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gmon.c revision 1.17.2.2
      1 /*	$NetBSD: gmon.c,v 1.17.2.2 2002/11/11 22:22:17 nathanw 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #if !defined(lint) && defined(LIBC_SCCS)
     38 #if 0
     39 static char sccsid[] = "@(#)gmon.c	8.1 (Berkeley) 6/4/93";
     40 #else
     41 __RCSID("$NetBSD: gmon.c,v 1.17.2.2 2002/11/11 22:22:17 nathanw Exp $");
     42 #endif
     43 #endif
     44 
     45 #include "namespace.h"
     46 #include <sys/param.h>
     47 #include <sys/time.h>
     48 #include <sys/gmon.h>
     49 #include <sys/sysctl.h>
     50 
     51 #include <stdio.h>
     52 #include <stdlib.h>
     53 #include <fcntl.h>
     54 #include <limits.h>
     55 #include <unistd.h>
     56 #include <err.h>
     57 #include "extern.h"
     58 
     59 struct gmonparam _gmonparam = { GMON_PROF_OFF };
     60 
     61 static u_int	s_scale;
     62 /* see profil(2) where this is describe (incorrectly) */
     63 #define		SCALE_1_TO_1	0x10000L
     64 
     65 #define ERR(s) write(STDERR_FILENO, s, sizeof(s))
     66 
     67 void	moncontrol __P((int));
     68 void	monstartup __P((u_long, u_long));
     69 void	_mcleanup __P((void));
     70 static int hertz __P((void));
     71 
     72 
     73 void
     74 monstartup(lowpc, highpc)
     75 	u_long lowpc;
     76 	u_long highpc;
     77 {
     78 	u_long o;
     79 	char *cp;
     80 	struct gmonparam *p = &_gmonparam;
     81 
     82 	/*
     83 	 * round lowpc and highpc to multiples of the density we're using
     84 	 * so the rest of the scaling (here and in gprof) stays in ints.
     85 	 */
     86 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
     87 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
     88 	p->textsize = p->highpc - p->lowpc;
     89 	p->kcountsize = p->textsize / HISTFRACTION;
     90 	p->hashfraction = HASHFRACTION;
     91 	p->fromssize = p->textsize / p->hashfraction;
     92 	p->tolimit = p->textsize * ARCDENSITY / 100;
     93 	if (p->tolimit < MINARCS)
     94 		p->tolimit = MINARCS;
     95 	else if (p->tolimit > MAXARCS)
     96 		p->tolimit = MAXARCS;
     97 	p->tossize = p->tolimit * sizeof(struct tostruct);
     98 
     99 	cp = sbrk((intptr_t)(p->kcountsize + p->fromssize + p->tossize));
    100 	if (cp == (char *)-1) {
    101 		ERR("monstartup: out of memory\n");
    102 		return;
    103 	}
    104 #ifdef notdef
    105 	memset(cp, 0, p->kcountsize + p->fromssize + p->tossize);
    106 #endif
    107 	p->tos = (struct tostruct *)(void *)cp;
    108 	cp += (size_t)p->tossize;
    109 	p->kcount = (u_short *)(void *)cp;
    110 	cp += (size_t)p->kcountsize;
    111 	p->froms = (u_short *)(void *)cp;
    112 
    113 	__minbrk = sbrk((intptr_t)0);
    114 	p->tos[0].link = 0;
    115 
    116 	o = p->highpc - p->lowpc;
    117 	if (p->kcountsize < o) {
    118 #ifndef notdef
    119 		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
    120 #else /* avoid floating point */
    121 		u_long quot = o / p->kcountsize;
    122 
    123 		if (quot >= 0x10000)
    124 			s_scale = 1;
    125 		else if (quot >= 0x100)
    126 			s_scale = 0x10000 / quot;
    127 		else if (o >= 0x800000)
    128 			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
    129 		else
    130 			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
    131 #endif
    132 	} else
    133 		s_scale = SCALE_1_TO_1;
    134 
    135 	moncontrol(1);
    136 }
    137 
    138 void
    139 _mcleanup()
    140 {
    141 	int fd;
    142 	int fromindex;
    143 	int endfrom;
    144 	u_long frompc;
    145 	int toindex;
    146 	struct rawarc rawarc;
    147 	struct gmonparam *p = &_gmonparam;
    148 	struct gmonhdr gmonhdr, *hdr;
    149 	struct clockinfo clockinfo;
    150 	int mib[2];
    151 	size_t size;
    152 	char *profdir;
    153 	char *proffile;
    154 	char  buf[PATH_MAX];
    155 	int len = sizeof(buf) - 1;
    156 #ifdef DEBUG
    157 	int log, len;
    158 	char buf2[200];
    159 #endif
    160 
    161 	/*
    162 	 * We disallow writing to the profiling file, if we are a
    163 	 * set{u,g}id program and our effective {u,g}id does not match
    164 	 * our real one.
    165 	 */
    166 	if (issetugid() && (geteuid() != getuid() || getegid() != getgid())) {
    167 		warnx("mcount: Profiling of set{u,g}id binaries is not"
    168 		    " allowed");
    169 		return;
    170 	}
    171 
    172 	if (p->state == GMON_PROF_ERROR)
    173 		ERR("_mcleanup: tos overflow\n");
    174 
    175 	size = sizeof(clockinfo);
    176 	mib[0] = CTL_KERN;
    177 	mib[1] = KERN_CLOCKRATE;
    178 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
    179 		/*
    180 		 * Best guess
    181 		 */
    182 		clockinfo.profhz = hertz();
    183 	} else if (clockinfo.profhz == 0) {
    184 		if (clockinfo.hz != 0)
    185 			clockinfo.profhz = clockinfo.hz;
    186 		else
    187 			clockinfo.profhz = hertz();
    188 	}
    189 
    190 	moncontrol(0);
    191 
    192 	if ((profdir = getenv("PROFDIR")) != NULL) {
    193 		const char *s;
    194 		char *t;
    195 		pid_t pid;
    196 		long divisor;
    197 
    198 		/* If PROFDIR contains a null value, no profiling
    199 		   output is produced */
    200 		if (*profdir == '\0') {
    201 			return;
    202 		}
    203 
    204 		t = buf;
    205 		s = profdir;
    206 		while ((*t = *s) != '\0') {
    207 			if (len-- == 0) {
    208 				warnx("_mcleanup: internal buffer overflow, PROFDIR too long");
    209 				return;
    210 			}
    211 			t++;
    212 			s++;
    213 		}
    214 		*t++ = '/';
    215 
    216 		/*
    217 		 * Copy and convert pid from a pid_t to a string.  For
    218 		 * best performance, divisor should be initialized to
    219 		 * the largest power of 10 less than PID_MAX.
    220 		 */
    221 		pid = getpid();
    222 		divisor=10000;
    223 		while (divisor > pid) divisor /= 10;	/* skip leading zeros */
    224 		do {
    225 			*t++ = (char)((pid/divisor) + '0');
    226 			pid %= (pid_t)divisor;
    227 		} while (divisor /= 10);
    228 		*t++ = '.';
    229 
    230 		s = getprogname();
    231 		while ((*t++ = *s++) != '\0')
    232 			;
    233 
    234 		proffile = buf;
    235 	} else {
    236 		proffile = "gmon.out";
    237 	}
    238 
    239 	fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0666);
    240 	if (fd < 0) {
    241 		warn("mcount: Cannot open `%s'", proffile);
    242 		return;
    243 	}
    244 #ifdef DEBUG
    245 	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
    246 	if (log < 0) {
    247 		warn("mcount: Cannot open `gmon.log'");
    248 		return;
    249 	}
    250 	len = snprintf(buf2, sizeof buf2, "[mcleanup1] kcount 0x%x ssiz %d\n",
    251 	    p->kcount, p->kcountsize);
    252 	write(log, buf2, len);
    253 #endif
    254 	hdr = (struct gmonhdr *)&gmonhdr;
    255 	hdr->lpc = p->lowpc;
    256 	hdr->hpc = p->highpc;
    257 	hdr->ncnt = (int)(p->kcountsize + sizeof(gmonhdr));
    258 	hdr->version = GMONVERSION;
    259 	hdr->profrate = clockinfo.profhz;
    260 	(void)write(fd, hdr, sizeof *hdr);
    261 	(void)write(fd, p->kcount, (size_t)p->kcountsize);
    262 	endfrom = (int)(p->fromssize / sizeof(*p->froms));
    263 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
    264 		if (p->froms[fromindex] == 0)
    265 			continue;
    266 
    267 		frompc = p->lowpc;
    268 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
    269 		for (toindex = p->froms[fromindex]; toindex != 0;
    270 		     toindex = p->tos[toindex].link) {
    271 #ifdef DEBUG
    272 			len = snprintf(buf2, sizeof buf2,
    273 			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
    274 				frompc, p->tos[toindex].selfpc,
    275 				p->tos[toindex].count);
    276 			write(log, buf2, len);
    277 #endif
    278 			rawarc.raw_frompc = frompc;
    279 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
    280 			rawarc.raw_count = p->tos[toindex].count;
    281 			write(fd, &rawarc, sizeof rawarc);
    282 		}
    283 	}
    284 	close(fd);
    285 }
    286 
    287 /*
    288  * Control profiling
    289  *	profiling is what mcount checks to see if
    290  *	all the data structures are ready.
    291  */
    292 void
    293 moncontrol(mode)
    294 	int mode;
    295 {
    296 	struct gmonparam *p = &_gmonparam;
    297 
    298 	if (mode) {
    299 		/* start */
    300 		profil((char *)(void *)p->kcount, (size_t)p->kcountsize,
    301 		    p->lowpc, s_scale);
    302 		p->state = GMON_PROF_ON;
    303 	} else {
    304 		/* stop */
    305 		profil(NULL, 0, (u_long)0, 0);
    306 		p->state = GMON_PROF_OFF;
    307 	}
    308 }
    309 
    310 /*
    311  * discover the tick frequency of the machine
    312  * if something goes wrong, we return 0, an impossible hertz.
    313  */
    314 static int
    315 hertz()
    316 {
    317 	struct itimerval tim;
    318 
    319 	tim.it_interval.tv_sec = 0;
    320 	tim.it_interval.tv_usec = 1;
    321 	tim.it_value.tv_sec = 0;
    322 	tim.it_value.tv_usec = 0;
    323 	setitimer(ITIMER_REAL, &tim, 0);
    324 	setitimer(ITIMER_REAL, 0, &tim);
    325 	if (tim.it_interval.tv_usec < 2)
    326 		return(0);
    327 	return (int)(1000000 / tim.it_interval.tv_usec);
    328 }
    329