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 .sv_thread_detach = NULL, 103 }; 104 105 #elif defined(__amd64__) 106 107 #define AOUT32_USRSTACK 0xbfc00000 108 #define AOUT32_PS_STRINGS \ 109 (AOUT32_USRSTACK - sizeof(struct freebsd32_ps_strings)) 110 #define AOUT32_MINUSER FREEBSD32_MINUSER 111 112 extern const char *freebsd32_syscallnames[]; 113 extern u_long ia32_maxssiz; 114 115 struct sysentvec aout_sysvec = { 116 .sv_size = FREEBSD32_SYS_MAXSYSCALL, 117 .sv_table = freebsd32_sysent, 118 .sv_mask = 0, 119 .sv_sigsize = 0, 120 .sv_sigtbl = NULL, 121 .sv_errsize = 0, 122 .sv_errtbl = NULL, 123 .sv_transtrap = NULL, 124 .sv_fixup = aout_fixup, 125 .sv_sendsig = ia32_sendsig, 126 .sv_sigcode = ia32_sigcode, 127 .sv_szsigcode = &sz_ia32_sigcode, 128 .sv_prepsyscall = NULL, 129 .sv_name = "FreeBSD a.out", 130 .sv_coredump = NULL, 131 .sv_imgact_try = NULL, 132 .sv_minsigstksz = MINSIGSTKSZ, 133 .sv_pagesize = IA32_PAGE_SIZE, 134 .sv_minuser = AOUT32_MINUSER, 135 .sv_maxuser = AOUT32_USRSTACK, 136 .sv_usrstack = AOUT32_USRSTACK, 137 .sv_psstrings = AOUT32_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_set_syscall_retval = ia32_set_syscall_retval, 145 .sv_fetch_syscall_args = ia32_fetch_syscall_args, 146 .sv_syscallnames = freebsd32_syscallnames, 147 }; 148 #else 149 #error "Port me" 150 #endif 151 152 static int 153 aout_fixup(register_t **stack_base, struct image_params *imgp) 154 { 155 156 *(char **)stack_base -= sizeof(uint32_t); 157 return (suword32(*stack_base, imgp->args->argc)); 158 } 159 160 static int 161 exec_aout_imgact(struct image_params *imgp) 162 { 163 const struct exec *a_out = (const struct exec *) imgp->image_header; 164 struct vmspace *vmspace; 165 vm_map_t map; 166 vm_object_t object; 167 vm_offset_t text_end, data_end; 168 unsigned long virtual_offset; 169 unsigned long file_offset; 170 unsigned long bss_size; 171 int error; 172 173 /* 174 * Linux and *BSD binaries look very much alike, 175 * only the machine id is different: 176 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI. 177 * NetBSD is in network byte order.. ugh. 178 */ 179 if (((a_out->a_midmag >> 16) & 0xff) != 0x86 && 180 ((a_out->a_midmag >> 16) & 0xff) != 0 && 181 ((((int)ntohl(a_out->a_midmag)) >> 16) & 0xff) != 0x86) 182 return -1; 183 184 /* 185 * Set file/virtual offset based on a.out variant. 186 * We do two cases: host byte order and network byte order 187 * (for NetBSD compatibility) 188 */ 189 switch ((int)(a_out->a_midmag & 0xffff)) { 190 case ZMAGIC: 191 virtual_offset = 0; 192 if (a_out->a_text) { 193 file_offset = PAGE_SIZE; 194 } else { 195 /* Bill's "screwball mode" */ 196 file_offset = 0; 197 } 198 break; 199 case QMAGIC: 200 virtual_offset = PAGE_SIZE; 201 file_offset = 0; 202 /* Pass PS_STRINGS for BSD/OS binaries only. */ 203 if (N_GETMID(*a_out) == MID_ZERO) 204 imgp->ps_strings = aout_sysvec.sv_psstrings; 205 break; 206 default: 207 /* NetBSD compatibility */ 208 switch ((int)(ntohl(a_out->a_midmag) & 0xffff)) { 209 case ZMAGIC: 210 case QMAGIC: 211 virtual_offset = PAGE_SIZE; 212 file_offset = 0; 213 break; 214 default: 215 return (-1); 216 } 217 } 218 219 bss_size = roundup(a_out->a_bss, PAGE_SIZE); 220 221 /* 222 * Check various fields in header for validity/bounds. 223 */ 224 if (/* entry point must lay with text region */ 225 a_out->a_entry < virtual_offset || 226 a_out->a_entry >= virtual_offset + a_out->a_text || 227 228 /* text and data size must each be page rounded */ 229 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK 230 231 #ifdef __amd64__ 232 || 233 /* overflows */ 234 virtual_offset + a_out->a_text + a_out->a_data + bss_size > UINT_MAX 235 #endif 236 ) 237 return (-1); 238 239 /* text + data can't exceed file size */ 240 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 241 return (EFAULT); 242 243 /* 244 * text/data/bss must not exceed limits 245 */ 246 PROC_LOCK(imgp->proc); 247 if (/* text can't exceed maximum text size */ 248 a_out->a_text > maxtsiz || 249 250 /* data + bss can't exceed rlimit */ 251 a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) || 252 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) { 253 PROC_UNLOCK(imgp->proc); 254 return (ENOMEM); 255 } 256 PROC_UNLOCK(imgp->proc); 257 258 /* 259 * Avoid a possible deadlock if the current address space is destroyed 260 * and that address space maps the locked vnode. In the common case, 261 * the locked vnode's v_usecount is decremented but remains greater 262 * than zero. Consequently, the vnode lock is not needed by vrele(). 263 * However, in cases where the vnode lock is external, such as nullfs, 264 * v_usecount may become zero. 265 */ 266 VOP_UNLOCK(imgp->vp, 0); 267 268 /* 269 * Destroy old process VM and create a new one (with a new stack) 270 */ 271 error = exec_new_vmspace(imgp, &aout_sysvec); 272 273 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); 274 if (error) 275 return (error); 276 277 /* 278 * The vm space can be changed by exec_new_vmspace 279 */ 280 vmspace = imgp->proc->p_vmspace; 281 282 object = imgp->object; 283 map = &vmspace->vm_map; 284 vm_map_lock(map); 285 vm_object_reference(object); 286 287 text_end = virtual_offset + a_out->a_text; 288 error = vm_map_insert(map, object, 289 file_offset, 290 virtual_offset, text_end, 291 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL, 292 MAP_COPY_ON_WRITE | MAP_PREFAULT); 293 if (error) { 294 vm_map_unlock(map); 295 vm_object_deallocate(object); 296 return (error); 297 } 298 data_end = text_end + a_out->a_data; 299 if (a_out->a_data) { 300 vm_object_reference(object); 301 error = vm_map_insert(map, object, 302 file_offset + a_out->a_text, 303 text_end, data_end, 304 VM_PROT_ALL, VM_PROT_ALL, 305 MAP_COPY_ON_WRITE | MAP_PREFAULT); 306 if (error) { 307 vm_map_unlock(map); 308 vm_object_deallocate(object); 309 return (error); 310 } 311 } 312 313 if (bss_size) { 314 error = vm_map_insert(map, NULL, 0, 315 data_end, data_end + bss_size, 316 VM_PROT_ALL, VM_PROT_ALL, 0); 317 if (error) { 318 vm_map_unlock(map); 319 return (error); 320 } 321 } 322 vm_map_unlock(map); 323 324 /* Fill in process VM information */ 325 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT; 326 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT; 327 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset; 328 vmspace->vm_daddr = (caddr_t) (uintptr_t) 329 (virtual_offset + a_out->a_text); 330 331 /* Fill in image_params */ 332 imgp->interpreted = 0; 333 imgp->entry_addr = a_out->a_entry; 334 335 imgp->proc->p_sysent = &aout_sysvec; 336 337 return (0); 338 } 339 340 /* 341 * Tell kern_execve.c about it, with a little help from the linker. 342 */ 343 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" }; 344 EXEC_SET(aout, aout_execsw); 345