[unix-history] / usr / src / sys / kern / kern_ktrace.c

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *	@(#)kern_ktrace.c	7.6 (Berkeley) %G%
 */

#ifdef KTRACE

#include "param.h"
#include "syscontext.h"
#include "proc.h"
#include "file.h"
#include "vnode.h"
#include "ktrace.h"
#include "malloc.h"

#include "syscalls.c"

extern int nsysent;
extern char *syscallnames[];

int ktrace_nocheck = 1;

struct ktr_header *
ktrgetheader(type)
{
	register struct ktr_header *kth;

	MALLOC(kth, struct ktr_header *, sizeof (struct ktr_header), 
		M_TEMP, M_WAITOK);
	kth->ktr_type = type;
	microtime(&kth->ktr_time);
	kth->ktr_pid = u.u_procp->p_pid;
	bcopy(u.u_procp->p_comm, kth->ktr_comm, MAXCOMLEN);
	return (kth);
}

ktrsyscall(vp, code, narg, args)
	struct vnode *vp;
	int code, narg, args[];
{
	struct	ktr_header *kth = ktrgetheader(KTR_SYSCALL);
	struct	ktr_syscall *ktp;
	register len = sizeof(struct ktr_syscall) + (narg * sizeof(int));
	int 	*argp, i;

	if (kth == NULL)
		return;
	MALLOC(ktp, struct ktr_syscall *, len, M_TEMP, M_WAITOK);
	ktp->ktr_code = code;
	ktp->ktr_narg = narg;
	argp = (int *)((char *)ktp + sizeof(struct ktr_syscall));
	for (i = 0; i < narg; i++)
		*argp++ = args[i];
	kth->ktr_buf = (caddr_t)ktp;
	kth->ktr_len = len;
	ktrwrite(vp, kth);
	FREE(ktp, M_TEMP);
	FREE(kth, M_TEMP);
}

ktrsysret(vp, code, error, retval)
	struct vnode *vp;
	int code, error, retval;
{
	struct ktr_header *kth = ktrgetheader(KTR_SYSRET);
	struct ktr_sysret ktp;

	if (kth == NULL)
		return;
	ktp.ktr_code = code;
	ktp.ktr_error = error;
	ktp.ktr_retval = retval;		/* what about val2 ? */

	kth->ktr_buf = (caddr_t)&ktp;
	kth->ktr_len = sizeof(struct ktr_sysret);

	ktrwrite(vp, kth);
	FREE(kth, M_TEMP);
}

ktrnamei(vp, path)
	struct vnode *vp;
	char *path;
{
	struct ktr_header *kth = ktrgetheader(KTR_NAMEI);

	if (kth == NULL)
		return;
	kth->ktr_len = strlen(path);
	kth->ktr_buf = path;

	ktrwrite(vp, kth);
	FREE(kth, M_TEMP);
}

ktrgenio(vp, fd, rw, iov, len, error)
	struct vnode *vp;
	int fd;
	enum uio_rw rw;
	register struct iovec *iov;
{
	struct ktr_header *kth = ktrgetheader(KTR_GENIO);
	register struct ktr_genio *ktp;
	register caddr_t cp;
	register int resid = len, cnt;
	
	if (kth == NULL || error)
		return;
	MALLOC(ktp, struct ktr_genio *, sizeof(struct ktr_genio) + len,
		M_TEMP, M_WAITOK);
	ktp->ktr_fd = fd;
	ktp->ktr_rw = rw;
	cp = (caddr_t)((char *)ktp + sizeof (struct ktr_genio));
	while (resid > 0) {
		if ((cnt = iov->iov_len) > resid)
			cnt = resid;
		if (copyin(iov->iov_base, cp, (unsigned)cnt))
			goto done;
		cp += cnt;
		resid -= cnt;
		iov++;
	}
	kth->ktr_buf = (caddr_t)ktp;
	kth->ktr_len = sizeof (struct ktr_genio) + len;

	ktrwrite(vp, kth);
done:
	FREE(kth, M_TEMP);
	FREE(ktp, M_TEMP);
}

ktrpsig(vp, sig, action, mask, code)
	struct	vnode *vp;
	sig_t	action;
{
	struct ktr_header *kth = ktrgetheader(KTR_PSIG);
	struct ktr_psig	kp;

	if (kth == NULL)
		return;
	kp.signo = (char)sig;
	kp.action = action;
	kp.mask = mask;
	kp.code = code;
	kth->ktr_buf = (caddr_t)&kp;
	kth->ktr_len = sizeof (struct ktr_psig);

	ktrwrite(vp, kth);
	FREE(kth, M_TEMP);
}

/* Interface and common routines */

/*
 * ktrace system call
 */
/* ARGSUSED */
ktrace(curp, uap, retval)
	struct proc *curp;
	register struct args {
		char	*fname;
		int	ops;
		int	facs;
		int	pid;
	} *uap;
	int *retval;
{
	register struct vnode *vp = NULL;
	register struct nameidata *ndp = &u.u_nd;
	register struct proc *p;
	register ops = KTROP(uap->ops);
	struct pgrp *pg;
	register int facs = uap->facs;
	register int ret = 0;
	int error = 0;

	/*
	 * Until security implications are thought through,
	 * limit tracing to root (unless ktrace_nocheck is set).
	 */
	if (!ktrace_nocheck && (error = suser(u.u_cred, &u.u_acflag)))
		RETURN (error);
	if (ops != KTROP_CLEAR) {
		/*
		 * an operation which requires a file argument.
		 */
		ndp->ni_segflg = UIO_USERSPACE;
		ndp->ni_dirp = uap->fname;
		if (error = vn_open(ndp, FREAD|FWRITE, 0))
			RETURN (error);
		vp = ndp->ni_vp;
		if (vp->v_type != VREG) {
			vrele(vp);
			RETURN (EACCES);
		}
	}
	/*
	 * Clear all uses of the tracefile
	 */
	if (ops == KTROP_CLEARFILE) {
		for (p = allproc; p != NULL; p = p->p_nxt) {
			if (p->p_tracep == vp) {
				p->p_tracep = NULL;
				p->p_traceflag = 0;
				vrele(vp);
			}
		}
		goto done;
	}
	/*
	 * need something to (un)trace
	 */
	if (!facs) {
		error = EINVAL;
		goto done;
	}
	/* 
	 * doit
	 */
	if (uap->pid < 0) {
		pg = pgfind(-uap->pid);
		if (pg == NULL) {
			error = ESRCH;
			goto done;
		}
		for (p = pg->pg_mem; p != NULL; p = p->p_pgrpnxt)
			if (uap->ops&KTRFLAG_DESCEND)
				ret |= ktrsetchildren(p, ops, facs, vp);
			else 
				ret |= ktrops(p, ops, facs, vp);
					
	} else {
		p = pfind(uap->pid);
		if (p == NULL) {
			error = ESRCH;
			goto done;
		}
		if (ops&KTRFLAG_DESCEND)
			ret |= ktrsetchildren(p, ops, facs, vp);
		else
			ret |= ktrops(p, ops, facs, vp);
	}
	if (!ret)
		error = EPERM;
done:
	if (vp != NULL)
		vrele(vp);
	RETURN (error);
}

ktrops(p, ops, facs, vp)
	struct proc *p;
	struct vnode *vp;
{

	if (u.u_uid && u.u_uid != p->p_uid)
		return 0;
	if (ops == KTROP_SET) {
		if (p->p_tracep != vp) { 
			/*
			 * if trace file already in use, relinquish
			 */
			if (p->p_tracep != NULL)
				vrele(p->p_tracep);
			VREF(vp);
			p->p_tracep = vp;
		}
		p->p_traceflag |= facs;
	} else {	
		/* KTROP_CLEAR */
		if (((p->p_traceflag &= ~facs) & ~KTRFAC_INHERIT) == 0) {
			/* no more tracing */
			p->p_traceflag = 0;
			if (p->p_tracep != NULL) {
				vrele(p->p_tracep);
				p->p_tracep = NULL;
			}
		}
	}

	return 1;
}

ktrsetchildren(top, ops, facs, vp)
	struct proc *top;
	struct vnode *vp;
{
	register struct proc *p;
	register int ret = 0;

	p = top;
	for (;;) {
		ret |= ktrops(p, ops, facs, vp);
		/*
		 * If this process has children, descend to them next,
		 * otherwise do any siblings, and if done with this level,
		 * follow back up the tree (but not past top).
		 */
		if (p->p_cptr)
			p = p->p_cptr;
		else if (p == top)
			return ret;
		else if (p->p_osptr)
			p = p->p_osptr;
		else for (;;) {
			p = p->p_pptr;
			if (p == top)
				return ret;
			if (p->p_osptr) {
				p = p->p_osptr;
				break;
			}
		}
	}
	/*NOTREACHED*/
}

ktrwrite(vp, kth)
	struct vnode *vp;
	register struct ktr_header *kth;
{
	struct uio auio;
	struct iovec aiov[2];
	struct proc *p;
	int error;

	if (vp == NULL)
		return;
	auio.uio_iov = &aiov[0];
	auio.uio_offset = 0;
	auio.uio_segflg = UIO_SYSSPACE;
	auio.uio_rw = UIO_WRITE;
	aiov[0].iov_base = (caddr_t)kth;
	aiov[0].iov_len = sizeof(struct ktr_header);
	auio.uio_resid = sizeof(struct ktr_header);
	auio.uio_iovcnt = 1;
	if (kth->ktr_len > 0) {
		auio.uio_iovcnt++;
		aiov[1].iov_base = kth->ktr_buf;
		aiov[1].iov_len = kth->ktr_len;
		auio.uio_resid += kth->ktr_len;
	}
	VOP_LOCK(vp);
	error = VOP_WRITE(vp, &auio, IO_UNIT|IO_APPEND, u.u_cred);
	VOP_UNLOCK(vp);
	if (!error)
		return;
	/*
	 * If error encountered, give up tracing on this vnode.
	 */
	uprintf("\ntrace write failed with errno %d, tracing stopped\n", error);
	for (p = allproc; p != NULL; p = p->p_nxt) {
		if (p->p_tracep == vp) {
			p->p_tracep = NULL;
			p->p_traceflag = 0;
			vrele(vp);
		}
	}
}
#endif
Commit	Line	Data
2d68027d MT	1	/*
	2	* Copyright (c) 1989 The Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms are permitted
	6	* provided that the above copyright notice and this paragraph are
	7	* duplicated in all such forms and that any documentation,
	8	* advertising materials, and other materials related to such
	9	* distribution and use acknowledge that the software was developed
	10	* by the University of California, Berkeley. The name of the
	11	* University may not be used to endorse or promote products derived
	12	* from this software without specific prior written permission.
	13	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
	14	* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
	15	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
	16	*
8b24ca5d	17	* @(#)kern_ktrace.c 7.6 (Berkeley) %G%
2d68027d MT	18	*/
	19
	20	#ifdef KTRACE
	21
	22	#include "param.h"
8b24ca5d	23	#include "syscontext.h"
2d68027d	24	#include "proc.h"
c4ec2128 KM	25	#include "file.h"
c4ec2128 KM	26	#include "vnode.h"
2d68027d MT	27	#include "ktrace.h"
	28	#include "malloc.h"
	29
f73d8bd6	30	#include "syscalls.c"
2d68027d MT	31
	32	extern int nsysent;
	33	extern char *syscallnames[];
	34
f73d8bd6 MT	35	int ktrace_nocheck = 1;
f73d8bd6 MT	36
2d68027d MT	37	struct ktr_header *
	38	ktrgetheader(type)
	39	{
	40	register struct ktr_header *kth;
	41
	42	MALLOC(kth, struct ktr_header *, sizeof (struct ktr_header),
	43	M_TEMP, M_WAITOK);
2d68027d	44	kth->ktr_type = type;
f73d8bd6	45	microtime(&kth->ktr_time);
2d68027d	46	kth->ktr_pid = u.u_procp->p_pid;
a97cc92e	47	bcopy(u.u_procp->p_comm, kth->ktr_comm, MAXCOMLEN);
2d68027d MT	48	return (kth);
	49	}
	50
8b24ca5d	51	ktrsyscall(vp, code, narg, args)
c4ec2128	52	struct vnode *vp;
8b24ca5d	53	int code, narg, args[];
2d68027d MT	54	{
	55	struct ktr_header *kth = ktrgetheader(KTR_SYSCALL);
	56	struct ktr_syscall *ktp;
	57	register len = sizeof(struct ktr_syscall) + (narg * sizeof(int));
	58	int *argp, i;
	59
f73d8bd6	60	if (kth == NULL)
2d68027d	61	return;
2d68027d	62	MALLOC(ktp, struct ktr_syscall *, len, M_TEMP, M_WAITOK);
2d68027d MT	63	ktp->ktr_code = code;
	64	ktp->ktr_narg = narg;
	65	argp = (int )((char )ktp + sizeof(struct ktr_syscall));
	66	for (i = 0; i < narg; i++)
8b24ca5d	67	*argp++ = args[i];
2d68027d MT	68	kth->ktr_buf = (caddr_t)ktp;
2d68027d MT	69	kth->ktr_len = len;
c4ec2128	70	ktrwrite(vp, kth);
2d68027d MT	71	FREE(ktp, M_TEMP);
	72	FREE(kth, M_TEMP);
	73	}
	74
8b24ca5d	75	ktrsysret(vp, code, error, retval)
c4ec2128	76	struct vnode *vp;
8b24ca5d	77	int code, error, retval;
2d68027d MT	78	{
2d68027d MT	79	struct ktr_header *kth = ktrgetheader(KTR_SYSRET);
a97cc92e	80	struct ktr_sysret ktp;
2d68027d	81
f73d8bd6	82	if (kth == NULL)
2d68027d	83	return;
a97cc92e	84	ktp.ktr_code = code;
8b24ca5d KM	85	ktp.ktr_error = error;
8b24ca5d KM	86	ktp.ktr_retval = retval; /* what about val2 ? */
2d68027d	87
a97cc92e	88	kth->ktr_buf = (caddr_t)&ktp;
2d68027d MT	89	kth->ktr_len = sizeof(struct ktr_sysret);
2d68027d MT	90
c4ec2128	91	ktrwrite(vp, kth);
2d68027d MT	92	FREE(kth, M_TEMP);
	93	}
	94
c4ec2128 KM	95	ktrnamei(vp, path)
c4ec2128 KM	96	struct vnode *vp;
2d68027d MT	97	char *path;
	98	{
	99	struct ktr_header *kth = ktrgetheader(KTR_NAMEI);
	100
f73d8bd6	101	if (kth == NULL)
2d68027d	102	return;
2d68027d MT	103	kth->ktr_len = strlen(path);
	104	kth->ktr_buf = path;
	105
c4ec2128	106	ktrwrite(vp, kth);
2d68027d MT	107	FREE(kth, M_TEMP);
	108	}
	109
8b24ca5d	110	ktrgenio(vp, fd, rw, iov, len, error)
c4ec2128	111	struct vnode *vp;
8b24ca5d	112	int fd;
f73d8bd6 MT	113	enum uio_rw rw;
	114	register struct iovec *iov;
	115	{
	116	struct ktr_header *kth = ktrgetheader(KTR_GENIO);
	117	register struct ktr_genio *ktp;
	118	register caddr_t cp;
	119	register int resid = len, cnt;
	120
8b24ca5d	121	if (kth == NULL \|\| error)
f73d8bd6 MT	122	return;
	123	MALLOC(ktp, struct ktr_genio *, sizeof(struct ktr_genio) + len,
	124	M_TEMP, M_WAITOK);
f73d8bd6 MT	125	ktp->ktr_fd = fd;
	126	ktp->ktr_rw = rw;
	127	cp = (caddr_t)((char *)ktp + sizeof (struct ktr_genio));
	128	while (resid > 0) {
	129	if ((cnt = iov->iov_len) > resid)
	130	cnt = resid;
e5e5e641	131	if (copyin(iov->iov_base, cp, (unsigned)cnt))
f73d8bd6 MT	132	goto done;
	133	cp += cnt;
	134	resid -= cnt;
	135	iov++;
	136	}
	137	kth->ktr_buf = (caddr_t)ktp;
	138	kth->ktr_len = sizeof (struct ktr_genio) + len;
	139
c4ec2128	140	ktrwrite(vp, kth);
f73d8bd6 MT	141	done:
	142	FREE(kth, M_TEMP);
	143	FREE(ktp, M_TEMP);
	144	}
	145
a97cc92e MT	146	ktrpsig(vp, sig, action, mask, code)
	147	struct vnode *vp;
	148	sig_t action;
	149	{
	150	struct ktr_header *kth = ktrgetheader(KTR_PSIG);
	151	struct ktr_psig kp;
	152
	153	if (kth == NULL)
	154	return;
	155	kp.signo = (char)sig;
	156	kp.action = action;
	157	kp.mask = mask;
	158	kp.code = code;
	159	kth->ktr_buf = (caddr_t)&kp;
	160	kth->ktr_len = sizeof (struct ktr_psig);
	161
	162	ktrwrite(vp, kth);
	163	FREE(kth, M_TEMP);
	164	}
	165
	166	/* Interface and common routines */
	167
2d68027d MT	168	/*
	169	* ktrace system call
	170	*/
8b24ca5d KM	171	/* ARGSUSED */
	172	ktrace(curp, uap, retval)
	173	struct proc *curp;
	174	register struct args {
2d68027d MT	175	char *fname;
	176	int ops;
	177	int facs;
f73d8bd6	178	int pid;
8b24ca5d KM	179	} *uap;
	180	int *retval;
	181	{
c4ec2128	182	register struct vnode *vp = NULL;
2d68027d MT	183	register struct nameidata *ndp = &u.u_nd;
2d68027d MT	184	register struct proc *p;
a97cc92e	185	register ops = KTROP(uap->ops);
2d68027d	186	struct pgrp *pg;
2d68027d	187	register int facs = uap->facs;
f73d8bd6	188	register int ret = 0;
8b24ca5d	189	int error = 0;
2d68027d MT	190
	191	/*
	192	* Until security implications are thought through,
f73d8bd6	193	* limit tracing to root (unless ktrace_nocheck is set).
2d68027d	194	*/
8b24ca5d KM	195	if (!ktrace_nocheck && (error = suser(u.u_cred, &u.u_acflag)))
8b24ca5d KM	196	RETURN (error);
2d68027d MT	197	if (ops != KTROP_CLEAR) {
	198	/*
	199	* an operation which requires a file argument.
	200	*/
2d68027d MT	201	ndp->ni_segflg = UIO_USERSPACE;
2d68027d MT	202	ndp->ni_dirp = uap->fname;
8b24ca5d KM	203	if (error = vn_open(ndp, FREAD\|FWRITE, 0))
8b24ca5d KM	204	RETURN (error);
c4ec2128 KM	205	vp = ndp->ni_vp;
c4ec2128 KM	206	if (vp->v_type != VREG) {
c4ec2128	207	vrele(vp);
8b24ca5d	208	RETURN (EACCES);
2d68027d	209	}
2d68027d MT	210	}
	211	/*
	212	* Clear all uses of the tracefile
	213	*/
	214	if (ops == KTROP_CLEARFILE) {
	215	for (p = allproc; p != NULL; p = p->p_nxt) {
c4ec2128	216	if (p->p_tracep == vp) {
2d68027d MT	217	p->p_tracep = NULL;
2d68027d MT	218	p->p_traceflag = 0;
c4ec2128	219	vrele(vp);
2d68027d MT	220	}
	221	}
	222	goto done;
	223	}
2d68027d MT	224	/*
	225	* need something to (un)trace
	226	*/
	227	if (!facs) {
8b24ca5d	228	error = EINVAL;
2d68027d MT	229	goto done;
2d68027d MT	230	}
a97cc92e MT	231	/*
	232	* doit
	233	*/
2d68027d MT	234	if (uap->pid < 0) {
	235	pg = pgfind(-uap->pid);
	236	if (pg == NULL) {
8b24ca5d	237	error = ESRCH;
2d68027d MT	238	goto done;
	239	}
	240	for (p = pg->pg_mem; p != NULL; p = p->p_pgrpnxt)
a97cc92e	241	if (uap->ops&KTRFLAG_DESCEND)
c4ec2128	242	ret \|= ktrsetchildren(p, ops, facs, vp);
2d68027d	243	else
c4ec2128	244	ret \|= ktrops(p, ops, facs, vp);
2d68027d MT	245
	246	} else {
	247	p = pfind(uap->pid);
	248	if (p == NULL) {
8b24ca5d	249	error = ESRCH;
2d68027d MT	250	goto done;
2d68027d MT	251	}
a97cc92e	252	if (ops&KTRFLAG_DESCEND)
c4ec2128	253	ret \|= ktrsetchildren(p, ops, facs, vp);
2d68027d	254	else
c4ec2128	255	ret \|= ktrops(p, ops, facs, vp);
2d68027d	256	}
f73d8bd6	257	if (!ret)
8b24ca5d	258	error = EPERM;
2d68027d	259	done:
c4ec2128 KM	260	if (vp != NULL)
c4ec2128 KM	261	vrele(vp);
8b24ca5d	262	RETURN (error);
2d68027d MT	263	}
2d68027d MT	264
c4ec2128	265	ktrops(p, ops, facs, vp)
2d68027d	266	struct proc *p;
c4ec2128	267	struct vnode *vp;
2d68027d	268	{
f73d8bd6 MT	269
	270	if (u.u_uid && u.u_uid != p->p_uid)
	271	return 0;
2d68027d	272	if (ops == KTROP_SET) {
a97cc92e	273	if (p->p_tracep != vp) {
2d68027d MT	274	/*
	275	* if trace file already in use, relinquish
	276	*/
	277	if (p->p_tracep != NULL)
c4ec2128	278	vrele(p->p_tracep);
2c0d2f20	279	VREF(vp);
c4ec2128	280	p->p_tracep = vp;
2d68027d MT	281	}
	282	p->p_traceflag \|= facs;
	283	} else {
	284	/* KTROP_CLEAR */
a97cc92e MT	285	if (((p->p_traceflag &= ~facs) & ~KTRFAC_INHERIT) == 0) {
	286	/* no more tracing */
	287	p->p_traceflag = 0;
2d68027d	288	if (p->p_tracep != NULL) {
c4ec2128	289	vrele(p->p_tracep);
2d68027d MT	290	p->p_tracep = NULL;
2d68027d MT	291	}
2d68027d MT	292	}
2d68027d MT	293	}
f73d8bd6 MT	294
f73d8bd6 MT	295	return 1;
2d68027d	296	}
f73d8bd6	297
c4ec2128	298	ktrsetchildren(top, ops, facs, vp)
2d68027d	299	struct proc *top;
c4ec2128	300	struct vnode *vp;
2d68027d MT	301	{
2d68027d MT	302	register struct proc *p;
f73d8bd6	303	register int ret = 0;
2d68027d MT	304
	305	p = top;
	306	for (;;) {
a97cc92e	307	ret \|= ktrops(p, ops, facs, vp);
2d68027d MT	308	/*
	309	* If this process has children, descend to them next,
	310	* otherwise do any siblings, and if done with this level,
	311	* follow back up the tree (but not past top).
	312	*/
	313	if (p->p_cptr)
	314	p = p->p_cptr;
	315	else if (p == top)
f73d8bd6	316	return ret;
2d68027d MT	317	else if (p->p_osptr)
	318	p = p->p_osptr;
	319	else for (;;) {
	320	p = p->p_pptr;
	321	if (p == top)
f73d8bd6	322	return ret;
2d68027d MT	323	if (p->p_osptr) {
	324	p = p->p_osptr;
	325	break;
	326	}
	327	}
	328	}
f73d8bd6	329	/NOTREACHED/
2d68027d MT	330	}
2d68027d MT	331
c4ec2128 KM	332	ktrwrite(vp, kth)
	333	struct vnode *vp;
	334	register struct ktr_header *kth;
2d68027d	335	{
c4ec2128 KM	336	struct uio auio;
c4ec2128 KM	337	struct iovec aiov[2];
e5e5e641	338	struct proc *p;
aeb44310	339	int error;
c4ec2128 KM	340
c4ec2128 KM	341	if (vp == NULL)
f73d8bd6	342	return;
c4ec2128 KM	343	auio.uio_iov = &aiov[0];
	344	auio.uio_offset = 0;
	345	auio.uio_segflg = UIO_SYSSPACE;
	346	auio.uio_rw = UIO_WRITE;
	347	aiov[0].iov_base = (caddr_t)kth;
	348	aiov[0].iov_len = sizeof(struct ktr_header);
	349	auio.uio_resid = sizeof(struct ktr_header);
	350	auio.uio_iovcnt = 1;
2d68027d	351	if (kth->ktr_len > 0) {
c4ec2128 KM	352	auio.uio_iovcnt++;
	353	aiov[1].iov_base = kth->ktr_buf;
	354	aiov[1].iov_len = kth->ktr_len;
	355	auio.uio_resid += kth->ktr_len;
2d68027d	356	}
aeb44310 KM	357	VOP_LOCK(vp);
	358	error = VOP_WRITE(vp, &auio, IO_UNIT\|IO_APPEND, u.u_cred);
	359	VOP_UNLOCK(vp);
e5e5e641 KM	360	if (!error)
	361	return;
	362	/*
	363	* If error encountered, give up tracing on this vnode.
	364	*/
	365	uprintf("\ntrace write failed with errno %d, tracing stopped\n", error);
	366	for (p = allproc; p != NULL; p = p->p_nxt) {
	367	if (p->p_tracep == vp) {
	368	p->p_tracep = NULL;
	369	p->p_traceflag = 0;
	370	vrele(vp);
	371	}
	372	}
2d68027d	373	}
2d68027d	374	#endif