netbsd32_execve.c revision 1.21
1/* $NetBSD: netbsd32_execve.c,v 1.21 2005/05/19 20:16:19 elad 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 1.21 2005/05/19 20:16:19 elad 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/sa.h> 53#include <sys/syscallargs.h> 54#include <sys/proc.h> 55#include <sys/acct.h> 56#include <sys/exec.h> 57 58#include <compat/netbsd32/netbsd32.h> 59#include <compat/netbsd32/netbsd32_syscall.h> 60#include <compat/netbsd32/netbsd32_syscallargs.h> 61 62#include <sys/verified_exec.h> 63 64/* this is provided by kern/kern_exec.c */ 65extern u_int exec_maxhdrsz; 66#if defined(LKM) || defined(_LKM) 67extern struct lock exec_lock; 68#endif 69 70/* 71 * Need to completly reimplement this syscall due to argument copying. 72 */ 73/* ARGSUSED */ 74int 75netbsd32_execve(l, v, retval) 76 struct lwp *l; 77 void *v; 78 register_t *retval; 79{ 80 struct netbsd32_execve_args /* { 81 syscallarg(const netbsd32_charp) path; 82 syscallarg(netbsd32_charpp) argp; 83 syscallarg(netbsd32_charpp) envp; 84 } */ *uap = v; 85 struct sys_execve_args ua; 86 caddr_t sg; 87 struct proc *p = l->l_proc; 88 89 NETBSD32TOP_UAP(path, const char); 90 NETBSD32TOP_UAP(argp, char *); 91 NETBSD32TOP_UAP(envp, char *); 92 sg = stackgap_init(p, 0); 93 CHECK_ALT_EXIST(p, &sg, SCARG(&ua, path)); 94 95 return netbsd32_execve2(l, &ua, retval); 96} 97 98int 99netbsd32_execve2(l, uap, retval) 100 struct lwp *l; 101 struct sys_execve_args *uap; 102 register_t *retval; 103{ 104 /* Function args */ 105 struct proc *p = l->l_proc; 106 int error, i; 107 struct exec_package pack; 108 struct nameidata nid; 109 struct vattr attr; 110 struct ucred *cred = p->p_ucred; 111 char *argp; 112 netbsd32_charp const *cpp; 113 char *dp; 114 netbsd32_charp sp; 115 long argc, envc; 116 size_t len; 117 char *stack; 118 struct ps_strings arginfo; 119 struct vmspace *vm; 120 char **tmpfap; 121 int szsigcode; 122 struct exec_vmcmd *base_vcp = NULL; 123 124 /* 125 * Init the namei data to point the file user's program name. 126 * This is done here rather than in check_exec(), so that it's 127 * possible to override this settings if any of makecmd/probe 128 * functions call check_exec() recursively - for example, 129 * see exec_script_makecmds(). 130 */ 131 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 132 133 /* 134 * initialize the fields of the exec package. 135 */ 136 pack.ep_name = SCARG(uap, path); 137 pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK); 138 pack.ep_hdrlen = exec_maxhdrsz; 139 pack.ep_hdrvalid = 0; 140 pack.ep_ndp = &nid; 141 pack.ep_emul_arg = NULL; 142 pack.ep_vmcmds.evs_cnt = 0; 143 pack.ep_vmcmds.evs_used = 0; 144 pack.ep_vap = &attr; 145 pack.ep_flags = 0; 146 147#if defined(LKM) || defined(_LKM) 148 lockmgr(&exec_lock, LK_SHARED, NULL); 149#endif 150 151 /* see if we can run it. */ 152#ifdef VERIFIED_EXEC 153 if ((error = check_exec(p, &pack, VERIEXEC_DIRECT)) != 0) 154#else 155 if ((error = check_exec(p, &pack)) != 0) 156#endif 157 goto freehdr; 158 159 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 160 161 /* allocate an argument buffer */ 162 argp = (char *) uvm_km_alloc(exec_map, NCARGS, 0, 163 UVM_KMF_PAGEABLE|UVM_KMF_WAITVA); 164#ifdef DIAGNOSTIC 165 if (argp == (vaddr_t) 0) 166 panic("netbsd32_execve: argp == NULL"); 167#endif 168 dp = argp; 169 argc = 0; 170 171 /* copy the fake args list, if there's one, freeing it as we go */ 172 if (pack.ep_flags & EXEC_HASARGL) { 173 tmpfap = pack.ep_fa; 174 while (*tmpfap != NULL) { 175 char *cp; 176 177 cp = *tmpfap; 178 while (*cp) 179 *dp++ = *cp++; 180 dp++; 181 182 FREE(*tmpfap, M_EXEC); 183 tmpfap++; argc++; 184 } 185 FREE(pack.ep_fa, M_EXEC); 186 pack.ep_flags &= ~EXEC_HASARGL; 187 } 188 189 /* Now get argv & environment */ 190 if (!(cpp = (netbsd32_charp *)SCARG(uap, argp))) { 191 error = EINVAL; 192 goto bad; 193 } 194 195 if (pack.ep_flags & EXEC_SKIPARG) 196 cpp++; 197 198 while (1) { 199 len = argp + ARG_MAX - dp; 200 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 201 goto bad; 202 if (!sp) 203 break; 204 if ((error = copyinstr((char *)(u_long)sp, dp, 205 len, &len)) != 0) { 206 if (error == ENAMETOOLONG) 207 error = E2BIG; 208 goto bad; 209 } 210 dp += len; 211 cpp++; 212 argc++; 213 } 214 215 envc = 0; 216 /* environment need not be there */ 217 if ((cpp = (netbsd32_charp *)SCARG(uap, envp)) != NULL ) { 218 while (1) { 219 len = argp + ARG_MAX - dp; 220 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 221 goto bad; 222 if (!sp) 223 break; 224 if ((error = copyinstr((char *)(u_long)sp, 225 dp, len, &len)) != 0) { 226 if (error == ENAMETOOLONG) 227 error = E2BIG; 228 goto bad; 229 } 230 dp += len; 231 cpp++; 232 envc++; 233 } 234 } 235 236 dp = (char *) ALIGN(dp); 237 238 szsigcode = pack.ep_es->es_emul->e_esigcode - 239 pack.ep_es->es_emul->e_sigcode; 240 241 /* Now check if args & environ fit into new stack */ 242 if (pack.ep_flags & EXEC_32) 243 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 244 sizeof(int) + sizeof(int) + dp + STACKGAPLEN + 245 szsigcode + sizeof(struct ps_strings)) - argp; 246 else 247 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 248 sizeof(char *) + sizeof(int) + dp + STACKGAPLEN + 249 szsigcode + sizeof(struct ps_strings)) - argp; 250 251 len = ALIGN(len); /* make the stack "safely" aligned */ 252 253 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 254 error = ENOMEM; 255 goto bad; 256 } 257 258 /* adjust "active stack depth" for process VSZ */ 259 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 260 261 /* 262 * Do whatever is necessary to prepare the address space 263 * for remapping. Note that this might replace the current 264 * vmspace with another! 265 */ 266 uvmspace_exec(l, VM_MIN_ADDRESS, (vaddr_t)pack.ep_minsaddr); 267 268 /* Now map address space */ 269 vm = p->p_vmspace; 270 vm->vm_taddr = (char *) pack.ep_taddr; 271 vm->vm_tsize = btoc(pack.ep_tsize); 272 vm->vm_daddr = (char *) pack.ep_daddr; 273 vm->vm_dsize = btoc(pack.ep_dsize); 274 vm->vm_ssize = btoc(pack.ep_ssize); 275 vm->vm_maxsaddr = (char *) pack.ep_maxsaddr; 276 vm->vm_minsaddr = (char *) pack.ep_minsaddr; 277 278 /* create the new process's VM space by running the vmcmds */ 279#ifdef DIAGNOSTIC 280 if (pack.ep_vmcmds.evs_used == 0) 281 panic("netbsd32_execve: no vmcmds"); 282#endif 283 for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) { 284 struct exec_vmcmd *vcp; 285 286 vcp = &pack.ep_vmcmds.evs_cmds[i]; 287 if (vcp->ev_flags & VMCMD_RELATIVE) { 288#ifdef DIAGNOSTIC 289 if (base_vcp == NULL) 290 panic("netbsd32_execve: relative vmcmd with no base"); 291 if (vcp->ev_flags & VMCMD_BASE) 292 panic("netbsd32_execve: illegal base & relative vmcmd"); 293#endif 294 vcp->ev_addr += base_vcp->ev_addr; 295 } 296 error = (*vcp->ev_proc)(p, vcp); 297#ifdef DEBUG 298 if (error) { 299 int j; 300 301 for (j = 0; j <= i; j++) 302 printf("vmcmd[%d] = %#lx/%#lx @ %#lx\n", j, 303 vcp[j-i].ev_addr, vcp[j-i].ev_len, 304 vcp[j-i].ev_offset); 305 } 306#endif 307 if (vcp->ev_flags & VMCMD_BASE) 308 base_vcp = vcp; 309 } 310 311 /* free the vmspace-creation commands, and release their references */ 312 kill_vmcmds(&pack.ep_vmcmds); 313 314 /* if an error happened, deallocate and punt */ 315 if (error) { 316#ifdef DEBUG 317 printf("netbsd32_execve: vmcmd %i failed: %d\n", i-1, error); 318#endif 319 goto exec_abort; 320 } 321 322 /* remember information about the process */ 323 arginfo.ps_nargvstr = argc; 324 arginfo.ps_nenvstr = envc; 325 326 stack = (char *) (vm->vm_minsaddr - len); 327 /* Now copy argc, args & environ to new stack */ 328 error = (*pack.ep_es->es_copyargs)(p, &pack, &arginfo, 329 &stack, argp); 330 if (error) { 331#ifdef DEBUG 332 printf("netbsd32_execve: copyargs failed\n"); 333#endif 334 goto exec_abort; 335 } 336 /* restore the stack back to its original point */ 337 stack = (char *) (vm->vm_minsaddr - len); 338 339 /* fill process ps_strings info */ 340 p->p_psstr = (struct ps_strings *)(vm->vm_minsaddr - 341 sizeof(struct ps_strings)); 342 p->p_psargv = offsetof(struct ps_strings, ps_argvstr); 343 p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr); 344 p->p_psenv = offsetof(struct ps_strings, ps_envstr); 345 p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr); 346 347 /* copy out the process's ps_strings structure */ 348 if (copyout(&arginfo, (char *)p->p_psstr, sizeof(arginfo))) { 349#ifdef DEBUG 350 printf("netbsd32_execve: ps_strings copyout failed\n"); 351#endif 352 goto exec_abort; 353 } 354 355 /* copy out the process's signal trapoline code */ 356 if (szsigcode) { 357 if (copyout((char *)pack.ep_es->es_emul->e_sigcode, 358 p->p_sigctx.ps_sigcode = (char *)p->p_psstr - szsigcode, 359 szsigcode)) { 360#ifdef DEBUG 361 printf("netbsd32_execve: sig trampoline copyout failed\n"); 362#endif 363 goto exec_abort; 364 } 365#ifdef PMAP_NEED_PROCWR 366 /* This is code. Let the pmap do what is needed. */ 367 pmap_procwr(p, (vaddr_t)p->p_sigctx.ps_sigcode, szsigcode); 368#endif 369 } 370 371 stopprofclock(p); /* stop profiling */ 372 fdcloseexec(p); /* handle close on exec */ 373 execsigs(p); /* reset catched signals */ 374 l->l_ctxlink = NULL; /* reset ucontext link */ 375 376 /* set command name & other accounting info */ 377 len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN); 378 memcpy(p->p_comm, nid.ni_cnd.cn_nameptr, len); 379 p->p_comm[len] = 0; 380 p->p_acflag &= ~AFORK; 381 382 /* record proc's vnode, for use by procfs and others */ 383 if (p->p_textvp) 384 vrele(p->p_textvp); 385 VREF(pack.ep_vp); 386 p->p_textvp = pack.ep_vp; 387 388 p->p_flag |= P_EXEC; 389 if (p->p_flag & P_PPWAIT) { 390 p->p_flag &= ~P_PPWAIT; 391 wakeup((caddr_t) p->p_pptr); 392 } 393 394 /* 395 * deal with set[ug]id. 396 * MNT_NOSUID has already been used to disable s[ug]id. 397 */ 398 if ((p->p_flag & P_TRACED) == 0 && 399 400 (((attr.va_mode & S_ISUID) != 0 && 401 p->p_ucred->cr_uid != attr.va_uid) || 402 403 ((attr.va_mode & S_ISGID) != 0 && 404 p->p_ucred->cr_gid != attr.va_gid))) { 405 /* 406 * Mark the process as SUGID before we do 407 * anything that might block. 408 */ 409 p_sugid(p); 410 411 p->p_ucred = crcopy(cred); 412#ifdef KTRACE 413 /* 414 * If process is being ktraced, turn off - unless 415 * root set it. 416 */ 417 if (p->p_tracep && !(p->p_traceflag & KTRFAC_ROOT)) 418 ktrderef(p); 419#endif 420 if (attr.va_mode & S_ISUID) 421 p->p_ucred->cr_uid = attr.va_uid; 422 if (attr.va_mode & S_ISGID) 423 p->p_ucred->cr_gid = attr.va_gid; 424 } else 425 p->p_flag &= ~P_SUGID; 426 p->p_cred->p_svuid = p->p_ucred->cr_uid; 427 p->p_cred->p_svgid = p->p_ucred->cr_gid; 428 429 doexechooks(p); 430 431 uvm_km_free(exec_map, (vaddr_t) argp, NCARGS, UVM_KMF_PAGEABLE); 432 433 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 434 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 435 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 436 vput(pack.ep_vp); 437 438 /* setup new registers and do misc. setup. */ 439 (*pack.ep_es->es_emul->e_setregs)(l, &pack, (u_long) stack); 440 if (pack.ep_es->es_setregs) 441 (*pack.ep_es->es_setregs)(l, &pack, (u_long) stack); 442 443 if (p->p_flag & P_TRACED) 444 psignal(p, SIGTRAP); 445 446 free(pack.ep_hdr, M_EXEC); 447 448 /* 449 * Call emulation specific exec hook. This can setup setup per-process 450 * p->p_emuldata or do any other per-process stuff an emulation needs. 451 * 452 * If we are executing process of different emulation than the 453 * original forked process, call e_proc_exit() of the old emulation 454 * first, then e_proc_exec() of new emulation. If the emulation is 455 * same, the exec hook code should deallocate any old emulation 456 * resources held previously by this process. 457 */ 458 if (p->p_emul && p->p_emul->e_proc_exit 459 && p->p_emul != pack.ep_es->es_emul) 460 (*p->p_emul->e_proc_exit)(p); 461 462 /* 463 * Call exec hook. Emulation code may NOT store reference to anything 464 * from &pack. 465 */ 466 if (pack.ep_es->es_emul->e_proc_exec) 467 (*pack.ep_es->es_emul->e_proc_exec)(p, &pack); 468 469 /* update p_emul, the old value is no longer needed */ 470 p->p_emul = pack.ep_es->es_emul; 471 472 /* ...and the same for p_execsw */ 473 p->p_execsw = pack.ep_es; 474 475#ifdef __HAVE_SYSCALL_INTERN 476 (*p->p_emul->e_syscall_intern)(p); 477#endif 478#ifdef KTRACE 479 if (KTRPOINT(p, KTR_EMUL)) 480 ktremul(p); 481#endif 482 483#if defined(LKM) || defined(_LKM) 484 lockmgr(&exec_lock, LK_RELEASE, NULL); 485#endif 486 487 return (EJUSTRETURN); 488 489bad: 490 /* free the vmspace-creation commands, and release their references */ 491 kill_vmcmds(&pack.ep_vmcmds); 492 /* kill any opened file descriptor, if necessary */ 493 if (pack.ep_flags & EXEC_HASFD) { 494 pack.ep_flags &= ~EXEC_HASFD; 495 (void) fdrelease(p, pack.ep_fd); 496 } 497 /* close and put the exec'd file */ 498 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 499 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 500 vput(pack.ep_vp); 501 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 502 uvm_km_free(exec_map, (vaddr_t) argp, NCARGS, UVM_KMF_PAGEABLE); 503 504freehdr: 505#if defined(LKM) || defined(_LKM) 506 lockmgr(&exec_lock, LK_RELEASE, NULL); 507#endif 508 509 free(pack.ep_hdr, M_EXEC); 510 return error; 511 512exec_abort: 513#if defined(LKM) || defined(_LKM) 514 lockmgr(&exec_lock, LK_RELEASE, NULL); 515#endif 516 517 /* 518 * the old process doesn't exist anymore. exit gracefully. 519 * get rid of the (new) address space we have created, if any, get rid 520 * of our namei data and vnode, and exit noting failure 521 */ 522 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 523 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 524 if (pack.ep_emul_arg) 525 FREE(pack.ep_emul_arg, M_TEMP); 526 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 527 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 528 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 529 vput(pack.ep_vp); 530 uvm_km_free(exec_map, (vaddr_t) argp, NCARGS, UVM_KMF_PAGEABLE); 531 free(pack.ep_hdr, M_EXEC); 532 exit1(l, W_EXITCODE(error, SIGABRT)); 533 534 /* NOTREACHED */ 535 return 0; 536} 537