Branch data     Line data    Source code

       1                 :            : /* Get abbreviation at given offset.
       2                 :            :    Copyright (C) 2003, 2004, 2005, 2006, 2014, 2017 Red Hat, Inc.
       3                 :            :    Copyright (C) 2025 Mark J. Wielaard <mark@klomp.org>
       4                 :            :    This file is part of elfutils.
       5                 :            :    Written by Ulrich Drepper <drepper@redhat.com>, 2003.
       6                 :            : 
       7                 :            :    This file is free software; you can redistribute it and/or modify
       8                 :            :    it under the terms of either
       9                 :            : 
      10                 :            :      * the GNU Lesser General Public License as published by the Free
      11                 :            :        Software Foundation; either version 3 of the License, or (at
      12                 :            :        your option) any later version
      13                 :            : 
      14                 :            :    or
      15                 :            : 
      16                 :            :      * the GNU General Public License as published by the Free
      17                 :            :        Software Foundation; either version 2 of the License, or (at
      18                 :            :        your option) any later version
      19                 :            : 
      20                 :            :    or both in parallel, as here.
      21                 :            : 
      22                 :            :    elfutils is distributed in the hope that it will be useful, but
      23                 :            :    WITHOUT ANY WARRANTY; without even the implied warranty of
      24                 :            :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      25                 :            :    General Public License for more details.
      26                 :            : 
      27                 :            :    You should have received copies of the GNU General Public License and
      28                 :            :    the GNU Lesser General Public License along with this program.  If
      29                 :            :    not, see <http://www.gnu.org/licenses/>.  */
      30                 :            : 
      31                 :            : #ifdef HAVE_CONFIG_H
      32                 :            : # include <config.h>
      33                 :            : #endif
      34                 :            : 
      35                 :            : #include <dwarf.h>
      36                 :            : #include "libdwP.h"
      37                 :            : 
      38                 :            : 
      39                 :            : Dwarf_Abbrev *
      40                 :            : internal_function
      41                 :    2762132 : __libdw_getabbrev (Dwarf *dbg, struct Dwarf_CU *cu, Dwarf_Off offset,
      42                 :            :                    size_t *lengthp)
      43                 :            : {
      44                 :            :   /* Don't fail if there is not .debug_abbrev section.  */
      45         [ -  + ]:    2762132 :   if (dbg->sectiondata[IDX_debug_abbrev] == NULL)
      46                 :            :     return NULL;
      47                 :            : 
      48         [ -  + ]:    2762132 :   if (offset >= dbg->sectiondata[IDX_debug_abbrev]->d_size)
      49                 :            :     {
      50                 :          0 :       __libdw_seterrno (DWARF_E_INVALID_OFFSET);
      51                 :          0 :       return NULL;
      52                 :            :     }
      53                 :            : 
      54                 :    2762132 :   const unsigned char *abbrevp
      55                 :    2762132 :     = (unsigned char *) dbg->sectiondata[IDX_debug_abbrev]->d_buf + offset;
      56                 :            : 
      57         [ +  + ]:    2762132 :   if (*abbrevp == '\0')
      58                 :            :     /* We are past the last entry.  */
      59                 :            :     return DWARF_END_ABBREV;
      60                 :            : 
      61                 :            :   /* 7.5.3 Abbreviations Tables
      62                 :            : 
      63                 :            :      [...] Each declaration begins with an unsigned LEB128 number
      64                 :            :      representing the abbreviation code itself.  [...]  The
      65                 :            :      abbreviation code is followed by another unsigned LEB128
      66                 :            :      number that encodes the entry's tag.  [...]
      67                 :            : 
      68                 :            :      [...] Following the tag encoding is a 1-byte value that
      69                 :            :      determines whether a debugging information entry using this
      70                 :            :      abbreviation has child entries or not. [...]
      71                 :            : 
      72                 :            :      [...] Finally, the child encoding is followed by a series of
      73                 :            :      attribute specifications. Each attribute specification
      74                 :            :      consists of two parts. The first part is an unsigned LEB128
      75                 :            :      number representing the attribute's name. The second part is
      76                 :            :      an unsigned LEB128 number representing the attribute's form.  */
      77                 :    2758584 :   const unsigned char *end = (dbg->sectiondata[IDX_debug_abbrev]->d_buf
      78                 :            :                               + dbg->sectiondata[IDX_debug_abbrev]->d_size);
      79                 :    2758584 :   const unsigned char *start_abbrevp = abbrevp;
      80                 :    2758584 :   unsigned int code;
      81                 :            :   // We start off with abbrevp at offset, which is checked above.
      82                 :    2758584 :   get_uleb128 (code, abbrevp, end);
      83                 :            : 
      84                 :            :   /* Check whether this code is already in the hash table.  */
      85                 :    2758584 :   bool foundit = false;
      86                 :    2758584 :   Dwarf_Abbrev *abb = NULL;
      87         [ +  + ]:    2758584 :   if (cu == NULL
      88         [ +  + ]:    2597764 :       || (abb = Dwarf_Abbrev_Hash_find (&cu->abbrev_hash, code)) == NULL)
      89         [ +  + ]:    2758572 :     abb = libdw_typed_alloc (dbg, Dwarf_Abbrev);
      90                 :            :   else
      91                 :            :     {
      92                 :         12 :       foundit = true;
      93                 :            : 
      94         [ -  + ]:         12 :       if (unlikely (abb->offset != offset))
      95                 :            :         {
      96                 :            :           /* A duplicate abbrev code at a different offset,
      97                 :            :              that should never happen.  */
      98                 :          0 :         invalid:
      99         [ #  # ]:          0 :           if (! foundit)
     100                 :          0 :             libdw_typed_unalloc (dbg, Dwarf_Abbrev);
     101                 :          0 :           __libdw_seterrno (DWARF_E_INVALID_DWARF);
     102                 :          0 :           return NULL;
     103                 :            :         }
     104                 :            : 
     105                 :            :       /* If the caller doesn't need the length we are done.  */
     106         [ -  + ]:         12 :       if (lengthp == NULL)
     107                 :          0 :         goto out;
     108                 :            :     }
     109                 :            : 
     110                 :            :   /* If there is already a value in the hash table we are going to
     111                 :            :      overwrite its content.  This must not be a problem, since the
     112                 :            :      content better be the same.  */
     113                 :    2758584 :   abb->code = code;
     114         [ -  + ]:    2758584 :   if (abbrevp >= end)
     115                 :          0 :     goto invalid;
     116                 :    2758584 :   get_uleb128 (abb->tag, abbrevp, end);
     117         [ -  + ]:    2758584 :   if (abbrevp + 1 >= end)
     118                 :          0 :     goto invalid;
     119                 :    2758584 :   abb->has_children = *abbrevp++ == DW_CHILDREN_yes;
     120                 :    2758584 :   abb->attrp = (unsigned char *) abbrevp;
     121                 :    2758584 :   abb->offset = offset;
     122                 :            : 
     123                 :            :   /* Skip over all the attributes and check rest of the abbrev is valid.  */
     124                 :   15518120 :   unsigned int attrname;
     125                 :   15518120 :   unsigned int attrform;
     126                 :   15518120 :   do
     127                 :            :     {
     128         [ -  + ]:   15518120 :       if (abbrevp >= end)
     129                 :          0 :         goto invalid;
     130                 :   15518120 :       get_uleb128 (attrname, abbrevp, end);
     131         [ -  + ]:   15518120 :       if (abbrevp >= end)
     132                 :          0 :         goto invalid;
     133                 :   15518120 :       get_uleb128 (attrform, abbrevp, end);
     134         [ +  + ]:   15518120 :       if (attrform == DW_FORM_implicit_const)
     135                 :            :         {
     136                 :    1131870 :           int64_t formval __attribute__((__unused__));
     137         [ -  + ]:    1131870 :           if (abbrevp >= end)
     138                 :          0 :             goto invalid;
     139                 :    1131870 :           get_sleb128 (formval, abbrevp, end);
     140                 :            :         }
     141                 :            :     }
     142         [ +  + ]:   15518120 :   while (attrname != 0 || attrform != 0);
     143                 :            : 
     144                 :            :   /* Return the length to the caller if she asked for it.  */
     145         [ +  - ]:    2758584 :   if (lengthp != NULL)
     146                 :    2758584 :     *lengthp = abbrevp - start_abbrevp;
     147                 :            : 
     148                 :            :   /* Add the entry to the hash table.  */
     149         [ +  + ]:    2758584 :   if (cu != NULL && ! foundit)
     150         [ +  - ]:    2597752 :     if (Dwarf_Abbrev_Hash_insert (&cu->abbrev_hash, abb->code, abb) == -1)
     151                 :            :       {
     152                 :            :         /* The entry was already in the table, remove the one we just
     153                 :            :            created and get the one already inserted.  */
     154                 :          0 :         libdw_typed_unalloc (dbg, Dwarf_Abbrev);
     155                 :          0 :         abb = Dwarf_Abbrev_Hash_find (&cu->abbrev_hash, code);
     156                 :            :       }
     157                 :            : 
     158                 :    2758584 :  out:
     159                 :            :   return abb;
     160                 :            : }
     161                 :            : 
     162                 :            : 
     163                 :            : Dwarf_Abbrev *
     164                 :       2520 : dwarf_getabbrev (Dwarf_Die *die, Dwarf_Off offset, size_t *lengthp)
     165                 :            : {
     166   [ +  -  +  + ]:       2520 :   if (die == NULL || die->cu == NULL)
     167                 :            :     return NULL;
     168                 :            : 
     169                 :        150 :   Dwarf_CU *cu = die->cu;
     170                 :        150 :   Dwarf *dbg = cu->dbg;
     171                 :        150 :   Dwarf_Off abbrev_offset = cu->orig_abbrev_offset;
     172                 :        150 :   Elf_Data *data = dbg->sectiondata[IDX_debug_abbrev];
     173         [ -  + ]:        150 :   if (data == NULL)
     174                 :            :     return NULL;
     175                 :            : 
     176         [ +  + ]:        150 :   if (offset >= data->d_size - abbrev_offset)
     177                 :            :     {
     178                 :         12 :       __libdw_seterrno (DWARF_E_INVALID_OFFSET);
     179                 :         12 :       return NULL;
     180                 :            :     }
     181                 :            : 
     182                 :        138 :   return __libdw_getabbrev (dbg, cu, abbrev_offset + offset, lengthp);
     183                 :            : }