| blob | e475421951f24b430d278abfb9892c891af3760d |
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 /* All users of this file have bfd_octets_per_byte (abfd, sec) == 1. */
39 #define OCTETS_PER_BYTE(ABFD, SEC) 1
41 static bfd_reloc_status_type ppc64_elf_ha_reloc
43 static bfd_reloc_status_type ppc64_elf_branch_reloc
45 static bfd_reloc_status_type ppc64_elf_brtaken_reloc
47 static bfd_reloc_status_type ppc64_elf_sectoff_reloc
49 static bfd_reloc_status_type ppc64_elf_sectoff_ha_reloc
51 static bfd_reloc_status_type ppc64_elf_toc_reloc
53 static bfd_reloc_status_type ppc64_elf_toc_ha_reloc
55 static bfd_reloc_status_type ppc64_elf_toc64_reloc
57 static bfd_reloc_status_type ppc64_elf_prefix_reloc
59 static bfd_reloc_status_type ppc64_elf_unhandled_reloc
61 static bfd_vma opd_entry_value
64 #define TARGET_LITTLE_SYM powerpc_elf64_le_vec
66 #define TARGET_BIG_SYM powerpc_elf64_vec
68 #define ELF_ARCH bfd_arch_powerpc
69 #define ELF_TARGET_ID PPC64_ELF_DATA
70 #define ELF_MACHINE_CODE EM_PPC64
71 #define ELF_MAXPAGESIZE 0x10000
72 #define ELF_COMMONPAGESIZE 0x1000
73 #define ELF_RELROPAGESIZE ELF_MAXPAGESIZE
74 #define elf_info_to_howto ppc64_elf_info_to_howto
76 #define elf_backend_want_got_sym 0
77 #define elf_backend_want_plt_sym 0
78 #define elf_backend_plt_alignment 3
79 #define elf_backend_plt_not_loaded 1
80 #define elf_backend_got_header_size 8
81 #define elf_backend_want_dynrelro 1
82 #define elf_backend_can_gc_sections 1
83 #define elf_backend_can_refcount 1
84 #define elf_backend_rela_normal 1
85 #define elf_backend_dtrel_excludes_plt 1
86 #define elf_backend_default_execstack 0
88 #define bfd_elf64_mkobject ppc64_elf_mkobject
89 #define bfd_elf64_bfd_reloc_type_lookup ppc64_elf_reloc_type_lookup
90 #define bfd_elf64_bfd_reloc_name_lookup ppc64_elf_reloc_name_lookup
91 #define bfd_elf64_bfd_merge_private_bfd_data ppc64_elf_merge_private_bfd_data
92 #define bfd_elf64_bfd_print_private_bfd_data ppc64_elf_print_private_bfd_data
93 #define bfd_elf64_new_section_hook ppc64_elf_new_section_hook
94 #define bfd_elf64_bfd_link_hash_table_create ppc64_elf_link_hash_table_create
95 #define bfd_elf64_get_synthetic_symtab ppc64_elf_get_synthetic_symtab
96 #define bfd_elf64_bfd_link_just_syms ppc64_elf_link_just_syms
97 #define bfd_elf64_bfd_gc_sections ppc64_elf_gc_sections
99 #define elf_backend_object_p ppc64_elf_object_p
100 #define elf_backend_grok_prstatus ppc64_elf_grok_prstatus
101 #define elf_backend_grok_psinfo ppc64_elf_grok_psinfo
102 #define elf_backend_write_core_note ppc64_elf_write_core_note
103 #define elf_backend_create_dynamic_sections _bfd_elf_create_dynamic_sections
104 #define elf_backend_copy_indirect_symbol ppc64_elf_copy_indirect_symbol
105 #define elf_backend_add_symbol_hook ppc64_elf_add_symbol_hook
106 #define elf_backend_check_directives ppc64_elf_before_check_relocs
107 #define elf_backend_notice_as_needed ppc64_elf_notice_as_needed
108 #define elf_backend_archive_symbol_lookup ppc64_elf_archive_symbol_lookup
109 #define elf_backend_check_relocs ppc64_elf_check_relocs
110 #define elf_backend_relocs_compatible _bfd_elf_relocs_compatible
111 #define elf_backend_gc_keep ppc64_elf_gc_keep
112 #define elf_backend_gc_mark_dynamic_ref ppc64_elf_gc_mark_dynamic_ref
113 #define elf_backend_gc_mark_hook ppc64_elf_gc_mark_hook
114 #define elf_backend_adjust_dynamic_symbol ppc64_elf_adjust_dynamic_symbol
115 #define elf_backend_hide_symbol ppc64_elf_hide_symbol
116 #define elf_backend_maybe_function_sym ppc64_elf_maybe_function_sym
117 #define elf_backend_always_size_sections ppc64_elf_func_desc_adjust
118 #define elf_backend_size_dynamic_sections ppc64_elf_size_dynamic_sections
119 #define elf_backend_hash_symbol ppc64_elf_hash_symbol
120 #define elf_backend_init_index_section _bfd_elf_init_2_index_sections
121 #define elf_backend_action_discarded ppc64_elf_action_discarded
122 #define elf_backend_relocate_section ppc64_elf_relocate_section
123 #define elf_backend_finish_dynamic_symbol ppc64_elf_finish_dynamic_symbol
124 #define elf_backend_reloc_type_class ppc64_elf_reloc_type_class
125 #define elf_backend_finish_dynamic_sections ppc64_elf_finish_dynamic_sections
126 #define elf_backend_link_output_symbol_hook ppc64_elf_output_symbol_hook
127 #define elf_backend_special_sections ppc64_elf_special_sections
128 #define elf_backend_merge_symbol_attribute ppc64_elf_merge_symbol_attribute
129 #define elf_backend_merge_symbol ppc64_elf_merge_symbol
130 #define elf_backend_get_reloc_section bfd_get_section_by_name
132 /* The name of the dynamic interpreter. This is put in the .interp
133 section. */
136 /* The size in bytes of an entry in the procedure linkage table. */
137 #define PLT_ENTRY_SIZE(htab) (htab->opd_abi ? 24 : 8)
138 #define LOCAL_PLT_ENTRY_SIZE(htab) (htab->opd_abi ? 16 : 8)
140 /* The initial size of the plt reserved for the dynamic linker. */
141 #define PLT_INITIAL_ENTRY_SIZE(htab) (htab->opd_abi ? 24 : 16)
143 /* Offsets to some stack save slots. */
144 #define STK_LR 16
145 #define STK_TOC(htab) (htab->opd_abi ? 40 : 24)
146 /* This one is dodgy. ELFv2 does not have a linker word, so use the
147 CR save slot. Used only by optimised __tls_get_addr call stub,
148 relying on __tls_get_addr_opt not saving CR.. */
149 #define STK_LINKER(htab) (htab->opd_abi ? 32 : 8)
151 /* TOC base pointers offset from start of TOC. */
152 #define TOC_BASE_OFF 0x8000
153 /* TOC base alignment. */
154 #define TOC_BASE_ALIGN 256
156 /* Offset of tp and dtp pointers from start of TLS block. */
157 #define TP_OFFSET 0x7000
158 #define DTP_OFFSET 0x8000
160 /* .plt call stub instructions. The normal stub is like this, but
161 sometimes the .plt entry crosses a 64k boundary and we need to
162 insert an addi to adjust r11. */
209 #define PADDI_R12_PC 0x0610000039800000ULL
210 #define PLD_R12_PC 0x04100000e5800000ULL
211 #define PNOP 0x0700000000000000ULL
213 /* __glink_PLTresolve stub instructions. We enter with the index in R0. */
214 #define GLINK_PLTRESOLVE_SIZE(htab) \
215 (8u + (htab->opd_abi ? 11 * 4 : 14 * 4))
216 /* 0: */
217 /* .quad plt0-1f */
218 /* __glink: */
221 /* 1: */
223 /* ld %2,(0b-1b)(%11) */
226 /* ld %12,0(%11) */
227 /* ld %2,8(%11) */
228 /* mtctr %12 */
229 /* ld %11,16(%11) */
230 /* bctr */
237 /* Pad with this. */
238 #define NOP 0x60000000
240 /* Some other nops. */
241 #define CROR_151515 0x4def7b82
242 #define CROR_313131 0x4ffffb82
244 /* .glink entries for the first 32k functions are two instructions. */
248 /* After that, we need two instructions to load the index, followed by
249 a branch. */
253 /* Instructions used by the save and restore reg functions. */
266 /* Since .opd is an array of descriptors and each entry will end up
267 with identical R_PPC64_RELATIVE relocs, there is really no need to
268 propagate .opd relocs; The dynamic linker should be taught to
269 relocate .opd without reloc entries. */
270 #ifndef NO_OPD_RELOCS
271 #define NO_OPD_RELOCS 0
272 #endif
274 #ifndef ARRAY_SIZE
275 #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
276 #endif
280 {
282 }
286 {
289 }
290 \f
291 /* Relocation HOWTO's. */
292 /* Like other ELF RELA targets that don't apply multiple
293 field-altering relocations to the same localation, src_mask is
294 always zero and pcrel_offset is the same as pc_relative.
295 PowerPC can always use a zero bitpos, even when the field is not at
296 the LSB. For example, a REL24 could use rightshift=2, bisize=24
297 and bitpos=2 which matches the ABI description, or as we do here,
298 rightshift=0, bitsize=26 and bitpos=0. */
299 #define HOW(type, size, bitsize, mask, rightshift, pc_relative, \
300 complain, special_func) \
301 HOWTO (type, rightshift, size, bitsize, pc_relative, 0, \
302 complain_overflow_ ## complain, special_func, \
303 #type, FALSE, 0, mask, pc_relative)
308 {
309 /* This reloc does nothing. */
311 bfd_elf_generic_reloc),
313 /* A standard 32 bit relocation. */
315 bfd_elf_generic_reloc),
317 /* An absolute 26 bit branch; the lower two bits must be zero.
318 FIXME: we don't check that, we just clear them. */
320 bfd_elf_generic_reloc),
322 /* A standard 16 bit relocation. */
324 bfd_elf_generic_reloc),
326 /* A 16 bit relocation without overflow. */
328 bfd_elf_generic_reloc),
330 /* Bits 16-31 of an address. */
332 bfd_elf_generic_reloc),
334 /* Bits 16-31 of an address, plus 1 if the contents of the low 16
335 bits, treated as a signed number, is negative. */
337 ppc64_elf_ha_reloc),
339 /* An absolute 16 bit branch; the lower two bits must be zero.
340 FIXME: we don't check that, we just clear them. */
342 ppc64_elf_branch_reloc),
344 /* An absolute 16 bit branch, for which bit 10 should be set to
345 indicate that the branch is expected to be taken. The lower two
346 bits must be zero. */
348 ppc64_elf_brtaken_reloc),
350 /* An absolute 16 bit branch, for which bit 10 should be set to
351 indicate that the branch is not expected to be taken. The lower
352 two bits must be zero. */
354 ppc64_elf_brtaken_reloc),
356 /* A relative 26 bit branch; the lower two bits must be zero. */
358 ppc64_elf_branch_reloc),
360 /* A variant of R_PPC64_REL24, used when r2 is not the toc pointer. */
362 ppc64_elf_branch_reloc),
364 /* A relative 16 bit branch; the lower two bits must be zero. */
366 ppc64_elf_branch_reloc),
368 /* A relative 16 bit branch. Bit 10 should be set to indicate that
369 the branch is expected to be taken. The lower two bits must be
370 zero. */
372 ppc64_elf_brtaken_reloc),
374 /* A relative 16 bit branch. Bit 10 should be set to indicate that
375 the branch is not expected to be taken. The lower two bits must
376 be zero. */
378 ppc64_elf_brtaken_reloc),
380 /* Like R_PPC64_ADDR16, but referring to the GOT table entry for the
381 symbol. */
383 ppc64_elf_unhandled_reloc),
385 /* Like R_PPC64_ADDR16_LO, but referring to the GOT table entry for
386 the symbol. */
388 ppc64_elf_unhandled_reloc),
390 /* Like R_PPC64_ADDR16_HI, but referring to the GOT table entry for
391 the symbol. */
393 ppc64_elf_unhandled_reloc),
395 /* Like R_PPC64_ADDR16_HA, but referring to the GOT table entry for
396 the symbol. */
398 ppc64_elf_unhandled_reloc),
400 /* This is used only by the dynamic linker. The symbol should exist
401 both in the object being run and in some shared library. The
402 dynamic linker copies the data addressed by the symbol from the
403 shared library into the object, because the object being
404 run has to have the data at some particular address. */
406 ppc64_elf_unhandled_reloc),
408 /* Like R_PPC64_ADDR64, but used when setting global offset table
409 entries. */
411 ppc64_elf_unhandled_reloc),
413 /* Created by the link editor. Marks a procedure linkage table
414 entry for a symbol. */
416 ppc64_elf_unhandled_reloc),
418 /* Used only by the dynamic linker. When the object is run, this
419 doubleword64 is set to the load address of the object, plus the
420 addend. */
422 bfd_elf_generic_reloc),
424 /* Like R_PPC64_ADDR32, but may be unaligned. */
426 bfd_elf_generic_reloc),
428 /* Like R_PPC64_ADDR16, but may be unaligned. */
430 bfd_elf_generic_reloc),
432 /* 32-bit PC relative. */
434 bfd_elf_generic_reloc),
436 /* 32-bit relocation to the symbol's procedure linkage table. */
438 ppc64_elf_unhandled_reloc),
440 /* 32-bit PC relative relocation to the symbol's procedure linkage table.
441 FIXME: R_PPC64_PLTREL32 not supported. */
443 ppc64_elf_unhandled_reloc),
445 /* Like R_PPC64_ADDR16_LO, but referring to the PLT table entry for
446 the symbol. */
448 ppc64_elf_unhandled_reloc),
450 /* Like R_PPC64_ADDR16_HI, but referring to the PLT table entry for
451 the symbol. */
453 ppc64_elf_unhandled_reloc),
455 /* Like R_PPC64_ADDR16_HA, but referring to the PLT table entry for
456 the symbol. */
458 ppc64_elf_unhandled_reloc),
460 /* 16-bit section relative relocation. */
462 ppc64_elf_sectoff_reloc),
464 /* Like R_PPC64_SECTOFF, but no overflow warning. */
466 ppc64_elf_sectoff_reloc),
468 /* 16-bit upper half section relative relocation. */
470 ppc64_elf_sectoff_reloc),
472 /* 16-bit upper half adjusted section relative relocation. */
474 ppc64_elf_sectoff_ha_reloc),
476 /* Like R_PPC64_REL24 without touching the two least significant bits. */
478 bfd_elf_generic_reloc),
480 /* Relocs in the 64-bit PowerPC ELF ABI, not in the 32-bit ABI. */
482 /* A standard 64-bit relocation. */
484 bfd_elf_generic_reloc),
486 /* The bits 32-47 of an address. */
488 bfd_elf_generic_reloc),
490 /* The bits 32-47 of an address, plus 1 if the contents of the low
491 16 bits, treated as a signed number, is negative. */
493 ppc64_elf_ha_reloc),
495 /* The bits 48-63 of an address. */
497 bfd_elf_generic_reloc),
499 /* The bits 48-63 of an address, plus 1 if the contents of the low
500 16 bits, treated as a signed number, is negative. */
502 ppc64_elf_ha_reloc),
504 /* Like ADDR64, but may be unaligned. */
506 bfd_elf_generic_reloc),
508 /* 64-bit relative relocation. */
510 bfd_elf_generic_reloc),
512 /* 64-bit relocation to the symbol's procedure linkage table. */
514 ppc64_elf_unhandled_reloc),
516 /* 64-bit PC relative relocation to the symbol's procedure linkage
517 table. */
518 /* FIXME: R_PPC64_PLTREL64 not supported. */
520 ppc64_elf_unhandled_reloc),
522 /* 16 bit TOC-relative relocation. */
523 /* R_PPC64_TOC16 47 half16* S + A - .TOC. */
525 ppc64_elf_toc_reloc),
527 /* 16 bit TOC-relative relocation without overflow. */
528 /* R_PPC64_TOC16_LO 48 half16 #lo (S + A - .TOC.) */
530 ppc64_elf_toc_reloc),
532 /* 16 bit TOC-relative relocation, high 16 bits. */
533 /* R_PPC64_TOC16_HI 49 half16 #hi (S + A - .TOC.) */
535 ppc64_elf_toc_reloc),
537 /* 16 bit TOC-relative relocation, high 16 bits, plus 1 if the
538 contents of the low 16 bits, treated as a signed number, is
539 negative. */
540 /* R_PPC64_TOC16_HA 50 half16 #ha (S + A - .TOC.) */
542 ppc64_elf_toc_ha_reloc),
544 /* 64-bit relocation; insert value of TOC base (.TOC.). */
545 /* R_PPC64_TOC 51 doubleword64 .TOC. */
547 ppc64_elf_toc64_reloc),
549 /* Like R_PPC64_GOT16, but also informs the link editor that the
550 value to relocate may (!) refer to a PLT entry which the link
551 editor (a) may replace with the symbol value. If the link editor
552 is unable to fully resolve the symbol, it may (b) create a PLT
553 entry and store the address to the new PLT entry in the GOT.
554 This permits lazy resolution of function symbols at run time.
555 The link editor may also skip all of this and just (c) emit a
556 R_PPC64_GLOB_DAT to tie the symbol to the GOT entry. */
557 /* FIXME: R_PPC64_PLTGOT16 not implemented. */
559 ppc64_elf_unhandled_reloc),
561 /* Like R_PPC64_PLTGOT16, but without overflow. */
562 /* FIXME: R_PPC64_PLTGOT16_LO not implemented. */
564 ppc64_elf_unhandled_reloc),
566 /* Like R_PPC64_PLT_GOT16, but using bits 16-31 of the address. */
567 /* FIXME: R_PPC64_PLTGOT16_HI not implemented. */
569 ppc64_elf_unhandled_reloc),
571 /* Like R_PPC64_PLT_GOT16, but using bits 16-31 of the address, plus
572 1 if the contents of the low 16 bits, treated as a signed number,
573 is negative. */
574 /* FIXME: R_PPC64_PLTGOT16_HA not implemented. */
576 ppc64_elf_unhandled_reloc),
578 /* Like R_PPC64_ADDR16, but for instructions with a DS field. */
580 bfd_elf_generic_reloc),
582 /* Like R_PPC64_ADDR16_LO, but for instructions with a DS field. */
584 bfd_elf_generic_reloc),
586 /* Like R_PPC64_GOT16, but for instructions with a DS field. */
588 ppc64_elf_unhandled_reloc),
590 /* Like R_PPC64_GOT16_LO, but for instructions with a DS field. */
592 ppc64_elf_unhandled_reloc),
594 /* Like R_PPC64_PLT16_LO, but for instructions with a DS field. */
596 ppc64_elf_unhandled_reloc),
598 /* Like R_PPC64_SECTOFF, but for instructions with a DS field. */
600 ppc64_elf_sectoff_reloc),
602 /* Like R_PPC64_SECTOFF_LO, but for instructions with a DS field. */
604 ppc64_elf_sectoff_reloc),
606 /* Like R_PPC64_TOC16, but for instructions with a DS field. */
608 ppc64_elf_toc_reloc),
610 /* Like R_PPC64_TOC16_LO, but for instructions with a DS field. */
612 ppc64_elf_toc_reloc),
614 /* Like R_PPC64_PLTGOT16, but for instructions with a DS field. */
615 /* FIXME: R_PPC64_PLTGOT16_DS not implemented. */
617 ppc64_elf_unhandled_reloc),
619 /* Like R_PPC64_PLTGOT16_LO, but for instructions with a DS field. */
620 /* FIXME: R_PPC64_PLTGOT16_LO not implemented. */
622 ppc64_elf_unhandled_reloc),
624 /* Marker relocs for TLS. */
626 bfd_elf_generic_reloc),
629 bfd_elf_generic_reloc),
632 bfd_elf_generic_reloc),
634 /* Marker reloc for optimizing r2 save in prologue rather than on
635 each plt call stub. */
637 bfd_elf_generic_reloc),
639 /* Marker relocs on inline plt call instructions. */
641 bfd_elf_generic_reloc),
644 bfd_elf_generic_reloc),
646 /* Computes the load module index of the load module that contains the
647 definition of its TLS sym. */
649 ppc64_elf_unhandled_reloc),
651 /* Computes a dtv-relative displacement, the difference between the value
652 of sym+add and the base address of the thread-local storage block that
653 contains the definition of sym, minus 0x8000. */
655 ppc64_elf_unhandled_reloc),
657 /* A 16 bit dtprel reloc. */
659 ppc64_elf_unhandled_reloc),
661 /* Like DTPREL16, but no overflow. */
663 ppc64_elf_unhandled_reloc),
665 /* Like DTPREL16_LO, but next higher group of 16 bits. */
667 ppc64_elf_unhandled_reloc),
669 /* Like DTPREL16_HI, but adjust for low 16 bits. */
671 ppc64_elf_unhandled_reloc),
673 /* Like DTPREL16_HI, but next higher group of 16 bits. */
675 ppc64_elf_unhandled_reloc),
677 /* Like DTPREL16_HIGHER, but adjust for low 16 bits. */
679 ppc64_elf_unhandled_reloc),
681 /* Like DTPREL16_HIGHER, but next higher group of 16 bits. */
683 ppc64_elf_unhandled_reloc),
685 /* Like DTPREL16_HIGHEST, but adjust for low 16 bits. */
687 ppc64_elf_unhandled_reloc),
689 /* Like DTPREL16, but for insns with a DS field. */
691 ppc64_elf_unhandled_reloc),
693 /* Like DTPREL16_DS, but no overflow. */
695 ppc64_elf_unhandled_reloc),
697 /* Computes a tp-relative displacement, the difference between the value of
698 sym+add and the value of the thread pointer (r13). */
700 ppc64_elf_unhandled_reloc),
702 /* A 16 bit tprel reloc. */
704 ppc64_elf_unhandled_reloc),
706 /* Like TPREL16, but no overflow. */
708 ppc64_elf_unhandled_reloc),
710 /* Like TPREL16_LO, but next higher group of 16 bits. */
712 ppc64_elf_unhandled_reloc),
714 /* Like TPREL16_HI, but adjust for low 16 bits. */
716 ppc64_elf_unhandled_reloc),
718 /* Like TPREL16_HI, but next higher group of 16 bits. */
720 ppc64_elf_unhandled_reloc),
722 /* Like TPREL16_HIGHER, but adjust for low 16 bits. */
724 ppc64_elf_unhandled_reloc),
726 /* Like TPREL16_HIGHER, but next higher group of 16 bits. */
728 ppc64_elf_unhandled_reloc),
730 /* Like TPREL16_HIGHEST, but adjust for low 16 bits. */
732 ppc64_elf_unhandled_reloc),
734 /* Like TPREL16, but for insns with a DS field. */
736 ppc64_elf_unhandled_reloc),
738 /* Like TPREL16_DS, but no overflow. */
740 ppc64_elf_unhandled_reloc),
742 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
743 with values (sym+add)@dtpmod and (sym+add)@dtprel, and computes the offset
744 to the first entry relative to the TOC base (r2). */
746 ppc64_elf_unhandled_reloc),
748 /* Like GOT_TLSGD16, but no overflow. */
750 ppc64_elf_unhandled_reloc),
752 /* Like GOT_TLSGD16_LO, but next higher group of 16 bits. */
754 ppc64_elf_unhandled_reloc),
756 /* Like GOT_TLSGD16_HI, but adjust for low 16 bits. */
758 ppc64_elf_unhandled_reloc),
760 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
761 with values (sym+add)@dtpmod and zero, and computes the offset to the
762 first entry relative to the TOC base (r2). */
764 ppc64_elf_unhandled_reloc),
766 /* Like GOT_TLSLD16, but no overflow. */
768 ppc64_elf_unhandled_reloc),
770 /* Like GOT_TLSLD16_LO, but next higher group of 16 bits. */
772 ppc64_elf_unhandled_reloc),
774 /* Like GOT_TLSLD16_HI, but adjust for low 16 bits. */
776 ppc64_elf_unhandled_reloc),
778 /* Allocates an entry in the GOT with value (sym+add)@dtprel, and computes
779 the offset to the entry relative to the TOC base (r2). */
781 ppc64_elf_unhandled_reloc),
783 /* Like GOT_DTPREL16_DS, but no overflow. */
785 ppc64_elf_unhandled_reloc),
787 /* Like GOT_DTPREL16_LO_DS, but next higher group of 16 bits. */
789 ppc64_elf_unhandled_reloc),
791 /* Like GOT_DTPREL16_HI, but adjust for low 16 bits. */
793 ppc64_elf_unhandled_reloc),
795 /* Allocates an entry in the GOT with value (sym+add)@tprel, and computes the
796 offset to the entry relative to the TOC base (r2). */
798 ppc64_elf_unhandled_reloc),
800 /* Like GOT_TPREL16_DS, but no overflow. */
802 ppc64_elf_unhandled_reloc),
804 /* Like GOT_TPREL16_LO_DS, but next higher group of 16 bits. */
806 ppc64_elf_unhandled_reloc),
808 /* Like GOT_TPREL16_HI, but adjust for low 16 bits. */
810 ppc64_elf_unhandled_reloc),
813 ppc64_elf_unhandled_reloc),
816 bfd_elf_generic_reloc),
818 /* A 16 bit relative relocation. */
820 bfd_elf_generic_reloc),
822 /* A 16 bit relative relocation without overflow. */
824 bfd_elf_generic_reloc),
826 /* The high order 16 bits of a relative address. */
828 bfd_elf_generic_reloc),
830 /* The high order 16 bits of a relative address, plus 1 if the contents of
831 the low 16 bits, treated as a signed number, is negative. */
833 ppc64_elf_ha_reloc),
836 bfd_elf_generic_reloc),
839 ppc64_elf_ha_reloc),
842 bfd_elf_generic_reloc),
845 ppc64_elf_ha_reloc),
848 bfd_elf_generic_reloc),
851 ppc64_elf_ha_reloc),
853 /* Like R_PPC64_REL16_HA but for split field in addpcis. */
855 ppc64_elf_ha_reloc),
857 /* A split-field reloc for addpcis, non-relative (gas internal use only). */
859 ppc64_elf_ha_reloc),
861 /* Like R_PPC64_ADDR16_HI, but no overflow. */
863 bfd_elf_generic_reloc),
865 /* Like R_PPC64_ADDR16_HA, but no overflow. */
867 ppc64_elf_ha_reloc),
869 /* Like R_PPC64_DTPREL16_HI, but no overflow. */
871 ppc64_elf_unhandled_reloc),
873 /* Like R_PPC64_DTPREL16_HA, but no overflow. */
875 ppc64_elf_unhandled_reloc),
877 /* Like R_PPC64_TPREL16_HI, but no overflow. */
879 ppc64_elf_unhandled_reloc),
881 /* Like R_PPC64_TPREL16_HA, but no overflow. */
883 ppc64_elf_unhandled_reloc),
885 /* Marker reloc on ELFv2 large-model function entry. */
887 bfd_elf_generic_reloc),
889 /* Like ADDR64, but use local entry point of function. */
891 bfd_elf_generic_reloc),
894 bfd_elf_generic_reloc),
897 bfd_elf_generic_reloc),
900 bfd_elf_generic_reloc),
903 ppc64_elf_prefix_reloc),
906 ppc64_elf_prefix_reloc),
909 ppc64_elf_prefix_reloc),
912 ppc64_elf_prefix_reloc),
915 ppc64_elf_prefix_reloc),
918 ppc64_elf_unhandled_reloc),
921 ppc64_elf_unhandled_reloc),
924 ppc64_elf_unhandled_reloc),
927 ppc64_elf_unhandled_reloc),
930 ppc64_elf_unhandled_reloc),
933 ppc64_elf_unhandled_reloc),
936 ppc64_elf_unhandled_reloc),
939 ppc64_elf_unhandled_reloc),
942 ppc64_elf_unhandled_reloc),
945 bfd_elf_generic_reloc),
948 ppc64_elf_ha_reloc),
951 bfd_elf_generic_reloc),
954 ppc64_elf_ha_reloc),
957 bfd_elf_generic_reloc),
960 ppc64_elf_ha_reloc),
963 bfd_elf_generic_reloc),
966 ppc64_elf_ha_reloc),
969 ppc64_elf_prefix_reloc),
972 ppc64_elf_prefix_reloc),
974 /* GNU extension to record C++ vtable hierarchy. */
976 NULL),
978 /* GNU extension to record C++ vtable member usage. */
980 NULL),
981 };
983 \f
984 /* Initialize the ppc64_elf_howto_table, so that linear accesses can
985 be done. */
987 static void
989 {
993 {
997 }
998 }
1002 bfd_reloc_code_real_type code)
1003 {
1007 /* Initialize howto table if needed. */
1011 {
1013 /* xgettext:c-format */
1314 }
1317 };
1322 {
1331 }
1333 /* Set the howto pointer for a PowerPC ELF reloc. */
1335 static bfd_boolean
1338 {
1341 /* Initialize howto table if needed. */
1347 {
1348 /* xgettext:c-format */
1353 }
1356 {
1357 /* xgettext:c-format */
1362 }
1365 }
1367 /* Handle the R_PPC64_ADDR16_HA and similar relocs. */
1369 static bfd_reloc_status_type
1373 {
1376 bfd_size_type octets;
1377 bfd_vma value;
1379 /* If this is a relocatable link (output_bfd test tells us), just
1380 call the generic function. Any adjustment will be done at final
1381 link time. */
1386 /* Adjust the addend for sign extension of the low 16 (or 34) bits.
1387 We won't actually be using the low bits, so trashing them
1388 doesn't matter. */
1395 else
1419 }
1421 static bfd_reloc_status_type
1425 {
1432 {
1440 }
1441 else
1442 {
1448 {
1452 {
1456 {
1459 }
1460 }
1461 }
1462 reloc_entry->addend
1464 }
1466 }
1468 static bfd_reloc_status_type
1472 {
1475 bfd_size_type octets;
1476 /* Assume 'at' branch hints. */
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. */
1495 {
1496 /* Set 'a' bit. This is 0b00010 in BO field for branch
1497 on CR(BI) insns (BO == 001at or 011at), and 0b01000
1498 for branch on CTR insns (BO == 1a00t or 1a01t). */
1503 else
1505 }
1506 else
1507 {
1509 bfd_vma from;
1521 /* Invert 'y' bit if not the default. */
1524 }
1526 out:
1529 }
1531 static bfd_reloc_status_type
1535 {
1536 /* If this is a relocatable link (output_bfd test tells us), just
1537 call the generic function. Any adjustment will be done at final
1538 link time. */
1543 /* Subtract the symbol section base address. */
1546 }
1548 static bfd_reloc_status_type
1552 {
1553 /* If this is a relocatable link (output_bfd test tells us), just
1554 call the generic function. Any adjustment will be done at final
1555 link time. */
1560 /* Subtract the symbol section base address. */
1563 /* Adjust the addend for sign extension of the low 16 bits. */
1566 }
1568 static bfd_reloc_status_type
1572 {
1573 bfd_vma TOCstart;
1575 /* If this is a relocatable link (output_bfd test tells us), just
1576 call the generic function. Any adjustment will be done at final
1577 link time. */
1586 /* Subtract the TOC base address. */
1589 }
1591 static bfd_reloc_status_type
1595 {
1596 bfd_vma TOCstart;
1598 /* If this is a relocatable link (output_bfd test tells us), just
1599 call the generic function. Any adjustment will be done at final
1600 link time. */
1609 /* Subtract the TOC base address. */
1612 /* Adjust the addend for sign extension of the low 16 bits. */
1615 }
1617 static bfd_reloc_status_type
1621 {
1622 bfd_vma TOCstart;
1623 bfd_size_type octets;
1625 /* If this is a relocatable link (output_bfd test tells us), just
1626 call the generic function. Any adjustment will be done at final
1627 link time. */
1639 }
1641 static bfd_reloc_status_type
1645 {
1647 bfd_vma targ;
1665 {
1670 }
1681 }
1683 static bfd_reloc_status_type
1687 {
1688 /* If this is a relocatable link (output_bfd test tells us), just
1689 call the generic function. Any adjustment will be done at final
1690 link time. */
1696 {
1701 }
1703 }
1705 /* Track GOT entries needed for a given symbol. We might need more
1706 than one got entry per symbol. */
1707 struct got_entry
1708 {
1711 /* The symbol addend that we'll be placing in the GOT. */
1712 bfd_vma addend;
1714 /* Unlike other ELF targets, we use separate GOT entries for the same
1715 symbol referenced from different input files. This is to support
1716 automatic multiple TOC/GOT sections, where the TOC base can vary
1717 from one input file to another. After partitioning into TOC groups
1718 we merge entries within the group.
1720 Point to the BFD owning this GOT entry. */
1723 /* Zero for non-tls entries, or TLS_TLS and one of TLS_GD, TLS_LD,
1724 TLS_TPREL or TLS_DTPREL for tls entries. */
1727 /* Non-zero if got.ent points to real entry. */
1730 /* Reference count until size_dynamic_sections, GOT offset thereafter. */
1731 union
1732 {
1733 bfd_signed_vma refcount;
1734 bfd_vma offset;
1737 };
1739 /* The same for PLT. */
1740 struct plt_entry
1741 {
1744 bfd_vma addend;
1746 union
1747 {
1748 bfd_signed_vma refcount;
1749 bfd_vma offset;
1751 };
1753 struct ppc64_elf_obj_tdata
1754 {
1757 /* Shortcuts to dynamic linker sections. */
1761 /* Used during garbage collection. We attach global symbols defined
1762 on removed .opd entries to this section so that the sym is removed. */
1765 /* TLS local dynamic got entry handling. Support for multiple GOT
1766 sections means we potentially need one of these for each input bfd. */
1769 union
1770 {
1771 /* A copy of relocs before they are modified for --emit-relocs. */
1774 /* Section contents. */
1778 /* Nonzero if this bfd has small toc/got relocs, ie. that expect
1779 the reloc to be in the range -32768 to 32767. */
1782 /* Set if toc/got ha relocs detected not using r2, or lo reloc
1783 instruction not one we handle. */
1786 /* Set if PLT/GOT/TOC relocs that can be optimised are present in
1787 this file. */
1789 };
1791 #define ppc64_elf_tdata(bfd) \
1792 ((struct ppc64_elf_obj_tdata *) (bfd)->tdata.any)
1794 #define ppc64_tlsld_got(bfd) \
1795 (&ppc64_elf_tdata (bfd)->tlsld_got)
1797 #define is_ppc64_elf(bfd) \
1798 (bfd_get_flavour (bfd) == bfd_target_elf_flavour \
1799 && elf_object_id (bfd) == PPC64_ELF_DATA)
1801 /* Override the generic function because we store some extras. */
1803 static bfd_boolean
1805 {
1807 PPC64_ELF_DATA);
1808 }
1810 /* Fix bad default arch selected for a 64 bit input bfd when the
1811 default is 32 bit. Also select arch based on apuinfo. */
1813 static bfd_boolean
1815 {
1820 {
1824 {
1825 /* Relies on arch after 32 bit default being 64 bit default. */
1828 }
1829 }
1831 }
1833 /* Support for core dump NOTE sections. */
1835 static bfd_boolean
1837 {
1843 /* pr_cursig */
1846 /* pr_pid */
1849 /* pr_reg */
1853 /* Make a ".reg/999" section. */
1856 }
1858 static bfd_boolean
1860 {
1872 }
1876 ...)
1877 {
1879 {
1884 {
1891 #if GCC_VERSION == 8000 || GCC_VERSION == 8001
1892 DIAGNOSTIC_PUSH;
1893 /* GCC 8.0 and 8.1 warn about 80 equals destination size with
1894 -Wstringop-truncation:
1895 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85643
1896 */
1897 DIAGNOSTIC_IGNORE_STRINGOP_TRUNCATION;
1898 #endif
1900 #if GCC_VERSION == 8000 || GCC_VERSION == 8001
1901 DIAGNOSTIC_POP;
1902 #endif
1906 }
1909 {
1928 }
1929 }
1930 }
1932 /* Add extra PPC sections. */
1935 {
1943 };
1949 };
1951 struct _ppc64_elf_section_data
1952 {
1955 union
1956 {
1957 /* An array with one entry for each opd function descriptor,
1958 and some spares since opd entries may be either 16 or 24 bytes. */
1959 #define OPD_NDX(OFF) ((OFF) >> 4)
1960 struct _opd_sec_data
1961 {
1962 /* Points to the function code section for local opd entries. */
1965 /* After editing .opd, adjust references to opd local syms. */
1969 /* An array for toc sections, indexed by offset/8. */
1970 struct _toc_sec_data
1971 {
1972 /* Specifies the relocation symbol index used at a given toc offset. */
1975 /* And the relocation addend. */
1982 /* Flag set when small branches are detected. Used to
1983 select suitable defaults for the stub group size. */
1986 /* Flag set when PLTCALL relocs are detected. */
1989 /* Flag set when section has PLT/GOT/TOC relocations that can be
1990 optimised. */
1992 };
1994 #define ppc64_elf_section_data(sec) \
1995 ((struct _ppc64_elf_section_data *) elf_section_data (sec))
1997 static bfd_boolean
1999 {
2001 {
2009 }
2012 }
2016 {
2022 }
2023 \f
2024 /* Parameters for the qsort hook. */
2028 /* qsort comparison function for ppc64_elf_get_synthetic_symtab. */
2030 static int
2032 {
2036 /* Section symbols first. */
2042 /* then .opd symbols. */
2044 {
2051 }
2053 /* then other code symbols. */
2067 {
2073 }
2081 /* For syms with the same value, prefer strong dynamic global function
2082 syms over other syms. */
2107 /* Finally, sort on where the symbol is in memory. The symbols will
2108 be in at most two malloc'd blocks, one for static syms, one for
2109 dynamic syms, and we distinguish the two blocks above by testing
2110 BSF_DYNAMIC. Since we are sorting the symbol pointers which were
2111 originally in the same order as the symbols (and we're not
2112 sorting the symbols themselves), this ensures a stable sort. */
2118 }
2120 /* Search SYMS for a symbol of the given VALUE. */
2124 bfd_vma value)
2125 {
2129 {
2131 {
2137 else
2139 }
2140 }
2141 else
2142 {
2144 {
2154 else
2156 }
2157 }
2159 }
2161 static bfd_boolean
2163 {
2168 }
2170 /* Create synthetic symbols, effectively restoring "dot-symbol" function
2171 entry syms. Also generate @plt symbols for the glink branch table.
2172 Returns count of synthetic symbols in RET or -1 on error. */
2174 static long
2179 {
2192 {
2196 }
2205 {
2217 {
2218 /* Use both symbol tables. */
2222 }
2225 else
2228 /* Trim uninteresting symbols. Interesting symbols are section,
2229 function, and notype symbols. */
2241 {
2242 /* Trim duplicate syms, since we may have merged the normal
2243 and dynamic symbols. Actually, we only care about syms
2244 that have different values, so trim any with the same
2245 value. Don't consider ifunc and ifunc resolver symbols
2246 duplicates however, because GDB wants to know whether a
2247 text symbol is an ifunc resolver. */
2249 {
2258 }
2260 }
2263 /* Note that here and in compare_symbols we can't compare opd and
2264 sym->section directly. With separate debug info files, the
2265 symbols will be extracted from the debug file while abfd passed
2266 to this function is the real binary. */
2295 }
2299 {
2314 {
2317 }
2321 {
2340 {
2344 }
2345 }
2351 {
2354 }
2359 {
2378 {
2390 /* Have udata.p point back to the original symbol this
2391 synthetic symbol was derived from. */
2393 s++;
2394 }
2395 }
2396 }
2397 else
2398 {
2408 {
2409 free_contents_and_exit_err:
2411 free_contents_and_exit:
2415 }
2419 {
2420 bfd_vma ent;
2422 /* Ignore bogus symbols. */
2428 {
2432 }
2433 }
2435 /* Get start of .glink stubs from DT_PPC64_GLINK. */
2438 {
2452 {
2453 Elf_Internal_Dyn dyn;
2460 {
2461 /* The first glink stub starts at DT_PPC64_GLINK plus 32.
2462 See comment in ppc64_elf_finish_dynamic_sections. */
2464 /* The .glink section usually does not survive the final
2465 link; search for the section (usually .text) where the
2466 glink stubs now reside. */
2470 }
2471 }
2474 }
2477 {
2478 /* Determine __glink trampoline by reading the relative branch
2479 from the first glink stub. */
2485 {
2489 {
2490 resolv_vma
2493 }
2497 }
2504 {
2514 {
2518 }
2519 }
2520 }
2531 {
2532 bfd_vma ent;
2539 {
2548 {
2554 else
2555 {
2558 }
2559 }
2565 {
2568 /* SEC_LOAD may not be set if SEC is from a separate debug
2569 info file. */
2574 }
2582 /* Have udata.p point back to the original symbol this
2583 synthetic symbol was derived from. */
2585 s++;
2586 }
2587 }
2591 {
2593 {
2594 /* Add a symbol for the main glink trampoline. */
2604 s++;
2605 count++;
2606 }
2608 /* FIXME: It would be very much nicer to put sym@plt on the
2609 stub rather than on the glink branch table entry. The
2610 objdump disassembler would then use a sensible symbol
2611 name on plt calls. The difficulty in doing so is
2612 a) finding the stubs, and,
2613 b) matching stubs against plt entries, and,
2614 c) there can be multiple stubs for a given plt entry.
2616 Solving (a) could be done by code scanning, but older
2617 ppc64 binaries used different stubs to current code.
2618 (b) is the tricky one since you need to known the toc
2619 pointer for at least one function that uses a pic stub to
2620 be able to calculate the plt address referenced.
2621 (c) means gdb would need to set multiple breakpoints (or
2622 find the glink branch itself) when setting breakpoints
2623 for pending shared library loads. */
2626 {
2630 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL set. Since
2631 we are defining a symbol, ensure one of them is set. */
2643 {
2648 }
2651 s++;
2653 {
2657 }
2658 else
2660 }
2662 }
2663 }
2665 done:
2668 }
2669 \f
2670 /* The following functions are specific to the ELF linker, while
2671 functions above are used generally. Those named ppc64_elf_* are
2672 called by the main ELF linker code. They appear in this file more
2673 or less in the order in which they are called. eg.
2674 ppc64_elf_check_relocs is called early in the link process,
2675 ppc64_elf_finish_dynamic_sections is one of the last functions
2676 called.
2678 PowerPC64-ELF uses a similar scheme to PowerPC64-XCOFF in that
2679 functions have both a function code symbol and a function descriptor
2680 symbol. A call to foo in a relocatable object file looks like:
2682 . .text
2683 . x:
2684 . bl .foo
2685 . nop
2687 The function definition in another object file might be:
2689 . .section .opd
2690 . foo: .quad .foo
2691 . .quad .TOC.@tocbase
2692 . .quad 0
2693 .
2694 . .text
2695 . .foo: blr
2697 When the linker resolves the call during a static link, the branch
2698 unsurprisingly just goes to .foo and the .opd information is unused.
2699 If the function definition is in a shared library, things are a little
2700 different: The call goes via a plt call stub, the opd information gets
2701 copied to the plt, and the linker patches the nop.
2703 . x:
2704 . bl .foo_stub
2705 . ld 2,40(1)
2706 .
2707 .
2708 . .foo_stub:
2709 . std 2,40(1) # in practice, the call stub
2710 . addis 11,2,Lfoo@toc@ha # is slightly optimized, but
2711 . addi 11,11,Lfoo@toc@l # this is the general idea
2712 . ld 12,0(11)
2713 . ld 2,8(11)
2714 . mtctr 12
2715 . ld 11,16(11)
2716 . bctr
2717 .
2718 . .section .plt
2719 . Lfoo: reloc (R_PPC64_JMP_SLOT, foo)
2721 The "reloc ()" notation is supposed to indicate that the linker emits
2722 an R_PPC64_JMP_SLOT reloc against foo. The dynamic linker does the opd
2723 copying.
2725 What are the difficulties here? Well, firstly, the relocations
2726 examined by the linker in check_relocs are against the function code
2727 sym .foo, while the dynamic relocation in the plt is emitted against
2728 the function descriptor symbol, foo. Somewhere along the line, we need
2729 to carefully copy dynamic link information from one symbol to the other.
2730 Secondly, the generic part of the elf linker will make .foo a dynamic
2731 symbol as is normal for most other backends. We need foo dynamic
2732 instead, at least for an application final link. However, when
2733 creating a shared library containing foo, we need to have both symbols
2734 dynamic so that references to .foo are satisfied during the early
2735 stages of linking. Otherwise the linker might decide to pull in a
2736 definition from some other object, eg. a static library.
2738 Update: As of August 2004, we support a new convention. Function
2739 calls may use the function descriptor symbol, ie. "bl foo". This
2740 behaves exactly as "bl .foo". */
2742 /* Of those relocs that might be copied as dynamic relocs, this
2743 function selects those that must be copied when linking a shared
2744 library or PIE, even when the symbol is local. */
2746 static int
2749 {
2751 {
2753 /* Only relative relocs can be resolved when the object load
2754 address isn't fixed. DTPREL64 is excluded because the
2755 dynamic linker needs to differentiate global dynamic from
2756 local dynamic __tls_index pairs when PPC64_OPT_TLS is set. */
2784 /* These relocations are relative but in a shared library the
2785 linker doesn't know the thread pointer base. */
2787 }
2788 }
2790 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
2791 copying dynamic variables from a shared lib into an app's dynbss
2792 section, and instead use a dynamic relocation to point into the
2793 shared lib. With code that gcc generates, it's vital that this be
2794 enabled; In the PowerPC64 ABI, the address of a function is actually
2795 the address of a function descriptor, which resides in the .opd
2796 section. gcc uses the descriptor directly rather than going via the
2797 GOT as some other ABI's do, which means that initialized function
2798 pointers must reference the descriptor. Thus, a function pointer
2799 initialized to the address of a function in a shared library will
2800 either require a copy reloc, or a dynamic reloc. Using a copy reloc
2801 redefines the function descriptor symbol to point to the copy. This
2802 presents a problem as a plt entry for that function is also
2803 initialized from the function descriptor symbol and the copy reloc
2804 may not be initialized first. */
2805 #define ELIMINATE_COPY_RELOCS 1
2807 /* Section name for stubs is the associated section name plus this
2808 string. */
2811 /* Linker stubs.
2812 ppc_stub_long_branch:
2813 Used when a 14 bit branch (or even a 24 bit branch) can't reach its
2814 destination, but a 24 bit branch in a stub section will reach.
2815 . b dest
2817 ppc_stub_plt_branch:
2818 Similar to the above, but a 24 bit branch in the stub section won't
2819 reach its destination.
2820 . addis %r11,%r2,xxx@toc@ha
2821 . ld %r12,xxx@toc@l(%r11)
2822 . mtctr %r12
2823 . bctr
2825 ppc_stub_plt_call:
2826 Used to call a function in a shared library. If it so happens that
2827 the plt entry referenced crosses a 64k boundary, then an extra
2828 "addi %r11,%r11,xxx@toc@l" will be inserted before the "mtctr".
2829 ppc_stub_plt_call_r2save starts with "std %r2,40(%r1)".
2830 . addis %r11,%r2,xxx@toc@ha
2831 . ld %r12,xxx+0@toc@l(%r11)
2832 . mtctr %r12
2833 . ld %r2,xxx+8@toc@l(%r11)
2834 . ld %r11,xxx+16@toc@l(%r11)
2835 . bctr
2837 ppc_stub_long_branch and ppc_stub_plt_branch may also have additional
2838 code to adjust the value and save r2 to support multiple toc sections.
2839 A ppc_stub_long_branch with an r2 offset looks like:
2840 . std %r2,40(%r1)
2841 . addis %r2,%r2,off@ha
2842 . addi %r2,%r2,off@l
2843 . b dest
2845 A ppc_stub_plt_branch with an r2 offset looks like:
2846 . std %r2,40(%r1)
2847 . addis %r11,%r2,xxx@toc@ha
2848 . ld %r12,xxx@toc@l(%r11)
2849 . addis %r2,%r2,off@ha
2850 . addi %r2,%r2,off@l
2851 . mtctr %r12
2852 . bctr
2854 All of the above stubs are shown as their ELFv1 variants. ELFv2
2855 variants exist too, simpler for plt calls since a new toc pointer
2856 and static chain are not loaded by the stub. In addition, ELFv2
2857 has some more complex stubs to handle calls marked with NOTOC
2858 relocs from functions where r2 is not a valid toc pointer. These
2859 come in two flavours, the ones shown below, and _both variants that
2860 start with "std %r2,24(%r1)" to save r2 in the unlikely event that
2861 one call is from a function where r2 is used as the toc pointer but
2862 needs a toc adjusting stub for small-model multi-toc, and another
2863 call is from a function where r2 is not valid.
2864 ppc_stub_long_branch_notoc:
2865 . mflr %r12
2866 . bcl 20,31,1f
2867 . 1:
2868 . mflr %r11
2869 . mtlr %r12
2870 . addis %r12,%r11,dest-1b@ha
2871 . addi %r12,%r12,dest-1b@l
2872 . b dest
2874 ppc_stub_plt_branch_notoc:
2875 . mflr %r12
2876 . bcl 20,31,1f
2877 . 1:
2878 . mflr %r11
2879 . mtlr %r12
2880 . lis %r12,xxx-1b@highest
2881 . ori %r12,%r12,xxx-1b@higher
2882 . sldi %r12,%r12,32
2883 . oris %r12,%r12,xxx-1b@high
2884 . ori %r12,%r12,xxx-1b@l
2885 . add %r12,%r11,%r12
2886 . mtctr %r12
2887 . bctr
2889 ppc_stub_plt_call_notoc:
2890 . mflr %r12
2891 . bcl 20,31,1f
2892 . 1:
2893 . mflr %r11
2894 . mtlr %r12
2895 . lis %r12,xxx-1b@highest
2896 . ori %r12,%r12,xxx-1b@higher
2897 . sldi %r12,%r12,32
2898 . oris %r12,%r12,xxx-1b@high
2899 . ori %r12,%r12,xxx-1b@l
2900 . ldx %r12,%r11,%r12
2901 . mtctr %r12
2902 . bctr
2904 There are also ELFv1 powerxx variants of these stubs.
2905 ppc_stub_long_branch_notoc:
2906 . pla %r12,dest@pcrel
2907 . b dest
2908 ppc_stub_plt_branch_notoc:
2909 . lis %r11,(dest-1f)@highesta34
2910 . ori %r11,%r11,(dest-1f)@highera34
2911 . sldi %r11,%r11,34
2912 . 1: pla %r12,dest@pcrel
2913 . add %r12,%r11,%r12
2914 . mtctr %r12
2915 . bctr
2916 ppc_stub_plt_call_notoc:
2917 . lis %r11,(xxx-1f)@highesta34
2918 . ori %r11,%r11,(xxx-1f)@highera34
2919 . sldi %r11,%r11,34
2920 . 1: pla %r12,xxx@pcrel
2921 . ldx %r12,%r11,%r12
2922 . mtctr %r12
2923 . bctr
2925 In cases where the high instructions would add zero, they are
2926 omitted and following instructions modified in some cases.
2927 For example, a powerxx ppc_stub_plt_call_notoc might simplify down
2928 to
2929 . pld %r12,xxx@pcrel
2930 . mtctr %r12
2931 . bctr
2933 For a given stub group (a set of sections all using the same toc
2934 pointer value) there will be just one stub type used for any
2935 particular function symbol. For example, if printf is called from
2936 code with the tocsave optimization (ie. r2 saved in function
2937 prologue) and therefore calls use a ppc_stub_plt_call linkage stub,
2938 and from other code without the tocsave optimization requiring a
2939 ppc_stub_plt_call_r2save linkage stub, a single stub of the latter
2940 type will be created. Calls with the tocsave optimization will
2941 enter this stub after the instruction saving r2. A similar
2942 situation exists when calls are marked with R_PPC64_REL24_NOTOC
2943 relocations. These require a ppc_stub_plt_call_notoc linkage stub
2944 to call an external function like printf. If other calls to printf
2945 require a ppc_stub_plt_call linkage stub then a single
2946 ppc_stub_plt_call_notoc linkage stub will be used for both types of
2947 call. If other calls to printf require a ppc_stub_plt_call_r2save
2948 linkage stub then a single ppc_stub_plt_call_both linkage stub will
2949 be created and calls not requiring r2 to be saved will enter the
2950 stub after the r2 save instruction. There is an analogous
2951 hierarchy of long branch and plt branch stubs for local call
2952 linkage. */
2954 enum ppc_stub_type
2955 {
2956 ppc_stub_none,
2957 ppc_stub_long_branch,
2958 ppc_stub_long_branch_r2off,
2959 ppc_stub_long_branch_notoc,
2961 ppc_stub_plt_branch,
2962 ppc_stub_plt_branch_r2off,
2963 ppc_stub_plt_branch_notoc,
2964 ppc_stub_plt_branch_both,
2965 ppc_stub_plt_call,
2966 ppc_stub_plt_call_r2save,
2967 ppc_stub_plt_call_notoc,
2968 ppc_stub_plt_call_both,
2969 ppc_stub_global_entry,
2970 ppc_stub_save_res
2971 };
2973 /* Information on stub grouping. */
2974 struct map_stub
2975 {
2976 /* The stub section. */
2978 /* This is the section to which stubs in the group will be attached. */
2980 /* Next group. */
2982 /* Whether to emit a copy of register save/restore functions in this
2983 group. */
2985 /* Current offset within stubs after the insn restoring lr in a
2986 _notoc or _both stub using bcl for pc-relative addressing, or
2987 after the insn restoring lr in a __tls_get_addr_opt plt stub. */
2989 /* Accumulated size of EH info emitted to describe return address
2990 if stubs modify lr. Does not include 17 byte FDE header. */
2992 /* Offset in glink_eh_frame to the start of EH info for this group. */
2994 };
2996 struct ppc_stub_hash_entry
2997 {
2998 /* Base hash table entry structure. */
3003 /* Group information. */
3006 /* Offset within stub_sec of the beginning of this stub. */
3007 bfd_vma stub_offset;
3009 /* Given the symbol's value and its section we can determine its final
3010 value when building the stubs (so the stub knows where to jump. */
3011 bfd_vma target_value;
3014 /* The symbol table entry, if any, that this was derived from. */
3018 /* Symbol type. */
3021 /* Symbol st_other. */
3023 };
3025 struct ppc_branch_hash_entry
3026 {
3027 /* Base hash table entry structure. */
3030 /* Offset within branch lookup table. */
3033 /* Generation marker. */
3035 };
3037 /* Used to track dynamic relocations for local symbols. */
3038 struct ppc_dyn_relocs
3039 {
3042 /* The input section of the reloc. */
3045 /* Total number of relocs copied for the input section. */
3048 /* Whether this entry is for STT_GNU_IFUNC symbols. */
3050 };
3052 struct ppc_link_hash_entry
3053 {
3056 union
3057 {
3058 /* A pointer to the most recently used stub hash entry against this
3059 symbol. */
3062 /* A pointer to the next symbol starting with a '.' */
3066 /* Track dynamic relocs copied for this symbol. */
3069 /* Link between function code and descriptor symbols. */
3072 /* Flag function code and descriptor symbols. */
3077 /* Whether global opd/toc sym has been adjusted or not.
3078 After ppc64_elf_edit_opd/ppc64_elf_edit_toc has run, this flag
3079 should be set for all globals defined in any opd/toc section. */
3082 /* Set if this is an out-of-line register save/restore function,
3083 with non-standard calling convention. */
3086 /* Set if a duplicate symbol with non-zero localentry is detected,
3087 even when the duplicate symbol does not provide a definition. */
3090 /* Contexts in which symbol is used in the GOT (or TOC).
3091 Bits are or'd into the mask as the corresponding relocs are
3092 encountered during check_relocs, with TLS_TLS being set when any
3093 of the other TLS bits are set. tls_optimize clears bits when
3094 optimizing to indicate the corresponding GOT entry type is not
3095 needed. If set, TLS_TLS is never cleared. tls_optimize may also
3096 set TLS_GDIE when a GD reloc turns into an IE one.
3097 These flags are also kept for local symbols. */
3108 /* The above field is also used to mark function symbols. In which
3109 case TLS_TLS will be 0. */
3113 };
3115 /* ppc64 ELF linker hash table. */
3117 struct ppc_link_hash_table
3118 {
3121 /* The stub hash table. */
3124 /* Another hash table for plt_branch stubs. */
3127 /* Hash table for function prologue tocsave. */
3128 htab_t tocsave_htab;
3130 /* Various options and other info passed from the linker. */
3133 /* The size of sec_info below. */
3136 /* Per-section array of extra section info. Done this way rather
3137 than as part of ppc64_elf_section_data so we have the info for
3138 non-ppc64 sections. */
3139 struct
3140 {
3141 /* Along with elf_gp, specifies the TOC pointer used by this section. */
3142 bfd_vma toc_off;
3144 union
3145 {
3146 /* The section group that this section belongs to. */
3148 /* A temp section list pointer. */
3153 /* Linked list of groups. */
3156 /* Temp used when calculating TOC pointers. */
3157 bfd_vma toc_curr;
3161 /* Used when adding symbols. */
3164 /* Shortcuts to get to dynamic linker sections. */
3174 /* Shortcut to .__tls_get_addr and __tls_get_addr. */
3178 /* The size of reliplt used by got entry relocs. */
3179 bfd_size_type got_reli_size;
3181 /* Statistics. */
3184 /* Number of stubs against global syms. */
3187 /* Set if we're linking code with function descriptors. */
3190 /* Support for multiple toc sections. */
3196 /* Set if tls optimization is enabled. */
3199 /* Set if inline plt calls should be converted to direct calls. */
3202 /* Set on error. */
3205 /* Whether func_desc_adjust needs to be run over symbols. */
3208 /* Whether there exist local gnu indirect function resolvers,
3209 referenced by dynamic relocations. */
3213 /* Whether plt calls for ELFv2 localentry:0 funcs have been optimized. */
3216 /* Whether calls are made via the PLT from NOTOC functions. */
3219 /* Whether to use powerxx instructions in linkage stubs. */
3222 /* Incremented every time we size stubs. */
3225 /* Small local sym cache. */
3227 };
3229 /* Rename some of the generic section flags to better document how they
3230 are used here. */
3232 /* Nonzero if this section has TLS related relocations. */
3233 #define has_tls_reloc sec_flg0
3235 /* Nonzero if this section has a call to __tls_get_addr lacking marker
3236 relocations. */
3237 #define nomark_tls_get_addr sec_flg1
3239 /* Nonzero if this section has any toc or got relocs. */
3240 #define has_toc_reloc sec_flg2
3242 /* Nonzero if this section has a call to another section that uses
3243 the toc or got. */
3244 #define makes_toc_func_call sec_flg3
3246 /* Recursion protection when determining above flag. */
3247 #define call_check_in_progress sec_flg4
3248 #define call_check_done sec_flg5
3250 /* Get the ppc64 ELF linker hash table from a link_info structure. */
3252 #define ppc_hash_table(p) \
3253 (elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) \
3254 == PPC64_ELF_DATA ? ((struct ppc_link_hash_table *) ((p)->hash)) : NULL)
3256 #define ppc_stub_hash_lookup(table, string, create, copy) \
3257 ((struct ppc_stub_hash_entry *) \
3258 bfd_hash_lookup ((table), (string), (create), (copy)))
3260 #define ppc_branch_hash_lookup(table, string, create, copy) \
3261 ((struct ppc_branch_hash_entry *) \
3262 bfd_hash_lookup ((table), (string), (create), (copy)))
3264 /* Create an entry in the stub hash table. */
3270 {
3271 /* Allocate the structure if it has not already been allocated by a
3272 subclass. */
3274 {
3278 }
3280 /* Call the allocation method of the superclass. */
3283 {
3286 /* Initialize the local fields. */
3296 }
3299 }
3301 /* Create an entry in the branch hash table. */
3307 {
3308 /* Allocate the structure if it has not already been allocated by a
3309 subclass. */
3311 {
3315 }
3317 /* Call the allocation method of the superclass. */
3320 {
3323 /* Initialize the local fields. */
3327 }
3330 }
3332 /* Create an entry in a ppc64 ELF linker hash table. */
3338 {
3339 /* Allocate the structure if it has not already been allocated by a
3340 subclass. */
3342 {
3346 }
3348 /* Call the allocation method of the superclass. */
3351 {
3358 /* When making function calls, old ABI code references function entry
3359 points (dot symbols), while new ABI code references the function
3360 descriptor symbol. We need to make any combination of reference and
3361 definition work together, without breaking archive linking.
3363 For a defined function "foo" and an undefined call to "bar":
3364 An old object defines "foo" and ".foo", references ".bar" (possibly
3365 "bar" too).
3366 A new object defines "foo" and references "bar".
3368 A new object thus has no problem with its undefined symbols being
3369 satisfied by definitions in an old object. On the other hand, the
3370 old object won't have ".bar" satisfied by a new object.
3372 Keep a list of newly added dot-symbols. */
3375 {
3381 }
3382 }
3385 }
3387 struct tocsave_entry
3388 {
3390 bfd_vma offset;
3391 };
3393 static hashval_t
3395 {
3398 }
3400 static int
3402 {
3406 }
3408 /* Destroy a ppc64 ELF linker hash table. */
3410 static void
3412 {
3421 }
3423 /* Create a ppc64 ELF linker hash table. */
3427 {
3437 PPC64_ELF_DATA))
3438 {
3441 }
3443 /* Init the stub hash table too. */
3446 {
3449 }
3451 /* And the branch hash table. */
3454 {
3458 }
3461 tocsave_htab_hash,
3462 tocsave_htab_eq,
3463 NULL);
3465 {
3468 }
3471 /* Initializing two fields of the union is just cosmetic. We really
3472 only care about glist, but when compiled on a 32-bit host the
3473 bfd_vma fields are larger. Setting the bfd_vma to zero makes
3474 debugger inspection of these fields look nicer. */
3485 }
3487 /* Create sections for linker generated code. */
3489 static bfd_boolean
3491 {
3493 flagword flags;
3500 {
3501 /* Create .sfpr for code to save and restore fp regs. */
3503 flags);
3507 }
3512 /* Create .glink for lazy dynamic linking support. */
3514 flags);
3519 /* The part of .glink used by global entry stubs, separate so that
3520 it can be aligned appropriately without affecting htab->glink. */
3522 flags);
3528 {
3533 flags);
3537 }
3553 /* Create branch lookup table for plt_branch stubs. */
3557 flags);
3562 /* Local plt entries, put in .branch_lt but a separate section for
3563 convenience. */
3565 flags);
3575 htab->relbrlt
3581 htab->relpltlocal
3588 }
3590 /* Satisfy the ELF linker by filling in some fields in our fake bfd. */
3592 bfd_boolean
3595 {
3600 /* Always hook our dynamic sections into the first bfd, which is the
3601 linker created stub bfd. This ensures that the GOT header is at
3602 the start of the output TOC section. */
3608 }
3610 /* Build a name for an entry in the stub hash table. */
3617 {
3619 ssize_t len;
3621 /* rel->r_addend is actually 64 bit, but who uses more than +/- 2^31
3622 offsets from a sym as a branch target? In fact, we could
3623 probably assume the addend is always zero. */
3627 {
3637 }
3638 else
3639 {
3650 }
3654 }
3656 /* Look up an entry in the stub hash. Stub entries are cached because
3657 creating the stub name takes a bit of time. */
3665 {
3669 /* If this input section is part of a group of sections sharing one
3670 stub section, then use the id of the first section in the group.
3671 Stub names need to include a section id, as there may well be
3672 more than one stub used to reach say, printf, and we need to
3673 distinguish between them. */
3681 {
3683 }
3684 else
3685 {
3698 }
3701 }
3703 /* Add a new stub entry to the stub hash. Not all fields of the new
3704 stub entry are initialised. */
3710 {
3721 {
3723 bfd_size_type len;
3738 }
3740 /* Enter this entry into the linker stub hash table. */
3744 {
3745 /* xgettext:c-format */
3749 }
3754 }
3756 /* Create .got and .rela.got sections in ABFD, and .got in dynobj if
3757 not already done. */
3759 static bfd_boolean
3761 {
3763 flagword flags;
3792 }
3794 /* Follow indirect and warning symbol links. */
3798 {
3803 }
3807 {
3809 }
3813 {
3815 }
3817 /* Merge PLT info on FROM with that on TO. */
3819 static void
3822 {
3824 {
3826 {
3831 {
3836 {
3840 }
3843 }
3845 }
3849 }
3850 }
3852 /* Copy the extra info we tack onto an elf_link_hash_entry. */
3854 static void
3858 {
3878 /* If we were called to copy over info for a weak sym, don't copy
3879 dyn_relocs, plt/got info, or dynindx. We used to copy dyn_relocs
3880 in order to simplify readonly_dynrelocs and save a field in the
3881 symbol hash entry, but that means dyn_relocs can't be used in any
3882 tests about a specific symbol, or affect other symbol flags which
3883 are then tested. */
3887 /* Copy over any dynamic relocs we may have on the indirect sym. */
3889 {
3891 {
3895 /* Add reloc counts against the indirect sym to the direct sym
3896 list. Merge any entries against the same section. */
3898 {
3903 {
3908 }
3911 }
3913 }
3917 }
3919 /* Copy over got entries that we may have already seen to the
3920 symbol which just became indirect. */
3922 {
3924 {
3929 {
3936 {
3940 }
3943 }
3945 }
3949 }
3951 /* And plt entries. */
3955 {
3963 }
3964 }
3966 /* Find the function descriptor hash entry from the given function code
3967 hash entry FH. Link the entries via their OH fields. */
3971 {
3975 {
3987 }
3993 }
3995 /* Make a fake function descriptor sym for the undefined code sym FH. */
4000 {
4005 ? BSF_WEAK
4022 }
4024 /* Fix function descriptor symbols defined in .opd sections to be
4025 function type. */
4027 static bfd_boolean
4035 {
4038 {
4045 /* If the symbol is a function defined in .opd, and the function
4046 code is in a discarded group, let it appear to be undefined. */
4052 {
4055 }
4056 }
4060 {
4064 }
4067 {
4071 {
4076 }
4077 }
4080 }
4082 /* Merge non-visibility st_other attributes: local entry point. */
4084 static void
4087 bfd_boolean definition,
4088 bfd_boolean dynamic)
4089 {
4093 }
4095 /* Hook called on merging a symbol. We use this to clear "fake" since
4096 we now have a real symbol. */
4098 static bfd_boolean
4102 bfd_boolean newdef ATTRIBUTE_UNUSED,
4103 bfd_boolean olddef ATTRIBUTE_UNUSED,
4106 {
4111 }
4113 /* This function makes an old ABI object reference to ".bar" cause the
4114 inclusion of a new ABI object archive that defines "bar".
4115 NAME is a symbol defined in an archive. Return a symbol in the hash
4116 table that might be satisfied by the archive symbols. */
4122 {
4129 /* Don't return this sym if it is a fake function descriptor
4130 created by add_symbol_adjust. */
4146 }
4148 /* This function satisfies all old ABI object references to ".bar" if a
4149 new ABI object defines "bar". Well, at least, undefined dot symbols
4150 are made weak. This stops later archive searches from including an
4151 object if we already have a function descriptor definition. It also
4152 prevents the linker complaining about undefined symbols.
4153 We also check and correct mismatched symbol visibility here. The
4154 most restrictive visibility of the function descriptor and the
4155 function entry symbol is used. */
4157 static bfd_boolean
4159 {
4182 {
4183 /* Make an undefined function descriptor sym, in order to
4184 pull in an --as-needed shared lib. Archives are handled
4185 elsewhere. */
4189 }
4192 {
4196 /* Make both descriptor and entry symbol have the most
4197 constraining visibility of either symbol. */
4203 /* Propagate reference flags from entry symbol to function
4204 descriptor symbol. */
4218 {
4221 }
4222 }
4225 }
4227 /* Set up opd section info and abiversion for IBFD, and process list
4228 of dot-symbols we made in link_hash_newfunc. */
4230 static bfd_boolean
4232 {
4238 {
4245 {
4246 /* xgettext:c-format */
4251 }
4252 }
4255 {
4256 /* For input files without an explicit abiversion in e_flags
4257 we should have flagged any with symbol st_other bits set
4258 as ELFv1 and above flagged those with .opd as ELFv2.
4259 Set the output abiversion if not yet set, and for any input
4260 still ambiguous, take its abiversion from the output.
4261 Differences in ABI are reported later. */
4266 }
4278 {
4279 /* Garbage collection needs some extra help with .opd sections.
4280 We don't want to necessarily keep everything referenced by
4281 relocs in .opd, as that would keep all functions. Instead,
4282 if we reference an .opd symbol (a function descriptor), we
4283 want to keep the function code symbol's section. This is
4284 easy for global symbols, but for local syms we need to keep
4285 information about the associated function section. */
4286 bfd_size_type amt;
4303 {
4310 {
4316 {
4320 }
4325 }
4326 }
4329 }
4333 {
4336 ;
4341 {
4345 }
4347 }
4349 }
4351 /* Undo hash table changes when an --as-needed input file is determined
4352 not to be needed. */
4354 static bfd_boolean
4358 {
4360 {
4367 }
4369 }
4371 /* If --just-symbols against a final linked binary, then assume we need
4372 toc adjusting stubs when calling functions defined there. */
4374 static void
4376 {
4380 {
4384 }
4386 }
4391 {
4397 {
4407 }
4410 {
4419 {
4431 }
4433 }
4440 }
4442 static bfd_boolean
4444 {
4451 {
4460 }
4463 }
4465 static bfd_boolean
4467 {
4479 }
4481 /* Relocs on inline plt call sequence insns prior to the call. */
4483 static bfd_boolean
4485 {
4494 }
4496 /* Look through the relocs for a section during the first phase, and
4497 calculate needed space in the global offset table, procedure
4498 linkage table, and dynamic reloc sections. */
4500 static bfd_boolean
4503 {
4511 bfd_boolean is_opd;
4516 /* Don't do anything special with non-loaded, non-alloced sections.
4517 In particular, any relocs in such sections should not affect GOT
4518 and PLT reference counting (ie. we don't allow them to create GOT
4519 or PLT entries), there's no possibility or desire to optimize TLS
4520 relocs, and there's not much point in propagating relocs to shared
4521 libs that the dynamic linker won't relocate. */
4541 {
4552 else
4553 {
4559 }
4563 {
4584 }
4587 {
4611 }
4615 {
4617 {
4620 }
4621 }
4622 else
4623 {
4630 {
4636 }
4637 }
4641 {
4644 /* These special tls relocs tie a call to __tls_get_addr with
4645 its parameter symbol. */
4648 else
4688 dogottls:
4699 dogot:
4700 /* This symbol requires a global offset table entry. */
4708 {
4711 }
4718 {
4729 {
4741 }
4744 }
4745 else
4746 /* This is a global offset table entry for a local symbol. */
4751 /* We may also need a plt entry if the symbol turns out to be
4752 an ifunc. */
4754 {
4757 }
4768 /* This symbol requires a procedure linkage table entry. */
4771 {
4778 }
4787 /* The following relocations don't need to propagate the
4788 relocation if linking a shared object since they are
4789 section relative. */
4810 /* Nor do these. */
4828 /* Not supported as a dynamic relocation. */
4831 {
4834 /* xgettext:c-format */
4841 }
4848 /* Fall through. */
4855 {
4856 /* We may need a copy reloc. */
4858 /* Strongly prefer a copy reloc over a dynamic reloc.
4859 glibc ld.so as of 2019-08 will error out if one of
4860 these relocations is emitted. */
4863 }
4866 /* Marker reloc. */
4870 /* This relocation describes the C++ object vtable hierarchy.
4871 Reconstruct it for later use during GC. */
4877 /* This relocation describes which C++ vtable entries are actually
4878 used. Record for later use during GC. */
4887 {
4890 /* Heuristic: If jumping outside our section, chances are
4891 we are going to need a stub. */
4893 {
4894 /* If the sym is weak it may be overridden later, so
4895 don't assume we know where a weak sym lives. */
4898 }
4899 else
4900 {
4909 }
4913 }
4919 /* Fall through. */
4923 rel24:
4926 {
4933 {
4938 /* We have a new-style __tls_get_addr call with
4939 a marker reloc. */
4940 ;
4941 else
4942 /* Mark this section as having an old-style call. */
4944 }
4946 }
4948 /* We may need a .plt entry if the function this reloc
4949 refers to is in a shared lib. */
4972 else
4981 /* This is the second reloc of a dtpmod, dtprel pair.
4982 Don't mark with TLS_DTPREL. */
4985 dotlstoc:
4988 {
4992 }
4993 else
5000 {
5001 bfd_size_type amt;
5003 /* One extra to simplify get_tls_mask. */
5014 }
5019 /* Mark the second slot of a GD or LD entry.
5020 -1 to indicate GD and -2 to indicate LD. */
5048 {
5051 }
5052 /* Fall through. */
5077 {
5078 /* We may need a .plt entry if this reloc refers to a
5079 function in a shared lib. */
5083 }
5084 /* Fall through. */
5095 /* We may need a copy reloc. */
5098 /* Don't propagate .opd relocs. */
5102 /* If we are creating a shared library, and this is a reloc
5103 against a global symbol, or a non PC relative reloc
5104 against a local symbol, then we need to copy the reloc
5105 into the shared library. However, if we are linking with
5106 -Bsymbolic, we do not need to copy a reloc against a
5107 global symbol which is defined in an object we are
5108 including in the link (i.e., DEF_REGULAR is set). At
5109 this point we have not seen all the input files, so it is
5110 possible that DEF_REGULAR is not set now but will be set
5111 later (it is never cleared). In case of a weak definition,
5112 DEF_REGULAR may be cleared later by a strong definition in
5113 a shared library. We account for that possibility below by
5114 storing information in the dyn_relocs field of the hash
5115 table entry. A similar situation occurs when creating
5116 shared libraries and symbol visibility changes render the
5117 symbol local.
5119 If on the other hand, we are creating an executable, we
5120 may need to keep relocations for symbols satisfied by a
5121 dynamic library if we manage to avoid copy relocs for the
5122 symbol. */
5123 dodyn:
5134 {
5135 /* We must copy these reloc types into the output file.
5136 Create a reloc section in dynobj and make room for
5137 this reloc. */
5139 {
5140 sreloc = _bfd_elf_make_dynamic_reloc_section
5145 }
5147 /* If this is a global symbol, we count the number of
5148 relocations we need for this symbol. */
5150 {
5157 {
5166 }
5170 }
5171 else
5172 {
5173 /* Track dynamic relocs needed for local syms too.
5174 We really need local syms available to do this
5175 easily. Oh well. */
5178 bfd_boolean is_ifunc;
5199 {
5208 }
5210 }
5211 }
5216 }
5217 }
5220 }
5222 /* Merge backend specific data from an object file to the output
5223 object file when linking. */
5225 static bfd_boolean
5227 {
5244 {
5245 _bfd_error_handler
5246 /* xgettext:c-format */
5250 }
5252 {
5253 _bfd_error_handler
5254 /* xgettext:c-format */
5259 }
5264 /* Merge Tag_compatibility attributes and any common GNU ones. */
5266 }
5268 static bfd_boolean
5270 {
5271 /* Print normal ELF private data. */
5275 {
5285 }
5288 }
5290 /* OFFSET in OPD_SEC specifies a function descriptor. Return the address
5291 of the code entry point, and its section, which must be in the same
5292 object as OPD_SEC. Returns (bfd_vma) -1 on error. */
5294 static bfd_vma
5296 bfd_vma offset,
5299 bfd_boolean in_code_sec)
5300 {
5304 bfd_vma val;
5306 /* No relocs implies we are linking a --just-symbols object, or looking
5307 at a final linked executable with addr2line or somesuch. */
5309 {
5313 {
5317 }
5319 /* PR 17512: file: 64b9dfbb. */
5325 {
5329 {
5334 else
5336 }
5337 else
5344 {
5348 }
5349 }
5351 }
5358 /* PR 17512: file: df8e1fd6. */
5362 /* Go find the opd reloc at the sym address. */
5367 {
5373 else
5374 {
5379 {
5385 {
5392 {
5398 {
5401 }
5402 }
5403 }
5406 {
5410 {
5413 {
5421 }
5423 }
5424 else
5425 {
5431 }
5437 }
5443 {
5446 else
5448 }
5451 }
5453 }
5454 }
5457 }
5459 /* If the ELF symbol SYM might be a function in SEC, return the
5460 function size and set *CODE_OFF to the function's entry point,
5461 otherwise return zero. */
5463 static bfd_size_type
5466 {
5467 bfd_size_type size;
5478 {
5485 {
5486 /* opd_entry_value will use cached relocs that have been
5487 adjusted, but with raw symbols. That means both local
5488 and global symbols need adjusting. */
5493 }
5498 /* An old ABI binary with dot-syms has a size of 24 on the .opd
5499 symbol. This size has nothing to do with the code size of the
5500 function, which is what we're supposed to return, but the
5501 code size isn't available without looking up the dot-sym.
5502 However, doing that would be a waste of time particularly
5503 since elf_find_function will look at the dot-sym anyway.
5504 Now, elf_find_function will keep the largest size of any
5505 function sym found at the code address of interest, so return
5506 1 here to avoid it incorrectly caching a larger function size
5507 for a small function. This does mean we return the wrong
5508 size for a new-ABI function of size 24, but all that does is
5509 disable caching for such functions. */
5512 }
5513 else
5514 {
5518 }
5522 }
5524 /* Return true if symbol is a strong function defined in an ELFv2
5525 object with st_other localentry bits of zero, ie. its local entry
5526 point coincides with its global entry point. */
5528 static bfd_boolean
5530 {
5538 }
5540 /* Return true if symbol is defined in a regular object file. */
5542 static bfd_boolean
5544 {
5549 }
5551 /* If FDH is a function descriptor symbol, return the associated code
5552 entry symbol if it is defined. Return NULL otherwise. */
5556 {
5558 {
5563 }
5565 }
5567 /* If FH is a function code entry symbol, return the associated
5568 function descriptor symbol if it is defined. Return NULL otherwise. */
5572 {
5575 {
5580 }
5582 }
5586 /* Garbage collect sections, after first dealing with dot-symbols. */
5588 static bfd_boolean
5590 {
5594 {
5597 }
5599 }
5601 /* Mark all our entry sym sections, both opd and code section. */
5603 static void
5605 {
5613 {
5627 {
5630 }
5639 }
5640 }
5642 /* Mark sections containing dynamically referenced symbols. When
5643 building shared libraries, we must assume that any visible symbol is
5644 referenced. */
5646 static bfd_boolean
5648 {
5654 /* Dynamic linking info is on the func descriptor sym. */
5675 {
5681 /* Function descriptor syms cause the associated
5682 function code sym section to be marked. */
5685 {
5688 }
5694 }
5697 }
5699 /* Return the section that should be marked against GC for a given
5700 relocation. */
5708 {
5711 /* Syms return NULL if we're marking .opd, so we avoid marking all
5712 function sections, as all functions are referenced in .opd. */
5718 {
5724 {
5731 {
5737 {
5738 /* -mcall-aixdesc code references the dot-symbol on
5739 a call reloc. Mark the function descriptor too
5740 against garbage collection. */
5745 }
5747 /* Function descriptor syms cause the associated
5748 function code sym section to be marked. */
5751 {
5752 /* They also mark their opd section. */
5756 }
5762 else
5772 }
5773 }
5774 }
5775 else
5776 {
5782 {
5786 }
5787 }
5790 }
5792 /* The maximum size of .sfpr. */
5793 #define SFPR_MAX (218*4)
5795 struct sfpr_def_parms
5796 {
5801 };
5803 /* Auto-generate _save*, _rest* functions in .sfpr.
5804 If STUB_SEC is non-null, define alias symbols in STUB_SEC
5805 instead. */
5807 static bfd_boolean
5811 {
5825 {
5833 {
5837 {
5845 {
5856 }
5857 }
5859 }
5861 {
5864 {
5874 {
5879 }
5880 }
5881 }
5883 {
5887 else
5890 }
5891 }
5894 }
5898 {
5901 }
5905 {
5911 }
5915 {
5918 }
5922 {
5929 {
5932 }
5935 }
5939 {
5942 }
5946 {
5950 }
5954 {
5957 }
5961 {
5965 }
5969 {
5972 }
5976 {
5982 }
5986 {
5989 }
5993 {
6000 {
6003 }
6006 }
6010 {
6014 }
6018 {
6022 }
6026 {
6031 }
6035 {
6039 }
6043 {
6048 }
6052 {
6056 }
6058 /* Called via elf_link_hash_traverse to transfer dynamic linking
6059 information on function code symbol entries to their corresponding
6060 function descriptor symbol entries. */
6062 static bfd_boolean
6064 {
6069 bfd_boolean force_local;
6087 /* Find the corresponding function descriptor symbol. */
6090 /* Resolve undefined references to dot-symbols as the value
6091 in the function descriptor, if we have one in a regular object.
6092 This is to satisfy cases like ".quad .foo". Calls to functions
6093 in dynamic objects are handled elsewhere. */
6103 {
6108 }
6111 {
6119 }
6121 /* Create a descriptor as undefined if necessary. */
6126 {
6130 }
6132 /* We can't support overriding of symbols on a fake descriptor. */
6139 /* Transfer dynamic linking information to the function descriptor. */
6141 {
6156 }
6158 /* Now that the info is on the function descriptor, clear the
6159 function code sym info. Any function code syms for which we
6160 don't have a definition in a regular file, we force local.
6161 This prevents a shared library from exporting syms that have
6162 been imported from another library. Function code syms that
6163 are really in the library we must leave global to prevent the
6164 linker dragging in a definition from a static library. */
6172 }
6175 {
6188 };
6190 /* Called near the start of bfd_elf_size_dynamic_sections. We use
6191 this hook to a) provide some gcc support functions, and b) transfer
6192 dynamic linking information gathered so far on function code symbol
6193 entries, to their corresponding function descriptor symbol entries. */
6195 static bfd_boolean
6198 {
6205 /* Provide any missing _save* and _rest* functions. */
6207 {
6216 }
6222 {
6224 /* Make .TOC. defined so as to prevent it being made dynamic.
6225 The wrong value here is fixed later in ppc64_elf_set_toc. */
6228 {
6234 }
6238 }
6241 {
6244 }
6247 }
6249 /* Find dynamic relocs for H that apply to read-only sections. */
6253 {
6259 {
6264 }
6266 }
6268 /* Return true if we have dynamic relocs against H or any of its weak
6269 aliases, that apply to read-only sections. Cannot be used after
6270 size_dynamic_sections. */
6272 static bfd_boolean
6274 {
6278 do
6279 {
6283 }
6287 }
6289 /* Return whether EH has pc-relative dynamic relocs. */
6291 static bfd_boolean
6293 {
6300 }
6302 /* Return true if a global entry stub will be created for H. Valid
6303 for ELFv2 before plt entries have been allocated. */
6305 static bfd_boolean
6307 {
6320 }
6322 /* Adjust a symbol defined by a dynamic object and referenced by a
6323 regular object. The current definition is in some section of the
6324 dynamic object, but we're not including those sections. We have to
6325 change the definition to something the rest of the link can
6326 understand. */
6328 static bfd_boolean
6331 {
6339 /* Deal with function syms. */
6343 {
6347 /* Discard dyn_relocs when non-pic if we've decided that a
6348 function symbol is local and not an ifunc. We keep dynamic
6349 relocs for ifuncs when local rather than always emitting a
6350 plt call stub for them and defining the symbol on the call
6351 stub. We can't do that for ELFv1 anyway (a function symbol
6352 is defined on a descriptor, not code) and it can be faster at
6353 run-time due to not needing to bounce through a stub. The
6354 dyn_relocs for ifuncs will be applied even in a static
6355 executable. */
6361 /* Clear procedure linkage table information for any symbol that
6362 won't need a .plt entry. */
6369 && local
6373 {
6377 }
6379 {
6380 /* Taking a function's address in a read/write section
6381 doesn't require us to define the function symbol in the
6382 executable on a global entry stub. A dynamic reloc can
6383 be used instead. The reason we prefer a few more dynamic
6384 relocs is that calling via a global entry stub costs a
6385 few more instructions, and pointer_equality_needed causes
6386 extra work in ld.so when resolving these symbols. */
6388 {
6390 {
6392 /* If we haven't seen a branch reloc and the symbol
6393 isn't an ifunc then we don't need a plt entry. */
6396 }
6398 /* We are going to be defining the function symbol on the
6399 plt stub, so no dyn_relocs needed when non-pic. */
6401 }
6403 /* ELFv2 function symbols can't have copy relocs. */
6405 }
6408 {
6409 /* If we haven't seen a branch reloc and the symbol isn't an
6410 ifunc then we don't need a plt entry. */
6414 }
6415 }
6416 else
6419 /* If this is a weak symbol, and there is a real definition, the
6420 processor independent code will have arranged for us to see the
6421 real definition first, and we can just use the same value. */
6423 {
6432 }
6434 /* If we are creating a shared library, we must presume that the
6435 only references to the symbol are via the global offset table.
6436 For such cases we need not do anything here; the relocations will
6437 be handled correctly by relocate_section. */
6441 /* If there are no references to this symbol that do not use the
6442 GOT, we don't need to generate a copy reloc. */
6446 /* Don't generate a copy reloc for symbols defined in the executable. */
6449 /* If -z nocopyreloc was given, don't generate them either. */
6452 /* If we don't find any dynamic relocs in read-only sections, then
6453 we'll be keeping the dynamic relocs and avoiding the copy reloc. */
6454 || (ELIMINATE_COPY_RELOCS
6458 /* Protected variables do not work with .dynbss. The copy in
6459 .dynbss won't be used by the shared library with the protected
6460 definition for the variable. Text relocations are preferable
6461 to an incorrect program. */
6466 {
6467 /* We should never get here, but unfortunately there are versions
6468 of gcc out there that improperly (for this ABI) put initialized
6469 function pointers, vtable refs and suchlike in read-only
6470 sections. Allow them to proceed, but warn that this might
6471 break at runtime. */
6476 }
6478 /* This is a reference to a symbol defined by a dynamic object which
6479 is not a function. */
6481 /* We must allocate the symbol in our .dynbss section, which will
6482 become part of the .bss section of the executable. There will be
6483 an entry for this symbol in the .dynsym section. The dynamic
6484 object will contain position independent code, so all references
6485 from the dynamic object to this symbol will go through the global
6486 offset table. The dynamic linker will use the .dynsym entry to
6487 determine the address it must put in the global offset table, so
6488 both the dynamic object and the regular object will refer to the
6489 same memory location for the variable. */
6491 {
6494 }
6495 else
6496 {
6499 }
6501 {
6502 /* We must generate a R_PPC64_COPY reloc to tell the dynamic
6503 linker to copy the initial value out of the dynamic object
6504 and into the runtime process image. */
6507 }
6509 /* We no longer want dyn_relocs. */
6512 }
6514 /* If given a function descriptor symbol, hide both the function code
6515 sym and the descriptor. */
6516 static void
6519 bfd_boolean force_local)
6520 {
6529 {
6533 {
6538 /* We aren't supposed to use alloca in BFD because on
6539 systems which do not have alloca the version in libiberty
6540 calls xmalloc, which might cause the program to crash
6541 when it runs out of memory. This function doesn't have a
6542 return status, so there's no way to gracefully return an
6543 error. So cheat. We know that string[-1] can be safely
6544 accessed; It's either a string in an ELF string table,
6545 or allocated in an objalloc structure. */
6554 /* Unfortunately, if it so happens that the string we were
6555 looking for was allocated immediately before this string,
6556 then we overwrote the string terminator. That's the only
6557 reason the lookup should fail. */
6559 {
6566 }
6568 {
6571 }
6572 }
6575 }
6576 }
6578 static bfd_boolean
6586 {
6590 {
6604 {
6610 }
6613 {
6618 }
6619 }
6620 else
6621 {
6626 {
6635 }
6648 {
6655 {
6661 }
6663 }
6664 }
6666 }
6668 /* Returns TLS_MASKP for the given REL symbol. Function return is 0 on
6669 error, 2 on a toc GD type suitable for optimization, 3 on a toc LD
6670 type suitable for optimization, and 1 otherwise. */
6672 static int
6679 {
6685 bfd_vma off;
6699 /* Look inside a TOC section too. */
6701 {
6704 }
6705 else
6721 }
6723 /* Find (or create) an entry in the tocsave hash table. */
6731 {
6736 hashval_t hash;
6743 {
6744 _bfd_error_handler
6747 }
6751 else
6762 {
6768 }
6770 }
6772 /* Adjust all global syms defined in opd sections. In gcc generated
6773 code for the old ABI, these will already have been done. */
6775 static bfd_boolean
6777 {
6796 {
6799 {
6800 /* This entry has been deleted. */
6803 {
6806 {
6809 }
6810 }
6813 }
6814 else
6817 }
6819 }
6821 /* Handles decrementing dynamic reloc counts for the reloc specified by
6822 R_INFO in section SEC. If LOCAL_SYMS is NULL, then H and SYM
6823 have already been determined. */
6825 static bfd_boolean
6832 {
6836 /* Can this reloc be dynamic? This switch, and later tests here
6837 should be kept in sync with the code in check_relocs. */
6840 {
6905 }
6908 {
6915 }
6929 ;
6930 else
6934 {
6939 /* elf_gc_sweep may have already removed all dyn relocs associated
6940 with local syms for a given section. Also, symbol flags are
6941 changed by elf_gc_sweep_symbol, confusing the test above. Don't
6942 report a dynreloc miscount. */
6947 {
6949 {
6956 }
6958 }
6959 }
6960 else
6961 {
6965 bfd_boolean is_ifunc;
6980 {
6982 {
6987 }
6989 }
6990 }
6992 /* xgettext:c-format */
6997 }
6999 /* Remove unused Official Procedure Descriptor entries. Currently we
7000 only remove those associated with functions in discarded link-once
7001 sections, or weakly defined functions that have been overridden. It
7002 would be possible to remove many more entries for statically linked
7003 applications. */
7005 bfd_boolean
7007 {
7018 {
7040 /* Look through the section relocs. */
7047 /* Read the relocations. */
7053 /* First run through the relocs to check they are sane, and to
7054 determine whether we need to edit this opd section. */
7060 {
7066 bfd_vma offset;
7068 /* .opd contains an array of 16 or 24 byte entries. We're
7069 only interested in the reloc pointing to a function entry
7070 point. */
7074 {
7075 /* If someone messes with .opd alignment then after a
7076 "ld -r" we might have padding in the middle of .opd.
7077 Also, there's nothing to prevent someone putting
7078 something silly in .opd with the assembler. No .opd
7079 optimization for them! */
7080 broken_opd:
7081 _bfd_error_handler
7085 }
7089 {
7090 _bfd_error_handler
7091 /* xgettext:c-format */
7096 }
7104 {
7108 else
7110 sym_sec);
7112 _bfd_error_handler
7113 /* xgettext:c-format */
7118 }
7120 /* opd entries are always for functions defined in the
7121 current input bfd. If the symbol isn't defined in the
7122 input bfd, then we won't be using the function in this
7123 bfd; It must be defined in a linkonce section in another
7124 bfd, or is weak. It's also possible that we are
7125 discarding the function due to a linker script /DISCARD/,
7126 which we test for via the output_section. */
7138 {
7140 {
7143 }
7145 {
7146 cnt_16b++;
7148 }
7150 }
7154 {
7156 cnt_16b++;
7159 }
7160 else
7162 }
7167 {
7172 bfd_size_type amt;
7181 /* This seems a waste of time as input .opd sections are all
7182 zeros as generated by gcc, but I suppose there's no reason
7183 this will always be so. We might start putting something in
7184 the third word of .opd entries. */
7186 {
7189 {
7192 error_ret:
7199 }
7202 }
7208 {
7213 }
7218 {
7226 bfd_boolean skip;
7239 /* See if the .opd entry is full 24 byte or
7240 16 byte (with fd_aux entry overlapped with next
7241 fd_func). */
7244 {
7247 }
7253 {
7256 {
7261 }
7262 }
7267 {
7269 {
7270 /* Arrange for the function descriptor sym
7271 to be dropped. */
7274 }
7279 else
7281 {
7293 }
7294 }
7295 else
7296 {
7297 /* We'll be keeping this opd entry. */
7301 {
7302 /* Redefine the function descriptor symbol to
7303 this location in the opd section. It is
7304 necessary to update the value here rather
7305 than using an array of adjustments as we do
7306 for local symbols, because various places
7307 in the generic ELF code use the value
7308 stored in u.def.value. */
7311 }
7313 /* Local syms are a bit tricky. We could
7314 tweak them as they can be cached, but
7315 we'd need to look through the local syms
7316 for the function descriptor sym which we
7317 don't have at the moment. So keep an
7318 array of adjustments. */
7326 {
7329 }
7331 /* We need to adjust any reloc offsets to point to the
7332 new opd entries. */
7334 {
7339 }
7340 }
7343 }
7348 {
7351 }
7353 /* Fudge the header size too, as this is used later in
7354 elf_bfd_final_link if we are emitting relocs. */
7358 }
7364 {
7367 else
7369 }
7370 }
7375 /* If we are doing a final link and the last .opd entry is just 16 byte
7376 long, add a 8 byte padding after it. */
7378 {
7382 {
7395 }
7396 else
7397 {
7403 }
7407 }
7410 }
7412 /* Analyze inline PLT call relocations to see whether calls to locally
7413 defined functions can be converted to direct calls. */
7415 bfd_boolean
7417 {
7427 /* A bl insn can reach -0x2000000 to 0x1fffffc. The limit is
7428 reduced somewhat to cater for possible stubs that might be added
7429 between the call and its destination. */
7431 {
7435 }
7436 else
7437 {
7441 }
7447 {
7452 }
7454 /* If a "bl" can reach anywhere in local code sections, then we can
7455 convert all inline PLT sequences to direct calls when the symbol
7456 is local. */
7458 {
7461 }
7463 /* Otherwise, go looking through relocs for cases where a direct
7464 call won't reach. Mark the symbol on any such reloc to disable
7465 the optimization and keep the PLT entry as it seems likely that
7466 this will be better than creating trampolines. Note that this
7467 will disable the optimization for all inline PLT calls to a
7468 particular symbol, not just those that won't reach. The
7469 difficulty in doing a more precise optimization is that the
7470 linker needs to make a decision depending on whether a
7471 particular R_PPC64_PLTCALL insn can be turned into a direct
7472 call, for each of the R_PPC64_PLTSEQ and R_PPC64_PLT16* insns in
7473 the sequence, and there is nothing that ties those relocs
7474 together except their symbol. */
7477 {
7490 {
7493 /* Read the relocations. */
7501 {
7517 {
7524 }
7527 {
7531 else
7545 }
7546 }
7549 }
7553 {
7556 else
7558 }
7559 }
7562 }
7564 /* Set htab->tls_get_addr and call the generic ELF tls_setup function. */
7566 asection *
7568 {
7583 /* Default to --no-plt-localentry, as this option can cause problems
7584 with symbol interposition. For example, glibc libpthread.so and
7585 libc.so duplicate many pthread symbols, with a fallback
7586 implementation in libc.so. In some cases the fallback does more
7587 work than the pthread implementation. __pthread_condattr_destroy
7588 is one such symbol: the libpthread.so implementation is
7589 localentry:0 while the libc.so implementation is localentry:8.
7590 An app that "cleverly" uses dlopen to only load necessary
7591 libraries at runtime may omit loading libpthread.so when not
7592 running multi-threaded, which then results in the libc.so
7593 fallback symbols being used and ld.so complaining. Now there
7594 are workarounds in ld (see non_zero_localentry) to detect the
7595 pthread situation, but that may not be the only case where
7596 --plt-localentry can cause trouble. */
7602 _bfd_error_handler
7609 /* Move dynamic linking info to the function descriptor sym. */
7616 {
7628 {
7629 /* If glibc supports an optimized __tls_get_addr call stub,
7630 signalled by the presence of __tls_get_addr_opt, and we'll
7631 be calling __tls_get_addr via a plt call stub, then
7632 make __tls_get_addr point to __tls_get_addr_opt. */
7640 {
7647 {
7653 {
7654 /* Use __tls_get_addr_opt in dynamic relocations. */
7660 }
7661 htab->tls_get_addr_fd
7665 {
7673 }
7677 {
7680 }
7681 }
7682 }
7683 }
7686 }
7688 }
7690 /* Return TRUE iff REL is a branch reloc with a global symbol matching
7691 HASH1 or HASH2. */
7693 static bfd_boolean
7698 {
7704 {
7712 }
7714 }
7716 /* Run through all the TLS relocs looking for optimization
7717 opportunities. The linker has been hacked (see ppc64elf.em) to do
7718 a preliminary section layout so that we know the TLS segment
7719 offsets. We can't optimize earlier because some optimizations need
7720 to know the tp offset, and we need to optimize before allocating
7721 dynamic relocations. */
7723 bfd_boolean
7725 {
7739 /* Make two passes over the relocs. On the first pass, mark toc
7740 entries involved with tls relocs, and check that tls relocs
7741 involved in setting up a tls_get_addr call are indeed followed by
7742 such a call. If they are not, we can't do any tls optimization.
7743 On the second pass twiddle tls_mask flags to notify
7744 relocate_section that optimization can be done, and adjust got
7745 and plt refcounts. */
7749 {
7755 {
7759 /* Read the relocations. */
7763 {
7766 }
7770 {
7778 bfd_vma value;
7787 {
7788 err_free_rel:
7798 }
7801 {
7807 else
7808 {
7811 }
7812 }
7813 else
7814 /* Symbols referenced by TLS relocs must be of type
7815 STT_TLS. So no need for .opd local sym adjust. */
7821 {
7827 {
7831 /* Note that even though the prefix insns
7832 allow a 1<<33 offset we use the same test
7833 as for addis;addi. There may be a mix of
7834 pcrel and non-pcrel code and the decision
7835 to optimise is per symbol, not per TLS
7836 sequence. */
7838 }
7839 }
7842 /* If this section has old-style __tls_get_addr calls
7843 without marker relocs, then check that each
7844 __tls_get_addr call reloc is preceded by a reloc
7845 that conceivably belongs to the __tls_get_addr arg
7846 setup insn. If we don't find matching arg setup
7847 relocs, don't do any tls optimization. */
7853 && !found_tls_get_addr_arg
7855 {
7861 }
7865 {
7871 /* Fall through. */
7875 /* These relocs should never be against a symbol
7876 defined in a shared lib. Leave them alone if
7877 that turns out to be the case. */
7881 /* LD -> LE */
7892 /* Fall through. */
7897 /* GD -> LE */
7899 else
7900 /* GD -> IE */
7912 {
7913 /* IE -> LE */
7918 }
7924 /* Fall through. */
7928 {
7934 {
7940 {
7952 }
7953 }
7955 }
7957 /* Fall through. */
7965 /* Mark this toc entry as referenced by a TLS
7966 code sequence. We can do that now in the
7967 case of R_PPC64_TLS, and after checking for
7968 tls_get_addr for the TOC16 relocs. */
7970 toc_ref
7977 else
7988 {
7991 }
8008 {
8009 /* IE -> LE */
8013 }
8026 {
8028 /* GD -> LE */
8030 else
8031 /* GD -> IE */
8034 }
8035 else
8036 {
8040 /* LD -> LE */
8043 }
8048 }
8051 {
8060 {
8062 {
8063 /* Check for toc tls entries. */
8073 {
8079 }
8080 }
8082 }
8084 /* Uh oh, we didn't find the expected call. We
8085 could just mark this symbol to exclude it
8086 from tls optimization but it's safer to skip
8087 the entire optimization. */
8088 /* xgettext:c-format */
8094 }
8096 /* If we don't have old-style __tls_get_addr calls
8097 without TLSGD/TLSLD marker relocs, and we haven't
8098 found a new-style __tls_get_addr call with a
8099 marker for this symbol, then we either have a
8100 broken object file or an -mlongcall style
8101 indirect call to __tls_get_addr without a marker.
8102 Disable optimization in this case. */
8111 {
8131 }
8137 {
8140 /* Adjust got entry for this reloc. */
8143 else
8155 {
8156 /* We managed to get rid of a got entry. */
8159 }
8160 }
8161 else
8162 {
8163 /* If we got rid of a DTPMOD/DTPREL reloc pair then
8164 we'll lose one or two dyn relocs. */
8170 {
8174 }
8175 }
8179 }
8183 }
8187 {
8190 else
8192 }
8193 }
8199 }
8201 /* Called via elf_link_hash_traverse from ppc64_elf_edit_toc to adjust
8202 the values of any global symbols in a toc section that has been
8203 edited. Globals in toc sections should be a rarity, so this function
8204 sets a flag if any are found in toc sections other than the one just
8205 edited, so that further hash table traversals can be avoided. */
8207 struct adjust_toc_info
8208 {
8211 bfd_boolean global_toc_syms;
8212 };
8216 static bfd_boolean
8218 {
8232 {
8235 else
8239 {
8240 _bfd_error_handler
8242 do
8246 }
8250 }
8255 }
8257 /* Return TRUE iff INSN with a relocation of R_TYPE is one we expect
8258 on a _LO variety toc/got reloc. */
8260 static bfd_boolean
8262 {
8280 /* Exclude lfqu by testing reloc. If relocs are ever
8281 defined for the reduced D field in psq_lu then those
8282 will need testing too. */
8288 /* Exclude stfqu. psq_stu as above for psq_lu. */
8292 }
8294 /* PCREL_OPT in one instance flags to the linker that a pair of insns:
8295 pld ra,symbol@got@pcrel
8296 load/store rt,off(ra)
8297 or
8298 pla ra,symbol@pcrel
8299 load/store rt,off(ra)
8300 may be translated to
8301 pload/pstore rt,symbol+off@pcrel
8302 nop.
8303 This function returns true if the optimization is possible, placing
8304 the prefix insn in *PINSN1, a NOP in *PINSN2 and the offset in *POFF.
8306 On entry to this function, the linker has already determined that
8307 the pld can be replaced with pla: *PINSN1 is that pla insn,
8308 while *PINSN2 is the second instruction. */
8310 static bfd_boolean
8312 {
8315 bfd_signed_vma off;
8318 {
8319 /* Check that regs match. */
8323 /* P8LS or PMLS form, non-pcrel. */
8332 }
8336 /* Check that regs match. */
8341 {
8356 /* These are the PMLS cases, where we just need to tack a prefix
8357 on the insn. */
8385 {
8390 }
8391 else
8392 {
8397 }
8414 }
8420 }
8422 /* Examine all relocs referencing .toc sections in order to remove
8423 unused .toc entries. */
8425 bfd_boolean
8427 {
8435 {
8458 /* Look at sections dropped from the final link. */
8462 {
8474 /* Run through the relocs to see which toc entries might be
8475 unused. */
8477 {
8483 bfd_vma val;
8487 {
8498 }
8510 else
8517 /* Anything in the toc ought to be aligned to 8 bytes.
8518 If not, don't mark as unused. */
8523 {
8527 }
8530 }
8534 }
8536 /* For largetoc loads of address constants, we can convert
8537 . addis rx,2,addr@got@ha
8538 . ld ry,addr@got@l(rx)
8539 to
8540 . addis rx,2,addr@toc@ha
8541 . addi ry,rx,addr@toc@l
8542 when addr is within 2G of the toc pointer. This then means
8543 that the word storing "addr" in the toc is no longer needed. */
8548 {
8549 /* Read toc relocs. */
8556 {
8582 {
8586 }
8587 else
8588 {
8592 }
8596 /* We don't yet know the exact toc pointer value, but we
8597 know it will be somewhere in the toc section. Don't
8598 optimize if the difference from any possible toc
8599 pointer is outside [ff..f80008000, 7fff7fff]. */
8609 {
8613 }
8617 }
8618 }
8625 {
8626 error_ret:
8640 }
8642 /* Now check all kept sections that might reference the toc.
8643 Check the toc itself last. */
8651 {
8664 {
8667 }
8669 /* Mark toc entries referenced as used. */
8670 do
8671 {
8674 {
8680 bfd_vma val;
8684 {
8691 /* In case we're taking addresses of toc entries. */
8697 }
8702 {
8705 }
8712 else
8720 {
8721 bfd_vma off;
8725 {
8734 {
8737 }
8740 /* Fall through. */
8743 /* Wrong sort of reloc, or not a ld. We may
8744 as well clear ref_from_discarded too. */
8746 }
8747 }
8751 /* For the toc section, we only mark as used if this
8752 entry itself isn't unused. */
8756 {
8757 /* Do all the relocs again, to catch reference
8758 chains. */
8761 }
8762 }
8763 }
8768 }
8770 /* Merge the used and skip arrays. Assume that TOC
8771 doublewords not appearing as either used or unused belong
8772 to an entry more than one doubleword in size. */
8776 {
8778 {
8783 }
8785 {
8788 }
8789 else
8791 }
8796 {
8802 /* Shuffle the toc contents, and at the same time convert the
8803 skip array from booleans into offsets. */
8812 {
8816 {
8819 }
8820 }
8825 /* Adjust addends for relocs against the toc section sym,
8826 and optimize any accesses we can. */
8828 {
8839 {
8844 bfd_vma val;
8848 {
8860 }
8872 else
8873 {
8877 }
8886 {
8887 Elf_Internal_Rela *tocrel
8892 {
8905 /* xgettext:c-format */
8912 }
8916 }
8923 }
8927 }
8929 /* We shouldn't have local or global symbols defined in the TOC,
8930 but handle them anyway. */
8937 {
8942 else
8946 {
8948 _bfd_error_handler
8951 do
8955 }
8959 }
8961 /* Adjust any global syms defined in this toc input section. */
8963 {
8969 }
8972 {
8975 bfd_size_type sz;
8977 /* Remove unused toc relocs, and adjust those we keep. */
8988 {
8993 }
9003 }
9004 }
9011 {
9014 else
9016 }
9018 }
9020 /* Look for cases where we can change an indirect GOT access to
9021 a GOT relative or PC relative access, possibly reducing the
9022 number of GOT entries. */
9024 {
9029 bfd_vma got;
9046 {
9055 {
9056 got_error_ret:
9065 }
9068 {
9082 {
9109 }
9112 {
9123 {
9129 /* xgettext:c-format */
9134 }
9135 }
9138 {
9139 /* Note that we don't delete GOT entries for
9140 R_PPC64_GOT16_DS since we'd need a lot more
9141 analysis. For starters, the preliminary layout is
9142 before the GOT, PLT, dynamic sections and stubs are
9143 laid out. Then we'd need to allow for changes in
9144 distance between sections caused by alignment. */
9152 }
9169 else
9174 /* Fudge factor to allow for the fact that the preliminary layout
9175 isn't exact. Reduce limits by this factor. */
9176 #define LIMIT_ADJUST(LIMIT) ((LIMIT) - (LIMIT) / 16)
9179 {
9225 }
9226 #undef LIMIT_ADJUST
9230 else
9231 {
9234 }
9242 }
9246 }
9250 {
9253 else
9255 }
9256 }
9259 }
9261 /* Return true iff input section I references the TOC using
9262 instructions limited to +/-32k offsets. */
9264 bfd_boolean
9266 {
9269 }
9271 /* Allocate space for one GOT entry. */
9273 static void
9277 {
9290 {
9293 }
9302 {
9305 }
9306 }
9308 /* This function merges got entries in the same toc group. */
9310 static void
9312 {
9322 {
9325 }
9326 }
9328 /* If H is undefined, make it dynamic if that makes sense. */
9330 static bfd_boolean
9333 {
9345 }
9347 /* Allocate space in .plt, .got and associated reloc sections for
9348 dynamic relocs. */
9350 static bfd_boolean
9352 {
9368 /* Run through the TLS GD got entries first if we're changing them
9369 to TPREL. */
9374 {
9375 /* This was a GD entry that has been converted to TPREL. If
9376 there happens to be a TPREL entry we can use that one. */
9383 {
9386 }
9388 /* If not, then we'll be using our own TPREL entry. */
9391 }
9393 /* Remove any list entry that won't generate a word in the GOT before
9394 we call merge_got_entries. Otherwise we risk merging to empty
9395 entries. */
9399 {
9402 {
9405 }
9406 else
9408 }
9409 else
9417 {
9418 /* Ensure we catch all the cases where this symbol should
9419 be made dynamic. */
9427 }
9429 /* If no dynamic sections we can't have dynamic relocs, except for
9430 IFUNCs which are handled even in static executables. */
9435 /* Discard relocs on undefined symbols that must be local. */
9440 /* Also discard relocs on undefined weak syms with non-default
9441 visibility, or when dynamic_undefined_weak says so. */
9446 {
9449 /* In the shared -Bsymbolic case, discard space allocated for
9450 dynamic pc-relative relocs against symbols which turn out to
9451 be defined in regular objects. For the normal shared case,
9452 discard space for relocs that have become local due to symbol
9453 visibility changes. */
9455 {
9456 /* Relocs that use pc_count are those that appear on a call
9457 insn, or certain REL relocs (see must_be_dyn_reloc) that
9458 can be generated via assembly. We want calls to
9459 protected symbols to resolve directly to the function
9460 rather than going via the plt. If people want function
9461 pointer comparisons to work as expected then they should
9462 avoid writing weird assembly. */
9464 {
9466 {
9471 else
9473 }
9474 }
9477 {
9478 /* Ensure we catch all the cases where this symbol
9479 should be made dynamic. */
9482 }
9483 }
9485 /* For a fixed position executable, discard space for
9486 relocs against symbols which are not dynamic. */
9488 {
9492 {
9493 /* Ensure we catch all the cases where this symbol
9494 should be made dynamic. */
9498 /* But if that didn't work out, discard dynamic relocs. */
9501 }
9502 else
9504 }
9506 /* Finally, allocate space. */
9508 {
9513 }
9514 }
9516 /* We might need a PLT entry when the symbol
9517 a) is dynamic, or
9518 b) is an ifunc, or
9519 c) has plt16 relocs and has been processed by adjust_dynamic_symbol, or
9520 d) has plt16 relocs and we are linking statically. */
9530 {
9535 {
9538 {
9540 {
9545 }
9546 else
9547 {
9552 }
9553 }
9554 else
9555 {
9556 /* If this is the first .plt entry, make room for the special
9557 first entry. */
9564 /* Make room for this entry. */
9567 /* Make room for the .glink code. */
9572 {
9573 /* We need bigger stubs past index 32767. */
9577 }
9578 else
9581 /* We also need to make an entry in the .rela.plt section. */
9583 }
9587 }
9588 else
9591 {
9594 }
9595 }
9596 else
9597 {
9600 }
9603 }
9605 #define PPC_LO(v) ((v) & 0xffff)
9606 #define PPC_HI(v) (((v) >> 16) & 0xffff)
9607 #define PPC_HA(v) PPC_HI ((v) + 0x8000)
9608 #define D34(v) \
9609 ((((v) & 0x3ffff0000ULL) << 16) | (v & 0xffff))
9610 #define HA34(v) ((v + (1ULL << 33)) >> 34)
9612 /* Called via elf_link_hash_traverse from ppc64_elf_size_dynamic_sections
9613 to set up space for global entry stubs. These are put in glink,
9614 after the branch table. */
9616 static bfd_boolean
9618 {
9643 {
9644 /* For ELFv2, if this symbol is not defined in a regular file
9645 and we are not generating a shared library or pie, then we
9646 need to define the symbol in the executable on a call stub.
9647 This is to avoid text relocations. */
9655 else
9657 /* Setting section alignment is delayed until we know it is
9658 non-empty. Otherwise the .text output section will be
9659 aligned at least to plt_stub_align even when no global
9660 entry stubs are needed. */
9671 /* Note that for --plt-stub-align negative we have a possible
9672 dependency between stub offset and size. Break that
9673 dependency by assuming the max stub size when calculating
9674 the stub offset. */
9682 }
9684 }
9686 /* Set DF_TEXTREL if we find any dynamic relocs that apply to
9687 read-only sections. */
9689 static bfd_boolean
9691 {
9699 {
9707 /* Not an error, just cut short the traversal. */
9709 }
9711 }
9713 /* Set the sizes of the dynamic sections. */
9715 static bfd_boolean
9718 {
9722 bfd_boolean relocs;
9735 {
9736 /* Set the contents of the .interp section to the interpreter. */
9738 {
9744 }
9745 }
9747 /* Set up .got offsets for local syms, and space for local dynamic
9748 relocs. */
9750 {
9756 bfd_size_type locsymcount;
9763 {
9767 {
9770 {
9771 /* Input section has been discarded, either because
9772 it is a copy of a linkonce section or due to
9773 linker script /DISCARD/, so we'll be discarding
9774 the relocs too. */
9775 }
9777 {
9784 }
9785 }
9786 }
9800 {
9806 {
9808 {
9811 }
9812 else
9813 {
9819 {
9822 }
9825 {
9828 }
9832 {
9835 }
9837 }
9838 }
9839 else
9841 }
9843 /* Allocate space for plt calls to local syms. */
9846 {
9851 {
9853 {
9858 }
9862 else
9863 {
9869 }
9870 }
9871 else
9873 }
9874 }
9876 /* Allocate global sym .plt and .got entries, and space for global
9877 sym dynamic relocs. */
9885 {
9893 {
9895 {
9898 }
9899 else
9900 {
9908 {
9911 }
9912 }
9913 }
9914 else
9916 }
9918 /* We now have determined the sizes of the various dynamic sections.
9919 Allocate memory for them. */
9922 {
9927 /* These haven't been allocated yet; don't strip. */
9937 {
9938 /* Strip this section if we don't need it; see the
9939 comment below. */
9940 }
9942 {
9944 /* Not sized yet. */
9946 }
9948 {
9950 {
9954 /* We use the reloc_count field as a counter if we need
9955 to copy relocs into the output file. */
9957 }
9958 }
9959 else
9960 {
9961 /* It's not one of our sections, so don't allocate space. */
9963 }
9966 {
9967 /* If we don't need this section, strip it from the
9968 output file. This is mostly to handle .rela.bss and
9969 .rela.plt. We must create both sections in
9970 create_dynamic_sections, because they must be created
9971 before the linker maps input sections to output
9972 sections. The linker does that before
9973 adjust_dynamic_symbol is called, and it is that
9974 function which decides whether anything needs to go
9975 into these sections. */
9978 }
9987 /* Allocate memory for the section contents. We use bfd_zalloc
9988 here in case unused entries are not reclaimed before the
9989 section's contents are written out. This should not happen,
9990 but this way if it does we get a R_PPC64_NONE reloc in .rela
9991 sections instead of garbage.
9992 We also rely on the section contents being zero when writing
9993 the GOT and .dynrelro. */
9997 }
10000 {
10006 {
10009 else
10010 {
10014 }
10015 }
10018 {
10021 else
10022 {
10028 }
10029 }
10030 }
10033 {
10034 bfd_boolean tls_opt;
10036 /* Add some entries to the .dynamic section. We fill in the
10037 values later, in ppc64_elf_finish_dynamic_sections, but we
10038 must add the entries now so that we get the correct size for
10039 the .dynamic section. The DT_DEBUG entry is filled in by the
10040 dynamic linker and used by the debugger. */
10041 #define add_dynamic_entry(TAG, VAL) \
10042 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
10045 {
10048 }
10051 {
10058 }
10061 {
10065 }
10071 {
10074 }
10077 {
10083 /* If any dynamic relocs apply to a read-only section,
10084 then we need a DT_TEXTREL entry. */
10089 {
10092 }
10093 }
10094 }
10095 #undef add_dynamic_entry
10098 }
10100 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
10102 static bfd_boolean
10104 {
10111 }
10113 /* Determine the type of stub needed, if any, for a call. */
10120 bfd_vma destination,
10122 {
10124 bfd_vma location;
10125 bfd_vma branch_offset;
10126 bfd_vma max_branch_offset;
10130 {
10135 {
10138 }
10143 {
10146 }
10148 /* Here, we know we don't have a plt entry. If we don't have a
10149 either a defined function descriptor or a defined entry symbol
10150 in a regular object file, then it is pointless trying to make
10151 any other type of stub. */
10155 }
10157 {
10164 {
10170 {
10173 }
10174 }
10175 }
10177 /* Determine where the call point is. */
10185 /* Determine if a long branch stub is needed. */
10193 /* We need a stub. Figure out whether a long_branch or plt_branch
10194 is needed later. */
10198 }
10200 /* Gets the address of a label (1:) in r11 and builds an offset in r12,
10201 then adds it to r11 (LOAD false) or loads r12 from r11+r12 (LOAD true).
10202 . mflr %r12
10203 . bcl 20,31,1f
10204 .1: mflr %r11
10205 . mtlr %r12
10206 . lis %r12,xxx-1b@highest
10207 . ori %r12,%r12,xxx-1b@higher
10208 . sldi %r12,%r12,32
10209 . oris %r12,%r12,xxx-1b@high
10210 . ori %r12,%r12,xxx-1b@l
10211 . add/ldx %r12,%r11,%r12 */
10215 {
10225 {
10228 else
10231 }
10233 {
10238 else
10241 }
10242 else
10243 {
10245 {
10248 }
10249 else
10250 {
10254 {
10257 }
10258 }
10260 {
10263 }
10265 {
10268 }
10270 {
10273 }
10276 else
10279 }
10281 }
10283 static unsigned int
10285 {
10291 else
10292 {
10295 else
10296 {
10300 }
10308 }
10310 }
10312 static unsigned int
10314 {
10320 else
10321 {
10330 }
10332 }
10337 {
10346 {
10353 }
10354 else
10355 {
10358 else
10359 {
10362 {
10368 }
10369 }
10373 {
10379 }
10381 {
10387 }
10388 }
10390 }
10394 bfd_boolean load)
10395 {
10398 {
10401 {
10404 }
10407 else
10413 }
10414 /* The minimum value for paddi is -0x200000000. The minimum value
10415 for li is -0x8000, which when shifted by 34 and added gives a
10416 minimum value of -0x2000200000000. The maximum value is
10417 0x1ffffffff+0x7fff<<34 which is 0x2000200000000-1. */
10419 {
10424 {
10427 }
10434 {
10437 }
10440 else
10442 }
10443 else
10444 {
10451 {
10454 }
10461 {
10464 }
10467 else
10469 }
10472 }
10474 static unsigned int
10476 {
10481 else
10483 }
10485 static unsigned int
10487 {
10492 else
10494 }
10500 {
10504 {
10511 }
10512 else
10513 {
10525 }
10530 }
10532 /* Emit .eh_frame opcode to advance pc by DELTA. */
10536 {
10541 {
10544 }
10546 {
10550 }
10551 else
10552 {
10556 }
10558 }
10560 /* Size of required .eh_frame opcode to advance pc by DELTA. */
10562 static unsigned int
10564 {
10566 /* DW_CFA_advance_loc+[1..63]. */
10569 /* DW_CFA_advance_loc1, byte. */
10572 /* DW_CFA_advance_loc2, 2 bytes. */
10574 /* DW_CFA_advance_loc4, 4 bytes. */
10576 }
10578 /* With power7 weakly ordered memory model, it is possible for ld.so
10579 to update a plt entry in one thread and have another thread see a
10580 stale zero toc entry. To avoid this we need some sort of acquire
10581 barrier in the call stub. One solution is to make the load of the
10582 toc word seem to appear to depend on the load of the function entry
10583 word. Another solution is to test for r2 being zero, and branch to
10584 the appropriate glink entry if so.
10586 . fake dep barrier compare
10587 . ld 12,xxx(2) ld 12,xxx(2)
10588 . mtctr 12 mtctr 12
10589 . xor 11,12,12 ld 2,xxx+8(2)
10590 . add 2,2,11 cmpldi 2,0
10591 . ld 2,xxx+8(2) bnectr+
10592 . bctr b <glink_entry>
10594 The solution involving the compare turns out to be faster, so
10595 that's what we use unless the branch won't reach. */
10597 #define ALWAYS_USE_FAKE_DEP 0
10598 #define ALWAYS_EMIT_R2SAVE 0
10603 bfd_vma off)
10604 {
10608 {
10610 {
10617 }
10618 else
10623 }
10632 {
10643 }
10648 {
10652 }
10654 }
10656 /* Depending on the sign of plt_stub_align:
10657 If positive, return the padding to align to a 2**plt_stub_align
10658 boundary.
10659 If negative, if this stub would cross fewer 2**plt_stub_align
10660 boundaries if we align, then return the padding needed to do so. */
10665 bfd_vma plt_off)
10666 {
10672 {
10677 }
10685 }
10687 /* Build a .plt call stub. */
10693 {
10705 && plt_load_toc
10706 && plt_thread_safe
10710 {
10719 to = (glinkoff
10734 }
10737 {
10739 {
10748 {
10750 {
10754 }
10755 else
10756 {
10761 {
10765 }
10766 }
10767 }
10768 }
10773 {
10776 }
10777 else
10778 {
10781 }
10784 {
10787 }
10790 {
10792 {
10795 }
10799 }
10800 }
10801 else
10802 {
10804 {
10810 {
10812 {
10816 }
10817 else
10818 {
10823 {
10827 }
10828 }
10829 }
10830 }
10837 {
10840 }
10843 {
10845 {
10848 }
10852 }
10853 }
10855 {
10859 }
10860 else
10863 }
10865 /* Build a special .plt call stub for __tls_get_addr. */
10867 #define LD_R11_0R3 0xe9630000
10868 #define LD_R12_0R3 0xe9830000
10869 #define MR_R0_R3 0x7c601b78
10870 #define CMPDI_R11_0 0x2c2b0000
10871 #define ADD_R3_R12_R13 0x7c6c6a14
10872 #define BEQLR 0x4d820020
10873 #define MR_R3_R0 0x7c030378
10874 #define STD_R11_0R1 0xf9610000
10875 #define BCTRL 0x4e800421
10876 #define LD_R11_0R1 0xe9610000
10877 #define MTLR_R11 0x7d6803a6
10883 {
10914 {
10931 }
10933 }
10937 {
10944 {
10945 bfd_size_type relsize;
10959 }
10963 }
10965 /* Convert the relocs R[0] thru R[-NUM_REL+1], which are all no-symbol
10966 forms, to the equivalent relocs against the global symbol given by
10967 STUB_ENTRY->H. */
10969 static bfd_boolean
10973 {
10977 bfd_vma symval;
10979 /* Relocs are always against symbols in their own object file. Fake
10980 up global sym hashes for the stub bfd (which has no symbols). */
10983 {
10984 bfd_size_type hsize;
10986 /* When called the first time, stub_globals will contain the
10987 total number of symbols seen during stub sizing. After
10988 allocating, stub_globals is used as an index to fill the
10989 hashes array. */
10996 }
11008 {
11011 {
11012 /* H is an opd symbol. The addend must be zero, and the
11013 branch reloc is the only one we can convert. */
11016 }
11017 else
11020 }
11022 }
11024 static bfd_vma
11027 {
11032 {
11033 /* Support linking -R objects. Get the toc pointer from the
11034 opd entry. */
11043 {
11049 }
11054 }
11057 }
11059 static bfd_boolean
11061 {
11074 /* Massage our args to the form they really have. */
11087 {
11090 /* Branches are relative. This is where we are going to. */
11096 /* And this is where we are coming from. */
11104 {
11108 {
11111 }
11115 {
11119 }
11121 {
11125 }
11127 }
11132 {
11133 _bfd_error_handler
11138 }
11141 {
11151 }
11160 {
11165 }
11177 {
11181 {
11182 /* Create a reloc for the branch lookup table entry. */
11183 Elf_Internal_Rela rela;
11196 }
11198 {
11202 /* brlt, being SEC_LINKER_CREATED does not go through the
11203 normal reloc processing. Symbols and offsets are not
11204 translated from input file to output file form, so
11205 set up the offset per the output file. */
11211 }
11212 }
11223 {
11230 }
11233 {
11245 {
11250 }
11251 }
11255 {
11257 {
11263 }
11264 else
11267 }
11268 else
11269 {
11273 {
11276 }
11281 {
11287 }
11288 else
11292 {
11296 }
11298 {
11302 }
11303 }
11324 {
11328 }
11330 {
11339 {
11342 else
11344 }
11346 }
11347 else
11357 {
11360 }
11361 else
11362 {
11363 /* The notoc stubs calculate their target (either a PLT entry or
11364 the global entry point of a function) relative to the PC
11365 returned by the "bcl" two instructions past the start of the
11366 sequence emitted by build_offset. The offset is therefore 8
11367 less than calculated from the start of the sequence. */
11371 }
11374 {
11375 bfd_vma from;
11383 }
11384 else
11385 {
11389 }
11393 {
11397 else
11398 {
11401 }
11407 else
11411 {
11420 }
11421 }
11426 {
11448 }
11456 {
11459 /* If the old-ABI "dot-symbol" is undefined make it weak so
11460 we don't get a link error from RELOC_FOR_GLOBAL_SYMBOL. */
11465 }
11467 /* Now build the stub. */
11476 {
11479 else
11481 }
11489 {
11491 /* xgettext:c-format */
11499 }
11503 {
11516 }
11522 else
11532 }
11537 {
11566 {
11576 }
11577 }
11580 }
11582 /* As above, but don't actually build the stub. Just bump offset so
11583 we know stub section sizes, and select plt_branch stubs where
11584 long_branch stubs won't do. */
11586 static bfd_boolean
11588 {
11596 /* Massage our args to the form they really have. */
11604 /* Make a note of the offset within the stubs for this entry. */
11611 {
11612 /* Don't make stubs to out-of-line register save/restore
11613 functions. Instead, emit copies of the functions. */
11617 }
11620 {
11623 /* Reset the stub type from the plt branch variant in case we now
11624 can reach with a shorter stub. */
11626 /* Fall through. */
11640 {
11643 {
11646 }
11653 }
11656 /* If the branch offset is too big, use a ppc_stub_plt_branch.
11657 Do the same for -R objects without function descriptors. */
11662 {
11669 {
11674 }
11677 {
11685 {
11688 }
11689 }
11699 {
11703 }
11707 {
11711 }
11712 else
11713 {
11722 }
11723 }
11725 {
11728 }
11734 /* Fall through. */
11751 {
11755 else
11759 }
11763 else
11765 /* Include branch insn plus those in the offset sequence. */
11767 /* The branch insn is at the end, or "extra" bytes along. So
11768 its offset will be "extra" bytes less that that already
11769 calculated. */
11773 {
11774 /* After the bcl, lr has been modified so we need to emit
11775 .eh_frame info saying the return address is in r12. */
11779 /* The eh_frame info will consist of a DW_CFA_advance_loc or
11780 variant, DW_CFA_register, 65, 12, DW_CFA_advance_loc+2,
11781 DW_CFA_restore_extended 65. */
11785 }
11787 /* If the branch can't reach, use a plt_branch. */
11789 {
11793 }
11813 {
11816 else
11818 }
11824 {
11830 }
11833 {
11837 else
11841 }
11846 {
11847 /* After the bcl, lr has been modified so we need to emit
11848 .eh_frame info saying the return address is in r12. */
11852 /* The eh_frame info will consist of a DW_CFA_advance_loc or
11853 variant, DW_CFA_register, 65, 12, DW_CFA_advance_loc+2,
11854 DW_CFA_restore_extended 65. */
11858 }
11870 {
11873 else
11875 }
11883 {
11888 }
11891 {
11899 }
11908 {
11909 /* After the bctrl, lr has been modified so we need to
11910 emit .eh_frame info saying the return address is
11911 on the stack. In fact we put the EH info specifying
11912 that the return address is on the stack *at* the
11913 call rather than after it, because the EH info for a
11914 call needs to be specified by that point.
11915 See libgcc/unwind-dw2.c execute_cfa_program. */
11917 /* The eh_frame info will consist of a DW_CFA_advance_loc
11918 or variant, DW_CFA_offset_externed_sf, 65, -stackoff,
11919 DW_CFA_advance_loc+4, DW_CFA_restore_extended, 65. */
11923 }
11929 }
11933 }
11935 /* Set up various things so that we can make a list of input sections
11936 for each output section included in the link. Returns -1 on error,
11937 0 when no stubs will be needed, and 1 on success. */
11939 int
11941 {
11943 bfd_size_type amt;
11955 /* Set toc_off for com, und, abs and ind sections. */
11960 }
11962 /* Set up for first pass at multitoc partitioning. */
11964 void
11966 {
11972 }
11974 /* The linker repeatedly calls this function for each TOC input section
11975 and linker generated GOT section. Group input bfds such that the toc
11976 within a group is less than 64k in size. */
11978 bfd_boolean
11980 {
11988 {
11989 /* Keep track of the first .toc or .got section for this input bfd. */
11993 {
11996 }
12004 {
12009 }
12011 /* toc_curr is the base address of this toc group. Set elf_gp
12012 for the input section to be the offset relative to the
12013 output toc base plus 0x8000. Making the input elf_gp an
12014 offset allows us to move the toc as a whole without
12015 recalculating input elf_gp. */
12019 /* Die if someone uses a linker script that doesn't keep input
12020 file .toc and .got together. */
12028 }
12030 /* During the second pass toc_first_sec points to the start of
12031 a toc group, and toc_curr is used to track the old elf_gp.
12032 We use toc_bfd to ensure we only look at each bfd once. */
12039 {
12042 }
12049 }
12051 /* Called via elf_link_hash_traverse to merge GOT entries for global
12052 symbol H. */
12054 static bfd_boolean
12056 {
12063 }
12065 /* Called via elf_link_hash_traverse to allocate GOT entries for global
12066 symbol H. */
12068 static bfd_boolean
12070 {
12080 }
12082 /* Called on the first multitoc pass after the last call to
12083 ppc64_elf_next_toc_section. This function removes duplicate GOT
12084 entries. */
12086 bfd_boolean
12088 {
12091 bfd_boolean done_something;
12098 /* Merge global sym got entries within a toc group. */
12101 /* And tlsld_got. */
12103 {
12112 {
12114 {
12122 {
12125 }
12126 }
12127 }
12128 }
12130 /* Zap sizes of got sections. */
12136 {
12144 {
12150 }
12151 }
12153 /* Now reallocate the got, local syms first. We don't need to
12154 allocate section contents again since we never increase size. */
12156 {
12162 bfd_size_type locsymcount;
12181 {
12185 {
12191 {
12194 }
12197 {
12200 }
12204 {
12207 }
12208 }
12209 }
12210 }
12215 {
12224 {
12229 {
12232 }
12233 }
12234 }
12239 {
12247 {
12251 }
12252 }
12257 /* Set up for second pass over toc sections to recalculate elf_gp
12258 on input sections. */
12263 }
12265 /* Called after second pass of multitoc partitioning. */
12267 void
12269 {
12272 /* After the second pass, toc_curr tracks the TOC offset used
12273 for code sections below in ppc64_elf_next_input_section. */
12275 }
12277 /* No toc references were found in ISEC. If the code in ISEC makes no
12278 calls, then there's no need to use toc adjusting stubs when branching
12279 into ISEC. Actually, indirect calls from ISEC are OK as they will
12280 load r2. Returns -1 on error, 0 for no stub needed, 1 for stub
12281 needed, and 2 if a cyclical call-graph was found but no other reason
12282 for a stub was detected. If called from the top level, a return of
12283 2 means the same as a return of 0. */
12285 static int
12287 {
12290 /* Mark this section as checked. */
12293 /* We know none of our code bearing sections will need toc stubs. */
12305 {
12315 /* Look for branches to outside of this section. */
12322 {
12330 bfd_vma sym_value;
12331 bfd_vma dest;
12346 {
12349 }
12351 /* Calls to dynamic lib functions go through a plt call stub
12352 that uses r2. */
12358 {
12361 }
12364 /* Ignore other undefined symbols. */
12367 /* Assume branches to other sections not included in the
12368 link need stubs too, to cover -R and absolute syms. */
12370 {
12373 }
12377 else
12378 {
12383 }
12386 /* If this branch reloc uses an opd sym, find the code section. */
12389 {
12391 {
12396 /* Assume deleted functions won't ever be called. */
12399 }
12405 }
12406 else
12407 dest = (sym_value
12411 /* Ignore branch to self. */
12415 /* If the called function uses the toc, we need a stub. */
12418 {
12421 }
12423 /* Assume any branch that needs a long branch stub might in fact
12424 need a plt_branch stub. A plt_branch stub uses r2. */
12431 {
12434 }
12436 /* If calling back to a section in the process of being
12437 tested, we can't say for sure that no toc adjusting stubs
12438 are needed, so don't return zero. */
12442 /* Branches to another section that itself doesn't have any TOC
12443 references are OK. Recursively call ourselves to check. */
12445 {
12448 /* Mark current section as indeterminate, so that other
12449 sections that call back to current won't be marked as
12450 known. */
12456 {
12460 }
12461 }
12462 }
12470 }
12476 {
12481 {
12488 }
12489 }
12495 }
12497 /* The linker repeatedly calls this function for each input section,
12498 in the order that input sections are linked into output sections.
12499 Build lists of input sections to determine groupings between which
12500 we may insert linker stubs. */
12502 bfd_boolean
12504 {
12512 {
12513 /* This happens to make the list in reverse order,
12514 which is what we want. */
12518 }
12521 {
12522 /* Analyse sections that aren't already flagged as needing a
12523 valid toc pointer. Exclude .fixup for the linux kernel.
12524 .fixup contains branches, but only back to the function that
12525 hit an exception. */
12530 {
12533 }
12534 /* Make all sections use the TOC assigned for this object file.
12535 This will be wrong for pasted sections; We fix that in
12536 check_pasted_section(). */
12539 }
12543 }
12545 /* Check that all .init and .fini sections use the same toc, if they
12546 have toc relocs. */
12548 static bfd_boolean
12550 {
12554 {
12561 {
12566 }
12571 {
12574 }
12576 /* Make sure the whole pasted function uses the same toc offset. */
12580 }
12582 }
12584 bfd_boolean
12586 {
12589 }
12591 /* See whether we can group stub sections together. Grouping stub
12592 sections may result in fewer stubs. More importantly, we need to
12593 put all .init* and .fini* stubs at the beginning of the .init or
12594 .fini output sections respectively, because glibc splits the
12595 _init and _fini functions into multiple parts. Putting a stub in
12596 the middle of a function is not a good idea. */
12598 static bfd_boolean
12600 bfd_size_type stub_group_size,
12601 bfd_boolean stubs_always_before_branch)
12602 {
12605 bfd_boolean suppress_size_errors;
12613 {
12614 /* Default values. */
12617 else
12620 }
12623 {
12631 {
12634 bfd_size_type total;
12635 bfd_boolean big_sec;
12636 bfd_vma curr_toc;
12638 bfd_size_type group_size;
12648 /* xgettext:c-format */
12661 /* OK, the size from the start of CURR to the end is less
12662 than group_size and thus can be handled by one stub
12663 section. (or the tail section is itself larger than
12664 group_size, in which case we may be toast.) We should
12665 really be keeping track of the total size of stubs added
12666 here, as stubs contribute to the final output section
12667 size. That's a little tricky, and this way will only
12668 break if stubs added make the total size more than 2^25,
12669 ie. for the default stub_group_size, if stubs total more
12670 than 2097152 bytes, or nearly 75000 plt call stubs. */
12682 do
12683 {
12685 /* Set up this stub group. */
12687 }
12690 /* But wait, there's more! Input sections up to group_size
12691 bytes before the stub section can be handled by it too.
12692 Don't do this if we have a really large section after the
12693 stubs, as adding more stubs increases the chance that
12694 branches may not reach into the stub section. */
12696 {
12705 {
12709 }
12710 }
12712 }
12713 }
12715 }
12718 {
12729 };
12731 /* Stripping output sections is normally done before dynamic section
12732 symbols have been allocated. This function is called later, and
12733 handles cases like htab->brlt which is mapped to its own output
12734 section. */
12736 static void
12738 {
12745 {
12749 }
12750 }
12752 /* Determine and set the size of the stub section for a final link.
12754 The basic idea here is to examine all the relocations looking for
12755 PC-relative calls to a target that is unreachable with a "bl"
12756 instruction. */
12758 bfd_boolean
12760 {
12761 bfd_size_type stub_group_size;
12762 bfd_boolean stubs_always_before_branch;
12773 {
12775 {
12777 /* libstdc++ */
12779 /* librt */
12782 /* libanl */
12784 /* libgomp */
12797 /* libgo */
12799 };
12803 {
12810 }
12811 }
12815 else
12821 #define STUB_SHRINK_ITER 20
12822 /* Loop until no stubs added. After iteration 20 of this loop we may
12823 exit on a stub section shrinking. This is to break out of a
12824 pathological case where adding stubs on one iteration decreases
12825 section gaps (perhaps due to alignment), which then requires
12826 fewer or smaller stubs on the next iteration. */
12829 {
12839 {
12847 /* We'll need the symbol table in a second. */
12852 /* Walk over each section attached to the input bfd. */
12856 {
12859 /* If there aren't any relocs, then there's nothing more
12860 to do. */
12868 /* If this section is a link-once section that will be
12869 discarded, then don't create any stubs. */
12874 /* Get the relocs. */
12875 internal_relocs
12881 /* Now examine each relocation. */
12885 {
12892 bfd_vma destination;
12894 bfd_boolean ok_dest;
12908 {
12911 }
12913 /* Only look for stubs on branch instructions. */
12921 /* Now determine the call target, its name, value,
12922 section. */
12932 {
12937 }
12940 {
12944 }
12947 {
12948 /* Recognise an old ABI func code entry sym, and
12949 use the func descriptor sym instead if it is
12950 defined. */
12953 {
12957 {
12962 }
12963 else
12965 }
12966 }
12967 else
12968 {
12971 }
12976 {
12978 destination = (sym_value
12984 }
12990 {
12991 bfd_vma dest;
12994 {
13000 }
13004 {
13007 {
13008 /* Fixup old ABI sym to point at code
13009 entry. */
13013 }
13014 }
13015 }
13017 /* Determine what (if any) linker stub is needed. */
13021 local_off);
13024 {
13034 }
13036 {
13037 /* Check whether we need a TOC adjusting stub.
13038 Since the linker pastes together pieces from
13039 different object files when creating the
13040 _init and _fini functions, it may be that a
13041 call to what looks like a local sym is in
13042 fact a call needing a TOC adjustment. */
13053 }
13058 /* __tls_get_addr calls might be eliminated. */
13066 {
13067 /* Get tls info. */
13075 }
13078 {
13087 {
13091 }
13092 else
13094 }
13096 /* Support for grouping stub sections. */
13099 /* Get the name of this stub. */
13107 {
13109 /* A stub has already been created, but it may
13110 not be the required type. We shouldn't be
13111 transitioning from plt_call to long_branch
13112 stubs or vice versa, but we might be
13113 upgrading from plt_call to plt_call_r2save or
13114 from long_branch to long_branch_r2off. */
13118 {
13132 {
13135 }
13137 {
13140 }
13141 else
13149 old_type += (ppc_stub_long_branch
13151 /* Fall through. */
13159 {
13162 }
13164 {
13167 }
13168 else
13171 }
13175 }
13179 {
13181 error_ret_free_internal:
13184 error_ret_free_local:
13190 }
13195 {
13198 }
13199 else
13200 {
13203 }
13206 stub_entry->symtype
13214 }
13216 /* We're done with the internal relocs, free them. */
13219 }
13223 {
13226 else
13228 }
13229 }
13231 /* We may have added some stubs. Find out the new size of the
13232 stub sections. */
13234 {
13238 {
13243 /* Past STUB_SHRINK_ITER, rawsize is the max size seen. */
13248 }
13249 }
13268 {
13271 }
13276 {
13290 }
13295 {
13299 }
13316 /* Ask the linker to do its stuff. */
13318 }
13322 {
13323 bfd_vma val;
13328 /* It is necessary to at least have a rough outline of the
13329 linker generated CIEs and FDEs written before
13330 bfd_elf_discard_info is run, in order for these FDEs to be
13331 indexed in .eh_frame_hdr. */
13340 /* CIE length (rewrite in case little-endian). */
13347 {
13351 /* FDE length. */
13354 /* CIE pointer. */
13358 /* Offset to stub section, written later. */
13360 /* stub section size. */
13363 /* Augmentation. */
13365 /* Make sure we don't have all nops. This is enough for
13366 elf-eh-frame.c to detect the last non-nop opcode. */
13369 }
13371 {
13374 /* FDE length. */
13377 /* CIE pointer. */
13381 /* Offset to .glink, written later. */
13383 /* .glink size. */
13386 /* Augmentation. */
13397 }
13398 /* Subsume any padding into the last FDE if user .eh_frame
13399 sections are aligned more than glink_eh_frame. Otherwise any
13400 zero padding will be seen as a terminator. */
13406 }
13413 }
13415 /* Called after we have determined section placement. If sections
13416 move, we'll be called again. Provide a value for TOCstart. */
13418 bfd_vma
13420 {
13425 {
13432 else
13433 {
13437 }
13443 {
13449 }
13450 }
13452 /* The TOC consists of sections .got, .toc, .tocbss, .plt in that
13453 order. The TOC starts where the first of these sections starts. */
13462 {
13463 /* This may happen for
13464 o references to TOC base (SYM@toc / TOC[tc0]) without a
13465 .toc directive
13466 o bad linker script
13467 o --gc-sections and empty TOC sections
13469 FIXME: Warn user? */
13471 /* Look for a likely section. We probably won't even be
13472 using TOCstart. */
13492 }
13498 /* Force alignment. */
13504 {
13508 {
13510 {
13513 }
13514 }
13515 else
13516 {
13521 }
13522 }
13524 }
13526 /* Called via elf_link_hash_traverse from ppc64_elf_build_stubs to
13527 write out any global entry stubs, and PLT relocations. */
13529 static bfd_boolean
13531 {
13547 {
13548 /* This symbol has an entry in the procedure linkage
13549 table. Set it up. */
13550 Elf_Internal_Rela rela;
13556 {
13562 {
13568 else
13570 }
13571 else
13572 {
13575 {
13579 else
13581 }
13582 else
13584 }
13591 {
13595 {
13599 }
13600 }
13601 else
13602 {
13609 }
13610 }
13611 else
13612 {
13624 }
13625 }
13640 {
13643 bfd_vma off;
13649 {
13652 else
13654 }
13659 {
13665 }
13669 {
13681 {
13691 }
13692 }
13695 {
13698 }
13705 }
13707 }
13709 /* Write PLT relocs for locals. */
13711 static bfd_boolean
13713 {
13718 {
13722 bfd_size_type locsymcount;
13741 {
13746 bfd_vma val;
13750 {
13755 }
13764 {
13768 }
13769 else
13770 {
13773 }
13776 {
13780 {
13783 }
13784 }
13785 else
13786 {
13787 Elf_Internal_Rela rela;
13792 {
13795 else
13797 }
13798 else
13799 {
13802 else
13804 }
13809 }
13810 }
13814 {
13817 else
13819 }
13820 }
13822 }
13824 /* Build all the stubs associated with the current output file.
13825 The stubs are kept in a hash table attached to the main linker
13826 hash table. This function is called via gldelf64ppc_finish. */
13828 bfd_boolean
13831 {
13841 /* Allocate memory to hold the linker stubs. */
13843 {
13848 {
13854 }
13855 }
13858 {
13860 bfd_vma plt0;
13862 /* Build the .glink plt call stub. */
13864 {
13871 {
13881 }
13882 }
13887 {
13895 }
13901 {
13922 }
13923 else
13924 {
13951 }
13956 /* Build the .glink lazy link call stubs. */
13959 {
13961 {
13963 {
13966 }
13967 else
13968 {
13972 p);
13974 }
13975 }
13978 indx++;
13980 }
13981 }
13983 /* Build .glink global entry stubs, and PLT relocs for globals. */
13990 {
13995 }
13997 {
14002 }
14004 /* Build the stubs as directed by the stub hash table. */
14017 {
14020 }
14024 {
14029 {
14035 }
14036 }
14040 {
14041 bfd_vma val;
14049 {
14050 /* Offset to stub section. */
14057 {
14058 _bfd_error_handler
14062 }
14065 }
14067 {
14068 /* Offset to .glink. */
14076 {
14077 _bfd_error_handler
14081 }
14084 }
14085 }
14089 {
14095 }
14098 {
14101 }
14107 {
14116 stub_sec_count),
14117 stub_sec_count);
14144 }
14146 }
14148 /* What to do when ld finds relocations against symbols defined in
14149 discarded sections. */
14151 static unsigned int
14153 {
14164 }
14166 /* These are the dynamic relocations supported by glibc. */
14168 static bfd_boolean
14170 {
14172 {
14223 }
14224 }
14226 /* The RELOCATE_SECTION function is called by the ELF backend linker
14227 to handle the relocations for a section.
14229 The relocs are always passed as Rela structures; if the section
14230 actually uses Rel structures, the r_addend field will always be
14231 zero.
14233 This function is responsible for adjust the section contents as
14234 necessary, and (if using Rela relocs and generating a
14235 relocatable output file) adjusting the reloc addend as
14236 necessary.
14238 This function does not have to worry about setting the reloc
14239 address or the reloc symbol index.
14241 LOCAL_SYMS is a pointer to the swapped in local symbols.
14243 LOCAL_SECTIONS is an array giving the section in the input file
14244 corresponding to the st_shndx field of each local symbol.
14246 The global hash table entry for the global symbols can be found
14247 via elf_sym_hashes (input_bfd).
14249 When generating relocatable output, this function must handle
14250 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
14251 going to be the section symbol corresponding to the output
14252 section, which means that the addend must be adjusted
14253 accordingly. */
14255 static bfd_boolean
14264 {
14271 Elf_Internal_Rela outrel;
14274 bfd_vma TOCstart;
14276 bfd_boolean is_opd;
14277 /* Assume 'at' branch hints. */
14282 /* Initialize howto table if needed. */
14290 /* Don't relocate stub sections. */
14295 {
14298 }
14309 {
14311 bfd_vma addend;
14312 bfd_reloc_status_type r;
14320 bfd_vma toc_addend;
14323 bfd_vma relocation;
14325 bfd_boolean warned;
14330 bfd_vma max_br_offset;
14331 bfd_vma from;
14332 Elf_Internal_Rela orig_rel;
14336 bfd_vma offset;
14338 again:
14344 /* For old style R_PPC64_TOC relocs with a zero symbol, use the
14345 symbol of the previous ADDR64 reloc. The symbol gives us the
14346 proper TOC base to use. */
14361 {
14362 /* It's a local symbol. */
14372 {
14377 else
14378 {
14379 /* If this is a relocation against the opd section sym
14380 and we have edited .opd, adjust the reloc addend so
14381 that ld -r and ld --emit-relocs output is correct.
14382 If it is a reloc against some other .opd symbol,
14383 then the symbol value will be adjusted later. */
14386 else
14388 }
14389 }
14390 }
14391 else
14392 {
14393 bfd_boolean ignored;
14404 {
14405 /* This is a symbol defined in a linker script. All
14406 such are defined in output sections, even those
14407 defined by simple assignment from a symbol defined in
14408 an input section. Transfer the symbol to an
14409 appropriate input .opd section, so that a branch to
14410 this symbol will be mapped to the location specified
14411 by the opd entry. */
14415 {
14420 {
14425 }
14426 }
14427 }
14428 }
14432 {
14440 /* For ld -r, remove relocations in debug sections against
14441 symbols defined in discarded sections. Not done for
14442 non-debug to preserve relocs in .eh_frame which the
14443 eh_frame editing code expects to be present. */
14446 wrel--;
14449 }
14455 {
14459 }
14461 /* TLS optimizations. Replace instruction sequences and relocs
14462 based on information we collected in tls_optimize. We edit
14463 RELOCS so that --emit-relocs will output something sensible
14464 for the final instruction stream. */
14471 {
14477 }
14482 {
14483 /* Check for toc tls entries. */
14492 }
14494 /* Check that tls relocs are used with tls syms, and non-tls
14495 relocs are used with non-tls syms. */
14502 {
14507 /* R_PPC64_TLS is OK against a symbol in the TOC. */
14508 ;
14509 else
14512 /* xgettext:c-format */
14514 /* xgettext:c-format */
14518 sym_name);
14519 }
14521 /* Ensure reloc mapping code below stays sane. */
14535 {
14553 {
14554 /* Check for toc tls entries. */
14564 {
14568 {
14572 }
14573 else
14574 {
14575 /* If we found a GD reloc pair, then we might be
14576 doing a GD->IE transition. */
14578 {
14583 }
14585 {
14589 }
14590 }
14591 }
14592 }
14599 {
14604 }
14611 {
14612 toctprel:
14621 {
14624 /* We changed the symbol. Start over in order to
14625 get h, sym, sec etc. right. */
14627 }
14628 else
14630 }
14636 {
14637 /* pld ra,sym@got@tprel@pcrel -> paddi ra,r13,sym@tprel */
14649 }
14655 {
14661 {
14663 /* Was PPC64_TLS which sits on insn boundary, now
14664 PPC64_TPREL16_LO which is at low-order half-word. */
14668 {
14671 /* We changed the symbol. Start over in order to
14672 get h, sym, sec etc. right. */
14674 }
14675 else
14677 }
14679 {
14680 /* For pcrel IE to LE we already have the full
14681 offset and thus don't need an addi here. A nop
14682 or mr will do. */
14684 {
14685 /* Extract regs from addi rt,ra,si. */
14690 else
14691 {
14692 /* Build or ra,rs,rb with rb==rs, ie. mr ra,rs. */
14695 }
14696 }
14698 }
14699 }
14712 {
14713 tls_gdld_hi:
14717 else
14718 {
14722 }
14724 }
14737 {
14740 tls_ldgd_opt:
14742 /* If not using the newer R_PPC64_TLSGD/LD to mark
14743 __tls_get_addr calls, we must trust that the call
14744 stays with its arg setup insns, ie. that the next
14745 reloc is the __tls_get_addr call associated with
14746 the current reloc. Edit both insns. */
14753 /* We read the low GOT_TLS (or TOC16) insn because we
14754 need to keep the destination reg. It may be
14755 something other than the usual r3, and moved to r3
14756 before the call by intervening code. */
14760 {
14761 /* IE */
14770 else
14774 }
14775 else
14776 {
14777 /* LE */
14782 {
14783 /* Was an LD reloc. */
14786 }
14788 {
14791 }
14795 {
14797 R_PPC64_TPREL16_LO);
14800 }
14801 }
14805 {
14808 {
14812 }
14813 }
14816 {
14817 /* We changed the symbol. Start over in order
14818 to get h, sym, sec etc. right. */
14820 }
14821 }
14826 {
14831 {
14832 /* IE, pla -> pld */
14835 }
14836 else
14837 {
14838 /* LE, pla pcrel -> paddi r13 */
14841 }
14847 }
14852 {
14866 }
14872 {
14878 {
14885 }
14891 {
14892 /* IE */
14895 }
14896 else
14897 {
14898 /* LE */
14900 {
14903 }
14906 {
14909 }
14910 else
14911 {
14915 }
14916 }
14918 /* Zap the reloc on the _tls_get_addr call too. */
14926 }
14932 {
14938 {
14945 }
14952 {
14955 }
14956 else
14957 {
14963 }
14965 /* Zap the reloc on the _tls_get_addr call too. */
14971 }
14978 {
14980 {
14984 else
14985 {
14988 }
14990 }
14991 }
14992 else
14993 {
14995 {
14999 }
15000 }
15005 {
15008 }
15016 {
15023 {
15030 }
15031 }
15032 else
15033 {
15038 {
15045 {
15052 }
15053 }
15054 }
15058 /* If we are generating a non-PIC executable, edit
15059 . 0: addis 2,12,.TOC.-0b@ha
15060 . addi 2,2,.TOC.-0b@l
15061 used by ELFv2 global entry points to set up r2, to
15062 . lis 2,.TOC.@ha
15063 . addi 2,2,.TOC.@l
15064 if .TOC. is in range. */
15075 {
15082 {
15089 }
15090 }
15092 }
15094 /* Handle other relocations that tweak non-addend part of insn. */
15100 {
15110 {
15117 }
15120 /* Branch taken prediction relocations. */
15124 /* Fall through. */
15126 /* Branch not taken prediction relocations. */
15131 /* Fall through. */
15135 /* Fall through. */
15141 /* Calls to functions with a different TOC, such as calls to
15142 shared objects, need to alter the TOC pointer. This is
15143 done using a linkage stub. A REL24 branching to these
15144 linkage stubs needs to be followed by a nop, as the nop
15145 will be replaced with an instruction to restore the TOC
15146 base pointer. */
15153 htab);
15168 {
15175 {
15176 /* The function doesn't use or change r2. */
15178 }
15180 {
15181 /* NOTOC calls don't need to restore r2. */
15183 }
15185 /* All of these stubs may modify r2, so there must be a
15186 branch and link followed by a nop. The nop is
15187 replaced by an insn to restore r2. */
15189 {
15195 {
15205 {
15210 {
15211 /* Special stub used, leave nop alone. */
15212 }
15213 else
15218 }
15219 }
15220 }
15223 {
15231 {
15232 /* Allow crt1 branch to go via a toc adjusting
15233 stub. Other calls that never return could do
15234 the same, if we could detect such. */
15236 }
15237 }
15240 {
15241 /* g++ as of 20130507 emits self-calls without a
15242 following nop. This is arguably wrong since we
15243 have conflicting information. On the one hand a
15244 global symbol and on the other a local call
15245 sequence, but don't error for this special case.
15246 It isn't possible to cheaply verify we have
15247 exactly such a call. Allow all calls to the same
15248 section. */
15252 {
15258 }
15261 }
15264 {
15268 /* xgettext:c-format */
15272 else
15274 /* xgettext:c-format */
15281 }
15287 }
15293 {
15294 /* The branch destination is the value of the opd entry. */
15300 {
15304 }
15305 }
15307 /* If the branch is out of reach we ought to have a long
15308 branch stub. */
15324 /* Don't use the stub if this branch is in range. */
15350 {
15351 /* Munge up the value and addend so that we call the stub
15352 rather than the procedure directly. */
15361 else
15390 }
15393 {
15395 {
15396 /* Set 'a' bit. This is 0b00010 in BO field for branch
15397 on CR(BI) insns (BO == 001at or 011at), and 0b01000
15398 for branch on CTR insns (BO == 1a00t or 1a01t). */
15403 else
15405 }
15406 else
15407 {
15408 /* Invert 'y' bit if not the default. */
15411 }
15414 }
15416 /* NOP out calls to undefined weak functions.
15417 We can thus call a weak function without first
15418 checking whether the function is defined. */
15426 {
15429 }
15436 {
15439 {
15444 }
15445 }
15453 {
15456 {
15461 }
15463 {
15466 }
15467 }
15476 {
15483 {
15484 /* Replace with paddi. */
15491 }
15492 }
15497 {
15505 {
15506 pcrelopt:
15510 {
15513 /* zero means next insn. */
15517 {
15519 bfd_signed_vma addend_off;
15523 {
15528 }
15530 {
15542 }
15543 }
15544 }
15545 }
15546 }
15548 }
15553 {
15555 /* xgettext:c-format */
15574 /* GOT16 relocations. Like an ADDR16 using the symbol's
15575 address in the GOT as relocation value instead of the
15576 symbol's value itself. Also, create a GOT entry for the
15577 symbol and put the symbol value there. */
15617 dogot:
15618 {
15619 /* Relocation is to the entry for this symbol in the global
15620 offset table. */
15623 bfd_vma off;
15630 else
15631 {
15633 {
15638 /* This is actually a static link, or it is a
15639 -Bsymbolic link and the symbol is defined
15640 locally, or the symbol was forced to be local
15641 because of a version file. */
15642 ;
15643 else
15644 {
15647 }
15649 }
15650 else
15651 {
15655 }
15662 }
15673 /* The offset must always be a multiple of 8. We use the
15674 least significant bit to record whether we have already
15675 processed this entry. */
15679 else
15680 {
15681 /* Generate relocs for the dynamic linker, except in
15682 the case of TLSLD where we'll use one entry per
15683 module. */
15685 bfd_boolean ifunc;
15693 {
15699 }
15709 {
15715 {
15719 {
15727 outrel.r_info
15729 }
15730 }
15737 else
15738 {
15741 else
15744 /* Write the .got section contents for the sake
15745 of prelink. */
15748 loc);
15749 }
15752 {
15755 {
15758 else
15760 }
15761 }
15766 }
15768 /* Init the .got section contents here if we're not
15769 emitting a reloc. */
15770 else
15771 {
15774 {
15777 else
15778 {
15781 else
15785 }
15788 {
15792 }
15793 }
15796 }
15797 }
15810 }
15825 /* Relocation is to the entry for this symbol in the
15826 procedure linkage table. */
15828 {
15833 {
15837 }
15839 {
15845 {
15847 bfd_vma got;
15853 {
15858 else
15860 }
15868 {
15872 }
15876 }
15877 }
15878 }
15882 /* Relocation value is TOC base. */
15887 ;
15890 else
15894 /* TOC16 relocs. We want the offset relative to the TOC base,
15895 which is the address of the start of the TOC plus 0x8000.
15896 The TOC consists of sections .got, .toc, .tocbss, and .plt,
15897 in this order. */
15909 /* Relocate against the beginning of the section. */
15960 {
15961 /* Make this relocation against an undefined weak symbol
15962 resolve to zero. This is really just a tweak, since
15963 code using weak externs ought to check that they are
15964 defined before using them. */
15972 }
15975 /* The TPREL16 relocs shouldn't really be used in shared
15976 libs or with non-local symbols as that will result in
15977 DT_TEXTREL being set, but support them anyway. */
16016 /* Fall through. */
16018 /* Relocations that may need to be propagated if this is a
16019 dynamic object. */
16053 dodyn:
16068 {
16071 bfd_vma out_off;
16074 /* When generating a dynamic object, these relocations
16075 are copied into the output file to be resolved at run
16076 time. */
16092 /* Optimize unaligned reloc use. */
16106 && !is_opd
16108 {
16112 }
16113 else
16114 {
16115 /* This symbol is local, or marked to become local,
16116 or this is an opd section reloc which must point
16117 at a local function. */
16120 {
16122 {
16123 /* Lie about opd entries. This case occurs
16124 when building shared libraries and we
16125 reference a function in another shared
16126 lib. The same thing happens for a weak
16127 definition in an application that's
16128 overridden by a strong definition in a
16129 shared lib. (I believe this is a generic
16130 bug in binutils handling of weak syms.)
16131 In these cases we won't use the opd
16132 entry in this lib. */
16134 }
16141 else
16142 {
16145 /* We need to relocate .opd contents for ld.so.
16146 Prelink also wants simple and consistent rules
16147 for relocs. This make all RELATIVE relocs have
16148 *r_offset equal to r_addend. */
16150 }
16151 }
16152 else
16153 {
16157 {
16159 /* xgettext:c-format */
16164 sym_name);
16166 }
16168 ;
16170 {
16173 }
16174 else
16175 {
16179 {
16180 /* TLS symbol values are relative to the
16181 TLS segment. Dynamic relocations for
16182 local TLS symbols therefore can't be
16183 reduced to a relocation against their
16184 section symbol because it holds the
16185 address of the section, not a value
16186 relative to the TLS segment. We could
16187 change the .tdata dynamic section symbol
16188 to be zero value but STN_UNDEF works
16189 and is used elsewhere, eg. for TPREL64
16190 GOT relocs against local TLS symbols. */
16193 }
16194 else
16195 {
16198 {
16202 else
16205 }
16207 }
16209 /* We are turning this relocation into one
16210 against a section symbol, so subtract out
16211 the output section's address but not the
16212 offset of the input section in the output
16213 section. */
16215 }
16218 }
16219 }
16225 {
16231 }
16244 {
16246 /* xgettext:c-format */
16249 input_bfd,
16251 sym_name);
16253 }
16255 /* If this reloc is against an external symbol, it will
16256 be computed at runtime, so there's no need to do
16257 anything now. However, for the sake of prelink ensure
16258 that the section contents are a known value. */
16260 {
16262 /* The value chosen here is quite arbitrary as ld.so
16263 ignores section contents except for the special
16264 case of .opd where the contents might be accessed
16265 before relocation. Choose zero, as that won't
16266 cause reloc overflow. */
16269 /* Use *r_offset == r_addend for R_PPC64_ADDR64 relocs
16270 to improve backward compatibility with older
16271 versions of ld. */
16274 /* Adjust pc_relative relocs to have zero in *r_offset. */
16277 }
16278 }
16286 /* We shouldn't ever see these dynamic relocs in relocatable
16287 files. */
16288 /* Fall through. */
16298 /* These ones haven't been implemented yet. */
16301 /* xgettext:c-format */
16303 input_bfd,
16309 }
16311 /* Multi-instruction sequences that access the TOC can be
16312 optimized, eg. addis ra,r2,0; addi rb,ra,x;
16313 to nop; addi rb,r2,x; */
16315 {
16325 /* These relocs would only be useful if building up an
16326 offset to later add to r2, perhaps in an indexed
16327 addressing mode instruction. Don't try to optimize.
16328 Unfortunately, the possibility of someone building up an
16329 offset like this or even with the HA relocs, means that
16330 we need to check the high insn when optimizing the low
16331 insn. */
16337 /* Fall through. */
16340 {
16341 /* No plt entry. Make this into a direct call. */
16350 }
16356 {
16359 }
16365 /* Fall through. */
16368 {
16374 }
16379 {
16382 }
16383 /* Fall through. */
16392 {
16394 nop_it:
16398 }
16404 {
16407 }
16408 /* Fall through. */
16419 {
16423 {
16424 /* Transform addic to addi when we change reg. */
16427 }
16428 else
16429 {
16432 }
16434 }
16439 {
16444 /* xgettext:c-format */
16449 else
16450 {
16453 }
16454 }
16460 {
16466 }
16468 }
16470 /* Do any further special processing. */
16472 {
16495 /* It's just possible that this symbol is a weak symbol
16496 that's not actually defined anywhere. In that case,
16497 'sec' would be NULL, and we should leave the symbol
16498 alone (it will be set to zero elsewhere in the link). */
16501 /* Fall through. */
16510 /* Add 0x10000 if sign bit in 0:15 is set.
16511 Bits 0:15 are not used. */
16545 /* If this reloc is against an lq, lxv, or stxv insn, then
16546 the value must be a multiple of 16. This is somewhat of
16547 a hack, but the "correct" way to do this by defining _DQ
16548 forms of all the _DS relocs bloats all reloc switches in
16549 this file. It doesn't make much sense to use these
16550 relocs in data, so testing the insn should be safe. */
16557 {
16560 /* xgettext:c-format */
16568 }
16570 }
16572 /* Dynamic relocs are not propagated for SEC_DEBUGGING sections
16573 because such sections are not SEC_ALLOC and thus ld.so will
16574 not process them. */
16581 {
16583 /* xgettext:c-format */
16589 }
16591 /* 16-bit fields in insns mostly have signed values, but a
16592 few insns have 16-bit unsigned values. Really, we should
16593 have different reloc types. */
16597 {
16612 {
16616 }
16617 }
16620 {
16621 /* Split field relocs aren't handled by _bfd_final_link_relocate. */
16640 else
16641 {
16663 }
16669 else
16670 {
16683 }
16690 }
16693 {
16698 {
16701 {
16706 }
16707 }
16710 {
16711 /* On code like "if (foo) foo();" don't report overflow
16712 on a branch to zero when foo is undefined. */
16724 }
16725 else
16726 {
16728 /* xgettext:c-format */
16733 }
16736 }
16737 copy_reloc:
16740 }
16743 {
16750 {
16751 /* It is too late to remove an empty reloc section. Leave
16752 one NONE reloc.
16753 ??? What is wrong with an empty section??? */
16756 }
16760 }
16762 /* If we're emitting relocations, then shortly after this function
16763 returns, reloc offsets and addends for this section will be
16764 adjusted. Worse, reloc symbol indices will be for the output
16765 file rather than the input. Save a copy of the relocs for
16766 opd_entry_value. */
16768 {
16769 bfd_size_type amt;
16777 }
16779 }
16781 /* Adjust the value of any local symbols in opd sections. */
16783 static int
16789 {
16792 bfd_vma value;
16811 }
16813 /* Finish up dynamic symbol handling. We set the contents of various
16814 dynamic sections here. */
16816 static bfd_boolean
16821 {
16832 {
16833 /* Mark the symbol as undefined, rather than as
16834 defined in glink. Leave the value if there were
16835 any relocations where pointer equality matters
16836 (this is a clue for the dynamic linker, to make
16837 function pointer comparisons work between an
16838 application and shared library), otherwise set it
16839 to zero. */
16844 {
16845 /* This breaks function pointer comparisons, but
16846 that is better than breaking tests for a NULL
16847 function pointer. */
16849 }
16851 }
16858 {
16859 /* This symbol needs a copy reloc. Set it up. */
16860 Elf_Internal_Rela rela;
16874 else
16879 }
16882 }
16884 /* Used to decide how to sort relocs in an optimal manner for the
16885 dynamic linker, before writing them out. */
16887 static enum elf_reloc_type_class
16891 {
16900 {
16909 }
16910 }
16912 /* Finish up the dynamic sections. */
16914 static bfd_boolean
16917 {
16930 {
16939 {
16940 Elf_Internal_Dyn dyn;
16946 {
16953 /* We stupidly defined DT_PPC64_GLINK to be the start
16954 of glink rather than the first entry point, which is
16955 what ld.so needs, and now have a bigger stub to
16956 support automatic multiple TOCs. */
17006 }
17009 }
17010 }
17014 {
17015 /* Fill in the first entry in the global offset table.
17016 We use it to hold the link-time TOCbase. */
17021 /* Set .got entry size. */
17024 }
17028 {
17029 /* Set .plt entry size. */
17032 }
17034 /* brlt is SEC_LINKER_CREATED, so we need to write out relocs for
17035 brlt ourselves if emitrelocations. */
17042 NULL))
17051 NULL))
17063 /* We need to handle writing out multiple GOT sections ourselves,
17064 since we didn't add them to DYNOBJ. We know dynobj is the first
17065 bfd. */
17067 {
17089 }
17092 }
17096 /* FreeBSD support */
17098 #undef TARGET_LITTLE_SYM
17099 #undef TARGET_LITTLE_NAME
17101 #undef TARGET_BIG_SYM
17102 #define TARGET_BIG_SYM powerpc_elf64_fbsd_vec
17103 #undef TARGET_BIG_NAME
17106 #undef ELF_OSABI
17107 #define ELF_OSABI ELFOSABI_FREEBSD
17109 #undef elf64_bed
17110 #define elf64_bed elf64_powerpc_fbsd_bed