/* ELF linking support for BFD.
- Copyright (C) 1995-2018 Free Software Foundation, Inc.
+ Copyright (C) 1995-2019 Free Software Foundation, Inc.
This file is part of BFD, the Binary File Descriptor library.
#include "sysdep.h"
#include "bfd.h"
-#include "bfd_stdint.h"
#include "bfdlink.h"
#include "libbfd.h"
#define ARCH_SIZE 0
if ((ibfd->flags
& (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0
&& bfd_get_flavour (ibfd) == bfd_target_elf_flavour
+ && elf_object_id (ibfd) == elf_hash_table_id (hash_table)
&& !((s = ibfd->sections) != NULL
&& s->sec_info_type == SEC_INFO_TYPE_JUST_SYMS))
{
&& !h->def_regular)
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->def_dynamic
- && !h->def_regular)
+ /* If this symbol 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 (h->def_dynamic && !h->def_regular)
h->verinfo.verdef = NULL;
/* Make sure this symbol is not garbage collected. */
|| h->ref_dynamic
|| bfd_link_dll (info)
|| elf_hash_table (info)->is_relocatable_executable)
+ && !h->forced_local
&& h->dynindx == -1)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
for (p = output_bfd->sections; p ; p = p->next)
if ((p->flags & SEC_EXCLUDE) == 0
&& (p->flags & SEC_ALLOC) != 0
+ && elf_hash_table (info)->dynamic_relocs
&& !(*bed->elf_backend_omit_section_dynsym) (output_bfd, info, p))
{
++dynsymcount;
if (! bfd_link_relocatable (info))
{
bh = &hi->root;
+ if (bh->type == bfd_link_hash_defined
+ && bh->u.def.section->owner != NULL
+ && (bh->u.def.section->owner->flags & BFD_PLUGIN) != 0)
+ {
+ /* Mark the previous definition from IR object as
+ undefined so that the generic linker will override
+ it. */
+ bh->type = bfd_link_hash_undefined;
+ bh->u.undef.abfd = bh->u.def.section->owner;
+ }
if (! (_bfd_generic_link_add_one_symbol
(info, abfd, shortname, BSF_INDIRECT,
bfd_ind_section_ptr,
return TRUE;
}
+/* Return TRUE and set *HIDE to TRUE if the versioned symbol is
+ hidden. Set *T_P to NULL if there is no match. */
+
+static bfd_boolean
+_bfd_elf_link_hide_versioned_symbol (struct bfd_link_info *info,
+ struct elf_link_hash_entry *h,
+ const char *version_p,
+ struct bfd_elf_version_tree **t_p,
+ bfd_boolean *hide)
+{
+ struct bfd_elf_version_tree *t;
+
+ /* Look for the version. If we find it, it is no longer weak. */
+ for (t = info->version_info; t != NULL; t = t->next)
+ {
+ if (strcmp (t->name, version_p) == 0)
+ {
+ size_t len;
+ char *alc;
+ struct bfd_elf_version_expr *d;
+
+ len = version_p - h->root.root.string;
+ alc = (char *) bfd_malloc (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.list != NULL)
+ d = (*t->match) (&t->globals, NULL, alc);
+
+ /* See if there is anything to force this symbol to
+ local scope. */
+ if (d == NULL && t->locals.list != NULL)
+ {
+ d = (*t->match) (&t->locals, NULL, alc);
+ if (d != NULL
+ && h->dynindx != -1
+ && ! info->export_dynamic)
+ *hide = TRUE;
+ }
+
+ free (alc);
+ break;
+ }
+ }
+
+ *t_p = t;
+
+ return TRUE;
+}
+
+/* Return TRUE if the symbol H is hidden by version script. */
+
+bfd_boolean
+_bfd_elf_link_hide_sym_by_version (struct bfd_link_info *info,
+ struct elf_link_hash_entry *h)
+{
+ const char *p;
+ bfd_boolean hide = FALSE;
+ const struct elf_backend_data *bed
+ = get_elf_backend_data (info->output_bfd);
+
+ /* Version script only hides symbols defined in regular objects. */
+ if (!h->def_regular && !ELF_COMMON_DEF_P (h))
+ return TRUE;
+
+ p = strchr (h->root.root.string, ELF_VER_CHR);
+ if (p != NULL && h->verinfo.vertree == NULL)
+ {
+ struct bfd_elf_version_tree *t;
+
+ ++p;
+ if (*p == ELF_VER_CHR)
+ ++p;
+
+ if (*p != '\0'
+ && _bfd_elf_link_hide_versioned_symbol (info, h, p, &t, &hide)
+ && hide)
+ {
+ if (hide)
+ (*bed->elf_backend_hide_symbol) (info, h, TRUE);
+ return TRUE;
+ }
+ }
+
+ /* If we don't have a version for this symbol, see if we can find
+ something. */
+ if (h->verinfo.vertree == NULL && info->version_info != NULL)
+ {
+ h->verinfo.vertree
+ = bfd_find_version_for_sym (info->version_info,
+ h->root.root.string, &hide);
+ if (h->verinfo.vertree != NULL && hide)
+ {
+ (*bed->elf_backend_hide_symbol) (info, h, TRUE);
+ return TRUE;
+ }
+ }
+
+ return FALSE;
+}
+
/* 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
const struct elf_backend_data *bed;
struct elf_info_failed eif;
char *p;
+ bfd_boolean hide;
sinfo = (struct elf_info_failed *) data;
info = sinfo->info;
return FALSE;
}
+ bed = get_elf_backend_data (info->output_bfd);
+
/* We only need version numbers for symbols defined in regular
objects. */
if (!h->def_regular)
- return TRUE;
+ {
+ /* Hide symbols defined in discarded input sections. */
+ if ((h->root.type == bfd_link_hash_defined
+ || h->root.type == bfd_link_hash_defweak)
+ && discarded_section (h->root.u.def.section))
+ (*bed->elf_backend_hide_symbol) (info, h, TRUE);
+ return TRUE;
+ }
- bed = get_elf_backend_data (info->output_bfd);
+ hide = FALSE;
p = strchr (h->root.root.string, ELF_VER_CHR);
if (p != NULL && h->verinfo.vertree == NULL)
{
if (*p == '\0')
return TRUE;
- /* Look for the version. If we find it, it is no longer weak. */
- for (t = sinfo->info->version_info; t != NULL; t = t->next)
+ if (!_bfd_elf_link_hide_versioned_symbol (info, h, p, &t, &hide))
{
- if (strcmp (t->name, p) == 0)
- {
- size_t len;
- char *alc;
- struct bfd_elf_version_expr *d;
-
- len = p - h->root.root.string;
- alc = (char *) bfd_malloc (len);
- if (alc == NULL)
- {
- sinfo->failed = TRUE;
- 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.list != NULL)
- d = (*t->match) (&t->globals, NULL, alc);
-
- /* See if there is anything to force this symbol to
- local scope. */
- if (d == NULL && t->locals.list != NULL)
- {
- d = (*t->match) (&t->locals, NULL, alc);
- if (d != NULL
- && h->dynindx != -1
- && ! info->export_dynamic)
- (*bed->elf_backend_hide_symbol) (info, h, TRUE);
- }
-
- free (alc);
- break;
- }
+ sinfo->failed = TRUE;
+ return FALSE;
}
+ if (hide)
+ (*bed->elf_backend_hide_symbol) (info, h, TRUE);
+
/* If we are building an application, we need to create a
version node for this version. */
if (t == NULL && bfd_link_executable (info))
/* If we don't have a version for this symbol, see if we can find
something. */
- if (h->verinfo.vertree == NULL && sinfo->info->version_info != NULL)
+ if (!hide
+ && h->verinfo.vertree == NULL
+ && sinfo->info->version_info != NULL)
{
- bfd_boolean hide;
-
h->verinfo.vertree
= bfd_find_version_for_sym (sinfo->info->version_info,
h->root.root.string, &hide);
}
erela = (const bfd_byte *) external_relocs;
- erelaend = erela + shdr->sh_size;
+ /* Setting erelaend like this and comparing with <= handles case of
+ a fuzzed object with sh_size not a multiple of sh_entsize. */
+ erelaend = erela + shdr->sh_size - shdr->sh_entsize;
irela = internal_relocs;
- while (erela < erelaend)
+ while (erela <= erelaend)
{
bfd_vma r_symndx;
&& (h->root.u.def.section->owner->flags & (DYNAMIC | BFD_PLUGIN)) == 0)
h->def_regular = 1;
+ /* Symbols defined in discarded sections shouldn't be dynamic. */
+ if (h->root.type == bfd_link_hash_undefined && h->indx == -3)
+ (*bed->elf_backend_hide_symbol) (eif->info, h, TRUE);
+
/* If a weak undefined symbol has non-default visibility, we also
hide it from the dynamic linker. */
- if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
- && h->root.type == bfd_link_hash_undefweak)
+ else if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
+ && h->root.type == bfd_link_hash_undefweak)
(*bed->elf_backend_hide_symbol) (eif->info, h, TRUE);
/* A hidden versioned symbol in executable should be forced local if
if (! is_elf_hash_table (hash_table))
return FALSE;
+ if (tag == DT_RELA || tag == DT_REL)
+ hash_table->dynamic_relocs = TRUE;
+
bed = get_elf_backend_data (hash_table->dynobj);
s = bfd_get_linker_section (hash_table->dynobj, ".dynamic");
BFD_ASSERT (s != NULL);
struct elf_link_hash_entry **sym_hash;
bfd_boolean dynamic;
Elf_External_Versym *extversym = NULL;
+ Elf_External_Versym *extversym_end = NULL;
Elf_External_Versym *ever;
struct elf_link_hash_entry *weaks;
struct elf_link_hash_entry **nondeflt_vers = NULL;
all sections contained fully therein. This makes relro
shared library sections appear as they will at run-time. */
phdr = elf_tdata (abfd)->phdr + elf_elfheader (abfd)->e_phnum;
- while (--phdr >= elf_tdata (abfd)->phdr)
+ while (phdr-- > elf_tdata (abfd)->phdr)
if (phdr->p_type == PT_GNU_RELRO)
{
for (s = abfd->sections; s != NULL; s = s->next)
Elf_Internal_Shdr *versymhdr;
versymhdr = &elf_tdata (abfd)->dynversym_hdr;
- extversym = (Elf_External_Versym *) bfd_malloc (versymhdr->sh_size);
+ amt = versymhdr->sh_size;
+ extversym = (Elf_External_Versym *) bfd_malloc (amt);
if (extversym == NULL)
goto error_free_sym;
- amt = versymhdr->sh_size;
if (bfd_seek (abfd, versymhdr->sh_offset, SEEK_SET) != 0
|| bfd_bread (extversym, amt, abfd) != amt)
goto error_free_vers;
+ extversym_end = extversym + (amt / sizeof (* extversym));
}
}
}
weaks = NULL;
- ever = extversym != NULL ? extversym + extsymoff : NULL;
+ if (extversym == NULL)
+ ever = NULL;
+ else if (extversym + extsymoff < extversym_end)
+ ever = extversym + extsymoff;
+ else
+ {
+ /* xgettext:c-format */
+ _bfd_error_handler (_("%pB: invalid version offset %lx (max %lx)"),
+ abfd, (long) extsymoff,
+ (long) (extversym_end - extversym) / sizeof (* extversym));
+ bfd_set_error (bfd_error_bad_value);
+ goto error_free_vers;
+ }
+
for (isym = isymbuf, isymend = isymbuf + extsymcount;
isym < isymend;
isym++, sym_hash++, ever = (ever != NULL ? ever + 1 : NULL))
else
iver.vs_vers = 0;
}
+ else if (ever >= extversym_end)
+ {
+ /* xgettext:c-format */
+ _bfd_error_handler (_("%pB: not enough version information"),
+ abfd);
+ bfd_set_error (bfd_error_bad_value);
+ goto error_free_vers;
+ }
else
_bfd_elf_swap_versym_in (abfd, ever, &iver);
(struct bfd_link_hash_entry **) sym_hash)))
goto error_free_vers;
- if ((flags & BSF_GNU_UNIQUE)
- && (abfd->flags & DYNAMIC) == 0
- && bfd_get_flavour (info->output_bfd) == bfd_target_elf_flavour)
- elf_tdata (info->output_bfd)->has_gnu_symbols |= elf_gnu_symbol_unique;
+ if ((abfd->flags & DYNAMIC) == 0
+ && (bfd_get_flavour (info->output_bfd)
+ == bfd_target_elf_flavour))
+ {
+ if (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC)
+ elf_tdata (info->output_bfd)->has_gnu_symbols
+ |= elf_gnu_symbol_ifunc;
+ if ((flags & BSF_GNU_UNIQUE))
+ elf_tdata (info->output_bfd)->has_gnu_symbols
+ |= elf_gnu_symbol_unique;
+ }
h = *sym_hash;
/* We need to make sure that indirect symbol dynamic flags are
asection *s;
/* Data first, since setting text_index_section changes
- _bfd_elf_link_omit_section_dynsym. */
+ _bfd_elf_omit_section_dynsym_default. */
for (s = output_bfd->sections; s != NULL; s = s->next)
if (((s->flags & (SEC_EXCLUDE | SEC_ALLOC | SEC_READONLY)) == SEC_ALLOC)
&& !_bfd_elf_omit_section_dynsym_default (output_bfd, info, s))
}
}
+/* Hide a symbol. */
+
+void
+_bfd_elf_link_hide_symbol (bfd *output_bfd,
+ struct bfd_link_info *info,
+ struct bfd_link_hash_entry *h)
+{
+ if (is_elf_hash_table (info->hash))
+ {
+ const struct elf_backend_data *bed
+ = get_elf_backend_data (output_bfd);
+ struct elf_link_hash_entry *eh
+ = (struct elf_link_hash_entry *) h;
+ bed->elf_backend_hide_symbol (info, eh, TRUE);
+ eh->def_dynamic = 0;
+ eh->ref_dynamic = 0;
+ eh->dynamic_def = 0;
+ }
+}
+
/* Initialize an ELF linker hash table. *TABLE has been zeroed by our
caller. */
/* If this symbol should be put in the .dynsym section, then put it
there now. We already know the symbol index. We also fill in
the entry in the .hash section. */
- if (elf_hash_table (flinfo->info)->dynsym != NULL
- && h->dynindx != -1
- && elf_hash_table (flinfo->info)->dynamic_sections_created)
+ if (h->dynindx != -1
+ && elf_hash_table (flinfo->info)->dynamic_sections_created
+ && elf_hash_table (flinfo->info)->dynsym != NULL
+ && !discarded_section (elf_hash_table (flinfo->info)->dynsym))
{
bfd_byte *esym;
if (ELF_ST_TYPE (osym.st_info) == STT_TLS)
{
/* STT_TLS symbols are relative to PT_TLS segment base. */
- BFD_ASSERT (elf_hash_table (flinfo->info)->tls_sec != NULL);
- osym.st_value -= elf_hash_table (flinfo->info)->tls_sec->vma;
+ if (elf_hash_table (flinfo->info)->tls_sec != NULL)
+ osym.st_value -= elf_hash_table (flinfo->info)->tls_sec->vma;
+ else
+ osym.st_info = ELF_ST_INFO (ELF_ST_BIND (osym.st_info),
+ STT_NOTYPE);
}
}
sym.st_value += osec->vma;
if (ELF_ST_TYPE (sym.st_info) == STT_TLS)
{
+ struct elf_link_hash_table *htab
+ = elf_hash_table (flinfo->info);
+
/* STT_TLS symbols are relative to PT_TLS
segment base. */
- BFD_ASSERT (elf_hash_table (flinfo->info)
- ->tls_sec != NULL);
- sym.st_value -= (elf_hash_table (flinfo->info)
- ->tls_sec->vma);
+ if (htab->tls_sec != NULL)
+ sym.st_value -= htab->tls_sec->vma;
+ else
+ sym.st_info
+ = ELF_ST_INFO (ELF_ST_BIND (sym.st_info),
+ STT_NOTYPE);
}
}
std_attrs_section = get_elf_backend_data (abfd)->obj_attrs_section;
for (o = abfd->sections; o != NULL; o = o->next)
{
+ bfd_boolean remove_section = FALSE;
+
if ((std_attrs_section && strcmp (o->name, std_attrs_section) == 0)
|| strcmp (o->name, ".gnu.attributes") == 0)
{
}
attr_size = bfd_elf_obj_attr_size (abfd);
+ bfd_set_section_size (abfd, o, attr_size);
+ /* Skip this section later on. */
+ o->map_head.link_order = NULL;
if (attr_size)
- {
- bfd_set_section_size (abfd, o, attr_size);
- attr_section = o;
- /* Skip this section later on. */
- o->map_head.link_order = NULL;
- }
+ attr_section = o;
else
- o->flags |= SEC_EXCLUDE;
+ remove_section = TRUE;
}
else if ((o->flags & SEC_GROUP) != 0 && o->size == 0)
{
/* Remove empty group section from linker output. */
+ remove_section = TRUE;
+ }
+ if (remove_section)
+ {
o->flags |= SEC_EXCLUDE;
bfd_section_list_remove (abfd, o);
abfd->section_count--;