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 1.28 1996/05/02 10:43:16 phk Exp $ 27 */ 28 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/resourcevar.h> 32 #include <sys/exec.h> 33 #include <sys/mman.h> 34 #include <sys/imgact.h> 35 #include <sys/imgact_aout.h> 36 #include <sys/kernel.h> 37 #include <sys/proc.h> 38 #include <sys/sysent.h> 39 #include <sys/vnode.h> 40 41 #include <vm/vm.h> 42 #include <vm/vm_param.h> 43 #include <vm/vm_prot.h> 44 #include <vm/lock.h> 45 #include <vm/pmap.h> 46 #include <vm/vm_map.h> 47 #include <vm/vm_extern.h> 48 49 static int exec_aout_imgact __P((struct image_params *imgp)); 50 51 static int 52 exec_aout_imgact(imgp) 53 struct image_params *imgp; 54 { 55 const struct exec *a_out = (const struct exec *) imgp->image_header; 56 struct vmspace *vmspace = imgp->proc->p_vmspace; 57 vm_offset_t vmaddr; 58 unsigned long virtual_offset; 59 unsigned long file_offset; 60 unsigned long bss_size; 61 int error; 62 63 /* 64 * Linux and *BSD binaries look very much alike, 65 * only the machine id is different: 66 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 67 * NetBSD is in network byte order.. ugh. 68 */ 69 if (((a_out->a_magic >> 16) & 0xff) != 0x86 && 70 ((a_out->a_magic >> 16) & 0xff) != 0 && 71 ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86) 72 return -1; 73 74 /* 75 * Set file/virtual offset based on a.out variant. 76 * We do two cases: host byte order and network byte order 77 * (for NetBSD compatibility) 78 */ 79 switch ((int)(a_out->a_magic & 0xffff)) { 80 case ZMAGIC: 81 virtual_offset = 0; 82 if (a_out->a_text) { 83 file_offset = PAGE_SIZE; 84 } else { 85 /* Bill's "screwball mode" */ 86 file_offset = 0; 87 } 88 break; 89 case QMAGIC: 90 virtual_offset = PAGE_SIZE; 91 file_offset = 0; 92 break; 93 default: 94 /* NetBSD compatibility */ 95 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) { 96 case ZMAGIC: 97 case QMAGIC: 98 virtual_offset = PAGE_SIZE; 99 file_offset = 0; 100 break; 101 default: 102 return (-1); 103 } 104 } 105 106 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 107 108 /* 109 * Check various fields in header for validity/bounds. 110 */ 111 if (/* entry point must lay with text region */ 112 a_out->a_entry < virtual_offset || 113 a_out->a_entry >= virtual_offset + a_out->a_text || 114 115 /* text and data size must each be page rounded */ 116 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK) 117 return (-1); 118 119 /* text + data can't exceed file size */ 120 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 121 return (EFAULT); 122 123 /* 124 * text/data/bss must not exceed limits 125 */ 126 if (/* text can't exceed maximum text size */ 127 a_out->a_text > MAXTSIZ || 128 129 /* data + bss can't exceed maximum data size */ 130 a_out->a_data + bss_size > MAXDSIZ || 131 132 /* data + bss can't exceed rlimit */ 133 a_out->a_data + bss_size > 134 imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur) 135 return (ENOMEM); 136 137 /* copy in arguments and/or environment from old process */ 138 error = exec_extract_strings(imgp); 139 if (error) 140 return (error); 141 142 /* 143 * Destroy old process VM and create a new one (with a new stack) 144 */ 145 exec_new_vmspace(imgp); 146 147 /* 148 * Map text/data read/execute 149 */ 150 vmaddr = virtual_offset; 151 error = 152 vm_mmap(&vmspace->vm_map, /* map */ 153 &vmaddr, /* address */ 154 a_out->a_text + a_out->a_data, /* size */ 155 VM_PROT_READ | VM_PROT_EXECUTE, /* protection */ 156 VM_PROT_ALL, /* max protection */ 157 MAP_PRIVATE | MAP_FIXED, /* flags */ 158 (caddr_t)imgp->vp, /* vnode */ 159 file_offset); /* offset */ 160 if (error) 161 return (error); 162 163 /* 164 * allow writing of data 165 */ 166 vm_map_protect(&vmspace->vm_map, 167 vmaddr + a_out->a_text, 168 vmaddr + a_out->a_text + a_out->a_data, 169 VM_PROT_ALL, 170 FALSE); 171 172 if (bss_size != 0) { 173 /* 174 * Allocate demand-zeroed area for uninitialized data 175 * "bss" = 'block started by symbol' - named after the IBM 7090 176 * instruction of the same name. 177 */ 178 vmaddr = virtual_offset + a_out->a_text + a_out->a_data; 179 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr, bss_size, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0); 180 if (error) 181 return (error); 182 } 183 184 /* Fill in process VM information */ 185 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 186 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 187 vmspace->vm_taddr = (caddr_t) virtual_offset; 188 vmspace->vm_daddr = (caddr_t) virtual_offset + a_out->a_text; 189 190 /* Fill in image_params */ 191 imgp->interpreted = 0; 192 imgp->entry_addr = a_out->a_entry; 193 194 imgp->proc->p_sysent = &aout_sysvec; 195 196 /* Indicate that this file should not be modified */ 197 imgp->vp->v_flag |= VTEXT; 198 199 return (0); 200 } 201 202 /* 203 * Tell kern_execve.c about it, with a little help from the linker. 204 * Since `const' objects end up in the text segment, TEXT_SET is the 205 * correct directive to use. 206 */ 207 static const struct execsw aout_execsw = { exec_aout_imgact, "a.out" }; 208 TEXT_SET(execsw_set, aout_execsw); 209