1 /*- 2 * Copyright (c) 1993, David Greenman 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/exec.h> 32 #include <sys/imgact.h> 33 #include <sys/imgact_aout.h> 34 #include <sys/kernel.h> 35 #include <sys/limits.h> 36 #include <sys/lock.h> 37 #include <sys/malloc.h> 38 #include <sys/mutex.h> 39 #include <sys/proc.h> 40 #include <sys/racct.h> 41 #include <sys/resourcevar.h> 42 #include <sys/signalvar.h> 43 #include <sys/syscall.h> 44 #include <sys/sysent.h> 45 #include <sys/systm.h> 46 #include <sys/vnode.h> 47 48 #include <machine/frame.h> 49 #include <machine/md_var.h> 50 51 #include <vm/vm.h> 52 #include <vm/pmap.h> 53 #include <vm/vm_map.h> 54 #include <vm/vm_object.h> 55 #include <vm/vm_param.h> 56 57 #ifdef __amd64__ 58 #include <compat/freebsd32/freebsd32_signal.h> 59 #include <compat/freebsd32/freebsd32_util.h> 60 #include <compat/freebsd32/freebsd32_proto.h> 61 #include <compat/freebsd32/freebsd32_syscall.h> 62 #include <compat/ia32/ia32_signal.h> 63 #endif 64 65 static int exec_aout_imgact(struct image_params *imgp); 66 static int aout_fixup(register_t **stack_base, struct image_params *imgp); 67 68 #if defined(__i386__) 69 struct sysentvec aout_sysvec = { 70 .sv_size = SYS_MAXSYSCALL, 71 .sv_table = sysent, 72 .sv_mask = 0, 73 .sv_sigsize = 0, 74 .sv_sigtbl = NULL, 75 .sv_errsize = 0, 76 .sv_errtbl = NULL, 77 .sv_transtrap = NULL, 78 .sv_fixup = aout_fixup, 79 .sv_sendsig = sendsig, 80 .sv_sigcode = sigcode, 81 .sv_szsigcode = &szsigcode, 82 .sv_prepsyscall = NULL, 83 .sv_name = "FreeBSD a.out", 84 .sv_coredump = NULL, 85 .sv_imgact_try = NULL, 86 .sv_minsigstksz = MINSIGSTKSZ, 87 .sv_pagesize = PAGE_SIZE, 88 .sv_minuser = VM_MIN_ADDRESS, 89 .sv_maxuser = VM_MAXUSER_ADDRESS, 90 .sv_usrstack = USRSTACK, 91 .sv_psstrings = 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 }; 103 104 #elif defined(__amd64__) 105 106 #define AOUT32_USRSTACK 0xbfc00000 107 #define AOUT32_PS_STRINGS \ 108 (AOUT32_USRSTACK - sizeof(struct freebsd32_ps_strings)) 109 110 extern const char *freebsd32_syscallnames[]; 111 extern u_long ia32_maxssiz; 112 113 struct sysentvec aout_sysvec = { 114 .sv_size = FREEBSD32_SYS_MAXSYSCALL, 115 .sv_table = freebsd32_sysent, 116 .sv_mask = 0, 117 .sv_sigsize = 0, 118 .sv_sigtbl = NULL, 119 .sv_errsize = 0, 120 .sv_errtbl = NULL, 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_prepsyscall = NULL, 127 .sv_name = "FreeBSD a.out", 128 .sv_coredump = NULL, 129 .sv_imgact_try = NULL, 130 .sv_minsigstksz = MINSIGSTKSZ, 131 .sv_pagesize = IA32_PAGE_SIZE, 132 .sv_minuser = 0, 133 .sv_maxuser = AOUT32_USRSTACK, 134 .sv_usrstack = AOUT32_USRSTACK, 135 .sv_psstrings = AOUT32_PS_STRINGS, 136 .sv_stackprot = VM_PROT_ALL, 137 .sv_copyout_strings = freebsd32_copyout_strings, 138 .sv_setregs = ia32_setregs, 139 .sv_fixlimit = ia32_fixlimit, 140 .sv_maxssiz = &ia32_maxssiz, 141 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32, 142 .sv_set_syscall_retval = ia32_set_syscall_retval, 143 .sv_fetch_syscall_args = ia32_fetch_syscall_args, 144 .sv_syscallnames = freebsd32_syscallnames, 145 }; 146 #else 147 #error "Port me" 148 #endif 149 150 static int 151 aout_fixup(register_t **stack_base, struct image_params *imgp) 152 { 153 154 *(char **)stack_base -= sizeof(uint32_t); 155 return (suword32(*stack_base, imgp->args->argc)); 156 } 157 158 static int 159 exec_aout_imgact(struct image_params *imgp) 160 { 161 const struct exec *a_out = (const struct exec *) imgp->image_header; 162 struct vmspace *vmspace; 163 vm_map_t map; 164 vm_object_t object; 165 vm_offset_t text_end, data_end; 166 unsigned long virtual_offset; 167 unsigned long file_offset; 168 unsigned long bss_size; 169 int error; 170 171 /* 172 * Linux and *BSD binaries look very much alike, 173 * only the machine id is different: 174 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 175 * NetBSD is in network byte order.. ugh. 176 */ 177 if (((a_out->a_magic >> 16) & 0xff) != 0x86 && 178 ((a_out->a_magic >> 16) & 0xff) != 0 && 179 ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86) 180 return -1; 181 182 /* 183 * Set file/virtual offset based on a.out variant. 184 * We do two cases: host byte order and network byte order 185 * (for NetBSD compatibility) 186 */ 187 switch ((int)(a_out->a_magic & 0xffff)) { 188 case ZMAGIC: 189 virtual_offset = 0; 190 if (a_out->a_text) { 191 file_offset = PAGE_SIZE; 192 } else { 193 /* Bill's "screwball mode" */ 194 file_offset = 0; 195 } 196 break; 197 case QMAGIC: 198 virtual_offset = PAGE_SIZE; 199 file_offset = 0; 200 /* Pass PS_STRINGS for BSD/OS binaries only. */ 201 if (N_GETMID(*a_out) == MID_ZERO) 202 imgp->ps_strings = aout_sysvec.sv_psstrings; 203 break; 204 default: 205 /* NetBSD compatibility */ 206 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) { 207 case ZMAGIC: 208 case QMAGIC: 209 virtual_offset = PAGE_SIZE; 210 file_offset = 0; 211 break; 212 default: 213 return (-1); 214 } 215 } 216 217 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 218 219 /* 220 * Check various fields in header for validity/bounds. 221 */ 222 if (/* entry point must lay with text region */ 223 a_out->a_entry < virtual_offset || 224 a_out->a_entry >= virtual_offset + a_out->a_text || 225 226 /* text and data size must each be page rounded */ 227 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK 228 229 #ifdef __amd64__ 230 || 231 /* overflows */ 232 virtual_offset + a_out->a_text + a_out->a_data + bss_size > UINT_MAX 233 #endif 234 ) 235 return (-1); 236 237 /* text + data can't exceed file size */ 238 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 239 return (EFAULT); 240 241 /* 242 * text/data/bss must not exceed limits 243 */ 244 PROC_LOCK(imgp->proc); 245 if (/* text can't exceed maximum text size */ 246 a_out->a_text > maxtsiz || 247 248 /* data + bss can't exceed rlimit */ 249 a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA) || 250 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) { 251 PROC_UNLOCK(imgp->proc); 252 return (ENOMEM); 253 } 254 PROC_UNLOCK(imgp->proc); 255 256 /* 257 * Avoid a possible deadlock if the current address space is destroyed 258 * and that address space maps the locked vnode. In the common case, 259 * the locked vnode's v_usecount is decremented but remains greater 260 * than zero. Consequently, the vnode lock is not needed by vrele(). 261 * However, in cases where the vnode lock is external, such as nullfs, 262 * v_usecount may become zero. 263 */ 264 VOP_UNLOCK(imgp->vp, 0); 265 266 /* 267 * Destroy old process VM and create a new one (with a new stack) 268 */ 269 error = exec_new_vmspace(imgp, &aout_sysvec); 270 271 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); 272 if (error) 273 return (error); 274 275 /* 276 * The vm space can be changed by exec_new_vmspace 277 */ 278 vmspace = imgp->proc->p_vmspace; 279 280 object = imgp->object; 281 map = &vmspace->vm_map; 282 vm_map_lock(map); 283 vm_object_reference(object); 284 285 text_end = virtual_offset + a_out->a_text; 286 error = vm_map_insert(map, object, 287 file_offset, 288 virtual_offset, text_end, 289 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL, 290 MAP_COPY_ON_WRITE | MAP_PREFAULT); 291 if (error) { 292 vm_map_unlock(map); 293 vm_object_deallocate(object); 294 return (error); 295 } 296 data_end = text_end + a_out->a_data; 297 if (a_out->a_data) { 298 vm_object_reference(object); 299 error = vm_map_insert(map, object, 300 file_offset + a_out->a_text, 301 text_end, data_end, 302 VM_PROT_ALL, VM_PROT_ALL, 303 MAP_COPY_ON_WRITE | MAP_PREFAULT); 304 if (error) { 305 vm_map_unlock(map); 306 vm_object_deallocate(object); 307 return (error); 308 } 309 } 310 311 if (bss_size) { 312 error = vm_map_insert(map, NULL, 0, 313 data_end, data_end + bss_size, 314 VM_PROT_ALL, VM_PROT_ALL, 0); 315 if (error) { 316 vm_map_unlock(map); 317 return (error); 318 } 319 } 320 vm_map_unlock(map); 321 322 /* Fill in process VM information */ 323 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 324 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 325 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset; 326 vmspace->vm_daddr = (caddr_t) (uintptr_t) 327 (virtual_offset + a_out->a_text); 328 329 /* Fill in image_params */ 330 imgp->interpreted = 0; 331 imgp->entry_addr = a_out->a_entry; 332 333 imgp->proc->p_sysent = &aout_sysvec; 334 335 return (0); 336 } 337 338 /* 339 * Tell kern_execve.c about it, with a little help from the linker. 340 */ 341 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" }; 342 EXEC_SET(aout, aout_execsw); 343