1 /* $OpenBSD: gmon.c,v 1.29 2016/05/07 19:30:52 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 PROTO_NORMAL(moncontrol); 52 PROTO_DEPRECATED(monstartup); 53 static int hertz(void); 54 55 void 56 monstartup(u_long lowpc, u_long highpc) 57 { 58 int o; 59 void *addr; 60 struct gmonparam *p = &_gmonparam; 61 62 /* 63 * round lowpc and highpc to multiples of the density we're using 64 * so the rest of the scaling (here and in gprof) stays in ints. 65 */ 66 p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER)); 67 p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER)); 68 p->textsize = p->highpc - p->lowpc; 69 p->kcountsize = p->textsize / HISTFRACTION; 70 p->hashfraction = HASHFRACTION; 71 p->fromssize = p->textsize / p->hashfraction; 72 p->tolimit = p->textsize * ARCDENSITY / 100; 73 if (p->tolimit < MINARCS) 74 p->tolimit = MINARCS; 75 else if (p->tolimit > MAXARCS) 76 p->tolimit = MAXARCS; 77 p->tossize = p->tolimit * sizeof(struct tostruct); 78 79 addr = mmap(NULL, p->kcountsize, PROT_READ|PROT_WRITE, 80 MAP_ANON|MAP_PRIVATE, -1, (off_t)0); 81 if (addr == MAP_FAILED) 82 goto mapfailed; 83 p->kcount = addr; 84 85 addr = mmap(NULL, p->fromssize, PROT_READ|PROT_WRITE, 86 MAP_ANON|MAP_PRIVATE, -1, (off_t)0); 87 if (addr == MAP_FAILED) 88 goto mapfailed; 89 p->froms = addr; 90 91 addr = mmap(NULL, p->tossize, PROT_READ|PROT_WRITE, 92 MAP_ANON|MAP_PRIVATE, -1, (off_t)0); 93 if (addr == MAP_FAILED) 94 goto mapfailed; 95 p->tos = addr; 96 p->tos[0].link = 0; 97 98 o = p->highpc - p->lowpc; 99 if (p->kcountsize < o) { 100 #ifndef notdef 101 s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1; 102 #else /* avoid floating point */ 103 int quot = o / p->kcountsize; 104 105 if (quot >= 0x10000) 106 s_scale = 1; 107 else if (quot >= 0x100) 108 s_scale = 0x10000 / quot; 109 else if (o >= 0x800000) 110 s_scale = 0x1000000 / (o / (p->kcountsize >> 8)); 111 else 112 s_scale = 0x1000000 / ((o << 8) / p->kcountsize); 113 #endif 114 } else 115 s_scale = SCALE_1_TO_1; 116 117 moncontrol(1); 118 return; 119 120 mapfailed: 121 if (p->kcount != NULL) { 122 munmap(p->kcount, p->kcountsize); 123 p->kcount = NULL; 124 } 125 if (p->froms != NULL) { 126 munmap(p->froms, p->fromssize); 127 p->froms = NULL; 128 } 129 if (p->tos != NULL) { 130 munmap(p->tos, p->tossize); 131 p->tos = NULL; 132 } 133 ERR("monstartup: out of memory\n"); 134 } 135 __strong_alias(_monstartup,monstartup); 136 137 void 138 _mcleanup(void) 139 { 140 int fd; 141 int fromindex; 142 int endfrom; 143 u_long frompc; 144 int toindex; 145 struct rawarc rawarc; 146 struct gmonparam *p = &_gmonparam; 147 struct gmonhdr gmonhdr, *hdr; 148 struct clockinfo clockinfo; 149 int mib[2]; 150 size_t size; 151 char *profdir; 152 char *proffile; 153 char buf[PATH_MAX]; 154 #ifdef DEBUG 155 int log, len; 156 char dbuf[200]; 157 #endif 158 159 if (p->state == GMON_PROF_ERROR) 160 ERR("_mcleanup: tos overflow\n"); 161 162 size = sizeof(clockinfo); 163 mib[0] = CTL_KERN; 164 mib[1] = KERN_CLOCKRATE; 165 if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) { 166 /* 167 * Best guess 168 */ 169 clockinfo.profhz = hertz(); 170 } else if (clockinfo.profhz == 0) { 171 if (clockinfo.hz != 0) 172 clockinfo.profhz = clockinfo.hz; 173 else 174 clockinfo.profhz = hertz(); 175 } 176 177 moncontrol(0); 178 179 if (issetugid() == 0 && (profdir = getenv("PROFDIR")) != NULL) { 180 char *s, *t, *limit; 181 pid_t pid; 182 long divisor; 183 184 /* If PROFDIR contains a null value, no profiling 185 output is produced */ 186 if (*profdir == '\0') { 187 return; 188 } 189 190 limit = buf + sizeof buf - 1 - 10 - 1 - 191 strlen(__progname) - 1; 192 t = buf; 193 s = profdir; 194 while((*t = *s) != '\0' && t < limit) { 195 t++; 196 s++; 197 } 198 *t++ = '/'; 199 200 /* 201 * Copy and convert pid from a pid_t to a string. For 202 * best performance, divisor should be initialized to 203 * the largest power of 10 less than PID_MAX. 204 */ 205 pid = getpid(); 206 divisor=10000; 207 while (divisor > pid) divisor /= 10; /* skip leading zeros */ 208 do { 209 *t++ = (pid/divisor) + '0'; 210 pid %= divisor; 211 } while (divisor /= 10); 212 *t++ = '.'; 213 214 s = __progname; 215 while ((*t++ = *s++) != '\0') 216 ; 217 218 proffile = buf; 219 } else { 220 proffile = "gmon.out"; 221 } 222 223 fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0664); 224 if (fd < 0) { 225 perror( proffile ); 226 return; 227 } 228 #ifdef DEBUG 229 log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664); 230 if (log < 0) { 231 perror("mcount: gmon.log"); 232 close(fd); 233 return; 234 } 235 snprintf(dbuf, sizeof dbuf, "[mcleanup1] kcount 0x%x ssiz %d\n", 236 p->kcount, p->kcountsize); 237 write(log, dbuf, strlen(dbuf)); 238 #endif 239 hdr = (struct gmonhdr *)&gmonhdr; 240 bzero(hdr, sizeof(*hdr)); 241 hdr->lpc = p->lowpc; 242 hdr->hpc = p->highpc; 243 hdr->ncnt = p->kcountsize + sizeof(gmonhdr); 244 hdr->version = GMONVERSION; 245 hdr->profrate = clockinfo.profhz; 246 write(fd, (char *)hdr, sizeof *hdr); 247 write(fd, p->kcount, p->kcountsize); 248 endfrom = p->fromssize / sizeof(*p->froms); 249 for (fromindex = 0; fromindex < endfrom; fromindex++) { 250 if (p->froms[fromindex] == 0) 251 continue; 252 253 frompc = p->lowpc; 254 frompc += fromindex * p->hashfraction * sizeof(*p->froms); 255 for (toindex = p->froms[fromindex]; toindex != 0; 256 toindex = p->tos[toindex].link) { 257 #ifdef DEBUG 258 (void) snprintf(dbuf, sizeof dbuf, 259 "[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" , 260 frompc, p->tos[toindex].selfpc, 261 p->tos[toindex].count); 262 write(log, dbuf, strlen(dbuf)); 263 #endif 264 rawarc.raw_frompc = frompc; 265 rawarc.raw_selfpc = p->tos[toindex].selfpc; 266 rawarc.raw_count = p->tos[toindex].count; 267 write(fd, &rawarc, sizeof rawarc); 268 } 269 } 270 close(fd); 271 #ifdef notyet 272 if (p->kcount != NULL) { 273 munmap(p->kcount, p->kcountsize); 274 p->kcount = NULL; 275 } 276 if (p->froms != NULL) { 277 munmap(p->froms, p->fromssize); 278 p->froms = NULL; 279 } 280 if (p->tos != NULL) { 281 munmap(p->tos, p->tossize); 282 p->tos = NULL; 283 } 284 #endif 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(int mode) 294 { 295 struct gmonparam *p = &_gmonparam; 296 297 if (mode) { 298 /* start */ 299 profil((char *)p->kcount, p->kcountsize, p->lowpc, 300 s_scale); 301 p->state = GMON_PROF_ON; 302 } else { 303 /* stop */ 304 profil(NULL, 0, 0, 0); 305 p->state = GMON_PROF_OFF; 306 } 307 } 308 DEF_WEAK(moncontrol); 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(void) 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 (1000000 / tim.it_interval.tv_usec); 328 } 329