xref: /openbsd-src/usr.sbin/kgmon/kgmon.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: kgmon.c,v 1.24 2016/08/27 01:50:07 guenther Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/file.h>
33 #include <sys/sysctl.h>
34 #include <sys/time.h>
35 #include <sys/gmon.h>
36 #include <errno.h>
37 #include <err.h>
38 #include <kvm.h>
39 #include <limits.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <unistd.h>
43 #include <string.h>
44 #include <nlist.h>
45 #include <ctype.h>
46 #include <paths.h>
47 
48 struct nlist nl[] = {
49 #define	N_GMONPARAM	0
50 	{ "__gmonparam" },
51 #define	N_PROFHZ	1
52 	{ "_profhz" },
53 	{ NULL }
54 };
55 
56 struct kvmvars {
57 	kvm_t	*kd;
58 	struct gmonparam gpm;
59 };
60 
61 extern char *__progname;
62 
63 int	bflag, cflag, hflag, kflag, rflag, pflag;
64 int	debug = 0;
65 void	kgmon(char *, char *, struct kvmvars *, int);
66 void	setprof(struct kvmvars *, int, int);
67 void	dumpstate(struct kvmvars *, int);
68 void	reset(struct kvmvars *, int);
69 void	kern_readonly(int);
70 int	getprof(struct kvmvars *, int);
71 int	getprofhz(struct kvmvars *);
72 int	openfiles(char *, char *, struct kvmvars *, int);
73 int	getncpu(void);
74 
75 int
76 main(int argc, char **argv)
77 {
78 	int ch, ncpu, cpuid = -1;
79 	struct kvmvars kvmvars;
80 	char *sys, *kmemf;
81 	const char *p;
82 
83 	kmemf = NULL;
84 	sys = NULL;
85 	while ((ch = getopt(argc, argv, "M:N:bc:hpr")) != -1) {
86 		switch(ch) {
87 
88 		case 'M':
89 			kmemf = optarg;
90 			kflag = 1;
91 			break;
92 
93 		case 'N':
94 			sys = optarg;
95 			break;
96 
97 		case 'b':
98 			bflag = 1;
99 			break;
100 
101 		case 'c':
102 			cflag = 1;
103 			cpuid = strtonum(optarg, 0, 1024, &p);
104 			if (p)
105 				errx(1, "illegal CPU id %s: %s", optarg, p);
106 			break;
107 
108 		case 'h':
109 			hflag = 1;
110 			break;
111 
112 		case 'p':
113 			pflag = 1;
114 			break;
115 
116 		case 'r':
117 			rflag = 1;
118 			break;
119 
120 		default:
121 			fprintf(stderr, "usage: %s [-bhpr] "
122 			    "[-c cpuid] [-M core] [-N system]\n", __progname);
123 			exit(1);
124 		}
125 	}
126 	argc -= optind;
127 	argv += optind;
128 
129 #define BACKWARD_COMPATIBILITY
130 #ifdef	BACKWARD_COMPATIBILITY
131 	if (*argv) {
132 		sys = *argv;
133 		if (*++argv) {
134 			kmemf = *argv;
135 			++kflag;
136 		}
137 	}
138 #endif
139 
140 	if (cflag) {
141 		kgmon(sys, kmemf, &kvmvars, cpuid);
142 	} else {
143 		ncpu = getncpu();
144 		for (cpuid = 0; cpuid < ncpu; cpuid++)
145 			kgmon(sys, kmemf, &kvmvars, cpuid);
146 	}
147 
148 	return (0);
149 }
150 
151 void
152 kgmon(char *sys, char *kmemf, struct kvmvars *kvp, int cpuid)
153 {
154 	int mode, disp, accessmode;
155 
156 	accessmode = openfiles(sys, kmemf, kvp, cpuid);
157 	mode = getprof(kvp, cpuid);
158 	if (hflag)
159 		disp = GMON_PROF_OFF;
160 	else if (bflag)
161 		disp = GMON_PROF_ON;
162 	else
163 		disp = mode;
164 	if (pflag)
165 		dumpstate(kvp, cpuid);
166 	if (rflag)
167 		reset(kvp, cpuid);
168 	if (accessmode == O_RDWR)
169 		setprof(kvp, cpuid, disp);
170 	printf("%s: kernel profiling is %s for cpu %d.\n", __progname,
171 	    disp == GMON_PROF_OFF ? "off" : "running", cpuid);
172 }
173 
174 /*
175  * Check that profiling is enabled and open any ncessary files.
176  */
177 int
178 openfiles(char *sys, char *kmemf, struct kvmvars *kvp, int cpuid)
179 {
180 	int mib[4], state, openmode;
181 	size_t size;
182 	char errbuf[_POSIX2_LINE_MAX];
183 
184 	if (!kflag) {
185 		mib[0] = CTL_KERN;
186 		mib[1] = KERN_PROF;
187 		mib[2] = GPROF_STATE;
188 		mib[3] = cpuid;
189 		size = sizeof state;
190 		if (sysctl(mib, 4, &state, &size, NULL, 0) < 0)
191 			errx(20, "profiling not defined in kernel.");
192 		if (!(bflag || hflag || rflag ||
193 		    (pflag && state == GMON_PROF_ON)))
194 			return (O_RDONLY);
195 		if (sysctl(mib, 4, NULL, NULL, &state, size) >= 0)
196 			return (O_RDWR);
197 		kern_readonly(state);
198 		return (O_RDONLY);
199 	}
200 	openmode = (bflag || hflag || pflag || rflag) ? O_RDWR : O_RDONLY;
201 	kvp->kd = kvm_openfiles(sys, kmemf, NULL, openmode, errbuf);
202 	if (kvp->kd == NULL) {
203 		if (openmode == O_RDWR) {
204 			openmode = O_RDONLY;
205 			kvp->kd = kvm_openfiles(sys, kmemf, NULL, O_RDONLY,
206 			    errbuf);
207 		}
208 		if (kvp->kd == NULL)
209 			errx(2, "kvm_openfiles: %s", errbuf);
210 		kern_readonly(GMON_PROF_ON);
211 	}
212 	if (kvm_nlist(kvp->kd, nl) < 0)
213 		errx(3, "%s: no namelist", sys ? sys : _PATH_UNIX);
214 	if (!nl[N_GMONPARAM].n_value)
215 		errx(20, "profiling not defined in kernel.");
216 	return (openmode);
217 }
218 
219 /*
220  * Suppress options that require a writable kernel.
221  */
222 void
223 kern_readonly(int mode)
224 {
225 	extern char *__progname;
226 
227 	(void)fprintf(stderr, "%s: kernel read-only: ", __progname);
228 	if (pflag && mode == GMON_PROF_ON)
229 		(void)fprintf(stderr, "data may be inconsistent\n");
230 	if (rflag)
231 		(void)fprintf(stderr, "-r suppressed\n");
232 	if (bflag)
233 		(void)fprintf(stderr, "-b suppressed\n");
234 	if (hflag)
235 		(void)fprintf(stderr, "-h suppressed\n");
236 	rflag = bflag = hflag = 0;
237 }
238 
239 /*
240  * Get the state of kernel profiling.
241  */
242 int
243 getprof(struct kvmvars *kvp, int cpuid)
244 {
245 	int mib[4];
246 	size_t size;
247 
248 	if (kflag) {
249 		size = kvm_read(kvp->kd, nl[N_GMONPARAM].n_value, &kvp->gpm,
250 		    sizeof kvp->gpm);
251 	} else {
252 		mib[0] = CTL_KERN;
253 		mib[1] = KERN_PROF;
254 		mib[2] = GPROF_GMONPARAM;
255 		mib[3] = cpuid;
256 		size = sizeof kvp->gpm;
257 		if (sysctl(mib, 4, &kvp->gpm, &size, NULL, 0) < 0)
258 			size = 0;
259 	}
260 	if (size != sizeof kvp->gpm)
261 		errx(4, "cannot get gmonparam: %s",
262 		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
263 	return (kvp->gpm.state);
264 }
265 
266 /*
267  * Enable or disable kernel profiling according to the state variable.
268  */
269 void
270 setprof(struct kvmvars *kvp, int cpuid, int state)
271 {
272 	struct gmonparam *p = (struct gmonparam *)nl[N_GMONPARAM].n_value;
273 	int mib[4], oldstate;
274 	size_t sz;
275 
276 	sz = sizeof(state);
277 	if (!kflag) {
278 		mib[0] = CTL_KERN;
279 		mib[1] = KERN_PROF;
280 		mib[2] = GPROF_STATE;
281 		mib[3] = cpuid;
282 		if (sysctl(mib, 4, &oldstate, &sz, NULL, 0) < 0)
283 			goto bad;
284 		if (oldstate == state)
285 			return;
286 		if (sysctl(mib, 4, NULL, NULL, &state, sz) >= 0)
287 			return;
288 	} else if (kvm_write(kvp->kd, (u_long)&p->state, (void *)&state, sz)
289 	    == sz)
290 		return;
291 bad:
292 	warnx("warning: cannot turn profiling %s",
293 	    state == GMON_PROF_OFF ? "off" : "on");
294 }
295 
296 /*
297  * Build the gmon.out file.
298  */
299 void
300 dumpstate(struct kvmvars *kvp, int cpuid)
301 {
302 	FILE *fp;
303 	struct rawarc rawarc;
304 	struct tostruct *tos;
305 	u_long frompc;
306 	u_short *froms, *tickbuf;
307 	int mib[4];
308 	size_t i;
309 	struct gmonhdr h;
310 	int fromindex, endfrom, toindex;
311 	char buf[16];
312 
313 	snprintf(buf, sizeof(buf), "gmon-%02d.out", cpuid);
314 
315 	setprof(kvp, cpuid, GMON_PROF_OFF);
316 	fp = fopen(buf, "w");
317 	if (fp == 0) {
318 		perror(buf);
319 		return;
320 	}
321 
322 	/*
323 	 * Build the gmon header and write it to a file.
324 	 */
325 	bzero(&h, sizeof(h));
326 	h.lpc = kvp->gpm.lowpc;
327 	h.hpc = kvp->gpm.highpc;
328 	h.ncnt = kvp->gpm.kcountsize + sizeof(h);
329 	h.version = GMONVERSION;
330 	h.profrate = getprofhz(kvp);
331 	fwrite((char *)&h, sizeof(h), 1, fp);
332 
333 	/*
334 	 * Write out the tick buffer.
335 	 */
336 	mib[0] = CTL_KERN;
337 	mib[1] = KERN_PROF;
338 	if ((tickbuf = malloc(kvp->gpm.kcountsize)) == NULL)
339 		errx(5, "cannot allocate kcount space");
340 	if (kflag) {
341 		i = kvm_read(kvp->kd, (u_long)kvp->gpm.kcount, (void *)tickbuf,
342 		    kvp->gpm.kcountsize);
343 	} else {
344 		mib[2] = GPROF_COUNT;
345 		mib[3] = cpuid;
346 		i = kvp->gpm.kcountsize;
347 		if (sysctl(mib, 4, tickbuf, &i, NULL, 0) < 0)
348 			i = 0;
349 	}
350 	if (i != kvp->gpm.kcountsize)
351 		errx(6, "read ticks: read %lu, got %zu: %s",
352 		    kvp->gpm.kcountsize, i,
353 		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
354 	if ((fwrite(tickbuf, kvp->gpm.kcountsize, 1, fp)) != 1)
355 		err(7, "writing tocks to gmon.out");
356 	free(tickbuf);
357 
358 	/*
359 	 * Write out the arc info.
360 	 */
361 	if ((froms = malloc(kvp->gpm.fromssize)) == NULL)
362 		errx(8, "cannot allocate froms space");
363 	if (kflag) {
364 		i = kvm_read(kvp->kd, (u_long)kvp->gpm.froms, (void *)froms,
365 		    kvp->gpm.fromssize);
366 	} else {
367 		mib[2] = GPROF_FROMS;
368 		mib[3] = cpuid;
369 		i = kvp->gpm.fromssize;
370 		if (sysctl(mib, 4, froms, &i, NULL, 0) < 0)
371 			i = 0;
372 	}
373 	if (i != kvp->gpm.fromssize)
374 		errx(9, "read froms: read %lu, got %zu: %s",
375 		    kvp->gpm.fromssize, i,
376 		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
377 	if ((tos = malloc(kvp->gpm.tossize)) == NULL)
378 		errx(10, "cannot allocate tos space");
379 	if (kflag) {
380 		i = kvm_read(kvp->kd, (u_long)kvp->gpm.tos, (void *)tos,
381 		    kvp->gpm.tossize);
382 	} else {
383 		mib[2] = GPROF_TOS;
384 		mib[3] = cpuid;
385 		i = kvp->gpm.tossize;
386 		if (sysctl(mib, 4, tos, &i, NULL, 0) < 0)
387 			i = 0;
388 	}
389 	if (i != kvp->gpm.tossize)
390 		errx(11, "read tos: read %lu, got %zu: %s",
391 		    kvp->gpm.tossize, i,
392 		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
393 	if (debug)
394 		warnx("lowpc 0x%lx, textsize 0x%lx",
395 		    kvp->gpm.lowpc, kvp->gpm.textsize);
396 	endfrom = kvp->gpm.fromssize / sizeof(*froms);
397 	for (fromindex = 0; fromindex < endfrom; ++fromindex) {
398 		if (froms[fromindex] == 0)
399 			continue;
400 		frompc = (u_long)kvp->gpm.lowpc +
401 		    (fromindex * kvp->gpm.hashfraction * sizeof(*froms));
402 		for (toindex = froms[fromindex]; toindex != 0;
403 		   toindex = tos[toindex].link) {
404 			if (debug)
405 			  warnx("[mcleanup] frompc 0x%lx selfpc 0x%lx count %ld",
406 			    frompc, tos[toindex].selfpc, tos[toindex].count);
407 			rawarc.raw_frompc = frompc;
408 			rawarc.raw_selfpc = (u_long)tos[toindex].selfpc;
409 			rawarc.raw_count = tos[toindex].count;
410 			fwrite((char *)&rawarc, sizeof(rawarc), 1, fp);
411 		}
412 	}
413 	fclose(fp);
414 }
415 
416 /*
417  * Get the profiling rate.
418  */
419 int
420 getprofhz(struct kvmvars *kvp)
421 {
422 	int mib[2], profrate;
423 	size_t size;
424 	struct clockinfo clockrate;
425 
426 	if (kflag) {
427 		profrate = 1;
428 		if (kvm_read(kvp->kd, nl[N_PROFHZ].n_value, &profrate,
429 		    sizeof profrate) != sizeof profrate)
430 			warnx("get clockrate: %s", kvm_geterr(kvp->kd));
431 		return (profrate);
432 	}
433 	mib[0] = CTL_KERN;
434 	mib[1] = KERN_CLOCKRATE;
435 	clockrate.profhz = 1;
436 	size = sizeof clockrate;
437 	if (sysctl(mib, 2, &clockrate, &size, NULL, 0) < 0)
438 		warn("get clockrate");
439 	return (clockrate.profhz);
440 }
441 
442 /*
443  * Reset the kernel profiling date structures.
444  */
445 void
446 reset(struct kvmvars *kvp, int cpuid)
447 {
448 	char *zbuf;
449 	u_long biggest;
450 	int mib[4];
451 
452 	setprof(kvp, cpuid, GMON_PROF_OFF);
453 
454 	biggest = kvp->gpm.kcountsize;
455 	if (kvp->gpm.fromssize > biggest)
456 		biggest = kvp->gpm.fromssize;
457 	if (kvp->gpm.tossize > biggest)
458 		biggest = kvp->gpm.tossize;
459 	if ((zbuf = malloc(biggest)) == NULL)
460 		errx(12, "cannot allocate zbuf space");
461 	bzero(zbuf, biggest);
462 	if (kflag) {
463 		if (kvm_write(kvp->kd, (u_long)kvp->gpm.kcount, zbuf,
464 		    kvp->gpm.kcountsize) != kvp->gpm.kcountsize)
465 			errx(13, "tickbuf zero: %s", kvm_geterr(kvp->kd));
466 		if (kvm_write(kvp->kd, (u_long)kvp->gpm.froms, zbuf,
467 		    kvp->gpm.fromssize) != kvp->gpm.fromssize)
468 			errx(14, "froms zero: %s", kvm_geterr(kvp->kd));
469 		if (kvm_write(kvp->kd, (u_long)kvp->gpm.tos, zbuf,
470 		    kvp->gpm.tossize) != kvp->gpm.tossize)
471 			errx(15, "tos zero: %s", kvm_geterr(kvp->kd));
472 		return;
473 	}
474 	mib[0] = CTL_KERN;
475 	mib[1] = KERN_PROF;
476 	mib[2] = GPROF_COUNT;
477 	mib[3] = cpuid;
478 	if (sysctl(mib, 4, NULL, NULL, zbuf, kvp->gpm.kcountsize) < 0)
479 		err(13, "tickbuf zero");
480 	mib[2] = GPROF_FROMS;
481 	if (sysctl(mib, 4, NULL, NULL, zbuf, kvp->gpm.fromssize) < 0)
482 		err(14, "froms zero");
483 	mib[2] = GPROF_TOS;
484 	if (sysctl(mib, 4, NULL, NULL, zbuf, kvp->gpm.tossize) < 0)
485 		err(15, "tos zero");
486 	free(zbuf);
487 }
488 
489 int
490 getncpu(void)
491 {
492 	int mib[2] = { CTL_HW, HW_NCPU };
493 	size_t size;
494 	int ncpu;
495 
496 	size = sizeof(ncpu);
497 	if (sysctl(mib, 2, &ncpu, &size, NULL, 0) < 0) {
498 		warnx("cannot read hw.ncpu");
499 		return (1);
500 	}
501 
502 	return (ncpu);
503 }
504