usr.sbin/pmcstat/pmcpl_gprof.c

   1 /*-
   2  * Copyright (c) 2005-2007, Joseph Koshy
   3  * Copyright (c) 2007 The FreeBSD Foundation
   4  * Copyright (c) 2009, Fabien Thomas
   5  * All rights reserved.
   6  *
   7  * Portions of this software were developed by A. Joseph Koshy under
   8  * sponsorship from the FreeBSD Foundation and Google, Inc.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * Transform a hwpmc(4) log into human readable form, and into
  34  * gprof(1) compatible profiles.
  35  */
  36
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD$");
  39
  40 #include <sys/param.h>
  41 #include <sys/endian.h>
  42 #include <sys/gmon.h>
  43 #include <sys/imgact_aout.h>
  44 #include <sys/imgact_elf.h>
  45 #include <sys/mman.h>
  46 #include <sys/pmc.h>
  47 #include <sys/queue.h>
  48 #include <sys/socket.h>
  49 #include <sys/stat.h>
  50 #include <sys/wait.h>
  51
  52 #include <netinet/in.h>
  53
  54 #include <assert.h>
  55 #include <curses.h>
  56 #include <err.h>
  57 #include <errno.h>
  58 #include <fcntl.h>
  59 #include <gelf.h>
  60 #include <libgen.h>
  61 #include <limits.h>
  62 #include <netdb.h>
  63 #include <pmc.h>
  64 #include <pmclog.h>
  65 #include <sysexits.h>
  66 #include <stdint.h>
  67 #include <stdio.h>
  68 #include <stdlib.h>
  69 #include <string.h>
  70 #include <unistd.h>
  71
  72 #include "pmcstat.h"
  73 #include "pmcstat_log.h"
  74 #include "pmcpl_callgraph.h"
  75 #include "pmcpl_gprof.h"
  76
  77 typedef uint64_t        WIDEHISTCOUNTER;
  78
  79 #define WIDEHISTCOUNTER_MAX             UINT64_MAX
  80 #define HISTCOUNTER_MAX                 USHRT_MAX
  81 #define WIDEHISTCOUNTER_GMONTYPE        ((int) 64)
  82 #define HISTCOUNTER_GMONTYPE            ((int) 0)
  83 static int hc_sz=0;
  84
  85 /*
  86  * struct pmcstat_gmonfile tracks a given 'gmon.out' file.  These
  87  * files are mmap()'ed in as needed.
  88  */
  89
  90 struct pmcstat_gmonfile {
  91         LIST_ENTRY(pmcstat_gmonfile)    pgf_next; /* list of entries */
  92         int             pgf_overflow;   /* whether a count overflowed */
  93         pmc_id_t        pgf_pmcid;      /* id of the associated pmc */
  94         size_t          pgf_nbuckets;   /* #buckets in this gmon.out */
  95         unsigned int    pgf_nsamples;   /* #samples in this gmon.out */
  96         pmcstat_interned_string pgf_name;       /* pathname of gmon.out file */
  97         size_t          pgf_ndatabytes; /* number of bytes mapped */
  98         void            *pgf_gmondata;  /* pointer to mmap'ed data */
  99         FILE            *pgf_file;      /* used when writing gmon arcs */
 100 };
 101
 102 /*
 103  * Prototypes
 104  */
 105
 106 static void     pmcstat_gmon_create_file(struct pmcstat_gmonfile *_pgf,
 107     struct pmcstat_image *_image);
 108 static pmcstat_interned_string pmcstat_gmon_create_name(const char *_sd,
 109     struct pmcstat_image *_img, pmc_id_t _pmcid);
 110 static void     pmcstat_gmon_map_file(struct pmcstat_gmonfile *_pgf);
 111 static void     pmcstat_gmon_unmap_file(struct pmcstat_gmonfile *_pgf);
 112
 113 static struct pmcstat_gmonfile *pmcstat_image_find_gmonfile(struct
 114     pmcstat_image *_i, pmc_id_t _id);
 115
 116 /*
 117  * Create a gmon.out file and size it.
 118  */
 119
 120 static void
 121 pmcstat_gmon_create_file(struct pmcstat_gmonfile *pgf,
 122     struct pmcstat_image *image)
 123 {
 124         int fd;
 125         size_t count;
 126         struct gmonhdr gm;
 127         const char *pathname;
 128         char buffer[DEFAULT_BUFFER_SIZE];
 129
 130         pathname = pmcstat_string_unintern(pgf->pgf_name);
 131         if ((fd = open(pathname, O_RDWR|O_NOFOLLOW|O_CREAT,
 132                  S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)) < 0)
 133                 err(EX_OSERR, "ERROR: Cannot open \"%s\"", pathname);
 134
 135         gm.lpc = image->pi_start;
 136         gm.hpc = image->pi_end;
 137         gm.ncnt = (pgf->pgf_nbuckets * hc_sz) + sizeof(struct gmonhdr);
 138         gm.version = GMONVERSION;
 139         gm.profrate = 0;                /* use ticks */
 140         if (args.pa_flags & FLAG_DO_WIDE_GPROF_HC)
 141                 gm.histcounter_type = WIDEHISTCOUNTER_GMONTYPE;
 142         else
 143                 gm.histcounter_type = HISTCOUNTER_GMONTYPE;
 144         gm.spare[0] = gm.spare[1] = 0;
 145
 146         /* Write out the gmon header */
 147         if (write(fd, &gm, sizeof(gm)) < 0)
 148                 goto error;
 149
 150         /* Zero fill the samples[] array */
 151         (void) memset(buffer, 0, sizeof(buffer));
 152
 153         count = pgf->pgf_ndatabytes - sizeof(struct gmonhdr);
 154         while (count > sizeof(buffer)) {
 155                 if (write(fd, &buffer, sizeof(buffer)) < 0)
 156                         goto error;
 157                 count -= sizeof(buffer);
 158         }
 159
 160         if (write(fd, &buffer, count) < 0)
 161                 goto error;
 162
 163         (void) close(fd);
 164
 165         return;
 166
 167  error:
 168         err(EX_OSERR, "ERROR: Cannot write \"%s\"", pathname);
 169 }
 170
 171 /*
 172  * Determine the full pathname of a gmon.out file for a given
 173  * (image,pmcid) combination.  Return the interned string.
 174  */
 175
 176 pmcstat_interned_string
 177 pmcstat_gmon_create_name(const char *samplesdir, struct pmcstat_image *image,
 178     pmc_id_t pmcid)
 179 {
 180         const char *pmcname;
 181         char fullpath[PATH_MAX];
 182
 183         pmcname = pmcstat_pmcid_to_name(pmcid);
 184         if (!pmcname)
 185                 err(EX_SOFTWARE, "ERROR: cannot find pmcid");
 186
 187         (void) snprintf(fullpath, sizeof(fullpath),
 188             "%s/%s/%s", samplesdir, pmcname,
 189             pmcstat_string_unintern(image->pi_samplename));
 190
 191         return (pmcstat_string_intern(fullpath));
 192 }
 193
 194
 195 /*
 196  * Mmap in a gmon.out file for processing.
 197  */
 198
 199 static void
 200 pmcstat_gmon_map_file(struct pmcstat_gmonfile *pgf)
 201 {
 202         int fd;
 203         const char *pathname;
 204
 205         pathname = pmcstat_string_unintern(pgf->pgf_name);
 206
 207         /* the gmon.out file must already exist */
 208         if ((fd = open(pathname, O_RDWR | O_NOFOLLOW, 0)) < 0)
 209                 err(EX_OSERR, "ERROR: cannot open \"%s\"", pathname);
 210
 211         pgf->pgf_gmondata = mmap(NULL, pgf->pgf_ndatabytes,
 212             PROT_READ|PROT_WRITE, MAP_NOSYNC|MAP_SHARED, fd, 0);
 213
 214         if (pgf->pgf_gmondata == MAP_FAILED)
 215                 err(EX_OSERR, "ERROR: cannot map \"%s\"", pathname);
 216
 217         (void) close(fd);
 218 }
 219
 220 /*
 221  * Unmap a gmon.out file after sync'ing its data to disk.
 222  */
 223
 224 static void
 225 pmcstat_gmon_unmap_file(struct pmcstat_gmonfile *pgf)
 226 {
 227         (void) msync(pgf->pgf_gmondata, pgf->pgf_ndatabytes,
 228             MS_SYNC);
 229         (void) munmap(pgf->pgf_gmondata, pgf->pgf_ndatabytes);
 230         pgf->pgf_gmondata = NULL;
 231 }
 232
 233 static void
 234 pmcstat_gmon_append_arc(struct pmcstat_image *image, pmc_id_t pmcid,
 235     uintptr_t rawfrom, uintptr_t rawto, uint32_t count)
 236 {
 237         struct rawarc arc;      /* from <sys/gmon.h> */
 238         const char *pathname;
 239         struct pmcstat_gmonfile *pgf;
 240
 241         if ((pgf = pmcstat_image_find_gmonfile(image, pmcid)) == NULL)
 242                 return;
 243
 244         if (pgf->pgf_file == NULL) {
 245                 pathname = pmcstat_string_unintern(pgf->pgf_name);
 246                 if ((pgf->pgf_file = fopen(pathname, "a")) == NULL)
 247                         return;
 248         }
 249
 250         arc.raw_frompc = rawfrom + image->pi_vaddr;
 251         arc.raw_selfpc = rawto + image->pi_vaddr;
 252         arc.raw_count = count;
 253
 254         (void) fwrite(&arc, sizeof(arc), 1, pgf->pgf_file);
 255
 256 }
 257
 258 static struct pmcstat_gmonfile *
 259 pmcstat_image_find_gmonfile(struct pmcstat_image *image, pmc_id_t pmcid)
 260 {
 261         struct pmcstat_gmonfile *pgf;
 262         LIST_FOREACH(pgf, &image->pi_gmlist, pgf_next)
 263             if (pgf->pgf_pmcid == pmcid)
 264                     return (pgf);
 265         return (NULL);
 266 }
 267
 268 static void
 269 pmcstat_cgnode_do_gmon_arcs(struct pmcstat_cgnode *cg, pmc_id_t pmcid)
 270 {
 271         struct pmcstat_cgnode *cgc;
 272
 273         /*
 274          * Look for child nodes that belong to the same image.
 275          */
 276
 277         LIST_FOREACH(cgc, &cg->pcg_children, pcg_sibling) {
 278                 if (cgc->pcg_image == cg->pcg_image)
 279                         pmcstat_gmon_append_arc(cg->pcg_image, pmcid,
 280                             cgc->pcg_func, cg->pcg_func, cgc->pcg_count);
 281                 if (cgc->pcg_nchildren > 0)
 282                         pmcstat_cgnode_do_gmon_arcs(cgc, pmcid);
 283         }
 284 }
 285
 286 static void
 287 pmcstat_callgraph_do_gmon_arcs_for_pmcid(pmc_id_t pmcid)
 288 {
 289         int n;
 290         struct pmcstat_cgnode_hash *pch;
 291
 292         for (n = 0; n < PMCSTAT_NHASH; n++)
 293                 LIST_FOREACH(pch, &pmcstat_cgnode_hash[n], pch_next)
 294                         if (pch->pch_pmcid == pmcid &&
 295                             pch->pch_cgnode->pcg_nchildren > 1)
 296                                 pmcstat_cgnode_do_gmon_arcs(pch->pch_cgnode,
 297                                     pmcid);
 298 }
 299
 300
 301 static void
 302 pmcstat_callgraph_do_gmon_arcs(void)
 303 {
 304         struct pmcstat_pmcrecord *pmcr;
 305
 306         LIST_FOREACH(pmcr, &pmcstat_pmcs, pr_next)
 307                 pmcstat_callgraph_do_gmon_arcs_for_pmcid(pmcr->pr_pmcid);
 308 }
 309
 310 void
 311 pmcpl_gmon_initimage(struct pmcstat_image *pi)
 312 {
 313         int count, nlen;
 314         char *sn;
 315         char name[NAME_MAX];
 316
 317         /*
 318          * Look for a suitable name for the sample files associated
 319          * with this image: if `basename(path)`+".gmon" is available,
 320          * we use that, otherwise we try iterating through
 321          * `basename(path)`+ "~" + NNN + ".gmon" till we get a free
 322          * entry.
 323          */
 324         if ((sn = basename(pmcstat_string_unintern(pi->pi_execpath))) == NULL)
 325                 err(EX_OSERR, "ERROR: Cannot process \"%s\"",
 326                     pmcstat_string_unintern(pi->pi_execpath));
 327
 328         nlen = strlen(sn);
 329         nlen = min(nlen, (int) (sizeof(name) - sizeof(".gmon")));
 330
 331         snprintf(name, sizeof(name), "%.*s.gmon", nlen, sn);
 332
 333         /* try use the unabridged name first */
 334         if (pmcstat_string_lookup(name) == NULL)
 335                 pi->pi_samplename = pmcstat_string_intern(name);
 336         else {
 337                 /*
 338                  * Otherwise use a prefix from the original name and
 339                  * up to 3 digits.
 340                  */
 341                 nlen = strlen(sn);
 342                 nlen = min(nlen, (int) (sizeof(name)-sizeof("~NNN.gmon")));
 343                 count = 0;
 344                 do {
 345                         if (++count > 999)
 346                                 errx(EX_CANTCREAT,
 347                                     "ERROR: cannot create a gmon file for"
 348                                     " \"%s\"", name);
 349                         snprintf(name, sizeof(name), "%.*s~%3.3d.gmon",
 350                             nlen, sn, count);
 351                         if (pmcstat_string_lookup(name) == NULL) {
 352                                 pi->pi_samplename =
 353                                     pmcstat_string_intern(name);
 354                                 count = 0;
 355                         }
 356                 } while (count > 0);
 357         }
 358
 359         LIST_INIT(&pi->pi_gmlist);
 360 }
 361
 362 void
 363 pmcpl_gmon_shutdownimage(struct pmcstat_image *pi)
 364 {
 365         struct pmcstat_gmonfile *pgf, *pgftmp;
 366
 367         LIST_FOREACH_SAFE(pgf, &pi->pi_gmlist, pgf_next, pgftmp) {
 368                 if (pgf->pgf_file)
 369                         (void) fclose(pgf->pgf_file);
 370                 LIST_REMOVE(pgf, pgf_next);
 371                 free(pgf);
 372         }
 373 }
 374
 375 void
 376 pmcpl_gmon_newpmc(pmcstat_interned_string ps, struct pmcstat_pmcrecord *pr)
 377 {
 378         struct stat st;
 379         char fullpath[PATH_MAX];
 380
 381         (void) pr;
 382
 383         /*
 384          * Create the appropriate directory to hold gmon.out files.
 385          */
 386
 387         (void) snprintf(fullpath, sizeof(fullpath), "%s/%s", args.pa_samplesdir,
 388             pmcstat_string_unintern(ps));
 389
 390         /* If the path name exists, it should be a directory */
 391         if (stat(fullpath, &st) == 0 && S_ISDIR(st.st_mode))
 392                 return;
 393
 394         if (mkdir(fullpath, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) < 0)
 395                 err(EX_OSERR, "ERROR: Cannot create directory \"%s\"",
 396                     fullpath);
 397 }
 398
 399 /*
 400  * Increment the bucket in the gmon.out file corresponding to 'pmcid'
 401  * and 'pc'.
 402  */
 403
 404 void
 405 pmcpl_gmon_process(struct pmcstat_process *pp, struct pmcstat_pmcrecord *pmcr,
 406     uint32_t nsamples, uintfptr_t *cc, int usermode, uint32_t cpu)
 407 {
 408         struct pmcstat_pcmap *map;
 409         struct pmcstat_image *image;
 410         struct pmcstat_gmonfile *pgf;
 411         uintfptr_t bucket;
 412         HISTCOUNTER *hc;
 413         WIDEHISTCOUNTER *whc;
 414         pmc_id_t pmcid;
 415
 416         (void) nsamples; (void) usermode; (void) cpu;
 417
 418         map = pmcstat_process_find_map(usermode ? pp : pmcstat_kernproc, cc[0]);
 419         if (map == NULL) {
 420                 /* Unknown offset. */
 421                 pmcstat_stats.ps_samples_unknown_offset++;
 422                 return;
 423         }
 424
 425         assert(cc[0] >= map->ppm_lowpc && cc[0] < map->ppm_highpc);
 426
 427         image = map->ppm_image;
 428         pmcid = pmcr->pr_pmcid;
 429
 430         /*
 431          * If this is the first time we are seeing a sample for
 432          * this executable image, try determine its parameters.
 433          */
 434         if (image->pi_type == PMCSTAT_IMAGE_UNKNOWN)
 435                 pmcstat_image_determine_type(image);
 436
 437         assert(image->pi_type != PMCSTAT_IMAGE_UNKNOWN);
 438
 439         /* Ignore samples in images that we know nothing about. */
 440         if (image->pi_type == PMCSTAT_IMAGE_INDETERMINABLE) {
 441                 pmcstat_stats.ps_samples_indeterminable++;
 442                 return;
 443         }
 444
 445         /*
 446          * Find the gmon file corresponding to 'pmcid', creating it if
 447          * needed.
 448          */
 449         pgf = pmcstat_image_find_gmonfile(image, pmcid);
 450         if (pgf == NULL) {
 451                 if (hc_sz == 0) {
 452                         /* Determine the correct histcounter size. */
 453                         if (args.pa_flags & FLAG_DO_WIDE_GPROF_HC)
 454                                 hc_sz = sizeof(WIDEHISTCOUNTER);
 455                         else
 456                                 hc_sz = sizeof(HISTCOUNTER);
 457                 }
 458
 459                 if ((pgf = calloc(1, sizeof(*pgf))) == NULL)
 460                         err(EX_OSERR, "ERROR:");
 461
 462                 pgf->pgf_gmondata = NULL;       /* mark as unmapped */
 463                 pgf->pgf_name = pmcstat_gmon_create_name(args.pa_samplesdir,
 464                     image, pmcid);
 465                 pgf->pgf_pmcid = pmcid;
 466                 assert(image->pi_end > image->pi_start);
 467                 pgf->pgf_nbuckets = howmany(image->pi_end - image->pi_start,
 468                     FUNCTION_ALIGNMENT);        /* see <machine/profile.h> */
 469                 pgf->pgf_ndatabytes = sizeof(struct gmonhdr) +
 470                     pgf->pgf_nbuckets * hc_sz;
 471                 pgf->pgf_nsamples = 0;
 472                 pgf->pgf_file = NULL;
 473
 474                 pmcstat_gmon_create_file(pgf, image);
 475
 476                 LIST_INSERT_HEAD(&image->pi_gmlist, pgf, pgf_next);
 477         }
 478
 479         /*
 480          * Map the gmon file in if needed.  It may have been mapped
 481          * out under memory pressure.
 482          */
 483         if (pgf->pgf_gmondata == NULL)
 484                 pmcstat_gmon_map_file(pgf);
 485
 486         assert(pgf->pgf_gmondata != NULL);
 487
 488         /*
 489          *
 490          */
 491
 492         bucket = (cc[0] - map->ppm_lowpc) / FUNCTION_ALIGNMENT;
 493
 494         assert(bucket < pgf->pgf_nbuckets);
 495
 496         if (args.pa_flags & FLAG_DO_WIDE_GPROF_HC) {
 497                 whc = (WIDEHISTCOUNTER *) ((uintptr_t) pgf->pgf_gmondata +
 498                     sizeof(struct gmonhdr));
 499
 500                 /* saturating add */
 501                 if (whc[bucket] < WIDEHISTCOUNTER_MAX)
 502                         whc[bucket]++;
 503                 else /* mark that an overflow occurred */
 504                         pgf->pgf_overflow = 1;
 505         } else {
 506                 hc = (HISTCOUNTER *) ((uintptr_t) pgf->pgf_gmondata +
 507                     sizeof(struct gmonhdr));
 508
 509                 /* saturating add */
 510                 if (hc[bucket] < HISTCOUNTER_MAX)
 511                         hc[bucket]++;
 512                 else /* mark that an overflow occurred */
 513                         pgf->pgf_overflow = 1;
 514         }
 515
 516         pgf->pgf_nsamples++;
 517 }
 518
 519 /*
 520  * Shutdown module.
 521  */
 522
 523 void
 524 pmcpl_gmon_shutdown(FILE *mf)
 525 {
 526         int i;
 527         struct pmcstat_gmonfile *pgf;
 528         struct pmcstat_image *pi;
 529
 530         /*
 531          * Sync back all gprof flat profile data.
 532          */
 533         for (i = 0; i < PMCSTAT_NHASH; i++) {
 534                 LIST_FOREACH(pi, &pmcstat_image_hash[i], pi_next) {
 535                         if (mf)
 536                                 (void) fprintf(mf, " \"%s\" => \"%s\"",
 537                                     pmcstat_string_unintern(pi->pi_execpath),
 538                                     pmcstat_string_unintern(
 539                                     pi->pi_samplename));
 540
 541                         /* flush gmon.out data to disk */
 542                         LIST_FOREACH(pgf, &pi->pi_gmlist, pgf_next) {
 543                                 pmcstat_gmon_unmap_file(pgf);
 544                                 if (mf)
 545                                         (void) fprintf(mf, " %s/%d",
 546                                             pmcstat_pmcid_to_name(
 547                                             pgf->pgf_pmcid),
 548                                             pgf->pgf_nsamples);
 549                                 if (pgf->pgf_overflow && args.pa_verbosity >= 1)
 550                                         warnx(
 551 "WARNING: profile \"%s\" overflowed.",
 552                                             pmcstat_string_unintern(
 553                                                 pgf->pgf_name));
 554                         }
 555
 556                         if (mf)
 557                                 (void) fprintf(mf, "\n");
 558                 }
 559         }
 560
 561         /*
 562          * Compute arcs and add these to the gprof files.
 563          */
 564         if (args.pa_flags & FLAG_DO_GPROF && args.pa_graphdepth > 1)
 565                 pmcstat_callgraph_do_gmon_arcs();
 566 }