/*
Copyright (C) 2000,2002,2003,2004,2005 Silicon Graphics, Inc. All Rights Reserved.
Portions Copyright (C) 2008-2010 Arxan Technologies, Inc. All Rights Reserved.
Portions Copyright (C) 2009-2017 David Anderson. All Rights Reserved.
Portions Copyright (C) 2010-2012 SN Systems Ltd. All Rights Reserved.
This program is free software; you can redistribute it and/or modify it
under the terms of version 2.1 of the GNU Lesser General Public License
as published by the Free Software Foundation.
This program is distributed in the hope that it would be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Further, this software is distributed without any warranty that it is
free of the rightful claim of any third person regarding infringement
or the like. Any license provided herein, whether implied or
otherwise, applies only to this software file. Patent licenses, if
any, provided herein do not apply to combinations of this program with
other software, or any other product whatsoever.
You should have received a copy of the GNU Lesser General Public
License along with this program; if not, write the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston MA 02110-1301,
USA.
*/
#include "config.h"
#include "dwarf_incl.h"
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <string.h>
#include <stdlib.h>
#include "dwarf_incl.h"
#include "dwarf_harmless.h"
/* For consistency, use the HAVE_LIBELF_H symbol */
#ifdef HAVE_ELF_H
#include <elf.h>
#endif
#ifdef HAVE_LIBELF_H
#include <libelf.h>
#else
#ifdef HAVE_LIBELF_LIBELF_H
#include <libelf/libelf.h>
#endif
#endif
#ifdef HAVE_ZLIB
#include "zlib.h"
#endif
#ifndef ELFCOMPRESS_ZLIB
#define ELFCOMPRESS_ZLIB 1
#endif
/* If your mingw elf.h is missing SHT_RELA and you do not
need SHT_RELA support
this define should work for you.
It is the elf value, hopefully it will
not cause trouble. If does not work, try -1
or something else
and let us know what works. */
#ifndef SHT_RELA
#define SHT_RELA 4
#endif
/* For COMDAT GROUPS. Guarantees we can compile. We hope. */
#ifndef SHT_GROUP
#define SHT_GROUP 17
#endif
#ifndef SHF_COMPRESSED
/* This from ubuntu xenial. Is in top of trunk binutils
as of February 2016. Elf Section Flag */
#define SHF_COMPRESSED (1 << 11)
#endif
#define DWARF_DBG_ERROR(dbg,errval,retval) \
_dwarf_error(dbg, error, errval); return(retval);
#define FALSE 0
#define TRUE 1
/* Global definition of the function pointer type, typedef
in dwarf_opaque.h */
_dwarf_get_elf_flags_func_ptr_type _dwarf_get_elf_flags_func_ptr;
/* This static is copied to the dbg on dbg init
so that the static need not be referenced at
run time, preserving better locality of
reference.
Value is 0 means do the string check.
Value non-zero means do not do the check.
*/
static Dwarf_Small _dwarf_assume_string_in_bounds;
static Dwarf_Small _dwarf_apply_relocs = 1;
/* Call this after calling dwarf_init but before doing anything else.
It applies to all objects, not just the current object. */
int
dwarf_set_reloc_application(int apply)
{
int oldval = _dwarf_apply_relocs;
_dwarf_apply_relocs = apply;
return oldval;
}
int
dwarf_set_stringcheck(int newval)
{
int oldval = _dwarf_assume_string_in_bounds;
_dwarf_assume_string_in_bounds = newval;
return oldval;
}
static int
startswith(const char * input, char* ckfor)
{
size_t cklen = strlen(ckfor);
if (! strncmp(input,ckfor,cklen)) {
return TRUE;
}
return FALSE;
}
#if 0
static int
endswith(const char * input, char* ckfor)
{
size_t inlen = strlen(input);
size_t endlen = strlen(ckfor);
const char * endck = 0;
if (endlen > inlen) {
return FALSE;
}
endck = input+inlen - endlen;
if (! strcmp(endck,ckfor) ) {
return TRUE;
}
return FALSE;
}
#endif
/* Unifies the basic duplicate/empty testing and section
data setting to one place. */
static int
get_basic_section_data(Dwarf_Debug dbg,
struct Dwarf_Section_s *secdata,
struct Dwarf_Obj_Access_Section_s *doas,
Dwarf_Half section_index,
unsigned group_number,
Dwarf_Error* error,
int duperr, int emptyerr )
{
/* There is an elf convention that section index 0 is reserved,
and that section is always empty.
Non-elf object formats must honor that by ensuring that
(when they assign numbers to 'sections' or 'section-like-things')
they never assign a real section section-number 0 to dss_index. */
if (secdata->dss_index != 0) {
DWARF_DBG_ERROR(dbg, duperr, DW_DLV_ERROR);
}
if (doas->size == 0) {
if (emptyerr == 0 ) {
/* Allow empty section. */
return DW_DLV_OK;
}
/* Know no reason to allow section */
DWARF_DBG_ERROR(dbg, emptyerr, DW_DLV_ERROR);
}
secdata->dss_index = section_index;
secdata->dss_size = doas->size;
secdata->dss_group_number = group_number;
secdata->dss_addr = doas->addr;
secdata->dss_link = doas->link;
secdata->dss_entrysize = doas->entrysize;
if (_dwarf_get_elf_flags_func_ptr) {
/* We do this so we do not need to update the public struct
Dwarf_Obj_Access_Section_s and thereby cause
binary and source incompatibility. */
Dwarf_Unsigned flags = 0;
Dwarf_Unsigned addralign = 0;
int res = 0;
int interr = 0;
struct Dwarf_Obj_Access_Interface_s *o = 0;
o = dbg->de_obj_file;
res = _dwarf_get_elf_flags_func_ptr(
o->object, section_index,
&flags,&addralign,
&interr);
if (res == DW_DLV_ERROR) {
/* Should never get here. */
DWARF_DBG_ERROR(dbg, interr, DW_DLV_ERROR);
}
if (res == DW_DLV_NO_ENTRY) {
return res;
}
secdata->dss_flags = flags;
secdata->dss_addralign = addralign;
if (flags & SHF_COMPRESSED) {
secdata->dss_requires_decompress = TRUE;
}
}
return DW_DLV_OK;
}
static void
add_rela_data_to_secdata( struct Dwarf_Section_s *secdata,
struct Dwarf_Obj_Access_Section_s *doas,
Dwarf_Half section_index)
{
secdata->dss_reloc_index = section_index;
secdata->dss_reloc_size = doas->size;
secdata->dss_reloc_entrysize = doas->entrysize;
secdata->dss_reloc_addr = doas->addr;
secdata->dss_reloc_symtab = doas->link;
secdata->dss_reloc_link = doas->link;
}
/* Used to add the specific information for a debug related section
Called on each section of interest by section name.
DWARF_MAX_DEBUG_SECTIONS must be large enough to allow
that all sections of interest fit in the table.
returns DW_DLV_ERROR or DW_DLV_OK.
*/
static int
add_debug_section_info(Dwarf_Debug dbg,
/* Name as seen in object file. */
const char *name,
unsigned obj_sec_num,
struct Dwarf_Section_s *secdata,
unsigned groupnum,
/* The have_dwarf flag is a somewhat imprecise
way to determine if there is at least one 'meaningful'
DWARF information section present in the object file.
If not set on some section we claim (later) that there
is no DWARF info present. see 'foundDwarf' in this file */
int duperr,int emptyerr,int have_dwarf,
int havezdebug,
int *err)
{
unsigned total_entries = dbg->de_debug_sections_total_entries;
if (secdata->dss_is_in_use) {
*err = duperr;
return DW_DLV_ERROR;
}
if (total_entries < DWARF_MAX_DEBUG_SECTIONS) {
struct Dwarf_dbg_sect_s *debug_section =
&dbg->de_debug_sections[total_entries];
secdata->dss_is_in_use = TRUE;
debug_section->ds_name = name;
debug_section->ds_number = obj_sec_num;
debug_section->ds_secdata = secdata;
debug_section->ds_groupnumber = groupnum;
secdata->dss_name = name;
secdata->dss_number = obj_sec_num;
secdata->dss_requires_decompress = havezdebug;
debug_section->ds_duperr = duperr;
debug_section->ds_emptyerr = emptyerr;
debug_section->ds_have_dwarf = have_dwarf;
debug_section->ds_have_zdebug = havezdebug;
++dbg->de_debug_sections_total_entries;
return DW_DLV_OK;
}
/* This represents a bug in libdwarf.
Mis-setup-DWARF_MAX_DEBUG_SECTIONS.
Or possibly a use of section groups that is
not supported. */
*err = DW_DLE_TOO_MANY_DEBUG;
return DW_DLV_ERROR;
}
#if 0
static void
dump_bytes(const char *msg,Dwarf_Small * start, long len)
{
Dwarf_Small *end = start + len;
Dwarf_Small *cur = start;
printf("dump_bytes: %s ",msg);
for (; cur < end; cur++) {
printf("%02x",*cur);
}
printf("\n");
}
static int
all_sig8_bits_zero(Dwarf_Sig8 *val)
{
unsigned u = 0;
for( ; u < sizeof(*val); ++u) {
if (val->signature[u] != 0) {
return FALSE;
}
}
return TRUE;
}
#endif
/* Return DW_DLV_OK etc. */
static int
set_up_section(Dwarf_Debug dbg,
/* Section name from object format. */
const char *secname,
/* Section number from object format */
unsigned obj_sec_num,
/* The name associated with this secdata */
const char *targname,
/* DW_GROUPNUMBER_ANY or BASE or DWO or some other group num */
unsigned groupnum_of_sec,
struct Dwarf_Section_s *secdata,
int duperr,int emptyerr,int have_dwarf,
int *err)
{
/* Here accomodate the .debug or .zdebug version, (and of
course non- .debug too, but those never zlib) .
SECNAMEMAX should be a little bigger than any section
name we care about as possibly compressed. */
#define SECNAMEMAX 30
char buildsecname[SECNAMEMAX];
unsigned secnamelen = strlen(secname);
static const char *dprefix = ".debug_";
static const char *zprefix = ".zdebug_";
int havezdebug = FALSE;
unsigned targnamelen = strlen(targname);
const char *finalname = targname;
if(secnamelen < SECNAMEMAX && strncmp(secname,zprefix,8) == 0) {
strcpy(buildsecname,zprefix);
/* Now lets see if a targname updated with z matches
secname. */
/* 2 ensures NUL and added 'z' are ok */
if ((targnamelen+2) < SECNAMEMAX && strncmp(targname,dprefix,7) == 0 ){
strcat(buildsecname,targname+7);
/* We turned tarname .debug_info to .zdebug_info, for example. */
finalname = buildsecname;
if (strcmp(finalname,secname) == 0) {
havezdebug = TRUE;
}
}
}
/* SETUP_SECTION. See also BUILDING_SECTIONS, BUILDING_MAP */
if(!strcmp(secname,finalname)) {
/* The section name is a match with targname, or
the .zdebug version of targname. */
int sectionerr = 0;
sectionerr = add_debug_section_info(dbg,secname,
obj_sec_num,
secdata,
groupnum_of_sec,
duperr,emptyerr, have_dwarf,
havezdebug,err);
if (sectionerr != DW_DLV_OK) {
/* *err is set already */
return sectionerr;
}
return DW_DLV_OK;
}
/* This is not the target section.
our caller will keep looking. */
return DW_DLV_NO_ENTRY;
}
#define SET_UP_SECTION(mdbg,mname,mtarg,mgrp,minfo,me1,me2,mdw,mer) \
{ \
int lerr = 0; \
lerr = set_up_section(mdbg, mname, \
/* scn_number from macro use context */ \
scn_number,mtarg,mgrp, \
minfo, \
me1,me2,mdw,mer); \
if (lerr != DW_DLV_NO_ENTRY) { \
return lerr; \
} /* else fall through. */ \
}
/* If running this long set of tests is slow
enough to matter one could set up a local
tsearch tree with all this content and search
it instead of this set of sequential tests.
Or use a switch(){} here with a search tree
to to turn name into index for the switch(). */
static int
enter_section_in_de_debug_sections_array(Dwarf_Debug dbg,
const char *scn_name,
/* This is the number of the section in the object file. */
unsigned scn_number,
unsigned group_number,
int *err)
{
/* Setup the table that contains the basic information about the
sections that are DWARF related. The entries are very unlikely
to change very often. */
SET_UP_SECTION(dbg,scn_name,".debug_info",
group_number,
&dbg->de_debug_info,
DW_DLE_DEBUG_INFO_DUPLICATE,DW_DLE_DEBUG_INFO_NULL,
TRUE,err);
SET_UP_SECTION(dbg,scn_name,".debug_info.dwo",
DW_GROUPNUMBER_DWO,
&dbg->de_debug_info,
DW_DLE_DEBUG_INFO_DUPLICATE,DW_DLE_DEBUG_INFO_NULL,
TRUE,err);
SET_UP_SECTION(dbg,scn_name,".debug_types",
group_number,
&dbg->de_debug_types,
DW_DLE_DEBUG_TYPES_DUPLICATE,DW_DLE_DEBUG_TYPES_NULL,
TRUE,err);
SET_UP_SECTION(dbg,scn_name,".debug_types.dwo",
DW_GROUPNUMBER_DWO,
&dbg->de_debug_types,
DW_DLE_DEBUG_TYPES_DUPLICATE,DW_DLE_DEBUG_TYPES_NULL,
TRUE,err);
SET_UP_SECTION(dbg,scn_name,".debug_abbrev",
group_number,
&dbg->de_debug_abbrev, /*03*/
DW_DLE_DEBUG_ABBREV_DUPLICATE,DW_DLE_DEBUG_ABBREV_NULL,
TRUE,err);
SET_UP_SECTION(dbg,scn_name,".debug_abbrev.dwo",
DW_GROUPNUMBER_DWO,
&dbg->de_debug_abbrev, /*03*/
DW_DLE_DEBUG_ABBREV_DUPLICATE,DW_DLE_DEBUG_ABBREV_NULL,
TRUE,err);
SET_UP_SECTION(dbg,scn_name,".debug_aranges",
group_number,
&dbg->de_debug_aranges,
DW_DLE_DEBUG_ARANGES_DUPLICATE,0,
FALSE,err);
SET_UP_SECTION(dbg,scn_name,".debug_line",
group_number,
&dbg->de_debug_line,
DW_DLE_DEBUG_LINE_DUPLICATE,0,
TRUE,err);
/* DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_line_str",
group_number,
&dbg->de_debug_line_str,
DW_DLE_DEBUG_LINE_DUPLICATE,0,
FALSE,err);
SET_UP_SECTION(dbg,scn_name,".debug_line.dwo",
DW_GROUPNUMBER_DWO,
&dbg->de_debug_line,
DW_DLE_DEBUG_LINE_DUPLICATE,0,
TRUE,err);
SET_UP_SECTION(dbg,scn_name,".debug_frame",
group_number,
&dbg->de_debug_frame,
DW_DLE_DEBUG_FRAME_DUPLICATE,0,
TRUE,err);
/* gnu egcs-1.1.2 data */
SET_UP_SECTION(dbg,scn_name,".eh_frame",
group_number,
&dbg->de_debug_frame_eh_gnu,
DW_DLE_DEBUG_FRAME_DUPLICATE,0,
TRUE,err);
SET_UP_SECTION(dbg,scn_name,".debug_loc",
group_number,
&dbg->de_debug_loc,
DW_DLE_DEBUG_LOC_DUPLICATE,0,
FALSE,err);
SET_UP_SECTION(dbg,scn_name,".debug_loc.dwo",
DW_GROUPNUMBER_DWO,
&dbg->de_debug_loc,
DW_DLE_DEBUG_LOC_DUPLICATE,0,
FALSE,err);
SET_UP_SECTION(dbg,scn_name,".debug_pubnames",
group_number,
&dbg->de_debug_pubnames,
DW_DLE_DEBUG_PUBNAMES_DUPLICATE,0,
FALSE,err);
SET_UP_SECTION(dbg,scn_name,".debug_str",
group_number,
&dbg->de_debug_str,
DW_DLE_DEBUG_STR_DUPLICATE,0,
FALSE,err);
SET_UP_SECTION(dbg,scn_name,".debug_str.dwo",
DW_GROUPNUMBER_DWO,
&dbg->de_debug_str,
DW_DLE_DEBUG_STR_DUPLICATE,0,
FALSE,err);
/* Section new in DWARF3. */
SET_UP_SECTION(dbg,scn_name,".debug_pubtypes",
group_number,
&dbg->de_debug_pubtypes,
/*13*/ DW_DLE_DEBUG_PUBTYPES_DUPLICATE,0,
FALSE,err);
/* DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_names",
group_number,
&dbg->de_debug_names,
/*13*/ DW_DLE_DEBUG_NAMES_DUPLICATE,0,
FALSE,err);
/* DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_loclists",
group_number,
&dbg->de_debug_loclists,
/*13*/ DW_DLE_DEBUG_LOClISTS_DUPLICATE,0,
FALSE,err);
/* DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_loclists.dwo",
DW_GROUPNUMBER_DWO,
&dbg->de_debug_loclists,
/*13*/ DW_DLE_DEBUG_LOClISTS_DUPLICATE,0,
FALSE,err);
/* DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_rnglists",
group_number,
&dbg->de_debug_rnglists,
/*13*/ DW_DLE_DEBUG_RNGLISTS_DUPLICATE,0,
FALSE,err);
/* DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_rnglists.dwo",
DW_GROUPNUMBER_DWO,
&dbg->de_debug_rnglists,
/*13*/ DW_DLE_DEBUG_RNGLISTS_DUPLICATE,0,
FALSE,err);
/* DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_str_offsets",
group_number,
&dbg->de_debug_str_offsets,
DW_DLE_DEBUG_STR_OFFSETS_DUPLICATE,0,
FALSE,err);
/* DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_str_offsets.dwo",
DW_GROUPNUMBER_DWO,
&dbg->de_debug_str_offsets,
DW_DLE_DEBUG_STR_OFFSETS_DUPLICATE,0,
FALSE,err);
/* SGI IRIX-only. */
SET_UP_SECTION(dbg,scn_name,".debug_funcnames",
group_number,
&dbg->de_debug_funcnames,
/*11*/ DW_DLE_DEBUG_FUNCNAMES_DUPLICATE,0,
FALSE,err);
/* SGI IRIX-only, created years before DWARF3. Content
essentially identical to .debug_pubtypes. */
SET_UP_SECTION(dbg,scn_name,".debug_typenames",
group_number,
&dbg->de_debug_typenames,
/*12*/ DW_DLE_DEBUG_TYPENAMES_DUPLICATE,0,
FALSE,err);
/* SGI IRIX-only. */
SET_UP_SECTION(dbg,scn_name,".debug_varnames",
group_number,
&dbg->de_debug_varnames,
DW_DLE_DEBUG_VARNAMES_DUPLICATE,0,
FALSE,err);
/* SGI IRIX-only. */
SET_UP_SECTION(dbg,scn_name,".debug_weaknames",
group_number,
&dbg->de_debug_weaknames,
DW_DLE_DEBUG_WEAKNAMES_DUPLICATE,0,
FALSE,err);
SET_UP_SECTION(dbg,scn_name,".debug_macinfo",
group_number,
&dbg->de_debug_macinfo,
DW_DLE_DEBUG_MACINFO_DUPLICATE,0,
TRUE,err);
/* ".debug_macinfo.dwo" is not allowed. */
/* DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_macro",
group_number,
&dbg->de_debug_macro,
DW_DLE_DEBUG_MACRO_DUPLICATE,0,
TRUE,err);
/* DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_macro.dwo",
DW_GROUPNUMBER_DWO,
&dbg->de_debug_macro,
DW_DLE_DEBUG_MACRO_DUPLICATE,0,
TRUE,err);
SET_UP_SECTION(dbg,scn_name,".debug_ranges",
group_number,
&dbg->de_debug_ranges,
DW_DLE_DEBUG_RANGES_DUPLICATE,0,
TRUE,err);
/* No .debug_ranges.dwo allowed. */
/* New DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_sup",
group_number,
&dbg->de_debug_sup,
DW_DLE_DEBUG_SUP_DUPLICATE,0,
TRUE,err);
/* No .debug_sup.dwo allowed. */
/* .symtab and .strtab have to be in any group. */
SET_UP_SECTION(dbg,scn_name,".symtab",
group_number,
&dbg->de_elf_symtab,
DW_DLE_DEBUG_SYMTAB_ERR,0,
FALSE,err);
SET_UP_SECTION(dbg,scn_name,".strtab",
group_number,
&dbg->de_elf_strtab,
DW_DLE_DEBUG_STRTAB_ERR,0,
FALSE,err);
/* New DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_addr",
group_number,
&dbg->de_debug_addr,
DW_DLE_DEBUG_ADDR_DUPLICATE,0,
TRUE,err);
/* No .debug_addr.dwo allowed. */
/* gdb added this. */
SET_UP_SECTION(dbg,scn_name,".gdb_index",
group_number,
&dbg->de_debug_gdbindex,
DW_DLE_DUPLICATE_GDB_INDEX,0,
FALSE,err);
/* New DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_names",
group_number,
&dbg->de_debug_names,
DW_DLE_DEBUG_NAMES_DUPLICATE,0,
FALSE,err);
/* No .debug_names.dwo allowed. */
/* gdb added this in DW4. It is in standard DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_cu_index",
DW_GROUPNUMBER_DWO,
&dbg->de_debug_cu_index,
DW_DLE_DUPLICATE_CU_INDEX,0,
FALSE,err);
/* gdb added this in DW4. It is in standard DWARF5 */
SET_UP_SECTION(dbg,scn_name,".debug_tu_index",
DW_GROUPNUMBER_DWO,
&dbg->de_debug_tu_index,
DW_DLE_DUPLICATE_TU_INDEX,0,
FALSE,err);
return DW_DLV_NO_ENTRY;
}
static int
is_section_name_known_already(Dwarf_Debug dbg, const char *scn_name)
{
unsigned i = 0;
for ( ; i < dbg->de_debug_sections_total_entries; ++i) {
struct Dwarf_dbg_sect_s *section = &dbg->de_debug_sections[i];
if (!strcmp(scn_name, section->ds_name)) {
/* The caller will declare this a duplicate, an error. */
return DW_DLV_OK;
}
}
/* This is normal, we expect we've not accepted scn_name already. */
return DW_DLV_NO_ENTRY;
}
/* Given an Elf ptr, set up dbg with pointers
to all the Dwarf data sections.
Return NULL on error.
This function is also responsible for determining
whether the given object contains Dwarf information
or not. The test currently used is that it contains
either a .debug_info or a .debug_frame section. If
not, it returns DW_DLV_NO_ENTRY causing dwarf_init() also to
return DW_DLV_NO_ENTRY. Earlier, we had thought of using only
the presence/absence of .debug_info to test, but we
added .debug_frame since there could be stripped objects
that have only a .debug_frame section for exception
processing.
DW_DLV_NO_ENTRY or DW_DLV_OK or DW_DLV_ERROR
This does not allow for section-groups in object files,
for which many .debug_info (and other DWARF) sections may exist.
We process. .rela (SHT_RELA) but not .rel (SHT_REL)
sections because with .rela the referencing section
offset value is zero whereas with .rel the
referencing section value is already correct for
the object itself. In other words, we do it because
of the definition of .rela relocations in Elf.
*/
/* For an object file with an incorrect rela section name,
readelf prints correct debug information,
as the tool takes the section type instead
of the section name. So check the
section name but test section type. */
static int
is_a_rela_section(const char *scn_name,int type)
{
if(startswith(scn_name,".rela.")) {
return TRUE;
}
if (type == SHT_RELA) {
return TRUE;
}
return FALSE;
}
/* ASSERT: names like .debug_ or .zdebug_ never passed in here! */
static int
is_a_special_section_semi_dwarf(const char *scn_name)
{
if (!strcmp(scn_name,".strtab") ||
!strcmp(scn_name,".symtab")) {
return TRUE;
}
/* It's not one of these special sections referenced in
the test. */
return FALSE;
}
static int
this_section_dwarf_relevant(const char *scn_name,int type)
{
/* A small helper function for _dwarf_setup(). */
if (startswith(scn_name, ".zdebug_") ||
startswith(scn_name, ".debug_")) {
/* standard debug */
return TRUE;
}
/* Now check if a special section could be
in a section_group, but though seems unlikely. */
if (!strcmp(scn_name, ".eh_frame")) {
/* This is not really a group related file, but
it is harmless to consider it such. */
return TRUE;
}
if(!strcmp(scn_name, ".gdb_index")) {
return TRUE;
}
if(is_a_special_section_semi_dwarf(scn_name)) {
return TRUE;
}
if(is_a_rela_section(scn_name,type)) {
return TRUE;
}
/* All sorts of sections are of no interest: .text
.rel. and many others. */
return FALSE;
}
/* This assumes any non-Elf object files have no SHT_GROUP
sections. So this code will not be invoked on non-Elf objects.
One supposes this is unlikely to match any non-Elf
version of COMDAT. */
static int
insert_sht_list_in_group_map(Dwarf_Debug dbg,
struct Dwarf_Obj_Access_Section_s *doas,
unsigned comdat_group_number,
unsigned section_number,
Dwarf_Unsigned section_count,
struct Dwarf_Obj_Access_Interface_s * obj,
unsigned *did_add_map,
Dwarf_Error *error)
{
struct Dwarf_Section_s secdata;
Dwarf_Small * data = 0;
int res = 0;
Dwarf_Small* secend = 0;
memset(&secdata,0,sizeof(secdata));
secdata.dss_size = doas->size;
secdata.dss_entrysize = doas->entrysize;
secdata.dss_group_number = 1; /* arbitrary. */
secdata.dss_index = section_number;
secdata.dss_name = ".group";
secdata.dss_number = section_number;
res = _dwarf_load_section(dbg,&secdata,error);
if (res != DW_DLV_OK) {
return res;
}
if (doas->entrysize != 4) {
_dwarf_error(dbg,error,DW_DLE_GROUP_INTERNAL_ERROR);
return DW_DLV_ERROR;
}
if (!secdata.dss_data) {
_dwarf_error(dbg,error,DW_DLE_GROUP_INTERNAL_ERROR);
return DW_DLV_ERROR;
}
/* So now pick up the data in dss_data.
It is an array of 32 bit fields.
Dwarf_ufixed. Zero is just a constant 1.
Each additional is a section number. */
data = secdata.dss_data;
secend = data + secdata.dss_size;
{
unsigned i = 1;
unsigned count = doas->size/doas->entrysize;
Dwarf_ufixed fval = 0;
/* The fields treatments with regard
to endianness is unclear. In any case a single
bit should be on, as 0x01000000
without any endiannes swapping.
Or so it seems given limited evidence.
We read with length checking and allow the
reader to byte swap and then fix things.
At least one test case has big-endian
data but little-endian SHT_GROUP data. */
READ_UNALIGNED_CK(dbg,fval,Dwarf_ufixed,
data,
sizeof(Dwarf_ufixed),
error,
secend);
if (fval != 1 && fval != 0x1000000) {
/* Could be corrupted elf object. */
_dwarf_error(dbg,error,DW_DLE_GROUP_INTERNAL_ERROR);
return DW_DLV_ERROR;
}
data = data + doas->entrysize;
for (i = 1 ; i < count ; ++i) {
Dwarf_ufixed val = 0;
READ_UNALIGNED_CK(dbg,val,Dwarf_ufixed,
data,
sizeof(Dwarf_ufixed),
error,
secend);
if (val > section_count) {
/* Might be confused endianness by
the compiler generating the SHT_GROUP.
This is pretty horrible. */
Dwarf_ufixed valr = 0;
_dwarf_memcpy_swap_bytes(&valr,&val,
sizeof(Dwarf_ufixed));
if (valr > section_count) {
_dwarf_error(dbg,error,DW_DLE_GROUP_INTERNAL_ERROR);
return DW_DLV_ERROR;
}
/* Ok. Yes, ugly. */
val = valr;
}
{
/* Ensure this group entry DWARF relevant before
adding to group map */
struct Dwarf_Obj_Access_Section_s doasx;
int resx = DW_DLV_ERROR;
int err = 0;
memset(&doasx,0,sizeof(doasx));
resx = obj->methods->get_section_info(obj->object,
val,
&doasx, &err);
if (resx == DW_DLV_NO_ENTRY){
/* Should we really ignore this? */
continue;
} else if (resx == DW_DLV_ERROR){
_dwarf_error(dbg,error,err);
return resx;
}
if (!this_section_dwarf_relevant(doasx.name,
doasx.type) ) {
continue;
}
data += sizeof(Dwarf_ufixed);
*did_add_map = TRUE;
res = _dwarf_insert_in_group_map(dbg,
comdat_group_number,val,
doasx.name,
error);
if (res != DW_DLV_OK) {
return res;
}
}
}
}
return DW_DLV_OK;
}
/* Split dwarf CUs can be in an object with non-split
or split may be in a separate object.
If all in one object the default is to deal with group_number
and ignore DW_GROUPNUMBER_DWO.
If only .dwo the default is DW_GROUPNUMBER_DWO(2).
Otherwise use DW_GROUP_NUMBER_BASE(1).
If there are COMDAT SHT_GROUP sections, these
are assigned group numbers 3-N as needed.
At present this makes the assumption that COMDAT group
(ie, SHT_GROUP) sections
have lower section numbers than the sections COMDAT refers to.
It is not clear whether this is guaranteed, COMDAT is not
an official Elf thing and documentation is scarce.
In the 1990's SGI folks and others formed a committee
and attempted to get COMDAT and a feature allowing section
numbers greater than 16 bits into Elf, but there was no
group that was able to approve such things.
This is called once at dbg init time.
*/
static int
determine_target_group(Dwarf_Unsigned section_count,
struct Dwarf_Obj_Access_Interface_s * obj,
unsigned *group_number_out,
Dwarf_Debug dbg,
Dwarf_Error *error)
{
unsigned obj_section_index = 0;
int found_group_one = 0;
int found_group_two = 0;
struct Dwarf_Group_Data_s *grp = 0;
unsigned comdat_group_next = 3;
unsigned lowest_comdat_groupnum = 0;
grp = &dbg->de_groupnumbers;
grp->gd_number_of_groups = 0;
grp->gd_number_of_sections = section_count;
if (grp->gd_map) {
_dwarf_error(dbg,error,DW_DLE_GROUP_INTERNAL_ERROR);
return DW_DLV_OK;
}
for (obj_section_index = 0; obj_section_index < section_count;
++obj_section_index) {
struct Dwarf_Obj_Access_Section_s doas;
int res = DW_DLV_ERROR;
int err = 0;
const char *scn_name = 0;
unsigned groupnumber = 0;
unsigned mapgroupnumber = 0;
memset(&doas,0,sizeof(doas));
res = obj->methods->get_section_info(obj->object,
obj_section_index,
&doas, &err);
if (res == DW_DLV_NO_ENTRY){
return res;
} else if (res == DW_DLV_ERROR){
_dwarf_error(dbg, error,err);
return res;
}
if (doas.type == SHT_GROUP) {
/* See assumptions in function comment above. */
unsigned did_add_map = 0;
/* Add to our map. Here we
are assuming SHT_GROUP records come first.
Till proven wrong. */
res = insert_sht_list_in_group_map(dbg,&doas,
comdat_group_next,
obj_section_index,
section_count,
obj,
&did_add_map,error);
if (res != DW_DLV_OK) {
return res;
}
if (!lowest_comdat_groupnum) {
lowest_comdat_groupnum = comdat_group_next;
}
if (did_add_map) {
++grp->gd_number_of_groups;
++comdat_group_next;
}
continue;
}
scn_name = doas.name;
if (!this_section_dwarf_relevant(scn_name,doas.type) ) {
continue;
}
/* Now at a 'normal' section, though we do not
quite know what group it is. */
res = _dwarf_section_get_target_group_from_map(dbg,
obj_section_index,&groupnumber,error);
if (res == DW_DLV_OK ) {
/* groupnumber is set. Fall through.
All COMDAT group should get here. */
mapgroupnumber = groupnumber;
} else if (res == DW_DLV_ERROR) {
return res;
} else { /* DW_DLV_NO_ENTRY */
/* Normal non-COMDAT. groupnumber is zero. */
}
/* BUILDING_MAP. See also BUILDING_SECTIONS, SETUP_SECTION */
if (!groupnumber) {
res =_dwarf_dwo_groupnumber_given_name(scn_name,
&groupnumber);
/* DW_DLV_ERROR impossible here. */
if (res == DW_DLV_OK) {
/* groupnumber set 2 */
} else {
/* This is what it has to be.
.rela in here too. */
groupnumber = DW_GROUPNUMBER_BASE;
}
}
if (is_a_rela_section(scn_name,doas.type)) {
unsigned linkgroup = 0;
res = _dwarf_section_get_target_group_from_map(dbg,
doas.info,
&linkgroup,error);
if (res == DW_DLV_OK ) {
/* Fall through.
linkgroup is in group map already. */
} else if (res == DW_DLV_ERROR) {
return res;
} else { /* DW_DLV_NO_ENTRY */
res = _dwarf_insert_in_group_map(dbg,
linkgroup,obj_section_index,
scn_name,
error);
if (res != DW_DLV_OK ) {
return res;
}
}
continue;
}
/* ASSERT: groupnumber non-zero now */
if (!is_a_special_section_semi_dwarf(scn_name)) {
if (mapgroupnumber) {
/* Already in group map */
continue;
}
/* !mapgroupnumber */
res = _dwarf_insert_in_group_map(dbg,
groupnumber,obj_section_index,
scn_name,
error);
if (res != DW_DLV_OK) {
return res;
}
if (groupnumber == 1) {
found_group_one++;
} else if (groupnumber == 2) {
found_group_two++;
}
continue;
}
}
if (found_group_two) {
++grp->gd_number_of_groups;
}
if (found_group_one) {
*group_number_out = DW_GROUPNUMBER_BASE;
++grp->gd_number_of_groups;
} else {
if (found_group_two) {
*group_number_out = DW_GROUPNUMBER_DWO;
} else {
if (lowest_comdat_groupnum) {
*group_number_out = lowest_comdat_groupnum;
} else {
*group_number_out = DW_GROUPNUMBER_BASE;
}
}
}
return DW_DLV_OK;
}
static int
_dwarf_setup(Dwarf_Debug dbg, Dwarf_Error * error)
{
const char *scn_name = 0;
struct Dwarf_Obj_Access_Interface_s * obj = 0;
int resn = 0;
struct Dwarf_Section_s **sections = 0;
Dwarf_Endianness endianness;
Dwarf_Unsigned section_count = 0;
unsigned default_group_number = 0;
unsigned foundDwarf = FALSE;
unsigned obj_section_index = 0;
dbg->de_assume_string_in_bounds = _dwarf_assume_string_in_bounds;
dbg->de_same_endian = 1;
dbg->de_copy_word = memcpy;
obj = dbg->de_obj_file;
endianness = obj->methods->get_byte_order(obj->object);
#ifdef WORDS_BIGENDIAN
dbg->de_big_endian_object = 1;
if (endianness == DW_OBJECT_LSB ) {
dbg->de_same_endian = 0;
dbg->de_big_endian_object = 0;
dbg->de_copy_word = _dwarf_memcpy_swap_bytes;
}
#else /* little endian */
dbg->de_big_endian_object = 0;
if (endianness == DW_OBJECT_MSB ) {
dbg->de_same_endian = 0;
dbg->de_big_endian_object = 1;
dbg->de_copy_word = _dwarf_memcpy_swap_bytes;
}
#endif /* !WORDS_BIGENDIAN */
/* The following de_length_size is Not Too Significant. Only used
one calculation, and an approximate one at that. */
dbg->de_length_size = obj->methods->get_length_size(obj->object);
dbg->de_pointer_size = obj->methods->get_pointer_size(obj->object);
section_count = obj->methods->get_section_count(obj->object);
resn = determine_target_group(section_count,obj,
&default_group_number,dbg,error);
if (resn == DW_DLV_ERROR) {
return DW_DLV_ERROR;
}
if (dbg->de_groupnumber == DW_GROUPNUMBER_ANY) {
dbg->de_groupnumber = default_group_number;
}
/* Allocate space to record references to debug sections, that can
be referenced by RELA sections in the 'sh_info' field. */
sections = (struct Dwarf_Section_s **)calloc(section_count + 1,
sizeof(struct Dwarf_Section_s *));
if (!sections) {
/* Impossible case, we hope. Give up. */
_dwarf_error(dbg, error, DW_DLE_SECTION_ERROR);
return DW_DLV_ERROR;
}
/* We can skip index 0 when considering ELF files, but not other
object types. Indeed regardless of the object type we should
skip section 0 here.
This is a convention. We depend on it.
Non-elf object access code should
(in itself) understand we will index beginning at 1 and adjust
itself to deal with this Elf convention. Without this
convention various parts of the code in this file won't work correctly.
A dss_index of 0 must not be used, even though we start at 0
here. So the get_section_info() must adapt to the situation
(the elf version does automatically as a result of Elf having
a section zero with zero length and an empty name). */
/* ASSERT: all group map entries set up. */
for (obj_section_index = 0; obj_section_index < section_count;
++obj_section_index) {
struct Dwarf_Obj_Access_Section_s doas;
int res = DW_DLV_ERROR;
int err = 0;
unsigned groupnumber = 0;
unsigned mapgroupnumber = 0;
res = _dwarf_section_get_target_group_from_map(dbg,obj_section_index,
&groupnumber,error);
if (res == DW_DLV_OK ) {
/* groupnumber is set. Fall through */
mapgroupnumber = groupnumber;
} else if (res == DW_DLV_ERROR) {
return res;
} else { /* DW_DLV_NO_ENTRY */
/* fall through, a BASE or DWO group, possibly */
}
memset(&doas,0,sizeof(doas));
res = obj->methods->get_section_info(obj->object,
obj_section_index,
&doas, &err);
if (res == DW_DLV_NO_ENTRY){
free(sections);
return res;
} else if (res == DW_DLV_ERROR){
free(sections);
DWARF_DBG_ERROR(dbg, err, DW_DLV_ERROR);
}
scn_name = doas.name;
if (!groupnumber) {
/* This finds dwo sections, group 2 */
res = _dwarf_dwo_groupnumber_given_name(scn_name,
&groupnumber);
if (res == DW_DLV_NO_ENTRY) {
/* No, must be group 1 */
groupnumber = DW_GROUPNUMBER_BASE;
}
}
if (!this_section_dwarf_relevant(scn_name,doas.type) ) {
continue;
}
if (!is_a_rela_section(scn_name,doas.type)
&& !is_a_special_section_semi_dwarf(scn_name)) {
/* We do these actions only for group-related
sections. Do for .debug_info etc,
never for .strtab or .rela.*
We already tested for relevance, so that part
is not news. */
if(mapgroupnumber == dbg->de_groupnumber) {
/* OK. Mapped. Part of the group.. This will
catch the cases where there are versions of
a section in multiple COMDATs and in BASE
an DWO to get the right one */
} else {
/* This section not mapped into this group. */
if (groupnumber == 1 && dbg->de_groupnumber > 2 &&
!_dwarf_section_in_group_by_name(dbg,scn_name,
dbg->de_groupnumber)) {
/* Load the section (but as group 1) */
} else {
continue;
}
}
}
/* BUILDING_SECTIONS. See also BUILDING_MAP, SETUP_SECTION */
{
/* Build up the sections table and the
de_debug* etc pointers in Dwarf_Debug. */
struct Dwarf_dbg_sect_s *section;
int found_match = FALSE;
res = is_section_name_known_already(dbg,scn_name);
if (res == DW_DLV_OK) {
/* DUPLICATE */
free(sections);
DWARF_DBG_ERROR(dbg, DW_DLE_SECTION_DUPLICATION,
DW_DLV_ERROR);
} else if (res == DW_DLV_ERROR) {
free(sections);
DWARF_DBG_ERROR(dbg, err, DW_DLV_ERROR);
}
/* No entry: new-to-us section, the normal case. */
res = enter_section_in_de_debug_sections_array(dbg,scn_name,
obj_section_index, groupnumber,&err);
if (res == DW_DLV_OK) {
section = &dbg->de_debug_sections[
dbg->de_debug_sections_total_entries-1];
res = get_basic_section_data(dbg,
section->ds_secdata, &doas,
obj_section_index,
groupnumber,
error,
section->ds_duperr,
section->ds_emptyerr);
if (res != DW_DLV_OK) {
free(sections);
return res;
}
sections[obj_section_index] = section->ds_secdata;
foundDwarf += section->ds_have_dwarf;
found_match = TRUE;
/* Normal section set up.
Fall through. */
} else if (res == DW_DLV_NO_ENTRY) {
/* We get here for relocation sections.
Fall through. */
} else {
free(sections);
DWARF_DBG_ERROR(dbg, err, DW_DLV_ERROR);
}
if (!found_match) {
/* For an object file with incorrect rela section name,
the 'readelf' tool, prints correct debug information,
as the tool takes the section type instead
of the section name. If the current section
is a RELA one and the 'sh_info'
refers to a debug section, add the relocation data. */
if (is_a_rela_section(scn_name,doas.type)) {
if ( doas.info < section_count) {
if (sections[doas.info]) {
add_rela_data_to_secdata(sections[doas.info],
&doas,
obj_section_index);
}
} else {
/* Something is wrong with the ELF file. */
free(sections);
DWARF_DBG_ERROR(dbg, DW_DLE_ELF_SECT_ERR, DW_DLV_ERROR);
}
}
}
/* Fetch next section */
}
}
/* Free table with section information. */
free(sections);
if (foundDwarf) {
return DW_DLV_OK;
}
return DW_DLV_NO_ENTRY;
}
/* There is one table per CU and one per TU, and each
table refers to the associated other DWARF data
for that CU or TU.
See DW_SECT_*
In DWARF4 the type units are in .debug_types
In DWARF5 the type units are in .debug_info.
*/
static int
load_debugfission_tables(Dwarf_Debug dbg,Dwarf_Error *error)
{
int i = 0;
if (dbg->de_debug_cu_index.dss_size ==0 &&
dbg->de_debug_tu_index.dss_size ==0) {
/* This is the normal case.
No debug fission. Not a .dwp object. */
return DW_DLV_NO_ENTRY;
}
for (i = 0; i < 2; ++i) {
Dwarf_Xu_Index_Header xuptr = 0;
struct Dwarf_Section_s* dwsect = 0;
Dwarf_Unsigned version = 0;
Dwarf_Unsigned number_of_cols /* L */ = 0;
Dwarf_Unsigned number_of_CUs /* N */ = 0;
Dwarf_Unsigned number_of_slots /* M */ = 0;
const char *secname = 0;
int res = 0;
const char *type = 0;
if (i == 0) {
dwsect = &dbg->de_debug_cu_index;
type = "cu";
} else {
dwsect = &dbg->de_debug_tu_index;
type = "tu";
}
if ( !dwsect->dss_size ) {
continue;
}
res = dwarf_get_xu_index_header(dbg,type,
&xuptr,&version,&number_of_cols,
&number_of_CUs,&number_of_slots,
&secname,error);
if (res == DW_DLV_NO_ENTRY) {
continue;
}
if (res != DW_DLV_OK) {
return res;
}
if (i == 0) {
dbg->de_cu_hashindex_data = xuptr;
} else {
dbg->de_tu_hashindex_data = xuptr;
}
}
return DW_DLV_OK;
}
/*
Use a Dwarf_Obj_Access_Interface to kick things off. All other
init routines eventually use this one.
The returned Dwarf_Debug contains a copy of *obj
the callers copy of *obj may be freed whenever the caller
wishes.
*/
int
dwarf_object_init(Dwarf_Obj_Access_Interface* obj, Dwarf_Handler errhand,
Dwarf_Ptr errarg, Dwarf_Debug* ret_dbg,
Dwarf_Error* error)
{
return dwarf_object_init_b(obj,errhand,errarg,
DW_GROUPNUMBER_ANY,ret_dbg,error);
}
/* New March 2017. Enables dealing with DWARF5 split dwarf more fully. */
int
dwarf_object_init_b(Dwarf_Obj_Access_Interface* obj, Dwarf_Handler errhand,
Dwarf_Ptr errarg,
unsigned groupnumber,
Dwarf_Debug* ret_dbg,
Dwarf_Error* error)
{
Dwarf_Debug dbg = 0;
int setup_result = DW_DLV_OK;
dbg = _dwarf_get_debug();
if (dbg == NULL) {
DWARF_DBG_ERROR(dbg, DW_DLE_DBG_ALLOC, DW_DLV_ERROR);
}
dbg->de_errhand = errhand;
dbg->de_errarg = errarg;
dbg->de_frame_rule_initial_value = DW_FRAME_REG_INITIAL_VALUE;
dbg->de_frame_reg_rules_entry_count = DW_FRAME_LAST_REG_NUM;
#ifdef HAVE_OLD_FRAME_CFA_COL
/* DW_FRAME_CFA_COL is really only suitable for old libdwarf frame
interfaces and its value of 0 there is only usable where
(as in MIPS) register 0 has no value other than 0 so
we can use the frame table column 0 for the CFA value
(and rely on client software to know when 'register 0'
is the cfa and when to just use a value 0 for register 0).
*/
dbg->de_frame_cfa_col_number = DW_FRAME_CFA_COL;
#else
dbg->de_frame_cfa_col_number = DW_FRAME_CFA_COL3;
#endif
dbg->de_frame_same_value_number = DW_FRAME_SAME_VAL;
dbg->de_frame_undefined_value_number = DW_FRAME_UNDEFINED_VAL;
dbg->de_obj_file = obj;
dbg->de_groupnumber = groupnumber;
setup_result = _dwarf_setup(dbg, error);
if (setup_result == DW_DLV_OK) {
int fission_result = load_debugfission_tables(dbg,error);
/* In most cases we get
setup_result == DW_DLV_NO_ENTRY here
as having debugfission (.dwp objects)
is fairly rare. */
if (fission_result == DW_DLV_ERROR) {
/* Something is very wrong. */
setup_result = fission_result;
}
}
if (setup_result != DW_DLV_OK) {
int freeresult = 0;
int myerr = 0;
/* We cannot use any _dwarf_setup()
error here as
we are freeing dbg, making that error (setup
as part of dbg) stale.
Hence we have to make a new error without a dbg.
But error might be NULL and the init call
error-handler function might be set.
*/
if ( (setup_result == DW_DLV_ERROR) && error ) {
/* Preserve our _dwarf_setup error number, but
this does not apply if error NULL. */
myerr = dwarf_errno(*error);
/* deallocate the soon-stale error pointer. */
dwarf_dealloc(dbg,*error,DW_DLA_ERROR);
*error = 0;
}
/* The status we want to return here is of _dwarf_setup,
not of the _dwarf_free_all_of_one_debug(dbg) call.
So use a local status variable for the free. */
freeresult = _dwarf_free_all_of_one_debug(dbg);
dbg = 0;
/* DW_DLV_NO_ENTRY not possible in freeresult */
if (freeresult == DW_DLV_ERROR) {
/* Use the _dwarf_setup error number.
If error is NULL the following will issue
a message on stderr and abort(), as without
dbg there is no error-handler function.
*/
_dwarf_error(NULL,error,DW_DLE_DBG_ALLOC);
return DW_DLV_ERROR;
}
if (setup_result == DW_DLV_ERROR) {
/* Use the _dwarf_setup error number.
If error is NULL the following will issue
a message on stderr and abort(), as without
dbg there is no error-handler function.
*/
_dwarf_error(NULL,error,myerr);
}
return setup_result;
}
dwarf_harmless_init(&dbg->de_harmless_errors,
DW_HARMLESS_ERROR_CIRCULAR_LIST_DEFAULT_SIZE);
*ret_dbg = dbg;
return DW_DLV_OK;
}
/* A finish routine that is completely unaware of ELF.
Frees all memory that was not previously freed by
dwarf_dealloc.
Aside frmo certain categories. */
int
dwarf_object_finish(Dwarf_Debug dbg, Dwarf_Error * error)
{
int res = _dwarf_free_all_of_one_debug(dbg);
if (res == DW_DLV_ERROR) {
DWARF_DBG_ERROR(dbg, DW_DLE_DBG_ALLOC, DW_DLV_ERROR);
}
return res;
}
#ifdef HAVE_ZLIB
/* case 1:
The input stream is assumed to contain
the four letters
ZLIB
Followed by 8 bytes of the size of the
uncompressed stream. Presented as
a big-endian binary number.
Following that is the stream to decompress.
case 2:
The section flag bit SHF_COMPRESSED (1 << 11)
must be set.
we then do the eqivalent of reading a
Elf32_External_Chdr
or
Elf64_External_Chdr
to get the type (which must be 1)
and the decompressed_length.
Then what follows the implicit Chdr is decompressed.
*/
/* ALLOWED_ZLIB_INFLATION is a heuristic, not necessarily right.
The test case klingler2/compresseddebug.amd64 actually
inflates about 8 times. */
#define ALLOWED_ZLIB_INFLATION 16
static int
do_decompress_zlib(Dwarf_Debug dbg,
struct Dwarf_Section_s *section,
Dwarf_Error * error)
{
Bytef *basesrc = (Bytef *)section->dss_data;
Bytef *src = (Bytef *)basesrc;
uLong srclen = section->dss_size;
Dwarf_Unsigned flags = section->dss_flags;
Dwarf_Small *endsection = 0;
int res = 0;
Bytef *dest = 0;
uLongf destlen = 0;
Dwarf_Unsigned uncompressed_len = 0;
endsection = basesrc + srclen;
if ((src + 12) >endsection) {
DWARF_DBG_ERROR(dbg, DW_DLE_ZLIB_SECTION_SHORT, DW_DLV_ERROR);
}
if(!strncmp("ZLIB",(const char *)src,4)) {
unsigned i = 0;
unsigned l = 8;
unsigned char *c = src+4;
for( ; i < l; ++i,c++) {
uncompressed_len <<= 8;
uncompressed_len += *c;
}
src = src + 12;
srclen -= 12;
} else if (flags & SHF_COMPRESSED) {
/* The prefix is a struct:
unsigned int type; followed by pad if following are 64bit!
size-of-target-address size
size-of-target-address
*/
Dwarf_Small *ptr = (Dwarf_Small *)src;
Dwarf_Unsigned type = 0;
Dwarf_Unsigned size = 0;
/* Dwarf_Unsigned addralign = 0; */
unsigned fldsize = dbg->de_pointer_size;
unsigned structsize = 3* fldsize;
READ_UNALIGNED_CK(dbg,type,Dwarf_Unsigned,ptr,
sizeof(Dwarf_ufixed),
error,endsection);
ptr += fldsize;
READ_UNALIGNED_CK(dbg,size,Dwarf_Unsigned,ptr,fldsize,
error,endsection);
ptr += fldsize;
if (type != ELFCOMPRESS_ZLIB) {
DWARF_DBG_ERROR(dbg, DW_DLE_ZDEBUG_INPUT_FORMAT_ODD,
DW_DLV_ERROR);
}
uncompressed_len = size;
/* Not using addralign.
READ_UNALIGNED(dbg,addralign,Dwarf_Unsigned,ptr,fldsize); */
src += structsize;
srclen -= structsize;
} else {
DWARF_DBG_ERROR(dbg, DW_DLE_ZDEBUG_INPUT_FORMAT_ODD,
DW_DLV_ERROR);
}
{
/* According to zlib.net zlib essentially never expands
the data when compressing. There is no statement
about any effective limit in the compression factor
though we, here, assume such a limit to check
for sanity in the object file.
These tests are heuristics. */
Dwarf_Unsigned max_inflated_len = srclen*ALLOWED_ZLIB_INFLATION;
if (srclen > 50) {
/* If srclen not super tiny lets check the following. */
if (uncompressed_len < (srclen/2)) {
/* Violates the approximate invariant about
compression not actually inflating. */
DWARF_DBG_ERROR(dbg, DW_DLE_ZLIB_UNCOMPRESS_ERROR,
DW_DLV_ERROR);
}
}
if (max_inflated_len < srclen) {
/* The calculation overflowed. */
DWARF_DBG_ERROR(dbg, DW_DLE_ZLIB_UNCOMPRESS_ERROR, DW_DLV_ERROR);
}
if (uncompressed_len > max_inflated_len) {
DWARF_DBG_ERROR(dbg, DW_DLE_ZLIB_UNCOMPRESS_ERROR, DW_DLV_ERROR);
}
}
if( (src +srclen) > endsection) {
DWARF_DBG_ERROR(dbg, DW_DLE_ZLIB_SECTION_SHORT, DW_DLV_ERROR);
}
destlen = uncompressed_len;
dest = malloc(destlen);
if(!dest) {
DWARF_DBG_ERROR(dbg, DW_DLE_ALLOC_FAIL, DW_DLV_ERROR);
}
res = uncompress(dest,&destlen,src,srclen);
if (res == Z_BUF_ERROR) {
free(dest);
DWARF_DBG_ERROR(dbg, DW_DLE_ZLIB_BUF_ERROR, DW_DLV_ERROR);
} else if (res == Z_MEM_ERROR) {
free(dest);
DWARF_DBG_ERROR(dbg, DW_DLE_ALLOC_FAIL, DW_DLV_ERROR);
} else if (res != Z_OK) {
free(dest);
/* Probably Z_DATA_ERROR. */
DWARF_DBG_ERROR(dbg, DW_DLE_ZLIB_DATA_ERROR, DW_DLV_ERROR);
}
/* Z_OK */
section->dss_data = dest;
section->dss_size = destlen;
section->dss_data_was_malloc = TRUE;
section->dss_requires_decompress = FALSE;
return DW_DLV_OK;
}
#endif /* HAVE_ZLIB */
/* Load the ELF section with the specified index and set its
dss_data pointer to the memory where it was loaded. */
int
_dwarf_load_section(Dwarf_Debug dbg,
struct Dwarf_Section_s *section,
Dwarf_Error * error)
{
int res = DW_DLV_ERROR;
int err = 0;
struct Dwarf_Obj_Access_Interface_s *o = 0;
/* check to see if the section is already loaded */
if (section->dss_data != NULL) {
return DW_DLV_OK;
}
o = dbg->de_obj_file;
/* There is an elf convention that section index 0 is reserved,
and that section is always empty.
Non-elf object formats must honor that by ensuring that
(when they assign numbers to 'sections' or 'section-like-things')
they never assign a real section section-number 0 to dss_index.
There is also a convention for 'bss' that that section and its
like sections have no data but do have a size.
That is never true of DWARF sections */
res = o->methods->load_section(
o->object, section->dss_index,
§ion->dss_data, &err);
if (res == DW_DLV_ERROR) {
DWARF_DBG_ERROR(dbg, err, DW_DLV_ERROR);
}
if (res == DW_DLV_NO_ENTRY) {
/* Gets this for section->dss_index 0.
Which by ELF definition is a section index
which is not used (reserved by Elf to
mean no-section-index).
Otherwise NULL dss_data gets error.
BSS would legitimately have no data, but
no DWARF related section could possbly be bss. */
return res;
}
if (section->dss_requires_decompress) {
if (!section->dss_data) {
/* Impossible. This makes no sense.
Corrupt object. */
DWARF_DBG_ERROR(dbg, DW_DLE_COMPRESSED_EMPTY_SECTION, DW_DLV_ERROR);
}
#ifdef HAVE_ZLIB
res = do_decompress_zlib(dbg,section,error);
if (res != DW_DLV_OK) {
return res;
}
#else
DWARF_DBG_ERROR(dbg,DW_DLE_ZDEBUG_REQUIRES_ZLIB, DW_DLV_ERROR);
#endif
}
if (_dwarf_apply_relocs == 0) {
return res;
}
if (section->dss_reloc_size == 0) {
return res;
}
if (!o->methods->relocate_a_section) {
return res;
}
/*apply relocations */
res = o->methods->relocate_a_section( o->object, section->dss_index,
dbg, &err);
if (res == DW_DLV_ERROR) {
DWARF_DBG_ERROR(dbg, err, DW_DLV_ERROR);
}
return res;
}
/* This is a hack so clients can verify offsets.
Added April 2005 so that debugger can detect broken offsets
(which happened in an IRIX -64 executable larger than 2GB
using MIPSpro 7.3.1.3 compilers. A couple .debug_pubnames
offsets were wrong.).
*/
int
dwarf_get_section_max_offsets(Dwarf_Debug dbg,
Dwarf_Unsigned * debug_info_size,
Dwarf_Unsigned * debug_abbrev_size,
Dwarf_Unsigned * debug_line_size,
Dwarf_Unsigned * debug_loc_size,
Dwarf_Unsigned * debug_aranges_size,
Dwarf_Unsigned * debug_macinfo_size,
Dwarf_Unsigned * debug_pubnames_size,
Dwarf_Unsigned * debug_str_size,
Dwarf_Unsigned * debug_frame_size,
Dwarf_Unsigned * debug_ranges_size,
Dwarf_Unsigned * debug_typenames_size)
{
*debug_info_size = dbg->de_debug_info.dss_size;
*debug_abbrev_size = dbg->de_debug_abbrev.dss_size;
*debug_line_size = dbg->de_debug_line.dss_size;
*debug_loc_size = dbg->de_debug_loc.dss_size;
*debug_aranges_size = dbg->de_debug_aranges.dss_size;
*debug_macinfo_size = dbg->de_debug_macinfo.dss_size;
*debug_pubnames_size = dbg->de_debug_pubnames.dss_size;
*debug_str_size = dbg->de_debug_str.dss_size;
*debug_frame_size = dbg->de_debug_frame.dss_size;
*debug_ranges_size = dbg->de_debug_ranges.dss_size;
*debug_typenames_size = dbg->de_debug_typenames.dss_size;
return DW_DLV_OK;
}
/* This adds the new types size (new section) to the output data.
Oct 27, 2011. */
int
dwarf_get_section_max_offsets_b(Dwarf_Debug dbg,
Dwarf_Unsigned * debug_info_size,
Dwarf_Unsigned * debug_abbrev_size,
Dwarf_Unsigned * debug_line_size,
Dwarf_Unsigned * debug_loc_size,
Dwarf_Unsigned * debug_aranges_size,
Dwarf_Unsigned * debug_macinfo_size,
Dwarf_Unsigned * debug_pubnames_size,
Dwarf_Unsigned * debug_str_size,
Dwarf_Unsigned * debug_frame_size,
Dwarf_Unsigned * debug_ranges_size,
Dwarf_Unsigned * debug_typenames_size,
Dwarf_Unsigned * debug_types_size)
{
*debug_info_size = dbg->de_debug_info.dss_size;
*debug_abbrev_size = dbg->de_debug_abbrev.dss_size;
*debug_line_size = dbg->de_debug_line.dss_size;
*debug_loc_size = dbg->de_debug_loc.dss_size;
*debug_aranges_size = dbg->de_debug_aranges.dss_size;
*debug_macinfo_size = dbg->de_debug_macinfo.dss_size;
*debug_pubnames_size = dbg->de_debug_pubnames.dss_size;
*debug_str_size = dbg->de_debug_str.dss_size;
*debug_frame_size = dbg->de_debug_frame.dss_size;
*debug_ranges_size = dbg->de_debug_ranges.dss_size;
*debug_typenames_size = dbg->de_debug_typenames.dss_size;
*debug_types_size = dbg->de_debug_types.dss_size;
return DW_DLV_OK;
}
/* Now with sections new to DWARF5 (unofficial list,preliminary) */
int
dwarf_get_section_max_offsets_c(Dwarf_Debug dbg,
Dwarf_Unsigned * debug_info_size,
Dwarf_Unsigned * debug_abbrev_size,
Dwarf_Unsigned * debug_line_size,
Dwarf_Unsigned * debug_loc_size,
Dwarf_Unsigned * debug_aranges_size,
Dwarf_Unsigned * debug_macinfo_size,
Dwarf_Unsigned * debug_pubnames_size,
Dwarf_Unsigned * debug_str_size,
Dwarf_Unsigned * debug_frame_size,
Dwarf_Unsigned * debug_ranges_size,
Dwarf_Unsigned * debug_typenames_size,
Dwarf_Unsigned * debug_types_size,
Dwarf_Unsigned * debug_macro_size,
Dwarf_Unsigned * debug_str_offsets_size,
Dwarf_Unsigned * debug_sup_size,
Dwarf_Unsigned * debug_cu_index_size,
Dwarf_Unsigned * debug_tu_index_size)
{
*debug_info_size = dbg->de_debug_info.dss_size;
*debug_abbrev_size = dbg->de_debug_abbrev.dss_size;
*debug_line_size = dbg->de_debug_line.dss_size;
*debug_loc_size = dbg->de_debug_loc.dss_size;
*debug_aranges_size = dbg->de_debug_aranges.dss_size;
*debug_macinfo_size = dbg->de_debug_macinfo.dss_size;
*debug_pubnames_size = dbg->de_debug_pubnames.dss_size;
*debug_str_size = dbg->de_debug_str.dss_size;
*debug_frame_size = dbg->de_debug_frame.dss_size;
*debug_ranges_size = dbg->de_debug_ranges.dss_size;
*debug_typenames_size = dbg->de_debug_typenames.dss_size;
*debug_types_size = dbg->de_debug_types.dss_size;
*debug_macro_size = dbg->de_debug_macro.dss_size;
*debug_str_offsets_size = dbg->de_debug_str_offsets.dss_size;
*debug_sup_size = dbg->de_debug_sup.dss_size;
*debug_cu_index_size = dbg->de_debug_cu_index.dss_size;
*debug_tu_index_size = dbg->de_debug_tu_index.dss_size;
return DW_DLV_OK;
}
/* Now with final sections new to DWARF5 (final) */
int
dwarf_get_section_max_offsets_d(Dwarf_Debug dbg,
Dwarf_Unsigned * debug_info_size,
Dwarf_Unsigned * debug_abbrev_size,
Dwarf_Unsigned * debug_line_size,
Dwarf_Unsigned * debug_loc_size,
Dwarf_Unsigned * debug_aranges_size,
Dwarf_Unsigned * debug_macinfo_size,
Dwarf_Unsigned * debug_pubnames_size,
Dwarf_Unsigned * debug_str_size,
Dwarf_Unsigned * debug_frame_size,
Dwarf_Unsigned * debug_ranges_size,
Dwarf_Unsigned * debug_typenames_size,
Dwarf_Unsigned * debug_types_size,
Dwarf_Unsigned * debug_macro_size,
Dwarf_Unsigned * debug_str_offsets_size,
Dwarf_Unsigned * debug_sup_size,
Dwarf_Unsigned * debug_cu_index_size,
Dwarf_Unsigned * debug_tu_index_size,
Dwarf_Unsigned * debug_names_size,
Dwarf_Unsigned * debug_loclists_size,
Dwarf_Unsigned * debug_rnglists_size)
{
*debug_info_size = dbg->de_debug_info.dss_size;
*debug_abbrev_size = dbg->de_debug_abbrev.dss_size;
*debug_line_size = dbg->de_debug_line.dss_size;
*debug_loc_size = dbg->de_debug_loc.dss_size;
*debug_aranges_size = dbg->de_debug_aranges.dss_size;
*debug_macinfo_size = dbg->de_debug_macinfo.dss_size;
*debug_pubnames_size = dbg->de_debug_pubnames.dss_size;
*debug_str_size = dbg->de_debug_str.dss_size;
*debug_frame_size = dbg->de_debug_frame.dss_size;
*debug_ranges_size = dbg->de_debug_ranges.dss_size;
*debug_typenames_size = dbg->de_debug_typenames.dss_size;
*debug_types_size = dbg->de_debug_types.dss_size;
*debug_macro_size = dbg->de_debug_macro.dss_size;
*debug_str_offsets_size = dbg->de_debug_str_offsets.dss_size;
*debug_sup_size = dbg->de_debug_sup.dss_size;
*debug_cu_index_size = dbg->de_debug_cu_index.dss_size;
*debug_tu_index_size = dbg->de_debug_tu_index.dss_size;
*debug_names_size = dbg->de_debug_names.dss_size;
*debug_loclists_size = dbg->de_debug_loclists.dss_size;
*debug_rnglists_size = dbg->de_debug_rnglists.dss_size;
return DW_DLV_OK;
}
/* Given a section name, get its size and address */
int
dwarf_get_section_info_by_name(Dwarf_Debug dbg,
const char *section_name,
Dwarf_Addr *section_addr,
Dwarf_Unsigned *section_size,
Dwarf_Error * error)
{
struct Dwarf_Obj_Access_Section_s doas;
struct Dwarf_Obj_Access_Interface_s * obj = 0;
Dwarf_Unsigned section_count = 0;
Dwarf_Half section_index = 0;
*section_addr = 0;
*section_size = 0;
obj = dbg->de_obj_file;
if (NULL == obj) {
return DW_DLV_NO_ENTRY;
}
section_count = obj->methods->get_section_count(obj->object);
/* We can skip index 0 when considering ELF files, but not other
object types. */
for (section_index = 0; section_index < section_count;
++section_index) {
int err = 0;
int res = obj->methods->get_section_info(obj->object,
section_index, &doas, &err);
if (res == DW_DLV_ERROR) {
DWARF_DBG_ERROR(dbg, err, DW_DLV_ERROR);
}
if (!strcmp(section_name,doas.name)) {
*section_addr = doas.addr;
*section_size = doas.size;
return DW_DLV_OK;
}
}
return DW_DLV_NO_ENTRY;
}
/* Given a section index, get its size and address */
int
dwarf_get_section_info_by_index(Dwarf_Debug dbg,
int section_index,
const char **section_name,
Dwarf_Addr *section_addr,
Dwarf_Unsigned *section_size,
Dwarf_Error * error)
{
*section_addr = 0;
*section_size = 0;
*section_name = NULL;
/* Check if we have a valid section index */
if (section_index >= 0 && section_index < dwarf_get_section_count(dbg)) {
int res = 0;
int err = 0;
struct Dwarf_Obj_Access_Section_s doas;
struct Dwarf_Obj_Access_Interface_s * obj = dbg->de_obj_file;
if (NULL == obj) {
return DW_DLV_NO_ENTRY;
}
res = obj->methods->get_section_info(obj->object,
section_index, &doas, &err);
if (res == DW_DLV_ERROR){
DWARF_DBG_ERROR(dbg, err, DW_DLV_ERROR);
}
*section_addr = doas.addr;
*section_size = doas.size;
*section_name = doas.name;
return DW_DLV_OK;
}
return DW_DLV_NO_ENTRY;
}
/* Get section count */
int
dwarf_get_section_count(Dwarf_Debug dbg)
{
struct Dwarf_Obj_Access_Interface_s * obj = dbg->de_obj_file;
if (NULL == obj) {
/* -1 */
return DW_DLV_NO_ENTRY;
}
return obj->methods->get_section_count(obj->object);
}
Dwarf_Cmdline_Options dwarf_cmdline_options = {
FALSE /* Use quiet mode by default. */
};
/* Lets libdwarf reflect a command line option, so we can get details
of some errors printed using libdwarf-internal information. */
void
dwarf_record_cmdline_options(Dwarf_Cmdline_Options options)
{
dwarf_cmdline_options = options;
}