1 /* $OpenBSD: gmon.c,v 1.32 2020/10/12 22:08:33 deraadt 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, 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, 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, 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 const int mib[2] = { CTL_KERN, KERN_CLOCKRATE }; 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 if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) == -1) { 164 /* 165 * Best guess 166 */ 167 clockinfo.profhz = hertz(); 168 } else if (clockinfo.profhz == 0) { 169 if (clockinfo.hz != 0) 170 clockinfo.profhz = clockinfo.hz; 171 else 172 clockinfo.profhz = hertz(); 173 } 174 175 moncontrol(0); 176 177 if (issetugid() == 0 && (profdir = getenv("PROFDIR")) != NULL) { 178 char *s, *t, *limit; 179 pid_t pid; 180 long divisor; 181 182 /* If PROFDIR contains a null value, no profiling 183 output is produced */ 184 if (*profdir == '\0') { 185 return; 186 } 187 188 limit = buf + sizeof buf - 1 - 10 - 1 - 189 strlen(__progname) - 1; 190 t = buf; 191 s = profdir; 192 while((*t = *s) != '\0' && t < limit) { 193 t++; 194 s++; 195 } 196 *t++ = '/'; 197 198 /* 199 * Copy and convert pid from a pid_t to a string. For 200 * best performance, divisor should be initialized to 201 * the largest power of 10 less than PID_MAX. 202 */ 203 pid = getpid(); 204 divisor=10000; 205 while (divisor > pid) divisor /= 10; /* skip leading zeros */ 206 do { 207 *t++ = (pid/divisor) + '0'; 208 pid %= divisor; 209 } while (divisor /= 10); 210 *t++ = '.'; 211 212 s = __progname; 213 while ((*t++ = *s++) != '\0') 214 ; 215 216 proffile = buf; 217 } else { 218 proffile = "gmon.out"; 219 } 220 221 fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0664); 222 if (fd == -1) { 223 perror( proffile ); 224 return; 225 } 226 #ifdef DEBUG 227 log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664); 228 if (log == -1) { 229 perror("mcount: gmon.log"); 230 close(fd); 231 return; 232 } 233 snprintf(dbuf, sizeof dbuf, "[mcleanup1] kcount 0x%x ssiz %d\n", 234 p->kcount, p->kcountsize); 235 write(log, dbuf, strlen(dbuf)); 236 #endif 237 hdr = (struct gmonhdr *)&gmonhdr; 238 bzero(hdr, sizeof(*hdr)); 239 hdr->lpc = p->lowpc; 240 hdr->hpc = p->highpc; 241 hdr->ncnt = p->kcountsize + sizeof(gmonhdr); 242 hdr->version = GMONVERSION; 243 hdr->profrate = clockinfo.profhz; 244 write(fd, (char *)hdr, sizeof *hdr); 245 write(fd, p->kcount, p->kcountsize); 246 endfrom = p->fromssize / sizeof(*p->froms); 247 for (fromindex = 0; fromindex < endfrom; fromindex++) { 248 if (p->froms[fromindex] == 0) 249 continue; 250 251 frompc = p->lowpc; 252 frompc += fromindex * p->hashfraction * sizeof(*p->froms); 253 for (toindex = p->froms[fromindex]; toindex != 0; 254 toindex = p->tos[toindex].link) { 255 #ifdef DEBUG 256 (void) snprintf(dbuf, sizeof dbuf, 257 "[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" , 258 frompc, p->tos[toindex].selfpc, 259 p->tos[toindex].count); 260 write(log, dbuf, strlen(dbuf)); 261 #endif 262 rawarc.raw_frompc = frompc; 263 rawarc.raw_selfpc = p->tos[toindex].selfpc; 264 rawarc.raw_count = p->tos[toindex].count; 265 write(fd, &rawarc, sizeof rawarc); 266 } 267 } 268 close(fd); 269 #ifdef notyet 270 if (p->kcount != NULL) { 271 munmap(p->kcount, p->kcountsize); 272 p->kcount = NULL; 273 } 274 if (p->froms != NULL) { 275 munmap(p->froms, p->fromssize); 276 p->froms = NULL; 277 } 278 if (p->tos != NULL) { 279 munmap(p->tos, p->tossize); 280 p->tos = NULL; 281 } 282 #endif 283 } 284 285 /* 286 * Control profiling 287 * profiling is what mcount checks to see if 288 * all the data structures are ready. 289 */ 290 void 291 moncontrol(int mode) 292 { 293 struct gmonparam *p = &_gmonparam; 294 295 if (mode) { 296 /* start */ 297 profil((char *)p->kcount, p->kcountsize, p->lowpc, 298 s_scale); 299 p->state = GMON_PROF_ON; 300 } else { 301 /* stop */ 302 profil(NULL, 0, 0, 0); 303 p->state = GMON_PROF_OFF; 304 } 305 } 306 DEF_WEAK(moncontrol); 307 308 /* 309 * discover the tick frequency of the machine 310 * if something goes wrong, we return 0, an impossible hertz. 311 */ 312 static int 313 hertz(void) 314 { 315 struct itimerval tim; 316 317 tim.it_interval.tv_sec = 0; 318 tim.it_interval.tv_usec = 1; 319 tim.it_value.tv_sec = 0; 320 tim.it_value.tv_usec = 0; 321 setitimer(ITIMER_REAL, &tim, 0); 322 setitimer(ITIMER_REAL, 0, &tim); 323 if (tim.it_interval.tv_usec < 2) 324 return(0); 325 return (1000000 / tim.it_interval.tv_usec); 326 } 327