1 /* $NetBSD: gmon.c,v 1.21 2003/08/07 16:43:02 agc 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 #if !defined(lint) && defined(LIBC_SCCS) 34 #if 0 35 static char sccsid[] = "@(#)gmon.c 8.1 (Berkeley) 6/4/93"; 36 #else 37 __RCSID("$NetBSD: gmon.c,v 1.21 2003/08/07 16:43:02 agc Exp $"); 38 #endif 39 #endif 40 41 #include "namespace.h" 42 #include <sys/param.h> 43 #include <sys/time.h> 44 #include <sys/gmon.h> 45 #include <sys/sysctl.h> 46 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <fcntl.h> 50 #include <limits.h> 51 #include <unistd.h> 52 #include <err.h> 53 #include "extern.h" 54 55 struct gmonparam _gmonparam = { GMON_PROF_OFF }; 56 57 static u_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(STDERR_FILENO, s, sizeof(s)) 62 63 void moncontrol __P((int)); 64 void monstartup __P((u_long, u_long)); 65 void _mcleanup __P((void)); 66 static int hertz __P((void)); 67 68 69 void 70 monstartup(lowpc, highpc) 71 u_long lowpc; 72 u_long highpc; 73 { 74 u_long o; 75 char *cp; 76 struct gmonparam *p = &_gmonparam; 77 78 /* 79 * round lowpc and highpc to multiples of the density we're using 80 * so the rest of the scaling (here and in gprof) stays in ints. 81 */ 82 p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER)); 83 p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER)); 84 p->textsize = p->highpc - p->lowpc; 85 p->kcountsize = p->textsize / HISTFRACTION; 86 p->hashfraction = HASHFRACTION; 87 p->fromssize = p->textsize / p->hashfraction; 88 p->tolimit = p->textsize * ARCDENSITY / 100; 89 if (p->tolimit < MINARCS) 90 p->tolimit = MINARCS; 91 else if (p->tolimit > MAXARCS) 92 p->tolimit = MAXARCS; 93 p->tossize = p->tolimit * sizeof(struct tostruct); 94 95 cp = sbrk((intptr_t)(p->kcountsize + p->fromssize + p->tossize)); 96 if (cp == (char *)-1) { 97 ERR("monstartup: out of memory\n"); 98 return; 99 } 100 #ifdef notdef 101 memset(cp, 0, p->kcountsize + p->fromssize + p->tossize); 102 #endif 103 p->tos = (struct tostruct *)(void *)cp; 104 cp += (size_t)p->tossize; 105 p->kcount = (u_short *)(void *)cp; 106 cp += (size_t)p->kcountsize; 107 p->froms = (u_short *)(void *)cp; 108 109 __minbrk = sbrk((intptr_t)0); 110 p->tos[0].link = 0; 111 112 o = p->highpc - p->lowpc; 113 if (p->kcountsize < o) { 114 #ifndef notdef 115 s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1; 116 #else /* avoid floating point */ 117 u_long quot = o / p->kcountsize; 118 119 if (quot >= 0x10000) 120 s_scale = 1; 121 else if (quot >= 0x100) 122 s_scale = 0x10000 / quot; 123 else if (o >= 0x800000) 124 s_scale = 0x1000000 / (o / (p->kcountsize >> 8)); 125 else 126 s_scale = 0x1000000 / ((o << 8) / p->kcountsize); 127 #endif 128 } else 129 s_scale = SCALE_1_TO_1; 130 131 moncontrol(1); 132 } 133 134 void 135 _mcleanup() 136 { 137 int fd; 138 int fromindex; 139 int endfrom; 140 u_long frompc; 141 int toindex; 142 struct rawarc rawarc; 143 struct gmonparam *p = &_gmonparam; 144 struct gmonhdr gmonhdr, *hdr; 145 struct clockinfo clockinfo; 146 int mib[2]; 147 size_t size; 148 char *profdir; 149 char *proffile; 150 char buf[PATH_MAX]; 151 #ifdef DEBUG 152 int log, len; 153 char buf2[200]; 154 #endif 155 156 /* 157 * We disallow writing to the profiling file, if we are a 158 * set{u,g}id program and our effective {u,g}id does not match 159 * our real one. 160 */ 161 if (issetugid() && (geteuid() != getuid() || getegid() != getgid())) { 162 warnx("mcount: Profiling of set{u,g}id binaries is not" 163 " allowed"); 164 return; 165 } 166 167 if (p->state == GMON_PROF_ERROR) 168 ERR("_mcleanup: tos overflow\n"); 169 170 size = sizeof(clockinfo); 171 mib[0] = CTL_KERN; 172 mib[1] = KERN_CLOCKRATE; 173 if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) { 174 /* 175 * Best guess 176 */ 177 clockinfo.profhz = hertz(); 178 } else if (clockinfo.profhz == 0) { 179 if (clockinfo.hz != 0) 180 clockinfo.profhz = clockinfo.hz; 181 else 182 clockinfo.profhz = hertz(); 183 } 184 185 moncontrol(0); 186 187 if ((profdir = getenv("PROFDIR")) != NULL) { 188 /* If PROFDIR contains a null value, no profiling 189 output is produced */ 190 if (*profdir == '\0') 191 return; 192 193 if (snprintf(buf, sizeof buf, "%s/%d.%s", 194 profdir, getpid(), getprogname()) >= sizeof buf) { 195 warnx("_mcleanup: internal buffer overflow, PROFDIR too long"); 196 return; 197 } 198 199 proffile = buf; 200 } else { 201 proffile = "gmon.out"; 202 } 203 204 fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0666); 205 if (fd < 0) { 206 warn("mcount: Cannot open `%s'", proffile); 207 return; 208 } 209 #ifdef DEBUG 210 log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664); 211 if (log < 0) { 212 warn("mcount: Cannot open `gmon.log'"); 213 return; 214 } 215 len = snprintf(buf2, sizeof buf2, "[mcleanup1] kcount 0x%x ssiz %d\n", 216 p->kcount, p->kcountsize); 217 write(log, buf2, len); 218 #endif 219 hdr = (struct gmonhdr *)&gmonhdr; 220 hdr->lpc = p->lowpc; 221 hdr->hpc = p->highpc; 222 hdr->ncnt = (int)(p->kcountsize + sizeof(gmonhdr)); 223 hdr->version = GMONVERSION; 224 hdr->profrate = clockinfo.profhz; 225 (void)write(fd, hdr, sizeof *hdr); 226 (void)write(fd, p->kcount, (size_t)p->kcountsize); 227 endfrom = (int)(p->fromssize / sizeof(*p->froms)); 228 for (fromindex = 0; fromindex < endfrom; fromindex++) { 229 if (p->froms[fromindex] == 0) 230 continue; 231 232 frompc = p->lowpc; 233 frompc += fromindex * p->hashfraction * sizeof(*p->froms); 234 for (toindex = p->froms[fromindex]; toindex != 0; 235 toindex = p->tos[toindex].link) { 236 #ifdef DEBUG 237 len = snprintf(buf2, sizeof buf2, 238 "[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" , 239 frompc, p->tos[toindex].selfpc, 240 p->tos[toindex].count); 241 write(log, buf2, len); 242 #endif 243 rawarc.raw_frompc = frompc; 244 rawarc.raw_selfpc = p->tos[toindex].selfpc; 245 rawarc.raw_count = p->tos[toindex].count; 246 write(fd, &rawarc, sizeof rawarc); 247 } 248 } 249 close(fd); 250 } 251 252 /* 253 * Control profiling 254 * profiling is what mcount checks to see if 255 * all the data structures are ready. 256 */ 257 void 258 moncontrol(mode) 259 int mode; 260 { 261 struct gmonparam *p = &_gmonparam; 262 263 if (mode) { 264 /* start */ 265 profil((char *)(void *)p->kcount, (size_t)p->kcountsize, 266 p->lowpc, s_scale); 267 p->state = GMON_PROF_ON; 268 } else { 269 /* stop */ 270 profil(NULL, 0, (u_long)0, 0); 271 p->state = GMON_PROF_OFF; 272 } 273 } 274 275 /* 276 * discover the tick frequency of the machine 277 * if something goes wrong, we return 0, an impossible hertz. 278 */ 279 static int 280 hertz() 281 { 282 struct itimerval tim; 283 284 tim.it_interval.tv_sec = 0; 285 tim.it_interval.tv_usec = 1; 286 tim.it_value.tv_sec = 0; 287 tim.it_value.tv_usec = 0; 288 setitimer(ITIMER_REAL, &tim, 0); 289 setitimer(ITIMER_REAL, 0, &tim); 290 if (tim.it_interval.tv_usec < 2) 291 return(0); 292 return (int)(1000000 / tim.it_interval.tv_usec); 293 } 294