lib/libc/gen/nlist_coff.c

   1 /* $NetBSD: nlist_coff.c,v 1.11 2012/03/22 14:18:34 christos Exp $ */
   2
   3 /*
   4  * Copyright (c) 1996 Christopher G. Demetriou
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *          This product includes software developed for the
  18  *          NetBSD Project.  See http://www.NetBSD.org/ for
  19  *          information about NetBSD.
  20  * 4. The name of the author may not be used to endorse or promote products
  21  *    derived from this software without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  *
  34  * <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>>
  35  */
  36
  37 #include <sys/cdefs.h>
  38 #if defined(LIBC_SCCS) && !defined(lint)
  39 __RCSID("$NetBSD: nlist_coff.c,v 1.11 2012/03/22 14:18:34 christos Exp $");
  40 #endif /* LIBC_SCCS and not lint */
  41
  42 #include "namespace.h"
  43 #include <sys/param.h>
  44 #include <sys/mman.h>
  45 #include <sys/stat.h>
  46 #include <sys/file.h>
  47
  48 #include <assert.h>
  49 #include <errno.h>
  50 #include <stdio.h>
  51 #include <string.h>
  52 #include <unistd.h>
  53 #include <nlist.h>
  54
  55 #include "nlist_private.h"
  56 #ifdef NLIST_COFF
  57 #include <sys/exec_coff.h>
  58 #endif
  59
  60 #ifdef NLIST_COFF
  61
  62 #define ES_LEN 18
  63 struct coff_extsym {
  64         union {
  65                 char u_name[8];
  66                 struct {
  67                         int u_zero;
  68                         int u_offset;
  69                 } s;
  70         } u;
  71         int32_t es_value;
  72         int16_t es_scnum;
  73         int16_t es_type;
  74         int8_t es_class;
  75         int8_t es_numaux;
  76 };
  77 #define es_name u.u_name
  78 #define es_zero u.s.u_zero
  79 #define es_offset u.s.u_offset
  80
  81 int
  82 __fdnlist_coff(int fd, struct nlist *list)
  83 {
  84         struct nlist *p;
  85         struct coff_filehdr *filehdrp;
  86         struct stat st;
  87         char *mappedfile;
  88         size_t mappedsize;
  89         u_long symoff, extstroff;
  90         int rv, nent;
  91         long i, nesyms;
  92
  93         _DIAGASSERT(fd != -1);
  94         _DIAGASSERT(list != NULL);
  95
  96         rv = -1;
  97
  98         /*
  99          * If we can't fstat() the file, something bad is going on.
 100          */
 101         if (fstat(fd, &st) < 0)
 102                 goto out;
 103
 104         /*
 105          * Map the file in its entirety.
 106          */
 107         if ((uintmax_t)st.st_size > (uintmax_t)SIZE_T_MAX) {
 108                 errno = EFBIG;
 109                 goto out;
 110         }
 111         mappedsize = (size_t)st.st_size;
 112         mappedfile = mmap(NULL, mappedsize, PROT_READ, MAP_PRIVATE|MAP_FILE,
 113             fd, 0);
 114         if (mappedfile == MAP_FAILED)
 115                 goto out;
 116
 117         /*
 118          * Make sure we can access the executable's header
 119          * directly, and make sure we recognize the executable
 120          * as an COFF binary.
 121          */
 122         if (mappedsize < sizeof (struct coff_filehdr))
 123                 goto unmap;
 124         filehdrp = (void *)&mappedfile[0];
 125
 126         if (COFF_BADMAG(filehdrp))
 127                 goto unmap;
 128
 129         /*
 130          * Find the symbol list.
 131          */
 132         symoff = filehdrp->f_symptr;
 133         nesyms = filehdrp->f_nsyms;
 134
 135         if (symoff + ES_LEN * nesyms > mappedsize)
 136                 goto unmap;
 137         extstroff = symoff + ES_LEN * nesyms;
 138
 139         nent = 0;
 140         for (p = list; !ISLAST(p); ++p) {
 141                 p->n_type = 0;
 142                 p->n_other = 0;
 143                 p->n_desc = 0;
 144                 p->n_value = 0;
 145                 ++nent;
 146         }
 147
 148         for (i = 0; i < nesyms; i++) {
 149                 char *symtabname;
 150                 const char *nlistname;
 151                 struct coff_extsym esym;
 152                 char name[10];
 153
 154                 memcpy(&esym, &mappedfile[symoff + ES_LEN * i], ES_LEN);
 155                 if (esym.es_numaux != 0) {
 156                         i += esym.es_numaux;    /* XXX Skip aux entry */
 157                         continue;
 158                 }
 159
 160                 if (esym.es_zero != 0) {
 161                         memcpy(name, esym.es_name, 8);
 162                         name[8] = 0;
 163                         symtabname = name;
 164                 } else if (esym.es_offset != 0)
 165                         symtabname = &mappedfile[extstroff + esym.es_offset];
 166                 else
 167                         continue;
 168
 169                 for (p = list; !ISLAST(p); p++) {
 170                         nlistname = N_NAME(p);
 171                         if (!strcmp(symtabname, nlistname)) {
 172                                 /*
 173                                  * Translate (roughly) from COFF to nlist
 174                                  */
 175                                 p->n_value = esym.es_value;
 176                                 p->n_type = N_EXT;              /* XXX */
 177                                 p->n_desc = 0;                  /* XXX */
 178                                 p->n_other = 0;                 /* XXX */
 179
 180                                 if (--nent <= 0)
 181                                         goto done;
 182                                 break;  /* into next run of outer loop */
 183                         }
 184                 }
 185         }
 186
 187 done:
 188         rv = nent;
 189 unmap:
 190         munmap(mappedfile, mappedsize);
 191 out:
 192         return rv;
 193 }
 194
 195 #endif /* NLIST_COFF */