usr.bin/ktrdump/ktrdump.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2002 Jake Burkholder
   5  * Copyright (c) 2004 Robert Watson
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include <sys/cdefs.h>
  31 __FBSDID("$FreeBSD$");
  32
  33 #include <sys/types.h>
  34 #include <sys/ktr.h>
  35 #include <sys/mman.h>
  36 #include <sys/stat.h>
  37
  38 #include <err.h>
  39 #include <fcntl.h>
  40 #include <kvm.h>
  41 #include <limits.h>
  42 #include <nlist.h>
  43 #include <stdint.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <unistd.h>
  48
  49 #define SBUFLEN 128
  50 #define USAGE \
  51         "usage: ktrdump [-cflqrtH] [-i ktrfile] [-M core] [-N system] [-o outfile]\n"
  52
  53 static void usage(void);
  54
  55 static struct nlist nl[] = {
  56         { "_ktr_version" },
  57         { "_ktr_entries" },
  58         { "_ktr_idx" },
  59         { "_ktr_buf" },
  60         { NULL }
  61 };
  62
  63 static int cflag;
  64 static int fflag;
  65 static int lflag;
  66 static int Mflag;
  67 static int Nflag;
  68 static int qflag;
  69 static int rflag;
  70 static int tflag;
  71 static int iflag;
  72 static int hflag;
  73
  74 static char corefile[PATH_MAX];
  75 static char execfile[PATH_MAX];
  76
  77 static char desc[SBUFLEN];
  78 static char errbuf[_POSIX2_LINE_MAX];
  79 static char fbuf[PATH_MAX];
  80 static char obuf[PATH_MAX];
  81 static char sbuf[KTR_PARMS][SBUFLEN];
  82
  83 /*
  84  * Reads the ktr trace buffer from kernel memory and prints the trace entries.
  85  */
  86 int
  87 main(int ac, char **av)
  88 {
  89         u_long parms[KTR_PARMS];
  90         struct ktr_entry *buf;
  91         uintmax_t tlast, tnow;
  92         unsigned long bufptr;
  93         struct stat sb;
  94         kvm_t *kd;
  95         FILE *out;
  96         char *p;
  97         int version;
  98         int entries;
  99         int count;
 100         int index, index2;
 101         int parm;
 102         int in;
 103         int c;
 104         int i = 0;
 105
 106         /*
 107          * Parse commandline arguments.
 108          */
 109         out = stdout;
 110         while ((c = getopt(ac, av, "cflqrtHe:i:m:M:N:o:")) != -1)
 111                 switch (c) {
 112                 case 'c':
 113                         cflag = 1;
 114                         break;
 115                 case 'N':
 116                 case 'e':
 117                         if (strlcpy(execfile, optarg, sizeof(execfile))
 118                             >= sizeof(execfile))
 119                                 errx(1, "%s: File name too long", optarg);
 120                         Nflag = 1;
 121                         break;
 122                 case 'f':
 123                         fflag = 1;
 124                         break;
 125                 case 'i':
 126                         iflag = 1;
 127                         if ((in = open(optarg, O_RDONLY)) == -1)
 128                                 err(1, "%s", optarg);
 129                         break;
 130                 case 'l':
 131                         lflag = 1;
 132                         break;
 133                 case 'M':
 134                 case 'm':
 135                         if (strlcpy(corefile, optarg, sizeof(corefile))
 136                             >= sizeof(corefile))
 137                                 errx(1, "%s: File name too long", optarg);
 138                         Mflag = 1;
 139                         break;
 140                 case 'o':
 141                         if ((out = fopen(optarg, "w")) == NULL)
 142                                 err(1, "%s", optarg);
 143                         break;
 144                 case 'q':
 145                         qflag++;
 146                         break;
 147                 case 'r':
 148                         rflag = 1;
 149                         break;
 150                 case 't':
 151                         tflag = 1;
 152                         break;
 153                 case 'H':
 154                         hflag = 1;
 155                         break;
 156                 case '?':
 157                 default:
 158                         usage();
 159                 }
 160         ac -= optind;
 161         av += optind;
 162         if (ac != 0)
 163                 usage();
 164
 165         /*
 166          * Open our execfile and corefile, resolve needed symbols and read in
 167          * the trace buffer.
 168          */
 169         if ((kd = kvm_openfiles(Nflag ? execfile : NULL,
 170             Mflag ? corefile : NULL, NULL, O_RDONLY, errbuf)) == NULL)
 171                 errx(1, "%s", errbuf);
 172         count = kvm_nlist(kd, nl);
 173         if (count == -1)
 174                 errx(1, "%s", kvm_geterr(kd));
 175         if (count > 0)
 176                 errx(1, "failed to resolve ktr symbols");
 177         if (kvm_read(kd, nl[0].n_value, &version, sizeof(version)) == -1)
 178                 errx(1, "%s", kvm_geterr(kd));
 179         if (version != KTR_VERSION)
 180                 errx(1, "ktr version mismatch");
 181         if (iflag) {
 182                 if (fstat(in, &sb) == -1)
 183                         errx(1, "stat");
 184                 entries = sb.st_size / sizeof(*buf);
 185                 index = 0;
 186                 buf = mmap(NULL, sb.st_size, PROT_READ, MAP_SHARED, in, 0);
 187                 if (buf == MAP_FAILED)
 188                         errx(1, "mmap");
 189         } else {
 190                 if (kvm_read(kd, nl[1].n_value, &entries, sizeof(entries))
 191                     == -1)
 192                         errx(1, "%s", kvm_geterr(kd));
 193                 if ((buf = malloc(sizeof(*buf) * entries)) == NULL)
 194                         err(1, NULL);
 195                 if (kvm_read(kd, nl[2].n_value, &index, sizeof(index)) == -1 ||
 196                     kvm_read(kd, nl[3].n_value, &bufptr,
 197                     sizeof(bufptr)) == -1 ||
 198                     kvm_read(kd, bufptr, buf, sizeof(*buf) * entries) == -1 ||
 199                     kvm_read(kd, nl[2].n_value, &index2, sizeof(index2)) == -1)
 200                         errx(1, "%s", kvm_geterr(kd));
 201         }
 202
 203         /*
 204          * Print a nice header.
 205          */
 206         if (!qflag) {
 207                 fprintf(out, "%-6s ", "index");
 208                 if (cflag)
 209                         fprintf(out, "%-3s ", "cpu");
 210                 if (tflag)
 211                         fprintf(out, "%-16s ", "timestamp");
 212                 if (fflag)
 213                         fprintf(out, "%-40s ", "file and line");
 214                 if (hflag)
 215                         fprintf(out, "%-18s ", "tid");
 216                 fprintf(out, "%s", "trace");
 217                 fprintf(out, "\n");
 218
 219                 fprintf(out, "------ ");
 220                 if (cflag)
 221                         fprintf(out, "--- ");
 222                 if (tflag)
 223                         fprintf(out, "---------------- ");
 224                 if (fflag)
 225                         fprintf(out,
 226                             "---------------------------------------- ");
 227                 if (hflag)
 228                         fprintf(out, "------------------ ");
 229                 fprintf(out, "----- ");
 230                 fprintf(out, "\n");
 231         }
 232
 233         tlast = -1;
 234         /*
 235          * Now tear through the trace buffer.
 236          *
 237          * In "live" mode, find the oldest entry (first non-NULL entry
 238          * after index2) and walk forward.  Otherwise, start with the
 239          * most recent entry and walk backwards.
 240          */
 241         if (!iflag) {
 242                 if (lflag) {
 243                         i = index2 + 1 % entries;
 244                         while (buf[i].ktr_desc == NULL && i != index) {
 245                                 i++;
 246                                 if (i == entries)
 247                                         i = 0;
 248                         }
 249                 } else {
 250                         i = index - 1;
 251                         if (i < 0)
 252                                 i = entries - 1;
 253                 }
 254         }
 255 dump_entries:
 256         for (;;) {
 257                 if (buf[i].ktr_desc == NULL)
 258                         break;
 259                 if (kvm_read(kd, (u_long)buf[i].ktr_desc, desc,
 260                     sizeof(desc)) == -1)
 261                         errx(1, "%s", kvm_geterr(kd));
 262                 desc[sizeof(desc) - 1] = '\0';
 263                 parm = 0;
 264                 for (p = desc; (c = *p++) != '\0';) {
 265                         if (c != '%')
 266                                 continue;
 267 next:                   if ((c = *p++) == '\0')
 268                                 break;
 269                         if (parm == KTR_PARMS)
 270                                 errx(1, "too many parameters in \"%s\"", desc);
 271                         switch (c) {
 272                         case '0': case '1': case '2': case '3': case '4':
 273                         case '5': case '6': case '7': case '8': case '9':
 274                         case '#': case '-': case ' ': case '+': case '\'':
 275                         case 'h': case 'l': case 'j': case 't': case 'z':
 276                         case 'q': case 'L': case '.':
 277                                 goto next;
 278                         case 's':
 279                                 if (kvm_read(kd, (u_long)buf[i].ktr_parms[parm],
 280                                     sbuf[parm], sizeof(sbuf[parm])) == -1)
 281                                         strcpy(sbuf[parm], "(null)");
 282                                 sbuf[parm][sizeof(sbuf[0]) - 1] = '\0';
 283                                 parms[parm] = (u_long)sbuf[parm];
 284                                 parm++;
 285                                 break;
 286                         default:
 287                                 parms[parm] = buf[i].ktr_parms[parm];
 288                                 parm++;
 289                                 break;
 290                         }
 291                 }
 292                 fprintf(out, "%6d ", i);
 293                 if (cflag)
 294                         fprintf(out, "%3d ", buf[i].ktr_cpu);
 295                 if (tflag) {
 296                         tnow = (uintmax_t)buf[i].ktr_timestamp;
 297                         if (rflag) {
 298                                 if (tlast == -1)
 299                                         tlast = tnow;
 300                                 fprintf(out, "%16ju ", !iflag ? tlast - tnow :
 301                                     tnow - tlast);
 302                                 tlast = tnow;
 303                         } else
 304                                 fprintf(out, "%16ju ", tnow);
 305                 }
 306                 if (fflag) {
 307                         if (kvm_read(kd, (u_long)buf[i].ktr_file, fbuf,
 308                             sizeof(fbuf)) == -1)
 309                                 strcpy(fbuf, "(null)");
 310                         snprintf(obuf, sizeof(obuf), "%s:%d", fbuf,
 311                             buf[i].ktr_line);
 312                         fprintf(out, "%-40s ", obuf);
 313                 }
 314                 if (hflag)
 315                         fprintf(out, "%p ", buf[i].ktr_thread);
 316                 fprintf(out, desc, parms[0], parms[1], parms[2], parms[3],
 317                     parms[4], parms[5]);
 318                 fprintf(out, "\n");
 319                 if (!iflag) {
 320                         /*
 321                          * 'index' and 'index2' are the values of 'ktr_idx'
 322                          * before and after the KTR buffer was copied into
 323                          * 'buf'. Since the KTR entries between 'index' and
 324                          * 'index2' were in flux while the KTR buffer was
 325                          * being copied to userspace we don't dump them.
 326                          */
 327                         if (lflag) {
 328                                 if (++i == entries)
 329                                         i = 0;
 330                                 if (i == index)
 331                                         break;
 332                         } else {
 333                                 if (i == index2)
 334                                         break;
 335                                 if (--i < 0)
 336                                         i = entries - 1;
 337                         }
 338                 } else {
 339                         if (++i == entries)
 340                                 break;
 341                 }
 342         }
 343
 344         /*
 345          * In "live" mode, poll 'ktr_idx' periodically and dump any
 346          * new entries since our last pass through the ring.
 347          */
 348         if (lflag && !iflag) {
 349                 while (index == index2) {
 350                         usleep(50 * 1000);
 351                         if (kvm_read(kd, nl[2].n_value, &index2,
 352                             sizeof(index2)) == -1)
 353                                 errx(1, "%s", kvm_geterr(kd));
 354                 }
 355                 i = index;
 356                 index = index2;
 357                 if (kvm_read(kd, bufptr, buf, sizeof(*buf) * entries) == -1 ||
 358                     kvm_read(kd, nl[2].n_value, &index2, sizeof(index2)) == -1)
 359                         errx(1, "%s", kvm_geterr(kd));
 360                 goto dump_entries;
 361         }
 362
 363         return (0);
 364 }
 365
 366 static void
 367 usage(void)
 368 {
 369
 370         fprintf(stderr, USAGE);
 371         exit(1);
 372 }