Optimize lwkt_rwlock.c a bit
[dragonfly.git] / sys / kern / kern_ktrace.c
CommitLineData
984263bc
MD
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 $
1de703da 35 * $DragonFly: src/sys/kern/kern_ktrace.c,v 1.2 2003/06/17 04:28:41 dillon Exp $
984263bc
MD
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>
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>
53
54#include <vm/vm_zone.h>
55static MALLOC_DEFINE(M_KTRACE, "KTRACE", "KTRACE");
56
57#ifdef KTRACE
58static struct ktr_header *ktrgetheader __P((int type));
59static void ktrwrite __P((struct vnode *, struct ktr_header *, struct uio *));
60static int ktrcanset __P((struct proc *,struct proc *));
61static int ktrsetchildren __P((struct proc *,struct proc *,int,int,struct vnode *));
62static int ktrops __P((struct proc *,struct proc *,int,int,struct vnode *));
63
64
65static struct ktr_header *
66ktrgetheader(type)
67 int type;
68{
69 register struct ktr_header *kth;
70 struct proc *p = curproc; /* XXX */
71
72 MALLOC(kth, struct ktr_header *, sizeof (struct ktr_header),
73 M_KTRACE, M_WAITOK);
74 kth->ktr_type = type;
75 microtime(&kth->ktr_time);
76 kth->ktr_pid = p->p_pid;
77 bcopy(p->p_comm, kth->ktr_comm, MAXCOMLEN + 1);
78 return (kth);
79}
80
81void
82ktrsyscall(vp, code, narg, args)
83 struct vnode *vp;
84 int code, narg;
85 register_t args[];
86{
87 struct ktr_header *kth;
88 struct ktr_syscall *ktp;
89 register int len = offsetof(struct ktr_syscall, ktr_args) +
90 (narg * sizeof(register_t));
91 struct proc *p = curproc; /* XXX */
92 register_t *argp;
93 int i;
94
95 p->p_traceflag |= KTRFAC_ACTIVE;
96 kth = ktrgetheader(KTR_SYSCALL);
97 MALLOC(ktp, struct ktr_syscall *, len, M_KTRACE, M_WAITOK);
98 ktp->ktr_code = code;
99 ktp->ktr_narg = narg;
100 argp = &ktp->ktr_args[0];
101 for (i = 0; i < narg; i++)
102 *argp++ = args[i];
103 kth->ktr_buf = (caddr_t)ktp;
104 kth->ktr_len = len;
105 ktrwrite(vp, kth, NULL);
106 FREE(ktp, M_KTRACE);
107 FREE(kth, M_KTRACE);
108 p->p_traceflag &= ~KTRFAC_ACTIVE;
109}
110
111void
112ktrsysret(vp, code, error, retval)
113 struct vnode *vp;
114 int code, error;
115 register_t retval;
116{
117 struct ktr_header *kth;
118 struct ktr_sysret ktp;
119 struct proc *p = curproc; /* XXX */
120
121 p->p_traceflag |= KTRFAC_ACTIVE;
122 kth = ktrgetheader(KTR_SYSRET);
123 ktp.ktr_code = code;
124 ktp.ktr_error = error;
125 ktp.ktr_retval = retval; /* what about val2 ? */
126
127 kth->ktr_buf = (caddr_t)&ktp;
128 kth->ktr_len = sizeof(struct ktr_sysret);
129
130 ktrwrite(vp, kth, NULL);
131 FREE(kth, M_KTRACE);
132 p->p_traceflag &= ~KTRFAC_ACTIVE;
133}
134
135void
136ktrnamei(vp, path)
137 struct vnode *vp;
138 char *path;
139{
140 struct ktr_header *kth;
141 struct proc *p = curproc; /* XXX */
142
143 /*
144 * don't let vp get ripped out from under us
145 */
146 if (vp)
147 VREF(vp);
148 p->p_traceflag |= KTRFAC_ACTIVE;
149 kth = ktrgetheader(KTR_NAMEI);
150 kth->ktr_len = strlen(path);
151 kth->ktr_buf = path;
152
153 ktrwrite(vp, kth, NULL);
154 if (vp)
155 vrele(vp);
156 FREE(kth, M_KTRACE);
157 p->p_traceflag &= ~KTRFAC_ACTIVE;
158}
159
160void
161ktrgenio(vp, fd, rw, uio, error)
162 struct vnode *vp;
163 int fd;
164 enum uio_rw rw;
165 struct uio *uio;
166 int error;
167{
168 struct ktr_header *kth;
169 struct ktr_genio ktg;
170 struct proc *p = curproc; /* XXX */
171
172 if (error)
173 return;
174 /*
175 * don't let p_tracep get ripped out from under us
176 */
177 if (vp)
178 VREF(vp);
179 p->p_traceflag |= KTRFAC_ACTIVE;
180 kth = ktrgetheader(KTR_GENIO);
181 ktg.ktr_fd = fd;
182 ktg.ktr_rw = rw;
183 kth->ktr_buf = (caddr_t)&ktg;
184 kth->ktr_len = sizeof(struct ktr_genio);
185 uio->uio_offset = 0;
186 uio->uio_rw = UIO_WRITE;
187
188 ktrwrite(vp, kth, uio);
189 if (vp)
190 vrele(vp);
191 FREE(kth, M_KTRACE);
192 p->p_traceflag &= ~KTRFAC_ACTIVE;
193}
194
195void
196ktrpsig(vp, sig, action, mask, code)
197 struct vnode *vp;
198 int sig;
199 sig_t action;
200 sigset_t *mask;
201 int code;
202{
203 struct ktr_header *kth;
204 struct ktr_psig kp;
205 struct proc *p = curproc; /* XXX */
206
207 /*
208 * don't let vp get ripped out from under us
209 */
210 if (vp)
211 VREF(vp);
212 p->p_traceflag |= KTRFAC_ACTIVE;
213 kth = ktrgetheader(KTR_PSIG);
214 kp.signo = (char)sig;
215 kp.action = action;
216 kp.mask = *mask;
217 kp.code = code;
218 kth->ktr_buf = (caddr_t)&kp;
219 kth->ktr_len = sizeof (struct ktr_psig);
220
221 ktrwrite(vp, kth, NULL);
222 if (vp)
223 vrele(vp);
224 FREE(kth, M_KTRACE);
225 p->p_traceflag &= ~KTRFAC_ACTIVE;
226}
227
228void
229ktrcsw(vp, out, user)
230 struct vnode *vp;
231 int out, user;
232{
233 struct ktr_header *kth;
234 struct ktr_csw kc;
235 struct proc *p = curproc; /* XXX */
236
237 /*
238 * don't let vp get ripped out from under us
239 */
240 if (vp)
241 VREF(vp);
242 p->p_traceflag |= KTRFAC_ACTIVE;
243 kth = ktrgetheader(KTR_CSW);
244 kc.out = out;
245 kc.user = user;
246 kth->ktr_buf = (caddr_t)&kc;
247 kth->ktr_len = sizeof (struct ktr_csw);
248
249 ktrwrite(vp, kth, NULL);
250 if (vp)
251 vrele(vp);
252 FREE(kth, M_KTRACE);
253 p->p_traceflag &= ~KTRFAC_ACTIVE;
254}
255#endif
256
257/* Interface and common routines */
258
259/*
260 * ktrace system call
261 */
262#ifndef _SYS_SYSPROTO_H_
263struct ktrace_args {
264 char *fname;
265 int ops;
266 int facs;
267 int pid;
268};
269#endif
270/* ARGSUSED */
271int
272ktrace(curp, uap)
273 struct proc *curp;
274 register struct ktrace_args *uap;
275{
276#ifdef KTRACE
277 register struct vnode *vp = NULL;
278 register struct proc *p;
279 struct pgrp *pg;
280 int facs = uap->facs & ~KTRFAC_ROOT;
281 int ops = KTROP(uap->ops);
282 int descend = uap->ops & KTRFLAG_DESCEND;
283 int ret = 0;
284 int error = 0;
285 struct nameidata nd;
286
287 curp->p_traceflag |= KTRFAC_ACTIVE;
288 if (ops != KTROP_CLEAR) {
289 /*
290 * an operation which requires a file argument.
291 */
292 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, uap->fname, curp);
293 error = vn_open(&nd, FREAD|FWRITE|O_NOFOLLOW, 0);
294 if (error) {
295 curp->p_traceflag &= ~KTRFAC_ACTIVE;
296 return (error);
297 }
298 NDFREE(&nd, NDF_ONLY_PNBUF);
299 vp = nd.ni_vp;
300 VOP_UNLOCK(vp, 0, curp);
301 if (vp->v_type != VREG) {
302 (void) vn_close(vp, FREAD|FWRITE, curp->p_ucred, curp);
303 curp->p_traceflag &= ~KTRFAC_ACTIVE;
304 return (EACCES);
305 }
306 }
307 /*
308 * Clear all uses of the tracefile. XXX umm, what happens to the
309 * loop if vn_close() blocks?
310 */
311 if (ops == KTROP_CLEARFILE) {
312 LIST_FOREACH(p, &allproc, p_list) {
313 if (p->p_tracep == vp) {
314 if (ktrcanset(curp, p) && p->p_tracep == vp) {
315 p->p_tracep = NULL;
316 p->p_traceflag = 0;
317 (void) vn_close(vp, FREAD|FWRITE,
318 p->p_ucred, p);
319 } else {
320 error = EPERM;
321 }
322 }
323 }
324 goto done;
325 }
326 /*
327 * need something to (un)trace (XXX - why is this here?)
328 */
329 if (!facs) {
330 error = EINVAL;
331 goto done;
332 }
333 /*
334 * do it
335 */
336 if (uap->pid < 0) {
337 /*
338 * by process group
339 */
340 pg = pgfind(-uap->pid);
341 if (pg == NULL) {
342 error = ESRCH;
343 goto done;
344 }
345 LIST_FOREACH(p, &pg->pg_members, p_pglist)
346 if (descend)
347 ret |= ktrsetchildren(curp, p, ops, facs, vp);
348 else
349 ret |= ktrops(curp, p, ops, facs, vp);
350
351 } else {
352 /*
353 * by pid
354 */
355 p = pfind(uap->pid);
356 if (p == NULL) {
357 error = ESRCH;
358 goto done;
359 }
360 if (descend)
361 ret |= ktrsetchildren(curp, p, ops, facs, vp);
362 else
363 ret |= ktrops(curp, p, ops, facs, vp);
364 }
365 if (!ret)
366 error = EPERM;
367done:
368 if (vp != NULL)
369 (void) vn_close(vp, FWRITE, curp->p_ucred, curp);
370 curp->p_traceflag &= ~KTRFAC_ACTIVE;
371 return (error);
372#else
373 return ENOSYS;
374#endif
375}
376
377/*
378 * utrace system call
379 */
380/* ARGSUSED */
381int
382utrace(curp, uap)
383 struct proc *curp;
384 register struct utrace_args *uap;
385{
386#ifdef KTRACE
387 struct ktr_header *kth;
388 struct proc *p = curproc; /* XXX */
389 struct vnode *vp;
390 register caddr_t cp;
391
392 if (!KTRPOINT(p, KTR_USER))
393 return (0);
394 if (SCARG(uap, len) > KTR_USER_MAXLEN)
395 return (EINVAL);
396 p->p_traceflag |= KTRFAC_ACTIVE;
397 /*
398 * don't let p_tracep get ripped out from under us while we are
399 * writing.
400 */
401 if ((vp = p->p_tracep) != NULL)
402 VREF(vp);
403 kth = ktrgetheader(KTR_USER);
404 MALLOC(cp, caddr_t, uap->len, M_KTRACE, M_WAITOK);
405 if (!copyin(uap->addr, cp, uap->len)) {
406 kth->ktr_buf = cp;
407 kth->ktr_len = uap->len;
408 ktrwrite(vp, kth, NULL);
409 }
410 if (vp)
411 vrele(vp);
412 FREE(kth, M_KTRACE);
413 FREE(cp, M_KTRACE);
414 p->p_traceflag &= ~KTRFAC_ACTIVE;
415
416 return (0);
417#else
418 return (ENOSYS);
419#endif
420}
421
422#ifdef KTRACE
423static int
424ktrops(curp, p, ops, facs, vp)
425 struct proc *p, *curp;
426 int ops, facs;
427 struct vnode *vp;
428{
429
430 if (!ktrcanset(curp, p))
431 return (0);
432 if (ops == KTROP_SET) {
433 if (p->p_tracep != vp) {
434 struct vnode *vtmp;
435
436 /*
437 * if trace file already in use, relinquish
438 */
439 VREF(vp);
440 while ((vtmp = p->p_tracep) != NULL) {
441 p->p_tracep = NULL;
442 vrele(vtmp);
443 }
444 p->p_tracep = vp;
445 }
446 p->p_traceflag |= facs;
447 if (curp->p_ucred->cr_uid == 0)
448 p->p_traceflag |= KTRFAC_ROOT;
449 } else {
450 /* KTROP_CLEAR */
451 if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
452 struct vnode *vtmp;
453
454 /* no more tracing */
455 p->p_traceflag = 0;
456 if ((vtmp = p->p_tracep) != NULL) {
457 p->p_tracep = NULL;
458 vrele(vtmp);
459 }
460 }
461 }
462
463 return (1);
464}
465
466static int
467ktrsetchildren(curp, top, ops, facs, vp)
468 struct proc *curp, *top;
469 int ops, facs;
470 struct vnode *vp;
471{
472 register struct proc *p;
473 register int ret = 0;
474
475 p = top;
476 for (;;) {
477 ret |= ktrops(curp, p, ops, facs, vp);
478 /*
479 * If this process has children, descend to them next,
480 * otherwise do any siblings, and if done with this level,
481 * follow back up the tree (but not past top).
482 */
483 if (!LIST_EMPTY(&p->p_children))
484 p = LIST_FIRST(&p->p_children);
485 else for (;;) {
486 if (p == top)
487 return (ret);
488 if (LIST_NEXT(p, p_sibling)) {
489 p = LIST_NEXT(p, p_sibling);
490 break;
491 }
492 p = p->p_pptr;
493 }
494 }
495 /*NOTREACHED*/
496}
497
498static void
499ktrwrite(vp, kth, uio)
500 struct vnode *vp;
501 register struct ktr_header *kth;
502 struct uio *uio;
503{
504 struct uio auio;
505 struct iovec aiov[2];
506 register struct proc *p = curproc; /* XXX */
507 int error;
508
509 if (vp == NULL)
510 return;
511 auio.uio_iov = &aiov[0];
512 auio.uio_offset = 0;
513 auio.uio_segflg = UIO_SYSSPACE;
514 auio.uio_rw = UIO_WRITE;
515 aiov[0].iov_base = (caddr_t)kth;
516 aiov[0].iov_len = sizeof(struct ktr_header);
517 auio.uio_resid = sizeof(struct ktr_header);
518 auio.uio_iovcnt = 1;
519 auio.uio_procp = curproc;
520 if (kth->ktr_len > 0) {
521 auio.uio_iovcnt++;
522 aiov[1].iov_base = kth->ktr_buf;
523 aiov[1].iov_len = kth->ktr_len;
524 auio.uio_resid += kth->ktr_len;
525 if (uio != NULL)
526 kth->ktr_len += uio->uio_resid;
527 }
528 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
529 (void)VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE);
530 error = VOP_WRITE(vp, &auio, IO_UNIT | IO_APPEND, p->p_ucred);
531 if (error == 0 && uio != NULL) {
532 (void)VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE);
533 error = VOP_WRITE(vp, uio, IO_UNIT | IO_APPEND, p->p_ucred);
534 }
535 VOP_UNLOCK(vp, 0, p);
536 if (!error)
537 return;
538 /*
539 * If error encountered, give up tracing on this vnode. XXX what
540 * happens to the loop if vrele() blocks?
541 */
542 log(LOG_NOTICE, "ktrace write failed, errno %d, tracing stopped\n",
543 error);
544 LIST_FOREACH(p, &allproc, p_list) {
545 if (p->p_tracep == vp) {
546 p->p_tracep = NULL;
547 p->p_traceflag = 0;
548 vrele(vp);
549 }
550 }
551}
552
553/*
554 * Return true if caller has permission to set the ktracing state
555 * of target. Essentially, the target can't possess any
556 * more permissions than the caller. KTRFAC_ROOT signifies that
557 * root previously set the tracing status on the target process, and
558 * so, only root may further change it.
559 *
560 * TODO: check groups. use caller effective gid.
561 */
562static int
563ktrcanset(callp, targetp)
564 struct proc *callp, *targetp;
565{
566 register struct pcred *caller = callp->p_cred;
567 register struct pcred *target = targetp->p_cred;
568
569 if (!PRISON_CHECK(callp, targetp))
570 return (0);
571 if ((caller->pc_ucred->cr_uid == target->p_ruid &&
572 target->p_ruid == target->p_svuid &&
573 caller->p_rgid == target->p_rgid && /* XXX */
574 target->p_rgid == target->p_svgid &&
575 (targetp->p_traceflag & KTRFAC_ROOT) == 0 &&
576 (targetp->p_flag & P_SUGID) == 0) ||
577 caller->pc_ucred->cr_uid == 0)
578 return (1);
579
580 return (0);
581}
582
583#endif /* KTRACE */