/* DW_EH_PE_* support for libdw unwinder. Copyright (C) 2009-2010 Red Hat, Inc. This file is part of Red Hat elfutils. Red Hat elfutils is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. Red Hat elfutils is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Red Hat elfutils; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. In addition, as a special exception, Red Hat, Inc. gives You the additional right to link the code of Red Hat elfutils with code licensed under any Open Source Initiative certified open source license (http://www.opensource.org/licenses/index.php) which requires the distribution of source code with any binary distribution and to distribute linked combinations of the two. Non-GPL Code permitted under this exception must only link to the code of Red Hat elfutils through those well defined interfaces identified in the file named EXCEPTION found in the source code files (the "Approved Interfaces"). The files of Non-GPL Code may instantiate templates or use macros or inline functions from the Approved Interfaces without causing the resulting work to be covered by the GNU General Public License. Only Red Hat, Inc. may make changes or additions to the list of Approved Interfaces. Red Hat's grant of this exception is conditioned upon your not adding any new exceptions. If you wish to add a new Approved Interface or exception, please contact Red Hat. You must obey the GNU General Public License in all respects for all of the Red Hat elfutils code and other code used in conjunction with Red Hat elfutils except the Non-GPL Code covered by this exception. If you modify this file, you may extend this exception to your version of the file, but you are not obligated to do so. If you do not wish to provide this exception without modification, you must delete this exception statement from your version and license this file solely under the GPL without exception. Red Hat elfutils is an included package of the Open Invention Network. An included package of the Open Invention Network is a package for which Open Invention Network licensees cross-license their patents. No patent license is granted, either expressly or impliedly, by designation as an included package. Should you wish to participate in the Open Invention Network licensing program, please visit www.openinventionnetwork.com . */ #ifndef _ENCODED_VALUE_H #define _ENCODED_VALUE_H 1 #include #include #include "libdwP.h" static size_t __attribute__ ((unused)) encoded_value_size (const Elf_Data *data, const unsigned char e_ident[], uint8_t encoding, const uint8_t *p) { if (encoding == DW_EH_PE_omit) return 0; switch (encoding & 0x07) { case DW_EH_PE_udata2: return 2; case DW_EH_PE_udata4: return 4; case DW_EH_PE_udata8: return 8; case DW_EH_PE_absptr: return e_ident[EI_CLASS] == ELFCLASS32 ? 4 : 8; case DW_EH_PE_uleb128: if (p != NULL) { const uint8_t *end = p; while (end < (uint8_t *) data->d_buf + data->d_size) if (*end++ & 0x80u) return end - p; } default: abort (); return 0; } } static inline int __attribute__ ((unused)) __libdw_cfi_read_address_inc (const Dwarf_CFI *cache, const unsigned char **addrp, int width, Dwarf_Addr *ret) { width = width ?: cache->e_ident[EI_CLASS] == ELFCLASS32 ? 4 : 8; if (cache->dbg != NULL) return __libdw_read_address_inc (cache->dbg, IDX_debug_frame, addrp, width, ret); /* Only .debug_frame might have relocation to consider. Read plain values from .eh_frame data. */ if (width == 4) *ret = read_4ubyte_unaligned_inc (cache, *addrp); else *ret = read_8ubyte_unaligned_inc (cache, *addrp); return 0; } static bool __attribute__ ((unused)) read_encoded_value (const Dwarf_CFI *cache, uint8_t encoding, const uint8_t **p, Dwarf_Addr *result) { *result = 0; switch (encoding & 0x70) { case DW_EH_PE_absptr: break; case DW_EH_PE_pcrel: *result = (cache->frame_vaddr + (*p - (const uint8_t *) cache->data->d.d_buf)); break; case DW_EH_PE_textrel: // ia64: segrel *result = cache->textrel; break; case DW_EH_PE_datarel: // i386: GOTOFF // ia64: gprel *result = cache->datarel; break; case DW_EH_PE_funcrel: /* XXX */ break; case DW_EH_PE_aligned: { const size_t size = encoded_value_size (&cache->data->d, cache->e_ident, encoding, *p); size_t align = ((cache->frame_vaddr + (*p - (const uint8_t *) cache->data->d.d_buf)) & (size - 1)); if (align != 0) *p += size - align; break; } default: abort (); } Dwarf_Addr value; switch (encoding & 0x0f) { case DW_EH_PE_udata2: value = read_2ubyte_unaligned_inc (cache, *p); break; case DW_EH_PE_sdata2: value = read_2sbyte_unaligned_inc (cache, *p); break; case DW_EH_PE_udata4: if (__libdw_cfi_read_address_inc (cache, p, 4, &value)) return true; break; case DW_EH_PE_sdata4: if (__libdw_cfi_read_address_inc (cache, p, 4, &value)) return true; value = (Dwarf_Sword) (Elf32_Sword) value; /* Sign-extend. */ break; case DW_EH_PE_udata8: case DW_EH_PE_sdata8: if (__libdw_cfi_read_address_inc (cache, p, 8, &value)) return true; break; case DW_EH_PE_absptr: if (__libdw_cfi_read_address_inc (cache, p, 0, &value)) return true; break; case DW_EH_PE_uleb128: get_uleb128 (value, *p); break; case DW_EH_PE_sleb128: get_sleb128 (value, *p); break; default: abort (); } *result += value; if (encoding & DW_EH_PE_indirect) { if (unlikely (*result < cache->frame_vaddr)) return true; *result -= cache->frame_vaddr; if (unlikely (*result > (cache->data->d.d_size - encoded_value_size (NULL, cache->e_ident, DW_EH_PE_absptr, NULL)))) return true; const uint8_t *ptr = cache->data->d.d_buf + *result; return __libdw_cfi_read_address_inc (cache, &ptr, 0, result); } return false; } #endif /* encoded-value.h */