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("$FreeBSD$"); 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 55 static int exec_aout_imgact(struct image_params *imgp); 56 static int aout_fixup(register_t **stack_base, struct image_params *imgp); 57 58 struct 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 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | 87 #if defined(__i386__) 88 SV_IA32 | SV_ILP32 89 #else 90 #error Choose SV_XXX flags for the platform 91 #endif 92 , 93 .sv_set_syscall_retval = cpu_set_syscall_retval, 94 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 95 .sv_syscallnames = syscallnames, 96 .sv_schedtail = NULL, 97 }; 98 99 static int 100 aout_fixup(stack_base, imgp) 101 register_t **stack_base; 102 struct image_params *imgp; 103 { 104 105 return (suword(--(*stack_base), imgp->args->argc)); 106 } 107 108 static int 109 exec_aout_imgact(imgp) 110 struct image_params *imgp; 111 { 112 const struct exec *a_out = (const struct exec *) imgp->image_header; 113 struct vmspace *vmspace; 114 vm_map_t map; 115 vm_object_t object; 116 vm_offset_t text_end, data_end; 117 unsigned long virtual_offset; 118 unsigned long file_offset; 119 unsigned long bss_size; 120 int error; 121 122 /* 123 * Linux and *BSD binaries look very much alike, 124 * only the machine id is different: 125 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 126 * NetBSD is in network byte order.. ugh. 127 */ 128 if (((a_out->a_magic >> 16) & 0xff) != 0x86 && 129 ((a_out->a_magic >> 16) & 0xff) != 0 && 130 ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86) 131 return -1; 132 133 /* 134 * Set file/virtual offset based on a.out variant. 135 * We do two cases: host byte order and network byte order 136 * (for NetBSD compatibility) 137 */ 138 switch ((int)(a_out->a_magic & 0xffff)) { 139 case ZMAGIC: 140 virtual_offset = 0; 141 if (a_out->a_text) { 142 file_offset = PAGE_SIZE; 143 } else { 144 /* Bill's "screwball mode" */ 145 file_offset = 0; 146 } 147 break; 148 case QMAGIC: 149 virtual_offset = PAGE_SIZE; 150 file_offset = 0; 151 /* Pass PS_STRINGS for BSD/OS binaries only. */ 152 if (N_GETMID(*a_out) == MID_ZERO) 153 imgp->ps_strings = aout_sysvec.sv_psstrings; 154 break; 155 default: 156 /* NetBSD compatibility */ 157 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) { 158 case ZMAGIC: 159 case QMAGIC: 160 virtual_offset = PAGE_SIZE; 161 file_offset = 0; 162 break; 163 default: 164 return (-1); 165 } 166 } 167 168 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 169 170 /* 171 * Check various fields in header for validity/bounds. 172 */ 173 if (/* entry point must lay with text region */ 174 a_out->a_entry < virtual_offset || 175 a_out->a_entry >= virtual_offset + a_out->a_text || 176 177 /* text and data size must each be page rounded */ 178 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK) 179 return (-1); 180 181 /* text + data can't exceed file size */ 182 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 183 return (EFAULT); 184 185 /* 186 * text/data/bss must not exceed limits 187 */ 188 PROC_LOCK(imgp->proc); 189 if (/* text can't exceed maximum text size */ 190 a_out->a_text > maxtsiz || 191 192 /* data + bss can't exceed rlimit */ 193 a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA)) { 194 PROC_UNLOCK(imgp->proc); 195 return (ENOMEM); 196 } 197 PROC_UNLOCK(imgp->proc); 198 199 /* 200 * Avoid a possible deadlock if the current address space is destroyed 201 * and that address space maps the locked vnode. In the common case, 202 * the locked vnode's v_usecount is decremented but remains greater 203 * than zero. Consequently, the vnode lock is not needed by vrele(). 204 * However, in cases where the vnode lock is external, such as nullfs, 205 * v_usecount may become zero. 206 */ 207 VOP_UNLOCK(imgp->vp, 0); 208 209 /* 210 * Destroy old process VM and create a new one (with a new stack) 211 */ 212 error = exec_new_vmspace(imgp, &aout_sysvec); 213 214 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); 215 if (error) 216 return (error); 217 218 /* 219 * The vm space can be changed by exec_new_vmspace 220 */ 221 vmspace = imgp->proc->p_vmspace; 222 223 object = imgp->object; 224 map = &vmspace->vm_map; 225 vm_map_lock(map); 226 vm_object_reference(object); 227 228 text_end = virtual_offset + a_out->a_text; 229 error = vm_map_insert(map, object, 230 file_offset, 231 virtual_offset, text_end, 232 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL, 233 MAP_COPY_ON_WRITE | MAP_PREFAULT); 234 if (error) { 235 vm_map_unlock(map); 236 vm_object_deallocate(object); 237 return (error); 238 } 239 data_end = text_end + a_out->a_data; 240 if (a_out->a_data) { 241 vm_object_reference(object); 242 error = vm_map_insert(map, object, 243 file_offset + a_out->a_text, 244 text_end, data_end, 245 VM_PROT_ALL, VM_PROT_ALL, 246 MAP_COPY_ON_WRITE | MAP_PREFAULT); 247 if (error) { 248 vm_map_unlock(map); 249 vm_object_deallocate(object); 250 return (error); 251 } 252 } 253 254 if (bss_size) { 255 error = vm_map_insert(map, NULL, 0, 256 data_end, data_end + bss_size, 257 VM_PROT_ALL, VM_PROT_ALL, 0); 258 if (error) { 259 vm_map_unlock(map); 260 return (error); 261 } 262 } 263 vm_map_unlock(map); 264 265 /* Fill in process VM information */ 266 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 267 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 268 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset; 269 vmspace->vm_daddr = (caddr_t) (uintptr_t) 270 (virtual_offset + a_out->a_text); 271 272 /* Fill in image_params */ 273 imgp->interpreted = 0; 274 imgp->entry_addr = a_out->a_entry; 275 276 imgp->proc->p_sysent = &aout_sysvec; 277 278 return (0); 279 } 280 281 /* 282 * Tell kern_execve.c about it, with a little help from the linker. 283 */ 284 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" }; 285 EXEC_SET(aout, aout_execsw); 286