Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame^] | 1 | /* Create descriptor from ELF handle for processing file. |
| 2 | Copyright (C) 2000, 2002 Red Hat, Inc. |
| 3 | Written by Ulrich Drepper <drepper@redhat.com>, 2000. |
| 4 | |
| 5 | This program is Open Source software; you can redistribute it and/or |
| 6 | modify it under the terms of the Open Software License version 1.0 as |
| 7 | published by the Open Source Initiative. |
| 8 | |
| 9 | You should have received a copy of the Open Software License along |
| 10 | with this program; if not, you may obtain a copy of the Open Software |
| 11 | License version 1.0 from http://www.opensource.org/licenses/osl.php or |
| 12 | by writing the Open Source Initiative c/o Lawrence Rosen, Esq., |
| 13 | 3001 King Ranch Road, Ukiah, CA 95482. */ |
| 14 | |
| 15 | #ifdef HAVE_CONFIG_H |
| 16 | # include <config.h> |
| 17 | #endif |
| 18 | |
| 19 | #include <assert.h> |
| 20 | #include <endian.h> |
| 21 | #include <gelf.h> |
| 22 | #include <stdlib.h> |
| 23 | #include <string.h> |
| 24 | |
| 25 | #include <libdwarfP.h> |
| 26 | |
| 27 | |
| 28 | /* Section names. */ |
| 29 | static const char dwarf_scnnames[IDX_last][17] = |
| 30 | { |
| 31 | [IDX_debug_info] = ".debug_info", |
| 32 | [IDX_debug_abbrev] = ".debug_abbrev", |
| 33 | [IDX_debug_aranges] = ".debug_aranges", |
| 34 | [IDX_debug_line] = ".debug_line", |
| 35 | [IDX_debug_frame] = ".debug_frame", |
| 36 | [IDX_eh_frame] = ".eh_frame", |
| 37 | [IDX_debug_loc] = ".debug_loc", |
| 38 | [IDX_debug_pubnames] = ".debug_pubnames", |
| 39 | [IDX_debug_str] = ".debug_str", |
| 40 | [IDX_debug_funcnames] = ".debug_funcnames", |
| 41 | [IDX_debug_typenames] = ".debug_typenames", |
| 42 | [IDX_debug_varnames] = ".debug_varnames", |
| 43 | [IDX_debug_weaknames] = ".debug_weaknames", |
| 44 | [IDX_debug_macinfo] = ".debug_macinfo" |
| 45 | }; |
| 46 | #define ndwarf_scnnames (sizeof (dwarf_scnnames) / sizeof (dwarf_scnnames[0])) |
| 47 | |
| 48 | |
| 49 | int |
| 50 | dwarf_elf_init (elf, access, errhand, errarg, dbg, error) |
| 51 | Elf *elf; |
| 52 | Dwarf_Unsigned access; |
| 53 | Dwarf_Handler errhand; |
| 54 | Dwarf_Ptr errarg; |
| 55 | Dwarf_Debug *dbg; |
| 56 | Dwarf_Error *error; |
| 57 | { |
| 58 | int result = DW_DLV_ERROR; |
| 59 | Dwarf_Debug newdbg; |
| 60 | GElf_Ehdr ehdr_mem; |
| 61 | GElf_Ehdr *ehdr; |
| 62 | Elf_Scn *scn; |
| 63 | |
| 64 | /* XXX For now nothing but read-only support is available. */ |
| 65 | if (access != DW_DLC_READ) |
| 66 | abort (); |
| 67 | |
| 68 | /* Get the ELF header of the file. We need various pieces of |
| 69 | information from it. */ |
| 70 | ehdr = gelf_getehdr (elf, &ehdr_mem); |
| 71 | if (ehdr == NULL) |
| 72 | { |
| 73 | struct Dwarf_Debug_s tmpdbg; |
| 74 | |
| 75 | tmpdbg.dbg_errhand = errhand; |
| 76 | tmpdbg.dbg_errarg = errarg; |
| 77 | |
| 78 | if (elf_kind (elf) != ELF_K_ELF) |
| 79 | __libdwarf_error (&tmpdbg, error, DW_E_NOELF); |
| 80 | else |
| 81 | __libdwarf_error (&tmpdbg, error, DW_E_GETEHDR_ERROR); |
| 82 | |
| 83 | return result; |
| 84 | } |
| 85 | |
| 86 | /* Allocate and fill the result data structure. */ |
| 87 | newdbg = (Dwarf_Debug) calloc (1, sizeof (struct Dwarf_Debug_s)); |
| 88 | if (newdbg == NULL) |
| 89 | { |
| 90 | struct Dwarf_Debug_s tmpdbg; |
| 91 | |
| 92 | tmpdbg.dbg_errhand = errhand; |
| 93 | tmpdbg.dbg_errarg = errarg; |
| 94 | |
| 95 | __libdwarf_error (&tmpdbg, error, DW_E_NOMEM); |
| 96 | } |
| 97 | else |
| 98 | { |
| 99 | /* We have been able to allocate the memory for the debug handle. */ |
| 100 | newdbg->dbg_errhand = errhand; |
| 101 | newdbg->dbg_errarg = errarg; |
| 102 | newdbg->elf = elf; |
| 103 | if ((BYTE_ORDER == LITTLE_ENDIAN |
| 104 | && ehdr->e_ident[EI_DATA] == ELFDATA2MSB) |
| 105 | || (BYTE_ORDER == BIG_ENDIAN |
| 106 | && ehdr->e_ident[EI_DATA] == ELFDATA2LSB)) |
| 107 | newdbg->other_byte_order = 1; |
| 108 | newdbg->access = access; |
| 109 | #ifdef DWARF_DEBUG |
| 110 | newdbg->memtag = DW_DLA_DEBUG; |
| 111 | #endif |
| 112 | |
| 113 | /* All done. */ |
| 114 | *dbg = newdbg; |
| 115 | result = DW_DLV_OK; |
| 116 | |
| 117 | /* Find out whether the file actually has the necessary DWARF |
| 118 | sections. */ |
| 119 | scn = NULL; |
| 120 | while ((scn = elf_nextscn (elf, scn)) != NULL) |
| 121 | { |
| 122 | GElf_Shdr shdr_mem; |
| 123 | GElf_Shdr *shdr; |
| 124 | const char *scnname; |
| 125 | size_t cnt; |
| 126 | Elf_Data *data; |
| 127 | |
| 128 | /* Get the section header data. */ |
| 129 | shdr = gelf_getshdr (scn, &shdr_mem); |
| 130 | if (shdr == NULL) |
| 131 | /* This should never happen. If it does something is |
| 132 | wrong in the libelf library. */ |
| 133 | abort (); |
| 134 | |
| 135 | /* We recognize the DWARF section by their names. This is |
| 136 | not very safe and stable but the best we can do. */ |
| 137 | scnname = elf_strptr (elf, ehdr->e_shstrndx, shdr->sh_name); |
| 138 | if (scnname == NULL) |
| 139 | { |
| 140 | /* The section name must be valid. Otherwise is the ELF file |
| 141 | invalid. */ |
| 142 | __libdwarf_error (newdbg, error, DW_E_INVALID_ELF); |
| 143 | break; |
| 144 | } |
| 145 | |
| 146 | /* Recognize the various sections. Most names start with |
| 147 | .debug_. */ |
| 148 | for (cnt = 0; cnt < ndwarf_scnnames; ++cnt) |
| 149 | if (strcmp (scnname, dwarf_scnnames[cnt]) == 0) |
| 150 | break; |
| 151 | |
| 152 | if (cnt < ndwarf_scnnames) |
| 153 | { |
| 154 | /* Found it. Remember where the data is. */ |
| 155 | assert (cnt < IDX_last); |
| 156 | if (unlikely (newdbg->sections[cnt].addr != NULL)) |
| 157 | { |
| 158 | /* A section appears twice. That's bad. */ |
| 159 | __libdwarf_error (newdbg, error, DW_E_INVALID_DWARF); |
| 160 | break; |
| 161 | } |
| 162 | |
| 163 | /* Get the section data. */ |
| 164 | data = elf_getdata (scn, NULL); |
| 165 | if (data != NULL && data->d_size != 0) |
| 166 | { |
| 167 | /* Yep, there is actually data available. */ |
| 168 | newdbg->sections[cnt].addr = data->d_buf; |
| 169 | newdbg->sections[cnt].size = data->d_size; |
| 170 | } |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | if (scn == NULL) |
| 175 | { |
| 176 | /* We looked at all the sections. Now determine whether all |
| 177 | the sections with debugging information we need are there. |
| 178 | |
| 179 | XXX Which sections are absolutely necessary? Add tests |
| 180 | if necessary. For now we require only .debug_info. Hopefully |
| 181 | this is correct. */ |
| 182 | if (newdbg->sections[IDX_debug_info].addr == NULL) |
| 183 | { |
| 184 | __libdwarf_error (newdbg, error, DW_E_NO_DWARF); |
| 185 | result = DW_DLV_NO_ENTRY; |
| 186 | } |
| 187 | else |
| 188 | result = DW_DLV_OK; |
| 189 | } |
| 190 | |
| 191 | if (result != DW_DLV_OK) |
| 192 | /* Something went wrong. */ |
| 193 | free (newdbg); |
| 194 | } |
| 195 | |
| 196 | return result; |
| 197 | } |