125b3c049e70834cf33790a28643ab058b507b35cBen Cheng/* Get register location expression for frame. 225b3c049e70834cf33790a28643ab058b507b35cBen Cheng Copyright (C) 2009-2010 Red Hat, Inc. 325b3c049e70834cf33790a28643ab058b507b35cBen Cheng This file is part of Red Hat elfutils. 425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 525b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat elfutils is free software; you can redistribute it and/or modify 625b3c049e70834cf33790a28643ab058b507b35cBen Cheng it under the terms of the GNU General Public License as published by the 725b3c049e70834cf33790a28643ab058b507b35cBen Cheng Free Software Foundation; version 2 of the License. 825b3c049e70834cf33790a28643ab058b507b35cBen Cheng 925b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat elfutils is distributed in the hope that it will be useful, but 1025b3c049e70834cf33790a28643ab058b507b35cBen Cheng WITHOUT ANY WARRANTY; without even the implied warranty of 1125b3c049e70834cf33790a28643ab058b507b35cBen Cheng MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 1225b3c049e70834cf33790a28643ab058b507b35cBen Cheng General Public License for more details. 1325b3c049e70834cf33790a28643ab058b507b35cBen Cheng 1425b3c049e70834cf33790a28643ab058b507b35cBen Cheng You should have received a copy of the GNU General Public License along 1525b3c049e70834cf33790a28643ab058b507b35cBen Cheng with Red Hat elfutils; if not, write to the Free Software Foundation, 1625b3c049e70834cf33790a28643ab058b507b35cBen Cheng Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 1725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 1825b3c049e70834cf33790a28643ab058b507b35cBen Cheng In addition, as a special exception, Red Hat, Inc. gives You the 1925b3c049e70834cf33790a28643ab058b507b35cBen Cheng additional right to link the code of Red Hat elfutils with code licensed 2025b3c049e70834cf33790a28643ab058b507b35cBen Cheng under any Open Source Initiative certified open source license 2125b3c049e70834cf33790a28643ab058b507b35cBen Cheng (http://www.opensource.org/licenses/index.php) which requires the 2225b3c049e70834cf33790a28643ab058b507b35cBen Cheng distribution of source code with any binary distribution and to 2325b3c049e70834cf33790a28643ab058b507b35cBen Cheng distribute linked combinations of the two. Non-GPL Code permitted under 2425b3c049e70834cf33790a28643ab058b507b35cBen Cheng this exception must only link to the code of Red Hat elfutils through 2525b3c049e70834cf33790a28643ab058b507b35cBen Cheng those well defined interfaces identified in the file named EXCEPTION 2625b3c049e70834cf33790a28643ab058b507b35cBen Cheng found in the source code files (the "Approved Interfaces"). The files 2725b3c049e70834cf33790a28643ab058b507b35cBen Cheng of Non-GPL Code may instantiate templates or use macros or inline 2825b3c049e70834cf33790a28643ab058b507b35cBen Cheng functions from the Approved Interfaces without causing the resulting 2925b3c049e70834cf33790a28643ab058b507b35cBen Cheng work to be covered by the GNU General Public License. Only Red Hat, 3025b3c049e70834cf33790a28643ab058b507b35cBen Cheng Inc. may make changes or additions to the list of Approved Interfaces. 3125b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat's grant of this exception is conditioned upon your not adding 3225b3c049e70834cf33790a28643ab058b507b35cBen Cheng any new exceptions. If you wish to add a new Approved Interface or 3325b3c049e70834cf33790a28643ab058b507b35cBen Cheng exception, please contact Red Hat. You must obey the GNU General Public 3425b3c049e70834cf33790a28643ab058b507b35cBen Cheng License in all respects for all of the Red Hat elfutils code and other 3525b3c049e70834cf33790a28643ab058b507b35cBen Cheng code used in conjunction with Red Hat elfutils except the Non-GPL Code 3625b3c049e70834cf33790a28643ab058b507b35cBen Cheng covered by this exception. If you modify this file, you may extend this 3725b3c049e70834cf33790a28643ab058b507b35cBen Cheng exception to your version of the file, but you are not obligated to do 3825b3c049e70834cf33790a28643ab058b507b35cBen Cheng so. If you do not wish to provide this exception without modification, 3925b3c049e70834cf33790a28643ab058b507b35cBen Cheng you must delete this exception statement from your version and license 4025b3c049e70834cf33790a28643ab058b507b35cBen Cheng this file solely under the GPL without exception. 4125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 4225b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat elfutils is an included package of the Open Invention Network. 4325b3c049e70834cf33790a28643ab058b507b35cBen Cheng An included package of the Open Invention Network is a package for which 4425b3c049e70834cf33790a28643ab058b507b35cBen Cheng Open Invention Network licensees cross-license their patents. No patent 4525b3c049e70834cf33790a28643ab058b507b35cBen Cheng license is granted, either expressly or impliedly, by designation as an 4625b3c049e70834cf33790a28643ab058b507b35cBen Cheng included package. Should you wish to participate in the Open Invention 4725b3c049e70834cf33790a28643ab058b507b35cBen Cheng Network licensing program, please visit www.openinventionnetwork.com 4825b3c049e70834cf33790a28643ab058b507b35cBen Cheng <http://www.openinventionnetwork.com>. */ 4925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 5025b3c049e70834cf33790a28643ab058b507b35cBen Cheng#ifdef HAVE_CONFIG_H 5125b3c049e70834cf33790a28643ab058b507b35cBen Cheng# include <config.h> 5225b3c049e70834cf33790a28643ab058b507b35cBen Cheng#endif 5325b3c049e70834cf33790a28643ab058b507b35cBen Cheng 5425b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include "cfi.h" 5525b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include <dwarf.h> 5625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 5725b3c049e70834cf33790a28643ab058b507b35cBen Chengint 5825b3c049e70834cf33790a28643ab058b507b35cBen Chengdwarf_frame_register (fs, regno, ops_mem, ops, nops) 5925b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwarf_Frame *fs; 6025b3c049e70834cf33790a28643ab058b507b35cBen Cheng int regno; 6125b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwarf_Op ops_mem[3]; 6225b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwarf_Op **ops; 6325b3c049e70834cf33790a28643ab058b507b35cBen Cheng size_t *nops; 6425b3c049e70834cf33790a28643ab058b507b35cBen Cheng{ 6525b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Maybe there was a previous error. */ 6625b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (fs == NULL) 6725b3c049e70834cf33790a28643ab058b507b35cBen Cheng return -1; 6825b3c049e70834cf33790a28643ab058b507b35cBen Cheng 6925b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (regno < 0)) 7025b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 7125b3c049e70834cf33790a28643ab058b507b35cBen Cheng __libdw_seterrno (DWARF_E_INVALID_ACCESS); 7225b3c049e70834cf33790a28643ab058b507b35cBen Cheng return -1; 7325b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 7425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 7525b3c049e70834cf33790a28643ab058b507b35cBen Cheng *ops = ops_mem; 7625b3c049e70834cf33790a28643ab058b507b35cBen Cheng *nops = 0; 7725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 7825b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely ((size_t) regno >= fs->nregs)) 7925b3c049e70834cf33790a28643ab058b507b35cBen Cheng goto default_rule; 8025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 8125b3c049e70834cf33790a28643ab058b507b35cBen Cheng const struct dwarf_frame_register *reg = &fs->regs[regno]; 8225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 8325b3c049e70834cf33790a28643ab058b507b35cBen Cheng switch (reg->rule) 8425b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 8525b3c049e70834cf33790a28643ab058b507b35cBen Cheng case reg_unspecified: 8625b3c049e70834cf33790a28643ab058b507b35cBen Cheng default_rule: 8725b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Use the default rule for registers not yet mentioned in CFI. */ 8825b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (fs->cache->default_same_value) 8925b3c049e70834cf33790a28643ab058b507b35cBen Cheng goto same_value; 9025b3c049e70834cf33790a28643ab058b507b35cBen Cheng /*FALLTHROUGH*/ 9125b3c049e70834cf33790a28643ab058b507b35cBen Cheng case reg_undefined: 9225b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* The value is known to be unavailable. */ 9325b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 9425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 9525b3c049e70834cf33790a28643ab058b507b35cBen Cheng case reg_same_value: 9625b3c049e70834cf33790a28643ab058b507b35cBen Cheng same_value: 9725b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* The location is not known here, but the caller might know it. */ 9825b3c049e70834cf33790a28643ab058b507b35cBen Cheng *ops = NULL; 9925b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 10025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 10125b3c049e70834cf33790a28643ab058b507b35cBen Cheng case reg_offset: 10225b3c049e70834cf33790a28643ab058b507b35cBen Cheng case reg_val_offset: 10325b3c049e70834cf33790a28643ab058b507b35cBen Cheng ops_mem[(*nops)++] = (Dwarf_Op) { .atom = DW_OP_call_frame_cfa }; 10425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (reg->value != 0) 10525b3c049e70834cf33790a28643ab058b507b35cBen Cheng ops_mem[(*nops)++] = (Dwarf_Op) { .atom = DW_OP_plus_uconst, 10625b3c049e70834cf33790a28643ab058b507b35cBen Cheng .number = reg->value }; 10725b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (reg->rule == reg_val_offset) 10825b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* A value, not a location. */ 10925b3c049e70834cf33790a28643ab058b507b35cBen Cheng ops_mem[(*nops)++] = (Dwarf_Op) { .atom = DW_OP_stack_value }; 11025b3c049e70834cf33790a28643ab058b507b35cBen Cheng *ops = ops_mem; 11125b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 11225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 11325b3c049e70834cf33790a28643ab058b507b35cBen Cheng case reg_register: 11425b3c049e70834cf33790a28643ab058b507b35cBen Cheng ops_mem[(*nops)++] = (Dwarf_Op) { .atom = DW_OP_regx, 11525b3c049e70834cf33790a28643ab058b507b35cBen Cheng .number = reg->value }; 11625b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 11725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 11825b3c049e70834cf33790a28643ab058b507b35cBen Cheng case reg_val_expression: 11925b3c049e70834cf33790a28643ab058b507b35cBen Cheng case reg_expression: 12025b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 12125b3c049e70834cf33790a28643ab058b507b35cBen Cheng unsigned int address_size = (fs->cache->e_ident[EI_CLASS] == ELFCLASS32 12225b3c049e70834cf33790a28643ab058b507b35cBen Cheng ? 4 : 8); 12325b3c049e70834cf33790a28643ab058b507b35cBen Cheng 12425b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwarf_Block block; 12525b3c049e70834cf33790a28643ab058b507b35cBen Cheng const uint8_t *p = fs->cache->data->d.d_buf + reg->value; 12625b3c049e70834cf33790a28643ab058b507b35cBen Cheng get_uleb128 (block.length, p); 12725b3c049e70834cf33790a28643ab058b507b35cBen Cheng block.data = (void *) p; 12825b3c049e70834cf33790a28643ab058b507b35cBen Cheng 12925b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Parse the expression into internal form. */ 13025b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (__libdw_intern_expression (NULL, 13125b3c049e70834cf33790a28643ab058b507b35cBen Cheng fs->cache->other_byte_order, 13225b3c049e70834cf33790a28643ab058b507b35cBen Cheng address_size, 4, 13325b3c049e70834cf33790a28643ab058b507b35cBen Cheng &fs->cache->expr_tree, &block, 13425b3c049e70834cf33790a28643ab058b507b35cBen Cheng true, reg->rule == reg_val_expression, 13525b3c049e70834cf33790a28643ab058b507b35cBen Cheng ops, nops, IDX_debug_frame) < 0) 13625b3c049e70834cf33790a28643ab058b507b35cBen Cheng return -1; 13725b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 13825b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 13925b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 14025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 14125b3c049e70834cf33790a28643ab058b507b35cBen Cheng return 0; 14225b3c049e70834cf33790a28643ab058b507b35cBen Cheng} 143