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 10:33:25 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         0,
  63         0,
  64         0,
  65         0,
  66         0,
  67         0,
  68         sendsig,
  69         sigcode,
  70         &szsigcode,
  71         "FreeBSD a.out",
  72         NULL,
  73         NULL,
  74         MINSIGSTKSZ
  75 };
  76
  77 static int
  78 exec_aout_imgact(struct image_params *imgp)
  79 {
  80         const struct exec *a_out = (const struct exec *) imgp->image_header;
  81         struct vmspace *vmspace;
  82         struct vnode *vp;
  83         int count;
  84         vm_map_t map;
  85         vm_object_t object;
  86         vm_offset_t text_end, data_end;
  87         unsigned long virtual_offset;
  88         unsigned long file_offset;
  89         unsigned long bss_size;
  90         int error;
  91
  92         /*
  93          * Linux and *BSD binaries look very much alike,
  94          * only the machine id is different:
  95          * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
  96          * NetBSD is in network byte order.. ugh.
  97          */
  98         if (((a_out->a_magic >> 16) & 0xff) != 0x86 &&
  99             ((a_out->a_magic >> 16) & 0xff) != 0 &&
 100             ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86)
 101                 return -1;
 102
 103         /*
 104          * Set file/virtual offset based on a.out variant.
 105          *      We do two cases: host byte order and network byte order
 106          *      (for NetBSD compatibility)
 107          */
 108         switch ((int)(a_out->a_magic & 0xffff)) {
 109         case ZMAGIC:
 110                 virtual_offset = 0;
 111                 if (a_out->a_text) {
 112                         file_offset = PAGE_SIZE;
 113                 } else {
 114                         /* Bill's "screwball mode" */
 115                         file_offset = 0;
 116                 }
 117                 break;
 118         case QMAGIC:
 119                 virtual_offset = PAGE_SIZE;
 120                 file_offset = 0;
 121                 /* Pass PS_STRINGS for BSD/OS binaries only. */
 122                 if (N_GETMID(*a_out) == MID_ZERO)
 123                         imgp->ps_strings = PS_STRINGS;
 124                 break;
 125         default:
 126                 /* NetBSD compatibility */
 127                 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
 128                 case ZMAGIC:
 129                 case QMAGIC:
 130                         virtual_offset = PAGE_SIZE;
 131                         file_offset = 0;
 132                         break;
 133                 default:
 134                         return (-1);
 135                 }
 136         }
 137
 138         bss_size = roundup(a_out->a_bss, PAGE_SIZE);
 139
 140         /*
 141          * Check various fields in header for validity/bounds.
 142          */
 143         if (/* entry point must lay with text region */
 144             a_out->a_entry < virtual_offset ||
 145             a_out->a_entry >= virtual_offset + a_out->a_text ||
 146
 147             /* text and data size must each be page rounded */
 148             a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
 149                 return (-1);
 150
 151         /* text + data can't exceed file size */
 152         if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
 153                 return (EFAULT);
 154
 155         /*
 156          * text/data/bss must not exceed limits
 157          */
 158         if (/* text can't exceed maximum text size */
 159             a_out->a_text > maxtsiz ||
 160
 161             /* data + bss can't exceed rlimit */
 162             a_out->a_data + bss_size >
 163                 imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur)
 164                         return (ENOMEM);
 165
 166         /*
 167          * Destroy old process VM and create a new one (with a new stack)
 168          */
 169         exec_new_vmspace(imgp, NULL);
 170
 171         /*
 172          * The vm space can be changed by exec_new_vmspace
 173          */
 174         vmspace = imgp->proc->p_vmspace;
 175
 176         vp = imgp->vp;
 177         map = &vmspace->vm_map;
 178         count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
 179         vm_map_lock(map);
 180         object = vp->v_object;
 181         vm_object_hold(object);
 182         vm_object_reference_locked(object);
 183
 184         text_end = virtual_offset + a_out->a_text;
 185         error = vm_map_insert(map, &count, object, NULL,
 186                 file_offset,
 187                 virtual_offset, text_end,
 188                 VM_MAPTYPE_NORMAL,
 189                 VM_SUBSYS_IMGACT,
 190                 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
 191                 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_PREFAULT_RELOCK);
 192
 193         if (error) {
 194                 vm_object_drop(object);
 195                 vm_map_unlock(map);
 196                 vm_map_entry_release(count);
 197                 return (error);
 198         }
 199
 200         data_end = text_end + a_out->a_data;
 201         if (a_out->a_data) {
 202                 vm_object_reference_locked(object);
 203                 error = vm_map_insert(map, &count, object, NULL,
 204                         file_offset + a_out->a_text,
 205                         text_end, data_end,
 206                         VM_MAPTYPE_NORMAL,
 207                         VM_SUBSYS_IMGACT,
 208                         VM_PROT_ALL, VM_PROT_ALL,
 209                         MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_PREFAULT_RELOCK);
 210                 if (error) {
 211                         vm_object_drop(object);
 212                         vm_map_unlock(map);
 213                         vm_map_entry_release(count);
 214                         return (error);
 215                 }
 216         }
 217         vm_object_drop(object);
 218
 219         if (bss_size) {
 220                 error = vm_map_insert(map, &count, NULL, NULL,
 221                         0, data_end, data_end + bss_size,
 222                         VM_MAPTYPE_NORMAL,
 223                         VM_SUBSYS_IMGACT,
 224                         VM_PROT_ALL, VM_PROT_ALL,
 225                         0);
 226                 if (error) {
 227                         vm_map_unlock(map);
 228                         vm_map_entry_release(count);
 229                         return (error);
 230                 }
 231         }
 232         vm_map_unlock(map);
 233         vm_map_entry_release(count);
 234
 235         /* Fill in process VM information */
 236         vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
 237         vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
 238         vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
 239         vmspace->vm_daddr = (caddr_t) (uintptr_t)
 240                             (virtual_offset + a_out->a_text);
 241
 242         /* Fill in image_params */
 243         imgp->interpreted = 0;
 244         imgp->entry_addr = a_out->a_entry;
 245
 246         imgp->proc->p_sysent = &aout_sysvec;
 247
 248         /* Indicate that this file should not be modified */
 249         vsetflags(imgp->vp, VTEXT);
 250
 251         return (0);
 252 }
 253
 254 /*
 255  * Tell kern_execve.c about it, with a little help from the linker.
 256  */
 257 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
 258 EXEC_SET(aout, aout_execsw);