freebsd-skq/usr.bin/ktrdump/ktrdump.c
Conrad Meyer 208a859459 ktrdump(8): Capsicumify
We restrict the (optional) input file and output files. It would be
nice to restrict the KVM files, but that's up to libkvm.

We wait until after kvm_nlist() is invoked to cap_enter() because
kldsym() isn't supported in the Capsicum sandbox.

Feedback from:	emaste@ (earlier versions)
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D7921
2016-12-16 01:59:28 +00:00

354 lines
8.6 KiB
C

/*-
* Copyright (c) 2002 Jake Burkholder
* Copyright (c) 2004 Robert Watson
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/capsicum.h>
#include <sys/ktr.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <capsicum_helpers.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <kvm.h>
#include <limits.h>
#include <nlist.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define SBUFLEN 128
#define USAGE \
"usage: ktrdump [-cfqrtH] [-i ktrfile] [-M core] [-N system] [-o outfile]\n"
static void usage(void);
static struct nlist nl[] = {
{ "_ktr_version" },
{ "_ktr_entries" },
{ "_ktr_idx" },
{ "_ktr_buf" },
{ NULL }
};
static int cflag;
static int fflag;
static int Mflag;
static int Nflag;
static int qflag;
static int rflag;
static int tflag;
static int iflag;
static int hflag;
static char corefile[PATH_MAX];
static char execfile[PATH_MAX];
static char outfile[PATH_MAX] = "stdout";
static char desc[SBUFLEN];
static char errbuf[_POSIX2_LINE_MAX];
static char fbuf[PATH_MAX];
static char obuf[PATH_MAX];
static char sbuf[KTR_PARMS][SBUFLEN];
/*
* Reads the ktr trace buffer from kernel memory and prints the trace entries.
*/
int
main(int ac, char **av)
{
u_long parms[KTR_PARMS];
struct ktr_entry *buf;
uintmax_t tlast, tnow;
unsigned long bufptr;
cap_rights_t rights;
struct stat sb;
kvm_t *kd;
FILE *out;
char *p;
int version;
int entries;
int index, index2;
int parm;
int in;
int c;
int i = 0;
/*
* Parse commandline arguments.
*/
out = stdout;
while ((c = getopt(ac, av, "cfqrtHe:i:m:M:N:o:")) != -1)
switch (c) {
case 'c':
cflag = 1;
break;
case 'N':
case 'e':
if (strlcpy(execfile, optarg, sizeof(execfile))
>= sizeof(execfile))
errx(1, "%s: File name too long", optarg);
Nflag = 1;
break;
case 'f':
fflag = 1;
break;
case 'i':
iflag = 1;
if ((in = open(optarg, O_RDONLY)) == -1)
err(1, "%s", optarg);
cap_rights_init(&rights, CAP_FSTAT, CAP_MMAP_R);
if (cap_rights_limit(in, &rights) < 0 &&
errno != ENOSYS)
err(1, "unable to limit rights for %s",
optarg);
break;
case 'M':
case 'm':
if (strlcpy(corefile, optarg, sizeof(corefile))
>= sizeof(corefile))
errx(1, "%s: File name too long", optarg);
Mflag = 1;
break;
case 'o':
if ((out = fopen(optarg, "w")) == NULL)
err(1, "%s", optarg);
strlcpy(outfile, optarg, sizeof(outfile));
break;
case 'q':
qflag++;
break;
case 'r':
rflag = 1;
break;
case 't':
tflag = 1;
break;
case 'H':
hflag = 1;
break;
case '?':
default:
usage();
}
ac -= optind;
av += optind;
if (ac != 0)
usage();
cap_rights_init(&rights, CAP_FSTAT, CAP_WRITE);
if (cap_rights_limit(fileno(out), &rights) < 0 && errno != ENOSYS)
err(1, "unable to limit rights for %s", outfile);
/*
* Open our execfile and corefile, resolve needed symbols and read in
* the trace buffer.
*/
if ((kd = kvm_openfiles(Nflag ? execfile : NULL,
Mflag ? corefile : NULL, NULL, O_RDONLY, errbuf)) == NULL)
errx(1, "%s", errbuf);
/*
* Cache NLS data, for strerror, for err(3), before entering capability
* mode.
*/
caph_cache_catpages();
if (kvm_nlist(kd, nl) != 0 ||
kvm_read(kd, nl[0].n_value, &version, sizeof(version)) == -1)
errx(1, "%s", kvm_geterr(kd));
if (version != KTR_VERSION)
errx(1, "ktr version mismatch");
/*
* Enter Capsicum sandbox.
*
* kvm_nlist() above uses kldsym(2) for native kernels, and that isn't
* allowed in the sandbox.
*/
if (cap_enter() < 0 && errno != ENOSYS)
err(1, "unable to enter capability mode");
if (iflag) {
if (fstat(in, &sb) == -1)
errx(1, "stat");
entries = sb.st_size / sizeof(*buf);
index = 0;
buf = mmap(NULL, sb.st_size, PROT_READ, MAP_SHARED, in, 0);
if (buf == MAP_FAILED)
errx(1, "mmap");
} else {
if (kvm_read(kd, nl[1].n_value, &entries, sizeof(entries))
== -1)
errx(1, "%s", kvm_geterr(kd));
if ((buf = malloc(sizeof(*buf) * entries)) == NULL)
err(1, NULL);
if (kvm_read(kd, nl[2].n_value, &index, sizeof(index)) == -1 ||
kvm_read(kd, nl[3].n_value, &bufptr,
sizeof(bufptr)) == -1 ||
kvm_read(kd, bufptr, buf, sizeof(*buf) * entries) == -1 ||
kvm_read(kd, nl[2].n_value, &index2, sizeof(index2)) == -1)
errx(1, "%s", kvm_geterr(kd));
}
/*
* Print a nice header.
*/
if (!qflag) {
fprintf(out, "%-6s ", "index");
if (cflag)
fprintf(out, "%-3s ", "cpu");
if (tflag)
fprintf(out, "%-16s ", "timestamp");
if (fflag)
fprintf(out, "%-40s ", "file and line");
if (hflag)
fprintf(out, "%-18s ", "tid");
fprintf(out, "%s", "trace");
fprintf(out, "\n");
fprintf(out, "------ ");
if (cflag)
fprintf(out, "--- ");
if (tflag)
fprintf(out, "---------------- ");
if (fflag)
fprintf(out,
"---------------------------------------- ");
if (hflag)
fprintf(out, "------------------ ");
fprintf(out, "----- ");
fprintf(out, "\n");
}
/*
* Now tear through the trace buffer.
*/
if (!iflag) {
i = index - 1;
if (i < 0)
i = entries - 1;
}
tlast = -1;
for (;;) {
if (buf[i].ktr_desc == NULL)
break;
if (kvm_read(kd, (u_long)buf[i].ktr_desc, desc,
sizeof(desc)) == -1)
errx(1, "%s", kvm_geterr(kd));
desc[sizeof(desc) - 1] = '\0';
parm = 0;
for (p = desc; (c = *p++) != '\0';) {
if (c != '%')
continue;
next: if ((c = *p++) == '\0')
break;
if (parm == KTR_PARMS)
errx(1, "too many parameters in \"%s\"", desc);
switch (c) {
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
case '#': case '-': case ' ': case '+': case '\'':
case 'h': case 'l': case 'j': case 't': case 'z':
case 'q': case 'L': case '.':
goto next;
case 's':
if (kvm_read(kd, (u_long)buf[i].ktr_parms[parm],
sbuf[parm], sizeof(sbuf[parm])) == -1)
strcpy(sbuf[parm], "(null)");
sbuf[parm][sizeof(sbuf[0]) - 1] = '\0';
parms[parm] = (u_long)sbuf[parm];
parm++;
break;
default:
parms[parm] = buf[i].ktr_parms[parm];
parm++;
break;
}
}
fprintf(out, "%6d ", i);
if (cflag)
fprintf(out, "%3d ", buf[i].ktr_cpu);
if (tflag) {
tnow = (uintmax_t)buf[i].ktr_timestamp;
if (rflag) {
if (tlast == -1)
tlast = tnow;
fprintf(out, "%16ju ", !iflag ? tlast - tnow :
tnow - tlast);
tlast = tnow;
} else
fprintf(out, "%16ju ", tnow);
}
if (fflag) {
if (kvm_read(kd, (u_long)buf[i].ktr_file, fbuf,
sizeof(fbuf)) == -1)
strcpy(fbuf, "(null)");
snprintf(obuf, sizeof(obuf), "%s:%d", fbuf,
buf[i].ktr_line);
fprintf(out, "%-40s ", obuf);
}
if (hflag)
fprintf(out, "%p ", buf[i].ktr_thread);
fprintf(out, desc, parms[0], parms[1], parms[2], parms[3],
parms[4], parms[5]);
fprintf(out, "\n");
if (!iflag) {
/*
* 'index' and 'index2' are the values of 'ktr_idx'
* before and after the KTR buffer was copied into
* 'buf'. Since the KTR entries between 'index' and
* 'index2' were in flux while the KTR buffer was
* being copied to userspace we don't dump them.
*/
if (i == index2)
break;
if (--i < 0)
i = entries - 1;
} else {
if (++i == entries)
break;
}
}
return (0);
}
static void
usage(void)
{
fprintf(stderr, USAGE);
exit(1);
}