X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=bfd%2Felfxx-x86.h;h=57d6d6e4087b39ecb0bcac8ba73d5dd0c2eac7f8;hb=539300fb929ada830ec7c4002fd59f0d86c823b1;hp=17aa10cd5606b4ac916046af851867c096cbeb1a;hpb=f47432d4b99a453f9107b7fd5e173384f983e679;p=deliverable%2Fbinutils-gdb.git diff --git a/bfd/elfxx-x86.h b/bfd/elfxx-x86.h index 17aa10cd56..57d6d6e408 100644 --- a/bfd/elfxx-x86.h +++ b/bfd/elfxx-x86.h @@ -1,5 +1,5 @@ /* x86 specific support for ELF - Copyright (C) 2017 Free Software Foundation, Inc. + Copyright (C) 2017-2019 Free Software Foundation, Inc. This file is part of BFD, the Binary File Descriptor library. @@ -23,8 +23,8 @@ #include "bfdlink.h" #include "libbfd.h" #include "elf-bfd.h" -#include "bfd_stdint.h" #include "hashtab.h" +#include "elf-linker-x86.h" #define PLT_CIE_LENGTH 20 #define PLT_FDE_LENGTH 36 @@ -49,19 +49,15 @@ #define SYMBOL_REFERENCES_LOCAL_P(INFO, H) \ _bfd_x86_elf_link_symbol_references_local ((INFO), (H)) -/* Is a undefined weak symbol which is resolved to 0. Reference to an - undefined weak symbol is resolved to 0 when building executable if - it isn't dynamic and - 1. Has non-GOT/non-PLT relocations in text section. Or - 2. Has no GOT/PLT relocation. - Local undefined weak symbol is always resolved to 0. - */ +/* TRUE if an undefined weak symbol should be resolved to 0. Local + undefined weak symbol is always resolved to 0. Reference to an + undefined weak symbol is resolved to 0 in executable if undefined + weak symbol should be resolved to 0 (zero_undefweak > 0). */ #define UNDEFINED_WEAK_RESOLVED_TO_ZERO(INFO, EH) \ ((EH)->elf.root.type == bfd_link_hash_undefweak \ && (SYMBOL_REFERENCES_LOCAL_P ((INFO), &(EH)->elf) \ || (bfd_link_executable (INFO) \ - && (!(EH)->has_got_reloc \ - || (EH)->has_non_got_reloc)))) + && (EH)->zero_undefweak > 0))) /* Should copy relocation be generated for a symbol. Don't generate copy relocation against a protected symbol defined in a shared @@ -74,6 +70,168 @@ && ((EH)->elf.root.u.def.section->owner->flags & DYNAMIC) != 0 \ && ((EH)->elf.root.u.def.section->flags & SEC_CODE) == 0) +/* TRUE if dynamic relocation is needed. If we are creating a shared + library, and this is a reloc against a global symbol, or a non PC + relative reloc against a local symbol, then we need to copy the reloc + into the shared library. However, if we are linking with -Bsymbolic, + we do not need to copy a reloc against a global symbol which is + defined in an object we are including in the link (i.e., DEF_REGULAR + is set). + + If PCREL_PLT is true, don't generate dynamic relocation in PIE for + PC-relative relocation against a dynamic function definition in data + section when PLT address can be used. + + If on the other hand, we are creating an executable, we may need to + keep relocations for symbols satisfied by a dynamic library if we + manage to avoid copy relocs for the symbol. + + We also need to generate dynamic pointer relocation against + STT_GNU_IFUNC symbol in the non-code section. */ +#define NEED_DYNAMIC_RELOCATION_P(INFO, PCREL_PLT, H, SEC, R_TYPE, \ + POINTER_TYPE) \ + ((bfd_link_pic (INFO) \ + && (! X86_PCREL_TYPE_P (R_TYPE) \ + || ((H) != NULL \ + && (! (bfd_link_pie (INFO) \ + || SYMBOLIC_BIND ((INFO), (H))) \ + || (H)->root.type == bfd_link_hash_defweak \ + || (!(bfd_link_pie (INFO) \ + && (PCREL_PLT) \ + && (H)->plt.refcount > 0 \ + && ((SEC)->flags & SEC_CODE) == 0 \ + && (H)->type == STT_FUNC \ + && (H)->def_dynamic) \ + && !(H)->def_regular))))) \ + || ((H) != NULL \ + && (H)->type == STT_GNU_IFUNC \ + && (R_TYPE) == POINTER_TYPE \ + && ((SEC)->flags & SEC_CODE) == 0) \ + || (ELIMINATE_COPY_RELOCS \ + && !bfd_link_pic (INFO) \ + && (H) != NULL \ + && ((H)->root.type == bfd_link_hash_defweak \ + || !(H)->def_regular))) + +/* TRUE if dynamic relocation should be generated. Don't copy a + pc-relative relocation into the output file if the symbol needs + copy reloc or the symbol is undefined when building executable. + Copy dynamic function pointer relocations. Don't generate dynamic + relocations against resolved undefined weak symbols in PIE, except + when PC32_RELOC is TRUE. Undefined weak symbol is bound locally + when PIC is false. */ +#define GENERATE_DYNAMIC_RELOCATION_P(INFO, EH, R_TYPE, \ + NEED_COPY_RELOC_IN_PIE, \ + RESOLVED_TO_ZERO, PC32_RELOC) \ + ((bfd_link_pic (INFO) \ + && !(NEED_COPY_RELOC_IN_PIE) \ + && ((EH) == NULL \ + || ((ELF_ST_VISIBILITY ((EH)->elf.other) == STV_DEFAULT \ + && (!(RESOLVED_TO_ZERO) || PC32_RELOC)) \ + || (EH)->elf.root.type != bfd_link_hash_undefweak)) \ + && ((!X86_PCREL_TYPE_P (R_TYPE) \ + && !X86_SIZE_TYPE_P (R_TYPE)) \ + || ! SYMBOL_CALLS_LOCAL ((INFO), &(EH)->elf))) \ + || (ELIMINATE_COPY_RELOCS \ + && !bfd_link_pic (INFO) \ + && (EH) != NULL \ + && (EH)->elf.dynindx != -1 \ + && (!(EH)->elf.non_got_ref \ + || ((EH)->elf.root.type == bfd_link_hash_undefweak \ + && !(RESOLVED_TO_ZERO))) \ + && (((EH)->elf.def_dynamic && !(EH)->elf.def_regular) \ + || (EH)->elf.root.type == bfd_link_hash_undefined))) + +/* TRUE if this input relocation should be copied to output. H->dynindx + may be -1 if this symbol was marked to become local. */ +#define COPY_INPUT_RELOC_P(INFO, H, R_TYPE) \ + ((H) != NULL \ + && (H)->dynindx != -1 \ + && (X86_PCREL_TYPE_P (R_TYPE) \ + || !(bfd_link_executable (INFO) || SYMBOLIC_BIND ((INFO), (H))) \ + || !(H)->def_regular)) + +/* TRUE if this is actually a static link, or it is a -Bsymbolic link + and the symbol is defined locally, or the symbol was forced to be + local because of a version file. */ +#define RESOLVED_LOCALLY_P(INFO, H, HTAB) \ + (!WILL_CALL_FINISH_DYNAMIC_SYMBOL ((HTAB)->elf.dynamic_sections_created, \ + bfd_link_pic (INFO), (H)) \ + || (bfd_link_pic (INFO) \ + && SYMBOL_REFERENCES_LOCAL_P ((INFO), (H))) \ + || (ELF_ST_VISIBILITY ((H)->other) \ + && (H)->root.type == bfd_link_hash_undefweak)) + +/* TRUE if this symbol isn't defined by a shared object. */ +#define SYMBOL_DEFINED_NON_SHARED_P(H) \ + ((H)->def_regular \ + || (H)->root.linker_def \ + || (H)->root.ldscript_def \ + || ((struct elf_x86_link_hash_entry *) (H))->linker_def \ + || ELF_COMMON_DEF_P (H)) + +/* TRUE if relative relocation should be generated. GOT reference to + global symbol in PIC will lead to dynamic symbol. It becomes a + problem when "time" or "times" is defined as a variable in an + executable, clashing with functions of the same name in libc. If a + symbol isn't undefined weak symbol, don't make it dynamic in PIC and + generate relative relocation. */ +#define GENERATE_RELATIVE_RELOC_P(INFO, H) \ + ((H)->dynindx == -1 \ + && !(H)->forced_local \ + && (H)->root.type != bfd_link_hash_undefweak \ + && bfd_link_pic (INFO)) + +/* TRUE if this is a pointer reference to a local IFUNC. */ +#define POINTER_LOCAL_IFUNC_P(INFO, H) \ + ((H)->dynindx == -1 \ + || (H)->forced_local \ + || bfd_link_executable (INFO)) + +/* TRUE if this is a PLT reference to a local IFUNC. */ +#define PLT_LOCAL_IFUNC_P(INFO, H) \ + ((H)->dynindx == -1 \ + || ((bfd_link_executable (INFO) \ + || ELF_ST_VISIBILITY ((H)->other) != STV_DEFAULT) \ + && (H)->def_regular \ + && (H)->type == STT_GNU_IFUNC)) + +/* TRUE if TLS IE->LE transition is OK. */ +#define TLS_TRANSITION_IE_TO_LE_P(INFO, H, TLS_TYPE) \ + (bfd_link_executable (INFO) \ + && (H) != NULL \ + && (H)->dynindx == -1 \ + && (TLS_TYPE & GOT_TLS_IE)) + +/* Verify that the symbol has an entry in the procedure linkage table. */ +#define VERIFY_PLT_ENTRY(INFO, H, PLT, GOTPLT, RELPLT, LOCAL_UNDEFWEAK) \ + do \ + { \ + if (((H)->dynindx == -1 \ + && !LOCAL_UNDEFWEAK \ + && !(((H)->forced_local || bfd_link_executable (INFO)) \ + && (H)->def_regular \ + && (H)->type == STT_GNU_IFUNC)) \ + || (PLT) == NULL \ + || (GOTPLT) == NULL \ + || (RELPLT) == NULL) \ + abort (); \ + } \ + while (0); + +/* Verify that the symbol supports copy relocation. */ +#define VERIFY_COPY_RELOC(H, HTAB) \ + do \ + { \ + if ((H)->dynindx == -1 \ + || ((H)->root.type != bfd_link_hash_defined \ + && (H)->root.type != bfd_link_hash_defweak) \ + || (HTAB)->elf.srelbss == NULL \ + || (HTAB)->elf.sreldynrelro == NULL) \ + abort (); \ + } \ + while (0); + /* x86 ELF linker hash entry. */ struct elf_x86_link_hash_entry @@ -85,11 +243,11 @@ struct elf_x86_link_hash_entry unsigned char tls_type; - /* TRUE if symbol has GOT or PLT relocations. */ - unsigned int has_got_reloc : 1; - - /* TRUE if symbol has non-GOT/non-PLT relocations in text sections. */ - unsigned int has_non_got_reloc : 1; + /* Bit 0: Symbol has no GOT nor PLT relocations. + Bit 1: Symbol has non-GOT/non-PLT relocations in text sections. + zero_undefweak is initialized to 1 and undefined weak symbol + should be resolved to 0 if zero_undefweak > 0. */ + unsigned int zero_undefweak : 2; /* Don't call finish_dynamic_symbol on this symbol. */ unsigned int no_finish_dynamic_symbol : 1; @@ -121,10 +279,6 @@ struct elf_x86_link_hash_entry is only used by x86-64. */ unsigned int needs_copy : 1; - /* Reference count of C/C++ function pointer relocations in read-write - section which can be resolved at run-time. */ - bfd_signed_vma func_pointer_refcount; - /* Information about the GOT PLT entry. Filled when there are both GOT and PLT relocations against the same function. */ union gotplt_union plt_got; @@ -139,15 +293,29 @@ struct elf_x86_link_hash_entry struct elf_x86_lazy_plt_layout { - /* The first entry in an absolute lazy procedure linkage table looks - like this. */ + /* The first entry in a lazy procedure linkage table looks like this. */ const bfd_byte *plt0_entry; - unsigned int plt0_entry_size; /* Size of PLT0 entry. */ + unsigned int plt0_entry_size; /* Size of PLT0 entry. */ - /* Later entries in an absolute lazy procedure linkage table look - like this. */ + /* Later entries in a lazy procedure linkage table look like this. */ const bfd_byte *plt_entry; - unsigned int plt_entry_size; /* Size of each PLT entry. */ + unsigned int plt_entry_size; /* Size of each PLT entry. */ + + /* The TLSDESC entry in a lazy procedure linkage table looks like + this. This is for x86-64 only. */ + const bfd_byte *plt_tlsdesc_entry; + unsigned int plt_tlsdesc_entry_size; /* Size of TLSDESC entry. */ + + /* Offsets into the TLSDESC entry that are to be replaced with + GOT+8 and GOT+TDG. These are for x86-64 only. */ + unsigned int plt_tlsdesc_got1_offset; + unsigned int plt_tlsdesc_got2_offset; + + /* Offset of the end of the PC-relative instructions containing + plt_tlsdesc_got1_offset and plt_tlsdesc_got2_offset. These + are for x86-64 only. */ + unsigned int plt_tlsdesc_got1_insn_end; + unsigned int plt_tlsdesc_got2_insn_end; /* Offsets into plt0_entry that are to be replaced with GOT[1] and GOT[2]. */ @@ -190,13 +358,14 @@ struct elf_x86_lazy_plt_layout struct elf_x86_non_lazy_plt_layout { - /* Entries in an absolute non-lazy procedure linkage table look like - this. */ + /* Entries in a non-lazy procedure linkage table look like this. */ const bfd_byte *plt_entry; - /* Entries in a PIC non-lazy procedure linkage table look like this. */ + /* Entries in a PIC non-lazy procedure linkage table look like this. + This is only used for i386 where absolute PLT and PIC PLT are + different. */ const bfd_byte *pic_plt_entry; - unsigned int plt_entry_size; /* Size of each PLT entry. */ + unsigned int plt_entry_size; /* Size of each PLT entry. */ /* Offsets into plt_entry that are to be replaced with... */ unsigned int plt_got_offset; /* ... address of this symbol in .got. */ @@ -212,13 +381,11 @@ struct elf_x86_non_lazy_plt_layout struct elf_x86_plt_layout { - /* The first entry in a lazy procedure linkage table looks like this. - This is only used for i386 where absolute PLT0 and PIC PLT0 are - different. */ + /* The first entry in a lazy procedure linkage table looks like this. */ const bfd_byte *plt0_entry; /* Entries in a procedure linkage table look like this. */ const bfd_byte *plt_entry; - unsigned int plt_entry_size; /* Size of each PLT entry. */ + unsigned int plt_entry_size; /* Size of each PLT entry. */ /* 1 has PLT0. */ unsigned int has_plt0; @@ -230,6 +397,9 @@ struct elf_x86_plt_layout This is only used for x86-64. */ unsigned int plt_got_insn_size; + /* Alignment of the .iplt section. */ + unsigned int iplt_alignment; + /* .eh_frame covering the .plt section. */ const bfd_byte *eh_frame_plt; unsigned int eh_frame_plt_size; @@ -256,6 +426,14 @@ struct elf_x86_plt_layout #define elf_x86_hash_entry(ent) \ ((struct elf_x86_link_hash_entry *)(ent)) +enum elf_x86_target_os +{ + is_normal, + is_solaris, + is_vxworks, + is_nacl +}; + /* x86 ELF linker hash table. */ struct elf_x86_link_hash_table @@ -311,10 +489,6 @@ struct elf_x86_link_hash_table to read-only sections. */ bfd_boolean readonly_dynrelocs_against_ifunc; - /* TRUE if this is a VxWorks x86 target. This is only used for - i386. */ - bfd_boolean is_vxworks; - /* The (unloaded but important) .rel.plt.unloaded section on VxWorks. This is used for i386 only. */ asection *srelplt2; @@ -329,10 +503,26 @@ struct elf_x86_link_hash_table yet. This is only used for x86-64. */ bfd_vma tlsdesc_plt; + /* Value used to fill the unused bytes of the first PLT entry. This + is only used for i386. */ + bfd_byte plt0_pad_byte; + + /* TRUE if GOT is referenced. */ + unsigned int got_referenced : 1; + + /* TRUE if PLT is PC-relative. PLT in PDE and PC-relative PLT in PIE + can be used as function address. + + NB: i386 has non-PIC PLT and PIC PLT. Only non-PIC PLT in PDE can + be used as function address. PIC PLT in PIE can't be used as + function address. */ + unsigned int pcrel_plt : 1; + bfd_vma (*r_info) (bfd_vma, bfd_vma); bfd_vma (*r_sym) (bfd_vma); bfd_boolean (*is_reloc_section) (const char *); enum elf_target_id target_id; + enum elf_x86_target_os target_os; unsigned int sizeof_reloc; unsigned int dt_reloc; unsigned int dt_reloc_sz; @@ -342,8 +532,23 @@ struct elf_x86_link_hash_table int dynamic_interpreter_size; const char *dynamic_interpreter; const char *tls_get_addr; + + /* Options passed from the linker. */ + struct elf_linker_x86_params *params; +}; + +/* Architecture-specific backend data for x86. */ + +struct elf_x86_backend_data +{ + /* Target system. */ + enum elf_x86_target_os target_os; }; +#define get_elf_x86_backend_data(abfd) \ + ((const struct elf_x86_backend_data *) \ + get_elf_backend_data (abfd)->arch_data) + struct elf_x86_init_table { /* The lazy PLT layout. */ @@ -358,11 +563,7 @@ struct elf_x86_init_table /* The non-lazy PLT layout for IBT. */ const struct elf_x86_non_lazy_plt_layout *non_lazy_ibt_plt; - /* TRUE if this is a normal x86 target. */ - bfd_boolean normal_target; - - /* TRUE if this is a VxWorks x86 target. */ - bfd_boolean is_vxworks; + bfd_byte plt0_pad_byte; bfd_vma (*r_info) (bfd_vma, bfd_vma); bfd_vma (*r_sym) (bfd_vma); @@ -454,6 +655,9 @@ extern bfd_boolean _bfd_x86_elf_link_check_relocs extern bfd_boolean _bfd_x86_elf_size_dynamic_sections (bfd *, struct bfd_link_info *); +extern struct elf_x86_link_hash_table *_bfd_x86_elf_finish_dynamic_sections + (bfd *, struct bfd_link_info *); + extern bfd_boolean _bfd_x86_elf_always_size_sections (bfd *, struct bfd_link_info *); @@ -474,6 +678,9 @@ extern bfd_boolean _bfd_x86_elf_hash_symbol extern bfd_boolean _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *, struct elf_link_hash_entry *); +extern void _bfd_x86_elf_hide_symbol + (struct bfd_link_info *, struct elf_link_hash_entry *, bfd_boolean); + extern bfd_boolean _bfd_x86_elf_link_symbol_references_local (struct bfd_link_info *, struct elf_link_hash_entry *); @@ -489,11 +696,18 @@ extern enum elf_property_kind _bfd_x86_elf_parse_gnu_properties (bfd *, unsigned int, bfd_byte *, unsigned int); extern bfd_boolean _bfd_x86_elf_merge_gnu_properties - (struct bfd_link_info *, bfd *, elf_property *, elf_property *); + (struct bfd_link_info *, bfd *, bfd *, elf_property *, elf_property *); + +extern void _bfd_x86_elf_link_fixup_gnu_properties + (struct bfd_link_info *, elf_property_list **); extern bfd * _bfd_x86_elf_link_setup_gnu_properties (struct bfd_link_info *, struct elf_x86_init_table *); +extern void _bfd_x86_elf_link_fixup_ifunc_symbol + (struct bfd_link_info *, struct elf_x86_link_hash_table *, + struct elf_link_hash_entry *, Elf_Internal_Sym *sym); + #define bfd_elf64_mkobject \ _bfd_x86_elf_mkobject #define bfd_elf32_mkobject \ @@ -524,8 +738,10 @@ extern bfd * _bfd_x86_elf_link_setup_gnu_properties #define elf_backend_gc_mark_hook \ _bfd_x86_elf_gc_mark_hook #define elf_backend_omit_section_dynsym \ - ((bfd_boolean (*) (bfd *, struct bfd_link_info *, asection *)) bfd_true) + _bfd_elf_omit_section_dynsym_all #define elf_backend_parse_gnu_properties \ _bfd_x86_elf_parse_gnu_properties #define elf_backend_merge_gnu_properties \ _bfd_x86_elf_merge_gnu_properties +#define elf_backend_fixup_gnu_properties \ + _bfd_x86_elf_link_fixup_gnu_properties