LCOV - code coverage report
Current view: top level - elfutils/src - arlib.c (source / functions) Hit Total Coverage
Test: lcov.out Lines: 85 100 85.0 %
Date: 2013-03-08 Functions: 5 5 100.0 %
Legend: Lines: hit not hit | Branches: + taken - not taken # not executed Branches: 42 76 55.3 %

           Branch data     Line data    Source code
       1                 :            : /* Functions to handle creation of Linux archives.
       2                 :            :    Copyright (C) 2007-2012 Red Hat, Inc.
       3                 :            :    This file is part of elfutils.
       4                 :            :    Written by Ulrich Drepper <drepper@redhat.com>, 2007.
       5                 :            : 
       6                 :            :    This file is free software; you can redistribute it and/or modify
       7                 :            :    it under the terms of the GNU General Public License as published by
       8                 :            :    the Free Software Foundation; either version 3 of the License, or
       9                 :            :    (at your option) any later version.
      10                 :            : 
      11                 :            :    elfutils is distributed in the hope that it will be useful, but
      12                 :            :    WITHOUT ANY WARRANTY; without even the implied warranty of
      13                 :            :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14                 :            :    GNU General Public License for more details.
      15                 :            : 
      16                 :            :    You should have received a copy of the GNU General Public License
      17                 :            :    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
      18                 :            : 
      19                 :            : #ifdef HAVE_CONFIG_H
      20                 :            : # include <config.h>
      21                 :            : #endif
      22                 :            : 
      23                 :            : #include <assert.h>
      24                 :            : #include <error.h>
      25                 :            : #include <gelf.h>
      26                 :            : #include <libintl.h>
      27                 :            : #include <stdio.h>
      28                 :            : #include <stdlib.h>
      29                 :            : #include <time.h>
      30                 :            : 
      31                 :            : #include <system.h>
      32                 :            : 
      33                 :            : #include "arlib.h"
      34                 :            : 
      35                 :            : 
      36                 :            : /* The one symbol table we hanble.  */
      37                 :            : struct arlib_symtab symtab;
      38                 :            : 
      39                 :            : 
      40                 :            : /* Initialize ARLIB_SYMTAB structure.  */
      41                 :            : void
      42                 :          4 : arlib_init (void)
      43                 :            : {
      44                 :            : #define obstack_chunk_alloc xmalloc
      45                 :            : #define obstack_chunk_free free
      46                 :          4 :   obstack_init (&symtab.symsoffob);
      47                 :          4 :   obstack_init (&symtab.symsnameob);
      48                 :          4 :   obstack_init (&symtab.longnamesob);
      49                 :            : 
      50                 :            :   /* We add the archive header here as well, that avoids allocating
      51                 :            :      another memory block.  */
      52                 :            :   struct ar_hdr ar_hdr;
      53                 :          4 :   memcpy (ar_hdr.ar_name, "/               ", sizeof (ar_hdr.ar_name));
      54                 :            :   /* Using snprintf here has a problem: the call always wants to add a
      55                 :            :      NUL byte.  We could use a trick whereby we specify the target
      56                 :            :      buffer size longer than it is and this would not actually fail,
      57                 :            :      since all the fields are consecutive and we fill them in
      58                 :            :      sequence (i.e., the NUL byte gets overwritten).  But
      59                 :            :      _FORTIFY_SOURCE=2 would not let us play these games.  Therefore
      60                 :            :      we play it safe.  */
      61                 :            :   char tmpbuf[sizeof (ar_hdr.ar_date) + 1];
      62                 :          4 :   memcpy (ar_hdr.ar_date, tmpbuf,
      63         [ +  - ]:          4 :           snprintf (tmpbuf, sizeof (tmpbuf), "%-*lld",
      64                 :            :                     (int) sizeof (ar_hdr.ar_date),
      65                 :            :                     (arlib_deterministic_output ? 0
      66                 :            :                      : (long long int) time (NULL))));
      67                 :            :   assert ((sizeof (struct ar_hdr)  % sizeof (uint32_t)) == 0);
      68                 :            : 
      69                 :            :   /* Note the string for the ar_uid and ar_gid cases is longer than
      70                 :            :      necessary.  This does not matter since we copy only as much as
      71                 :            :      necessary but it helps the compiler to use the same string for
      72                 :            :      the ar_mode case.  */
      73                 :          4 :   memcpy (ar_hdr.ar_uid, "0       ", sizeof (ar_hdr.ar_uid));
      74                 :          4 :   memcpy (ar_hdr.ar_gid, "0       ", sizeof (ar_hdr.ar_gid));
      75                 :          4 :   memcpy (ar_hdr.ar_mode, "0       ", sizeof (ar_hdr.ar_mode));
      76                 :          4 :   memcpy (ar_hdr.ar_fmag, ARFMAG, sizeof (ar_hdr.ar_fmag));
      77                 :            : 
      78                 :            :   /* Add the archive header to the file content.  */
      79         [ -  + ]:          4 :   obstack_grow (&symtab.symsoffob, &ar_hdr, sizeof (ar_hdr));
      80                 :            : 
      81                 :            :   /* The first word in the offset table specifies the size.  Create
      82                 :            :      such an entry now.  The real value will be filled-in later.  For
      83                 :            :      all supported platforms the following is true.  */
      84                 :            :   assert (sizeof (uint32_t) == sizeof (int));
      85         [ -  + ]:          4 :   obstack_int_grow (&symtab.symsoffob, 0);
      86                 :            : 
      87                 :            :   /* The long name obstack also gets its archive header.  As above,
      88                 :            :      some of the input strings are longer than required but we only
      89                 :            :      copy the necessary part.  */
      90                 :          4 :   memcpy (ar_hdr.ar_name, "//              ", sizeof (ar_hdr.ar_name));
      91                 :          4 :   memcpy (ar_hdr.ar_date, "            ", sizeof (ar_hdr.ar_date));
      92                 :          4 :   memcpy (ar_hdr.ar_uid, "            ", sizeof (ar_hdr.ar_uid));
      93                 :          4 :   memcpy (ar_hdr.ar_gid, "            ", sizeof (ar_hdr.ar_gid));
      94                 :          4 :   memcpy (ar_hdr.ar_mode, "            ", sizeof (ar_hdr.ar_mode));
      95                 :            :   /* The ar_size field will be filled in later and ar_fmag is already OK.  */
      96         [ -  + ]:          4 :   obstack_grow (&symtab.longnamesob, &ar_hdr, sizeof (ar_hdr));
      97                 :            : 
      98                 :            :   /* All other members are zero.  */
      99                 :          4 :   symtab.symsofflen = 0;
     100                 :          4 :   symtab.symsoff = NULL;
     101                 :          4 :   symtab.symsnamelen = 0;
     102                 :          4 :   symtab.symsname = NULL;
     103                 :          4 : }
     104                 :            : 
     105                 :            : 
     106                 :            : /* Finalize ARLIB_SYMTAB content.  */
     107                 :            : void
     108                 :          4 : arlib_finalize (void)
     109                 :            : {
     110                 :            :   char tmpbuf[sizeof (((struct ar_hdr *) NULL)->ar_size) + 1];
     111                 :            : 
     112                 :          8 :   symtab.longnameslen = obstack_object_size (&symtab.longnamesob);
     113         [ -  + ]:          4 :   if (symtab.longnameslen != sizeof (struct ar_hdr))
     114                 :            :     {
     115         [ #  # ]:          0 :       if ((symtab.longnameslen & 1) != 0)
     116                 :            :         {
     117                 :            :           /* Add one more byte to make length even.  */
     118         [ #  # ]:          0 :           obstack_grow (&symtab.longnamesob, "\n", 1);
     119                 :          0 :           ++symtab.longnameslen;
     120                 :            :         }
     121                 :            : 
     122 [ #  # ][ #  # ]:          0 :       symtab.longnames = obstack_finish (&symtab.longnamesob);
     123                 :            : 
     124                 :          0 :       memcpy (&((struct ar_hdr *) symtab.longnames)->ar_size, tmpbuf,
     125                 :          0 :               snprintf (tmpbuf, sizeof (tmpbuf), "%-*zu",
     126                 :            :                         (int) sizeof (((struct ar_hdr *) NULL)->ar_size),
     127                 :          0 :                         symtab.longnameslen - sizeof (struct ar_hdr)));
     128                 :            :     }
     129                 :            : 
     130                 :          8 :   symtab.symsofflen = obstack_object_size (&symtab.symsoffob);
     131         [ -  + ]:          4 :   assert (symtab.symsofflen % sizeof (uint32_t) == 0);
     132         [ +  - ]:          4 :   if (symtab.symsofflen != 0)
     133                 :            :     {
     134 [ -  + ][ -  + ]:          4 :       symtab.symsoff = (uint32_t *) obstack_finish (&symtab.symsoffob);
     135                 :            : 
     136                 :            :       /* Fill in the number of offsets now.  */
     137                 :          4 :       symtab.symsoff[AR_HDR_WORDS] = le_bswap_32 ((symtab.symsofflen
     138                 :            :                                                     - sizeof (struct ar_hdr))
     139                 :            :                                                    / sizeof (uint32_t) - 1);
     140                 :            :     }
     141                 :            : 
     142                 :          8 :   symtab.symsnamelen = obstack_object_size (&symtab.symsnameob);
     143         [ +  + ]:          4 :   if ((symtab.symsnamelen & 1) != 0)
     144                 :            :     {
     145                 :            :       /* Add one more NUL byte to make length even.  */
     146         [ -  + ]:          2 :       obstack_grow (&symtab.symsnameob, "", 1);
     147                 :          2 :       ++symtab.symsnamelen;
     148                 :            :     }
     149 [ +  + ][ -  + ]:          4 :   symtab.symsname = obstack_finish (&symtab.symsnameob);
     150                 :            : 
     151                 :            :   /* Determine correction for the offsets in the symbol table.   */
     152                 :          4 :   off_t disp = 0;
     153         [ +  + ]:          4 :   if (symtab.symsnamelen > 0)
     154                 :          2 :     disp = symtab.symsofflen + symtab.symsnamelen;
     155         [ -  + ]:          4 :   if (symtab.longnameslen > sizeof (struct ar_hdr))
     156                 :          0 :     disp += symtab.longnameslen;
     157                 :            : 
     158 [ +  + ][ +  - ]:          4 :   if (disp != 0 && symtab.symsoff != NULL)
     159                 :            :     {
     160                 :          4 :       uint32_t nsyms = le_bswap_32 (symtab.symsoff[AR_HDR_WORDS]);
     161                 :            : 
     162         [ +  + ]:          9 :       for (uint32_t cnt = 1; cnt <= nsyms; ++cnt)
     163                 :            :         {
     164                 :         14 :           uint32_t val = le_bswap_32 (symtab.symsoff[AR_HDR_WORDS + cnt]);
     165                 :          7 :           val += disp;
     166                 :         14 :           symtab.symsoff[AR_HDR_WORDS + cnt] = le_bswap_32 (val);
     167                 :            :         }
     168                 :            :     }
     169                 :            : 
     170                 :            :   /* See comment for ar_date above.  */
     171                 :          4 :   memcpy (&((struct ar_hdr *) symtab.symsoff)->ar_size, tmpbuf,
     172                 :          4 :           snprintf (tmpbuf, sizeof (tmpbuf), "%-*zu",
     173                 :            :                     (int) sizeof (((struct ar_hdr *) NULL)->ar_size),
     174                 :          4 :                     symtab.symsofflen + symtab.symsnamelen
     175                 :            :                     - sizeof (struct ar_hdr)));
     176                 :          4 : }
     177                 :            : 
     178                 :            : 
     179                 :            : /* Free resources for ARLIB_SYMTAB.  */
     180                 :            : void
     181                 :          4 : arlib_fini (void)
     182                 :            : {
     183                 :          4 :   obstack_free (&symtab.symsoffob, NULL);
     184                 :          4 :   obstack_free (&symtab.symsnameob, NULL);
     185                 :          4 :   obstack_free (&symtab.longnamesob, NULL);
     186                 :          4 : }
     187                 :            : 
     188                 :            : 
     189                 :            : /* Add name a file offset of a symbol.  */
     190                 :            : void
     191                 :          7 : arlib_add_symref (const char *symname, off_t symoff)
     192                 :            : {
     193                 :            :   /* For all supported platforms the following is true.  */
     194                 :            :   assert (sizeof (uint32_t) == sizeof (int));
     195         [ -  + ]:          7 :   obstack_int_grow (&symtab.symsoffob, (int) le_bswap_32 (symoff));
     196                 :            : 
     197                 :          7 :   size_t symname_len = strlen (symname) + 1;
     198         [ -  + ]:          7 :   obstack_grow (&symtab.symsnameob, symname, symname_len);
     199                 :          7 : }
     200                 :            : 
     201                 :            : 
     202                 :            : /* Add symbols from ELF with value OFFSET to the symbol table SYMTAB.  */
     203                 :            : void
     204                 :         11 : arlib_add_symbols (Elf *elf, const char *arfname, const char *membername,
     205                 :            :                    off_t off)
     206                 :            : {
     207         [ -  + ]:         11 :   if (sizeof (off) > sizeof (uint32_t) && off > ~((uint32_t) 0))
     208                 :            :     /* The archive is too big.  */
     209                 :          0 :     error (EXIT_FAILURE, 0, gettext ("the archive '%s' is too large"),
     210                 :            :            arfname);
     211                 :            : 
     212                 :            :   /* We only add symbol tables for ELF files.  It makes not much sense
     213                 :            :      to add symbols from executables but we do so for compatibility.
     214                 :            :      For DSOs and executables we use the dynamic symbol table, for
     215                 :            :      relocatable files all the DT_SYMTAB tables.  */
     216         [ +  + ]:         11 :   if (elf_kind (elf) != ELF_K_ELF)
     217                 :            :     return;
     218                 :            : 
     219                 :            :   GElf_Ehdr ehdr_mem;
     220                 :          7 :   GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem);
     221         [ -  + ]:          7 :   if (ehdr == NULL)
     222                 :          0 :     error (EXIT_FAILURE, 0, gettext ("cannot read ELF header of %s(%s): %s"),
     223                 :            :            arfname, membername, elf_errmsg (-1));
     224                 :            : 
     225                 :            :   GElf_Word symtype;
     226         [ -  + ]:          7 :   if (ehdr->e_type == ET_REL)
     227                 :            :     symtype = SHT_SYMTAB;
     228         [ #  # ]:          0 :   else if (ehdr->e_type == ET_EXEC || ehdr->e_type == ET_DYN)
     229                 :            :     symtype = SHT_DYNSYM;
     230                 :            :   else
     231                 :            :     /* We do not handle that type.  */
     232                 :            :     return;
     233                 :            : 
     234                 :            :   /* Iterate over all sections.  */
     235                 :          7 :   Elf_Scn *scn = NULL;
     236         [ +  + ]:         67 :   while ((scn = elf_nextscn (elf, scn)) != NULL)
     237                 :            :     {
     238                 :            :       /* Get the section header.  */
     239                 :            :       GElf_Shdr shdr_mem;
     240                 :         56 :       GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
     241         [ -  + ]:         56 :       if (shdr == NULL)
     242                 :          0 :         continue;
     243                 :            : 
     244         [ +  + ]:         56 :       if (shdr->sh_type != symtype)
     245                 :         49 :         continue;
     246                 :            : 
     247                 :          7 :       Elf_Data *data = elf_getdata (scn, NULL);
     248         [ -  + ]:          7 :       if (data == NULL)
     249                 :          0 :         continue;
     250                 :            : 
     251                 :          7 :       int nsyms = shdr->sh_size / shdr->sh_entsize;
     252         [ +  + ]:         14 :       for (int ndx = shdr->sh_info; ndx < nsyms; ++ndx)
     253                 :            :         {
     254                 :            :           GElf_Sym sym_mem;
     255                 :          7 :           GElf_Sym *sym = gelf_getsym (data, ndx, &sym_mem);
     256         [ -  + ]:          7 :           if (sym == NULL)
     257                 :          0 :             continue;
     258                 :            : 
     259                 :            :           /* Ignore undefined symbols.  */
     260         [ -  + ]:          7 :           if (sym->st_shndx == SHN_UNDEF)
     261                 :          0 :             continue;
     262                 :            : 
     263                 :            :           /* Use this symbol.  */
     264                 :          7 :           const char *symname = elf_strptr (elf, shdr->sh_link, sym->st_name);
     265         [ +  - ]:          7 :           if (symname != NULL)
     266                 :          7 :             arlib_add_symref (symname, off);
     267                 :            :         }
     268                 :            : 
     269                 :            :       /* Only relocatable files can have more than one symbol table.  */
     270         [ +  - ]:         56 :       if (ehdr->e_type != ET_REL)
     271                 :            :         break;
     272                 :            :     }
     273                 :         12 : }

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