/* $NetBSD: dwarf_loclist.c,v 1.4 2022/05/01 17:20:47 jkoshy Exp $ */
/*-
* Copyright (c) 2009,2014 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"
__RCSID("$NetBSD: dwarf_loclist.c,v 1.4 2022/05/01 17:20:47 jkoshy Exp $");
ELFTC_VCSID("Id: dwarf_loclist.c 3066 2014-06-06 19:36:06Z kaiwang27");
static int
copy_locdesc(Dwarf_Debug dbg, Dwarf_Locdesc *dst, Dwarf_Locdesc *src,
Dwarf_Error *error)
{
assert(src != NULL && dst != NULL);
dst->ld_lopc = src->ld_lopc;
dst->ld_hipc = src->ld_hipc;
dst->ld_cents = src->ld_cents;
if (dst->ld_cents > 0) {
dst->ld_s = calloc(dst->ld_cents, sizeof(Dwarf_Loc));
if (dst->ld_s == NULL) {
DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
return (DW_DLE_MEMORY);
}
memcpy(dst->ld_s, src->ld_s, src->ld_cents *
sizeof(Dwarf_Loc));
} else
dst->ld_s = NULL;
return (DW_DLE_NONE);
}
int
dwarf_loclist_n(Dwarf_Attribute at, Dwarf_Locdesc ***llbuf,
Dwarf_Signed *listlen, Dwarf_Error *error)
{
Dwarf_Debug dbg;
int ret;
dbg = at != NULL ? at->at_die->die_dbg : NULL;
if (at == NULL || llbuf == NULL || listlen == NULL) {
DWARF_SET_ERROR(dbg, error, DW_DLE_ARGUMENT);
return (DW_DLV_ERROR);
}
switch (at->at_attrib) {
case DW_AT_location:
case DW_AT_string_length:
case DW_AT_return_addr:
case DW_AT_data_member_location:
case DW_AT_frame_base:
case DW_AT_segment:
case DW_AT_static_link:
case DW_AT_use_location:
case DW_AT_vtable_elem_location:
switch (at->at_form) {
case DW_FORM_data4:
case DW_FORM_data8:
/*
* DW_FORM_data[48] can not be used as section offset
* since DWARF4. For DWARF[23], the application needs
* to determine if DW_FORM_data[48] is representing
* a constant or a section offset.
*/
if (at->at_die->die_cu->cu_version >= 4) {
DWARF_SET_ERROR(dbg, error, DW_DLE_NO_ENTRY);
return (DW_DLV_NO_ENTRY);
}
/* FALLTHROUGH */
case DW_FORM_sec_offset:
ret = _dwarf_loclist_find(dbg, at->at_die->die_cu,
at->u[0].u64, llbuf, listlen, NULL, error);
if (ret == DW_DLE_NO_ENTRY) {
DWARF_SET_ERROR(dbg, error, ret);
return (DW_DLV_NO_ENTRY);
}
if (ret != DW_DLE_NONE)
return (DW_DLV_ERROR);
return (DW_DLV_OK);
case DW_FORM_block:
case DW_FORM_block1:
case DW_FORM_block2:
case DW_FORM_block4:
case DW_FORM_exprloc:
if (at->at_ld == NULL) {
ret = _dwarf_loc_add(at->at_die, at, error);
if (ret != DW_DLE_NONE)
return (DW_DLV_ERROR);
}
*llbuf = calloc(1, sizeof(Dwarf_Locdesc *));
if (*llbuf == NULL) {
DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
return (DW_DLV_ERROR);
}
(*llbuf)[0] = calloc(1, sizeof(Dwarf_Locdesc));
if ((*llbuf)[0] == NULL) {
free(*llbuf);
DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
return (DW_DLV_ERROR);
}
if (copy_locdesc(dbg, (*llbuf)[0], at->at_ld, error) !=
DW_DLE_NONE) {
free((*llbuf)[0]);
free(*llbuf);
return (DW_DLV_ERROR);
}
*listlen = 1;
return (DW_DLV_OK);
default:
/* Malformed Attr? */
DWARF_SET_ERROR(dbg, error, DW_DLE_ATTR_FORM_BAD);
return (DW_DLV_NO_ENTRY);
}
default:
/* Wrong attr supplied. */
DWARF_SET_ERROR(dbg, error, DW_DLE_ARGUMENT);
return (DW_DLV_ERROR);
}
}
int
dwarf_loclist(Dwarf_Attribute at, Dwarf_Locdesc **llbuf,
Dwarf_Signed *listlen, Dwarf_Error *error)
{
Dwarf_Locdesc **_llbuf;
int i, ret;
ret = dwarf_loclist_n(at, &_llbuf, listlen, error);
if (ret != DW_DLV_OK)
return (ret);
/* Only return the first location description of the list. */
*llbuf = _llbuf[0];
/* Free the rest of the list. */
for (i = 1; i < *listlen; i++) {
if (_llbuf[i]->ld_s)
free(_llbuf[i]->ld_s);
free(_llbuf[i]);
}
free(_llbuf);
*listlen = 1;
return (DW_DLV_OK);
}
int
dwarf_get_loclist_entry(Dwarf_Debug dbg, Dwarf_Unsigned offset,
Dwarf_Addr *hipc, Dwarf_Addr *lopc, Dwarf_Ptr *data,
Dwarf_Unsigned *entry_len, Dwarf_Unsigned *next_entry,
Dwarf_Error *error)
{
Dwarf_Locdesc *ld, **llbuf;
Dwarf_Section *ds;
Dwarf_Signed listlen;
int i, ret;
/*
* Note that this API sometimes will not work correctly because
* it assumes that all units have the same pointer size and offset
* size.
*/
if (dbg == NULL || hipc == NULL || lopc == NULL || data == NULL ||
entry_len == NULL || next_entry == NULL) {
DWARF_SET_ERROR(dbg, error, DW_DLE_ARGUMENT);
return (DW_DLV_ERROR);
}
ret = _dwarf_loclist_find(dbg, STAILQ_FIRST(&dbg->dbg_cu), offset,
&llbuf, &listlen, entry_len, error);
if (ret == DW_DLE_NO_ENTRY) {
DWARF_SET_ERROR(dbg, error, DW_DLV_NO_ENTRY);
return (DW_DLV_NO_ENTRY);
} else if (ret != DW_DLE_NONE)
return (DW_DLV_ERROR);
*hipc = *lopc = 0;
for (i = 0; i < listlen; i++) {
ld = llbuf[i];
if (i == 0) {
*hipc = ld->ld_hipc;
*lopc = ld->ld_lopc;
} else {
if (ld->ld_lopc < *lopc)
*lopc = ld->ld_lopc;
if (ld->ld_hipc > *hipc)
*hipc = ld->ld_hipc;
}
}
ds = _dwarf_find_section(dbg, ".debug_loc");
assert(ds != NULL);
*data = (uint8_t *) ds->ds_data + offset;
*next_entry = offset + *entry_len;
return (DW_DLV_OK);
}
int
dwarf_loclist_from_expr(Dwarf_Debug dbg, Dwarf_Ptr bytes_in,
Dwarf_Unsigned bytes_len, Dwarf_Locdesc **llbuf, Dwarf_Signed *listlen,
Dwarf_Error *error)
{
return (dwarf_loclist_from_expr_a(dbg, bytes_in, bytes_len,
dbg->dbg_pointer_size, llbuf, listlen, error));
}
int
dwarf_loclist_from_expr_a(Dwarf_Debug dbg, Dwarf_Ptr bytes_in,
Dwarf_Unsigned bytes_len, Dwarf_Half addr_size, Dwarf_Locdesc **llbuf,
Dwarf_Signed *listlen, Dwarf_Error *error)
{
Dwarf_Half offset_size;
Dwarf_Small version;
/*
* Obtain offset size and DWARF version from the current
* Compilation Unit or Type Unit. These values are needed
* for correctly parsing DW_OP_GNU_implicit_pointer operator.
*
* Note that dwarf_loclist_from_expr_b() should be used instead
* if the application knows correct values for offset size
* and DWARF version.
*/
if (dbg->dbg_cu_current) {
offset_size = dbg->dbg_cu_current->cu_length_size == 4 ? 4 : 8;
version = dbg->dbg_cu_current->cu_version;
} else if (dbg->dbg_tu_current) {
offset_size = dbg->dbg_tu_current->cu_length_size == 4 ? 4 : 8;
version = dbg->dbg_tu_current->cu_version;
} else {
/* Default values if no CU/TU context. */
offset_size = 4;
version = 2; /* DWARF2 */
}
return (dwarf_loclist_from_expr_b(dbg, bytes_in, bytes_len, addr_size,
offset_size, version, llbuf, listlen, error));
}
int
dwarf_loclist_from_expr_b(Dwarf_Debug dbg, Dwarf_Ptr bytes_in,
Dwarf_Unsigned bytes_len, Dwarf_Half addr_size, Dwarf_Half offset_size,
Dwarf_Small version, Dwarf_Locdesc **llbuf, Dwarf_Signed *listlen,
Dwarf_Error *error)
{
Dwarf_Locdesc *ld;
int ret;
if (dbg == NULL || bytes_in == NULL || bytes_len == 0 ||
llbuf == NULL || listlen == NULL) {
DWARF_SET_ERROR(dbg, error, DW_DLE_ARGUMENT);
return (DW_DLV_ERROR);
}
if (addr_size != 4 && addr_size != 8) {
DWARF_SET_ERROR(dbg, error, DW_DLE_ARGUMENT);
return (DW_DLV_ERROR);
}
if (offset_size != 4 && offset_size != 8) {
DWARF_SET_ERROR(dbg, error, DW_DLE_ARGUMENT);
return (DW_DLV_ERROR);
}
ret = _dwarf_loc_fill_locexpr(dbg, &ld, bytes_in, bytes_len, addr_size,
offset_size, version, error);
if (ret != DW_DLE_NONE)
return (DW_DLV_ERROR);
*llbuf = ld;
*listlen = 1;
return (DW_DLV_OK);
}