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.\" @(#)kdump.1 8.1 (Berkeley) 6/6/93 33.\" $FreeBSD$ 34.\" 35.Dd November 12, 2005 36.Dt KDUMP 1 37.Os 38.Sh NAME 39.Nm kdump 40.Nd display kernel trace data 41.Sh SYNOPSIS 42.Nm 43.Op Fl dEnlHRsT 44.Op Fl f Ar trfile 45.Op Fl m Ar maxdata 46.Op Fl p Ar pid 47.Op Fl t Op cnisuw 48.Sh DESCRIPTION 49The 50.Nm 51command displays the kernel trace files produced with 52.Xr ktrace 1 53in human readable format. 54By default, the file 55.Pa ktrace.out 56in the current directory is displayed. 57.Pp 58The options are as follows: 59.Bl -tag -width Fl 60.It Fl d 61Display all numbers in decimal. 62.It Fl E 63Display elapsed timestamps (time since beginning of trace). 64.It Fl f Ar trfile 65Display the specified file instead of 66.Pa ktrace.out . 67.It Fl H 68List the thread ID (tid) of the thread with each trace record, if available. 69If no thread ID is available, 0 will be printed. 70.It Fl l 71Loop reading the trace file, once the end-of-file is reached, waiting for 72more data. 73.It Fl m Ar maxdata 74Display at most 75.Ar maxdata 76bytes when decoding 77.Tn I/O . 78.It Fl n 79Suppress ad hoc translations. 80Normally 81.Nm 82tries to decode many system calls into a more human readable format. 83For example, 84.Xr ioctl 2 85values are replaced with the macro name and 86.Va errno 87values are replaced with the 88.Xr strerror 3 89string. 90Suppressing this feature yields a more consistent output format and is 91easily amenable to further processing. 92.It Fl p Ar pid 93Display only trace events that correspond to the process 94.Ar pid . 95This may be useful when there are multiple processes recorded in the 96same trace file. 97.It Fl R 98Display relative timestamps (time since previous entry). 99.It Fl s 100Suppress display of I/O data. 101.It Fl T 102Display absolute timestamps for each entry (seconds since epoch). 103.It Fl t Ar cnisuw 104See the 105.Fl t 106option of 107.Xr ktrace 1 . 108.El 109.Pp 110The output format of 111.Nm 112is line oriented with several fields. 113The example below shows a section of a kdump generated by the following 114commands: 115.Bd -literal -offset indent 116?> ktrace echo "ktrace" 117 118?> kdump 119 120 85045 echo CALL writev(0x1,0x804b030,0x2) 121 85045 echo GIO fd 1 wrote 7 bytes 122 "ktrace 123 " 124 85045 echo RET writev 7 125.Ed 126.Pp 127The first field is the PID of the process being traced. 128The second field is the name of the program being traced. 129The third field is the operation that the kernel performed 130on behalf of the process. 131If thread IDs are being printed, then an additional thread ID column will be 132added to the output between the PID field and program name field. 133.Pp 134In the first line above, the kernel executes the 135.Xr writev 2 136system call on behalf of the process so this is a 137.Li CALL 138operation. 139The fourth field shows the system call that was executed, 140including its arguments. 141The 142.Xr writev 2 143system call takes a file descriptor, in this case 1, or standard 144output, then a pointer to the iovector to write, and the number of 145iovectors that are to be written. 146In the second line we see the operation was 147.Li GIO , 148for general I/O, and that file descriptor 1 had 149seven bytes written to it. 150This is followed by the seven bytes that were written, the string 151.Qq Li ktrace 152with a carriage return and line feed. 153The last line is the 154.Li RET 155operation, showing a return from the kernel, what system call we are 156returning from, and the return value that the process received. 157Seven bytes were written by the 158.Xr writev 2 159system call, so 7 is the return value. 160.Pp 161The possible operations are: 162.Bl -column -offset indent ".Li GENIO" ".No data from user process" 163.It Sy Name Ta Sy Operation Ta Sy Fourth field 164.It Li CALL Ta enter syscall Ta syscall name and arguments 165.It Li RET Ta return from syscall Ta syscall name and return value 166.It Li NAMI Ta file name lookup Ta path to file 167.It Li GENIO Ta general I/O Ta fd, read/write, number of bytes 168.It Li SIG Ta signal Ta signal name, handler, mask, code 169.It Li CSW Ta context switch Ta stop/resume user/kernel 170.It Li USER Ta data from user process Ta the data 171.El 172.Sh SEE ALSO 173.Xr ktrace 1 174.Sh HISTORY 175The 176.Nm 177command appeared in 178.Bx 4.4 . 179