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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 1.3 2003/06/23 17:55:41 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 __P((int type));
59 static void ktrwrite __P((struct vnode *, struct ktr_header *, struct uio *));
60 static int ktrcanset __P((struct proc *,struct proc *));
61 static int ktrsetchildren __P((struct proc *,struct proc *,int,int,struct vnode *));
62 static int ktrops __P((struct proc *,struct proc *,int,int,struct vnode *));
65 static struct ktr_header *
69 register 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 register 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 */
262 #ifndef _SYS_SYSPROTO_H_
272 ktrace(struct ktrace_args *uap)
275 struct proc *curp = curproc;
276 struct vnode *vp = NULL;
279 int facs = uap->facs & ~KTRFAC_ROOT;
280 int ops = KTROP(uap->ops);
281 int descend = uap->ops & KTRFLAG_DESCEND;
286 curp->p_traceflag |= KTRFAC_ACTIVE;
287 if (ops != KTROP_CLEAR) {
289 * an operation which requires a file argument.
291 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, uap->fname, curp);
292 error = vn_open(&nd, FREAD|FWRITE|O_NOFOLLOW, 0);
294 curp->p_traceflag &= ~KTRFAC_ACTIVE;
297 NDFREE(&nd, NDF_ONLY_PNBUF);
299 VOP_UNLOCK(vp, 0, curp);
300 if (vp->v_type != VREG) {
301 (void) vn_close(vp, FREAD|FWRITE, curp->p_ucred, curp);
302 curp->p_traceflag &= ~KTRFAC_ACTIVE;
307 * Clear all uses of the tracefile. XXX umm, what happens to the
308 * loop if vn_close() blocks?
310 if (ops == KTROP_CLEARFILE) {
311 LIST_FOREACH(p, &allproc, p_list) {
312 if (p->p_tracep == vp) {
313 if (ktrcanset(curp, p) && p->p_tracep == vp) {
316 (void) vn_close(vp, FREAD|FWRITE,
326 * need something to (un)trace (XXX - why is this here?)
339 pg = pgfind(-uap->pid);
344 LIST_FOREACH(p, &pg->pg_members, p_pglist)
346 ret |= ktrsetchildren(curp, p, ops, facs, vp);
348 ret |= ktrops(curp, p, ops, facs, vp);
360 ret |= ktrsetchildren(curp, p, ops, facs, vp);
362 ret |= ktrops(curp, p, ops, facs, vp);
368 (void) vn_close(vp, FWRITE, curp->p_ucred, curp);
369 curp->p_traceflag &= ~KTRFAC_ACTIVE;
381 utrace(struct utrace_args *uap)
384 struct ktr_header *kth;
385 struct proc *p = curproc; /* XXX */
389 if (!KTRPOINT(p, KTR_USER))
391 if (SCARG(uap, len) > KTR_USER_MAXLEN)
393 p->p_traceflag |= KTRFAC_ACTIVE;
395 * don't let p_tracep get ripped out from under us while we are
398 if ((vp = p->p_tracep) != NULL)
400 kth = ktrgetheader(KTR_USER);
401 MALLOC(cp, caddr_t, uap->len, M_KTRACE, M_WAITOK);
402 if (!copyin(uap->addr, cp, uap->len)) {
404 kth->ktr_len = uap->len;
405 ktrwrite(vp, kth, NULL);
411 p->p_traceflag &= ~KTRFAC_ACTIVE;
421 ktrops(curp, p, ops, facs, vp)
422 struct proc *p, *curp;
427 if (!ktrcanset(curp, p))
429 if (ops == KTROP_SET) {
430 if (p->p_tracep != vp) {
434 * if trace file already in use, relinquish
437 while ((vtmp = p->p_tracep) != NULL) {
443 p->p_traceflag |= facs;
444 if (curp->p_ucred->cr_uid == 0)
445 p->p_traceflag |= KTRFAC_ROOT;
448 if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
451 /* no more tracing */
453 if ((vtmp = p->p_tracep) != NULL) {
464 ktrsetchildren(curp, top, ops, facs, vp)
465 struct proc *curp, *top;
469 register struct proc *p;
470 register int ret = 0;
474 ret |= ktrops(curp, p, ops, facs, vp);
476 * If this process has children, descend to them next,
477 * otherwise do any siblings, and if done with this level,
478 * follow back up the tree (but not past top).
480 if (!LIST_EMPTY(&p->p_children))
481 p = LIST_FIRST(&p->p_children);
485 if (LIST_NEXT(p, p_sibling)) {
486 p = LIST_NEXT(p, p_sibling);
496 ktrwrite(vp, kth, uio)
498 register struct ktr_header *kth;
502 struct iovec aiov[2];
503 register struct proc *p = curproc; /* XXX */
508 auio.uio_iov = &aiov[0];
510 auio.uio_segflg = UIO_SYSSPACE;
511 auio.uio_rw = UIO_WRITE;
512 aiov[0].iov_base = (caddr_t)kth;
513 aiov[0].iov_len = sizeof(struct ktr_header);
514 auio.uio_resid = sizeof(struct ktr_header);
516 auio.uio_procp = curproc;
517 if (kth->ktr_len > 0) {
519 aiov[1].iov_base = kth->ktr_buf;
520 aiov[1].iov_len = kth->ktr_len;
521 auio.uio_resid += kth->ktr_len;
523 kth->ktr_len += uio->uio_resid;
525 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
526 (void)VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE);
527 error = VOP_WRITE(vp, &auio, IO_UNIT | IO_APPEND, p->p_ucred);
528 if (error == 0 && uio != NULL) {
529 (void)VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE);
530 error = VOP_WRITE(vp, uio, IO_UNIT | IO_APPEND, p->p_ucred);
532 VOP_UNLOCK(vp, 0, p);
536 * If error encountered, give up tracing on this vnode. XXX what
537 * happens to the loop if vrele() blocks?
539 log(LOG_NOTICE, "ktrace write failed, errno %d, tracing stopped\n",
541 LIST_FOREACH(p, &allproc, p_list) {
542 if (p->p_tracep == vp) {
551 * Return true if caller has permission to set the ktracing state
552 * of target. Essentially, the target can't possess any
553 * more permissions than the caller. KTRFAC_ROOT signifies that
554 * root previously set the tracing status on the target process, and
555 * so, only root may further change it.
557 * TODO: check groups. use caller effective gid.
560 ktrcanset(struct proc *callp, struct proc *targetp)
562 struct ucred *caller = callp->p_ucred;
563 struct ucred *target = targetp->p_ucred;
565 if (!PRISON_CHECK(caller, target))
567 if ((caller->cr_uid == target->cr_ruid &&
568 target->cr_ruid == target->cr_svuid &&
569 caller->cr_rgid == target->cr_rgid && /* XXX */
570 target->cr_rgid == target->cr_svgid &&
571 (targetp->p_traceflag & KTRFAC_ROOT) == 0 &&
572 (targetp->p_flag & P_SUGID) == 0) ||