lib/libc/gen/nlist_coff.c

   1 /* $NetBSD: nlist_coff.c,v 1.7 2009/02/16 10:40:45 lukem 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 1.7 2009/02/16 10:40:45 lukem 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 #define BAD             do { rv = -1; goto out; } while (/*CONSTCOND*/0)
  62 #define BADUNMAP        do { rv = -1; goto unmap; } while (/*CONSTCOND*/0)
  63
  64 #define ES_LEN 18
  65 struct coff_extsym {
  66         union {
  67                 char u_name[8];
  68                 struct {
  69                         int u_zero;
  70                         int u_offset;
  71                 } s;
  72         } u;
  73         int32_t es_value;
  74         int16_t es_scnum;
  75         int16_t es_type;
  76         int8_t es_class;
  77         int8_t es_numaux;
  78 };
  79 #define es_name u.u_name
  80 #define es_zero u.s.u_zero
  81 #define es_offset u.s.u_offset
  82
  83 int
  84 __fdnlist_coff(fd, list)
  85         int fd;
  86         struct nlist *list;
  87 {
  88         struct nlist *p;
  89         struct coff_filehdr *filehdrp;
  90         struct stat st;
  91         char *mappedfile;
  92         size_t mappedsize;
  93         u_long symoff, extstroff;
  94         int rv, nent;
  95         long i, nesyms;
  96
  97         _DIAGASSERT(fd != -1);
  98         _DIAGASSERT(list != NULL);
  99
 100         rv = -1;
 101
 102         /*
 103          * If we can't fstat() the file, something bad is going on.
 104          */
 105         if (fstat(fd, &st) < 0)
 106                 BAD;
 107
 108         /*
 109          * Map the file in its entirety.
 110          */
 111         if ((uintmax_t)st.st_size > (uintmax_t)SIZE_T_MAX) {
 112                 errno = EFBIG;
 113                 BAD;
 114         }
 115         mappedsize = st.st_size;
 116         mappedfile = mmap(NULL, mappedsize, PROT_READ, MAP_PRIVATE|MAP_FILE,
 117             fd, 0);
 118         if (mappedfile == (char *)-1)
 119                 BAD;
 120
 121         /*
 122          * Make sure we can access the executable's header
 123          * directly, and make sure we recognize the executable
 124          * as an COFF binary.
 125          */
 126         if (mappedsize < sizeof (struct coff_filehdr))
 127                 BADUNMAP;
 128         filehdrp = (struct coff_filehdr *)&mappedfile[0];
 129
 130         if (COFF_BADMAG(filehdrp))
 131                 BADUNMAP;
 132
 133         /*
 134          * Find the symbol list.
 135          */
 136         symoff = filehdrp->f_symptr;
 137         nesyms = filehdrp->f_nsyms;
 138
 139         if (symoff + ES_LEN * nesyms > mappedsize)
 140                 BADUNMAP;
 141         extstroff = symoff + ES_LEN * nesyms;
 142
 143         nent = 0;
 144         for (p = list; !ISLAST(p); ++p) {
 145                 p->n_type = 0;
 146                 p->n_other = 0;
 147                 p->n_desc = 0;
 148                 p->n_value = 0;
 149                 ++nent;
 150         }
 151
 152         for (i = 0; i < nesyms; i++) {
 153                 char *symtabname;
 154                 const char *nlistname;
 155                 struct coff_extsym esym;
 156                 char name[10];
 157
 158                 memcpy(&esym, &mappedfile[symoff + ES_LEN * i], ES_LEN);
 159                 if (esym.es_numaux != 0) {
 160                         i += esym.es_numaux;    /* XXX Skip aux entry */
 161                         continue;
 162                 }
 163
 164                 if (esym.es_zero != 0) {
 165                         memcpy(name, esym.es_name, 8);
 166                         name[8] = 0;
 167                         symtabname = name;
 168                 } else if (esym.es_offset != 0)
 169                         symtabname = &mappedfile[extstroff + esym.es_offset];
 170                 else
 171                         continue;
 172
 173                 for (p = list; !ISLAST(p); p++) {
 174                         nlistname = N_NAME(p);
 175                         if (!strcmp(symtabname, nlistname)) {
 176                                 /*
 177                                  * Translate (roughly) from COFF to nlist
 178                                  */
 179                                 p->n_value = esym.es_value;
 180                                 p->n_type = N_EXT;              /* XXX */
 181                                 p->n_desc = 0;                  /* XXX */
 182                                 p->n_other = 0;                 /* XXX */
 183
 184                                 if (--nent <= 0)
 185                                         goto done;
 186                                 break;  /* into next run of outer loop */
 187                         }
 188                 }
 189         }
 190
 191 done:
 192         rv = nent;
 193 unmap:
 194         munmap(mappedfile, mappedsize);
 195 out:
 196         return (rv);
 197 }
 198
 199 #endif /* NLIST_COFF */