kgmon.c revision 160022 
1/*
2 * Copyright (c) 1983, 1992, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#ifndef lint
31static const char copyright[] =
32"@(#) Copyright (c) 1983, 1992, 1993\n\
33	The Regents of the University of California.  All rights reserved.\n";
34#endif /* not lint */
35
36#ifndef lint
37#if 0
38static char sccsid[] = "@(#)kgmon.c	8.1 (Berkeley) 6/6/93";
39#endif
40static const char rcsid[] =
41  "$FreeBSD: head/usr.sbin/kgmon/kgmon.c 160022 2006-06-29 09:18:16Z delphij $";
42#endif /* not lint */
43
44#include <sys/param.h>
45#include <sys/file.h>
46#include <sys/time.h>
47#include <sys/sysctl.h>
48#include <sys/gmon.h>
49#include <ctype.h>
50#include <err.h>
51#include <errno.h>
52#include <kvm.h>
53#include <limits.h>
54#include <nlist.h>
55#include <paths.h>
56#include <stddef.h>
57#include <stdio.h>
58#include <stdlib.h>
59#include <string.h>
60#include <unistd.h>
61
62struct nlist nl[] = {
63#define	N_GMONPARAM	0
64	{ "__gmonparam" },
65#define	N_PROFHZ	1
66	{ "_profhz" },
67	{ NULL },
68};
69
70struct kvmvars {
71	kvm_t	*kd;
72	struct gmonparam gpm;
73};
74
75int	Bflag, bflag, hflag, kflag, rflag, pflag;
76int	debug = 0;
77int	getprof(struct kvmvars *);
78int	getprofhz(struct kvmvars *);
79void	kern_readonly(int);
80int	openfiles(char *, char *, struct kvmvars *);
81void	setprof(struct kvmvars *kvp, int state);
82void	dumpstate(struct kvmvars *kvp);
83void	reset(struct kvmvars *kvp);
84static void usage(void);
85
86int
87main(int argc, char **argv)
88{
89	int ch, mode, disp, accessmode;
90	struct kvmvars kvmvars;
91	char *system, *kmemf;
92
93	seteuid(getuid());
94	kmemf = NULL;
95	system = NULL;
96	while ((ch = getopt(argc, argv, "M:N:Bbhpr")) != -1) {
97		switch((char)ch) {
98
99		case 'M':
100			kmemf = optarg;
101			kflag = 1;
102			break;
103
104		case 'N':
105			system = optarg;
106			break;
107
108		case 'B':
109			Bflag = 1;
110			break;
111
112		case 'b':
113			bflag = 1;
114			break;
115
116		case 'h':
117			hflag = 1;
118			break;
119
120		case 'p':
121			pflag = 1;
122			break;
123
124		case 'r':
125			rflag = 1;
126			break;
127
128		default:
129			usage();
130		}
131	}
132	argc -= optind;
133	argv += optind;
134
135#define BACKWARD_COMPATIBILITY
136#ifdef	BACKWARD_COMPATIBILITY
137	if (*argv) {
138		system = *argv;
139		if (*++argv) {
140			kmemf = *argv;
141			++kflag;
142		}
143	}
144#endif
145	if (system == NULL)
146		system = (char *)getbootfile();
147	accessmode = openfiles(system, kmemf, &kvmvars);
148	mode = getprof(&kvmvars);
149	if (hflag)
150		disp = GMON_PROF_OFF;
151	else if (Bflag)
152		disp = GMON_PROF_HIRES;
153	else if (bflag)
154		disp = GMON_PROF_ON;
155	else
156		disp = mode;
157	if (pflag)
158		dumpstate(&kvmvars);
159	if (rflag)
160		reset(&kvmvars);
161	if (accessmode == O_RDWR)
162		setprof(&kvmvars, disp);
163	(void)fprintf(stdout, "kgmon: kernel profiling is %s.\n",
164		      disp == GMON_PROF_OFF ? "off" :
165		      disp == GMON_PROF_HIRES ? "running (high resolution)" :
166		      disp == GMON_PROF_ON ? "running" :
167		      disp == GMON_PROF_BUSY ? "busy" :
168		      disp == GMON_PROF_ERROR ? "off (error)" :
169		      "in an unknown state");
170	return (0);
171}
172
173static void
174usage()
175{
176	fprintf(stderr, "usage: kgmon [-Bbhrp] [-M core] [-N system]\n");
177	exit(1);
178}
179
180/*
181 * Check that profiling is enabled and open any necessary files.
182 */
183int
184openfiles(system, kmemf, kvp)
185	char *system;
186	char *kmemf;
187	struct kvmvars *kvp;
188{
189	size_t size;
190	int mib[3], state, openmode;
191	char errbuf[_POSIX2_LINE_MAX];
192
193	if (!kflag) {
194		mib[0] = CTL_KERN;
195		mib[1] = KERN_PROF;
196		mib[2] = GPROF_STATE;
197		size = sizeof state;
198		if (sysctl(mib, 3, &state, &size, NULL, 0) < 0)
199			errx(20, "profiling not defined in kernel");
200		if (!(Bflag || bflag || hflag || rflag ||
201		    (pflag &&
202		     (state == GMON_PROF_HIRES || state == GMON_PROF_ON))))
203			return (O_RDONLY);
204		(void)seteuid(0);
205		if (sysctl(mib, 3, NULL, NULL, &state, size) >= 0)
206			return (O_RDWR);
207		(void)seteuid(getuid());
208		kern_readonly(state);
209		return (O_RDONLY);
210	}
211	openmode = (Bflag || bflag || hflag || pflag || rflag)
212		   ? O_RDWR : O_RDONLY;
213	kvp->kd = kvm_openfiles(system, kmemf, NULL, openmode, errbuf);
214	if (kvp->kd == NULL) {
215		if (openmode == O_RDWR) {
216			openmode = O_RDONLY;
217			kvp->kd = kvm_openfiles(system, kmemf, NULL, O_RDONLY,
218			    errbuf);
219		}
220		if (kvp->kd == NULL)
221			errx(2, "kvm_openfiles: %s", errbuf);
222		kern_readonly(GMON_PROF_ON);
223	}
224	if (kvm_nlist(kvp->kd, nl) < 0)
225		errx(3, "%s: no namelist", system);
226	if (!nl[N_GMONPARAM].n_value)
227		errx(20, "profiling not defined in kernel");
228	return (openmode);
229}
230
231/*
232 * Suppress options that require a writable kernel.
233 */
234void
235kern_readonly(mode)
236	int mode;
237{
238
239	(void)fprintf(stderr, "kgmon: kernel read-only: ");
240	if (pflag && (mode == GMON_PROF_HIRES || mode == GMON_PROF_ON))
241		(void)fprintf(stderr, "data may be inconsistent\n");
242	if (rflag)
243		(void)fprintf(stderr, "-r supressed\n");
244	if (Bflag)
245		(void)fprintf(stderr, "-B supressed\n");
246	if (bflag)
247		(void)fprintf(stderr, "-b supressed\n");
248	if (hflag)
249		(void)fprintf(stderr, "-h supressed\n");
250	rflag = Bflag = bflag = hflag = 0;
251}
252
253/*
254 * Get the state of kernel profiling.
255 */
256int
257getprof(kvp)
258	struct kvmvars *kvp;
259{
260	size_t size;
261	int mib[3];
262
263	if (kflag) {
264		size = kvm_read(kvp->kd, nl[N_GMONPARAM].n_value, &kvp->gpm,
265		    sizeof kvp->gpm);
266	} else {
267		mib[0] = CTL_KERN;
268		mib[1] = KERN_PROF;
269		mib[2] = GPROF_GMONPARAM;
270		size = sizeof kvp->gpm;
271		if (sysctl(mib, 3, &kvp->gpm, &size, NULL, 0) < 0)
272			size = 0;
273	}
274
275	/*
276	 * Accept certain undersized "structs" from old kernels.  We need
277	 * everything up to hashfraction, and want profrate and
278	 * histcounter_type.  Assume that the kernel doesn't put garbage
279	 * in any padding that is returned instead of profrate and
280	 * histcounter_type.  This is a bad assumption for dead kernels,
281	 * since kvm_read() will normally return garbage for bytes beyond
282	 * the end of the actual kernel struct, if any.
283	 */
284	if (size < offsetof(struct gmonparam, hashfraction) +
285	    sizeof(kvp->gpm.hashfraction) || size > sizeof(kvp->gpm))
286		errx(4, "cannot get gmonparam: %s",
287		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
288	bzero((char *)&kvp->gpm + size, sizeof(kvp->gpm) - size);
289	if (kvp->gpm.profrate == 0)
290		kvp->gpm.profrate = getprofhz(kvp);
291#ifdef __i386__
292	if (kvp->gpm.histcounter_type == 0) {
293		/*
294		 * This fixup only works for not-so-old i386 kernels.  The
295		 * magic 16 is the kernel FUNCTION_ALIGNMENT.  64-bit
296		 * counters are signed; smaller counters are unsigned.
297		 */
298		kvp->gpm.histcounter_type = 16 /
299		    (kvp->gpm.textsize / kvp->gpm.kcountsize) * CHAR_BIT;
300		if (kvp->gpm.histcounter_type == 64)
301			kvp->gpm.histcounter_type = -64;
302	}
303#endif
304
305	return (kvp->gpm.state);
306}
307
308/*
309 * Enable or disable kernel profiling according to the state variable.
310 */
311void
312setprof(kvp, state)
313	struct kvmvars *kvp;
314	int state;
315{
316	struct gmonparam *p = (struct gmonparam *)nl[N_GMONPARAM].n_value;
317	size_t sz;
318	int mib[3], oldstate;
319
320	sz = sizeof(state);
321	if (!kflag) {
322		mib[0] = CTL_KERN;
323		mib[1] = KERN_PROF;
324		mib[2] = GPROF_STATE;
325		if (sysctl(mib, 3, &oldstate, &sz, NULL, 0) < 0)
326			goto bad;
327		if (oldstate == state)
328			return;
329		(void)seteuid(0);
330		if (sysctl(mib, 3, NULL, NULL, &state, sz) >= 0) {
331			(void)seteuid(getuid());
332			return;
333		}
334		(void)seteuid(getuid());
335	} else if (kvm_write(kvp->kd, (u_long)&p->state, (void *)&state, sz)
336	    == sz)
337		return;
338bad:
339	warnx("warning: cannot turn profiling %s",
340	    state == GMON_PROF_OFF ? "off" : "on");
341}
342
343/*
344 * Build the gmon.out file.
345 */
346void
347dumpstate(kvp)
348	struct kvmvars *kvp;
349{
350	register FILE *fp;
351	struct rawarc rawarc;
352	struct tostruct *tos;
353	u_long frompc;
354	u_short *froms, *tickbuf;
355	size_t i;
356	int mib[3];
357	struct gmonhdr h;
358	int fromindex, endfrom, toindex;
359
360	setprof(kvp, GMON_PROF_OFF);
361	fp = fopen("gmon.out", "w");
362	if (fp == 0) {
363		warn("gmon.out");
364		return;
365	}
366
367	/*
368	 * Build the gmon header and write it to a file.
369	 */
370	bzero(&h, sizeof(h));
371	h.lpc = kvp->gpm.lowpc;
372	h.hpc = kvp->gpm.highpc;
373	h.ncnt = kvp->gpm.kcountsize + sizeof(h);
374	h.version = GMONVERSION;
375	h.profrate = kvp->gpm.profrate;
376	h.histcounter_type = kvp->gpm.histcounter_type;
377	fwrite((char *)&h, sizeof(h), 1, fp);
378
379	/*
380	 * Write out the tick buffer.
381	 */
382	mib[0] = CTL_KERN;
383	mib[1] = KERN_PROF;
384	if ((tickbuf = (u_short *)malloc(kvp->gpm.kcountsize)) == NULL)
385		errx(5, "cannot allocate kcount space");
386	if (kflag) {
387		i = kvm_read(kvp->kd, (u_long)kvp->gpm.kcount, (void *)tickbuf,
388		    kvp->gpm.kcountsize);
389	} else {
390		mib[2] = GPROF_COUNT;
391		i = kvp->gpm.kcountsize;
392		if (sysctl(mib, 3, tickbuf, &i, NULL, 0) < 0)
393			i = 0;
394	}
395	if (i != kvp->gpm.kcountsize)
396		errx(6, "read ticks: read %lu, got %ld: %s",
397		    kvp->gpm.kcountsize, (long)i,
398		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
399	if ((fwrite(tickbuf, kvp->gpm.kcountsize, 1, fp)) != 1)
400		err(7, "writing tocks to gmon.out");
401	free(tickbuf);
402
403	/*
404	 * Write out the arc info.
405	 */
406	if ((froms = (u_short *)malloc(kvp->gpm.fromssize)) == NULL)
407		errx(8, "cannot allocate froms space");
408	if (kflag) {
409		i = kvm_read(kvp->kd, (u_long)kvp->gpm.froms, (void *)froms,
410		    kvp->gpm.fromssize);
411	} else {
412		mib[2] = GPROF_FROMS;
413		i = kvp->gpm.fromssize;
414		if (sysctl(mib, 3, froms, &i, NULL, 0) < 0)
415			i = 0;
416	}
417	if (i != kvp->gpm.fromssize)
418		errx(9, "read froms: read %lu, got %ld: %s",
419		    kvp->gpm.fromssize, (long)i,
420		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
421	if ((tos = (struct tostruct *)malloc(kvp->gpm.tossize)) == NULL)
422		errx(10, "cannot allocate tos space");
423	if (kflag) {
424		i = kvm_read(kvp->kd, (u_long)kvp->gpm.tos, (void *)tos,
425		    kvp->gpm.tossize);
426	} else {
427		mib[2] = GPROF_TOS;
428		i = kvp->gpm.tossize;
429		if (sysctl(mib, 3, tos, &i, NULL, 0) < 0)
430			i = 0;
431	}
432	if (i != kvp->gpm.tossize)
433		errx(11, "read tos: read %lu, got %ld: %s",
434		    kvp->gpm.tossize, (long)i,
435		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
436	if (debug)
437		warnx("lowpc 0x%lx, textsize 0x%lx",
438		    (unsigned long)kvp->gpm.lowpc, kvp->gpm.textsize);
439	endfrom = kvp->gpm.fromssize / sizeof(*froms);
440	for (fromindex = 0; fromindex < endfrom; ++fromindex) {
441		if (froms[fromindex] == 0)
442			continue;
443		frompc = (u_long)kvp->gpm.lowpc +
444		    (fromindex * kvp->gpm.hashfraction * sizeof(*froms));
445		for (toindex = froms[fromindex]; toindex != 0;
446		     toindex = tos[toindex].link) {
447			if (debug)
448				warnx("[mcleanup] frompc 0x%lx selfpc 0x%lx "
449				    "count %ld", frompc, tos[toindex].selfpc,
450				    tos[toindex].count);
451			rawarc.raw_frompc = frompc;
452			rawarc.raw_selfpc = (u_long)tos[toindex].selfpc;
453			rawarc.raw_count = tos[toindex].count;
454			fwrite((char *)&rawarc, sizeof(rawarc), 1, fp);
455		}
456	}
457	fclose(fp);
458}
459
460/*
461 * Get the profiling rate.
462 */
463int
464getprofhz(kvp)
465	struct kvmvars *kvp;
466{
467	size_t size;
468	int mib[2], profrate;
469	struct clockinfo clockrate;
470
471	if (kflag) {
472		profrate = 1;
473		if (kvm_read(kvp->kd, nl[N_PROFHZ].n_value, &profrate,
474		    sizeof profrate) != sizeof profrate)
475			warnx("get clockrate: %s", kvm_geterr(kvp->kd));
476		return (profrate);
477	}
478	mib[0] = CTL_KERN;
479	mib[1] = KERN_CLOCKRATE;
480	clockrate.profhz = 1;
481	size = sizeof clockrate;
482	if (sysctl(mib, 2, &clockrate, &size, NULL, 0) < 0)
483		warn("get clockrate");
484	return (clockrate.profhz);
485}
486
487/*
488 * Reset the kernel profiling date structures.
489 */
490void
491reset(kvp)
492	struct kvmvars *kvp;
493{
494	char *zbuf;
495	u_long biggest;
496	int mib[3];
497
498	setprof(kvp, GMON_PROF_OFF);
499
500	biggest = kvp->gpm.kcountsize;
501	if (kvp->gpm.fromssize > biggest)
502		biggest = kvp->gpm.fromssize;
503	if (kvp->gpm.tossize > biggest)
504		biggest = kvp->gpm.tossize;
505	if ((zbuf = (char *)malloc(biggest)) == NULL)
506		errx(12, "cannot allocate zbuf space");
507	bzero(zbuf, biggest);
508	if (kflag) {
509		if (kvm_write(kvp->kd, (u_long)kvp->gpm.kcount, zbuf,
510		    kvp->gpm.kcountsize) != kvp->gpm.kcountsize)
511			errx(13, "tickbuf zero: %s", kvm_geterr(kvp->kd));
512		if (kvm_write(kvp->kd, (u_long)kvp->gpm.froms, zbuf,
513		    kvp->gpm.fromssize) != kvp->gpm.fromssize)
514			errx(14, "froms zero: %s", kvm_geterr(kvp->kd));
515		if (kvm_write(kvp->kd, (u_long)kvp->gpm.tos, zbuf,
516		    kvp->gpm.tossize) != kvp->gpm.tossize)
517			errx(15, "tos zero: %s", kvm_geterr(kvp->kd));
518		return;
519	}
520	(void)seteuid(0);
521	mib[0] = CTL_KERN;
522	mib[1] = KERN_PROF;
523	mib[2] = GPROF_COUNT;
524	if (sysctl(mib, 3, NULL, NULL, zbuf, kvp->gpm.kcountsize) < 0)
525		err(13, "tickbuf zero");
526	mib[2] = GPROF_FROMS;
527	if (sysctl(mib, 3, NULL, NULL, zbuf, kvp->gpm.fromssize) < 0)
528		err(14, "froms zero");
529	mib[2] = GPROF_TOS;
530	if (sysctl(mib, 3, NULL, NULL, zbuf, kvp->gpm.tossize) < 0)
531		err(15, "tos zero");
532	(void)seteuid(getuid());
533	free(zbuf);
534}
535