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