1.\" Copyright (c) 1990 The Regents of the University of California. 2.\" 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 5.5 (Berkeley) 7/26/91 33.\" 34.Dd July 26, 1991 35.Dt KTRACE 1 36.Os 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 \&$ trace -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 truncating 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.El 118.It Ar command 119Execute 120.Ar command 121with the specified trace flags. 122.El 123.Pp 124The 125.Fl p , 126.Fl g , 127and 128.Ar command 129options are mutually exclusive. 130.Sh EXAMPLES 131# trace all kernel operations of process id 34 132.Dl $ ktrace -p 34 133.Pp 134# trace all kernel operations of processes in process group 15 and 135# pass the trace flags to all current and future children 136.Dl $ ktrace -idg 15 137.Pp 138# disable all tracing of process 65 139.Dl $ ktrace -cp 65 140.Pp 141# disable tracing signals on process 70 and all current children 142.Dl $ ktrace -t s -cdp 70 143.Pp 144# enable tracing of 145.Tn I/O 146on process 67 147.Dl $ ktrace -ti -p 67 148.Pp 149# run the command "w", tracing only system calls 150.Dl $ ktrace -tc w 151.Pp 152# disable all tracing to the file "tracedata" 153.Dl $ ktrace -c -f tracedata 154.Pp 155# disable tracing of all processes owned by the user 156.Dl $ ktrace -C 157.Sh SEE ALSO 158.Xr kdump 1 159.Sh HISTORY 160The 161.Nm ktrace 162command is 163.Ud . 164