sys/kern/kern_ktrace.c

   1 /*
   2  * Copyright (c) 1989, 1993
   3  *      The Regents of the University of California.  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  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)kern_ktrace.c       8.2 (Berkeley) 9/23/93
  30  * $FreeBSD: src/sys/kern/kern_ktrace.c,v 1.35.2.6 2002/07/05 22:36:38 darrenr Exp $
  31  */
  32
  33 #include "opt_ktrace.h"
  34
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/sysproto.h>
  38 #include <sys/kernel.h>
  39 #include <sys/proc.h>
  40 #include <sys/fcntl.h>
  41 #include <sys/lock.h>
  42 #include <sys/nlookup.h>
  43 #include <sys/vnode.h>
  44 #include <sys/ktrace.h>
  45 #include <sys/malloc.h>
  46 #include <sys/syslog.h>
  47 #include <sys/sysent.h>
  48
  49 #include <vm/vm_zone.h>
  50
  51 #include <sys/mplock2.h>
  52
  53 static MALLOC_DEFINE(M_KTRACE, "KTRACE", "KTRACE");
  54
  55 #ifdef KTRACE
  56 static void ktrgetheader (struct ktr_header *kth, int type);
  57 static struct ktr_syscall *ktrgetsyscall(struct ktr_header *kth,
  58                                 struct ktr_syscall *ktp_cache, int narg);
  59 static void ktrputsyscall(struct ktr_syscall *ktp_cache,
  60                                 struct ktr_syscall *ktp);
  61 static void ktrwrite (struct lwp *, struct ktr_header *, struct uio *);
  62 static int ktrcanset (struct thread *,struct proc *);
  63 static int ktrsetchildren (struct thread *, struct proc *,
  64                                 int, int, ktrace_node_t);
  65 static int ktrops (struct thread *,struct proc *,int,int, ktrace_node_t);
  66
  67 /*
  68  * MPSAFE
  69  */
  70 static
  71 void
  72 ktrgetheader(struct ktr_header *kth, int type)
  73 {
  74         thread_t td = curthread;
  75         struct proc *p = td->td_proc;
  76         struct lwp *lp = td->td_lwp;
  77
  78         kth->ktr_type = type;
  79         /* XXX threaded flag is a hack at the moment */
  80         kth->ktr_flags = (p->p_nthreads > 1) ? KTRH_THREADED : 0;
  81         kth->ktr_flags |= KTRH_CPUID_ENCODE(td->td_gd->gd_cpuid);
  82         /*microtime(&kth->ktr_time); set in ktrwrite */
  83         kth->ktr_pid = p->p_pid;
  84         kth->ktr_tid = lp->lwp_tid;
  85         bcopy(p->p_comm, kth->ktr_comm, MAXCOMLEN + 1);
  86 }
  87
  88 static
  89 struct ktr_syscall *
  90 ktrgetsyscall(struct ktr_header *kth, struct ktr_syscall *ktp_cache, int narg)
  91 {
  92         size_t len;
  93
  94         len = offsetof(struct ktr_syscall, ktr_args[narg]);
  95         if (len > sizeof(*ktp_cache))
  96                 ktp_cache = kmalloc(len, M_KTRACE, M_WAITOK);
  97         kth->ktr_buf = (caddr_t)ktp_cache;
  98         kth->ktr_len = (int)len;
  99         return (ktp_cache);
 100 }
 101
 102 static
 103 void
 104 ktrputsyscall(struct ktr_syscall *ktp_cache, struct ktr_syscall *ktp)
 105 {
 106         if (ktp != ktp_cache)
 107                 kfree(ktp, M_KTRACE);
 108 }
 109
 110 void
 111 ktrsyscall(struct lwp *lp, int code, int narg, register_t args[])
 112 {
 113         struct ktr_header kth;
 114         struct ktr_syscall ktp_cache;
 115         struct ktr_syscall *ktp;
 116         register_t *argp;
 117         int i;
 118
 119         /*
 120          * Setting the active bit prevents a ktrace recursion from the
 121          * ktracing op itself.
 122          */
 123         lp->lwp_traceflag |= KTRFAC_ACTIVE;
 124         ktrgetheader(&kth, KTR_SYSCALL);
 125
 126         ktp = ktrgetsyscall(&kth, &ktp_cache, narg);
 127         ktp->ktr_code = code;
 128         ktp->ktr_narg = narg;
 129         argp = &ktp->ktr_args[0];
 130         for (i = 0; i < narg; i++)
 131                 *argp++ = args[i];
 132         ktrwrite(lp, &kth, NULL);
 133
 134         ktrputsyscall(&ktp_cache, ktp);
 135         lp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 136 }
 137
 138 void
 139 ktrsysret(struct lwp *lp, int code, int error, register_t retval)
 140 {
 141         struct ktr_header kth;
 142         struct ktr_sysret ktp;
 143
 144         lp->lwp_traceflag |= KTRFAC_ACTIVE;
 145         ktrgetheader(&kth, KTR_SYSRET);
 146
 147         ktp.ktr_code = code;
 148         ktp.ktr_error = error;
 149         if (error == 0)
 150                 ktp.ktr_retval = retval;                /* what about val2 ? */
 151         else
 152                 ktp.ktr_retval = 0;
 153
 154         kth.ktr_buf = (caddr_t)&ktp;
 155         kth.ktr_len = (int)sizeof(struct ktr_sysret);
 156
 157         ktrwrite(lp, &kth, NULL);
 158         lp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 159 }
 160
 161 void
 162 ktrnamei(struct lwp *lp, char *path)
 163 {
 164         struct ktr_header kth;
 165
 166         lp->lwp_traceflag |= KTRFAC_ACTIVE;
 167         ktrgetheader(&kth, KTR_NAMEI);
 168
 169         kth.ktr_len = (int)strlen(path);
 170         kth.ktr_buf = path;
 171
 172         ktrwrite(lp, &kth, NULL);
 173         lp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 174 }
 175
 176 void
 177 ktrgenio(struct lwp *lp, int fd, enum uio_rw rw, struct uio *uio, int error)
 178 {
 179         struct ktr_header kth;
 180         struct ktr_genio ktg;
 181
 182         if (error)
 183                 return;
 184         lp->lwp_traceflag |= KTRFAC_ACTIVE;
 185         ktrgetheader(&kth, KTR_GENIO);
 186
 187         ktg.ktr_fd = fd;
 188         ktg.ktr_rw = rw;
 189         kth.ktr_buf = (caddr_t)&ktg;
 190         kth.ktr_len = (int)sizeof(struct ktr_genio);
 191         uio->uio_offset = 0;
 192         uio->uio_rw = UIO_WRITE;
 193
 194         ktrwrite(lp, &kth, uio);
 195         lp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 196 }
 197
 198 void
 199 ktrpsig(struct lwp *lp, int sig, sig_t action, sigset_t *mask, int code)
 200 {
 201         struct ktr_header kth;
 202         struct ktr_psig kp;
 203
 204         lp->lwp_traceflag |= KTRFAC_ACTIVE;
 205         ktrgetheader(&kth, KTR_PSIG);
 206
 207         kp.signo = (char)sig;
 208         kp.action = action;
 209         kp.mask = *mask;
 210         kp.code = code;
 211         kth.ktr_buf = (caddr_t)&kp;
 212         kth.ktr_len = (int)sizeof(struct ktr_psig);
 213
 214         ktrwrite(lp, &kth, NULL);
 215         lp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 216 }
 217
 218 void
 219 ktrcsw(struct lwp *lp, int out, int user)
 220 {
 221         struct ktr_header kth;
 222         struct ktr_csw kc;
 223
 224         lp->lwp_traceflag |= KTRFAC_ACTIVE;
 225         ktrgetheader(&kth, KTR_CSW);
 226
 227         kc.out = out;
 228         kc.user = user;
 229         kth.ktr_buf = (caddr_t)&kc;
 230         kth.ktr_len = (int)sizeof(struct ktr_csw);
 231
 232         ktrwrite(lp, &kth, NULL);
 233         lp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 234 }
 235 #endif
 236
 237 /* Interface and common routines */
 238
 239 #ifdef KTRACE
 240 /*
 241  * ktrace system call
 242  */
 243 struct ktrace_clear_info {
 244         ktrace_node_t tracenode;
 245         int rootclear;
 246         int error;
 247 };
 248
 249 static int ktrace_clear_callback(struct proc *p, void *data);
 250
 251 #endif
 252
 253 /*
 254  * MPALMOSTSAFE
 255  */
 256 int
 257 sys_ktrace(struct ktrace_args *uap)
 258 {
 259 #ifdef KTRACE
 260         struct ktrace_clear_info info;
 261         struct thread *td = curthread;
 262         struct proc *curp = td->td_proc;
 263         struct proc *p;
 264         struct pgrp *pg;
 265         int facs = uap->facs & ~KTRFAC_ROOT;
 266         int ops = KTROP(uap->ops);
 267         int descend = uap->ops & KTRFLAG_DESCEND;
 268         int ret = 0;
 269         int error = 0;
 270         struct nlookupdata nd;
 271         ktrace_node_t tracenode = NULL;
 272
 273         get_mplock();
 274         curp->p_traceflag |= KTRFAC_ACTIVE;
 275         if (ops != KTROP_CLEAR) {
 276                 /*
 277                  * an operation which requires a file argument.
 278                  */
 279                 error = nlookup_init(&nd, uap->fname,
 280                                         UIO_USERSPACE, NLC_LOCKVP);
 281                 if (error == 0)
 282                         error = vn_open(&nd, NULL, FREAD|FWRITE|O_NOFOLLOW, 0);
 283                 if (error == 0 && nd.nl_open_vp->v_type != VREG)
 284                         error = EACCES;
 285                 if (error) {
 286                         curp->p_traceflag &= ~KTRFAC_ACTIVE;
 287                         nlookup_done(&nd);
 288                         goto done;
 289                 }
 290                 tracenode = kmalloc(sizeof(struct ktrace_node), M_KTRACE,
 291                                     M_WAITOK | M_ZERO);
 292                 tracenode->kn_vp = nd.nl_open_vp;
 293                 tracenode->kn_refs = 1;
 294                 nd.nl_open_vp = NULL;
 295                 nlookup_done(&nd);
 296                 vn_unlock(tracenode->kn_vp);
 297         }
 298         /*
 299          * Clear all uses of the tracefile.  Not the most efficient operation
 300          * in the world.
 301          */
 302         if (ops == KTROP_CLEARFILE) {
 303                 info.tracenode = tracenode;
 304                 info.error = 0;
 305                 info.rootclear = 0;
 306                 allproc_scan(ktrace_clear_callback, &info);
 307                 error = info.error;
 308                 goto done;
 309         }
 310         /*
 311          * need something to (un)trace (XXX - why is this here?)
 312          */
 313         if (!facs) {
 314                 error = EINVAL;
 315                 goto done;
 316         }
 317         /*
 318          * do it
 319          */
 320         if (uap->pid < 0) {
 321                 /*
 322                  * By process group.  Process group is referenced, preventing
 323                  * disposal.
 324                  */
 325                 pg = pgfind(-uap->pid);
 326                 if (pg == NULL) {
 327                         error = ESRCH;
 328                         goto done;
 329                 }
 330                 lwkt_gettoken(&pg->pg_token);
 331                 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
 332                         PHOLD(p);
 333                         if (descend)
 334                                 ret |= ktrsetchildren(td, p, ops, facs, tracenode);
 335                         else
 336                                 ret |= ktrops(td, p, ops, facs, tracenode);
 337                         PRELE(p);
 338                 }
 339                 lwkt_reltoken(&pg->pg_token);
 340                 pgrel(pg);
 341         } else {
 342                 /*
 343                  * by pid
 344                  */
 345                 p = pfind(uap->pid);
 346                 if (p == NULL) {
 347                         error = ESRCH;
 348                         goto done;
 349                 }
 350                 if (descend)
 351                         ret |= ktrsetchildren(td, p, ops, facs, tracenode);
 352                 else
 353                         ret |= ktrops(td, p, ops, facs, tracenode);
 354                 PRELE(p);
 355         }
 356         if (!ret)
 357                 error = EPERM;
 358 done:
 359         if (tracenode)
 360                 ktrdestroy(&tracenode);
 361         curp->p_traceflag &= ~KTRFAC_ACTIVE;
 362         rel_mplock();
 363         return (error);
 364 #else
 365         return ENOSYS;
 366 #endif
 367 }
 368
 369 #ifdef KTRACE
 370
 371 /*
 372  * NOTE: NOT MPSAFE (yet)
 373  */
 374 static int
 375 ktrace_clear_callback(struct proc *p, void *data)
 376 {
 377         struct ktrace_clear_info *info = data;
 378
 379         if (p->p_tracenode) {
 380                 if (info->rootclear) {
 381                         if (p->p_tracenode == info->tracenode) {
 382                                 ktrdestroy(&p->p_tracenode);
 383                                 p->p_traceflag = 0;
 384                         }
 385                 } else {
 386                         if (p->p_tracenode->kn_vp == info->tracenode->kn_vp) {
 387                                 if (ktrcanset(curthread, p)) {
 388                                         ktrdestroy(&p->p_tracenode);
 389                                         p->p_traceflag = 0;
 390                                 } else {
 391                                         info->error = EPERM;
 392                                 }
 393                         }
 394                 }
 395         }
 396         return(0);
 397 }
 398
 399 #endif
 400
 401 /*
 402  * utrace system call
 403  *
 404  * MPALMOSTSAFE
 405  */
 406 int
 407 sys_utrace(struct utrace_args *uap)
 408 {
 409 #ifdef KTRACE
 410         struct ktr_header kth;
 411         struct thread *td = curthread;  /* XXX */
 412         char cp_cache[64];
 413         caddr_t cp;
 414
 415         if (!KTRPOINT(td, KTR_USER))
 416                 return (0);
 417         if (uap->len > KTR_USER_MAXLEN)
 418                 return (EINVAL);
 419         td->td_lwp->lwp_traceflag |= KTRFAC_ACTIVE;
 420         ktrgetheader(&kth, KTR_USER);
 421         if (uap->len <= sizeof(cp_cache))
 422                 cp = cp_cache;
 423         else
 424                 cp = kmalloc(uap->len, M_KTRACE, M_WAITOK);
 425
 426         if (!copyin(uap->addr, cp, uap->len)) {
 427                 kth.ktr_buf = cp;
 428                 kth.ktr_len = uap->len;
 429                 ktrwrite(td->td_lwp, &kth, NULL);
 430         }
 431         if (cp != cp_cache)
 432                 kfree(cp, M_KTRACE);
 433         td->td_lwp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 434
 435         return (0);
 436 #else
 437         return (ENOSYS);
 438 #endif
 439 }
 440
 441 void
 442 ktrdestroy(struct ktrace_node **tracenodep)
 443 {
 444         ktrace_node_t tracenode;
 445
 446         if ((tracenode = *tracenodep) != NULL) {
 447                 *tracenodep = NULL;
 448                 KKASSERT(tracenode->kn_refs > 0);
 449                 if (atomic_fetchadd_int(&tracenode->kn_refs, -1) == 1) {
 450                         vn_close(tracenode->kn_vp, FREAD|FWRITE, NULL);
 451                         tracenode->kn_vp = NULL;
 452                         kfree(tracenode, M_KTRACE);
 453                 }
 454         }
 455 }
 456
 457 /*
 458  * This allows a process to inherit a ref on a tracenode and is also used
 459  * as a temporary ref to prevent a tracenode from being destroyed out from
 460  * under an active operation.
 461  */
 462 ktrace_node_t
 463 ktrinherit(ktrace_node_t tracenode)
 464 {
 465         if (tracenode) {
 466                 KKASSERT(tracenode->kn_refs > 0);
 467                 atomic_add_int(&tracenode->kn_refs, 1);
 468         }
 469         return(tracenode);
 470 }
 471
 472 #ifdef KTRACE
 473 static int
 474 ktrops(struct thread *td, struct proc *p, int ops, int facs,
 475        ktrace_node_t tracenode)
 476 {
 477         ktrace_node_t oldnode;
 478
 479         if (!ktrcanset(td, p))
 480                 return (0);
 481         if (ops == KTROP_SET) {
 482                 if ((oldnode = p->p_tracenode) != tracenode) {
 483                         p->p_tracenode = ktrinherit(tracenode);
 484                         ktrdestroy(&oldnode);
 485                 }
 486                 p->p_traceflag |= facs;
 487                 if (td->td_ucred->cr_uid == 0)
 488                         p->p_traceflag |= KTRFAC_ROOT;
 489         } else {
 490                 /* KTROP_CLEAR */
 491                 if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
 492                         /* no more tracing */
 493                         p->p_traceflag = 0;
 494                         ktrdestroy(&p->p_tracenode);
 495                 }
 496         }
 497
 498         return (1);
 499 }
 500
 501 static int
 502 ktrsetchildren(struct thread *td, struct proc *top, int ops, int facs,
 503                ktrace_node_t tracenode)
 504 {
 505         struct proc *p;
 506         struct proc *np;
 507         int ret = 0;
 508
 509         p = top;
 510         PHOLD(p);
 511         lwkt_gettoken(&p->p_token);
 512
 513         for (;;) {
 514                 ret |= ktrops(td, p, ops, facs, tracenode);
 515
 516                 /*
 517                  * If this process has children, descend to them next,
 518                  * otherwise do any siblings, and if done with this level,
 519                  * follow back up the tree (but not past top).
 520                  */
 521                 if ((np = LIST_FIRST(&p->p_children)) != NULL) {
 522                         PHOLD(np);
 523                 }
 524                 while (np == NULL) {
 525                         if (p == top)
 526                                 break;
 527                         if ((np = LIST_NEXT(p, p_sibling)) != NULL) {
 528                                 PHOLD(np);
 529                                 break;
 530                         }
 531
 532                         /*
 533                          * recurse up to parent, set p in our inner
 534                          * loop when doing this.  np can be NULL if
 535                          * we race a reparenting to init (thus 'top'
 536                          * is skipped past and never encountered).
 537                          */
 538                         np = p->p_pptr;
 539                         if (np == NULL)
 540                                 break;
 541                         PHOLD(np);
 542                         lwkt_reltoken(&p->p_token);
 543                         PRELE(p);
 544                         p = np;
 545                         lwkt_gettoken(&p->p_token);
 546                         np = NULL;
 547                 }
 548                 lwkt_reltoken(&p->p_token);
 549                 PRELE(p);
 550                 p = np;
 551                 if (p == NULL)
 552                         break;
 553                 /* Already held, but we need the token too */
 554                 lwkt_gettoken(&p->p_token);
 555         }
 556         return (ret);
 557 }
 558
 559 static void
 560 ktrwrite(struct lwp *lp, struct ktr_header *kth, struct uio *uio)
 561 {
 562         struct ktrace_clear_info info;
 563         struct uio auio;
 564         struct iovec aiov[2];
 565         int error;
 566         ktrace_node_t tracenode;
 567
 568         /*
 569          * We have to ref our tracenode to prevent it from being ripped out
 570          * from under us while we are trying to use it.   p_tracenode can
 571          * go away at any time if another process gets a write error.
 572          *
 573          * XXX not MP safe
 574          */
 575         if (lp->lwp_proc->p_tracenode == NULL)
 576                 return;
 577         tracenode = ktrinherit(lp->lwp_proc->p_tracenode);
 578         auio.uio_iov = &aiov[0];
 579         auio.uio_offset = 0;
 580         auio.uio_segflg = UIO_SYSSPACE;
 581         auio.uio_rw = UIO_WRITE;
 582         aiov[0].iov_base = (caddr_t)kth;
 583         aiov[0].iov_len = sizeof(struct ktr_header);
 584         auio.uio_resid = sizeof(struct ktr_header);
 585         auio.uio_iovcnt = 1;
 586         auio.uio_td = curthread;
 587         if (kth->ktr_len > 0) {
 588                 auio.uio_iovcnt++;
 589                 aiov[1].iov_base = kth->ktr_buf;
 590                 aiov[1].iov_len = kth->ktr_len;
 591                 auio.uio_resid += kth->ktr_len;
 592                 if (uio != NULL)
 593                         kth->ktr_len += uio->uio_resid;
 594         }
 595
 596         /*
 597          * NOTE: Must set timestamp after obtaining lock to ensure no
 598          *       timestamp reversals in the output file.
 599          */
 600         vn_lock(tracenode->kn_vp, LK_EXCLUSIVE | LK_RETRY);
 601         microtime(&kth->ktr_time);
 602         error = VOP_WRITE(tracenode->kn_vp, &auio,
 603                           IO_UNIT | IO_APPEND, lp->lwp_thread->td_ucred);
 604         if (error == 0 && uio != NULL) {
 605                 error = VOP_WRITE(tracenode->kn_vp, uio,
 606                               IO_UNIT | IO_APPEND, lp->lwp_thread->td_ucred);
 607         }
 608         vn_unlock(tracenode->kn_vp);
 609         if (error) {
 610                 /*
 611                  * If an error occured, give up tracing on all processes
 612                  * using this tracenode.  This is not MP safe but is
 613                  * blocking-safe.
 614                  */
 615                 log(LOG_NOTICE,
 616                     "ktrace write failed, errno %d, tracing stopped\n", error);
 617                 info.tracenode = tracenode;
 618                 info.error = 0;
 619                 info.rootclear = 1;
 620                 allproc_scan(ktrace_clear_callback, &info);
 621         }
 622         ktrdestroy(&tracenode);
 623 }
 624
 625 /*
 626  * Return true if caller has permission to set the ktracing state
 627  * of target.  Essentially, the target can't possess any
 628  * more permissions than the caller.  KTRFAC_ROOT signifies that
 629  * root previously set the tracing status on the target process, and
 630  * so, only root may further change it.
 631  *
 632  * TODO: check groups.  use caller effective gid.
 633  */
 634 static int
 635 ktrcanset(struct thread *calltd, struct proc *targetp)
 636 {
 637         struct ucred *caller = calltd->td_ucred;
 638         struct ucred *target = targetp->p_ucred;
 639
 640         if (!PRISON_CHECK(caller, target))
 641                 return (0);
 642         if ((caller->cr_uid == target->cr_ruid &&
 643              target->cr_ruid == target->cr_svuid &&
 644              caller->cr_rgid == target->cr_rgid &&      /* XXX */
 645              target->cr_rgid == target->cr_svgid &&
 646              (targetp->p_traceflag & KTRFAC_ROOT) == 0 &&
 647              (targetp->p_flags & P_SUGID) == 0) ||
 648              caller->cr_uid == 0)
 649                 return (1);
 650
 651         return (0);
 652 }
 653
 654 #endif /* KTRACE */