imgact_aout.c revision 175202
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 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: head/sys/kern/imgact_aout.c 175202 2008-01-10 01:10:58Z attilio $"); 29 30#include <sys/param.h> 31#include <sys/exec.h> 32#include <sys/imgact.h> 33#include <sys/imgact_aout.h> 34#include <sys/kernel.h> 35#include <sys/lock.h> 36#include <sys/malloc.h> 37#include <sys/mutex.h> 38#include <sys/proc.h> 39#include <sys/resourcevar.h> 40#include <sys/signalvar.h> 41#include <sys/syscall.h> 42#include <sys/sysent.h> 43#include <sys/systm.h> 44#include <sys/vnode.h> 45 46#include <machine/frame.h> 47#include <machine/md_var.h> 48 49#include <vm/vm.h> 50#include <vm/pmap.h> 51#include <vm/vm_map.h> 52#include <vm/vm_object.h> 53#include <vm/vm_param.h> 54 55static int exec_aout_imgact(struct image_params *imgp); 56static int aout_fixup(register_t **stack_base, struct image_params *imgp); 57 58struct sysentvec aout_sysvec = { 59 SYS_MAXSYSCALL, 60 sysent, 61 0, 62 0, 63 NULL, 64 0, 65 NULL, 66 NULL, 67 aout_fixup, 68 sendsig, 69 sigcode, 70 &szsigcode, 71 NULL, 72 "FreeBSD a.out", 73 NULL, 74 NULL, 75 MINSIGSTKSZ, 76 PAGE_SIZE, 77 VM_MIN_ADDRESS, 78 VM_MAXUSER_ADDRESS, 79 USRSTACK, 80 PS_STRINGS, 81 VM_PROT_ALL, 82 exec_copyout_strings, 83 exec_setregs, 84 NULL 85}; 86 87static int 88aout_fixup(stack_base, imgp) 89 register_t **stack_base; 90 struct image_params *imgp; 91{ 92 93 return (suword(--(*stack_base), imgp->args->argc)); 94} 95 96static int 97exec_aout_imgact(imgp) 98 struct image_params *imgp; 99{ 100 const struct exec *a_out = (const struct exec *) imgp->image_header; 101 struct vmspace *vmspace; 102 vm_map_t map; 103 vm_object_t object; 104 vm_offset_t text_end, data_end; 105 unsigned long virtual_offset; 106 unsigned long file_offset; 107 unsigned long bss_size; 108 int error; 109 110 /* 111 * Linux and *BSD binaries look very much alike, 112 * only the machine id is different: 113 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 114 * NetBSD is in network byte order.. ugh. 115 */ 116 if (((a_out->a_magic >> 16) & 0xff) != 0x86 && 117 ((a_out->a_magic >> 16) & 0xff) != 0 && 118 ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86) 119 return -1; 120 121 /* 122 * Set file/virtual offset based on a.out variant. 123 * We do two cases: host byte order and network byte order 124 * (for NetBSD compatibility) 125 */ 126 switch ((int)(a_out->a_magic & 0xffff)) { 127 case ZMAGIC: 128 virtual_offset = 0; 129 if (a_out->a_text) { 130 file_offset = PAGE_SIZE; 131 } else { 132 /* Bill's "screwball mode" */ 133 file_offset = 0; 134 } 135 break; 136 case QMAGIC: 137 virtual_offset = PAGE_SIZE; 138 file_offset = 0; 139 /* Pass PS_STRINGS for BSD/OS binaries only. */ 140 if (N_GETMID(*a_out) == MID_ZERO) 141 imgp->ps_strings = aout_sysvec.sv_psstrings; 142 break; 143 default: 144 /* NetBSD compatibility */ 145 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) { 146 case ZMAGIC: 147 case QMAGIC: 148 virtual_offset = PAGE_SIZE; 149 file_offset = 0; 150 break; 151 default: 152 return (-1); 153 } 154 } 155 156 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 157 158 /* 159 * Check various fields in header for validity/bounds. 160 */ 161 if (/* entry point must lay with text region */ 162 a_out->a_entry < virtual_offset || 163 a_out->a_entry >= virtual_offset + a_out->a_text || 164 165 /* text and data size must each be page rounded */ 166 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK) 167 return (-1); 168 169 /* text + data can't exceed file size */ 170 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 171 return (EFAULT); 172 173 /* 174 * text/data/bss must not exceed limits 175 */ 176 PROC_LOCK(imgp->proc); 177 if (/* text can't exceed maximum text size */ 178 a_out->a_text > maxtsiz || 179 180 /* data + bss can't exceed rlimit */ 181 a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA)) { 182 PROC_UNLOCK(imgp->proc); 183 return (ENOMEM); 184 } 185 PROC_UNLOCK(imgp->proc); 186 187 /* 188 * Avoid a possible deadlock if the current address space is destroyed 189 * and that address space maps the locked vnode. In the common case, 190 * the locked vnode's v_usecount is decremented but remains greater 191 * than zero. Consequently, the vnode lock is not needed by vrele(). 192 * However, in cases where the vnode lock is external, such as nullfs, 193 * v_usecount may become zero. 194 */ 195 VOP_UNLOCK(imgp->vp, 0, curthread); 196 197 /* 198 * Destroy old process VM and create a new one (with a new stack) 199 */ 200 error = exec_new_vmspace(imgp, &aout_sysvec); 201 202 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); 203 if (error) 204 return (error); 205 206 /* 207 * The vm space can be changed by exec_new_vmspace 208 */ 209 vmspace = imgp->proc->p_vmspace; 210 211 object = imgp->object; 212 map = &vmspace->vm_map; 213 vm_map_lock(map); 214 vm_object_reference(object); 215 216 text_end = virtual_offset + a_out->a_text; 217 error = vm_map_insert(map, object, 218 file_offset, 219 virtual_offset, text_end, 220 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL, 221 MAP_COPY_ON_WRITE | MAP_PREFAULT); 222 if (error) { 223 vm_map_unlock(map); 224 vm_object_deallocate(object); 225 return (error); 226 } 227 data_end = text_end + a_out->a_data; 228 if (a_out->a_data) { 229 vm_object_reference(object); 230 error = vm_map_insert(map, object, 231 file_offset + a_out->a_text, 232 text_end, data_end, 233 VM_PROT_ALL, VM_PROT_ALL, 234 MAP_COPY_ON_WRITE | MAP_PREFAULT); 235 if (error) { 236 vm_map_unlock(map); 237 vm_object_deallocate(object); 238 return (error); 239 } 240 } 241 242 if (bss_size) { 243 error = vm_map_insert(map, NULL, 0, 244 data_end, data_end + bss_size, 245 VM_PROT_ALL, VM_PROT_ALL, 0); 246 if (error) { 247 vm_map_unlock(map); 248 return (error); 249 } 250 } 251 vm_map_unlock(map); 252 253 /* Fill in process VM information */ 254 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 255 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 256 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset; 257 vmspace->vm_daddr = (caddr_t) (uintptr_t) 258 (virtual_offset + a_out->a_text); 259 260 /* Fill in image_params */ 261 imgp->interpreted = 0; 262 imgp->entry_addr = a_out->a_entry; 263 264 imgp->proc->p_sysent = &aout_sysvec; 265 266 return (0); 267} 268 269/* 270 * Tell kern_execve.c about it, with a little help from the linker. 271 */ 272static struct execsw aout_execsw = { exec_aout_imgact, "a.out" }; 273EXEC_SET(aout, aout_execsw); 274