| /* Create descriptor from ELF handle for processing file. |
| Copyright (C) 2000, 2002 Red Hat, Inc. |
| Written by Ulrich Drepper <drepper@redhat.com>, 2000. |
| |
| This program is Open Source software; you can redistribute it and/or |
| modify it under the terms of the Open Software License version 1.0 as |
| published by the Open Source Initiative. |
| |
| You should have received a copy of the Open Software License along |
| with this program; if not, you may obtain a copy of the Open Software |
| License version 1.0 from http://www.opensource.org/licenses/osl.php or |
| by writing the Open Source Initiative c/o Lawrence Rosen, Esq., |
| 3001 King Ranch Road, Ukiah, CA 95482. */ |
| |
| #ifdef HAVE_CONFIG_H |
| # include <config.h> |
| #endif |
| |
| #include <assert.h> |
| #include <endian.h> |
| #include <gelf.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include <libdwarfP.h> |
| |
| |
| /* Section names. */ |
| static const char dwarf_scnnames[IDX_last][17] = |
| { |
| [IDX_debug_info] = ".debug_info", |
| [IDX_debug_abbrev] = ".debug_abbrev", |
| [IDX_debug_aranges] = ".debug_aranges", |
| [IDX_debug_line] = ".debug_line", |
| [IDX_debug_frame] = ".debug_frame", |
| [IDX_eh_frame] = ".eh_frame", |
| [IDX_debug_loc] = ".debug_loc", |
| [IDX_debug_pubnames] = ".debug_pubnames", |
| [IDX_debug_str] = ".debug_str", |
| [IDX_debug_funcnames] = ".debug_funcnames", |
| [IDX_debug_typenames] = ".debug_typenames", |
| [IDX_debug_varnames] = ".debug_varnames", |
| [IDX_debug_weaknames] = ".debug_weaknames", |
| [IDX_debug_macinfo] = ".debug_macinfo" |
| }; |
| #define ndwarf_scnnames (sizeof (dwarf_scnnames) / sizeof (dwarf_scnnames[0])) |
| |
| |
| int |
| dwarf_elf_init (elf, access, errhand, errarg, dbg, error) |
| Elf *elf; |
| Dwarf_Unsigned access; |
| Dwarf_Handler errhand; |
| Dwarf_Ptr errarg; |
| Dwarf_Debug *dbg; |
| Dwarf_Error *error; |
| { |
| int result = DW_DLV_ERROR; |
| Dwarf_Debug newdbg; |
| GElf_Ehdr ehdr_mem; |
| GElf_Ehdr *ehdr; |
| Elf_Scn *scn; |
| |
| /* XXX For now nothing but read-only support is available. */ |
| if (access != DW_DLC_READ) |
| abort (); |
| |
| /* Get the ELF header of the file. We need various pieces of |
| information from it. */ |
| ehdr = gelf_getehdr (elf, &ehdr_mem); |
| if (ehdr == NULL) |
| { |
| struct Dwarf_Debug_s tmpdbg; |
| |
| tmpdbg.dbg_errhand = errhand; |
| tmpdbg.dbg_errarg = errarg; |
| |
| if (elf_kind (elf) != ELF_K_ELF) |
| __libdwarf_error (&tmpdbg, error, DW_E_NOELF); |
| else |
| __libdwarf_error (&tmpdbg, error, DW_E_GETEHDR_ERROR); |
| |
| return result; |
| } |
| |
| /* Allocate and fill the result data structure. */ |
| newdbg = (Dwarf_Debug) calloc (1, sizeof (struct Dwarf_Debug_s)); |
| if (newdbg == NULL) |
| { |
| struct Dwarf_Debug_s tmpdbg; |
| |
| tmpdbg.dbg_errhand = errhand; |
| tmpdbg.dbg_errarg = errarg; |
| |
| __libdwarf_error (&tmpdbg, error, DW_E_NOMEM); |
| } |
| else |
| { |
| /* We have been able to allocate the memory for the debug handle. */ |
| newdbg->dbg_errhand = errhand; |
| newdbg->dbg_errarg = errarg; |
| newdbg->elf = elf; |
| if ((BYTE_ORDER == LITTLE_ENDIAN |
| && ehdr->e_ident[EI_DATA] == ELFDATA2MSB) |
| || (BYTE_ORDER == BIG_ENDIAN |
| && ehdr->e_ident[EI_DATA] == ELFDATA2LSB)) |
| newdbg->other_byte_order = 1; |
| newdbg->access = access; |
| #ifdef DWARF_DEBUG |
| newdbg->memtag = DW_DLA_DEBUG; |
| #endif |
| |
| /* All done. */ |
| *dbg = newdbg; |
| result = DW_DLV_OK; |
| |
| /* Find out whether the file actually has the necessary DWARF |
| sections. */ |
| scn = NULL; |
| while ((scn = elf_nextscn (elf, scn)) != NULL) |
| { |
| GElf_Shdr shdr_mem; |
| GElf_Shdr *shdr; |
| const char *scnname; |
| size_t cnt; |
| Elf_Data *data; |
| |
| /* Get the section header data. */ |
| shdr = gelf_getshdr (scn, &shdr_mem); |
| if (shdr == NULL) |
| /* This should never happen. If it does something is |
| wrong in the libelf library. */ |
| abort (); |
| |
| /* We recognize the DWARF section by their names. This is |
| not very safe and stable but the best we can do. */ |
| scnname = elf_strptr (elf, ehdr->e_shstrndx, shdr->sh_name); |
| if (scnname == NULL) |
| { |
| /* The section name must be valid. Otherwise is the ELF file |
| invalid. */ |
| __libdwarf_error (newdbg, error, DW_E_INVALID_ELF); |
| break; |
| } |
| |
| /* Recognize the various sections. Most names start with |
| .debug_. */ |
| for (cnt = 0; cnt < ndwarf_scnnames; ++cnt) |
| if (strcmp (scnname, dwarf_scnnames[cnt]) == 0) |
| break; |
| |
| if (cnt < ndwarf_scnnames) |
| { |
| /* Found it. Remember where the data is. */ |
| assert (cnt < IDX_last); |
| if (unlikely (newdbg->sections[cnt].addr != NULL)) |
| { |
| /* A section appears twice. That's bad. */ |
| __libdwarf_error (newdbg, error, DW_E_INVALID_DWARF); |
| break; |
| } |
| |
| /* Get the section data. */ |
| data = elf_getdata (scn, NULL); |
| if (data != NULL && data->d_size != 0) |
| { |
| /* Yep, there is actually data available. */ |
| newdbg->sections[cnt].addr = data->d_buf; |
| newdbg->sections[cnt].size = data->d_size; |
| } |
| } |
| } |
| |
| if (scn == NULL) |
| { |
| /* We looked at all the sections. Now determine whether all |
| the sections with debugging information we need are there. |
| |
| XXX Which sections are absolutely necessary? Add tests |
| if necessary. For now we require only .debug_info. Hopefully |
| this is correct. */ |
| if (newdbg->sections[IDX_debug_info].addr == NULL) |
| { |
| __libdwarf_error (newdbg, error, DW_E_NO_DWARF); |
| result = DW_DLV_NO_ENTRY; |
| } |
| else |
| result = DW_DLV_OK; |
| } |
| |
| if (result != DW_DLV_OK) |
| /* Something went wrong. */ |
| free (newdbg); |
| } |
| |
| return result; |
| } |