usr/src/cmd/ctfconvert/ctfconvert.c

   1 /*
   2  * This file and its contents are supplied under the terms of the
   3  * Common Development and Distribution License ("CDDL"), version 1.0.
   4  * You may only use this file in accordance with the terms of version
   5  * 1.0 of the CDDL.
   6  *
   7  * A full copy of the text of the CDDL should have accompanied this
   8  * source.  A copy of the CDDL is also available via the Internet at
   9  * http://www.illumos.org/license/CDDL.
  10  */
  11
  12 /*
  13  * Copyright (c) 2015, Joyent, Inc.
  14  */
  15
  16 /*
  17  * Create CTF from extant debugging information
  18  */
  19
  20 #include <stdio.h>
  21 #include <unistd.h>
  22 #include <stdlib.h>
  23 #include <stdarg.h>
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #include <fcntl.h>
  27 #include <errno.h>
  28 #include <libelf.h>
  29 #include <libctf.h>
  30 #include <string.h>
  31 #include <libgen.h>
  32 #include <limits.h>
  33 #include <strings.h>
  34 #include <sys/debug.h>
  35
  36 #define CTFCONVERT_OK           0
  37 #define CTFCONVERT_FATAL        1
  38 #define CTFCONVERT_USAGE        2
  39
  40 #define CTFCONVERT_DEFAULT_NTHREADS     4
  41
  42 static char *ctfconvert_progname;
  43
  44 static void
  45 ctfconvert_fatal(const char *fmt, ...)
  46 {
  47         va_list ap;
  48
  49         (void) fprintf(stderr, "%s: ", ctfconvert_progname);
  50         va_start(ap, fmt);
  51         (void) vfprintf(stderr, fmt, ap);
  52         va_end(ap);
  53
  54         exit(CTFCONVERT_FATAL);
  55 }
  56
  57
  58 static void
  59 ctfconvert_usage(const char *fmt, ...)
  60 {
  61         if (fmt != NULL) {
  62                 va_list ap;
  63
  64                 (void) fprintf(stderr, "%s: ", ctfconvert_progname);
  65                 va_start(ap, fmt);
  66                 (void) vfprintf(stderr, fmt, ap);
  67                 va_end(ap);
  68         }
  69
  70         (void) fprintf(stderr, "Usage: %s [-is] [-j nthrs] [-l label | "
  71             "-L labelenv] [-o outfile] input\n"
  72             "\n"
  73             "\t-i  ignore files not built partially from C sources\n"
  74             "\t-j  use nthrs threads to perform the merge\n"
  75             "\t-k  keep around original input file on failure\n"
  76             "\t-o  copy input to outfile and add CTF\n"
  77             "\t-l  set output container's label to specified value\n"
  78             "\t-L  set output container's label to value from environment\n",
  79             ctfconvert_progname);
  80 }
  81
  82 /*
  83  * This is a bit unfortunate. Traditionally we do type uniquification across all
  84  * modules in the kernel, including ip and unix against genunix. However, when
  85  * _MACHDEP is defined, then the cpu_t ends up having an additional member
  86  * (cpu_m), thus changing the ability for us to uniquify against it. This in
  87  * turn causes a lot of type sprawl, as there's a lot of things that end up
  88  * referring to the cpu_t and it chains out from there.
  89  *
  90  * So, if we find that a cpu_t has been defined and it has a couple of useful
  91  * sentinel members and it does *not* have the cpu_m member, then we will try
  92  * and lookup or create a forward declaration to the machcpu, append it to the
  93  * end, and update the file.
  94  *
  95  * This currently is only invoked if an undocumented option -X is passed. This
  96  * value is private to illumos and it can be changed at any time inside of it,
  97  * so if -X wants to be used for something, it should be. The ability to rely on
  98  * -X for others is strictly not an interface in any way, shape, or form.
  99  *
 100  * The following struct contains most of the information that we care about and
 101  * that we want to validate exists before we decide what to do.
 102  */
 103
 104 typedef struct ctfconvert_fixup {
 105         boolean_t       cf_cyclic;      /* Do we have a cpu_cyclic member */
 106         boolean_t       cf_mcpu;        /* We have a cpu_m member */
 107         boolean_t       cf_lastpad;     /* Is the pad member the last entry */
 108         ulong_t         cf_padoff;      /* offset of the pad */
 109 } ctfconvert_fixup_t;
 110
 111 /* ARGSUSED */
 112 static int
 113 ctfconvert_fixup_genunix_cb(const char *name, ctf_id_t tid, ulong_t off,
 114     void *arg)
 115 {
 116         ctfconvert_fixup_t *cfp = arg;
 117
 118         cfp->cf_lastpad = B_FALSE;
 119         if (strcmp(name, "cpu_cyclic") == 0) {
 120                 cfp->cf_cyclic = B_TRUE;
 121                 return (0);
 122         }
 123
 124         if (strcmp(name, "cpu_m") == 0) {
 125                 cfp->cf_mcpu = B_TRUE;
 126                 return (0);
 127         }
 128
 129         if (strcmp(name, "cpu_m_pad") == 0) {
 130                 cfp->cf_lastpad = B_TRUE;
 131                 cfp->cf_padoff = off;
 132                 return (0);
 133         }
 134
 135         return (0);
 136 }
 137
 138 static void
 139 ctfconvert_fixup_genunix(ctf_file_t *fp)
 140 {
 141         ctf_id_t cpuid, mcpu;
 142         ssize_t sz;
 143         ctfconvert_fixup_t cf;
 144         int model, ptrsz;
 145
 146         cpuid = ctf_lookup_by_name(fp, "struct cpu");
 147         if (cpuid == CTF_ERR)
 148                 return;
 149
 150         if (ctf_type_kind(fp, cpuid) != CTF_K_STRUCT)
 151                 return;
 152
 153         if ((sz = ctf_type_size(fp, cpuid)) == CTF_ERR)
 154                 return;
 155
 156         model = ctf_getmodel(fp);
 157         VERIFY(model == CTF_MODEL_ILP32 || model == CTF_MODEL_LP64);
 158         ptrsz = model == CTF_MODEL_ILP32 ? 4 : 8;
 159
 160         bzero(&cf, sizeof (ctfconvert_fixup_t));
 161         if (ctf_member_iter(fp, cpuid, ctfconvert_fixup_genunix_cb, &cf) ==
 162             CTF_ERR)
 163                 return;
 164
 165         /*
 166          * Finally, we want to verify that the cpu_m is actually the last member
 167          * that we have here.
 168          */
 169         if (cf.cf_cyclic == B_FALSE || cf.cf_mcpu == B_TRUE ||
 170             cf.cf_lastpad == B_FALSE) {
 171                 return;
 172         }
 173
 174         if (cf.cf_padoff + ptrsz * NBBY != sz * NBBY) {
 175                 return;
 176         }
 177
 178         /*
 179          * Okay, we're going to do this, try to find a struct machcpu. We either
 180          * want a forward or a struct. If we find something else, error. If we
 181          * find nothing, add a forward and then add the member.
 182          */
 183         mcpu = ctf_lookup_by_name(fp, "struct machcpu");
 184         if (mcpu == CTF_ERR) {
 185                 mcpu = ctf_add_forward(fp, CTF_ADD_NONROOT, "machcpu",
 186                     CTF_K_STRUCT);
 187                 if (mcpu == CTF_ERR) {
 188                         ctfconvert_fatal("failed to add 'struct machcpu' "
 189                             "forward: %s", ctf_errmsg(ctf_errno(fp)));
 190                 }
 191         } else {
 192                 int kind;
 193                 if ((kind = ctf_type_kind(fp, mcpu)) == CTF_ERR) {
 194                         ctfconvert_fatal("failed to get the type kind for "
 195                             "the struct machcpu: %s",
 196                             ctf_errmsg(ctf_errno(fp)));
 197                 }
 198
 199                 if (kind != CTF_K_STRUCT && kind != CTF_K_FORWARD)
 200                         ctfconvert_fatal("encountered a struct machcpu of the "
 201                             "wrong type, found type kind %d\n", kind);
 202         }
 203
 204         if (ctf_update(fp) == CTF_ERR) {
 205                 ctfconvert_fatal("failed to update output file: %s\n",
 206                     ctf_errmsg(ctf_errno(fp)));
 207         }
 208
 209         if (ctf_add_member(fp, cpuid, "cpu_m", mcpu, sz * NBBY) == CTF_ERR) {
 210                 ctfconvert_fatal("failed to add the m_cpu member: %s\n",
 211                     ctf_errmsg(ctf_errno(fp)));
 212         }
 213
 214         if (ctf_update(fp) == CTF_ERR) {
 215                 ctfconvert_fatal("failed to update output file: %s\n",
 216                     ctf_errmsg(ctf_errno(fp)));
 217         }
 218
 219         VERIFY(ctf_type_size(fp, cpuid) == sz);
 220 }
 221
 222 int
 223 main(int argc, char *argv[])
 224 {
 225         int c, ifd, err;
 226         boolean_t keep = B_FALSE;
 227         uint_t flags = 0;
 228         uint_t nthreads = CTFCONVERT_DEFAULT_NTHREADS;
 229         const char *outfile = NULL;
 230         const char *label = NULL;
 231         const char *infile = NULL;
 232         char *tmpfile;
 233         ctf_file_t *ofp;
 234         long argj;
 235         char *eptr;
 236         char buf[4096];
 237         boolean_t optx = B_FALSE;
 238
 239         ctfconvert_progname = basename(argv[0]);
 240
 241         while ((c = getopt(argc, argv, ":j:kl:L:o:iX")) != -1) {
 242                 switch (c) {
 243                 case 'k':
 244                         keep = B_TRUE;
 245                         break;
 246                 case 'l':
 247                         label = optarg;
 248                         break;
 249                 case 'L':
 250                         label = getenv(optarg);
 251                         break;
 252                 case 'j':
 253                         errno = 0;
 254                         argj = strtol(optarg, &eptr, 10);
 255                         if (errno != 0 || argj == LONG_MAX ||
 256                             argj == LONG_MIN || argj <= 0 ||
 257                             argj > UINT_MAX || *eptr != '\0') {
 258                                 ctfconvert_fatal("invalid argument for -j: "
 259                                     "%s\n", optarg);
 260                         }
 261                         nthreads = (uint_t)argj;
 262                         break;
 263                 case 'o':
 264                         outfile = optarg;
 265                         break;
 266                 case 'i':
 267                         flags |= CTF_CONVERT_F_IGNNONC;
 268                         break;
 269                 case 'X':
 270                         optx = B_TRUE;
 271                         break;
 272                 case ':':
 273                         ctfconvert_usage("Option -%c requires an operand\n",
 274                             optopt);
 275                         return (CTFCONVERT_USAGE);
 276                 case '?':
 277                         ctfconvert_usage("Unknown option: -%c\n", optopt);
 278                         return (CTFCONVERT_USAGE);
 279                 }
 280         }
 281
 282         argv += optind;
 283         argc -= optind;
 284
 285         if (argc < 1) {
 286                 ctfconvert_usage("Missing required input file\n");
 287                 return (CTFCONVERT_USAGE);
 288         }
 289         infile = argv[0];
 290
 291         if (elf_version(EV_CURRENT) == EV_NONE)
 292                 ctfconvert_fatal("failed to initialize libelf: library is "
 293                     "out of date\n");
 294
 295         ifd = open(infile, O_RDONLY);
 296         if (ifd < 0) {
 297                 ctfconvert_fatal("failed to open input file %s: %s\n", infile,
 298                     strerror(errno));
 299         }
 300
 301         /*
 302          * By default we remove the input file on failure unless we've been
 303          * given an output file or -k has been specified.
 304          */
 305         if (outfile != NULL && strcmp(infile, outfile) != 0)
 306                 keep = B_TRUE;
 307
 308         ofp = ctf_fdconvert(ifd, label, nthreads, flags, &err, buf,
 309             sizeof (buf));
 310         if (ofp == NULL) {
 311                 /*
 312                  * -i says that we shouldn't concern ourselves with source files
 313                  * that weren't built from C source code in part. Because this
 314                  * has been traditionally used across all of illumos, we still
 315                  * honor it.
 316                  */
 317                 if ((flags & CTF_CONVERT_F_IGNNONC) != 0 &&
 318                     err == ECTF_CONVNOCSRC) {
 319                         exit(CTFCONVERT_OK);
 320                 }
 321                 if (keep == B_FALSE)
 322                         (void) unlink(infile);
 323                 ctfconvert_fatal("CTF conversion failed: %s\n",
 324                     err == ECTF_CONVBKERR ? buf : ctf_errmsg(err));
 325         }
 326
 327         if (optx == B_TRUE)
 328                 ctfconvert_fixup_genunix(ofp);
 329
 330         tmpfile = NULL;
 331         if (outfile == NULL || strcmp(infile, outfile) == 0) {
 332                 if (asprintf(&tmpfile, "%s.ctf", infile) == -1) {
 333                         if (keep == B_FALSE)
 334                                 (void) unlink(infile);
 335                         ctfconvert_fatal("failed to allocate memory for "
 336                             "temporary file: %s\n", strerror(errno));
 337                 }
 338                 outfile = tmpfile;
 339         }
 340         err = ctf_elfwrite(ofp, infile, outfile, CTF_ELFWRITE_F_COMPRESS);
 341         if (err == CTF_ERR) {
 342                 (void) unlink(outfile);
 343                 if (keep == B_FALSE)
 344                         (void) unlink(infile);
 345                 ctfconvert_fatal("failed to write CTF section to output file: "
 346                     "%s", ctf_errmsg(ctf_errno(ofp)));
 347         }
 348         ctf_close(ofp);
 349
 350         if (tmpfile != NULL) {
 351                 if (rename(tmpfile, infile) != 0) {
 352                         int e = errno;
 353                         (void) unlink(outfile);
 354                         if (keep == B_FALSE)
 355                                 (void) unlink(infile);
 356                         ctfconvert_fatal("failed to rename temporary file: "
 357                             "%s\n", strerror(e));
 358                 }
 359         }
 360         free(tmpfile);
 361
 362         return (CTFCONVERT_OK);
 363 }