diff options
Diffstat (limited to 'libdw/cie.c')
| -rw-r--r-- | libdw/cie.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/libdw/cie.c b/libdw/cie.c new file mode 100644 index 00000000..08752a6d --- /dev/null +++ b/libdw/cie.c @@ -0,0 +1,193 @@ +/* CIE reading. + Copyright (C) 2009 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 + <http://www.openinventionnetwork.com>. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include "cfi.h" +#include "encoded-value.h" +#include <search.h> +#include <stdlib.h> + + +static int +compare_cie (const void *a, const void *b) +{ + const struct dwarf_cie *cie1 = a; + const struct dwarf_cie *cie2 = b; + if (cie1->offset < cie2->offset) + return -1; + if (cie1->offset > cie2->offset) + return 1; + return 0; +} + +/* There is no CIE at OFFSET in the tree. Add it. */ +static struct dwarf_cie * +intern_new_cie (Dwarf_CFI *cache, Dwarf_Off offset, const Dwarf_CIE *info) +{ + struct dwarf_cie *cie = malloc (sizeof (struct dwarf_cie)); + if (cie == NULL) + { + __libdw_seterrno (DWARF_E_NOMEM); + return NULL; + } + + cie->offset = offset; + cie->code_alignment_factor = info->code_alignment_factor; + cie->data_alignment_factor = info->data_alignment_factor; + cie->return_address_register = info->return_address_register; + + cie->fde_augmentation_data_size = 0; + cie->sized_augmentation_data = false; + cie->signal_frame = false; + + cie->fde_encoding = DW_EH_PE_absptr; + cie->lsda_encoding = DW_EH_PE_omit; + + /* Grok the augmentation string and its data. */ + const uint8_t *data = info->augmentation_data; + for (const char *ap = info->augmentation; *ap != '\0'; ++ap) + { + uint8_t encoding; + switch (*ap) + { + case 'z': + cie->sized_augmentation_data = true; + continue; + + case 'S': + cie->signal_frame = true; + continue; + + case 'L': /* LSDA pointer encoding byte. */ + cie->lsda_encoding = *data++; + if (!cie->sized_augmentation_data) + cie->fde_augmentation_data_size + += encoded_value_size (&cache->data->d, cache->e_ident, + cie->lsda_encoding, NULL); + continue; + + case 'R': /* FDE address encoding byte. */ + cie->fde_encoding = *data++; + continue; + + case 'P': /* Skip personality routine. */ + encoding = *data++; + data += encoded_value_size (&cache->data->d, cache->e_ident, + encoding, data); + continue; + + default: + /* Unknown augmentation string. If we have 'z' we can ignore it, + otherwise we must bail out. */ + if (cie->sized_augmentation_data) + continue; + } + /* We only get here when we need to bail out. */ + break; + } + + /* Save the initial instructions to be played out into initial state. */ + cie->initial_instructions = info->initial_instructions; + cie->initial_instructions_end = info->initial_instructions_end; + cie->initial_state = NULL; + + /* Add the new entry to the search tree. */ + if (tsearch (cie, &cache->cie_tree, &compare_cie) == NULL) + { + free (cie); + __libdw_seterrno (DWARF_E_NOMEM); + return NULL; + } + + return cie; +} + +/* Look up a CIE_pointer for random access. */ +struct dwarf_cie * +internal_function +__libdw_find_cie (Dwarf_CFI *cache, Dwarf_Off offset) +{ + const struct dwarf_cie cie_key = { .offset = offset }; + struct dwarf_cie **found = tfind (&cie_key, &cache->cie_tree, &compare_cie); + if (found != NULL) + return *found; + + /* We have not read this CIE yet. Go find it. */ + Dwarf_Off next_offset = offset; + Dwarf_CFI_Entry entry; + int result = INTUSE(dwarf_next_cfi) (cache->e_ident, + &cache->data->d, CFI_IS_EH (cache), + offset, &next_offset, &entry); + if (result != 0 || entry.cie.CIE_id != DW_CIE_ID_64) + { + __libdw_seterrno (DWARF_E_INVALID_DWARF); + return NULL; + } + + /* If this happened to be what we would have read next, notice it. */ + if (cache->next_offset == offset) + cache->next_offset = next_offset; + + return intern_new_cie (cache, offset, &entry.cie); +} + +/* Enter a CIE encountered while reading through for FDEs. */ +void +internal_function +__libdw_intern_cie (Dwarf_CFI *cache, Dwarf_Off offset, const Dwarf_CIE *info) +{ + const struct dwarf_cie cie_key = { .offset = offset }; + struct dwarf_cie **found = tfind (&cie_key, &cache->cie_tree, &compare_cie); + if (found == NULL) + /* We have not read this CIE yet. Enter it. */ + (void) intern_new_cie (cache, offset, info); +} |