diff options
Diffstat (limited to 'binutils-2.25/bfd/elf-vxworks.c')
| -rw-r--r-- | binutils-2.25/bfd/elf-vxworks.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/binutils-2.25/bfd/elf-vxworks.c b/binutils-2.25/bfd/elf-vxworks.c new file mode 100644 index 00000000..bb9dbbba --- /dev/null +++ b/binutils-2.25/bfd/elf-vxworks.c @@ -0,0 +1,301 @@ +/* VxWorks support for ELF + Copyright 2005, 2006, 2007, 2009, 2012 Free Software Foundation, Inc. + + This file is part of BFD, the Binary File Descriptor library. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, + MA 02111-1307, USA. */ + +/* This file provides routines used by all VxWorks targets. */ + +#include "sysdep.h" +#include "bfd.h" +#include "libbfd.h" +#include "elf-bfd.h" +#include "elf-vxworks.h" +#include "elf/vxworks.h" + +/* Return true if symbol NAME, as defined by ABFD, is one of the special + __GOTT_BASE__ or __GOTT_INDEX__ symbols. */ + +static bfd_boolean +elf_vxworks_gott_symbol_p (bfd *abfd, const char *name) +{ + char leading; + + leading = bfd_get_symbol_leading_char (abfd); + if (leading) + { + if (*name != leading) + return FALSE; + name++; + } + return (strcmp (name, "__GOTT_BASE__") == 0 + || strcmp (name, "__GOTT_INDEX__") == 0); +} + +/* Tweak magic VxWorks symbols as they are loaded. */ +bfd_boolean +elf_vxworks_add_symbol_hook (bfd *abfd, + struct bfd_link_info *info, + Elf_Internal_Sym *sym, + const char **namep, + flagword *flagsp, + asection **secp ATTRIBUTE_UNUSED, + bfd_vma *valp ATTRIBUTE_UNUSED) +{ + /* Ideally these "magic" symbols would be exported by libc.so.1 + which would be found via a DT_NEEDED tag, and then handled + specially by the linker at runtime. Except shared libraries + don't even link to libc.so.1 by default... + If the symbol is imported from, or will be put in a shared library, + give the symbol weak binding to get the desired samantics. + This transformation will be undone in + elf_i386_vxworks_link_output_symbol_hook. */ + if ((info->shared || abfd->flags & DYNAMIC) + && elf_vxworks_gott_symbol_p (abfd, *namep)) + { + sym->st_info = ELF_ST_INFO (STB_WEAK, ELF_ST_TYPE (sym->st_info)); + *flagsp |= BSF_WEAK; + } + + return TRUE; +} + +/* Perform VxWorks-specific handling of the create_dynamic_sections hook. + When creating an executable, set *SRELPLT2_OUT to the .rel(a).plt.unloaded + section. */ + +bfd_boolean +elf_vxworks_create_dynamic_sections (bfd *dynobj, struct bfd_link_info *info, + asection **srelplt2_out) +{ + struct elf_link_hash_table *htab; + const struct elf_backend_data *bed; + asection *s; + + htab = elf_hash_table (info); + bed = get_elf_backend_data (dynobj); + + if (!info->shared) + { + s = bfd_make_section_anyway_with_flags (dynobj, + bed->default_use_rela_p + ? ".rela.plt.unloaded" + : ".rel.plt.unloaded", + SEC_HAS_CONTENTS | SEC_IN_MEMORY + | SEC_READONLY + | SEC_LINKER_CREATED); + if (s == NULL + || !bfd_set_section_alignment (dynobj, s, bed->s->log_file_align)) + return FALSE; + + *srelplt2_out = s; + } + + /* Mark the GOT and PLT symbols as having relocations; they might + not, but we won't know for sure until we build the GOT in + finish_dynamic_symbol. Also make sure that the GOT symbol + is entered into the dynamic symbol table; the loader uses it + to initialize __GOTT_BASE__[__GOTT_INDEX__]. */ + if (htab->hgot) + { + htab->hgot->indx = -2; + htab->hgot->other &= ~ELF_ST_VISIBILITY (-1); + htab->hgot->forced_local = 0; + if (!bfd_elf_link_record_dynamic_symbol (info, htab->hgot)) + return FALSE; + } + if (htab->hplt) + { + htab->hplt->indx = -2; + htab->hplt->type = STT_FUNC; + } + + return TRUE; +} + +/* Tweak magic VxWorks symbols as they are written to the output file. */ +int +elf_vxworks_link_output_symbol_hook (struct bfd_link_info *info + ATTRIBUTE_UNUSED, + const char *name, + Elf_Internal_Sym *sym, + asection *input_sec ATTRIBUTE_UNUSED, + struct elf_link_hash_entry *h) +{ + /* Reverse the effects of the hack in elf_vxworks_add_symbol_hook. */ + if (h + && h->root.type == bfd_link_hash_undefweak + && elf_vxworks_gott_symbol_p (h->root.u.undef.abfd, name)) + sym->st_info = ELF_ST_INFO (STB_GLOBAL, ELF_ST_TYPE (sym->st_info)); + + return 1; +} + +/* Copy relocations into the output file. Fixes up relocations against PLT + entries, then calls the generic routine. */ + +bfd_boolean +elf_vxworks_emit_relocs (bfd *output_bfd, + asection *input_section, + Elf_Internal_Shdr *input_rel_hdr, + Elf_Internal_Rela *internal_relocs, + struct elf_link_hash_entry **rel_hash) +{ + const struct elf_backend_data *bed; + int j; + + bed = get_elf_backend_data (output_bfd); + + if (output_bfd->flags & (DYNAMIC|EXEC_P)) + { + Elf_Internal_Rela *irela; + Elf_Internal_Rela *irelaend; + struct elf_link_hash_entry **hash_ptr; + + for (irela = internal_relocs, + irelaend = irela + (NUM_SHDR_ENTRIES (input_rel_hdr) + * bed->s->int_rels_per_ext_rel), + hash_ptr = rel_hash; + irela < irelaend; + irela += bed->s->int_rels_per_ext_rel, + hash_ptr++) + { + if (*hash_ptr + && (*hash_ptr)->def_dynamic + && !(*hash_ptr)->def_regular + && ((*hash_ptr)->root.type == bfd_link_hash_defined + || (*hash_ptr)->root.type == bfd_link_hash_defweak) + && (*hash_ptr)->root.u.def.section->output_section != NULL) + { + /* This is a relocation from an executable or shared + library against a symbol in a different shared + library. We are creating a definition in the output + file but it does not come from any of our normal (.o) + files. ie. a PLT stub. Normally this would be a + relocation against against SHN_UNDEF with the VMA of + the PLT stub. This upsets the VxWorks loader. + Convert it to a section-relative relocation. This + gets some other symbols (for instance .dynbss), but + is conservatively correct. */ + for (j = 0; j < bed->s->int_rels_per_ext_rel; j++) + { + asection *sec = (*hash_ptr)->root.u.def.section; + int this_idx = sec->output_section->target_index; + + irela[j].r_info + = ELF32_R_INFO (this_idx, ELF32_R_TYPE (irela[j].r_info)); + irela[j].r_addend += (*hash_ptr)->root.u.def.value; + irela[j].r_addend += sec->output_offset; + } + /* Stop the generic routine adjusting this entry. */ + *hash_ptr = NULL; + } + } + } + return _bfd_elf_link_output_relocs (output_bfd, input_section, + input_rel_hdr, internal_relocs, + rel_hash); +} + + +/* Set the sh_link and sh_info fields on the static plt relocation secton. */ + +void +elf_vxworks_final_write_processing (bfd *abfd, + bfd_boolean linker ATTRIBUTE_UNUSED) +{ + asection * sec; + struct bfd_elf_section_data *d; + + sec = bfd_get_section_by_name (abfd, ".rel.plt.unloaded"); + if (!sec) + sec = bfd_get_section_by_name (abfd, ".rela.plt.unloaded"); + if (!sec) + return; + d = elf_section_data (sec); + d->this_hdr.sh_link = elf_onesymtab (abfd); + sec = bfd_get_section_by_name (abfd, ".plt"); + if (sec) + d->this_hdr.sh_info = elf_section_data (sec)->this_idx; +} + +/* Add the dynamic entries required by VxWorks. These point to the + tls sections. */ + +bfd_boolean +elf_vxworks_add_dynamic_entries (bfd *output_bfd, struct bfd_link_info *info) +{ + if (bfd_get_section_by_name (output_bfd, ".tls_data")) + { + if (!_bfd_elf_add_dynamic_entry (info, DT_VX_WRS_TLS_DATA_START, 0) + || !_bfd_elf_add_dynamic_entry (info, DT_VX_WRS_TLS_DATA_SIZE, 0) + || !_bfd_elf_add_dynamic_entry (info, DT_VX_WRS_TLS_DATA_ALIGN, 0)) + return FALSE; + } + if (bfd_get_section_by_name (output_bfd, ".tls_vars")) + { + if (!_bfd_elf_add_dynamic_entry (info, DT_VX_WRS_TLS_VARS_START, 0) + || !_bfd_elf_add_dynamic_entry (info, DT_VX_WRS_TLS_VARS_SIZE, 0)) + return FALSE; + } + return TRUE; +} + +/* If *DYN is one of the VxWorks-specific dynamic entries, then fill + in the value now and return TRUE. Otherwise return FALSE. */ + +bfd_boolean +elf_vxworks_finish_dynamic_entry (bfd *output_bfd, Elf_Internal_Dyn *dyn) +{ + asection *sec; + + switch (dyn->d_tag) + { + default: + return FALSE; + + case DT_VX_WRS_TLS_DATA_START: + sec = bfd_get_section_by_name (output_bfd, ".tls_data"); + dyn->d_un.d_ptr = sec->vma; + break; + + case DT_VX_WRS_TLS_DATA_SIZE: + sec = bfd_get_section_by_name (output_bfd, ".tls_data"); + dyn->d_un.d_val = sec->size; + break; + + case DT_VX_WRS_TLS_DATA_ALIGN: + sec = bfd_get_section_by_name (output_bfd, ".tls_data"); + dyn->d_un.d_val + = (bfd_size_type)1 << bfd_get_section_alignment (output_bfd, + sec); + break; + + case DT_VX_WRS_TLS_VARS_START: + sec = bfd_get_section_by_name (output_bfd, ".tls_vars"); + dyn->d_un.d_ptr = sec->vma; + break; + + case DT_VX_WRS_TLS_VARS_SIZE: + sec = bfd_get_section_by_name (output_bfd, ".tls_vars"); + dyn->d_un.d_val = sec->size; + break; + } + return TRUE; +} + + |