }
10101 }
10102 }
10107 {
10110 }
10111 else
10112 {
10115 }
10118 {
10121 }
10124 {
10126 {
10129 }
10133 }
10134 }
10135 else
10136 {
10138 {
10144 {
10146 {
10150 }
10151 else
10152 {
10157 {
10161 }
10162 }
10163 }
10164 }
10171 {
10174 }
10177 {
10179 {
10182 }
10186 }
10187 }
10189 {
10193 }
10194 else
10197 }
10199 /* Build a special .plt call stub for __tls_get_addr. */
10201 #define LD_R11_0R3 0xe9630000
10202 #define LD_R12_0R3 0xe9830000
10203 #define MR_R0_R3 0x7c601b78
10204 #define CMPDI_R11_0 0x2c2b0000
10205 #define ADD_R3_R12_R13 0x7c6c6a14
10206 #define BEQLR 0x4d820020
10207 #define MR_R3_R0 0x7c030378
10208 #define STD_R11_0R1 0xf9610000
10209 #define BCTRL 0x4e800421
10210 #define LD_R11_0R1 0xe9610000
10211 #define MTLR_R11 0x7d6803a6
10217 {
10248 {
10265 }
10267 }
10271 {
10278 {
10279 bfd_size_type relsize;
10293 }
10297 }
10299 /* Convert the relocs R[0] thru R[-NUM_REL+1], which are all no-symbol
10300 forms, to the equivalent relocs against the global symbol given by
10301 STUB_ENTRY->H. */
10303 static bfd_boolean
10307 {
10311 bfd_vma symval;
10313 /* Relocs are always against symbols in their own object file. Fake
10314 up global sym hashes for the stub bfd (which has no symbols). */
10317 {
10318 bfd_size_type hsize;
10320 /* When called the first time, stub_globals will contain the
10321 total number of symbols seen during stub sizing. After
10322 allocating, stub_globals is used as an index to fill the
10323 hashes array. */
10330 }
10342 {
10345 {
10346 /* H is an opd symbol. The addend must be zero, and the
10347 branch reloc is the only one we can convert. */
10350 }
10351 else
10354 }
10356 }
10358 static bfd_vma
10361 {
10366 {
10367 /* Support linking -R objects. Get the toc pointer from the
10368 opd entry. */
10377 {
10383 }
10388 }
10391 }
10393 static bfd_boolean
10395 {
10407 /* Massage our args to the form they really have. */
10420 {
10423 /* Branches are relative. This is where we are going to. */
10429 /* And this is where we are coming from. */
10437 {
10441 {
10444 }
10448 {
10452 }
10454 {
10458 }
10460 }
10465 {
10466 _bfd_error_handler
10471 }
10474 {
10484 }
10493 {
10498 }
10510 {
10514 {
10515 /* Create a reloc for the branch lookup table entry. */
10516 Elf_Internal_Rela rela;
10529 }
10531 {
10535 /* brlt, being SEC_LINKER_CREATED does not go through the
10536 normal reloc processing. Symbols and offsets are not
10537 translated from input file to output file form, so
10538 set up the offset per the output file. */
10544 }
10545 }
10556 {
10563 }
10566 {
10578 {
10583 }
10584 }
10588 {
10590 {
10596 }
10597 else
10600 }
10601 else
10602 {
10606 {
10609 }
10614 {
10620 }
10621 else
10625 {
10629 }
10631 {
10635 }
10636 }
10657 {
10661 }
10663 {
10672 {
10675 else
10677 }
10679 }
10680 else
10688 /* The notoc stubs calculate their target (either a PLT entry or
10689 the global entry point of a function) relative to the PC
10690 returned by the "bcl" two instructions past the start of the
10691 sequence emitted by build_offset. The offset is therefore 8
10692 less than calculated from the start of the sequence. */
10697 {
10698 bfd_vma from;
10706 }
10707 else
10708 {
10712 }
10716 {
10717 bfd_vma roff;
10726 {
10735 }
10736 }
10740 {
10762 }
10770 {
10773 /* If the old-ABI "dot-symbol" is undefined make it weak so
10774 we don't get a link error from RELOC_FOR_GLOBAL_SYMBOL. */
10779 }
10781 /* Now build the stub. */
10790 {
10793 else
10795 }
10803 {
10805 /* xgettext:c-format */
10813 }
10817 {
10830 }
10836 else
10846 }
10851 {
10880 {
10890 }
10891 }
10894 }
10896 /* As above, but don't actually build the stub. Just bump offset so
10897 we know stub section sizes, and select plt_branch stubs where
10898 long_branch stubs won't do. */
10900 static bfd_boolean
10902 {
10910 /* Massage our args to the form they really have. */
10918 /* Make a note of the offset within the stubs for this entry. */
10925 {
10926 /* Don't make stubs to out-of-line register save/restore
10927 functions. Instead, emit copies of the functions. */
10931 }
10934 {
10937 /* Reset the stub type from the plt branch variant in case we now
10938 can reach with a shorter stub. */
10940 /* Fall through. */
10954 {
10957 {
10960 }
10967 }
10970 /* If the branch offset is too big, use a ppc_stub_plt_branch.
10971 Do the same for -R objects without function descriptors. */
10976 {
10983 {
10988 }
10991 {
10999 {
11002 }
11003 }
11013 {
11017 }
11021 {
11025 }
11026 else
11027 {
11036 }
11037 }
11039 {
11042 }
11048 /* Fall through. */
11064 {
11068 }
11071 /* Include branch insn plus those in the offset sequence. */
11073 /* The branch insn is at the end, or "extra" bytes along. So
11074 its offset will be "extra" bytes less that that already
11075 calculated. */
11078 /* After the bcl, lr has been modified so we need to emit
11079 .eh_frame info saying the return address is in r12. */
11083 /* The eh_frame info will consist of a DW_CFA_advance_loc or
11084 variant, DW_CFA_register, 65, 12, DW_CFA_advance_loc+2,
11085 DW_CFA_restore_extended 65. */
11090 /* If the branch can't reach, use a plt_branch. */
11092 {
11096 }
11116 {
11119 else
11121 }
11126 {
11132 }
11135 {
11139 }
11143 /* After the bcl, lr has been modified so we need to emit
11144 .eh_frame info saying the return address is in r12. */
11148 /* The eh_frame info will consist of a DW_CFA_advance_loc or
11149 variant, DW_CFA_register, 65, 12, DW_CFA_advance_loc+2,
11150 DW_CFA_restore_extended 65. */
11165 {
11168 else
11170 }
11178 {
11183 }
11186 {
11194 }
11203 {
11204 /* After the bctrl, lr has been modified so we need to
11205 emit .eh_frame info saying the return address is
11206 on the stack. In fact we put the EH info specifying
11207 that the return address is on the stack *at* the
11208 call rather than after it, because the EH info for a
11209 call needs to be specified by that point.
11210 See libgcc/unwind-dw2.c execute_cfa_program. */
11212 /* The eh_frame info will consist of a DW_CFA_advance_loc
11213 or variant, DW_CFA_offset_externed_sf, 65, -stackoff,
11214 DW_CFA_advance_loc+4, DW_CFA_restore_extended, 65. */
11218 }
11224 }
11228 }
11230 /* Set up various things so that we can make a list of input sections
11231 for each output section included in the link. Returns -1 on error,
11232 0 when no stubs will be needed, and 1 on success. */
11234 int
11236 {
11238 bfd_size_type amt;
11250 /* Set toc_off for com, und, abs and ind sections. */
11255 }
11257 /* Set up for first pass at multitoc partitioning. */
11259 void
11261 {
11267 }
11269 /* The linker repeatedly calls this function for each TOC input section
11270 and linker generated GOT section. Group input bfds such that the toc
11271 within a group is less than 64k in size. */
11273 bfd_boolean
11275 {
11283 {
11284 /* Keep track of the first .toc or .got section for this input bfd. */
11288 {
11291 }
11299 {
11304 }
11306 /* toc_curr is the base address of this toc group. Set elf_gp
11307 for the input section to be the offset relative to the
11308 output toc base plus 0x8000. Making the input elf_gp an
11309 offset allows us to move the toc as a whole without
11310 recalculating input elf_gp. */
11314 /* Die if someone uses a linker script that doesn't keep input
11315 file .toc and .got together. */
11323 }
11325 /* During the second pass toc_first_sec points to the start of
11326 a toc group, and toc_curr is used to track the old elf_gp.
11327 We use toc_bfd to ensure we only look at each bfd once. */
11334 {
11337 }
11344 }
11346 /* Called via elf_link_hash_traverse to merge GOT entries for global
11347 symbol H. */
11349 static bfd_boolean
11351 {
11358 }
11360 /* Called via elf_link_hash_traverse to allocate GOT entries for global
11361 symbol H. */
11363 static bfd_boolean
11365 {
11375 }
11377 /* Called on the first multitoc pass after the last call to
11378 ppc64_elf_next_toc_section. This function removes duplicate GOT
11379 entries. */
11381 bfd_boolean
11383 {
11386 bfd_boolean done_something;
11393 /* Merge global sym got entries within a toc group. */
11396 /* And tlsld_got. */
11398 {
11407 {
11409 {
11417 {
11420 }
11421 }
11422 }
11423 }
11425 /* Zap sizes of got sections. */
11431 {
11439 {
11445 }
11446 }
11448 /* Now reallocate the got, local syms first. We don't need to
11449 allocate section contents again since we never increase size. */
11451 {
11457 bfd_size_type locsymcount;
11476 {
11480 {
11486 {
11489 }
11492 {
11495 }
11499 {
11502 }
11503 }
11504 }
11505 }
11510 {
11519 {
11524 {
11527 }
11528 }
11529 }
11534 {
11542 {
11546 }
11547 }
11552 /* Set up for second pass over toc sections to recalculate elf_gp
11553 on input sections. */
11558 }
11560 /* Called after second pass of multitoc partitioning. */
11562 void
11564 {
11567 /* After the second pass, toc_curr tracks the TOC offset used
11568 for code sections below in ppc64_elf_next_input_section. */
11570 }
11572 /* No toc references were found in ISEC. If the code in ISEC makes no
11573 calls, then there's no need to use toc adjusting stubs when branching
11574 into ISEC. Actually, indirect calls from ISEC are OK as they will
11575 load r2. Returns -1 on error, 0 for no stub needed, 1 for stub
11576 needed, and 2 if a cyclical call-graph was found but no other reason
11577 for a stub was detected. If called from the top level, a return of
11578 2 means the same as a return of 0. */
11580 static int
11582 {
11585 /* Mark this section as checked. */
11588 /* We know none of our code bearing sections will need toc stubs. */
11600 {
11610 /* Look for branches to outside of this section. */
11617 {
11625 bfd_vma sym_value;
11626 bfd_vma dest;
11640 {
11643 }
11645 /* Calls to dynamic lib functions go through a plt call stub
11646 that uses r2. */
11652 {
11655 }
11658 /* Ignore other undefined symbols. */
11661 /* Assume branches to other sections not included in the
11662 link need stubs too, to cover -R and absolute syms. */
11664 {
11667 }
11671 else
11672 {
11677 }
11680 /* If this branch reloc uses an opd sym, find the code section. */
11683 {
11685 {
11690 /* Assume deleted functions won't ever be called. */
11693 }
11699 }
11700 else
11701 dest = (sym_value
11705 /* Ignore branch to self. */
11709 /* If the called function uses the toc, we need a stub. */
11712 {
11715 }
11717 /* Assume any branch that needs a long branch stub might in fact
11718 need a plt_branch stub. A plt_branch stub uses r2. */
11725 {
11728 }
11730 /* If calling back to a section in the process of being
11731 tested, we can't say for sure that no toc adjusting stubs
11732 are needed, so don't return zero. */
11736 /* Branches to another section that itself doesn't have any TOC
11737 references are OK. Recursively call ourselves to check. */
11739 {
11742 /* Mark current section as indeterminate, so that other
11743 sections that call back to current won't be marked as
11744 known. */
11750 {
11754 }
11755 }
11756 }
11764 }
11770 {
11775 {
11782 }
11783 }
11789 }
11791 /* The linker repeatedly calls this function for each input section,
11792 in the order that input sections are linked into output sections.
11793 Build lists of input sections to determine groupings between which
11794 we may insert linker stubs. */
11796 bfd_boolean
11798 {
11806 {
11807 /* This happens to make the list in reverse order,
11808 which is what we want. */
11812 }
11815 {
11816 /* Analyse sections that aren't already flagged as needing a
11817 valid toc pointer. Exclude .fixup for the linux kernel.
11818 .fixup contains branches, but only back to the function that
11819 hit an exception. */
11824 {
11827 }
11828 /* Make all sections use the TOC assigned for this object file.
11829 This will be wrong for pasted sections; We fix that in
11830 check_pasted_section(). */
11833 }
11837 }
11839 /* Check that all .init and .fini sections use the same toc, if they
11840 have toc relocs. */
11842 static bfd_boolean
11844 {
11848 {
11855 {
11860 }
11865 {
11868 }
11870 /* Make sure the whole pasted function uses the same toc offset. */
11874 }
11876 }
11878 bfd_boolean
11880 {
11883 }
11885 /* See whether we can group stub sections together. Grouping stub
11886 sections may result in fewer stubs. More importantly, we need to
11887 put all .init* and .fini* stubs at the beginning of the .init or
11888 .fini output sections respectively, because glibc splits the
11889 _init and _fini functions into multiple parts. Putting a stub in
11890 the middle of a function is not a good idea. */
11892 static bfd_boolean
11894 bfd_size_type stub_group_size,
11895 bfd_boolean stubs_always_before_branch)
11896 {
11899 bfd_boolean suppress_size_errors;
11907 {
11908 /* Default values. */
11911 else
11914 }
11917 {
11925 {
11928 bfd_size_type total;
11929 bfd_boolean big_sec;
11930 bfd_vma curr_toc;
11932 bfd_size_type group_size;
11942 /* xgettext:c-format */
11955 /* OK, the size from the start of CURR to the end is less
11956 than group_size and thus can be handled by one stub
11957 section. (or the tail section is itself larger than
11958 group_size, in which case we may be toast.) We should
11959 really be keeping track of the total size of stubs added
11960 here, as stubs contribute to the final output section
11961 size. That's a little tricky, and this way will only
11962 break if stubs added make the total size more than 2^25,
11963 ie. for the default stub_group_size, if stubs total more
11964 than 2097152 bytes, or nearly 75000 plt call stubs. */
11976 do
11977 {
11979 /* Set up this stub group. */
11981 }
11984 /* But wait, there's more! Input sections up to group_size
11985 bytes before the stub section can be handled by it too.
11986 Don't do this if we have a really large section after the
11987 stubs, as adding more stubs increases the chance that
11988 branches may not reach into the stub section. */
11990 {
11999 {
12003 }
12004 }
12006 }
12007 }
12009 }
12012 {
12023 };
12025 /* Stripping output sections is normally done before dynamic section
12026 symbols have been allocated. This function is called later, and
12027 handles cases like htab->brlt which is mapped to its own output
12028 section. */
12030 static void
12032 {
12039 {
12043 }
12044 }
12046 /* Determine and set the size of the stub section for a final link.
12048 The basic idea here is to examine all the relocations looking for
12049 PC-relative calls to a target that is unreachable with a "bl"
12050 instruction. */
12052 bfd_boolean
12054 {
12055 bfd_size_type stub_group_size;
12056 bfd_boolean stubs_always_before_branch;
12067 {
12069 {
12071 /* libstdc++ */
12073 /* librt */
12076 /* libanl */
12078 /* libgomp */
12091 /* libgo */
12093 };
12097 {
12104 }
12105 }
12109 else
12115 #define STUB_SHRINK_ITER 20
12116 /* Loop until no stubs added. After iteration 20 of this loop we may
12117 exit on a stub section shrinking. This is to break out of a
12118 pathological case where adding stubs on one iteration decreases
12119 section gaps (perhaps due to alignment), which then requires
12120 fewer or smaller stubs on the next iteration. */
12123 {
12133 {
12141 /* We'll need the symbol table in a second. */
12146 /* Walk over each section attached to the input bfd. */
12150 {
12153 /* If there aren't any relocs, then there's nothing more
12154 to do. */
12162 /* If this section is a link-once section that will be
12163 discarded, then don't create any stubs. */
12168 /* Get the relocs. */
12169 internal_relocs
12175 /* Now examine each relocation. */
12179 {
12186 bfd_vma destination;
12188 bfd_boolean ok_dest;
12202 {
12205 }
12207 /* Only look for stubs on branch instructions. */
12215 /* Now determine the call target, its name, value,
12216 section. */
12226 {
12231 }
12234 {
12238 }
12241 {
12242 /* Recognise an old ABI func code entry sym, and
12243 use the func descriptor sym instead if it is
12244 defined. */
12247 {
12251 {
12256 }
12257 else
12259 }
12260 }
12261 else
12262 {
12265 }
12270 {
12272 destination = (sym_value
12278 }
12284 {
12285 bfd_vma dest;
12288 {
12294 }
12298 {
12301 {
12302 /* Fixup old ABI sym to point at code
12303 entry. */
12307 }
12308 }
12309 }
12311 /* Determine what (if any) linker stub is needed. */
12315 local_off);
12318 {
12328 }
12330 {
12331 /* Check whether we need a TOC adjusting stub.
12332 Since the linker pastes together pieces from
12333 different object files when creating the
12334 _init and _fini functions, it may be that a
12335 call to what looks like a local sym is in
12336 fact a call needing a TOC adjustment. */
12347 }
12352 /* __tls_get_addr calls might be eliminated. */
12360 {
12361 /* Get tls info. */
12369 }
12372 {
12381 {
12385 }
12386 else
12388 }
12390 /* Support for grouping stub sections. */
12393 /* Get the name of this stub. */
12401 {
12403 /* A stub has already been created, but it may
12404 not be the required type. We shouldn't be
12405 transitioning from plt_call to long_branch
12406 stubs or vice versa, but we might be
12407 upgrading from plt_call to plt_call_r2save or
12408 from long_branch to long_branch_r2off. */
12412 {
12426 {
12429 }
12431 {
12434 }
12435 else
12443 old_type += (ppc_stub_long_branch
12445 /* Fall through. */
12453 {
12456 }
12458 {
12461 }
12462 else
12465 }
12469 }
12473 {
12475 error_ret_free_internal:
12478 error_ret_free_local:
12484 }
12489 {
12492 }
12493 else
12494 {
12497 }
12500 stub_entry->symtype
12508 }
12510 /* We're done with the internal relocs, free them. */
12513 }
12517 {
12520 else
12522 }
12523 }
12525 /* We may have added some stubs. Find out the new size of the
12526 stub sections. */
12528 {
12532 {
12537 /* Past STUB_SHRINK_ITER, rawsize is the max size seen. */
12542 }
12543 }
12562 {
12565 }
12570 {
12584 }
12589 {
12593 }
12610 /* Ask the linker to do its stuff. */
12612 }
12616 {
12617 bfd_vma val;
12622 /* It is necessary to at least have a rough outline of the
12623 linker generated CIEs and FDEs written before
12624 bfd_elf_discard_info is run, in order for these FDEs to be
12625 indexed in .eh_frame_hdr. */
12634 /* CIE length (rewrite in case little-endian). */
12641 {
12645 /* FDE length. */
12648 /* CIE pointer. */
12652 /* Offset to stub section, written later. */
12654 /* stub section size. */
12657 /* Augmentation. */
12659 /* Make sure we don't have all nops. This is enough for
12660 elf-eh-frame.c to detect the last non-nop opcode. */
12663 }
12665 {
12668 /* FDE length. */
12671 /* CIE pointer. */
12675 /* Offset to .glink, written later. */
12677 /* .glink size. */
12680 /* Augmentation. */
12691 }
12692 /* Subsume any padding into the last FDE if user .eh_frame
12693 sections are aligned more than glink_eh_frame. Otherwise any
12694 zero padding will be seen as a terminator. */
12700 }
12707 }
12709 /* Called after we have determined section placement. If sections
12710 move, we'll be called again. Provide a value for TOCstart. */
12712 bfd_vma
12714 {
12719 {
12726 else
12727 {
12731 }
12737 {
12743 }
12744 }
12746 /* The TOC consists of sections .got, .toc, .tocbss, .plt in that
12747 order. The TOC starts where the first of these sections starts. */
12756 {
12757 /* This may happen for
12758 o references to TOC base (SYM@toc / TOC[tc0]) without a
12759 .toc directive
12760 o bad linker script
12761 o --gc-sections and empty TOC sections
12763 FIXME: Warn user? */
12765 /* Look for a likely section. We probably won't even be
12766 using TOCstart. */
12786 }
12792 /* Force alignment. */
12798 {
12802 {
12804 {
12807 }
12808 }
12809 else
12810 {
12815 }
12816 }
12818 }
12820 /* Called via elf_link_hash_traverse from ppc64_elf_build_stubs to
12821 write out any global entry stubs, and PLT relocations. */
12823 static bfd_boolean
12825 {
12841 {
12842 /* This symbol has an entry in the procedure linkage
12843 table. Set it up. */
12844 Elf_Internal_Rela rela;
12850 {
12856 {
12862 else
12864 }
12865 else
12866 {
12869 {
12873 else
12875 }
12876 else
12878 }
12885 {
12889 {
12893 }
12894 }
12895 else
12896 {
12903 }
12904 }
12905 else
12906 {
12918 }
12919 }
12934 {
12937 bfd_vma off;
12943 {
12946 else
12948 }
12953 {
12959 }
12963 {
12975 {
12985 }
12986 }
12989 {
12992 }
12999 }
13001 }
13003 /* Write PLT relocs for locals. */
13005 static bfd_boolean
13007 {
13012 {
13016 bfd_size_type locsymcount;
13035 {
13040 bfd_vma val;
13044 {
13049 }
13058 {
13062 }
13063 else
13064 {
13067 }
13070 {
13074 {
13077 }
13078 }
13079 else
13080 {
13081 Elf_Internal_Rela rela;
13086 {
13089 else
13091 }
13092 else
13093 {
13096 else
13098 }
13103 }
13104 }
13108 {
13111 else
13113 }
13114 }
13116 }
13118 /* Build all the stubs associated with the current output file.
13119 The stubs are kept in a hash table attached to the main linker
13120 hash table. This function is called via gldelf64ppc_finish. */
13122 bfd_boolean
13125 {
13135 /* Allocate memory to hold the linker stubs. */
13137 {
13142 {
13148 }
13149 }
13152 {
13154 bfd_vma plt0;
13156 /* Build the .glink plt call stub. */
13158 {
13165 {
13175 }
13176 }
13181 {
13189 }
13195 {
13216 }
13217 else
13218 {
13245 }
13250 /* Build the .glink lazy link call stubs. */
13253 {
13255 {
13257 {
13260 }
13261 else
13262 {
13266 p);
13268 }
13269 }
13272 indx++;
13274 }
13275 }
13277 /* Build .glink global entry stubs, and PLT relocs for globals. */
13284 {
13289 }
13291 {
13296 }
13298 /* Build the stubs as directed by the stub hash table. */
13311 {
13314 }
13318 {
13323 {
13329 }
13330 }
13334 {
13335 bfd_vma val;
13343 {
13344 /* Offset to stub section. */
13351 {
13352 _bfd_error_handler
13356 }
13359 }
13361 {
13362 /* Offset to .glink. */
13370 {
13371 _bfd_error_handler
13375 }
13378 }
13379 }
13383 {
13389 }
13392 {
13395 }
13401 {
13410 stub_sec_count),
13411 stub_sec_count);
13438 }
13440 }
13442 /* What to do when ld finds relocations against symbols defined in
13443 discarded sections. */
13445 static unsigned int
13447 {
13458 }
13460 /* The RELOCATE_SECTION function is called by the ELF backend linker
13461 to handle the relocations for a section.
13463 The relocs are always passed as Rela structures; if the section
13464 actually uses Rel structures, the r_addend field will always be
13465 zero.
13467 This function is responsible for adjust the section contents as
13468 necessary, and (if using Rela relocs and generating a
13469 relocatable output file) adjusting the reloc addend as
13470 necessary.
13472 This function does not have to worry about setting the reloc
13473 address or the reloc symbol index.
13475 LOCAL_SYMS is a pointer to the swapped in local symbols.
13477 LOCAL_SECTIONS is an array giving the section in the input file
13478 corresponding to the st_shndx field of each local symbol.
13480 The global hash table entry for the global symbols can be found
13481 via elf_sym_hashes (input_bfd).
13483 When generating relocatable output, this function must handle
13484 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
13485 going to be the section symbol corresponding to the output
13486 section, which means that the addend must be adjusted
13487 accordingly. */
13489 static bfd_boolean
13498 {
13505 Elf_Internal_Rela outrel;
13508 bfd_vma TOCstart;
13510 bfd_boolean is_opd;
13511 /* Assume 'at' branch hints. */
13515 /* Initialize howto table if needed. */
13523 /* Don't relocate stub sections. */
13528 {
13531 }
13542 {
13544 bfd_vma addend;
13545 bfd_reloc_status_type r;
13553 bfd_vma toc_addend;
13556 bfd_vma relocation;
13558 bfd_boolean warned;
13563 bfd_vma max_br_offset;
13564 bfd_vma from;
13565 Elf_Internal_Rela orig_rel;
13569 again:
13575 /* For old style R_PPC64_TOC relocs with a zero symbol, use the
13576 symbol of the previous ADDR64 reloc. The symbol gives us the
13577 proper TOC base to use. */
13592 {
13593 /* It's a local symbol. */
13603 {
13608 else
13609 {
13610 /* If this is a relocation against the opd section sym
13611 and we have edited .opd, adjust the reloc addend so
13612 that ld -r and ld --emit-relocs output is correct.
13613 If it is a reloc against some other .opd symbol,
13614 then the symbol value will be adjusted later. */
13617 else
13619 }
13620 }
13621 }
13622 else
13623 {
13624 bfd_boolean ignored;
13635 {
13636 /* This is a symbol defined in a linker script. All
13637 such are defined in output sections, even those
13638 defined by simple assignment from a symbol defined in
13639 an input section. Transfer the symbol to an
13640 appropriate input .opd section, so that a branch to
13641 this symbol will be mapped to the location specified
13642 by the opd entry. */
13646 {
13651 {
13656 }
13657 }
13658 }
13659 }
13663 {
13671 /* For ld -r, remove relocations in debug sections against
13672 symbols defined in discarded sections. Not done for
13673 non-debug to preserve relocs in .eh_frame which the
13674 eh_frame editing code expects to be present. */
13677 wrel--;
13680 }
13686 {
13690 }
13692 /* TLS optimizations. Replace instruction sequences and relocs
13693 based on information we collected in tls_optimize. We edit
13694 RELOCS so that --emit-relocs will output something sensible
13695 for the final instruction stream. */
13702 {
13708 }
13713 {
13714 /* Check for toc tls entries. */
13723 }
13725 /* Check that tls relocs are used with tls syms, and non-tls
13726 relocs are used with non-tls syms. */
13736 {
13741 /* R_PPC64_TLS is OK against a symbol in the TOC. */
13742 ;
13743 else
13746 /* xgettext:c-format */
13748 /* xgettext:c-format */
13752 sym_name);
13753 }
13755 /* Ensure reloc mapping code below stays sane. */
13769 {
13787 {
13788 /* Check for toc tls entries. */
13798 {
13802 {
13806 }
13807 else
13808 {
13809 /* If we found a GD reloc pair, then we might be
13810 doing a GD->IE transition. */
13812 {
13817 }
13819 {
13823 }
13824 }
13825 }
13826 }
13833 {
13838 }
13845 {
13846 toctprel:
13855 {
13858 /* We changed the symbol. Start over in order to
13859 get h, sym, sec etc. right. */
13861 }
13862 else
13864 }
13870 {
13876 /* Was PPC64_TLS which sits on insn boundary, now
13877 PPC64_TPREL16_LO which is at low-order half-word. */
13881 {
13884 /* We changed the symbol. Start over in order to
13885 get h, sym, sec etc. right. */
13887 }
13888 else
13890 }
13903 {
13904 tls_gdld_hi:
13908 else
13909 {
13913 }
13915 }
13928 {
13930 bfd_vma offset;
13932 tls_ldgd_opt:
13934 /* If not using the newer R_PPC64_TLSGD/LD to mark
13935 __tls_get_addr calls, we must trust that the call
13936 stays with its arg setup insns, ie. that the next
13937 reloc is the __tls_get_addr call associated with
13938 the current reloc. Edit both insns. */
13945 /* We read the low GOT_TLS (or TOC16) insn because we
13946 need to keep the destination reg. It may be
13947 something other than the usual r3, and moved to r3
13948 before the call by intervening code. */
13952 {
13953 /* IE */
13962 else
13965 }
13966 else
13967 {
13968 /* LE */
13973 {
13974 /* Was an LD reloc. */
13979 r_symndx++)
13989 }
13991 {
13994 }
13998 {
14000 R_PPC64_TPREL16_LO);
14003 }
14004 }
14008 {
14011 {
14015 }
14016 }
14019 {
14020 /* We changed the symbol. Start over in order
14021 to get h, sym, sec etc. right. */
14023 }
14024 }
14030 {
14035 {
14039 }
14045 {
14046 /* IE */
14049 }
14050 else
14051 {
14052 /* LE */
14054 {
14057 }
14061 }
14063 /* Zap the reloc on the _tls_get_addr call too. */
14069 }
14075 {
14080 {
14084 }
14093 r_symndx++)
14107 /* Zap the reloc on the _tls_get_addr call too. */
14113 }
14120 {
14122 {
14126 else
14127 {
14130 }
14132 }
14133 }
14134 else
14135 {
14137 {
14141 }
14142 }
14147 {
14150 }
14158 {
14165 {
14172 }
14173 }
14174 else
14175 {
14180 {
14187 {
14194 }
14195 }
14196 }
14200 /* If we are generating a non-PIC executable, edit
14201 . 0: addis 2,12,.TOC.-0b@ha
14202 . addi 2,2,.TOC.-0b@l
14203 used by ELFv2 global entry points to set up r2, to
14204 . lis 2,.TOC.@ha
14205 . addi 2,2,.TOC.@l
14206 if .TOC. is in range. */
14217 {
14224 {
14231 }
14232 }
14234 }
14236 /* Handle other relocations that tweak non-addend part of insn. */
14242 {
14252 {
14259 }
14262 /* Branch taken prediction relocations. */
14266 /* Fall through. */
14268 /* Branch not taken prediction relocations. */
14273 /* Fall through. */
14277 /* Fall through. */
14282 /* Calls to functions with a different TOC, such as calls to
14283 shared objects, need to alter the TOC pointer. This is
14284 done using a linkage stub. A REL24 branching to these
14285 linkage stubs needs to be followed by a nop, as the nop
14286 will be replaced with an instruction to restore the TOC
14287 base pointer. */
14294 htab);
14308 {
14315 {
14316 /* The function doesn't use or change r2. */
14318 }
14320 {
14321 /* NOTOC calls don't need to restore r2. */
14323 }
14325 /* All of these stubs may modify r2, so there must be a
14326 branch and link followed by a nop. The nop is
14327 replaced by an insn to restore r2. */
14329 {
14335 {
14345 {
14350 {
14351 /* Special stub used, leave nop alone. */
14352 }
14353 else
14358 }
14359 }
14360 }
14363 {
14371 {
14372 /* Allow crt1 branch to go via a toc adjusting
14373 stub. Other calls that never return could do
14374 the same, if we could detect such. */
14376 }
14377 }
14380 {
14381 /* g++ as of 20130507 emits self-calls without a
14382 following nop. This is arguably wrong since we
14383 have conflicting information. On the one hand a
14384 global symbol and on the other a local call
14385 sequence, but don't error for this special case.
14386 It isn't possible to cheaply verify we have
14387 exactly such a call. Allow all calls to the same
14388 section. */
14392 {
14398 }
14401 }
14404 {
14408 /* xgettext:c-format */
14412 else
14414 /* xgettext:c-format */
14421 }
14427 }
14433 {
14434 /* The branch destination is the value of the opd entry. */
14440 {
14444 }
14445 }
14447 /* If the branch is out of reach we ought to have a long
14448 branch stub. */
14464 /* Don't use the stub if this branch is in range. */
14490 {
14491 /* Munge up the value and addend so that we call the stub
14492 rather than the procedure directly. */
14501 else
14525 }
14528 {
14530 {
14531 /* Set 'a' bit. This is 0b00010 in BO field for branch
14532 on CR(BI) insns (BO == 001at or 011at), and 0b01000
14533 for branch on CTR insns (BO == 1a00t or 1a01t). */
14538 else
14540 }
14541 else
14542 {
14543 /* Invert 'y' bit if not the default. */
14546 }
14549 }
14551 /* NOP out calls to undefined weak functions.
14552 We can thus call a weak function without first
14553 checking whether the function is defined. */
14561 {
14564 }
14571 {
14574 {
14579 }
14580 }
14588 {
14591 {
14596 }
14598 {
14601 }
14602 }
14604 }
14606 /* Set `addend'. */
14610 {
14612 /* xgettext:c-format */
14630 /* GOT16 relocations. Like an ADDR16 using the symbol's
14631 address in the GOT as relocation value instead of the
14632 symbol's value itself. Also, create a GOT entry for the
14633 symbol and put the symbol value there. */
14668 dogot:
14669 {
14670 /* Relocation is to the entry for this symbol in the global
14671 offset table. */
14674 bfd_vma off;
14682 else
14683 {
14685 {
14690 /* This is actually a static link, or it is a
14691 -Bsymbolic link and the symbol is defined
14692 locally, or the symbol was forced to be local
14693 because of a version file. */
14694 ;
14695 else
14696 {
14699 }
14701 }
14702 else
14703 {
14707 }
14714 }
14725 /* The offset must always be a multiple of 8. We use the
14726 least significant bit to record whether we have already
14727 processed this entry. */
14731 else
14732 {
14733 /* Generate relocs for the dynamic linker, except in
14734 the case of TLSLD where we'll use one entry per
14735 module. */
14737 bfd_boolean ifunc;
14745 {
14751 }
14763 {
14769 {
14773 {
14781 outrel.r_info
14783 }
14784 }
14791 else
14792 {
14795 else
14798 /* Write the .got section contents for the sake
14799 of prelink. */
14802 loc);
14803 }
14806 {
14809 {
14812 else
14814 }
14815 }
14820 }
14822 /* Init the .got section contents here if we're not
14823 emitting a reloc. */
14824 else
14825 {
14828 {
14831 else
14832 {
14835 else
14839 }
14842 {
14846 }
14847 }
14850 }
14851 }
14858 }
14869 /* Relocation is to the entry for this symbol in the
14870 procedure linkage table. */
14872 {
14877 {
14881 }
14883 {
14889 {
14891 bfd_vma got;
14897 {
14902 else
14904 }
14912 {
14916 }
14920 }
14921 }
14922 }
14926 /* Relocation value is TOC base. */
14931 ;
14934 else
14938 /* TOC16 relocs. We want the offset relative to the TOC base,
14939 which is the address of the start of the TOC plus 0x8000.
14940 The TOC consists of sections .got, .toc, .tocbss, and .plt,
14941 in this order. */
14951 /* Relocate against the beginning of the section. */
14997 {
14998 /* Make this relocation against an undefined weak symbol
14999 resolve to zero. This is really just a tweak, since
15000 code using weak externs ought to check that they are
15001 defined before using them. */
15009 }
15012 /* The TPREL16 relocs shouldn't really be used in shared
15013 libs or with non-local symbols as that will result in
15014 DT_TEXTREL being set, but support them anyway. */
15052 /* Fall through. */
15054 /* Relocations that may need to be propagated if this is a
15055 dynamic object. */
15080 dodyn:
15095 {
15098 bfd_vma out_off;
15101 /* When generating a dynamic object, these relocations
15102 are copied into the output file to be resolved at run
15103 time. */
15119 /* Optimize unaligned reloc use. */
15133 && !is_opd
15135 {
15139 }
15140 else
15141 {
15142 /* This symbol is local, or marked to become local,
15143 or this is an opd section reloc which must point
15144 at a local function. */
15147 {
15149 {
15150 /* Lie about opd entries. This case occurs
15151 when building shared libraries and we
15152 reference a function in another shared
15153 lib. The same thing happens for a weak
15154 definition in an application that's
15155 overridden by a strong definition in a
15156 shared lib. (I believe this is a generic
15157 bug in binutils handling of weak syms.)
15158 In these cases we won't use the opd
15159 entry in this lib. */
15161 }
15168 else
15169 {
15172 /* We need to relocate .opd contents for ld.so.
15173 Prelink also wants simple and consistent rules
15174 for relocs. This make all RELATIVE relocs have
15175 *r_offset equal to r_addend. */
15177 }
15178 }
15179 else
15180 {
15184 {
15186 /* xgettext:c-format */
15191 sym_name);
15193 }
15195 ;
15197 {
15200 }
15201 else
15202 {
15209 {
15213 else
15216 }
15219 /* We are turning this relocation into one
15220 against a section symbol, so subtract out
15221 the output section's address but not the
15222 offset of the input section in the output
15223 section. */
15225 }
15228 }
15229 }
15235 {
15241 }
15252 /* If this reloc is against an external symbol, it will
15253 be computed at runtime, so there's no need to do
15254 anything now. However, for the sake of prelink ensure
15255 that the section contents are a known value. */
15257 {
15259 /* The value chosen here is quite arbitrary as ld.so
15260 ignores section contents except for the special
15261 case of .opd where the contents might be accessed
15262 before relocation. Choose zero, as that won't
15263 cause reloc overflow. */
15266 /* Use *r_offset == r_addend for R_PPC64_ADDR64 relocs
15267 to improve backward compatibility with older
15268 versions of ld. */
15271 /* Adjust pc_relative relocs to have zero in *r_offset. */
15274 }
15275 }
15283 /* We shouldn't ever see these dynamic relocs in relocatable
15284 files. */
15285 /* Fall through. */
15295 /* These ones haven't been implemented yet. */
15298 /* xgettext:c-format */
15300 input_bfd,
15306 }
15308 /* Multi-instruction sequences that access the TOC can be
15309 optimized, eg. addis ra,r2,0; addi rb,ra,x;
15310 to nop; addi rb,r2,x; */
15312 {
15322 /* These relocs would only be useful if building up an
15323 offset to later add to r2, perhaps in an indexed
15324 addressing mode instruction. Don't try to optimize.
15325 Unfortunately, the possibility of someone building up an
15326 offset like this or even with the HA relocs, means that
15327 we need to check the high insn when optimizing the low
15328 insn. */
15333 {
15334 /* No plt entry. Make this into a direct call. */
15342 }
15347 {
15350 }
15355 {
15358 }
15359 /* Fall through. */
15368 {
15370 nop_it:
15374 }
15380 {
15383 }
15384 /* Fall through. */
15395 {
15399 {
15400 /* Transform addic to addi when we change reg. */
15403 }
15404 else
15405 {
15408 }
15410 }
15415 {
15420 /* xgettext:c-format */
15425 else
15426 {
15429 }
15430 }
15436 {
15442 }
15444 }
15446 /* Do any further special processing. */
15448 {
15471 /* It's just possible that this symbol is a weak symbol
15472 that's not actually defined anywhere. In that case,
15473 'sec' would be NULL, and we should leave the symbol
15474 alone (it will be set to zero elsewhere in the link). */
15477 /* Fall through. */
15486 /* Add 0x10000 if sign bit in 0:15 is set.
15487 Bits 0:15 are not used. */
15512 /* If this reloc is against an lq, lxv, or stxv insn, then
15513 the value must be a multiple of 16. This is somewhat of
15514 a hack, but the "correct" way to do this by defining _DQ
15515 forms of all the _DS relocs bloats all reloc switches in
15516 this file. It doesn't make much sense to use these
15517 relocs in data, so testing the insn should be safe. */
15524 {
15527 /* xgettext:c-format */
15535 }
15537 }
15539 /* Dynamic relocs are not propagated for SEC_DEBUGGING sections
15540 because such sections are not SEC_ALLOC and thus ld.so will
15541 not process them. */
15548 {
15550 /* xgettext:c-format */
15556 }
15558 /* 16-bit fields in insns mostly have signed values, but a
15559 few insns have 16-bit unsigned values. Really, we should
15560 have different reloc types. */
15564 {
15579 {
15583 }
15584 }
15587 {
15588 /* Split field reloc isn't handled by _bfd_final_link_relocate. */
15591 else
15592 {
15605 }
15606 }
15607 else
15612 {
15617 {
15620 {
15625 }
15626 }
15629 {
15630 /* On code like "if (foo) foo();" don't report overflow
15631 on a branch to zero when foo is undefined. */
15643 }
15644 else
15645 {
15647 /* xgettext:c-format */
15652 }
15655 }
15656 copy_reloc:
15659 }
15662 {
15669 {
15670 /* It is too late to remove an empty reloc section. Leave
15671 one NONE reloc.
15672 ??? What is wrong with an empty section??? */
15675 }
15679 }
15681 /* If we're emitting relocations, then shortly after this function
15682 returns, reloc offsets and addends for this section will be
15683 adjusted. Worse, reloc symbol indices will be for the output
15684 file rather than the input. Save a copy of the relocs for
15685 opd_entry_value. */
15687 {
15688 bfd_size_type amt;
15696 }
15698 }
15700 /* Adjust the value of any local symbols in opd sections. */
15702 static int
15708 {
15711 bfd_vma value;
15730 }
15732 /* Finish up dynamic symbol handling. We set the contents of various
15733 dynamic sections here. */
15735 static bfd_boolean
15740 {
15751 {
15752 /* Mark the symbol as undefined, rather than as
15753 defined in glink. Leave the value if there were
15754 any relocations where pointer equality matters
15755 (this is a clue for the dynamic linker, to make
15756 function pointer comparisons work between an
15757 application and shared library), otherwise set it
15758 to zero. */
15763 {
15764 /* This breaks function pointer comparisons, but
15765 that is better than breaking tests for a NULL
15766 function pointer. */
15768 }
15770 }
15773 {
15774 /* This symbol needs a copy reloc. Set it up. */
15775 Elf_Internal_Rela rela;
15793 else
15798 }
15801 }
15803 /* Used to decide how to sort relocs in an optimal manner for the
15804 dynamic linker, before writing them out. */
15806 static enum elf_reloc_type_class
15810 {
15819 {
15828 }
15829 }
15831 /* Finish up the dynamic sections. */
15833 static bfd_boolean
15836 {
15849 {
15858 {
15859 Elf_Internal_Dyn dyn;
15865 {
15872 /* We stupidly defined DT_PPC64_GLINK to be the start
15873 of glink rather than the first entry point, which is
15874 what ld.so needs, and now have a bigger stub to
15875 support automatic multiple TOCs. */
15924 }
15927 }
15928 }
15932 {
15933 /* Fill in the first entry in the global offset table.
15934 We use it to hold the link-time TOCbase. */
15939 /* Set .got entry size. */
15942 }
15946 {
15947 /* Set .plt entry size. */
15950 }
15952 /* brlt is SEC_LINKER_CREATED, so we need to write out relocs for
15953 brlt ourselves if emitrelocations. */
15960 NULL))
15969 NULL))
15981 /* We need to handle writing out multiple GOT sections ourselves,
15982 since we didn't add them to DYNOBJ. We know dynobj is the first
15983 bfd. */
15985 {
16007 }
16010 }
16014 /* FreeBSD support */
16016 #undef TARGET_LITTLE_SYM
16017 #undef TARGET_LITTLE_NAME
16019 #undef TARGET_BIG_SYM
16020 #define TARGET_BIG_SYM powerpc_elf64_fbsd_vec
16021 #undef TARGET_BIG_NAME
16024 #undef ELF_OSABI
16025 #define ELF_OSABI ELFOSABI_FREEBSD
16027 #undef elf64_bed
16028 #define elf64_bed elf64_powerpc_fbsd_bed