textclient/src/ecrash.c

   1 /*
   2  * author: David Frascone
   3  *
   4  * eCrash Implementation
   5  *
   6  * eCrash will allow you to capture stack traces in the
   7  * event of a crash, and write those traces to disk, stdout,
   8  * or any other file handle.
   9  *
  10  * modified to integrate closer into citadel by Wilfried Goesgens
  11  *
  12  * vim: ts=4
  13  *
  14  * This program is open source software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 3 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  27  */
  28
  29 #include "sysdep.h"
  30 #include <stdio.h>
  31 #include <unistd.h>
  32 #include <stdlib.h>
  33 #include <stdarg.h>
  34 #include <string.h>
  35 #include <fcntl.h>
  36 #include <syslog.h>
  37 #include <sys/types.h>
  38 #include <sys/stat.h>
  39 #include <pthread.h>
  40 #include <libcitadel.h>
  41 #include "ecrash.h"
  42
  43 #define NIY()   printf("function not implemented yet!\n");
  44 #ifdef HAVE_BACKTRACE
  45 #include <execinfo.h>
  46 static eCrashParameters gbl_params;
  47
  48 static int    gbl_backtraceEntries;
  49 static void **gbl_backtraceBuffer;
  50 static char **gbl_backtraceSymbols;
  51 static int    gbl_backtraceDoneFlag = 0;
  52
  53 static void *stack_frames[50];
  54 static size_t size, NThread;
  55 static char **strings;
  56
  57 /*
  58  * Private structures for our thread list
  59  */
  60 typedef struct thread_list_node{
  61         char *threadName;
  62         pthread_t thread;
  63         int backtraceSignal;
  64         sighandler_t oldHandler;
  65         struct thread_list_node *Next;
  66 } ThreadListNode;
  67
  68 static pthread_mutex_t ThreadListMutex = PTHREAD_MUTEX_INITIALIZER;
  69 static ThreadListNode *ThreadList = NULL;
  70
  71 /*********************************************************************
  72  *********************************************************************
  73  **     P  R  I  V  A  T  E      F  U  N  C  T  I  O  N  S
  74  *********************************************************************
  75  ********************************************************************/
  76
  77
  78 /*!
  79  * Insert a node into our threadList
  80  *
  81  * @param name   Text string indicating our thread
  82  * @param thread Our Thread Id
  83  * @param signo  Signal to create backtrace with
  84  * @param old_handler Our old handler for signo
  85  *
  86  * @returns zero on success
  87  */
  88 static int addThreadToList(char *name, pthread_t thread,int signo,
  89                                            sighandler_t old_handler)
  90 {
  91         ThreadListNode *node;
  92
  93         node = malloc(sizeof(ThreadListNode));
  94         if (!node) return -1;
  95
  96         DPRINTF(ECRASH_DEBUG_VERBOSE,
  97                                         "Adding thread 0x%08x (%s)\n", (unsigned int)thread, name);
  98         node->threadName = strdup(name);
  99         node->thread = thread;
 100         node->backtraceSignal = signo;
 101         node->oldHandler = old_handler;
 102
 103         /* And, add it to the list */
 104         pthread_mutex_lock(&ThreadListMutex);
 105         node->Next = ThreadList;
 106         ThreadList = node;
 107         pthread_mutex_unlock(&ThreadListMutex);
 108
 109         return 0;
 110
 111 } // addThreadToList
 112
 113 /*!
 114  * Remove a node from our threadList
 115  *
 116  * @param thread Our Thread Id
 117  *
 118  * @returns zero on success
 119  */
 120 static int removeThreadFromList(pthread_t thread)
 121 {
 122         ThreadListNode *Probe, *Prev=NULL;
 123         ThreadListNode *Removed = NULL;
 124
 125         DPRINTF(ECRASH_DEBUG_VERBOSE,
 126                                         "Removing thread 0x%08x from list . . .\n", (unsigned int)thread);
 127         pthread_mutex_lock(&ThreadListMutex);
 128         for (Probe=ThreadList;Probe != NULL; Probe = Probe->Next) {
 129                 if (Probe->thread == thread) {
 130                         // We found it!  Unlink it and move on!
 131                         Removed = Probe;
 132                         if (Prev == NULL) { // head of list
 133                                 ThreadList = Probe->Next;
 134                         } else {
 135                                 // Prev != null, so we need to link around ourselves.
 136                                 Prev->Next = Probe->Next;
 137                         }
 138                         Removed->Next = NULL;
 139                         break;
 140                 }
 141
 142                 Prev = Probe;
 143         }
 144         pthread_mutex_unlock(&ThreadListMutex);
 145
 146         // Now, if something is in Removed, free it, and return success
 147         if (Removed) {
 148             DPRINTF(ECRASH_DEBUG_VERBOSE,
 149                                                 "   Found %s -- removing\n", Removed->threadName);
 150                 // Reset the signal handler
 151                 signal(Removed->backtraceSignal, Removed->oldHandler);
 152
 153                 // And free the allocated memory
 154                 free (Removed->threadName);
 155                 free (Removed);
 156
 157                 return 0;
 158         } else {
 159             DPRINTF(ECRASH_DEBUG_VERBOSE,
 160                                                 "   Not Found\n");
 161                 return -1; // Not Found
 162         }
 163 } // removeThreadFromList
 164
 165 /*!
 166  * Print out a line of output to all our destinations
 167  *
 168  * One by one, output a line of text to all of our output destinations.
 169  *
 170  * Return failure if we fail to output to any of them.
 171  *
 172  * @param format   Normal printf style vararg format
 173  *
 174  * @returns nothing// bytes written, or error on failure.
 175  */
 176 static void outputPrintf(char *format, ...)
 177 {
 178         va_list ap;
 179
 180         va_start(ap, format);
 181
 182         vsyslog(LOG_CRIT|LOG_NDELAY|LOG_MAIL, format, ap);
 183 } // outputPrintf
 184
 185
 186
 187 /*!
 188  * Dump our backtrace into a global location
 189  *
 190  * This function will dump out our backtrace into our
 191  * global holding area.
 192  *
 193  */
 194 static void createGlobalBacktrace( void )
 195 {
 196
 197         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 198         for (NThread = 0; NThread < size; NThread++)
 199         {
 200                 syslog(LOG_CRIT|LOG_NDELAY|LOG_MAIL, "RAW: %p  ", stack_frames[NThread]);
 201         }
 202         strings = backtrace_symbols(stack_frames, size);
 203         for (NThread = 0; NThread < size; NThread++) {
 204                 if (strings != NULL) {
 205                         syslog(LOG_CRIT|LOG_NDELAY|LOG_MAIL, "RAW: %p  ", strings[NThread]);
 206                 }
 207         }
 208 } /* createGlobalBacktrace */
 209 static void outputRawtrace( void )
 210 {
 211
 212         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 213         for (NThread = 0; NThread < size; NThread++)
 214         {
 215                 syslog(LOG_CRIT|LOG_NDELAY|LOG_MAIL, "RAW: %p  ", stack_frames[NThread]);
 216         }
 217 } /* createGlobalBacktrace */
 218
 219 /*!
 220  * Print out (to all the fds, etc), or global backtrace
 221  */
 222 static void outputGlobalBacktrace ( void )
 223 {
 224         int i;
 225
 226         for (i=0; i < gbl_backtraceEntries; i++) {
 227                 if (gbl_backtraceSymbols != FALSE) {
 228                         outputPrintf("*      Frame %02x: %s\n",
 229                                      i, gbl_backtraceSymbols[i]);
 230                 } else {
 231                         outputPrintf("*      Frame %02x: %p\n", i,
 232                                      gbl_backtraceBuffer[i]);
 233                 }
 234         }
 235 } // outputGlobalBacktrace
 236
 237 /*!
 238  * Output our current stack's backtrace
 239  */
 240 static void outputBacktrace( void )
 241 {
 242         createGlobalBacktrace();
 243         outputGlobalBacktrace();
 244 } /* outputBacktrace */
 245
 246 static void outputBacktraceThreads( void )
 247 {
 248         ThreadListNode *probe;
 249         int i;
 250
 251         // When we're backtracing, don't worry about the mutex . . hopefully
 252         // we're in a safe place.
 253
 254         for (probe=ThreadList; probe; probe=probe->Next) {
 255                 gbl_backtraceDoneFlag = 0;
 256                 pthread_kill(probe->thread, probe->backtraceSignal);
 257                 for (i=0; i < gbl_params.threadWaitTime; i++) {
 258                         if (gbl_backtraceDoneFlag)
 259                                 break;
 260                         sleep(1);
 261                 }
 262                 if (gbl_backtraceDoneFlag) {
 263                         outputPrintf("*  Backtrace of \"%s\" (0x%08x)\n",
 264                                                  probe->threadName, (unsigned int)probe->thread);
 265                         outputGlobalBacktrace();
 266                 } else {
 267                         outputPrintf("*  Error: unable to get backtrace of \"%s\" (0x%08x)\n",
 268                                                  probe->threadName, (unsigned int)probe->thread);
 269                 }
 270                 outputPrintf("*\n");
 271         }
 272 } // outputBacktraceThreads
 273
 274
 275 /*!
 276  * Handle signals (crash signals)
 277  *
 278  * This function will catch all crash signals, and will output the
 279  * crash dump.
 280  *
 281  * It will physically write (and sync) the current thread's information
 282  * before it attempts to send signals to other threads.
 283  *
 284  * @param signum Signal received.
 285  */
 286 static void crash_handler(int signo)
 287 {
 288         outputRawtrace();
 289         outputPrintf("*********************************************************\n");
 290         outputPrintf("*               eCrash Crash Handler\n");
 291         outputPrintf("*********************************************************\n");
 292         outputPrintf("*\n");
 293         outputPrintf("*  Got a crash! signo=%d\n", signo);
 294         outputPrintf("*\n");
 295         outputPrintf("*  Offending Thread's Backtrace:\n");
 296         outputPrintf("*\n");
 297         outputBacktrace();
 298         outputPrintf("*\n");
 299
 300         if (gbl_params.dumpAllThreads != FALSE) {
 301                 outputBacktraceThreads();
 302         }
 303
 304         outputPrintf("*\n");
 305         outputPrintf("*********************************************************\n");
 306         outputPrintf("*               eCrash Crash Handler\n");
 307         outputPrintf("*********************************************************\n");
 308
 309         exit(signo);
 310 } // crash_handler
 311
 312 /*!
 313  * Handle signals (bt signals)
 314  *
 315  * This function shoudl be called to generate a crashdump into our
 316  * global area.  Once the dump has been completed, this function will
 317  * return after tickling a global.  Since mutexes are not async
 318  * signal safe, the main thread, after signaling us to generate our
 319  * own backtrace, will sleep for a few seconds waiting for us to complete.
 320  *
 321  * @param signum Signal received.
 322  */
 323 static void bt_handler(int signo)
 324 {
 325         createGlobalBacktrace();
 326         gbl_backtraceDoneFlag=1;
 327 } // bt_handler
 328
 329 /*!
 330  * Validate a passed-in symbol table
 331  *
 332  * For now, just print it out (if verbose), and make sure it's
 333  * sorted and none of the pointers are zero.
 334  */
 335 static int ValidateSymbolTable( void )
 336 {
 337         int i;
 338         int rc=0;
 339         unsigned long lastAddress =0;
 340
 341         // Get out of here if the table is empty
 342         if (!gbl_params.symbolTable) return 0;
 343
 344         // Dump it in verbose mode
 345         DPRINTF(ECRASH_DEBUG_VERBOSE,
 346                                         "Symbol Table Provided with %d symbols\n",
 347                                         gbl_params.symbolTable->numSymbols);
 348         for (i=0; i < gbl_params.symbolTable->numSymbols; i++){
 349                 // Dump it in verbose mode
 350                 DPRINTF(ECRASH_DEBUG_VERBOSE,
 351                                 "%-30s %p\n",
 352                                 gbl_params.symbolTable->symbols[i].function,
 353                                 gbl_params.symbolTable->symbols[i].address);
 354                 if (lastAddress >
 355                     (unsigned long)gbl_params.symbolTable->symbols[i].address) {
 356                         DPRINTF(ECRASH_DEBUG_ERROR,
 357                                         "Error: symbol table is not sorted (last=%p, current=%p)\n",
 358                                         (void *)lastAddress,
 359                                         gbl_params.symbolTable->symbols[i].address);
 360                         rc = -1;
 361                 }
 362
 363         } // for
 364
 365         return rc;
 366
 367 } // ValidateSymbolTable
 368
 369 /*********************************************************************
 370  *********************************************************************
 371  **      P  U  B  L  I  C      F  U  N  C  T  I  O  N  S
 372  *********************************************************************
 373  ********************************************************************/
 374
 375 /*!
 376  * Initialize eCrash.
 377  *
 378  * This function must be called before calling any other eCrash
 379  * functions.  It sets up the global behavior of the system, and
 380  * registers the calling thread for crash dumps.
 381  *
 382  * @param params Our input parameters.  The passed in structure will be copied.
 383  *
 384  * @return Zero on success.
 385  */
 386 int eCrash_Init(eCrashParameters *params)
 387 {
 388         int sigIndex;
 389         int ret = 0;
 390 #ifdef DO_SIGNALS_RIGHT
 391         sigset_t blocked;
 392         struct sigaction act;
 393 #endif
 394
 395         DPRINTF(ECRASH_DEBUG_VERY_VERBOSE,"Init Starting params = %p\n", params);
 396
 397         // Allocate our backtrace area
 398         gbl_backtraceBuffer = malloc(sizeof(void *) * (params->maxStackDepth+5));
 399
 400 #ifdef DO_SIGNALS_RIGHT
 401         sigemptyset(&blocked);
 402         act.sa_sigaction = crash_handler;
 403         act.sa_mask = blocked;
 404         act.sa_flags = SA_SIGINFO;
 405 #endif
 406
 407         if (params != NULL) {
 408                 // Make ourselves a global copy of params.
 409                 gbl_params = *params;
 410                 gbl_params.filename = strdup(params->filename);
 411
 412                 // Set our defaults, if they weren't specified
 413                 if (gbl_params.maxStackDepth == 0 )
 414                         gbl_params.maxStackDepth = ECRASH_DEFAULT_STACK_DEPTH;
 415
 416                 if (gbl_params.defaultBacktraceSignal == 0 )
 417                         gbl_params.defaultBacktraceSignal = ECRASH_DEFAULT_BACKTRACE_SIGNAL;
 418
 419                 if (gbl_params.threadWaitTime == 0 )
 420                         gbl_params.threadWaitTime = ECRASH_DEFAULT_THREAD_WAIT_TIME;
 421
 422                 if (gbl_params.debugLevel == 0 )
 423                         gbl_params.debugLevel = ECRASH_DEBUG_DEFAULT;
 424
 425                 // Copy our symbol table
 426                 if (gbl_params.symbolTable) {
 427                     DPRINTF(ECRASH_DEBUG_VERBOSE,
 428                                                         "symbolTable @ %p -- %d symbols\n", gbl_params.symbolTable,
 429                                                 gbl_params.symbolTable->numSymbols);
 430                         // Make a copy of our symbol table
 431                         gbl_params.symbolTable = malloc(sizeof(eCrashSymbolTable));
 432                         memcpy(gbl_params.symbolTable, params->symbolTable,
 433                                    sizeof(eCrashSymbolTable));
 434
 435                         // Now allocate / copy the actual table.
 436                         gbl_params.symbolTable->symbols = malloc(sizeof(eCrashSymbol) *
 437                                                                      gbl_params.symbolTable->numSymbols);
 438                         memcpy(gbl_params.symbolTable->symbols,
 439                                    params->symbolTable->symbols,
 440                                    sizeof(eCrashSymbol) * gbl_params.symbolTable->numSymbols);
 441
 442                         ValidateSymbolTable();
 443                 }
 444
 445                 // And, finally, register for our signals
 446                 for (sigIndex=0; gbl_params.signals[sigIndex] != 0; sigIndex++) {
 447                         DPRINTF(ECRASH_DEBUG_VERY_VERBOSE,
 448                                                         "   Catching signal[%d] %d\n", sigIndex,
 449                                         gbl_params.signals[sigIndex]);
 450
 451                         // I know there's a better way to catch signals with pthreads.
 452                         // I'll do it later TODO
 453                         signal(gbl_params.signals[sigIndex], crash_handler);
 454                 }
 455         } else {
 456                 DPRINTF(ECRASH_DEBUG_ERROR, "   Error:  Null Params!\n");
 457                 ret = -1;
 458         }
 459         DPRINTF(ECRASH_DEBUG_VERY_VERBOSE, "Init Complete ret=%d\n", ret);
 460         return ret;
 461 } /* eCrash_Init */
 462
 463 /*!
 464  * UnInitialize eCrash.
 465  *
 466  * This function may be called to de-activate eCrash, release the
 467  * signal handlers, and free any memory allocated by eCrash.
 468  *
 469  * @return Zero on success.
 470  */
 471 int eCrash_Uninit( void )
 472 {
 473         NIY();
 474
 475         return 0;
 476 } /* eCrash_Uninit */
 477
 478 /*!
 479  * Register a thread for backtracing on crash.
 480  *
 481  * This function must be called by any thread wanting it's stack
 482  * dumped in the event of a crash.  The thread my specify what
 483  * signal should be used, or the default, SIGUSR1 will be used.
 484  *
 485  * @param signo Signal to use to generate dump (default: SIGUSR1)
 486  *
 487  * @return Zero on success.
 488  */
 489 int eCrash_RegisterThread(char *name, int signo)
 490 {
 491         sighandler_t old_handler;
 492
 493         // Register for our signal
 494         if (signo == 0) {
 495                 signo = gbl_params.defaultBacktraceSignal;
 496         }
 497
 498         old_handler = signal(signo, bt_handler);
 499         return addThreadToList(name, pthread_self(), signo, old_handler);
 500
 501 } /* eCrash_RegisterThread */
 502
 503 /*!
 504  * Un-register a thread for stack dumps.
 505  *
 506  * This function may be called to un-register any previously
 507  * registered thread.
 508  *
 509  * @return Zero on success.
 510  */
 511 int eCrash_UnregisterThread( void )
 512 {
 513         return removeThreadFromList(pthread_self());
 514 } /* eCrash_UnregisterThread */
 515
 516 #endif