/* .eh_frame section optimization.
- Copyright (C) 2001-2014 Free Software Foundation, Inc.
+ Copyright (C) 2001-2020 Free Software Foundation, Inc.
Written by Jakub Jelinek <jakub@redhat.com>.
This file is part of BFD, the Binary File Descriptor library.
return size;
}
-/* Return the size that ENTRY will have in the output. ALIGNMENT is the
- required alignment of ENTRY in bytes. */
+/* Return the size that ENTRY will have in the output. */
static unsigned int
-size_of_output_cie_fde (struct eh_cie_fde *entry, unsigned int alignment)
+size_of_output_cie_fde (struct eh_cie_fde *entry)
{
if (entry->removed)
return 0;
return 4;
return (entry->size
+ extra_augmentation_string_bytes (entry)
- + extra_augmentation_data_bytes (entry)
- + alignment - 1) & -alignment;
+ + extra_augmentation_data_bytes (entry));
+}
+
+/* Return the offset of the FDE or CIE after ENT. */
+
+static unsigned int
+next_cie_fde_offset (const struct eh_cie_fde *ent,
+ const struct eh_cie_fde *last,
+ const asection *sec)
+{
+ while (++ent < last)
+ {
+ if (!ent->removed)
+ return ent->new_offset;
+ }
+ return sec->size;
}
/* Assume that the bytes between *ITER and END are CFA instructions.
return encoding | DW_EH_PE_pcrel;
}
+/* Examine each .eh_frame_entry section and discard those
+ those that are marked SEC_EXCLUDE. */
+
+static void
+bfd_elf_discard_eh_frame_entry (struct eh_frame_hdr_info *hdr_info)
+{
+ unsigned int i;
+ for (i = 0; i < hdr_info->array_count; i++)
+ {
+ if (hdr_info->u.compact.entries[i]->flags & SEC_EXCLUDE)
+ {
+ unsigned int j;
+ for (j = i + 1; j < hdr_info->array_count; j++)
+ hdr_info->u.compact.entries[j-1] = hdr_info->u.compact.entries[j];
+
+ hdr_info->array_count--;
+ hdr_info->u.compact.entries[hdr_info->array_count] = NULL;
+ i--;
+ }
+ }
+}
+
+/* Add a .eh_frame_entry section. */
+
+static void
+bfd_elf_record_eh_frame_entry (struct eh_frame_hdr_info *hdr_info,
+ asection *sec)
+{
+ if (hdr_info->array_count == hdr_info->u.compact.allocated_entries)
+ {
+ if (hdr_info->u.compact.allocated_entries == 0)
+ {
+ hdr_info->frame_hdr_is_compact = TRUE;
+ hdr_info->u.compact.allocated_entries = 2;
+ hdr_info->u.compact.entries =
+ bfd_malloc (hdr_info->u.compact.allocated_entries
+ * sizeof (hdr_info->u.compact.entries[0]));
+ }
+ else
+ {
+ hdr_info->u.compact.allocated_entries *= 2;
+ hdr_info->u.compact.entries =
+ bfd_realloc (hdr_info->u.compact.entries,
+ hdr_info->u.compact.allocated_entries
+ * sizeof (hdr_info->u.compact.entries[0]));
+ }
+
+ BFD_ASSERT (hdr_info->u.compact.entries);
+ }
+
+ hdr_info->u.compact.entries[hdr_info->array_count++] = sec;
+}
+
+/* Parse a .eh_frame_entry section. Figure out which text section it
+ references. */
+
+bfd_boolean
+_bfd_elf_parse_eh_frame_entry (struct bfd_link_info *info,
+ asection *sec, struct elf_reloc_cookie *cookie)
+{
+ struct elf_link_hash_table *htab;
+ struct eh_frame_hdr_info *hdr_info;
+ unsigned long r_symndx;
+ asection *text_sec;
+
+ htab = elf_hash_table (info);
+ hdr_info = &htab->eh_info;
+
+ if (sec->size == 0
+ || sec->sec_info_type != SEC_INFO_TYPE_NONE)
+ {
+ return TRUE;
+ }
+
+ if (sec->output_section && bfd_is_abs_section (sec->output_section))
+ {
+ /* At least one of the sections is being discarded from the
+ link, so we should just ignore them. */
+ return TRUE;
+ }
+
+ if (cookie->rel == cookie->relend)
+ return FALSE;
+
+ /* The first relocation is the function start. */
+ r_symndx = cookie->rel->r_info >> cookie->r_sym_shift;
+ if (r_symndx == STN_UNDEF)
+ return FALSE;
+
+ text_sec = _bfd_elf_section_for_symbol (cookie, r_symndx, FALSE);
+
+ if (text_sec == NULL)
+ return FALSE;
+
+ elf_section_eh_frame_entry (text_sec) = sec;
+ if (text_sec->output_section
+ && bfd_is_abs_section (text_sec->output_section))
+ sec->flags |= SEC_EXCLUDE;
+
+ sec->sec_info_type = SEC_INFO_TYPE_EH_FRAME_ENTRY;
+ elf_section_data (sec)->sec_info = text_sec;
+ bfd_elf_record_eh_frame_entry (hdr_info, sec);
+ return TRUE;
+}
+
/* Try to parse .eh_frame section SEC, which belongs to ABFD. Store the
information in the section's sec_info field on success. COOKIE
describes the relocations in SEC. */
REQUIRE (bfd_malloc_and_get_section (abfd, sec, &ehbuf));
- if (sec->size >= 4
- && bfd_get_32 (abfd, ehbuf) == 0
- && cookie->rel == cookie->relend)
- {
- /* Empty .eh_frame section. */
- free (ehbuf);
- return;
- }
-
/* If .eh_frame section size doesn't fit into int, we cannot handle
it (it would need to use 64-bit .eh_frame format anyway). */
REQUIRE (sec->size == (unsigned int) sec->size);
sec_info = (struct eh_frame_sec_info *)
bfd_zmalloc (sizeof (struct eh_frame_sec_info)
- + (num_entries - 1) * sizeof (struct eh_cie_fde));
+ + (num_entries - 1) * sizeof (struct eh_cie_fde));
REQUIRE (sec_info);
/* We need to have a "struct cie" for each CIE in this section. */
- local_cies = (struct cie *) bfd_zmalloc (num_cies * sizeof (*local_cies));
- REQUIRE (local_cies);
+ if (num_cies)
+ {
+ local_cies = (struct cie *) bfd_zmalloc (num_cies * sizeof (*local_cies));
+ REQUIRE (local_cies);
+ }
/* FIXME: octets_per_byte. */
#define ENSURE_NO_RELOCS(buf) \
if (hdr_length == 0)
{
/* A zero-length CIE should only be found at the end of
- the section. */
+ the section, but allow multiple terminators. */
+ while (skip_bytes (&buf, ehbuf + sec->size, 4))
+ REQUIRE (bfd_get_32 (abfd, buf - 4) == 0);
REQUIRE ((bfd_size_type) (buf - ehbuf) == sec->size);
ENSURE_NO_RELOCS (buf);
sec_info->count++;
strcpy (cie->augmentation, (char *) buf);
buf = (bfd_byte *) strchr ((char *) buf, '\0') + 1;
+ this_inf->u.cie.aug_str_len = buf - start - 1;
ENSURE_NO_RELOCS (buf);
if (buf[0] == 'e' && buf[1] == 'h')
{
{
aug++;
REQUIRE (read_uleb128 (&buf, end, &cie->augmentation_size));
- ENSURE_NO_RELOCS (buf);
+ ENSURE_NO_RELOCS (buf);
}
while (*aug != '\0')
switch (*aug++)
{
+ case 'B':
+ break;
case 'L':
REQUIRE (read_byte (&buf, end, &cie->lsda_encoding));
ENSURE_NO_RELOCS (buf);
{
length = -(buf - ehbuf) & (per_width - 1);
REQUIRE (skip_bytes (&buf, end, length));
+ if (per_width == 8)
+ this_inf->u.cie.per_encoding_aligned8 = 1;
}
this_inf->u.cie.personality_offset = buf - start;
ENSURE_NO_RELOCS (buf);
goto free_no_table;
}
}
+ this_inf->u.cie.aug_data_len
+ = buf - start - 1 - this_inf->u.cie.aug_str_len;
/* For shared libraries, try to get rid of as many RELATIVE relocs
as possible. */
- if (info->shared
- && !info->relocatable
+ if (bfd_link_pic (info)
&& (get_elf_backend_data (abfd)
->elf_backend_can_make_relative_eh_frame
(abfd, info, sec)))
buf += initial_insn_length;
ENSURE_NO_RELOCS (buf);
- if (!info->relocatable)
+ if (!bfd_link_relocatable (info))
{
/* Keep info for merging cies. */
this_inf->u.cie.u.full_cie = cie;
REQUIRE (GET_RELOC (buf));
/* Chain together the FDEs for each section. */
- rsec = _bfd_elf_gc_mark_rsec (info, sec, gc_mark_hook, cookie);
+ rsec = _bfd_elf_gc_mark_rsec (info, sec, gc_mark_hook,
+ cookie, NULL);
/* RSEC will be NULL if FDE was cleared out as it was belonging to
a discarded SHT_GROUP. */
if (rsec)
&& read_value (abfd, buf - length, length, FALSE) == 0)
{
(*info->callbacks->minfo)
- (_("discarding zero address range FDE in %B(%A).\n"),
+ /* xgettext:c-format */
+ (_("discarding zero address range FDE in %pB(%pA).\n"),
abfd, sec);
this_inf->u.fde.cie_inf = NULL;
}
bfd_byte *p;
this_inf->set_loc = (unsigned int *)
- bfd_malloc ((set_loc_count + 1) * sizeof (unsigned int));
+ bfd_malloc ((set_loc_count + 1) * sizeof (unsigned int));
REQUIRE (this_inf->set_loc);
this_inf->set_loc[0] = set_loc_count;
p = insns;
elf_section_data (sec)->sec_info = sec_info;
sec->sec_info_type = SEC_INFO_TYPE_EH_FRAME;
- if (!info->relocatable)
+ if (!bfd_link_relocatable (info))
{
/* Keep info for merging cies. */
sec_info->cies = local_cies;
goto success;
free_no_table:
- (*info->callbacks->einfo)
- (_("%P: error in %B(%A); no .eh_frame_hdr table will be created.\n"),
+ _bfd_error_handler
+ /* xgettext:c-format */
+ (_("error in %pB(%pA); no .eh_frame_hdr table will be created"),
abfd, sec);
- hdr_info->table = FALSE;
- if (sec_info)
- free (sec_info);
+ hdr_info->u.dwarf.table = FALSE;
+ free (sec_info);
success:
- if (ehbuf)
- free (ehbuf);
- if (local_cies)
- free (local_cies);
+ free (ehbuf);
+ free (local_cies);
#undef REQUIRE
}
+/* Order eh_frame_hdr entries by the VMA of their text section. */
+
+static int
+cmp_eh_frame_hdr (const void *a, const void *b)
+{
+ bfd_vma text_a;
+ bfd_vma text_b;
+ asection *sec;
+
+ sec = *(asection *const *)a;
+ sec = (asection *) elf_section_data (sec)->sec_info;
+ text_a = sec->output_section->vma + sec->output_offset;
+ sec = *(asection *const *)b;
+ sec = (asection *) elf_section_data (sec)->sec_info;
+ text_b = sec->output_section->vma + sec->output_offset;
+
+ if (text_a < text_b)
+ return -1;
+ return text_a > text_b;
+
+}
+
+/* Add space for a CANTUNWIND terminator to SEC if the text sections
+ referenced by it and NEXT are not contiguous, or NEXT is NULL. */
+
+static void
+add_eh_frame_hdr_terminator (asection *sec,
+ asection *next)
+{
+ bfd_vma end;
+ bfd_vma next_start;
+ asection *text_sec;
+
+ if (next)
+ {
+ /* See if there is a gap (presumably a text section without unwind info)
+ between these two entries. */
+ text_sec = (asection *) elf_section_data (sec)->sec_info;
+ end = text_sec->output_section->vma + text_sec->output_offset
+ + text_sec->size;
+ text_sec = (asection *) elf_section_data (next)->sec_info;
+ next_start = text_sec->output_section->vma + text_sec->output_offset;
+ if (end == next_start)
+ return;
+ }
+
+ /* Add space for a CANTUNWIND terminator. */
+ if (!sec->rawsize)
+ sec->rawsize = sec->size;
+
+ bfd_set_section_size (sec, sec->size + 8);
+}
+
+/* Finish a pass over all .eh_frame_entry sections. */
+
+bfd_boolean
+_bfd_elf_end_eh_frame_parsing (struct bfd_link_info *info)
+{
+ struct eh_frame_hdr_info *hdr_info;
+ unsigned int i;
+
+ hdr_info = &elf_hash_table (info)->eh_info;
+
+ if (info->eh_frame_hdr_type != COMPACT_EH_HDR
+ || hdr_info->array_count == 0)
+ return FALSE;
+
+ bfd_elf_discard_eh_frame_entry (hdr_info);
+
+ qsort (hdr_info->u.compact.entries, hdr_info->array_count,
+ sizeof (asection *), cmp_eh_frame_hdr);
+
+ for (i = 0; i < hdr_info->array_count - 1; i++)
+ {
+ add_eh_frame_hdr_terminator (hdr_info->u.compact.entries[i],
+ hdr_info->u.compact.entries[i + 1]);
+ }
+
+ /* Add a CANTUNWIND terminator after the last entry. */
+ add_eh_frame_hdr_terminator (hdr_info->u.compact.entries[i], NULL);
+ return TRUE;
+}
+
/* Mark all relocations against CIE or FDE ENT, which occurs in
.eh_frame section SEC. COOKIE describes the relocations in SEC;
its "rel" field can be changed freely. */
}
if (per_binds_local
- && info->shared
- && !info->relocatable
+ && bfd_link_pic (info)
&& (cie->per_encoding & 0x70) == DW_EH_PE_absptr
&& (get_elf_backend_data (abfd)
->elf_backend_can_make_relative_eh_frame (abfd, info, sec)))
/* See if we can merge this CIE with an earlier one. */
cie_compute_hash (cie);
- if (hdr_info->cies == NULL)
+ if (hdr_info->u.dwarf.cies == NULL)
{
- hdr_info->cies = htab_try_create (1, cie_hash, cie_eq, free);
- if (hdr_info->cies == NULL)
+ hdr_info->u.dwarf.cies = htab_try_create (1, cie_hash, cie_eq, free);
+ if (hdr_info->u.dwarf.cies == NULL)
return cie_inf;
}
- loc = htab_find_slot_with_hash (hdr_info->cies, cie, cie->hash, INSERT);
+ loc = htab_find_slot_with_hash (hdr_info->u.dwarf.cies, cie,
+ cie->hash, INSERT);
if (loc == NULL)
return cie_inf;
return new_cie->cie_inf;
}
+/* For a given OFFSET in SEC, return the delta to the new location
+ after .eh_frame editing. */
+
+static bfd_signed_vma
+offset_adjust (bfd_vma offset, const asection *sec)
+{
+ struct eh_frame_sec_info *sec_info
+ = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info;
+ unsigned int lo, hi, mid;
+ struct eh_cie_fde *ent = NULL;
+ bfd_signed_vma delta;
+
+ lo = 0;
+ hi = sec_info->count;
+ if (hi == 0)
+ return 0;
+
+ while (lo < hi)
+ {
+ mid = (lo + hi) / 2;
+ ent = &sec_info->entry[mid];
+ if (offset < ent->offset)
+ hi = mid;
+ else if (mid + 1 >= hi)
+ break;
+ else if (offset >= ent[1].offset)
+ lo = mid + 1;
+ else
+ break;
+ }
+
+ if (!ent->removed)
+ delta = (bfd_vma) ent->new_offset - (bfd_vma) ent->offset;
+ else if (ent->cie && ent->u.cie.merged)
+ {
+ struct eh_cie_fde *cie = ent->u.cie.u.merged_with;
+ delta = ((bfd_vma) cie->new_offset + cie->u.cie.u.sec->output_offset
+ - (bfd_vma) ent->offset - sec->output_offset);
+ }
+ else
+ {
+ /* Is putting the symbol on the next entry best for a deleted
+ CIE/FDE? */
+ struct eh_cie_fde *last = sec_info->entry + sec_info->count;
+ delta = ((bfd_vma) next_cie_fde_offset (ent, last, sec)
+ - (bfd_vma) ent->offset);
+ return delta;
+ }
+
+ /* Account for editing within this CIE/FDE. */
+ offset -= ent->offset;
+ if (ent->cie)
+ {
+ unsigned int extra
+ = ent->add_augmentation_size + ent->u.cie.add_fde_encoding;
+ if (extra == 0
+ || offset <= 9u + ent->u.cie.aug_str_len)
+ return delta;
+ delta += extra;
+ if (offset <= 9u + ent->u.cie.aug_str_len + ent->u.cie.aug_data_len)
+ return delta;
+ delta += extra;
+ }
+ else
+ {
+ unsigned int ptr_size, width, extra = ent->add_augmentation_size;
+ if (offset <= 12 || extra == 0)
+ return delta;
+ ptr_size = (get_elf_backend_data (sec->owner)
+ ->elf_backend_eh_frame_address_size (sec->owner, sec));
+ width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size);
+ if (offset <= 8 + 2 * width)
+ return delta;
+ delta += extra;
+ }
+
+ return delta;
+}
+
+/* Adjust a global symbol defined in .eh_frame, so that it stays
+ relative to its original CIE/FDE. It is assumed that a symbol
+ defined at the beginning of a CIE/FDE belongs to that CIE/FDE
+ rather than marking the end of the previous CIE/FDE. This matters
+ when a CIE is merged with a previous CIE, since the symbol is
+ moved to the merged CIE. */
+
+bfd_boolean
+_bfd_elf_adjust_eh_frame_global_symbol (struct elf_link_hash_entry *h,
+ void *arg ATTRIBUTE_UNUSED)
+{
+ asection *sym_sec;
+ bfd_signed_vma delta;
+
+ if (h->root.type != bfd_link_hash_defined
+ && h->root.type != bfd_link_hash_defweak)
+ return TRUE;
+
+ sym_sec = h->root.u.def.section;
+ if (sym_sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME
+ || elf_section_data (sym_sec)->sec_info == NULL)
+ return TRUE;
+
+ delta = offset_adjust (h->root.u.def.value, sym_sec);
+ h->root.u.def.value += delta;
+
+ return TRUE;
+}
+
+/* The same for all local symbols defined in .eh_frame. Returns true
+ if any symbol was changed. */
+
+static int
+adjust_eh_frame_local_symbols (const asection *sec,
+ struct elf_reloc_cookie *cookie)
+{
+ unsigned int shndx;
+ Elf_Internal_Sym *sym;
+ Elf_Internal_Sym *end_sym;
+ int adjusted = 0;
+
+ shndx = elf_section_data (sec)->this_idx;
+ end_sym = cookie->locsyms + cookie->locsymcount;
+ for (sym = cookie->locsyms + 1; sym < end_sym; ++sym)
+ if (sym->st_info <= ELF_ST_INFO (STB_LOCAL, STT_OBJECT)
+ && sym->st_shndx == shndx)
+ {
+ bfd_signed_vma delta = offset_adjust (sym->st_value, sec);
+
+ if (delta != 0)
+ {
+ adjusted = 1;
+ sym->st_value += delta;
+ }
+ }
+ return adjusted;
+}
+
/* This function is called for each input file before the .eh_frame
section is relocated. It discards duplicate CIEs and FDEs for discarded
functions. The function returns TRUE iff any entries have been
struct eh_cie_fde *ent;
struct eh_frame_sec_info *sec_info;
struct eh_frame_hdr_info *hdr_info;
- unsigned int ptr_size, offset;
+ unsigned int ptr_size, offset, eh_alignment;
+ int changed;
if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME)
return FALSE;
}
if (keep)
{
- if (info->shared
+ if (bfd_link_pic (info)
&& (((ent->fde_encoding & 0x70) == DW_EH_PE_absptr
&& ent->make_relative == 0)
|| (ent->fde_encoding & 0x70) == DW_EH_PE_aligned))
{
+ static int num_warnings_issued = 0;
+
/* If a shared library uses absolute pointers
which we cannot turn into PC relative,
don't create the binary search table,
since it is affected by runtime relocations. */
- hdr_info->table = FALSE;
- (*info->callbacks->einfo)
- (_("%P: FDE encoding in %B(%A) prevents .eh_frame_hdr"
- " table being created.\n"), abfd, sec);
+ hdr_info->u.dwarf.table = FALSE;
+ /* Only warn if --eh-frame-hdr was specified. */
+ if (info->eh_frame_hdr_type != 0)
+ {
+ if (num_warnings_issued < 10)
+ {
+ _bfd_error_handler
+ /* xgettext:c-format */
+ (_("FDE encoding in %pB(%pA) prevents .eh_frame_hdr"
+ " table being created"), abfd, sec);
+ num_warnings_issued ++;
+ }
+ else if (num_warnings_issued == 10)
+ {
+ _bfd_error_handler
+ (_("further warnings about FDE encoding preventing .eh_frame_hdr generation dropped"));
+ num_warnings_issued ++;
+ }
+ }
}
ent->removed = 0;
- hdr_info->fde_count++;
+ hdr_info->u.dwarf.fde_count++;
ent->u.fde.cie_inf = find_merged_cie (abfd, info, sec, hdr_info,
cookie, ent->u.fde.cie_inf);
}
}
- if (sec_info->cies)
- {
- free (sec_info->cies);
- sec_info->cies = NULL;
- }
+ free (sec_info->cies);
+ sec_info->cies = NULL;
+ /* It may be that some .eh_frame input section has greater alignment
+ than other .eh_frame sections. In that case we run the risk of
+ padding with zeros before that section, which would be seen as a
+ zero terminator. Alignment padding must be added *inside* the
+ last FDE instead. For other FDEs we align according to their
+ encoding, in order to align FDE address range entries naturally. */
offset = 0;
+ changed = 0;
for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent)
if (!ent->removed)
{
+ eh_alignment = 4;
+ if (ent->size == 4)
+ ;
+ else if (ent->cie)
+ {
+ if (ent->u.cie.per_encoding_aligned8)
+ eh_alignment = 8;
+ }
+ else
+ {
+ eh_alignment = get_DW_EH_PE_width (ent->fde_encoding, ptr_size);
+ if (eh_alignment < 4)
+ eh_alignment = 4;
+ }
+ offset = (offset + eh_alignment - 1) & -eh_alignment;
ent->new_offset = offset;
- offset += size_of_output_cie_fde (ent, ptr_size);
+ if (ent->new_offset != ent->offset)
+ changed = 1;
+ offset += size_of_output_cie_fde (ent);
}
+ eh_alignment = 4;
+ offset = (offset + eh_alignment - 1) & -eh_alignment;
sec->rawsize = sec->size;
sec->size = offset;
- return offset != sec->rawsize;
+ if (sec->size != sec->rawsize)
+ changed = 1;
+
+ if (changed && adjust_eh_frame_local_symbols (sec, cookie))
+ {
+ Elf_Internal_Shdr *symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
+ symtab_hdr->contents = (unsigned char *) cookie->locsyms;
+ }
+ return changed;
}
/* This function is called for .eh_frame_hdr section after
htab = elf_hash_table (info);
hdr_info = &htab->eh_info;
- if (hdr_info->cies != NULL)
+ if (!hdr_info->frame_hdr_is_compact && hdr_info->u.dwarf.cies != NULL)
{
- htab_delete (hdr_info->cies);
- hdr_info->cies = NULL;
+ htab_delete (hdr_info->u.dwarf.cies);
+ hdr_info->u.dwarf.cies = NULL;
}
sec = hdr_info->hdr_sec;
if (sec == NULL)
return FALSE;
- sec->size = EH_FRAME_HDR_SIZE;
- if (hdr_info->table)
- sec->size += 4 + hdr_info->fde_count * 8;
+ if (info->eh_frame_hdr_type == COMPACT_EH_HDR)
+ {
+ /* For compact frames we only add the header. The actual table comes
+ from the .eh_frame_entry sections. */
+ sec->size = 8;
+ }
+ else
+ {
+ sec->size = EH_FRAME_HDR_SIZE;
+ if (hdr_info->u.dwarf.table)
+ sec->size += 4 + hdr_info->u.dwarf.fde_count * 8;
+ }
elf_eh_frame_hdr (abfd) = sec;
return TRUE;
/* Return true if there is at least one non-empty .eh_frame section in
input files. Can only be called after ld has mapped input to
output sections, and before sections are stripped. */
+
bfd_boolean
_bfd_elf_eh_frame_present (struct bfd_link_info *info)
{
return FALSE;
}
+/* Return true if there is at least one .eh_frame_entry section in
+ input files. */
+
+bfd_boolean
+_bfd_elf_eh_frame_entry_present (struct bfd_link_info *info)
+{
+ asection *o;
+ bfd *abfd;
+
+ for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
+ {
+ for (o = abfd->sections; o; o = o->next)
+ {
+ const char *name = bfd_section_name (o);
+
+ if (strcmp (name, ".eh_frame_entry")
+ && !bfd_is_abs_section (o->output_section))
+ return TRUE;
+ }
+ }
+ return FALSE;
+}
+
/* This function is called from size_dynamic_sections.
It needs to decide whether .eh_frame_hdr should be output or not,
because when the dynamic symbol table has been sized it is too late
{
struct elf_link_hash_table *htab;
struct eh_frame_hdr_info *hdr_info;
+ struct bfd_link_hash_entry *bh = NULL;
+ struct elf_link_hash_entry *h;
htab = elf_hash_table (info);
hdr_info = &htab->eh_info;
return TRUE;
if (bfd_is_abs_section (hdr_info->hdr_sec->output_section)
- || !info->eh_frame_hdr
- || !_bfd_elf_eh_frame_present (info))
+ || info->eh_frame_hdr_type == 0
+ || (info->eh_frame_hdr_type == DWARF2_EH_HDR
+ && !_bfd_elf_eh_frame_present (info))
+ || (info->eh_frame_hdr_type == COMPACT_EH_HDR
+ && !_bfd_elf_eh_frame_entry_present (info)))
{
hdr_info->hdr_sec->flags |= SEC_EXCLUDE;
hdr_info->hdr_sec = NULL;
return TRUE;
}
- hdr_info->table = TRUE;
+ /* Add a hidden symbol so that systems without access to PHDRs can
+ find the table. */
+ if (! (_bfd_generic_link_add_one_symbol
+ (info, info->output_bfd, "__GNU_EH_FRAME_HDR", BSF_LOCAL,
+ hdr_info->hdr_sec, 0, NULL, FALSE, FALSE, &bh)))
+ return FALSE;
+
+ h = (struct elf_link_hash_entry *) bh;
+ h->def_regular = 1;
+ h->other = STV_HIDDEN;
+ get_elf_backend_data
+ (info->output_bfd)->elf_backend_hide_symbol (info, h, TRUE);
+
+ if (!hdr_info->frame_hdr_is_compact)
+ hdr_info->u.dwarf.table = TRUE;
return TRUE;
}
+ extra_augmentation_data_bytes (sec_info->entry + mid));
}
+/* Write out .eh_frame_entry section. Add CANTUNWIND terminator if needed.
+ Also check that the contents look sane. */
+
+bfd_boolean
+_bfd_elf_write_section_eh_frame_entry (bfd *abfd, struct bfd_link_info *info,
+ asection *sec, bfd_byte *contents)
+{
+ const struct elf_backend_data *bed;
+ bfd_byte cantunwind[8];
+ bfd_vma addr;
+ bfd_vma last_addr;
+ bfd_vma offset;
+ asection *text_sec = (asection *) elf_section_data (sec)->sec_info;
+
+ if (!sec->rawsize)
+ sec->rawsize = sec->size;
+
+ BFD_ASSERT (sec->sec_info_type == SEC_INFO_TYPE_EH_FRAME_ENTRY);
+
+ /* Check to make sure that the text section corresponding to this eh_frame_entry
+ section has not been excluded. In particular, mips16 stub entries will be
+ excluded outside of the normal process. */
+ if (sec->flags & SEC_EXCLUDE
+ || text_sec->flags & SEC_EXCLUDE)
+ return TRUE;
+
+ if (!bfd_set_section_contents (abfd, sec->output_section, contents,
+ sec->output_offset, sec->rawsize))
+ return FALSE;
+
+ last_addr = bfd_get_signed_32 (abfd, contents);
+ /* Check that all the entries are in order. */
+ for (offset = 8; offset < sec->rawsize; offset += 8)
+ {
+ addr = bfd_get_signed_32 (abfd, contents + offset) + offset;
+ if (addr <= last_addr)
+ {
+ /* xgettext:c-format */
+ _bfd_error_handler (_("%pB: %pA not in order"), sec->owner, sec);
+ return FALSE;
+ }
+
+ last_addr = addr;
+ }
+
+ addr = text_sec->output_section->vma + text_sec->output_offset
+ + text_sec->size;
+ addr &= ~1;
+ addr -= (sec->output_section->vma + sec->output_offset + sec->rawsize);
+ if (addr & 1)
+ {
+ /* xgettext:c-format */
+ _bfd_error_handler (_("%pB: %pA invalid input section size"),
+ sec->owner, sec);
+ bfd_set_error (bfd_error_bad_value);
+ return FALSE;
+ }
+ if (last_addr >= addr + sec->rawsize)
+ {
+ /* xgettext:c-format */
+ _bfd_error_handler (_("%pB: %pA points past end of text section"),
+ sec->owner, sec);
+ bfd_set_error (bfd_error_bad_value);
+ return FALSE;
+ }
+
+ if (sec->size == sec->rawsize)
+ return TRUE;
+
+ bed = get_elf_backend_data (abfd);
+ BFD_ASSERT (sec->size == sec->rawsize + 8);
+ BFD_ASSERT ((addr & 1) == 0);
+ BFD_ASSERT (bed->cant_unwind_opcode);
+
+ bfd_put_32 (abfd, addr, cantunwind);
+ bfd_put_32 (abfd, (*bed->cant_unwind_opcode) (info), cantunwind + 4);
+ return bfd_set_section_contents (abfd, sec->output_section, cantunwind,
+ sec->output_offset + sec->rawsize, 8);
+}
+
/* Write out .eh_frame section. This is called with the relocated
contents. */
struct elf_link_hash_table *htab;
struct eh_frame_hdr_info *hdr_info;
unsigned int ptr_size;
- struct eh_cie_fde *ent;
+ struct eh_cie_fde *ent, *last_ent;
if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME)
/* FIXME: octets_per_byte. */
htab = elf_hash_table (info);
hdr_info = &htab->eh_info;
- if (hdr_info->table && hdr_info->array == NULL)
- hdr_info->array = (struct eh_frame_array_ent *)
- bfd_malloc (hdr_info->fde_count * sizeof(*hdr_info->array));
- if (hdr_info->array == NULL)
+ if (hdr_info->u.dwarf.table && hdr_info->u.dwarf.array == NULL)
+ {
+ hdr_info->frame_hdr_is_compact = FALSE;
+ hdr_info->u.dwarf.array = (struct eh_frame_array_ent *)
+ bfd_malloc (hdr_info->u.dwarf.fde_count
+ * sizeof (*hdr_info->u.dwarf.array));
+ }
+ if (hdr_info->u.dwarf.array == NULL)
hdr_info = NULL;
/* The new offsets can be bigger or smaller than the original offsets.
if (!ent->removed && ent->new_offset < ent->offset)
memmove (contents + ent->new_offset, contents + ent->offset, ent->size);
- for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent)
+ last_ent = sec_info->entry + sec_info->count;
+ for (ent = sec_info->entry; ent < last_ent; ++ent)
{
unsigned char *buf, *end;
unsigned int new_size;
if (ent->size == 4)
{
/* Any terminating FDE must be at the end of the section. */
- BFD_ASSERT (ent == sec_info->entry + sec_info->count - 1);
+ BFD_ASSERT (ent == last_ent - 1);
continue;
}
buf = contents + ent->new_offset;
end = buf + ent->size;
- new_size = size_of_output_cie_fde (ent, ptr_size);
+ new_size = next_cie_fde_offset (ent, last_ent, sec) - ent->new_offset;
/* Update the size. It may be shrinked. */
bfd_put_32 (abfd, new_size - 4, buf);
|| ent->u.cie.per_encoding_relative)
{
char *aug;
- unsigned int action, extra_string, extra_data;
+ unsigned int version, action, extra_string, extra_data;
unsigned int per_width, per_encoding;
/* Need to find 'R' or 'L' augmentation's argument and modify
extra_string = extra_augmentation_string_bytes (ent);
extra_data = extra_augmentation_data_bytes (ent);
- /* Skip length, id and version. */
- buf += 9;
+ /* Skip length, id. */
+ buf += 8;
+ version = *buf++;
aug = (char *) buf;
buf += strlen (aug) + 1;
skip_leb128 (&buf, end);
skip_leb128 (&buf, end);
- skip_leb128 (&buf, end);
+ if (version == 1)
+ skip_bytes (&buf, end, 1);
+ else
+ skip_leb128 (&buf, end);
if (*aug == 'z')
{
/* The uleb128 will always be a single byte for the kind
value = ((ent->new_offset + sec->output_offset + 4)
- (cie->new_offset + cie->u.cie.u.sec->output_offset));
bfd_put_32 (abfd, value, buf);
- if (info->relocatable)
+ if (bfd_link_relocatable (info))
continue;
buf += 4;
width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size);
address += elf_gp (abfd);
break;
default:
- (*info->callbacks->einfo)
- (_("%P: DW_EH_PE_datarel unspecified"
- " for this architecture.\n"));
+ _bfd_error_handler
+ (_("DW_EH_PE_datarel unspecified"
+ " for this architecture"));
/* Fall thru */
case bfd_arch_frv:
case bfd_arch_i386:
+ case bfd_arch_nios2:
BFD_ASSERT (htab->hgot != NULL
&& ((htab->hgot->root.type
== bfd_link_hash_defined)
dwarf_vma is 64-bit. */
if (sizeof (address) > 4 && ptr_size == 4)
address &= 0xffffffff;
- hdr_info->array[hdr_info->array_count].initial_loc = address;
- hdr_info->array[hdr_info->array_count].range
+ hdr_info->u.dwarf.array[hdr_info->array_count].initial_loc
+ = address;
+ hdr_info->u.dwarf.array[hdr_info->array_count].range
= read_value (abfd, buf + width, width, FALSE);
- hdr_info->array[hdr_info->array_count++].fde
+ hdr_info->u.dwarf.array[hdr_info->array_count++].fde
= (sec->output_section->vma
+ sec->output_offset
+ ent->new_offset);
}
}
- /* We don't align the section to its section alignment since the
- runtime library only expects all CIE/FDE records aligned at
- the pointer size. _bfd_elf_discard_section_eh_frame should
- have padded CIE/FDE records to multiple of pointer size with
- size_of_output_cie_fde. */
- if ((sec->size % ptr_size) != 0)
- abort ();
-
/* FIXME: octets_per_byte. */
return bfd_set_section_contents (abfd, sec->output_section,
contents, (file_ptr) sec->output_offset,
return 0;
}
-/* Write out .eh_frame_hdr section. This must be called after
- _bfd_elf_write_section_eh_frame has been called on all input
- .eh_frame sections.
- .eh_frame_hdr format:
+/* Reorder .eh_frame_entry sections to match the associated text sections.
+ This routine is called during the final linking step, just before writing
+ the contents. At this stage, sections in the eh_frame_hdr_info are already
+ sorted in order of increasing text section address and so we simply need
+ to make the .eh_frame_entrys follow that same order. Note that it is
+ invalid for a linker script to try to force a particular order of
+ .eh_frame_entry sections. */
+
+bfd_boolean
+_bfd_elf_fixup_eh_frame_hdr (struct bfd_link_info *info)
+{
+ asection *sec = NULL;
+ asection *osec;
+ struct eh_frame_hdr_info *hdr_info;
+ unsigned int i;
+ bfd_vma offset;
+ struct bfd_link_order *p;
+
+ hdr_info = &elf_hash_table (info)->eh_info;
+
+ if (hdr_info->hdr_sec == NULL
+ || info->eh_frame_hdr_type != COMPACT_EH_HDR
+ || hdr_info->array_count == 0)
+ return TRUE;
+
+ /* Change section output offsets to be in text section order. */
+ offset = 8;
+ osec = hdr_info->u.compact.entries[0]->output_section;
+ for (i = 0; i < hdr_info->array_count; i++)
+ {
+ sec = hdr_info->u.compact.entries[i];
+ if (sec->output_section != osec)
+ {
+ _bfd_error_handler
+ (_("invalid output section for .eh_frame_entry: %pA"),
+ sec->output_section);
+ return FALSE;
+ }
+ sec->output_offset = offset;
+ offset += sec->size;
+ }
+
+
+ /* Fix the link_order to match. */
+ for (p = sec->output_section->map_head.link_order; p != NULL; p = p->next)
+ {
+ if (p->type != bfd_indirect_link_order)
+ abort();
+
+ p->offset = p->u.indirect.section->output_offset;
+ if (p->next != NULL)
+ i--;
+ }
+
+ if (i != 0)
+ {
+ _bfd_error_handler
+ (_("invalid contents in %pA section"), osec);
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/* The .eh_frame_hdr format for Compact EH frames:
+ ubyte version (2)
+ ubyte eh_ref_enc (DW_EH_PE_* encoding of typinfo references)
+ uint32_t count (Number of entries in table)
+ [array from .eh_frame_entry sections] */
+
+static bfd_boolean
+write_compact_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info)
+{
+ struct elf_link_hash_table *htab;
+ struct eh_frame_hdr_info *hdr_info;
+ asection *sec;
+ const struct elf_backend_data *bed;
+ bfd_vma count;
+ bfd_byte contents[8];
+ unsigned int i;
+
+ htab = elf_hash_table (info);
+ hdr_info = &htab->eh_info;
+ sec = hdr_info->hdr_sec;
+
+ if (sec->size != 8)
+ abort();
+
+ for (i = 0; i < sizeof (contents); i++)
+ contents[i] = 0;
+
+ contents[0] = COMPACT_EH_HDR;
+ bed = get_elf_backend_data (abfd);
+
+ BFD_ASSERT (bed->compact_eh_encoding);
+ contents[1] = (*bed->compact_eh_encoding) (info);
+
+ count = (sec->output_section->size - 8) / 8;
+ bfd_put_32 (abfd, count, contents + 4);
+ return bfd_set_section_contents (abfd, sec->output_section, contents,
+ (file_ptr) sec->output_offset, sec->size);
+}
+
+/* The .eh_frame_hdr format for DWARF frames:
+
ubyte version (currently 1)
- ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of
+ ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of
.eh_frame section)
ubyte fde_count_enc (DW_EH_PE_* encoding of total FDE count
number (or DW_EH_PE_omit if there is no
FDE initial_location field and FDE address,
sorted by increasing initial_loc). */
-bfd_boolean
-_bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info)
+static bfd_boolean
+write_dwarf_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info)
{
struct elf_link_hash_table *htab;
struct eh_frame_hdr_info *hdr_info;
htab = elf_hash_table (info);
hdr_info = &htab->eh_info;
sec = hdr_info->hdr_sec;
+ bfd_byte *contents;
+ asection *eh_frame_sec;
+ bfd_size_type size;
+ bfd_vma encoded_eh_frame;
+
+ size = EH_FRAME_HDR_SIZE;
+ if (hdr_info->u.dwarf.array
+ && hdr_info->array_count == hdr_info->u.dwarf.fde_count)
+ size += 4 + hdr_info->u.dwarf.fde_count * 8;
+ contents = (bfd_byte *) bfd_malloc (size);
+ if (contents == NULL)
+ return FALSE;
- if (info->eh_frame_hdr && sec != NULL)
+ eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame");
+ if (eh_frame_sec == NULL)
{
- bfd_byte *contents;
- asection *eh_frame_sec;
- bfd_size_type size;
- bfd_vma encoded_eh_frame;
-
- size = EH_FRAME_HDR_SIZE;
- if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count)
- size += 4 + hdr_info->fde_count * 8;
- contents = (bfd_byte *) bfd_malloc (size);
- if (contents == NULL)
- return FALSE;
+ free (contents);
+ return FALSE;
+ }
- eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame");
- if (eh_frame_sec == NULL)
- {
- free (contents);
- return FALSE;
- }
+ memset (contents, 0, EH_FRAME_HDR_SIZE);
+ /* Version. */
+ contents[0] = 1;
+ /* .eh_frame offset. */
+ contents[1] = get_elf_backend_data (abfd)->elf_backend_encode_eh_address
+ (abfd, info, eh_frame_sec, 0, sec, 4, &encoded_eh_frame);
- memset (contents, 0, EH_FRAME_HDR_SIZE);
- /* Version. */
- contents[0] = 1;
- /* .eh_frame offset. */
- contents[1] = get_elf_backend_data (abfd)->elf_backend_encode_eh_address
- (abfd, info, eh_frame_sec, 0, sec, 4, &encoded_eh_frame);
+ if (hdr_info->u.dwarf.array
+ && hdr_info->array_count == hdr_info->u.dwarf.fde_count)
+ {
+ /* FDE count encoding. */
+ contents[2] = DW_EH_PE_udata4;
+ /* Search table encoding. */
+ contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4;
+ }
+ else
+ {
+ contents[2] = DW_EH_PE_omit;
+ contents[3] = DW_EH_PE_omit;
+ }
+ bfd_put_32 (abfd, encoded_eh_frame, contents + 4);
- if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count)
+ if (contents[2] != DW_EH_PE_omit)
+ {
+ unsigned int i;
+ bfd_boolean overlap, overflow;
+
+ bfd_put_32 (abfd, hdr_info->u.dwarf.fde_count,
+ contents + EH_FRAME_HDR_SIZE);
+ qsort (hdr_info->u.dwarf.array, hdr_info->u.dwarf.fde_count,
+ sizeof (*hdr_info->u.dwarf.array), vma_compare);
+ overlap = FALSE;
+ overflow = FALSE;
+ for (i = 0; i < hdr_info->u.dwarf.fde_count; i++)
{
- /* FDE count encoding. */
- contents[2] = DW_EH_PE_udata4;
- /* Search table encoding. */
- contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4;
+ bfd_vma val;
+
+ val = hdr_info->u.dwarf.array[i].initial_loc
+ - sec->output_section->vma;
+ val = ((val & 0xffffffff) ^ 0x80000000) - 0x80000000;
+ if (elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64
+ && (hdr_info->u.dwarf.array[i].initial_loc
+ != sec->output_section->vma + val))
+ overflow = TRUE;
+ bfd_put_32 (abfd, val, contents + EH_FRAME_HDR_SIZE + i * 8 + 4);
+ val = hdr_info->u.dwarf.array[i].fde - sec->output_section->vma;
+ val = ((val & 0xffffffff) ^ 0x80000000) - 0x80000000;
+ if (elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64
+ && (hdr_info->u.dwarf.array[i].fde
+ != sec->output_section->vma + val))
+ overflow = TRUE;
+ bfd_put_32 (abfd, val, contents + EH_FRAME_HDR_SIZE + i * 8 + 8);
+ if (i != 0
+ && (hdr_info->u.dwarf.array[i].initial_loc
+ < (hdr_info->u.dwarf.array[i - 1].initial_loc
+ + hdr_info->u.dwarf.array[i - 1].range)))
+ overlap = TRUE;
}
- else
+ if (overflow)
+ _bfd_error_handler (_(".eh_frame_hdr entry overflow"));
+ if (overlap)
+ _bfd_error_handler (_(".eh_frame_hdr refers to overlapping FDEs"));
+ if (overflow || overlap)
{
- contents[2] = DW_EH_PE_omit;
- contents[3] = DW_EH_PE_omit;
+ bfd_set_error (bfd_error_bad_value);
+ retval = FALSE;
}
- bfd_put_32 (abfd, encoded_eh_frame, contents + 4);
-
- if (contents[2] != DW_EH_PE_omit)
- {
- unsigned int i;
+ }
- bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE);
- qsort (hdr_info->array, hdr_info->fde_count,
- sizeof (*hdr_info->array), vma_compare);
- for (i = 0; i < hdr_info->fde_count; i++)
- {
- bfd_vma val;
-
- val = hdr_info->array[i].initial_loc - sec->output_section->vma;
- val = ((val & 0xffffffff) ^ 0x80000000) - 0x80000000;
- if (elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64
- && (hdr_info->array[i].initial_loc
- != sec->output_section->vma + val))
- (*info->callbacks->einfo)
- (_("%X%P: .eh_frame_hdr table[%u] PC overflow.\n"), i);
- bfd_put_32 (abfd, val, contents + EH_FRAME_HDR_SIZE + i * 8 + 4);
-
- val = hdr_info->array[i].fde - sec->output_section->vma;
- val = ((val & 0xffffffff) ^ 0x80000000) - 0x80000000;
- if (elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64
- && (hdr_info->array[i].fde
- != sec->output_section->vma + val))
- (*info->callbacks->einfo)
- (_("%X%P: .eh_frame_hdr table[%u] FDE overflow.\n"), i);
- bfd_put_32 (abfd, val, contents + EH_FRAME_HDR_SIZE + i * 8 + 8);
-
- if (i != 0
- && (hdr_info->array[i].initial_loc
- < (hdr_info->array[i - 1].initial_loc
- + hdr_info->array[i - 1].range)))
- (*info->callbacks->einfo)
- (_("%X%P: .eh_frame_hdr table[%u] FDE at %V overlaps "
- "table[%u] FDE at %V.\n"),
- i - 1, hdr_info->array[i - 1].fde,
- i, hdr_info->array[i].fde);
- }
- }
+ /* FIXME: octets_per_byte. */
+ if (!bfd_set_section_contents (abfd, sec->output_section, contents,
+ (file_ptr) sec->output_offset,
+ sec->size))
+ retval = FALSE;
+ free (contents);
- /* FIXME: octets_per_byte. */
- if (!bfd_set_section_contents (abfd, sec->output_section, contents,
- (file_ptr) sec->output_offset,
- sec->size))
- retval = FALSE;
- free (contents);
- }
- if (hdr_info->array != NULL)
- free (hdr_info->array);
+ free (hdr_info->u.dwarf.array);
return retval;
}
+/* Write out .eh_frame_hdr section. This must be called after
+ _bfd_elf_write_section_eh_frame has been called on all input
+ .eh_frame sections. */
+
+bfd_boolean
+_bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info)
+{
+ struct elf_link_hash_table *htab;
+ struct eh_frame_hdr_info *hdr_info;
+ asection *sec;
+
+ htab = elf_hash_table (info);
+ hdr_info = &htab->eh_info;
+ sec = hdr_info->hdr_sec;
+
+ if (info->eh_frame_hdr_type == 0 || sec == NULL)
+ return TRUE;
+
+ if (info->eh_frame_hdr_type == COMPACT_EH_HDR)
+ return write_compact_eh_frame_hdr (abfd, info);
+ else
+ return write_dwarf_eh_frame_hdr (abfd, info);
+}
+
/* Return the width of FDE addresses. This is the default implementation. */
unsigned int
-_bfd_elf_eh_frame_address_size (bfd *abfd, asection *sec ATTRIBUTE_UNUSED)
+_bfd_elf_eh_frame_address_size (bfd *abfd, const asection *sec ATTRIBUTE_UNUSED)
{
return elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64 ? 8 : 4;
}
projects / thirdparty / binutils-gdb.git / blobdiff