freebsd-dev/usr.bin/gcore/gcore.c
2001-05-03 00:35:53 +00:00

339 lines
8.5 KiB
C

/*-
* 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. 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.
*/
#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 */
#ifndef lint
#if 0
static char sccsid[] = "@(#)gcore.c 8.2 (Berkeley) 9/23/93";
#endif
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
/*
* 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 <sys/param.h>
#include <sys/lock.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/sysctl.h>
#include <machine/elf.h>
#include <machine/vmparam.h>
#include <a.out.h>
#include <err.h>
#include <fcntl.h>
#include <kvm.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "extern.h"
static void core __P((int, int, struct kinfo_proc *));
static void datadump __P((int, int, struct kinfo_proc *, u_long, int));
static void killed __P((int));
static void restart_target __P((void));
static void usage __P((void)) __dead2;
static void userdump __P((int, struct kinfo_proc *, u_long, int));
kvm_t *kd;
static int data_offset;
static pid_t pid;
int
main(argc, argv)
int argc;
char *argv[];
{
struct kinfo_proc *ki = NULL;
struct exec exec;
int ch, cnt, efd, fd, sflag, uid;
char *binfile, *corefile;
char errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN];
int is_aout;
sflag = 0;
corefile = NULL;
while ((ch = getopt(argc, argv, "c:s")) != -1) {
switch (ch) {
case 'c':
corefile = optarg;
break;
case 's':
sflag = 1;
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]);
asprintf(&binfile, "/proc/%d/file", pid);
if (binfile == NULL)
errx(1, "allocation failure");
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);
cnt = read(efd, &exec, sizeof(exec));
if (cnt != sizeof(exec))
errx(1, "%s exec header: %s",
binfile, cnt > 0 ? strerror(EIO) : strerror(errno));
if (!N_BADMAG(exec)) {
is_aout = 1;
/*
* This legacy a.out support uses the kvm interface instead
* of procfs.
*/
kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf);
if (kd == NULL)
errx(1, "%s", errbuf);
uid = getuid();
ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt);
if (ki == NULL || cnt != 1)
errx(1, "%d: not found", pid);
if (ki->ki_ruid != uid && uid != 0)
errx(1, "%d: not owner", pid);
if (ki->ki_stat == SZOMB)
errx(1, "%d: zombie", pid);
if (ki->ki_flag & P_WEXIT)
errx(1, "%d: process exiting", pid);
if (ki->ki_flag & P_SYSTEM) /* Swapper or pagedaemon. */
errx(1, "%d: system process", pid);
if (exec.a_text != ptoa(ki->ki_tsize))
errx(1, "The executable %s does not belong to"
" process %d!\n"
"Text segment size (in bytes): executable %ld,"
" process %d", binfile, pid, exec.a_text,
ptoa(ki->ki_tsize));
data_offset = N_DATOFF(exec);
} else if (IS_ELF(*(Elf_Ehdr *)&exec)) {
is_aout = 0;
close(efd);
} else
errx(1, "Invalid executable file");
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);
if (sflag) {
signal(SIGHUP, killed);
signal(SIGINT, killed);
signal(SIGTERM, killed);
if (kill(pid, SIGSTOP) == -1)
err(1, "%d: stop signal", pid);
atexit(restart_target);
}
if (is_aout)
core(efd, fd, ki);
else
elf_coredump(fd, pid);
(void)close(fd);
exit(0);
}
/*
* core --
* Build the core file.
*/
void
core(efd, fd, ki)
int efd;
int fd;
struct kinfo_proc *ki;
{
union {
struct user user;
char ubytes[ctob(UPAGES)];
} uarea;
int tsize = ki->ki_tsize;
int dsize = ki->ki_dsize;
int ssize = ki->ki_ssize;
int cnt;
/* Read in user struct */
cnt = kvm_read(kd, (u_long)ki->ki_addr, &uarea, sizeof(uarea));
if (cnt != sizeof(uarea))
errx(1, "read user structure: %s",
cnt > 0 ? strerror(EIO) : strerror(errno));
/*
* Fill in the eproc vm parameters, since these are garbage unless
* the kernel is dumping core or something.
*/
uarea.user.u_kproc = *ki;
/* Dump user area */
cnt = write(fd, &uarea, sizeof(uarea));
if (cnt != sizeof(uarea))
errx(1, "write user structure: %s",
cnt > 0 ? strerror(EIO) : strerror(errno));
/* Dump data segment */
datadump(efd, fd, ki, USRTEXT + ctob(tsize), dsize);
/* Dump stack segment */
userdump(fd, ki, USRSTACK - ctob(ssize), ssize);
/* Dump machine dependent portions of the core. */
md_core(kd, fd, ki);
}
void
datadump(efd, fd, kp, addr, npage)
register int efd;
register int fd;
struct kinfo_proc *kp;
register u_long addr;
register int npage;
{
register int cc, delta;
char buffer[PAGE_SIZE];
delta = data_offset - addr;
while (--npage >= 0) {
cc = kvm_uread(kd, kp, addr, buffer, PAGE_SIZE);
if (cc != PAGE_SIZE) {
/* Try to read the page from the executable. */
if (lseek(efd, (off_t)addr + delta, SEEK_SET) == -1)
err(1, "seek executable: %s", strerror(errno));
cc = read(efd, buffer, sizeof(buffer));
if (cc != sizeof(buffer)) {
if (cc < 0)
err(1, "read executable");
else /* Assume untouched bss page. */
bzero(buffer, sizeof(buffer));
}
}
cc = write(fd, buffer, PAGE_SIZE);
if (cc != PAGE_SIZE)
errx(1, "write data segment: %s",
cc > 0 ? strerror(EIO) : strerror(errno));
addr += PAGE_SIZE;
}
}
static void
killed(sig)
int sig;
{
restart_target();
signal(sig, SIG_DFL);
kill(getpid(), sig);
}
static void
restart_target()
{
kill(pid, SIGCONT);
}
void
userdump(fd, kp, addr, npage)
register int fd;
struct kinfo_proc *kp;
register u_long addr;
register int npage;
{
register int cc;
char buffer[PAGE_SIZE];
while (--npage >= 0) {
cc = kvm_uread(kd, kp, addr, buffer, PAGE_SIZE);
if (cc != PAGE_SIZE)
/* Could be an untouched fill-with-zero page. */
bzero(buffer, PAGE_SIZE);
cc = write(fd, buffer, PAGE_SIZE);
if (cc != PAGE_SIZE)
errx(1, "write stack segment: %s",
cc > 0 ? strerror(EIO) : strerror(errno));
addr += PAGE_SIZE;
}
}
void
usage()
{
(void)fprintf(stderr, "usage: gcore [-s] [-c core] executable pid\n");
exit(1);
}