1.\" Copyright (c) 1990, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)ktrace.1 8.1 (Berkeley) 6/6/93 33.\" 34.Dd June 6, 1993 35.Dt KTRACE 1 36.Os BSD 4.4 37.Sh NAME 38.Nm ktrace 39.Nd enable kernel process tracing 40.Sh SYNOPSIS 41.Nm ktrace 42.Op Fl aCcdi 43.Op Fl f Ar trfile 44.Op Fl g Ar pgrp 45.Op Fl p Ar pid 46.Op Fl t Ar trstr 47.Nm ktrace 48.Op Fl adi 49.Op Fl f Ar trfile 50.Op Fl t Ar trstr 51command 52.Sh DESCRIPTION 53.Nm Ktrace 54enables kernel trace logging for the specified processes. 55Kernel trace data is logged to the file 56.Pa ktrace.out . 57The kernel operations that are traced include system calls, namei 58translations, signal processing, and 59.Tn I/O . 60.Pp 61Once tracing is enabled on a process, trace data will be logged until 62either the process exits or the trace point is cleared. 63A traced process can generate enormous amounts of log data quickly; 64It is strongly suggested that users memorize how to disable tracing before 65attempting to trace a process. 66The following command is sufficient to disable tracing on all user owned 67processes, and, if executed by root, all processes: 68.Pp 69.Dl \&$ ktrace -C 70.Pp 71The trace file is not human readable; use 72.Xr kdump 1 73to decode it. 74.Pp 75The options are as follows: 76.Bl -tag -width indent 77.It Fl a 78Append to the trace file instead of recreating it. 79.It Fl C 80Disable tracing on all user owned processes, and, if executed by root, all 81processes in the system. 82.It Fl c 83Clear the trace points associated with the specified file or processes. 84.It Fl d 85Descendants; perform the operation for all current children of the 86designated processes. 87.It Fl f Ar file 88Log trace records to 89.Ar file 90instead of 91.Pa ktrace.out . 92.It Fl g Ar pgid 93Enable (disable) tracing on all processes in the process group (only one 94.Fl g 95flag is permitted). 96.It Fl i 97Inherit; pass the trace flags to all future children of the designated 98processes. 99.It Fl p Ar pid 100Enable (disable) tracing on the indicated process id (only one 101.Fl p 102flag is permitted). 103.It Fl t Ar trstr 104The string argument represents the kernel trace points, one per letter. 105The following table equates the letters with the tracepoints: 106.Pp 107.Bl -tag -width flag -compact 108.It Cm c 109trace system calls 110.It Cm n 111trace namei translations 112.It Cm i 113trace 114.Tn I/O 115.It Cm s 116trace signal processing 117.It Cm u 118userland traces 119.It Cm w 120context switches 121.El 122.It Ar command 123Execute 124.Ar command 125with the specified trace flags. 126.El 127.Pp 128The 129.Fl p , 130.Fl g , 131and 132.Ar command 133options are mutually exclusive. 134.Sh EXAMPLES 135# trace all kernel operations of process id 34 136.Dl $ ktrace -p 34 137.Pp 138# trace all kernel operations of processes in process group 15 and 139# pass the trace flags to all current and future children 140.Dl $ ktrace -idg 15 141.Pp 142# disable all tracing of process 65 143.Dl $ ktrace -cp 65 144.Pp 145# disable tracing signals on process 70 and all current children 146.Dl $ ktrace -t s -cdp 70 147.Pp 148# enable tracing of 149.Tn I/O 150on process 67 151.Dl $ ktrace -ti -p 67 152.Pp 153# run the command "w", tracing only system calls 154.Dl $ ktrace -tc w 155.Pp 156# disable all tracing to the file "tracedata" 157.Dl $ ktrace -c -f tracedata 158.Pp 159# disable tracing of all processes owned by the user 160.Dl $ ktrace -C 161.Sh SEE ALSO 162.Xr kdump 1 163.Sh BUGS 164Only works if 165.Ar file 166is a regular file. 167.Sh HISTORY 168The 169.Nm ktrace 170command appears in 171.Bx 4.4 . 172