Remove some uses of the SCARG macro.
[dragonfly.git] / sys / kern / kern_ktrace.c
CommitLineData
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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. 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.
20 *
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
31 * SUCH DAMAGE.
32 *
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 $
ab2eb4eb 35 * $DragonFly: src/sys/kern/kern_ktrace.c,v 1.18 2005/03/29 00:35:55 drhodus Exp $
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36 */
37
38#include "opt_ktrace.h"
39
40#include <sys/param.h>
41#include <sys/systm.h>
42#include <sys/sysproto.h>
43#include <sys/kernel.h>
44#include <sys/proc.h>
45#include <sys/fcntl.h>
46#include <sys/lock.h>
fad57d0e 47#include <sys/nlookup.h>
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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>
53
54#include <vm/vm_zone.h>
55static MALLOC_DEFINE(M_KTRACE, "KTRACE", "KTRACE");
56
57#ifdef KTRACE
402ed7e1
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58static struct ktr_header *ktrgetheader (int type);
59static void ktrwrite (struct vnode *, struct ktr_header *, struct uio *);
60static int ktrcanset (struct proc *,struct proc *);
61static int ktrsetchildren (struct proc *,struct proc *,int,int,struct vnode *);
62static int ktrops (struct proc *,struct proc *,int,int,struct vnode *);
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63
64
65static struct ktr_header *
2b9ccab7 66ktrgetheader(int type)
984263bc 67{
1fd87d54 68 struct ktr_header *kth;
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69 struct proc *p = curproc; /* XXX */
70
71 MALLOC(kth, struct ktr_header *, sizeof (struct ktr_header),
72 M_KTRACE, M_WAITOK);
73 kth->ktr_type = type;
74 microtime(&kth->ktr_time);
75 kth->ktr_pid = p->p_pid;
76 bcopy(p->p_comm, kth->ktr_comm, MAXCOMLEN + 1);
77 return (kth);
78}
79
80void
2b9ccab7 81ktrsyscall(struct vnode *vp, int code, int narg, register_t args[])
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82{
83 struct ktr_header *kth;
84 struct ktr_syscall *ktp;
1fd87d54 85 int len = offsetof(struct ktr_syscall, ktr_args) +
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86 (narg * sizeof(register_t));
87 struct proc *p = curproc; /* XXX */
88 register_t *argp;
89 int i;
90
91 p->p_traceflag |= KTRFAC_ACTIVE;
92 kth = ktrgetheader(KTR_SYSCALL);
93 MALLOC(ktp, struct ktr_syscall *, len, M_KTRACE, M_WAITOK);
94 ktp->ktr_code = code;
95 ktp->ktr_narg = narg;
96 argp = &ktp->ktr_args[0];
97 for (i = 0; i < narg; i++)
98 *argp++ = args[i];
99 kth->ktr_buf = (caddr_t)ktp;
100 kth->ktr_len = len;
101 ktrwrite(vp, kth, NULL);
102 FREE(ktp, M_KTRACE);
103 FREE(kth, M_KTRACE);
104 p->p_traceflag &= ~KTRFAC_ACTIVE;
105}
106
107void
2b9ccab7 108ktrsysret(struct vnode *vp, int code, int error, register_t retval)
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109{
110 struct ktr_header *kth;
111 struct ktr_sysret ktp;
112 struct proc *p = curproc; /* XXX */
113
114 p->p_traceflag |= KTRFAC_ACTIVE;
115 kth = ktrgetheader(KTR_SYSRET);
116 ktp.ktr_code = code;
117 ktp.ktr_error = error;
118 ktp.ktr_retval = retval; /* what about val2 ? */
119
120 kth->ktr_buf = (caddr_t)&ktp;
121 kth->ktr_len = sizeof(struct ktr_sysret);
122
123 ktrwrite(vp, kth, NULL);
124 FREE(kth, M_KTRACE);
125 p->p_traceflag &= ~KTRFAC_ACTIVE;
126}
127
128void
2b9ccab7 129ktrnamei(struct vnode *vp, char *path)
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130{
131 struct ktr_header *kth;
132 struct proc *p = curproc; /* XXX */
133
134 /*
135 * don't let vp get ripped out from under us
136 */
137 if (vp)
597aea93 138 vref(vp);
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139 p->p_traceflag |= KTRFAC_ACTIVE;
140 kth = ktrgetheader(KTR_NAMEI);
141 kth->ktr_len = strlen(path);
142 kth->ktr_buf = path;
143
144 ktrwrite(vp, kth, NULL);
145 if (vp)
146 vrele(vp);
147 FREE(kth, M_KTRACE);
148 p->p_traceflag &= ~KTRFAC_ACTIVE;
149}
150
151void
2b9ccab7 152ktrgenio(struct vnode *vp, int fd, enum uio_rw rw, struct uio *uio, int error)
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153{
154 struct ktr_header *kth;
155 struct ktr_genio ktg;
156 struct proc *p = curproc; /* XXX */
157
158 if (error)
159 return;
160 /*
161 * don't let p_tracep get ripped out from under us
162 */
163 if (vp)
597aea93 164 vref(vp);
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165 p->p_traceflag |= KTRFAC_ACTIVE;
166 kth = ktrgetheader(KTR_GENIO);
167 ktg.ktr_fd = fd;
168 ktg.ktr_rw = rw;
169 kth->ktr_buf = (caddr_t)&ktg;
170 kth->ktr_len = sizeof(struct ktr_genio);
171 uio->uio_offset = 0;
172 uio->uio_rw = UIO_WRITE;
173
174 ktrwrite(vp, kth, uio);
175 if (vp)
176 vrele(vp);
177 FREE(kth, M_KTRACE);
178 p->p_traceflag &= ~KTRFAC_ACTIVE;
179}
180
181void
2b9ccab7 182ktrpsig(struct vnode *vp, int sig, sig_t action, sigset_t *mask, int code)
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183{
184 struct ktr_header *kth;
185 struct ktr_psig kp;
186 struct proc *p = curproc; /* XXX */
187
188 /*
189 * don't let vp get ripped out from under us
190 */
191 if (vp)
597aea93 192 vref(vp);
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193 p->p_traceflag |= KTRFAC_ACTIVE;
194 kth = ktrgetheader(KTR_PSIG);
195 kp.signo = (char)sig;
196 kp.action = action;
197 kp.mask = *mask;
198 kp.code = code;
199 kth->ktr_buf = (caddr_t)&kp;
200 kth->ktr_len = sizeof (struct ktr_psig);
201
202 ktrwrite(vp, kth, NULL);
203 if (vp)
204 vrele(vp);
205 FREE(kth, M_KTRACE);
206 p->p_traceflag &= ~KTRFAC_ACTIVE;
207}
208
209void
2b9ccab7 210ktrcsw(struct vnode *vp, int out, int user)
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211{
212 struct ktr_header *kth;
213 struct ktr_csw kc;
214 struct proc *p = curproc; /* XXX */
215
216 /*
217 * don't let vp get ripped out from under us
218 */
219 if (vp)
597aea93 220 vref(vp);
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221 p->p_traceflag |= KTRFAC_ACTIVE;
222 kth = ktrgetheader(KTR_CSW);
223 kc.out = out;
224 kc.user = user;
225 kth->ktr_buf = (caddr_t)&kc;
226 kth->ktr_len = sizeof (struct ktr_csw);
227
228 ktrwrite(vp, kth, NULL);
229 if (vp)
230 vrele(vp);
231 FREE(kth, M_KTRACE);
232 p->p_traceflag &= ~KTRFAC_ACTIVE;
233}
234#endif
235
236/* Interface and common routines */
237
238/*
239 * ktrace system call
240 */
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241/* ARGSUSED */
242int
41c20dac 243ktrace(struct ktrace_args *uap)
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244{
245#ifdef KTRACE
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246 struct thread *td = curthread;
247 struct proc *curp = td->td_proc;
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248 struct vnode *vp = NULL;
249 struct proc *p;
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250 struct pgrp *pg;
251 int facs = uap->facs & ~KTRFAC_ROOT;
252 int ops = KTROP(uap->ops);
253 int descend = uap->ops & KTRFLAG_DESCEND;
254 int ret = 0;
255 int error = 0;
fad57d0e 256 struct nlookupdata nd;
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257
258 curp->p_traceflag |= KTRFAC_ACTIVE;
259 if (ops != KTROP_CLEAR) {
260 /*
261 * an operation which requires a file argument.
262 */
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263 error = nlookup_init(&nd, uap->fname,
264 UIO_USERSPACE, NLC_LOCKVP);
265 if (error == 0)
266 error = vn_open(&nd, NULL, FREAD|FWRITE|O_NOFOLLOW, 0);
267 if (error == 0 && nd.nl_open_vp->v_type != VREG)
268 error = EACCES;
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269 if (error) {
270 curp->p_traceflag &= ~KTRFAC_ACTIVE;
fad57d0e 271 nlookup_done(&nd);
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272 return (error);
273 }
fad57d0e
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274 vp = nd.nl_open_vp;
275 nd.nl_open_vp = NULL;
276 nlookup_done(&nd);
5fd012e0 277 VOP_UNLOCK(vp, 0, td);
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278 }
279 /*
280 * Clear all uses of the tracefile. XXX umm, what happens to the
281 * loop if vn_close() blocks?
282 */
283 if (ops == KTROP_CLEARFILE) {
f62004ad 284 FOREACH_PROC_IN_SYSTEM(p) {
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285 if (p->p_tracep == vp) {
286 if (ktrcanset(curp, p) && p->p_tracep == vp) {
287 p->p_tracep = NULL;
288 p->p_traceflag = 0;
fad57d0e 289 vn_close(vp, FREAD|FWRITE, td);
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290 } else {
291 error = EPERM;
292 }
293 }
294 }
295 goto done;
296 }
297 /*
298 * need something to (un)trace (XXX - why is this here?)
299 */
300 if (!facs) {
301 error = EINVAL;
302 goto done;
303 }
304 /*
305 * do it
306 */
307 if (uap->pid < 0) {
308 /*
309 * by process group
310 */
311 pg = pgfind(-uap->pid);
312 if (pg == NULL) {
313 error = ESRCH;
314 goto done;
315 }
fad57d0e 316 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
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317 if (descend)
318 ret |= ktrsetchildren(curp, p, ops, facs, vp);
319 else
320 ret |= ktrops(curp, p, ops, facs, vp);
fad57d0e 321 }
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322 } else {
323 /*
324 * by pid
325 */
326 p = pfind(uap->pid);
327 if (p == NULL) {
328 error = ESRCH;
329 goto done;
330 }
331 if (descend)
332 ret |= ktrsetchildren(curp, p, ops, facs, vp);
333 else
334 ret |= ktrops(curp, p, ops, facs, vp);
335 }
336 if (!ret)
337 error = EPERM;
338done:
339 if (vp != NULL)
fad57d0e 340 vn_close(vp, FWRITE, td);
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341 curp->p_traceflag &= ~KTRFAC_ACTIVE;
342 return (error);
343#else
344 return ENOSYS;
345#endif
346}
347
348/*
349 * utrace system call
350 */
351/* ARGSUSED */
352int
41c20dac 353utrace(struct utrace_args *uap)
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354{
355#ifdef KTRACE
356 struct ktr_header *kth;
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357 struct thread *td = curthread; /* XXX */
358 struct proc *p = td->td_proc;
984263bc 359 struct vnode *vp;
1fd87d54 360 caddr_t cp;
984263bc 361
dadab5e9 362 if (!KTRPOINT(td, KTR_USER))
984263bc 363 return (0);
ab2eb4eb 364 if (uap->len > KTR_USER_MAXLEN)
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365 return (EINVAL);
366 p->p_traceflag |= KTRFAC_ACTIVE;
367 /*
368 * don't let p_tracep get ripped out from under us while we are
369 * writing.
370 */
371 if ((vp = p->p_tracep) != NULL)
597aea93 372 vref(vp);
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373 kth = ktrgetheader(KTR_USER);
374 MALLOC(cp, caddr_t, uap->len, M_KTRACE, M_WAITOK);
375 if (!copyin(uap->addr, cp, uap->len)) {
376 kth->ktr_buf = cp;
377 kth->ktr_len = uap->len;
378 ktrwrite(vp, kth, NULL);
379 }
380 if (vp)
381 vrele(vp);
382 FREE(kth, M_KTRACE);
383 FREE(cp, M_KTRACE);
384 p->p_traceflag &= ~KTRFAC_ACTIVE;
385
386 return (0);
387#else
388 return (ENOSYS);
389#endif
390}
391
392#ifdef KTRACE
393static int
2b9ccab7 394ktrops(struct proc *curp, struct proc *p, int ops, int facs, struct vnode *vp)
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395{
396
397 if (!ktrcanset(curp, p))
398 return (0);
399 if (ops == KTROP_SET) {
400 if (p->p_tracep != vp) {
401 struct vnode *vtmp;
402
403 /*
404 * if trace file already in use, relinquish
405 */
597aea93 406 vref(vp);
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407 while ((vtmp = p->p_tracep) != NULL) {
408 p->p_tracep = NULL;
409 vrele(vtmp);
410 }
411 p->p_tracep = vp;
412 }
413 p->p_traceflag |= facs;
414 if (curp->p_ucred->cr_uid == 0)
415 p->p_traceflag |= KTRFAC_ROOT;
416 } else {
417 /* KTROP_CLEAR */
418 if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
419 struct vnode *vtmp;
420
421 /* no more tracing */
422 p->p_traceflag = 0;
423 if ((vtmp = p->p_tracep) != NULL) {
424 p->p_tracep = NULL;
425 vrele(vtmp);
426 }
427 }
428 }
429
430 return (1);
431}
432
433static int
2b9ccab7
EN
434ktrsetchildren(struct proc *curp, struct proc *top, int ops, int facs,
435 struct vnode *vp)
984263bc 436{
1fd87d54
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437 struct proc *p;
438 int ret = 0;
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439
440 p = top;
441 for (;;) {
442 ret |= ktrops(curp, p, ops, facs, vp);
443 /*
444 * If this process has children, descend to them next,
445 * otherwise do any siblings, and if done with this level,
446 * follow back up the tree (but not past top).
447 */
448 if (!LIST_EMPTY(&p->p_children))
449 p = LIST_FIRST(&p->p_children);
450 else for (;;) {
451 if (p == top)
452 return (ret);
453 if (LIST_NEXT(p, p_sibling)) {
454 p = LIST_NEXT(p, p_sibling);
455 break;
456 }
457 p = p->p_pptr;
458 }
459 }
460 /*NOTREACHED*/
461}
462
463static void
dadab5e9 464ktrwrite(struct vnode *vp, struct ktr_header *kth, struct uio *uio)
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465{
466 struct uio auio;
467 struct iovec aiov[2];
dadab5e9
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468 struct thread *td = curthread;
469 struct proc *p = td->td_proc; /* XXX */
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470 int error;
471
472 if (vp == NULL)
473 return;
474 auio.uio_iov = &aiov[0];
475 auio.uio_offset = 0;
476 auio.uio_segflg = UIO_SYSSPACE;
477 auio.uio_rw = UIO_WRITE;
478 aiov[0].iov_base = (caddr_t)kth;
479 aiov[0].iov_len = sizeof(struct ktr_header);
480 auio.uio_resid = sizeof(struct ktr_header);
481 auio.uio_iovcnt = 1;
dadab5e9 482 auio.uio_td = curthread;
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483 if (kth->ktr_len > 0) {
484 auio.uio_iovcnt++;
485 aiov[1].iov_base = kth->ktr_buf;
486 aiov[1].iov_len = kth->ktr_len;
487 auio.uio_resid += kth->ktr_len;
488 if (uio != NULL)
489 kth->ktr_len += uio->uio_resid;
490 }
6bdbb368 491 VOP_LEASE(vp, td, p->p_ucred, LEASE_WRITE);
5fd012e0 492 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
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493 error = VOP_WRITE(vp, &auio, IO_UNIT | IO_APPEND, p->p_ucred);
494 if (error == 0 && uio != NULL) {
6bdbb368 495 VOP_LEASE(vp, td, p->p_ucred, LEASE_WRITE);
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496 error = VOP_WRITE(vp, uio, IO_UNIT | IO_APPEND, p->p_ucred);
497 }
5fd012e0 498 VOP_UNLOCK(vp, 0, td);
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499 if (!error)
500 return;
501 /*
502 * If error encountered, give up tracing on this vnode. XXX what
503 * happens to the loop if vrele() blocks?
504 */
505 log(LOG_NOTICE, "ktrace write failed, errno %d, tracing stopped\n",
506 error);
f62004ad 507 FOREACH_PROC_IN_SYSTEM(p) {
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508 if (p->p_tracep == vp) {
509 p->p_tracep = NULL;
510 p->p_traceflag = 0;
511 vrele(vp);
512 }
513 }
514}
515
516/*
517 * Return true if caller has permission to set the ktracing state
518 * of target. Essentially, the target can't possess any
519 * more permissions than the caller. KTRFAC_ROOT signifies that
520 * root previously set the tracing status on the target process, and
521 * so, only root may further change it.
522 *
523 * TODO: check groups. use caller effective gid.
524 */
525static int
41c20dac 526ktrcanset(struct proc *callp, struct proc *targetp)
984263bc 527{
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MD
528 struct ucred *caller = callp->p_ucred;
529 struct ucred *target = targetp->p_ucred;
984263bc 530
41c20dac 531 if (!PRISON_CHECK(caller, target))
984263bc 532 return (0);
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MD
533 if ((caller->cr_uid == target->cr_ruid &&
534 target->cr_ruid == target->cr_svuid &&
535 caller->cr_rgid == target->cr_rgid && /* XXX */
536 target->cr_rgid == target->cr_svgid &&
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537 (targetp->p_traceflag & KTRFAC_ROOT) == 0 &&
538 (targetp->p_flag & P_SUGID) == 0) ||
41c20dac 539 caller->cr_uid == 0)
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540 return (1);
541
542 return (0);
543}
544
545#endif /* KTRACE */