sys/lib/libsa/exec.c

   1 /*      $NetBSD: exec.c,v 1.28 2009/12/29 20:21:46 elad Exp $   */
   2
   3 /*-
   4  * Copyright (c) 1982, 1986, 1990, 1993
   5  *      The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/param.h>
  33 #include <sys/reboot.h>
  34 #ifndef SA_EXEC_ANYOWNER
  35 #include <sys/stat.h>
  36 #endif
  37 #include <sys/exec_aout.h>
  38 #ifdef _STANDALONE
  39 #include <lib/libkern/libkern.h>
  40 #else
  41 #include <string.h>
  42 #endif
  43
  44 #include "stand.h"
  45
  46 void
  47 exec(char *path, char *loadaddr, int howto)
  48 {
  49 #ifndef SA_EXEC_ANYOWNER
  50         struct stat sb;
  51 #endif
  52         struct exec x;
  53         int io, i;
  54         char *addr, *ssym, *esym;
  55
  56         io = open(path, 0);
  57         if (io < 0)
  58                 return;
  59
  60 #ifndef SA_EXEC_ANYOWNER
  61         (void) fstat(io, &sb);
  62         if (sb.st_uid || (sb.st_mode & 2)) {
  63                 printf("non-secure file, will not load\n");
  64                 close(io);
  65                 errno = EPERM;
  66                 return;
  67         }
  68 #endif
  69
  70         i = read(io, (char *)&x, sizeof(x));
  71         if (i != sizeof(x) || N_BADMAG(x)) {
  72                 errno = EFTYPE;
  73                 return;
  74         }
  75
  76         /* Text */
  77         printf("%ld", x.a_text);
  78         addr = loadaddr;
  79         if (N_GETMAGIC(x) == ZMAGIC) {
  80                 (void)memcpy(addr, &x, sizeof(x));
  81                 addr += sizeof(x);
  82                 x.a_text -= sizeof(x);
  83         }
  84         if (read(io, (char *)addr, x.a_text) != (ssize_t)x.a_text)
  85                 goto shread;
  86         addr += x.a_text;
  87         if (N_GETMAGIC(x) == ZMAGIC || N_GETMAGIC(x) == NMAGIC)
  88                 while ((long)addr & (N_PAGSIZ(x) - 1))
  89                         *addr++ = 0;
  90
  91         /* Data */
  92         printf("+%ld", x.a_data);
  93         if (read(io, addr, x.a_data) != (ssize_t)x.a_data)
  94                 goto shread;
  95         addr += x.a_data;
  96
  97         /* Bss */
  98         printf("+%ld", x.a_bss);
  99         for (i = 0; i < (int)x.a_bss; i++)
 100                 *addr++ = 0;
 101
 102         /* Symbols */
 103         ssym = addr;
 104         (void)memcpy(addr, &x.a_syms, sizeof(x.a_syms));
 105         addr += sizeof(x.a_syms);
 106         if (x.a_syms) {
 107                 printf("+[%ld", x.a_syms);
 108                 if (read(io, addr, x.a_syms) != (ssize_t)x.a_syms)
 109                         goto shread;
 110                 addr += x.a_syms;
 111         }
 112
 113         i = 0;
 114         if (x.a_syms && read(io, &i, sizeof(int)) != sizeof(int))
 115                 goto shread;
 116
 117         (void)memcpy(addr, &i, sizeof(int));
 118         if (i) {
 119                 i -= sizeof(int);
 120                 addr += sizeof(int);
 121                 if (read(io, addr, i) != i)
 122                         goto shread;
 123                 addr += i;
 124         }
 125
 126         if (x.a_syms) {
 127                 /* and that many bytes of (debug symbols?) */
 128                 printf("+%d]", i);
 129         }
 130
 131         close(io);
 132
 133 #define round_to_size(x) \
 134         (((int)(x) + sizeof(int) - 1) & ~(sizeof(int) - 1))
 135         esym = (char *)round_to_size(addr - loadaddr);
 136 #undef round_to_size
 137
 138         /* and note the end address of all this */
 139         printf(" total=0x%lx\n", (u_long)addr);
 140
 141         /*
 142          * Machine-dependent code must now adjust the
 143          * entry point.  This used to be done here,
 144          * but some systems may need to relocate the
 145          * loaded file before jumping to it, and the
 146          * displayed start address would be wrong.
 147          */
 148
 149 #ifdef EXEC_DEBUG
 150         printf("ssym=0x%x esym=0x%x\n", ssym, esym);
 151         printf("\n\nReturn to boot...\n");
 152         getchar();
 153 #endif
 154
 155         machdep_start((char *)x.a_entry, howto, loadaddr, ssym, esym);
 156
 157         /* exec failed */
 158         errno = ENOEXEC;
 159         return;
 160
 161 shread:
 162         close(io);
 163         errno = EIO;
 164         return;
 165 }