| 1 | /* ELF core file support for BFD. |
| 2 | Copyright 1995, 1996, 1997, 1998, 2000, 2001, 2002 |
| 3 | Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of BFD, the Binary File Descriptor library. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | char* |
| 22 | elf_core_file_failing_command (abfd) |
| 23 | bfd *abfd; |
| 24 | { |
| 25 | return elf_tdata (abfd)->core_command; |
| 26 | } |
| 27 | |
| 28 | int |
| 29 | elf_core_file_failing_signal (abfd) |
| 30 | bfd *abfd; |
| 31 | { |
| 32 | return elf_tdata (abfd)->core_signal; |
| 33 | } |
| 34 | |
| 35 | bfd_boolean |
| 36 | elf_core_file_matches_executable_p (core_bfd, exec_bfd) |
| 37 | bfd *core_bfd; |
| 38 | bfd *exec_bfd; |
| 39 | { |
| 40 | char* corename; |
| 41 | |
| 42 | /* xvecs must match if both are ELF files for the same target. */ |
| 43 | |
| 44 | if (core_bfd->xvec != exec_bfd->xvec) |
| 45 | { |
| 46 | bfd_set_error (bfd_error_system_call); |
| 47 | return FALSE; |
| 48 | } |
| 49 | |
| 50 | /* See if the name in the corefile matches the executable name. */ |
| 51 | |
| 52 | corename = elf_tdata (core_bfd)->core_program; |
| 53 | if (corename != NULL) |
| 54 | { |
| 55 | const char* execname = strrchr (exec_bfd->filename, '/'); |
| 56 | execname = execname ? execname + 1 : exec_bfd->filename; |
| 57 | |
| 58 | if (strcmp(execname, corename) != 0) |
| 59 | return FALSE; |
| 60 | } |
| 61 | |
| 62 | return TRUE; |
| 63 | } |
| 64 | |
| 65 | /* Core files are simply standard ELF formatted files that partition |
| 66 | the file using the execution view of the file (program header table) |
| 67 | rather than the linking view. In fact, there is no section header |
| 68 | table in a core file. |
| 69 | |
| 70 | The process status information (including the contents of the general |
| 71 | register set) and the floating point register set are stored in a |
| 72 | segment of type PT_NOTE. We handcraft a couple of extra bfd sections |
| 73 | that allow standard bfd access to the general registers (.reg) and the |
| 74 | floating point registers (.reg2). |
| 75 | |
| 76 | */ |
| 77 | |
| 78 | const bfd_target * |
| 79 | elf_core_file_p (abfd) |
| 80 | bfd *abfd; |
| 81 | { |
| 82 | Elf_External_Ehdr x_ehdr; /* Elf file header, external form */ |
| 83 | Elf_Internal_Ehdr *i_ehdrp; /* Elf file header, internal form */ |
| 84 | Elf_Internal_Phdr *i_phdrp; /* Elf program header, internal form */ |
| 85 | unsigned int phindex; |
| 86 | struct elf_backend_data *ebd; |
| 87 | struct bfd_preserve preserve; |
| 88 | bfd_size_type amt; |
| 89 | |
| 90 | preserve.marker = NULL; |
| 91 | |
| 92 | /* Read in the ELF header in external format. */ |
| 93 | if (bfd_bread ((PTR) &x_ehdr, (bfd_size_type) sizeof (x_ehdr), abfd) |
| 94 | != sizeof (x_ehdr)) |
| 95 | { |
| 96 | if (bfd_get_error () != bfd_error_system_call) |
| 97 | goto wrong; |
| 98 | else |
| 99 | goto fail; |
| 100 | } |
| 101 | |
| 102 | /* Check the magic number. */ |
| 103 | if (! elf_file_p (&x_ehdr)) |
| 104 | goto wrong; |
| 105 | |
| 106 | /* FIXME: Check EI_VERSION here ! */ |
| 107 | |
| 108 | /* Check the address size ("class"). */ |
| 109 | if (x_ehdr.e_ident[EI_CLASS] != ELFCLASS) |
| 110 | goto wrong; |
| 111 | |
| 112 | /* Check the byteorder. */ |
| 113 | switch (x_ehdr.e_ident[EI_DATA]) |
| 114 | { |
| 115 | case ELFDATA2MSB: /* Big-endian */ |
| 116 | if (! bfd_big_endian (abfd)) |
| 117 | goto wrong; |
| 118 | break; |
| 119 | case ELFDATA2LSB: /* Little-endian */ |
| 120 | if (! bfd_little_endian (abfd)) |
| 121 | goto wrong; |
| 122 | break; |
| 123 | default: |
| 124 | goto wrong; |
| 125 | } |
| 126 | |
| 127 | /* Give abfd an elf_obj_tdata. */ |
| 128 | amt = sizeof (struct elf_obj_tdata); |
| 129 | preserve.marker = bfd_zalloc (abfd, amt); |
| 130 | if (preserve.marker == NULL) |
| 131 | goto fail; |
| 132 | if (!bfd_preserve_save (abfd, &preserve)) |
| 133 | goto fail; |
| 134 | |
| 135 | elf_tdata (abfd) = preserve.marker; |
| 136 | |
| 137 | /* Swap in the rest of the header, now that we have the byte order. */ |
| 138 | i_ehdrp = elf_elfheader (abfd); |
| 139 | elf_swap_ehdr_in (abfd, &x_ehdr, i_ehdrp); |
| 140 | |
| 141 | #if DEBUG & 1 |
| 142 | elf_debug_file (i_ehdrp); |
| 143 | #endif |
| 144 | |
| 145 | ebd = get_elf_backend_data (abfd); |
| 146 | |
| 147 | /* Check that the ELF e_machine field matches what this particular |
| 148 | BFD format expects. */ |
| 149 | |
| 150 | if (ebd->elf_machine_code != i_ehdrp->e_machine |
| 151 | && (ebd->elf_machine_alt1 == 0 |
| 152 | || i_ehdrp->e_machine != ebd->elf_machine_alt1) |
| 153 | && (ebd->elf_machine_alt2 == 0 |
| 154 | || i_ehdrp->e_machine != ebd->elf_machine_alt2)) |
| 155 | { |
| 156 | const bfd_target * const *target_ptr; |
| 157 | |
| 158 | if (ebd->elf_machine_code != EM_NONE) |
| 159 | goto wrong; |
| 160 | |
| 161 | /* This is the generic ELF target. Let it match any ELF target |
| 162 | for which we do not have a specific backend. */ |
| 163 | |
| 164 | for (target_ptr = bfd_target_vector; *target_ptr != NULL; target_ptr++) |
| 165 | { |
| 166 | struct elf_backend_data *back; |
| 167 | |
| 168 | if ((*target_ptr)->flavour != bfd_target_elf_flavour) |
| 169 | continue; |
| 170 | back = (struct elf_backend_data *) (*target_ptr)->backend_data; |
| 171 | if (back->elf_machine_code == i_ehdrp->e_machine) |
| 172 | { |
| 173 | /* target_ptr is an ELF backend which matches this |
| 174 | object file, so reject the generic ELF target. */ |
| 175 | goto wrong; |
| 176 | } |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | /* If there is no program header, or the type is not a core file, then |
| 181 | we are hosed. */ |
| 182 | if (i_ehdrp->e_phoff == 0 || i_ehdrp->e_type != ET_CORE) |
| 183 | goto wrong; |
| 184 | |
| 185 | /* Does BFD's idea of the phdr size match the size |
| 186 | recorded in the file? */ |
| 187 | if (i_ehdrp->e_phentsize != sizeof (Elf_External_Phdr)) |
| 188 | goto wrong; |
| 189 | |
| 190 | /* Move to the start of the program headers. */ |
| 191 | if (bfd_seek (abfd, (file_ptr) i_ehdrp->e_phoff, SEEK_SET) != 0) |
| 192 | goto wrong; |
| 193 | |
| 194 | /* Allocate space for the program headers. */ |
| 195 | amt = sizeof (*i_phdrp) * i_ehdrp->e_phnum; |
| 196 | i_phdrp = (Elf_Internal_Phdr *) bfd_alloc (abfd, amt); |
| 197 | if (!i_phdrp) |
| 198 | goto fail; |
| 199 | |
| 200 | elf_tdata (abfd)->phdr = i_phdrp; |
| 201 | |
| 202 | /* Read and convert to internal form. */ |
| 203 | for (phindex = 0; phindex < i_ehdrp->e_phnum; ++phindex) |
| 204 | { |
| 205 | Elf_External_Phdr x_phdr; |
| 206 | if (bfd_bread ((PTR) &x_phdr, (bfd_size_type) sizeof (x_phdr), abfd) |
| 207 | != sizeof (x_phdr)) |
| 208 | goto fail; |
| 209 | |
| 210 | elf_swap_phdr_in (abfd, &x_phdr, i_phdrp + phindex); |
| 211 | } |
| 212 | |
| 213 | /* Set the machine architecture. Do this before processing the |
| 214 | program headers since we need to know the architecture type |
| 215 | when processing the notes of some systems' core files. */ |
| 216 | if (! bfd_default_set_arch_mach (abfd, ebd->arch, 0)) |
| 217 | { |
| 218 | /* It's OK if this fails for the generic target. */ |
| 219 | if (ebd->elf_machine_code != EM_NONE) |
| 220 | goto fail; |
| 221 | } |
| 222 | |
| 223 | /* Process each program header. */ |
| 224 | for (phindex = 0; phindex < i_ehdrp->e_phnum; ++phindex) |
| 225 | { |
| 226 | if (! bfd_section_from_phdr (abfd, i_phdrp + phindex, (int) phindex)) |
| 227 | goto fail; |
| 228 | } |
| 229 | |
| 230 | /* Save the entry point from the ELF header. */ |
| 231 | bfd_get_start_address (abfd) = i_ehdrp->e_entry; |
| 232 | |
| 233 | /* Let the backend double check the format and override global |
| 234 | information. */ |
| 235 | if (ebd->elf_backend_object_p) |
| 236 | { |
| 237 | if (! (*ebd->elf_backend_object_p) (abfd)) |
| 238 | goto wrong; |
| 239 | } |
| 240 | |
| 241 | bfd_preserve_finish (abfd, &preserve); |
| 242 | return abfd->xvec; |
| 243 | |
| 244 | wrong: |
| 245 | /* There is way too much undoing of half-known state here. The caller, |
| 246 | bfd_check_format_matches, really shouldn't iterate on live bfd's to |
| 247 | check match/no-match like it does. We have to rely on that a call to |
| 248 | bfd_default_set_arch_mach with the previously known mach, undoes what |
| 249 | was done by the first bfd_default_set_arch_mach (with mach 0) here. |
| 250 | For this to work, only elf-data and the mach may be changed by the |
| 251 | target-specific elf_backend_object_p function. Note that saving the |
| 252 | whole bfd here and restoring it would be even worse; the first thing |
| 253 | you notice is that the cached bfd file position gets out of sync. */ |
| 254 | bfd_set_error (bfd_error_wrong_format); |
| 255 | |
| 256 | fail: |
| 257 | if (preserve.marker != NULL) |
| 258 | bfd_preserve_restore (abfd, &preserve); |
| 259 | return NULL; |
| 260 | } |