1 /* $OpenBSD: gmon.c,v 1.21 2013/02/12 07:31:13 mpi 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/param.h> 32 #include <sys/time.h> 33 #include <sys/gmon.h> 34 #include <sys/mman.h> 35 #include <sys/sysctl.h> 36 37 #include <stdio.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <fcntl.h> 41 #include <limits.h> 42 #include <unistd.h> 43 44 struct gmonparam _gmonparam = { GMON_PROF_OFF }; 45 46 static int s_scale; 47 /* see profil(2) where this is describe (incorrectly) */ 48 #define SCALE_1_TO_1 0x10000L 49 50 #define ROUNDDOWN(x,y)(((x)/(y))*(y)) 51 #define ROUNDUP(x,y)((((x)+(y)-1)/(y))*(y)) 52 53 #define ERR(s) write(STDERR_FILENO, s, sizeof(s)) 54 55 void moncontrol(int); 56 static int hertz(void); 57 void monstartup(u_long lowpc, u_long highpc); 58 void _mcleanup(void); 59 60 void 61 monstartup(u_long lowpc, u_long highpc) 62 { 63 int o; 64 void *addr; 65 struct gmonparam *p = &_gmonparam; 66 67 /* 68 * round lowpc and highpc to multiples of the density we're using 69 * so the rest of the scaling (here and in gprof) stays in ints. 70 */ 71 p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER)); 72 p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER)); 73 p->textsize = p->highpc - p->lowpc; 74 p->kcountsize = p->textsize / HISTFRACTION; 75 p->hashfraction = HASHFRACTION; 76 p->fromssize = p->textsize / p->hashfraction; 77 p->tolimit = p->textsize * ARCDENSITY / 100; 78 if (p->tolimit < MINARCS) 79 p->tolimit = MINARCS; 80 else if (p->tolimit > MAXARCS) 81 p->tolimit = MAXARCS; 82 p->tossize = p->tolimit * sizeof(struct tostruct); 83 84 addr = mmap((void *)0, p->kcountsize, PROT_READ|PROT_WRITE, 85 MAP_ANON|MAP_PRIVATE, -1, (off_t)0); 86 if (addr == MAP_FAILED) 87 goto mapfailed; 88 p->kcount = addr; 89 90 addr = mmap((void *)0, p->fromssize, PROT_READ|PROT_WRITE, 91 MAP_ANON|MAP_PRIVATE, -1, (off_t)0); 92 if (addr == MAP_FAILED) 93 goto mapfailed; 94 p->froms = addr; 95 96 addr = mmap((void *)0, p->tossize, PROT_READ|PROT_WRITE, 97 MAP_ANON|MAP_PRIVATE, -1, (off_t)0); 98 if (addr == MAP_FAILED) 99 goto mapfailed; 100 p->tos = addr; 101 p->tos[0].link = 0; 102 103 o = p->highpc - p->lowpc; 104 if (p->kcountsize < o) { 105 #ifndef notdef 106 s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1; 107 #else /* avoid floating point */ 108 int quot = o / p->kcountsize; 109 110 if (quot >= 0x10000) 111 s_scale = 1; 112 else if (quot >= 0x100) 113 s_scale = 0x10000 / quot; 114 else if (o >= 0x800000) 115 s_scale = 0x1000000 / (o / (p->kcountsize >> 8)); 116 else 117 s_scale = 0x1000000 / ((o << 8) / p->kcountsize); 118 #endif 119 } else 120 s_scale = SCALE_1_TO_1; 121 122 moncontrol(1); 123 return; 124 125 mapfailed: 126 if (p->kcount != NULL) { 127 munmap(p->kcount, p->kcountsize); 128 p->kcount = NULL; 129 } 130 if (p->froms != NULL) { 131 munmap(p->froms, p->fromssize); 132 p->froms = NULL; 133 } 134 if (p->tos != NULL) { 135 munmap(p->tos, p->tossize); 136 p->tos = NULL; 137 } 138 ERR("monstartup: out of memory\n"); 139 } 140 141 void 142 _mcleanup(void) 143 { 144 int fd; 145 int fromindex; 146 int endfrom; 147 u_long frompc; 148 int toindex; 149 struct rawarc rawarc; 150 struct gmonparam *p = &_gmonparam; 151 struct gmonhdr gmonhdr, *hdr; 152 struct clockinfo clockinfo; 153 int mib[2]; 154 size_t size; 155 char *profdir; 156 char *proffile; 157 char buf[PATH_MAX]; 158 #ifdef DEBUG 159 int log, len; 160 char dbuf[200]; 161 #endif 162 163 if (p->state == GMON_PROF_ERROR) 164 ERR("_mcleanup: tos overflow\n"); 165 166 size = sizeof(clockinfo); 167 mib[0] = CTL_KERN; 168 mib[1] = KERN_CLOCKRATE; 169 if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) { 170 /* 171 * Best guess 172 */ 173 clockinfo.profhz = hertz(); 174 } else if (clockinfo.profhz == 0) { 175 if (clockinfo.hz != 0) 176 clockinfo.profhz = clockinfo.hz; 177 else 178 clockinfo.profhz = hertz(); 179 } 180 181 moncontrol(0); 182 183 if (issetugid() == 0 && (profdir = getenv("PROFDIR")) != NULL) { 184 extern char *__progname; 185 char *s, *t, *limit; 186 pid_t pid; 187 long divisor; 188 189 /* If PROFDIR contains a null value, no profiling 190 output is produced */ 191 if (*profdir == '\0') { 192 return; 193 } 194 195 limit = buf + sizeof buf - 1 - 10 - 1 - 196 strlen(__progname) - 1; 197 t = buf; 198 s = profdir; 199 while((*t = *s) != '\0' && t < limit) { 200 t++; 201 s++; 202 } 203 *t++ = '/'; 204 205 /* 206 * Copy and convert pid from a pid_t to a string. For 207 * best performance, divisor should be initialized to 208 * the largest power of 10 less than PID_MAX. 209 */ 210 pid = getpid(); 211 divisor=10000; 212 while (divisor > pid) divisor /= 10; /* skip leading zeros */ 213 do { 214 *t++ = (pid/divisor) + '0'; 215 pid %= divisor; 216 } while (divisor /= 10); 217 *t++ = '.'; 218 219 s = __progname; 220 while ((*t++ = *s++) != '\0') 221 ; 222 223 proffile = buf; 224 } else { 225 proffile = "gmon.out"; 226 } 227 228 fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0664); 229 if (fd < 0) { 230 perror( proffile ); 231 return; 232 } 233 #ifdef DEBUG 234 log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664); 235 if (log < 0) { 236 perror("mcount: gmon.log"); 237 return; 238 } 239 snprintf(dbuf, sizeof dbuf, "[mcleanup1] kcount 0x%x ssiz %d\n", 240 p->kcount, p->kcountsize); 241 write(log, dbuf, strlen(dbuf)); 242 #endif 243 hdr = (struct gmonhdr *)&gmonhdr; 244 bzero(hdr, sizeof(*hdr)); 245 hdr->lpc = p->lowpc; 246 hdr->hpc = p->highpc; 247 hdr->ncnt = p->kcountsize + sizeof(gmonhdr); 248 hdr->version = GMONVERSION; 249 hdr->profrate = clockinfo.profhz; 250 write(fd, (char *)hdr, sizeof *hdr); 251 write(fd, p->kcount, p->kcountsize); 252 endfrom = p->fromssize / sizeof(*p->froms); 253 for (fromindex = 0; fromindex < endfrom; fromindex++) { 254 if (p->froms[fromindex] == 0) 255 continue; 256 257 frompc = p->lowpc; 258 frompc += fromindex * p->hashfraction * sizeof(*p->froms); 259 for (toindex = p->froms[fromindex]; toindex != 0; 260 toindex = p->tos[toindex].link) { 261 #ifdef DEBUG 262 (void) snprintf(dbuf, sizeof dbuf, 263 "[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" , 264 frompc, p->tos[toindex].selfpc, 265 p->tos[toindex].count); 266 write(log, dbuf, strlen(dbuf)); 267 #endif 268 rawarc.raw_frompc = frompc; 269 rawarc.raw_selfpc = p->tos[toindex].selfpc; 270 rawarc.raw_count = p->tos[toindex].count; 271 write(fd, &rawarc, sizeof rawarc); 272 } 273 } 274 close(fd); 275 #ifdef notyet 276 if (p->kcount != NULL) { 277 munmap(p->kcount, p->kcountsize); 278 p->kcount = NULL; 279 } 280 if (p->froms != NULL) { 281 munmap(p->froms, p->fromssize); 282 p->froms = NULL; 283 } 284 if (p->tos != NULL) { 285 munmap(p->tos, p->tossize); 286 p->tos = NULL; 287 } 288 #endif 289 } 290 291 /* 292 * Control profiling 293 * profiling is what mcount checks to see if 294 * all the data structures are ready. 295 */ 296 void 297 moncontrol(int mode) 298 { 299 struct gmonparam *p = &_gmonparam; 300 301 if (mode) { 302 /* start */ 303 profil((char *)p->kcount, p->kcountsize, p->lowpc, 304 s_scale); 305 p->state = GMON_PROF_ON; 306 } else { 307 /* stop */ 308 profil((char *)0, 0, 0, 0); 309 p->state = GMON_PROF_OFF; 310 } 311 } 312 313 /* 314 * discover the tick frequency of the machine 315 * if something goes wrong, we return 0, an impossible hertz. 316 */ 317 static int 318 hertz(void) 319 { 320 struct itimerval tim; 321 322 tim.it_interval.tv_sec = 0; 323 tim.it_interval.tv_usec = 1; 324 tim.it_value.tv_sec = 0; 325 tim.it_value.tv_usec = 0; 326 setitimer(ITIMER_REAL, &tim, 0); 327 setitimer(ITIMER_REAL, 0, &tim); 328 if (tim.it_interval.tv_usec < 2) 329 return(0); 330 return (1000000 / tim.it_interval.tv_usec); 331 } 332