netbsd32_execve.c revision 1.20
1/* $NetBSD: netbsd32_execve.c,v 1.20 2005/04/01 11:59:36 yamt 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 1.20 2005/04/01 11:59:36 yamt 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/* this is provided by kern/kern_exec.c */ 63extern u_int exec_maxhdrsz; 64#if defined(LKM) || defined(_LKM) 65extern struct lock exec_lock; 66#endif 67 68/* 69 * Need to completly reimplement this syscall due to argument copying. 70 */ 71/* ARGSUSED */ 72int 73netbsd32_execve(l, v, retval) 74 struct lwp *l; 75 void *v; 76 register_t *retval; 77{ 78 struct netbsd32_execve_args /* { 79 syscallarg(const netbsd32_charp) path; 80 syscallarg(netbsd32_charpp) argp; 81 syscallarg(netbsd32_charpp) envp; 82 } */ *uap = v; 83 struct sys_execve_args ua; 84 caddr_t sg; 85 struct proc *p = l->l_proc; 86 87 NETBSD32TOP_UAP(path, const char); 88 NETBSD32TOP_UAP(argp, char *); 89 NETBSD32TOP_UAP(envp, char *); 90 sg = stackgap_init(p, 0); 91 CHECK_ALT_EXIST(p, &sg, SCARG(&ua, path)); 92 93 return netbsd32_execve2(l, &ua, retval); 94} 95 96int 97netbsd32_execve2(l, uap, retval) 98 struct lwp *l; 99 struct sys_execve_args *uap; 100 register_t *retval; 101{ 102 /* Function args */ 103 struct proc *p = l->l_proc; 104 int error, i; 105 struct exec_package pack; 106 struct nameidata nid; 107 struct vattr attr; 108 struct ucred *cred = p->p_ucred; 109 char *argp; 110 netbsd32_charp const *cpp; 111 char *dp; 112 netbsd32_charp sp; 113 long argc, envc; 114 size_t len; 115 char *stack; 116 struct ps_strings arginfo; 117 struct vmspace *vm; 118 char **tmpfap; 119 int szsigcode; 120 struct exec_vmcmd *base_vcp = NULL; 121 122 /* 123 * Init the namei data to point the file user's program name. 124 * This is done here rather than in check_exec(), so that it's 125 * possible to override this settings if any of makecmd/probe 126 * functions call check_exec() recursively - for example, 127 * see exec_script_makecmds(). 128 */ 129 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 130 131 /* 132 * initialize the fields of the exec package. 133 */ 134 pack.ep_name = SCARG(uap, path); 135 pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK); 136 pack.ep_hdrlen = exec_maxhdrsz; 137 pack.ep_hdrvalid = 0; 138 pack.ep_ndp = &nid; 139 pack.ep_emul_arg = NULL; 140 pack.ep_vmcmds.evs_cnt = 0; 141 pack.ep_vmcmds.evs_used = 0; 142 pack.ep_vap = &attr; 143 pack.ep_flags = 0; 144 145#if defined(LKM) || defined(_LKM) 146 lockmgr(&exec_lock, LK_SHARED, NULL); 147#endif 148 149 /* see if we can run it. */ 150 if ((error = check_exec(p, &pack)) != 0) 151 goto freehdr; 152 153 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 154 155 /* allocate an argument buffer */ 156 argp = (char *) uvm_km_alloc(exec_map, NCARGS, 0, 157 UVM_KMF_PAGEABLE|UVM_KMF_WAITVA); 158#ifdef DIAGNOSTIC 159 if (argp == (vaddr_t) 0) 160 panic("netbsd32_execve: argp == NULL"); 161#endif 162 dp = argp; 163 argc = 0; 164 165 /* copy the fake args list, if there's one, freeing it as we go */ 166 if (pack.ep_flags & EXEC_HASARGL) { 167 tmpfap = pack.ep_fa; 168 while (*tmpfap != NULL) { 169 char *cp; 170 171 cp = *tmpfap; 172 while (*cp) 173 *dp++ = *cp++; 174 dp++; 175 176 FREE(*tmpfap, M_EXEC); 177 tmpfap++; argc++; 178 } 179 FREE(pack.ep_fa, M_EXEC); 180 pack.ep_flags &= ~EXEC_HASARGL; 181 } 182 183 /* Now get argv & environment */ 184 if (!(cpp = (netbsd32_charp *)SCARG(uap, argp))) { 185 error = EINVAL; 186 goto bad; 187 } 188 189 if (pack.ep_flags & EXEC_SKIPARG) 190 cpp++; 191 192 while (1) { 193 len = argp + ARG_MAX - dp; 194 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 195 goto bad; 196 if (!sp) 197 break; 198 if ((error = copyinstr((char *)(u_long)sp, dp, 199 len, &len)) != 0) { 200 if (error == ENAMETOOLONG) 201 error = E2BIG; 202 goto bad; 203 } 204 dp += len; 205 cpp++; 206 argc++; 207 } 208 209 envc = 0; 210 /* environment need not be there */ 211 if ((cpp = (netbsd32_charp *)SCARG(uap, envp)) != NULL ) { 212 while (1) { 213 len = argp + ARG_MAX - dp; 214 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 215 goto bad; 216 if (!sp) 217 break; 218 if ((error = copyinstr((char *)(u_long)sp, 219 dp, len, &len)) != 0) { 220 if (error == ENAMETOOLONG) 221 error = E2BIG; 222 goto bad; 223 } 224 dp += len; 225 cpp++; 226 envc++; 227 } 228 } 229 230 dp = (char *) ALIGN(dp); 231 232 szsigcode = pack.ep_es->es_emul->e_esigcode - 233 pack.ep_es->es_emul->e_sigcode; 234 235 /* Now check if args & environ fit into new stack */ 236 if (pack.ep_flags & EXEC_32) 237 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 238 sizeof(int) + sizeof(int) + dp + STACKGAPLEN + 239 szsigcode + sizeof(struct ps_strings)) - argp; 240 else 241 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 242 sizeof(char *) + sizeof(int) + dp + STACKGAPLEN + 243 szsigcode + sizeof(struct ps_strings)) - argp; 244 245 len = ALIGN(len); /* make the stack "safely" aligned */ 246 247 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 248 error = ENOMEM; 249 goto bad; 250 } 251 252 /* adjust "active stack depth" for process VSZ */ 253 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 254 255 /* 256 * Do whatever is necessary to prepare the address space 257 * for remapping. Note that this might replace the current 258 * vmspace with another! 259 */ 260 uvmspace_exec(l, VM_MIN_ADDRESS, (vaddr_t)pack.ep_minsaddr); 261 262 /* Now map address space */ 263 vm = p->p_vmspace; 264 vm->vm_taddr = (char *) pack.ep_taddr; 265 vm->vm_tsize = btoc(pack.ep_tsize); 266 vm->vm_daddr = (char *) pack.ep_daddr; 267 vm->vm_dsize = btoc(pack.ep_dsize); 268 vm->vm_ssize = btoc(pack.ep_ssize); 269 vm->vm_maxsaddr = (char *) pack.ep_maxsaddr; 270 vm->vm_minsaddr = (char *) pack.ep_minsaddr; 271 272 /* create the new process's VM space by running the vmcmds */ 273#ifdef DIAGNOSTIC 274 if (pack.ep_vmcmds.evs_used == 0) 275 panic("netbsd32_execve: no vmcmds"); 276#endif 277 for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) { 278 struct exec_vmcmd *vcp; 279 280 vcp = &pack.ep_vmcmds.evs_cmds[i]; 281 if (vcp->ev_flags & VMCMD_RELATIVE) { 282#ifdef DIAGNOSTIC 283 if (base_vcp == NULL) 284 panic("netbsd32_execve: relative vmcmd with no base"); 285 if (vcp->ev_flags & VMCMD_BASE) 286 panic("netbsd32_execve: illegal base & relative vmcmd"); 287#endif 288 vcp->ev_addr += base_vcp->ev_addr; 289 } 290 error = (*vcp->ev_proc)(p, vcp); 291#ifdef DEBUG 292 if (error) { 293 int j; 294 295 for (j = 0; j <= i; j++) 296 printf("vmcmd[%d] = %#lx/%#lx @ %#lx\n", j, 297 vcp[j-i].ev_addr, vcp[j-i].ev_len, 298 vcp[j-i].ev_offset); 299 } 300#endif 301 if (vcp->ev_flags & VMCMD_BASE) 302 base_vcp = vcp; 303 } 304 305 /* free the vmspace-creation commands, and release their references */ 306 kill_vmcmds(&pack.ep_vmcmds); 307 308 /* if an error happened, deallocate and punt */ 309 if (error) { 310#ifdef DEBUG 311 printf("netbsd32_execve: vmcmd %i failed: %d\n", i-1, error); 312#endif 313 goto exec_abort; 314 } 315 316 /* remember information about the process */ 317 arginfo.ps_nargvstr = argc; 318 arginfo.ps_nenvstr = envc; 319 320 stack = (char *) (vm->vm_minsaddr - len); 321 /* Now copy argc, args & environ to new stack */ 322 error = (*pack.ep_es->es_copyargs)(p, &pack, &arginfo, 323 &stack, argp); 324 if (error) { 325#ifdef DEBUG 326 printf("netbsd32_execve: copyargs failed\n"); 327#endif 328 goto exec_abort; 329 } 330 /* restore the stack back to its original point */ 331 stack = (char *) (vm->vm_minsaddr - len); 332 333 /* fill process ps_strings info */ 334 p->p_psstr = (struct ps_strings *)(vm->vm_minsaddr - 335 sizeof(struct ps_strings)); 336 p->p_psargv = offsetof(struct ps_strings, ps_argvstr); 337 p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr); 338 p->p_psenv = offsetof(struct ps_strings, ps_envstr); 339 p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr); 340 341 /* copy out the process's ps_strings structure */ 342 if (copyout(&arginfo, (char *)p->p_psstr, sizeof(arginfo))) { 343#ifdef DEBUG 344 printf("netbsd32_execve: ps_strings copyout failed\n"); 345#endif 346 goto exec_abort; 347 } 348 349 /* copy out the process's signal trapoline code */ 350 if (szsigcode) { 351 if (copyout((char *)pack.ep_es->es_emul->e_sigcode, 352 p->p_sigctx.ps_sigcode = (char *)p->p_psstr - szsigcode, 353 szsigcode)) { 354#ifdef DEBUG 355 printf("netbsd32_execve: sig trampoline copyout failed\n"); 356#endif 357 goto exec_abort; 358 } 359#ifdef PMAP_NEED_PROCWR 360 /* This is code. Let the pmap do what is needed. */ 361 pmap_procwr(p, (vaddr_t)p->p_sigctx.ps_sigcode, szsigcode); 362#endif 363 } 364 365 stopprofclock(p); /* stop profiling */ 366 fdcloseexec(p); /* handle close on exec */ 367 execsigs(p); /* reset catched signals */ 368 l->l_ctxlink = NULL; /* reset ucontext link */ 369 370 /* set command name & other accounting info */ 371 len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN); 372 memcpy(p->p_comm, nid.ni_cnd.cn_nameptr, len); 373 p->p_comm[len] = 0; 374 p->p_acflag &= ~AFORK; 375 376 /* record proc's vnode, for use by procfs and others */ 377 if (p->p_textvp) 378 vrele(p->p_textvp); 379 VREF(pack.ep_vp); 380 p->p_textvp = pack.ep_vp; 381 382 p->p_flag |= P_EXEC; 383 if (p->p_flag & P_PPWAIT) { 384 p->p_flag &= ~P_PPWAIT; 385 wakeup((caddr_t) p->p_pptr); 386 } 387 388 /* 389 * deal with set[ug]id. 390 * MNT_NOSUID has already been used to disable s[ug]id. 391 */ 392 if ((p->p_flag & P_TRACED) == 0 && 393 394 (((attr.va_mode & S_ISUID) != 0 && 395 p->p_ucred->cr_uid != attr.va_uid) || 396 397 ((attr.va_mode & S_ISGID) != 0 && 398 p->p_ucred->cr_gid != attr.va_gid))) { 399 /* 400 * Mark the process as SUGID before we do 401 * anything that might block. 402 */ 403 p_sugid(p); 404 405 p->p_ucred = crcopy(cred); 406#ifdef KTRACE 407 /* 408 * If process is being ktraced, turn off - unless 409 * root set it. 410 */ 411 if (p->p_tracep && !(p->p_traceflag & KTRFAC_ROOT)) 412 ktrderef(p); 413#endif 414 if (attr.va_mode & S_ISUID) 415 p->p_ucred->cr_uid = attr.va_uid; 416 if (attr.va_mode & S_ISGID) 417 p->p_ucred->cr_gid = attr.va_gid; 418 } else 419 p->p_flag &= ~P_SUGID; 420 p->p_cred->p_svuid = p->p_ucred->cr_uid; 421 p->p_cred->p_svgid = p->p_ucred->cr_gid; 422 423 doexechooks(p); 424 425 uvm_km_free(exec_map, (vaddr_t) argp, NCARGS, UVM_KMF_PAGEABLE); 426 427 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 428 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 429 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 430 vput(pack.ep_vp); 431 432 /* setup new registers and do misc. setup. */ 433 (*pack.ep_es->es_emul->e_setregs)(l, &pack, (u_long) stack); 434 if (pack.ep_es->es_setregs) 435 (*pack.ep_es->es_setregs)(l, &pack, (u_long) stack); 436 437 if (p->p_flag & P_TRACED) 438 psignal(p, SIGTRAP); 439 440 free(pack.ep_hdr, M_EXEC); 441 442 /* 443 * Call emulation specific exec hook. This can setup setup per-process 444 * p->p_emuldata or do any other per-process stuff an emulation needs. 445 * 446 * If we are executing process of different emulation than the 447 * original forked process, call e_proc_exit() of the old emulation 448 * first, then e_proc_exec() of new emulation. If the emulation is 449 * same, the exec hook code should deallocate any old emulation 450 * resources held previously by this process. 451 */ 452 if (p->p_emul && p->p_emul->e_proc_exit 453 && p->p_emul != pack.ep_es->es_emul) 454 (*p->p_emul->e_proc_exit)(p); 455 456 /* 457 * Call exec hook. Emulation code may NOT store reference to anything 458 * from &pack. 459 */ 460 if (pack.ep_es->es_emul->e_proc_exec) 461 (*pack.ep_es->es_emul->e_proc_exec)(p, &pack); 462 463 /* update p_emul, the old value is no longer needed */ 464 p->p_emul = pack.ep_es->es_emul; 465 466 /* ...and the same for p_execsw */ 467 p->p_execsw = pack.ep_es; 468 469#ifdef __HAVE_SYSCALL_INTERN 470 (*p->p_emul->e_syscall_intern)(p); 471#endif 472#ifdef KTRACE 473 if (KTRPOINT(p, KTR_EMUL)) 474 ktremul(p); 475#endif 476 477#if defined(LKM) || defined(_LKM) 478 lockmgr(&exec_lock, LK_RELEASE, NULL); 479#endif 480 481 return (EJUSTRETURN); 482 483bad: 484 /* free the vmspace-creation commands, and release their references */ 485 kill_vmcmds(&pack.ep_vmcmds); 486 /* kill any opened file descriptor, if necessary */ 487 if (pack.ep_flags & EXEC_HASFD) { 488 pack.ep_flags &= ~EXEC_HASFD; 489 (void) fdrelease(p, pack.ep_fd); 490 } 491 /* close and put the exec'd file */ 492 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 493 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 494 vput(pack.ep_vp); 495 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 496 uvm_km_free(exec_map, (vaddr_t) argp, NCARGS, UVM_KMF_PAGEABLE); 497 498freehdr: 499#if defined(LKM) || defined(_LKM) 500 lockmgr(&exec_lock, LK_RELEASE, NULL); 501#endif 502 503 free(pack.ep_hdr, M_EXEC); 504 return error; 505 506exec_abort: 507#if defined(LKM) || defined(_LKM) 508 lockmgr(&exec_lock, LK_RELEASE, NULL); 509#endif 510 511 /* 512 * the old process doesn't exist anymore. exit gracefully. 513 * get rid of the (new) address space we have created, if any, get rid 514 * of our namei data and vnode, and exit noting failure 515 */ 516 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 517 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 518 if (pack.ep_emul_arg) 519 FREE(pack.ep_emul_arg, M_TEMP); 520 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 521 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 522 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 523 vput(pack.ep_vp); 524 uvm_km_free(exec_map, (vaddr_t) argp, NCARGS, UVM_KMF_PAGEABLE); 525 free(pack.ep_hdr, M_EXEC); 526 exit1(l, W_EXITCODE(error, SIGABRT)); 527 528 /* NOTREACHED */ 529 return 0; 530} 531