sys/kern/imgact_aout.c

   1 /*
   2  * Copyright (c) 1993, David Greenman
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/sys/kern/imgact_aout.c,v 1.59.2.5 2001/11/03 01:41:08 ps Exp $
  27  * $DragonFly: src/sys/kern/imgact_aout.c,v 1.14 2007/02/01 11:33:25 corecode Exp $
  28  */
  29
  30 #include <sys/param.h>
  31 #include <sys/resourcevar.h>
  32 #include <sys/exec.h>
  33 #include <sys/fcntl.h>
  34 #include <sys/imgact.h>
  35 #include <sys/imgact_aout.h>
  36 #include <sys/kernel.h>
  37 #include <sys/malloc.h>
  38 #include <sys/systm.h>
  39 #include <sys/proc.h>
  40 #include <sys/namei.h>
  41 #include <sys/pioctl.h>
  42 #include <sys/signalvar.h>
  43 #include <sys/stat.h>
  44 #include <sys/sysent.h>
  45 #include <sys/syscall.h>
  46 #include <sys/vnode.h>
  47 #include <machine/md_var.h>
  48
  49 #include <vm/vm.h>
  50 #include <vm/vm_param.h>
  51 #include <sys/lock.h>
  52 #include <vm/pmap.h>
  53 #include <vm/vm_map.h>
  54 #include <vm/vm_object.h>
  55 #include <sys/user.h>
  56
  57 static int      exec_aout_imgact (struct image_params *imgp);
  58
  59 struct sysentvec aout_sysvec = {
  60         SYS_MAXSYSCALL,
  61         sysent,
  62         -1,
  63         0,
  64         0,
  65         0,
  66         0,
  67         0,
  68         0,
  69         sendsig,
  70         sigcode,
  71         &szsigcode,
  72         0,
  73         "FreeBSD a.out",
  74         NULL,
  75         NULL,
  76         MINSIGSTKSZ
  77 };
  78
  79 static int
  80 exec_aout_imgact(struct image_params *imgp)
  81 {
  82         const struct exec *a_out = (const struct exec *) imgp->image_header;
  83         struct vmspace *vmspace;
  84         struct vnode *vp;
  85         int count;
  86         vm_map_t map;
  87         vm_object_t object;
  88         vm_offset_t text_end, data_end;
  89         unsigned long virtual_offset;
  90         unsigned long file_offset;
  91         unsigned long bss_size;
  92         int error;
  93
  94         /*
  95          * Linux and *BSD binaries look very much alike,
  96          * only the machine id is different:
  97          * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
  98          * NetBSD is in network byte order.. ugh.
  99          */
 100         if (((a_out->a_magic >> 16) & 0xff) != 0x86 &&
 101             ((a_out->a_magic >> 16) & 0xff) != 0 &&
 102             ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86)
 103                 return -1;
 104
 105         /*
 106          * Set file/virtual offset based on a.out variant.
 107          *      We do two cases: host byte order and network byte order
 108          *      (for NetBSD compatibility)
 109          */
 110         switch ((int)(a_out->a_magic & 0xffff)) {
 111         case ZMAGIC:
 112                 virtual_offset = 0;
 113                 if (a_out->a_text) {
 114                         file_offset = PAGE_SIZE;
 115                 } else {
 116                         /* Bill's "screwball mode" */
 117                         file_offset = 0;
 118                 }
 119                 break;
 120         case QMAGIC:
 121                 virtual_offset = PAGE_SIZE;
 122                 file_offset = 0;
 123                 /* Pass PS_STRINGS for BSD/OS binaries only. */
 124                 if (N_GETMID(*a_out) == MID_ZERO)
 125                         imgp->ps_strings = PS_STRINGS;
 126                 break;
 127         default:
 128                 /* NetBSD compatibility */
 129                 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
 130                 case ZMAGIC:
 131                 case QMAGIC:
 132                         virtual_offset = PAGE_SIZE;
 133                         file_offset = 0;
 134                         break;
 135                 default:
 136                         return (-1);
 137                 }
 138         }
 139
 140         bss_size = roundup(a_out->a_bss, PAGE_SIZE);
 141
 142         /*
 143          * Check various fields in header for validity/bounds.
 144          */
 145         if (/* entry point must lay with text region */
 146             a_out->a_entry < virtual_offset ||
 147             a_out->a_entry >= virtual_offset + a_out->a_text ||
 148
 149             /* text and data size must each be page rounded */
 150             a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
 151                 return (-1);
 152
 153         /* text + data can't exceed file size */
 154         if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
 155                 return (EFAULT);
 156
 157         /*
 158          * text/data/bss must not exceed limits
 159          */
 160         if (/* text can't exceed maximum text size */
 161             a_out->a_text > maxtsiz ||
 162
 163             /* data + bss can't exceed rlimit */
 164             a_out->a_data + bss_size >
 165                 imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur)
 166                         return (ENOMEM);
 167
 168         /*
 169          * Destroy old process VM and create a new one (with a new stack)
 170          */
 171         exec_new_vmspace(imgp, NULL);
 172
 173         /*
 174          * The vm space can be changed by exec_new_vmspace
 175          */
 176         vmspace = imgp->proc->p_vmspace;
 177
 178         vp = imgp->vp;
 179         map = &vmspace->vm_map;
 180         count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
 181         vm_map_lock(map);
 182         object = vp->v_object;
 183         vm_object_reference(object);
 184
 185         text_end = virtual_offset + a_out->a_text;
 186         error = vm_map_insert(map, &count, object,
 187                 file_offset,
 188                 virtual_offset, text_end,
 189                 VM_MAPTYPE_NORMAL,
 190                 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
 191                 MAP_COPY_ON_WRITE | MAP_PREFAULT);
 192         if (error) {
 193                 vm_map_unlock(map);
 194                 vm_map_entry_release(count);
 195                 return (error);
 196         }
 197         data_end = text_end + a_out->a_data;
 198         if (a_out->a_data) {
 199                 vm_object_reference(object);
 200                 error = vm_map_insert(map, &count, object,
 201                         file_offset + a_out->a_text,
 202                         text_end, data_end,
 203                         VM_MAPTYPE_NORMAL,
 204                         VM_PROT_ALL, VM_PROT_ALL,
 205                         MAP_COPY_ON_WRITE | MAP_PREFAULT);
 206                 if (error) {
 207                         vm_map_unlock(map);
 208                         vm_map_entry_release(count);
 209                         return (error);
 210                 }
 211         }
 212
 213         if (bss_size) {
 214                 error = vm_map_insert(map, &count, NULL, 0,
 215                         data_end, data_end + bss_size,
 216                         VM_MAPTYPE_NORMAL,
 217                         VM_PROT_ALL, VM_PROT_ALL,
 218                         0);
 219                 if (error) {
 220                         vm_map_unlock(map);
 221                         vm_map_entry_release(count);
 222                         return (error);
 223                 }
 224         }
 225         vm_map_unlock(map);
 226         vm_map_entry_release(count);
 227
 228         /* Fill in process VM information */
 229         vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
 230         vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
 231         vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
 232         vmspace->vm_daddr = (caddr_t) (uintptr_t)
 233                             (virtual_offset + a_out->a_text);
 234
 235         /* Fill in image_params */
 236         imgp->interpreted = 0;
 237         imgp->entry_addr = a_out->a_entry;
 238
 239         imgp->proc->p_sysent = &aout_sysvec;
 240
 241         /* Indicate that this file should not be modified */
 242         imgp->vp->v_flag |= VTEXT;
 243
 244         return (0);
 245 }
 246
 247 /*
 248  * Tell kern_execve.c about it, with a little help from the linker.
 249  */
 250 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
 251 EXEC_SET(aout, aout_execsw);