1/* ELF core file support for BFD. 2 Copyright 1995, 1996, 1997, 1998, 2000, 2001, 2002, 2003 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 21char* 22elf_core_file_failing_command (bfd *abfd) 23{ 24 return elf_tdata (abfd)->core_command; 25} 26 27int 28elf_core_file_failing_signal (bfd *abfd) 29{ 30 return elf_tdata (abfd)->core_signal; 31} 32 33bfd_boolean 34elf_core_file_matches_executable_p (bfd *core_bfd, bfd *exec_bfd) 35{ 36 char* corename; 37 38 /* xvecs must match if both are ELF files for the same target. */ 39 40 if (core_bfd->xvec != exec_bfd->xvec) 41 { 42 bfd_set_error (bfd_error_system_call); 43 return FALSE; 44 } 45 46 /* See if the name in the corefile matches the executable name. */ 47 corename = elf_tdata (core_bfd)->core_program; 48 if (corename != NULL) 49 { 50 const char* execname = strrchr (exec_bfd->filename, '/'); 51 52 execname = execname ? execname + 1 : exec_bfd->filename; 53 54 if (strcmp (execname, corename) != 0) 55 return FALSE; 56 } 57 58 return TRUE; 59} 60 61/* Core files are simply standard ELF formatted files that partition 62 the file using the execution view of the file (program header table) 63 rather than the linking view. In fact, there is no section header 64 table in a core file. 65 66 The process status information (including the contents of the general 67 register set) and the floating point register set are stored in a 68 segment of type PT_NOTE. We handcraft a couple of extra bfd sections 69 that allow standard bfd access to the general registers (.reg) and the 70 floating point registers (.reg2). */ 71 72const bfd_target * 73elf_core_file_p (bfd *abfd) 74{ 75 Elf_External_Ehdr x_ehdr; /* Elf file header, external form. */ 76 Elf_Internal_Ehdr *i_ehdrp; /* Elf file header, internal form. */ 77 Elf_Internal_Phdr *i_phdrp; /* Elf program header, internal form. */ 78 unsigned int phindex; 79 const struct elf_backend_data *ebd; 80 struct bfd_preserve preserve; 81 bfd_size_type amt; 82 83 preserve.marker = NULL; 84 85 /* Read in the ELF header in external format. */ 86 if (bfd_bread (&x_ehdr, sizeof (x_ehdr), abfd) != sizeof (x_ehdr)) 87 { 88 if (bfd_get_error () != bfd_error_system_call) 89 goto wrong; 90 else 91 goto fail; 92 } 93 94 /* Check the magic number. */ 95 if (! elf_file_p (&x_ehdr)) 96 goto wrong; 97 98 /* FIXME: Check EI_VERSION here ! */ 99 100 /* Check the address size ("class"). */ 101 if (x_ehdr.e_ident[EI_CLASS] != ELFCLASS) 102 goto wrong; 103 104 /* Check the byteorder. */ 105 switch (x_ehdr.e_ident[EI_DATA]) 106 { 107 case ELFDATA2MSB: /* Big-endian. */ 108 if (! bfd_big_endian (abfd)) 109 goto wrong; 110 break; 111 case ELFDATA2LSB: /* Little-endian. */ 112 if (! bfd_little_endian (abfd)) 113 goto wrong; 114 break; 115 default: 116 goto wrong; 117 } 118 119 if (!bfd_preserve_save (abfd, &preserve)) 120 goto fail; 121 122 /* Give abfd an elf_obj_tdata. */ 123 if (! (*abfd->xvec->_bfd_set_format[bfd_core]) (abfd)) 124 goto fail; 125 preserve.marker = elf_tdata (abfd); 126 127 /* Swap in the rest of the header, now that we have the byte order. */ 128 i_ehdrp = elf_elfheader (abfd); 129 elf_swap_ehdr_in (abfd, &x_ehdr, i_ehdrp); 130 131#if DEBUG & 1 132 elf_debug_file (i_ehdrp); 133#endif 134 135 ebd = get_elf_backend_data (abfd); 136 137 /* Check that the ELF e_machine field matches what this particular 138 BFD format expects. */ 139 140 if (ebd->elf_machine_code != i_ehdrp->e_machine 141 && (ebd->elf_machine_alt1 == 0 142 || i_ehdrp->e_machine != ebd->elf_machine_alt1) 143 && (ebd->elf_machine_alt2 == 0 144 || i_ehdrp->e_machine != ebd->elf_machine_alt2)) 145 { 146 const bfd_target * const *target_ptr; 147 148 if (ebd->elf_machine_code != EM_NONE) 149 goto wrong; 150 151 /* This is the generic ELF target. Let it match any ELF target 152 for which we do not have a specific backend. */ 153 154 for (target_ptr = bfd_target_vector; *target_ptr != NULL; target_ptr++) 155 { 156 const struct elf_backend_data *back; 157 158 if ((*target_ptr)->flavour != bfd_target_elf_flavour) 159 continue; 160 back = (const struct elf_backend_data *) (*target_ptr)->backend_data; 161 if (back->elf_machine_code == i_ehdrp->e_machine 162 || (back->elf_machine_alt1 != 0 163 && i_ehdrp->e_machine == back->elf_machine_alt1) 164 || (back->elf_machine_alt2 != 0 165 && i_ehdrp->e_machine == back->elf_machine_alt2)) 166 { 167 /* target_ptr is an ELF backend which matches this 168 object file, so reject the generic ELF target. */ 169 goto wrong; 170 } 171 } 172 } 173 174 /* If there is no program header, or the type is not a core file, then 175 we are hosed. */ 176 if (i_ehdrp->e_phoff == 0 || i_ehdrp->e_type != ET_CORE) 177 goto wrong; 178 179 /* Does BFD's idea of the phdr size match the size 180 recorded in the file? */ 181 if (i_ehdrp->e_phentsize != sizeof (Elf_External_Phdr)) 182 goto wrong; 183 184 /* Move to the start of the program headers. */ 185 if (bfd_seek (abfd, (file_ptr) i_ehdrp->e_phoff, SEEK_SET) != 0) 186 goto wrong; 187 188 /* Allocate space for the program headers. */ 189 amt = sizeof (*i_phdrp) * i_ehdrp->e_phnum; 190 i_phdrp = bfd_alloc (abfd, amt); 191 if (!i_phdrp) 192 goto fail; 193 194 elf_tdata (abfd)->phdr = i_phdrp; 195 196 /* Read and convert to internal form. */ 197 for (phindex = 0; phindex < i_ehdrp->e_phnum; ++phindex) 198 { 199 Elf_External_Phdr x_phdr; 200 201 if (bfd_bread (&x_phdr, sizeof (x_phdr), abfd) != sizeof (x_phdr)) 202 goto fail; 203 204 elf_swap_phdr_in (abfd, &x_phdr, i_phdrp + phindex); 205 } 206 207 /* Set the machine architecture. Do this before processing the 208 program headers since we need to know the architecture type 209 when processing the notes of some systems' core files. */ 210 if (! bfd_default_set_arch_mach (abfd, ebd->arch, 0)) 211 { 212 /* It's OK if this fails for the generic target. */ 213 if (ebd->elf_machine_code != EM_NONE) 214 goto fail; 215 } 216 217 /* Process each program header. */ 218 for (phindex = 0; phindex < i_ehdrp->e_phnum; ++phindex) 219 if (! bfd_section_from_phdr (abfd, i_phdrp + phindex, (int) phindex)) 220 goto fail; 221 222 /* Save the entry point from the ELF header. */ 223 bfd_get_start_address (abfd) = i_ehdrp->e_entry; 224 225 /* Let the backend double check the format and override global 226 information. */ 227 if (ebd->elf_backend_object_p 228 && (! (*ebd->elf_backend_object_p) (abfd))) 229 goto wrong; 230 231 bfd_preserve_finish (abfd, &preserve); 232 return abfd->xvec; 233 234wrong: 235 /* There is way too much undoing of half-known state here. The caller, 236 bfd_check_format_matches, really shouldn't iterate on live bfd's to 237 check match/no-match like it does. We have to rely on that a call to 238 bfd_default_set_arch_mach with the previously known mach, undoes what 239 was done by the first bfd_default_set_arch_mach (with mach 0) here. 240 For this to work, only elf-data and the mach may be changed by the 241 target-specific elf_backend_object_p function. Note that saving the 242 whole bfd here and restoring it would be even worse; the first thing 243 you notice is that the cached bfd file position gets out of sync. */ 244 bfd_set_error (bfd_error_wrong_format); 245 246fail: 247 if (preserve.marker != NULL) 248 bfd_preserve_restore (abfd, &preserve); 249 return NULL; 250} 251