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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by David Greenman 16 * 4. The name of the developer may be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 * $Id: imgact_aout.c,v 1.21 1995/12/15 02:57:40 peter Exp $ 32 */ 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/resourcevar.h> 37 #include <sys/exec.h> 38 #include <sys/mman.h> 39 #include <sys/imgact.h> 40 #include <sys/imgact_aout.h> 41 #include <sys/kernel.h> 42 #include <sys/sysent.h> 43 44 #include <vm/vm.h> 45 #include <vm/vm_param.h> 46 #include <vm/vm_prot.h> 47 #include <vm/lock.h> 48 #include <vm/pmap.h> 49 #include <vm/vm_map.h> 50 #include <vm/vm_extern.h> 51 52 static int exec_aout_imgact __P((struct image_params *imgp)); 53 54 static int 55 exec_aout_imgact(imgp) 56 struct image_params *imgp; 57 { 58 struct exec *a_out = (struct exec *) imgp->image_header; 59 struct vmspace *vmspace = imgp->proc->p_vmspace; 60 unsigned long vmaddr, virtual_offset; 61 unsigned long file_offset; 62 unsigned long bss_size; 63 int error; 64 65 #if defined(COMPAT_LINUX) || defined(LINUX) 66 /* 67 * Linux and *BSD binaries look very much alike, 68 * only the machine id is different: 69 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 70 */ 71 if (((a_out->a_magic >> 16) & 0xff) != 0x86 && 72 ((a_out->a_magic >> 16) & 0xff) != 0) 73 return -1; 74 #endif /* COMPAT_LINUX || defined(LINUX) */ 75 76 /* 77 * Set file/virtual offset based on a.out variant. 78 * We do two cases: host byte order and network byte order 79 * (for NetBSD compatibility) 80 */ 81 switch ((int)(a_out->a_magic & 0xffff)) { 82 case ZMAGIC: 83 virtual_offset = 0; 84 if (a_out->a_text) { 85 file_offset = NBPG; 86 } else { 87 /* Bill's "screwball mode" */ 88 file_offset = 0; 89 } 90 break; 91 case QMAGIC: 92 virtual_offset = NBPG; 93 file_offset = 0; 94 break; 95 default: 96 /* NetBSD compatibility */ 97 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) { 98 case ZMAGIC: 99 case QMAGIC: 100 virtual_offset = NBPG; 101 file_offset = 0; 102 break; 103 default: 104 return (-1); 105 } 106 } 107 108 bss_size = roundup(a_out->a_bss, NBPG); 109 110 /* 111 * Check various fields in header for validity/bounds. 112 */ 113 if (/* entry point must lay with text region */ 114 a_out->a_entry < virtual_offset || 115 a_out->a_entry >= virtual_offset + a_out->a_text || 116 117 /* text and data size must each be page rounded */ 118 a_out->a_text % NBPG || 119 a_out->a_data % NBPG) 120 return (-1); 121 122 /* text + data can't exceed file size */ 123 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 124 return (EFAULT); 125 126 /* 127 * text/data/bss must not exceed limits 128 */ 129 if (/* text can't exceed maximum text size */ 130 a_out->a_text > MAXTSIZ || 131 132 /* data + bss can't exceed maximum data size */ 133 a_out->a_data + bss_size > MAXDSIZ || 134 135 /* data + bss can't exceed rlimit */ 136 a_out->a_data + bss_size > 137 imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur) 138 return (ENOMEM); 139 140 /* copy in arguments and/or environment from old process */ 141 error = exec_extract_strings(imgp); 142 if (error) 143 return (error); 144 145 /* 146 * Destroy old process VM and create a new one (with a new stack) 147 */ 148 exec_new_vmspace(imgp); 149 150 /* 151 * Map text/data read/execute 152 */ 153 vmaddr = virtual_offset; 154 error = 155 vm_mmap(&vmspace->vm_map, /* map */ 156 &vmaddr, /* address */ 157 a_out->a_text + a_out->a_data, /* size */ 158 VM_PROT_READ | VM_PROT_EXECUTE, /* protection */ 159 VM_PROT_ALL, /* max protection */ 160 MAP_PRIVATE | MAP_FIXED, /* flags */ 161 (caddr_t)imgp->vp, /* vnode */ 162 file_offset); /* offset */ 163 if (error) 164 return (error); 165 166 /* 167 * allow writing of data 168 */ 169 vm_map_protect(&vmspace->vm_map, 170 vmaddr + a_out->a_text, 171 vmaddr + a_out->a_text + a_out->a_data, 172 VM_PROT_ALL, 173 FALSE); 174 175 if (bss_size != 0) { 176 /* 177 * Allocate demand-zeroed area for uninitialized data 178 * "bss" = 'block started by symbol' - named after the IBM 7090 179 * instruction of the same name. 180 */ 181 vmaddr = virtual_offset + a_out->a_text + a_out->a_data; 182 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr, bss_size, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0); 183 if (error) 184 return (error); 185 } 186 187 /* Fill in process VM information */ 188 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 189 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 190 vmspace->vm_taddr = (caddr_t) virtual_offset; 191 vmspace->vm_daddr = (caddr_t) virtual_offset + a_out->a_text; 192 193 /* Fill in image_params */ 194 imgp->interpreted = 0; 195 imgp->entry_addr = a_out->a_entry; 196 197 imgp->proc->p_sysent = &aout_sysvec; 198 199 /* Indicate that this file should not be modified */ 200 imgp->vp->v_flag |= VTEXT; 201 202 return (0); 203 } 204 205 /* 206 * Tell kern_execve.c about it, with a little help from the linker. 207 * Since `const' objects end up in the text segment, TEXT_SET is the 208 * correct directive to use. 209 */ 210 static const struct execsw aout_execsw = { exec_aout_imgact, "a.out" }; 211 TEXT_SET(execsw_set, aout_execsw); 212