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