1 /* $NetBSD: netbsd32_execve.c,v 1.13 2002/09/16 03:41:40 martin Exp $ */ 2 3 /* 4 * Copyright (c) 1998, 2001 Matthew R. Green 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 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 25 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 __KERNEL_RCSID(0, "$NetBSD: netbsd32_execve.c,v 1.13 2002/09/16 03:41:40 martin Exp $"); 33 34 #if defined(_KERNEL_OPT) 35 #include "opt_ktrace.h" 36 #endif 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/malloc.h> 41 #include <sys/mount.h> 42 #include <sys/stat.h> 43 #include <sys/wait.h> 44 #include <sys/ktrace.h> 45 #include <sys/vnode.h> 46 #include <sys/file.h> 47 #include <sys/filedesc.h> 48 #include <sys/namei.h> 49 50 #include <uvm/uvm_extern.h> 51 52 #include <sys/syscallargs.h> 53 #include <sys/proc.h> 54 #include <sys/acct.h> 55 #include <sys/exec.h> 56 57 #include <compat/netbsd32/netbsd32.h> 58 #include <compat/netbsd32/netbsd32_syscall.h> 59 #include <compat/netbsd32/netbsd32_syscallargs.h> 60 61 /* this is provided by kern/kern_exec.c */ 62 extern u_int exec_maxhdrsz; 63 #if defined(LKM) || defined(_LKM) 64 extern struct lock exec_lock; 65 #endif 66 67 /* 68 * Need to completly reimplement this syscall due to argument copying. 69 */ 70 /* ARGSUSED */ 71 int 72 netbsd32_execve(p, v, retval) 73 struct proc *p; 74 void *v; 75 register_t *retval; 76 { 77 struct netbsd32_execve_args /* { 78 syscallarg(const netbsd32_charp) path; 79 syscallarg(netbsd32_charpp) argp; 80 syscallarg(netbsd32_charpp) envp; 81 } */ *uap = v; 82 struct sys_execve_args ua; 83 caddr_t sg; 84 85 NETBSD32TOP_UAP(path, const char); 86 NETBSD32TOP_UAP(argp, char *); 87 NETBSD32TOP_UAP(envp, char *); 88 sg = stackgap_init(p, 0); 89 CHECK_ALT_EXIST(p, &sg, SCARG(&ua, path)); 90 91 return netbsd32_execve2(p, &ua, retval); 92 } 93 94 int 95 netbsd32_execve2(p, uap, retval) 96 struct proc *p; 97 struct sys_execve_args *uap; 98 register_t *retval; 99 { 100 /* Function args */ 101 int error, i; 102 struct exec_package pack; 103 struct nameidata nid; 104 struct vattr attr; 105 struct ucred *cred = p->p_ucred; 106 char *argp; 107 netbsd32_charp const *cpp; 108 char *dp; 109 netbsd32_charp sp; 110 long argc, envc; 111 size_t len; 112 char *stack; 113 struct ps_strings arginfo; 114 struct vmspace *vm; 115 char **tmpfap; 116 int szsigcode; 117 struct exec_vmcmd *base_vcp = NULL; 118 119 /* 120 * Init the namei data to point the file user's program name. 121 * This is done here rather than in check_exec(), so that it's 122 * possible to override this settings if any of makecmd/probe 123 * functions call check_exec() recursively - for example, 124 * see exec_script_makecmds(). 125 */ 126 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 127 128 /* 129 * initialize the fields of the exec package. 130 */ 131 pack.ep_name = SCARG(uap, path); 132 pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK); 133 pack.ep_hdrlen = exec_maxhdrsz; 134 pack.ep_hdrvalid = 0; 135 pack.ep_ndp = &nid; 136 pack.ep_emul_arg = NULL; 137 pack.ep_vmcmds.evs_cnt = 0; 138 pack.ep_vmcmds.evs_used = 0; 139 pack.ep_vap = &attr; 140 pack.ep_flags = 0; 141 142 #if defined(LKM) || defined(_LKM) 143 lockmgr(&exec_lock, LK_SHARED, NULL); 144 #endif 145 146 /* see if we can run it. */ 147 if ((error = check_exec(p, &pack)) != 0) 148 goto freehdr; 149 150 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 151 152 /* allocate an argument buffer */ 153 argp = (char *) uvm_km_valloc_wait(exec_map, NCARGS); 154 #ifdef DIAGNOSTIC 155 if (argp == (vaddr_t) 0) 156 panic("netbsd32_execve: argp == NULL"); 157 #endif 158 dp = argp; 159 argc = 0; 160 161 /* copy the fake args list, if there's one, freeing it as we go */ 162 if (pack.ep_flags & EXEC_HASARGL) { 163 tmpfap = pack.ep_fa; 164 while (*tmpfap != NULL) { 165 char *cp; 166 167 cp = *tmpfap; 168 while (*cp) 169 *dp++ = *cp++; 170 dp++; 171 172 FREE(*tmpfap, M_EXEC); 173 tmpfap++; argc++; 174 } 175 FREE(pack.ep_fa, M_EXEC); 176 pack.ep_flags &= ~EXEC_HASARGL; 177 } 178 179 /* Now get argv & environment */ 180 if (!(cpp = (netbsd32_charp *)SCARG(uap, argp))) { 181 error = EINVAL; 182 goto bad; 183 } 184 185 if (pack.ep_flags & EXEC_SKIPARG) 186 cpp++; 187 188 while (1) { 189 len = argp + ARG_MAX - dp; 190 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 191 goto bad; 192 if (!sp) 193 break; 194 if ((error = copyinstr((char *)(u_long)sp, dp, 195 len, &len)) != 0) { 196 if (error == ENAMETOOLONG) 197 error = E2BIG; 198 goto bad; 199 } 200 dp += len; 201 cpp++; 202 argc++; 203 } 204 205 envc = 0; 206 /* environment need not be there */ 207 if ((cpp = (netbsd32_charp *)SCARG(uap, envp)) != NULL ) { 208 while (1) { 209 len = argp + ARG_MAX - dp; 210 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 211 goto bad; 212 if (!sp) 213 break; 214 if ((error = copyinstr((char *)(u_long)sp, 215 dp, len, &len)) != 0) { 216 if (error == ENAMETOOLONG) 217 error = E2BIG; 218 goto bad; 219 } 220 dp += len; 221 cpp++; 222 envc++; 223 } 224 } 225 226 dp = (char *) ALIGN(dp); 227 228 szsigcode = pack.ep_es->es_emul->e_esigcode - 229 pack.ep_es->es_emul->e_sigcode; 230 231 /* Now check if args & environ fit into new stack */ 232 if (pack.ep_flags & EXEC_32) 233 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 234 sizeof(int) + sizeof(int) + dp + STACKGAPLEN + 235 szsigcode + sizeof(struct ps_strings)) - argp; 236 else 237 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 238 sizeof(char *) + sizeof(int) + dp + STACKGAPLEN + 239 szsigcode + sizeof(struct ps_strings)) - argp; 240 241 len = ALIGN(len); /* make the stack "safely" aligned */ 242 243 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 244 error = ENOMEM; 245 goto bad; 246 } 247 248 /* adjust "active stack depth" for process VSZ */ 249 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 250 251 /* 252 * Do whatever is necessary to prepare the address space 253 * for remapping. Note that this might replace the current 254 * vmspace with another! 255 */ 256 uvmspace_exec(p, VM_MIN_ADDRESS, (vaddr_t)pack.ep_minsaddr); 257 258 /* Now map address space */ 259 vm = p->p_vmspace; 260 vm->vm_taddr = (char *) pack.ep_taddr; 261 vm->vm_tsize = btoc(pack.ep_tsize); 262 vm->vm_daddr = (char *) pack.ep_daddr; 263 vm->vm_dsize = btoc(pack.ep_dsize); 264 vm->vm_ssize = btoc(pack.ep_ssize); 265 vm->vm_maxsaddr = (char *) pack.ep_maxsaddr; 266 vm->vm_minsaddr = (char *) pack.ep_minsaddr; 267 268 /* create the new process's VM space by running the vmcmds */ 269 #ifdef DIAGNOSTIC 270 if (pack.ep_vmcmds.evs_used == 0) 271 panic("netbsd32_execve: no vmcmds"); 272 #endif 273 for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) { 274 struct exec_vmcmd *vcp; 275 276 vcp = &pack.ep_vmcmds.evs_cmds[i]; 277 if (vcp->ev_flags & VMCMD_RELATIVE) { 278 #ifdef DIAGNOSTIC 279 if (base_vcp == NULL) 280 panic("netbsd32_execve: relative vmcmd with no base"); 281 if (vcp->ev_flags & VMCMD_BASE) 282 panic("netbsd32_execve: illegal base & relative vmcmd"); 283 #endif 284 vcp->ev_addr += base_vcp->ev_addr; 285 } 286 error = (*vcp->ev_proc)(p, vcp); 287 #ifdef DEBUG 288 if (error) { 289 int j; 290 291 for (j = 0; j <= i; j++) 292 printf("vmcmd[%d] = %#lx/%#lx @ %#lx\n", j, 293 vcp[j-i].ev_addr, vcp[j-i].ev_len, 294 vcp[j-i].ev_offset); 295 } 296 #endif 297 if (vcp->ev_flags & VMCMD_BASE) 298 base_vcp = vcp; 299 } 300 301 /* free the vmspace-creation commands, and release their references */ 302 kill_vmcmds(&pack.ep_vmcmds); 303 304 /* if an error happened, deallocate and punt */ 305 if (error) { 306 #ifdef DEBUG 307 printf("netbsd32_execve: vmcmd %i failed: %d\n", i-1, error); 308 #endif 309 goto exec_abort; 310 } 311 312 /* remember information about the process */ 313 arginfo.ps_nargvstr = argc; 314 arginfo.ps_nenvstr = envc; 315 316 stack = (char *) (vm->vm_minsaddr - len); 317 /* Now copy argc, args & environ to new stack */ 318 error = (*pack.ep_es->es_copyargs)(p, &pack, &arginfo, 319 &stack, argp); 320 if (error) { 321 #ifdef DEBUG 322 printf("netbsd32_execve: copyargs failed\n"); 323 #endif 324 goto exec_abort; 325 } 326 /* restore the stack back to its original point */ 327 stack = (char *) (vm->vm_minsaddr - len); 328 329 /* fill process ps_strings info */ 330 p->p_psstr = (struct ps_strings *)(vm->vm_minsaddr - 331 sizeof(struct ps_strings)); 332 p->p_psargv = offsetof(struct ps_strings, ps_argvstr); 333 p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr); 334 p->p_psenv = offsetof(struct ps_strings, ps_envstr); 335 p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr); 336 337 /* copy out the process's ps_strings structure */ 338 if (copyout(&arginfo, (char *)p->p_psstr, sizeof(arginfo))) { 339 #ifdef DEBUG 340 printf("netbsd32_execve: ps_strings copyout failed\n"); 341 #endif 342 goto exec_abort; 343 } 344 345 /* copy out the process's signal trapoline code */ 346 if (szsigcode) { 347 if (copyout((char *)pack.ep_es->es_emul->e_sigcode, 348 p->p_sigctx.ps_sigcode = (char *)p->p_psstr - szsigcode, 349 szsigcode)) { 350 #ifdef DEBUG 351 printf("netbsd32_execve: sig trampoline copyout failed\n"); 352 #endif 353 goto exec_abort; 354 } 355 #ifdef PMAP_NEED_PROCWR 356 /* This is code. Let the pmap do what is needed. */ 357 pmap_procwr(p, (vaddr_t)p->p_sigctx.ps_sigcode, szsigcode); 358 #endif 359 } 360 361 stopprofclock(p); /* stop profiling */ 362 fdcloseexec(p); /* handle close on exec */ 363 execsigs(p); /* reset catched signals */ 364 p->p_ctxlink = NULL; /* reset ucontext link */ 365 366 /* set command name & other accounting info */ 367 len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN); 368 memcpy(p->p_comm, nid.ni_cnd.cn_nameptr, len); 369 p->p_comm[len] = 0; 370 p->p_acflag &= ~AFORK; 371 372 /* record proc's vnode, for use by procfs and others */ 373 if (p->p_textvp) 374 vrele(p->p_textvp); 375 VREF(pack.ep_vp); 376 p->p_textvp = pack.ep_vp; 377 378 p->p_flag |= P_EXEC; 379 if (p->p_flag & P_PPWAIT) { 380 p->p_flag &= ~P_PPWAIT; 381 wakeup((caddr_t) p->p_pptr); 382 } 383 384 /* 385 * deal with set[ug]id. 386 * MNT_NOSUID has already been used to disable s[ug]id. 387 */ 388 if ((p->p_flag & P_TRACED) == 0 && 389 390 (((attr.va_mode & S_ISUID) != 0 && 391 p->p_ucred->cr_uid != attr.va_uid) || 392 393 ((attr.va_mode & S_ISGID) != 0 && 394 p->p_ucred->cr_gid != attr.va_gid))) { 395 /* 396 * Mark the process as SUGID before we do 397 * anything that might block. 398 */ 399 p_sugid(p); 400 401 p->p_ucred = crcopy(cred); 402 #ifdef KTRACE 403 /* 404 * If process is being ktraced, turn off - unless 405 * root set it. 406 */ 407 if (p->p_tracep && !(p->p_traceflag & KTRFAC_ROOT)) 408 ktrderef(p); 409 #endif 410 if (attr.va_mode & S_ISUID) 411 p->p_ucred->cr_uid = attr.va_uid; 412 if (attr.va_mode & S_ISGID) 413 p->p_ucred->cr_gid = attr.va_gid; 414 } else 415 p->p_flag &= ~P_SUGID; 416 p->p_cred->p_svuid = p->p_ucred->cr_uid; 417 p->p_cred->p_svgid = p->p_ucred->cr_gid; 418 419 doexechooks(p); 420 421 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 422 423 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 424 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 425 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 426 vput(pack.ep_vp); 427 428 /* setup new registers and do misc. setup. */ 429 (*pack.ep_es->es_emul->e_setregs)(p, &pack, (u_long) stack); 430 if (pack.ep_es->es_setregs) 431 (*pack.ep_es->es_setregs)(p, &pack, (u_long) stack); 432 433 if (p->p_flag & P_TRACED) 434 psignal(p, SIGTRAP); 435 436 free(pack.ep_hdr, M_EXEC); 437 438 /* 439 * Call emulation specific exec hook. This can setup setup per-process 440 * p->p_emuldata or do any other per-process stuff an emulation needs. 441 * 442 * If we are executing process of different emulation than the 443 * original forked process, call e_proc_exit() of the old emulation 444 * first, then e_proc_exec() of new emulation. If the emulation is 445 * same, the exec hook code should deallocate any old emulation 446 * resources held previously by this process. 447 */ 448 if (p->p_emul && p->p_emul->e_proc_exit 449 && p->p_emul != pack.ep_es->es_emul) 450 (*p->p_emul->e_proc_exit)(p); 451 452 /* 453 * Call exec hook. Emulation code may NOT store reference to anything 454 * from &pack. 455 */ 456 if (pack.ep_es->es_emul->e_proc_exec) 457 (*pack.ep_es->es_emul->e_proc_exec)(p, &pack); 458 459 /* update p_emul, the old value is no longer needed */ 460 p->p_emul = pack.ep_es->es_emul; 461 462 #ifdef KTRACE 463 if (KTRPOINT(p, KTR_EMUL)) 464 ktremul(p); 465 #endif 466 467 #if defined(LKM) || defined(_LKM) 468 lockmgr(&exec_lock, LK_RELEASE, NULL); 469 #endif 470 471 return (EJUSTRETURN); 472 473 bad: 474 /* free the vmspace-creation commands, and release their references */ 475 kill_vmcmds(&pack.ep_vmcmds); 476 /* kill any opened file descriptor, if necessary */ 477 if (pack.ep_flags & EXEC_HASFD) { 478 pack.ep_flags &= ~EXEC_HASFD; 479 (void) fdrelease(p, pack.ep_fd); 480 } 481 /* close and put the exec'd file */ 482 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 483 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 484 vput(pack.ep_vp); 485 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 486 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 487 488 freehdr: 489 #if defined(LKM) || defined(_LKM) 490 lockmgr(&exec_lock, LK_RELEASE, NULL); 491 #endif 492 493 free(pack.ep_hdr, M_EXEC); 494 return error; 495 496 exec_abort: 497 #if defined(LKM) || defined(_LKM) 498 lockmgr(&exec_lock, LK_RELEASE, NULL); 499 #endif 500 501 /* 502 * the old process doesn't exist anymore. exit gracefully. 503 * get rid of the (new) address space we have created, if any, get rid 504 * of our namei data and vnode, and exit noting failure 505 */ 506 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 507 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 508 if (pack.ep_emul_arg) 509 FREE(pack.ep_emul_arg, M_TEMP); 510 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 511 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 512 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 513 vput(pack.ep_vp); 514 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 515 free(pack.ep_hdr, M_EXEC); 516 exit1(p, W_EXITCODE(error, SIGABRT)); 517 518 /* NOTREACHED */ 519 return 0; 520 } 521