X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=bfd%2Felf-eh-frame.c;h=7a129b00f8d78fecd8c450ef8aca564eea4a9485;hb=1b2e4380ebe4e3113fbe890130d57d9f62693b04;hp=63b6ba45f94b1b4da8de625e47c641e5552b7242;hpb=ca92cecbbead0c883df57e70fdb5b2541febd43b;p=deliverable%2Fbinutils-gdb.git diff --git a/bfd/elf-eh-frame.c b/bfd/elf-eh-frame.c index 63b6ba45f9..7a129b00f8 100644 --- a/bfd/elf-eh-frame.c +++ b/bfd/elf-eh-frame.c @@ -1,6 +1,5 @@ /* .eh_frame section optimization. - Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007 - Free Software Foundation, Inc. + Copyright (C) 2001-2020 Free Software Foundation, Inc. Written by Jakub Jelinek . This file is part of BFD, the Binary File Descriptor library. @@ -24,7 +23,7 @@ #include "bfd.h" #include "libbfd.h" #include "elf-bfd.h" -#include "elf/dwarf2.h" +#include "dwarf2.h" #define EH_FRAME_HDR_SIZE 8 @@ -41,16 +40,18 @@ struct cie bfd_vma augmentation_size; union { struct elf_link_hash_entry *h; - bfd_vma val; + struct { + unsigned int bfd_id; + unsigned int index; + } sym; + unsigned int reloc_index; } personality; - asection *output_sec; struct eh_cie_fde *cie_inf; unsigned char per_encoding; unsigned char lsda_encoding; unsigned char fde_encoding; unsigned char initial_insn_length; - unsigned char make_relative; - unsigned char make_lsda_relative; + unsigned char can_make_lsda_relative; unsigned char initial_instructions[50]; }; @@ -215,8 +216,8 @@ write_value (bfd *abfd, bfd_byte *buf, bfd_vma value, int width) static int cie_eq (const void *e1, const void *e2) { - const struct cie *c1 = e1; - const struct cie *c2 = e2; + const struct cie *c1 = (const struct cie *) e1; + const struct cie *c2 = (const struct cie *) e2; if (c1->hash == c2->hash && c1->length == c2->length @@ -230,11 +231,13 @@ cie_eq (const void *e1, const void *e2) && c1->augmentation_size == c2->augmentation_size && memcmp (&c1->personality, &c2->personality, sizeof (c1->personality)) == 0 - && c1->output_sec == c2->output_sec + && (c1->cie_inf->u.cie.u.sec->output_section + == c2->cie_inf->u.cie.u.sec->output_section) && c1->per_encoding == c2->per_encoding && c1->lsda_encoding == c2->lsda_encoding && c1->fde_encoding == c2->fde_encoding && c1->initial_insn_length == c2->initial_insn_length + && c1->initial_insn_length <= sizeof (c1->initial_instructions) && memcmp (c1->initial_instructions, c2->initial_instructions, c1->initial_insn_length) == 0) @@ -246,7 +249,7 @@ cie_eq (const void *e1, const void *e2) static hashval_t cie_hash (const void *e) { - const struct cie *c = e; + const struct cie *c = (const struct cie *) e; return c->hash; } @@ -254,6 +257,7 @@ static hashval_t cie_compute_hash (struct cie *c) { hashval_t h = 0; + size_t len; h = iterative_hash_object (c->length, h); h = iterative_hash_object (c->version, h); h = iterative_hash (c->augmentation, strlen (c->augmentation) + 1, h); @@ -262,12 +266,15 @@ cie_compute_hash (struct cie *c) h = iterative_hash_object (c->ra_column, h); h = iterative_hash_object (c->augmentation_size, h); h = iterative_hash_object (c->personality, h); - h = iterative_hash_object (c->output_sec, h); + h = iterative_hash_object (c->cie_inf->u.cie.u.sec->output_section, h); h = iterative_hash_object (c->per_encoding, h); h = iterative_hash_object (c->lsda_encoding, h); h = iterative_hash_object (c->fde_encoding, h); h = iterative_hash_object (c->initial_insn_length, h); - h = iterative_hash (c->initial_instructions, c->initial_insn_length, h); + len = c->initial_insn_length; + if (len > sizeof (c->initial_instructions)) + len = sizeof (c->initial_instructions); + h = iterative_hash (c->initial_instructions, len, h); c->hash = h; return h; } @@ -283,7 +290,7 @@ extra_augmentation_string_bytes (struct eh_cie_fde *entry) { if (entry->add_augmentation_size) size++; - if (entry->add_fde_encoding) + if (entry->u.cie.add_fde_encoding) size++; } return size; @@ -295,26 +302,17 @@ static INLINE unsigned int extra_augmentation_data_bytes (struct eh_cie_fde *entry) { unsigned int size = 0; - if (entry->cie) - { - if (entry->add_augmentation_size) - size++; - if (entry->add_fde_encoding) - size++; - } - else - { - if (entry->u.fde.cie_inf->add_augmentation_size) - size++; - } + if (entry->add_augmentation_size) + size++; + if (entry->cie && entry->u.cie.add_fde_encoding) + size++; return size; } -/* Return the size that ENTRY will have in the output. ALIGNMENT is the - required alignment of ENTRY in bytes. */ +/* Return the size that ENTRY will have in the output. */ static unsigned int -size_of_output_cie_fde (struct eh_cie_fde *entry, unsigned int alignment) +size_of_output_cie_fde (struct eh_cie_fde *entry) { if (entry->removed) return 0; @@ -322,8 +320,22 @@ size_of_output_cie_fde (struct eh_cie_fde *entry, unsigned int alignment) return 4; return (entry->size + extra_augmentation_string_bytes (entry) - + extra_augmentation_data_bytes (entry) - + alignment - 1) & -alignment; + + extra_augmentation_data_bytes (entry)); +} + +/* Return the offset of the FDE or CIE after ENT. */ + +static unsigned int +next_cie_fde_offset (const struct eh_cie_fde *ent, + const struct eh_cie_fde *last, + const asection *sec) +{ + while (++ent < last) + { + if (!ent->removed) + return ent->new_offset; + } + return sec->size; } /* Assume that the bytes between *ITER and END are CFA instructions. @@ -431,17 +443,131 @@ skip_non_nops (bfd_byte *buf, bfd_byte *end, unsigned int encoded_ptr_width, return last; } -/* Called before calling _bfd_elf_parse_eh_frame on every input bfd's - .eh_frame section. */ +/* Convert absolute encoding ENCODING into PC-relative form. + SIZE is the size of a pointer. */ -void -_bfd_elf_begin_eh_frame_parsing (struct bfd_link_info *info) +static unsigned char +make_pc_relative (unsigned char encoding, unsigned int ptr_size) +{ + if ((encoding & 0x7f) == DW_EH_PE_absptr) + switch (ptr_size) + { + case 2: + encoding |= DW_EH_PE_sdata2; + break; + case 4: + encoding |= DW_EH_PE_sdata4; + break; + case 8: + encoding |= DW_EH_PE_sdata8; + break; + } + return encoding | DW_EH_PE_pcrel; +} + +/* Examine each .eh_frame_entry section and discard those + those that are marked SEC_EXCLUDE. */ + +static void +bfd_elf_discard_eh_frame_entry (struct eh_frame_hdr_info *hdr_info) +{ + unsigned int i; + for (i = 0; i < hdr_info->array_count; i++) + { + if (hdr_info->u.compact.entries[i]->flags & SEC_EXCLUDE) + { + unsigned int j; + for (j = i + 1; j < hdr_info->array_count; j++) + hdr_info->u.compact.entries[j-1] = hdr_info->u.compact.entries[j]; + + hdr_info->array_count--; + hdr_info->u.compact.entries[hdr_info->array_count] = NULL; + i--; + } + } +} + +/* Add a .eh_frame_entry section. */ + +static void +bfd_elf_record_eh_frame_entry (struct eh_frame_hdr_info *hdr_info, + asection *sec) +{ + if (hdr_info->array_count == hdr_info->u.compact.allocated_entries) + { + if (hdr_info->u.compact.allocated_entries == 0) + { + hdr_info->frame_hdr_is_compact = TRUE; + hdr_info->u.compact.allocated_entries = 2; + hdr_info->u.compact.entries = + bfd_malloc (hdr_info->u.compact.allocated_entries + * sizeof (hdr_info->u.compact.entries[0])); + } + else + { + hdr_info->u.compact.allocated_entries *= 2; + hdr_info->u.compact.entries = + bfd_realloc (hdr_info->u.compact.entries, + hdr_info->u.compact.allocated_entries + * sizeof (hdr_info->u.compact.entries[0])); + } + + BFD_ASSERT (hdr_info->u.compact.entries); + } + + hdr_info->u.compact.entries[hdr_info->array_count++] = sec; +} + +/* Parse a .eh_frame_entry section. Figure out which text section it + references. */ + +bfd_boolean +_bfd_elf_parse_eh_frame_entry (struct bfd_link_info *info, + asection *sec, struct elf_reloc_cookie *cookie) { + struct elf_link_hash_table *htab; struct eh_frame_hdr_info *hdr_info; + unsigned long r_symndx; + asection *text_sec; - hdr_info = &elf_hash_table (info)->eh_info; - if (!hdr_info->parsed_eh_frames && !info->relocatable) - hdr_info->cies = htab_try_create (1, cie_hash, cie_eq, free); + 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 @@ -462,26 +588,21 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, bfd_byte *last_fde; struct eh_cie_fde *this_inf; unsigned int hdr_length, hdr_id; - struct extended_cie - { - struct cie *cie; - struct eh_cie_fde *local_cie; - } *ecies = NULL, *ecie; - unsigned int ecie_count; - struct cie *cie, *local_cies = NULL, tmp_cie; + 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 (hdr_info->parsed_eh_frames) - return; - if (sec->size == 0) + if (sec->size == 0 + || sec->sec_info_type != SEC_INFO_TYPE_NONE) { /* This file does not contain .eh_frame information. */ return; @@ -498,15 +619,6 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, 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); @@ -542,33 +654,36 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, REQUIRE (skip_bytes (&buf, end, hdr_length - 4)); } - sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info) - + (num_entries - 1) * sizeof (struct eh_cie_fde)); + 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); - ecies = bfd_zmalloc (num_cies * sizeof (*ecies)); - REQUIRE (ecies); - - /* If we're not merging CIE entries (such as for a relocatable link), - we need to have a "struct cie" for each CIE in this section. */ - if (hdr_info->cies == NULL) + /* We need to have a "struct cie" for each CIE in this section. */ + if (num_cies) { - local_cies = bfd_zmalloc (num_cies * sizeof (*local_cies)); + local_cies = (struct cie *) bfd_zmalloc (num_cies * sizeof (*local_cies)); REQUIRE (local_cies); } + /* FIXME: octets_per_byte. */ #define ENSURE_NO_RELOCS(buf) \ - REQUIRE (!(cookie->rel < cookie->relend \ - && (cookie->rel->r_offset \ - < (bfd_size_type) ((buf) - ehbuf)) \ - && cookie->rel->r_info != 0)) + 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 \ @@ -576,7 +691,8 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, ? cookie->rel : NULL) buf = ehbuf; - ecie_count = 0; + cie_count = 0; + gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook; while ((bfd_size_type) (buf - ehbuf) != sec->size) { char *aug; @@ -602,7 +718,9 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, if (hdr_length == 0) { /* A zero-length CIE should only be found at the end of - the section. */ + the section, but allow multiple terminators. */ + while (skip_bytes (&buf, ehbuf + sec->size, 4)) + REQUIRE (bfd_get_32 (abfd, buf - 4) == 0); REQUIRE ((bfd_size_type) (buf - ehbuf) == sec->size); ENSURE_NO_RELOCS (buf); sec_info->count++; @@ -619,28 +737,23 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, /* CIE */ this_inf->cie = 1; - /* If we're merging CIEs, construct the struct cie in TMP_CIE; - we'll enter it into the global pool later. Otherwise point - CIE to one of the section-local cie structures. */ - if (local_cies) - cie = local_cies + ecie_count; - else - { - cie = &tmp_cie; - memset (cie, 0, sizeof (*cie)); - } + /* Point CIE to one of the section-local cie structures. */ + cie = local_cies + cie_count++; + cie->cie_inf = this_inf; cie->length = hdr_length; - cie->output_sec = sec->output_section; start = buf; REQUIRE (read_byte (&buf, end, &cie->version)); /* Cannot handle unknown versions. */ - REQUIRE (cie->version == 1 || cie->version == 3); + 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') { @@ -651,6 +764,13 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, 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) @@ -671,12 +791,14 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, { aug++; REQUIRE (read_uleb128 (&buf, end, &cie->augmentation_size)); - ENSURE_NO_RELOCS (buf); + ENSURE_NO_RELOCS (buf); } while (*aug != '\0') switch (*aug++) { + case 'B': + break; case 'L': REQUIRE (read_byte (&buf, end, &cie->lsda_encoding)); ENSURE_NO_RELOCS (buf); @@ -697,71 +819,24 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, per_width = get_DW_EH_PE_width (cie->per_encoding, ptr_size); REQUIRE (per_width); - if ((cie->per_encoding & 0xf0) == DW_EH_PE_aligned) + 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. */ - if (GET_RELOC (buf) != NULL) - { - unsigned long r_symndx; - -#ifdef BFD64 - if (elf_elfheader (abfd)->e_ident[EI_CLASS] - == ELFCLASS64) - r_symndx = ELF64_R_SYM (cookie->rel->r_info); - else -#endif - r_symndx = ELF32_R_SYM (cookie->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; - } - else - { - Elf_Internal_Sym *sym; - asection *sym_sec; - bfd_vma val; - - sym = &cookie->locsyms[r_symndx]; - sym_sec = (bfd_section_from_elf_index - (abfd, sym->st_shndx)); - if (sym_sec != NULL) - { - if (sym_sec->kept_section != NULL) - sym_sec = sym_sec->kept_section; - if (sym_sec->output_section != NULL) - { - val = (sym->st_value - + sym_sec->output_offset - + sym_sec->output_section->vma); - cie->personality.val = val; - cie->local_personality = 1; - } - } - } - - /* Cope with MIPS-style composite relocations. */ - do - cookie->rel++; - while (GET_RELOC (buf) != NULL); - } + 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)); - REQUIRE (cie->local_personality || cie->personality.h); } break; default: @@ -769,35 +844,33 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, goto free_no_table; } } + this_inf->u.cie.aug_data_len + = buf - start - 1 - this_inf->u.cie.aug_str_len; /* For shared libraries, try to get rid of as many RELATIVE relocs as possible. */ - if (info->shared + if (bfd_link_pic (info) && (get_elf_backend_data (abfd) ->elf_backend_can_make_relative_eh_frame (abfd, info, sec))) { - if ((cie->fde_encoding & 0xf0) == DW_EH_PE_absptr) - cie->make_relative = 1; + 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 & 0xf0) != DW_EH_PE_aligned) + && (cie->per_encoding & 0x70) != DW_EH_PE_aligned) { if (*cie->augmentation == 0) this_inf->add_augmentation_size = 1; - this_inf->add_fde_encoding = 1; - cie->make_relative = 1; + this_inf->u.cie.add_fde_encoding = 1; + this_inf->make_relative = 1; } - } - if (info->shared - && (get_elf_backend_data (abfd) - ->elf_backend_can_make_lsda_relative_eh_frame - (abfd, info, sec)) - && (cie->lsda_encoding & 0xf0) == DW_EH_PE_absptr) - cie->make_lsda_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. */ @@ -805,42 +878,74 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, cie->fde_encoding = DW_EH_PE_absptr; initial_insn_length = end - buf; - if (initial_insn_length <= sizeof (cie->initial_instructions)) - { - cie->initial_insn_length = initial_insn_length; - memcpy (cie->initial_instructions, buf, initial_insn_length); - } + 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); - this_inf->make_relative = cie->make_relative; - this_inf->make_lsda_relative = cie->make_lsda_relative; - this_inf->per_encoding_relative - = (cie->per_encoding & 0x70) == DW_EH_PE_pcrel; + 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 (ecie = ecies; ecie < ecies + ecie_count; ++ecie) - if (cie_offset == ecie->local_cie->offset) + 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 (ecie != ecies + ecie_count); - cie = ecie->cie; - this_inf->u.fde.cie_inf = ecie->local_cie; + 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); - REQUIRE (GET_RELOC (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 %pB(%pA).\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)); @@ -852,6 +957,9 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, 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. */ @@ -864,6 +972,16 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, 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); } @@ -887,14 +1005,14 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, cie->length -= end - insns_end; } if (set_loc_count - && ((cie->fde_encoding & 0xf0) == DW_EH_PE_pcrel - || cie->make_relative)) + && ((cie->fde_encoding & 0x70) == DW_EH_PE_pcrel + || this_inf->make_relative)) { unsigned int cnt; bfd_byte *p; - this_inf->set_loc = bfd_malloc ((set_loc_count + 1) - * sizeof (unsigned int)); + 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; @@ -910,70 +1028,438 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, this_inf->removed = 1; this_inf->fde_encoding = cie->fde_encoding; this_inf->lsda_encoding = cie->lsda_encoding; - if (this_inf->cie) - { - /* We have now finished constructing the struct cie. */ - if (hdr_info->cies != NULL) - { - /* See if we can merge this CIE with an earlier one. */ - void **loc; - - cie_compute_hash (cie); - loc = htab_find_slot_with_hash (hdr_info->cies, cie, - cie->hash, INSERT); - REQUIRE (loc); - if (*loc == HTAB_EMPTY_ENTRY) - { - *loc = malloc (sizeof (struct cie)); - REQUIRE (*loc); - memcpy (*loc, cie, sizeof (struct cie)); - } - cie = (struct cie *) *loc; - } - this_inf->u.cie.merged = cie->cie_inf; - ecies[ecie_count].cie = cie; - ecies[ecie_count++].local_cie = this_inf; - } sec_info->count++; } BFD_ASSERT (sec_info->count == num_entries); - BFD_ASSERT (ecie_count == num_cies); + BFD_ASSERT (cie_count == num_cies); elf_section_data (sec)->sec_info = sec_info; - sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME; + 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) - (_("%P: error in %B(%A); no .eh_frame_hdr table will be created.\n"), + _bfd_error_handler + /* xgettext:c-format */ + (_("error in %pB(%pA); no .eh_frame_hdr table will be created"), abfd, sec); - hdr_info->table = FALSE; - if (sec_info) - free (sec_info); + hdr_info->u.dwarf.table = FALSE; + free (sec_info); success: - if (ehbuf) - free (ehbuf); - if (ecies) - free (ecies); - if (local_cies) - free (local_cies); + free (ehbuf); + free (local_cies); #undef REQUIRE } -/* Finish a pass over all .eh_frame sections. */ +/* Order eh_frame_hdr entries by the VMA of their text section. */ -void +static int +cmp_eh_frame_hdr (const void *a, const void *b) +{ + bfd_vma text_a; + bfd_vma text_b; + asection *sec; + + sec = *(asection *const *)a; + sec = (asection *) elf_section_data (sec)->sec_info; + text_a = sec->output_section->vma + sec->output_offset; + sec = *(asection *const *)b; + sec = (asection *) elf_section_data (sec)->sec_info; + text_b = sec->output_section->vma + sec->output_offset; + + if (text_a < text_b) + return -1; + return text_a > text_b; + +} + +/* Add space for a CANTUNWIND terminator to SEC if the text sections + referenced by it and NEXT are not contiguous, or NEXT is NULL. */ + +static void +add_eh_frame_hdr_terminator (asection *sec, + asection *next) +{ + bfd_vma end; + bfd_vma next_start; + asection *text_sec; + + if (next) + { + /* See if there is a gap (presumably a text section without unwind info) + between these two entries. */ + text_sec = (asection *) elf_section_data (sec)->sec_info; + end = text_sec->output_section->vma + text_sec->output_offset + + text_sec->size; + text_sec = (asection *) elf_section_data (next)->sec_info; + next_start = text_sec->output_section->vma + text_sec->output_offset; + if (end == next_start) + return; + } + + /* Add space for a CANTUNWIND terminator. */ + if (!sec->rawsize) + sec->rawsize = sec->size; + + bfd_set_section_size (sec, sec->size + 8); +} + +/* Finish a pass over all .eh_frame_entry sections. */ + +bfd_boolean _bfd_elf_end_eh_frame_parsing (struct bfd_link_info *info) { struct eh_frame_hdr_info *hdr_info; + unsigned int i; hdr_info = &elf_hash_table (info)->eh_info; - if (hdr_info->cies != NULL) + + 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 = NULL; + bfd_signed_vma delta; + + lo = 0; + hi = sec_info->count; + if (hi == 0) + return 0; + + while (lo < hi) + { + mid = (lo + hi) / 2; + ent = &sec_info->entry[mid]; + if (offset < ent->offset) + hi = mid; + else if (mid + 1 >= hi) + break; + else if (offset >= ent[1].offset) + lo = mid + 1; + else + break; + } + + if (!ent->removed) + delta = (bfd_vma) ent->new_offset - (bfd_vma) ent->offset; + else if (ent->cie && ent->u.cie.merged) + { + struct eh_cie_fde *cie = ent->u.cie.u.merged_with; + delta = ((bfd_vma) cie->new_offset + cie->u.cie.u.sec->output_offset + - (bfd_vma) ent->offset - sec->output_offset); + } + else + { + /* Is putting the symbol on the next entry best for a deleted + CIE/FDE? */ + struct eh_cie_fde *last = sec_info->entry + sec_info->count; + delta = ((bfd_vma) next_cie_fde_offset (ent, last, sec) + - (bfd_vma) ent->offset); + return delta; + } + + /* Account for editing within this CIE/FDE. */ + offset -= ent->offset; + if (ent->cie) { - htab_delete (hdr_info->cies); - hdr_info->cies = NULL; + 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; } - hdr_info->parsed_eh_frames = TRUE; + 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 @@ -987,75 +1473,136 @@ _bfd_elf_discard_section_eh_frame bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *), struct elf_reloc_cookie *cookie) { - struct eh_cie_fde *ent, *cie, *merged; + struct eh_cie_fde *ent; struct eh_frame_sec_info *sec_info; struct eh_frame_hdr_info *hdr_info; - unsigned int ptr_size, offset; + unsigned int ptr_size, offset, eh_alignment; + int changed; + + if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME) + return FALSE; 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->cie) + 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) { - cookie->rel = cookie->rels + ent->reloc_index; - BFD_ASSERT (cookie->rel < cookie->relend - && cookie->rel->r_offset == ent->offset + 8); - if (!(*reloc_symbol_deleted_p) (ent->offset + 8, cookie)) + 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 { - if (info->shared - && (((ent->fde_encoding & 0xf0) == DW_EH_PE_absptr - && ent->u.fde.cie_inf->make_relative == 0) - || (ent->fde_encoding & 0xf0) == DW_EH_PE_aligned)) + 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->table = FALSE; - (*info->callbacks->einfo) - (_("%P: fde encoding in %B(%A) prevents .eh_frame_hdr" - " table being created.\n"), abfd, sec); - } - ent->removed = 0; - hdr_info->fde_count++; - - cie = ent->u.fde.cie_inf; - if (cie->removed) - { - merged = cie->u.cie.merged; - if (!merged->removed) - /* We have decided to keep the group representative. */ - ent->u.fde.cie_inf = merged; - else if (merged->u.cie.merged != merged) - /* We didn't keep the original group representative, - but we did keep an alternative. */ - ent->u.fde.cie_inf = merged->u.cie.merged; - else + hdr_info->u.dwarf.table = FALSE; + /* Only warn if --eh-frame-hdr was specified. */ + if (info->eh_frame_hdr_type != 0) { - /* Make the local CIE represent the merged group. */ - merged->u.cie.merged = cie; - cie->removed = 0; + if (num_warnings_issued < 10) + { + _bfd_error_handler + /* xgettext:c-format */ + (_("FDE encoding in %pB(%pA) prevents .eh_frame_hdr" + " table being created"), abfd, sec); + num_warnings_issued ++; + } + else if (num_warnings_issued == 10) + { + _bfd_error_handler + (_("further warnings about FDE encoding preventing .eh_frame_hdr generation dropped")); + num_warnings_issued ++; + } } } + ent->removed = 0; + hdr_info->u.dwarf.fde_count++; + ent->u.fde.cie_inf = find_merged_cie (abfd, info, sec, hdr_info, + cookie, ent->u.fde.cie_inf); } } - ptr_size = (get_elf_backend_data (sec->owner) - ->elf_backend_eh_frame_address_size (sec->owner, sec)); + free (sec_info->cies); + sec_info->cies = NULL; + + /* It may be that some .eh_frame input section has greater alignment + than other .eh_frame sections. In that case we run the risk of + padding with zeros before that section, which would be seen as a + zero terminator. Alignment padding must be added *inside* the + last FDE instead. For other FDEs we align according to their + encoding, in order to align FDE address range entries naturally. */ offset = 0; + changed = 0; for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) if (!ent->removed) { + eh_alignment = 4; + if (ent->size == 4) + ; + else if (ent->cie) + { + if (ent->u.cie.per_encoding_aligned8) + eh_alignment = 8; + } + else + { + eh_alignment = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); + if (eh_alignment < 4) + eh_alignment = 4; + } + offset = (offset + eh_alignment - 1) & -eh_alignment; ent->new_offset = offset; - offset += size_of_output_cie_fde (ent, ptr_size); + if (ent->new_offset != ent->offset) + changed = 1; + offset += size_of_output_cie_fde (ent); } + eh_alignment = 4; + offset = (offset + eh_alignment - 1) & -eh_alignment; sec->rawsize = sec->size; sec->size = offset; - return offset != sec->rawsize; + if (sec->size != sec->rawsize) + changed = 1; + + if (changed && adjust_eh_frame_local_symbols (sec, cookie)) + { + Elf_Internal_Shdr *symtab_hdr = &elf_tdata (abfd)->symtab_hdr; + symtab_hdr->contents = (unsigned char *) cookie->locsyms; + } + return changed; } /* This function is called for .eh_frame_hdr section after @@ -1072,18 +1619,77 @@ _bfd_elf_discard_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) 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; - sec->size = EH_FRAME_HDR_SIZE; - if (hdr_info->table) - sec->size += 4 + hdr_info->fde_count * 8; + if (info->eh_frame_hdr_type == COMPACT_EH_HDR) + { + /* For compact frames we only add the header. The actual table comes + from the .eh_frame_entry sections. */ + sec->size = 8; + } + else + { + sec->size = EH_FRAME_HDR_SIZE; + if (hdr_info->u.dwarf.table) + sec->size += 4 + hdr_info->u.dwarf.fde_count * 8; + } - elf_tdata (abfd)->eh_frame_hdr = sec; + 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_section_name (o); + + if (strcmp (name, ".eh_frame_entry") + && !bfd_is_abs_section (o->output_section)) + return TRUE; + } + } + return FALSE; +} + /* This function is called from size_dynamic_sections. It needs to decide whether .eh_frame_hdr should be output or not, because when the dynamic symbol table has been sized it is too late @@ -1092,41 +1698,43 @@ _bfd_elf_discard_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) bfd_boolean _bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info) { - asection *o; - bfd *abfd; 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)) + 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; } - abfd = NULL; - if (info->eh_frame_hdr) - for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next) - { - /* Count only sections which have at least a single CIE or FDE. - There cannot be any CIE or FDE <= 8 bytes. */ - o = bfd_get_section_by_name (abfd, ".eh_frame"); - if (o && o->size > 8 && !bfd_is_abs_section (o->output_section)) - break; - } + /* 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; - if (abfd == NULL) - { - hdr_info->hdr_sec->flags |= SEC_EXCLUDE; - hdr_info->hdr_sec = NULL; - return TRUE; - } + 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); - hdr_info->table = TRUE; + if (!hdr_info->frame_hdr_is_compact) + hdr_info->u.dwarf.table = TRUE; return TRUE; } @@ -1137,27 +1745,20 @@ _bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info) bfd_vma _bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, - struct bfd_link_info *info, + struct bfd_link_info *info ATTRIBUTE_UNUSED, asection *sec, bfd_vma offset) { struct eh_frame_sec_info *sec_info; - struct elf_link_hash_table *htab; - struct eh_frame_hdr_info *hdr_info; unsigned int lo, hi, mid; - if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) + if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME) return offset; - sec_info = elf_section_data (sec)->sec_info; + sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info; if (offset >= sec->rawsize) return offset - sec->rawsize + sec->size; - htab = elf_hash_table (info); - hdr_info = &htab->eh_info; - if (hdr_info->offsets_adjusted) - offset += sec->output_offset; - lo = 0; hi = sec_info->count; mid = 0; @@ -1179,32 +1780,33 @@ _bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, 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].u.fde.cie_inf->make_relative + && 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->make_lsda_relative - && (offset == (sec_info->entry[mid].offset + 8 - + sec_info->entry[mid].lsda_offset)) - && (sec_info->entry[mid].u.fde.cie_inf->need_lsda_relative - || !hdr_info->offsets_adjusted)) - { - sec_info->entry[mid].u.fde.cie_inf->need_lsda_relative = 1; - return (bfd_vma) -2; - } + && 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].cie - ? sec_info->entry[mid].make_relative - : sec_info->entry[mid].u.fde.cie_inf->make_relative) + && sec_info->entry[mid].make_relative && (offset >= sec_info->entry[mid].offset + 8 + sec_info->entry[mid].set_loc[1])) { @@ -1216,8 +1818,6 @@ _bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, return (bfd_vma) -2; } - if (hdr_info->offsets_adjusted) - offset -= sec->output_offset; /* Any new augmentation bytes go before the first relocation. */ return (offset + sec_info->entry[mid].new_offset - sec_info->entry[mid].offset @@ -1225,6 +1825,86 @@ _bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, + extra_augmentation_data_bytes (sec_info->entry + mid)); } +/* Write out .eh_frame_entry section. Add CANTUNWIND terminator if needed. + Also check that the contents look sane. */ + +bfd_boolean +_bfd_elf_write_section_eh_frame_entry (bfd *abfd, struct bfd_link_info *info, + asection *sec, bfd_byte *contents) +{ + const struct elf_backend_data *bed; + bfd_byte cantunwind[8]; + bfd_vma addr; + bfd_vma last_addr; + bfd_vma offset; + asection *text_sec = (asection *) elf_section_data (sec)->sec_info; + + if (!sec->rawsize) + sec->rawsize = sec->size; + + BFD_ASSERT (sec->sec_info_type == SEC_INFO_TYPE_EH_FRAME_ENTRY); + + /* Check to make sure that the text section corresponding to this eh_frame_entry + section has not been excluded. In particular, mips16 stub entries will be + excluded outside of the normal process. */ + if (sec->flags & SEC_EXCLUDE + || text_sec->flags & SEC_EXCLUDE) + return TRUE; + + if (!bfd_set_section_contents (abfd, sec->output_section, contents, + sec->output_offset, sec->rawsize)) + return FALSE; + + last_addr = bfd_get_signed_32 (abfd, contents); + /* Check that all the entries are in order. */ + for (offset = 8; offset < sec->rawsize; offset += 8) + { + addr = bfd_get_signed_32 (abfd, contents + offset) + offset; + if (addr <= last_addr) + { + /* xgettext:c-format */ + _bfd_error_handler (_("%pB: %pA not in order"), sec->owner, sec); + return FALSE; + } + + last_addr = addr; + } + + addr = text_sec->output_section->vma + text_sec->output_offset + + text_sec->size; + addr &= ~1; + addr -= (sec->output_section->vma + sec->output_offset + sec->rawsize); + if (addr & 1) + { + /* xgettext:c-format */ + _bfd_error_handler (_("%pB: %pA invalid input section size"), + sec->owner, sec); + bfd_set_error (bfd_error_bad_value); + return FALSE; + } + if (last_addr >= addr + sec->rawsize) + { + /* xgettext:c-format */ + _bfd_error_handler (_("%pB: %pA points past end of text section"), + sec->owner, sec); + bfd_set_error (bfd_error_bad_value); + return FALSE; + } + + if (sec->size == sec->rawsize) + return TRUE; + + bed = get_elf_backend_data (abfd); + BFD_ASSERT (sec->size == sec->rawsize + 8); + BFD_ASSERT ((addr & 1) == 0); + BFD_ASSERT (bed->cant_unwind_opcode); + + bfd_put_32 (abfd, addr, cantunwind); + bfd_put_32 (abfd, (*bed->cant_unwind_opcode) (info), cantunwind + 4); + return bfd_set_section_contents (abfd, sec->output_section, cantunwind, + sec->output_offset + sec->rawsize, 8); +} + /* Write out .eh_frame section. This is called with the relocated contents. */ @@ -1238,9 +1918,10 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, struct elf_link_hash_table *htab; struct eh_frame_hdr_info *hdr_info; unsigned int ptr_size; - struct eh_cie_fde *ent; + struct eh_cie_fde *ent, *last_ent; - if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) + 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); @@ -1248,46 +1929,18 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, ->elf_backend_eh_frame_address_size (abfd, sec)); BFD_ASSERT (ptr_size != 0); - sec_info = elf_section_data (sec)->sec_info; + sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info; htab = elf_hash_table (info); hdr_info = &htab->eh_info; - /* First convert all offsets to output section offsets, so that a - CIE offset is valid if the CIE is used by a FDE from some other - section. This can happen when duplicate CIEs are deleted in - _bfd_elf_discard_section_eh_frame. We do all sections here because - this function might not be called on sections in the same order as - _bfd_elf_discard_section_eh_frame. */ - if (!hdr_info->offsets_adjusted) + if (hdr_info->u.dwarf.table && hdr_info->u.dwarf.array == NULL) { - bfd *ibfd; - asection *eh; - struct eh_frame_sec_info *eh_inf; - - for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next) - { - if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour - || (ibfd->flags & DYNAMIC) != 0) - continue; - - eh = bfd_get_section_by_name (ibfd, ".eh_frame"); - if (eh == NULL || eh->sec_info_type != ELF_INFO_TYPE_EH_FRAME) - continue; - - eh_inf = elf_section_data (eh)->sec_info; - for (ent = eh_inf->entry; ent < eh_inf->entry + eh_inf->count; ++ent) - { - ent->offset += eh->output_offset; - ent->new_offset += eh->output_offset; - } - } - hdr_info->offsets_adjusted = TRUE; + 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->table && hdr_info->array == NULL) - hdr_info->array - = bfd_malloc (hdr_info->fde_count * sizeof(*hdr_info->array)); - if (hdr_info->array == NULL) + if (hdr_info->u.dwarf.array == NULL) hdr_info = NULL; /* The new offsets can be bigger or smaller than the original offsets. @@ -1297,15 +1950,14 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, 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 - sec->output_offset, - contents + ent->offset - sec->output_offset, ent->size); + 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 - sec->output_offset, - contents + ent->offset - sec->output_offset, ent->size); + memmove (contents + ent->new_offset, contents + ent->offset, ent->size); - for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) + last_ent = sec_info->entry + sec_info->count; + for (ent = sec_info->entry; ent < last_ent; ++ent) { unsigned char *buf, *end; unsigned int new_size; @@ -1316,13 +1968,13 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, if (ent->size == 4) { /* Any terminating FDE must be at the end of the section. */ - BFD_ASSERT (ent == sec_info->entry + sec_info->count - 1); + BFD_ASSERT (ent == last_ent - 1); continue; } - buf = contents + ent->new_offset - sec->output_offset; + buf = contents + ent->new_offset; end = buf + ent->size; - new_size = size_of_output_cie_fde (ent, ptr_size); + new_size = next_cie_fde_offset (ent, last_ent, sec) - ent->new_offset; /* Update the size. It may be shrinked. */ bfd_put_32 (abfd, new_size - 4, buf); @@ -1335,28 +1987,32 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, { /* CIE */ if (ent->make_relative - || ent->need_lsda_relative - || ent->per_encoding_relative) + || ent->u.cie.make_lsda_relative + || ent->u.cie.per_encoding_relative) { char *aug; - unsigned int action, extra_string, extra_data; + unsigned int version, action, extra_string, extra_data; unsigned int per_width, per_encoding; /* Need to find 'R' or 'L' augmentation's argument and modify DW_EH_PE_* value. */ action = ((ent->make_relative ? 1 : 0) - | (ent->need_lsda_relative ? 2 : 0) - | (ent->per_encoding_relative ? 4 : 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; + /* Skip length, id. */ + buf += 8; + version = *buf++; aug = (char *) buf; buf += strlen (aug) + 1; skip_leb128 (&buf, end); skip_leb128 (&buf, end); - skip_leb128 (&buf, end); + if (version == 1) + skip_bytes (&buf, end, 1); + else + skip_leb128 (&buf, end); if (*aug == 'z') { /* The uleb128 will always be a single byte for the kind @@ -1376,11 +2032,11 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, *aug++ = 'z'; *buf++ = extra_data - 1; } - if (ent->add_fde_encoding) + if (ent->u.cie.add_fde_encoding) { BFD_ASSERT (action & 1); *aug++ = 'R'; - *buf++ = DW_EH_PE_pcrel; + *buf++ = make_pc_relative (DW_EH_PE_absptr, ptr_size); action &= ~1; } @@ -1391,18 +2047,20 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, if (action & 2) { BFD_ASSERT (*buf == ent->lsda_encoding); - *buf |= DW_EH_PE_pcrel; + *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->per_encoding_relative); - if ((per_encoding & 0xf0) == DW_EH_PE_aligned) + == 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))); @@ -1412,8 +2070,15 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, val = read_value (abfd, buf, per_width, get_DW_EH_PE_signed (per_encoding)); - val += ent->offset - ent->new_offset; - val -= extra_string + extra_data; + 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; } @@ -1423,7 +2088,7 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, if (action & 1) { BFD_ASSERT (*buf == ent->fde_encoding); - *buf |= DW_EH_PE_pcrel; + *buf = make_pc_relative (*buf, ptr_size); action &= ~1; } buf++; @@ -1446,8 +2111,11 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, /* Skip length. */ cie = ent->u.fde.cie_inf; buf += 4; - value = ent->new_offset + 4 - cie->new_offset; + 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, @@ -1455,27 +2123,52 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, address = value; if (value) { - switch (ent->fde_encoding & 0xf0) + switch (ent->fde_encoding & 0x70) { - case DW_EH_PE_indirect: case DW_EH_PE_textrel: BFD_ASSERT (hdr_info == NULL); break; case DW_EH_PE_datarel: { - asection *got = bfd_get_section_by_name (abfd, ".got"); - - BFD_ASSERT (got != NULL); - address += got->vma; + switch (abfd->arch_info->arch) + { + case bfd_arch_ia64: + BFD_ASSERT (elf_gp (abfd) != 0); + address += elf_gp (abfd); + break; + default: + _bfd_error_handler + (_("DW_EH_PE_datarel unspecified" + " for this architecture")); + /* Fall thru */ + case bfd_arch_frv: + case bfd_arch_i386: + case bfd_arch_nios2: + BFD_ASSERT (htab->hgot != NULL + && ((htab->hgot->root.type + == bfd_link_hash_defined) + || (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 += ent->offset - ent->new_offset; - address += sec->output_section->vma + ent->offset + 8; + value += (bfd_vma) ent->offset - ent->new_offset; + address += (sec->output_section->vma + + sec->output_offset + + ent->offset + 8); break; } - if (cie->make_relative) - value -= sec->output_section->vma + ent->new_offset + 8; + if (ent->make_relative) + value -= (sec->output_section->vma + + sec->output_offset + + ent->new_offset + 8); write_value (abfd, buf, value, width); } @@ -1483,13 +2176,23 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, if (hdr_info) { - hdr_info->array[hdr_info->array_count].initial_loc = address; - hdr_info->array[hdr_info->array_count++].fde - = sec->output_section->vma + ent->new_offset; + /* 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 & 0xf0) == DW_EH_PE_pcrel - || cie->need_lsda_relative) + 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); @@ -1497,15 +2200,16 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, get_DW_EH_PE_signed (ent->lsda_encoding)); if (value) { - if ((ent->lsda_encoding & 0xf0) == DW_EH_PE_pcrel) - value += ent->offset - ent->new_offset; - else if (cie->need_lsda_relative) - value -= (sec->output_section->vma + ent->new_offset + 8 - + ent->lsda_offset); + 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 (cie->add_augmentation_size) + else if (ent->add_augmentation_size) { /* Skip the PC and length and insert a zero byte for the augmentation size. */ @@ -1517,7 +2221,7 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, if (ent->set_loc) { /* Adjust DW_CFA_set_loc. */ - unsigned int cnt, width; + unsigned int cnt; bfd_vma new_offset; width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); @@ -1527,7 +2231,6 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, for (cnt = 1; cnt <= ent->set_loc[0]; cnt++) { - bfd_vma value; buf = start + ent->set_loc[cnt]; value = read_value (abfd, buf, width, @@ -1535,25 +2238,19 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, if (!value) continue; - if ((ent->fde_encoding & 0xf0) == DW_EH_PE_pcrel) - value += ent->offset + 8 - new_offset; - if (cie->make_relative) - value -= sec->output_section->vma + new_offset - + ent->set_loc[cnt]; + 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); } } } } - /* We don't align the section to its section alignment since the - runtime library only expects all CIE/FDE records aligned at - the pointer size. _bfd_elf_discard_section_eh_frame should - have padded CIE/FDE records to multiple of pointer size with - size_of_output_cie_fde. */ - if ((sec->size % ptr_size) != 0) - abort (); - + /* FIXME: octets_per_byte. */ return bfd_set_section_contents (abfd, sec->output_section, contents, (file_ptr) sec->output_offset, sec->size); @@ -1565,21 +2262,126 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, static int vma_compare (const void *a, const void *b) { - const struct eh_frame_array_ent *p = a; - const struct eh_frame_array_ent *q = 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; } -/* Write out .eh_frame_hdr section. This must be called after - _bfd_elf_write_section_eh_frame has been called on all input - .eh_frame sections. - .eh_frame_hdr format: +/* Reorder .eh_frame_entry sections to match the associated text sections. + This routine is called during the final linking step, just before writing + the contents. At this stage, sections in the eh_frame_hdr_info are already + sorted in order of increasing text section address and so we simply need + to make the .eh_frame_entrys follow that same order. Note that it is + invalid for a linker script to try to force a particular order of + .eh_frame_entry sections. */ + +bfd_boolean +_bfd_elf_fixup_eh_frame_hdr (struct bfd_link_info *info) +{ + asection *sec = NULL; + asection *osec; + struct eh_frame_hdr_info *hdr_info; + unsigned int i; + bfd_vma offset; + struct bfd_link_order *p; + + hdr_info = &elf_hash_table (info)->eh_info; + + if (hdr_info->hdr_sec == NULL + || info->eh_frame_hdr_type != COMPACT_EH_HDR + || hdr_info->array_count == 0) + return TRUE; + + /* Change section output offsets to be in text section order. */ + offset = 8; + osec = hdr_info->u.compact.entries[0]->output_section; + for (i = 0; i < hdr_info->array_count; i++) + { + sec = hdr_info->u.compact.entries[i]; + if (sec->output_section != osec) + { + _bfd_error_handler + (_("invalid output section for .eh_frame_entry: %pA"), + sec->output_section); + return FALSE; + } + sec->output_offset = offset; + offset += sec->size; + } + + + /* Fix the link_order to match. */ + for (p = sec->output_section->map_head.link_order; p != NULL; p = p->next) + { + if (p->type != bfd_indirect_link_order) + abort(); + + p->offset = p->u.indirect.section->output_offset; + if (p->next != NULL) + i--; + } + + if (i != 0) + { + _bfd_error_handler + (_("invalid contents in %pA section"), osec); + return FALSE; + } + + return TRUE; +} + +/* The .eh_frame_hdr format for Compact EH frames: + ubyte version (2) + ubyte eh_ref_enc (DW_EH_PE_* encoding of typinfo references) + uint32_t count (Number of entries in table) + [array from .eh_frame_entry sections] */ + +static bfd_boolean +write_compact_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) +{ + struct elf_link_hash_table *htab; + struct eh_frame_hdr_info *hdr_info; + asection *sec; + const struct elf_backend_data *bed; + bfd_vma count; + bfd_byte contents[8]; + unsigned int i; + + htab = elf_hash_table (info); + hdr_info = &htab->eh_info; + sec = hdr_info->hdr_sec; + + if (sec->size != 8) + abort(); + + for (i = 0; i < sizeof (contents); i++) + contents[i] = 0; + + contents[0] = COMPACT_EH_HDR; + bed = get_elf_backend_data (abfd); + + BFD_ASSERT (bed->compact_eh_encoding); + contents[1] = (*bed->compact_eh_encoding) (info); + + count = (sec->output_section->size - 8) / 8; + bfd_put_32 (abfd, count, contents + 4); + return bfd_set_section_contents (abfd, sec->output_section, contents, + (file_ptr) sec->output_offset, sec->size); +} + +/* The .eh_frame_hdr format for DWARF frames: + ubyte version (currently 1) - ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of + ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of .eh_frame section) ubyte fde_count_enc (DW_EH_PE_* encoding of total FDE count number (or DW_EH_PE_omit if there is no @@ -1596,28 +2398,27 @@ vma_compare (const void *a, const void *b) FDE initial_location field and FDE address, sorted by increasing initial_loc). */ -bfd_boolean -_bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) +static bfd_boolean +write_dwarf_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) { struct elf_link_hash_table *htab; struct eh_frame_hdr_info *hdr_info; asection *sec; - bfd_byte *contents; - asection *eh_frame_sec; - bfd_size_type size; - bfd_boolean retval; - bfd_vma encoded_eh_frame; + bfd_boolean retval = TRUE; htab = elf_hash_table (info); hdr_info = &htab->eh_info; sec = hdr_info->hdr_sec; - if (sec == NULL) - return TRUE; + bfd_byte *contents; + asection *eh_frame_sec; + bfd_size_type size; + bfd_vma encoded_eh_frame; size = EH_FRAME_HDR_SIZE; - if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) - size += 4 + hdr_info->fde_count * 8; - contents = bfd_malloc (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; @@ -1629,15 +2430,19 @@ _bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) } memset (contents, 0, EH_FRAME_HDR_SIZE); - contents[0] = 1; /* Version. */ + /* 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); /* .eh_frame offset. */ + (abfd, info, eh_frame_sec, 0, sec, 4, &encoded_eh_frame); - if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) + if (hdr_info->u.dwarf.array + && hdr_info->array_count == hdr_info->u.dwarf.fde_count) { - contents[2] = DW_EH_PE_udata4; /* FDE count encoding. */ - contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; /* Search table enc. */ + /* FDE count encoding. */ + contents[2] = DW_EH_PE_udata4; + /* Search table encoding. */ + contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; } else { @@ -1649,33 +2454,89 @@ _bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) if (contents[2] != DW_EH_PE_omit) { unsigned int i; - - bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE); - qsort (hdr_info->array, hdr_info->fde_count, sizeof (*hdr_info->array), - vma_compare); - for (i = 0; i < hdr_info->fde_count; i++) + bfd_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_put_32 (abfd, - hdr_info->array[i].initial_loc - - sec->output_section->vma, - contents + EH_FRAME_HDR_SIZE + i * 8 + 4); - bfd_put_32 (abfd, - hdr_info->array[i].fde - sec->output_section->vma, - contents + EH_FRAME_HDR_SIZE + i * 8 + 8); + 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) + _bfd_error_handler (_(".eh_frame_hdr entry overflow")); + if (overlap) + _bfd_error_handler (_(".eh_frame_hdr refers to overlapping FDEs")); + if (overflow || overlap) + { + bfd_set_error (bfd_error_bad_value); + retval = FALSE; } } - retval = bfd_set_section_contents (abfd, sec->output_section, - contents, (file_ptr) sec->output_offset, - sec->size); + /* 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); + + free (hdr_info->u.dwarf.array); return retval; } +/* Write out .eh_frame_hdr section. This must be called after + _bfd_elf_write_section_eh_frame has been called on all input + .eh_frame sections. */ + +bfd_boolean +_bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) +{ + struct elf_link_hash_table *htab; + struct eh_frame_hdr_info *hdr_info; + asection *sec; + + htab = elf_hash_table (info); + hdr_info = &htab->eh_info; + sec = hdr_info->hdr_sec; + + if (info->eh_frame_hdr_type == 0 || sec == NULL) + return TRUE; + + if (info->eh_frame_hdr_type == COMPACT_EH_HDR) + return write_compact_eh_frame_hdr (abfd, info); + else + return write_dwarf_eh_frame_hdr (abfd, info); +} + /* Return the width of FDE addresses. This is the default implementation. */ unsigned int -_bfd_elf_eh_frame_address_size (bfd *abfd, asection *sec ATTRIBUTE_UNUSED) +_bfd_elf_eh_frame_address_size (bfd *abfd, const asection *sec ATTRIBUTE_UNUSED) { return elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64 ? 8 : 4; }