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 * $Id: imgact_aout.c,v 1.35 1997/08/26 00:02:23 bde Exp $ 27 */ 28 29 #include <sys/param.h> 30 #include <sys/resourcevar.h> 31 #include <sys/exec.h> 32 #include <sys/mman.h> 33 #include <sys/imgact.h> 34 #include <sys/imgact_aout.h> 35 #include <sys/kernel.h> 36 #include <sys/proc.h> 37 #include <sys/sysent.h> 38 #include <sys/vnode.h> 39 40 #include <vm/vm.h> 41 #include <vm/vm_param.h> 42 #include <vm/vm_prot.h> 43 #include <sys/lock.h> 44 #include <vm/pmap.h> 45 #include <vm/vm_map.h> 46 #include <vm/vm_extern.h> 47 48 static int exec_aout_imgact __P((struct image_params *imgp)); 49 50 static int 51 exec_aout_imgact(imgp) 52 struct image_params *imgp; 53 { 54 const struct exec *a_out = (const struct exec *) imgp->image_header; 55 struct vmspace *vmspace; 56 vm_offset_t vmaddr; 57 unsigned long virtual_offset; 58 unsigned long file_offset; 59 unsigned long bss_size; 60 int error; 61 62 /* 63 * Linux and *BSD binaries look very much alike, 64 * only the machine id is different: 65 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 66 * NetBSD is in network byte order.. ugh. 67 */ 68 if (((a_out->a_magic >> 16) & 0xff) != 0x86 && 69 ((a_out->a_magic >> 16) & 0xff) != 0 && 70 ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86) 71 return -1; 72 73 /* 74 * Set file/virtual offset based on a.out variant. 75 * We do two cases: host byte order and network byte order 76 * (for NetBSD compatibility) 77 */ 78 switch ((int)(a_out->a_magic & 0xffff)) { 79 case ZMAGIC: 80 virtual_offset = 0; 81 if (a_out->a_text) { 82 file_offset = PAGE_SIZE; 83 } else { 84 /* Bill's "screwball mode" */ 85 file_offset = 0; 86 } 87 break; 88 case QMAGIC: 89 virtual_offset = PAGE_SIZE; 90 file_offset = 0; 91 break; 92 default: 93 /* NetBSD compatibility */ 94 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) { 95 case ZMAGIC: 96 case QMAGIC: 97 virtual_offset = PAGE_SIZE; 98 file_offset = 0; 99 break; 100 default: 101 return (-1); 102 } 103 } 104 105 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 106 107 /* 108 * Check various fields in header for validity/bounds. 109 */ 110 if (/* entry point must lay with text region */ 111 a_out->a_entry < virtual_offset || 112 a_out->a_entry >= virtual_offset + a_out->a_text || 113 114 /* text and data size must each be page rounded */ 115 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK) 116 return (-1); 117 118 /* text + data can't exceed file size */ 119 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 120 return (EFAULT); 121 122 /* 123 * text/data/bss must not exceed limits 124 */ 125 if (/* text can't exceed maximum text size */ 126 a_out->a_text > MAXTSIZ || 127 128 /* data + bss can't exceed rlimit */ 129 a_out->a_data + bss_size > 130 imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur) 131 return (ENOMEM); 132 133 /* copy in arguments and/or environment from old process */ 134 error = exec_extract_strings(imgp); 135 if (error) 136 return (error); 137 138 /* 139 * Destroy old process VM and create a new one (with a new stack) 140 */ 141 exec_new_vmspace(imgp); 142 143 /* 144 * The vm space can be changed by exec_new_vmspace 145 */ 146 vmspace = imgp->proc->p_vmspace; 147 148 /* 149 * Map text/data read/execute 150 */ 151 vmaddr = virtual_offset; 152 error = 153 vm_mmap(&vmspace->vm_map, /* map */ 154 &vmaddr, /* address */ 155 a_out->a_text + a_out->a_data, /* size */ 156 VM_PROT_READ | VM_PROT_EXECUTE, /* protection */ 157 VM_PROT_ALL, /* max protection */ 158 MAP_PRIVATE | MAP_FIXED, /* flags */ 159 (caddr_t)imgp->vp, /* vnode */ 160 file_offset); /* offset */ 161 if (error) 162 return (error); 163 164 /* 165 * allow writing of data 166 */ 167 vm_map_protect(&vmspace->vm_map, 168 vmaddr + a_out->a_text, 169 vmaddr + a_out->a_text + a_out->a_data, 170 VM_PROT_ALL, 171 FALSE); 172 173 if (bss_size != 0) { 174 /* 175 * Allocate demand-zeroed area for uninitialized data 176 * "bss" = 'block started by symbol' - named after the IBM 7090 177 * instruction of the same name. 178 */ 179 vmaddr = virtual_offset + a_out->a_text + a_out->a_data; 180 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr, bss_size, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0); 181 if (error) 182 return (error); 183 } 184 185 /* Fill in process VM information */ 186 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 187 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 188 vmspace->vm_taddr = (caddr_t) virtual_offset; 189 vmspace->vm_daddr = (caddr_t) virtual_offset + a_out->a_text; 190 191 /* Fill in image_params */ 192 imgp->interpreted = 0; 193 imgp->entry_addr = a_out->a_entry; 194 195 imgp->proc->p_sysent = &aout_sysvec; 196 197 /* Indicate that this file should not be modified */ 198 imgp->vp->v_flag |= VTEXT; 199 200 return (0); 201 } 202 203 /* 204 * Tell kern_execve.c about it, with a little help from the linker. 205 * Since `const' objects end up in the text segment, TEXT_SET is the 206 * correct directive to use. 207 */ 208 static const struct execsw aout_execsw = { exec_aout_imgact, "a.out" }; 209 TEXT_SET(execsw_set, aout_execsw); 210