LCOV - code coverage report
Current view: top level - libdw - cie.c (source / functions) Hit Total Coverage
Test: elfutils-0.172 Lines: 68 79 86.1 %
Date: 2018-06-11 22:52:14 Functions: 4 4 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /* CIE reading.
       2             :    Copyright (C) 2009-2010 Red Hat, Inc.
       3             :    This file is part of elfutils.
       4             : 
       5             :    This file is free software; you can redistribute it and/or modify
       6             :    it under the terms of either
       7             : 
       8             :      * the GNU Lesser General Public License as published by the Free
       9             :        Software Foundation; either version 3 of the License, or (at
      10             :        your option) any later version
      11             : 
      12             :    or
      13             : 
      14             :      * the GNU General Public License as published by the Free
      15             :        Software Foundation; either version 2 of the License, or (at
      16             :        your option) any later version
      17             : 
      18             :    or both in parallel, as here.
      19             : 
      20             :    elfutils is distributed in the hope that it will be useful, but
      21             :    WITHOUT ANY WARRANTY; without even the implied warranty of
      22             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      23             :    General Public License for more details.
      24             : 
      25             :    You should have received copies of the GNU General Public License and
      26             :    the GNU Lesser General Public License along with this program.  If
      27             :    not, see <http://www.gnu.org/licenses/>.  */
      28             : 
      29             : #ifdef HAVE_CONFIG_H
      30             : # include <config.h>
      31             : #endif
      32             : 
      33             : #include "cfi.h"
      34             : #include "encoded-value.h"
      35             : #include <assert.h>
      36             : #include <search.h>
      37             : #include <stdlib.h>
      38             : 
      39             : 
      40             : static int
      41       25996 : compare_cie (const void *a, const void *b)
      42             : {
      43       25996 :   const struct dwarf_cie *cie1 = a;
      44       25996 :   const struct dwarf_cie *cie2 = b;
      45       25996 :   if (cie1->offset < cie2->offset)
      46             :     return -1;
      47       19638 :   if (cie1->offset > cie2->offset)
      48             :     return 1;
      49       17295 :   return 0;
      50             : }
      51             : 
      52             : /* There is no CIE at OFFSET in the tree.  Add it.  */
      53             : static struct dwarf_cie *
      54         160 : intern_new_cie (Dwarf_CFI *cache, Dwarf_Off offset, const Dwarf_CIE *info)
      55             : {
      56         160 :   struct dwarf_cie *cie = malloc (sizeof (struct dwarf_cie));
      57         160 :   if (cie == NULL)
      58             :     {
      59           0 :       __libdw_seterrno (DWARF_E_NOMEM);
      60           0 :       return NULL;
      61             :     }
      62             : 
      63         160 :   cie->offset = offset;
      64         160 :   cie->code_alignment_factor = info->code_alignment_factor;
      65         160 :   cie->data_alignment_factor = info->data_alignment_factor;
      66         160 :   cie->return_address_register = info->return_address_register;
      67             : 
      68         160 :   cie->fde_augmentation_data_size = 0;
      69         160 :   cie->sized_augmentation_data = false;
      70         160 :   cie->signal_frame = false;
      71             : 
      72         160 :   cie->fde_encoding = DW_EH_PE_absptr;
      73         160 :   cie->lsda_encoding = DW_EH_PE_omit;
      74             : 
      75             :   /* Grok the augmentation string and its data.  */
      76         160 :   const uint8_t *data = info->augmentation_data;
      77         456 :   for (const char *ap = info->augmentation; *ap != '\0'; ++ap)
      78             :     {
      79             :       uint8_t encoding;
      80         296 :       switch (*ap)
      81             :         {
      82         129 :         case 'z':
      83         129 :           cie->sized_augmentation_data = true;
      84         129 :           continue;
      85             : 
      86           3 :         case 'S':
      87           3 :           cie->signal_frame = true;
      88           3 :           continue;
      89             : 
      90          17 :         case 'L':               /* LSDA pointer encoding byte.  */
      91          17 :           cie->lsda_encoding = *data++;
      92          17 :           if (!cie->sized_augmentation_data)
      93             :             cie->fde_augmentation_data_size
      94           0 :               += encoded_value_size (&cache->data->d, cache->e_ident,
      95             :                                      cie->lsda_encoding, NULL);
      96          17 :           continue;
      97             : 
      98         126 :         case 'R':               /* FDE address encoding byte.  */
      99         126 :           cie->fde_encoding = *data++;
     100         126 :           continue;
     101             : 
     102          21 :         case 'P':               /* Skip personality routine.  */
     103          21 :           encoding = *data++;
     104          21 :           data += encoded_value_size (&cache->data->d, cache->e_ident,
     105             :                                       encoding, data);
     106          21 :           continue;
     107             : 
     108           0 :         default:
     109             :           /* Unknown augmentation string.  If we have 'z' we can ignore it,
     110             :              otherwise we must bail out.  */
     111           0 :           if (cie->sized_augmentation_data)
     112           0 :             continue;
     113             :         }
     114             :       /* We only get here when we need to bail out.  */
     115             :       break;
     116             :     }
     117             : 
     118         160 :   if ((cie->fde_encoding & 0x0f) == DW_EH_PE_absptr)
     119             :     {
     120             :       /* Canonicalize encoding to a specific size.  */
     121             :       assert (DW_EH_PE_absptr == 0);
     122             : 
     123             :       /* XXX should get from dwarf_next_cfi with v4 header.  */
     124          57 :       uint_fast8_t address_size
     125          34 :         = cache->e_ident[EI_CLASS] == ELFCLASS32 ? 4 : 8;
     126             :       switch (address_size)
     127             :         {
     128             :         case 8:
     129          23 :           cie->fde_encoding |= DW_EH_PE_udata8;
     130          23 :           break;
     131             :         case 4:
     132          11 :           cie->fde_encoding |= DW_EH_PE_udata4;
     133          11 :           break;
     134             :         default:
     135             :           free (cie);
     136             :           __libdw_seterrno (DWARF_E_INVALID_DWARF);
     137             :           return NULL;
     138             :         }
     139         126 :     }
     140             : 
     141             :   /* Save the initial instructions to be played out into initial state.  */
     142         160 :   cie->initial_instructions = info->initial_instructions;
     143         160 :   cie->initial_instructions_end = info->initial_instructions_end;
     144         160 :   cie->initial_state = NULL;
     145             : 
     146             :   /* Add the new entry to the search tree.  */
     147         160 :   if (tsearch (cie, &cache->cie_tree, &compare_cie) == NULL)
     148             :     {
     149           0 :       free (cie);
     150           0 :       __libdw_seterrno (DWARF_E_NOMEM);
     151           0 :       return NULL;
     152             :     }
     153             : 
     154             :   return cie;
     155             : }
     156             : 
     157             : /* Look up a CIE_pointer for random access.  */
     158             : struct dwarf_cie *
     159             : internal_function
     160       17369 : __libdw_find_cie (Dwarf_CFI *cache, Dwarf_Off offset)
     161             : {
     162       17369 :   const struct dwarf_cie cie_key = { .offset = offset };
     163       17369 :   struct dwarf_cie **found = tfind (&cie_key, &cache->cie_tree, &compare_cie);
     164       17369 :   if (found != NULL)
     165       17295 :     return *found;
     166             : 
     167             :   /* We have not read this CIE yet.  Go find it.  */
     168          74 :   Dwarf_Off next_offset = offset;
     169             :   Dwarf_CFI_Entry entry;
     170         148 :   int result = INTUSE(dwarf_next_cfi) (cache->e_ident,
     171         148 :                                        &cache->data->d, CFI_IS_EH (cache),
     172             :                                        offset, &next_offset, &entry);
     173          74 :   if (result != 0 || entry.cie.CIE_id != DW_CIE_ID_64)
     174             :     {
     175           0 :       __libdw_seterrno (DWARF_E_INVALID_DWARF);
     176           0 :       return NULL;
     177             :     }
     178             : 
     179             :   /* If this happened to be what we would have read next, notice it.  */
     180          74 :   if (cache->next_offset == offset)
     181          35 :     cache->next_offset = next_offset;
     182             : 
     183          74 :   return intern_new_cie (cache, offset, &entry.cie);
     184             : }
     185             : 
     186             : /* Enter a CIE encountered while reading through for FDEs.  */
     187             : void
     188             : internal_function
     189          86 : __libdw_intern_cie (Dwarf_CFI *cache, Dwarf_Off offset, const Dwarf_CIE *info)
     190             : {
     191          86 :   const struct dwarf_cie cie_key = { .offset = offset };
     192          86 :   struct dwarf_cie **found = tfind (&cie_key, &cache->cie_tree, &compare_cie);
     193          86 :   if (found == NULL)
     194             :     /* We have not read this CIE yet.  Enter it.  */
     195          86 :     (void) intern_new_cie (cache, offset, info);
     196          86 : }

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