LCOV - code coverage report
Current view: top level - libdw - cie.c (source / functions) Hit Total Coverage
Test: elfutils-0.189 Lines: 71 83 85.5 %
Date: 2023-08-28 19:26:08 Functions: 4 4 100.0 %
Legend: Lines: hit not hit | Branches: + taken - not taken # not executed Branches: 25 34 73.5 %

           Branch data     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                 :      27896 : compare_cie (const void *a, const void *b)
      42                 :            : {
      43                 :      27896 :   const struct dwarf_cie *cie1 = a;
      44                 :      27896 :   const struct dwarf_cie *cie2 = b;
      45         [ +  + ]:      27896 :   if (cie1->offset < cie2->offset)
      46                 :            :     return -1;
      47         [ +  + ]:      21544 :   if (cie1->offset > cie2->offset)
      48                 :       2354 :     return 1;
      49                 :            :   return 0;
      50                 :            : }
      51                 :            : 
      52                 :            : /* There is no CIE at OFFSET in the tree.  Add it.  */
      53                 :            : static struct dwarf_cie *
      54                 :        155 : intern_new_cie (Dwarf_CFI *cache, Dwarf_Off offset, const Dwarf_CIE *info)
      55                 :            : {
      56                 :        155 :   struct dwarf_cie *cie = malloc (sizeof (struct dwarf_cie));
      57         [ -  + ]:        155 :   if (cie == NULL)
      58                 :            :     {
      59                 :          0 :       __libdw_seterrno (DWARF_E_NOMEM);
      60                 :          0 :       return NULL;
      61                 :            :     }
      62                 :            : 
      63                 :        155 :   cie->offset = offset;
      64                 :        155 :   cie->code_alignment_factor = info->code_alignment_factor;
      65                 :        155 :   cie->data_alignment_factor = info->data_alignment_factor;
      66                 :        155 :   cie->return_address_register = info->return_address_register;
      67                 :            : 
      68                 :        155 :   cie->fde_augmentation_data_size = 0;
      69                 :        155 :   cie->sized_augmentation_data = false;
      70                 :        155 :   cie->signal_frame = false;
      71                 :            : 
      72                 :        155 :   cie->fde_encoding = DW_EH_PE_absptr;
      73                 :        155 :   cie->lsda_encoding = DW_EH_PE_omit;
      74                 :            : 
      75                 :            :   /* Grok the augmentation string and its data.  */
      76                 :        155 :   const uint8_t *data = info->augmentation_data;
      77         [ +  + ]:        417 :   for (const char *ap = info->augmentation; *ap != '\0'; ++ap)
      78                 :            :     {
      79                 :        262 :       uint8_t encoding;
      80   [ +  +  +  +  :        262 :       switch (*ap)
                   +  - ]
      81                 :            :         {
      82                 :        112 :         case 'z':
      83                 :        112 :           cie->sized_augmentation_data = true;
      84                 :        112 :           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                 :          0 :             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                 :        109 :         case 'R':               /* FDE address encoding byte.  */
      99                 :        109 :           cie->fde_encoding = *data++;
     100                 :        109 :           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         [ +  + ]:        155 :   if ((cie->fde_encoding & 0x0f) == DW_EH_PE_absptr)
     119                 :            :     {
     120                 :            :       /* Canonicalize encoding to a specific size.  */
     121                 :         46 :       assert (DW_EH_PE_absptr == 0);
     122                 :            : 
     123                 :            :       /* XXX should get from dwarf_next_cfi with v4 header.  */
     124                 :         92 :       uint_fast8_t address_size
     125         [ +  + ]:         46 :         = cache->e_ident[EI_CLASS] == ELFCLASS32 ? 4 : 8;
     126                 :         46 :       switch (address_size)
     127                 :            :         {
     128                 :            :         case 8:
     129                 :         28 :           cie->fde_encoding |= DW_EH_PE_udata8;
     130                 :         28 :           break;
     131                 :            :         case 4:
     132                 :         18 :           cie->fde_encoding |= DW_EH_PE_udata4;
     133                 :         18 :           break;
     134                 :            :         default:
     135                 :            :           free (cie);
     136                 :            :           __libdw_seterrno (DWARF_E_INVALID_DWARF);
     137                 :            :           return NULL;
     138                 :            :         }
     139                 :            :     }
     140                 :            : 
     141                 :            :   /* Save the initial instructions to be played out into initial state.  */
     142                 :        155 :   cie->initial_instructions = info->initial_instructions;
     143                 :        155 :   cie->initial_instructions_end = info->initial_instructions_end;
     144                 :        155 :   cie->initial_state = NULL;
     145                 :            : 
     146                 :            :   /* Add the new entry to the search tree.  */
     147         [ -  + ]:        155 :   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                 :      19247 : __libdw_find_cie (Dwarf_CFI *cache, Dwarf_Off offset)
     161                 :            : {
     162                 :      19247 :   const struct dwarf_cie cie_key = { .offset = offset };
     163                 :      19247 :   struct dwarf_cie **found = tfind (&cie_key, &cache->cie_tree, &compare_cie);
     164         [ +  + ]:      19247 :   if (found != NULL)
     165                 :      19190 :     return *found;
     166                 :            : 
     167                 :            :   /* We have not read this CIE yet.  Go find it.  */
     168                 :         57 :   Dwarf_Off next_offset = offset;
     169                 :         57 :   Dwarf_CFI_Entry entry;
     170                 :        114 :   int result = INTUSE(dwarf_next_cfi) (cache->e_ident,
     171                 :         57 :                                        &cache->data->d, CFI_IS_EH (cache),
     172                 :            :                                        offset, &next_offset, &entry);
     173   [ +  -  -  + ]:         57 :   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         [ +  + ]:         57 :   if (cache->next_offset == offset)
     181                 :         22 :     cache->next_offset = next_offset;
     182                 :            : 
     183                 :         57 :   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                 :         98 : __libdw_intern_cie (Dwarf_CFI *cache, Dwarf_Off offset, const Dwarf_CIE *info)
     190                 :            : {
     191                 :         98 :   const struct dwarf_cie cie_key = { .offset = offset };
     192                 :         98 :   struct dwarf_cie **found = tfind (&cie_key, &cache->cie_tree, &compare_cie);
     193         [ +  - ]:         98 :   if (found == NULL)
     194                 :            :     /* We have not read this CIE yet.  Enter it.  */
     195                 :         98 :     (void) intern_new_cie (cache, offset, info);
     196                 :         98 : }

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