1 /* $OpenBSD: gmon.c,v 1.24 2015/05/06 23:52:49 jsg 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 static int hertz(void); 53 void monstartup(u_long lowpc, u_long highpc); 54 void _mcleanup(void); 55 56 void 57 monstartup(u_long lowpc, u_long highpc) 58 { 59 int o; 60 void *addr; 61 struct gmonparam *p = &_gmonparam; 62 63 /* 64 * round lowpc and highpc to multiples of the density we're using 65 * so the rest of the scaling (here and in gprof) stays in ints. 66 */ 67 p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER)); 68 p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER)); 69 p->textsize = p->highpc - p->lowpc; 70 p->kcountsize = p->textsize / HISTFRACTION; 71 p->hashfraction = HASHFRACTION; 72 p->fromssize = p->textsize / p->hashfraction; 73 p->tolimit = p->textsize * ARCDENSITY / 100; 74 if (p->tolimit < MINARCS) 75 p->tolimit = MINARCS; 76 else if (p->tolimit > MAXARCS) 77 p->tolimit = MAXARCS; 78 p->tossize = p->tolimit * sizeof(struct tostruct); 79 80 addr = mmap((void *)0, p->kcountsize, PROT_READ|PROT_WRITE, 81 MAP_ANON|MAP_PRIVATE, -1, (off_t)0); 82 if (addr == MAP_FAILED) 83 goto mapfailed; 84 p->kcount = addr; 85 86 addr = mmap((void *)0, p->fromssize, PROT_READ|PROT_WRITE, 87 MAP_ANON|MAP_PRIVATE, -1, (off_t)0); 88 if (addr == MAP_FAILED) 89 goto mapfailed; 90 p->froms = addr; 91 92 addr = mmap((void *)0, p->tossize, PROT_READ|PROT_WRITE, 93 MAP_ANON|MAP_PRIVATE, -1, (off_t)0); 94 if (addr == MAP_FAILED) 95 goto mapfailed; 96 p->tos = addr; 97 p->tos[0].link = 0; 98 99 o = p->highpc - p->lowpc; 100 if (p->kcountsize < o) { 101 #ifndef notdef 102 s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1; 103 #else /* avoid floating point */ 104 int quot = o / p->kcountsize; 105 106 if (quot >= 0x10000) 107 s_scale = 1; 108 else if (quot >= 0x100) 109 s_scale = 0x10000 / quot; 110 else if (o >= 0x800000) 111 s_scale = 0x1000000 / (o / (p->kcountsize >> 8)); 112 else 113 s_scale = 0x1000000 / ((o << 8) / p->kcountsize); 114 #endif 115 } else 116 s_scale = SCALE_1_TO_1; 117 118 moncontrol(1); 119 return; 120 121 mapfailed: 122 if (p->kcount != NULL) { 123 munmap(p->kcount, p->kcountsize); 124 p->kcount = NULL; 125 } 126 if (p->froms != NULL) { 127 munmap(p->froms, p->fromssize); 128 p->froms = NULL; 129 } 130 if (p->tos != NULL) { 131 munmap(p->tos, p->tossize); 132 p->tos = NULL; 133 } 134 ERR("monstartup: out of memory\n"); 135 } 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 extern char *__progname; 181 char *s, *t, *limit; 182 pid_t pid; 183 long divisor; 184 185 /* If PROFDIR contains a null value, no profiling 186 output is produced */ 187 if (*profdir == '\0') { 188 return; 189 } 190 191 limit = buf + sizeof buf - 1 - 10 - 1 - 192 strlen(__progname) - 1; 193 t = buf; 194 s = profdir; 195 while((*t = *s) != '\0' && t < limit) { 196 t++; 197 s++; 198 } 199 *t++ = '/'; 200 201 /* 202 * Copy and convert pid from a pid_t to a string. For 203 * best performance, divisor should be initialized to 204 * the largest power of 10 less than PID_MAX. 205 */ 206 pid = getpid(); 207 divisor=10000; 208 while (divisor > pid) divisor /= 10; /* skip leading zeros */ 209 do { 210 *t++ = (pid/divisor) + '0'; 211 pid %= divisor; 212 } while (divisor /= 10); 213 *t++ = '.'; 214 215 s = __progname; 216 while ((*t++ = *s++) != '\0') 217 ; 218 219 proffile = buf; 220 } else { 221 proffile = "gmon.out"; 222 } 223 224 fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0664); 225 if (fd < 0) { 226 perror( proffile ); 227 return; 228 } 229 #ifdef DEBUG 230 log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664); 231 if (log < 0) { 232 perror("mcount: gmon.log"); 233 close(fd); 234 return; 235 } 236 snprintf(dbuf, sizeof dbuf, "[mcleanup1] kcount 0x%x ssiz %d\n", 237 p->kcount, p->kcountsize); 238 write(log, dbuf, strlen(dbuf)); 239 #endif 240 hdr = (struct gmonhdr *)&gmonhdr; 241 bzero(hdr, sizeof(*hdr)); 242 hdr->lpc = p->lowpc; 243 hdr->hpc = p->highpc; 244 hdr->ncnt = p->kcountsize + sizeof(gmonhdr); 245 hdr->version = GMONVERSION; 246 hdr->profrate = clockinfo.profhz; 247 write(fd, (char *)hdr, sizeof *hdr); 248 write(fd, p->kcount, p->kcountsize); 249 endfrom = p->fromssize / sizeof(*p->froms); 250 for (fromindex = 0; fromindex < endfrom; fromindex++) { 251 if (p->froms[fromindex] == 0) 252 continue; 253 254 frompc = p->lowpc; 255 frompc += fromindex * p->hashfraction * sizeof(*p->froms); 256 for (toindex = p->froms[fromindex]; toindex != 0; 257 toindex = p->tos[toindex].link) { 258 #ifdef DEBUG 259 (void) snprintf(dbuf, sizeof dbuf, 260 "[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" , 261 frompc, p->tos[toindex].selfpc, 262 p->tos[toindex].count); 263 write(log, dbuf, strlen(dbuf)); 264 #endif 265 rawarc.raw_frompc = frompc; 266 rawarc.raw_selfpc = p->tos[toindex].selfpc; 267 rawarc.raw_count = p->tos[toindex].count; 268 write(fd, &rawarc, sizeof rawarc); 269 } 270 } 271 close(fd); 272 #ifdef notyet 273 if (p->kcount != NULL) { 274 munmap(p->kcount, p->kcountsize); 275 p->kcount = NULL; 276 } 277 if (p->froms != NULL) { 278 munmap(p->froms, p->fromssize); 279 p->froms = NULL; 280 } 281 if (p->tos != NULL) { 282 munmap(p->tos, p->tossize); 283 p->tos = NULL; 284 } 285 #endif 286 } 287 288 /* 289 * Control profiling 290 * profiling is what mcount checks to see if 291 * all the data structures are ready. 292 */ 293 void 294 moncontrol(int mode) 295 { 296 struct gmonparam *p = &_gmonparam; 297 298 if (mode) { 299 /* start */ 300 profil((char *)p->kcount, p->kcountsize, p->lowpc, 301 s_scale); 302 p->state = GMON_PROF_ON; 303 } else { 304 /* stop */ 305 profil((char *)0, 0, 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(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