2570 lines
73 KiB
C
2570 lines
73 KiB
C
/* .eh_frame section optimization.
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Copyright (C) 2001-2017 Free Software Foundation, Inc.
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Written by Jakub Jelinek <jakub@redhat.com>.
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This file is part of BFD, the Binary File Descriptor library.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
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MA 02110-1301, USA. */
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#include "sysdep.h"
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#include "bfd.h"
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#include "libbfd.h"
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#include "elf-bfd.h"
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#include "dwarf2.h"
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#define EH_FRAME_HDR_SIZE 8
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struct cie
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{
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unsigned int length;
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unsigned int hash;
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unsigned char version;
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unsigned char local_personality;
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char augmentation[20];
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bfd_vma code_align;
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bfd_signed_vma data_align;
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bfd_vma ra_column;
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bfd_vma augmentation_size;
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union {
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struct elf_link_hash_entry *h;
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struct {
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unsigned int bfd_id;
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unsigned int index;
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} sym;
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unsigned int reloc_index;
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} personality;
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struct eh_cie_fde *cie_inf;
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unsigned char per_encoding;
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unsigned char lsda_encoding;
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unsigned char fde_encoding;
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unsigned char initial_insn_length;
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unsigned char can_make_lsda_relative;
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unsigned char initial_instructions[50];
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};
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/* If *ITER hasn't reached END yet, read the next byte into *RESULT and
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move onto the next byte. Return true on success. */
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static inline bfd_boolean
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read_byte (bfd_byte **iter, bfd_byte *end, unsigned char *result)
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{
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if (*iter >= end)
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return FALSE;
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*result = *((*iter)++);
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return TRUE;
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}
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/* Move *ITER over LENGTH bytes, or up to END, whichever is closer.
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Return true it was possible to move LENGTH bytes. */
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static inline bfd_boolean
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skip_bytes (bfd_byte **iter, bfd_byte *end, bfd_size_type length)
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{
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if ((bfd_size_type) (end - *iter) < length)
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{
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*iter = end;
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return FALSE;
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}
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*iter += length;
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return TRUE;
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}
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/* Move *ITER over an leb128, stopping at END. Return true if the end
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of the leb128 was found. */
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static bfd_boolean
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skip_leb128 (bfd_byte **iter, bfd_byte *end)
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{
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unsigned char byte;
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do
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if (!read_byte (iter, end, &byte))
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return FALSE;
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while (byte & 0x80);
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return TRUE;
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}
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/* Like skip_leb128, but treat the leb128 as an unsigned value and
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store it in *VALUE. */
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static bfd_boolean
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read_uleb128 (bfd_byte **iter, bfd_byte *end, bfd_vma *value)
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{
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bfd_byte *start, *p;
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start = *iter;
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if (!skip_leb128 (iter, end))
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return FALSE;
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p = *iter;
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*value = *--p;
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while (p > start)
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*value = (*value << 7) | (*--p & 0x7f);
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return TRUE;
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}
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/* Like read_uleb128, but for signed values. */
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static bfd_boolean
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read_sleb128 (bfd_byte **iter, bfd_byte *end, bfd_signed_vma *value)
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{
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bfd_byte *start, *p;
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start = *iter;
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if (!skip_leb128 (iter, end))
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return FALSE;
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p = *iter;
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*value = ((*--p & 0x7f) ^ 0x40) - 0x40;
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while (p > start)
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*value = (*value << 7) | (*--p & 0x7f);
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return TRUE;
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}
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/* Return 0 if either encoding is variable width, or not yet known to bfd. */
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static
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int get_DW_EH_PE_width (int encoding, int ptr_size)
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{
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/* DW_EH_PE_ values of 0x60 and 0x70 weren't defined at the time .eh_frame
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was added to bfd. */
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if ((encoding & 0x60) == 0x60)
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return 0;
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switch (encoding & 7)
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{
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case DW_EH_PE_udata2: return 2;
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case DW_EH_PE_udata4: return 4;
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case DW_EH_PE_udata8: return 8;
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case DW_EH_PE_absptr: return ptr_size;
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default:
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break;
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}
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return 0;
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}
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#define get_DW_EH_PE_signed(encoding) (((encoding) & DW_EH_PE_signed) != 0)
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/* Read a width sized value from memory. */
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static bfd_vma
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read_value (bfd *abfd, bfd_byte *buf, int width, int is_signed)
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{
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bfd_vma value;
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switch (width)
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{
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case 2:
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if (is_signed)
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value = bfd_get_signed_16 (abfd, buf);
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else
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value = bfd_get_16 (abfd, buf);
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break;
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case 4:
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if (is_signed)
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value = bfd_get_signed_32 (abfd, buf);
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else
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value = bfd_get_32 (abfd, buf);
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break;
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case 8:
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if (is_signed)
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value = bfd_get_signed_64 (abfd, buf);
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else
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value = bfd_get_64 (abfd, buf);
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break;
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default:
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BFD_FAIL ();
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return 0;
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}
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return value;
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}
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/* Store a width sized value to memory. */
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static void
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write_value (bfd *abfd, bfd_byte *buf, bfd_vma value, int width)
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{
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switch (width)
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{
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case 2: bfd_put_16 (abfd, value, buf); break;
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case 4: bfd_put_32 (abfd, value, buf); break;
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case 8: bfd_put_64 (abfd, value, buf); break;
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default: BFD_FAIL ();
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}
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}
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/* Return one if C1 and C2 CIEs can be merged. */
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static int
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cie_eq (const void *e1, const void *e2)
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{
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const struct cie *c1 = (const struct cie *) e1;
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const struct cie *c2 = (const struct cie *) e2;
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if (c1->hash == c2->hash
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&& c1->length == c2->length
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&& c1->version == c2->version
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&& c1->local_personality == c2->local_personality
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&& strcmp (c1->augmentation, c2->augmentation) == 0
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&& strcmp (c1->augmentation, "eh") != 0
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&& c1->code_align == c2->code_align
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&& c1->data_align == c2->data_align
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&& c1->ra_column == c2->ra_column
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&& c1->augmentation_size == c2->augmentation_size
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&& memcmp (&c1->personality, &c2->personality,
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sizeof (c1->personality)) == 0
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&& (c1->cie_inf->u.cie.u.sec->output_section
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== c2->cie_inf->u.cie.u.sec->output_section)
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&& c1->per_encoding == c2->per_encoding
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&& c1->lsda_encoding == c2->lsda_encoding
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&& c1->fde_encoding == c2->fde_encoding
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&& c1->initial_insn_length == c2->initial_insn_length
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&& c1->initial_insn_length <= sizeof (c1->initial_instructions)
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&& memcmp (c1->initial_instructions,
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c2->initial_instructions,
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c1->initial_insn_length) == 0)
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return 1;
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return 0;
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}
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static hashval_t
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cie_hash (const void *e)
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{
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const struct cie *c = (const struct cie *) e;
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return c->hash;
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}
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static hashval_t
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cie_compute_hash (struct cie *c)
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{
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hashval_t h = 0;
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size_t len;
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h = iterative_hash_object (c->length, h);
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h = iterative_hash_object (c->version, h);
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h = iterative_hash (c->augmentation, strlen (c->augmentation) + 1, h);
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h = iterative_hash_object (c->code_align, h);
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h = iterative_hash_object (c->data_align, h);
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h = iterative_hash_object (c->ra_column, h);
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h = iterative_hash_object (c->augmentation_size, h);
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h = iterative_hash_object (c->personality, h);
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h = iterative_hash_object (c->cie_inf->u.cie.u.sec->output_section, h);
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h = iterative_hash_object (c->per_encoding, h);
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h = iterative_hash_object (c->lsda_encoding, h);
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h = iterative_hash_object (c->fde_encoding, h);
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h = iterative_hash_object (c->initial_insn_length, h);
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len = c->initial_insn_length;
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if (len > sizeof (c->initial_instructions))
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len = sizeof (c->initial_instructions);
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h = iterative_hash (c->initial_instructions, len, h);
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c->hash = h;
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return h;
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}
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/* Return the number of extra bytes that we'll be inserting into
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ENTRY's augmentation string. */
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static INLINE unsigned int
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extra_augmentation_string_bytes (struct eh_cie_fde *entry)
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{
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unsigned int size = 0;
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if (entry->cie)
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{
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if (entry->add_augmentation_size)
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size++;
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if (entry->u.cie.add_fde_encoding)
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size++;
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}
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return size;
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}
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/* Likewise ENTRY's augmentation data. */
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static INLINE unsigned int
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extra_augmentation_data_bytes (struct eh_cie_fde *entry)
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{
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unsigned int size = 0;
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if (entry->add_augmentation_size)
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size++;
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if (entry->cie && entry->u.cie.add_fde_encoding)
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size++;
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return size;
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}
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/* Return the size that ENTRY will have in the output. */
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static unsigned int
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size_of_output_cie_fde (struct eh_cie_fde *entry)
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{
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if (entry->removed)
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return 0;
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if (entry->size == 4)
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return 4;
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return (entry->size
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+ extra_augmentation_string_bytes (entry)
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+ extra_augmentation_data_bytes (entry));
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}
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/* Return the offset of the FDE or CIE after ENT. */
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static unsigned int
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next_cie_fde_offset (const struct eh_cie_fde *ent,
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const struct eh_cie_fde *last,
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const asection *sec)
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{
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while (++ent < last)
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{
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if (!ent->removed)
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return ent->new_offset;
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}
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return sec->size;
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}
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/* Assume that the bytes between *ITER and END are CFA instructions.
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Try to move *ITER past the first instruction and return true on
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success. ENCODED_PTR_WIDTH gives the width of pointer entries. */
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static bfd_boolean
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skip_cfa_op (bfd_byte **iter, bfd_byte *end, unsigned int encoded_ptr_width)
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{
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bfd_byte op;
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bfd_vma length;
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if (!read_byte (iter, end, &op))
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return FALSE;
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switch (op & 0xc0 ? op & 0xc0 : op)
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{
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case DW_CFA_nop:
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case DW_CFA_advance_loc:
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case DW_CFA_restore:
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case DW_CFA_remember_state:
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case DW_CFA_restore_state:
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case DW_CFA_GNU_window_save:
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/* No arguments. */
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return TRUE;
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case DW_CFA_offset:
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case DW_CFA_restore_extended:
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case DW_CFA_undefined:
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case DW_CFA_same_value:
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case DW_CFA_def_cfa_register:
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case DW_CFA_def_cfa_offset:
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case DW_CFA_def_cfa_offset_sf:
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case DW_CFA_GNU_args_size:
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/* One leb128 argument. */
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return skip_leb128 (iter, end);
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case DW_CFA_val_offset:
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case DW_CFA_val_offset_sf:
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case DW_CFA_offset_extended:
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case DW_CFA_register:
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case DW_CFA_def_cfa:
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case DW_CFA_offset_extended_sf:
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case DW_CFA_GNU_negative_offset_extended:
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case DW_CFA_def_cfa_sf:
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/* Two leb128 arguments. */
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return (skip_leb128 (iter, end)
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&& skip_leb128 (iter, end));
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case DW_CFA_def_cfa_expression:
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/* A variable-length argument. */
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return (read_uleb128 (iter, end, &length)
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&& skip_bytes (iter, end, length));
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case DW_CFA_expression:
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case DW_CFA_val_expression:
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/* A leb128 followed by a variable-length argument. */
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return (skip_leb128 (iter, end)
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&& read_uleb128 (iter, end, &length)
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&& skip_bytes (iter, end, length));
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case DW_CFA_set_loc:
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return skip_bytes (iter, end, encoded_ptr_width);
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case DW_CFA_advance_loc1:
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return skip_bytes (iter, end, 1);
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case DW_CFA_advance_loc2:
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return skip_bytes (iter, end, 2);
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case DW_CFA_advance_loc4:
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return skip_bytes (iter, end, 4);
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case DW_CFA_MIPS_advance_loc8:
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return skip_bytes (iter, end, 8);
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default:
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return FALSE;
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}
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}
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/* Try to interpret the bytes between BUF and END as CFA instructions.
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If every byte makes sense, return a pointer to the first DW_CFA_nop
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padding byte, or END if there is no padding. Return null otherwise.
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ENCODED_PTR_WIDTH is as for skip_cfa_op. */
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static bfd_byte *
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skip_non_nops (bfd_byte *buf, bfd_byte *end, unsigned int encoded_ptr_width,
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unsigned int *set_loc_count)
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{
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bfd_byte *last;
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last = buf;
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while (buf < end)
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if (*buf == DW_CFA_nop)
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buf++;
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else
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{
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if (*buf == DW_CFA_set_loc)
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++*set_loc_count;
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if (!skip_cfa_op (&buf, end, encoded_ptr_width))
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return 0;
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last = buf;
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}
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return last;
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}
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/* Convert absolute encoding ENCODING into PC-relative form.
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SIZE is the size of a pointer. */
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static unsigned char
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make_pc_relative (unsigned char encoding, unsigned int ptr_size)
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{
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if ((encoding & 0x7f) == DW_EH_PE_absptr)
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switch (ptr_size)
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{
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case 2:
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encoding |= DW_EH_PE_sdata2;
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break;
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case 4:
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encoding |= DW_EH_PE_sdata4;
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break;
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case 8:
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encoding |= DW_EH_PE_sdata8;
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break;
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}
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return encoding | DW_EH_PE_pcrel;
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}
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/* Examine each .eh_frame_entry section and discard those
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those that are marked SEC_EXCLUDE. */
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static void
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bfd_elf_discard_eh_frame_entry (struct eh_frame_hdr_info *hdr_info)
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{
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unsigned int i;
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for (i = 0; i < hdr_info->array_count; i++)
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{
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if (hdr_info->u.compact.entries[i]->flags & SEC_EXCLUDE)
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{
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unsigned int j;
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for (j = i + 1; j < hdr_info->array_count; j++)
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hdr_info->u.compact.entries[j-1] = hdr_info->u.compact.entries[j];
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hdr_info->array_count--;
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hdr_info->u.compact.entries[hdr_info->array_count] = NULL;
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i--;
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}
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}
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}
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|
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/* Add a .eh_frame_entry section. */
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static void
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bfd_elf_record_eh_frame_entry (struct eh_frame_hdr_info *hdr_info,
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asection *sec)
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{
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if (hdr_info->array_count == hdr_info->u.compact.allocated_entries)
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{
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if (hdr_info->u.compact.allocated_entries == 0)
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{
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hdr_info->frame_hdr_is_compact = TRUE;
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hdr_info->u.compact.allocated_entries = 2;
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hdr_info->u.compact.entries =
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bfd_malloc (hdr_info->u.compact.allocated_entries
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* sizeof (hdr_info->u.compact.entries[0]));
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}
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else
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{
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hdr_info->u.compact.allocated_entries *= 2;
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hdr_info->u.compact.entries =
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bfd_realloc (hdr_info->u.compact.entries,
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hdr_info->u.compact.allocated_entries
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* sizeof (hdr_info->u.compact.entries[0]));
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}
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BFD_ASSERT (hdr_info->u.compact.entries);
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}
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hdr_info->u.compact.entries[hdr_info->array_count++] = sec;
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}
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|
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/* Parse a .eh_frame_entry section. Figure out which text section it
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references. */
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|
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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. */
|
|
|
|
void
|
|
_bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
|
|
asection *sec, struct elf_reloc_cookie *cookie)
|
|
{
|
|
#define REQUIRE(COND) \
|
|
do \
|
|
if (!(COND)) \
|
|
goto free_no_table; \
|
|
while (0)
|
|
|
|
bfd_byte *ehbuf = NULL, *buf, *end;
|
|
bfd_byte *last_fde;
|
|
struct eh_cie_fde *this_inf;
|
|
unsigned int hdr_length, hdr_id;
|
|
unsigned int cie_count;
|
|
struct cie *cie, *local_cies = NULL;
|
|
struct elf_link_hash_table *htab;
|
|
struct eh_frame_hdr_info *hdr_info;
|
|
struct eh_frame_sec_info *sec_info = NULL;
|
|
unsigned int ptr_size;
|
|
unsigned int num_cies;
|
|
unsigned int num_entries;
|
|
elf_gc_mark_hook_fn gc_mark_hook;
|
|
|
|
htab = elf_hash_table (info);
|
|
hdr_info = &htab->eh_info;
|
|
|
|
if (sec->size == 0
|
|
|| sec->sec_info_type != SEC_INFO_TYPE_NONE)
|
|
{
|
|
/* This file does not contain .eh_frame information. */
|
|
return;
|
|
}
|
|
|
|
if (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;
|
|
}
|
|
|
|
/* Read the frame unwind information from abfd. */
|
|
|
|
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);
|
|
|
|
ptr_size = (get_elf_backend_data (abfd)
|
|
->elf_backend_eh_frame_address_size (abfd, sec));
|
|
REQUIRE (ptr_size != 0);
|
|
|
|
/* Go through the section contents and work out how many FDEs and
|
|
CIEs there are. */
|
|
buf = ehbuf;
|
|
end = ehbuf + sec->size;
|
|
num_cies = 0;
|
|
num_entries = 0;
|
|
while (buf != end)
|
|
{
|
|
num_entries++;
|
|
|
|
/* Read the length of the entry. */
|
|
REQUIRE (skip_bytes (&buf, end, 4));
|
|
hdr_length = bfd_get_32 (abfd, buf - 4);
|
|
|
|
/* 64-bit .eh_frame is not supported. */
|
|
REQUIRE (hdr_length != 0xffffffff);
|
|
if (hdr_length == 0)
|
|
break;
|
|
|
|
REQUIRE (skip_bytes (&buf, end, 4));
|
|
hdr_id = bfd_get_32 (abfd, buf - 4);
|
|
if (hdr_id == 0)
|
|
num_cies++;
|
|
|
|
REQUIRE (skip_bytes (&buf, end, hdr_length - 4));
|
|
}
|
|
|
|
sec_info = (struct eh_frame_sec_info *)
|
|
bfd_zmalloc (sizeof (struct eh_frame_sec_info)
|
|
+ (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);
|
|
|
|
/* FIXME: octets_per_byte. */
|
|
#define ENSURE_NO_RELOCS(buf) \
|
|
while (cookie->rel < cookie->relend \
|
|
&& (cookie->rel->r_offset \
|
|
< (bfd_size_type) ((buf) - ehbuf))) \
|
|
{ \
|
|
REQUIRE (cookie->rel->r_info == 0); \
|
|
cookie->rel++; \
|
|
}
|
|
|
|
/* FIXME: octets_per_byte. */
|
|
#define SKIP_RELOCS(buf) \
|
|
while (cookie->rel < cookie->relend \
|
|
&& (cookie->rel->r_offset \
|
|
< (bfd_size_type) ((buf) - ehbuf))) \
|
|
cookie->rel++
|
|
|
|
/* FIXME: octets_per_byte. */
|
|
#define GET_RELOC(buf) \
|
|
((cookie->rel < cookie->relend \
|
|
&& (cookie->rel->r_offset \
|
|
== (bfd_size_type) ((buf) - ehbuf))) \
|
|
? cookie->rel : NULL)
|
|
|
|
buf = ehbuf;
|
|
cie_count = 0;
|
|
gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook;
|
|
while ((bfd_size_type) (buf - ehbuf) != sec->size)
|
|
{
|
|
char *aug;
|
|
bfd_byte *start, *insns, *insns_end;
|
|
bfd_size_type length;
|
|
unsigned int set_loc_count;
|
|
|
|
this_inf = sec_info->entry + sec_info->count;
|
|
last_fde = buf;
|
|
|
|
/* Read the length of the entry. */
|
|
REQUIRE (skip_bytes (&buf, ehbuf + sec->size, 4));
|
|
hdr_length = bfd_get_32 (abfd, buf - 4);
|
|
|
|
/* The CIE/FDE must be fully contained in this input section. */
|
|
REQUIRE ((bfd_size_type) (buf - ehbuf) + hdr_length <= sec->size);
|
|
end = buf + hdr_length;
|
|
|
|
this_inf->offset = last_fde - ehbuf;
|
|
this_inf->size = 4 + hdr_length;
|
|
this_inf->reloc_index = cookie->rel - cookie->rels;
|
|
|
|
if (hdr_length == 0)
|
|
{
|
|
/* A zero-length CIE should only be found at the end of
|
|
the section. */
|
|
REQUIRE ((bfd_size_type) (buf - ehbuf) == sec->size);
|
|
ENSURE_NO_RELOCS (buf);
|
|
sec_info->count++;
|
|
break;
|
|
}
|
|
|
|
REQUIRE (skip_bytes (&buf, end, 4));
|
|
hdr_id = bfd_get_32 (abfd, buf - 4);
|
|
|
|
if (hdr_id == 0)
|
|
{
|
|
unsigned int initial_insn_length;
|
|
|
|
/* CIE */
|
|
this_inf->cie = 1;
|
|
|
|
/* Point CIE to one of the section-local cie structures. */
|
|
cie = local_cies + cie_count++;
|
|
|
|
cie->cie_inf = this_inf;
|
|
cie->length = hdr_length;
|
|
start = buf;
|
|
REQUIRE (read_byte (&buf, end, &cie->version));
|
|
|
|
/* Cannot handle unknown versions. */
|
|
REQUIRE (cie->version == 1
|
|
|| cie->version == 3
|
|
|| cie->version == 4);
|
|
REQUIRE (strlen ((char *) buf) < sizeof (cie->augmentation));
|
|
|
|
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')
|
|
{
|
|
/* GCC < 3.0 .eh_frame CIE */
|
|
/* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__
|
|
is private to each CIE, so we don't need it for anything.
|
|
Just skip it. */
|
|
REQUIRE (skip_bytes (&buf, end, ptr_size));
|
|
SKIP_RELOCS (buf);
|
|
}
|
|
if (cie->version >= 4)
|
|
{
|
|
REQUIRE (buf + 1 < end);
|
|
REQUIRE (buf[0] == ptr_size);
|
|
REQUIRE (buf[1] == 0);
|
|
buf += 2;
|
|
}
|
|
REQUIRE (read_uleb128 (&buf, end, &cie->code_align));
|
|
REQUIRE (read_sleb128 (&buf, end, &cie->data_align));
|
|
if (cie->version == 1)
|
|
{
|
|
REQUIRE (buf < end);
|
|
cie->ra_column = *buf++;
|
|
}
|
|
else
|
|
REQUIRE (read_uleb128 (&buf, end, &cie->ra_column));
|
|
ENSURE_NO_RELOCS (buf);
|
|
cie->lsda_encoding = DW_EH_PE_omit;
|
|
cie->fde_encoding = DW_EH_PE_omit;
|
|
cie->per_encoding = DW_EH_PE_omit;
|
|
aug = cie->augmentation;
|
|
if (aug[0] != 'e' || aug[1] != 'h')
|
|
{
|
|
if (*aug == 'z')
|
|
{
|
|
aug++;
|
|
REQUIRE (read_uleb128 (&buf, end, &cie->augmentation_size));
|
|
ENSURE_NO_RELOCS (buf);
|
|
}
|
|
|
|
while (*aug != '\0')
|
|
switch (*aug++)
|
|
{
|
|
case 'L':
|
|
REQUIRE (read_byte (&buf, end, &cie->lsda_encoding));
|
|
ENSURE_NO_RELOCS (buf);
|
|
REQUIRE (get_DW_EH_PE_width (cie->lsda_encoding, ptr_size));
|
|
break;
|
|
case 'R':
|
|
REQUIRE (read_byte (&buf, end, &cie->fde_encoding));
|
|
ENSURE_NO_RELOCS (buf);
|
|
REQUIRE (get_DW_EH_PE_width (cie->fde_encoding, ptr_size));
|
|
break;
|
|
case 'S':
|
|
break;
|
|
case 'P':
|
|
{
|
|
int per_width;
|
|
|
|
REQUIRE (read_byte (&buf, end, &cie->per_encoding));
|
|
per_width = get_DW_EH_PE_width (cie->per_encoding,
|
|
ptr_size);
|
|
REQUIRE (per_width);
|
|
if ((cie->per_encoding & 0x70) == DW_EH_PE_aligned)
|
|
{
|
|
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);
|
|
/* Ensure we have a reloc here. */
|
|
REQUIRE (GET_RELOC (buf));
|
|
cie->personality.reloc_index
|
|
= cookie->rel - cookie->rels;
|
|
/* Cope with MIPS-style composite relocations. */
|
|
do
|
|
cookie->rel++;
|
|
while (GET_RELOC (buf) != NULL);
|
|
REQUIRE (skip_bytes (&buf, end, per_width));
|
|
}
|
|
break;
|
|
default:
|
|
/* Unrecognized augmentation. Better bail out. */
|
|
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 (bfd_link_pic (info)
|
|
&& (get_elf_backend_data (abfd)
|
|
->elf_backend_can_make_relative_eh_frame
|
|
(abfd, info, sec)))
|
|
{
|
|
if ((cie->fde_encoding & 0x70) == DW_EH_PE_absptr)
|
|
this_inf->make_relative = 1;
|
|
/* If the CIE doesn't already have an 'R' entry, it's fairly
|
|
easy to add one, provided that there's no aligned data
|
|
after the augmentation string. */
|
|
else if (cie->fde_encoding == DW_EH_PE_omit
|
|
&& (cie->per_encoding & 0x70) != DW_EH_PE_aligned)
|
|
{
|
|
if (*cie->augmentation == 0)
|
|
this_inf->add_augmentation_size = 1;
|
|
this_inf->u.cie.add_fde_encoding = 1;
|
|
this_inf->make_relative = 1;
|
|
}
|
|
|
|
if ((cie->lsda_encoding & 0x70) == DW_EH_PE_absptr)
|
|
cie->can_make_lsda_relative = 1;
|
|
}
|
|
|
|
/* If FDE encoding was not specified, it defaults to
|
|
DW_EH_absptr. */
|
|
if (cie->fde_encoding == DW_EH_PE_omit)
|
|
cie->fde_encoding = DW_EH_PE_absptr;
|
|
|
|
initial_insn_length = end - buf;
|
|
cie->initial_insn_length = initial_insn_length;
|
|
memcpy (cie->initial_instructions, buf,
|
|
initial_insn_length <= sizeof (cie->initial_instructions)
|
|
? initial_insn_length : sizeof (cie->initial_instructions));
|
|
insns = buf;
|
|
buf += initial_insn_length;
|
|
ENSURE_NO_RELOCS (buf);
|
|
|
|
if (!bfd_link_relocatable (info))
|
|
{
|
|
/* Keep info for merging cies. */
|
|
this_inf->u.cie.u.full_cie = cie;
|
|
this_inf->u.cie.per_encoding_relative
|
|
= (cie->per_encoding & 0x70) == DW_EH_PE_pcrel;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Find the corresponding CIE. */
|
|
unsigned int cie_offset = this_inf->offset + 4 - hdr_id;
|
|
for (cie = local_cies; cie < local_cies + cie_count; cie++)
|
|
if (cie_offset == cie->cie_inf->offset)
|
|
break;
|
|
|
|
/* Ensure this FDE references one of the CIEs in this input
|
|
section. */
|
|
REQUIRE (cie != local_cies + cie_count);
|
|
this_inf->u.fde.cie_inf = cie->cie_inf;
|
|
this_inf->make_relative = cie->cie_inf->make_relative;
|
|
this_inf->add_augmentation_size
|
|
= cie->cie_inf->add_augmentation_size;
|
|
|
|
ENSURE_NO_RELOCS (buf);
|
|
if ((sec->flags & SEC_LINKER_CREATED) == 0 || cookie->rels != NULL)
|
|
{
|
|
asection *rsec;
|
|
|
|
REQUIRE (GET_RELOC (buf));
|
|
|
|
/* Chain together the FDEs for each section. */
|
|
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)
|
|
{
|
|
REQUIRE (rsec->owner == abfd);
|
|
this_inf->u.fde.next_for_section = elf_fde_list (rsec);
|
|
elf_fde_list (rsec) = this_inf;
|
|
}
|
|
}
|
|
|
|
/* Skip the initial location and address range. */
|
|
start = buf;
|
|
length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size);
|
|
REQUIRE (skip_bytes (&buf, end, 2 * length));
|
|
|
|
SKIP_RELOCS (buf - length);
|
|
if (!GET_RELOC (buf - length)
|
|
&& read_value (abfd, buf - length, length, FALSE) == 0)
|
|
{
|
|
(*info->callbacks->minfo)
|
|
/* xgettext:c-format */
|
|
(_("discarding zero address range FDE in %B(%A).\n"),
|
|
abfd, sec);
|
|
this_inf->u.fde.cie_inf = NULL;
|
|
}
|
|
|
|
/* Skip the augmentation size, if present. */
|
|
if (cie->augmentation[0] == 'z')
|
|
REQUIRE (read_uleb128 (&buf, end, &length));
|
|
else
|
|
length = 0;
|
|
|
|
/* Of the supported augmentation characters above, only 'L'
|
|
adds augmentation data to the FDE. This code would need to
|
|
be adjusted if any future augmentations do the same thing. */
|
|
if (cie->lsda_encoding != DW_EH_PE_omit)
|
|
{
|
|
SKIP_RELOCS (buf);
|
|
if (cie->can_make_lsda_relative && GET_RELOC (buf))
|
|
cie->cie_inf->u.cie.make_lsda_relative = 1;
|
|
this_inf->lsda_offset = buf - start;
|
|
/* If there's no 'z' augmentation, we don't know where the
|
|
CFA insns begin. Assume no padding. */
|
|
if (cie->augmentation[0] != 'z')
|
|
length = end - buf;
|
|
}
|
|
|
|
/* Skip over the augmentation data. */
|
|
REQUIRE (skip_bytes (&buf, end, length));
|
|
insns = buf;
|
|
|
|
buf = last_fde + 4 + hdr_length;
|
|
|
|
/* For NULL RSEC (cleared FDE belonging to a discarded section)
|
|
the relocations are commonly cleared. We do not sanity check if
|
|
all these relocations are cleared as (1) relocations to
|
|
.gcc_except_table will remain uncleared (they will get dropped
|
|
with the drop of this unused FDE) and (2) BFD already safely drops
|
|
relocations of any type to .eh_frame by
|
|
elf_section_ignore_discarded_relocs.
|
|
TODO: The .gcc_except_table entries should be also filtered as
|
|
.eh_frame entries; or GCC could rather use COMDAT for them. */
|
|
SKIP_RELOCS (buf);
|
|
}
|
|
|
|
/* Try to interpret the CFA instructions and find the first
|
|
padding nop. Shrink this_inf's size so that it doesn't
|
|
include the padding. */
|
|
length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size);
|
|
set_loc_count = 0;
|
|
insns_end = skip_non_nops (insns, end, length, &set_loc_count);
|
|
/* If we don't understand the CFA instructions, we can't know
|
|
what needs to be adjusted there. */
|
|
if (insns_end == NULL
|
|
/* For the time being we don't support DW_CFA_set_loc in
|
|
CIE instructions. */
|
|
|| (set_loc_count && this_inf->cie))
|
|
goto free_no_table;
|
|
this_inf->size -= end - insns_end;
|
|
if (insns_end != end && this_inf->cie)
|
|
{
|
|
cie->initial_insn_length -= end - insns_end;
|
|
cie->length -= end - insns_end;
|
|
}
|
|
if (set_loc_count
|
|
&& ((cie->fde_encoding & 0x70) == DW_EH_PE_pcrel
|
|
|| this_inf->make_relative))
|
|
{
|
|
unsigned int cnt;
|
|
bfd_byte *p;
|
|
|
|
this_inf->set_loc = (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;
|
|
cnt = 0;
|
|
while (p < end)
|
|
{
|
|
if (*p == DW_CFA_set_loc)
|
|
this_inf->set_loc[++cnt] = p + 1 - start;
|
|
REQUIRE (skip_cfa_op (&p, end, length));
|
|
}
|
|
}
|
|
|
|
this_inf->removed = 1;
|
|
this_inf->fde_encoding = cie->fde_encoding;
|
|
this_inf->lsda_encoding = cie->lsda_encoding;
|
|
sec_info->count++;
|
|
}
|
|
BFD_ASSERT (sec_info->count == num_entries);
|
|
BFD_ASSERT (cie_count == num_cies);
|
|
|
|
elf_section_data (sec)->sec_info = sec_info;
|
|
sec->sec_info_type = SEC_INFO_TYPE_EH_FRAME;
|
|
if (!bfd_link_relocatable (info))
|
|
{
|
|
/* Keep info for merging cies. */
|
|
sec_info->cies = local_cies;
|
|
local_cies = NULL;
|
|
}
|
|
goto success;
|
|
|
|
free_no_table:
|
|
(*info->callbacks->einfo)
|
|
/* xgettext:c-format */
|
|
(_("%P: error in %B(%A); no .eh_frame_hdr table will be created.\n"),
|
|
abfd, sec);
|
|
hdr_info->u.dwarf.table = FALSE;
|
|
if (sec_info)
|
|
free (sec_info);
|
|
success:
|
|
if (ehbuf)
|
|
free (ehbuf);
|
|
if (local_cies)
|
|
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->owner, 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. */
|
|
|
|
static bfd_boolean
|
|
mark_entry (struct bfd_link_info *info, asection *sec,
|
|
struct eh_cie_fde *ent, elf_gc_mark_hook_fn gc_mark_hook,
|
|
struct elf_reloc_cookie *cookie)
|
|
{
|
|
/* FIXME: octets_per_byte. */
|
|
for (cookie->rel = cookie->rels + ent->reloc_index;
|
|
cookie->rel < cookie->relend
|
|
&& cookie->rel->r_offset < ent->offset + ent->size;
|
|
cookie->rel++)
|
|
if (!_bfd_elf_gc_mark_reloc (info, sec, gc_mark_hook, cookie))
|
|
return FALSE;
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
/* Mark all the relocations against FDEs that relate to code in input
|
|
section SEC. The FDEs belong to .eh_frame section EH_FRAME, whose
|
|
relocations are described by COOKIE. */
|
|
|
|
bfd_boolean
|
|
_bfd_elf_gc_mark_fdes (struct bfd_link_info *info, asection *sec,
|
|
asection *eh_frame, elf_gc_mark_hook_fn gc_mark_hook,
|
|
struct elf_reloc_cookie *cookie)
|
|
{
|
|
struct eh_cie_fde *fde, *cie;
|
|
|
|
for (fde = elf_fde_list (sec); fde; fde = fde->u.fde.next_for_section)
|
|
{
|
|
if (!mark_entry (info, eh_frame, fde, gc_mark_hook, cookie))
|
|
return FALSE;
|
|
|
|
/* At this stage, all cie_inf fields point to local CIEs, so we
|
|
can use the same cookie to refer to them. */
|
|
cie = fde->u.fde.cie_inf;
|
|
if (cie != NULL && !cie->u.cie.gc_mark)
|
|
{
|
|
cie->u.cie.gc_mark = 1;
|
|
if (!mark_entry (info, eh_frame, cie, gc_mark_hook, cookie))
|
|
return FALSE;
|
|
}
|
|
}
|
|
return TRUE;
|
|
}
|
|
|
|
/* Input section SEC of ABFD is an .eh_frame section that contains the
|
|
CIE described by CIE_INF. Return a version of CIE_INF that is going
|
|
to be kept in the output, adding CIE_INF to the output if necessary.
|
|
|
|
HDR_INFO is the .eh_frame_hdr information and COOKIE describes the
|
|
relocations in REL. */
|
|
|
|
static struct eh_cie_fde *
|
|
find_merged_cie (bfd *abfd, struct bfd_link_info *info, asection *sec,
|
|
struct eh_frame_hdr_info *hdr_info,
|
|
struct elf_reloc_cookie *cookie,
|
|
struct eh_cie_fde *cie_inf)
|
|
{
|
|
unsigned long r_symndx;
|
|
struct cie *cie, *new_cie;
|
|
Elf_Internal_Rela *rel;
|
|
void **loc;
|
|
|
|
/* Use CIE_INF if we have already decided to keep it. */
|
|
if (!cie_inf->removed)
|
|
return cie_inf;
|
|
|
|
/* If we have merged CIE_INF with another CIE, use that CIE instead. */
|
|
if (cie_inf->u.cie.merged)
|
|
return cie_inf->u.cie.u.merged_with;
|
|
|
|
cie = cie_inf->u.cie.u.full_cie;
|
|
|
|
/* Assume we will need to keep CIE_INF. */
|
|
cie_inf->removed = 0;
|
|
cie_inf->u.cie.u.sec = sec;
|
|
|
|
/* If we are not merging CIEs, use CIE_INF. */
|
|
if (cie == NULL)
|
|
return cie_inf;
|
|
|
|
if (cie->per_encoding != DW_EH_PE_omit)
|
|
{
|
|
bfd_boolean per_binds_local;
|
|
|
|
/* Work out the address of personality routine, or at least
|
|
enough info that we could calculate the address had we made a
|
|
final section layout. The symbol on the reloc is enough,
|
|
either the hash for a global, or (bfd id, index) pair for a
|
|
local. The assumption here is that no one uses addends on
|
|
the reloc. */
|
|
rel = cookie->rels + cie->personality.reloc_index;
|
|
memset (&cie->personality, 0, sizeof (cie->personality));
|
|
#ifdef BFD64
|
|
if (elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64)
|
|
r_symndx = ELF64_R_SYM (rel->r_info);
|
|
else
|
|
#endif
|
|
r_symndx = ELF32_R_SYM (rel->r_info);
|
|
if (r_symndx >= cookie->locsymcount
|
|
|| ELF_ST_BIND (cookie->locsyms[r_symndx].st_info) != STB_LOCAL)
|
|
{
|
|
struct elf_link_hash_entry *h;
|
|
|
|
r_symndx -= cookie->extsymoff;
|
|
h = cookie->sym_hashes[r_symndx];
|
|
|
|
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;
|
|
|
|
cie->personality.h = h;
|
|
per_binds_local = SYMBOL_REFERENCES_LOCAL (info, h);
|
|
}
|
|
else
|
|
{
|
|
Elf_Internal_Sym *sym;
|
|
asection *sym_sec;
|
|
|
|
sym = &cookie->locsyms[r_symndx];
|
|
sym_sec = bfd_section_from_elf_index (abfd, sym->st_shndx);
|
|
if (sym_sec == NULL)
|
|
return cie_inf;
|
|
|
|
if (sym_sec->kept_section != NULL)
|
|
sym_sec = sym_sec->kept_section;
|
|
if (sym_sec->output_section == NULL)
|
|
return cie_inf;
|
|
|
|
cie->local_personality = 1;
|
|
cie->personality.sym.bfd_id = abfd->id;
|
|
cie->personality.sym.index = r_symndx;
|
|
per_binds_local = TRUE;
|
|
}
|
|
|
|
if (per_binds_local
|
|
&& 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)))
|
|
{
|
|
cie_inf->u.cie.make_per_encoding_relative = 1;
|
|
cie_inf->u.cie.per_encoding_relative = 1;
|
|
}
|
|
}
|
|
|
|
/* See if we can merge this CIE with an earlier one. */
|
|
cie_compute_hash (cie);
|
|
if (hdr_info->u.dwarf.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->u.dwarf.cies, cie,
|
|
cie->hash, INSERT);
|
|
if (loc == NULL)
|
|
return cie_inf;
|
|
|
|
new_cie = (struct cie *) *loc;
|
|
if (new_cie == NULL)
|
|
{
|
|
/* Keep CIE_INF and record it in the hash table. */
|
|
new_cie = (struct cie *) malloc (sizeof (struct cie));
|
|
if (new_cie == NULL)
|
|
return cie_inf;
|
|
|
|
memcpy (new_cie, cie, sizeof (struct cie));
|
|
*loc = new_cie;
|
|
}
|
|
else
|
|
{
|
|
/* Merge CIE_INF with NEW_CIE->CIE_INF. */
|
|
cie_inf->removed = 1;
|
|
cie_inf->u.cie.merged = 1;
|
|
cie_inf->u.cie.u.merged_with = new_cie->cie_inf;
|
|
if (cie_inf->u.cie.make_lsda_relative)
|
|
new_cie->cie_inf->u.cie.make_lsda_relative = 1;
|
|
}
|
|
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;
|
|
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
|
|
deleted. */
|
|
|
|
bfd_boolean
|
|
_bfd_elf_discard_section_eh_frame
|
|
(bfd *abfd, struct bfd_link_info *info, asection *sec,
|
|
bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *),
|
|
struct elf_reloc_cookie *cookie)
|
|
{
|
|
struct eh_cie_fde *ent;
|
|
struct eh_frame_sec_info *sec_info;
|
|
struct eh_frame_hdr_info *hdr_info;
|
|
unsigned int ptr_size, offset, eh_alignment;
|
|
int changed;
|
|
|
|
if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME)
|
|
return FALSE;
|
|
|
|
sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info;
|
|
if (sec_info == NULL)
|
|
return FALSE;
|
|
|
|
ptr_size = (get_elf_backend_data (sec->owner)
|
|
->elf_backend_eh_frame_address_size (sec->owner, sec));
|
|
|
|
hdr_info = &elf_hash_table (info)->eh_info;
|
|
for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent)
|
|
if (ent->size == 4)
|
|
/* There should only be one zero terminator, on the last input
|
|
file supplying .eh_frame (crtend.o). Remove any others. */
|
|
ent->removed = sec->map_head.s != NULL;
|
|
else if (!ent->cie && ent->u.fde.cie_inf != NULL)
|
|
{
|
|
bfd_boolean keep;
|
|
if ((sec->flags & SEC_LINKER_CREATED) != 0 && cookie->rels == NULL)
|
|
{
|
|
unsigned int width
|
|
= get_DW_EH_PE_width (ent->fde_encoding, ptr_size);
|
|
bfd_vma value
|
|
= read_value (abfd, sec->contents + ent->offset + 8 + width,
|
|
width, get_DW_EH_PE_signed (ent->fde_encoding));
|
|
keep = value != 0;
|
|
}
|
|
else
|
|
{
|
|
cookie->rel = cookie->rels + ent->reloc_index;
|
|
/* FIXME: octets_per_byte. */
|
|
BFD_ASSERT (cookie->rel < cookie->relend
|
|
&& cookie->rel->r_offset == ent->offset + 8);
|
|
keep = !(*reloc_symbol_deleted_p) (ent->offset + 8, cookie);
|
|
}
|
|
if (keep)
|
|
{
|
|
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->u.dwarf.table = FALSE;
|
|
if (num_warnings_issued < 10)
|
|
{
|
|
(*info->callbacks->einfo)
|
|
/* xgettext:c-format */
|
|
(_("%P: FDE encoding in %B(%A) prevents .eh_frame_hdr"
|
|
" table being created.\n"), abfd, sec);
|
|
num_warnings_issued ++;
|
|
}
|
|
else if (num_warnings_issued == 10)
|
|
{
|
|
(*info->callbacks->einfo)
|
|
(_("%P: Further warnings about FDE encoding preventing .eh_frame_hdr generation dropped.\n"));
|
|
num_warnings_issued ++;
|
|
}
|
|
}
|
|
ent->removed = 0;
|
|
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;
|
|
}
|
|
|
|
/* 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;
|
|
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;
|
|
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
|
|
_bfd_elf_discard_section_eh_frame has been called on all .eh_frame
|
|
input sections. It finalizes the size of .eh_frame_hdr section. */
|
|
|
|
bfd_boolean
|
|
_bfd_elf_discard_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;
|
|
|
|
if (!hdr_info->frame_hdr_is_compact && hdr_info->u.dwarf.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;
|
|
|
|
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)
|
|
{
|
|
asection *eh = bfd_get_section_by_name (info->output_bfd, ".eh_frame");
|
|
|
|
if (eh == NULL)
|
|
return FALSE;
|
|
|
|
/* Count only sections which have at least a single CIE or FDE.
|
|
There cannot be any CIE or FDE <= 8 bytes. */
|
|
for (eh = eh->map_head.s; eh != NULL; eh = eh->map_head.s)
|
|
if (eh->size > 8)
|
|
return TRUE;
|
|
|
|
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_get_section_name (abfd, 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
|
|
to strip sections. */
|
|
|
|
bfd_boolean
|
|
_bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info)
|
|
{
|
|
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;
|
|
if (hdr_info->hdr_sec == NULL)
|
|
return TRUE;
|
|
|
|
if (bfd_is_abs_section (hdr_info->hdr_sec->output_section)
|
|
|| 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;
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
|
|
/* Adjust an address in the .eh_frame section. Given OFFSET within
|
|
SEC, this returns the new offset in the adjusted .eh_frame section,
|
|
or -1 if the address refers to a CIE/FDE which has been removed
|
|
or to offset with dynamic relocation which is no longer needed. */
|
|
|
|
bfd_vma
|
|
_bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED,
|
|
struct bfd_link_info *info ATTRIBUTE_UNUSED,
|
|
asection *sec,
|
|
bfd_vma offset)
|
|
{
|
|
struct eh_frame_sec_info *sec_info;
|
|
unsigned int lo, hi, mid;
|
|
|
|
if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME)
|
|
return offset;
|
|
sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info;
|
|
|
|
if (offset >= sec->rawsize)
|
|
return offset - sec->rawsize + sec->size;
|
|
|
|
lo = 0;
|
|
hi = sec_info->count;
|
|
mid = 0;
|
|
while (lo < hi)
|
|
{
|
|
mid = (lo + hi) / 2;
|
|
if (offset < sec_info->entry[mid].offset)
|
|
hi = mid;
|
|
else if (offset
|
|
>= sec_info->entry[mid].offset + sec_info->entry[mid].size)
|
|
lo = mid + 1;
|
|
else
|
|
break;
|
|
}
|
|
|
|
BFD_ASSERT (lo < hi);
|
|
|
|
/* FDE or CIE was removed. */
|
|
if (sec_info->entry[mid].removed)
|
|
return (bfd_vma) -1;
|
|
|
|
/* If converting personality pointers to DW_EH_PE_pcrel, there will be
|
|
no need for run-time relocation against the personality field. */
|
|
if (sec_info->entry[mid].cie
|
|
&& sec_info->entry[mid].u.cie.make_per_encoding_relative
|
|
&& offset == (sec_info->entry[mid].offset + 8
|
|
+ sec_info->entry[mid].u.cie.personality_offset))
|
|
return (bfd_vma) -2;
|
|
|
|
/* If converting to DW_EH_PE_pcrel, there will be no need for run-time
|
|
relocation against FDE's initial_location field. */
|
|
if (!sec_info->entry[mid].cie
|
|
&& sec_info->entry[mid].make_relative
|
|
&& offset == sec_info->entry[mid].offset + 8)
|
|
return (bfd_vma) -2;
|
|
|
|
/* If converting LSDA pointers to DW_EH_PE_pcrel, there will be no need
|
|
for run-time relocation against LSDA field. */
|
|
if (!sec_info->entry[mid].cie
|
|
&& sec_info->entry[mid].u.fde.cie_inf->u.cie.make_lsda_relative
|
|
&& offset == (sec_info->entry[mid].offset + 8
|
|
+ sec_info->entry[mid].lsda_offset))
|
|
return (bfd_vma) -2;
|
|
|
|
/* If converting to DW_EH_PE_pcrel, there will be no need for run-time
|
|
relocation against DW_CFA_set_loc's arguments. */
|
|
if (sec_info->entry[mid].set_loc
|
|
&& sec_info->entry[mid].make_relative
|
|
&& (offset >= sec_info->entry[mid].offset + 8
|
|
+ sec_info->entry[mid].set_loc[1]))
|
|
{
|
|
unsigned int cnt;
|
|
|
|
for (cnt = 1; cnt <= sec_info->entry[mid].set_loc[0]; cnt++)
|
|
if (offset == sec_info->entry[mid].offset + 8
|
|
+ sec_info->entry[mid].set_loc[cnt])
|
|
return (bfd_vma) -2;
|
|
}
|
|
|
|
/* Any new augmentation bytes go before the first relocation. */
|
|
return (offset + sec_info->entry[mid].new_offset
|
|
- sec_info->entry[mid].offset
|
|
+ extra_augmentation_string_bytes (sec_info->entry + mid)
|
|
+ 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 (_("%B: %A 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 (_("%B: %A 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 (_("%B: %A 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. */
|
|
|
|
bfd_boolean
|
|
_bfd_elf_write_section_eh_frame (bfd *abfd,
|
|
struct bfd_link_info *info,
|
|
asection *sec,
|
|
bfd_byte *contents)
|
|
{
|
|
struct eh_frame_sec_info *sec_info;
|
|
struct elf_link_hash_table *htab;
|
|
struct eh_frame_hdr_info *hdr_info;
|
|
unsigned int ptr_size;
|
|
struct eh_cie_fde *ent, *last_ent;
|
|
|
|
if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME)
|
|
/* FIXME: octets_per_byte. */
|
|
return bfd_set_section_contents (abfd, sec->output_section, contents,
|
|
sec->output_offset, sec->size);
|
|
|
|
ptr_size = (get_elf_backend_data (abfd)
|
|
->elf_backend_eh_frame_address_size (abfd, sec));
|
|
BFD_ASSERT (ptr_size != 0);
|
|
|
|
sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info;
|
|
htab = elf_hash_table (info);
|
|
hdr_info = &htab->eh_info;
|
|
|
|
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.
|
|
We therefore need to make two passes over the section: one backward
|
|
pass to move entries up and one forward pass to move entries down.
|
|
The two passes won't interfere with each other because entries are
|
|
not reordered */
|
|
for (ent = sec_info->entry + sec_info->count; ent-- != sec_info->entry;)
|
|
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)
|
|
if (!ent->removed && ent->new_offset < ent->offset)
|
|
memmove (contents + ent->new_offset, contents + ent->offset, ent->size);
|
|
|
|
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->removed)
|
|
continue;
|
|
|
|
if (ent->size == 4)
|
|
{
|
|
/* Any terminating FDE must be at the end of the section. */
|
|
BFD_ASSERT (ent == last_ent - 1);
|
|
continue;
|
|
}
|
|
|
|
buf = contents + ent->new_offset;
|
|
end = buf + ent->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);
|
|
|
|
/* Filling the extra bytes with DW_CFA_nops. */
|
|
if (new_size != ent->size)
|
|
memset (end, 0, new_size - ent->size);
|
|
|
|
if (ent->cie)
|
|
{
|
|
/* CIE */
|
|
if (ent->make_relative
|
|
|| ent->u.cie.make_lsda_relative
|
|
|| ent->u.cie.per_encoding_relative)
|
|
{
|
|
char *aug;
|
|
unsigned int action, extra_string, extra_data;
|
|
unsigned int per_width, per_encoding;
|
|
|
|
/* Need to find 'R' or 'L' augmentation's argument and modify
|
|
DW_EH_PE_* value. */
|
|
action = ((ent->make_relative ? 1 : 0)
|
|
| (ent->u.cie.make_lsda_relative ? 2 : 0)
|
|
| (ent->u.cie.per_encoding_relative ? 4 : 0));
|
|
extra_string = extra_augmentation_string_bytes (ent);
|
|
extra_data = extra_augmentation_data_bytes (ent);
|
|
|
|
/* Skip length, id and version. */
|
|
buf += 9;
|
|
aug = (char *) buf;
|
|
buf += strlen (aug) + 1;
|
|
skip_leb128 (&buf, end);
|
|
skip_leb128 (&buf, end);
|
|
skip_leb128 (&buf, end);
|
|
if (*aug == 'z')
|
|
{
|
|
/* The uleb128 will always be a single byte for the kind
|
|
of augmentation strings that we're prepared to handle. */
|
|
*buf++ += extra_data;
|
|
aug++;
|
|
}
|
|
|
|
/* Make room for the new augmentation string and data bytes. */
|
|
memmove (buf + extra_string + extra_data, buf, end - buf);
|
|
memmove (aug + extra_string, aug, buf - (bfd_byte *) aug);
|
|
buf += extra_string;
|
|
end += extra_string + extra_data;
|
|
|
|
if (ent->add_augmentation_size)
|
|
{
|
|
*aug++ = 'z';
|
|
*buf++ = extra_data - 1;
|
|
}
|
|
if (ent->u.cie.add_fde_encoding)
|
|
{
|
|
BFD_ASSERT (action & 1);
|
|
*aug++ = 'R';
|
|
*buf++ = make_pc_relative (DW_EH_PE_absptr, ptr_size);
|
|
action &= ~1;
|
|
}
|
|
|
|
while (action)
|
|
switch (*aug++)
|
|
{
|
|
case 'L':
|
|
if (action & 2)
|
|
{
|
|
BFD_ASSERT (*buf == ent->lsda_encoding);
|
|
*buf = make_pc_relative (*buf, ptr_size);
|
|
action &= ~2;
|
|
}
|
|
buf++;
|
|
break;
|
|
case 'P':
|
|
if (ent->u.cie.make_per_encoding_relative)
|
|
*buf = make_pc_relative (*buf, ptr_size);
|
|
per_encoding = *buf++;
|
|
per_width = get_DW_EH_PE_width (per_encoding, ptr_size);
|
|
BFD_ASSERT (per_width != 0);
|
|
BFD_ASSERT (((per_encoding & 0x70) == DW_EH_PE_pcrel)
|
|
== ent->u.cie.per_encoding_relative);
|
|
if ((per_encoding & 0x70) == DW_EH_PE_aligned)
|
|
buf = (contents
|
|
+ ((buf - contents + per_width - 1)
|
|
& ~((bfd_size_type) per_width - 1)));
|
|
if (action & 4)
|
|
{
|
|
bfd_vma val;
|
|
|
|
val = read_value (abfd, buf, per_width,
|
|
get_DW_EH_PE_signed (per_encoding));
|
|
if (ent->u.cie.make_per_encoding_relative)
|
|
val -= (sec->output_section->vma
|
|
+ sec->output_offset
|
|
+ (buf - contents));
|
|
else
|
|
{
|
|
val += (bfd_vma) ent->offset - ent->new_offset;
|
|
val -= extra_string + extra_data;
|
|
}
|
|
write_value (abfd, buf, val, per_width);
|
|
action &= ~4;
|
|
}
|
|
buf += per_width;
|
|
break;
|
|
case 'R':
|
|
if (action & 1)
|
|
{
|
|
BFD_ASSERT (*buf == ent->fde_encoding);
|
|
*buf = make_pc_relative (*buf, ptr_size);
|
|
action &= ~1;
|
|
}
|
|
buf++;
|
|
break;
|
|
case 'S':
|
|
break;
|
|
default:
|
|
BFD_FAIL ();
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* FDE */
|
|
bfd_vma value, address;
|
|
unsigned int width;
|
|
bfd_byte *start;
|
|
struct eh_cie_fde *cie;
|
|
|
|
/* Skip length. */
|
|
cie = ent->u.fde.cie_inf;
|
|
buf += 4;
|
|
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 (bfd_link_relocatable (info))
|
|
continue;
|
|
buf += 4;
|
|
width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size);
|
|
value = read_value (abfd, buf, width,
|
|
get_DW_EH_PE_signed (ent->fde_encoding));
|
|
address = value;
|
|
if (value)
|
|
{
|
|
switch (ent->fde_encoding & 0x70)
|
|
{
|
|
case DW_EH_PE_textrel:
|
|
BFD_ASSERT (hdr_info == NULL);
|
|
break;
|
|
case DW_EH_PE_datarel:
|
|
{
|
|
switch (abfd->arch_info->arch)
|
|
{
|
|
case bfd_arch_ia64:
|
|
BFD_ASSERT (elf_gp (abfd) != 0);
|
|
address += elf_gp (abfd);
|
|
break;
|
|
default:
|
|
(*info->callbacks->einfo)
|
|
(_("%P: DW_EH_PE_datarel unspecified"
|
|
" for this architecture.\n"));
|
|
/* Fall thru */
|
|
case bfd_arch_frv:
|
|
case bfd_arch_i386:
|
|
BFD_ASSERT (htab->hgot != NULL
|
|
&& ((htab->hgot->root.type
|
|
== bfd_link_hash_defined)
|
|
|| (htab->hgot->root.type
|
|
== bfd_link_hash_defweak)));
|
|
address
|
|
+= (htab->hgot->root.u.def.value
|
|
+ htab->hgot->root.u.def.section->output_offset
|
|
+ (htab->hgot->root.u.def.section->output_section
|
|
->vma));
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
case DW_EH_PE_pcrel:
|
|
value += (bfd_vma) ent->offset - ent->new_offset;
|
|
address += (sec->output_section->vma
|
|
+ sec->output_offset
|
|
+ ent->offset + 8);
|
|
break;
|
|
}
|
|
if (ent->make_relative)
|
|
value -= (sec->output_section->vma
|
|
+ sec->output_offset
|
|
+ ent->new_offset + 8);
|
|
write_value (abfd, buf, value, width);
|
|
}
|
|
|
|
start = buf;
|
|
|
|
if (hdr_info)
|
|
{
|
|
/* The address calculation may overflow, giving us a
|
|
value greater than 4G on a 32-bit target when
|
|
dwarf_vma is 64-bit. */
|
|
if (sizeof (address) > 4 && ptr_size == 4)
|
|
address &= 0xffffffff;
|
|
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->u.dwarf.array[hdr_info->array_count++].fde
|
|
= (sec->output_section->vma
|
|
+ sec->output_offset
|
|
+ ent->new_offset);
|
|
}
|
|
|
|
if ((ent->lsda_encoding & 0x70) == DW_EH_PE_pcrel
|
|
|| cie->u.cie.make_lsda_relative)
|
|
{
|
|
buf += ent->lsda_offset;
|
|
width = get_DW_EH_PE_width (ent->lsda_encoding, ptr_size);
|
|
value = read_value (abfd, buf, width,
|
|
get_DW_EH_PE_signed (ent->lsda_encoding));
|
|
if (value)
|
|
{
|
|
if ((ent->lsda_encoding & 0x70) == DW_EH_PE_pcrel)
|
|
value += (bfd_vma) ent->offset - ent->new_offset;
|
|
else if (cie->u.cie.make_lsda_relative)
|
|
value -= (sec->output_section->vma
|
|
+ sec->output_offset
|
|
+ ent->new_offset + 8 + ent->lsda_offset);
|
|
write_value (abfd, buf, value, width);
|
|
}
|
|
}
|
|
else if (ent->add_augmentation_size)
|
|
{
|
|
/* Skip the PC and length and insert a zero byte for the
|
|
augmentation size. */
|
|
buf += width * 2;
|
|
memmove (buf + 1, buf, end - buf);
|
|
*buf = 0;
|
|
}
|
|
|
|
if (ent->set_loc)
|
|
{
|
|
/* Adjust DW_CFA_set_loc. */
|
|
unsigned int cnt;
|
|
bfd_vma new_offset;
|
|
|
|
width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size);
|
|
new_offset = ent->new_offset + 8
|
|
+ extra_augmentation_string_bytes (ent)
|
|
+ extra_augmentation_data_bytes (ent);
|
|
|
|
for (cnt = 1; cnt <= ent->set_loc[0]; cnt++)
|
|
{
|
|
buf = start + ent->set_loc[cnt];
|
|
|
|
value = read_value (abfd, buf, width,
|
|
get_DW_EH_PE_signed (ent->fde_encoding));
|
|
if (!value)
|
|
continue;
|
|
|
|
if ((ent->fde_encoding & 0x70) == DW_EH_PE_pcrel)
|
|
value += (bfd_vma) ent->offset + 8 - new_offset;
|
|
if (ent->make_relative)
|
|
value -= (sec->output_section->vma
|
|
+ sec->output_offset
|
|
+ new_offset + ent->set_loc[cnt]);
|
|
write_value (abfd, buf, value, width);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* FIXME: octets_per_byte. */
|
|
return bfd_set_section_contents (abfd, sec->output_section,
|
|
contents, (file_ptr) sec->output_offset,
|
|
sec->size);
|
|
}
|
|
|
|
/* Helper function used to sort .eh_frame_hdr search table by increasing
|
|
VMA of FDE initial location. */
|
|
|
|
static int
|
|
vma_compare (const void *a, const void *b)
|
|
{
|
|
const struct eh_frame_array_ent *p = (const struct eh_frame_array_ent *) a;
|
|
const struct eh_frame_array_ent *q = (const struct eh_frame_array_ent *) b;
|
|
if (p->initial_loc > q->initial_loc)
|
|
return 1;
|
|
if (p->initial_loc < q->initial_loc)
|
|
return -1;
|
|
if (p->range > q->range)
|
|
return 1;
|
|
if (p->range < q->range)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
/* 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: %A"),
|
|
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 %A 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
|
|
.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
|
|
binary search table computed))
|
|
ubyte table_enc (DW_EH_PE_* encoding of binary search table,
|
|
or DW_EH_PE_omit if not present.
|
|
DW_EH_PE_datarel is using address of
|
|
.eh_frame_hdr section start as base)
|
|
[encoded] eh_frame_ptr (pointer to start of .eh_frame section)
|
|
optionally followed by:
|
|
[encoded] fde_count (total number of FDEs in .eh_frame section)
|
|
fde_count x [encoded] initial_loc, fde
|
|
(array of encoded pairs containing
|
|
FDE initial_location field and FDE address,
|
|
sorted by increasing initial_loc). */
|
|
|
|
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;
|
|
asection *sec;
|
|
bfd_boolean retval = TRUE;
|
|
|
|
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;
|
|
|
|
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);
|
|
|
|
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 (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++)
|
|
{
|
|
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;
|
|
}
|
|
if (overflow)
|
|
(*info->callbacks->einfo) (_("%P: .eh_frame_hdr entry overflow.\n"));
|
|
if (overlap)
|
|
(*info->callbacks->einfo)
|
|
(_("%P: .eh_frame_hdr refers to overlapping FDEs.\n"));
|
|
if (overflow || overlap)
|
|
{
|
|
bfd_set_error (bfd_error_bad_value);
|
|
retval = FALSE;
|
|
}
|
|
}
|
|
|
|
/* 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->u.dwarf.array != NULL)
|
|
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, const asection *sec ATTRIBUTE_UNUSED)
|
|
{
|
|
return elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64 ? 8 : 4;
|
|
}
|
|
|
|
/* Decide whether we can use a PC-relative encoding within the given
|
|
EH frame section. This is the default implementation. */
|
|
|
|
bfd_boolean
|
|
_bfd_elf_can_make_relative (bfd *input_bfd ATTRIBUTE_UNUSED,
|
|
struct bfd_link_info *info ATTRIBUTE_UNUSED,
|
|
asection *eh_frame_section ATTRIBUTE_UNUSED)
|
|
{
|
|
return TRUE;
|
|
}
|
|
|
|
/* Select an encoding for the given address. Preference is given to
|
|
PC-relative addressing modes. */
|
|
|
|
bfd_byte
|
|
_bfd_elf_encode_eh_address (bfd *abfd ATTRIBUTE_UNUSED,
|
|
struct bfd_link_info *info ATTRIBUTE_UNUSED,
|
|
asection *osec, bfd_vma offset,
|
|
asection *loc_sec, bfd_vma loc_offset,
|
|
bfd_vma *encoded)
|
|
{
|
|
*encoded = osec->vma + offset -
|
|
(loc_sec->output_section->vma + loc_sec->output_offset + loc_offset);
|
|
return DW_EH_PE_pcrel | DW_EH_PE_sdata4;
|
|
}
|