73e8f06ac5
-k switch causes gcore to use ptrace(PT_COREDUMP) instead of manually reading process memory and constructing the core. Reviewed by: markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D29955
107 lines
3.3 KiB
Groff
107 lines
3.3 KiB
Groff
.\" Copyright (c) 1983, 1990, 1992, 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. 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.
|
|
.\"
|
|
.\" @(#)gcore.1 8.2 (Berkeley) 4/18/94
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd April 24, 2021
|
|
.Dt GCORE 1
|
|
.Os
|
|
.Sh NAME
|
|
.Nm gcore
|
|
.Nd get core images of running process
|
|
.Sh SYNOPSIS
|
|
.Nm
|
|
.Op Fl f
|
|
.Op Fl k
|
|
.Op Fl c Ar core
|
|
.Op Ar executable
|
|
.Ar pid
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
utility creates a core image of the specified process,
|
|
suitable for use with
|
|
.Xr gdb 1 .
|
|
By default, the core is written to the file
|
|
.Dq Pa core.<pid> .
|
|
The process identifier,
|
|
.Ar pid ,
|
|
must be given on the command line.
|
|
.Pp
|
|
The following options are available:
|
|
.Bl -tag -width indent
|
|
.It Fl c
|
|
Write the core file to the specified file instead of
|
|
.Dq Pa core.<pid> .
|
|
.It Fl f
|
|
Dumps all available segments, excluding only malformed and undumpable
|
|
segments.
|
|
Unlike the default invocation, this flag dumps mappings of devices which
|
|
may invalidate the state of device transactions or trigger other unexpected
|
|
behavior.
|
|
As a result, this flag should only be used when the behavior of the
|
|
application and any devices it has mapped is fully understood and any side
|
|
effects can be controlled or tolerated.
|
|
.It Fl k
|
|
Use the
|
|
.Xr ptrace 2
|
|
.Dv PT_COREDUMP
|
|
kernel facility to write the core dump, instead of reading the process'
|
|
memory and constructing the dump file in
|
|
.Nm
|
|
itself.
|
|
This is faster, and the dump is written by the
|
|
same kernel code that writes core dumps upon fatal signals.
|
|
.El
|
|
.Sh FILES
|
|
.Bl -tag -width /var/log/messages -compact
|
|
.It Pa core.<pid>
|
|
the core image
|
|
.El
|
|
.Sh HISTORY
|
|
A
|
|
.Nm
|
|
utility appeared in
|
|
.Bx 4.2 .
|
|
.Sh BUGS
|
|
Because of the
|
|
.Xr ptrace 2
|
|
usage
|
|
.Nm
|
|
may not work with processes which are actively being investigated with
|
|
.Xr truss 1
|
|
or
|
|
.Xr gdb 1 .
|
|
Additionally, interruptable sleeps may exit with EINTR.
|
|
.Pp
|
|
The
|
|
.Nm
|
|
utility is not compatible with the original
|
|
.Bx 4.2
|
|
version.
|