lib/libc/gmon/gmon.c

   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  * 3. 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  * @(#)gmon.c   8.1 (Berkeley) 6/4/93
  30  * $FreeBSD: src/lib/libc/gmon/gmon.c,v 1.22 2007/01/09 00:27:58 imp Exp $
  31  */
  32
  33 #include "namespace.h"
  34 #include <sys/param.h>
  35 #include <sys/time.h>
  36 #include <sys/gmon.h>
  37 #include <sys/sysctl.h>
  38
  39 #include <err.h>
  40 #include <fcntl.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44 #include <unistd.h>
  45 #include "un-namespace.h"
  46
  47 #include "libc_private.h"
  48
  49 #if defined(__x86_64__)
  50 extern char *minbrk __asm (".minbrk");
  51 #else
  52 extern char *minbrk __asm ("minbrk");
  53 #endif
  54
  55 struct gmonparam _gmonparam = { .state = GMON_PROF_OFF };
  56
  57 static int      s_scale;
  58 /* see profil(2) where this is describe (incorrectly) */
  59 #define         SCALE_1_TO_1    0x10000L
  60
  61 #define ERR(s) _write(2, s, sizeof(s))
  62
  63 void    moncontrol(int);
  64 static int hertz(void);
  65
  66 void
  67 monstartup(u_long lowpc, u_long highpc)
  68 {
  69         int o;
  70         char *cp;
  71         struct gmonparam *p = &_gmonparam;
  72
  73         /*
  74          * round lowpc and highpc to multiples of the density we're using
  75          * so the rest of the scaling (here and in gprof) stays in ints.
  76          */
  77         p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
  78         p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
  79         p->textsize = p->highpc - p->lowpc;
  80         p->kcountsize = p->textsize / HISTFRACTION;
  81         p->hashfraction = HASHFRACTION;
  82         p->fromssize = p->textsize / HASHFRACTION;
  83         p->tolimit = p->textsize * ARCDENSITY / 100;
  84         if (p->tolimit < MINARCS)
  85                 p->tolimit = MINARCS;
  86         else if (p->tolimit > MAXARCS)
  87                 p->tolimit = MAXARCS;
  88         p->tossize = p->tolimit * sizeof(struct tostruct);
  89
  90         cp = sbrk(p->kcountsize + p->fromssize + p->tossize);
  91         if (cp == (char *)-1) {
  92                 ERR("monstartup: out of memory\n");
  93                 return;
  94         }
  95 #ifdef notdef
  96         bzero(cp, p->kcountsize + p->fromssize + p->tossize);
  97 #endif
  98         p->tos = (struct tostruct *)cp;
  99         cp += p->tossize;
 100         p->kcount = (u_short *)cp;
 101         cp += p->kcountsize;
 102         p->froms = (u_short *)cp;
 103
 104         minbrk = sbrk(0);
 105         p->tos[0].link = 0;
 106
 107         o = p->highpc - p->lowpc;
 108         if (p->kcountsize < o)
 109                 s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
 110         else
 111                 s_scale = SCALE_1_TO_1;
 112
 113         moncontrol(1);
 114 }
 115
 116 void
 117 _mcleanup(void)
 118 {
 119         int fd;
 120         int fromindex;
 121         int endfrom;
 122         u_long frompc;
 123         int toindex;
 124         struct rawarc rawarc;
 125         struct gmonparam *p = &_gmonparam;
 126         struct gmonhdr gmonhdr, *hdr;
 127         struct clockinfo clockinfo;
 128         char outname[128];
 129         int mib[2];
 130         size_t size;
 131 #ifdef DEBUG
 132         int log, len;
 133         char buf[200];
 134 #endif
 135
 136         if (p->state == GMON_PROF_ERROR)
 137                 ERR("_mcleanup: tos overflow\n");
 138
 139         size = sizeof(clockinfo);
 140         mib[0] = CTL_KERN;
 141         mib[1] = KERN_CLOCKRATE;
 142         if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
 143                 /*
 144                  * Best guess
 145                  */
 146                 clockinfo.profhz = hertz();
 147         } else if (clockinfo.profhz == 0) {
 148                 if (clockinfo.hz != 0)
 149                         clockinfo.profhz = clockinfo.hz;
 150                 else
 151                         clockinfo.profhz = hertz();
 152         }
 153
 154         moncontrol(0);
 155         snprintf(outname, sizeof(outname), "%s.gmon", _getprogname());
 156         fd = _open(outname, O_CREAT|O_TRUNC|O_WRONLY|O_CLOEXEC, 0666);
 157         if (fd < 0) {
 158                 _warn("_mcleanup: %s", outname);
 159                 return;
 160         }
 161 #ifdef DEBUG
 162         log = _open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY|O_CLOEXEC, 0664);
 163         if (log < 0) {
 164                 _warn("_mcleanup: gmon.log");
 165                 return;
 166         }
 167         len = sprintf(buf, "[mcleanup1] kcount 0x%p ssiz %lu\n",
 168             p->kcount, p->kcountsize);
 169         _write(log, buf, len);
 170 #endif
 171         hdr = (struct gmonhdr *)&gmonhdr;
 172         bzero(hdr, sizeof(*hdr));
 173         hdr->lpc = p->lowpc;
 174         hdr->hpc = p->highpc;
 175         hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
 176         hdr->version = GMONVERSION;
 177         hdr->profrate = clockinfo.profhz;
 178         _write(fd, (char *)hdr, sizeof *hdr);
 179         _write(fd, p->kcount, p->kcountsize);
 180         endfrom = p->fromssize / sizeof(*p->froms);
 181         for (fromindex = 0; fromindex < endfrom; fromindex++) {
 182                 if (p->froms[fromindex] == 0)
 183                         continue;
 184
 185                 frompc = p->lowpc;
 186                 frompc += fromindex * p->hashfraction * sizeof(*p->froms);
 187                 for (toindex = p->froms[fromindex]; toindex != 0;
 188                      toindex = p->tos[toindex].link) {
 189 #ifdef DEBUG
 190                         len = sprintf(buf,
 191                         "[mcleanup2] frompc 0x%lx selfpc 0x%lx count %lu\n" ,
 192                                 frompc, p->tos[toindex].selfpc,
 193                                 p->tos[toindex].count);
 194                         _write(log, buf, len);
 195 #endif
 196                         rawarc.raw_frompc = frompc;
 197                         rawarc.raw_selfpc = p->tos[toindex].selfpc;
 198                         rawarc.raw_count = p->tos[toindex].count;
 199                         _write(fd, &rawarc, sizeof rawarc);
 200                 }
 201         }
 202         _close(fd);
 203 }
 204
 205 /*
 206  * Control profiling
 207  *      profiling is what mcount checks to see if
 208  *      all the data structures are ready.
 209  */
 210 void
 211 moncontrol(int mode)
 212 {
 213         struct gmonparam *p = &_gmonparam;
 214
 215         if (mode) {
 216                 /* start */
 217                 profil((char *)p->kcount, p->kcountsize, p->lowpc, s_scale);
 218                 p->state = GMON_PROF_ON;
 219         } else {
 220                 /* stop */
 221                 profil(NULL, 0, 0, 0);
 222                 p->state = GMON_PROF_OFF;
 223         }
 224 }
 225
 226 /*
 227  * discover the tick frequency of the machine
 228  * if something goes wrong, we return 0, an impossible hertz.
 229  */
 230 static int
 231 hertz(void)
 232 {
 233         struct itimerval tim;
 234
 235         tim.it_interval.tv_sec = 0;
 236         tim.it_interval.tv_usec = 1;
 237         tim.it_value.tv_sec = 0;
 238         tim.it_value.tv_usec = 0;
 239         setitimer(ITIMER_REAL, &tim, 0);
 240         setitimer(ITIMER_REAL, 0, &tim);
 241         if (tim.it_interval.tv_usec < 2)
 242                 return(0);
 243         return (1000000 / tim.it_interval.tv_usec);
 244 }