/*
Copyright (C) 2000-2005 Silicon Graphics, Inc. All Rights Reserved.
Portions Copyright 2007-2010 Sun Microsystems, Inc. All rights reserved.
Portions Copyright 2008-2010 Arxan Technologies, Inc. All Rights Reserved.
Portions Copyright 2009-2017 David Anderson. All rights reserved.
Portions Copyright 2009-2010 Novell Inc. All rights reserved.
Portions Copyright 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 "dwarf_elf_access.h"
/* Include Relocation definitions in the case of Windows */
#ifdef _WIN32
#include "dwarf_reloc_arm.h"
#include "dwarf_reloc_mips.h"
#include "dwarf_reloc_ppc.h"
#include "dwarf_reloc_ppc64.h"
#include "dwarf_reloc_x86_64.h"
#include "dwarf_reloc_386.h"
#endif /* _WIN32 */
#ifdef HAVE_ELF_H
#include <elf.h>
/* Relocation definitions are in sys/elf_{mach}.h on Solaris. */
#ifdef HAVE_SYS_ELF_AMD64_H
#include <sys/elf_amd64.h>
#endif
#ifdef HAVE_SYS_ELF_386_H
#include <sys/elf_386.h>
#endif
#ifdef HAVE_SYS_ELF_SPARC_H
#include <sys/elf_SPARC.h>
#endif
#endif
#ifdef HAVE_LIBELF_H
#include <libelf.h>
#else
#ifdef HAVE_LIBELF_LIBELF_H
#include <libelf/libelf.h>
#else
#error Without libelf.h dwarf_elf_access.c cannot compile, so giving up.
#endif
#endif
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <string.h>
#include <stdlib.h>
#define FALSE 0
#define TRUE 1
#ifndef EM_MIPS
/* This is the standard elf value EM_MIPS. */
#define EM_MIPS 8
#endif
#ifndef EM_K10M
#define EM_K10M 181 /* Intel K10M */
#endif
#ifndef EM_L10M
#define EM_L10M 180 /* Intel L10M */
#endif
#ifndef EM_AARCH64
#define EM_AARCH64 183 /* Arm 64 */
#endif
#ifndef R_AARCH64_ABS64
#define R_AARCH64_ABS64 0x101
#endif
#ifndef R_AARCH64_ABS32
#define R_AARCH64_ABS32 0x102
#endif
#ifndef R_MIPS_64
#define R_MIPS_64 18
#endif
#ifndef R_MIPS_TLS_TPREL64
#define R_MIPS_TLS_TPREL64 48
#endif
#ifndef EM_IA_64
#define EM_IA_64 50
#endif
#ifndef R_IA64_SECREL32LSB
#define R_IA64_SECREL32LSB 0x65
#endif
#ifndef R_IA64_DIR32MSB
#define R_IA64_DIR32MSB 0x24
#endif
#ifndef R_IA64_DIR32LSB
#define R_IA64_DIR32LSB 0x25
#endif
#ifndef R_IA64_DIR64MSB
#define R_IA64_DIR64MSB 0x26
#endif
#ifndef R_IA64_DIR64LSB
#define R_IA64_DIR64LSB 0x27
#endif
#ifndef R_IA64_SECREL64LSB
#define R_IA64_SECREL64LSB 0x67
#endif
#ifndef R_IA64_SECREL64MSB
#define R_IA64_SECREL64MSB 0x66
#endif
#ifndef R_IA64_DTPREL32LSB
#define R_IA64_DTPREL32LSB 0xb5
#endif
#ifndef R_IA64_DTPREL32MSB
#define R_IA64_DTPREL32MSB 0xb4
#endif
#ifndef R_IA64_DTPREL64LSB
#define R_IA64_DTPREL64LSB 0xb7
#endif
#ifndef R_IA64_DTPREL64MSB
#define R_IA64_DTPREL64MSB 0xb6
#endif
#ifndef EM_S390
#define EM_S390 22
#endif
#ifndef R_390_TLS_LDO32
#define R_390_TLS_LDO32 52
#endif
#ifndef R_390_TLS_LDO64
#define R_390_TLS_LDO64 53
#endif
#ifndef R_390_32
#define R_390_32 4
#endif
#ifndef R_390_64
#define R_390_64 22
#endif
#ifndef EM_SH
#define EM_SH 42
#endif
#ifndef R_SH_DIR32
#define R_SH_DIR32 1
#endif
#ifndef R_SH_TLS_DTPOFF32
#define R_SH_TLS_DTPOFF32 150
#endif
#ifdef HAVE_ELF64_GETEHDR
extern Elf64_Ehdr *elf64_getehdr(Elf *);
#endif
#ifdef HAVE_ELF64_GETSHDR
extern Elf64_Shdr *elf64_getshdr(Elf_Scn *);
#endif
#ifdef WORDS_BIGENDIAN
#define WRITE_UNALIGNED(dbg,dest,source, srclength,len_out) \
{ \
dbg->de_copy_word(dest, \
((char *)source) +srclength-len_out, \
len_out) ; \
}
#else /* LITTLE ENDIAN */
#define WRITE_UNALIGNED(dbg,dest,source, srclength,len_out) \
{ \
dbg->de_copy_word( (dest) , \
((char *)source) , \
len_out) ; \
}
#endif
typedef struct {
dwarf_elf_handle elf;
int is_64bit;
Dwarf_Small length_size;
Dwarf_Small pointer_size;
Dwarf_Unsigned section_count;
Dwarf_Endianness endianness;
Dwarf_Small machine;
int libdwarf_owns_elf;
Elf32_Ehdr *ehdr32;
#ifdef HAVE_ELF64_GETEHDR
Elf64_Ehdr *ehdr64;
#endif
/* Elf symtab and its strtab. Initialized at first
call to do relocations, the actual data is in the Dwarf_Debug
struct, not allocated locally here. */
struct Dwarf_Section_s *symtab;
struct Dwarf_Section_s *strtab;
} dwarf_elf_object_access_internals_t;
struct Dwarf_Elf_Rela {
Dwarf_ufixed64 r_offset;
/*Dwarf_ufixed64 r_info; */
Dwarf_ufixed64 r_type;
Dwarf_ufixed64 r_symidx;
Dwarf_ufixed64 r_addend;
};
static int dwarf_elf_object_access_load_section(void* obj_in,
Dwarf_Half section_index,
Dwarf_Small** section_data,
int* error);
/* dwarf_elf_object_access_internals_init()
On error, set *error with libdwarf error code.
*/
static int
dwarf_elf_object_access_internals_init(void* obj_in,
dwarf_elf_handle elf,
int* error)
{
dwarf_elf_object_access_internals_t*obj =
(dwarf_elf_object_access_internals_t*)obj_in;
char *ehdr_ident = 0;
Dwarf_Half machine = 0;
obj->elf = elf;
if ((ehdr_ident = elf_getident(elf, NULL)) == NULL) {
*error = DW_DLE_ELF_GETIDENT_ERROR;
return DW_DLV_ERROR;
}
obj->is_64bit = (ehdr_ident[EI_CLASS] == ELFCLASS64);
if (ehdr_ident[EI_DATA] == ELFDATA2LSB){
obj->endianness = DW_OBJECT_LSB;
} else if (ehdr_ident[EI_DATA] == ELFDATA2MSB){
obj->endianness = DW_OBJECT_MSB;
}
if (obj->is_64bit) {
#ifdef HAVE_ELF64_GETEHDR
obj->ehdr64 = elf64_getehdr(elf);
if (obj->ehdr64 == NULL) {
*error = DW_DLE_ELF_GETEHDR_ERROR;
return DW_DLV_ERROR;
}
obj->section_count = obj->ehdr64->e_shnum;
machine = obj->ehdr64->e_machine;
obj->machine = machine;
#else
*error = DW_DLE_NO_ELF64_SUPPORT;
return DW_DLV_ERROR;
#endif
} else {
obj->ehdr32 = elf32_getehdr(elf);
if (obj->ehdr32 == NULL) {
*error = DW_DLE_ELF_GETEHDR_ERROR;
return DW_DLV_ERROR;
}
obj->section_count = obj->ehdr32->e_shnum;
machine = obj->ehdr32->e_machine;
obj->machine = machine;
}
/* The following length_size is Not Too Significant. Only used
one calculation, and an approximate one at that. */
obj->length_size = obj->is_64bit ? 8 : 4;
obj->pointer_size = obj->is_64bit ? 8 : 4;
#ifdef _WIN32
if (obj->is_64bit && machine == EM_PPC64) {
/* The SNC compiler generates the EM_PPC64 machine type for the
PS3 platform, but is a 32 bits pointer size in user mode. */
obj->pointer_size = 4;
}
#endif /* _WIN32 */
if (obj->is_64bit && machine != EM_MIPS) {
/* MIPS/IRIX makes pointer size and length size 8 for -64.
Other platforms make length 4 always. */
/* 4 here supports 32bit-offset dwarf2, as emitted by cygnus
tools, and the dwarfv2.1 64bit extension setting.
This is not the same as the size-of-an-offset, which
is 4 in 32bit dwarf and 8 in 64bit dwarf. */
obj->length_size = 4;
}
return DW_DLV_OK;
}
/* dwarf_elf_object_access_get_byte_order */
static
Dwarf_Endianness
dwarf_elf_object_access_get_byte_order(void* obj_in)
{
dwarf_elf_object_access_internals_t*obj =
(dwarf_elf_object_access_internals_t*)obj_in;
return obj->endianness;
}
/* dwarf_elf_object_access_get_section_count() */
static
Dwarf_Unsigned
dwarf_elf_object_access_get_section_count(void * obj_in)
{
dwarf_elf_object_access_internals_t*obj =
(dwarf_elf_object_access_internals_t*)obj_in;
return obj->section_count;
}
static int
_dwarf_get_elf_flags_func(
void* obj_in,
Dwarf_Half section_index,
Dwarf_Unsigned *flags_out,
Dwarf_Unsigned *addralign_out,
int *error)
{
dwarf_elf_object_access_internals_t*obj =
(dwarf_elf_object_access_internals_t*)obj_in;
Elf32_Shdr *shdr32 = 0;
#ifdef HAVE_ELF64_GETSHDR
Elf64_Shdr *shdr64 = 0;
#endif
Elf_Scn *scn = 0;
scn = elf_getscn(obj->elf, section_index);
if (scn == NULL) {
*error = DW_DLE_MDE;
return DW_DLV_ERROR;
}
if (obj->is_64bit) {
#ifdef HAVE_ELF64_GETSHDR
shdr64 = elf64_getshdr(scn);
if (shdr64 == NULL) {
*error = DW_DLE_ELF_GETSHDR_ERROR;
return DW_DLV_ERROR;
}
/* Get also section 'sh_type' and sh_info' fields, so the caller
can use it for additional tasks that require that info. */
*flags_out = shdr64->sh_flags;
*addralign_out = shdr64->sh_addralign;
return DW_DLV_OK;
#else
*error = DW_DLE_MISSING_ELF64_SUPPORT;
return DW_DLV_ERROR;
#endif /* HAVE_ELF64_GETSHDR */
}
if ((shdr32 = elf32_getshdr(scn)) == NULL) {
*error = DW_DLE_ELF_GETSHDR_ERROR;
return DW_DLV_ERROR;
}
/* Get also the section type, so the caller can use it for
additional tasks that require to know the section type. */
*flags_out = shdr32->sh_flags;
*addralign_out = shdr32->sh_addralign;
return DW_DLV_OK;
}
/* dwarf_elf_object_access_get_section()
If writing a function vaguely like this for a non-elf object,
be sure that when section-index is passed in as zero that
you set the fields in *ret_scn_doas to reflect an empty section
with an empty string as the section name. Adjust your
section indexes of your non-elf-reading-code
for all the necessary functions in Dwarf_Obj_Access_Methods_s
accordingly.
Should have gotten sh_flags, sh_addralign too.
But Dwarf_Obj_Access_Section is publically defined so changing
it is quite painful for everyone.
*/
static
int
dwarf_elf_object_access_get_section_info(
void* obj_in,
Dwarf_Half section_index,
Dwarf_Obj_Access_Section* ret_scn_doas,
int* error)
{
dwarf_elf_object_access_internals_t*obj =
(dwarf_elf_object_access_internals_t*)obj_in;
Elf32_Shdr *shdr32 = 0;
#ifdef HAVE_ELF64_GETSHDR
Elf64_Shdr *shdr64 = 0;
#endif
Elf_Scn *scn = 0;
scn = elf_getscn(obj->elf, section_index);
if (scn == NULL) {
*error = DW_DLE_MDE;
return DW_DLV_ERROR;
}
if (obj->is_64bit) {
#ifdef HAVE_ELF64_GETSHDR
shdr64 = elf64_getshdr(scn);
if (shdr64 == NULL) {
*error = DW_DLE_ELF_GETSHDR_ERROR;
return DW_DLV_ERROR;
}
/* Get also section 'sh_type' and sh_info' fields, so the caller
can use it for additional tasks that require that info. */
ret_scn_doas->type = shdr64->sh_type;
ret_scn_doas->size = shdr64->sh_size;
ret_scn_doas->addr = shdr64->sh_addr;
ret_scn_doas->link = shdr64->sh_link;
ret_scn_doas->info = shdr64->sh_info;
ret_scn_doas->entrysize = shdr64->sh_entsize;
ret_scn_doas->name = elf_strptr(obj->elf, obj->ehdr64->e_shstrndx,
shdr64->sh_name);
if (ret_scn_doas->name == NULL) {
*error = DW_DLE_ELF_STRPTR_ERROR;
return DW_DLV_ERROR;
}
return DW_DLV_OK;
#else
*error = DW_DLE_MISSING_ELF64_SUPPORT;
return DW_DLV_ERROR;
#endif /* HAVE_ELF64_GETSHDR */
}
if ((shdr32 = elf32_getshdr(scn)) == NULL) {
*error = DW_DLE_ELF_GETSHDR_ERROR;
return DW_DLV_ERROR;
}
/* Get also the section type, so the caller can use it for
additional tasks that require to know the section type. */
ret_scn_doas->type = shdr32->sh_type;
ret_scn_doas->size = shdr32->sh_size;
ret_scn_doas->addr = shdr32->sh_addr;
ret_scn_doas->link = shdr32->sh_link;
ret_scn_doas->info = shdr32->sh_info;
ret_scn_doas->entrysize = shdr32->sh_entsize;
ret_scn_doas->name = elf_strptr(obj->elf, obj->ehdr32->e_shstrndx,
shdr32->sh_name);
if (ret_scn_doas->name == NULL) {
*error = DW_DLE_ELF_STRPTR_ERROR;
return DW_DLV_ERROR;
}
return DW_DLV_OK;
}
/* dwarf_elf_object_access_get_length_size */
static
Dwarf_Small
dwarf_elf_object_access_get_length_size(void* obj_in)
{
dwarf_elf_object_access_internals_t*obj =
(dwarf_elf_object_access_internals_t*)obj_in;
return obj->length_size;
}
/* dwarf_elf_object_access_get_pointer_size */
static
Dwarf_Small
dwarf_elf_object_access_get_pointer_size(void* obj_in)
{
dwarf_elf_object_access_internals_t*obj =
(dwarf_elf_object_access_internals_t*)obj_in;
return obj->pointer_size;
}
#define MATCH_REL_SEC(i_,s_,r_) \
if (i_ == s_.dss_index) { \
*r_ = &s_; \
return DW_DLV_OK; \
}
static int
find_section_to_relocate(Dwarf_Debug dbg,Dwarf_Half section_index,
struct Dwarf_Section_s **relocatablesec, int *error)
{
MATCH_REL_SEC(section_index,dbg->de_debug_info,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_abbrev,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_line,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_loc,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_aranges,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_macinfo,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_pubnames,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_ranges,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_frame,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_frame_eh_gnu,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_pubtypes,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_funcnames,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_typenames,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_varnames,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_weaknames,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_types,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_macro,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_rnglists,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_loclists,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_aranges,relocatablesec);
MATCH_REL_SEC(section_index,dbg->de_debug_sup,relocatablesec);
/* dbg-> de_debug_tu_index,reloctablesec); */
/* dbg-> de_debug_cu_index,reloctablesec); */
/* dbg-> de_debug_gdbindex,reloctablesec); */
/* dbg-> de_debug_str,syms); */
/* de_elf_symtab,syms); */
/* de_elf_strtab,syms); */
*error = DW_DLE_RELOC_SECTION_MISMATCH;
return DW_DLV_ERROR;
}
#undef MATCH_REL_SEC
static void
get_rela_elf32(Dwarf_Small *data, unsigned int i,
UNUSEDARG int endianness,
UNUSEDARG int machine,
struct Dwarf_Elf_Rela *relap)
{
Elf32_Rela *relp = (Elf32_Rela*)(data + (i * sizeof(Elf32_Rela)));
relap->r_offset = relp->r_offset;
/*
relap->r_info = relp->r_info;
*/
relap->r_type = ELF32_R_TYPE(relp->r_info);
relap->r_symidx = ELF32_R_SYM(relp->r_info);
relap->r_addend = relp->r_addend;
}
static void
get_rela_elf64(Dwarf_Small *data, unsigned int i,
int endianness,
int machine,
struct Dwarf_Elf_Rela *relap)
{
#ifdef HAVE_ELF64_RELA
Elf64_Rela * relp = (Elf64_Rela*)(data + (i * sizeof(Elf64_Rela)));
relap->r_offset = relp->r_offset;
/*
relap->r_info = relp->r_info;
*/
#define ELF64MIPS_REL_SYM(i) ((i) & 0xffffffff)
#define ELF64MIPS_REL_TYPE(i) ((i >> 56) &0xff)
if (machine == EM_MIPS && endianness == DW_OBJECT_LSB ){
/* This is really wierd. Treat this very specially.
The Elf64 LE MIPS object used for
testing (that has rela) wants the
values as sym ssym type3 type2 type, treating
each value as independent value. But libelf xlate
treats it as something else so we fudge here.
It is unclear
how to precisely characterize where these relocations
were used.
SGI MIPS on IRIX never used .rela relocations.
The BE 64bit elf MIPS test object with rela uses traditional
elf relocation layouts, not this special case. */
/* We ignore the special TYPE2 and TYPE3, they should be
value R_MIPS_NONE in rela. */
relap->r_type = ELF64MIPS_REL_TYPE(relp->r_info);
relap->r_symidx = ELF64MIPS_REL_SYM(relp->r_info);
#undef MIPS64SYM
#undef MIPS64TYPE
} else
{
relap->r_type = ELF64_R_TYPE(relp->r_info);
relap->r_symidx = ELF64_R_SYM(relp->r_info);
}
relap->r_addend = relp->r_addend;
#endif
}
static void
get_relocations_array(Dwarf_Bool is_64bit,
int endianness,
int machine,
Dwarf_Small *data,
unsigned int num_relocations,
struct Dwarf_Elf_Rela *relap)
{
unsigned int i = 0;
void (*get_relocations)(Dwarf_Small *data, unsigned int i,
int endianness,
int machine,
struct Dwarf_Elf_Rela *relap);
/* Handle 32/64 bit issue */
if (is_64bit) {
get_relocations = get_rela_elf64;
} else {
get_relocations = get_rela_elf32;
}
for (i=0; i < num_relocations; i++) {
get_relocations(data, i,endianness,machine,
&(relap[i]));
}
}
static int
get_relocation_entries(Dwarf_Bool is_64bit,
int endianness,
int machine,
Dwarf_Small *relocation_section,
Dwarf_Unsigned relocation_section_size,
Dwarf_Unsigned relocation_section_entrysize,
struct Dwarf_Elf_Rela **relas,
unsigned int *nrelas,
int *error)
{
unsigned int relocation_size = 0;
if (is_64bit) {
#ifdef HAVE_ELF64_RELA
relocation_size = sizeof(Elf64_Rela);
#else
*error = DW_DLE_MISSING_ELF64_SUPPORT;
return DW_DLV_ERROR;
#endif
} else {
relocation_size = sizeof(Elf32_Rela);
}
if (relocation_size != relocation_section_entrysize) {
/* Means our struct definition does not match the
real object. */
*error = DW_DLE_RELOC_SECTION_LENGTH_ODD;
return DW_DLV_ERROR;
}
if (relocation_section == NULL) {
*error = DW_DLE_RELOC_SECTION_PTR_NULL;
return(DW_DLV_ERROR);
}
if ((relocation_section_size != 0)) {
size_t bytescount = 0;
if (relocation_section_size%relocation_size) {
*error = DW_DLE_RELOC_SECTION_LENGTH_ODD;
return DW_DLV_ERROR;
}
*nrelas = relocation_section_size/relocation_size;
bytescount = (*nrelas) * sizeof(struct Dwarf_Elf_Rela);
*relas = malloc(bytescount);
if (!*relas) {
*error = DW_DLE_MAF;
return(DW_DLV_ERROR);
}
memset(*relas,0,bytescount);
get_relocations_array(is_64bit,endianness,machine,
relocation_section,
*nrelas, *relas);
}
return(DW_DLV_OK);
}
/* We have a EM_QUALCOMM_DSP6 relocatable object
test case in dwarf regression tests, atefail/ig_server.
Values for QUALCOMM were derived from this executable.
The r = 0 in the function will get optimized away
when not needed.
*/
#define EM_QUALCOMM_DSP6 0xa4
#define QUALCOMM_REL32 6
static Dwarf_Bool
is_32bit_abs_reloc(unsigned int type, Dwarf_Half machine)
{
Dwarf_Bool r = 0;
switch (machine) {
#if defined(EM_MIPS) && defined (R_MIPS_32)
case EM_MIPS:
r = (0
#if defined (R_MIPS_32)
| (type == R_MIPS_32)
#endif
#if defined (R_MIPS_TLS_DTPREL32)
| (type == R_MIPS_TLS_DTPREL32)
#endif /* DTPREL32 */
);
break;
#endif /* MIPS case */
#if defined(EM_SPARC32PLUS) && defined (R_SPARC_UA32)
case EM_SPARC32PLUS:
r = (0
#if defined(R_SPARC_UA32)
| (type == R_SPARC_UA32)
#endif
#if defined(R_SPARC_TLS_DTPOFF32)
| (type == R_SPARC_TLS_DTPOFF32)
#endif
);
break;
#endif
#if defined(EM_SPARCV9) && defined (R_SPARC_UA32)
case EM_SPARCV9:
r = (type == R_SPARC_UA32);
break;
#endif
#if defined(EM_SPARC) && defined (R_SPARC_UA32)
case EM_SPARC:
r = (0
#if defined(R_SPARC_UA32)
| (type == R_SPARC_UA32)
#endif
#if (R_SPARC_TLS_DTPOFF32)
| (type == R_SPARC_TLS_DTPOFF32)
#endif
);
break;
#endif /* EM_SPARC */
#if defined(EM_386) && defined (R_386_32)
case EM_386:
r = (0
#if defined (R_386_32)
| (type == R_386_32)
#endif
#if defined (R_386_TLS_LDO_32)
| (type == R_386_TLS_LDO_32)
#endif
#if defined (R_386_TLS_DTPOFF32)
| (type == R_386_TLS_DTPOFF32)
#endif
);
break;
#endif /* EM_386 */
#if defined (EM_SH) && defined (R_SH_DIR32)
case EM_SH:
r = (0
#if defined (R_SH_DIR32)
| (type == R_SH_DIR32)
#endif
#if defined (R_SH_DTPOFF32)
| (type == R_SH_TLS_DTPOFF32)
#endif
);
break;
#endif /* SH */
#if defined(EM_IA_64) && defined (R_IA64_SECREL32LSB)
case EM_IA_64: /* 32bit? ! */
r = (0
#if defined (R_IA64_SECREL32LSB)
| (type == R_IA64_SECREL32LSB)
#endif
#if defined (R_IA64_DIR32LSB)
| (type == R_IA64_DIR32LSB)
#endif
#if defined (R_IA64_DTPREL32LSB)
| (type == R_IA64_DTPREL32LSB)
#endif
);
break;
#endif /* EM_IA_64 */
#if defined(EM_ARM) && defined (R_ARM_ABS32)
case EM_ARM:
case EM_AARCH64:
r = (0
#if defined (R_ARM_ABS32)
| ( type == R_ARM_ABS32)
#endif
#if defined (R_AARCH64_ABS32)
| ( type == R_AARCH64_ABS32)
#endif
#if defined (R_ARM_TLS_LDO32)
| ( type == R_ARM_TLS_LDO32)
#endif
);
break;
#endif /* EM_ARM */
/* On FreeBSD R_PPC64_ADDR32 not defined
so we use the R_PPC_ names which
have the proper value.
Our headers have:
R_PPC64_ADDR64 38
R_PPC_ADDR32 1 so we use this one
R_PPC64_ADDR32 R_PPC_ADDR32
R_PPC64_DTPREL32 110 which may be wrong/unavailable
R_PPC64_DTPREL64 78
R_PPC_DTPREL32 78
*/
#if defined(EM_PPC64) && defined (R_PPC_ADDR32)
case EM_PPC64:
r = (0
#if defined(R_PPC_ADDR32)
| (type == R_PPC_ADDR32)
#endif
#if defined(R_PPC64_DTPREL32)
| (type == R_PPC64_DTPREL32)
#endif
);
break;
#endif /* EM_PPC64 */
#if defined(EM_PPC) && defined (R_PPC_ADDR32)
case EM_PPC:
r = (0
#if defined (R_PPC_ADDR32)
| (type == R_PPC_ADDR32)
#endif
#if defined (R_PPC_DTPREL32)
| (type == R_PPC_DTPREL32)
#endif
);
break;
#endif /* EM_PPC */
#if defined(EM_S390) && defined (R_390_32)
case EM_S390:
r = (0
#if defined (R_390_32)
| (type == R_390_32)
#endif
#if defined (R_390_TLS_LDO32)
| (type == R_390_TLS_LDO32)
#endif
);
break;
#endif /* EM_S390 */
#if defined(EM_X86_64) && ( defined(R_X86_64_32) || defined(R_X86_64_PC32) || defined(R_X86_64_DTPOFF32) )
#if defined(EM_K10M)
case EM_K10M:
#endif
#if defined(EM_L10M)
case EM_L10M:
#endif
case EM_X86_64:
r = (0
#if defined (R_X86_64_PC32)
| (type == R_X86_64_PC32)
#endif
#if defined (R_X86_64_32)
| (type == R_X86_64_32)
#endif
#if defined (R_X86_64_DTPOFF32)
| (type == R_X86_64_DTPOFF32)
#endif
);
break;
#endif /* EM_X86_64 */
case EM_QUALCOMM_DSP6:
r = (type == QUALCOMM_REL32);
break;
}
return r;
}
static Dwarf_Bool
is_64bit_abs_reloc(unsigned int type, Dwarf_Half machine)
{
Dwarf_Bool r = 0;
switch (machine) {
#if defined(EM_MIPS) && defined (R_MIPS_64)
case EM_MIPS:
r = (0
#if defined (R_MIPS_64)
| (type == R_MIPS_64)
#endif
#if defined (R_MIPS_32)
| (type == R_MIPS_32)
#endif
#if defined(R_MIPS_TLS_DTPREL64)
| (type == R_MIPS_TLS_DTPREL64)
#endif
);
break;
#endif /* EM_MIPS */
#if defined(EM_SPARC32PLUS) && defined (R_SPARC_UA64)
case EM_SPARC32PLUS:
r = (type == R_SPARC_UA64);
break;
#endif
#if defined(EM_SPARCV9) && defined (R_SPARC_UA64)
case EM_SPARCV9:
r = (0
#if defined (R_SPARC_UA64)
| (type == R_SPARC_UA64)
#endif
#if defined (R_SPARC_TLS_DTPOFF64)
| (type == R_SPARC_TLS_DTPOFF64)
#endif
);
break;
#endif
#if defined(EM_SPARC) && defined (R_SPARC_UA64)
case EM_SPARC:
r = (0
#if defined(R_SPARC_UA64)
| (type == R_SPARC_UA64)
#endif
#if defined (R_SPARC_TLS_DTPOFF64)
| (type == R_SPARC_TLS_DTPOFF64)
#endif
);
break;
#endif /* EM_SPARC */
#if defined(EM_IA_64) && defined (R_IA64_SECREL64LSB)
case EM_IA_64: /* 64bit */
r = (0
#if defined (R_IA64_SECREL64LSB)
| (type == R_IA64_SECREL64LSB)
#endif
#if defined (R_IA64_SECREL32LSB)
| (type == R_IA64_SECREL32LSB)
#endif
#if defined (R_IA64_DIR64LSB)
| (type == R_IA64_DIR64LSB)
#endif
#if defined (R_IA64_DTPREL64LSB)
| (type == R_IA64_DTPREL64LSB)
#endif
#if defined (R_IA64_REL32LSB)
| (type == R_IA64_REL32LSB)
#endif
);
break;
#endif /* EM_IA_64 */
#if defined(EM_PPC64) && defined (R_PPC64_ADDR64)
case EM_PPC64:
r = (0
#if defined(R_PPC64_ADDR64)
| (type == R_PPC64_ADDR64)
#endif
#if defined(R_PPC64_DTPREL64)
| (type == R_PPC64_DTPREL64)
#endif
);
break;
#endif /* EM_PPC64 */
#if defined(EM_S390) && defined (R_390_64)
case EM_S390:
r = (0
#if defined(R_390_64)
| (type == R_390_64)
#endif
#if defined(R_390_TLS_LDO64)
| (type == R_390_TLS_LDO64)
#endif
);
break;
#endif /* EM_390 */
#if defined(EM_X86_64) && defined (R_X86_64_64)
#if defined(EM_K10M)
case EM_K10M:
#endif
#if defined(EM_L10M)
case EM_L10M:
#endif
case EM_X86_64:
r = (0
#if defined (R_X86_64_64)
| (type == R_X86_64_64)
#endif
#if defined (R_X86_64_DTPOFF32)
| (type == R_X86_64_DTPOFF64)
#endif
);
break;
#endif /* EM_X86_64 */
#if defined(EM_AARCH64) && defined (R_AARCH64_ABS64)
case EM_AARCH64:
r = (0
#if defined (R_AARCH64_ABS64)
| ( type == R_AARCH64_ABS64)
#endif
);
break;
#endif /* EM_AARCH64 */
}
return r;
}
/* Returns DW_DLV_OK if it works, else DW_DLV_ERROR.
The caller may decide to ignore the errors or report them. */
static int
update_entry(Dwarf_Debug dbg,
Dwarf_Bool is_64bit,
UNUSEDARG Dwarf_Endianness endianess,
UNUSEDARG Dwarf_Half machine,
struct Dwarf_Elf_Rela *rela,
Dwarf_Small *target_section,
Dwarf_Unsigned target_section_size,
Dwarf_Small *symtab_section_data,
Dwarf_Unsigned symtab_section_size,
Dwarf_Unsigned symtab_section_entrysize,
int *error)
{
unsigned int type = 0;
unsigned int sym_idx = 0;
#ifdef HAVE_ELF64_SYM
Elf64_Sym sym_buf;
Elf64_Sym *sym = 0;
#else
Elf32_Sym sym_buf;
Elf32_Sym *sym = 0;
#endif
Elf32_Sym *sym32 = 0;
Dwarf_ufixed64 offset = 0;
Dwarf_sfixed64 addend = 0;
Dwarf_Unsigned reloc_size = 0;
Dwarf_Unsigned symtab_entry_count = 0;
if (symtab_section_entrysize == 0) {
*error = DW_DLE_SYMTAB_SECTION_ENTRYSIZE_ZERO;
return DW_DLV_ERROR;
}
symtab_entry_count = symtab_section_size/symtab_section_entrysize;
/* Dwarf_Elf_Rela dereferencing */
offset = rela->r_offset;
addend = rela->r_addend;
type = rela->r_type;
sym_idx = rela->r_symidx;
if (sym_idx >= symtab_entry_count) {
*error = DW_DLE_RELOC_SECTION_SYMBOL_INDEX_BAD;
return DW_DLV_ERROR;
}
if (offset >= target_section_size) {
/* If offset really big, any add will overflow.
So lets stop early if offset is corrupt. */
*error = DW_DLE_RELOC_INVALID;
return DW_DLV_ERROR;
}
if (is_64bit) {
#ifdef HAVE_ELF64_SYM
sym = &((Elf64_Sym*)symtab_section_data)[sym_idx];
#endif
} else {
sym32 = &((Elf32_Sym*)symtab_section_data)[sym_idx];
/* Convert Elf32_Sym struct to Elf64_Sym struct. We point at
an Elf64_Sym local variable (sym_buf) to allow us to use the
same pointer (sym) for both 32-bit and 64-bit instances. */
sym = &sym_buf;
sym->st_name = sym32->st_name;
sym->st_info = sym32->st_info;
sym->st_other = sym32->st_other;
sym->st_shndx = sym32->st_shndx;
sym->st_value = sym32->st_value;
sym->st_size = sym32->st_size;
}
/* Determine relocation size */
if (is_32bit_abs_reloc(type, machine)) {
reloc_size = 4;
} else if (is_64bit_abs_reloc(type, machine)) {
reloc_size = 8;
} else {
*error = DW_DLE_RELOC_SECTION_RELOC_TARGET_SIZE_UNKNOWN;
return DW_DLV_ERROR;
}
if ( (offset + reloc_size) < offset) {
/* Another check for overflow. */
*error = DW_DLE_RELOC_INVALID;
return DW_DLV_ERROR;
}
if ( (offset + reloc_size) > target_section_size) {
*error = DW_DLE_RELOC_INVALID;
return DW_DLV_ERROR;
}
{
/* Assuming we do not need to do a READ_UNALIGNED here
at target_section + offset and add its value to
outval. Some ABIs say no read (for example MIPS),
but if some do then which ones? */
Dwarf_Unsigned outval = sym->st_value + addend;
/* The 0th byte goes at offset. */
WRITE_UNALIGNED(dbg,target_section + offset,
&outval,sizeof(outval),reloc_size);
}
return DW_DLV_OK;
}
/* Somewhat arbitrarily, we attempt to apply all the relocations we can
and still notify the caller of at least one error if we found
any errors. */
static int
apply_rela_entries(Dwarf_Debug dbg,
Dwarf_Bool is_64bit,
Dwarf_Endianness endianess,
Dwarf_Half machine,
Dwarf_Small *target_section,
Dwarf_Unsigned target_section_size,
Dwarf_Small *symtab_section,
Dwarf_Unsigned symtab_section_size,
Dwarf_Unsigned symtab_section_entrysize,
struct Dwarf_Elf_Rela *relas, unsigned int nrelas,
int *error)
{
int return_res = DW_DLV_OK;
if ((target_section != NULL) && (relas != NULL)) {
unsigned int i;
if (symtab_section_entrysize == 0) {
*error = DW_DLE_SYMTAB_SECTION_ENTRYSIZE_ZERO;
return DW_DLV_ERROR;
}
if (symtab_section_size%symtab_section_entrysize) {
*error = DW_DLE_SYMTAB_SECTION_LENGTH_ODD;
return DW_DLV_ERROR;
}
for (i = 0; i < nrelas; i++) {
int res = update_entry(dbg, is_64bit,
endianess,
machine,
&(relas)[i],
target_section,
target_section_size,
symtab_section,
symtab_section_size,
symtab_section_entrysize,
error);
if (res != DW_DLV_OK) {
return_res = res;
}
}
}
return return_res;
}
static int
loop_through_relocations(
Dwarf_Debug dbg,
dwarf_elf_object_access_internals_t* obj,
struct Dwarf_Section_s *relocatablesec,
int *error)
{
Dwarf_Small *target_section = 0;
Dwarf_Small *symtab_section = obj->symtab->dss_data;
Dwarf_Unsigned symtab_section_entrysize = obj->symtab->dss_entrysize;
Dwarf_Unsigned symtab_section_size = obj->symtab->dss_size;
Dwarf_Small *relocation_section = relocatablesec->dss_reloc_data;
Dwarf_Unsigned relocation_section_size =
relocatablesec->dss_reloc_size;
Dwarf_Unsigned relocation_section_entrysize = relocatablesec->dss_reloc_entrysize;
int ret = DW_DLV_ERROR;
struct Dwarf_Elf_Rela *relas = 0;
unsigned int nrelas = 0;
Dwarf_Small *mspace = 0;
ret = get_relocation_entries(obj->is_64bit,
obj->endianness,
obj->machine,
relocation_section,
relocation_section_size,
relocation_section_entrysize,
&relas, &nrelas, error);
if (ret != DW_DLV_OK) {
free(relas);
return ret;
}
if(!relocatablesec->dss_data_was_malloc) {
/* Some systems read Elf in read-only memory via mmap or the like.
So the only safe thing is to copy the current data into
malloc space and refer to the malloc space instead of the
space returned by the elf library */
mspace = malloc(relocatablesec->dss_size);
if (!mspace) {
*error = DW_DLE_RELOC_SECTION_MALLOC_FAIL;
return DW_DLV_ERROR;
}
memcpy(mspace,relocatablesec->dss_data,relocatablesec->dss_size);
relocatablesec->dss_data = mspace;
target_section = relocatablesec->dss_data;
relocatablesec->dss_data_was_malloc = TRUE;
}
target_section = relocatablesec->dss_data;
ret = apply_rela_entries(
dbg,
obj->is_64bit,
obj->endianness, obj->machine,
target_section,
relocatablesec->dss_size,
symtab_section,
symtab_section_size,
symtab_section_entrysize,
relas, nrelas, error);
free(relas);
return ret;
}
/* Find the section data in dbg and find all the relevant
sections. Then do relocations.
*/
static int
dwarf_elf_object_relocate_a_section(void* obj_in,
Dwarf_Half section_index,
Dwarf_Debug dbg,
int* error)
{
int res = DW_DLV_ERROR;
dwarf_elf_object_access_internals_t*obj = 0;
struct Dwarf_Section_s * relocatablesec = 0;
if (section_index == 0) {
return DW_DLV_NO_ENTRY;
}
obj = (dwarf_elf_object_access_internals_t*)obj_in;
/* The section to relocate must already be loaded into memory. */
res = find_section_to_relocate(dbg, section_index,&relocatablesec,error);
if (res != DW_DLV_OK) {
return res;
}
/* Sun and possibly others do not always set sh_link in .debug_* sections.
So we cannot do full consistency checks. */
if (relocatablesec->dss_reloc_index == 0 ) {
/* Something is wrong. */
*error = DW_DLE_RELOC_SECTION_MISSING_INDEX;
return DW_DLV_ERROR;
}
/* Now load the relocations themselves. */
res = dwarf_elf_object_access_load_section(obj_in,
relocatablesec->dss_reloc_index,
&relocatablesec->dss_reloc_data, error);
if (res != DW_DLV_OK) {
return res;
}
/* Now get the symtab. */
if (!obj->symtab) {
obj->symtab = &dbg->de_elf_symtab;
obj->strtab = &dbg->de_elf_strtab;
}
if (obj->symtab->dss_index != relocatablesec->dss_reloc_link) {
/* Something is wrong. */
*error = DW_DLE_RELOC_MISMATCH_RELOC_INDEX;
return DW_DLV_ERROR;
}
if (obj->strtab->dss_index != obj->symtab->dss_link) {
/* Something is wrong. */
*error = DW_DLE_RELOC_MISMATCH_STRTAB_INDEX;
return DW_DLV_ERROR;
}
if (!obj->symtab->dss_data) {
/* Now load the symtab */
res = dwarf_elf_object_access_load_section(obj_in,
obj->symtab->dss_index,
&obj->symtab->dss_data, error);
if (res != DW_DLV_OK) {
return res;
}
}
if (!obj->strtab->dss_data) {
/* Now load the strtab */
res = dwarf_elf_object_access_load_section(obj_in,
obj->strtab->dss_index,
&obj->strtab->dss_data,error);
if (res != DW_DLV_OK){
return res;
}
}
/* We have all the data we need in memory. */
res = loop_through_relocations(dbg,obj,relocatablesec,error);
return res;
}
/* dwarf_elf_object_access_load_section()
We are only asked to load sections that
libdwarf really needs.
It would be much better if a 'user data pointer'
were passed through these interfaces so one
part of libdwarf could pass through to this.
Or even just if a Dwarf_Debug were passed in.
Sigh. */
static int
dwarf_elf_object_access_load_section(void* obj_in,
Dwarf_Half section_index,
Dwarf_Small** section_data,
int* error)
{
dwarf_elf_object_access_internals_t*obj =
(dwarf_elf_object_access_internals_t*)obj_in;
if (section_index == 0) {
return DW_DLV_NO_ENTRY;
}
{
Elf_Scn *scn = 0;
Elf_Data *data = 0;
scn = elf_getscn(obj->elf, section_index);
if (scn == NULL) {
/* The section_index does not exist or
obj->elf is NULL. */
*error = DW_DLE_MDE;
return DW_DLV_ERROR;
}
/* When using libelf as a producer, section data may be stored
in multiple buffers. In libdwarf however, we only use libelf
as a consumer (there is a dwarf producer API, but it doesn't
use libelf). Because of this, this single call to elf_getdata
will retrieve the entire section in a single contiguous
buffer. */
data = elf_getdata(scn, NULL);
if (data == NULL) {
/* Most likely means that the Elf section header
is damaged/corrupt and the data is
impossible to read into
memory. The size specified in the
Elf section is too large to allocate memory
for so the data could not be loaded. */
*error = DW_DLE_MDE;
return DW_DLV_ERROR;
}
if (!data->d_buf) {
/* If NULL it means 'the section has no data'
according to libelf documentation.
No DWARF-related section should ever have
'no data'. Happens if a section type is
SHT_NOBITS and no section libdwarf
wants to look at should be SHT_NOBITS. */
*error = DW_DLE_MDE;
return DW_DLV_ERROR;
}
*section_data = data->d_buf;
}
return DW_DLV_OK;
}
/* dwarf_elf_access method table. */
static const struct Dwarf_Obj_Access_Methods_s dwarf_elf_object_access_methods =
{
dwarf_elf_object_access_get_section_info,
dwarf_elf_object_access_get_byte_order,
dwarf_elf_object_access_get_length_size,
dwarf_elf_object_access_get_pointer_size,
dwarf_elf_object_access_get_section_count,
dwarf_elf_object_access_load_section,
dwarf_elf_object_relocate_a_section
};
/* Interface for the ELF object file implementation.
On error this should set *err with the
libdwarf error code.
*/
int
dwarf_elf_object_access_init(dwarf_elf_handle elf,
int libdwarf_owns_elf,
Dwarf_Obj_Access_Interface** ret_obj,
int *err)
{
int res = 0;
dwarf_elf_object_access_internals_t *internals = 0;
Dwarf_Obj_Access_Interface *intfc = 0;
internals = malloc(sizeof(dwarf_elf_object_access_internals_t));
if (!internals) {
*err = DW_DLE_ALLOC_FAIL;
/* Impossible case, we hope. Give up. */
return DW_DLV_ERROR;
}
memset(internals,0,sizeof(*internals));
res = dwarf_elf_object_access_internals_init(internals, elf, err);
if (res != DW_DLV_OK){
/* *err is already set. */
free(internals);
return DW_DLV_ERROR;
}
internals->libdwarf_owns_elf = libdwarf_owns_elf;
intfc = malloc(sizeof(Dwarf_Obj_Access_Interface));
if (!intfc) {
/* Impossible case, we hope. Give up. */
*err = DW_DLE_ALLOC_FAIL;
free(internals);
return DW_DLV_ERROR;
}
/* Initialize the interface struct */
intfc->object = internals;
intfc->methods = &dwarf_elf_object_access_methods;
/* An access method hidden from non-elf. Needed to
handle new-ish SHF_COMPRESSED flag in elf. */
_dwarf_get_elf_flags_func_ptr = _dwarf_get_elf_flags_func;
*ret_obj = intfc;
return DW_DLV_OK;
}
/* Clean up the Dwarf_Obj_Access_Interface returned by elf_access_init. */
void
dwarf_elf_object_access_finish(Dwarf_Obj_Access_Interface* obj)
{
if (!obj) {
return;
}
if (obj->object) {
dwarf_elf_object_access_internals_t *internals =
(dwarf_elf_object_access_internals_t *)obj->object;
if (internals->libdwarf_owns_elf){
elf_end(internals->elf);
}
}
free(obj->object);
free(obj);
}
/* This function returns the Elf * pointer
associated with a Dwarf_Debug.
This function only makes sense if ELF is implied. */
int
dwarf_get_elf(Dwarf_Debug dbg, dwarf_elf_handle * elf,
Dwarf_Error * error)
{
struct Dwarf_Obj_Access_Interface_s * obj = 0;
if (dbg == NULL) {
_dwarf_error(NULL, error, DW_DLE_DBG_NULL);
return (DW_DLV_ERROR);
}
obj = dbg->de_obj_file;
if (obj) {
dwarf_elf_object_access_internals_t *internals =
(dwarf_elf_object_access_internals_t*)obj->object;
if (internals->elf == NULL) {
_dwarf_error(dbg, error, DW_DLE_FNO);
return (DW_DLV_ERROR);
}
*elf = internals->elf;
return DW_DLV_OK;
}
_dwarf_error(dbg, error, DW_DLE_FNO);
return DW_DLV_ERROR;
}