174 lines
5.6 KiB
Groff
174 lines
5.6 KiB
Groff
.\" $NetBSD: ktrace.2,v 1.6 1999/03/22 19:45:05 garbled Exp $
|
|
.\"
|
|
.\" Copyright (c) 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)ktrace.2 8.1 (Berkeley) 6/4/93
|
|
.\"
|
|
.Dd June 4, 1993
|
|
.Dt KTRACE 2
|
|
.Os
|
|
.Sh NAME
|
|
.Nm ktrace
|
|
.Nd process tracing
|
|
.Sh SYNOPSIS
|
|
.Fd #include <sys/types.h>
|
|
.Fd #include <sys/ktrace.h>
|
|
.Ft int
|
|
.Fn ktrace "const char *tracefile" "int ops" "int trpoints" "int pid"
|
|
.Ft int
|
|
.Fn fktrace "const int fd" "int ops" "int trpoints" "int pid"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn ktrace
|
|
function enables or disables tracing of one or more processes.
|
|
Users may only trace their own processes.
|
|
Only the super-user can trace setuid or setgid programs.
|
|
.Pp
|
|
The
|
|
.Ar tracefile
|
|
gives the pathname of the file to be used for tracing.
|
|
The file must exist and be writable by the calling process.
|
|
All trace records are always appended to the file,
|
|
so the file must be truncated to zero length to discard
|
|
previous trace data.
|
|
If tracing points are being disabled (see KTROP_CLEAR below),
|
|
.Ar tracefile
|
|
may be NULL. If using
|
|
.Fn fktrace
|
|
then instead of passing a filename as
|
|
.Ar tracefile,
|
|
a file descriptor is passed as
|
|
.Ar fd
|
|
and behaviour is otherwise the same.
|
|
.Pp
|
|
The
|
|
.Nm ops
|
|
parameter specifies the requested ktrace operation.
|
|
The defined operations are:
|
|
.Bl -column KTRFLAG_DESCENDXXX -offset indent
|
|
.It KTROP_SET Enable trace points specified in Ar trpoints .
|
|
.It KTROP_CLEAR Disable trace points specified in Ar trpoints .
|
|
.It KTROP_CLEARFILE Stop all tracing.
|
|
.It KTRFLAG_DESCEND The tracing change should apply to the
|
|
specified process and all its current children.
|
|
.El
|
|
.Pp
|
|
The
|
|
.Nm trpoints
|
|
parameter specifies the trace points of interest.
|
|
The defined trace points are:
|
|
.Bl -column KTRFAC_SYSCALLXXX -offset indent
|
|
.It KTRFAC_SYSCALL Trace system calls.
|
|
.It KTRFAC_SYSRET Trace return values from system calls.
|
|
.It KTRFAC_NAMEI Trace name lookup operations.
|
|
.It KTRFAC_GENIO Trace all I/O (note that this option can
|
|
generate much output).
|
|
.It KTRFAC_PSIG Trace posted signals.
|
|
.It KTRFAC_CSW Trace context switch points.
|
|
.It KTRFAC_EMUL Trace emulation changes.
|
|
.It KTRFAC_INHERIT Inherit tracing to future children.
|
|
.El
|
|
.Pp
|
|
Each tracing event outputs a record composed of a generic header
|
|
followed by a trace point specific structure.
|
|
The generic header is:
|
|
.Bd -literal
|
|
struct ktr_header {
|
|
int ktr_len; /* length of buf */
|
|
short ktr_type; /* trace record type */
|
|
pid_t ktr_pid; /* process id */
|
|
char ktr_comm[MAXCOMLEN+1]; /* command name */
|
|
struct timeval ktr_time; /* timestamp */
|
|
caddr_t ktr_buf;
|
|
};
|
|
.Ed
|
|
.Pp
|
|
The
|
|
.Nm ktr_len
|
|
field specifies the length of the
|
|
.Nm ktr_type
|
|
data that follows this header.
|
|
The
|
|
.Nm ktr_pid
|
|
and
|
|
.Nm ktr_comm
|
|
fields specify the process and command generating the record.
|
|
The
|
|
.Nm ktr_time
|
|
field gives the time (with microsecond resolution)
|
|
that the record was generated.
|
|
The
|
|
.Nm ktr_buf
|
|
is an internal kernel pointer and is not useful.
|
|
.Pp
|
|
The generic header is followed by
|
|
.Nm ktr_len
|
|
bytes of a
|
|
.Nm ktr_type
|
|
record.
|
|
The type specific records are defined in the
|
|
.Pa <sys/ktrace.h>
|
|
include file.
|
|
.Sh RETURN VALUES
|
|
On successful completion a value of 0 is returned.
|
|
Otherwise, a value of -1 is returned and
|
|
.Va errno
|
|
is set to show the error.
|
|
.Sh ERRORS
|
|
.Fn ktrace
|
|
will fail if:
|
|
.Bl -tag -width ENAMETOOLONGAA
|
|
.It Bq Er ENOTDIR
|
|
A component of the path prefix is not a directory.
|
|
.It Bq Er EINVAL
|
|
The pathname contains a character with the high-order bit set.
|
|
.It Bq Er ENAMETOOLONG
|
|
A component of a pathname exceeded 255 characters,
|
|
or an entire path name exceeded 1023 characters.
|
|
.It Bq Er ENOENT
|
|
The named tracefile does not exist.
|
|
.It Bq Er EACCES
|
|
Search permission is denied for a component of the path prefix.
|
|
.It Bq Er ELOOP
|
|
Too many symbolic links were encountered in translating the pathname.
|
|
.It Bq Er EIO
|
|
An I/O error occurred while reading from or writing to the file system.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr ktrace 1 ,
|
|
.Xr kdump 1
|
|
.Sh HISTORY
|
|
A
|
|
.Nm ktrace
|
|
function call first appeared in
|
|
.Bx 4.4 .
|