2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * @(#)kern_ktrace.c 8.2 (Berkeley) 9/23/93
34 * $FreeBSD: src/sys/kern/kern_ktrace.c,v 1.35.2.6 2002/07/05 22:36:38 darrenr Exp $
35 * $DragonFly: src/sys/kern/kern_ktrace.c,v 1.10 2003/09/23 05:03:51 dillon Exp $
38 #include "opt_ktrace.h"
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/sysproto.h>
43 #include <sys/kernel.h>
45 #include <sys/fcntl.h>
47 #include <sys/namei.h>
48 #include <sys/vnode.h>
49 #include <sys/ktrace.h>
50 #include <sys/malloc.h>
51 #include <sys/syslog.h>
52 #include <sys/sysent.h>
54 #include <vm/vm_zone.h>
55 static MALLOC_DEFINE(M_KTRACE, "KTRACE", "KTRACE");
58 static struct ktr_header *ktrgetheader (int type);
59 static void ktrwrite (struct vnode *, struct ktr_header *, struct uio *);
60 static int ktrcanset (struct proc *,struct proc *);
61 static int ktrsetchildren (struct proc *,struct proc *,int,int,struct vnode *);
62 static int ktrops (struct proc *,struct proc *,int,int,struct vnode *);
65 static struct ktr_header *
69 struct ktr_header *kth;
70 struct proc *p = curproc; /* XXX */
72 MALLOC(kth, struct ktr_header *, sizeof (struct ktr_header),
75 microtime(&kth->ktr_time);
76 kth->ktr_pid = p->p_pid;
77 bcopy(p->p_comm, kth->ktr_comm, MAXCOMLEN + 1);
82 ktrsyscall(vp, code, narg, args)
87 struct ktr_header *kth;
88 struct ktr_syscall *ktp;
89 int len = offsetof(struct ktr_syscall, ktr_args) +
90 (narg * sizeof(register_t));
91 struct proc *p = curproc; /* XXX */
95 p->p_traceflag |= KTRFAC_ACTIVE;
96 kth = ktrgetheader(KTR_SYSCALL);
97 MALLOC(ktp, struct ktr_syscall *, len, M_KTRACE, M_WAITOK);
100 argp = &ktp->ktr_args[0];
101 for (i = 0; i < narg; i++)
103 kth->ktr_buf = (caddr_t)ktp;
105 ktrwrite(vp, kth, NULL);
108 p->p_traceflag &= ~KTRFAC_ACTIVE;
112 ktrsysret(vp, code, error, retval)
117 struct ktr_header *kth;
118 struct ktr_sysret ktp;
119 struct proc *p = curproc; /* XXX */
121 p->p_traceflag |= KTRFAC_ACTIVE;
122 kth = ktrgetheader(KTR_SYSRET);
124 ktp.ktr_error = error;
125 ktp.ktr_retval = retval; /* what about val2 ? */
127 kth->ktr_buf = (caddr_t)&ktp;
128 kth->ktr_len = sizeof(struct ktr_sysret);
130 ktrwrite(vp, kth, NULL);
132 p->p_traceflag &= ~KTRFAC_ACTIVE;
140 struct ktr_header *kth;
141 struct proc *p = curproc; /* XXX */
144 * don't let vp get ripped out from under us
148 p->p_traceflag |= KTRFAC_ACTIVE;
149 kth = ktrgetheader(KTR_NAMEI);
150 kth->ktr_len = strlen(path);
153 ktrwrite(vp, kth, NULL);
157 p->p_traceflag &= ~KTRFAC_ACTIVE;
161 ktrgenio(vp, fd, rw, uio, error)
168 struct ktr_header *kth;
169 struct ktr_genio ktg;
170 struct proc *p = curproc; /* XXX */
175 * don't let p_tracep get ripped out from under us
179 p->p_traceflag |= KTRFAC_ACTIVE;
180 kth = ktrgetheader(KTR_GENIO);
183 kth->ktr_buf = (caddr_t)&ktg;
184 kth->ktr_len = sizeof(struct ktr_genio);
186 uio->uio_rw = UIO_WRITE;
188 ktrwrite(vp, kth, uio);
192 p->p_traceflag &= ~KTRFAC_ACTIVE;
196 ktrpsig(vp, sig, action, mask, code)
203 struct ktr_header *kth;
205 struct proc *p = curproc; /* XXX */
208 * don't let vp get ripped out from under us
212 p->p_traceflag |= KTRFAC_ACTIVE;
213 kth = ktrgetheader(KTR_PSIG);
214 kp.signo = (char)sig;
218 kth->ktr_buf = (caddr_t)&kp;
219 kth->ktr_len = sizeof (struct ktr_psig);
221 ktrwrite(vp, kth, NULL);
225 p->p_traceflag &= ~KTRFAC_ACTIVE;
229 ktrcsw(vp, out, user)
233 struct ktr_header *kth;
235 struct proc *p = curproc; /* XXX */
238 * don't let vp get ripped out from under us
242 p->p_traceflag |= KTRFAC_ACTIVE;
243 kth = ktrgetheader(KTR_CSW);
246 kth->ktr_buf = (caddr_t)&kc;
247 kth->ktr_len = sizeof (struct ktr_csw);
249 ktrwrite(vp, kth, NULL);
253 p->p_traceflag &= ~KTRFAC_ACTIVE;
257 /* Interface and common routines */
264 ktrace(struct ktrace_args *uap)
267 struct thread *td = curthread;
268 struct proc *curp = td->td_proc;
269 struct vnode *vp = NULL;
272 int facs = uap->facs & ~KTRFAC_ROOT;
273 int ops = KTROP(uap->ops);
274 int descend = uap->ops & KTRFLAG_DESCEND;
279 curp->p_traceflag |= KTRFAC_ACTIVE;
280 if (ops != KTROP_CLEAR) {
282 * an operation which requires a file argument.
284 NDINIT(&nd, NAMEI_LOOKUP, CNP_NOFOLLOW, UIO_USERSPACE,
286 error = vn_open(&nd, FREAD|FWRITE|O_NOFOLLOW, 0);
288 curp->p_traceflag &= ~KTRFAC_ACTIVE;
291 NDFREE(&nd, NDF_ONLY_PNBUF);
293 VOP_UNLOCK(vp, 0, td);
294 if (vp->v_type != VREG) {
295 (void) vn_close(vp, FREAD|FWRITE, td);
296 curp->p_traceflag &= ~KTRFAC_ACTIVE;
301 * Clear all uses of the tracefile. XXX umm, what happens to the
302 * loop if vn_close() blocks?
304 if (ops == KTROP_CLEARFILE) {
305 FOREACH_PROC_IN_SYSTEM(p) {
306 if (p->p_tracep == vp) {
307 if (ktrcanset(curp, p) && p->p_tracep == vp) {
310 (void) vn_close(vp, FREAD|FWRITE, td);
319 * need something to (un)trace (XXX - why is this here?)
332 pg = pgfind(-uap->pid);
337 LIST_FOREACH(p, &pg->pg_members, p_pglist)
339 ret |= ktrsetchildren(curp, p, ops, facs, vp);
341 ret |= ktrops(curp, p, ops, facs, vp);
353 ret |= ktrsetchildren(curp, p, ops, facs, vp);
355 ret |= ktrops(curp, p, ops, facs, vp);
361 (void) vn_close(vp, FWRITE, td);
362 curp->p_traceflag &= ~KTRFAC_ACTIVE;
374 utrace(struct utrace_args *uap)
377 struct ktr_header *kth;
378 struct thread *td = curthread; /* XXX */
379 struct proc *p = td->td_proc;
383 if (!KTRPOINT(td, KTR_USER))
385 if (SCARG(uap, len) > KTR_USER_MAXLEN)
387 p->p_traceflag |= KTRFAC_ACTIVE;
389 * don't let p_tracep get ripped out from under us while we are
392 if ((vp = p->p_tracep) != NULL)
394 kth = ktrgetheader(KTR_USER);
395 MALLOC(cp, caddr_t, uap->len, M_KTRACE, M_WAITOK);
396 if (!copyin(uap->addr, cp, uap->len)) {
398 kth->ktr_len = uap->len;
399 ktrwrite(vp, kth, NULL);
405 p->p_traceflag &= ~KTRFAC_ACTIVE;
415 ktrops(curp, p, ops, facs, vp)
416 struct proc *p, *curp;
421 if (!ktrcanset(curp, p))
423 if (ops == KTROP_SET) {
424 if (p->p_tracep != vp) {
428 * if trace file already in use, relinquish
431 while ((vtmp = p->p_tracep) != NULL) {
437 p->p_traceflag |= facs;
438 if (curp->p_ucred->cr_uid == 0)
439 p->p_traceflag |= KTRFAC_ROOT;
442 if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
445 /* no more tracing */
447 if ((vtmp = p->p_tracep) != NULL) {
458 ktrsetchildren(curp, top, ops, facs, vp)
459 struct proc *curp, *top;
468 ret |= ktrops(curp, p, ops, facs, vp);
470 * If this process has children, descend to them next,
471 * otherwise do any siblings, and if done with this level,
472 * follow back up the tree (but not past top).
474 if (!LIST_EMPTY(&p->p_children))
475 p = LIST_FIRST(&p->p_children);
479 if (LIST_NEXT(p, p_sibling)) {
480 p = LIST_NEXT(p, p_sibling);
490 ktrwrite(struct vnode *vp, struct ktr_header *kth, struct uio *uio)
493 struct iovec aiov[2];
494 struct thread *td = curthread;
495 struct proc *p = td->td_proc; /* XXX */
500 auio.uio_iov = &aiov[0];
502 auio.uio_segflg = UIO_SYSSPACE;
503 auio.uio_rw = UIO_WRITE;
504 aiov[0].iov_base = (caddr_t)kth;
505 aiov[0].iov_len = sizeof(struct ktr_header);
506 auio.uio_resid = sizeof(struct ktr_header);
508 auio.uio_td = curthread;
509 if (kth->ktr_len > 0) {
511 aiov[1].iov_base = kth->ktr_buf;
512 aiov[1].iov_len = kth->ktr_len;
513 auio.uio_resid += kth->ktr_len;
515 kth->ktr_len += uio->uio_resid;
517 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
518 (void)VOP_LEASE(vp, td, p->p_ucred, LEASE_WRITE);
519 error = VOP_WRITE(vp, &auio, IO_UNIT | IO_APPEND, p->p_ucred);
520 if (error == 0 && uio != NULL) {
521 (void)VOP_LEASE(vp, td, p->p_ucred, LEASE_WRITE);
522 error = VOP_WRITE(vp, uio, IO_UNIT | IO_APPEND, p->p_ucred);
524 VOP_UNLOCK(vp, 0, td);
528 * If error encountered, give up tracing on this vnode. XXX what
529 * happens to the loop if vrele() blocks?
531 log(LOG_NOTICE, "ktrace write failed, errno %d, tracing stopped\n",
533 FOREACH_PROC_IN_SYSTEM(p) {
534 if (p->p_tracep == vp) {
543 * Return true if caller has permission to set the ktracing state
544 * of target. Essentially, the target can't possess any
545 * more permissions than the caller. KTRFAC_ROOT signifies that
546 * root previously set the tracing status on the target process, and
547 * so, only root may further change it.
549 * TODO: check groups. use caller effective gid.
552 ktrcanset(struct proc *callp, struct proc *targetp)
554 struct ucred *caller = callp->p_ucred;
555 struct ucred *target = targetp->p_ucred;
557 if (!PRISON_CHECK(caller, target))
559 if ((caller->cr_uid == target->cr_ruid &&
560 target->cr_ruid == target->cr_svuid &&
561 caller->cr_rgid == target->cr_rgid && /* XXX */
562 target->cr_rgid == target->cr_svgid &&
563 (targetp->p_traceflag & KTRFAC_ROOT) == 0 &&
564 (targetp->p_flag & P_SUGID) == 0) ||