diff options
Diffstat (limited to 'bfd/elfxx-sparc.c')
| -rw-r--r-- | bfd/elfxx-sparc.c | 214 |
1 files changed, 186 insertions, 28 deletions
diff --git a/bfd/elfxx-sparc.c b/bfd/elfxx-sparc.c index 80fda1b..c978aad 100644 --- a/bfd/elfxx-sparc.c +++ b/bfd/elfxx-sparc.c @@ -683,6 +683,20 @@ struct _bfd_sparc_elf_dyn_relocs bfd_size_type pc_count; }; +/* Is an undefined weak symbol resolved to 0 ? + Reference to an undefined weak symbol is resolved to 0 when + building an executable if it isn't dynamic and + 1. Has non-GOT/non-PLT relocations in text section. + Or + 2. Has no GOT/PLT relocation. */ +#define UNDEFINED_WEAK_RESOLVED_TO_ZERO(INFO, EH) \ + ((EH)->elf.root.type == bfd_link_hash_undefweak \ + && bfd_link_executable (INFO) \ + && (_bfd_sparc_elf_hash_table (INFO)->interp == NULL \ + || !(EH)->has_got_reloc \ + || (EH)->has_non_got_reloc \ + || !(INFO)->dynamic_undefined_weak)) + /* SPARC ELF linker hash entry. */ struct _bfd_sparc_elf_link_hash_entry @@ -697,6 +711,13 @@ struct _bfd_sparc_elf_link_hash_entry #define GOT_TLS_GD 2 #define GOT_TLS_IE 3 unsigned char tls_type; + + /* Symbol has GOT or PLT relocations. */ + unsigned int has_got_reloc : 1; + + /* Symbol has non-GOT/non-PLT relocations in text sections. */ + unsigned int has_non_got_reloc : 1; + }; #define _bfd_sparc_elf_hash_entry(ent) ((struct _bfd_sparc_elf_link_hash_entry *)(ent)) @@ -1018,6 +1039,8 @@ link_hash_newfunc (struct bfd_hash_entry *entry, eh = (struct _bfd_sparc_elf_link_hash_entry *) entry; eh->dyn_relocs = NULL; eh->tls_type = GOT_UNKNOWN; + eh->has_got_reloc = 0; + eh->has_non_got_reloc = 0; } return entry; @@ -1313,6 +1336,11 @@ _bfd_sparc_elf_copy_indirect_symbol (struct bfd_link_info *info, edir->tls_type = eind->tls_type; eind->tls_type = GOT_UNKNOWN; } + + /* Copy has_got_reloc and has_non_got_reloc. */ + edir->has_got_reloc |= eind->has_got_reloc; + edir->has_non_got_reloc |= eind->has_non_got_reloc; + _bfd_elf_link_hash_copy_indirect (info, dir, ind); } @@ -1400,6 +1428,7 @@ _bfd_sparc_elf_check_relocs (bfd *abfd, struct bfd_link_info *info, unsigned int r_type; unsigned long r_symndx; struct elf_link_hash_entry *h; + struct _bfd_sparc_elf_link_hash_entry *eh; Elf_Internal_Sym *isym; r_symndx = SPARC_ELF_R_SYMNDX (htab, rel->r_info); @@ -1487,11 +1516,15 @@ _bfd_sparc_elf_check_relocs (bfd *abfd, struct bfd_link_info *info, } r_type = sparc_elf_tls_transition (info, abfd, r_type, h == NULL); + eh = (struct _bfd_sparc_elf_link_hash_entry *) h; + switch (r_type) { case R_SPARC_TLS_LDM_HI22: case R_SPARC_TLS_LDM_LO10: htab->tls_ldm_got.refcount += 1; + if (eh != NULL) + eh->has_got_reloc = 1; break; case R_SPARC_TLS_LE_HIX22: @@ -1609,6 +1642,9 @@ _bfd_sparc_elf_check_relocs (bfd *abfd, struct bfd_link_info *info, if (!_bfd_elf_create_got_section (htab->elf.dynobj, info)) return FALSE; } + + if (eh != NULL) + eh->has_got_reloc = 1; break; case R_SPARC_TLS_GD_CALL: @@ -1677,6 +1713,9 @@ _bfd_sparc_elf_check_relocs (bfd *abfd, struct bfd_link_info *info, goto r_sparc_plt32; } h->plt.refcount += 1; + + eh = (struct _bfd_sparc_elf_link_hash_entry *) h; + eh->has_got_reloc = 1; break; case R_SPARC_PC10: @@ -1730,6 +1769,9 @@ _bfd_sparc_elf_check_relocs (bfd *abfd, struct bfd_link_info *info, if (h != NULL) h->non_got_ref = 1; + if (eh != NULL && (sec->flags & SEC_CODE) != 0) + eh->has_non_got_reloc = 1; + r_sparc_plt32: if (h != NULL && !bfd_link_pic (info)) { @@ -2073,6 +2115,24 @@ _bfd_sparc_elf_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info, return TRUE; } +/* Remove undefined weak symbol from the dynamic symbol table if it + is resolved to 0. */ + +bfd_boolean +_bfd_sparc_elf_fixup_symbol (struct bfd_link_info *info, + struct elf_link_hash_entry *h) +{ + if (h->dynindx != -1 + && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, + _bfd_sparc_elf_hash_entry (h))) + { + h->dynindx = -1; + _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr, + h->dynstr_index); + } + return TRUE; +} + /* Adjust a symbol defined by a dynamic object and referenced by a regular object. The current definition is in some section of the dynamic object, but we're not including those sections. We have to @@ -2228,6 +2288,7 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) struct _bfd_sparc_elf_link_hash_table *htab; struct _bfd_sparc_elf_link_hash_entry *eh; struct _bfd_sparc_elf_dyn_relocs *p; + bfd_boolean resolved_to_zero; if (h->root.type == bfd_link_hash_indirect) return TRUE; @@ -2236,6 +2297,9 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) htab = _bfd_sparc_elf_hash_table (info); BFD_ASSERT (htab != NULL); + eh = (struct _bfd_sparc_elf_link_hash_entry *) h; + resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh); + if ((htab->elf.dynamic_sections_created && h->plt.refcount > 0) || (h->type == STT_GNU_IFUNC @@ -2245,7 +2309,8 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) /* Make sure this symbol is output as a dynamic symbol. Undefined weak syms won't yet be marked as dynamic. */ if (h->dynindx == -1 - && !h->forced_local) + && !h->forced_local + && !resolved_to_zero) { if (! bfd_elf_link_record_dynamic_symbol (info, h)) return FALSE; @@ -2307,11 +2372,16 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) /* Make room for this entry. */ s->size += htab->plt_entry_size; - /* We also need to make an entry in the .rela.plt section. */ - if (s == htab->elf.splt) - htab->elf.srelplt->size += SPARC_ELF_RELA_BYTES (htab); - else - htab->elf.irelplt->size += SPARC_ELF_RELA_BYTES (htab); + /* There should be no PLT relocations against resolved undefined + weak symbols in the executable. */ + if (!resolved_to_zero) + { + /* We also need to make an entry in the .rela.plt section. */ + if (s == htab->elf.splt) + htab->elf.srelplt->size += SPARC_ELF_RELA_BYTES (htab); + else + htab->elf.irelplt->size += SPARC_ELF_RELA_BYTES (htab); + } if (htab->is_vxworks) { @@ -2351,7 +2421,8 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) /* Make sure this symbol is output as a dynamic symbol. Undefined weak syms won't yet be marked as dynamic. */ if (h->dynindx == -1 - && !h->forced_local) + && !h->forced_local + && !resolved_to_zero) { if (! bfd_elf_link_record_dynamic_symbol (info, h)) return FALSE; @@ -2366,22 +2437,25 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) dyn = htab->elf.dynamic_sections_created; /* R_SPARC_TLS_IE_{HI22,LO10} needs one dynamic relocation, R_SPARC_TLS_GD_{HI22,LO10} needs one if local symbol and two if - global. */ + global. No dynamic relocations are needed against resolved + undefined weak symbols in an executable. */ if ((tls_type == GOT_TLS_GD && h->dynindx == -1) || tls_type == GOT_TLS_IE || h->type == STT_GNU_IFUNC) htab->elf.srelgot->size += SPARC_ELF_RELA_BYTES (htab); else if (tls_type == GOT_TLS_GD) htab->elf.srelgot->size += 2 * SPARC_ELF_RELA_BYTES (htab); - else if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, - bfd_link_pic (info), - h)) + else if (((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT + && !resolved_to_zero) + || h->root.type != bfd_link_hash_undefweak) + && WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, + bfd_link_pic (info), + h)) htab->elf.srelgot->size += SPARC_ELF_RELA_BYTES (htab); } else h->got.offset = (bfd_vma) -1; - eh = (struct _bfd_sparc_elf_link_hash_entry *) h; if (eh->dyn_relocs == NULL) return TRUE; @@ -2422,12 +2496,44 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) } /* Also discard relocs on undefined weak syms with non-default - visibility. */ + visibility or in PIE. */ if (eh->dyn_relocs != NULL && h->root.type == bfd_link_hash_undefweak) { - if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT) - eh->dyn_relocs = NULL; + /* An undefined weak symbol is never + bound locally in a shared library. */ + + if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT + || resolved_to_zero) + { + if (h->non_got_ref) + { + /* Keep dynamic non-GOT/non-PLT relocation so that we + can branch to 0 without PLT. */ + struct _bfd_sparc_elf_dyn_relocs **pp; + + for (pp = &eh->dyn_relocs; (p = *pp) != NULL;) + if (p->pc_count == 0) + *pp = p->next; + else + { + /* Remove other relocations. */ + p->count = p->pc_count; + pp = &p->next; + } + + if (eh->dyn_relocs != NULL) + { + /* Make sure undefined weak symbols are output + as dynamic symbols in PIEs for dynamic non-GOT + non-PLT reloations. */ + if (! bfd_elf_link_record_dynamic_symbol (info, h)) + return FALSE; + } + } + else + eh->dyn_relocs = NULL; + } /* Make sure undefined weak symbols are output as a dynamic symbol in PIEs. */ @@ -2445,7 +2551,9 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) symbols which turn out to need copy relocs or are not dynamic. */ - if (!h->non_got_ref + if ((!h->non_got_ref + || (h->root.type == bfd_link_hash_undefweak + && !resolved_to_zero)) && ((h->def_dynamic && !h->def_regular) || (htab->elf.dynamic_sections_created @@ -2455,7 +2563,8 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) /* Make sure this symbol is output as a dynamic symbol. Undefined weak syms won't yet be marked as dynamic. */ if (h->dynindx == -1 - && !h->forced_local) + && !h->forced_local + && !resolved_to_zero) { if (! bfd_elf_link_record_dynamic_symbol (info, h)) return FALSE; @@ -2564,12 +2673,13 @@ _bfd_sparc_elf_size_dynamic_sections (bfd *output_bfd, { /* Set the contents of the .interp section to the interpreter. */ if (bfd_link_executable (info) && !info->nointerp) - { - s = bfd_get_linker_section (dynobj, ".interp"); - BFD_ASSERT (s != NULL); - s->size = htab->dynamic_interpreter_size; - s->contents = (unsigned char *) htab->dynamic_interpreter; - } + { + s = bfd_get_linker_section (dynobj, ".interp"); + BFD_ASSERT (s != NULL); + s->size = htab->dynamic_interpreter_size; + s->contents = (unsigned char *) htab->dynamic_interpreter; + htab->interp = s; + } } /* Set up .got offsets for local syms, and space for local dynamic @@ -3007,12 +3117,14 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd, reloc_howto_type *howto; unsigned long r_symndx; struct elf_link_hash_entry *h; + struct _bfd_sparc_elf_link_hash_entry *eh; Elf_Internal_Sym *sym; asection *sec; bfd_vma relocation, off; bfd_reloc_status_type r; bfd_boolean is_plt = FALSE; bfd_boolean unresolved_reloc; + bfd_boolean resolved_to_zero; r_type = SPARC_ELF_R_TYPE (rel->r_info); if (r_type == R_SPARC_GNU_VTINHERIT @@ -3191,6 +3303,10 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd, } } + eh = (struct _bfd_sparc_elf_link_hash_entry *) h; + resolved_to_zero = (eh != NULL + && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh)); + switch (r_type) { case R_SPARC_GOTDATA_OP_HIX22: @@ -3419,10 +3535,14 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd, || is_vxworks_tls) break; + /* Copy dynamic function pointer relocations. Don't generate + dynamic relocations against resolved undefined weak symbols + in PIE. */ if ((bfd_link_pic (info) && (h == NULL - || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT - || h->root.type != bfd_link_hash_undefweak) + || ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT + && !resolved_to_zero) + || h->root.type != bfd_link_hash_undefweak)) && (! howto->pc_relative || !SYMBOL_CALLS_LOCAL (info, h))) || (!bfd_link_pic (info) @@ -3431,7 +3551,8 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd, && !h->non_got_ref && ((h->def_dynamic && !h->def_regular) - || h->root.type == bfd_link_hash_undefweak + || (h->root.type == bfd_link_hash_undefweak + && !resolved_to_zero) || h->root.type == bfd_link_hash_undefined))) { Elf_Internal_Rela outrel; @@ -4352,11 +4473,20 @@ _bfd_sparc_elf_finish_dynamic_symbol (bfd *output_bfd, { struct _bfd_sparc_elf_link_hash_table *htab; const struct elf_backend_data *bed; + struct _bfd_sparc_elf_link_hash_entry *eh; + bfd_boolean local_undefweak; htab = _bfd_sparc_elf_hash_table (info); BFD_ASSERT (htab != NULL); bed = get_elf_backend_data (output_bfd); + eh = (struct _bfd_sparc_elf_link_hash_entry *) h; + + /* We keep PLT/GOT entries without dynamic PLT/GOT relocations for + resolved undefined weak symbols in executable so that their + references have value 0 at run-time. */ + local_undefweak = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh); + if (h->plt.offset != (bfd_vma) -1) { asection *splt; @@ -4480,7 +4610,8 @@ _bfd_sparc_elf_finish_dynamic_symbol (bfd *output_bfd, loc += rela_index * bed->s->sizeof_rela; bed->s->swap_reloca_out (output_bfd, &rela, loc); - if (!h->def_regular) + if (!local_undefweak + && !h->def_regular) { /* Mark the symbol as undefined, rather than as defined in the .plt section. Leave the value alone. */ @@ -4494,9 +4625,12 @@ _bfd_sparc_elf_finish_dynamic_symbol (bfd *output_bfd, } } + /* Don't generate dynamic GOT relocation against undefined weak + symbol in executable. */ if (h->got.offset != (bfd_vma) -1 && _bfd_sparc_elf_hash_entry(h)->tls_type != GOT_TLS_GD - && _bfd_sparc_elf_hash_entry(h)->tls_type != GOT_TLS_IE) + && _bfd_sparc_elf_hash_entry(h)->tls_type != GOT_TLS_IE + && !local_undefweak) { asection *sgot; asection *srela; @@ -4787,6 +4921,25 @@ finish_local_dynamic_symbol (void **slot, void *inf) h, NULL); } +/* Finish up undefined weak symbol handling in PIE. Fill its PLT entry + here since undefined weak symbol may not be dynamic and may not be + called for _bfd_sparc_elf_finish_dynamic_symbol. */ + +static bfd_boolean +pie_finish_undefweak_symbol (struct bfd_hash_entry *bh, + void *inf) +{ + struct elf_link_hash_entry *h = (struct elf_link_hash_entry *) bh; + struct bfd_link_info *info = (struct bfd_link_info *) inf; + + if (h->root.type != bfd_link_hash_undefweak + || h->dynindx != -1) + return TRUE; + + return _bfd_sparc_elf_finish_dynamic_symbol (info->output_bfd, info, + h, NULL); +} + bfd_boolean _bfd_sparc_elf_finish_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info) { @@ -4853,6 +5006,11 @@ _bfd_sparc_elf_finish_dynamic_sections (bfd *output_bfd, struct bfd_link_info *i /* Fill PLT and GOT entries for local STT_GNU_IFUNC symbols. */ htab_traverse (htab->loc_hash_table, finish_local_dynamic_symbol, info); + /* Fill PLT entries for undefined weak symbols in PIE. */ + if (bfd_link_pie (info)) + bfd_hash_traverse (&info->hash->table, + pie_finish_undefweak_symbol, + info); return TRUE; } |