Branch data     Line data    Source code

       1                 :            : /* Free resources associated with Elf descriptor.
       2                 :            :    Copyright (C) 1998,1999,2000,2001,2002,2004,2005,2007,2015,2016 Red Hat, Inc.
       3                 :            :    Copyright (C) 2023 Mark J. Wielaard <mark@klomp.org>
       4                 :            :    This file is part of elfutils.
       5                 :            :    Written by Ulrich Drepper <drepper@redhat.com>, 1998.
       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 <assert.h>
      36                 :            : #include <search.h>
      37                 :            : #include <stddef.h>
      38                 :            : #include <stdlib.h>
      39                 :            : 
      40                 :            : #include "libelfP.h"
      41                 :            : 
      42                 :            : 
      43                 :            : static void
      44                 :       2052 : free_chunk (void *n)
      45                 :            : {
      46                 :       2052 :   Elf_Data_Chunk *rawchunk = (Elf_Data_Chunk *)n;
      47         [ +  + ]:       2052 :   if (rawchunk->dummy_scn.flags & ELF_F_MALLOCED)
      48                 :       1146 :     free (rawchunk->data.d.d_buf);
      49                 :       2052 :   free (rawchunk);
      50                 :       2052 : }
      51                 :            : 
      52                 :            : int
      53                 :      35088 : elf_end (Elf *elf)
      54                 :            : {
      55                 :      35096 :   Elf *parent;
      56                 :            : 
      57         [ +  + ]:      35096 :   if (elf == NULL)
      58                 :            :     /* This is allowed and is a no-op.  */
      59                 :            :     return 0;
      60                 :            : 
      61                 :            :   /* Make sure we are alone.  */
      62                 :      34350 :   rwlock_wrlock (elf->lock);
      63                 :            : 
      64   [ +  +  +  - ]:      34350 :   if (elf->ref_count != 0 && --elf->ref_count != 0)
      65                 :            :     {
      66                 :            :       /* Not yet the last activation.  */
      67                 :            :       int result = elf->ref_count;
      68                 :            :       rwlock_unlock (elf->lock);
      69                 :            :       return result;
      70                 :            :     }
      71                 :            : 
      72         [ +  + ]:      34350 :   if (elf->kind == ELF_K_AR)
      73                 :            :     {
      74                 :            :       /* We cannot remove the descriptor now since we still have some
      75                 :            :          descriptors which depend on it.  But we can free the archive
      76                 :            :          symbol table since this is only available via the archive ELF
      77                 :            :          descriptor.  The long name table cannot be freed yet since
      78                 :            :          the archive headers for the ELF files in the archive point
      79                 :            :          into this array.  */
      80         [ +  - ]:        326 :       if (elf->state.ar.ar_sym != (Elf_Arsym *) -1l)
      81                 :        326 :         free (elf->state.ar.ar_sym);
      82                 :        326 :       elf->state.ar.ar_sym = NULL;
      83                 :            : 
      84         [ +  + ]:        326 :       if (elf->state.ar.children != NULL)
      85                 :            :         {
      86                 :            :           rwlock_unlock(elf->lock);
      87                 :            :           return 0;
      88                 :            :         }
      89                 :            :     }
      90                 :            : 
      91                 :            :   /* Remove this structure from the children list.  */
      92                 :      34342 :   parent = elf->parent;
      93         [ +  + ]:      34342 :   if (parent != NULL)
      94                 :            :     {
      95                 :            :       /* This is tricky.  Lock must be acquire from the father to
      96                 :            :          the child but here we already have the child lock.  We
      97                 :            :          solve this problem by giving free the child lock.  The
      98                 :            :          state of REF_COUNT==0 is handled all over the library, so
      99                 :            :          this should be ok.  */
     100                 :      14546 :       rwlock_unlock (elf->lock);
     101                 :      14546 :       rwlock_rdlock (parent->lock);
     102                 :      14546 :       rwlock_wrlock (elf->lock);
     103                 :            : 
     104         [ +  + ]:      14546 :       if (parent->state.ar.children == elf)
     105                 :      14538 :         parent->state.ar.children = elf->next;
     106                 :            :       else
     107                 :            :         {
     108                 :            :           struct Elf *child = parent->state.ar.children;
     109                 :            : 
     110         [ +  + ]:         10 :           while (child->next != elf)
     111                 :            :             child = child->next;
     112                 :            : 
     113                 :          8 :           child->next = elf->next;
     114                 :            :         }
     115                 :            : 
     116                 :      34342 :       rwlock_unlock (parent->lock);
     117                 :            :     }
     118                 :            : 
     119                 :            :   /* This was the last activation.  Free all resources.  */
     120      [ +  +  + ]:      34342 :   switch (elf->kind)
     121                 :            :     {
     122                 :        318 :     case ELF_K_AR:
     123         [ +  + ]:        318 :       if (elf->state.ar.long_names != NULL)
     124                 :        204 :         free (elf->state.ar.long_names);
     125                 :            :       break;
     126                 :            : 
     127                 :      32682 :     case ELF_K_ELF:
     128                 :            :       {
     129                 :      32682 :         void *rawchunks
     130                 :            :           = (elf->class == ELFCLASS32
     131                 :            :              || (offsetof (struct Elf, state.elf32.rawchunks)
     132                 :            :                  == offsetof (struct Elf, state.elf64.rawchunks))
     133                 :            :              ? elf->state.elf32.rawchunks
     134                 :            :              : elf->state.elf64.rawchunks);
     135                 :      32682 :         tdestroy (rawchunks, free_chunk);
     136                 :            : 
     137                 :      32682 :         Elf_ScnList *list = (elf->class == ELFCLASS32
     138                 :            :                              || (offsetof (struct Elf, state.elf32.scns)
     139                 :            :                                  == offsetof (struct Elf, state.elf64.scns))
     140                 :            :                              ? &elf->state.elf32.scns
     141                 :            :                              : &elf->state.elf64.scns);
     142                 :            : 
     143                 :      34652 :         do
     144                 :            :           {
     145                 :            :             /* Free all separately allocated section headers.  */
     146                 :      34652 :             size_t cnt = list->max;
     147                 :            : 
     148         [ +  + ]:   13159462 :             while (cnt-- > 0)
     149                 :            :               {
     150                 :            :                 /* These pointers can be NULL; it's safe to use
     151                 :            :                    'free' since it will check for this.  */
     152                 :   13124810 :                 Elf_Scn *scn = &list->data[cnt];
     153                 :   13124810 :                 Elf_Data_List *runp;
     154                 :            : 
     155         [ +  + ]:   13124810 :                 if ((scn->shdr_flags & ELF_F_MALLOCED) != 0)
     156                 :            :                   /* It doesn't matter which pointer.  */
     157                 :    3305834 :                   free (scn->shdr.e32);
     158                 :            : 
     159                 :            :                 /* Free zdata if uncompressed, but not yet used as
     160                 :            :                    rawdata_base.  If it is already used it will be
     161                 :            :                    freed below.  */
     162         [ +  + ]:   13124810 :                 if (scn->zdata_base != scn->rawdata_base)
     163                 :            :                   {
     164                 :    3719722 :                     free (scn->zdata_base);
     165                 :    3719722 :                     scn->zdata_base = NULL;
     166                 :            :                   }
     167                 :            : 
     168                 :            :                 /* If the file has the same byte order and the
     169                 :            :                    architecture doesn't require overly stringent
     170                 :            :                    alignment the raw data buffer is the same as the
     171                 :            :                    one used for presenting to the caller.  */
     172         [ +  + ]:   13124810 :                 if (scn->data_base != scn->rawdata_base)
     173                 :     540100 :                   free (scn->data_base);
     174                 :            : 
     175                 :            :                 /* The section data is allocated if we couldn't mmap
     176                 :            :                    the file.  Or if we had to decompress.  */
     177         [ +  + ]:   13124810 :                 if (elf->map_address == NULL
     178         [ +  + ]:    8042286 :                     || scn->rawdata_base == scn->zdata_base
     179         [ -  + ]:    2255550 :                     || (scn->flags & ELF_F_MALLOCED) != 0)
     180                 :   10869260 :                   free (scn->rawdata_base);
     181                 :            : 
     182                 :            :                 /* Free the list of data buffers for the section.
     183                 :            :                    We don't free the buffers themselves since this
     184                 :            :                    is the users job.  */
     185                 :   13124810 :                 runp = scn->data_list.next;
     186         [ +  + ]:   13124998 :                 while (runp != NULL)
     187                 :            :                   {
     188                 :        188 :                     Elf_Data_List *oldp = runp;
     189                 :        188 :                     runp = runp->next;
     190         [ +  - ]:        188 :                     if ((oldp->flags & ELF_F_MALLOCED) != 0)
     191                 :        188 :                       free (oldp);
     192                 :            :                   }
     193                 :            :               }
     194                 :            : 
     195                 :            :             /* Free the memory for the array.  */
     196                 :      34652 :             Elf_ScnList *oldp = list;
     197                 :      34652 :             list = list->next;
     198   [ +  +  -  + ]:      34652 :             assert (list == NULL || oldp->cnt == oldp->max);
     199         [ +  + ]:      34652 :             if (oldp != (elf->class == ELFCLASS32
     200                 :            :                          || (offsetof (struct Elf, state.elf32.scns)
     201                 :            :                              == offsetof (struct Elf, state.elf64.scns))
     202                 :            :                          ? &elf->state.elf32.scns
     203                 :            :                          : &elf->state.elf64.scns))
     204                 :       1970 :               free (oldp);
     205                 :            :           }
     206         [ +  + ]:      34652 :         while (list != NULL);
     207                 :            :       }
     208                 :            : 
     209                 :            :       /* Free the section header.  */
     210         [ +  + ]:      32682 :       if (elf->state.elf.shdr_malloced  != 0)
     211                 :       4964 :         free (elf->class == ELFCLASS32
     212                 :            :               || (offsetof (struct Elf, state.elf32.shdr)
     213                 :            :                   == offsetof (struct Elf, state.elf64.shdr))
     214                 :       4964 :               ? (void *) elf->state.elf32.shdr
     215                 :            :               : (void *) elf->state.elf64.shdr);
     216                 :            : 
     217                 :            :       /* Free the program header.  */
     218         [ +  + ]:      32682 :       if ((elf->state.elf.phdr_flags & ELF_F_MALLOCED) != 0)
     219                 :       2944 :         free (elf->class == ELFCLASS32
     220                 :            :               || (offsetof (struct Elf, state.elf32.phdr)
     221                 :            :                   == offsetof (struct Elf, state.elf64.phdr))
     222                 :       2944 :               ? (void *) elf->state.elf32.phdr
     223                 :            :               : (void *) elf->state.elf64.phdr);
     224                 :            :       break;
     225                 :            : 
     226                 :            :     default:
     227                 :            :       break;
     228                 :            :     }
     229                 :            : 
     230   [ +  +  +  + ]:      34342 :   if (elf->map_address != NULL && parent == NULL)
     231                 :            :     {
     232                 :            :       /* The file was read or mapped for this descriptor.  */
     233         [ +  + ]:      16212 :       if ((elf->flags & ELF_F_MALLOCED) != 0)
     234                 :        138 :         free (elf->map_address);
     235         [ +  + ]:      16074 :       else if ((elf->flags & ELF_F_MMAPPED) != 0)
     236                 :      15976 :         munmap (elf->map_address, elf->maximum_size);
     237                 :            :     }
     238                 :            : 
     239                 :      34342 :   rwlock_unlock (elf->lock);
     240                 :      34342 :   rwlock_fini (elf->lock);
     241                 :            : 
     242                 :            :   /* Finally the descriptor itself.  */
     243                 :      34342 :   free (elf);
     244                 :            : 
     245         [ +  + ]:      14546 :   return (parent != NULL && parent->ref_count == 0
     246         [ +  + ]:      34342 :           ? INTUSE(elf_end) (parent) : 0);
     247                 :            : }
     248                 :            : INTDEF(elf_end)