diff --git a/usr.bin/gcore/gcore.1 b/usr.bin/gcore/gcore.1 index 55db2aed3e3a..aa93a5ef1fe0 100644 --- a/usr.bin/gcore/gcore.1 +++ b/usr.bin/gcore/gcore.1 @@ -1,94 +1,106 @@ .\" 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 July 13, 2016 +.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. . 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. . .It Fl f -Dumps all available segments, excluding only malformed and undumpable segments. +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. 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. diff --git a/usr.bin/gcore/gcore.c b/usr.bin/gcore/gcore.c index cbbfea82085b..8055193625f9 100644 --- a/usr.bin/gcore/gcore.c +++ b/usr.bin/gcore/gcore.c @@ -1,170 +1,227 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 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. */ #ifndef lint static const char copyright[] = "@(#) Copyright (c) 1992, 1993\n\ The Regents of the University of California. All rights reserved.\n"; #endif /* not lint */ #if 0 #ifndef lint static char sccsid[] = "@(#)gcore.c 8.2 (Berkeley) 9/23/93"; #endif /* not lint */ #endif #include __FBSDID("$FreeBSD$"); /* * Originally written by Eric Cooper in Fall 1981. * Inspired by a version 6 program by Len Levin, 1978. * Several pieces of code lifted from Bill Joy's 4BSD ps. * Most recently, hacked beyond recognition for 4.4BSD by Steven McCanne, * Lawrence Berkeley Laboratory. * * Portions of this software were developed by the Computer Systems * Engineering group at Lawrence Berkeley Laboratory under DARPA * contract BG 91-66 and contributed to Berkeley. */ #include +#include #include #include #include #include +#include #include #include +#include #include #include #include #include #include "extern.h" int pflags; static void killed(int); static void usage(void) __dead2; static pid_t pid; +static bool kflag = false; SET_DECLARE(dumpset, struct dumpers); static int open_corefile(char *corefile) { char fname[MAXPATHLEN]; + int fd; if (corefile == NULL) { (void)snprintf(fname, sizeof(fname), "core.%d", pid); corefile = fname; } fd = open(corefile, O_RDWR | O_CREAT | O_TRUNC, DEFFILEMODE); if (fd < 0) err(1, "%s", corefile); return (fd); } +static void +kcoredump(int fd, pid_t pid) +{ + struct ptrace_coredump pc; + int error, res, ret, waited; + + error = ptrace(PT_ATTACH, pid, NULL, 0); + if (error != 0) + err(1, "attach"); + + waited = waitpid(pid, &res, 0); + if (waited == -1) + err(1, "wait for STOP"); + + ret = 0; + memset(&pc, 0, sizeof(pc)); + pc.pc_fd = fd; + pc.pc_flags = (pflags & PFLAGS_FULL) != 0 ? PC_ALL : 0; + error = ptrace(PT_COREDUMP, pid, (void *)&pc, sizeof(pc)); + if (error == -1) { + warn("coredump"); + ret = 1; + } + + waited = waitpid(pid, &res, WNOHANG); + if (waited == -1) { + warn("wait after coredump"); + ret = 1; + } + + error = ptrace(PT_DETACH, pid, NULL, 0); + if (error == -1) { + warn("detach failed, check process status"); + ret = 1; + } + + exit(ret); +} + int main(int argc, char *argv[]) { int ch, efd, fd, name[4]; char *binfile, *corefile; char passpath[MAXPATHLEN]; struct dumpers **d, *dumper; size_t len; pflags = 0; corefile = NULL; - while ((ch = getopt(argc, argv, "c:f")) != -1) { + while ((ch = getopt(argc, argv, "c:fk")) != -1) { switch (ch) { case 'c': corefile = optarg; break; case 'f': pflags |= PFLAGS_FULL; break; + case 'k': + kflag = true; + break; default: usage(); break; } } argv += optind; argc -= optind; + /* XXX we should check that the pid argument is really a number */ switch (argc) { case 1: pid = atoi(argv[0]); + break; + case 2: + binfile = argv[0]; + pid = atoi(argv[1]); + break; + default: + usage(); + } + + if (kflag) { + fd = open_corefile(corefile); + kcoredump(fd, pid); + } + + if (argc == 1) { name[0] = CTL_KERN; name[1] = KERN_PROC; name[2] = KERN_PROC_PATHNAME; name[3] = pid; len = sizeof(passpath); if (sysctl(name, 4, passpath, &len, NULL, 0) == -1) errx(1, "kern.proc.pathname failure"); binfile = passpath; - break; - case 2: - pid = atoi(argv[1]); - binfile = argv[0]; - break; - default: - usage(); } efd = open(binfile, O_RDONLY, 0); if (efd < 0) err(1, "%s", binfile); dumper = NULL; SET_FOREACH(d, dumpset) { lseek(efd, 0, SEEK_SET); if (((*d)->ident)(efd, pid, binfile)) { dumper = (*d); lseek(efd, 0, SEEK_SET); break; } } if (dumper == NULL) errx(1, "Invalid executable file"); fd = open_corefile(corefile); dumper->dump(efd, fd, pid); (void)close(fd); (void)close(efd); exit(0); } void usage(void) { - (void)fprintf(stderr, "usage: gcore [-c core] [executable] pid\n"); + (void)fprintf(stderr, + "usage: gcore [-kf] [-c core] [executable] pid\n"); exit(1); }