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_transtrap = NULL, 80 .sv_fixup = aout_fixup, 81 .sv_sendsig = sendsig, 82 .sv_sigcode = sigcode, 83 .sv_szsigcode = &szsigcode, 84 .sv_name = "FreeBSD a.out", 85 .sv_coredump = NULL, 86 .sv_imgact_try = NULL, 87 .sv_minsigstksz = MINSIGSTKSZ, 88 .sv_minuser = VM_MIN_ADDRESS, 89 .sv_maxuser = AOUT32_USRSTACK, 90 .sv_usrstack = AOUT32_USRSTACK, 91 .sv_psstrings = AOUT32_PS_STRINGS, 92 .sv_psstringssz = sizeof(struct ps_strings), 93 .sv_stackprot = VM_PROT_ALL, 94 .sv_copyout_strings = exec_copyout_strings, 95 .sv_setregs = exec_setregs, 96 .sv_fixlimit = NULL, 97 .sv_maxssiz = NULL, 98 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32, 99 .sv_set_syscall_retval = cpu_set_syscall_retval, 100 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 101 .sv_syscallnames = syscallnames, 102 .sv_schedtail = NULL, 103 .sv_thread_detach = NULL, 104 .sv_trap = NULL, 105 .sv_onexec_old = exec_onexec_old, 106 .sv_onexit = exit_onexit, 107 .sv_set_fork_retval = x86_set_fork_retval, 108 }; 109 110 #elif defined(__amd64__) 111 112 #include "vdso_ia32_offsets.h" 113 114 extern const char _binary_elf_vdso32_so_1_start[]; 115 extern const char _binary_elf_vdso32_so_1_end[]; 116 extern char _binary_elf_vdso32_so_1_size; 117 118 #define AOUT32_PS_STRINGS \ 119 (AOUT32_USRSTACK - sizeof(struct freebsd32_ps_strings)) 120 #define AOUT32_MINUSER FREEBSD32_MINUSER 121 122 extern const char *freebsd32_syscallnames[]; 123 extern u_long ia32_maxssiz; 124 125 static int aout_szsigcode; 126 127 struct sysentvec aout_sysvec = { 128 .sv_size = FREEBSD32_SYS_MAXSYSCALL, 129 .sv_table = freebsd32_sysent, 130 .sv_transtrap = NULL, 131 .sv_fixup = aout_fixup, 132 .sv_sendsig = ia32_sendsig, 133 .sv_sigcode = _binary_elf_vdso32_so_1_start, 134 .sv_szsigcode = &aout_szsigcode, 135 .sv_name = "FreeBSD a.out", 136 .sv_coredump = NULL, 137 .sv_imgact_try = NULL, 138 .sv_minsigstksz = MINSIGSTKSZ, 139 .sv_minuser = AOUT32_MINUSER, 140 .sv_maxuser = AOUT32_USRSTACK, 141 .sv_usrstack = AOUT32_USRSTACK, 142 .sv_psstrings = AOUT32_PS_STRINGS, 143 .sv_psstringssz = sizeof(struct freebsd32_ps_strings), 144 .sv_stackprot = VM_PROT_ALL, 145 .sv_copyout_strings = freebsd32_copyout_strings, 146 .sv_setregs = ia32_setregs, 147 .sv_fixlimit = ia32_fixlimit, 148 .sv_maxssiz = &ia32_maxssiz, 149 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32, 150 .sv_set_syscall_retval = ia32_set_syscall_retval, 151 .sv_fetch_syscall_args = ia32_fetch_syscall_args, 152 .sv_syscallnames = freebsd32_syscallnames, 153 .sv_onexec_old = exec_onexec_old, 154 .sv_onexit = exit_onexit, 155 .sv_set_fork_retval = x86_set_fork_retval, 156 }; 157 158 static void 159 aout_sysent(void *arg __unused) 160 { 161 aout_szsigcode = (int)(uintptr_t)&_binary_elf_vdso32_so_1_size; 162 } 163 SYSINIT(aout_sysent, SI_SUB_EXEC, SI_ORDER_ANY, aout_sysent, NULL); 164 #else 165 #error "Only ia32 arch is supported" 166 #endif 167 168 static int 169 aout_fixup(uintptr_t *stack_base, struct image_params *imgp) 170 { 171 172 *stack_base -= sizeof(uint32_t); 173 if (suword32((void *)*stack_base, imgp->args->argc) != 0) 174 return (EFAULT); 175 return (0); 176 } 177 178 static int 179 exec_aout_imgact(struct image_params *imgp) 180 { 181 const struct exec *a_out; 182 struct vmspace *vmspace; 183 vm_map_t map; 184 vm_object_t object; 185 vm_offset_t text_end, data_end; 186 unsigned long virtual_offset; 187 unsigned long file_offset; 188 unsigned long bss_size; 189 int error; 190 191 a_out = (const struct exec *)imgp->image_header; 192 193 /* 194 * Linux and *BSD binaries look very much alike, 195 * only the machine id is different: 196 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 197 * NetBSD is in network byte order.. ugh. 198 */ 199 if (((a_out->a_midmag >> 16) & 0xff) != 0x86 && 200 ((a_out->a_midmag >> 16) & 0xff) != 0 && 201 ((((int)ntohl(a_out->a_midmag)) >> 16) & 0xff) != 0x86) 202 return (-1); 203 204 /* 205 * Set file/virtual offset based on a.out variant. 206 * We do two cases: host byte order and network byte order 207 * (for NetBSD compatibility) 208 */ 209 switch ((int)(a_out->a_midmag & 0xffff)) { 210 case ZMAGIC: 211 virtual_offset = 0; 212 if (a_out->a_text) { 213 file_offset = PAGE_SIZE; 214 } else { 215 /* Bill's "screwball mode" */ 216 file_offset = 0; 217 } 218 break; 219 case QMAGIC: 220 virtual_offset = PAGE_SIZE; 221 file_offset = 0; 222 /* Pass PS_STRINGS for BSD/OS binaries only. */ 223 if (N_GETMID(*a_out) == MID_ZERO) 224 imgp->ps_strings = (void *)aout_sysvec.sv_psstrings; 225 break; 226 default: 227 /* NetBSD compatibility */ 228 switch ((int)(ntohl(a_out->a_midmag) & 0xffff)) { 229 case ZMAGIC: 230 case QMAGIC: 231 virtual_offset = PAGE_SIZE; 232 file_offset = 0; 233 break; 234 default: 235 return (-1); 236 } 237 } 238 239 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 240 241 /* 242 * Check various fields in header for validity/bounds. 243 */ 244 if (/* entry point must lay with text region */ 245 a_out->a_entry < virtual_offset || 246 a_out->a_entry >= virtual_offset + a_out->a_text || 247 248 /* text and data size must each be page rounded */ 249 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK 250 251 #ifdef __amd64__ 252 || 253 /* overflows */ 254 virtual_offset + a_out->a_text + a_out->a_data + bss_size > UINT_MAX 255 #endif 256 ) 257 return (-1); 258 259 /* text + data can't exceed file size */ 260 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 261 return (EFAULT); 262 263 /* 264 * text/data/bss must not exceed limits 265 */ 266 PROC_LOCK(imgp->proc); 267 if (/* text can't exceed maximum text size */ 268 a_out->a_text > maxtsiz || 269 270 /* data + bss can't exceed rlimit */ 271 a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) || 272 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) { 273 PROC_UNLOCK(imgp->proc); 274 return (ENOMEM); 275 } 276 PROC_UNLOCK(imgp->proc); 277 278 /* 279 * Avoid a possible deadlock if the current address space is destroyed 280 * and that address space maps the locked vnode. In the common case, 281 * the locked vnode's v_usecount is decremented but remains greater 282 * than zero. Consequently, the vnode lock is not needed by vrele(). 283 * However, in cases where the vnode lock is external, such as nullfs, 284 * v_usecount may become zero. 285 */ 286 VOP_UNLOCK(imgp->vp); 287 288 /* 289 * Destroy old process VM and create a new one (with a new stack) 290 */ 291 error = exec_new_vmspace(imgp, &aout_sysvec); 292 293 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 294 if (error) 295 return (error); 296 297 /* 298 * The vm space can be changed by exec_new_vmspace 299 */ 300 vmspace = imgp->proc->p_vmspace; 301 302 object = imgp->object; 303 map = &vmspace->vm_map; 304 vm_map_lock(map); 305 vm_object_reference(object); 306 307 text_end = virtual_offset + a_out->a_text; 308 error = vm_map_insert(map, object, 309 file_offset, 310 virtual_offset, text_end, 311 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL, 312 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC); 313 if (error) { 314 vm_map_unlock(map); 315 vm_object_deallocate(object); 316 return (error); 317 } 318 VOP_SET_TEXT_CHECKED(imgp->vp); 319 data_end = text_end + a_out->a_data; 320 if (a_out->a_data) { 321 vm_object_reference(object); 322 error = vm_map_insert(map, object, 323 file_offset + a_out->a_text, 324 text_end, data_end, 325 VM_PROT_ALL, VM_PROT_ALL, 326 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC); 327 if (error) { 328 vm_map_unlock(map); 329 vm_object_deallocate(object); 330 return (error); 331 } 332 VOP_SET_TEXT_CHECKED(imgp->vp); 333 } 334 335 if (bss_size) { 336 error = vm_map_insert(map, NULL, 0, 337 data_end, data_end + bss_size, 338 VM_PROT_ALL, VM_PROT_ALL, 0); 339 if (error) { 340 vm_map_unlock(map); 341 return (error); 342 } 343 } 344 vm_map_unlock(map); 345 346 /* Fill in process VM information */ 347 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 348 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 349 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset; 350 vmspace->vm_daddr = (caddr_t) (uintptr_t) 351 (virtual_offset + a_out->a_text); 352 353 error = exec_map_stack(imgp); 354 if (error != 0) 355 return (error); 356 357 /* Fill in image_params */ 358 imgp->interpreted = 0; 359 imgp->entry_addr = a_out->a_entry; 360 361 imgp->proc->p_sysent = &aout_sysvec; 362 363 return (0); 364 } 365 366 /* 367 * Tell kern_execve.c about it, with a little help from the linker. 368 */ 369 static struct execsw aout_execsw = { 370 .ex_imgact = exec_aout_imgact, 371 .ex_name = "a.out" 372 }; 373 EXEC_SET(aout, aout_execsw); 374