From: Alan Modra Date: Thu, 21 Aug 2014 23:37:35 +0000 (+0930) Subject: Index PowerPC64 linker generated .eh_frame in .eh_frame_hdr X-Git-Tag: binutils-2_25~514 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=da44f4e5464f82dec79eb5885961c6466dd3bf6a;p=external%2Fbinutils.git Index PowerPC64 linker generated .eh_frame in .eh_frame_hdr I noticed recently that .eh_frame FDEs generated by the linker for call stubs and .glink weren't being indexed in .eh_frame_hdr, due to bfd_elf_discard_info being run before the linker generated .eh_frame sections were available for parsing. This patch moves code around in elf64-ppc.c and ppc64elf.em to avoid that problem. Another problem fixed here is that --gc-sections parses .eh_frame early, and the existing machinery allows only one go at parsing the .eh_frame sections. That resulted in the linker generated .eh_frame CIEs not being merged and no .eh_frame_hdr index entries for those FDEs. It turns out that all the info from parsing .eh_frame is attached to the section, so order of parsing isn't important, and after parsing sec_info_type being set will prevent a section being parsed again. At least, when parsing doesn't hit an error. So there isn't really any need for "parsed_eh_frame". "merge_cies" is also redundant, which means _bfd_elf_{begin,end}_eh_frame_parsing can also disappear. bfd/ * elf-bfd.h (struct eh_frame_hdr_info): Delete merge_cies and parsed_eh_frames. (_bfd_elf_begin_eh_frame_parsing): Delete. (_bfd_elf_end_eh_frame_parsing): Delete. * elf-eh-frame.c (_bfd_elf_begin_eh_frame_parsing): Delete. (_bfd_elf_end_eh_frame_parsing): Delete. (_bfd_elf_parse_eh_frame): Don't test parsed_eh_frame. Test !info->relocatable in place of merge_cies. * elflink.c (bfd_elf_gc_sections, bfd_elf_discard_info): Adjust. * elf64-ppc.c (glink_eh_frame_cie): Pad to multiple of 8. (ppc64_elf_size_stubs): Likewise pad stub FDE. (ppc64_elf_build_stubs): Move code setting glink .eh_frame to.. (ppc64_elf_size_stubs): ..here and.. (ppc64_elf_finish_dynamic_sections): ..here. ld/ * emultempl/ppc64elf.em (gld${EMULATION_NAME}_after_allocation): Call bfd_elf_discard_info after generating glink .eh_frame. Delete redundant test on ppc64_elf_setup_section_lists status. --- diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 4534296..ae00acb 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,20 @@ +2014-08-22 Alan Modra + + * elf-bfd.h (struct eh_frame_hdr_info): Delete merge_cies and + parsed_eh_frames. + (_bfd_elf_begin_eh_frame_parsing): Delete. + (_bfd_elf_end_eh_frame_parsing): Delete. + * elf-eh-frame.c (_bfd_elf_begin_eh_frame_parsing): Delete. + (_bfd_elf_end_eh_frame_parsing): Delete. + (_bfd_elf_parse_eh_frame): Don't test parsed_eh_frame. Test + !info->relocatable in place of merge_cies. + * elflink.c (bfd_elf_gc_sections, bfd_elf_discard_info): Adjust. + * elf64-ppc.c (glink_eh_frame_cie): Pad to multiple of 8. + (ppc64_elf_size_stubs): Likewise pad stub FDE. + (ppc64_elf_build_stubs): Move code setting glink .eh_frame to.. + (ppc64_elf_size_stubs): ..here and.. + (ppc64_elf_finish_dynamic_sections): ..here. + 2014-08-21 Maciej W. Rozycki * elf64-ppc.h (ppc64_elf_set_toc): Fix indentation. diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h index a06c54b..63ffa85 100644 --- a/bfd/elf-bfd.h +++ b/bfd/elf-bfd.h @@ -383,10 +383,6 @@ struct eh_frame_hdr_info asection *hdr_sec; unsigned int fde_count, array_count; struct eh_frame_array_ent *array; - /* TRUE if we should try to merge CIEs between input sections. */ - bfd_boolean merge_cies; - /* TRUE if all .eh_frames have been parsd. */ - bfd_boolean parsed_eh_frames; /* TRUE if .eh_frame_hdr should contain the sorted search table. We build it if we successfully read all .eh_frame input sections and recognize them. */ @@ -1968,13 +1964,8 @@ extern bfd_boolean _bfd_elf_strtab_emit extern void _bfd_elf_strtab_finalize (struct elf_strtab_hash *); -extern void _bfd_elf_begin_eh_frame_parsing - (struct bfd_link_info *info); extern void _bfd_elf_parse_eh_frame (bfd *, struct bfd_link_info *, asection *, struct elf_reloc_cookie *); -extern void _bfd_elf_end_eh_frame_parsing - (struct bfd_link_info *info); - extern bfd_boolean _bfd_elf_discard_section_eh_frame (bfd *, struct bfd_link_info *, asection *, bfd_boolean (*) (bfd_vma, void *), struct elf_reloc_cookie *); diff --git a/bfd/elf-eh-frame.c b/bfd/elf-eh-frame.c index 0f0a563..7783b08 100644 --- a/bfd/elf-eh-frame.c +++ b/bfd/elf-eh-frame.c @@ -452,18 +452,6 @@ make_pc_relative (unsigned char encoding, unsigned int ptr_size) return encoding | DW_EH_PE_pcrel; } -/* Called before calling _bfd_elf_parse_eh_frame on every input bfd's - .eh_frame section. */ - -void -_bfd_elf_begin_eh_frame_parsing (struct bfd_link_info *info) -{ - struct eh_frame_hdr_info *hdr_info; - - hdr_info = &elf_hash_table (info)->eh_info; - hdr_info->merge_cies = !info->relocatable; -} - /* 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. */ @@ -494,8 +482,6 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, htab = elf_hash_table (info); hdr_info = &htab->eh_info; - if (hdr_info->parsed_eh_frames) - return; if (sec->size == 0 || sec->sec_info_type != SEC_INFO_TYPE_NONE) @@ -777,7 +763,8 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, buf += initial_insn_length; ENSURE_NO_RELOCS (buf); - if (hdr_info->merge_cies) + if (!info->relocatable) + /* 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; @@ -911,8 +898,9 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, elf_section_data (sec)->sec_info = sec_info; sec->sec_info_type = SEC_INFO_TYPE_EH_FRAME; - if (hdr_info->merge_cies) + if (!info->relocatable) { + /* Keep info for merging cies. */ sec_info->cies = local_cies; local_cies = NULL; } @@ -933,17 +921,6 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, #undef REQUIRE } -/* Finish a pass over all .eh_frame sections. */ - -void -_bfd_elf_end_eh_frame_parsing (struct bfd_link_info *info) -{ - struct eh_frame_hdr_info *hdr_info; - - hdr_info = &elf_hash_table (info)->eh_info; - hdr_info->parsed_eh_frames = 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. */ diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c index ca2dd4c..2b9b07e 100644 --- a/bfd/elf64-ppc.c +++ b/bfd/elf64-ppc.c @@ -11894,7 +11894,8 @@ static const unsigned char glink_eh_frame_cie[] = 65, /* RA reg. */ 1, /* Augmentation size. */ DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding. */ - DW_CFA_def_cfa, 1, 0 /* def_cfa: r1 offset 0. */ + DW_CFA_def_cfa, 1, 0, /* def_cfa: r1 offset 0. */ + 0, 0, 0, 0 }; /* Stripping output sections is normally done before dynamic section @@ -12326,7 +12327,7 @@ ppc64_elf_size_stubs (struct bfd_link_info *info) stub_sec != NULL; stub_sec = stub_sec->next) if ((stub_sec->flags & SEC_LINKER_CREATED) == 0) - size += 20; + size += 24; if (htab->glink != NULL && htab->glink->size != 0) size += 24; if (size != 0) @@ -12366,6 +12367,89 @@ ppc64_elf_size_stubs (struct bfd_link_info *info) (*htab->params->layout_sections_again) (); } + if (htab->glink_eh_frame != NULL + && htab->glink_eh_frame->size != 0) + { + bfd_vma val; + bfd_byte *p, *last_fde; + size_t last_fde_len, size, align, pad; + asection *stub_sec; + + p = bfd_zalloc (htab->glink_eh_frame->owner, htab->glink_eh_frame->size); + if (p == NULL) + return FALSE; + htab->glink_eh_frame->contents = p; + last_fde = p; + + memcpy (p, glink_eh_frame_cie, sizeof (glink_eh_frame_cie)); + /* CIE length (rewrite in case little-endian). */ + last_fde_len = sizeof (glink_eh_frame_cie) - 4; + bfd_put_32 (htab->elf.dynobj, last_fde_len, p); + p += sizeof (glink_eh_frame_cie); + + for (stub_sec = htab->params->stub_bfd->sections; + stub_sec != NULL; + stub_sec = stub_sec->next) + if ((stub_sec->flags & SEC_LINKER_CREATED) == 0) + { + last_fde = p; + last_fde_len = 20; + /* FDE length. */ + bfd_put_32 (htab->elf.dynobj, 20, p); + p += 4; + /* CIE pointer. */ + val = p - htab->glink_eh_frame->contents; + bfd_put_32 (htab->elf.dynobj, val, p); + p += 4; + /* Offset to stub section, written later. */ + p += 4; + /* stub section size. */ + bfd_put_32 (htab->elf.dynobj, stub_sec->size, p); + p += 4; + /* Augmentation. */ + p += 1; + /* Pad. */ + p += 7; + } + if (htab->glink != NULL && htab->glink->size != 0) + { + last_fde = p; + last_fde_len = 20; + /* FDE length. */ + bfd_put_32 (htab->elf.dynobj, 20, p); + p += 4; + /* CIE pointer. */ + val = p - htab->glink_eh_frame->contents; + bfd_put_32 (htab->elf.dynobj, val, p); + p += 4; + /* Offset to .glink, written later. */ + p += 4; + /* .glink size. */ + bfd_put_32 (htab->elf.dynobj, htab->glink->size - 8, p); + p += 4; + /* Augmentation. */ + p += 1; + + *p++ = DW_CFA_advance_loc + 1; + *p++ = DW_CFA_register; + *p++ = 65; + *p++ = 12; + *p++ = DW_CFA_advance_loc + 4; + *p++ = DW_CFA_restore_extended; + *p++ = 65; + } + /* Subsume any padding into the last FDE if user .eh_frame + sections are aligned more than glink_eh_frame. Otherwise any + zero padding will be seen as a terminator. */ + size = p - htab->glink_eh_frame->contents; + align = 1; + align <<= htab->glink_eh_frame->output_section->alignment_power; + align -= 1; + pad = ((size + align) & ~align) - size; + htab->glink_eh_frame->size = size + pad; + bfd_put_32 (htab->elf.dynobj, last_fde_len + pad, last_fde); + } + maybe_strip_output (info, htab->brlt); if (htab->glink_eh_frame != NULL) maybe_strip_output (info, htab->glink_eh_frame); @@ -12723,117 +12807,6 @@ ppc64_elf_build_stubs (struct bfd_link_info *info, return FALSE; } - if (htab->glink_eh_frame != NULL - && htab->glink_eh_frame->size != 0) - { - bfd_vma val; - bfd_byte *last_fde; - size_t last_fde_len, size, align, pad; - - p = bfd_zalloc (htab->glink_eh_frame->owner, htab->glink_eh_frame->size); - if (p == NULL) - return FALSE; - htab->glink_eh_frame->contents = p; - last_fde = p; - - htab->glink_eh_frame->rawsize = htab->glink_eh_frame->size; - - memcpy (p, glink_eh_frame_cie, sizeof (glink_eh_frame_cie)); - /* CIE length (rewrite in case little-endian). */ - last_fde_len = sizeof (glink_eh_frame_cie) - 4; - bfd_put_32 (htab->elf.dynobj, last_fde_len, p); - p += sizeof (glink_eh_frame_cie); - - for (stub_sec = htab->params->stub_bfd->sections; - stub_sec != NULL; - stub_sec = stub_sec->next) - if ((stub_sec->flags & SEC_LINKER_CREATED) == 0) - { - last_fde = p; - last_fde_len = 16; - /* FDE length. */ - bfd_put_32 (htab->elf.dynobj, 16, p); - p += 4; - /* CIE pointer. */ - val = p - htab->glink_eh_frame->contents; - bfd_put_32 (htab->elf.dynobj, val, p); - p += 4; - /* Offset to stub section. */ - val = (stub_sec->output_section->vma - + stub_sec->output_offset); - val -= (htab->glink_eh_frame->output_section->vma - + htab->glink_eh_frame->output_offset); - val -= p - htab->glink_eh_frame->contents; - if (val + 0x80000000 > 0xffffffff) - { - info->callbacks->einfo - (_("%P: %s offset too large for .eh_frame sdata4 encoding"), - stub_sec->name); - return FALSE; - } - bfd_put_32 (htab->elf.dynobj, val, p); - p += 4; - /* stub section size. */ - bfd_put_32 (htab->elf.dynobj, stub_sec->rawsize, p); - p += 4; - /* Augmentation. */ - p += 1; - /* Pad. */ - p += 3; - } - if (htab->glink != NULL && htab->glink->size != 0) - { - last_fde = p; - last_fde_len = 20; - /* FDE length. */ - bfd_put_32 (htab->elf.dynobj, 20, p); - p += 4; - /* CIE pointer. */ - val = p - htab->glink_eh_frame->contents; - bfd_put_32 (htab->elf.dynobj, val, p); - p += 4; - /* Offset to .glink. */ - val = (htab->glink->output_section->vma - + htab->glink->output_offset - + 8); - val -= (htab->glink_eh_frame->output_section->vma - + htab->glink_eh_frame->output_offset); - val -= p - htab->glink_eh_frame->contents; - if (val + 0x80000000 > 0xffffffff) - { - info->callbacks->einfo - (_("%P: %s offset too large for .eh_frame sdata4 encoding"), - htab->glink->name); - return FALSE; - } - bfd_put_32 (htab->elf.dynobj, val, p); - p += 4; - /* .glink size. */ - bfd_put_32 (htab->elf.dynobj, htab->glink->size - 8, p); - p += 4; - /* Augmentation. */ - p += 1; - - *p++ = DW_CFA_advance_loc + 1; - *p++ = DW_CFA_register; - *p++ = 65; - *p++ = 12; - *p++ = DW_CFA_advance_loc + 4; - *p++ = DW_CFA_restore_extended; - *p++ = 65; - } - /* Subsume any padding into the last FDE if user .eh_frame - sections are aligned more than glink_eh_frame. Otherwise any - zero padding will be seen as a terminator. */ - size = p - htab->glink_eh_frame->contents; - align = 1; - align <<= htab->glink_eh_frame->output_section->alignment_power; - align -= 1; - pad = ((size + align) & ~align) - size; - htab->glink_eh_frame->size = size + pad; - bfd_put_32 (htab->elf.dynobj, last_fde_len + pad, last_fde); - } - /* Build the stubs as directed by the stub hash table. */ bfd_hash_traverse (&htab->stub_hash_table, ppc_build_one_stub, info); @@ -12859,6 +12832,9 @@ ppc64_elf_build_stubs (struct bfd_link_info *info, break; } + /* Note that the glink_eh_frame check here is not only testing that + the generated size matched the calculated size but also that + bfd_elf_discard_info didn't make any changes to the section. */ if (stub_sec != NULL || (htab->glink_eh_frame != NULL && htab->glink_eh_frame->rawsize != htab->glink_eh_frame->size)) @@ -15126,13 +15102,81 @@ ppc64_elf_finish_dynamic_sections (bfd *output_bfd, NULL)) return FALSE; - if (htab->glink_eh_frame != NULL - && htab->glink_eh_frame->sec_info_type == SEC_INFO_TYPE_EH_FRAME - && !_bfd_elf_write_section_eh_frame (output_bfd, info, - htab->glink_eh_frame, - htab->glink_eh_frame->contents)) - return FALSE; + && htab->glink_eh_frame->size != 0) + { + bfd_vma val; + bfd_byte *p; + asection *stub_sec; + + p = htab->glink_eh_frame->contents + sizeof (glink_eh_frame_cie); + for (stub_sec = htab->params->stub_bfd->sections; + stub_sec != NULL; + stub_sec = stub_sec->next) + if ((stub_sec->flags & SEC_LINKER_CREATED) == 0) + { + /* FDE length. */ + p += 4; + /* CIE pointer. */ + p += 4; + /* Offset to stub section. */ + val = (stub_sec->output_section->vma + + stub_sec->output_offset); + val -= (htab->glink_eh_frame->output_section->vma + + htab->glink_eh_frame->output_offset + + (p - htab->glink_eh_frame->contents)); + if (val + 0x80000000 > 0xffffffff) + { + info->callbacks->einfo + (_("%P: %s offset too large for .eh_frame sdata4 encoding"), + stub_sec->name); + return FALSE; + } + bfd_put_32 (dynobj, val, p); + p += 4; + /* stub section size. */ + p += 4; + /* Augmentation. */ + p += 1; + /* Pad. */ + p += 7; + } + if (htab->glink != NULL && htab->glink->size != 0) + { + /* FDE length. */ + p += 4; + /* CIE pointer. */ + p += 4; + /* Offset to .glink. */ + val = (htab->glink->output_section->vma + + htab->glink->output_offset + + 8); + val -= (htab->glink_eh_frame->output_section->vma + + htab->glink_eh_frame->output_offset + + (p - htab->glink_eh_frame->contents)); + if (val + 0x80000000 > 0xffffffff) + { + info->callbacks->einfo + (_("%P: %s offset too large for .eh_frame sdata4 encoding"), + htab->glink->name); + return FALSE; + } + bfd_put_32 (dynobj, val, p); + p += 4; + /* .glink size. */ + p += 4; + /* Augmentation. */ + p += 1; + /* Ops. */ + p += 7; + } + + if (htab->glink_eh_frame->sec_info_type == SEC_INFO_TYPE_EH_FRAME + && !_bfd_elf_write_section_eh_frame (output_bfd, info, + htab->glink_eh_frame, + htab->glink_eh_frame->contents)) + return FALSE; + } /* We need to handle writing out multiple GOT sections ourselves, since we didn't add them to DYNOBJ. We know dynobj is the first diff --git a/bfd/elflink.c b/bfd/elflink.c index c80ee82..658e584 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -12154,6 +12154,7 @@ bfd_elf_gc_sections (bfd *abfd, struct bfd_link_info *info) bfd *sub; elf_gc_mark_hook_fn gc_mark_hook; const struct elf_backend_data *bed = get_elf_backend_data (abfd); + struct elf_link_hash_table *htab; if (!bed->can_gc_sections || !is_elf_hash_table (info->hash)) @@ -12163,10 +12164,10 @@ bfd_elf_gc_sections (bfd *abfd, struct bfd_link_info *info) } bed->gc_keep (info); + htab = elf_hash_table (info); /* Try to parse each bfd's .eh_frame section. Point elf_eh_frame_section at the .eh_frame section if we can mark the FDEs individually. */ - _bfd_elf_begin_eh_frame_parsing (info); for (sub = info->input_bfds; sub != NULL; sub = sub->link.next) { asection *sec; @@ -12183,27 +12184,20 @@ bfd_elf_gc_sections (bfd *abfd, struct bfd_link_info *info) sec = bfd_get_next_section_by_name (sec); } } - _bfd_elf_end_eh_frame_parsing (info); /* Apply transitive closure to the vtable entry usage info. */ - elf_link_hash_traverse (elf_hash_table (info), - elf_gc_propagate_vtable_entries_used, - &ok); + elf_link_hash_traverse (htab, elf_gc_propagate_vtable_entries_used, &ok); if (!ok) return FALSE; /* Kill the vtable relocations that were not used. */ - elf_link_hash_traverse (elf_hash_table (info), - elf_gc_smash_unused_vtentry_relocs, - &ok); + elf_link_hash_traverse (htab, elf_gc_smash_unused_vtentry_relocs, &ok); if (!ok) return FALSE; /* Mark dynamically referenced symbols. */ - if (elf_hash_table (info)->dynamic_sections_created) - elf_link_hash_traverse (elf_hash_table (info), - bed->gc_mark_dynamic_ref, - info); + if (htab->dynamic_sections_created) + elf_link_hash_traverse (htab, bed->gc_mark_dynamic_ref, info); /* Grovel through relocs to find out who stays ... */ gc_mark_hook = bed->gc_mark_hook; @@ -12682,7 +12676,6 @@ bfd_elf_discard_info (bfd *output_bfd, struct bfd_link_info *info) { asection *i; - _bfd_elf_begin_eh_frame_parsing (info); for (i = o->map_head.s; i != NULL; i = i->map_head.s) { if (i->size == 0) @@ -12703,7 +12696,6 @@ bfd_elf_discard_info (bfd *output_bfd, struct bfd_link_info *info) fini_reloc_cookie_for_section (&cookie, i); } - _bfd_elf_end_eh_frame_parsing (info); } for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next) diff --git a/ld/ChangeLog b/ld/ChangeLog index 54c2755..d065c3a 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,9 @@ +2014-08-22 Alan Modra + + * emultempl/ppc64elf.em (gld${EMULATION_NAME}_after_allocation): Call + bfd_elf_discard_info after generating glink .eh_frame. Delete + redundant test on ppc64_elf_setup_section_lists status. + 2014-08-20 Maciej W. Rozycki * emultempl/armelf.em (OPTION_STUBGROUP_SIZE): Fix formatting. diff --git a/ld/emultempl/ppc64elf.em b/ld/emultempl/ppc64elf.em index 3e316af..914fc52 100644 --- a/ld/emultempl/ppc64elf.em +++ b/ld/emultempl/ppc64elf.em @@ -460,19 +460,6 @@ gld${EMULATION_NAME}_after_allocation (void) { int ret; - /* bfd_elf_discard_info just plays with data and debugging sections, - ie. doesn't affect code size, so we can delay resizing the - sections. It's likely we'll resize everything in the process of - adding stubs. */ - ret = bfd_elf_discard_info (link_info.output_bfd, &link_info); - if (ret < 0) - { - einfo ("%X%P: .eh_frame/.stab edit: %E\n"); - return; - } - else if (ret > 0) - need_laying_out = 1; - /* If generating a relocatable output file, then we don't have any stubs. */ if (stub_file != NULL && !link_info.relocatable) @@ -480,7 +467,7 @@ gld${EMULATION_NAME}_after_allocation (void) ret = ppc64_elf_setup_section_lists (&link_info); if (ret < 0) einfo ("%X%P: can not size stub section: %E\n"); - else if (ret > 0) + else { ppc64_elf_start_multitoc_partition (&link_info); @@ -510,6 +497,19 @@ gld${EMULATION_NAME}_after_allocation (void) } } + /* We can't parse and merge .eh_frame until the glink .eh_frame has + been generated. Otherwise the glink .eh_frame CIE won't be + merged with other CIEs, and worse, the glink .eh_frame FDEs won't + be listed in .eh_frame_hdr. */ + ret = bfd_elf_discard_info (link_info.output_bfd, &link_info); + if (ret < 0) + { + einfo ("%X%P: .eh_frame/.stab edit: %E\n"); + return; + } + else if (ret > 0) + need_laying_out = 1; + if (need_laying_out != -1) { gld${EMULATION_NAME}_map_segments (need_laying_out);