1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1993, David Greenman 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/exec.h> 34 #include <sys/imgact.h> 35 #include <sys/imgact_aout.h> 36 #include <sys/kernel.h> 37 #include <sys/limits.h> 38 #include <sys/lock.h> 39 #include <sys/malloc.h> 40 #include <sys/mutex.h> 41 #include <sys/proc.h> 42 #include <sys/racct.h> 43 #include <sys/resourcevar.h> 44 #include <sys/signalvar.h> 45 #include <sys/syscall.h> 46 #include <sys/sysent.h> 47 #include <sys/systm.h> 48 #include <sys/vnode.h> 49 50 #include <machine/frame.h> 51 #include <machine/md_var.h> 52 53 #include <vm/vm.h> 54 #include <vm/pmap.h> 55 #include <vm/vm_map.h> 56 #include <vm/vm_object.h> 57 #include <vm/vm_param.h> 58 59 #ifdef __amd64__ 60 #include <compat/freebsd32/freebsd32_signal.h> 61 #include <compat/freebsd32/freebsd32_util.h> 62 #include <compat/freebsd32/freebsd32_proto.h> 63 #include <compat/freebsd32/freebsd32_syscall.h> 64 #include <compat/ia32/ia32_signal.h> 65 #endif 66 67 static int exec_aout_imgact(struct image_params *imgp); 68 static int aout_fixup(register_t **stack_base, struct image_params *imgp); 69 70 #define AOUT32_USRSTACK 0xbfc00000 71 72 #if defined(__i386__) 73 74 #define AOUT32_PS_STRINGS (AOUT32_USRSTACK - sizeof(struct ps_strings)) 75 76 struct sysentvec aout_sysvec = { 77 .sv_size = SYS_MAXSYSCALL, 78 .sv_table = sysent, 79 .sv_errsize = 0, 80 .sv_errtbl = NULL, 81 .sv_transtrap = NULL, 82 .sv_fixup = aout_fixup, 83 .sv_sendsig = sendsig, 84 .sv_sigcode = sigcode, 85 .sv_szsigcode = &szsigcode, 86 .sv_name = "FreeBSD a.out", 87 .sv_coredump = NULL, 88 .sv_imgact_try = NULL, 89 .sv_minsigstksz = MINSIGSTKSZ, 90 .sv_minuser = VM_MIN_ADDRESS, 91 .sv_maxuser = AOUT32_USRSTACK, 92 .sv_usrstack = AOUT32_USRSTACK, 93 .sv_psstrings = AOUT32_PS_STRINGS, 94 .sv_stackprot = VM_PROT_ALL, 95 .sv_copyout_strings = exec_copyout_strings, 96 .sv_setregs = exec_setregs, 97 .sv_fixlimit = NULL, 98 .sv_maxssiz = NULL, 99 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32, 100 .sv_set_syscall_retval = cpu_set_syscall_retval, 101 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 102 .sv_syscallnames = syscallnames, 103 .sv_schedtail = NULL, 104 .sv_thread_detach = NULL, 105 .sv_trap = NULL, 106 }; 107 108 #elif defined(__amd64__) 109 110 #define AOUT32_PS_STRINGS \ 111 (AOUT32_USRSTACK - sizeof(struct freebsd32_ps_strings)) 112 #define AOUT32_MINUSER FREEBSD32_MINUSER 113 114 extern const char *freebsd32_syscallnames[]; 115 extern u_long ia32_maxssiz; 116 117 struct sysentvec aout_sysvec = { 118 .sv_size = FREEBSD32_SYS_MAXSYSCALL, 119 .sv_table = freebsd32_sysent, 120 .sv_errsize = 0, 121 .sv_errtbl = NULL, 122 .sv_transtrap = NULL, 123 .sv_fixup = aout_fixup, 124 .sv_sendsig = ia32_sendsig, 125 .sv_sigcode = ia32_sigcode, 126 .sv_szsigcode = &sz_ia32_sigcode, 127 .sv_name = "FreeBSD a.out", 128 .sv_coredump = NULL, 129 .sv_imgact_try = NULL, 130 .sv_minsigstksz = MINSIGSTKSZ, 131 .sv_minuser = AOUT32_MINUSER, 132 .sv_maxuser = AOUT32_USRSTACK, 133 .sv_usrstack = AOUT32_USRSTACK, 134 .sv_psstrings = AOUT32_PS_STRINGS, 135 .sv_stackprot = VM_PROT_ALL, 136 .sv_copyout_strings = freebsd32_copyout_strings, 137 .sv_setregs = ia32_setregs, 138 .sv_fixlimit = ia32_fixlimit, 139 .sv_maxssiz = &ia32_maxssiz, 140 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32, 141 .sv_set_syscall_retval = ia32_set_syscall_retval, 142 .sv_fetch_syscall_args = ia32_fetch_syscall_args, 143 .sv_syscallnames = freebsd32_syscallnames, 144 }; 145 #else 146 #error "Port me" 147 #endif 148 149 static int 150 aout_fixup(register_t **stack_base, struct image_params *imgp) 151 { 152 153 *(char **)stack_base -= sizeof(uint32_t); 154 return (suword32(*stack_base, imgp->args->argc)); 155 } 156 157 static int 158 exec_aout_imgact(struct image_params *imgp) 159 { 160 const struct exec *a_out = (const struct exec *) imgp->image_header; 161 struct vmspace *vmspace; 162 vm_map_t map; 163 vm_object_t object; 164 vm_offset_t text_end, data_end; 165 unsigned long virtual_offset; 166 unsigned long file_offset; 167 unsigned long bss_size; 168 int error; 169 170 /* 171 * Linux and *BSD binaries look very much alike, 172 * only the machine id is different: 173 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 174 * NetBSD is in network byte order.. ugh. 175 */ 176 if (((a_out->a_midmag >> 16) & 0xff) != 0x86 && 177 ((a_out->a_midmag >> 16) & 0xff) != 0 && 178 ((((int)ntohl(a_out->a_midmag)) >> 16) & 0xff) != 0x86) 179 return -1; 180 181 /* 182 * Set file/virtual offset based on a.out variant. 183 * We do two cases: host byte order and network byte order 184 * (for NetBSD compatibility) 185 */ 186 switch ((int)(a_out->a_midmag & 0xffff)) { 187 case ZMAGIC: 188 virtual_offset = 0; 189 if (a_out->a_text) { 190 file_offset = PAGE_SIZE; 191 } else { 192 /* Bill's "screwball mode" */ 193 file_offset = 0; 194 } 195 break; 196 case QMAGIC: 197 virtual_offset = PAGE_SIZE; 198 file_offset = 0; 199 /* Pass PS_STRINGS for BSD/OS binaries only. */ 200 if (N_GETMID(*a_out) == MID_ZERO) 201 imgp->ps_strings = aout_sysvec.sv_psstrings; 202 break; 203 default: 204 /* NetBSD compatibility */ 205 switch ((int)(ntohl(a_out->a_midmag) & 0xffff)) { 206 case ZMAGIC: 207 case QMAGIC: 208 virtual_offset = PAGE_SIZE; 209 file_offset = 0; 210 break; 211 default: 212 return (-1); 213 } 214 } 215 216 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 217 218 /* 219 * Check various fields in header for validity/bounds. 220 */ 221 if (/* entry point must lay with text region */ 222 a_out->a_entry < virtual_offset || 223 a_out->a_entry >= virtual_offset + a_out->a_text || 224 225 /* text and data size must each be page rounded */ 226 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK 227 228 #ifdef __amd64__ 229 || 230 /* overflows */ 231 virtual_offset + a_out->a_text + a_out->a_data + bss_size > UINT_MAX 232 #endif 233 ) 234 return (-1); 235 236 /* text + data can't exceed file size */ 237 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 238 return (EFAULT); 239 240 /* 241 * text/data/bss must not exceed limits 242 */ 243 PROC_LOCK(imgp->proc); 244 if (/* text can't exceed maximum text size */ 245 a_out->a_text > maxtsiz || 246 247 /* data + bss can't exceed rlimit */ 248 a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) || 249 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) { 250 PROC_UNLOCK(imgp->proc); 251 return (ENOMEM); 252 } 253 PROC_UNLOCK(imgp->proc); 254 255 /* 256 * Avoid a possible deadlock if the current address space is destroyed 257 * and that address space maps the locked vnode. In the common case, 258 * the locked vnode's v_usecount is decremented but remains greater 259 * than zero. Consequently, the vnode lock is not needed by vrele(). 260 * However, in cases where the vnode lock is external, such as nullfs, 261 * v_usecount may become zero. 262 */ 263 VOP_UNLOCK(imgp->vp, 0); 264 265 /* 266 * Destroy old process VM and create a new one (with a new stack) 267 */ 268 error = exec_new_vmspace(imgp, &aout_sysvec); 269 270 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 271 if (error) 272 return (error); 273 274 /* 275 * The vm space can be changed by exec_new_vmspace 276 */ 277 vmspace = imgp->proc->p_vmspace; 278 279 object = imgp->object; 280 map = &vmspace->vm_map; 281 vm_map_lock(map); 282 vm_object_reference(object); 283 284 text_end = virtual_offset + a_out->a_text; 285 error = vm_map_insert(map, object, 286 file_offset, 287 virtual_offset, text_end, 288 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL, 289 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC); 290 if (error) { 291 vm_map_unlock(map); 292 vm_object_deallocate(object); 293 return (error); 294 } 295 VOP_SET_TEXT_CHECKED(imgp->vp); 296 data_end = text_end + a_out->a_data; 297 if (a_out->a_data) { 298 vm_object_reference(object); 299 error = vm_map_insert(map, object, 300 file_offset + a_out->a_text, 301 text_end, data_end, 302 VM_PROT_ALL, VM_PROT_ALL, 303 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC); 304 if (error) { 305 vm_map_unlock(map); 306 vm_object_deallocate(object); 307 return (error); 308 } 309 VOP_SET_TEXT_CHECKED(imgp->vp); 310 } 311 312 if (bss_size) { 313 error = vm_map_insert(map, NULL, 0, 314 data_end, data_end + bss_size, 315 VM_PROT_ALL, VM_PROT_ALL, 0); 316 if (error) { 317 vm_map_unlock(map); 318 return (error); 319 } 320 } 321 vm_map_unlock(map); 322 323 /* Fill in process VM information */ 324 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 325 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 326 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset; 327 vmspace->vm_daddr = (caddr_t) (uintptr_t) 328 (virtual_offset + a_out->a_text); 329 330 /* Fill in image_params */ 331 imgp->interpreted = 0; 332 imgp->entry_addr = a_out->a_entry; 333 334 imgp->proc->p_sysent = &aout_sysvec; 335 336 return (0); 337 } 338 339 /* 340 * Tell kern_execve.c about it, with a little help from the linker. 341 */ 342 static struct execsw aout_execsw = { 343 .ex_imgact = exec_aout_imgact, 344 .ex_name = "a.out" 345 }; 346 EXEC_SET(aout, aout_execsw); 347