1 /* $NetBSD: gmon.c,v 1.18 2002/04/26 16:39:52 christos 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 1.18 2002/04/26 16:39:52 christos 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 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 int 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