diff options
Diffstat (limited to 'bfd/elflink.c')
| -rw-r--r-- | bfd/elflink.c | 2035 |
1 files changed, 2017 insertions, 18 deletions
diff --git a/bfd/elflink.c b/bfd/elflink.c index 962c104..0519459 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -25,6 +25,9 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #define ARCH_SIZE 0 #include "elf-bfd.h" +static bfd_boolean elf_link_read_relocs_from_section + PARAMS ((bfd *, Elf_Internal_Shdr *, PTR, Elf_Internal_Rela *)); + bfd_boolean _bfd_elf_create_got_section (abfd, info) bfd *abfd; @@ -104,33 +107,159 @@ _bfd_elf_create_got_section (abfd, info) return TRUE; } -/* Create dynamic sections when linking against a dynamic object. */ +/* 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. */ bfd_boolean -_bfd_elf_create_dynamic_sections (abfd, info) +_bfd_elf_link_create_dynamic_sections (abfd, info) bfd *abfd; struct bfd_link_info *info; { - flagword flags, pltflags; - asection *s; - struct elf_backend_data *bed = get_elf_backend_data (abfd); - int ptralign; + flagword flags; + register asection *s; + struct elf_link_hash_entry *h; + struct bfd_link_hash_entry *bh; + struct elf_backend_data *bed; - switch (bed->s->arch_size) + if (! is_elf_hash_table (info)) + return FALSE; + + 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) { - case 32: - ptralign = 2; - break; + s = bfd_make_section (abfd, ".interp"); + if (s == NULL + || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)) + return FALSE; + } - case 64: - ptralign = 3; - break; + if (! info->traditional_format + && info->hash->creator->flavour == bfd_target_elf_flavour) + { + s = bfd_make_section (abfd, ".eh_frame_hdr"); + if (s == NULL + || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) + || ! bfd_set_section_alignment (abfd, s, 2)) + return FALSE; + elf_hash_table (info)->eh_info.hdr_sec = s; + } - default: - bfd_set_error (bfd_error_bad_value); - return FALSE; + bed = get_elf_backend_data (abfd); + + /* 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, bed->s->log_file_align)) + 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, bed->s->log_file_align)) + 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, bed->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 = _bfd_elf_strtab_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, bed->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. */ + bh = NULL; + if (! (_bfd_generic_link_add_one_symbol + (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, (bfd_vma) 0, + (const char *) 0, FALSE, get_elf_backend_data (abfd)->collect, &bh))) + return FALSE; + h = (struct elf_link_hash_entry *) bh; + 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, bed->s->log_file_align)) + return FALSE; + elf_section_data (s)->this_hdr.sh_entsize = bed->s->sizeof_hash_entry; + + /* 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. */ + if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info)) + return FALSE; + + elf_hash_table (info)->dynamic_sections_created = TRUE; + + return TRUE; +} + +/* Create dynamic sections when linking against a dynamic object. */ + +bfd_boolean +_bfd_elf_create_dynamic_sections (abfd, info) + bfd *abfd; + struct bfd_link_info *info; +{ + flagword flags, pltflags; + asection *s; + struct elf_backend_data *bed = get_elf_backend_data (abfd); + /* We need to create .plt, .rel[a].plt, .got, .got.plt, .dynbss, and .rel[a].bss sections. */ @@ -175,7 +304,7 @@ _bfd_elf_create_dynamic_sections (abfd, info) bed->default_use_rela_p ? ".rela.plt" : ".rel.plt"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) - || ! bfd_set_section_alignment (abfd, s, ptralign)) + || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align)) return FALSE; if (! _bfd_elf_create_got_section (abfd, info)) @@ -212,7 +341,7 @@ _bfd_elf_create_dynamic_sections (abfd, info) ? ".rela.bss" : ".rel.bss")); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) - || ! bfd_set_section_alignment (abfd, s, ptralign)) + || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align)) return FALSE; } } @@ -306,6 +435,70 @@ _bfd_elf_link_record_dynamic_symbol (info, h) return TRUE; } + +/* Record an assignment to a symbol made by a linker script. We need + this in case some dynamic object refers to this symbol. */ + +bfd_boolean +bfd_elf_record_link_assignment (output_bfd, info, name, provide) + bfd *output_bfd ATTRIBUTE_UNUSED; + struct bfd_link_info *info; + const char *name; + bfd_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; + + /* If this symbol is not being provided by the linker script, and it is + currently defined by a dynamic object, but not by a regular object, + then clear out any version information because the symbol will not be + associated with the dynamic object any more. */ + 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->verinfo.verdef = NULL; + + h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; + + 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; +} /* Record a new local dynamic symbol. Returns 0 on failure, 1 on success, and 2 on a failure caused by attempting to record a symbol @@ -477,6 +670,1230 @@ _bfd_elf_link_renumber_dynsyms (output_bfd, info) return elf_hash_table (info)->dynsymcount = dynsymcount; } + +/* This function is called when we want to define a new symbol. It + handles the various cases which arise when we find a definition in + a dynamic object, or when there is already a definition in a + dynamic object. The new symbol is described by NAME, SYM, PSEC, + and PVALUE. We set SYM_HASH to the hash table entry. We set + OVERRIDE if the old symbol is overriding a new definition. We set + TYPE_CHANGE_OK if it is OK for the type to change. We set + SIZE_CHANGE_OK if it is OK for the size to change. By OK to + change, we mean that we shouldn't warn if the type or size does + change. DT_NEEDED indicates if it comes from a DT_NEEDED entry of + a shared object. */ + +bfd_boolean +_bfd_elf_merge_symbol (abfd, info, name, sym, psec, pvalue, sym_hash, skip, + override, type_change_ok, size_change_ok, dt_needed) + bfd *abfd; + struct bfd_link_info *info; + const char *name; + Elf_Internal_Sym *sym; + asection **psec; + bfd_vma *pvalue; + struct elf_link_hash_entry **sym_hash; + bfd_boolean *skip; + bfd_boolean *override; + bfd_boolean *type_change_ok; + bfd_boolean *size_change_ok; + bfd_boolean dt_needed; +{ + asection *sec; + struct elf_link_hash_entry *h; + struct elf_link_hash_entry *flip; + int bind; + bfd *oldbfd; + bfd_boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon; + bfd_boolean newweakdef, oldweakdef, newweakundef, oldweakundef; + + *skip = FALSE; + *override = FALSE; + + sec = *psec; + bind = ELF_ST_BIND (sym->st_info); + + 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) + return FALSE; + *sym_hash = h; + + /* This code is for coping with dynamic objects, and is only useful + if we are doing an ELF link. */ + if (info->hash->creator != abfd->xvec) + return TRUE; + + /* For merging, we only care about real symbols. */ + + 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; + + /* If we just created the symbol, mark it as being an ELF symbol. + Other than that, there is nothing to do--there is no merge issue + with a newly defined symbol--so we just return. */ + + if (h->root.type == bfd_link_hash_new) + { + h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF; + return TRUE; + } + + /* OLDBFD is a BFD associated with the existing symbol. */ + + switch (h->root.type) + { + default: + oldbfd = NULL; + break; + + case bfd_link_hash_undefined: + case bfd_link_hash_undefweak: + oldbfd = h->root.u.undef.abfd; + break; + + case bfd_link_hash_defined: + case bfd_link_hash_defweak: + oldbfd = h->root.u.def.section->owner; + break; + + case bfd_link_hash_common: + oldbfd = h->root.u.c.p->section->owner; + break; + } + + /* In cases involving weak versioned symbols, we may wind up trying + to merge a symbol with itself. Catch that here, to avoid the + confusion that results if we try to override a symbol with + itself. The additional tests catch cases like + _GLOBAL_OFFSET_TABLE_, which are regular symbols defined in a + dynamic object, which we do want to handle here. */ + if (abfd == oldbfd + && ((abfd->flags & DYNAMIC) == 0 + || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)) + return TRUE; + + /* NEWDYN and OLDDYN indicate whether the new or old symbol, + respectively, is from a dynamic object. */ + + if ((abfd->flags & DYNAMIC) != 0) + newdyn = TRUE; + else + newdyn = FALSE; + + if (oldbfd != NULL) + olddyn = (oldbfd->flags & DYNAMIC) != 0; + else + { + asection *hsec; + + /* This code handles the special SHN_MIPS_{TEXT,DATA} section + indices used by MIPS ELF. */ + switch (h->root.type) + { + default: + hsec = NULL; + break; + + case bfd_link_hash_defined: + case bfd_link_hash_defweak: + hsec = h->root.u.def.section; + break; + + case bfd_link_hash_common: + hsec = h->root.u.c.p->section; + break; + } + + if (hsec == NULL) + olddyn = FALSE; + else + olddyn = (hsec->symbol->flags & BSF_DYNAMIC) != 0; + } + + /* NEWDEF and OLDDEF indicate whether the new or old symbol, + respectively, appear to be a definition rather than reference. */ + + if (bfd_is_und_section (sec) || bfd_is_com_section (sec)) + newdef = FALSE; + else + newdef = TRUE; + + if (h->root.type == bfd_link_hash_undefined + || h->root.type == bfd_link_hash_undefweak + || h->root.type == bfd_link_hash_common) + olddef = FALSE; + else + olddef = TRUE; + + /* We need to rememeber if a symbol has a definition in a dynamic + object or is weak in all dynamic objects. Internal and hidden + visibility will make it unavailable to dynamic objects. */ + if (newdyn && (h->elf_link_hash_flags & ELF_LINK_DYNAMIC_DEF) == 0) + { + if (!bfd_is_und_section (sec)) + h->elf_link_hash_flags |= ELF_LINK_DYNAMIC_DEF; + else + { + /* Check if this symbol is weak in all dynamic objects. If it + is the first time we see it in a dynamic object, we mark + if it is weak. Otherwise, we clear it. */ + if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0) + { + if (bind == STB_WEAK) + h->elf_link_hash_flags |= ELF_LINK_DYNAMIC_WEAK; + } + else if (bind != STB_WEAK) + h->elf_link_hash_flags &= ~ELF_LINK_DYNAMIC_WEAK; + } + } + + /* If the old symbol has non-default visibility, we ignore the new + definition from a dynamic object. */ + if (newdyn + && ELF_ST_VISIBILITY (h->other) + && !bfd_is_und_section (sec)) + { + *skip = TRUE; + /* Make sure this symbol is dynamic. */ + h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC; + /* A protected symbol has external availability. Make sure it is + recorded as dynamic. + + FIXME: Should we check type and size for protected symbol? */ + if (ELF_ST_VISIBILITY (h->other) == STV_PROTECTED) + return _bfd_elf_link_record_dynamic_symbol (info, h); + else + return TRUE; + } + else if (!newdyn + && ELF_ST_VISIBILITY (sym->st_other) + && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0) + { + /* If the new symbol with non-default visibility comes from a + relocatable file and the old definition comes from a dynamic + object, we remove the old definition. */ + if ((*sym_hash)->root.type == bfd_link_hash_indirect) + h = *sym_hash; + h->root.type = bfd_link_hash_new; + h->root.u.undef.abfd = NULL; + if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) + { + h->elf_link_hash_flags &= ~ELF_LINK_HASH_DEF_DYNAMIC; + h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC; + } + /* FIXME: Should we check type and size for protected symbol? */ + h->size = 0; + h->type = 0; + return TRUE; + } + + /* We need to treat weak definiton right, depending on if there is a + definition from a dynamic object. */ + if (bind == STB_WEAK) + { + if (olddef) + { + newweakdef = TRUE; + newweakundef = FALSE; + } + else + { + newweakdef = FALSE; + newweakundef = TRUE; + } + } + else + newweakdef = newweakundef = FALSE; + + /* If the new weak definition comes from a relocatable file and the + old symbol comes from a dynamic object, we treat the new one as + strong. */ + if (newweakdef && !newdyn && olddyn) + newweakdef = FALSE; + + if (h->root.type == bfd_link_hash_defweak) + { + oldweakdef = TRUE; + oldweakundef = FALSE; + } + else if (h->root.type == bfd_link_hash_undefweak) + { + oldweakdef = FALSE; + oldweakundef = TRUE; + } + else + oldweakdef = oldweakundef = FALSE; + + /* If the old weak definition comes from a relocatable file and the + new symbol comes from a dynamic object, we treat the old one as + strong. */ + if (oldweakdef && !olddyn && newdyn) + oldweakdef = FALSE; + + /* NEWDYNCOMMON and OLDDYNCOMMON indicate whether the new or old + symbol, respectively, appears to be a common symbol in a dynamic + object. If a symbol appears in an uninitialized section, and is + not weak, and is not a function, then it may be a common symbol + which was resolved when the dynamic object was created. We want + to treat such symbols specially, because they raise special + considerations when setting the symbol size: if the symbol + appears as a common symbol in a regular object, and the size in + the regular object is larger, we must make sure that we use the + larger size. This problematic case can always be avoided in C, + but it must be handled correctly when using Fortran shared + libraries. + + Note that if NEWDYNCOMMON is set, NEWDEF will be set, and + likewise for OLDDYNCOMMON and OLDDEF. + + Note that this test is just a heuristic, and that it is quite + possible to have an uninitialized symbol in a shared object which + is really a definition, rather than a common symbol. This could + lead to some minor confusion when the symbol really is a common + symbol in some regular object. However, I think it will be + harmless. */ + + if (newdyn + && newdef + && (sec->flags & SEC_ALLOC) != 0 + && (sec->flags & SEC_LOAD) == 0 + && sym->st_size > 0 + && !newweakdef + && !newweakundef + && ELF_ST_TYPE (sym->st_info) != STT_FUNC) + newdyncommon = TRUE; + else + newdyncommon = FALSE; + + if (olddyn + && olddef + && h->root.type == bfd_link_hash_defined + && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 + && (h->root.u.def.section->flags & SEC_ALLOC) != 0 + && (h->root.u.def.section->flags & SEC_LOAD) == 0 + && h->size > 0 + && h->type != STT_FUNC) + olddyncommon = TRUE; + else + olddyncommon = FALSE; + + /* It's OK to change the type if either the existing symbol or the + new symbol is weak unless it comes from a DT_NEEDED entry of + a shared object, in which case, the DT_NEEDED entry may not be + required at the run time. */ + + if ((! dt_needed && oldweakdef) + || oldweakundef + || newweakdef + || newweakundef) + *type_change_ok = TRUE; + + /* It's OK to change the size if either the existing symbol or the + new symbol is weak, or if the old symbol is undefined. */ + + if (*type_change_ok + || h->root.type == bfd_link_hash_undefined) + *size_change_ok = TRUE; + + /* If both the old and the new symbols look like common symbols in a + dynamic object, set the size of the symbol to the larger of the + two. */ + + if (olddyncommon + && newdyncommon + && sym->st_size != h->size) + { + /* Since we think we have two common symbols, issue a multiple + common warning if desired. Note that we only warn if the + size is different. If the size is the same, we simply let + the old symbol override the new one as normally happens with + symbols defined in dynamic objects. */ + + if (! ((*info->callbacks->multiple_common) + (info, h->root.root.string, oldbfd, bfd_link_hash_common, + h->size, abfd, bfd_link_hash_common, sym->st_size))) + return FALSE; + + if (sym->st_size > h->size) + h->size = sym->st_size; + + *size_change_ok = TRUE; + } + + /* If we are looking at a dynamic object, and we have found a + definition, we need to see if the symbol was already defined by + some other object. If so, we want to use the existing + definition, and we do not want to report a multiple symbol + definition error; we do this by clobbering *PSEC 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. We also permit a common symbol in a regular + object to override a weak symbol in a shared object. + + We prefer a non-weak definition in a shared library to a weak + definition in the executable unless it comes from a DT_NEEDED + entry of a shared object, in which case, the DT_NEEDED entry + may not be required at the run time. */ + + if (newdyn + && newdef + && (olddef + || (h->root.type == bfd_link_hash_common + && (newweakdef + || newweakundef + || ELF_ST_TYPE (sym->st_info) == STT_FUNC))) + && (!oldweakdef + || dt_needed + || newweakdef + || newweakundef)) + { + *override = TRUE; + newdef = FALSE; + newdyncommon = FALSE; + + *psec = sec = bfd_und_section_ptr; + *size_change_ok = TRUE; + + /* If we get here when the old symbol is a common symbol, then + we are explicitly letting it override a weak symbol or + function in a dynamic object, and we don't want to warn about + a type change. If the old symbol is a defined symbol, a type + change warning may still be appropriate. */ + + if (h->root.type == bfd_link_hash_common) + *type_change_ok = TRUE; + } + + /* Handle the special case of an old common symbol merging with a + new symbol which looks like a common symbol in a shared object. + We change *PSEC and *PVALUE to make the new symbol look like a + common symbol, and let _bfd_generic_link_add_one_symbol will do + the right thing. */ + + if (newdyncommon + && h->root.type == bfd_link_hash_common) + { + *override = TRUE; + newdef = FALSE; + newdyncommon = FALSE; + *pvalue = sym->st_size; + *psec = sec = bfd_com_section_ptr; + *size_change_ok = TRUE; + } + + /* If the old symbol is from a dynamic object, and the new symbol is + a definition which is not from a dynamic object, then the new + symbol overrides the old symbol. Symbols from regular files + always take precedence over symbols from dynamic objects, even if + they are defined after the dynamic object in the link. + + As above, we again permit a common symbol in a regular object to + override a definition in a shared object if the shared object + symbol is a function or is weak. + + As above, we permit a non-weak definition in a shared object to + override a weak definition in a regular object. */ + + flip = NULL; + if (! newdyn + && (newdef + || (bfd_is_com_section (sec) + && (oldweakdef || h->type == STT_FUNC))) + && olddyn + && olddef + && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 + && ((!newweakdef && !newweakundef) || oldweakdef)) + { + /* 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; + + olddef = FALSE; + olddyncommon = FALSE; + + /* We again permit a type change when a common symbol may be + overriding a function. */ + + if (bfd_is_com_section (sec)) + *type_change_ok = TRUE; + + if ((*sym_hash)->root.type == bfd_link_hash_indirect) + flip = *sym_hash; + else + /* 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; + } + + /* Handle the special case of a new common symbol merging with an + old symbol that looks like it might be a common symbol defined in + a shared object. Note that we have already handled the case in + which a new common symbol should simply override the definition + in the shared library. */ + + if (! newdyn + && bfd_is_com_section (sec) + && olddyncommon) + { + /* It would be best if we could set the hash table entry to a + common symbol, but we don't know what to use for the section + or the alignment. */ + if (! ((*info->callbacks->multiple_common) + (info, h->root.root.string, oldbfd, bfd_link_hash_common, + h->size, abfd, bfd_link_hash_common, sym->st_size))) + return FALSE; + + /* If the predumed common symbol in the dynamic object is + larger, pretend that the new symbol has its size. */ + + if (h->size > *pvalue) + *pvalue = h->size; + + /* FIXME: We no longer know the alignment required by the symbol + in the dynamic object, so we just wind up using the one from + the regular object. */ + + olddef = FALSE; + olddyncommon = FALSE; + + h->root.type = bfd_link_hash_undefined; + h->root.u.undef.abfd = h->root.u.def.section->owner; + + *size_change_ok = TRUE; + *type_change_ok = TRUE; + + if ((*sym_hash)->root.type == bfd_link_hash_indirect) + flip = *sym_hash; + else + h->verinfo.vertree = NULL; + } + + if (flip != NULL) + { + /* Handle the case where we had a versioned symbol in a dynamic + library and now find a definition in a normal object. In this + case, we make the versioned symbol point to the normal one. */ + struct elf_backend_data *bed = get_elf_backend_data (abfd); + flip->root.type = h->root.type; + h->root.type = bfd_link_hash_indirect; + h->root.u.i.link = (struct bfd_link_hash_entry *) flip; + (*bed->elf_backend_copy_indirect_symbol) (bed, flip, h); + flip->root.u.undef.abfd = h->root.u.undef.abfd; + if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) + { + h->elf_link_hash_flags &= ~ELF_LINK_HASH_DEF_DYNAMIC; + flip->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC; + } + } + + /* Handle the special case of a weak definition in a regular object + followed by a non-weak definition in a shared object. In this + case, we prefer the definition in the shared object unless it + comes from a DT_NEEDED entry of a shared object, in which case, + the DT_NEEDED entry may not be required at the run time. */ + if (olddef + && ! dt_needed + && oldweakdef + && newdef + && newdyn + && !newweakdef + && !newweakundef) + { + /* To make this work we have to frob the flags so that the rest + of the code does not think we are using the regular + definition. */ + if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0) + h->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR; + else if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0) + h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC; + h->elf_link_hash_flags &= ~ (ELF_LINK_HASH_DEF_REGULAR + | ELF_LINK_HASH_DEF_DYNAMIC); + + /* If H is the target of an indirection, we want the caller to + use H rather than the indirect symbol. Otherwise if we are + defining a new indirect symbol we will wind up attaching it + to the entry we are overriding. */ + *sym_hash = h; + } + + /* Handle the special case of a non-weak definition in a shared + object followed by a weak definition in a regular object. In + this case we prefer the definition in the shared object. To make + this work we have to tell the caller to not treat the new symbol + as a definition. */ + if (olddef + && olddyn + && !oldweakdef + && newdef + && ! newdyn + && (newweakdef || newweakundef)) + *override = TRUE; + + return TRUE; +} + +/* This function is called to create an indirect symbol from the + default for the symbol with the default version if needed. The + symbol is described by H, NAME, SYM, PSEC, VALUE, and OVERRIDE. We + set DYNSYM if the new indirect symbol is dynamic. DT_NEEDED + indicates if it comes from a DT_NEEDED entry of a shared object. */ + +bfd_boolean +_bfd_elf_add_default_symbol (abfd, info, h, name, sym, psec, value, + dynsym, override, dt_needed) + bfd *abfd; + struct bfd_link_info *info; + struct elf_link_hash_entry *h; + const char *name; + Elf_Internal_Sym *sym; + asection **psec; + bfd_vma *value; + bfd_boolean *dynsym; + bfd_boolean override; + bfd_boolean dt_needed; +{ + bfd_boolean type_change_ok; + bfd_boolean size_change_ok; + bfd_boolean skip; + char *shortname; + struct elf_link_hash_entry *hi; + struct bfd_link_hash_entry *bh; + struct elf_backend_data *bed; + bfd_boolean collect; + bfd_boolean dynamic; + char *p; + size_t len, shortlen; + asection *sec; + + /* 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. */ + p = strchr (name, ELF_VER_CHR); + if (p == NULL || p[1] != ELF_VER_CHR) + return TRUE; + + if (override) + { + /* We are overridden by an old defition. We need to check if we + need to create the indirect symbol from the default name. */ + hi = elf_link_hash_lookup (elf_hash_table (info), name, TRUE, + FALSE, FALSE); + BFD_ASSERT (hi != NULL); + if (hi == h) + return TRUE; + while (hi->root.type == bfd_link_hash_indirect + || hi->root.type == bfd_link_hash_warning) + { + hi = (struct elf_link_hash_entry *) hi->root.u.i.link; + if (hi == h) + return TRUE; + } + } + + bed = get_elf_backend_data (abfd); + collect = bed->collect; + dynamic = (abfd->flags & DYNAMIC) != 0; + + shortlen = p - name; + shortname = bfd_hash_allocate (&info->hash->table, shortlen + 1); + if (shortname == NULL) + return FALSE; + memcpy (shortname, name, shortlen); + shortname[shortlen] = '\0'; + + /* We are going to create a new symbol. Merge it with any existing + symbol with this name. For the purposes of the merge, act as + though we were defining the symbol we just defined, although we + actually going to define an indirect symbol. */ + type_change_ok = FALSE; + size_change_ok = FALSE; + sec = *psec; + if (!_bfd_elf_merge_symbol (abfd, info, shortname, sym, &sec, value, + &hi, &skip, &override, &type_change_ok, + &size_change_ok, dt_needed)) + return FALSE; + + if (skip) + goto nondefault; + + if (! override) + { + bh = &hi->root; + if (! (_bfd_generic_link_add_one_symbol + (info, abfd, shortname, BSF_INDIRECT, bfd_ind_section_ptr, + (bfd_vma) 0, name, FALSE, collect, &bh))) + return FALSE; + hi = (struct elf_link_hash_entry *) bh; + } + else + { + /* In this case the symbol named SHORTNAME is overriding the + indirect symbol we want to add. We were planning on making + SHORTNAME an indirect symbol referring to NAME. SHORTNAME + is the name without a version. NAME is the fully versioned + name, and it is the default version. + + Overriding means that we already saw a definition for the + symbol SHORTNAME in a regular object, and it is overriding + the symbol defined in the dynamic object. + + When this happens, we actually want to change NAME, the + symbol we just added, to refer to SHORTNAME. This will cause + references to NAME in the shared object to become references + to SHORTNAME in the regular object. This is what we expect + when we override a function in a shared object: that the + references in the shared object will be mapped to the + definition in the regular object. */ + + while (hi->root.type == bfd_link_hash_indirect + || hi->root.type == bfd_link_hash_warning) + hi = (struct elf_link_hash_entry *) hi->root.u.i.link; + + h->root.type = bfd_link_hash_indirect; + h->root.u.i.link = (struct bfd_link_hash_entry *) hi; + if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) + { + h->elf_link_hash_flags &=~ ELF_LINK_HASH_DEF_DYNAMIC; + hi->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC; + if (hi->elf_link_hash_flags + & (ELF_LINK_HASH_REF_REGULAR + | ELF_LINK_HASH_DEF_REGULAR)) + { + if (! _bfd_elf_link_record_dynamic_symbol (info, hi)) + return FALSE; + } + } + + /* Now set HI to H, so that the following code will set the + other fields correctly. */ + hi = h; + } + + /* If there is a duplicate definition somewhere, then HI may not + point to an indirect symbol. We will have reported an error to + the user in that case. */ + + if (hi->root.type == bfd_link_hash_indirect) + { + struct elf_link_hash_entry *ht; + + /* If the symbol became indirect, then we assume that we have + not seen a definition before. */ + BFD_ASSERT ((hi->elf_link_hash_flags + & (ELF_LINK_HASH_DEF_DYNAMIC + | ELF_LINK_HASH_DEF_REGULAR)) == 0); + + ht = (struct elf_link_hash_entry *) hi->root.u.i.link; + (*bed->elf_backend_copy_indirect_symbol) (bed, ht, hi); + + /* See if the new flags lead us to realize that the symbol must + be dynamic. */ + if (! *dynsym) + { + if (! dynamic) + { + if (info->shared + || ((hi->elf_link_hash_flags + & ELF_LINK_HASH_REF_DYNAMIC) != 0)) + *dynsym = TRUE; + } + else + { + if ((hi->elf_link_hash_flags + & ELF_LINK_HASH_REF_REGULAR) != 0) + *dynsym = TRUE; + } + } + } + + /* We also need to define an indirection from the nondefault version + of the symbol. */ + +nondefault: + len = strlen (name); + shortname = bfd_hash_allocate (&info->hash->table, len); + if (shortname == NULL) + return FALSE; + memcpy (shortname, name, shortlen); + memcpy (shortname + shortlen, p + 1, len - shortlen); + + /* Once again, merge with any existing symbol. */ + type_change_ok = FALSE; + size_change_ok = FALSE; + sec = *psec; + if (!_bfd_elf_merge_symbol (abfd, info, shortname, sym, &sec, value, + &hi, &skip, &override, &type_change_ok, + &size_change_ok, dt_needed)) + return FALSE; + + if (skip) + return TRUE; + + if (override) + { + /* Here SHORTNAME is a versioned name, so we don't expect to see + the type of override we do in the case above unless it is + overridden by a versioned definiton. */ + if (hi->root.type != bfd_link_hash_defined + && hi->root.type != bfd_link_hash_defweak) + (*_bfd_error_handler) + (_("%s: warning: unexpected redefinition of indirect versioned symbol `%s'"), + bfd_archive_filename (abfd), shortname); + } + else + { + bh = &hi->root; + if (! (_bfd_generic_link_add_one_symbol + (info, abfd, shortname, BSF_INDIRECT, + bfd_ind_section_ptr, (bfd_vma) 0, name, FALSE, collect, &bh))) + return FALSE; + hi = (struct elf_link_hash_entry *) bh; + + /* If there is a duplicate definition somewhere, then HI may not + point to an indirect symbol. We will have reported an error + to the user in that case. */ + + if (hi->root.type == bfd_link_hash_indirect) + { + /* If the symbol became indirect, then we assume that we have + not seen a definition before. */ + BFD_ASSERT ((hi->elf_link_hash_flags + & (ELF_LINK_HASH_DEF_DYNAMIC + | ELF_LINK_HASH_DEF_REGULAR)) == 0); + + (*bed->elf_backend_copy_indirect_symbol) (bed, h, hi); + + /* See if the new flags lead us to realize that the symbol + must be dynamic. */ + if (! *dynsym) + { + if (! dynamic) + { + if (info->shared + || ((hi->elf_link_hash_flags + & ELF_LINK_HASH_REF_DYNAMIC) != 0)) + *dynsym = TRUE; + } + else + { + if ((hi->elf_link_hash_flags + & ELF_LINK_HASH_REF_REGULAR) != 0) + *dynsym = TRUE; + } + } + } + } + + return TRUE; +} + +/* This routine is used to export all defined symbols into the dynamic + symbol table. It is called via elf_link_hash_traverse. */ + +bfd_boolean +_bfd_elf_export_symbol (h, data) + struct elf_link_hash_entry *h; + PTR data; +{ + struct elf_info_failed *eif = (struct elf_info_failed *) data; + + /* Ignore indirect symbols. These are added by the versioning code. */ + if (h->root.type == bfd_link_hash_indirect) + return TRUE; + + if (h->root.type == bfd_link_hash_warning) + h = (struct elf_link_hash_entry *) h->root.u.i.link; + + if (h->dynindx == -1 + && (h->elf_link_hash_flags + & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0) + { + struct bfd_elf_version_tree *t; + struct bfd_elf_version_expr *d; + + for (t = eif->verdefs; t != NULL; t = t->next) + { + if (t->globals != NULL) + { + for (d = t->globals; d != NULL; d = d->next) + { + if ((*d->match) (d, h->root.root.string)) + goto doit; + } + } + + if (t->locals != NULL) + { + for (d = t->locals ; d != NULL; d = d->next) + { + if ((*d->match) (d, h->root.root.string)) + return TRUE; + } + } + } + + if (!eif->verdefs) + { + doit: + 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. */ + +bfd_boolean +_bfd_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; + bfd_size_type amt; + + if (h->root.type == bfd_link_hash_warning) + h = (struct elf_link_hash_entry *) h->root.u.i.link; + + /* 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->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 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) + { + amt = sizeof *t; + t = (Elf_Internal_Verneed *) bfd_zalloc (rinfo->output_bfd, amt); + 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; + } + + amt = sizeof *a; + a = (Elf_Internal_Vernaux *) bfd_zalloc (rinfo->output_bfd, amt); + + /* 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. */ + +bfd_boolean +_bfd_elf_link_assign_sym_version (h, data) + struct elf_link_hash_entry *h; + PTR data; +{ + struct elf_assign_sym_version_info *sinfo; + struct bfd_link_info *info; + struct elf_backend_data *bed; + struct elf_info_failed eif; + char *p; + bfd_size_type amt; + + sinfo = (struct elf_assign_sym_version_info *) data; + info = sinfo->info; + + if (h->root.type == bfd_link_hash_warning) + h = (struct elf_link_hash_entry *) h->root.u.i.link; + + /* Fix the symbol flags. */ + eif.failed = FALSE; + eif.info = info; + if (! _bfd_elf_fix_symbol_flags (h, &eif)) + { + if (eif.failed) + sinfo->failed = TRUE; + return FALSE; + } + + /* 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; + + bed = get_elf_backend_data (sinfo->output_bfd); + p = strchr (h->root.root.string, ELF_VER_CHR); + if (p != NULL && h->verinfo.vertree == NULL) + { + struct bfd_elf_version_tree *t; + bfd_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) + { + size_t len; + char *alc; + struct bfd_elf_version_expr *d; + + len = p - h->root.root.string; + alc = bfd_malloc ((bfd_size_type) len); + if (alc == NULL) + return FALSE; + memcpy (alc, h->root.root.string, len - 1); + alc[len - 1] = '\0'; + if (alc[len - 2] == ELF_VER_CHR) + alc[len - 2] = '\0'; + + h->verinfo.vertree = t; + t->used = TRUE; + d = NULL; + + if (t->globals != NULL) + { + for (d = t->globals; d != NULL; d = d->next) + if ((*d->match) (d, alc)) + break; + } + + /* See if there is anything to force this symbol to + local scope. */ + if (d == NULL && t->locals != NULL) + { + for (d = t->locals; d != NULL; d = d->next) + { + if ((*d->match) (d, alc)) + { + if (h->dynindx != -1 + && info->shared + && ! info->export_dynamic) + { + (*bed->elf_backend_hide_symbol) (info, h, TRUE); + } + + break; + } + } + } + + free (alc); + break; + } + } + + /* If we are building an application, we need to create a + version node for this version. */ + if (t == NULL && ! info->shared) + { + struct bfd_elf_version_tree **pp; + int version_index; + + /* If we aren't going to export this symbol, we don't need + to worry about it. */ + if (h->dynindx == -1) + return TRUE; + + amt = sizeof *t; + t = ((struct bfd_elf_version_tree *) + bfd_alloc (sinfo->output_bfd, amt)); + if (t == NULL) + { + sinfo->failed = TRUE; + return FALSE; + } + + t->next = NULL; + t->name = p; + t->globals = NULL; + t->locals = NULL; + t->deps = NULL; + t->name_indx = (unsigned int) -1; + t->used = TRUE; + + version_index = 1; + /* Don't count anonymous version tag. */ + if (sinfo->verdefs != NULL && sinfo->verdefs->vernum == 0) + version_index = 0; + for (pp = &sinfo->verdefs; *pp != NULL; pp = &(*pp)->next) + ++version_index; + t->vernum = version_index; + + *pp = t; + + h->verinfo.vertree = t; + } + else if (t == NULL) + { + /* We could not find the version for a symbol when + generating a shared archive. Return an error. */ + (*_bfd_error_handler) + (_("%s: undefined versioned symbol name %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 *local_ver; + struct bfd_elf_version_expr *d; + + /* See if can find what version this symbol is in. If the + symbol is supposed to be local, then don't actually register + it. */ + local_ver = NULL; + for (t = sinfo->verdefs; t != NULL; t = t->next) + { + if (t->globals != NULL) + { + bfd_boolean matched; + + matched = FALSE; + for (d = t->globals; d != NULL; d = d->next) + { + if ((*d->match) (d, h->root.root.string)) + { + if (d->symver) + matched = TRUE; + else + { + /* There is a version without definition. Make + the symbol the default definition for this + version. */ + h->verinfo.vertree = t; + local_ver = NULL; + d->script = 1; + break; + } + } + } + + if (d != NULL) + break; + else if (matched) + /* There is no undefined version for this symbol. Hide the + default one. */ + (*bed->elf_backend_hide_symbol) (info, h, TRUE); + } + + if (t->locals != NULL) + { + for (d = t->locals; d != NULL; d = d->next) + { + /* If the match is "*", keep looking for a more + explicit, perhaps even global, match. */ + if (d->pattern[0] == '*' && d->pattern[1] == '\0') + local_ver = t; + else if ((*d->match) (d, h->root.root.string)) + { + local_ver = t; + break; + } + } + + if (d != NULL) + break; + } + } + + if (local_ver != NULL) + { + h->verinfo.vertree = local_ver; + if (h->dynindx != -1 + && info->shared + && ! info->export_dynamic) + { + (*bed->elf_backend_hide_symbol) (info, h, TRUE); + } + } + } + + return TRUE; +} /* Create a special linker section, or return a pointer to a linker section already created */ @@ -650,3 +2067,585 @@ _bfd_elf_make_linker_section_rela (dynobj, lsect, alignment) return TRUE; } + +/* Read and swap the relocs from the section indicated by SHDR. This + may be either a REL or a RELA section. The relocations are + translated into RELA relocations and stored in INTERNAL_RELOCS, + which should have already been allocated to contain enough space. + The EXTERNAL_RELOCS are a buffer where the external form of the + relocations should be stored. + + Returns FALSE if something goes wrong. */ + +static bfd_boolean +elf_link_read_relocs_from_section (abfd, shdr, external_relocs, + internal_relocs) + bfd *abfd; + Elf_Internal_Shdr *shdr; + PTR external_relocs; + Elf_Internal_Rela *internal_relocs; +{ + struct elf_backend_data *bed; + void (*swap_in) PARAMS ((bfd *, const bfd_byte *, Elf_Internal_Rela *)); + const bfd_byte *erela; + const bfd_byte *erelaend; + Elf_Internal_Rela *irela; + + /* If there aren't any relocations, that's OK. */ + if (!shdr) + return TRUE; + + /* Position ourselves at the start of the section. */ + if (bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0) + return FALSE; + + /* Read the relocations. */ + if (bfd_bread (external_relocs, shdr->sh_size, abfd) != shdr->sh_size) + return FALSE; + + bed = get_elf_backend_data (abfd); + + /* Convert the external relocations to the internal format. */ + if (shdr->sh_entsize == bed->s->sizeof_rel) + swap_in = bed->s->swap_reloc_in; + else if (shdr->sh_entsize == bed->s->sizeof_rela) + swap_in = bed->s->swap_reloca_in; + else + { + bfd_set_error (bfd_error_wrong_format); + return FALSE; + } + + erela = external_relocs; + erelaend = erela + NUM_SHDR_ENTRIES (shdr) * shdr->sh_entsize; + irela = internal_relocs; + while (erela < erelaend) + { + (*swap_in) (abfd, erela, irela); + irela += bed->s->int_rels_per_ext_rel; + erela += shdr->sh_entsize; + } + + return TRUE; +} + +/* Read and swap the relocs for a section O. 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. If O has two relocation + sections (both REL and RELA relocations), then the REL_HDR + relocations will appear first in INTERNAL_RELOCS, followed by the + REL_HDR2 relocations. */ + +Elf_Internal_Rela * +_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; + bfd_boolean keep_memory; +{ + Elf_Internal_Shdr *rel_hdr; + PTR alloc1 = NULL; + Elf_Internal_Rela *alloc2 = NULL; + struct elf_backend_data *bed = get_elf_backend_data (abfd); + + 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) + { + bfd_size_type size; + + size = o->reloc_count; + size *= bed->s->int_rels_per_ext_rel * 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) + { + bfd_size_type size = rel_hdr->sh_size; + + if (elf_section_data (o)->rel_hdr2) + size += elf_section_data (o)->rel_hdr2->sh_size; + alloc1 = (PTR) bfd_malloc (size); + if (alloc1 == NULL) + goto error_return; + external_relocs = alloc1; + } + + if (!elf_link_read_relocs_from_section (abfd, rel_hdr, + external_relocs, + internal_relocs)) + goto error_return; + if (!elf_link_read_relocs_from_section + (abfd, + elf_section_data (o)->rel_hdr2, + ((bfd_byte *) external_relocs) + rel_hdr->sh_size, + internal_relocs + (NUM_SHDR_ENTRIES (rel_hdr) + * bed->s->int_rels_per_ext_rel))) + goto error_return; + + /* 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; +} + +/* Compute the size of, and allocate space for, REL_HDR which is the + section header for a section containing relocations for O. */ + +bfd_boolean +_bfd_elf_link_size_reloc_section (abfd, rel_hdr, o) + bfd *abfd; + Elf_Internal_Shdr *rel_hdr; + asection *o; +{ + bfd_size_type reloc_count; + bfd_size_type num_rel_hashes; + + /* Figure out how many relocations there will be. */ + if (rel_hdr == &elf_section_data (o)->rel_hdr) + reloc_count = elf_section_data (o)->rel_count; + else + reloc_count = elf_section_data (o)->rel_count2; + + num_rel_hashes = o->reloc_count; + if (num_rel_hashes < reloc_count) + num_rel_hashes = reloc_count; + + /* That allows us to calculate the size of the section. */ + rel_hdr->sh_size = rel_hdr->sh_entsize * reloc_count; + + /* The contents field must last into write_object_contents, so we + allocate it with bfd_alloc rather than malloc. Also since we + cannot be sure that the contents will actually be filled in, + we zero the allocated space. */ + rel_hdr->contents = (PTR) bfd_zalloc (abfd, rel_hdr->sh_size); + if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0) + return FALSE; + + /* We only allocate one set of hash entries, so we only do it the + first time we are called. */ + if (elf_section_data (o)->rel_hashes == NULL + && num_rel_hashes) + { + struct elf_link_hash_entry **p; + + p = ((struct elf_link_hash_entry **) + bfd_zmalloc (num_rel_hashes + * sizeof (struct elf_link_hash_entry *))); + if (p == NULL) + return FALSE; + + elf_section_data (o)->rel_hashes = p; + } + + return TRUE; +} + +/* Copy the relocations indicated by the INTERNAL_RELOCS (which + originated from the section given by INPUT_REL_HDR) to the + OUTPUT_BFD. */ + +bfd_boolean +_bfd_elf_link_output_relocs (output_bfd, input_section, input_rel_hdr, + internal_relocs) + bfd *output_bfd; + asection *input_section; + Elf_Internal_Shdr *input_rel_hdr; + Elf_Internal_Rela *internal_relocs; +{ + Elf_Internal_Rela *irela; + Elf_Internal_Rela *irelaend; + bfd_byte *erel; + Elf_Internal_Shdr *output_rel_hdr; + asection *output_section; + unsigned int *rel_countp = NULL; + struct elf_backend_data *bed; + void (*swap_out) PARAMS ((bfd *, const Elf_Internal_Rela *, bfd_byte *)); + + output_section = input_section->output_section; + output_rel_hdr = NULL; + + if (elf_section_data (output_section)->rel_hdr.sh_entsize + == input_rel_hdr->sh_entsize) + { + output_rel_hdr = &elf_section_data (output_section)->rel_hdr; + rel_countp = &elf_section_data (output_section)->rel_count; + } + else if (elf_section_data (output_section)->rel_hdr2 + && (elf_section_data (output_section)->rel_hdr2->sh_entsize + == input_rel_hdr->sh_entsize)) + { + output_rel_hdr = elf_section_data (output_section)->rel_hdr2; + rel_countp = &elf_section_data (output_section)->rel_count2; + } + else + { + (*_bfd_error_handler) + (_("%s: relocation size mismatch in %s section %s"), + bfd_get_filename (output_bfd), + bfd_archive_filename (input_section->owner), + input_section->name); + bfd_set_error (bfd_error_wrong_object_format); + return FALSE; + } + + bed = get_elf_backend_data (output_bfd); + if (input_rel_hdr->sh_entsize == bed->s->sizeof_rel) + swap_out = bed->s->swap_reloc_out; + else if (input_rel_hdr->sh_entsize == bed->s->sizeof_rela) + swap_out = bed->s->swap_reloca_out; + else + abort (); + + erel = output_rel_hdr->contents; + erel += *rel_countp * input_rel_hdr->sh_entsize; + irela = internal_relocs; + irelaend = irela + (NUM_SHDR_ENTRIES (input_rel_hdr) + * bed->s->int_rels_per_ext_rel); + while (irela < irelaend) + { + (*swap_out) (output_bfd, irela, erel); + irela += bed->s->int_rels_per_ext_rel; + erel += input_rel_hdr->sh_entsize; + } + + /* Bump the counter, so that we know where to add the next set of + relocations. */ + *rel_countp += NUM_SHDR_ENTRIES (input_rel_hdr); + + return TRUE; +} + +/* Fix up the flags for a symbol. This handles various cases which + can only be fixed after all the input files are seen. This is + currently called by both adjust_dynamic_symbol and + assign_sym_version, which is unnecessary but perhaps more robust in + the face of future changes. */ + +bfd_boolean +_bfd_elf_fix_symbol_flags (h, eif) + struct elf_link_hash_entry *h; + struct elf_info_failed *eif; +{ + /* 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) + { + while (h->root.type == bfd_link_hash_indirect) + h = (struct elf_link_hash_entry *) h->root.u.i.link; + + 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 + | ELF_LINK_HASH_REF_REGULAR_NONWEAK); + 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 + | ELF_LINK_HASH_REF_REGULAR_NONWEAK); + else + h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; + } + + if (h->dynindx == -1 + && ((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; + } + } + } + else + { + /* Unfortunately, ELF_LINK_NON_ELF is only correct if the symbol + was first seen in a non-ELF file. Fortunately, if the symbol + was first seen in an ELF file, we're probably OK unless the + symbol was defined in a non-ELF file. Catch that case here. + FIXME: We're still in trouble if the symbol was first seen in + a dynamic object, and then later in a non-ELF regular object. */ + if ((h->root.type == bfd_link_hash_defined + || h->root.type == bfd_link_hash_defweak) + && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0 + && (h->root.u.def.section->owner != NULL + ? (bfd_get_flavour (h->root.u.def.section->owner) + != bfd_target_elf_flavour) + : (bfd_is_abs_section (h->root.u.def.section) + && (h->elf_link_hash_flags + & ELF_LINK_HASH_DEF_DYNAMIC) == 0))) + h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; + } + + /* 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, and we can accomplish that by forcing it local. + Likewise, if the symbol has hidden or internal visibility. + FIXME: It might be that we also do not need a PLT for other + non-hidden visibilities, but we would have to tell that to the + backend specifically; we can't just clear PLT-related data here. */ + if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0 + && eif->info->shared + && is_elf_hash_table (eif->info) + && (eif->info->symbolic + || ELF_ST_VISIBILITY (h->other) == STV_INTERNAL + || ELF_ST_VISIBILITY (h->other) == STV_HIDDEN) + && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0) + { + struct elf_backend_data *bed; + bfd_boolean force_local; + + bed = get_elf_backend_data (elf_hash_table (eif->info)->dynobj); + + force_local = (ELF_ST_VISIBILITY (h->other) == STV_INTERNAL + || ELF_ST_VISIBILITY (h->other) == STV_HIDDEN); + (*bed->elf_backend_hide_symbol) (eif->info, h, force_local); + } + + /* If a weak undefined symbol has non-default visibility, we also + hide it from the dynamic linker. */ + if (ELF_ST_VISIBILITY (h->other) + && h->root.type == bfd_link_hash_undefweak) + { + struct elf_backend_data *bed; + bed = get_elf_backend_data (elf_hash_table (eif->info)->dynobj); + (*bed->elf_backend_hide_symbol) (eif->info, h, TRUE); + } + + /* If this is a weak defined symbol in a dynamic object, and we know + the real definition in the dynamic object, copy interesting flags + over to the real definition. */ + if (h->weakdef != NULL) + { + struct elf_link_hash_entry *weakdef; + + weakdef = h->weakdef; + if (h->root.type == bfd_link_hash_indirect) + h = (struct elf_link_hash_entry *) h->root.u.i.link; + + BFD_ASSERT (h->root.type == bfd_link_hash_defined + || h->root.type == bfd_link_hash_defweak); + 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 the real definition is defined by a regular object file, + don't do anything special. See the longer description in + _bfd_elf_adjust_dynamic_symbol, below. */ + if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0) + h->weakdef = NULL; + else + { + struct elf_backend_data *bed; + + bed = get_elf_backend_data (elf_hash_table (eif->info)->dynobj); + (*bed->elf_backend_copy_indirect_symbol) (bed, weakdef, h); + } + } + + 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. */ + +bfd_boolean +_bfd_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; + + if (! is_elf_hash_table (eif->info)) + return FALSE; + + if (h->root.type == bfd_link_hash_warning) + { + h->plt = elf_hash_table (eif->info)->init_offset; + h->got = elf_hash_table (eif->info)->init_offset; + + /* When warning symbols are created, they **replace** the "real" + entry in the hash table, thus we never get to see the real + symbol in a hash traversal. So look at it now. */ + h = (struct elf_link_hash_entry *) h->root.u.i.link; + } + + /* Ignore indirect symbols. These are added by the versioning code. */ + if (h->root.type == bfd_link_hash_indirect) + return TRUE; + + /* Fix the symbol flags. */ + if (! _bfd_elf_fix_symbol_flags (h, eif)) + return FALSE; + + /* 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)))) + { + h->plt = elf_hash_table (eif->info)->init_offset; + 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) + { + /* If we get to this point, we know there is an implicit + reference by a regular object file via the weak symbol H. + FIXME: Is this really true? What if the traversal finds + H->WEAKDEF before it finds H? */ + h->weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR; + + if (! _bfd_elf_adjust_dynamic_symbol (h->weakdef, (PTR) eif)) + return FALSE; + } + + /* If a symbol has no type and no size and does not require a PLT + entry, then we are probably about to do the wrong thing here: we + are probably going to create a COPY reloc for an empty object. + This case can arise when a shared object is built with assembly + code, and the assembly code fails to set the symbol type. */ + if (h->size == 0 + && h->type == STT_NOTYPE + && (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0) + (*_bfd_error_handler) + (_("warning: type and size of dynamic symbol `%s' are not defined"), + h->root.root.string); + + 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; +} + +/* Adjust all external symbols pointing into SEC_MERGE sections + to reflect the object merging within the sections. */ + +bfd_boolean +_bfd_elf_link_sec_merge_syms (h, data) + struct elf_link_hash_entry *h; + PTR data; +{ + asection *sec; + + if (h->root.type == bfd_link_hash_warning) + h = (struct elf_link_hash_entry *) h->root.u.i.link; + + if ((h->root.type == bfd_link_hash_defined + || h->root.type == bfd_link_hash_defweak) + && ((sec = h->root.u.def.section)->flags & SEC_MERGE) + && sec->sec_info_type == ELF_INFO_TYPE_MERGE) + { + bfd *output_bfd = (bfd *) data; + + h->root.u.def.value = + _bfd_merged_section_offset (output_bfd, + &h->root.u.def.section, + elf_section_data (sec)->sec_info, + h->root.u.def.value, (bfd_vma) 0); + } + + return TRUE; +} |