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kgmon.c revision 1.20
      1 /*	$NetBSD: kgmon.c,v 1.20 2006/08/13 00:20:25 dyoung 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/cdefs.h>
     33 #ifndef lint
     34 __COPYRIGHT("@(#) Copyright (c) 1983, 1992, 1993\n\
     35 	The Regents of the University of California.  All rights reserved.\n");
     36 #endif /* not lint */
     37 
     38 #ifndef lint
     39 #if 0
     40 static char sccsid[] = "from: @(#)kgmon.c	8.1 (Berkeley) 6/6/93";
     41 #else
     42 __RCSID("$NetBSD: kgmon.c,v 1.20 2006/08/13 00:20:25 dyoung Exp $");
     43 #endif
     44 #endif /* not lint */
     45 
     46 #include <sys/param.h>
     47 #include <sys/file.h>
     48 #include <sys/sysctl.h>
     49 #include <sys/gmon.h>
     50 
     51 #include <ctype.h>
     52 #include <errno.h>
     53 #include <kvm.h>
     54 #include <err.h>
     55 #include <limits.h>
     56 #include <nlist.h>
     57 #include <stdio.h>
     58 #include <stdlib.h>
     59 #include <string.h>
     60 #include <unistd.h>
     61 
     62 static struct nlist nl[] = {
     63 #define	N_GMONPARAM	0
     64 	{ "__gmonparam" },
     65 #define	N_PROFHZ	1
     66 	{ "_profhz" },
     67 	{ 0, }
     68 };
     69 
     70 struct kvmvars {
     71 	kvm_t	*kd;
     72 	struct gmonparam gpm;
     73 };
     74 
     75 static int	bflag, hflag, kflag, rflag, pflag;
     76 static int	debug = 0;
     77 static void	setprof(struct kvmvars *kvp, int state);
     78 static void	dumpstate(struct kvmvars *kvp);
     79 static void	reset(struct kvmvars *kvp);
     80 static int	openfiles(char *, char *, struct kvmvars *);
     81 static int	getprof(struct kvmvars *);
     82 static void	kern_readonly(int);
     83 static int	getprofhz(struct kvmvars *);
     84 
     85 int
     86 main(int argc, char **argv)
     87 {
     88 	int ch, mode, disp, accessmode;
     89 	struct kvmvars kvmvars;
     90 	char *system, *kmemf;
     91 
     92 	setprogname(argv[0]);
     93 	seteuid(getuid());
     94 	kmemf = NULL;
     95 	system = NULL;
     96 	while ((ch = getopt(argc, argv, "M:N:bdhpr")) != -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 'h':
    113 			hflag = 1;
    114 			break;
    115 
    116 		case 'p':
    117 			pflag = 1;
    118 			break;
    119 
    120 		case 'r':
    121 			rflag = 1;
    122 			break;
    123 
    124 		case 'd':
    125 			debug = 1;
    126 			break;
    127 
    128 		default:
    129 			(void)fprintf(stderr,
    130 			    "usage: %s [-bdhrp] [-M core] [-N system]\n",
    131 			    getprogname());
    132 			exit(1);
    133 		}
    134 	}
    135 	argc -= optind;
    136 	argv += optind;
    137 
    138 #define BACKWARD_COMPATIBILITY
    139 #ifdef	BACKWARD_COMPATIBILITY
    140 	if (*argv) {
    141 		system = *argv;
    142 		if (*++argv) {
    143 			kmemf = *argv;
    144 			++kflag;
    145 		}
    146 	}
    147 #endif
    148 	accessmode = openfiles(system, kmemf, &kvmvars);
    149 	mode = getprof(&kvmvars);
    150 	if (hflag)
    151 		disp = GMON_PROF_OFF;
    152 	else if (bflag)
    153 		disp = GMON_PROF_ON;
    154 	else
    155 		disp = mode;
    156 	if (pflag)
    157 		dumpstate(&kvmvars);
    158 	if (rflag)
    159 		reset(&kvmvars);
    160 	if (accessmode == O_RDWR)
    161 		setprof(&kvmvars, disp);
    162 	(void)fprintf(stdout, "%s: kernel profiling is %s.\n",
    163 	     getprogname(), disp == GMON_PROF_OFF ? "off" : "running");
    164 	return (0);
    165 }
    166 
    167 /*
    168  * Check that profiling is enabled and open any ncessary files.
    169  */
    170 static int
    171 openfiles(char *system, char *kmemf, struct kvmvars *kvp)
    172 {
    173 	int mib[3], state, openmode;
    174 	size_t size;
    175 	char errbuf[_POSIX2_LINE_MAX];
    176 
    177 	if (!kflag) {
    178 		mib[0] = CTL_KERN;
    179 		mib[1] = KERN_PROF;
    180 		mib[2] = GPROF_STATE;
    181 		size = sizeof state;
    182 		if (sysctl(mib, 3, &state, &size, NULL, 0) < 0)
    183 			err(EXIT_FAILURE, "profiling not defined in kernel");
    184 		if (!(bflag || hflag || rflag ||
    185 		    (pflag && state == GMON_PROF_ON)))
    186 			return (O_RDONLY);
    187 		(void)seteuid(0);
    188 		if (sysctl(mib, 3, NULL, NULL, &state, size) >= 0)
    189 			return (O_RDWR);
    190 		(void)seteuid(getuid());
    191 		kern_readonly(state);
    192 		return (O_RDONLY);
    193 	}
    194 	openmode = (bflag || hflag || pflag || rflag) ? O_RDWR : O_RDONLY;
    195 	kvp->kd = kvm_openfiles(system, kmemf, NULL, openmode, errbuf);
    196 	if (kvp->kd == NULL) {
    197 		if (openmode == O_RDWR) {
    198 			openmode = O_RDONLY;
    199 			kvp->kd = kvm_openfiles(system, kmemf, NULL, O_RDONLY,
    200 			    errbuf);
    201 		}
    202 		if (kvp->kd == NULL)
    203 			errx(EXIT_FAILURE, "kvm_openfiles: %s", errbuf);
    204 		kern_readonly(GMON_PROF_ON);
    205 	}
    206 	if (kvm_nlist(kvp->kd, nl) < 0)
    207 		errx(EXIT_FAILURE, "%s: no namelist", system);
    208 	if (!nl[N_GMONPARAM].n_value)
    209 		errx(EXIT_FAILURE, "profiling not defined in kernel");
    210 	return (openmode);
    211 }
    212 
    213 /*
    214  * Suppress options that require a writable kernel.
    215  */
    216 static void
    217 kern_readonly(int mode)
    218 {
    219 
    220 	(void)fprintf(stderr, "%s: kernel read-only: ", getprogname());
    221 	if (pflag && mode == GMON_PROF_ON)
    222 		(void)fprintf(stderr, "data may be inconsistent\n");
    223 	if (rflag)
    224 		(void)fprintf(stderr, "-r supressed\n");
    225 	if (bflag)
    226 		(void)fprintf(stderr, "-b supressed\n");
    227 	if (hflag)
    228 		(void)fprintf(stderr, "-h supressed\n");
    229 	rflag = bflag = hflag = 0;
    230 }
    231 
    232 /*
    233  * Get the state of kernel profiling.
    234  */
    235 static int
    236 getprof(struct kvmvars *kvp)
    237 {
    238 	int mib[3];
    239 	size_t size;
    240 
    241 	if (kflag) {
    242 		size = kvm_read(kvp->kd, nl[N_GMONPARAM].n_value, &kvp->gpm,
    243 		    sizeof kvp->gpm);
    244 	} else {
    245 		mib[0] = CTL_KERN;
    246 		mib[1] = KERN_PROF;
    247 		mib[2] = GPROF_GMONPARAM;
    248 		size = sizeof kvp->gpm;
    249 		if (sysctl(mib, 3, &kvp->gpm, &size, NULL, 0) < 0)
    250 			size = 0;
    251 	}
    252 	if (size != sizeof kvp->gpm)
    253 		errx(EXIT_FAILURE, "cannot get gmonparam: %s",
    254 		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
    255 	return (kvp->gpm.state);
    256 }
    257 
    258 /*
    259  * Enable or disable kernel profiling according to the state variable.
    260  */
    261 static void
    262 setprof(struct kvmvars *kvp, int state)
    263 {
    264 	struct gmonparam *p = (struct gmonparam *)nl[N_GMONPARAM].n_value;
    265 	int mib[3], oldstate;
    266 	size_t sz;
    267 
    268 	sz = sizeof(state);
    269 	if (!kflag) {
    270 		mib[0] = CTL_KERN;
    271 		mib[1] = KERN_PROF;
    272 		mib[2] = GPROF_STATE;
    273 		if (sysctl(mib, 3, &oldstate, &sz, NULL, 0) < 0)
    274 			goto bad;
    275 		if (oldstate == state)
    276 			return;
    277 		(void)seteuid(0);
    278 		if (sysctl(mib, 3, NULL, NULL, &state, sz) >= 0) {
    279 			(void)seteuid(getuid());
    280 			return;
    281 		}
    282 		(void)seteuid(getuid());
    283 	} else if (kvm_write(kvp->kd, (u_long)&p->state, (void *)&state, sz)
    284 	    == sz)
    285 		return;
    286 bad:
    287 	warnx("cannot turn profiling %s", state == GMON_PROF_OFF ?
    288 	    "off" : "on");
    289 }
    290 
    291 /*
    292  * Build the gmon.out file.
    293  */
    294 static void
    295 dumpstate(struct kvmvars *kvp)
    296 {
    297 	FILE *fp;
    298 	struct rawarc rawarc;
    299 	struct tostruct *tos;
    300 	u_long frompc;
    301 	u_short *froms, *tickbuf;
    302 	int mib[3];
    303 	size_t i;
    304 	struct gmonhdr h;
    305 	int fromindex, endfrom, toindex;
    306 
    307 	setprof(kvp, GMON_PROF_OFF);
    308 	fp = fopen("gmon.out", "w");
    309 	if (fp == NULL) {
    310 		warn("cannot open `gmon.out'");
    311 		return;
    312 	}
    313 
    314 	/*
    315 	 * Build the gmon header and write it to a file.
    316 	 */
    317 	bzero(&h, sizeof(h));
    318 	h.lpc = kvp->gpm.lowpc;
    319 	h.hpc = kvp->gpm.highpc;
    320 	h.ncnt = kvp->gpm.kcountsize + sizeof(h);
    321 	h.version = GMONVERSION;
    322 	h.profrate = getprofhz(kvp);
    323 	if (fwrite((char *)&h, sizeof(h), 1, fp) != 1)
    324 		err(EXIT_FAILURE, "writing header to gmon.out");
    325 
    326 	/*
    327 	 * Write out the tick buffer.
    328 	 */
    329 	mib[0] = CTL_KERN;
    330 	mib[1] = KERN_PROF;
    331 	if ((tickbuf = malloc(kvp->gpm.kcountsize)) == NULL)
    332 		err(EXIT_FAILURE, "cannot allocate kcount space");
    333 	if (kflag) {
    334 		i = kvm_read(kvp->kd, (u_long)kvp->gpm.kcount, (void *)tickbuf,
    335 		    kvp->gpm.kcountsize);
    336 	} else {
    337 		mib[2] = GPROF_COUNT;
    338 		i = kvp->gpm.kcountsize;
    339 		if (sysctl(mib, 3, tickbuf, &i, NULL, 0) < 0)
    340 			i = 0;
    341 	}
    342 	if (i != kvp->gpm.kcountsize)
    343 		errx(EXIT_FAILURE, "read ticks: read %lu, got %lu: %s",
    344 		    kvp->gpm.kcountsize, (u_long)i,
    345 		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
    346 	if ((fwrite(tickbuf, kvp->gpm.kcountsize, 1, fp)) != 1)
    347 		err(EXIT_FAILURE, "writing tocks to gmon.out");
    348 	free(tickbuf);
    349 
    350 	/*
    351 	 * Write out the arc info.
    352 	 */
    353 	if ((froms = malloc(kvp->gpm.fromssize)) == NULL)
    354 		err(EXIT_FAILURE, "cannot allocate froms space");
    355 	if (kflag) {
    356 		i = kvm_read(kvp->kd, (u_long)kvp->gpm.froms, (void *)froms,
    357 		    kvp->gpm.fromssize);
    358 	} else {
    359 		mib[2] = GPROF_FROMS;
    360 		i = kvp->gpm.fromssize;
    361 		if (sysctl(mib, 3, froms, &i, NULL, 0) < 0)
    362 			i = 0;
    363 	}
    364 	if (i != kvp->gpm.fromssize)
    365 		errx(EXIT_FAILURE, "read froms: read %lu, got %lu: %s",
    366 		    kvp->gpm.fromssize, (u_long)i,
    367 		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
    368 	if ((tos = malloc(kvp->gpm.tossize)) == NULL)
    369 		err(EXIT_FAILURE, "cannot allocate tos space");
    370 	if (kflag) {
    371 		i = kvm_read(kvp->kd, (u_long)kvp->gpm.tos, (void *)tos,
    372 		    kvp->gpm.tossize);
    373 	} else {
    374 		mib[2] = GPROF_TOS;
    375 		i = kvp->gpm.tossize;
    376 		if (sysctl(mib, 3, tos, &i, NULL, 0) < 0)
    377 			i = 0;
    378 	}
    379 	if (i != kvp->gpm.tossize)
    380 		errx(EXIT_FAILURE, "read tos: read %lu, got %lu: %s",
    381 		    kvp->gpm.tossize, (u_long)i,
    382 		    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
    383 	if (debug)
    384 		(void)fprintf(stderr, "%s: lowpc 0x%lx, textsize 0x%lx\n",
    385 		     getprogname(), kvp->gpm.lowpc, kvp->gpm.textsize);
    386 	endfrom = kvp->gpm.fromssize / sizeof(*froms);
    387 	for (fromindex = 0; fromindex < endfrom; ++fromindex) {
    388 		if (froms[fromindex] == 0)
    389 			continue;
    390 		frompc = (u_long)kvp->gpm.lowpc +
    391 		    (fromindex * kvp->gpm.hashfraction * sizeof(*froms));
    392 		for (toindex = froms[fromindex]; toindex != 0;
    393 		   toindex = tos[toindex].link) {
    394 			if (debug)
    395 			    (void)fprintf(stderr,
    396 			    "%s: [mcleanup] frompc 0x%lx selfpc 0x%lx count %ld\n",
    397 			    getprogname(), frompc, tos[toindex].selfpc,
    398 			    tos[toindex].count);
    399 			rawarc.raw_frompc = frompc;
    400 			rawarc.raw_selfpc = (u_long)tos[toindex].selfpc;
    401 			rawarc.raw_count = tos[toindex].count;
    402 			if (fwrite((char *)&rawarc, sizeof(rawarc), 1,fp) != 1){
    403 				err(EXIT_FAILURE,
    404 				    "writing raw arc to gmon.out");
    405 			}
    406 		}
    407 	}
    408 	free(tos);
    409 	fclose(fp);
    410 }
    411 
    412 /*
    413  * Get the profiling rate.
    414  */
    415 static int
    416 getprofhz(struct kvmvars *kvp)
    417 {
    418 	int mib[2], profrate;
    419 	size_t size;
    420 	struct clockinfo clockrate;
    421 
    422 	if (kflag) {
    423 		profrate = 1;
    424 		if (kvm_read(kvp->kd, nl[N_PROFHZ].n_value, &profrate,
    425 		    sizeof profrate) != sizeof profrate)
    426 			warnx("get clockrate: %s", kvm_geterr(kvp->kd));
    427 		return (profrate);
    428 	}
    429 	mib[0] = CTL_KERN;
    430 	mib[1] = KERN_CLOCKRATE;
    431 	clockrate.profhz = 1;
    432 	size = sizeof clockrate;
    433 	if (sysctl(mib, 2, &clockrate, &size, NULL, 0) < 0)
    434 		warn("get clockrate");
    435 	return (clockrate.profhz);
    436 }
    437 
    438 /*
    439  * Reset the kernel profiling date structures.
    440  */
    441 static void
    442 reset(struct kvmvars *kvp)
    443 {
    444 	char *zbuf;
    445 	u_long biggest;
    446 	int mib[3];
    447 
    448 	setprof(kvp, GMON_PROF_OFF);
    449 
    450 	biggest = kvp->gpm.kcountsize;
    451 	if (kvp->gpm.fromssize > biggest)
    452 		biggest = kvp->gpm.fromssize;
    453 	if (kvp->gpm.tossize > biggest)
    454 		biggest = kvp->gpm.tossize;
    455 	if ((zbuf = malloc(biggest)) == NULL)
    456 		err(EXIT_FAILURE, "cannot allocate zbuf space");
    457 	bzero(zbuf, biggest);
    458 	if (kflag) {
    459 		if (kvm_write(kvp->kd, (u_long)kvp->gpm.kcount, zbuf,
    460 		    kvp->gpm.kcountsize) != kvp->gpm.kcountsize)
    461 			errx(EXIT_FAILURE, "tickbuf zero: %s",
    462 			     kvm_geterr(kvp->kd));
    463 		if (kvm_write(kvp->kd, (u_long)kvp->gpm.froms, zbuf,
    464 		    kvp->gpm.fromssize) != kvp->gpm.fromssize)
    465 			errx(EXIT_FAILURE, "froms zero: %s",
    466 			     kvm_geterr(kvp->kd));
    467 		if (kvm_write(kvp->kd, (u_long)kvp->gpm.tos, zbuf,
    468 		    kvp->gpm.tossize) != kvp->gpm.tossize)
    469 			errx(EXIT_FAILURE, "tos zero: %s", kvm_geterr(kvp->kd));
    470 		free(zbuf);
    471 		return;
    472 	}
    473 	(void)seteuid(0);
    474 	mib[0] = CTL_KERN;
    475 	mib[1] = KERN_PROF;
    476 	mib[2] = GPROF_COUNT;
    477 	if (sysctl(mib, 3, NULL, NULL, zbuf, kvp->gpm.kcountsize) < 0)
    478 		err(EXIT_FAILURE, "tickbuf zero");
    479 	mib[2] = GPROF_FROMS;
    480 	if (sysctl(mib, 3, NULL, NULL, zbuf, kvp->gpm.fromssize) < 0)
    481 		err(EXIT_FAILURE, "froms zero");
    482 	mib[2] = GPROF_TOS;
    483 	if (sysctl(mib, 3, NULL, NULL, zbuf, kvp->gpm.tossize) < 0)
    484 		err(EXIT_FAILURE, "tos zero");
    485 	(void)seteuid(getuid());
    486 	free(zbuf);
    487 }
    488