lib/libc/gmon/gmon.c

   1 /*      $NetBSD: gmon.c,v 1.35 2014/09/18 13:58:20 christos Exp $       */
   2
   3 /*
   4  * Copyright (c) 2003, 2004 Wasabi Systems, Inc.
   5  * All rights reserved.
   6  *
   7  * Written by Nathan J. Williams for Wasabi Systems, Inc.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed for the NetBSD Project by
  20  *      Wasabi Systems, Inc.
  21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
  22  *    or promote products derived from this software without specific prior
  23  *    written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
  29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  * POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 /*-
  39  * Copyright (c) 1983, 1992, 1993
  40  *      The Regents of the University of California.  All rights reserved.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions
  44  * are met:
  45  * 1. Redistributions of source code must retain the above copyright
  46  *    notice, this list of conditions and the following disclaimer.
  47  * 2. Redistributions in binary form must reproduce the above copyright
  48  *    notice, this list of conditions and the following disclaimer in the
  49  *    documentation and/or other materials provided with the distribution.
  50  * 3. Neither the name of the University nor the names of its contributors
  51  *    may be used to endorse or promote products derived from this software
  52  *    without specific prior written permission.
  53  *
  54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  64  * SUCH DAMAGE.
  65  */
  66
  67 #include <sys/cdefs.h>
  68 #if !defined(lint) && defined(LIBC_SCCS)
  69 #if 0
  70 static char sccsid[] = "@(#)gmon.c      8.1 (Berkeley) 6/4/93";
  71 #else
  72 __RCSID("$NetBSD: gmon.c,v 1.35 2014/09/18 13:58:20 christos Exp $");
  73 #endif
  74 #endif
  75
  76 #include "namespace.h"
  77 #include <sys/param.h>
  78 #include <sys/time.h>
  79 #include <sys/gmon.h>
  80 #include <sys/mman.h>
  81 #include <sys/sysctl.h>
  82
  83 #include <stdio.h>
  84 #include <stdlib.h>
  85 #include <string.h>
  86 #include <fcntl.h>
  87 #include <limits.h>
  88 #include <unistd.h>
  89 #include <err.h>
  90 #include "extern.h"
  91 #include "reentrant.h"
  92
  93 struct gmonparam _gmonparam = { .state = GMON_PROF_OFF };
  94
  95 #ifdef _REENTRANT
  96 struct gmonparam *_gmonfree;
  97 struct gmonparam *_gmoninuse;
  98 mutex_t _gmonlock = MUTEX_INITIALIZER;
  99 thread_key_t _gmonkey;
 100 struct gmonparam _gmondummy;
 101 #endif
 102
 103 static u_int    s_scale;
 104 /* see profil(2) where this is describe (incorrectly) */
 105 #define         SCALE_1_TO_1    0x10000L
 106
 107 void    moncontrol(int);
 108 void    monstartup(u_long, u_long);
 109 void    _mcleanup(void);
 110 static int hertz(void);
 111
 112 #ifdef _REENTRANT
 113 static void _m_gmon_destructor(void *);
 114 struct gmonparam *_m_gmon_alloc(void)
 115     __attribute__((__no_instrument_function__));
 116 static void _m_gmon_merge(void);
 117 static void _m_gmon_merge_two(struct gmonparam *, struct gmonparam *);
 118 #endif
 119
 120 void
 121 monstartup(u_long lowpc, u_long highpc)
 122 {
 123         u_long o;
 124         char *cp;
 125         struct gmonparam *p = &_gmonparam;
 126
 127         /*
 128          * round lowpc and highpc to multiples of the density we're using
 129          * so the rest of the scaling (here and in gprof) stays in ints.
 130          */
 131         p->lowpc = rounddown(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
 132         p->highpc = roundup(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
 133         p->textsize = p->highpc - p->lowpc;
 134         p->kcountsize = p->textsize / HISTFRACTION;
 135         p->hashfraction = HASHFRACTION;
 136         p->fromssize = p->textsize / p->hashfraction;
 137         p->tolimit = p->textsize * ARCDENSITY / 100;
 138         if (p->tolimit < MINARCS)
 139                 p->tolimit = MINARCS;
 140         else if (p->tolimit > MAXARCS)
 141                 p->tolimit = MAXARCS;
 142         p->tossize = p->tolimit * sizeof(struct tostruct);
 143
 144         cp = sbrk((intptr_t)(p->kcountsize + p->fromssize + p->tossize));
 145         if (cp == (char *)-1) {
 146                 warnx("%s: out of memory", __func__);
 147                 return;
 148         }
 149 #ifdef notdef
 150         (void)memset(cp, 0, p->kcountsize + p->fromssize + p->tossize);
 151 #endif
 152         p->tos = (struct tostruct *)(void *)cp;
 153         cp += (size_t)p->tossize;
 154         p->kcount = (u_short *)(void *)cp;
 155         cp += (size_t)p->kcountsize;
 156         p->froms = (u_short *)(void *)cp;
 157
 158         __minbrk = sbrk((intptr_t)0);
 159         p->tos[0].link = 0;
 160
 161         o = p->highpc - p->lowpc;
 162         if (p->kcountsize < o) {
 163 #ifndef notdef
 164                 s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
 165 #else /* avoid floating point */
 166                 u_long quot = o / p->kcountsize;
 167
 168                 if (quot >= 0x10000)
 169                         s_scale = 1;
 170                 else if (quot >= 0x100)
 171                         s_scale = 0x10000 / quot;
 172                 else if (o >= 0x800000)
 173                         s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
 174                 else
 175                         s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
 176 #endif
 177         } else
 178                 s_scale = SCALE_1_TO_1;
 179
 180 #ifdef _REENTRANT
 181         _gmondummy.state = GMON_PROF_BUSY;
 182         thr_keycreate(&_gmonkey, _m_gmon_destructor);
 183 #endif
 184         moncontrol(1);
 185 }
 186
 187 #ifdef _REENTRANT
 188 static void
 189 _m_gmon_destructor(void *arg)
 190 {
 191         struct gmonparam *p = arg, *q, **prev;
 192
 193         if (p == &_gmondummy)
 194                 return;
 195
 196         thr_setspecific(_gmonkey, &_gmondummy);
 197
 198         mutex_lock(&_gmonlock);
 199         /* XXX eww, linear list traversal. */
 200         for (q = _gmoninuse, prev = &_gmoninuse;
 201              q != NULL;
 202              prev = (struct gmonparam **)(void *)&q->kcount,    /* XXX */
 203                  q = (struct gmonparam *)(void *)q->kcount) {
 204                 if (q == p)
 205                         *prev = (struct gmonparam *)(void *)q->kcount;
 206         }
 207         p->kcount = (u_short *)(void *)_gmonfree;
 208         _gmonfree = p;
 209         mutex_unlock(&_gmonlock);
 210
 211         thr_setspecific(_gmonkey, NULL);
 212 }
 213
 214 struct gmonparam *
 215 _m_gmon_alloc(void)
 216 {
 217         struct gmonparam *p;
 218         char *cp;
 219
 220         mutex_lock(&_gmonlock);
 221         if (_gmonfree != NULL) {
 222                 p = _gmonfree;
 223                 _gmonfree = (struct gmonparam *)(void *)p->kcount;
 224                 p->kcount = (u_short *)(void *)_gmoninuse;
 225                 _gmoninuse = p;
 226         } else {
 227                 mutex_unlock(&_gmonlock);
 228                 cp = mmap(NULL,
 229                     (size_t)(sizeof (struct gmonparam) +
 230                         _gmonparam.fromssize + _gmonparam.tossize),
 231                     PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, (off_t)0);
 232                 p = (void *)cp;
 233                 *p = _gmonparam;
 234                 p->kcount = NULL;
 235                 cp += sizeof (struct gmonparam);
 236                 memset(cp, 0, (size_t)(p->fromssize + p->tossize));
 237                 p->froms = (u_short *)(void *)cp;
 238                 p->tos = (struct tostruct *)(void *)(cp + p->fromssize);
 239                 mutex_lock(&_gmonlock);
 240                 p->kcount = (u_short *)(void *)_gmoninuse;
 241                 _gmoninuse = p;
 242         }
 243         mutex_unlock(&_gmonlock);
 244         thr_setspecific(_gmonkey, p);
 245
 246         return p;
 247 }
 248
 249 static void
 250 _m_gmon_merge_two(struct gmonparam *p, struct gmonparam *q)
 251 {
 252         u_long fromindex;
 253         u_short *frompcindex, qtoindex, toindex;
 254         u_long selfpc;
 255         u_long endfrom;
 256         long count;
 257         struct tostruct *top;
 258
 259         endfrom = (q->fromssize / sizeof(*q->froms));
 260         for (fromindex = 0; fromindex < endfrom; fromindex++) {
 261                 if (q->froms[fromindex] == 0)
 262                         continue;
 263                 for (qtoindex = q->froms[fromindex]; qtoindex != 0;
 264                      qtoindex = q->tos[qtoindex].link) {
 265                         selfpc = q->tos[qtoindex].selfpc;
 266                         count = q->tos[qtoindex].count;
 267                         /* cribbed from mcount */
 268                         frompcindex = &p->froms[fromindex];
 269                         toindex = *frompcindex;
 270                         if (toindex == 0) {
 271                                 /*
 272                                  *      first time traversing this arc
 273                                  */
 274                                 toindex = ++p->tos[0].link;
 275                                 if (toindex >= p->tolimit)
 276                                         /* halt further profiling */
 277                                         goto overflow;
 278
 279                                 *frompcindex = (u_short)toindex;
 280                                 top = &p->tos[(size_t)toindex];
 281                                 top->selfpc = selfpc;
 282                                 top->count = count;
 283                                 top->link = 0;
 284                                 goto done;
 285                         }
 286                         top = &p->tos[(size_t)toindex];
 287                         if (top->selfpc == selfpc) {
 288                                 /*
 289                                  * arc at front of chain; usual case.
 290                                  */
 291                                 top->count+= count;
 292                                 goto done;
 293                         }
 294                         /*
 295                          * have to go looking down chain for it.
 296                          * top points to what we are looking at,
 297                          * we know it is not at the head of the chain.
 298                          */
 299                         for (; /* goto done */; ) {
 300                                 if (top->link == 0) {
 301                                         /*
 302                                          * top is end of the chain and
 303                                          * none of the chain had
 304                                          * top->selfpc == selfpc.  so
 305                                          * we allocate a new tostruct
 306                                          * and link it to the head of
 307                                          * the chain.
 308                                          */
 309                                         toindex = ++p->tos[0].link;
 310                                         if (toindex >= p->tolimit)
 311                                                 goto overflow;
 312
 313                                         top = &p->tos[(size_t)toindex];
 314                                         top->selfpc = selfpc;
 315                                         top->count = count;
 316                                         top->link = *frompcindex;
 317                                         *frompcindex = (u_short)toindex;
 318                                         goto done;
 319                                 }
 320                                 /*
 321                                  * otherwise, check the next arc on the chain.
 322                                  */
 323                                 top = &p->tos[top->link];
 324                                 if (top->selfpc == selfpc) {
 325                                         /*
 326                                          * there it is.
 327                                          * add to its count.
 328                                          */
 329                                         top->count += count;
 330                                         goto done;
 331                                 }
 332
 333                         }
 334
 335                 done: ;
 336                 }
 337
 338         }
 339  overflow: ;
 340
 341 }
 342
 343 static void
 344 _m_gmon_merge(void)
 345 {
 346         struct gmonparam *q;
 347
 348         mutex_lock(&_gmonlock);
 349
 350         for (q = _gmonfree; q != NULL;
 351             q = (struct gmonparam *)(void *)q->kcount)
 352                 _m_gmon_merge_two(&_gmonparam, q);
 353
 354         for (q = _gmoninuse; q != NULL;
 355             q = (struct gmonparam *)(void *)q->kcount) {
 356                 q->state = GMON_PROF_OFF;
 357                 _m_gmon_merge_two(&_gmonparam, q);
 358         }
 359
 360         mutex_unlock(&_gmonlock);
 361 }
 362 #endif
 363
 364 void
 365 _mcleanup(void)
 366 {
 367         int fd;
 368         int fromindex;
 369         int endfrom;
 370         u_long frompc;
 371         int toindex;
 372         struct rawarc rawarc;
 373         struct gmonparam *p = &_gmonparam;
 374         struct gmonhdr gmonhdr, *hdr;
 375         struct clockinfo clockinfo;
 376 #if !defined(__minix)
 377         int mib[2];
 378         size_t size;
 379 #endif /* !defined(__minix) */
 380         char *profdir;
 381         const char *proffile;
 382         char  buf[PATH_MAX];
 383 #ifdef DEBUG
 384         int logfd, len;
 385         char buf2[200];
 386 #endif
 387
 388         /*
 389          * We disallow writing to the profiling file, if we are a
 390          * set{u,g}id program and our effective {u,g}id does not match
 391          * our real one.
 392          */
 393         if (issetugid() && (geteuid() != getuid() || getegid() != getgid())) {
 394                 warnx("%s: Profiling of set{u,g}id binaries is not"
 395                     " allowed", __func__);
 396                 return;
 397         }
 398
 399         if (p->state == GMON_PROF_ERROR)
 400                 warnx("%s: tos overflow", __func__);
 401
 402 #if defined(__minix)
 403         clockinfo.profhz = sysconf(_SC_CLK_TCK);
 404 #else
 405         size = sizeof(clockinfo);
 406         mib[0] = CTL_KERN;
 407         mib[1] = KERN_CLOCKRATE;
 408         if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
 409                 /*
 410                  * Best guess
 411                  */
 412                 clockinfo.profhz = hertz();
 413         } else if (clockinfo.profhz == 0) {
 414                 if (clockinfo.hz != 0)
 415                         clockinfo.profhz = clockinfo.hz;
 416                 else
 417                         clockinfo.profhz = hertz();
 418         }
 419 #endif /* defined(__minix) */
 420
 421         moncontrol(0);
 422
 423         if ((profdir = getenv("PROFDIR")) != NULL) {
 424                 /* If PROFDIR contains a null value, no profiling
 425                    output is produced */
 426                 if (*profdir == '\0')
 427                         return;
 428
 429                 if (snprintf(buf, sizeof buf, "%s/%d.%s",
 430                     profdir, getpid(), getprogname()) >= (int)(sizeof buf)) {
 431                         warnx("%s: internal buffer overflow, PROFDIR too long",
 432                             __func__);
 433                         return;
 434                 }
 435
 436                 proffile = buf;
 437         } else {
 438                 proffile = "gmon.out";
 439         }
 440
 441 #define OPEN_FLAGS (O_CREAT | O_TRUNC | O_WRONLY | O_CLOEXEC)
 442         fd = open(proffile, OPEN_FLAGS, 0666);
 443         if (fd < 0) {
 444                 warn("%s: Cannot open `%s'", __func__, proffile);
 445                 return;
 446         }
 447 #ifdef DEBUG
 448         logfd = open("gmon.log", OPEN_FLAGS, 0664);
 449         if (logfd < 0) {
 450                 warn("%s: Cannot open `%s'", __func__, "gmon.log");
 451                 (void)close(fd);
 452                 return;
 453         }
 454         len = snprintf(buf2, sizeof buf2, "[mcleanup1] kcount %p ssiz %lu\n",
 455             p->kcount, p->kcountsize);
 456         (void)write(logfd, buf2, (size_t)len);
 457 #endif
 458 #ifdef _REENTRANT
 459         _m_gmon_merge();
 460 #endif
 461         hdr = (struct gmonhdr *)&gmonhdr;
 462         hdr->lpc = p->lowpc;
 463         hdr->hpc = p->highpc;
 464         hdr->ncnt = (int)(p->kcountsize + sizeof(gmonhdr));
 465         hdr->version = GMONVERSION;
 466         hdr->profrate = clockinfo.profhz;
 467         (void)write(fd, hdr, sizeof *hdr);
 468         (void)write(fd, p->kcount, (size_t)p->kcountsize);
 469         endfrom = (int)(p->fromssize / sizeof(*p->froms));
 470         for (fromindex = 0; fromindex < endfrom; fromindex++) {
 471                 if (p->froms[fromindex] == 0)
 472                         continue;
 473
 474                 frompc = p->lowpc;
 475                 frompc += fromindex * p->hashfraction * sizeof(*p->froms);
 476                 for (toindex = p->froms[fromindex]; toindex != 0;
 477                      toindex = p->tos[toindex].link) {
 478 #ifdef DEBUG
 479                         len = snprintf(buf2, sizeof buf2,
 480                         "[mcleanup2] frompc 0x%lx selfpc 0x%lx count %lu\n" ,
 481                                 (u_long)frompc, (u_long)p->tos[toindex].selfpc,
 482                                 (u_long)p->tos[toindex].count);
 483                         (void)write(logfd, buf2, (size_t)len);
 484 #endif
 485                         rawarc.raw_frompc = frompc;
 486                         rawarc.raw_selfpc = p->tos[toindex].selfpc;
 487                         rawarc.raw_count = p->tos[toindex].count;
 488                         (void)write(fd, &rawarc, sizeof rawarc);
 489                 }
 490         }
 491         (void)close(fd);
 492 #ifdef DEBUG
 493         (void)close(logfd);
 494 #endif
 495 }
 496
 497 /*
 498  * Control profiling
 499  *      profiling is what mcount checks to see if
 500  *      all the data structures are ready.
 501  */
 502 void
 503 moncontrol(int mode)
 504 {
 505         struct gmonparam *p = &_gmonparam;
 506
 507         if (mode) {
 508                 /* start */
 509                 profil((char *)(void *)p->kcount, (size_t)p->kcountsize,
 510                     p->lowpc, s_scale);
 511                 p->state = GMON_PROF_ON;
 512         } else {
 513                 /* stop */
 514                 profil(NULL, 0, (u_long)0, 0);
 515                 p->state = GMON_PROF_OFF;
 516         }
 517 }
 518
 519 #if !defined(__minix)
 520 /*
 521  * discover the tick frequency of the machine
 522  * if something goes wrong, we return 0, an impossible hertz.
 523  */
 524 static int
 525 hertz(void)
 526 {
 527         struct itimerspec tim;
 528         timer_t t;
 529         int rv = 0;
 530
 531         tim.it_interval.tv_sec = 0;
 532         tim.it_interval.tv_nsec = 1;
 533         tim.it_value.tv_sec = 0;
 534         tim.it_value.tv_nsec = 0;
 535
 536         if (timer_create(CLOCK_REALTIME, NULL, &t) == -1)
 537                 return 0;
 538
 539         if (timer_settime(t, 0, &tim, NULL) == -1)
 540                 goto out;
 541
 542         if (timer_gettime(t, &tim) == -1)
 543                 goto out;
 544
 545         if (tim.it_interval.tv_nsec < 2)
 546                 goto out;
 547
 548         rv = (int)(1000000000LL / tim.it_interval.tv_nsec);
 549 out:
 550         (void)timer_delete(t);
 551         return rv;
 552 }
 553 #endif /* !defined(__minix) */