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 "server.h"
  42 /// #include "sysdep_decls.h"
  43 //#include "support.h"
  44 ///#include "config.h"
  45 //#include "citserver.h"
  46 #include "ecrash.h"
  47
  48 #define NIY()   printf("function not implemented yet!\n");
  49 #ifdef HAVE_BACKTRACE
  50 #include <execinfo.h>
  51 static eCrashParameters gbl_params;
  52
  53 static int    gbl_backtraceEntries;
  54 static void **gbl_backtraceBuffer;
  55 static char **gbl_backtraceSymbols;
  56 static int    gbl_backtraceDoneFlag = 0;
  57
  58 static void *stack_frames[50];
  59 static size_t size, NThread;
  60 static char **strings;
  61
  62 /*
  63  * Private structures for our thread list
  64  */
  65 typedef struct thread_list_node{
  66         char *threadName;
  67         pthread_t thread;
  68         int backtraceSignal;
  69         sighandler_t oldHandler;
  70         struct thread_list_node *Next;
  71 } ThreadListNode;
  72
  73 static pthread_mutex_t ThreadListMutex = PTHREAD_MUTEX_INITIALIZER;
  74 static ThreadListNode *ThreadList = NULL;
  75
  76 /*********************************************************************
  77  *********************************************************************
  78  **     P  R  I  V  A  T  E      F  U  N  C  T  I  O  N  S
  79  *********************************************************************
  80  ********************************************************************/
  81
  82
  83 /*!
  84  * Insert a node into our threadList
  85  *
  86  * @param name   Text string indicating our thread
  87  * @param thread Our Thread Id
  88  * @param signo  Signal to create backtrace with
  89  * @param old_handler Our old handler for signo
  90  *
  91  * @returns zero on success
  92  */
  93 static int addThreadToList(char *name, pthread_t thread,int signo,
  94                                            sighandler_t old_handler)
  95 {
  96         ThreadListNode *node;
  97
  98         node = malloc(sizeof(ThreadListNode));
  99         if (!node) return -1;
 100
 101         DPRINTF(ECRASH_DEBUG_VERBOSE,
 102                                         "Adding thread 0x%08x (%s)\n", (unsigned int)thread, name);
 103         node->threadName = strdup(name);
 104         node->thread = thread;
 105         node->backtraceSignal = signo;
 106         node->oldHandler = old_handler;
 107
 108         /* And, add it to the list */
 109         pthread_mutex_lock(&ThreadListMutex);
 110         node->Next = ThreadList;
 111         ThreadList = node;
 112         pthread_mutex_unlock(&ThreadListMutex);
 113
 114         return 0;
 115
 116 } // addThreadToList
 117
 118 /*!
 119  * Remove a node from our threadList
 120  *
 121  * @param thread Our Thread Id
 122  *
 123  * @returns zero on success
 124  */
 125 static int removeThreadFromList(pthread_t thread)
 126 {
 127         ThreadListNode *Probe, *Prev=NULL;
 128         ThreadListNode *Removed = NULL;
 129
 130         DPRINTF(ECRASH_DEBUG_VERBOSE,
 131                                         "Removing thread 0x%08x from list . . .\n", (unsigned int)thread);
 132         pthread_mutex_lock(&ThreadListMutex);
 133         for (Probe=ThreadList;Probe != NULL; Probe = Probe->Next) {
 134                 if (Probe->thread == thread) {
 135                         // We found it!  Unlink it and move on!
 136                         Removed = Probe;
 137                         if (Prev == NULL) { // head of list
 138                                 ThreadList = Probe->Next;
 139                         } else {
 140                                 // Prev != null, so we need to link around ourselves.
 141                                 Prev->Next = Probe->Next;
 142                         }
 143                         Removed->Next = NULL;
 144                         break;
 145                 }
 146
 147                 Prev = Probe;
 148         }
 149         pthread_mutex_unlock(&ThreadListMutex);
 150
 151         // Now, if something is in Removed, free it, and return success
 152         if (Removed) {
 153             DPRINTF(ECRASH_DEBUG_VERBOSE,
 154                                                 "   Found %s -- removing\n", Removed->threadName);
 155                 // Reset the signal handler
 156                 signal(Removed->backtraceSignal, Removed->oldHandler);
 157
 158                 // And free the allocated memory
 159                 free (Removed->threadName);
 160                 free (Removed);
 161
 162                 return 0;
 163         } else {
 164             DPRINTF(ECRASH_DEBUG_VERBOSE,
 165                                                 "   Not Found\n");
 166                 return -1; // Not Found
 167         }
 168 } // removeThreadFromList
 169
 170 /*!
 171  * Print out a line of output to all our destinations
 172  *
 173  * One by one, output a line of text to all of our output destinations.
 174  *
 175  * Return failure if we fail to output to any of them.
 176  *
 177  * @param format   Normal printf style vararg format
 178  *
 179  * @returns nothing// bytes written, or error on failure.
 180  */
 181 static void outputPrintf(char *format, ...)
 182 {
 183         va_list ap;
 184
 185         va_start(ap, format);
 186
 187         vsyslog(LOG_CRIT|LOG_NDELAY|LOG_MAIL, format, ap);
 188 } // outputPrintf
 189
 190
 191
 192 /*!
 193  * Dump our backtrace into a global location
 194  *
 195  * This function will dump out our backtrace into our
 196  * global holding area.
 197  *
 198  */
 199 static void createGlobalBacktrace( void )
 200 {
 201
 202         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 203         for (NThread = 0; NThread < size; NThread++)
 204         {
 205                 syslog(LOG_CRIT|LOG_NDELAY|LOG_MAIL, "RAW: %p  ", stack_frames[NThread]);
 206         }
 207         strings = backtrace_symbols(stack_frames, size);
 208         for (NThread = 0; NThread < size; NThread++) {
 209                 if (strings != NULL) {
 210                         syslog(LOG_CRIT|LOG_NDELAY|LOG_MAIL, "RAW: %p  ", strings[NThread]);
 211                 }
 212         }
 213 } /* createGlobalBacktrace */
 214 static void outputRawtrace( void )
 215 {
 216
 217         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 218         for (NThread = 0; NThread < size; NThread++)
 219         {
 220                 syslog(LOG_CRIT|LOG_NDELAY|LOG_MAIL, "RAW: %p  ", stack_frames[NThread]);
 221         }
 222 } /* createGlobalBacktrace */
 223
 224 /*!
 225  * Print out (to all the fds, etc), or global backtrace
 226  */
 227 static void outputGlobalBacktrace ( void )
 228 {
 229         int i;
 230
 231         for (i=0; i < gbl_backtraceEntries; i++) {
 232                 if (gbl_backtraceSymbols != FALSE) {
 233                         outputPrintf("*      Frame %02x: %s\n",
 234                                      i, gbl_backtraceSymbols[i]);
 235                 } else {
 236                         outputPrintf("*      Frame %02x: %p\n", i,
 237                                      gbl_backtraceBuffer[i]);
 238                 }
 239         }
 240 } // outputGlobalBacktrace
 241
 242 /*!
 243  * Output our current stack's backtrace
 244  */
 245 static void outputBacktrace( void )
 246 {
 247         createGlobalBacktrace();
 248         outputGlobalBacktrace();
 249 } /* outputBacktrace */
 250
 251 static void outputBacktraceThreads( void )
 252 {
 253         ThreadListNode *probe;
 254         int i;
 255
 256         // When we're backtracing, don't worry about the mutex . . hopefully
 257         // we're in a safe place.
 258
 259         for (probe=ThreadList; probe; probe=probe->Next) {
 260                 gbl_backtraceDoneFlag = 0;
 261                 pthread_kill(probe->thread, probe->backtraceSignal);
 262                 for (i=0; i < gbl_params.threadWaitTime; i++) {
 263                         if (gbl_backtraceDoneFlag)
 264                                 break;
 265                         sleep(1);
 266                 }
 267                 if (gbl_backtraceDoneFlag) {
 268                         outputPrintf("*  Backtrace of \"%s\" (0x%08x)\n",
 269                                                  probe->threadName, (unsigned int)probe->thread);
 270                         outputGlobalBacktrace();
 271                 } else {
 272                         outputPrintf("*  Error: unable to get backtrace of \"%s\" (0x%08x)\n",
 273                                                  probe->threadName, (unsigned int)probe->thread);
 274                 }
 275                 outputPrintf("*\n");
 276         }
 277 } // outputBacktraceThreads
 278
 279
 280 /*!
 281  * Handle signals (crash signals)
 282  *
 283  * This function will catch all crash signals, and will output the
 284  * crash dump.
 285  *
 286  * It will physically write (and sync) the current thread's information
 287  * before it attempts to send signals to other threads.
 288  *
 289  * @param signum Signal received.
 290  */
 291 static void crash_handler(int signo)
 292 {
 293         outputRawtrace();
 294         outputPrintf("*********************************************************\n");
 295         outputPrintf("*               eCrash Crash Handler\n");
 296         outputPrintf("*********************************************************\n");
 297         outputPrintf("*\n");
 298         outputPrintf("*  Got a crash! signo=%d\n", signo);
 299         outputPrintf("*\n");
 300         outputPrintf("*  Offending Thread's Backtrace:\n");
 301         outputPrintf("*\n");
 302         outputBacktrace();
 303         outputPrintf("*\n");
 304
 305         if (gbl_params.dumpAllThreads != FALSE) {
 306                 outputBacktraceThreads();
 307         }
 308
 309         outputPrintf("*\n");
 310         outputPrintf("*********************************************************\n");
 311         outputPrintf("*               eCrash Crash Handler\n");
 312         outputPrintf("*********************************************************\n");
 313
 314         exit(signo);
 315 } // crash_handler
 316
 317 /*!
 318  * Handle signals (bt signals)
 319  *
 320  * This function shoudl be called to generate a crashdump into our
 321  * global area.  Once the dump has been completed, this function will
 322  * return after tickling a global.  Since mutexes are not async
 323  * signal safe, the main thread, after signaling us to generate our
 324  * own backtrace, will sleep for a few seconds waiting for us to complete.
 325  *
 326  * @param signum Signal received.
 327  */
 328 static void bt_handler(int signo)
 329 {
 330         createGlobalBacktrace();
 331         gbl_backtraceDoneFlag=1;
 332 } // bt_handler
 333
 334 /*!
 335  * Validate a passed-in symbol table
 336  *
 337  * For now, just print it out (if verbose), and make sure it's
 338  * sorted and none of the pointers are zero.
 339  */
 340 static int ValidateSymbolTable( void )
 341 {
 342         int i;
 343         int rc=0;
 344         unsigned long lastAddress =0;
 345
 346         // Get out of here if the table is empty
 347         if (!gbl_params.symbolTable) return 0;
 348
 349         // Dump it in verbose mode
 350         DPRINTF(ECRASH_DEBUG_VERBOSE,
 351                                         "Symbol Table Provided with %d symbols\n",
 352                                         gbl_params.symbolTable->numSymbols);
 353         for (i=0; i < gbl_params.symbolTable->numSymbols; i++){
 354                 // Dump it in verbose mode
 355                 DPRINTF(ECRASH_DEBUG_VERBOSE,
 356                                 "%-30s %p\n",
 357                                 gbl_params.symbolTable->symbols[i].function,
 358                                 gbl_params.symbolTable->symbols[i].address);
 359                 if (lastAddress >
 360                     (unsigned long)gbl_params.symbolTable->symbols[i].address) {
 361                         DPRINTF(ECRASH_DEBUG_ERROR,
 362                                         "Error: symbol table is not sorted (last=%p, current=%p)\n",
 363                                         (void *)lastAddress,
 364                                         gbl_params.symbolTable->symbols[i].address);
 365                         rc = -1;
 366                 }
 367
 368         } // for
 369
 370         return rc;
 371
 372 } // ValidateSymbolTable
 373
 374 /*********************************************************************
 375  *********************************************************************
 376  **      P  U  B  L  I  C      F  U  N  C  T  I  O  N  S
 377  *********************************************************************
 378  ********************************************************************/
 379
 380 /*!
 381  * Initialize eCrash.
 382  *
 383  * This function must be called before calling any other eCrash
 384  * functions.  It sets up the global behavior of the system, and
 385  * registers the calling thread for crash dumps.
 386  *
 387  * @param params Our input parameters.  The passed in structure will be copied.
 388  *
 389  * @return Zero on success.
 390  */
 391 int eCrash_Init(eCrashParameters *params)
 392 {
 393         int sigIndex;
 394         int ret = 0;
 395 #ifdef DO_SIGNALS_RIGHT
 396         sigset_t blocked;
 397         struct sigaction act;
 398 #endif
 399
 400         DPRINTF(ECRASH_DEBUG_VERY_VERBOSE,"Init Starting params = %p\n", params);
 401
 402         // Allocate our backtrace area
 403         gbl_backtraceBuffer = malloc(sizeof(void *) * (params->maxStackDepth+5));
 404
 405 #ifdef DO_SIGNALS_RIGHT
 406         sigemptyset(&blocked);
 407         act.sa_sigaction = crash_handler;
 408         act.sa_mask = blocked;
 409         act.sa_flags = SA_SIGINFO;
 410 #endif
 411
 412         if (params != NULL) {
 413                 // Make ourselves a global copy of params.
 414                 gbl_params = *params;
 415                 gbl_params.filename = strdup(params->filename);
 416
 417                 // Set our defaults, if they weren't specified
 418                 if (gbl_params.maxStackDepth == 0 )
 419                         gbl_params.maxStackDepth = ECRASH_DEFAULT_STACK_DEPTH;
 420
 421                 if (gbl_params.defaultBacktraceSignal == 0 )
 422                         gbl_params.defaultBacktraceSignal = ECRASH_DEFAULT_BACKTRACE_SIGNAL;
 423
 424                 if (gbl_params.threadWaitTime == 0 )
 425                         gbl_params.threadWaitTime = ECRASH_DEFAULT_THREAD_WAIT_TIME;
 426
 427                 if (gbl_params.debugLevel == 0 )
 428                         gbl_params.debugLevel = ECRASH_DEBUG_DEFAULT;
 429
 430                 // Copy our symbol table
 431                 if (gbl_params.symbolTable) {
 432                     DPRINTF(ECRASH_DEBUG_VERBOSE,
 433                                                         "symbolTable @ %p -- %d symbols\n", gbl_params.symbolTable,
 434                                                 gbl_params.symbolTable->numSymbols);
 435                         // Make a copy of our symbol table
 436                         gbl_params.symbolTable = malloc(sizeof(eCrashSymbolTable));
 437                         memcpy(gbl_params.symbolTable, params->symbolTable,
 438                                    sizeof(eCrashSymbolTable));
 439
 440                         // Now allocate / copy the actual table.
 441                         gbl_params.symbolTable->symbols = malloc(sizeof(eCrashSymbol) *
 442                                                                      gbl_params.symbolTable->numSymbols);
 443                         memcpy(gbl_params.symbolTable->symbols,
 444                                    params->symbolTable->symbols,
 445                                    sizeof(eCrashSymbol) * gbl_params.symbolTable->numSymbols);
 446
 447                         ValidateSymbolTable();
 448                 }
 449
 450                 // And, finally, register for our signals
 451                 for (sigIndex=0; gbl_params.signals[sigIndex] != 0; sigIndex++) {
 452                         DPRINTF(ECRASH_DEBUG_VERY_VERBOSE,
 453                                                         "   Catching signal[%d] %d\n", sigIndex,
 454                                         gbl_params.signals[sigIndex]);
 455
 456                         // I know there's a better way to catch signals with pthreads.
 457                         // I'll do it later TODO
 458                         signal(gbl_params.signals[sigIndex], crash_handler);
 459                 }
 460         } else {
 461                 DPRINTF(ECRASH_DEBUG_ERROR, "   Error:  Null Params!\n");
 462                 ret = -1;
 463         }
 464         DPRINTF(ECRASH_DEBUG_VERY_VERBOSE, "Init Complete ret=%d\n", ret);
 465         return ret;
 466 } /* eCrash_Init */
 467
 468 /*!
 469  * UnInitialize eCrash.
 470  *
 471  * This function may be called to de-activate eCrash, release the
 472  * signal handlers, and free any memory allocated by eCrash.
 473  *
 474  * @return Zero on success.
 475  */
 476 int eCrash_Uninit( void )
 477 {
 478         NIY();
 479
 480         return 0;
 481 } /* eCrash_Uninit */
 482
 483 /*!
 484  * Register a thread for backtracing on crash.
 485  *
 486  * This function must be called by any thread wanting it's stack
 487  * dumped in the event of a crash.  The thread my specify what
 488  * signal should be used, or the default, SIGUSR1 will be used.
 489  *
 490  * @param signo Signal to use to generate dump (default: SIGUSR1)
 491  *
 492  * @return Zero on success.
 493  */
 494 int eCrash_RegisterThread(char *name, int signo)
 495 {
 496         sighandler_t old_handler;
 497
 498         // Register for our signal
 499         if (signo == 0) {
 500                 signo = gbl_params.defaultBacktraceSignal;
 501         }
 502
 503         old_handler = signal(signo, bt_handler);
 504         return addThreadToList(name, pthread_self(), signo, old_handler);
 505
 506 } /* eCrash_RegisterThread */
 507
 508 /*!
 509  * Un-register a thread for stack dumps.
 510  *
 511  * This function may be called to un-register any previously
 512  * registered thread.
 513  *
 514  * @return Zero on success.
 515  */
 516 int eCrash_UnregisterThread( void )
 517 {
 518         return removeThreadFromList(pthread_self());
 519 } /* eCrash_UnregisterThread */
 520
 521 #endif