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