1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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/param.h> 30 #include <sys/exec.h> 31 #include <sys/imgact.h> 32 #include <sys/imgact_aout.h> 33 #include <sys/kernel.h> 34 #include <sys/limits.h> 35 #include <sys/lock.h> 36 #include <sys/malloc.h> 37 #include <sys/mutex.h> 38 #include <sys/proc.h> 39 #include <sys/racct.h> 40 #include <sys/resourcevar.h> 41 #include <sys/signalvar.h> 42 #include <sys/syscall.h> 43 #include <sys/sysent.h> 44 #include <sys/systm.h> 45 #include <sys/vnode.h> 46 47 #include <machine/frame.h> 48 #include <machine/md_var.h> 49 50 #include <vm/vm.h> 51 #include <vm/pmap.h> 52 #include <vm/vm_map.h> 53 #include <vm/vm_object.h> 54 #include <vm/vm_param.h> 55 56 #ifdef __amd64__ 57 #include <compat/freebsd32/freebsd32_signal.h> 58 #include <compat/freebsd32/freebsd32_util.h> 59 #include <compat/freebsd32/freebsd32_proto.h> 60 #include <compat/freebsd32/freebsd32_syscall.h> 61 #include <compat/ia32/ia32_signal.h> 62 #endif 63 64 static int exec_aout_imgact(struct image_params *imgp); 65 static int aout_fixup(uintptr_t *stack_base, struct image_params *imgp); 66 67 #define AOUT32_USRSTACK 0xbfc00000 68 69 #if defined(__i386__) 70 71 #define AOUT32_PS_STRINGS (AOUT32_USRSTACK - sizeof(struct ps_strings)) 72 73 struct sysentvec aout_sysvec = { 74 .sv_size = SYS_MAXSYSCALL, 75 .sv_table = sysent, 76 .sv_fixup = aout_fixup, 77 .sv_sendsig = sendsig, 78 .sv_sigcode = sigcode, 79 .sv_szsigcode = &szsigcode, 80 .sv_name = "FreeBSD a.out", 81 .sv_coredump = NULL, 82 .sv_minsigstksz = MINSIGSTKSZ, 83 .sv_minuser = VM_MIN_ADDRESS, 84 .sv_maxuser = AOUT32_USRSTACK, 85 .sv_usrstack = AOUT32_USRSTACK, 86 .sv_psstrings = AOUT32_PS_STRINGS, 87 .sv_psstringssz = sizeof(struct ps_strings), 88 .sv_stackprot = VM_PROT_ALL, 89 .sv_copyout_strings = exec_copyout_strings, 90 .sv_setregs = exec_setregs, 91 .sv_fixlimit = NULL, 92 .sv_maxssiz = NULL, 93 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32 | 94 SV_SIGSYS, 95 .sv_set_syscall_retval = cpu_set_syscall_retval, 96 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 97 .sv_syscallnames = syscallnames, 98 .sv_schedtail = NULL, 99 .sv_thread_detach = NULL, 100 .sv_trap = NULL, 101 .sv_onexec_old = exec_onexec_old, 102 .sv_onexit = exit_onexit, 103 .sv_set_fork_retval = x86_set_fork_retval, 104 }; 105 106 #elif defined(__amd64__) 107 108 #include "vdso_ia32_offsets.h" 109 110 extern const char _binary_elf_vdso32_so_1_start[]; 111 extern const char _binary_elf_vdso32_so_1_end[]; 112 extern char _binary_elf_vdso32_so_1_size; 113 114 #define AOUT32_PS_STRINGS \ 115 (AOUT32_USRSTACK - sizeof(struct freebsd32_ps_strings)) 116 #define AOUT32_MINUSER FREEBSD32_MINUSER 117 118 extern const char *freebsd32_syscallnames[]; 119 extern u_long ia32_maxssiz; 120 121 static int aout_szsigcode; 122 123 struct sysentvec aout_sysvec = { 124 .sv_size = FREEBSD32_SYS_MAXSYSCALL, 125 .sv_table = freebsd32_sysent, 126 .sv_fixup = aout_fixup, 127 .sv_sendsig = ia32_sendsig, 128 .sv_sigcode = _binary_elf_vdso32_so_1_start, 129 .sv_szsigcode = &aout_szsigcode, 130 .sv_name = "FreeBSD a.out", 131 .sv_coredump = NULL, 132 .sv_minsigstksz = MINSIGSTKSZ, 133 .sv_minuser = AOUT32_MINUSER, 134 .sv_maxuser = AOUT32_USRSTACK, 135 .sv_usrstack = AOUT32_USRSTACK, 136 .sv_psstrings = AOUT32_PS_STRINGS, 137 .sv_psstringssz = sizeof(struct freebsd32_ps_strings), 138 .sv_stackprot = VM_PROT_ALL, 139 .sv_copyout_strings = freebsd32_copyout_strings, 140 .sv_setregs = ia32_setregs, 141 .sv_fixlimit = ia32_fixlimit, 142 .sv_maxssiz = &ia32_maxssiz, 143 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32 | 144 SV_SIGSYS, 145 .sv_set_syscall_retval = ia32_set_syscall_retval, 146 .sv_fetch_syscall_args = ia32_fetch_syscall_args, 147 .sv_syscallnames = freebsd32_syscallnames, 148 .sv_onexec_old = exec_onexec_old, 149 .sv_onexit = exit_onexit, 150 .sv_set_fork_retval = x86_set_fork_retval, 151 }; 152 153 static void 154 aout_sysent(void *arg __unused) 155 { 156 aout_szsigcode = (int)(uintptr_t)&_binary_elf_vdso32_so_1_size; 157 } 158 SYSINIT(aout_sysent, SI_SUB_EXEC, SI_ORDER_ANY, aout_sysent, NULL); 159 #else 160 #error "Only ia32 arch is supported" 161 #endif 162 163 static int 164 aout_fixup(uintptr_t *stack_base, struct image_params *imgp) 165 { 166 167 *stack_base -= sizeof(uint32_t); 168 if (suword32((void *)*stack_base, imgp->args->argc) != 0) 169 return (EFAULT); 170 return (0); 171 } 172 173 static int 174 exec_aout_imgact(struct image_params *imgp) 175 { 176 const struct exec *a_out; 177 struct vmspace *vmspace; 178 vm_map_t map; 179 vm_object_t object; 180 vm_offset_t text_end, data_end; 181 unsigned long virtual_offset; 182 unsigned long file_offset; 183 unsigned long bss_size; 184 int error; 185 186 a_out = (const struct exec *)imgp->image_header; 187 188 /* 189 * Linux and *BSD binaries look very much alike, 190 * only the machine id is different: 191 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 192 * NetBSD is in network byte order.. ugh. 193 */ 194 if (((a_out->a_midmag >> 16) & 0xff) != 0x86 && 195 ((a_out->a_midmag >> 16) & 0xff) != 0 && 196 ((((int)ntohl(a_out->a_midmag)) >> 16) & 0xff) != 0x86) 197 return (-1); 198 199 /* 200 * Set file/virtual offset based on a.out variant. 201 * We do two cases: host byte order and network byte order 202 * (for NetBSD compatibility) 203 */ 204 switch ((int)(a_out->a_midmag & 0xffff)) { 205 case ZMAGIC: 206 virtual_offset = 0; 207 if (a_out->a_text) { 208 file_offset = PAGE_SIZE; 209 } else { 210 /* Bill's "screwball mode" */ 211 file_offset = 0; 212 } 213 break; 214 case QMAGIC: 215 virtual_offset = PAGE_SIZE; 216 file_offset = 0; 217 /* Pass PS_STRINGS for BSD/OS binaries only. */ 218 if (N_GETMID(*a_out) == MID_ZERO) 219 imgp->ps_strings = (void *)aout_sysvec.sv_psstrings; 220 break; 221 default: 222 /* NetBSD compatibility */ 223 switch ((int)(ntohl(a_out->a_midmag) & 0xffff)) { 224 case ZMAGIC: 225 case QMAGIC: 226 virtual_offset = PAGE_SIZE; 227 file_offset = 0; 228 break; 229 default: 230 return (-1); 231 } 232 } 233 234 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 235 236 /* 237 * Check various fields in header for validity/bounds. 238 */ 239 if (/* entry point must lay with text region */ 240 a_out->a_entry < virtual_offset || 241 a_out->a_entry >= virtual_offset + a_out->a_text || 242 243 /* text and data size must each be page rounded */ 244 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK 245 246 #ifdef __amd64__ 247 || 248 /* overflows */ 249 virtual_offset + a_out->a_text + a_out->a_data + bss_size > UINT_MAX 250 #endif 251 ) 252 return (-1); 253 254 /* text + data can't exceed file size */ 255 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 256 return (EFAULT); 257 258 /* 259 * text/data/bss must not exceed limits 260 */ 261 PROC_LOCK(imgp->proc); 262 if (/* text can't exceed maximum text size */ 263 a_out->a_text > maxtsiz || 264 265 /* data + bss can't exceed rlimit */ 266 a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) || 267 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) { 268 PROC_UNLOCK(imgp->proc); 269 return (ENOMEM); 270 } 271 PROC_UNLOCK(imgp->proc); 272 273 /* 274 * Avoid a possible deadlock if the current address space is destroyed 275 * and that address space maps the locked vnode. In the common case, 276 * the locked vnode's v_usecount is decremented but remains greater 277 * than zero. Consequently, the vnode lock is not needed by vrele(). 278 * However, in cases where the vnode lock is external, such as nullfs, 279 * v_usecount may become zero. 280 */ 281 VOP_UNLOCK(imgp->vp); 282 283 /* 284 * Destroy old process VM and create a new one (with a new stack) 285 */ 286 error = exec_new_vmspace(imgp, &aout_sysvec); 287 288 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 289 if (error) 290 return (error); 291 292 /* 293 * The vm space can be changed by exec_new_vmspace 294 */ 295 vmspace = imgp->proc->p_vmspace; 296 297 object = imgp->object; 298 map = &vmspace->vm_map; 299 vm_map_lock(map); 300 vm_object_reference(object); 301 302 text_end = virtual_offset + a_out->a_text; 303 error = vm_map_insert(map, object, 304 file_offset, 305 virtual_offset, text_end, 306 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL, 307 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC); 308 if (error) { 309 vm_map_unlock(map); 310 vm_object_deallocate(object); 311 return (error); 312 } 313 VOP_SET_TEXT_CHECKED(imgp->vp); 314 data_end = text_end + a_out->a_data; 315 if (a_out->a_data) { 316 vm_object_reference(object); 317 error = vm_map_insert(map, object, 318 file_offset + a_out->a_text, 319 text_end, data_end, 320 VM_PROT_ALL, VM_PROT_ALL, 321 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC); 322 if (error) { 323 vm_map_unlock(map); 324 vm_object_deallocate(object); 325 return (error); 326 } 327 VOP_SET_TEXT_CHECKED(imgp->vp); 328 } 329 330 if (bss_size) { 331 error = vm_map_insert(map, NULL, 0, 332 data_end, data_end + bss_size, 333 VM_PROT_ALL, VM_PROT_ALL, 0); 334 if (error) { 335 vm_map_unlock(map); 336 return (error); 337 } 338 } 339 vm_map_unlock(map); 340 341 /* Fill in process VM information */ 342 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 343 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 344 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset; 345 vmspace->vm_daddr = (caddr_t) (uintptr_t) 346 (virtual_offset + a_out->a_text); 347 348 error = exec_map_stack(imgp); 349 if (error != 0) 350 return (error); 351 352 /* Fill in image_params */ 353 imgp->interpreted = 0; 354 imgp->entry_addr = a_out->a_entry; 355 356 imgp->proc->p_sysent = &aout_sysvec; 357 358 return (0); 359 } 360 361 /* 362 * Tell kern_execve.c about it, with a little help from the linker. 363 */ 364 static struct execsw aout_execsw = { 365 .ex_imgact = exec_aout_imgact, 366 .ex_name = "a.out" 367 }; 368 EXEC_SET(aout, aout_execsw); 369