/* $NetBSD: libdwarf_loc.c,v 1.4 2022/05/01 17:20:47 jkoshy Exp $ */
/*-
* Copyright (c) 2007 John Birrell (jb@freebsd.org)
* Copyright (c) 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: libdwarf_loc.c,v 1.4 2022/05/01 17:20:47 jkoshy Exp $");
ELFTC_VCSID("Id: libdwarf_loc.c 3070 2014-06-23 03:08:33Z kaiwang27");
/*
* Given an array of bytes of length 'len' representing a
* DWARF expression, compute the number of operations based
* on there being one byte describing the operation and
* zero or more bytes of operands as defined in the standard
* for each operation type. Also, if lbuf is non-null, store
* the opcode and oprand in it.
*/
static int
_dwarf_loc_fill_loc(Dwarf_Debug dbg, Dwarf_Locdesc *lbuf, uint8_t pointer_size,
uint8_t offset_size, uint8_t version, uint8_t *p, int len)
{
int count;
uint64_t operand1;
uint64_t operand2;
uint8_t *ps, *pe, s;
count = 0;
ps = p;
pe = p + len;
/*
* Process each byte. If an error occurs, then the
* count will be set to -1.
*/
while (p < pe) {
operand1 = 0;
operand2 = 0;
if (lbuf != NULL) {
lbuf->ld_s[count].lr_atom = *p;
lbuf->ld_s[count].lr_offset = p - ps;
}
switch (*p++) {
/* Operations with no operands. */
case DW_OP_deref:
case DW_OP_reg0:
case DW_OP_reg1:
case DW_OP_reg2:
case DW_OP_reg3:
case DW_OP_reg4:
case DW_OP_reg5:
case DW_OP_reg6:
case DW_OP_reg7:
case DW_OP_reg8:
case DW_OP_reg9:
case DW_OP_reg10:
case DW_OP_reg11:
case DW_OP_reg12:
case DW_OP_reg13:
case DW_OP_reg14:
case DW_OP_reg15:
case DW_OP_reg16:
case DW_OP_reg17:
case DW_OP_reg18:
case DW_OP_reg19:
case DW_OP_reg20:
case DW_OP_reg21:
case DW_OP_reg22:
case DW_OP_reg23:
case DW_OP_reg24:
case DW_OP_reg25:
case DW_OP_reg26:
case DW_OP_reg27:
case DW_OP_reg28:
case DW_OP_reg29:
case DW_OP_reg30:
case DW_OP_reg31:
case DW_OP_lit0:
case DW_OP_lit1:
case DW_OP_lit2:
case DW_OP_lit3:
case DW_OP_lit4:
case DW_OP_lit5:
case DW_OP_lit6:
case DW_OP_lit7:
case DW_OP_lit8:
case DW_OP_lit9:
case DW_OP_lit10:
case DW_OP_lit11:
case DW_OP_lit12:
case DW_OP_lit13:
case DW_OP_lit14:
case DW_OP_lit15:
case DW_OP_lit16:
case DW_OP_lit17:
case DW_OP_lit18:
case DW_OP_lit19:
case DW_OP_lit20:
case DW_OP_lit21:
case DW_OP_lit22:
case DW_OP_lit23:
case DW_OP_lit24:
case DW_OP_lit25:
case DW_OP_lit26:
case DW_OP_lit27:
case DW_OP_lit28:
case DW_OP_lit29:
case DW_OP_lit30:
case DW_OP_lit31:
case DW_OP_dup:
case DW_OP_drop:
case DW_OP_over:
case DW_OP_swap:
case DW_OP_rot:
case DW_OP_xderef:
case DW_OP_abs:
case DW_OP_and:
case DW_OP_div:
case DW_OP_minus:
case DW_OP_mod:
case DW_OP_mul:
case DW_OP_neg:
case DW_OP_not:
case DW_OP_or:
case DW_OP_plus:
case DW_OP_shl:
case DW_OP_shr:
case DW_OP_shra:
case DW_OP_xor:
case DW_OP_eq:
case DW_OP_ge:
case DW_OP_gt:
case DW_OP_le:
case DW_OP_lt:
case DW_OP_ne:
case DW_OP_nop:
case DW_OP_push_object_address:
case DW_OP_form_tls_address:
case DW_OP_call_frame_cfa:
case DW_OP_stack_value:
case DW_OP_GNU_push_tls_address:
case DW_OP_GNU_uninit:
break;
/* Operations with 1-byte operands. */
case DW_OP_const1u:
case DW_OP_pick:
case DW_OP_deref_size:
case DW_OP_xderef_size:
operand1 = *p++;
break;
case DW_OP_const1s:
operand1 = (int8_t) *p++;
break;
/* Operations with 2-byte operands. */
case DW_OP_call2:
case DW_OP_const2u:
case DW_OP_bra:
case DW_OP_skip:
operand1 = dbg->decode(&p, 2);
break;
case DW_OP_const2s:
operand1 = (int16_t) dbg->decode(&p, 2);
break;
/* Operations with 4-byte operands. */
case DW_OP_call4:
case DW_OP_const4u:
case DW_OP_GNU_parameter_ref:
operand1 = dbg->decode(&p, 4);
break;
case DW_OP_const4s:
operand1 = (int32_t) dbg->decode(&p, 4);
break;
/* Operations with 8-byte operands. */
case DW_OP_const8u:
case DW_OP_const8s:
operand1 = dbg->decode(&p, 8);
break;
/* Operations with an unsigned LEB128 operand. */
case DW_OP_constu:
case DW_OP_plus_uconst:
case DW_OP_regx:
case DW_OP_piece:
case DW_OP_GNU_deref_type:
case DW_OP_GNU_convert:
case DW_OP_GNU_reinterpret:
operand1 = _dwarf_decode_uleb128(&p);
break;
/* Operations with a signed LEB128 operand. */
case DW_OP_consts:
case DW_OP_breg0:
case DW_OP_breg1:
case DW_OP_breg2:
case DW_OP_breg3:
case DW_OP_breg4:
case DW_OP_breg5:
case DW_OP_breg6:
case DW_OP_breg7:
case DW_OP_breg8:
case DW_OP_breg9:
case DW_OP_breg10:
case DW_OP_breg11:
case DW_OP_breg12:
case DW_OP_breg13:
case DW_OP_breg14:
case DW_OP_breg15:
case DW_OP_breg16:
case DW_OP_breg17:
case DW_OP_breg18:
case DW_OP_breg19:
case DW_OP_breg20:
case DW_OP_breg21:
case DW_OP_breg22:
case DW_OP_breg23:
case DW_OP_breg24:
case DW_OP_breg25:
case DW_OP_breg26:
case DW_OP_breg27:
case DW_OP_breg28:
case DW_OP_breg29:
case DW_OP_breg30:
case DW_OP_breg31:
case DW_OP_fbreg:
operand1 = _dwarf_decode_sleb128(&p);
break;
/*
* Oeration with two unsigned LEB128 operands.
*/
case DW_OP_bit_piece:
case DW_OP_GNU_regval_type:
operand1 = _dwarf_decode_uleb128(&p);
operand2 = _dwarf_decode_uleb128(&p);
break;
/*
* Operations with an unsigned LEB128 operand
* followed by a signed LEB128 operand.
*/
case DW_OP_bregx:
operand1 = _dwarf_decode_uleb128(&p);
operand2 = _dwarf_decode_sleb128(&p);
break;
/*
* Operation with an unsigned LEB128 operand
* representing the size of a block, followed
* by the block content.
*
* Store the size of the block in the operand1
* and a pointer to the block in the operand2.
*/
case DW_OP_implicit_value:
case DW_OP_GNU_entry_value:
operand1 = _dwarf_decode_uleb128(&p);
operand2 = (Dwarf_Unsigned) (uintptr_t) p;
p += operand1;
break;
/* Target address size operand. */
case DW_OP_addr:
case DW_OP_GNU_addr_index:
case DW_OP_GNU_const_index:
operand1 = dbg->decode(&p, pointer_size);
break;
/* Offset size operand. */
case DW_OP_call_ref:
operand1 = dbg->decode(&p, offset_size);
break;
/*
* The first byte is address byte length, followed by
* the address value. If the length is 0, the address
* size is the same as target pointer size.
*/
case DW_OP_GNU_encoded_addr:
s = *p++;
if (s == 0)
s = pointer_size;
operand1 = dbg->decode(&p, s);
break;
/*
* Operand1: DIE offset (size depending on DWARF version)
* DWARF2: pointer size
* DWARF{3,4}: offset size
*
* Operand2: SLEB128
*/
case DW_OP_GNU_implicit_pointer:
if (version == 2)
operand1 = dbg->decode(&p, pointer_size);
else
operand1 = dbg->decode(&p, offset_size);
operand2 = _dwarf_decode_sleb128(&p);
break;
/*
* Operand1: DIE offset (ULEB128)
* Operand2: pointer to a block. The block's first byte
* is its size.
*/
case DW_OP_GNU_const_type:
operand1 = _dwarf_decode_uleb128(&p);
operand2 = (Dwarf_Unsigned) (uintptr_t) p;
s = *p++;
p += s;
break;
/* All other operations cause an error. */
default:
count = -1;
goto done;
}
if (lbuf != NULL) {
lbuf->ld_s[count].lr_number = operand1;
lbuf->ld_s[count].lr_number2 = operand2;
}
count++;
}
done:
return (count);
}
int
_dwarf_loc_expr_add_atom(Dwarf_Debug dbg, uint8_t *out, uint8_t *end,
Dwarf_Small atom, Dwarf_Unsigned operand1, Dwarf_Unsigned operand2,
int *length, Dwarf_Error *error)
{
uint8_t buf[64];
uint8_t *p, *pe;
uint64_t offset;
int len;
if (out != NULL && end != NULL) {
p = out;
pe = end;
} else {
p = out = buf;
pe = &buf[sizeof(buf)];
}
switch (atom) {
/* Operations with no operands. */
case DW_OP_deref:
case DW_OP_reg0:
case DW_OP_reg1:
case DW_OP_reg2:
case DW_OP_reg3:
case DW_OP_reg4:
case DW_OP_reg5:
case DW_OP_reg6:
case DW_OP_reg7:
case DW_OP_reg8:
case DW_OP_reg9:
case DW_OP_reg10:
case DW_OP_reg11:
case DW_OP_reg12:
case DW_OP_reg13:
case DW_OP_reg14:
case DW_OP_reg15:
case DW_OP_reg16:
case DW_OP_reg17:
case DW_OP_reg18:
case DW_OP_reg19:
case DW_OP_reg20:
case DW_OP_reg21:
case DW_OP_reg22:
case DW_OP_reg23:
case DW_OP_reg24:
case DW_OP_reg25:
case DW_OP_reg26:
case DW_OP_reg27:
case DW_OP_reg28:
case DW_OP_reg29:
case DW_OP_reg30:
case DW_OP_reg31:
case DW_OP_lit0:
case DW_OP_lit1:
case DW_OP_lit2:
case DW_OP_lit3:
case DW_OP_lit4:
case DW_OP_lit5:
case DW_OP_lit6:
case DW_OP_lit7:
case DW_OP_lit8:
case DW_OP_lit9:
case DW_OP_lit10:
case DW_OP_lit11:
case DW_OP_lit12:
case DW_OP_lit13:
case DW_OP_lit14:
case DW_OP_lit15:
case DW_OP_lit16:
case DW_OP_lit17:
case DW_OP_lit18:
case DW_OP_lit19:
case DW_OP_lit20:
case DW_OP_lit21:
case DW_OP_lit22:
case DW_OP_lit23:
case DW_OP_lit24:
case DW_OP_lit25:
case DW_OP_lit26:
case DW_OP_lit27:
case DW_OP_lit28:
case DW_OP_lit29:
case DW_OP_lit30:
case DW_OP_lit31:
case DW_OP_dup:
case DW_OP_drop:
case DW_OP_over:
case DW_OP_swap:
case DW_OP_rot:
case DW_OP_xderef:
case DW_OP_abs:
case DW_OP_and:
case DW_OP_div:
case DW_OP_minus:
case DW_OP_mod:
case DW_OP_mul:
case DW_OP_neg:
case DW_OP_not:
case DW_OP_or:
case DW_OP_plus:
case DW_OP_shl:
case DW_OP_shr:
case DW_OP_shra:
case DW_OP_xor:
case DW_OP_eq:
case DW_OP_ge:
case DW_OP_gt:
case DW_OP_le:
case DW_OP_lt:
case DW_OP_ne:
case DW_OP_nop:
case DW_OP_GNU_push_tls_address:
*p++ = atom;
break;
/* Operations with 1-byte operands. */
case DW_OP_const1u:
case DW_OP_const1s:
case DW_OP_pick:
case DW_OP_deref_size:
case DW_OP_xderef_size:
*p++ = atom;
*p++ = (uint8_t) operand1;
break;
/* Operations with 2-byte operands. */
case DW_OP_const2u:
case DW_OP_const2s:
case DW_OP_bra:
case DW_OP_skip:
*p++ = atom;
offset = 0;
dbg->write(p, &offset, operand1, 2);
p += 2;
break;
/* Operations with 4-byte operands. */
case DW_OP_const4u:
case DW_OP_const4s:
*p++ = atom;
offset = 0;
dbg->write(p, &offset, operand1, 4);
p += 4;
break;
/* Operations with 8-byte operands. */
case DW_OP_const8u:
case DW_OP_const8s:
*p++ = atom;
offset = 0;
dbg->write(p, &offset, operand1, 8);
p += 8;
break;
/* Operations with an unsigned LEB128 operand. */
case DW_OP_constu:
case DW_OP_plus_uconst:
case DW_OP_regx:
case DW_OP_piece:
*p++ = atom;
len = _dwarf_write_uleb128(p, pe, operand1);
assert(len > 0);
p += len;
break;
/* Operations with a signed LEB128 operand. */
case DW_OP_consts:
case DW_OP_breg0:
case DW_OP_breg1:
case DW_OP_breg2:
case DW_OP_breg3:
case DW_OP_breg4:
case DW_OP_breg5:
case DW_OP_breg6:
case DW_OP_breg7:
case DW_OP_breg8:
case DW_OP_breg9:
case DW_OP_breg10:
case DW_OP_breg11:
case DW_OP_breg12:
case DW_OP_breg13:
case DW_OP_breg14:
case DW_OP_breg15:
case DW_OP_breg16:
case DW_OP_breg17:
case DW_OP_breg18:
case DW_OP_breg19:
case DW_OP_breg20:
case DW_OP_breg21:
case DW_OP_breg22:
case DW_OP_breg23:
case DW_OP_breg24:
case DW_OP_breg25:
case DW_OP_breg26:
case DW_OP_breg27:
case DW_OP_breg28:
case DW_OP_breg29:
case DW_OP_breg30:
case DW_OP_breg31:
case DW_OP_fbreg:
*p++ = atom;
len = _dwarf_write_sleb128(p, pe, operand1);
assert(len > 0);
p += len;
break;
/*
* Operations with an unsigned LEB128 operand
* followed by a signed LEB128 operand.
*/
case DW_OP_bregx:
*p++ = atom;
len = _dwarf_write_uleb128(p, pe, operand1);
assert(len > 0);
p += len;
len = _dwarf_write_sleb128(p, pe, operand2);
assert(len > 0);
p += len;
break;
/* Target address size operand. */
case DW_OP_addr:
*p++ = atom;
offset = 0;
dbg->write(p, &offset, operand1, dbg->dbg_pointer_size);
p += dbg->dbg_pointer_size;
break;
/* All other operations cause an error. */
default:
DWARF_SET_ERROR(dbg, error, DW_DLE_LOC_EXPR_BAD);
return (DW_DLE_LOC_EXPR_BAD);
}
if (length)
*length = p - out;
return (DW_DLE_NONE);
}
int
_dwarf_loc_fill_locdesc(Dwarf_Debug dbg, Dwarf_Locdesc *llbuf, uint8_t *in,
uint64_t in_len, uint8_t pointer_size, uint8_t offset_size,
uint8_t version, Dwarf_Error *error)
{
int num;
assert(llbuf != NULL);
assert(in != NULL);
assert(in_len > 0);
/* Compute the number of locations. */
if ((num = _dwarf_loc_fill_loc(dbg, NULL, pointer_size, offset_size,
version, in, in_len)) < 0) {
DWARF_SET_ERROR(dbg, error, DW_DLE_LOC_EXPR_BAD);
return (DW_DLE_LOC_EXPR_BAD);
}
llbuf->ld_cents = num;
if (num <= 0)
return (DW_DLE_NONE);
if ((llbuf->ld_s = calloc(num, sizeof(Dwarf_Loc))) == NULL) {
DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
return (DW_DLE_MEMORY);
}
(void) _dwarf_loc_fill_loc(dbg, llbuf, pointer_size, offset_size,
version, in, in_len);
return (DW_DLE_NONE);
}
int
_dwarf_loc_fill_locexpr(Dwarf_Debug dbg, Dwarf_Locdesc **ret_llbuf, uint8_t *in,
uint64_t in_len, uint8_t pointer_size, uint8_t offset_size,
uint8_t version, Dwarf_Error *error)
{
Dwarf_Locdesc *llbuf;
int ret;
if ((llbuf = malloc(sizeof(Dwarf_Locdesc))) == NULL) {
DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
return (DW_DLE_MEMORY);
}
llbuf->ld_lopc = 0;
llbuf->ld_hipc = ~0ULL;
llbuf->ld_s = NULL;
ret = _dwarf_loc_fill_locdesc(dbg, llbuf, in, in_len, pointer_size,
offset_size, version, error);
if (ret != DW_DLE_NONE) {
free(llbuf);
return (ret);
}
*ret_llbuf = llbuf;
return (ret);
}
int
_dwarf_loc_add(Dwarf_Die die, Dwarf_Attribute at, Dwarf_Error *error)
{
Dwarf_Debug dbg;
Dwarf_CU cu;
int ret;
assert(at->at_ld == NULL);
assert(at->u[1].u8p != NULL);
assert(at->u[0].u64 > 0);
cu = die->die_cu;
assert(cu != NULL);
dbg = cu->cu_dbg;
assert(dbg != NULL);
ret = _dwarf_loc_fill_locexpr(dbg, &at->at_ld, at->u[1].u8p,
at->u[0].u64, cu->cu_pointer_size, cu->cu_length_size == 4 ? 4 : 8,
cu->cu_version, error);
return (ret);
}