1 /* $OpenBSD: gmon.c,v 1.25 2015/09/14 14:17:10 guenther Exp $ */ 2 /*- 3 * Copyright (c) 1983, 1992, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/time.h> 32 #include <sys/gmon.h> 33 #include <sys/mman.h> 34 #include <sys/sysctl.h> 35 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <string.h> 39 #include <fcntl.h> 40 #include <limits.h> 41 #include <unistd.h> 42 43 struct gmonparam _gmonparam = { GMON_PROF_OFF }; 44 45 static int s_scale; 46 /* see profil(2) where this is describe (incorrectly) */ 47 #define SCALE_1_TO_1 0x10000L 48 49 #define ERR(s) write(STDERR_FILENO, s, sizeof(s)) 50 51 void moncontrol(int); 52 PROTO_NORMAL(moncontrol); 53 static int hertz(void); 54 void monstartup(u_long lowpc, u_long highpc); 55 void _mcleanup(void); 56 57 void 58 monstartup(u_long lowpc, u_long highpc) 59 { 60 int o; 61 void *addr; 62 struct gmonparam *p = &_gmonparam; 63 64 /* 65 * round lowpc and highpc to multiples of the density we're using 66 * so the rest of the scaling (here and in gprof) stays in ints. 67 */ 68 p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER)); 69 p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER)); 70 p->textsize = p->highpc - p->lowpc; 71 p->kcountsize = p->textsize / HISTFRACTION; 72 p->hashfraction = HASHFRACTION; 73 p->fromssize = p->textsize / p->hashfraction; 74 p->tolimit = p->textsize * ARCDENSITY / 100; 75 if (p->tolimit < MINARCS) 76 p->tolimit = MINARCS; 77 else if (p->tolimit > MAXARCS) 78 p->tolimit = MAXARCS; 79 p->tossize = p->tolimit * sizeof(struct tostruct); 80 81 addr = mmap((void *)0, p->kcountsize, PROT_READ|PROT_WRITE, 82 MAP_ANON|MAP_PRIVATE, -1, (off_t)0); 83 if (addr == MAP_FAILED) 84 goto mapfailed; 85 p->kcount = addr; 86 87 addr = mmap((void *)0, p->fromssize, PROT_READ|PROT_WRITE, 88 MAP_ANON|MAP_PRIVATE, -1, (off_t)0); 89 if (addr == MAP_FAILED) 90 goto mapfailed; 91 p->froms = addr; 92 93 addr = mmap((void *)0, p->tossize, PROT_READ|PROT_WRITE, 94 MAP_ANON|MAP_PRIVATE, -1, (off_t)0); 95 if (addr == MAP_FAILED) 96 goto mapfailed; 97 p->tos = addr; 98 p->tos[0].link = 0; 99 100 o = p->highpc - p->lowpc; 101 if (p->kcountsize < o) { 102 #ifndef notdef 103 s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1; 104 #else /* avoid floating point */ 105 int quot = o / p->kcountsize; 106 107 if (quot >= 0x10000) 108 s_scale = 1; 109 else if (quot >= 0x100) 110 s_scale = 0x10000 / quot; 111 else if (o >= 0x800000) 112 s_scale = 0x1000000 / (o / (p->kcountsize >> 8)); 113 else 114 s_scale = 0x1000000 / ((o << 8) / p->kcountsize); 115 #endif 116 } else 117 s_scale = SCALE_1_TO_1; 118 119 moncontrol(1); 120 return; 121 122 mapfailed: 123 if (p->kcount != NULL) { 124 munmap(p->kcount, p->kcountsize); 125 p->kcount = NULL; 126 } 127 if (p->froms != NULL) { 128 munmap(p->froms, p->fromssize); 129 p->froms = NULL; 130 } 131 if (p->tos != NULL) { 132 munmap(p->tos, p->tossize); 133 p->tos = NULL; 134 } 135 ERR("monstartup: out of memory\n"); 136 } 137 138 void 139 _mcleanup(void) 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 #ifdef DEBUG 156 int log, len; 157 char dbuf[200]; 158 #endif 159 160 if (p->state == GMON_PROF_ERROR) 161 ERR("_mcleanup: tos overflow\n"); 162 163 size = sizeof(clockinfo); 164 mib[0] = CTL_KERN; 165 mib[1] = KERN_CLOCKRATE; 166 if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) { 167 /* 168 * Best guess 169 */ 170 clockinfo.profhz = hertz(); 171 } else if (clockinfo.profhz == 0) { 172 if (clockinfo.hz != 0) 173 clockinfo.profhz = clockinfo.hz; 174 else 175 clockinfo.profhz = hertz(); 176 } 177 178 moncontrol(0); 179 180 if (issetugid() == 0 && (profdir = getenv("PROFDIR")) != NULL) { 181 extern char *__progname; 182 char *s, *t, *limit; 183 pid_t pid; 184 long divisor; 185 186 /* If PROFDIR contains a null value, no profiling 187 output is produced */ 188 if (*profdir == '\0') { 189 return; 190 } 191 192 limit = buf + sizeof buf - 1 - 10 - 1 - 193 strlen(__progname) - 1; 194 t = buf; 195 s = profdir; 196 while((*t = *s) != '\0' && t < limit) { 197 t++; 198 s++; 199 } 200 *t++ = '/'; 201 202 /* 203 * Copy and convert pid from a pid_t to a string. For 204 * best performance, divisor should be initialized to 205 * the largest power of 10 less than PID_MAX. 206 */ 207 pid = getpid(); 208 divisor=10000; 209 while (divisor > pid) divisor /= 10; /* skip leading zeros */ 210 do { 211 *t++ = (pid/divisor) + '0'; 212 pid %= divisor; 213 } while (divisor /= 10); 214 *t++ = '.'; 215 216 s = __progname; 217 while ((*t++ = *s++) != '\0') 218 ; 219 220 proffile = buf; 221 } else { 222 proffile = "gmon.out"; 223 } 224 225 fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0664); 226 if (fd < 0) { 227 perror( proffile ); 228 return; 229 } 230 #ifdef DEBUG 231 log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664); 232 if (log < 0) { 233 perror("mcount: gmon.log"); 234 close(fd); 235 return; 236 } 237 snprintf(dbuf, sizeof dbuf, "[mcleanup1] kcount 0x%x ssiz %d\n", 238 p->kcount, p->kcountsize); 239 write(log, dbuf, strlen(dbuf)); 240 #endif 241 hdr = (struct gmonhdr *)&gmonhdr; 242 bzero(hdr, sizeof(*hdr)); 243 hdr->lpc = p->lowpc; 244 hdr->hpc = p->highpc; 245 hdr->ncnt = p->kcountsize + sizeof(gmonhdr); 246 hdr->version = GMONVERSION; 247 hdr->profrate = clockinfo.profhz; 248 write(fd, (char *)hdr, sizeof *hdr); 249 write(fd, p->kcount, p->kcountsize); 250 endfrom = p->fromssize / sizeof(*p->froms); 251 for (fromindex = 0; fromindex < endfrom; fromindex++) { 252 if (p->froms[fromindex] == 0) 253 continue; 254 255 frompc = p->lowpc; 256 frompc += fromindex * p->hashfraction * sizeof(*p->froms); 257 for (toindex = p->froms[fromindex]; toindex != 0; 258 toindex = p->tos[toindex].link) { 259 #ifdef DEBUG 260 (void) snprintf(dbuf, sizeof dbuf, 261 "[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" , 262 frompc, p->tos[toindex].selfpc, 263 p->tos[toindex].count); 264 write(log, dbuf, strlen(dbuf)); 265 #endif 266 rawarc.raw_frompc = frompc; 267 rawarc.raw_selfpc = p->tos[toindex].selfpc; 268 rawarc.raw_count = p->tos[toindex].count; 269 write(fd, &rawarc, sizeof rawarc); 270 } 271 } 272 close(fd); 273 #ifdef notyet 274 if (p->kcount != NULL) { 275 munmap(p->kcount, p->kcountsize); 276 p->kcount = NULL; 277 } 278 if (p->froms != NULL) { 279 munmap(p->froms, p->fromssize); 280 p->froms = NULL; 281 } 282 if (p->tos != NULL) { 283 munmap(p->tos, p->tossize); 284 p->tos = NULL; 285 } 286 #endif 287 } 288 289 /* 290 * Control profiling 291 * profiling is what mcount checks to see if 292 * all the data structures are ready. 293 */ 294 void 295 moncontrol(int mode) 296 { 297 struct gmonparam *p = &_gmonparam; 298 299 if (mode) { 300 /* start */ 301 profil((char *)p->kcount, p->kcountsize, p->lowpc, 302 s_scale); 303 p->state = GMON_PROF_ON; 304 } else { 305 /* stop */ 306 profil((char *)0, 0, 0, 0); 307 p->state = GMON_PROF_OFF; 308 } 309 } 310 DEF_WEAK(moncontrol); 311 312 /* 313 * discover the tick frequency of the machine 314 * if something goes wrong, we return 0, an impossible hertz. 315 */ 316 static int 317 hertz(void) 318 { 319 struct itimerval tim; 320 321 tim.it_interval.tv_sec = 0; 322 tim.it_interval.tv_usec = 1; 323 tim.it_value.tv_sec = 0; 324 tim.it_value.tv_usec = 0; 325 setitimer(ITIMER_REAL, &tim, 0); 326 setitimer(ITIMER_REAL, 0, &tim); 327 if (tim.it_interval.tv_usec < 2) 328 return(0); 329 return (1000000 / tim.it_interval.tv_usec); 330 } 331