bsd/kern/kern_ktrace.c

   1 /*
   2  * Copyright (c) 2000-2001 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  23 /*
  24  * Copyright (c) 1989, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions
  29  * are met:
  30  * 1. Redistributions of source code must retain the above copyright
  31  *    notice, this list of conditions and the following disclaimer.
  32  * 2. Redistributions in binary form must reproduce the above copyright
  33  *    notice, this list of conditions and the following disclaimer in the
  34  *    documentation and/or other materials provided with the distribution.
  35  * 3. All advertising materials mentioning features or use of this software
  36  *    must display the following acknowledgement:
  37  *      This product includes software developed by the University of
  38  *      California, Berkeley and its contributors.
  39  * 4. Neither the name of the University nor the names of its contributors
  40  *    may be used to endorse or promote products derived from this software
  41  *    without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  *
  55  *      @(#)kern_ktrace.c       8.2 (Berkeley) 9/23/93
  56  * $FreeBSD: src/sys/kern/kern_ktrace.c,v 1.35.2.4 2001/03/05 13:09:01 obrien Exp $
  57  */
  58
  59
  60 #include <sys/param.h>
  61 #include <sys/systm.h>
  62 #include <sys/types.h>
  63 #include <sys/proc.h>
  64 #include <sys/file.h>
  65 #include <sys/namei.h>
  66 #include <sys/vnode.h>
  67 #if KTRACE
  68 #include <sys/ktrace.h>
  69 #endif
  70 #include <sys/malloc.h>
  71 #include <sys/syslog.h>
  72
  73 #if KTRACE
  74 static struct ktr_header *ktrgetheader __P((int type));
  75 static void ktrwrite __P((struct vnode *, struct ktr_header *,
  76         struct uio *, int));
  77 static int ktrcanset __P((struct proc *,struct proc *));
  78 static int ktrsetchildren __P((struct proc *,struct proc *,
  79         int, int, struct vnode *));
  80 static int ktrops __P((struct proc *,struct proc *,int,int,struct vnode *));
  81
  82
  83 static struct ktr_header *
  84 ktrgetheader(type)
  85         int type;
  86 {
  87         register struct ktr_header *kth;
  88         struct proc *p = current_proc();        /* XXX */
  89
  90         MALLOC(kth, struct ktr_header *, sizeof (struct ktr_header),
  91                 M_KTRACE, M_WAITOK);
  92         kth->ktr_type = type;
  93         microtime(&kth->ktr_time);
  94         kth->ktr_pid = p->p_pid;
  95         bcopy(p->p_comm, kth->ktr_comm, MAXCOMLEN);
  96         return (kth);
  97 }
  98 #endif
  99
 100 void
 101 ktrsyscall(p, code, narg, args, funnel_type)
 102         struct proc *p;
 103         int code, narg;
 104         register_t args[];
 105         int funnel_type;
 106 {
 107 #if KTRACE
 108         struct vnode *vp;
 109         struct  ktr_header *kth;
 110         struct  ktr_syscall *ktp;
 111         register int len;
 112         register_t *argp;
 113         int i;
 114
 115         if (!KTRPOINT(p, KTR_SYSCALL))
 116                 return;
 117
 118         vp = p->p_tracep;
 119         len = __offsetof(struct ktr_syscall, ktr_args) +
 120             (narg * sizeof(register_t));
 121         p->p_traceflag |= KTRFAC_ACTIVE;
 122         kth = ktrgetheader(KTR_SYSCALL);
 123         MALLOC(ktp, struct ktr_syscall *, len, M_KTRACE, M_WAITOK);
 124         ktp->ktr_code = code;
 125         ktp->ktr_narg = narg;
 126         argp = &ktp->ktr_args[0];
 127         for (i = 0; i < narg; i++)
 128                 *argp++ = args[i];
 129         kth->ktr_buf = (caddr_t)ktp;
 130         kth->ktr_len = len;
 131         ktrwrite(vp, kth, NULL, funnel_type);
 132         FREE(ktp, M_KTRACE);
 133         FREE(kth, M_KTRACE);
 134         p->p_traceflag &= ~KTRFAC_ACTIVE;
 135 #else
 136         return;
 137 #endif
 138 }
 139
 140 void
 141 ktrsysret(p, code, error, retval, funnel_type)
 142         struct proc *p;
 143         int code, error;
 144         register_t retval;
 145         int funnel_type;
 146 {
 147 #if KTRACE
 148         struct vnode *vp;
 149         struct ktr_header *kth;
 150         struct ktr_sysret ktp;
 151
 152         if (!KTRPOINT(p, KTR_SYSRET))
 153                 return;
 154
 155         vp = p->p_tracep;
 156         p->p_traceflag |= KTRFAC_ACTIVE;
 157         kth = ktrgetheader(KTR_SYSRET);
 158         ktp.ktr_code = code;
 159         ktp.ktr_error = error;
 160         ktp.ktr_retval = retval;                /* what about val2 ? */
 161
 162         kth->ktr_buf = (caddr_t)&ktp;
 163         kth->ktr_len = sizeof(struct ktr_sysret);
 164
 165         ktrwrite(vp, kth, NULL, funnel_type);
 166         FREE(kth, M_KTRACE);
 167         p->p_traceflag &= ~KTRFAC_ACTIVE;
 168 #else
 169         return;
 170 #endif
 171 }
 172
 173 #if KTRACE
 174 void
 175 ktrnamei(vp, path)
 176         struct vnode *vp;
 177         char *path;
 178 {
 179         struct ktr_header *kth;
 180         struct proc *p = current_proc();        /* XXX */
 181
 182         p->p_traceflag |= KTRFAC_ACTIVE;
 183         kth = ktrgetheader(KTR_NAMEI);
 184         kth->ktr_len = strlen(path);
 185         kth->ktr_buf = path;
 186
 187         ktrwrite(vp, kth, NULL, KERNEL_FUNNEL);
 188         FREE(kth, M_KTRACE);
 189         p->p_traceflag &= ~KTRFAC_ACTIVE;
 190 }
 191
 192 void
 193 ktrgenio(vp, fd, rw, uio, error, funnel_type)
 194         struct vnode *vp;
 195         int fd;
 196         enum uio_rw rw;
 197         struct uio *uio;
 198         int error;
 199         int funnel_type;
 200 {
 201         struct ktr_header *kth;
 202         struct ktr_genio ktg;
 203         struct proc *p = current_proc();        /* XXX */
 204
 205         if (error)
 206                 return;
 207
 208         p->p_traceflag |= KTRFAC_ACTIVE;
 209         kth = ktrgetheader(KTR_GENIO);
 210         ktg.ktr_fd = fd;
 211         ktg.ktr_rw = rw;
 212         kth->ktr_buf = (caddr_t)&ktg;
 213         kth->ktr_len = sizeof(struct ktr_genio);
 214         uio->uio_offset = 0;
 215         uio->uio_rw = UIO_WRITE;
 216
 217         ktrwrite(vp, kth, uio, funnel_type);
 218         FREE(kth, M_KTRACE);
 219         p->p_traceflag &= ~KTRFAC_ACTIVE;
 220 }
 221
 222 void
 223 ktrpsig(vp, sig, action, mask, code, funnel_type)
 224         struct vnode *vp;
 225         int sig;
 226         sig_t action;
 227         sigset_t *mask;
 228         int code;
 229         int funnel_type;
 230 {
 231         struct ktr_header *kth;
 232         struct ktr_psig kp;
 233         struct proc *p = current_proc();        /* XXX */
 234
 235         p->p_traceflag |= KTRFAC_ACTIVE;
 236         kth = ktrgetheader(KTR_PSIG);
 237         kp.signo = (char)sig;
 238         kp.action = action;
 239         kp.mask = *mask;
 240         kp.code = code;
 241         kth->ktr_buf = (caddr_t)&kp;
 242         kth->ktr_len = sizeof (struct ktr_psig);
 243
 244         ktrwrite(vp, kth, NULL, funnel_type);
 245         FREE(kth, M_KTRACE);
 246         p->p_traceflag &= ~KTRFAC_ACTIVE;
 247 }
 248
 249 void
 250 ktrcsw(vp, out, user, funnel_type)
 251         struct vnode *vp;
 252         int out, user;
 253         int funnel_type;
 254 {
 255         struct ktr_header *kth;
 256         struct  ktr_csw kc;
 257         struct proc *p = current_proc();        /* XXX */
 258
 259         p->p_traceflag |= KTRFAC_ACTIVE;
 260         kth = ktrgetheader(KTR_CSW);
 261         kc.out = out;
 262         kc.user = user;
 263         kth->ktr_buf = (caddr_t)&kc;
 264         kth->ktr_len = sizeof (struct ktr_csw);
 265
 266         ktrwrite(vp, kth, NULL, funnel_type);
 267         FREE(kth, M_KTRACE);
 268         p->p_traceflag &= ~KTRFAC_ACTIVE;
 269 }
 270 #endif /* KTRACE */
 271
 272 /* Interface and common routines */
 273
 274 /*
 275  * ktrace system call
 276  */
 277 struct ktrace_args {
 278         char    *fname;
 279         int     ops;
 280         int     facs;
 281         int     pid;
 282 };
 283 /* ARGSUSED */
 284 int
 285 ktrace(curp, uap, retval)
 286         struct proc *curp;
 287         register struct ktrace_args *uap;
 288         register_t *retval;
 289 {
 290 #if KTRACE
 291         register struct vnode *vp = NULL;
 292         register struct proc *p;
 293         struct pgrp *pg;
 294         int facs = uap->facs & ~KTRFAC_ROOT;
 295         int ops = KTROP(uap->ops);
 296         int descend = uap->ops & KTRFLAG_DESCEND;
 297         int ret = 0;
 298         int error = 0;
 299         struct nameidata nd;
 300
 301         curp->p_traceflag |= KTRFAC_ACTIVE;
 302         if (ops != KTROP_CLEAR) {
 303                 /*
 304                  * an operation which requires a file argument.
 305                  */
 306                 NDINIT(&nd, LOOKUP, (NOFOLLOW|LOCKLEAF), UIO_USERSPACE, uap->fname, curp);
 307                 error = vn_open(&nd, FREAD|FWRITE|O_NOFOLLOW, 0);
 308                 if (error) {
 309                         curp->p_traceflag &= ~KTRFAC_ACTIVE;
 310                         return (error);
 311                 }
 312                 vp = nd.ni_vp;
 313                 VOP_UNLOCK(vp, 0, curp);
 314                 if (vp->v_type != VREG) {
 315                         (void) vn_close(vp, FREAD|FWRITE, curp->p_ucred, curp);
 316                         curp->p_traceflag &= ~KTRFAC_ACTIVE;
 317                         return (EACCES);
 318                 }
 319         }
 320         /*
 321          * Clear all uses of the tracefile
 322          */
 323         if (ops == KTROP_CLEARFILE) {
 324                 LIST_FOREACH(p, &allproc, p_list) {
 325                         if (p->p_tracep == vp) {
 326                                 if (ktrcanset(curp, p)) {
 327                                         struct vnode *tvp = p->p_tracep;
 328                                         /* no more tracing */
 329                                         p->p_traceflag = 0;
 330                                         if (tvp != NULL) {
 331                                                 p->p_tracep = NULL;
 332                                                 vrele(tvp);
 333                                         }
 334                                 } else
 335                                         error = EPERM;
 336                         }
 337                 }
 338                 goto done;
 339         }
 340
 341         /*
 342          * need something to (un)trace (XXX - why is this here?)
 343          */
 344         if (!facs) {
 345                 error = EINVAL;
 346                 goto done;
 347         }
 348         /*
 349          * do it
 350          */
 351         if (uap->pid < 0) {
 352                 /*
 353                  * by process group
 354                  */
 355                 pg = pgfind(-uap->pid);
 356                 if (pg == NULL) {
 357                         error = ESRCH;
 358                         goto done;
 359                 }
 360                 LIST_FOREACH(p, &pg->pg_members, p_pglist)
 361                         if (descend)
 362                                 ret |= ktrsetchildren(curp, p, ops, facs, vp);
 363                         else
 364                                 ret |= ktrops(curp, p, ops, facs, vp);
 365
 366         } else {
 367                 /*
 368                  * by pid
 369                  */
 370                 p = pfind(uap->pid);
 371                 if (p == NULL) {
 372                         error = ESRCH;
 373                         goto done;
 374                 }
 375                 if (descend)
 376                         ret |= ktrsetchildren(curp, p, ops, facs, vp);
 377                 else
 378                         ret |= ktrops(curp, p, ops, facs, vp);
 379         }
 380         if (!ret)
 381                 error = EPERM;
 382 done:
 383         if (vp != NULL)
 384                 (void) vn_close(vp, FWRITE, curp->p_ucred, curp);
 385         curp->p_traceflag &= ~KTRFAC_ACTIVE;
 386         return (error);
 387 #else
 388         return ENOSYS;
 389 #endif
 390 }
 391
 392 /*
 393  * utrace system call
 394  */
 395 struct  utrace_args {
 396         const void *    addr;
 397         size_t  len;
 398 };
 399
 400 /* ARGSUSED */
 401 int
 402 utrace(curp, uap, retval)
 403         struct proc *curp;
 404         register struct utrace_args *uap;
 405         register_t *retval;
 406 {
 407 #if KTRACE
 408         struct ktr_header *kth;
 409         struct proc *p = current_proc();        /* XXX */
 410         register caddr_t cp;
 411
 412         if (!KTRPOINT(p, KTR_USER))
 413                 return (0);
 414         if (uap->len > KTR_USER_MAXLEN)
 415                 return (EINVAL);
 416         p->p_traceflag |= KTRFAC_ACTIVE;
 417         kth = ktrgetheader(KTR_USER);
 418         MALLOC(cp, caddr_t, uap->len, M_KTRACE, M_WAITOK);
 419         if (!copyin(uap->addr, cp, uap->len)) {
 420                 kth->ktr_buf = cp;
 421                 kth->ktr_len = uap->len;
 422                 ktrwrite(p->p_tracep, kth, NULL, KERNEL_FUNNEL);
 423         }
 424         FREE(kth, M_KTRACE);
 425         FREE(cp, M_KTRACE);
 426         p->p_traceflag &= ~KTRFAC_ACTIVE;
 427
 428         return (0);
 429 #else
 430         return (ENOSYS);
 431 #endif
 432 }
 433
 434 #if KTRACE
 435 static int
 436 ktrops(curp, p, ops, facs, vp)
 437         struct proc *p, *curp;
 438         int ops, facs;
 439         struct vnode *vp;
 440 {
 441         struct vnode *tvp;
 442
 443         if (!ktrcanset(curp, p))
 444                 return (0);
 445         if (ops == KTROP_SET) {
 446                 if (p->p_tracep != vp) {
 447                         /*
 448                          * if trace file already in use, relinquish
 449                          */
 450                         tvp = p->p_tracep;
 451                         VREF(vp);
 452                         p->p_tracep = vp;
 453                         if (tvp != NULL)
 454                                 vrele(tvp);
 455                 }
 456                 p->p_traceflag |= facs;
 457                 if (curp->p_ucred->cr_uid == 0)
 458                         p->p_traceflag |= KTRFAC_ROOT;
 459         } else {
 460                 /* KTROP_CLEAR */
 461                 if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
 462                         /* no more tracing */
 463                         tvp = p->p_tracep;
 464                         p->p_traceflag = 0;
 465                         if (tvp != NULL) {
 466                                 p->p_tracep = NULL;
 467                                 vrele(tvp);
 468                         }
 469                 }
 470         }
 471
 472         return (1);
 473 }
 474
 475 static int
 476 ktrsetchildren(curp, top, ops, facs, vp)
 477         struct proc *curp, *top;
 478         int ops, facs;
 479         struct vnode *vp;
 480 {
 481         register struct proc *p;
 482         register int ret = 0;
 483
 484         p = top;
 485         for (;;) {
 486                 ret |= ktrops(curp, p, ops, facs, vp);
 487                 /*
 488                  * If this process has children, descend to them next,
 489                  * otherwise do any siblings, and if done with this level,
 490                  * follow back up the tree (but not past top).
 491                  */
 492                 if (!LIST_EMPTY(&p->p_children))
 493                         p = LIST_FIRST(&p->p_children);
 494                 else for (;;) {
 495                         if (p == top)
 496                                 return (ret);
 497                         if (LIST_NEXT(p, p_sibling)) {
 498                                 p = LIST_NEXT(p, p_sibling);
 499                                 break;
 500                         }
 501                         p = p->p_pptr;
 502                 }
 503         }
 504         /*NOTREACHED*/
 505 }
 506
 507 static void
 508 ktrwrite(vp, kth, uio, funnel_type)
 509         struct vnode *vp;
 510         register struct ktr_header *kth;
 511         struct uio *uio;
 512 {
 513         struct uio auio;
 514         struct iovec aiov[2];
 515         register struct proc *p = current_proc();       /* XXX */
 516         int error;
 517
 518         if (vp == NULL)
 519                 return;
 520
 521         if (funnel_type == -1) {
 522                 funnel_t *f = thread_funnel_get();
 523                 if(f == THR_FUNNEL_NULL)
 524                         funnel_type = NO_FUNNEL;
 525                 else if (f == (funnel_t *)network_flock)
 526                         funnel_type = NETWORK_FUNNEL;
 527                 else if (f == (funnel_t *)kernel_flock)
 528                         funnel_type = KERNEL_FUNNEL;
 529         }
 530
 531         switch (funnel_type) {
 532         case KERNEL_FUNNEL:
 533                 /* Nothing more to do */
 534                 break;
 535         case NETWORK_FUNNEL:
 536                 thread_funnel_switch(NETWORK_FUNNEL, KERNEL_FUNNEL);
 537                 break;
 538         case NO_FUNNEL:
 539                 (void) thread_funnel_set(kernel_flock, TRUE);
 540                 break;
 541         default:
 542                 panic("Invalid funnel (%)", funnel_type);
 543         }
 544         auio.uio_iov = &aiov[0];
 545         auio.uio_offset = 0;
 546         auio.uio_segflg = UIO_SYSSPACE;
 547         auio.uio_rw = UIO_WRITE;
 548         aiov[0].iov_base = (caddr_t)kth;
 549         aiov[0].iov_len = sizeof(struct ktr_header);
 550         auio.uio_resid = sizeof(struct ktr_header);
 551         auio.uio_iovcnt = 1;
 552         auio.uio_procp = current_proc();
 553         if (kth->ktr_len > 0) {
 554                 auio.uio_iovcnt++;
 555                 aiov[1].iov_base = kth->ktr_buf;
 556                 aiov[1].iov_len = kth->ktr_len;
 557                 auio.uio_resid += kth->ktr_len;
 558                 if (uio != NULL)
 559                         kth->ktr_len += uio->uio_resid;
 560         }
 561         error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
 562         if (error)
 563                 goto bad;
 564         (void)VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE);
 565         error = VOP_WRITE(vp, &auio, IO_UNIT | IO_APPEND, p->p_ucred);
 566         if (error == 0 && uio != NULL) {
 567                 (void)VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE);
 568                 error = VOP_WRITE(vp, uio, IO_UNIT | IO_APPEND, p->p_ucred);
 569         }
 570         VOP_UNLOCK(vp, 0, p);
 571         if (!error) {
 572                 switch (funnel_type) {
 573                 case KERNEL_FUNNEL:
 574                         /* Nothing more to do */
 575                         break;
 576                 case NETWORK_FUNNEL:
 577                         thread_funnel_switch(KERNEL_FUNNEL, NETWORK_FUNNEL);
 578                         /* switch funnel to NETWORK_FUNNEL */
 579                         break;
 580                 case NO_FUNNEL:
 581                          (void) thread_funnel_set(kernel_flock, FALSE);
 582                         break;
 583                 default:
 584                         panic("Invalid funnel (%)", funnel_type);
 585                 }
 586                 return;
 587         }
 588
 589 bad:
 590         /*
 591          * If error encountered, give up tracing on this vnode.
 592          */
 593         log(LOG_NOTICE, "ktrace write failed, errno %d, tracing stopped\n",
 594             error);
 595         LIST_FOREACH(p, &allproc, p_list) {
 596                 if (p->p_tracep == vp) {
 597                         p->p_tracep = NULL;
 598                         p->p_traceflag = 0;
 599                         vrele(vp);
 600                 }
 601         }
 602
 603         switch (funnel_type) {
 604         case KERNEL_FUNNEL:
 605                 /* Nothing more to do */
 606                 break;
 607         case NETWORK_FUNNEL:
 608                 thread_funnel_switch(KERNEL_FUNNEL, NETWORK_FUNNEL);
 609                 /* switch funnel to NETWORK_FUNNEL */
 610                 break;
 611         case NO_FUNNEL:
 612                  (void) thread_funnel_set(kernel_flock, FALSE);
 613                 break;
 614         default:
 615                 panic("Invalid funnel (%)", funnel_type);
 616         }
 617 }
 618
 619 /*
 620  * Return true if caller has permission to set the ktracing state
 621  * of target.  Essentially, the target can't possess any
 622  * more permissions than the caller.  KTRFAC_ROOT signifies that
 623  * root previously set the tracing status on the target process, and
 624  * so, only root may further change it.
 625  *
 626  * TODO: check groups.  use caller effective gid.
 627  */
 628 static int
 629 ktrcanset(callp, targetp)
 630         struct proc *callp, *targetp;
 631 {
 632         register struct pcred *caller = callp->p_cred;
 633         register struct pcred *target = targetp->p_cred;
 634
 635         if (!PRISON_CHECK(callp, targetp))
 636                 return (0);
 637         if ((caller->pc_ucred->cr_uid == target->p_ruid &&
 638              target->p_ruid == target->p_svuid &&
 639              caller->p_rgid == target->p_rgid &&        /* XXX */
 640              target->p_rgid == target->p_svgid &&
 641              (targetp->p_traceflag & KTRFAC_ROOT) == 0) ||
 642              caller->pc_ucred->cr_uid == 0)
 643                 return (1);
 644
 645         return (0);
 646 }
 647
 648 #endif /* KTRACE */