From ff59fc360e31b2d4b84e810753f128035e7c9e4a Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Mon, 9 Jul 2007 21:23:43 +0000 Subject: [PATCH] 2007-07-09 Roland McGrath * elf-bfd.h (struct elf_obj_tdata): Add members emit_note_gnu_build_id and note_gnu_build_id_sec. * elf.c (_bfd_id_note_section_size): New global function. (read_hex, _bfd_elf_write_build_id_section): New static functions. (_bfd_elf_write_object_contents): Call _bfd_elf_write_build_id_section if emit_note_gnu_build_id is set. * Makefile.am (elf.lo): Update dependencies. --- bfd/Makefile.am | 3 +- bfd/elf.c | 156 +++++++++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 157 insertions(+), 2 deletions(-) diff --git a/bfd/Makefile.am b/bfd/Makefile.am index 48919af..508c180 100644 --- a/bfd/Makefile.am +++ b/bfd/Makefile.am @@ -1298,7 +1298,8 @@ efi-app-ia32.lo: efi-app-ia32.c $(INCDIR)/filenames.h \ peicode.h libpei.h elf.lo: elf.c $(INCDIR)/filenames.h $(INCDIR)/bfdlink.h \ $(INCDIR)/hashtab.h elf-bfd.h $(INCDIR)/elf/common.h \ - $(INCDIR)/elf/internal.h $(INCDIR)/elf/external.h $(INCDIR)/libiberty.h + $(INCDIR)/elf/internal.h $(INCDIR)/elf/external.h $(INCDIR)/libiberty.h \ + $(INCDIR)/safe-ctype.h $(INCDIR)/md5.h elf32-am33lin.lo: elf32-am33lin.c $(INCDIR)/filenames.h \ elf-bfd.h $(INCDIR)/elf/common.h $(INCDIR)/elf/internal.h \ $(INCDIR)/elf/external.h $(INCDIR)/bfdlink.h $(INCDIR)/elf/mn10300.h \ diff --git a/bfd/elf.c b/bfd/elf.c index 62c024d..2d08a97 100644 --- a/bfd/elf.c +++ b/bfd/elf.c @@ -42,6 +42,8 @@ SECTION #define ARCH_SIZE 0 #include "elf-bfd.h" #include "libiberty.h" +#include "safe-ctype.h" +#include "md5.h" static int elf_sort_sections (const void *, const void *); static bfd_boolean assign_file_positions_except_relocs (bfd *, struct bfd_link_info *); @@ -5073,6 +5075,149 @@ _bfd_elf_assign_file_positions_for_relocs (bfd *abfd) elf_tdata (abfd)->next_file_pos = off; } +bfd_size_type +_bfd_id_note_section_size (bfd *abfd, struct bfd_link_info *link_info) +{ + const char *style = link_info->emit_note_gnu_build_id; + bfd_size_type size; + + abfd = abfd; + + size = offsetof (Elf_External_Note, name[sizeof "GNU"]); + size = BFD_ALIGN (size, 4); + + if (!strcmp (style, "md5") || !strcmp (style, "uuid")) + size += 128 / 8; +#if 0 /* libiberty has md5 but not sha1 */ + else if (!strcmp (style, "sha1")) + size += 160 / 8; +#endif + else if (!strncmp (style, "0x", 2)) + { + /* ID is in string form (hex). Convert to bits. */ + const char *id = style + 2; + do + { + if (ISXDIGIT (id[0]) && ISXDIGIT (id[1])) + { + ++size; + id += 2; + } + else if (*id == '-' || *id == ':') + ++id; + else + { + size = 0; + break; + } + } while (*id != '\0'); + } + else + size = 0; + + return size; +} + +static unsigned char +read_hex (const char xdigit) +{ + if (ISDIGIT (xdigit)) + return xdigit - '0'; + if (ISUPPER (xdigit)) + return xdigit - 'A' + 0xa; + if (ISLOWER (xdigit)) + return xdigit - 'a' + 0xa; + abort (); + return 0; +} + +static bfd_boolean +_bfd_elf_write_build_id_section (bfd *abfd, const char *style) +{ + const struct elf_backend_data *bed = get_elf_backend_data (abfd); + asection *asec; + Elf_Internal_Shdr *i_shdr; + unsigned char *contents, *id_bits; + bfd_size_type size; + Elf_External_Note *e_note; + + asec = elf_tdata (abfd)->note_gnu_build_id_sec; + if (asec->output_section == NULL) + { + _bfd_error_handler (_(".note.gnu.build-id section missing")); + return FALSE; + } + i_shdr = &elf_section_data (asec->output_section)->this_hdr; + + if (i_shdr->contents == NULL) + { + BFD_ASSERT (asec->output_offset == 0); + i_shdr->contents = bfd_zalloc (abfd, i_shdr->sh_size); + if (i_shdr->contents == NULL) + return FALSE; + } + contents = i_shdr->contents + asec->output_offset; + + e_note = (void *) contents; + size = offsetof (Elf_External_Note, name[sizeof "GNU"]); + size = BFD_ALIGN (size, 4); + id_bits = contents + size; + size = asec->size - size; + + bfd_h_put_32 (abfd, sizeof "GNU", &e_note->namesz); + bfd_h_put_32 (abfd, size, &e_note->descsz); + bfd_h_put_32 (abfd, NT_GNU_BUILD_ID, &e_note->type); + memcpy (e_note->name, "GNU", sizeof "GNU"); + + if (!strcmp (style, "md5")) + { + struct md5_ctx ctx; + md5_init_ctx (&ctx); + if (bed->s->checksum_contents (abfd, + (void (*) (const void *, size_t, void *)) + &md5_process_bytes, + &ctx)) + md5_finish_ctx (&ctx, id_bits); + else + return FALSE; + } + else if (!strcmp (style, "uuid")) + { + int n; + int fd = open ("/dev/urandom", O_RDONLY); + if (fd < 0) + return FALSE; + n = read (fd, id_bits, size); + close (fd); + if (n < (int) size) + return FALSE; + } + else if (!strncmp (style, "0x", 2)) + { + /* ID is in string form (hex). Convert to bits. */ + const char *id = style + 2; + size_t n = 0; + do + { + if (ISXDIGIT (id[0]) && ISXDIGIT (id[1])) + { + id_bits[n] = read_hex (*id++) << 4; + id_bits[n++] |= read_hex (*id++); + } + else if (*id == '-' || *id == ':') + ++id; + else + abort (); /* Should have been validated earlier. */ + } while (*id != '\0'); + } + else + abort (); /* Should have been validated earlier. */ + + size = i_shdr->sh_size; + return (bfd_seek (abfd, i_shdr->sh_offset, SEEK_SET) == 0 + && bfd_bwrite (i_shdr->contents, size, abfd) == size); +} + bfd_boolean _bfd_elf_write_object_contents (bfd *abfd) { @@ -5081,6 +5226,7 @@ _bfd_elf_write_object_contents (bfd *abfd) Elf_Internal_Shdr **i_shdrp; bfd_boolean failed; unsigned int count, num_sec; + char *id_style; if (! abfd->output_has_begun && ! _bfd_elf_compute_section_file_positions (abfd, NULL)) @@ -5124,7 +5270,15 @@ _bfd_elf_write_object_contents (bfd *abfd) (*bed->elf_backend_final_write_processing) (abfd, elf_tdata (abfd)->linker); - return bed->s->write_shdrs_and_ehdr (abfd); + if (!bed->s->write_shdrs_and_ehdr (abfd)) + return FALSE; + + /* This is last since write_shdrs_and_ehdr can touch i_shdrp[0]. */ + id_style = elf_tdata (abfd)->emit_note_gnu_build_id; + if (id_style && !_bfd_elf_write_build_id_section (abfd, id_style)) + return FALSE; + + return TRUE; } bfd_boolean -- 2.7.4