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/*-
* Copyright (c) 2010 Kai Wang
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "_libdwarf.h"
ELFTC_VCSID("$Id: libdwarf_reloc.c 3198 2015-05-14 18:36:19Z emaste $");
Dwarf_Unsigned
_dwarf_get_reloc_type(Dwarf_P_Debug dbg, int is64)
{
assert(dbg != NULL);
switch (dbg->dbgp_isa) {
case DW_ISA_AARCH64:
return (is64 ? R_AARCH64_ABS64 : R_AARCH64_ABS32);
case DW_ISA_X86:
return (R_386_32);
case DW_ISA_X86_64:
return (is64 ? R_X86_64_64 : R_X86_64_32);
case DW_ISA_SPARC:
return (is64 ? R_SPARC_UA64 : R_SPARC_UA32);
case DW_ISA_PPC:
return (R_PPC_ADDR32);
case DW_ISA_ARM:
return (R_ARM_ABS32);
case DW_ISA_MIPS:
return (is64 ? R_MIPS_64 : R_MIPS_32);
case DW_ISA_IA64:
return (is64 ? R_IA_64_DIR64LSB : R_IA_64_DIR32LSB);
default:
break;
}
return (0); /* NOT REACHED */
}
int
_dwarf_get_reloc_size(Dwarf_Debug dbg, Dwarf_Unsigned rel_type)
{
switch (dbg->dbg_machine) {
case EM_NONE:
break;
case EM_AARCH64:
if (rel_type == R_AARCH64_ABS32)
return (4);
else if (rel_type == R_AARCH64_ABS64)
return (8);
break;
case EM_ARM:
if (rel_type == R_ARM_ABS32)
return (4);
break;
case EM_386:
case EM_IAMCU:
if (rel_type == R_386_32)
return (4);
break;
case EM_X86_64:
if (rel_type == R_X86_64_32)
return (4);
else if (rel_type == R_X86_64_64)
return (8);
break;
case EM_SPARC:
if (rel_type == R_SPARC_UA32)
return (4);
else if (rel_type == R_SPARC_UA64)
return (8);
break;
case EM_PPC:
if (rel_type == R_PPC_ADDR32)
return (4);
break;
case EM_MIPS:
if (rel_type == R_MIPS_32)
return (4);
else if (rel_type == R_MIPS_64)
return (8);
break;
case EM_IA_64:
if (rel_type == R_IA_64_SECREL32LSB)
return (4);
else if (rel_type == R_IA_64_DIR64LSB)
return (8);
break;
default:
break;
}
/* unknown relocation. */
return (0);
}
int
_dwarf_reloc_section_init(Dwarf_P_Debug dbg, Dwarf_Rel_Section *drsp,
Dwarf_P_Section ref, Dwarf_Error *error)
{
Dwarf_Rel_Section drs;
char name[128];
int pseudo;
assert(dbg != NULL && drsp != NULL && ref != NULL);
if ((drs = calloc(1, sizeof(struct _Dwarf_Rel_Section))) == NULL) {
DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
return (DW_DLE_MEMORY);
}
drs->drs_ref = ref;
/*
* FIXME The logic here is most likely wrong. It should
* be the ISA that determines relocation type.
*/
if (dbg->dbgp_flags & DW_DLC_SIZE_64)
drs->drs_addend = 1;
else
drs->drs_addend = 0;
if (dbg->dbgp_flags & DW_DLC_SYMBOLIC_RELOCATIONS)
pseudo = 1;
else
pseudo = 0;
snprintf(name, sizeof(name), "%s%s",
drs->drs_addend ? ".rela" : ".rel", ref->ds_name);
if (_dwarf_section_init(dbg, &drs->drs_ds, name, pseudo, error) !=
DW_DLE_NONE) {
free(drs);
DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
return (DW_DLE_MEMORY);
}
STAILQ_INIT(&drs->drs_dre);
STAILQ_INSERT_TAIL(&dbg->dbgp_drslist, drs, drs_next);
dbg->dbgp_drscnt++;
*drsp = drs;
return (DW_DLE_NONE);
}
void
_dwarf_reloc_section_free(Dwarf_P_Debug dbg, Dwarf_Rel_Section *drsp)
{
Dwarf_Rel_Section drs, tdrs;
Dwarf_Rel_Entry dre, tdre;
assert(dbg != NULL && drsp != NULL);
if (*drsp == NULL)
return;
STAILQ_FOREACH_SAFE(drs, &dbg->dbgp_drslist, drs_next, tdrs) {
if (drs != *drsp)
continue;
STAILQ_REMOVE(&dbg->dbgp_drslist, drs, _Dwarf_Rel_Section,
drs_next);
STAILQ_FOREACH_SAFE(dre, &drs->drs_dre, dre_next, tdre) {
STAILQ_REMOVE(&drs->drs_dre, dre, _Dwarf_Rel_Entry,
dre_next);
free(dre);
}
if ((dbg->dbgp_flags & DW_DLC_SYMBOLIC_RELOCATIONS) == 0)
_dwarf_section_free(dbg, &drs->drs_ds);
else {
if (drs->drs_ds->ds_name)
free(drs->drs_ds->ds_name);
free(drs->drs_ds);
}
free(drs);
*drsp = NULL;
dbg->dbgp_drscnt--;
break;
}
}
int
_dwarf_reloc_entry_add(Dwarf_P_Debug dbg, Dwarf_Rel_Section drs,
Dwarf_P_Section ds, unsigned char type, unsigned char length,
Dwarf_Unsigned offset, Dwarf_Unsigned symndx, Dwarf_Unsigned addend,
const char *secname, Dwarf_Error *error)
{
Dwarf_Rel_Entry dre;
Dwarf_Unsigned reloff;
int ret;
assert(drs != NULL);
assert(offset <= ds->ds_size);
reloff = offset;
/*
* If the DW_DLC_SYMBOLIC_RELOCATIONS flag is set or ElfXX_Rel
* is used instead of ELfXX_Rela, we need to write the addend
* in the storage unit to be relocated. Otherwise write 0 in the
* storage unit and the addend will be written into relocation
* section later.
*/
if ((dbg->dbgp_flags & DW_DLC_SYMBOLIC_RELOCATIONS) ||
drs->drs_addend == 0)
ret = dbg->write_alloc(&ds->ds_data, &ds->ds_cap, &offset,
addend, length, error);
else
ret = dbg->write_alloc(&ds->ds_data, &ds->ds_cap, &offset,
0, length, error);
if (ret != DW_DLE_NONE)
return (ret);
if (offset > ds->ds_size)
ds->ds_size = offset;
if ((dre = calloc(1, sizeof(struct _Dwarf_Rel_Entry))) == NULL) {
DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
return (DW_DLE_MEMORY);
}
STAILQ_INSERT_TAIL(&drs->drs_dre, dre, dre_next);
dre->dre_type = type;
dre->dre_length = length;
dre->dre_offset = reloff;
dre->dre_symndx = symndx;
dre->dre_addend = addend;
dre->dre_secname = secname;
drs->drs_drecnt++;
return (DW_DLE_NONE);
}
int
_dwarf_reloc_entry_add_pair(Dwarf_P_Debug dbg, Dwarf_Rel_Section drs,
Dwarf_P_Section ds, unsigned char length, Dwarf_Unsigned offset,
Dwarf_Unsigned symndx, Dwarf_Unsigned esymndx, Dwarf_Unsigned symoff,
Dwarf_Unsigned esymoff, Dwarf_Error *error)
{
Dwarf_Rel_Entry dre;
Dwarf_Unsigned reloff;
int ret;
assert(drs != NULL);
assert(offset <= ds->ds_size);
assert(dbg->dbgp_flags & DW_DLC_SYMBOLIC_RELOCATIONS);
reloff = offset;
/* Write net offset into section stream. */
ret = dbg->write_alloc(&ds->ds_data, &ds->ds_cap, &offset,
esymoff - symoff, length, error);
if (ret != DW_DLE_NONE)
return (ret);
if (offset > ds->ds_size)
ds->ds_size = offset;
if ((dre = calloc(2, sizeof(struct _Dwarf_Rel_Entry))) == NULL) {
DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
return (DW_DLE_MEMORY);
}
STAILQ_INSERT_TAIL(&drs->drs_dre, &dre[0], dre_next);
STAILQ_INSERT_TAIL(&drs->drs_dre, &dre[1], dre_next);
dre[0].dre_type = dwarf_drt_first_of_length_pair;
dre[0].dre_length = length;
dre[0].dre_offset = reloff;
dre[0].dre_symndx = symndx;
dre[0].dre_addend = 0;
dre[0].dre_secname = NULL;
dre[1].dre_type = dwarf_drt_second_of_length_pair;
dre[1].dre_length = length;
dre[1].dre_offset = reloff;
dre[1].dre_symndx = esymndx;
dre[1].dre_addend = 0;
dre[1].dre_secname = NULL;
drs->drs_drecnt += 2;
return (DW_DLE_NONE);
}
int
_dwarf_reloc_section_finalize(Dwarf_P_Debug dbg, Dwarf_Rel_Section drs,
Dwarf_Error *error)
{
Dwarf_P_Section ds;
Dwarf_Unsigned unit;
int ret, size;
assert(dbg != NULL && drs != NULL && drs->drs_ds != NULL &&
drs->drs_ref != NULL);
ds = drs->drs_ds;
/*
* Calculate the size (in bytes) of the relocation section.
*/
if (dbg->dbgp_flags & DW_DLC_SIZE_64)
unit = drs->drs_addend ? sizeof(Elf64_Rela) : sizeof(Elf64_Rel);
else
unit = drs->drs_addend ? sizeof(Elf32_Rela) : sizeof(Elf32_Rel);
assert(ds->ds_size == 0);
size = drs->drs_drecnt * unit;
/*
* Discard this relocation section if there is no entry in it.
*/
if (size == 0) {
_dwarf_reloc_section_free(dbg, &drs);
return (DW_DLE_NONE);
}
/*
* If we are under stream mode, realloc the section data block to
* this size.
*/
if ((dbg->dbgp_flags & DW_DLC_SYMBOLIC_RELOCATIONS) == 0) {
ds->ds_cap = size;
if ((ds->ds_data = realloc(ds->ds_data, (size_t) ds->ds_cap)) ==
NULL) {
DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
return (DW_DLE_MEMORY);
}
}
/*
* Notify the application the creation of this relocation section.
* Note that the section link here should point to the .symtab
* section, we set it to 0 since we have no way to know .symtab
* section index.
*/
ret = _dwarf_pro_callback(dbg, ds->ds_name, size,
drs->drs_addend ? SHT_RELA : SHT_REL, 0, 0, drs->drs_ref->ds_ndx,
&ds->ds_symndx, NULL);
if (ret < 0) {
DWARF_SET_ERROR(dbg, error, DW_DLE_ELF_SECT_ERR);
return (DW_DLE_ELF_SECT_ERR);
}
ds->ds_ndx = ret;
return (DW_DLE_NONE);
}
int
_dwarf_reloc_section_gen(Dwarf_P_Debug dbg, Dwarf_Rel_Section drs,
Dwarf_Error *error)
{
Dwarf_Rel_Entry dre;
Dwarf_P_Section ds;
Dwarf_Unsigned type;
int ret;
assert((dbg->dbgp_flags & DW_DLC_SYMBOLIC_RELOCATIONS) == 0);
assert(drs->drs_ds != NULL && drs->drs_ds->ds_size == 0);
assert(!STAILQ_EMPTY(&drs->drs_dre));
ds = drs->drs_ds;
STAILQ_FOREACH(dre, &drs->drs_dre, dre_next) {
assert(dre->dre_length == 4 || dre->dre_length == 8);
type = _dwarf_get_reloc_type(dbg, dre->dre_length == 8);
if (dbg->dbgp_flags & DW_DLC_SIZE_64) {
/* Write r_offset (8 bytes) */
ret = dbg->write_alloc(&ds->ds_data, &ds->ds_cap,
&ds->ds_size, dre->dre_offset, 8, error);
if (ret != DW_DLE_NONE)
return (ret);
/* Write r_info (8 bytes) */
ret = dbg->write_alloc(&ds->ds_data, &ds->ds_cap,
&ds->ds_size, ELF64_R_INFO(dre->dre_symndx, type),
8, error);
if (ret != DW_DLE_NONE)
return (ret);
/* Write r_addend (8 bytes) */
if (drs->drs_addend) {
ret = dbg->write_alloc(&ds->ds_data,
&ds->ds_cap, &ds->ds_size, dre->dre_addend,
8, error);
if (ret != DW_DLE_NONE)
return (ret);
}
} else {
/* Write r_offset (4 bytes) */
ret = dbg->write_alloc(&ds->ds_data, &ds->ds_cap,
&ds->ds_size, dre->dre_offset, 4, error);
if (ret != DW_DLE_NONE)
return (ret);
/* Write r_info (4 bytes) */
ret = dbg->write_alloc(&ds->ds_data, &ds->ds_cap,
&ds->ds_size, ELF32_R_INFO(dre->dre_symndx, type),
4, error);
if (ret != DW_DLE_NONE)
return (ret);
/* Write r_addend (4 bytes) */
if (drs->drs_addend) {
ret = dbg->write_alloc(&ds->ds_data,
&ds->ds_cap, &ds->ds_size, dre->dre_addend,
4, error);
if (ret != DW_DLE_NONE)
return (ret);
}
}
}
assert(ds->ds_size == ds->ds_cap);
return (DW_DLE_NONE);
}
int
_dwarf_reloc_gen(Dwarf_P_Debug dbg, Dwarf_Error *error)
{
Dwarf_Rel_Section drs;
Dwarf_Rel_Entry dre;
Dwarf_P_Section ds;
int ret;
STAILQ_FOREACH(drs, &dbg->dbgp_drslist, drs_next) {
/*
* Update relocation entries: translate any section name
* reference to section symbol index.
*/
STAILQ_FOREACH(dre, &drs->drs_dre, dre_next) {
if (dre->dre_secname == NULL)
continue;
ds = _dwarf_pro_find_section(dbg, dre->dre_secname);
assert(ds != NULL && ds->ds_symndx != 0);
dre->dre_symndx = ds->ds_symndx;
}
/*
* Generate ELF relocation section if we are under stream
* mode.
*/
if ((dbg->dbgp_flags & DW_DLC_SYMBOLIC_RELOCATIONS) == 0) {
ret = _dwarf_reloc_section_gen(dbg, drs, error);
if (ret != DW_DLE_NONE)
return (ret);
}
}
return (DW_DLE_NONE);
}
void
_dwarf_reloc_cleanup(Dwarf_P_Debug dbg)
{
Dwarf_Rel_Section drs, tdrs;
Dwarf_Rel_Entry dre, tdre;
assert(dbg != NULL && dbg->dbg_mode == DW_DLC_WRITE);
STAILQ_FOREACH_SAFE(drs, &dbg->dbgp_drslist, drs_next, tdrs) {
STAILQ_REMOVE(&dbg->dbgp_drslist, drs, _Dwarf_Rel_Section,
drs_next);
free(drs->drs_drd);
STAILQ_FOREACH_SAFE(dre, &drs->drs_dre, dre_next, tdre) {
STAILQ_REMOVE(&drs->drs_dre, dre, _Dwarf_Rel_Entry,
dre_next);
free(dre);
}
if (dbg->dbgp_flags & DW_DLC_SYMBOLIC_RELOCATIONS) {
if (drs->drs_ds) {
if (drs->drs_ds->ds_name)
free(drs->drs_ds->ds_name);
free(drs->drs_ds);
}
}
free(drs);
}
dbg->dbgp_drscnt = 0;
dbg->dbgp_drspos = NULL;
}
|