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 #define AOUT32_PS_STRINGS \ 112 (AOUT32_USRSTACK - sizeof(struct freebsd32_ps_strings)) 113 #define AOUT32_MINUSER FREEBSD32_MINUSER 114 115 extern const char *freebsd32_syscallnames[]; 116 extern u_long ia32_maxssiz; 117 118 struct sysentvec aout_sysvec = { 119 .sv_size = FREEBSD32_SYS_MAXSYSCALL, 120 .sv_table = freebsd32_sysent, 121 .sv_transtrap = NULL, 122 .sv_fixup = aout_fixup, 123 .sv_sendsig = ia32_sendsig, 124 .sv_sigcode = ia32_sigcode, 125 .sv_szsigcode = &sz_ia32_sigcode, 126 .sv_name = "FreeBSD a.out", 127 .sv_coredump = NULL, 128 .sv_imgact_try = NULL, 129 .sv_minsigstksz = MINSIGSTKSZ, 130 .sv_minuser = AOUT32_MINUSER, 131 .sv_maxuser = AOUT32_USRSTACK, 132 .sv_usrstack = AOUT32_USRSTACK, 133 .sv_psstrings = AOUT32_PS_STRINGS, 134 .sv_stackprot = VM_PROT_ALL, 135 .sv_copyout_strings = freebsd32_copyout_strings, 136 .sv_setregs = ia32_setregs, 137 .sv_fixlimit = ia32_fixlimit, 138 .sv_maxssiz = &ia32_maxssiz, 139 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32, 140 .sv_set_syscall_retval = ia32_set_syscall_retval, 141 .sv_fetch_syscall_args = ia32_fetch_syscall_args, 142 .sv_syscallnames = freebsd32_syscallnames, 143 .sv_onexec_old = exec_onexec_old, 144 .sv_onexit = exit_onexit, 145 .sv_set_fork_retval = x86_set_fork_retval, 146 }; 147 #else 148 #error "Port me" 149 #endif 150 151 static int 152 aout_fixup(uintptr_t *stack_base, struct image_params *imgp) 153 { 154 155 *stack_base -= sizeof(uint32_t); 156 if (suword32((void *)*stack_base, imgp->args->argc) != 0) 157 return (EFAULT); 158 return (0); 159 } 160 161 static int 162 exec_aout_imgact(struct image_params *imgp) 163 { 164 const struct exec *a_out = (const struct exec *) imgp->image_header; 165 struct vmspace *vmspace; 166 vm_map_t map; 167 vm_object_t object; 168 vm_offset_t text_end, data_end; 169 unsigned long virtual_offset; 170 unsigned long file_offset; 171 unsigned long bss_size; 172 int error; 173 174 /* 175 * Linux and *BSD binaries look very much alike, 176 * only the machine id is different: 177 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 178 * NetBSD is in network byte order.. ugh. 179 */ 180 if (((a_out->a_midmag >> 16) & 0xff) != 0x86 && 181 ((a_out->a_midmag >> 16) & 0xff) != 0 && 182 ((((int)ntohl(a_out->a_midmag)) >> 16) & 0xff) != 0x86) 183 return -1; 184 185 /* 186 * Set file/virtual offset based on a.out variant. 187 * We do two cases: host byte order and network byte order 188 * (for NetBSD compatibility) 189 */ 190 switch ((int)(a_out->a_midmag & 0xffff)) { 191 case ZMAGIC: 192 virtual_offset = 0; 193 if (a_out->a_text) { 194 file_offset = PAGE_SIZE; 195 } else { 196 /* Bill's "screwball mode" */ 197 file_offset = 0; 198 } 199 break; 200 case QMAGIC: 201 virtual_offset = PAGE_SIZE; 202 file_offset = 0; 203 /* Pass PS_STRINGS for BSD/OS binaries only. */ 204 if (N_GETMID(*a_out) == MID_ZERO) 205 imgp->ps_strings = (void *)aout_sysvec.sv_psstrings; 206 break; 207 default: 208 /* NetBSD compatibility */ 209 switch ((int)(ntohl(a_out->a_midmag) & 0xffff)) { 210 case ZMAGIC: 211 case QMAGIC: 212 virtual_offset = PAGE_SIZE; 213 file_offset = 0; 214 break; 215 default: 216 return (-1); 217 } 218 } 219 220 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 221 222 /* 223 * Check various fields in header for validity/bounds. 224 */ 225 if (/* entry point must lay with text region */ 226 a_out->a_entry < virtual_offset || 227 a_out->a_entry >= virtual_offset + a_out->a_text || 228 229 /* text and data size must each be page rounded */ 230 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK 231 232 #ifdef __amd64__ 233 || 234 /* overflows */ 235 virtual_offset + a_out->a_text + a_out->a_data + bss_size > UINT_MAX 236 #endif 237 ) 238 return (-1); 239 240 /* text + data can't exceed file size */ 241 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 242 return (EFAULT); 243 244 /* 245 * text/data/bss must not exceed limits 246 */ 247 PROC_LOCK(imgp->proc); 248 if (/* text can't exceed maximum text size */ 249 a_out->a_text > maxtsiz || 250 251 /* data + bss can't exceed rlimit */ 252 a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) || 253 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) { 254 PROC_UNLOCK(imgp->proc); 255 return (ENOMEM); 256 } 257 PROC_UNLOCK(imgp->proc); 258 259 /* 260 * Avoid a possible deadlock if the current address space is destroyed 261 * and that address space maps the locked vnode. In the common case, 262 * the locked vnode's v_usecount is decremented but remains greater 263 * than zero. Consequently, the vnode lock is not needed by vrele(). 264 * However, in cases where the vnode lock is external, such as nullfs, 265 * v_usecount may become zero. 266 */ 267 VOP_UNLOCK(imgp->vp); 268 269 /* 270 * Destroy old process VM and create a new one (with a new stack) 271 */ 272 error = exec_new_vmspace(imgp, &aout_sysvec); 273 274 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 275 if (error) 276 return (error); 277 278 /* 279 * The vm space can be changed by exec_new_vmspace 280 */ 281 vmspace = imgp->proc->p_vmspace; 282 283 object = imgp->object; 284 map = &vmspace->vm_map; 285 vm_map_lock(map); 286 vm_object_reference(object); 287 288 text_end = virtual_offset + a_out->a_text; 289 error = vm_map_insert(map, object, 290 file_offset, 291 virtual_offset, text_end, 292 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL, 293 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC); 294 if (error) { 295 vm_map_unlock(map); 296 vm_object_deallocate(object); 297 return (error); 298 } 299 VOP_SET_TEXT_CHECKED(imgp->vp); 300 data_end = text_end + a_out->a_data; 301 if (a_out->a_data) { 302 vm_object_reference(object); 303 error = vm_map_insert(map, object, 304 file_offset + a_out->a_text, 305 text_end, data_end, 306 VM_PROT_ALL, 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 } 315 316 if (bss_size) { 317 error = vm_map_insert(map, NULL, 0, 318 data_end, data_end + bss_size, 319 VM_PROT_ALL, VM_PROT_ALL, 0); 320 if (error) { 321 vm_map_unlock(map); 322 return (error); 323 } 324 } 325 vm_map_unlock(map); 326 327 /* Fill in process VM information */ 328 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 329 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 330 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset; 331 vmspace->vm_daddr = (caddr_t) (uintptr_t) 332 (virtual_offset + a_out->a_text); 333 334 /* Fill in image_params */ 335 imgp->interpreted = 0; 336 imgp->entry_addr = a_out->a_entry; 337 338 imgp->proc->p_sysent = &aout_sysvec; 339 340 return (0); 341 } 342 343 /* 344 * Tell kern_execve.c about it, with a little help from the linker. 345 */ 346 static struct execsw aout_execsw = { 347 .ex_imgact = exec_aout_imgact, 348 .ex_name = "a.out" 349 }; 350 EXEC_SET(aout, aout_execsw); 351