imgact_aout.c revision 183322
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 183322 2008-09-24 10:14:37Z kib $"); 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 .sv_size = SYS_MAXSYSCALL, 60 .sv_table = sysent, 61 .sv_mask = 0, 62 .sv_sigsize = 0, 63 .sv_sigtbl = NULL, 64 .sv_errsize = 0, 65 .sv_errtbl = NULL, 66 .sv_transtrap = NULL, 67 .sv_fixup = aout_fixup, 68 .sv_sendsig = sendsig, 69 .sv_sigcode = sigcode, 70 .sv_szsigcode = &szsigcode, 71 .sv_prepsyscall = NULL, 72 .sv_name = "FreeBSD a.out", 73 .sv_coredump = NULL, 74 .sv_imgact_try = NULL, 75 .sv_minsigstksz = MINSIGSTKSZ, 76 .sv_pagesize = PAGE_SIZE, 77 .sv_minuser = VM_MIN_ADDRESS, 78 .sv_maxuser = VM_MAXUSER_ADDRESS, 79 .sv_usrstack = USRSTACK, 80 .sv_psstrings = PS_STRINGS, 81 .sv_stackprot = VM_PROT_ALL, 82 .sv_copyout_strings = exec_copyout_strings, 83 .sv_setregs = exec_setregs, 84 .sv_fixlimit = NULL, 85 .sv_maxssiz = NULL 86}; 87 88static int 89aout_fixup(stack_base, imgp) 90 register_t **stack_base; 91 struct image_params *imgp; 92{ 93 94 return (suword(--(*stack_base), imgp->args->argc)); 95} 96 97static int 98exec_aout_imgact(imgp) 99 struct image_params *imgp; 100{ 101 const struct exec *a_out = (const struct exec *) imgp->image_header; 102 struct vmspace *vmspace; 103 vm_map_t map; 104 vm_object_t object; 105 vm_offset_t text_end, data_end; 106 unsigned long virtual_offset; 107 unsigned long file_offset; 108 unsigned long bss_size; 109 int error; 110 111 /* 112 * Linux and *BSD binaries look very much alike, 113 * only the machine id is different: 114 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 115 * NetBSD is in network byte order.. ugh. 116 */ 117 if (((a_out->a_magic >> 16) & 0xff) != 0x86 && 118 ((a_out->a_magic >> 16) & 0xff) != 0 && 119 ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86) 120 return -1; 121 122 /* 123 * Set file/virtual offset based on a.out variant. 124 * We do two cases: host byte order and network byte order 125 * (for NetBSD compatibility) 126 */ 127 switch ((int)(a_out->a_magic & 0xffff)) { 128 case ZMAGIC: 129 virtual_offset = 0; 130 if (a_out->a_text) { 131 file_offset = PAGE_SIZE; 132 } else { 133 /* Bill's "screwball mode" */ 134 file_offset = 0; 135 } 136 break; 137 case QMAGIC: 138 virtual_offset = PAGE_SIZE; 139 file_offset = 0; 140 /* Pass PS_STRINGS for BSD/OS binaries only. */ 141 if (N_GETMID(*a_out) == MID_ZERO) 142 imgp->ps_strings = aout_sysvec.sv_psstrings; 143 break; 144 default: 145 /* NetBSD compatibility */ 146 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) { 147 case ZMAGIC: 148 case QMAGIC: 149 virtual_offset = PAGE_SIZE; 150 file_offset = 0; 151 break; 152 default: 153 return (-1); 154 } 155 } 156 157 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 158 159 /* 160 * Check various fields in header for validity/bounds. 161 */ 162 if (/* entry point must lay with text region */ 163 a_out->a_entry < virtual_offset || 164 a_out->a_entry >= virtual_offset + a_out->a_text || 165 166 /* text and data size must each be page rounded */ 167 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK) 168 return (-1); 169 170 /* text + data can't exceed file size */ 171 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 172 return (EFAULT); 173 174 /* 175 * text/data/bss must not exceed limits 176 */ 177 PROC_LOCK(imgp->proc); 178 if (/* text can't exceed maximum text size */ 179 a_out->a_text > maxtsiz || 180 181 /* data + bss can't exceed rlimit */ 182 a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA)) { 183 PROC_UNLOCK(imgp->proc); 184 return (ENOMEM); 185 } 186 PROC_UNLOCK(imgp->proc); 187 188 /* 189 * Avoid a possible deadlock if the current address space is destroyed 190 * and that address space maps the locked vnode. In the common case, 191 * the locked vnode's v_usecount is decremented but remains greater 192 * than zero. Consequently, the vnode lock is not needed by vrele(). 193 * However, in cases where the vnode lock is external, such as nullfs, 194 * v_usecount may become zero. 195 */ 196 VOP_UNLOCK(imgp->vp, 0); 197 198 /* 199 * Destroy old process VM and create a new one (with a new stack) 200 */ 201 error = exec_new_vmspace(imgp, &aout_sysvec); 202 203 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); 204 if (error) 205 return (error); 206 207 /* 208 * The vm space can be changed by exec_new_vmspace 209 */ 210 vmspace = imgp->proc->p_vmspace; 211 212 object = imgp->object; 213 map = &vmspace->vm_map; 214 vm_map_lock(map); 215 vm_object_reference(object); 216 217 text_end = virtual_offset + a_out->a_text; 218 error = vm_map_insert(map, object, 219 file_offset, 220 virtual_offset, text_end, 221 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL, 222 MAP_COPY_ON_WRITE | MAP_PREFAULT); 223 if (error) { 224 vm_map_unlock(map); 225 vm_object_deallocate(object); 226 return (error); 227 } 228 data_end = text_end + a_out->a_data; 229 if (a_out->a_data) { 230 vm_object_reference(object); 231 error = vm_map_insert(map, object, 232 file_offset + a_out->a_text, 233 text_end, data_end, 234 VM_PROT_ALL, VM_PROT_ALL, 235 MAP_COPY_ON_WRITE | MAP_PREFAULT); 236 if (error) { 237 vm_map_unlock(map); 238 vm_object_deallocate(object); 239 return (error); 240 } 241 } 242 243 if (bss_size) { 244 error = vm_map_insert(map, NULL, 0, 245 data_end, data_end + bss_size, 246 VM_PROT_ALL, VM_PROT_ALL, 0); 247 if (error) { 248 vm_map_unlock(map); 249 return (error); 250 } 251 } 252 vm_map_unlock(map); 253 254 /* Fill in process VM information */ 255 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 256 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 257 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset; 258 vmspace->vm_daddr = (caddr_t) (uintptr_t) 259 (virtual_offset + a_out->a_text); 260 261 /* Fill in image_params */ 262 imgp->interpreted = 0; 263 imgp->entry_addr = a_out->a_entry; 264 265 imgp->proc->p_sysent = &aout_sysvec; 266 267 return (0); 268} 269 270/* 271 * Tell kern_execve.c about it, with a little help from the linker. 272 */ 273static struct execsw aout_execsw = { exec_aout_imgact, "a.out" }; 274EXEC_SET(aout, aout_execsw); 275