gdb/proc-api.c

   1 /* Machine independent support for Solaris /proc (process file system) for GDB.
   2
   3    Copyright (C) 1999-2022 Free Software Foundation, Inc.
   4
   5    Written by Michael Snyder at Cygnus Solutions.
   6    Based on work by Fred Fish, Stu Grossman, Geoff Noer, and others.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 /*
  24  * Pretty-print trace of api calls to the /proc api
  25  */
  26
  27 #include "defs.h"
  28 #include "gdbcmd.h"
  29 #include "completer.h"
  30
  31 #include <sys/types.h>
  32 #include <sys/procfs.h>
  33 #include <sys/proc.h>   /* for struct proc */
  34 #include <sys/user.h>   /* for struct user */
  35 #include <fcntl.h>      /* for O_RDWR etc.  */
  36 #include "gdbsupport/gdb_wait.h"
  37
  38 #include "proc-utils.h"
  39
  40 /*  Much of the information used in the /proc interface, particularly for
  41     printing status information, is kept as tables of structures of the
  42     following form.  These tables can be used to map numeric values to
  43     their symbolic names and to a string that describes their specific use.  */
  44
  45 struct trans {
  46   long value;                   /* The numeric value */
  47   const char *name;             /* The equivalent symbolic value */
  48   const char *desc;             /* Short description of value */
  49 };
  50
  51 static bool  procfs_trace   = false;
  52 static FILE *procfs_file     = NULL;
  53 static std::string procfs_filename = "procfs_trace";
  54
  55 static void
  56 prepare_to_trace (void)
  57 {
  58   if (procfs_trace)                     /* if procfs tracing turned on */
  59     if (procfs_file == NULL)            /* if output file not yet open */
  60       procfs_file = fopen (procfs_filename.c_str (), "a");      /* open output file */
  61 }
  62
  63 static void
  64 set_procfs_trace_cmd (const char *args,
  65                       int from_tty, struct cmd_list_element *c)
  66 {
  67 #if 0   /* not sure what I might actually need to do here, if anything */
  68   if (procfs_file)
  69     fflush (procfs_file);
  70 #endif
  71 }
  72
  73 static void
  74 set_procfs_file_cmd (const char *args,
  75                      int from_tty, struct cmd_list_element *c)
  76 {
  77   /* Just changed the filename for procfs tracing.
  78      If a file was already open, close it.  */
  79   if (procfs_file)
  80     fclose (procfs_file);
  81   procfs_file = NULL;
  82 }
  83
  84 static struct trans rw_table[] = {
  85   { PCAGENT,  "PCAGENT",  "create agent lwp with regs from argument" },
  86   { PCCFAULT, "PCCFAULT", "clear current fault" },
  87   { PCCSIG,   "PCCSIG",   "clear current signal" },
  88   { PCDSTOP,  "PCDSTOP",  "post stop request" },
  89   { PCKILL,   "PCKILL",   "post a signal" },
  90   { PCNICE,   "PCNICE",   "set nice priority" },
  91   { PCREAD,   "PCREAD",   "read from the address space" },
  92   { PCWRITE,  "PCWRITE",  "write to the address space" },
  93   { PCRUN,    "PCRUN",    "make process/lwp runnable" },
  94   { PCSASRS,  "PCSASRS",  "set ancillary state registers" },
  95   { PCSCRED,  "PCSCRED",  "set process credentials" },
  96   { PCSENTRY, "PCSENTRY", "set traced syscall entry set" },
  97   { PCSET,    "PCSET",    "set modes" },
  98   { PCSEXIT,  "PCSEXIT",  "set traced syscall exit  set" },
  99   { PCSFAULT, "PCSFAULT", "set traced fault set" },
 100   { PCSFPREG, "PCSFPREG", "set floating point registers" },
 101   { PCSHOLD,  "PCSHOLD",  "set signal mask" },
 102   { PCSREG,   "PCSREG",   "set general registers" },
 103   { PCSSIG,   "PCSSIG",   "set current signal" },
 104   { PCSTOP,   "PCSTOP",   "post stop request and wait" },
 105   { PCSTRACE, "PCSTRACE", "set traced signal set" },
 106   { PCSVADDR, "PCSVADDR", "set pc virtual address" },
 107   { PCSXREG,  "PCSXREG",  "set extra registers" },
 108   { PCTWSTOP, "PCTWSTOP", "wait for stop, with timeout arg" },
 109   { PCUNKILL, "PCUNKILL", "delete a pending signal" },
 110   { PCUNSET,  "PCUNSET",  "unset modes" },
 111   { PCWATCH,  "PCWATCH",  "set/unset watched memory area" },
 112   { PCWSTOP,  "PCWSTOP",  "wait for process/lwp to stop, no timeout" },
 113   { 0,        NULL,      NULL }
 114 };
 115
 116 static off_t lseek_offset;
 117
 118 int
 119 write_with_trace (int fd, void *varg, size_t len, char *file, int line)
 120 {
 121   int i = ARRAY_SIZE (rw_table) - 1;
 122   int ret;
 123   procfs_ctl_t *arg = (procfs_ctl_t *) varg;
 124
 125   prepare_to_trace ();
 126   if (procfs_trace)
 127     {
 128       procfs_ctl_t opcode = arg[0];
 129       for (i = 0; rw_table[i].name != NULL; i++)
 130         if (rw_table[i].value == opcode)
 131           break;
 132
 133       if (info_verbose)
 134         fprintf (procfs_file ? procfs_file : stdout,
 135                  "%s:%d -- ", file, line);
 136       switch (opcode) {
 137       case PCSET:
 138         fprintf (procfs_file ? procfs_file : stdout,
 139                  "write (PCSET,   %s) %s\n",
 140                  arg[1] == PR_FORK  ? "PR_FORK"  :
 141                  arg[1] == PR_RLC   ? "PR_RLC"   :
 142                  arg[1] == PR_ASYNC ? "PR_ASYNC" :
 143                  "<unknown flag>",
 144                  info_verbose ? rw_table[i].desc : "");
 145         break;
 146       case PCUNSET:
 147         fprintf (procfs_file ? procfs_file : stdout,
 148                  "write (PCRESET, %s) %s\n",
 149                  arg[1] == PR_FORK  ? "PR_FORK"  :
 150                  arg[1] == PR_RLC   ? "PR_RLC"   :
 151                  arg[1] == PR_ASYNC ? "PR_ASYNC" :
 152                  "<unknown flag>",
 153                  info_verbose ? rw_table[i].desc : "");
 154         break;
 155       case PCSTRACE:
 156         fprintf (procfs_file ? procfs_file : stdout,
 157                  "write (PCSTRACE) ");
 158         proc_prettyfprint_signalset (procfs_file ? procfs_file : stdout,
 159                                      (sigset_t *) &arg[1], 0);
 160         break;
 161       case PCSFAULT:
 162         fprintf (procfs_file ? procfs_file : stdout,
 163                  "write (PCSFAULT) ");
 164         proc_prettyfprint_faultset (procfs_file ? procfs_file : stdout,
 165                                     (fltset_t *) &arg[1], 0);
 166         break;
 167       case PCSENTRY:
 168         fprintf (procfs_file ? procfs_file : stdout,
 169                  "write (PCSENTRY) ");
 170         proc_prettyfprint_syscalls (procfs_file ? procfs_file : stdout,
 171                                     (sysset_t *) &arg[1], 0);
 172         break;
 173       case PCSEXIT:
 174         fprintf (procfs_file ? procfs_file : stdout,
 175                  "write (PCSEXIT) ");
 176         proc_prettyfprint_syscalls (procfs_file ? procfs_file : stdout,
 177                                     (sysset_t *) &arg[1], 0);
 178         break;
 179       case PCSHOLD:
 180         fprintf (procfs_file ? procfs_file : stdout,
 181                  "write (PCSHOLD) ");
 182         proc_prettyfprint_signalset (procfs_file ? procfs_file : stdout,
 183                                      (sigset_t *) &arg[1], 0);
 184         break;
 185       case PCSSIG:
 186         fprintf (procfs_file ? procfs_file : stdout,
 187                  "write (PCSSIG) ");
 188         proc_prettyfprint_signal (procfs_file ? procfs_file : stdout,
 189                                   arg[1] ? ((siginfo_t *) &arg[1])->si_signo
 190                                          : 0,
 191                                   0);
 192         fprintf (procfs_file ? procfs_file : stdout, "\n");
 193         break;
 194       case PCRUN:
 195         fprintf (procfs_file ? procfs_file : stdout,
 196                  "write (PCRUN) ");
 197         if (arg[1] & PRCSIG)
 198           fprintf (procfs_file ? procfs_file : stdout, "clearSig ");
 199         if (arg[1] & PRCFAULT)
 200           fprintf (procfs_file ? procfs_file : stdout, "clearFlt ");
 201         if (arg[1] & PRSTEP)
 202           fprintf (procfs_file ? procfs_file : stdout, "step ");
 203         if (arg[1] & PRSABORT)
 204           fprintf (procfs_file ? procfs_file : stdout, "syscallAbort ");
 205         if (arg[1] & PRSTOP)
 206           fprintf (procfs_file ? procfs_file : stdout, "stopReq ");
 207
 208         fprintf (procfs_file ? procfs_file : stdout, "\n");
 209         break;
 210       case PCKILL:
 211         fprintf (procfs_file ? procfs_file : stdout,
 212                  "write (PCKILL) ");
 213         proc_prettyfprint_signal (procfs_file ? procfs_file : stdout,
 214                                   arg[1], 0);
 215         fprintf (procfs_file ? procfs_file : stdout, "\n");
 216         break;
 217       default:
 218         {
 219           if (rw_table[i].name)
 220             fprintf (procfs_file ? procfs_file : stdout,
 221                      "write (%s) %s\n",
 222                      rw_table[i].name,
 223                      info_verbose ? rw_table[i].desc : "");
 224           else
 225             {
 226               if (lseek_offset != -1)
 227                 fprintf (procfs_file ? procfs_file : stdout,
 228                          "write (<unknown>, %lud bytes at 0x%08lx) \n",
 229                          (unsigned long) len, (unsigned long) lseek_offset);
 230               else
 231                 fprintf (procfs_file ? procfs_file : stdout,
 232                          "write (<unknown>, %lud bytes) \n",
 233                          (unsigned long) len);
 234             }
 235           break;
 236         }
 237       }
 238       if (procfs_file)
 239         fflush (procfs_file);
 240     }
 241   errno = 0;
 242   ret = write (fd, (void *) arg, len);
 243   if (procfs_trace && ret != len)
 244     {
 245       fprintf (procfs_file ? procfs_file : stdout,
 246                "[write (%s) FAILED! (%s)]\n",
 247                rw_table[i].name != NULL ?
 248                rw_table[i].name : "<unknown>",
 249                safe_strerror (errno));
 250       if (procfs_file)
 251         fflush (procfs_file);
 252     }
 253
 254   lseek_offset = -1;
 255   return ret;
 256 }
 257
 258 off_t
 259 lseek_with_trace (int fd, off_t offset, int whence, char *file, int line)
 260 {
 261   off_t ret;
 262
 263   prepare_to_trace ();
 264   errno = 0;
 265   ret = lseek (fd, offset, whence);
 266   lseek_offset = ret;
 267   if (procfs_trace && (ret == -1 || errno != 0))
 268     {
 269       fprintf (procfs_file ? procfs_file : stdout,
 270                "[lseek (0x%08lx) FAILED! (%s)]\n",
 271                (unsigned long) offset, safe_strerror (errno));
 272       if (procfs_file)
 273         fflush (procfs_file);
 274     }
 275
 276   return ret;
 277 }
 278
 279 int
 280 open_with_trace (char *filename, int mode, char *file, int line)
 281 {
 282   int ret;
 283
 284   prepare_to_trace ();
 285   errno = 0;
 286   ret = open (filename, mode);
 287   if (procfs_trace)
 288     {
 289       if (info_verbose)
 290         fprintf (procfs_file ? procfs_file : stdout,
 291                  "%s:%d -- ", file, line);
 292
 293       if (errno)
 294         {
 295           fprintf (procfs_file ? procfs_file : stdout,
 296                    "[open FAILED! (%s) line %d]\\n",
 297                    safe_strerror (errno), line);
 298         }
 299       else
 300         {
 301           fprintf (procfs_file ? procfs_file : stdout,
 302                    "%d = open (%s, ", ret, filename);
 303           if (mode == O_RDONLY)
 304             fprintf (procfs_file ? procfs_file : stdout, "O_RDONLY) %d\n",
 305                      line);
 306           else if (mode == O_WRONLY)
 307             fprintf (procfs_file ? procfs_file : stdout, "O_WRONLY) %d\n",
 308                      line);
 309           else if (mode == O_RDWR)
 310             fprintf (procfs_file ? procfs_file : stdout, "O_RDWR)   %d\n",
 311                      line);
 312         }
 313       if (procfs_file)
 314         fflush (procfs_file);
 315     }
 316
 317   return ret;
 318 }
 319
 320 int
 321 close_with_trace (int fd, char *file, int line)
 322 {
 323   int ret;
 324
 325   prepare_to_trace ();
 326   errno = 0;
 327   ret = close (fd);
 328   if (procfs_trace)
 329     {
 330       if (info_verbose)
 331         fprintf (procfs_file ? procfs_file : stdout,
 332                  "%s:%d -- ", file, line);
 333       if (errno)
 334         fprintf (procfs_file ? procfs_file : stdout,
 335                  "[close FAILED! (%s)]\n", safe_strerror (errno));
 336       else
 337         fprintf (procfs_file ? procfs_file : stdout,
 338                  "%d = close (%d)\n", ret, fd);
 339       if (procfs_file)
 340         fflush (procfs_file);
 341     }
 342
 343   return ret;
 344 }
 345
 346 pid_t
 347 wait_with_trace (int *wstat, char *file, int line)
 348 {
 349   int ret, lstat = 0;
 350
 351   prepare_to_trace ();
 352   if (procfs_trace)
 353     {
 354       if (info_verbose)
 355         fprintf (procfs_file ? procfs_file : stdout,
 356                  "%s:%d -- ", file, line);
 357       fprintf (procfs_file ? procfs_file : stdout,
 358                "wait (line %d) ", line);
 359       if (procfs_file)
 360         fflush (procfs_file);
 361     }
 362   errno = 0;
 363   ret = wait (&lstat);
 364   if (procfs_trace)
 365     {
 366       if (errno)
 367         fprintf (procfs_file ? procfs_file : stdout,
 368                  "[wait FAILED! (%s)]\n", safe_strerror (errno));
 369       else
 370         fprintf (procfs_file ? procfs_file : stdout,
 371                  "returned pid %d, status 0x%x\n", ret, lstat);
 372       if (procfs_file)
 373         fflush (procfs_file);
 374     }
 375   if (wstat)
 376     *wstat = lstat;
 377
 378   return ret;
 379 }
 380
 381 void
 382 procfs_note (const char *msg, const char *file, int line)
 383 {
 384   prepare_to_trace ();
 385   if (procfs_trace)
 386     {
 387       if (info_verbose)
 388         fprintf (procfs_file ? procfs_file : stdout,
 389                  "%s:%d -- ", file, line);
 390       fprintf (procfs_file ? procfs_file : stdout, "%s", msg);
 391       if (procfs_file)
 392         fflush (procfs_file);
 393     }
 394 }
 395
 396 void
 397 proc_prettyfprint_status (long flags, int why, int what, int thread)
 398 {
 399   prepare_to_trace ();
 400   if (procfs_trace)
 401     {
 402       if (thread)
 403         fprintf (procfs_file ? procfs_file : stdout,
 404                  "Thread %d: ", thread);
 405
 406       proc_prettyfprint_flags (procfs_file ? procfs_file : stdout,
 407                                flags, 0);
 408
 409       if (flags & (PR_STOPPED | PR_ISTOP))
 410         proc_prettyfprint_why (procfs_file ? procfs_file : stdout,
 411                                why, what, 0);
 412       if (procfs_file)
 413         fflush (procfs_file);
 414     }
 415 }
 416
 417 void _initialize_proc_api ();
 418 void
 419 _initialize_proc_api ()
 420 {
 421   add_setshow_boolean_cmd ("procfs-trace", no_class, &procfs_trace, _("\
 422 Set tracing for /proc api calls."), _("\
 423 Show tracing for /proc api calls."), NULL,
 424                            set_procfs_trace_cmd,
 425                            NULL, /* FIXME: i18n: */
 426                            &setlist, &showlist);
 427
 428   add_setshow_filename_cmd ("procfs-file", no_class, &procfs_filename, _("\
 429 Set filename for /proc tracefile."), _("\
 430 Show filename for /proc tracefile."), NULL,
 431                             set_procfs_file_cmd,
 432                             NULL, /* FIXME: i18n: */
 433                             &setlist, &showlist);
 434 }