/* ELF linker support. Copyright 1995, 1996, 1997 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 2 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. */ /* ELF linker code. */ static boolean elf_link_add_object_symbols PARAMS ((bfd *, struct bfd_link_info *)); static boolean elf_link_add_archive_symbols PARAMS ((bfd *, struct bfd_link_info *)); static boolean elf_export_symbol PARAMS ((struct elf_link_hash_entry *, PTR)); static boolean elf_adjust_dynamic_symbol PARAMS ((struct elf_link_hash_entry *, PTR)); static boolean elf_link_find_version_dependencies PARAMS ((struct elf_link_hash_entry *, PTR)); static boolean elf_link_find_version_dependencies PARAMS ((struct elf_link_hash_entry *, PTR)); static boolean elf_link_assign_sym_version PARAMS ((struct elf_link_hash_entry *, PTR)); static boolean elf_link_renumber_dynsyms PARAMS ((struct elf_link_hash_entry *, PTR)); /* This struct is used to pass information to routines called via elf_link_hash_traverse which must return failure. */ struct elf_info_failed { boolean failed; struct bfd_link_info *info; }; /* Given an ELF BFD, add symbols to the global hash table as appropriate. */ boolean elf_bfd_link_add_symbols (abfd, info) bfd *abfd; struct bfd_link_info *info; { switch (bfd_get_format (abfd)) { case bfd_object: return elf_link_add_object_symbols (abfd, info); case bfd_archive: return elf_link_add_archive_symbols (abfd, info); default: bfd_set_error (bfd_error_wrong_format); return false; } } /* Add symbols from an ELF archive file to the linker hash table. We don't use _bfd_generic_link_add_archive_symbols because of a problem which arises on UnixWare. The UnixWare libc.so is an archive which includes an entry libc.so.1 which defines a bunch of symbols. The libc.so archive also includes a number of other object files, which also define symbols, some of which are the same as those defined in libc.so.1. Correct linking requires that we consider each object file in turn, and include it if it defines any symbols we need. _bfd_generic_link_add_archive_symbols does not do this; it looks through the list of undefined symbols, and includes any object file which defines them. When this algorithm is used on UnixWare, it winds up pulling in libc.so.1 early and defining a bunch of symbols. This means that some of the other objects in the archive are not included in the link, which is incorrect since they precede libc.so.1 in the archive. Fortunately, ELF archive handling is simpler than that done by _bfd_generic_link_add_archive_symbols, which has to allow for a.out oddities. In ELF, if we find a symbol in the archive map, and the symbol is currently undefined, we know that we must pull in that object file. Unfortunately, we do have to make multiple passes over the symbol table until nothing further is resolved. */ static boolean elf_link_add_archive_symbols (abfd, info) bfd *abfd; struct bfd_link_info *info; { symindex c; boolean *defined = NULL; boolean *included = NULL; carsym *symdefs; boolean loop; if (! bfd_has_map (abfd)) { /* An empty archive is a special case. */ if (bfd_openr_next_archived_file (abfd, (bfd *) NULL) == NULL) return true; bfd_set_error (bfd_error_no_armap); return false; } /* Keep track of all symbols we know to be already defined, and all files we know to be already included. This is to speed up the second and subsequent passes. */ c = bfd_ardata (abfd)->symdef_count; if (c == 0) return true; defined = (boolean *) bfd_malloc (c * sizeof (boolean)); included = (boolean *) bfd_malloc (c * sizeof (boolean)); if (defined == (boolean *) NULL || included == (boolean *) NULL) goto error_return; memset (defined, 0, c * sizeof (boolean)); memset (included, 0, c * sizeof (boolean)); symdefs = bfd_ardata (abfd)->symdefs; do { file_ptr last; symindex i; carsym *symdef; carsym *symdefend; loop = false; last = -1; symdef = symdefs; symdefend = symdef + c; for (i = 0; symdef < symdefend; symdef++, i++) { struct elf_link_hash_entry *h; bfd *element; struct bfd_link_hash_entry *undefs_tail; symindex mark; if (defined[i] || included[i]) continue; if (symdef->file_offset == last) { included[i] = true; continue; } h = elf_link_hash_lookup (elf_hash_table (info), symdef->name, false, false, false); if (h == NULL) { char *p, *copy; /* If this is a default version (the name contains @@), look up the symbol again without the version. The effect is that references to the symbol without the version will be matched by the default symbol in the archive. */ p = strchr (symdef->name, ELF_VER_CHR); if (p == NULL || p[1] != ELF_VER_CHR) continue; copy = bfd_alloc (abfd, p - symdef->name + 1); if (copy == NULL) goto error_return; memcpy (copy, symdef->name, p - symdef->name); copy[p - symdef->name] = '\0'; h = elf_link_hash_lookup (elf_hash_table (info), copy, false, false, false); bfd_release (abfd, copy); } if (h == NULL) continue; if (h->root.type != bfd_link_hash_undefined) { if (h->root.type != bfd_link_hash_undefweak) defined[i] = true; continue; } /* We need to include this archive member. */ element = _bfd_get_elt_at_filepos (abfd, symdef->file_offset); if (element == (bfd *) NULL) goto error_return; if (! bfd_check_format (element, bfd_object)) goto error_return; /* Doublecheck that we have not included this object already--it should be impossible, but there may be something wrong with the archive. */ if (element->archive_pass != 0) { bfd_set_error (bfd_error_bad_value); goto error_return; } element->archive_pass = 1; undefs_tail = info->hash->undefs_tail; if (! (*info->callbacks->add_archive_element) (info, element, symdef->name)) goto error_return; if (! elf_link_add_object_symbols (element, info)) goto error_return; /* If there are any new undefined symbols, we need to make another pass through the archive in order to see whether they can be defined. FIXME: This isn't perfect, because common symbols wind up on undefs_tail and because an undefined symbol which is defined later on in this pass does not require another pass. This isn't a bug, but it does make the code less efficient than it could be. */ if (undefs_tail != info->hash->undefs_tail) loop = true; /* Look backward to mark all symbols from this object file which we have already seen in this pass. */ mark = i; do { included[mark] = true; if (mark == 0) break; --mark; } while (symdefs[mark].file_offset == symdef->file_offset); /* We mark subsequent symbols from this object file as we go on through the loop. */ last = symdef->file_offset; } } while (loop); free (defined); free (included); return true; error_return: if (defined != (boolean *) NULL) free (defined); if (included != (boolean *) NULL) free (included); return false; } /* Add symbols from an ELF object file to the linker hash table. */ static boolean elf_link_add_object_symbols (abfd, info) bfd *abfd; struct bfd_link_info *info; { boolean (*add_symbol_hook) PARAMS ((bfd *, struct bfd_link_info *, const Elf_Internal_Sym *, const char **, flagword *, asection **, bfd_vma *)); boolean (*check_relocs) PARAMS ((bfd *, struct bfd_link_info *, asection *, const Elf_Internal_Rela *)); boolean collect; Elf_Internal_Shdr *hdr; size_t symcount; size_t extsymcount; size_t extsymoff; Elf_External_Sym *buf = NULL; struct elf_link_hash_entry **sym_hash; boolean dynamic; bfd_byte *dynver = NULL; Elf_External_Versym *extversym = NULL; Elf_External_Versym *ever; Elf_External_Dyn *dynbuf = NULL; struct elf_link_hash_entry *weaks; Elf_External_Sym *esym; Elf_External_Sym *esymend; add_symbol_hook = get_elf_backend_data (abfd)->elf_add_symbol_hook; collect = get_elf_backend_data (abfd)->collect; if ((abfd->flags & DYNAMIC) == 0) dynamic = false; else { dynamic = true; /* You can't use -r against a dynamic object. Also, there's no hope of using a dynamic object which does not exactly match the format of the output file. */ if (info->relocateable || info->hash->creator != abfd->xvec) { bfd_set_error (bfd_error_invalid_operation); goto error_return; } } /* As a GNU extension, any input sections which are named .gnu.warning.SYMBOL are treated as warning symbols for the given symbol. This differs from .gnu.warning sections, which generate warnings when they are included in an output file. */ if (! info->shared) { asection *s; for (s = abfd->sections; s != NULL; s = s->next) { const char *name; name = bfd_get_section_name (abfd, s); if (strncmp (name, ".gnu.warning.", sizeof ".gnu.warning." - 1) == 0) { char *msg; bfd_size_type sz; name += sizeof ".gnu.warning." - 1; /* If this is a shared object, then look up the symbol in the hash table. If it is there, and it is already been defined, then we will not be using the entry from this shared object, so we don't need to warn. FIXME: If we see the definition in a regular object later on, we will warn, but we shouldn't. The only fix is to keep track of what warnings we are supposed to emit, and then handle them all at the end of the link. */ if (dynamic && abfd->xvec == info->hash->creator) { struct elf_link_hash_entry *h; h = elf_link_hash_lookup (elf_hash_table (info), name, false, false, true); /* FIXME: What about bfd_link_hash_common? */ if (h != NULL && (h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak)) { /* We don't want to issue this warning. Clobber the section size so that the warning does not get copied into the output file. */ s->_raw_size = 0; continue; } } sz = bfd_section_size (abfd, s); msg = (char *) bfd_alloc (abfd, sz); if (msg == NULL) goto error_return; if (! bfd_get_section_contents (abfd, s, msg, (file_ptr) 0, sz)) goto error_return; if (! (_bfd_generic_link_add_one_symbol (info, abfd, name, BSF_WARNING, s, (bfd_vma) 0, msg, false, collect, (struct bfd_link_hash_entry **) NULL))) goto error_return; if (! info->relocateable) { /* Clobber the section size so that the warning does not get copied into the output file. */ s->_raw_size = 0; } } } } /* If this is a dynamic object, we always link against the .dynsym symbol table, not the .symtab symbol table. The dynamic linker will only see the .dynsym symbol table, so there is no reason to look at .symtab for a dynamic object. */ if (! dynamic || elf_dynsymtab (abfd) == 0) hdr = &elf_tdata (abfd)->symtab_hdr; else hdr = &elf_tdata (abfd)->dynsymtab_hdr; if (dynamic) { /* Read in any version definitions. */ if (elf_dynverdef (abfd) != 0) { Elf_Internal_Shdr *verdefhdr; bfd_byte *dynver; int i; const Elf_External_Verdef *extverdef; Elf_Internal_Verdef *intverdef; verdefhdr = &elf_tdata (abfd)->dynverdef_hdr; elf_tdata (abfd)->verdef = ((Elf_Internal_Verdef *) bfd_zalloc (abfd, verdefhdr->sh_info * sizeof (Elf_Internal_Verdef))); if (elf_tdata (abfd)->verdef == NULL) goto error_return; dynver = (bfd_byte *) bfd_malloc (verdefhdr->sh_size); if (dynver == NULL) goto error_return; if (bfd_seek (abfd, verdefhdr->sh_offset, SEEK_SET) != 0 || (bfd_read ((PTR) dynver, 1, hdr->sh_size, abfd) != hdr->sh_size)) goto error_return; extverdef = (const Elf_External_Verdef *) dynver; intverdef = elf_tdata (abfd)->verdef; for (i = 0; i < verdefhdr->sh_info; i++, intverdef++) { const Elf_External_Verdaux *extverdaux; Elf_Internal_Verdaux intverdaux; _bfd_elf_swap_verdef_in (abfd, extverdef, intverdef); /* Pick up the name of the version. */ extverdaux = ((const Elf_External_Verdaux *) (bfd_byte *) extverdef + intverdef->vd_aux); _bfd_elf_swap_verdaux_in (abfd, extverdaux, &intverdaux); intverdef->vd_bfd = abfd; intverdef->vd_nodename = bfd_elf_string_from_elf_section (abfd, verdefhdr->sh_link, intverdaux.vda_name); extverdef = ((const Elf_External_Verdef *) (bfd_byte *) extverdef + intverdef->vd_next); } free (dynver); dynver = NULL; } /* Read in the symbol versions, but don't bother to convert them to internal format. */ if (elf_dynversym (abfd) != 0) { Elf_Internal_Shdr *versymhdr; versymhdr = &elf_tdata (abfd)->dynversym_hdr; extversym = (Elf_External_Versym *) bfd_malloc (hdr->sh_size); if (extversym == NULL) goto error_return; if (bfd_seek (abfd, versymhdr->sh_offset, SEEK_SET) != 0 || (bfd_read ((PTR) extversym, 1, versymhdr->sh_size, abfd) != versymhdr->sh_size)) goto error_return; } } symcount = hdr->sh_size / sizeof (Elf_External_Sym); /* The sh_info field of the symtab header tells us where the external symbols start. We don't care about the local symbols at this point. */ if (elf_bad_symtab (abfd)) { extsymcount = symcount; extsymoff = 0; } else { extsymcount = symcount - hdr->sh_info; extsymoff = hdr->sh_info; } buf = ((Elf_External_Sym *) bfd_malloc (extsymcount * sizeof (Elf_External_Sym))); if (buf == NULL && extsymcount != 0) goto error_return; /* We store a pointer to the hash table entry for each external symbol. */ sym_hash = ((struct elf_link_hash_entry **) bfd_alloc (abfd, extsymcount * sizeof (struct elf_link_hash_entry *))); if (sym_hash == NULL) goto error_return; elf_sym_hashes (abfd) = sym_hash; if (! dynamic) { /* If we are creating a shared library, create all the dynamic sections immediately. We need to attach them to something, so we attach them to this BFD, provided it is the right format. FIXME: If there are no input BFD's of the same format as the output, we can't make a shared library. */ if (info->shared && ! elf_hash_table (info)->dynamic_sections_created && abfd->xvec == info->hash->creator) { if (! elf_link_create_dynamic_sections (abfd, info)) goto error_return; } } else { asection *s; boolean add_needed; const char *name; bfd_size_type oldsize; bfd_size_type strindex; /* Find the name to use in a DT_NEEDED entry that refers to this object. If the object has a DT_SONAME entry, we use it. Otherwise, if the generic linker stuck something in elf_dt_name, we use that. Otherwise, we just use the file name. If the generic linker put a null string into elf_dt_name, we don't make a DT_NEEDED entry at all, even if there is a DT_SONAME entry. */ add_needed = true; name = bfd_get_filename (abfd); if (elf_dt_name (abfd) != NULL) { name = elf_dt_name (abfd); if (*name == '\0') add_needed = false; } s = bfd_get_section_by_name (abfd, ".dynamic"); if (s != NULL) { Elf_External_Dyn *extdyn; Elf_External_Dyn *extdynend; int elfsec; unsigned long link; dynbuf = (Elf_External_Dyn *) bfd_malloc ((size_t) s->_raw_size); if (dynbuf == NULL) goto error_return; if (! bfd_get_section_contents (abfd, s, (PTR) dynbuf, (file_ptr) 0, s->_raw_size)) goto error_return; elfsec = _bfd_elf_section_from_bfd_section (abfd, s); if (elfsec == -1) goto error_return; link = elf_elfsections (abfd)[elfsec]->sh_link; extdyn = dynbuf; extdynend = extdyn + s->_raw_size / sizeof (Elf_External_Dyn); for (; extdyn < extdynend; extdyn++) { Elf_Internal_Dyn dyn; elf_swap_dyn_in (abfd, extdyn, &dyn); if (dyn.d_tag == DT_SONAME) { name = bfd_elf_string_from_elf_section (abfd, link, dyn.d_un.d_val); if (name == NULL) goto error_return; } if (dyn.d_tag == DT_NEEDED) { struct bfd_link_needed_list *n, **pn; char *fnm, *anm; n = ((struct bfd_link_needed_list *) bfd_alloc (abfd, sizeof (struct bfd_link_needed_list))); fnm = bfd_elf_string_from_elf_section (abfd, link, dyn.d_un.d_val); if (n == NULL || fnm == NULL) goto error_return; anm = bfd_alloc (abfd, strlen (fnm) + 1); if (anm == NULL) goto error_return; strcpy (anm, fnm); n->name = anm; n->by = abfd; n->next = NULL; for (pn = &elf_hash_table (info)->needed; *pn != NULL; pn = &(*pn)->next) ; *pn = n; } } free (dynbuf); dynbuf = NULL; } /* We do not want to include any of the sections in a dynamic object in the output file. We hack by simply clobbering the list of sections in the BFD. This could be handled more cleanly by, say, a new section flag; the existing SEC_NEVER_LOAD flag is not the one we want, because that one still implies that the section takes up space in the output file. */ abfd->sections = NULL; abfd->section_count = 0; /* If this is the first dynamic object found in the link, create the special sections required for dynamic linking. */ if (! elf_hash_table (info)->dynamic_sections_created) { if (! elf_link_create_dynamic_sections (abfd, info)) goto error_return; } if (add_needed) { /* Add a DT_NEEDED entry for this dynamic object. */ oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr); strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr, name, true, false); if (strindex == (bfd_size_type) -1) goto error_return; if (oldsize == _bfd_stringtab_size (elf_hash_table (info)->dynstr)) { asection *sdyn; Elf_External_Dyn *dyncon, *dynconend; /* The hash table size did not change, which means that the dynamic object name was already entered. If we have already included this dynamic object in the link, just ignore it. There is no reason to include a particular dynamic object more than once. */ sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj, ".dynamic"); BFD_ASSERT (sdyn != NULL); dyncon = (Elf_External_Dyn *) sdyn->contents; dynconend = (Elf_External_Dyn *) (sdyn->contents + sdyn->_raw_size); for (; dyncon < dynconend; dyncon++) { Elf_Internal_Dyn dyn; elf_swap_dyn_in (elf_hash_table (info)->dynobj, dyncon, &dyn); if (dyn.d_tag == DT_NEEDED && dyn.d_un.d_val == strindex) { if (buf != NULL) free (buf); if (extversym != NULL) free (extversym); return true; } } } if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex)) goto error_return; } /* Save the SONAME, if there is one, because sometimes the linker emulation code will need to know it. */ if (*name == '\0') name = bfd_get_filename (abfd); elf_dt_name (abfd) = name; } if (bfd_seek (abfd, hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym), SEEK_SET) != 0 || (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd) != extsymcount * sizeof (Elf_External_Sym))) goto error_return; weaks = NULL; ever = extversym != NULL ? extversym + hdr->sh_info : NULL; esymend = buf + extsymcount; for (esym = buf; esym < esymend; esym++, sym_hash++, ever = (ever != NULL ? ever + 1 : NULL)) { Elf_Internal_Sym sym; int bind; bfd_vma value; asection *sec; flagword flags; const char *name; struct elf_link_hash_entry *h; boolean definition; boolean size_change_ok, type_change_ok; boolean new_weakdef; elf_swap_symbol_in (abfd, esym, &sym); flags = BSF_NO_FLAGS; sec = NULL; value = sym.st_value; *sym_hash = NULL; bind = ELF_ST_BIND (sym.st_info); if (bind == STB_LOCAL) { /* This should be impossible, since ELF requires that all global symbols follow all local symbols, and that sh_info point to the first global symbol. Unfortunatealy, Irix 5 screws this up. */ continue; } else if (bind == STB_GLOBAL) { if (sym.st_shndx != SHN_UNDEF && sym.st_shndx != SHN_COMMON) flags = BSF_GLOBAL; else flags = 0; } else if (bind == STB_WEAK) flags = BSF_WEAK; else { /* Leave it up to the processor backend. */ } if (sym.st_shndx == SHN_UNDEF) sec = bfd_und_section_ptr; else if (sym.st_shndx > 0 && sym.st_shndx < SHN_LORESERVE) { sec = section_from_elf_index (abfd, sym.st_shndx); if (sec != NULL) value -= sec->vma; else sec = bfd_abs_section_ptr; } else if (sym.st_shndx == SHN_ABS) sec = bfd_abs_section_ptr; else if (sym.st_shndx == SHN_COMMON) { sec = bfd_com_section_ptr; /* What ELF calls the size we call the value. What ELF calls the value we call the alignment. */ value = sym.st_size; } else { /* Leave it up to the processor backend. */ } name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name); if (name == (const char *) NULL) goto error_return; if (add_symbol_hook) { if (! (*add_symbol_hook) (abfd, info, &sym, &name, &flags, &sec, &value)) goto error_return; /* The hook function sets the name to NULL if this symbol should be skipped for some reason. */ if (name == (const char *) NULL) continue; } /* Sanity check that all possibilities were handled. */ if (sec == (asection *) NULL) { bfd_set_error (bfd_error_bad_value); goto error_return; } if (bfd_is_und_section (sec) || bfd_is_com_section (sec)) definition = false; else definition = true; size_change_ok = false; type_change_ok = get_elf_backend_data (abfd)->type_change_ok; if (info->hash->creator->flavour == bfd_target_elf_flavour) { Elf_Internal_Versym iver; int vernum; boolean override; if (ever != NULL) { _bfd_elf_swap_versym_in (abfd, ever, &iver); vernum = iver.vs_vers & VERSYM_VERSION; /* If this is a hidden symbol, or if it is not version 1, we append the version name to the symbol name. However, we do not modify a non-hidden absolute symbol, because it might be the version symbol itself. FIXME: What if it isn't? */ if ((iver.vs_vers & VERSYM_HIDDEN) != 0 || (vernum > 1 && ! bfd_is_abs_section (sec))) { const char *verstr; int namelen, newlen; char *newname, *p; if (vernum > 1) verstr = elf_tdata (abfd)->verdef[vernum - 1].vd_nodename; else verstr = ""; namelen = strlen (name); newlen = namelen + strlen (verstr) + 2; if ((iver.vs_vers & VERSYM_HIDDEN) == 0) ++newlen; newname = (char *) bfd_alloc (abfd, newlen); if (newname == NULL) goto error_return; strcpy (newname, name); p = newname + namelen; *p++ = ELF_VER_CHR; if ((iver.vs_vers & VERSYM_HIDDEN) == 0) *p++ = ELF_VER_CHR; strcpy (p, verstr); name = newname; } } /* We need to look up the symbol now in order to get some of the dynamic object handling right. We pass the hash table entry in to _bfd_generic_link_add_one_symbol so that it does not have to look it up again. */ if (! bfd_is_und_section (sec)) h = elf_link_hash_lookup (elf_hash_table (info), name, true, false, false); else h = ((struct elf_link_hash_entry *) bfd_wrapped_link_hash_lookup (abfd, info, name, true, false, false)); if (h == NULL) goto error_return; *sym_hash = h; if (h->root.type == bfd_link_hash_new) h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF; while (h->root.type == bfd_link_hash_indirect || h->root.type == bfd_link_hash_warning) h = (struct elf_link_hash_entry *) h->root.u.i.link; /* It's OK to change the type if it used to be a weak definition. */ if (h->root.type == bfd_link_hash_defweak || h->root.type == bfd_link_hash_undefweak) type_change_ok = true; /* It's OK to change the size if it used to be a weak definition, or if it used to be undefined, or if we will be overriding an old definition. */ if (type_change_ok || h->root.type == bfd_link_hash_undefined) size_change_ok = true; override = false; /* If we are looking at a dynamic object, and this is a definition, we need to see if it has already been defined by some other object. If it has, we want to use the existing definition, and we do not want to report a multiple symbol definition error; we do this by clobbering sec to be bfd_und_section_ptr. We treat a common symbol as a definition if the symbol in the shared library is a function, since common symbols always represent variables; this can cause confusion in principle, but any such confusion would seem to indicate an erroneous program or shared library. */ if (dynamic && definition) { if (h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak || (h->root.type == bfd_link_hash_common && (bind == STB_WEAK || ELF_ST_TYPE (sym.st_info) == STT_FUNC))) { override = true; sec = bfd_und_section_ptr; definition = false; size_change_ok = true; if (h->root.type == bfd_link_hash_common) type_change_ok = true; } } /* Similarly, if we are not looking at a dynamic object, and we have a definition, we want to override any definition we may have from a dynamic object. Symbols from regular files always take precedence over symbols from dynamic objects, even if they are defined after the dynamic object in the link. */ if (! dynamic && (definition || (bfd_is_com_section (sec) && (h->root.type == bfd_link_hash_defweak || h->type == STT_FUNC))) && (h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak) && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 && (h->root.u.def.section->owner->flags & DYNAMIC) != 0) { override = true; /* Change the hash table entry to undefined, and let _bfd_generic_link_add_one_symbol do the right thing with the new definition. */ h->root.type = bfd_link_hash_undefined; h->root.u.undef.abfd = h->root.u.def.section->owner; size_change_ok = true; if (bfd_is_com_section (sec)) type_change_ok = true; /* This union may have been set to be non-NULL when this symbol was seen in a dynamic object. We must force the union to be NULL, so that it is correct for a regular symbol. */ h->verinfo.vertree = NULL; } if (ever != NULL && ! override && vernum > 1 && (h->verinfo.verdef == NULL || definition)) h->verinfo.verdef = &elf_tdata (abfd)->verdef[vernum - 1]; } if (! (_bfd_generic_link_add_one_symbol (info, abfd, name, flags, sec, value, (const char *) NULL, false, collect, (struct bfd_link_hash_entry **) sym_hash))) goto error_return; h = *sym_hash; while (h->root.type == bfd_link_hash_indirect || h->root.type == bfd_link_hash_warning) h = (struct elf_link_hash_entry *) h->root.u.i.link; *sym_hash = h; new_weakdef = false; if (dynamic && definition && (flags & BSF_WEAK) != 0 && ELF_ST_TYPE (sym.st_info) != STT_FUNC && info->hash->creator->flavour == bfd_target_elf_flavour && h->weakdef == NULL) { /* Keep a list of all weak defined non function symbols from a dynamic object, using the weakdef field. Later in this function we will set the weakdef field to the correct value. We only put non-function symbols from dynamic objects on this list, because that happens to be the only time we need to know the normal symbol corresponding to a weak symbol, and the information is time consuming to figure out. If the weakdef field is not already NULL, then this symbol was already defined by some previous dynamic object, and we will be using that previous definition anyhow. */ h->weakdef = weaks; weaks = h; new_weakdef = true; } /* Get the alignment of a common symbol. */ if (sym.st_shndx == SHN_COMMON && h->root.type == bfd_link_hash_common) h->root.u.c.p->alignment_power = bfd_log2 (sym.st_value); if (info->hash->creator->flavour == bfd_target_elf_flavour) { int old_flags; boolean dynsym; int new_flag; /* Remember the symbol size and type. */ if (sym.st_size != 0 && (definition || h->size == 0)) { if (h->size != 0 && h->size != sym.st_size && ! size_change_ok) (*_bfd_error_handler) ("Warning: size of symbol `%s' changed from %lu to %lu in %s", name, (unsigned long) h->size, (unsigned long) sym.st_size, bfd_get_filename (abfd)); h->size = sym.st_size; } if (ELF_ST_TYPE (sym.st_info) != STT_NOTYPE && (definition || h->type == STT_NOTYPE)) { if (h->type != STT_NOTYPE && h->type != ELF_ST_TYPE (sym.st_info) && ! type_change_ok) (*_bfd_error_handler) ("Warning: type of symbol `%s' changed from %d to %d in %s", name, h->type, ELF_ST_TYPE (sym.st_info), bfd_get_filename (abfd)); h->type = ELF_ST_TYPE (sym.st_info); } if (sym.st_other != 0 && (definition || h->other == 0)) h->other = sym.st_other; /* Set a flag in the hash table entry indicating the type of reference or definition we just found. Keep a count of the number of dynamic symbols we find. A dynamic symbol is one which is referenced or defined by both a regular object and a shared object. */ old_flags = h->elf_link_hash_flags; dynsym = false; if (! dynamic) { if (! definition) new_flag = ELF_LINK_HASH_REF_REGULAR; else new_flag = ELF_LINK_HASH_DEF_REGULAR; if (info->shared || (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC | ELF_LINK_HASH_REF_DYNAMIC)) != 0) dynsym = true; } else { if (! definition) new_flag = ELF_LINK_HASH_REF_DYNAMIC; else new_flag = ELF_LINK_HASH_DEF_DYNAMIC; if ((old_flags & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0 || (h->weakdef != NULL && ! new_weakdef && h->weakdef->dynindx != -1)) dynsym = true; } h->elf_link_hash_flags |= new_flag; /* If this symbol has a version, and it is the default version, we create an indirect symbol from the default name to the fully decorated name. This will cause external references which do not specify a version to be bound to this version of the symbol. */ if (definition) { char *p; p = strchr (name, ELF_VER_CHR); if (p != NULL && p[1] == ELF_VER_CHR) { char *shortname; struct elf_link_hash_entry *hi; shortname = bfd_hash_allocate (&info->hash->table, p - name + 1); if (shortname == NULL) goto error_return; strncpy (shortname, name, p - name); shortname[p - name] = '\0'; hi = NULL; if (! (_bfd_generic_link_add_one_symbol (info, abfd, shortname, BSF_INDIRECT, bfd_ind_section_ptr, (bfd_vma) 0, name, false, collect, (struct bfd_link_hash_entry **) &hi))) goto error_return; if (hi->root.type == bfd_link_hash_indirect) hi->elf_link_hash_flags &= ~ ELF_LINK_NON_ELF; } } if (dynsym && h->dynindx == -1) { if (! _bfd_elf_link_record_dynamic_symbol (info, h)) goto error_return; if (h->weakdef != NULL && ! new_weakdef && h->weakdef->dynindx == -1) { if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef)) goto error_return; } } } } /* Now set the weakdefs field correctly for all the weak defined symbols we found. The only way to do this is to search all the symbols. Since we only need the information for non functions in dynamic objects, that's the only time we actually put anything on the list WEAKS. We need this information so that if a regular object refers to a symbol defined weakly in a dynamic object, the real symbol in the dynamic object is also put in the dynamic symbols; we also must arrange for both symbols to point to the same memory location. We could handle the general case of symbol aliasing, but a general symbol alias can only be generated in assembler code, handling it correctly would be very time consuming, and other ELF linkers don't handle general aliasing either. */ while (weaks != NULL) { struct elf_link_hash_entry *hlook; asection *slook; bfd_vma vlook; struct elf_link_hash_entry **hpp; struct elf_link_hash_entry **hppend; hlook = weaks; weaks = hlook->weakdef; hlook->weakdef = NULL; BFD_ASSERT (hlook->root.type == bfd_link_hash_defined || hlook->root.type == bfd_link_hash_defweak || hlook->root.type == bfd_link_hash_common || hlook->root.type == bfd_link_hash_indirect); slook = hlook->root.u.def.section; vlook = hlook->root.u.def.value; hpp = elf_sym_hashes (abfd); hppend = hpp + extsymcount; for (; hpp < hppend; hpp++) { struct elf_link_hash_entry *h; h = *hpp; if (h != NULL && h != hlook && h->root.type == bfd_link_hash_defined && h->root.u.def.section == slook && h->root.u.def.value == vlook) { hlook->weakdef = h; /* If the weak definition is in the list of dynamic symbols, make sure the real definition is put there as well. */ if (hlook->dynindx != -1 && h->dynindx == -1) { if (! _bfd_elf_link_record_dynamic_symbol (info, h)) goto error_return; } /* If the real definition is in the list of dynamic symbols, make sure the weak definition is put there as well. If we don't do this, then the dynamic loader might not merge the entries for the real definition and the weak definition. */ if (h->dynindx != -1 && hlook->dynindx == -1) { if (! _bfd_elf_link_record_dynamic_symbol (info, hlook)) goto error_return; } break; } } } if (buf != NULL) { free (buf); buf = NULL; } if (extversym != NULL) { free (extversym); extversym = NULL; } /* If this object is the same format as the output object, and it is not a shared library, then let the backend look through the relocs. This is required to build global offset table entries and to arrange for dynamic relocs. It is not required for the particular common case of linking non PIC code, even when linking against shared libraries, but unfortunately there is no way of knowing whether an object file has been compiled PIC or not. Looking through the relocs is not particularly time consuming. The problem is that we must either (1) keep the relocs in memory, which causes the linker to require additional runtime memory or (2) read the relocs twice from the input file, which wastes time. This would be a good case for using mmap. I have no idea how to handle linking PIC code into a file of a different format. It probably can't be done. */ check_relocs = get_elf_backend_data (abfd)->check_relocs; if (! dynamic && abfd->xvec == info->hash->creator && check_relocs != NULL) { asection *o; for (o = abfd->sections; o != NULL; o = o->next) { Elf_Internal_Rela *internal_relocs; boolean ok; if ((o->flags & SEC_RELOC) == 0 || o->reloc_count == 0) continue; internal_relocs = (NAME(_bfd_elf,link_read_relocs) (abfd, o, (PTR) NULL, (Elf_Internal_Rela *) NULL, info->keep_memory)); if (internal_relocs == NULL) goto error_return; ok = (*check_relocs) (abfd, info, o, internal_relocs); if (! info->keep_memory) free (internal_relocs); if (! ok) goto error_return; } } /* If this is a non-traditional, non-relocateable link, try to optimize the handling of the .stab/.stabstr sections. */ if (! dynamic && ! info->relocateable && ! info->traditional_format && info->hash->creator->flavour == bfd_target_elf_flavour && (info->strip != strip_all && info->strip != strip_debugger)) { asection *stab, *stabstr; stab = bfd_get_section_by_name (abfd, ".stab"); if (stab != NULL) { stabstr = bfd_get_section_by_name (abfd, ".stabstr"); if (stabstr != NULL) { struct bfd_elf_section_data *secdata; secdata = elf_section_data (stab); if (! _bfd_link_section_stabs (abfd, &elf_hash_table (info)->stab_info, stab, stabstr, &secdata->stab_info)) goto error_return; } } } return true; error_return: if (buf != NULL) free (buf); if (dynbuf != NULL) free (dynbuf); if (dynver != NULL) free (dynver); if (extversym != NULL) free (extversym); return false; } /* Create some sections which will be filled in with dynamic linking information. ABFD is an input file which requires dynamic sections to be created. The dynamic sections take up virtual memory space when the final executable is run, so we need to create them before addresses are assigned to the output sections. We work out the actual contents and size of these sections later. */ boolean elf_link_create_dynamic_sections (abfd, info) bfd *abfd; struct bfd_link_info *info; { flagword flags; register asection *s; struct elf_link_hash_entry *h; struct elf_backend_data *bed; if (elf_hash_table (info)->dynamic_sections_created) return true; /* Make sure that all dynamic sections use the same input BFD. */ if (elf_hash_table (info)->dynobj == NULL) elf_hash_table (info)->dynobj = abfd; else abfd = elf_hash_table (info)->dynobj; /* Note that we set the SEC_IN_MEMORY flag for all of these sections. */ flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_LINKER_CREATED); /* A dynamically linked executable has a .interp section, but a shared library does not. */ if (! info->shared) { s = bfd_make_section (abfd, ".interp"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)) return false; } /* Create sections to hold version informations. These are removed if they are not needed. */ s = bfd_make_section (abfd, ".gnu.version_d"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) || ! bfd_set_section_alignment (abfd, s, 2)) return false; s = bfd_make_section (abfd, ".gnu.version"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) || ! bfd_set_section_alignment (abfd, s, 1)) return false; s = bfd_make_section (abfd, ".gnu.version_r"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) || ! bfd_set_section_alignment (abfd, s, 2)) return false; s = bfd_make_section (abfd, ".dynsym"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN)) return false; s = bfd_make_section (abfd, ".dynstr"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)) return false; /* Create a strtab to hold the dynamic symbol names. */ if (elf_hash_table (info)->dynstr == NULL) { elf_hash_table (info)->dynstr = elf_stringtab_init (); if (elf_hash_table (info)->dynstr == NULL) return false; } s = bfd_make_section (abfd, ".dynamic"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags) || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN)) return false; /* The special symbol _DYNAMIC is always set to the start of the .dynamic section. This call occurs before we have processed the symbols for any dynamic object, so we don't have to worry about overriding a dynamic definition. We could set _DYNAMIC in a linker script, but we only want to define it if we are, in fact, creating a .dynamic section. We don't want to define it if there is no .dynamic section, since on some ELF platforms the start up code examines it to decide how to initialize the process. */ h = NULL; if (! (_bfd_generic_link_add_one_symbol (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, (bfd_vma) 0, (const char *) NULL, false, get_elf_backend_data (abfd)->collect, (struct bfd_link_hash_entry **) &h))) return false; h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; h->type = STT_OBJECT; if (info->shared && ! _bfd_elf_link_record_dynamic_symbol (info, h)) return false; s = bfd_make_section (abfd, ".hash"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN)) return false; /* Let the backend create the rest of the sections. This lets the backend set the right flags. The backend will normally create the .got and .plt sections. */ bed = get_elf_backend_data (abfd); if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info)) return false; elf_hash_table (info)->dynamic_sections_created = true; return true; } /* Add an entry to the .dynamic table. */ boolean elf_add_dynamic_entry (info, tag, val) struct bfd_link_info *info; bfd_vma tag; bfd_vma val; { Elf_Internal_Dyn dyn; bfd *dynobj; asection *s; size_t newsize; bfd_byte *newcontents; dynobj = elf_hash_table (info)->dynobj; s = bfd_get_section_by_name (dynobj, ".dynamic"); BFD_ASSERT (s != NULL); newsize = s->_raw_size + sizeof (Elf_External_Dyn); newcontents = (bfd_byte *) bfd_realloc (s->contents, newsize); if (newcontents == NULL) return false; dyn.d_tag = tag; dyn.d_un.d_val = val; elf_swap_dyn_out (dynobj, &dyn, (Elf_External_Dyn *) (newcontents + s->_raw_size)); s->_raw_size = newsize; s->contents = newcontents; return true; } /* Read and swap the relocs for a section. They may have been cached. If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are not NULL, they are used as buffers to read into. They are known to be large enough. If the INTERNAL_RELOCS relocs argument is NULL, the return value is allocated using either malloc or bfd_alloc, according to the KEEP_MEMORY argument. */ Elf_Internal_Rela * NAME(_bfd_elf,link_read_relocs) (abfd, o, external_relocs, internal_relocs, keep_memory) bfd *abfd; asection *o; PTR external_relocs; Elf_Internal_Rela *internal_relocs; boolean keep_memory; { Elf_Internal_Shdr *rel_hdr; PTR alloc1 = NULL; Elf_Internal_Rela *alloc2 = NULL; if (elf_section_data (o)->relocs != NULL) return elf_section_data (o)->relocs; if (o->reloc_count == 0) return NULL; rel_hdr = &elf_section_data (o)->rel_hdr; if (internal_relocs == NULL) { size_t size; size = o->reloc_count * sizeof (Elf_Internal_Rela); if (keep_memory) internal_relocs = (Elf_Internal_Rela *) bfd_alloc (abfd, size); else internal_relocs = alloc2 = (Elf_Internal_Rela *) bfd_malloc (size); if (internal_relocs == NULL) goto error_return; } if (external_relocs == NULL) { alloc1 = (PTR) bfd_malloc ((size_t) rel_hdr->sh_size); if (alloc1 == NULL) goto error_return; external_relocs = alloc1; } if ((bfd_seek (abfd, rel_hdr->sh_offset, SEEK_SET) != 0) || (bfd_read (external_relocs, 1, rel_hdr->sh_size, abfd) != rel_hdr->sh_size)) goto error_return; /* Swap in the relocs. For convenience, we always produce an Elf_Internal_Rela array; if the relocs are Rel, we set the addend to 0. */ if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel)) { Elf_External_Rel *erel; Elf_External_Rel *erelend; Elf_Internal_Rela *irela; erel = (Elf_External_Rel *) external_relocs; erelend = erel + o->reloc_count; irela = internal_relocs; for (; erel < erelend; erel++, irela++) { Elf_Internal_Rel irel; elf_swap_reloc_in (abfd, erel, &irel); irela->r_offset = irel.r_offset; irela->r_info = irel.r_info; irela->r_addend = 0; } } else { Elf_External_Rela *erela; Elf_External_Rela *erelaend; Elf_Internal_Rela *irela; BFD_ASSERT (rel_hdr->sh_entsize == sizeof (Elf_External_Rela)); erela = (Elf_External_Rela *) external_relocs; erelaend = erela + o->reloc_count; irela = internal_relocs; for (; erela < erelaend; erela++, irela++) elf_swap_reloca_in (abfd, erela, irela); } /* Cache the results for next time, if we can. */ if (keep_memory) elf_section_data (o)->relocs = internal_relocs; if (alloc1 != NULL) free (alloc1); /* Don't free alloc2, since if it was allocated we are passing it back (under the name of internal_relocs). */ return internal_relocs; error_return: if (alloc1 != NULL) free (alloc1); if (alloc2 != NULL) free (alloc2); return NULL; } /* Record an assignment to a symbol made by a linker script. We need this in case some dynamic object refers to this symbol. */ /*ARGSUSED*/ boolean NAME(bfd_elf,record_link_assignment) (output_bfd, info, name, provide) bfd *output_bfd; struct bfd_link_info *info; const char *name; boolean provide; { struct elf_link_hash_entry *h; if (info->hash->creator->flavour != bfd_target_elf_flavour) return true; h = elf_link_hash_lookup (elf_hash_table (info), name, true, true, false); if (h == NULL) return false; if (h->root.type == bfd_link_hash_new) h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF; /* If this symbol is being provided by the linker script, and it is currently defined by a dynamic object, but not by a regular object, then mark it as undefined so that the generic linker will force the correct value. */ if (provide && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) h->root.type = bfd_link_hash_undefined; h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; h->type = STT_OBJECT; if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC | ELF_LINK_HASH_REF_DYNAMIC)) != 0 || info->shared) && h->dynindx == -1) { if (! _bfd_elf_link_record_dynamic_symbol (info, h)) return false; /* If this is a weak defined symbol, and we know a corresponding real symbol from the same dynamic object, make sure the real symbol is also made into a dynamic symbol. */ if (h->weakdef != NULL && h->weakdef->dynindx == -1) { if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef)) return false; } } return true; } /* This structure is used to pass information to elf_link_assign_sym_version. */ struct elf_assign_sym_version_info { /* Output BFD. */ bfd *output_bfd; /* General link information. */ struct bfd_link_info *info; /* Version tree. */ struct bfd_elf_version_tree *verdefs; /* Whether we are exporting all dynamic symbols. */ boolean export_dynamic; /* Whether we removed any symbols from the dynamic symbol table. */ boolean removed_dynamic; /* Whether we had a failure. */ boolean failed; }; /* This structure is used to pass information to elf_link_find_version_dependencies. */ struct elf_find_verdep_info { /* Output BFD. */ bfd *output_bfd; /* General link information. */ struct bfd_link_info *info; /* The number of dependencies. */ unsigned int vers; /* Whether we had a failure. */ boolean failed; }; /* Array used to determine the number of hash table buckets to use based on the number of symbols there are. If there are fewer than 3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets, fewer than 37 we use 17 buckets, and so forth. We never use more than 32771 buckets. */ static const size_t elf_buckets[] = { 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209, 16411, 32771, 0 }; /* Set up the sizes and contents of the ELF dynamic sections. This is called by the ELF linker emulation before_allocation routine. We must set the sizes of the sections before the linker sets the addresses of the various sections. */ boolean NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath, export_dynamic, filter_shlib, auxiliary_filters, info, sinterpptr, verdefs) bfd *output_bfd; const char *soname; const char *rpath; boolean export_dynamic; const char *filter_shlib; const char * const *auxiliary_filters; struct bfd_link_info *info; asection **sinterpptr; struct bfd_elf_version_tree *verdefs; { bfd_size_type soname_indx; bfd *dynobj; struct elf_backend_data *bed; *sinterpptr = NULL; soname_indx = -1; if (info->hash->creator->flavour != bfd_target_elf_flavour) return true; /* The backend may have to create some sections regardless of whether we're dynamic or not. */ bed = get_elf_backend_data (output_bfd); if (bed->elf_backend_always_size_sections && ! (*bed->elf_backend_always_size_sections) (output_bfd, info)) return false; dynobj = elf_hash_table (info)->dynobj; /* If there were no dynamic objects in the link, there is nothing to do here. */ if (dynobj == NULL) return true; /* If we are supposed to export all symbols into the dynamic symbol table (this is not the normal case), then do so. */ if (export_dynamic) { struct elf_info_failed eif; eif.failed = false; eif.info = info; elf_link_hash_traverse (elf_hash_table (info), elf_export_symbol, (PTR) &eif); if (eif.failed) return false; } if (elf_hash_table (info)->dynamic_sections_created) { struct elf_info_failed eif; struct elf_link_hash_entry *h; bfd_size_type strsize; *sinterpptr = bfd_get_section_by_name (dynobj, ".interp"); BFD_ASSERT (*sinterpptr != NULL || info->shared); if (soname != NULL) { soname_indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, soname, true, true); if (soname_indx == (bfd_size_type) -1 || ! elf_add_dynamic_entry (info, DT_SONAME, soname_indx)) return false; } if (info->symbolic) { if (! elf_add_dynamic_entry (info, DT_SYMBOLIC, 0)) return false; } if (rpath != NULL) { bfd_size_type indx; indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, rpath, true, true); if (indx == (bfd_size_type) -1 || ! elf_add_dynamic_entry (info, DT_RPATH, indx)) return false; } if (filter_shlib != NULL) { bfd_size_type indx; indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, filter_shlib, true, true); if (indx == (bfd_size_type) -1 || ! elf_add_dynamic_entry (info, DT_FILTER, indx)) return false; } if (auxiliary_filters != NULL) { const char * const *p; for (p = auxiliary_filters; *p != NULL; p++) { bfd_size_type indx; indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, *p, true, true); if (indx == (bfd_size_type) -1 || ! elf_add_dynamic_entry (info, DT_AUXILIARY, indx)) return false; } } /* Find all symbols which were defined in a dynamic object and make the backend pick a reasonable value for them. */ eif.failed = false; eif.info = info; elf_link_hash_traverse (elf_hash_table (info), elf_adjust_dynamic_symbol, (PTR) &eif); if (eif.failed) return false; /* Add some entries to the .dynamic section. We fill in some of the values later, in elf_bfd_final_link, but we must add the entries now so that we know the final size of the .dynamic section. */ h = elf_link_hash_lookup (elf_hash_table (info), "_init", false, false, false); if (h != NULL && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR | ELF_LINK_HASH_DEF_REGULAR)) != 0) { if (! elf_add_dynamic_entry (info, DT_INIT, 0)) return false; } h = elf_link_hash_lookup (elf_hash_table (info), "_fini", false, false, false); if (h != NULL && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR | ELF_LINK_HASH_DEF_REGULAR)) != 0) { if (! elf_add_dynamic_entry (info, DT_FINI, 0)) return false; } strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr); if (! elf_add_dynamic_entry (info, DT_HASH, 0) || ! elf_add_dynamic_entry (info, DT_STRTAB, 0) || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0) || ! elf_add_dynamic_entry (info, DT_STRSZ, strsize) || ! elf_add_dynamic_entry (info, DT_SYMENT, sizeof (Elf_External_Sym))) return false; } /* The backend must work out the sizes of all the other dynamic sections. */ if (! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info)) return false; if (elf_hash_table (info)->dynamic_sections_created) { size_t dynsymcount; asection *s; size_t i; size_t bucketcount = 0; Elf_Internal_Sym isym; /* Set up the version definition section. */ s = bfd_get_section_by_name (dynobj, ".gnu.version_d"); BFD_ASSERT (s != NULL); if (verdefs == NULL) { struct elf_assign_sym_version_info sinfo; asection **spp; /* No version script was used. In this case, we just check that there were no version overrides for any symbols. */ sinfo.output_bfd = output_bfd; sinfo.info = info; sinfo.verdefs = verdefs; sinfo.removed_dynamic = false; sinfo.export_dynamic = export_dynamic; sinfo.failed = false; elf_link_hash_traverse (elf_hash_table (info), elf_link_assign_sym_version, (PTR) &sinfo); if (sinfo.failed) return false; /* Don't include this section in the output file. */ for (spp = &output_bfd->sections; *spp != s->output_section; spp = &(*spp)->next) ; *spp = s->output_section->next; --output_bfd->section_count; } else { struct elf_assign_sym_version_info sinfo; unsigned int cdefs; bfd_size_type size; struct bfd_elf_version_tree *t; bfd_byte *p; Elf_Internal_Verdef def; Elf_Internal_Verdaux defaux; /* Attach all of the symbols to their version information. This may cause some symbols to be unexported. */ sinfo.output_bfd = output_bfd; sinfo.info = info; sinfo.verdefs = verdefs; sinfo.export_dynamic = export_dynamic; sinfo.removed_dynamic = false; sinfo.failed = false; elf_link_hash_traverse (elf_hash_table (info), elf_link_assign_sym_version, (PTR) &sinfo); if (sinfo.failed) return false; if (sinfo.removed_dynamic) { /* Some dynamic symbols were changed to be local symbols. In this case, we renumber all of the dynamic symbols, so that we don't have a hole. FIXME: The names of the removed symbols will still be in the dynamic string table, wasting space. */ elf_hash_table (info)->dynsymcount = 1; elf_link_hash_traverse (elf_hash_table (info), elf_link_renumber_dynsyms, (PTR) info); } cdefs = 0; size = 0; /* Make space for the base version. */ size += sizeof (Elf_External_Verdef); size += sizeof (Elf_External_Verdaux); ++cdefs; for (t = verdefs; t != NULL; t = t->next) { struct bfd_elf_version_deps *n; size += sizeof (Elf_External_Verdef); size += sizeof (Elf_External_Verdaux); ++cdefs; for (n = t->deps; n != NULL; n = n->next) size += sizeof (Elf_External_Verdaux); } s->_raw_size = size; s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size); if (s->contents == NULL && s->_raw_size != 0) return false; /* Fill in the version definition section. */ p = s->contents; def.vd_version = VER_DEF_CURRENT; def.vd_flags = VER_FLG_BASE; def.vd_ndx = 1; def.vd_cnt = 1; def.vd_aux = sizeof (Elf_External_Verdef); def.vd_next = (sizeof (Elf_External_Verdef) + sizeof (Elf_External_Verdaux)); if (soname_indx != -1) { def.vd_hash = bfd_elf_hash ((const unsigned char *) soname); defaux.vda_name = soname_indx; } else { const char *name; bfd_size_type indx; name = output_bfd->filename; def.vd_hash = bfd_elf_hash ((const unsigned char *) name); indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, name, true, false); if (indx == (bfd_size_type) -1) return false; defaux.vda_name = indx; } defaux.vda_next = 0; _bfd_elf_swap_verdef_out (output_bfd, &def, (Elf_External_Verdef *)p); p += sizeof (Elf_External_Verdef); _bfd_elf_swap_verdaux_out (output_bfd, &defaux, (Elf_External_Verdaux *) p); p += sizeof (Elf_External_Verdaux); for (t = verdefs; t != NULL; t = t->next) { unsigned int cdeps; struct bfd_elf_version_deps *n; struct elf_link_hash_entry *h; cdeps = 0; for (n = t->deps; n != NULL; n = n->next) ++cdeps; /* Add a symbol representing this version. */ h = NULL; if (! (_bfd_generic_link_add_one_symbol (info, dynobj, t->name, BSF_GLOBAL, bfd_abs_section_ptr, (bfd_vma) 0, (const char *) NULL, false, get_elf_backend_data (dynobj)->collect, (struct bfd_link_hash_entry **) &h))) return false; h->elf_link_hash_flags &= ~ ELF_LINK_NON_ELF; h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; h->type = STT_OBJECT; h->verinfo.vertree = t; if (info->shared) { if (! _bfd_elf_link_record_dynamic_symbol (info, h)) return false; } def.vd_version = VER_DEF_CURRENT; def.vd_flags = 0; if (t->globals == NULL && t->locals == NULL && ! t->used) def.vd_flags |= VER_FLG_WEAK; def.vd_ndx = t->vernum + 1; def.vd_cnt = cdeps + 1; def.vd_hash = bfd_elf_hash ((const unsigned char *) t->name); def.vd_aux = sizeof (Elf_External_Verdef); if (t->next != NULL) def.vd_next = (sizeof (Elf_External_Verdef) + (cdeps + 1) * sizeof (Elf_External_Verdaux)); else def.vd_next = 0; _bfd_elf_swap_verdef_out (output_bfd, &def, (Elf_External_Verdef *) p); p += sizeof (Elf_External_Verdef); defaux.vda_name = h->dynstr_index; if (t->deps == NULL) defaux.vda_next = 0; else defaux.vda_next = sizeof (Elf_External_Verdaux); t->name_indx = defaux.vda_name; _bfd_elf_swap_verdaux_out (output_bfd, &defaux, (Elf_External_Verdaux *) p); p += sizeof (Elf_External_Verdaux); for (n = t->deps; n != NULL; n = n->next) { defaux.vda_name = n->version_needed->name_indx; if (n->next == NULL) defaux.vda_next = 0; else defaux.vda_next = sizeof (Elf_External_Verdaux); _bfd_elf_swap_verdaux_out (output_bfd, &defaux, (Elf_External_Verdaux *) p); p += sizeof (Elf_External_Verdaux); } } if (! elf_add_dynamic_entry (info, DT_VERDEF, 0) || ! elf_add_dynamic_entry (info, DT_VERDEFNUM, cdefs)) return false; elf_tdata (output_bfd)->cverdefs = cdefs; } /* Work out the size of the version reference section. */ s = bfd_get_section_by_name (dynobj, ".gnu.version_r"); BFD_ASSERT (s != NULL); { struct elf_find_verdep_info sinfo; sinfo.output_bfd = output_bfd; sinfo.info = info; sinfo.vers = elf_tdata (output_bfd)->cverdefs; if (sinfo.vers == 0) sinfo.vers = 1; sinfo.failed = false; elf_link_hash_traverse (elf_hash_table (info), elf_link_find_version_dependencies, (PTR) &sinfo); if (elf_tdata (output_bfd)->verref == NULL) { asection **spp; /* We don't have any version definitions, so we can just remove the section. */ for (spp = &output_bfd->sections; *spp != s->output_section; spp = &(*spp)->next) ; *spp = s->output_section->next; --output_bfd->section_count; } else { Elf_Internal_Verneed *t; unsigned int size; unsigned int crefs; bfd_byte *p; /* Build the version definition section. */ for (t = elf_tdata (output_bfd)->verref; t != NULL; t = t->vn_nextref) { Elf_Internal_Vernaux *a; size += sizeof (Elf_External_Verneed); ++crefs; for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr) size += sizeof (Elf_External_Vernaux); } s->_raw_size = size; s->contents = (bfd_byte *) bfd_alloc (output_bfd, size); if (s->contents == NULL) return false; p = s->contents; for (t = elf_tdata (output_bfd)->verref; t != NULL; t = t->vn_nextref) { unsigned int caux; Elf_Internal_Vernaux *a; bfd_size_type indx; caux = 0; for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr) ++caux; t->vn_version = VER_NEED_CURRENT; t->vn_cnt = caux; indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, t->vn_bfd->filename, true, false); if (indx == (bfd_size_type) -1) return false; t->vn_file = indx; t->vn_aux = sizeof (Elf_External_Verneed); if (t->vn_nextref == NULL) t->vn_next = 0; else t->vn_next = (sizeof (Elf_External_Verneed) + caux * sizeof (Elf_External_Vernaux)); _bfd_elf_swap_verneed_out (output_bfd, t, (Elf_External_Verneed *) p); p += sizeof (Elf_External_Verneed); for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr) { a->vna_hash = bfd_elf_hash ((const unsigned char *) a->vna_nodename); indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, a->vna_nodename, true, false); if (indx == (bfd_size_type) -1) return false; a->vna_name = indx; if (a->vna_nextptr == NULL) a->vna_next = 0; else a->vna_next = sizeof (Elf_External_Vernaux); _bfd_elf_swap_vernaux_out (output_bfd, a, (Elf_External_Vernaux *) p); p += sizeof (Elf_External_Vernaux); } } if (! elf_add_dynamic_entry (info, DT_VERNEED, 0) || ! elf_add_dynamic_entry (info, DT_VERNEEDNUM, crefs)) return false; elf_tdata (output_bfd)->cverrefs = crefs; } } dynsymcount = elf_hash_table (info)->dynsymcount; /* Work out the size of the symbol version section. */ s = bfd_get_section_by_name (dynobj, ".gnu.version"); BFD_ASSERT (s != NULL); if (dynsymcount == 0 || (verdefs == NULL && elf_tdata (output_bfd)->verref == NULL)) { asection **spp; /* We don't need any symbol versions; just discard the section. */ for (spp = &output_bfd->sections; *spp != s->output_section; spp = &(*spp)->next) ; *spp = s->output_section->next; --output_bfd->section_count; } else { Elf_Internal_Versym intversym; s->_raw_size = dynsymcount * sizeof (Elf_External_Versym); s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size); if (s->contents == NULL) return false; intversym.vs_vers = 0; _bfd_elf_swap_versym_out (output_bfd, &intversym, (Elf_External_Versym *) s->contents); if (! elf_add_dynamic_entry (info, DT_VERSYM, 0)) return false; } /* Set the size of the .dynsym and .hash sections. We counted the number of dynamic symbols in elf_link_add_object_symbols. We will build the contents of .dynsym and .hash when we build the final symbol table, because until then we do not know the correct value to give the symbols. We built the .dynstr section as we went along in elf_link_add_object_symbols. */ s = bfd_get_section_by_name (dynobj, ".dynsym"); BFD_ASSERT (s != NULL); s->_raw_size = dynsymcount * sizeof (Elf_External_Sym); s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size); if (s->contents == NULL && s->_raw_size != 0) return false; /* The first entry in .dynsym is a dummy symbol. */ isym.st_value = 0; isym.st_size = 0; isym.st_name = 0; isym.st_info = 0; isym.st_other = 0; isym.st_shndx = 0; elf_swap_symbol_out (output_bfd, &isym, (PTR) (Elf_External_Sym *) s->contents); for (i = 0; elf_buckets[i] != 0; i++) { bucketcount = elf_buckets[i]; if (dynsymcount < elf_buckets[i + 1]) break; } s = bfd_get_section_by_name (dynobj, ".hash"); BFD_ASSERT (s != NULL); s->_raw_size = (2 + bucketcount + dynsymcount) * (ARCH_SIZE / 8); s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size); if (s->contents == NULL) return false; memset (s->contents, 0, (size_t) s->_raw_size); put_word (output_bfd, bucketcount, s->contents); put_word (output_bfd, dynsymcount, s->contents + (ARCH_SIZE / 8)); elf_hash_table (info)->bucketcount = bucketcount; s = bfd_get_section_by_name (dynobj, ".dynstr"); BFD_ASSERT (s != NULL); s->_raw_size = _bfd_stringtab_size (elf_hash_table (info)->dynstr); if (! elf_add_dynamic_entry (info, DT_NULL, 0)) return false; } return true; } /* Make the backend pick a good value for a dynamic symbol. This is called via elf_link_hash_traverse, and also calls itself recursively. */ static boolean elf_adjust_dynamic_symbol (h, data) struct elf_link_hash_entry *h; PTR data; { struct elf_info_failed *eif = (struct elf_info_failed *) data; bfd *dynobj; struct elf_backend_data *bed; /* Ignore indirect symbols. There are added by the versioning code. */ if (h->root.type == bfd_link_hash_indirect) return true; /* If this symbol was mentioned in a non-ELF file, try to set DEF_REGULAR and REF_REGULAR correctly. This is the only way to permit a non-ELF file to correctly refer to a symbol defined in an ELF dynamic object. */ if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) != 0) { if (h->root.type != bfd_link_hash_defined && h->root.type != bfd_link_hash_defweak) h->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR; else { if (h->root.u.def.section->owner != NULL && (bfd_get_flavour (h->root.u.def.section->owner) == bfd_target_elf_flavour)) h->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR; else h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; } if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0) { if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h)) { eif->failed = true; return false; } } } /* If this is a final link, and the symbol was defined as a common symbol in a regular object file, and there was no definition in any dynamic object, then the linker will have allocated space for the symbol in a common section but the ELF_LINK_HASH_DEF_REGULAR flag will not have been set. */ if (h->root.type == bfd_link_hash_defined && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0 && (h->root.u.def.section->owner->flags & DYNAMIC) == 0) h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; /* If -Bsymbolic was used (which means to bind references to global symbols to the definition within the shared object), and this symbol was defined in a regular object, then it actually doesn't need a PLT entry. */ if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0 && eif->info->shared && eif->info->symbolic && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0) h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT; /* If this symbol does not require a PLT entry, and it is not defined by a dynamic object, or is not referenced by a regular object, ignore it. We do have to handle a weak defined symbol, even if no regular object refers to it, if we decided to add it to the dynamic symbol table. FIXME: Do we normally need to worry about symbols which are defined by one dynamic object and referenced by another one? */ if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0 || ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0 && (h->weakdef == NULL || h->weakdef->dynindx == -1)))) return true; /* If we've already adjusted this symbol, don't do it again. This can happen via a recursive call. */ if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0) return true; /* Don't look at this symbol again. Note that we must set this after checking the above conditions, because we may look at a symbol once, decide not to do anything, and then get called recursively later after REF_REGULAR is set below. */ h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED; /* If this is a weak definition, and we know a real definition, and the real symbol is not itself defined by a regular object file, then get a good value for the real definition. We handle the real symbol first, for the convenience of the backend routine. Note that there is a confusing case here. If the real definition is defined by a regular object file, we don't get the real symbol from the dynamic object, but we do get the weak symbol. If the processor backend uses a COPY reloc, then if some routine in the dynamic object changes the real symbol, we will not see that change in the corresponding weak symbol. This is the way other ELF linkers work as well, and seems to be a result of the shared library model. I will clarify this issue. Most SVR4 shared libraries define the variable _timezone and define timezone as a weak synonym. The tzset call changes _timezone. If you write extern int timezone; int _timezone = 5; int main () { tzset (); printf ("%d %d\n", timezone, _timezone); } you might expect that, since timezone is a synonym for _timezone, the same number will print both times. However, if the processor backend uses a COPY reloc, then actually timezone will be copied into your process image, and, since you define _timezone yourself, _timezone will not. Thus timezone and _timezone will wind up at different memory locations. The tzset call will set _timezone, leaving timezone unchanged. */ if (h->weakdef != NULL) { struct elf_link_hash_entry *weakdef; BFD_ASSERT (h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak); weakdef = h->weakdef; BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined || weakdef->root.type == bfd_link_hash_defweak); BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC); if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0) { /* This symbol is defined by a regular object file, so we will not do anything special. Clear weakdef for the convenience of the processor backend. */ h->weakdef = NULL; } else { /* There is an implicit reference by a regular object file via the weak symbol. */ weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR; if (! elf_adjust_dynamic_symbol (weakdef, (PTR) eif)) return false; } } dynobj = elf_hash_table (eif->info)->dynobj; bed = get_elf_backend_data (dynobj); if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h)) { eif->failed = true; return false; } return true; } /* This routine is used to export all defined symbols into the dynamic symbol table. It is called via elf_link_hash_traverse. */ static boolean elf_export_symbol (h, data) struct elf_link_hash_entry *h; PTR data; { struct elf_info_failed *eif = (struct elf_info_failed *) data; if (h->dynindx == -1 && (h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0) { if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h)) { eif->failed = true; return false; } } return true; } /* Look through the symbols which are defined in other shared libraries and referenced here. Update the list of version dependencies. This will be put into the .gnu.version_r section. This function is called via elf_link_hash_traverse. */ static boolean elf_link_find_version_dependencies (h, data) struct elf_link_hash_entry *h; PTR data; { struct elf_find_verdep_info *rinfo = (struct elf_find_verdep_info *) data; Elf_Internal_Verneed *t; Elf_Internal_Vernaux *a; /* We only care about symbols defined in shared objects with version information. */ if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0 || h->dynindx == -1 || h->verinfo.verdef == NULL) return true; /* See if we already know about this version. */ for (t = elf_tdata (rinfo->output_bfd)->verref; t != NULL; t = t->vn_nextref) { if (t->vn_bfd == h->verinfo.verdef->vd_bfd) continue; for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr) if (a->vna_nodename == h->verinfo.verdef->vd_nodename) return true; break; } /* This is a new version. Add it to tree we are building. */ if (t == NULL) { t = (Elf_Internal_Verneed *) bfd_zalloc (rinfo->output_bfd, sizeof *t); if (t == NULL) { rinfo->failed = true; return false; } t->vn_bfd = h->verinfo.verdef->vd_bfd; t->vn_nextref = elf_tdata (rinfo->output_bfd)->verref; elf_tdata (rinfo->output_bfd)->verref = t; } a = (Elf_Internal_Vernaux *) bfd_zalloc (rinfo->output_bfd, sizeof *a); /* Note that we are copying a string pointer here, and testing it above. If bfd_elf_string_from_elf_section is ever changed to discard the string data when low in memory, this will have to be fixed. */ a->vna_nodename = h->verinfo.verdef->vd_nodename; a->vna_flags = h->verinfo.verdef->vd_flags; a->vna_nextptr = t->vn_auxptr; h->verinfo.verdef->vd_exp_refno = rinfo->vers; ++rinfo->vers; a->vna_other = h->verinfo.verdef->vd_exp_refno + 1; t->vn_auxptr = a; return true; } /* Figure out appropriate versions for all the symbols. We may not have the version number script until we have read all of the input files, so until that point we don't know which symbols should be local. This function is called via elf_link_hash_traverse. */ static boolean elf_link_assign_sym_version (h, data) struct elf_link_hash_entry *h; PTR data; { struct elf_assign_sym_version_info *sinfo = (struct elf_assign_sym_version_info *) data; struct bfd_link_info *info = sinfo->info; char *p; /* We only need version numbers for symbols defined in regular objects. */ if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) return true; p = strchr (h->root.root.string, ELF_VER_CHR); if (p != NULL && h->verinfo.vertree == NULL) { struct bfd_elf_version_tree *t; boolean hidden; hidden = true; /* There are two consecutive ELF_VER_CHR characters if this is not a hidden symbol. */ ++p; if (*p == ELF_VER_CHR) { hidden = false; ++p; } /* If there is no version string, we can just return out. */ if (*p == '\0') { if (hidden) h->elf_link_hash_flags |= ELF_LINK_HIDDEN; return true; } /* Look for the version. If we find it, it is no longer weak. */ for (t = sinfo->verdefs; t != NULL; t = t->next) { if (strcmp (t->name, p) == 0) { h->verinfo.vertree = t; t->used = true; break; } } if (t == NULL) { /* We could not find the version. Return an error. FIXME: Why? */ (*_bfd_error_handler) ("%s: invalid version %s", bfd_get_filename (sinfo->output_bfd), h->root.root.string); bfd_set_error (bfd_error_bad_value); sinfo->failed = true; return false; } if (hidden) h->elf_link_hash_flags |= ELF_LINK_HIDDEN; } /* If we don't have a version for this symbol, see if we can find something. */ if (h->verinfo.vertree == NULL && sinfo->verdefs != NULL) { struct bfd_elf_version_tree *t; struct bfd_elf_version_tree *deflt; struct bfd_elf_version_expr *d; /* See if can find what version this symbol is in. If the symbol is supposed to eb local, then don't actually register it. */ deflt = NULL; for (t = sinfo->verdefs; t != NULL; t = t->next) { if (t->globals != NULL) { for (d = t->globals; d != NULL; d = d->next) { if (fnmatch (d->match, h->root.root.string, 0) == 0) { h->verinfo.vertree = t; break; } } if (d != NULL) break; } if (t->locals != NULL) { for (d = t->locals; d != NULL; d = d->next) { if (d->match[0] == '*' && d->match[1] == '\0') deflt = t; else if (fnmatch (d->match, h->root.root.string, 0) == 0) { h->verinfo.vertree = t; if (h->dynindx != -1 && info->shared && ! sinfo->export_dynamic && (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0) { sinfo->removed_dynamic = true; h->dynindx = -1; /* FIXME: The name of the symbol has already been recorded in the dynamic string table section. */ } break; } } if (d != NULL) break; } } if (deflt != NULL && h->verinfo.vertree == NULL) { h->verinfo.vertree = deflt; if (h->dynindx != -1 && info->shared && ! sinfo->export_dynamic && (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0) { sinfo->removed_dynamic = true; h->dynindx = -1; /* FIXME: The name of the symbol has already been recorded in the dynamic string table section. */ } } } return true; } /* This function is used to renumber the dynamic symbols, if some of them are removed because they are marked as local. This is called via elf_link_hash_traverse. */ static boolean elf_link_renumber_dynsyms (h, data) struct elf_link_hash_entry *h; PTR data; { struct bfd_link_info *info = (struct bfd_link_info *) data; if (h->dynindx != -1) { h->dynindx = elf_hash_table (info)->dynsymcount; ++elf_hash_table (info)->dynsymcount; } return true; } /* Final phase of ELF linker. */ /* A structure we use to avoid passing large numbers of arguments. */ struct elf_final_link_info { /* General link information. */ struct bfd_link_info *info; /* Output BFD. */ bfd *output_bfd; /* Symbol string table. */ struct bfd_strtab_hash *symstrtab; /* .dynsym section. */ asection *dynsym_sec; /* .hash section. */ asection *hash_sec; /* symbol version section (.gnu.version). */ asection *symver_sec; /* Buffer large enough to hold contents of any section. */ bfd_byte *contents; /* Buffer large enough to hold external relocs of any section. */ PTR external_relocs; /* Buffer large enough to hold internal relocs of any section. */ Elf_Internal_Rela *internal_relocs; /* Buffer large enough to hold external local symbols of any input BFD. */ Elf_External_Sym *external_syms; /* Buffer large enough to hold internal local symbols of any input BFD. */ Elf_Internal_Sym *internal_syms; /* Array large enough to hold a symbol index for each local symbol of any input BFD. */ long *indices; /* Array large enough to hold a section pointer for each local symbol of any input BFD. */ asection **sections; /* Buffer to hold swapped out symbols. */ Elf_External_Sym *symbuf; /* Number of swapped out symbols in buffer. */ size_t symbuf_count; /* Number of symbols which fit in symbuf. */ size_t symbuf_size; }; static boolean elf_link_output_sym PARAMS ((struct elf_final_link_info *, const char *, Elf_Internal_Sym *, asection *)); static boolean elf_link_flush_output_syms PARAMS ((struct elf_final_link_info *)); static boolean elf_link_output_extsym PARAMS ((struct elf_link_hash_entry *, PTR)); static boolean elf_link_input_bfd PARAMS ((struct elf_final_link_info *, bfd *)); static boolean elf_reloc_link_order PARAMS ((bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *)); /* This struct is used to pass information to routines called via elf_link_hash_traverse which must return failure. */ struct elf_finfo_failed { boolean failed; struct elf_final_link_info *finfo; }; /* Do the final step of an ELF link. */ boolean elf_bfd_final_link (abfd, info) bfd *abfd; struct bfd_link_info *info; { boolean dynamic; bfd *dynobj; struct elf_final_link_info finfo; register asection *o; register struct bfd_link_order *p; register bfd *sub; size_t max_contents_size; size_t max_external_reloc_size; size_t max_internal_reloc_count; size_t max_sym_count; file_ptr off; Elf_Internal_Sym elfsym; unsigned int i; Elf_Internal_Shdr *symtab_hdr; Elf_Internal_Shdr *symstrtab_hdr; struct elf_backend_data *bed = get_elf_backend_data (abfd); struct elf_finfo_failed eif; if (info->shared) abfd->flags |= DYNAMIC; dynamic = elf_hash_table (info)->dynamic_sections_created; dynobj = elf_hash_table (info)->dynobj; finfo.info = info; finfo.output_bfd = abfd; finfo.symstrtab = elf_stringtab_init (); if (finfo.symstrtab == NULL) return false; if (! dynamic) { finfo.dynsym_sec = NULL; finfo.hash_sec = NULL; finfo.symver_sec = NULL; } else { finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym"); finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash"); BFD_ASSERT (finfo.dynsym_sec != NULL && finfo.hash_sec != NULL); finfo.symver_sec = bfd_get_section_by_name (dynobj, ".gnu.version"); /* Note that it is OK if symver_sec is NULL. */ } finfo.contents = NULL; finfo.external_relocs = NULL; finfo.internal_relocs = NULL; finfo.external_syms = NULL; finfo.internal_syms = NULL; finfo.indices = NULL; finfo.sections = NULL; finfo.symbuf = NULL; finfo.symbuf_count = 0; /* Count up the number of relocations we will output for each output section, so that we know the sizes of the reloc sections. We also figure out some maximum sizes. */ max_contents_size = 0; max_external_reloc_size = 0; max_internal_reloc_count = 0; max_sym_count = 0; for (o = abfd->sections; o != (asection *) NULL; o = o->next) { o->reloc_count = 0; for (p = o->link_order_head; p != NULL; p = p->next) { if (p->type == bfd_section_reloc_link_order || p->type == bfd_symbol_reloc_link_order) ++o->reloc_count; else if (p->type == bfd_indirect_link_order) { asection *sec; sec = p->u.indirect.section; /* Mark all sections which are to be included in the link. This will normally be every section. We need to do this so that we can identify any sections which the linker has decided to not include. */ sec->linker_mark = true; if (info->relocateable) o->reloc_count += sec->reloc_count; if (sec->_raw_size > max_contents_size) max_contents_size = sec->_raw_size; if (sec->_cooked_size > max_contents_size) max_contents_size = sec->_cooked_size; /* We are interested in just local symbols, not all symbols. */ if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour && (sec->owner->flags & DYNAMIC) == 0) { size_t sym_count; if (elf_bad_symtab (sec->owner)) sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size / sizeof (Elf_External_Sym)); else sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info; if (sym_count > max_sym_count) max_sym_count = sym_count; if ((sec->flags & SEC_RELOC) != 0) { size_t ext_size; ext_size = elf_section_data (sec)->rel_hdr.sh_size; if (ext_size > max_external_reloc_size) max_external_reloc_size = ext_size; if (sec->reloc_count > max_internal_reloc_count) max_internal_reloc_count = sec->reloc_count; } } } } if (o->reloc_count > 0) o->flags |= SEC_RELOC; else { /* Explicitly clear the SEC_RELOC flag. The linker tends to set it (this is probably a bug) and if it is set assign_section_numbers will create a reloc section. */ o->flags &=~ SEC_RELOC; } /* If the SEC_ALLOC flag is not set, force the section VMA to zero. This is done in elf_fake_sections as well, but forcing the VMA to 0 here will ensure that relocs against these sections are handled correctly. */ if ((o->flags & SEC_ALLOC) == 0 && ! o->user_set_vma) o->vma = 0; } /* Figure out the file positions for everything but the symbol table and the relocs. We set symcount to force assign_section_numbers to create a symbol table. */ abfd->symcount = info->strip == strip_all ? 0 : 1; BFD_ASSERT (! abfd->output_has_begun); if (! _bfd_elf_compute_section_file_positions (abfd, info)) goto error_return; /* That created the reloc sections. Set their sizes, and assign them file positions, and allocate some buffers. */ for (o = abfd->sections; o != NULL; o = o->next) { if ((o->flags & SEC_RELOC) != 0) { Elf_Internal_Shdr *rel_hdr; register struct elf_link_hash_entry **p, **pend; rel_hdr = &elf_section_data (o)->rel_hdr; rel_hdr->sh_size = rel_hdr->sh_entsize * o->reloc_count; /* The contents field must last into write_object_contents, so we allocate it with bfd_alloc rather than malloc. */ rel_hdr->contents = (PTR) bfd_alloc (abfd, rel_hdr->sh_size); if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0) goto error_return; p = ((struct elf_link_hash_entry **) bfd_malloc (o->reloc_count * sizeof (struct elf_link_hash_entry *))); if (p == NULL && o->reloc_count != 0) goto error_return; elf_section_data (o)->rel_hashes = p; pend = p + o->reloc_count; for (; p < pend; p++) *p = NULL; /* Use the reloc_count field as an index when outputting the relocs. */ o->reloc_count = 0; } } _bfd_elf_assign_file_positions_for_relocs (abfd); /* We have now assigned file positions for all the sections except .symtab and .strtab. We start the .symtab section at the current file position, and write directly to it. We build the .strtab section in memory. */ abfd->symcount = 0; symtab_hdr = &elf_tdata (abfd)->symtab_hdr; /* sh_name is set in prep_headers. */ symtab_hdr->sh_type = SHT_SYMTAB; symtab_hdr->sh_flags = 0; symtab_hdr->sh_addr = 0; symtab_hdr->sh_size = 0; symtab_hdr->sh_entsize = sizeof (Elf_External_Sym); /* sh_link is set in assign_section_numbers. */ /* sh_info is set below. */ /* sh_offset is set just below. */ symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */ off = elf_tdata (abfd)->next_file_pos; off = _bfd_elf_assign_file_position_for_section (symtab_hdr, off, true); /* Note that at this point elf_tdata (abfd)->next_file_pos is incorrect. We do not yet know the size of the .symtab section. We correct next_file_pos below, after we do know the size. */ /* Allocate a buffer to hold swapped out symbols. This is to avoid continuously seeking to the right position in the file. */ if (! info->keep_memory || max_sym_count < 20) finfo.symbuf_size = 20; else finfo.symbuf_size = max_sym_count; finfo.symbuf = ((Elf_External_Sym *) bfd_malloc (finfo.symbuf_size * sizeof (Elf_External_Sym))); if (finfo.symbuf == NULL) goto error_return; /* Start writing out the symbol table. The first symbol is always a dummy symbol. */ if (info->strip != strip_all || info->relocateable) { elfsym.st_value = 0; elfsym.st_size = 0; elfsym.st_info = 0; elfsym.st_other = 0; elfsym.st_shndx = SHN_UNDEF; if (! elf_link_output_sym (&finfo, (const char *) NULL, &elfsym, bfd_und_section_ptr)) goto error_return; } #if 0 /* Some standard ELF linkers do this, but we don't because it causes bootstrap comparison failures. */ /* Output a file symbol for the output file as the second symbol. We output this even if we are discarding local symbols, although I'm not sure if this is correct. */ elfsym.st_value = 0; elfsym.st_size = 0; elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE); elfsym.st_other = 0; elfsym.st_shndx = SHN_ABS; if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd), &elfsym, bfd_abs_section_ptr)) goto error_return; #endif /* Output a symbol for each section. We output these even if we are discarding local symbols, since they are used for relocs. These symbols have no names. We store the index of each one in the index field of the section, so that we can find it again when outputting relocs. */ if (info->strip != strip_all || info->relocateable) { elfsym.st_value = 0; elfsym.st_size = 0; elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION); elfsym.st_other = 0; for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++) { o = section_from_elf_index (abfd, i); if (o != NULL) o->target_index = abfd->symcount; elfsym.st_shndx = i; if (! elf_link_output_sym (&finfo, (const char *) NULL, &elfsym, o)) goto error_return; } } /* Allocate some memory to hold information read in from the input files. */ finfo.contents = (bfd_byte *) bfd_malloc (max_contents_size); finfo.external_relocs = (PTR) bfd_malloc (max_external_reloc_size); finfo.internal_relocs = ((Elf_Internal_Rela *) bfd_malloc (max_internal_reloc_count * sizeof (Elf_Internal_Rela))); finfo.external_syms = ((Elf_External_Sym *) bfd_malloc (max_sym_count * sizeof (Elf_External_Sym))); finfo.internal_syms = ((Elf_Internal_Sym *) bfd_malloc (max_sym_count * sizeof (Elf_Internal_Sym))); finfo.indices = (long *) bfd_malloc (max_sym_count * sizeof (long)); finfo.sections = ((asection **) bfd_malloc (max_sym_count * sizeof (asection *))); if ((finfo.contents == NULL && max_contents_size != 0) || (finfo.external_relocs == NULL && max_external_reloc_size != 0) || (finfo.internal_relocs == NULL && max_internal_reloc_count != 0) || (finfo.external_syms == NULL && max_sym_count != 0) || (finfo.internal_syms == NULL && max_sym_count != 0) || (finfo.indices == NULL && max_sym_count != 0) || (finfo.sections == NULL && max_sym_count != 0)) goto error_return; /* Since ELF permits relocations to be against local symbols, we must have the local symbols available when we do the relocations. Since we would rather only read the local symbols once, and we would rather not keep them in memory, we handle all the relocations for a single input file at the same time. Unfortunately, there is no way to know the total number of local symbols until we have seen all of them, and the local symbol indices precede the global symbol indices. This means that when we are generating relocateable output, and we see a reloc against a global symbol, we can not know the symbol index until we have finished examining all the local symbols to see which ones we are going to output. To deal with this, we keep the relocations in memory, and don't output them until the end of the link. This is an unfortunate waste of memory, but I don't see a good way around it. Fortunately, it only happens when performing a relocateable link, which is not the common case. FIXME: If keep_memory is set we could write the relocs out and then read them again; I don't know how bad the memory loss will be. */ for (sub = info->input_bfds; sub != NULL; sub = sub->next) sub->output_has_begun = false; for (o = abfd->sections; o != NULL; o = o->next) { for (p = o->link_order_head; p != NULL; p = p->next) { if (p->type == bfd_indirect_link_order && (bfd_get_flavour (p->u.indirect.section->owner) == bfd_target_elf_flavour)) { sub = p->u.indirect.section->owner; if (! sub->output_has_begun) { if (! elf_link_input_bfd (&finfo, sub)) goto error_return; sub->output_has_begun = true; } } else if (p->type == bfd_section_reloc_link_order || p->type == bfd_symbol_reloc_link_order) { if (! elf_reloc_link_order (abfd, info, o, p)) goto error_return; } else { if (! _bfd_default_link_order (abfd, info, o, p)) goto error_return; } } } /* That wrote out all the local symbols. Finish up the symbol table with the global symbols. */ /* The sh_info field records the index of the first non local symbol. */ symtab_hdr->sh_info = abfd->symcount; if (dynamic) elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info = 1; /* We get the global symbols from the hash table. */ eif.failed = false; eif.finfo = &finfo; elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym, (PTR) &eif); if (eif.failed) return false; /* Flush all symbols to the file. */ if (! elf_link_flush_output_syms (&finfo)) return false; /* Now we know the size of the symtab section. */ off += symtab_hdr->sh_size; /* Finish up and write out the symbol string table (.strtab) section. */ symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr; /* sh_name was set in prep_headers. */ symstrtab_hdr->sh_type = SHT_STRTAB; symstrtab_hdr->sh_flags = 0; symstrtab_hdr->sh_addr = 0; symstrtab_hdr->sh_size = _bfd_stringtab_size (finfo.symstrtab); symstrtab_hdr->sh_entsize = 0; symstrtab_hdr->sh_link = 0; symstrtab_hdr->sh_info = 0; /* sh_offset is set just below. */ symstrtab_hdr->sh_addralign = 1; off = _bfd_elf_assign_file_position_for_section (symstrtab_hdr, off, true); elf_tdata (abfd)->next_file_pos = off; if (abfd->symcount > 0) { if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0 || ! _bfd_stringtab_emit (abfd, finfo.symstrtab)) return false; } /* Adjust the relocs to have the correct symbol indices. */ for (o = abfd->sections; o != NULL; o = o->next) { struct elf_link_hash_entry **rel_hash; Elf_Internal_Shdr *rel_hdr; if ((o->flags & SEC_RELOC) == 0) continue; rel_hash = elf_section_data (o)->rel_hashes; rel_hdr = &elf_section_data (o)->rel_hdr; for (i = 0; i < o->reloc_count; i++, rel_hash++) { if (*rel_hash == NULL) continue; BFD_ASSERT ((*rel_hash)->indx >= 0); if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel)) { Elf_External_Rel *erel; Elf_Internal_Rel irel; erel = (Elf_External_Rel *) rel_hdr->contents + i; elf_swap_reloc_in (abfd, erel, &irel); irel.r_info = ELF_R_INFO ((*rel_hash)->indx, ELF_R_TYPE (irel.r_info)); elf_swap_reloc_out (abfd, &irel, erel); } else { Elf_External_Rela *erela; Elf_Internal_Rela irela; BFD_ASSERT (rel_hdr->sh_entsize == sizeof (Elf_External_Rela)); erela = (Elf_External_Rela *) rel_hdr->contents + i; elf_swap_reloca_in (abfd, erela, &irela); irela.r_info = ELF_R_INFO ((*rel_hash)->indx, ELF_R_TYPE (irela.r_info)); elf_swap_reloca_out (abfd, &irela, erela); } } /* Set the reloc_count field to 0 to prevent write_relocs from trying to swap the relocs out itself. */ o->reloc_count = 0; } /* If we are linking against a dynamic object, or generating a shared library, finish up the dynamic linking information. */ if (dynamic) { Elf_External_Dyn *dyncon, *dynconend; /* Fix up .dynamic entries. */ o = bfd_get_section_by_name (dynobj, ".dynamic"); BFD_ASSERT (o != NULL); dyncon = (Elf_External_Dyn *) o->contents; dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size); for (; dyncon < dynconend; dyncon++) { Elf_Internal_Dyn dyn; const char *name; unsigned int type; elf_swap_dyn_in (dynobj, dyncon, &dyn); switch (dyn.d_tag) { default: break; /* SVR4 linkers seem to set DT_INIT and DT_FINI based on magic _init and _fini symbols. This is pretty ugly, but we are compatible. */ case DT_INIT: name = "_init"; goto get_sym; case DT_FINI: name = "_fini"; get_sym: { struct elf_link_hash_entry *h; h = elf_link_hash_lookup (elf_hash_table (info), name, false, false, true); if (h != NULL && (h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak)) { dyn.d_un.d_val = h->root.u.def.value; o = h->root.u.def.section; if (o->output_section != NULL) dyn.d_un.d_val += (o->output_section->vma + o->output_offset); else { /* The symbol is imported from another shared library and does not apply to this one. */ dyn.d_un.d_val = 0; } elf_swap_dyn_out (dynobj, &dyn, dyncon); } } break; case DT_HASH: name = ".hash"; goto get_vma; case DT_STRTAB: name = ".dynstr"; goto get_vma; case DT_SYMTAB: name = ".dynsym"; goto get_vma; case DT_VERDEF: name = ".gnu.version_d"; goto get_vma; case DT_VERNEED: name = ".gnu.version_r"; goto get_vma; case DT_VERSYM: name = ".gnu.version"; get_vma: o = bfd_get_section_by_name (abfd, name); BFD_ASSERT (o != NULL); dyn.d_un.d_ptr = o->vma; elf_swap_dyn_out (dynobj, &dyn, dyncon); break; case DT_REL: case DT_RELA: case DT_RELSZ: case DT_RELASZ: if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ) type = SHT_REL; else type = SHT_RELA; dyn.d_un.d_val = 0; for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++) { Elf_Internal_Shdr *hdr; hdr = elf_elfsections (abfd)[i]; if (hdr->sh_type == type && (hdr->sh_flags & SHF_ALLOC) != 0) { if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ) dyn.d_un.d_val += hdr->sh_size; else { if (dyn.d_un.d_val == 0 || hdr->sh_addr < dyn.d_un.d_val) dyn.d_un.d_val = hdr->sh_addr; } } } elf_swap_dyn_out (dynobj, &dyn, dyncon); break; } } } /* If we have created any dynamic sections, then output them. */ if (dynobj != NULL) { if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info)) goto error_return; for (o = dynobj->sections; o != NULL; o = o->next) { if ((o->flags & SEC_HAS_CONTENTS) == 0 || o->_raw_size == 0) continue; if ((o->flags & SEC_LINKER_CREATED) == 0) { /* At this point, we are only interested in sections created by elf_link_create_dynamic_sections. */ continue; } if ((elf_section_data (o->output_section)->this_hdr.sh_type != SHT_STRTAB) || strcmp (bfd_get_section_name (abfd, o), ".dynstr") != 0) { if (! bfd_set_section_contents (abfd, o->output_section, o->contents, o->output_offset, o->_raw_size)) goto error_return; } else { file_ptr off; /* The contents of the .dynstr section are actually in a stringtab. */ off = elf_section_data (o->output_section)->this_hdr.sh_offset; if (bfd_seek (abfd, off, SEEK_SET) != 0 || ! _bfd_stringtab_emit (abfd, elf_hash_table (info)->dynstr)) goto error_return; } } } /* If we have optimized stabs strings, output them. */ if (elf_hash_table (info)->stab_info != NULL) { if (! _bfd_write_stab_strings (abfd, &elf_hash_table (info)->stab_info)) goto error_return; } if (finfo.symstrtab != NULL) _bfd_stringtab_free (finfo.symstrtab); if (finfo.contents != NULL) free (finfo.contents); if (finfo.external_relocs != NULL) free (finfo.external_relocs); if (finfo.internal_relocs != NULL) free (finfo.internal_relocs); if (finfo.external_syms != NULL) free (finfo.external_syms); if (finfo.internal_syms != NULL) free (finfo.internal_syms); if (finfo.indices != NULL) free (finfo.indices); if (finfo.sections != NULL) free (finfo.sections); if (finfo.symbuf != NULL) free (finfo.symbuf); for (o = abfd->sections; o != NULL; o = o->next) { if ((o->flags & SEC_RELOC) != 0 && elf_section_data (o)->rel_hashes != NULL) free (elf_section_data (o)->rel_hashes); } elf_tdata (abfd)->linker = true; return true; error_return: if (finfo.symstrtab != NULL) _bfd_stringtab_free (finfo.symstrtab); if (finfo.contents != NULL) free (finfo.contents); if (finfo.external_relocs != NULL) free (finfo.external_relocs); if (finfo.internal_relocs != NULL) free (finfo.internal_relocs); if (finfo.external_syms != NULL) free (finfo.external_syms); if (finfo.internal_syms != NULL) free (finfo.internal_syms); if (finfo.indices != NULL) free (finfo.indices); if (finfo.sections != NULL) free (finfo.sections); if (finfo.symbuf != NULL) free (finfo.symbuf); for (o = abfd->sections; o != NULL; o = o->next) { if ((o->flags & SEC_RELOC) != 0 && elf_section_data (o)->rel_hashes != NULL) free (elf_section_data (o)->rel_hashes); } return false; } /* Add a symbol to the output symbol table. */ static boolean elf_link_output_sym (finfo, name, elfsym, input_sec) struct elf_final_link_info *finfo; const char *name; Elf_Internal_Sym *elfsym; asection *input_sec; { boolean (*output_symbol_hook) PARAMS ((bfd *, struct bfd_link_info *info, const char *, Elf_Internal_Sym *, asection *)); output_symbol_hook = get_elf_backend_data (finfo->output_bfd)-> elf_backend_link_output_symbol_hook; if (output_symbol_hook != NULL) { if (! ((*output_symbol_hook) (finfo->output_bfd, finfo->info, name, elfsym, input_sec))) return false; } if (name == (const char *) NULL || *name == '\0') elfsym->st_name = 0; else { elfsym->st_name = (unsigned long) _bfd_stringtab_add (finfo->symstrtab, name, true, false); if (elfsym->st_name == (unsigned long) -1) return false; } if (finfo->symbuf_count >= finfo->symbuf_size) { if (! elf_link_flush_output_syms (finfo)) return false; } elf_swap_symbol_out (finfo->output_bfd, elfsym, (PTR) (finfo->symbuf + finfo->symbuf_count)); ++finfo->symbuf_count; ++finfo->output_bfd->symcount; return true; } /* Flush the output symbols to the file. */ static boolean elf_link_flush_output_syms (finfo) struct elf_final_link_info *finfo; { if (finfo->symbuf_count > 0) { Elf_Internal_Shdr *symtab; symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr; if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size, SEEK_SET) != 0 || (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count, sizeof (Elf_External_Sym), finfo->output_bfd) != finfo->symbuf_count * sizeof (Elf_External_Sym))) return false; symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym); finfo->symbuf_count = 0; } return true; } /* Add an external symbol to the symbol table. This is called from the hash table traversal routine. */ static boolean elf_link_output_extsym (h, data) struct elf_link_hash_entry *h; PTR data; { struct elf_finfo_failed *eif = (struct elf_finfo_failed *) data; struct elf_final_link_info *finfo = eif->finfo; boolean strip; Elf_Internal_Sym sym; asection *input_sec; /* If we are not creating a shared library, and this symbol is referenced by a shared library but is not defined anywhere, then warn that it is undefined. If we do not do this, the runtime linker will complain that the symbol is undefined when the program is run. We don't have to worry about symbols that are referenced by regular files, because we will already have issued warnings for them. */ if (! finfo->info->relocateable && ! finfo->info->shared && h->root.type == bfd_link_hash_undefined && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0) { if (! ((*finfo->info->callbacks->undefined_symbol) (finfo->info, h->root.root.string, h->root.u.undef.abfd, (asection *) NULL, 0))) { eif->failed = true; return false; } } /* We don't want to output symbols that have never been mentioned by a regular file, or that we have been told to strip. However, if h->indx is set to -2, the symbol is used by a reloc and we must output it. */ if (h->indx == -2) strip = false; else if (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0) && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0) strip = true; else if (finfo->info->strip == strip_all || (finfo->info->strip == strip_some && bfd_hash_lookup (finfo->info->keep_hash, h->root.root.string, false, false) == NULL)) strip = true; else strip = false; /* If we're stripping it, and it's not a dynamic symbol, there's nothing else to do. */ if (strip && h->dynindx == -1) return true; sym.st_value = 0; sym.st_size = h->size; sym.st_other = h->other; if (h->root.type == bfd_link_hash_undefweak || h->root.type == bfd_link_hash_defweak) sym.st_info = ELF_ST_INFO (STB_WEAK, h->type); else sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type); switch (h->root.type) { default: case bfd_link_hash_new: abort (); return false; case bfd_link_hash_undefined: input_sec = bfd_und_section_ptr; sym.st_shndx = SHN_UNDEF; break; case bfd_link_hash_undefweak: input_sec = bfd_und_section_ptr; sym.st_shndx = SHN_UNDEF; break; case bfd_link_hash_defined: case bfd_link_hash_defweak: { input_sec = h->root.u.def.section; if (input_sec->output_section != NULL) { sym.st_shndx = _bfd_elf_section_from_bfd_section (finfo->output_bfd, input_sec->output_section); if (sym.st_shndx == (unsigned short) -1) { eif->failed = true; return false; } /* ELF symbols in relocateable files are section relative, but in nonrelocateable files they are virtual addresses. */ sym.st_value = h->root.u.def.value + input_sec->output_offset; if (! finfo->info->relocateable) sym.st_value += input_sec->output_section->vma; } else { BFD_ASSERT ((input_sec->owner->flags & DYNAMIC) != 0); sym.st_shndx = SHN_UNDEF; input_sec = bfd_und_section_ptr; } } break; case bfd_link_hash_common: input_sec = bfd_com_section_ptr; sym.st_shndx = SHN_COMMON; sym.st_value = 1 << h->root.u.c.p->alignment_power; break; case bfd_link_hash_indirect: /* These symbols are created by symbol versioning. They point to the decorated version of the name. For example, if the symbol foo@@GNU_1.2 is the default, which should be used when foo is used with no version, then we add an indirect symbol foo which points to foo@@GNU_1.2. */ if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) != 0) return true; /* Fall through. */ case bfd_link_hash_warning: /* We can't represent these symbols in ELF, although a warning symbol may have come from a .gnu.warning.SYMBOL section. We just put the target symbol in the hash table. If the target symbol does not really exist, don't do anything. */ if (h->root.u.i.link->type == bfd_link_hash_new) return true; return (elf_link_output_extsym ((struct elf_link_hash_entry *) h->root.u.i.link, data)); } /* If this symbol should be put in the .dynsym section, then put it there now. We have already know the symbol index. We also fill in the entry in the .hash section. */ if (h->dynindx != -1 && elf_hash_table (finfo->info)->dynamic_sections_created) { struct elf_backend_data *bed; char *p, *copy; const char *name; size_t bucketcount; size_t bucket; bfd_byte *bucketpos; bfd_vma chain; sym.st_name = h->dynstr_index; /* Give the processor backend a chance to tweak the symbol value, and also to finish up anything that needs to be done for this symbol. */ bed = get_elf_backend_data (finfo->output_bfd); if (! ((*bed->elf_backend_finish_dynamic_symbol) (finfo->output_bfd, finfo->info, h, &sym))) { eif->failed = true; return false; } elf_swap_symbol_out (finfo->output_bfd, &sym, (PTR) (((Elf_External_Sym *) finfo->dynsym_sec->contents) + h->dynindx)); /* We didn't include the version string in the dynamic string table, so we must not consider it in the hash table. */ name = h->root.root.string; p = strchr (name, ELF_VER_CHR); if (p == NULL) copy = NULL; else { copy = bfd_alloc (finfo->output_bfd, p - name + 1); strncpy (copy, name, p - name); copy[p - name] = '\0'; name = copy; } bucketcount = elf_hash_table (finfo->info)->bucketcount; bucket = bfd_elf_hash ((const unsigned char *) name) % bucketcount; bucketpos = ((bfd_byte *) finfo->hash_sec->contents + (bucket + 2) * (ARCH_SIZE / 8)); chain = get_word (finfo->output_bfd, bucketpos); put_word (finfo->output_bfd, h->dynindx, bucketpos); put_word (finfo->output_bfd, chain, ((bfd_byte *) finfo->hash_sec->contents + (bucketcount + 2 + h->dynindx) * (ARCH_SIZE / 8))); if (copy != NULL) bfd_release (finfo->output_bfd, copy); if (finfo->symver_sec != NULL && finfo->symver_sec->contents != NULL) { Elf_Internal_Versym iversym; if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) { if (h->verinfo.verdef == NULL) iversym.vs_vers = 0; else iversym.vs_vers = h->verinfo.verdef->vd_exp_refno + 1; } else { if (h->verinfo.vertree == NULL) iversym.vs_vers = 1; else iversym.vs_vers = h->verinfo.vertree->vernum + 1; } if ((h->elf_link_hash_flags & ELF_LINK_HIDDEN) != 0) iversym.vs_vers |= VERSYM_HIDDEN; _bfd_elf_swap_versym_out (finfo->output_bfd, &iversym, (((Elf_External_Versym *) finfo->symver_sec->contents) + h->dynindx)); } } /* If we're stripping it, then it was just a dynamic symbol, and there's nothing else to do. */ if (strip) return true; h->indx = finfo->output_bfd->symcount; if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec)) { eif->failed = true; return false; } return true; } /* Link an input file into the linker output file. This function handles all the sections and relocations of the input file at once. This is so that we only have to read the local symbols once, and don't have to keep them in memory. */ static boolean elf_link_input_bfd (finfo, input_bfd) struct elf_final_link_info *finfo; bfd *input_bfd; { boolean (*relocate_section) PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *, Elf_Internal_Rela *, Elf_Internal_Sym *, asection **)); bfd *output_bfd; Elf_Internal_Shdr *symtab_hdr; size_t locsymcount; size_t extsymoff; Elf_External_Sym *external_syms; Elf_External_Sym *esym; Elf_External_Sym *esymend; Elf_Internal_Sym *isym; long *pindex; asection **ppsection; asection *o; output_bfd = finfo->output_bfd; relocate_section = get_elf_backend_data (output_bfd)->elf_backend_relocate_section; /* If this is a dynamic object, we don't want to do anything here: we don't want the local symbols, and we don't want the section contents. */ if ((input_bfd->flags & DYNAMIC) != 0) return true; symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr; if (elf_bad_symtab (input_bfd)) { locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym); extsymoff = 0; } else { locsymcount = symtab_hdr->sh_info; extsymoff = symtab_hdr->sh_info; } /* Read the local symbols. */ if (symtab_hdr->contents != NULL) external_syms = (Elf_External_Sym *) symtab_hdr->contents; else if (locsymcount == 0) external_syms = NULL; else { external_syms = finfo->external_syms; if (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0 || (bfd_read (external_syms, sizeof (Elf_External_Sym), locsymcount, input_bfd) != locsymcount * sizeof (Elf_External_Sym))) return false; } /* Swap in the local symbols and write out the ones which we know are going into the output file. */ esym = external_syms; esymend = esym + locsymcount; isym = finfo->internal_syms; pindex = finfo->indices; ppsection = finfo->sections; for (; esym < esymend; esym++, isym++, pindex++, ppsection++) { asection *isec; const char *name; Elf_Internal_Sym osym; elf_swap_symbol_in (input_bfd, esym, isym); *pindex = -1; if (elf_bad_symtab (input_bfd)) { if (ELF_ST_BIND (isym->st_info) != STB_LOCAL) { *ppsection = NULL; continue; } } if (isym->st_shndx == SHN_UNDEF) isec = bfd_und_section_ptr; else if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE) isec = section_from_elf_index (input_bfd, isym->st_shndx); else if (isym->st_shndx == SHN_ABS) isec = bfd_abs_section_ptr; else if (isym->st_shndx == SHN_COMMON) isec = bfd_com_section_ptr; else { /* Who knows? */ isec = NULL; } *ppsection = isec; /* Don't output the first, undefined, symbol. */ if (esym == external_syms) continue; /* If we are stripping all symbols, we don't want to output this one. */ if (finfo->info->strip == strip_all) continue; /* We never output section symbols. Instead, we use the section symbol of the corresponding section in the output file. */ if (ELF_ST_TYPE (isym->st_info) == STT_SECTION) continue; /* If we are discarding all local symbols, we don't want to output this one. If we are generating a relocateable output file, then some of the local symbols may be required by relocs; we output them below as we discover that they are needed. */ if (finfo->info->discard == discard_all) continue; /* If this symbol is defined in a section which we are discarding, we don't need to keep it. For the benefit of the MIPS ELF linker, we check SEC_EXCLUDE as well as linker_mark. */ if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE && isec != NULL && (! isec->linker_mark || (! finfo->info->relocateable && (isec->flags & SEC_EXCLUDE) != 0))) continue; /* Get the name of the symbol. */ name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link, isym->st_name); if (name == NULL) return false; /* See if we are discarding symbols with this name. */ if ((finfo->info->strip == strip_some && (bfd_hash_lookup (finfo->info->keep_hash, name, false, false) == NULL)) || (finfo->info->discard == discard_l && strncmp (name, finfo->info->lprefix, finfo->info->lprefix_len) == 0)) continue; /* If we get here, we are going to output this symbol. */ osym = *isym; /* Adjust the section index for the output file. */ osym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd, isec->output_section); if (osym.st_shndx == (unsigned short) -1) return false; *pindex = output_bfd->symcount; /* ELF symbols in relocateable files are section relative, but in executable files they are virtual addresses. Note that this code assumes that all ELF sections have an associated BFD section with a reasonable value for output_offset; below we assume that they also have a reasonable value for output_section. Any special sections must be set up to meet these requirements. */ osym.st_value += isec->output_offset; if (! finfo->info->relocateable) osym.st_value += isec->output_section->vma; if (! elf_link_output_sym (finfo, name, &osym, isec)) return false; } /* Relocate the contents of each section. */ for (o = input_bfd->sections; o != NULL; o = o->next) { bfd_byte *contents; if (! o->linker_mark) { /* This section was omitted from the link. */ continue; } if ((o->flags & SEC_HAS_CONTENTS) == 0 || (o->_raw_size == 0 && (o->flags & SEC_RELOC) == 0)) continue; if ((o->flags & SEC_LINKER_CREATED) != 0) { /* Section was created by elf_link_create_dynamic_sections or somesuch. */ continue; } /* Get the contents of the section. They have been cached by a relaxation routine. Note that o is a section in an input file, so the contents field will not have been set by any of the routines which work on output files. */ if (elf_section_data (o)->this_hdr.contents != NULL) contents = elf_section_data (o)->this_hdr.contents; else { contents = finfo->contents; if (! bfd_get_section_contents (input_bfd, o, contents, (file_ptr) 0, o->_raw_size)) return false; } if ((o->flags & SEC_RELOC) != 0) { Elf_Internal_Rela *internal_relocs; /* Get the swapped relocs. */ internal_relocs = (NAME(_bfd_elf,link_read_relocs) (input_bfd, o, finfo->external_relocs, finfo->internal_relocs, false)); if (internal_relocs == NULL && o->reloc_count > 0) return false; /* Relocate the section by invoking a back end routine. The back end routine is responsible for adjusting the section contents as necessary, and (if using Rela relocs and generating a relocateable output file) adjusting the reloc addend as necessary. The back end routine does not have to worry about setting the reloc address or the reloc symbol index. The back end routine is given a pointer to the swapped in internal symbols, and can access the hash table entries for the external symbols via elf_sym_hashes (input_bfd). When generating relocateable output, the back end routine must handle STB_LOCAL/STT_SECTION symbols specially. The output symbol is going to be a section symbol corresponding to the output section, which will require the addend to be adjusted. */ if (! (*relocate_section) (output_bfd, finfo->info, input_bfd, o, contents, internal_relocs, finfo->internal_syms, finfo->sections)) return false; if (finfo->info->relocateable) { Elf_Internal_Rela *irela; Elf_Internal_Rela *irelaend; struct elf_link_hash_entry **rel_hash; Elf_Internal_Shdr *input_rel_hdr; Elf_Internal_Shdr *output_rel_hdr; /* Adjust the reloc addresses and symbol indices. */ irela = internal_relocs; irelaend = irela + o->reloc_count; rel_hash = (elf_section_data (o->output_section)->rel_hashes + o->output_section->reloc_count); for (; irela < irelaend; irela++, rel_hash++) { unsigned long r_symndx; Elf_Internal_Sym *isym; asection *sec; irela->r_offset += o->output_offset; r_symndx = ELF_R_SYM (irela->r_info); if (r_symndx == 0) continue; if (r_symndx >= locsymcount || (elf_bad_symtab (input_bfd) && finfo->sections[r_symndx] == NULL)) { long indx; /* This is a reloc against a global symbol. We have not yet output all the local symbols, so we do not know the symbol index of any global symbol. We set the rel_hash entry for this reloc to point to the global hash table entry for this symbol. The symbol index is then set at the end of elf_bfd_final_link. */ indx = r_symndx - extsymoff; *rel_hash = elf_sym_hashes (input_bfd)[indx]; /* Setting the index to -2 tells elf_link_output_extsym that this symbol is used by a reloc. */ BFD_ASSERT ((*rel_hash)->indx < 0); (*rel_hash)->indx = -2; continue; } /* This is a reloc against a local symbol. */ *rel_hash = NULL; isym = finfo->internal_syms + r_symndx; sec = finfo->sections[r_symndx]; if (ELF_ST_TYPE (isym->st_info) == STT_SECTION) { /* I suppose the backend ought to fill in the section of any STT_SECTION symbol against a processor specific section. If we have discarded a section, the output_section will be the absolute section. */ if (sec != NULL && (bfd_is_abs_section (sec) || (sec->output_section != NULL && bfd_is_abs_section (sec->output_section)))) r_symndx = 0; else if (sec == NULL || sec->owner == NULL) { bfd_set_error (bfd_error_bad_value); return false; } else { r_symndx = sec->output_section->target_index; BFD_ASSERT (r_symndx != 0); } } else { if (finfo->indices[r_symndx] == -1) { unsigned long link; const char *name; asection *osec; if (finfo->info->strip == strip_all) { /* You can't do ld -r -s. */ bfd_set_error (bfd_error_invalid_operation); return false; } /* This symbol was skipped earlier, but since it is needed by a reloc, we must output it now. */ link = symtab_hdr->sh_link; name = bfd_elf_string_from_elf_section (input_bfd, link, isym->st_name); if (name == NULL) return false; osec = sec->output_section; isym->st_shndx = _bfd_elf_section_from_bfd_section (output_bfd, osec); if (isym->st_shndx == (unsigned short) -1) return false; isym->st_value += sec->output_offset; if (! finfo->info->relocateable) isym->st_value += osec->vma; finfo->indices[r_symndx] = output_bfd->symcount; if (! elf_link_output_sym (finfo, name, isym, sec)) return false; } r_symndx = finfo->indices[r_symndx]; } irela->r_info = ELF_R_INFO (r_symndx, ELF_R_TYPE (irela->r_info)); } /* Swap out the relocs. */ input_rel_hdr = &elf_section_data (o)->rel_hdr; output_rel_hdr = &elf_section_data (o->output_section)->rel_hdr; BFD_ASSERT (output_rel_hdr->sh_entsize == input_rel_hdr->sh_entsize); irela = internal_relocs; irelaend = irela + o->reloc_count; if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel)) { Elf_External_Rel *erel; erel = ((Elf_External_Rel *) output_rel_hdr->contents + o->output_section->reloc_count); for (; irela < irelaend; irela++, erel++) { Elf_Internal_Rel irel; irel.r_offset = irela->r_offset; irel.r_info = irela->r_info; BFD_ASSERT (irela->r_addend == 0); elf_swap_reloc_out (output_bfd, &irel, erel); } } else { Elf_External_Rela *erela; BFD_ASSERT (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rela)); erela = ((Elf_External_Rela *) output_rel_hdr->contents + o->output_section->reloc_count); for (; irela < irelaend; irela++, erela++) elf_swap_reloca_out (output_bfd, irela, erela); } o->output_section->reloc_count += o->reloc_count; } } /* Write out the modified section contents. */ if (elf_section_data (o)->stab_info == NULL) { if (! bfd_set_section_contents (output_bfd, o->output_section, contents, o->output_offset, (o->_cooked_size != 0 ? o->_cooked_size : o->_raw_size))) return false; } else { if (! _bfd_write_section_stabs (output_bfd, o, &elf_section_data (o)->stab_info, contents)) return false; } } return true; } /* Generate a reloc when linking an ELF file. This is a reloc requested by the linker, and does come from any input file. This is used to build constructor and destructor tables when linking with -Ur. */ static boolean elf_reloc_link_order (output_bfd, info, output_section, link_order) bfd *output_bfd; struct bfd_link_info *info; asection *output_section; struct bfd_link_order *link_order; { reloc_howto_type *howto; long indx; bfd_vma offset; bfd_vma addend; struct elf_link_hash_entry **rel_hash_ptr; Elf_Internal_Shdr *rel_hdr; howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc); if (howto == NULL) { bfd_set_error (bfd_error_bad_value); return false; } addend = link_order->u.reloc.p->addend; /* Figure out the symbol index. */ rel_hash_ptr = (elf_section_data (output_section)->rel_hashes + output_section->reloc_count); if (link_order->type == bfd_section_reloc_link_order) { indx = link_order->u.reloc.p->u.section->target_index; BFD_ASSERT (indx != 0); *rel_hash_ptr = NULL; } else { struct elf_link_hash_entry *h; /* Treat a reloc against a defined symbol as though it were actually against the section. */ h = ((struct elf_link_hash_entry *) bfd_wrapped_link_hash_lookup (output_bfd, info, link_order->u.reloc.p->u.name, false, false, true)); if (h != NULL && (h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak)) { asection *section; section = h->root.u.def.section; indx = section->output_section->target_index; *rel_hash_ptr = NULL; /* It seems that we ought to add the symbol value to the addend here, but in practice it has already been added because it was passed to constructor_callback. */ addend += section->output_section->vma + section->output_offset; } else if (h != NULL) { /* Setting the index to -2 tells elf_link_output_extsym that this symbol is used by a reloc. */ h->indx = -2; *rel_hash_ptr = h; indx = 0; } else { if (! ((*info->callbacks->unattached_reloc) (info, link_order->u.reloc.p->u.name, (bfd *) NULL, (asection *) NULL, (bfd_vma) 0))) return false; indx = 0; } } /* If this is an inplace reloc, we must write the addend into the object file. */ if (howto->partial_inplace && addend != 0) { bfd_size_type size; bfd_reloc_status_type rstat; bfd_byte *buf; boolean ok; size = bfd_get_reloc_size (howto); buf = (bfd_byte *) bfd_zmalloc (size); if (buf == (bfd_byte *) NULL) return false; rstat = _bfd_relocate_contents (howto, output_bfd, addend, buf); switch (rstat) { case bfd_reloc_ok: break; default: case bfd_reloc_outofrange: abort (); case bfd_reloc_overflow: if (! ((*info->callbacks->reloc_overflow) (info, (link_order->type == bfd_section_reloc_link_order ? bfd_section_name (output_bfd, link_order->u.reloc.p->u.section) : link_order->u.reloc.p->u.name), howto->name, addend, (bfd *) NULL, (asection *) NULL, (bfd_vma) 0))) { free (buf); return false; } break; } ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf, (file_ptr) link_order->offset, size); free (buf); if (! ok) return false; } /* The address of a reloc is relative to the section in a relocateable file, and is a virtual address in an executable file. */ offset = link_order->offset; if (! info->relocateable) offset += output_section->vma; rel_hdr = &elf_section_data (output_section)->rel_hdr; if (rel_hdr->sh_type == SHT_REL) { Elf_Internal_Rel irel; Elf_External_Rel *erel; irel.r_offset = offset; irel.r_info = ELF_R_INFO (indx, howto->type); erel = ((Elf_External_Rel *) rel_hdr->contents + output_section->reloc_count); elf_swap_reloc_out (output_bfd, &irel, erel); } else { Elf_Internal_Rela irela; Elf_External_Rela *erela; irela.r_offset = offset; irela.r_info = ELF_R_INFO (indx, howto->type); irela.r_addend = addend; erela = ((Elf_External_Rela *) rel_hdr->contents + output_section->reloc_count); elf_swap_reloca_out (output_bfd, &irela, erela); } ++output_section->reloc_count; return true; } /* Allocate a pointer to live in a linker created section. */ boolean elf_create_pointer_linker_section (abfd, info, lsect, h, rel) bfd *abfd; struct bfd_link_info *info; elf_linker_section_t *lsect; struct elf_link_hash_entry *h; const Elf_Internal_Rela *rel; { elf_linker_section_pointers_t **ptr_linker_section_ptr = NULL; elf_linker_section_pointers_t *linker_section_ptr; unsigned long r_symndx = ELF_R_SYM (rel->r_info);; BFD_ASSERT (lsect != NULL); /* Is this a global symbol? */ if (h != NULL) { /* Has this symbol already been allocated, if so, our work is done */ if (_bfd_elf_find_pointer_linker_section (h->linker_section_pointer, rel->r_addend, lsect->which)) return true; ptr_linker_section_ptr = &h->linker_section_pointer; /* Make sure this symbol is output as a dynamic symbol. */ if (h->dynindx == -1) { if (! elf_link_record_dynamic_symbol (info, h)) return false; } if (lsect->rel_section) lsect->rel_section->_raw_size += sizeof (Elf_External_Rela); } else /* Allocation of a pointer to a local symbol */ { elf_linker_section_pointers_t **ptr = elf_local_ptr_offsets (abfd); /* Allocate a table to hold the local symbols if first time */ if (!ptr) { int num_symbols = elf_tdata (abfd)->symtab_hdr.sh_info; register unsigned int i; ptr = (elf_linker_section_pointers_t **) bfd_alloc (abfd, num_symbols * sizeof (elf_linker_section_pointers_t *)); if (!ptr) return false; elf_local_ptr_offsets (abfd) = ptr; for (i = 0; i < num_symbols; i++) ptr[i] = (elf_linker_section_pointers_t *)0; } /* Has this symbol already been allocated, if so, our work is done */ if (_bfd_elf_find_pointer_linker_section (ptr[r_symndx], rel->r_addend, lsect->which)) return true; ptr_linker_section_ptr = &ptr[r_symndx]; if (info->shared) { /* If we are generating a shared object, we need to output a R__RELATIVE reloc so that the dynamic linker can adjust this GOT entry. */ BFD_ASSERT (lsect->rel_section != NULL); lsect->rel_section->_raw_size += sizeof (Elf_External_Rela); } } /* Allocate space for a pointer in the linker section, and allocate a new pointer record from internal memory. */ BFD_ASSERT (ptr_linker_section_ptr != NULL); linker_section_ptr = (elf_linker_section_pointers_t *) bfd_alloc (abfd, sizeof (elf_linker_section_pointers_t)); if (!linker_section_ptr) return false; linker_section_ptr->next = *ptr_linker_section_ptr; linker_section_ptr->addend = rel->r_addend; linker_section_ptr->which = lsect->which; linker_section_ptr->written_address_p = false; *ptr_linker_section_ptr = linker_section_ptr; #if 0 if (lsect->hole_size && lsect->hole_offset < lsect->max_hole_offset) { linker_section_ptr->offset = lsect->section->_raw_size - lsect->hole_size + (ARCH_SIZE / 8); lsect->hole_offset += ARCH_SIZE / 8; lsect->sym_offset += ARCH_SIZE / 8; if (lsect->sym_hash) /* Bump up symbol value if needed */ { lsect->sym_hash->root.u.def.value += ARCH_SIZE / 8; #ifdef DEBUG fprintf (stderr, "Bump up %s by %ld, current value = %ld\n", lsect->sym_hash->root.root.string, (long)ARCH_SIZE / 8, (long)lsect->sym_hash->root.u.def.value); #endif } } else #endif linker_section_ptr->offset = lsect->section->_raw_size; lsect->section->_raw_size += ARCH_SIZE / 8; #ifdef DEBUG fprintf (stderr, "Create pointer in linker section %s, offset = %ld, section size = %ld\n", lsect->name, (long)linker_section_ptr->offset, (long)lsect->section->_raw_size); #endif return true; } #if ARCH_SIZE==64 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_64 (BFD, VAL, ADDR) #endif #if ARCH_SIZE==32 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_32 (BFD, VAL, ADDR) #endif /* Fill in the address for a pointer generated in alinker section. */ bfd_vma elf_finish_pointer_linker_section (output_bfd, input_bfd, info, lsect, h, relocation, rel, relative_reloc) bfd *output_bfd; bfd *input_bfd; struct bfd_link_info *info; elf_linker_section_t *lsect; struct elf_link_hash_entry *h; bfd_vma relocation; const Elf_Internal_Rela *rel; int relative_reloc; { elf_linker_section_pointers_t *linker_section_ptr; BFD_ASSERT (lsect != NULL); if (h != NULL) /* global symbol */ { linker_section_ptr = _bfd_elf_find_pointer_linker_section (h->linker_section_pointer, rel->r_addend, lsect->which); BFD_ASSERT (linker_section_ptr != NULL); if (! elf_hash_table (info)->dynamic_sections_created || (info->shared && info->symbolic && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))) { /* This is actually a static link, or it is a -Bsymbolic link and the symbol is defined locally. We must initialize this entry in the global section. When doing a dynamic link, we create a .rela. relocation entry to initialize the value. This is done in the finish_dynamic_symbol routine. */ if (!linker_section_ptr->written_address_p) { linker_section_ptr->written_address_p = true; bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend, lsect->section->contents + linker_section_ptr->offset); } } } else /* local symbol */ { unsigned long r_symndx = ELF_R_SYM (rel->r_info); BFD_ASSERT (elf_local_ptr_offsets (input_bfd) != NULL); BFD_ASSERT (elf_local_ptr_offsets (input_bfd)[r_symndx] != NULL); linker_section_ptr = _bfd_elf_find_pointer_linker_section (elf_local_ptr_offsets (input_bfd)[r_symndx], rel->r_addend, lsect->which); BFD_ASSERT (linker_section_ptr != NULL); /* Write out pointer if it hasn't been rewritten out before */ if (!linker_section_ptr->written_address_p) { linker_section_ptr->written_address_p = true; bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend, lsect->section->contents + linker_section_ptr->offset); if (info->shared) { asection *srel = lsect->rel_section; Elf_Internal_Rela outrel; /* We need to generate a relative reloc for the dynamic linker. */ if (!srel) lsect->rel_section = srel = bfd_get_section_by_name (elf_hash_table (info)->dynobj, lsect->rel_name); BFD_ASSERT (srel != NULL); outrel.r_offset = (lsect->section->output_section->vma + lsect->section->output_offset + linker_section_ptr->offset); outrel.r_info = ELF_R_INFO (0, relative_reloc); outrel.r_addend = 0; elf_swap_reloca_out (output_bfd, &outrel, (((Elf_External_Rela *) lsect->section->contents) + lsect->section->reloc_count)); ++lsect->section->reloc_count; } } } relocation = (lsect->section->output_offset + linker_section_ptr->offset - lsect->hole_offset - lsect->sym_offset); #ifdef DEBUG fprintf (stderr, "Finish pointer in linker section %s, offset = %ld (0x%lx)\n", lsect->name, (long)relocation, (long)relocation); #endif /* Subtract out the addend, because it will get added back in by the normal processing. */ return relocation - linker_section_ptr->addend; }