xref: /openbsd-src/usr.sbin/kgmon/kgmon.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /*	$OpenBSD: kgmon.c,v 1.20 2013/11/27 13:32:02 okan 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/param.h>
33 #include <sys/file.h>
34 #include <sys/sysctl.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 	seteuid(getuid());
84 	kmemf = NULL;
85 	sys = NULL;
86 	while ((ch = getopt(argc, argv, "M:N:bc:hpr")) != -1) {
87 		switch(ch) {
88 
89 		case 'M':
90 			kmemf = optarg;
91 			kflag = 1;
92 			break;
93 
94 		case 'N':
95 			sys = optarg;
96 			break;
97 
98 		case 'b':
99 			bflag = 1;
100 			break;
101 
102 		case 'c':
103 			cflag = 1;
104 			cpuid = strtonum(optarg, 0, 1024, &p);
105 			if (p)
106 				errx(1, "illegal CPU id %s: %s", optarg, p);
107 			break;
108 
109 		case 'h':
110 			hflag = 1;
111 			break;
112 
113 		case 'p':
114 			pflag = 1;
115 			break;
116 
117 		case 'r':
118 			rflag = 1;
119 			break;
120 
121 		default:
122 			fprintf(stderr, "usage: %s [-bhpr] "
123 			    "[-c cpuid] [-M core] [-N system]\n", __progname);
124 			exit(1);
125 		}
126 	}
127 	argc -= optind;
128 	argv += optind;
129 
130 #define BACKWARD_COMPATIBILITY
131 #ifdef	BACKWARD_COMPATIBILITY
132 	if (*argv) {
133 		sys = *argv;
134 		if (*++argv) {
135 			kmemf = *argv;
136 			++kflag;
137 		}
138 	}
139 #endif
140 
141 	if (cflag) {
142 		kgmon(sys, kmemf, &kvmvars, cpuid);
143 	} else {
144 		ncpu = getncpu();
145 		for (cpuid = 0; cpuid < ncpu; cpuid++)
146 			kgmon(sys, kmemf, &kvmvars, cpuid);
147 	}
148 
149 	return (0);
150 }
151 
152 void
153 kgmon(char *sys, char *kmemf, struct kvmvars *kvp, int cpuid)
154 {
155 	int mode, disp, accessmode;
156 
157 	accessmode = openfiles(sys, kmemf, kvp, cpuid);
158 	mode = getprof(kvp, cpuid);
159 	if (hflag)
160 		disp = GMON_PROF_OFF;
161 	else if (bflag)
162 		disp = GMON_PROF_ON;
163 	else
164 		disp = mode;
165 	if (pflag)
166 		dumpstate(kvp, cpuid);
167 	if (rflag)
168 		reset(kvp, cpuid);
169 	if (accessmode == O_RDWR)
170 		setprof(kvp, cpuid, disp);
171 	printf("%s: kernel profiling is %s for cpu %d.\n", __progname,
172 	    disp == GMON_PROF_OFF ? "off" : "running", cpuid);
173 }
174 
175 /*
176  * Check that profiling is enabled and open any ncessary files.
177  */
178 int
179 openfiles(char *sys, char *kmemf, struct kvmvars *kvp, int cpuid)
180 {
181 	int mib[4], state, openmode;
182 	size_t size;
183 	char errbuf[_POSIX2_LINE_MAX];
184 
185 	if (!kflag) {
186 		mib[0] = CTL_KERN;
187 		mib[1] = KERN_PROF;
188 		mib[2] = GPROF_STATE;
189 		mib[3] = cpuid;
190 		size = sizeof state;
191 		if (sysctl(mib, 4, &state, &size, NULL, 0) < 0)
192 			errx(20, "profiling not defined in kernel.");
193 		if (!(bflag || hflag || rflag ||
194 		    (pflag && state == GMON_PROF_ON)))
195 			return (O_RDONLY);
196 		(void)seteuid(0);
197 		if (sysctl(mib, 4, NULL, NULL, &state, size) >= 0)
198 			return (O_RDWR);
199 		(void)seteuid(getuid());
200 		kern_readonly(state);
201 		return (O_RDONLY);
202 	}
203 	openmode = (bflag || hflag || pflag || rflag) ? O_RDWR : O_RDONLY;
204 	kvp->kd = kvm_openfiles(sys, kmemf, NULL, openmode, errbuf);
205 	if (kvp->kd == NULL) {
206 		if (openmode == O_RDWR) {
207 			openmode = O_RDONLY;
208 			kvp->kd = kvm_openfiles(sys, kmemf, NULL, O_RDONLY,
209 			    errbuf);
210 		}
211 		if (kvp->kd == NULL)
212 			errx(2, "kvm_openfiles: %s", errbuf);
213 		kern_readonly(GMON_PROF_ON);
214 	}
215 	if (kvm_nlist(kvp->kd, nl) < 0)
216 		errx(3, "%s: no namelist", sys ? sys : _PATH_UNIX);
217 	if (!nl[N_GMONPARAM].n_value)
218 		errx(20, "profiling not defined in kernel.");
219 	return (openmode);
220 }
221 
222 /*
223  * Suppress options that require a writable kernel.
224  */
225 void
226 kern_readonly(int mode)
227 {
228 	extern char *__progname;
229 
230 	(void)fprintf(stderr, "%s: kernel read-only: ", __progname);
231 	if (pflag && mode == GMON_PROF_ON)
232 		(void)fprintf(stderr, "data may be inconsistent\n");
233 	if (rflag)
234 		(void)fprintf(stderr, "-r suppressed\n");
235 	if (bflag)
236 		(void)fprintf(stderr, "-b suppressed\n");
237 	if (hflag)
238 		(void)fprintf(stderr, "-h suppressed\n");
239 	rflag = bflag = hflag = 0;
240 }
241 
242 /*
243  * Get the state of kernel profiling.
244  */
245 int
246 getprof(struct kvmvars *kvp, int cpuid)
247 {
248 	int mib[4];
249 	size_t size;
250 
251 	if (kflag) {
252 		size = kvm_read(kvp->kd, nl[N_GMONPARAM].n_value, &kvp->gpm,
253 		    sizeof kvp->gpm);
254 	} else {
255 		mib[0] = CTL_KERN;
256 		mib[1] = KERN_PROF;
257 		mib[2] = GPROF_GMONPARAM;
258 		mib[3] = cpuid;
259 		size = sizeof kvp->gpm;
260 		if (sysctl(mib, 4, &kvp->gpm, &size, NULL, 0) < 0)
261 			size = 0;
262 	}
263 	if (size != sizeof kvp->gpm)
264 		errx(4, "cannot get gmonparam: %s",
265 		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
266 	return (kvp->gpm.state);
267 }
268 
269 /*
270  * Enable or disable kernel profiling according to the state variable.
271  */
272 void
273 setprof(struct kvmvars *kvp, int cpuid, int state)
274 {
275 	struct gmonparam *p = (struct gmonparam *)nl[N_GMONPARAM].n_value;
276 	int mib[4], oldstate;
277 	size_t sz;
278 
279 	sz = sizeof(state);
280 	if (!kflag) {
281 		mib[0] = CTL_KERN;
282 		mib[1] = KERN_PROF;
283 		mib[2] = GPROF_STATE;
284 		mib[3] = cpuid;
285 		if (sysctl(mib, 4, &oldstate, &sz, NULL, 0) < 0)
286 			goto bad;
287 		if (oldstate == state)
288 			return;
289 		(void)seteuid(0);
290 		if (sysctl(mib, 4, NULL, NULL, &state, sz) >= 0) {
291 			(void)seteuid(getuid());
292 			return;
293 		}
294 		(void)seteuid(getuid());
295 	} else if (kvm_write(kvp->kd, (u_long)&p->state, (void *)&state, sz)
296 	    == sz)
297 		return;
298 bad:
299 	warnx("warning: cannot turn profiling %s",
300 	    state == GMON_PROF_OFF ? "off" : "on");
301 }
302 
303 /*
304  * Build the gmon.out file.
305  */
306 void
307 dumpstate(struct kvmvars *kvp, int cpuid)
308 {
309 	FILE *fp;
310 	struct rawarc rawarc;
311 	struct tostruct *tos;
312 	u_long frompc;
313 	u_short *froms, *tickbuf;
314 	int mib[4];
315 	size_t i;
316 	struct gmonhdr h;
317 	int fromindex, endfrom, toindex;
318 	char buf[16];
319 
320 	snprintf(buf, sizeof(buf), "gmon-%02d.out", cpuid);
321 
322 	setprof(kvp, cpuid, GMON_PROF_OFF);
323 	fp = fopen(buf, "w");
324 	if (fp == 0) {
325 		perror(buf);
326 		return;
327 	}
328 
329 	/*
330 	 * Build the gmon header and write it to a file.
331 	 */
332 	bzero(&h, sizeof(h));
333 	h.lpc = kvp->gpm.lowpc;
334 	h.hpc = kvp->gpm.highpc;
335 	h.ncnt = kvp->gpm.kcountsize + sizeof(h);
336 	h.version = GMONVERSION;
337 	h.profrate = getprofhz(kvp);
338 	fwrite((char *)&h, sizeof(h), 1, fp);
339 
340 	/*
341 	 * Write out the tick buffer.
342 	 */
343 	mib[0] = CTL_KERN;
344 	mib[1] = KERN_PROF;
345 	if ((tickbuf = (u_short *)malloc(kvp->gpm.kcountsize)) == NULL)
346 		errx(5, "cannot allocate kcount space");
347 	if (kflag) {
348 		i = kvm_read(kvp->kd, (u_long)kvp->gpm.kcount, (void *)tickbuf,
349 		    kvp->gpm.kcountsize);
350 	} else {
351 		mib[2] = GPROF_COUNT;
352 		mib[3] = cpuid;
353 		i = kvp->gpm.kcountsize;
354 		if (sysctl(mib, 4, tickbuf, &i, NULL, 0) < 0)
355 			i = 0;
356 	}
357 	if (i != kvp->gpm.kcountsize)
358 		errx(6, "read ticks: read %lu, got %zu: %s",
359 		    kvp->gpm.kcountsize, i,
360 		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
361 	if ((fwrite(tickbuf, kvp->gpm.kcountsize, 1, fp)) != 1)
362 		err(7, "writing tocks to gmon.out");
363 	free(tickbuf);
364 
365 	/*
366 	 * Write out the arc info.
367 	 */
368 	if ((froms = (u_short *)malloc(kvp->gpm.fromssize)) == NULL)
369 		errx(8, "cannot allocate froms space");
370 	if (kflag) {
371 		i = kvm_read(kvp->kd, (u_long)kvp->gpm.froms, (void *)froms,
372 		    kvp->gpm.fromssize);
373 	} else {
374 		mib[2] = GPROF_FROMS;
375 		mib[3] = cpuid;
376 		i = kvp->gpm.fromssize;
377 		if (sysctl(mib, 4, froms, &i, NULL, 0) < 0)
378 			i = 0;
379 	}
380 	if (i != kvp->gpm.fromssize)
381 		errx(9, "read froms: read %lu, got %zu: %s",
382 		    kvp->gpm.fromssize, i,
383 		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
384 	if ((tos = (struct tostruct *)malloc(kvp->gpm.tossize)) == NULL)
385 		errx(10, "cannot allocate tos space");
386 	if (kflag) {
387 		i = kvm_read(kvp->kd, (u_long)kvp->gpm.tos, (void *)tos,
388 		    kvp->gpm.tossize);
389 	} else {
390 		mib[2] = GPROF_TOS;
391 		mib[3] = cpuid;
392 		i = kvp->gpm.tossize;
393 		if (sysctl(mib, 4, tos, &i, NULL, 0) < 0)
394 			i = 0;
395 	}
396 	if (i != kvp->gpm.tossize)
397 		errx(11, "read tos: read %lu, got %zu: %s",
398 		    kvp->gpm.tossize, i,
399 		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
400 	if (debug)
401 		warnx("lowpc 0x%lx, textsize 0x%lx",
402 		    kvp->gpm.lowpc, kvp->gpm.textsize);
403 	endfrom = kvp->gpm.fromssize / sizeof(*froms);
404 	for (fromindex = 0; fromindex < endfrom; ++fromindex) {
405 		if (froms[fromindex] == 0)
406 			continue;
407 		frompc = (u_long)kvp->gpm.lowpc +
408 		    (fromindex * kvp->gpm.hashfraction * sizeof(*froms));
409 		for (toindex = froms[fromindex]; toindex != 0;
410 		   toindex = tos[toindex].link) {
411 			if (debug)
412 			  warnx("[mcleanup] frompc 0x%lx selfpc 0x%lx count %ld",
413 			    frompc, tos[toindex].selfpc, tos[toindex].count);
414 			rawarc.raw_frompc = frompc;
415 			rawarc.raw_selfpc = (u_long)tos[toindex].selfpc;
416 			rawarc.raw_count = tos[toindex].count;
417 			fwrite((char *)&rawarc, sizeof(rawarc), 1, fp);
418 		}
419 	}
420 	fclose(fp);
421 }
422 
423 /*
424  * Get the profiling rate.
425  */
426 int
427 getprofhz(struct kvmvars *kvp)
428 {
429 	int mib[2], profrate;
430 	size_t size;
431 	struct clockinfo clockrate;
432 
433 	if (kflag) {
434 		profrate = 1;
435 		if (kvm_read(kvp->kd, nl[N_PROFHZ].n_value, &profrate,
436 		    sizeof profrate) != sizeof profrate)
437 			warnx("get clockrate: %s", kvm_geterr(kvp->kd));
438 		return (profrate);
439 	}
440 	mib[0] = CTL_KERN;
441 	mib[1] = KERN_CLOCKRATE;
442 	clockrate.profhz = 1;
443 	size = sizeof clockrate;
444 	if (sysctl(mib, 2, &clockrate, &size, NULL, 0) < 0)
445 		warn("get clockrate");
446 	return (clockrate.profhz);
447 }
448 
449 /*
450  * Reset the kernel profiling date structures.
451  */
452 void
453 reset(struct kvmvars *kvp, int cpuid)
454 {
455 	char *zbuf;
456 	u_long biggest;
457 	int mib[4];
458 
459 	setprof(kvp, cpuid, GMON_PROF_OFF);
460 
461 	biggest = kvp->gpm.kcountsize;
462 	if (kvp->gpm.fromssize > biggest)
463 		biggest = kvp->gpm.fromssize;
464 	if (kvp->gpm.tossize > biggest)
465 		biggest = kvp->gpm.tossize;
466 	if ((zbuf = (char *)malloc(biggest)) == NULL)
467 		errx(12, "cannot allocate zbuf space");
468 	bzero(zbuf, biggest);
469 	if (kflag) {
470 		if (kvm_write(kvp->kd, (u_long)kvp->gpm.kcount, zbuf,
471 		    kvp->gpm.kcountsize) != kvp->gpm.kcountsize)
472 			errx(13, "tickbuf zero: %s", kvm_geterr(kvp->kd));
473 		if (kvm_write(kvp->kd, (u_long)kvp->gpm.froms, zbuf,
474 		    kvp->gpm.fromssize) != kvp->gpm.fromssize)
475 			errx(14, "froms zero: %s", kvm_geterr(kvp->kd));
476 		if (kvm_write(kvp->kd, (u_long)kvp->gpm.tos, zbuf,
477 		    kvp->gpm.tossize) != kvp->gpm.tossize)
478 			errx(15, "tos zero: %s", kvm_geterr(kvp->kd));
479 		return;
480 	}
481 	(void)seteuid(0);
482 	mib[0] = CTL_KERN;
483 	mib[1] = KERN_PROF;
484 	mib[2] = GPROF_COUNT;
485 	mib[3] = cpuid;
486 	if (sysctl(mib, 4, NULL, NULL, zbuf, kvp->gpm.kcountsize) < 0)
487 		err(13, "tickbuf zero");
488 	mib[2] = GPROF_FROMS;
489 	if (sysctl(mib, 4, NULL, NULL, zbuf, kvp->gpm.fromssize) < 0)
490 		err(14, "froms zero");
491 	mib[2] = GPROF_TOS;
492 	if (sysctl(mib, 4, NULL, NULL, zbuf, kvp->gpm.tossize) < 0)
493 		err(15, "tos zero");
494 	(void)seteuid(getuid());
495 	free(zbuf);
496 }
497 
498 int
499 getncpu(void)
500 {
501 	int mib[2] = { CTL_HW, HW_NCPU };
502 	size_t size;
503 	int ncpu;
504 
505 	size = sizeof(ncpu);
506 	if (sysctl(mib, 2, &ncpu, &size, NULL, 0) < 0) {
507 		warnx("cannot read hw.ncpu");
508 		return (1);
509 	}
510 
511 	return (ncpu);
512 }
513