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(uintptr_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(uintptr_t *stack_base, struct image_params *imgp) 151 { 152 153 *stack_base -= sizeof(uint32_t); 154 if (suword32((void *)*stack_base, imgp->args->argc) != 0) 155 return (EFAULT); 156 return (0); 157 } 158 159 static int 160 exec_aout_imgact(struct image_params *imgp) 161 { 162 const struct exec *a_out = (const struct exec *) imgp->image_header; 163 struct vmspace *vmspace; 164 vm_map_t map; 165 vm_object_t object; 166 vm_offset_t text_end, data_end; 167 unsigned long virtual_offset; 168 unsigned long file_offset; 169 unsigned long bss_size; 170 int error; 171 172 /* 173 * Linux and *BSD binaries look very much alike, 174 * only the machine id is different: 175 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 176 * NetBSD is in network byte order.. ugh. 177 */ 178 if (((a_out->a_midmag >> 16) & 0xff) != 0x86 && 179 ((a_out->a_midmag >> 16) & 0xff) != 0 && 180 ((((int)ntohl(a_out->a_midmag)) >> 16) & 0xff) != 0x86) 181 return -1; 182 183 /* 184 * Set file/virtual offset based on a.out variant. 185 * We do two cases: host byte order and network byte order 186 * (for NetBSD compatibility) 187 */ 188 switch ((int)(a_out->a_midmag & 0xffff)) { 189 case ZMAGIC: 190 virtual_offset = 0; 191 if (a_out->a_text) { 192 file_offset = PAGE_SIZE; 193 } else { 194 /* Bill's "screwball mode" */ 195 file_offset = 0; 196 } 197 break; 198 case QMAGIC: 199 virtual_offset = PAGE_SIZE; 200 file_offset = 0; 201 /* Pass PS_STRINGS for BSD/OS binaries only. */ 202 if (N_GETMID(*a_out) == MID_ZERO) 203 imgp->ps_strings = aout_sysvec.sv_psstrings; 204 break; 205 default: 206 /* NetBSD compatibility */ 207 switch ((int)(ntohl(a_out->a_midmag) & 0xffff)) { 208 case ZMAGIC: 209 case QMAGIC: 210 virtual_offset = PAGE_SIZE; 211 file_offset = 0; 212 break; 213 default: 214 return (-1); 215 } 216 } 217 218 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 219 220 /* 221 * Check various fields in header for validity/bounds. 222 */ 223 if (/* entry point must lay with text region */ 224 a_out->a_entry < virtual_offset || 225 a_out->a_entry >= virtual_offset + a_out->a_text || 226 227 /* text and data size must each be page rounded */ 228 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK 229 230 #ifdef __amd64__ 231 || 232 /* overflows */ 233 virtual_offset + a_out->a_text + a_out->a_data + bss_size > UINT_MAX 234 #endif 235 ) 236 return (-1); 237 238 /* text + data can't exceed file size */ 239 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 240 return (EFAULT); 241 242 /* 243 * text/data/bss must not exceed limits 244 */ 245 PROC_LOCK(imgp->proc); 246 if (/* text can't exceed maximum text size */ 247 a_out->a_text > maxtsiz || 248 249 /* data + bss can't exceed rlimit */ 250 a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) || 251 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) { 252 PROC_UNLOCK(imgp->proc); 253 return (ENOMEM); 254 } 255 PROC_UNLOCK(imgp->proc); 256 257 /* 258 * Avoid a possible deadlock if the current address space is destroyed 259 * and that address space maps the locked vnode. In the common case, 260 * the locked vnode's v_usecount is decremented but remains greater 261 * than zero. Consequently, the vnode lock is not needed by vrele(). 262 * However, in cases where the vnode lock is external, such as nullfs, 263 * v_usecount may become zero. 264 */ 265 VOP_UNLOCK(imgp->vp); 266 267 /* 268 * Destroy old process VM and create a new one (with a new stack) 269 */ 270 error = exec_new_vmspace(imgp, &aout_sysvec); 271 272 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 273 if (error) 274 return (error); 275 276 /* 277 * The vm space can be changed by exec_new_vmspace 278 */ 279 vmspace = imgp->proc->p_vmspace; 280 281 object = imgp->object; 282 map = &vmspace->vm_map; 283 vm_map_lock(map); 284 vm_object_reference(object); 285 286 text_end = virtual_offset + a_out->a_text; 287 error = vm_map_insert(map, object, 288 file_offset, 289 virtual_offset, text_end, 290 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL, 291 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC); 292 if (error) { 293 vm_map_unlock(map); 294 vm_object_deallocate(object); 295 return (error); 296 } 297 VOP_SET_TEXT_CHECKED(imgp->vp); 298 data_end = text_end + a_out->a_data; 299 if (a_out->a_data) { 300 vm_object_reference(object); 301 error = vm_map_insert(map, object, 302 file_offset + a_out->a_text, 303 text_end, data_end, 304 VM_PROT_ALL, VM_PROT_ALL, 305 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC); 306 if (error) { 307 vm_map_unlock(map); 308 vm_object_deallocate(object); 309 return (error); 310 } 311 VOP_SET_TEXT_CHECKED(imgp->vp); 312 } 313 314 if (bss_size) { 315 error = vm_map_insert(map, NULL, 0, 316 data_end, data_end + bss_size, 317 VM_PROT_ALL, VM_PROT_ALL, 0); 318 if (error) { 319 vm_map_unlock(map); 320 return (error); 321 } 322 } 323 vm_map_unlock(map); 324 325 /* Fill in process VM information */ 326 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 327 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 328 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset; 329 vmspace->vm_daddr = (caddr_t) (uintptr_t) 330 (virtual_offset + a_out->a_text); 331 332 /* Fill in image_params */ 333 imgp->interpreted = 0; 334 imgp->entry_addr = a_out->a_entry; 335 336 imgp->proc->p_sysent = &aout_sysvec; 337 338 return (0); 339 } 340 341 /* 342 * Tell kern_execve.c about it, with a little help from the linker. 343 */ 344 static struct execsw aout_execsw = { 345 .ex_imgact = exec_aout_imgact, 346 .ex_name = "a.out" 347 }; 348 EXEC_SET(aout, aout_execsw); 349