gdb/thread-db.c

   1 /* libthread_db assisted debugging support, generic parts.
   2    Copyright 1999, 2000, 2001 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include "defs.h"
  22
  23 #include "gdb_assert.h"
  24 #include <dlfcn.h>
  25 #include "gdb_proc_service.h"
  26 #include "gdb_thread_db.h"
  27
  28 #include "bfd.h"
  29 #include "gdbthread.h"
  30 #include "inferior.h"
  31 #include "symfile.h"
  32 #include "objfiles.h"
  33 #include "target.h"
  34 #include "regcache.h"
  35
  36 #ifndef LIBTHREAD_DB_SO
  37 #define LIBTHREAD_DB_SO "libthread_db.so.1"
  38 #endif
  39
  40 /* If we're running on GNU/Linux, we must explicitly attach to any new
  41    threads.  */
  42
  43 /* FIXME: There is certainly some room for improvements:
  44    - Cache LWP ids.
  45    - Bypass libthread_db when fetching or storing registers for
  46    threads bound to a LWP.  */
  47
  48 /* This module's target vector.  */
  49 static struct target_ops thread_db_ops;
  50
  51 /* The target vector that we call for things this module can't handle.  */
  52 static struct target_ops *target_beneath;
  53
  54 /* Pointer to the next function on the objfile event chain.  */
  55 static void (*target_new_objfile_chain) (struct objfile *objfile);
  56
  57 /* Non-zero if we're using this module's target vector.  */
  58 static int using_thread_db;
  59
  60 /* Non-zero if we have to keep this module's target vector active
  61    across re-runs.  */
  62 static int keep_thread_db;
  63
  64 /* Non-zero if we have determined the signals used by the threads
  65    library.  */
  66 static int thread_signals;
  67 static sigset_t thread_stop_set;
  68 static sigset_t thread_print_set;
  69
  70 /* Structure that identifies the child process for the
  71    <proc_service.h> interface.  */
  72 static struct ps_prochandle proc_handle;
  73
  74 /* Connection to the libthread_db library.  */
  75 static td_thragent_t *thread_agent;
  76
  77 /* Pointers to the libthread_db functions.  */
  78
  79 static td_err_e (*td_init_p) (void);
  80
  81 static td_err_e (*td_ta_new_p) (struct ps_prochandle *ps, td_thragent_t **ta);
  82 static td_err_e (*td_ta_map_id2thr_p) (const td_thragent_t *ta, thread_t pt,
  83                                        td_thrhandle_t *__th);
  84 static td_err_e (*td_ta_map_lwp2thr_p) (const td_thragent_t *ta, lwpid_t lwpid,
  85                                         td_thrhandle_t *th);
  86 static td_err_e (*td_ta_thr_iter_p) (const td_thragent_t *ta,
  87                                      td_thr_iter_f *callback,
  88                                      void *cbdata_p, td_thr_state_e state,
  89                                      int ti_pri, sigset_t *ti_sigmask_p,
  90                                      unsigned int ti_user_flags);
  91 static td_err_e (*td_ta_event_addr_p) (const td_thragent_t *ta,
  92                                        td_event_e event, td_notify_t *ptr);
  93 static td_err_e (*td_ta_set_event_p) (const td_thragent_t *ta,
  94                                       td_thr_events_t *event);
  95 static td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta,
  96                                          td_event_msg_t *msg);
  97
  98 static td_err_e (*td_thr_validate_p) (const td_thrhandle_t *th);
  99 static td_err_e (*td_thr_get_info_p) (const td_thrhandle_t *th,
 100                                       td_thrinfo_t *infop);
 101 static td_err_e (*td_thr_getfpregs_p) (const td_thrhandle_t *th,
 102                                        gdb_prfpregset_t *regset);
 103 static td_err_e (*td_thr_getgregs_p) (const td_thrhandle_t *th,
 104                                       prgregset_t gregs);
 105 static td_err_e (*td_thr_setfpregs_p) (const td_thrhandle_t *th,
 106                                        const gdb_prfpregset_t *fpregs);
 107 static td_err_e (*td_thr_setgregs_p) (const td_thrhandle_t *th,
 108                                       prgregset_t gregs);
 109 static td_err_e (*td_thr_event_enable_p) (const td_thrhandle_t *th, int event);
 110
 111 /* Location of the thread creation event breakpoint.  The code at this
 112    location in the child process will be called by the pthread library
 113    whenever a new thread is created.  By setting a special breakpoint
 114    at this location, GDB can detect when a new thread is created.  We
 115    obtain this location via the td_ta_event_addr call.  */
 116 static CORE_ADDR td_create_bp_addr;
 117
 118 /* Location of the thread death event breakpoint.  */
 119 static CORE_ADDR td_death_bp_addr;
 120
 121 /* Prototypes for local functions.  */
 122 static void thread_db_find_new_threads (void);
 123 \f
 124
 125 /* Building process ids.  */
 126
 127 #define GET_PID(ptid)           ptid_get_pid (ptid)
 128 #define GET_LWP(ptid)           ptid_get_lwp (ptid)
 129 #define GET_THREAD(ptid)        ptid_get_tid (ptid)
 130
 131 #define is_lwp(ptid)            (GET_LWP (ptid) != 0)
 132 #define is_thread(ptid)         (GET_THREAD (ptid) != 0)
 133
 134 #define BUILD_LWP(lwp, pid)     ptid_build (pid, lwp, 0)
 135 #define BUILD_THREAD(tid, pid)  ptid_build (pid, 0, tid)
 136 \f
 137
 138 struct private_thread_info
 139 {
 140   /* Cached LWP id.  Must come first, see lin-lwp.c.  */
 141   lwpid_t lwpid;
 142 };
 143 \f
 144
 145 static char *
 146 thread_db_err_str (td_err_e err)
 147 {
 148   static char buf[64];
 149
 150   switch (err)
 151     {
 152     case TD_OK:
 153       return "generic 'call succeeded'";
 154     case TD_ERR:
 155       return "generic error";
 156     case TD_NOTHR:
 157       return "no thread to satisfy query";
 158     case TD_NOSV:
 159       return "no sync handle to satisfy query";
 160     case TD_NOLWP:
 161       return "no LWP to satisfy query";
 162     case TD_BADPH:
 163       return "invalid process handle";
 164     case TD_BADTH:
 165       return "invalid thread handle";
 166     case TD_BADSH:
 167       return "invalid synchronization handle";
 168     case TD_BADTA:
 169       return "invalid thread agent";
 170     case TD_BADKEY:
 171       return "invalid key";
 172     case TD_NOMSG:
 173       return "no event message for getmsg";
 174     case TD_NOFPREGS:
 175       return "FPU register set not available";
 176     case TD_NOLIBTHREAD:
 177       return "application not linked with libthread";
 178     case TD_NOEVENT:
 179       return "requested event is not supported";
 180     case TD_NOCAPAB:
 181       return "capability not available";
 182     case TD_DBERR:
 183       return "debugger service failed";
 184     case TD_NOAPLIC:
 185       return "operation not applicable to";
 186     case TD_NOTSD:
 187       return "no thread-specific data for this thread";
 188     case TD_MALLOC:
 189       return "malloc failed";
 190     case TD_PARTIALREG:
 191       return "only part of register set was written/read";
 192     case TD_NOXREGS:
 193       return "X register set not available for this thread";
 194     default:
 195       snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err);
 196       return buf;
 197     }
 198 }
 199
 200 static char *
 201 thread_db_state_str (td_thr_state_e state)
 202 {
 203   static char buf[64];
 204
 205   switch (state)
 206     {
 207     case TD_THR_STOPPED:
 208       return "stopped by debugger";
 209     case TD_THR_RUN:
 210       return "runnable";
 211     case TD_THR_ACTIVE:
 212       return "active";
 213     case TD_THR_ZOMBIE:
 214       return "zombie";
 215     case TD_THR_SLEEP:
 216       return "sleeping";
 217     case TD_THR_STOPPED_ASLEEP:
 218       return "stopped by debugger AND blocked";
 219     default:
 220       snprintf (buf, sizeof (buf), "unknown thread_db state %d", state);
 221       return buf;
 222     }
 223 }
 224 \f
 225
 226 /* Convert between user-level thread ids and LWP ids.  */
 227
 228 static ptid_t
 229 thread_from_lwp (ptid_t ptid)
 230 {
 231   td_thrinfo_t ti;
 232   td_thrhandle_t th;
 233   td_err_e err;
 234
 235   if (GET_LWP (ptid) == 0)
 236     ptid = BUILD_LWP (GET_PID (ptid), GET_PID (ptid));
 237
 238   gdb_assert (is_lwp (ptid));
 239
 240   err = td_ta_map_lwp2thr_p (thread_agent, GET_LWP (ptid), &th);
 241   if (err != TD_OK)
 242     error ("Cannot find user-level thread for LWP %ld: %s",
 243            GET_LWP (ptid), thread_db_err_str (err));
 244
 245   err = td_thr_get_info_p (&th, &ti);
 246   if (err != TD_OK)
 247     error ("Cannot get thread info: %s", thread_db_err_str (err));
 248
 249   return BUILD_THREAD (ti.ti_tid, GET_PID (ptid));
 250 }
 251
 252 static ptid_t
 253 lwp_from_thread (ptid_t ptid)
 254 {
 255   td_thrinfo_t ti;
 256   td_thrhandle_t th;
 257   td_err_e err;
 258
 259   if (!is_thread (ptid))
 260     return ptid;
 261
 262   err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (ptid), &th);
 263   if (err != TD_OK)
 264     error ("Cannot find thread %ld: %s",
 265            (long) GET_THREAD (ptid), thread_db_err_str (err));
 266
 267   err = td_thr_get_info_p (&th, &ti);
 268   if (err != TD_OK)
 269     error ("Cannot get thread info: %s", thread_db_err_str (err));
 270
 271   return BUILD_LWP (ti.ti_lid, GET_PID (ptid));
 272 }
 273 \f
 274
 275 void
 276 thread_db_init (struct target_ops *target)
 277 {
 278   target_beneath = target;
 279 }
 280
 281 static int
 282 thread_db_load (void)
 283 {
 284   void *handle;
 285   td_err_e err;
 286
 287   handle = dlopen (LIBTHREAD_DB_SO, RTLD_NOW);
 288   if (handle == NULL)
 289     return 0;
 290
 291   /* Initialize pointers to the dynamic library functions we will use.
 292      Essential functions first.  */
 293
 294   td_init_p = dlsym (handle, "td_init");
 295   if (td_init_p == NULL)
 296     return 0;
 297
 298   td_ta_new_p = dlsym (handle, "td_ta_new");
 299   if (td_ta_new_p == NULL)
 300     return 0;
 301
 302   td_ta_map_id2thr_p = dlsym (handle, "td_ta_map_id2thr");
 303   if (td_ta_map_id2thr_p == NULL)
 304     return 0;
 305
 306   td_ta_map_lwp2thr_p = dlsym (handle, "td_ta_map_lwp2thr");
 307   if (td_ta_map_lwp2thr_p == NULL)
 308     return 0;
 309
 310   td_ta_thr_iter_p = dlsym (handle, "td_ta_thr_iter");
 311   if (td_ta_thr_iter_p == NULL)
 312     return 0;
 313
 314   td_thr_validate_p = dlsym (handle, "td_thr_validate");
 315   if (td_thr_validate_p == NULL)
 316     return 0;
 317
 318   td_thr_get_info_p = dlsym (handle, "td_thr_get_info");
 319   if (td_thr_get_info_p == NULL)
 320     return 0;
 321
 322   td_thr_getfpregs_p = dlsym (handle, "td_thr_getfpregs");
 323   if (td_thr_getfpregs_p == NULL)
 324     return 0;
 325
 326   td_thr_getgregs_p = dlsym (handle, "td_thr_getgregs");
 327   if (td_thr_getgregs_p == NULL)
 328     return 0;
 329
 330   td_thr_setfpregs_p = dlsym (handle, "td_thr_setfpregs");
 331   if (td_thr_setfpregs_p == NULL)
 332     return 0;
 333
 334   td_thr_setgregs_p = dlsym (handle, "td_thr_setgregs");
 335   if (td_thr_setgregs_p == NULL)
 336     return 0;
 337
 338   /* Initialize the library.  */
 339   err = td_init_p ();
 340   if (err != TD_OK)
 341     {
 342       warning ("Cannot initialize libthread_db: %s", thread_db_err_str (err));
 343       return 0;
 344     }
 345
 346   /* These are not essential.  */
 347   td_ta_event_addr_p = dlsym (handle, "td_ta_event_addr");
 348   td_ta_set_event_p = dlsym (handle, "td_ta_set_event");
 349   td_ta_event_getmsg_p = dlsym (handle, "td_ta_event_getmsg");
 350   td_thr_event_enable_p = dlsym (handle, "td_thr_event_enable");
 351
 352   return 1;
 353 }
 354
 355 static void
 356 enable_thread_event_reporting (void)
 357 {
 358   td_thr_events_t events;
 359   td_notify_t notify;
 360   td_err_e err;
 361
 362   /* We cannot use the thread event reporting facility if these
 363      functions aren't available.  */
 364   if (td_ta_event_addr_p == NULL || td_ta_set_event_p == NULL
 365       || td_ta_event_getmsg_p == NULL || td_thr_event_enable_p == NULL)
 366     return;
 367
 368   /* Set the process wide mask saying which events we're interested in.  */
 369   td_event_emptyset (&events);
 370   td_event_addset (&events, TD_CREATE);
 371 #if 0
 372   /* FIXME: kettenis/2000-04-23: The event reporting facility is
 373      broken for TD_DEATH events in glibc 2.1.3, so don't enable it for
 374      now.  */
 375   td_event_addset (&events, TD_DEATH);
 376 #endif
 377
 378   err = td_ta_set_event_p (thread_agent, &events);
 379   if (err != TD_OK)
 380     {
 381       warning ("Unable to set global thread event mask: %s",
 382                thread_db_err_str (err));
 383       return;
 384     }
 385
 386   /* Delete previous thread event breakpoints, if any.  */
 387   remove_thread_event_breakpoints ();
 388
 389   /* Get address for thread creation breakpoint.  */
 390   err = td_ta_event_addr_p (thread_agent, TD_CREATE, &notify);
 391   if (err != TD_OK)
 392     {
 393       warning ("Unable to get location for thread creation breakpoint: %s",
 394                thread_db_err_str (err));
 395       return;
 396     }
 397
 398   /* Set up the breakpoint.  */
 399   td_create_bp_addr = (CORE_ADDR) notify.u.bptaddr;
 400   create_thread_event_breakpoint (td_create_bp_addr);
 401
 402   /* Get address for thread death breakpoint.  */
 403   err = td_ta_event_addr_p (thread_agent, TD_DEATH, &notify);
 404   if (err != TD_OK)
 405     {
 406       warning ("Unable to get location for thread death breakpoint: %s",
 407                thread_db_err_str (err));
 408       return;
 409     }
 410
 411   /* Set up the breakpoint.  */
 412   td_death_bp_addr = (CORE_ADDR) notify.u.bptaddr;
 413   create_thread_event_breakpoint (td_death_bp_addr);
 414 }
 415
 416 static void
 417 disable_thread_event_reporting (void)
 418 {
 419   td_thr_events_t events;
 420
 421   /* Set the process wide mask saying we aren't interested in any
 422      events anymore.  */
 423   td_event_emptyset (&events);
 424   td_ta_set_event_p (thread_agent, &events);
 425
 426   /* Delete thread event breakpoints, if any.  */
 427   remove_thread_event_breakpoints ();
 428   td_create_bp_addr = 0;
 429   td_death_bp_addr = 0;
 430 }
 431
 432 static void
 433 check_thread_signals (void)
 434 {
 435 #ifdef GET_THREAD_SIGNALS
 436   if (!thread_signals)
 437     {
 438       sigset_t mask;
 439       int i;
 440
 441       GET_THREAD_SIGNALS (&mask);
 442       sigemptyset (&thread_stop_set);
 443       sigemptyset (&thread_print_set);
 444
 445       for (i = 1; i < NSIG; i++)
 446         {
 447           if (sigismember (&mask, i))
 448             {
 449               if (signal_stop_update (target_signal_from_host (i), 0))
 450                 sigaddset (&thread_stop_set, i);
 451               if (signal_print_update (target_signal_from_host (i), 0))
 452                 sigaddset (&thread_print_set, i);
 453               thread_signals = 1;
 454             }
 455         }
 456     }
 457 #endif
 458 }
 459
 460 static void
 461 disable_thread_signals (void)
 462 {
 463 #ifdef GET_THREAD_SIGNALS
 464   if (thread_signals)
 465     {
 466       int i;
 467
 468       for (i = 1; i < NSIG; i++)
 469         {
 470           if (sigismember (&thread_stop_set, i))
 471             signal_stop_update (target_signal_from_host (i), 1);
 472           if (sigismember (&thread_print_set, i))
 473             signal_print_update (target_signal_from_host (i), 1);
 474         }
 475
 476       thread_signals = 0;
 477     }
 478 #endif
 479 }
 480
 481 static void
 482 thread_db_new_objfile (struct objfile *objfile)
 483 {
 484   td_err_e err;
 485
 486   /* Don't attempt to use thread_db on targets which can not run
 487      (core files).  */
 488   if (objfile == NULL || !target_has_execution)
 489     {
 490       /* All symbols have been discarded.  If the thread_db target is
 491          active, deactivate it now.  */
 492       if (using_thread_db)
 493         {
 494           gdb_assert (proc_handle.pid == 0);
 495           unpush_target (&thread_db_ops);
 496           using_thread_db = 0;
 497         }
 498
 499       keep_thread_db = 0;
 500
 501       goto quit;
 502     }
 503
 504   if (using_thread_db)
 505     /* Nothing to do.  The thread library was already detected and the
 506        target vector was already activated.  */
 507     goto quit;
 508
 509   /* Initialize the structure that identifies the child process.  Note
 510      that at this point there is no guarantee that we actually have a
 511      child process.  */
 512   proc_handle.pid = GET_PID (inferior_ptid);
 513
 514   /* Now attempt to open a connection to the thread library.  */
 515   err = td_ta_new_p (&proc_handle, &thread_agent);
 516   switch (err)
 517     {
 518     case TD_NOLIBTHREAD:
 519       /* No thread library was detected.  */
 520       break;
 521
 522     case TD_OK:
 523       /* The thread library was detected.  Activate the thread_db target.  */
 524       push_target (&thread_db_ops);
 525       using_thread_db = 1;
 526
 527       /* If the thread library was detected in the main symbol file
 528          itself, we assume that the program was statically linked
 529          against the thread library and well have to keep this
 530          module's target vector activated until forever...  Well, at
 531          least until all symbols have been discarded anyway (see
 532          above).  */
 533       if (objfile == symfile_objfile)
 534         {
 535           gdb_assert (proc_handle.pid == 0);
 536           keep_thread_db = 1;
 537         }
 538
 539       /* We can only poke around if there actually is a child process.
 540          If there is no child process alive, postpone the steps below
 541          until one has been created.  */
 542       if (proc_handle.pid != 0)
 543         {
 544           enable_thread_event_reporting ();
 545           thread_db_find_new_threads ();
 546         }
 547       break;
 548
 549     default:
 550       warning ("Cannot initialize thread debugging library: %s",
 551                thread_db_err_str (err));
 552       break;
 553     }
 554
 555  quit:
 556   if (target_new_objfile_chain)
 557     target_new_objfile_chain (objfile);
 558 }
 559
 560 static void
 561 attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
 562                const td_thrinfo_t *ti_p, int verbose)
 563 {
 564   struct thread_info *tp;
 565   td_err_e err;
 566
 567   check_thread_signals ();
 568
 569   if (verbose)
 570     printf_unfiltered ("[New %s]\n", target_pid_to_str (ptid));
 571
 572   /* Add the thread to GDB's thread list.  */
 573   tp = add_thread (ptid);
 574   tp->private = xmalloc (sizeof (struct private_thread_info));
 575   tp->private->lwpid = ti_p->ti_lid;
 576
 577   if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
 578     return;                     /* A zombie thread -- do not attach.  */
 579
 580   /* Under GNU/Linux, we have to attach to each and every thread.  */
 581 #ifdef ATTACH_LWP
 582   ATTACH_LWP (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid)), 0);
 583 #endif
 584
 585   /* Enable thread event reporting for this thread.  */
 586   err = td_thr_event_enable_p (th_p, 1);
 587   if (err != TD_OK)
 588     error ("Cannot enable thread event reporting for %s: %s",
 589            target_pid_to_str (ptid), thread_db_err_str (err));
 590 }
 591
 592 static void
 593 thread_db_attach (char *args, int from_tty)
 594 {
 595   target_beneath->to_attach (args, from_tty);
 596
 597   /* Destroy thread info; it's no longer valid.  */
 598   init_thread_list ();
 599
 600   /* The child process is now the actual multi-threaded
 601      program.  Snatch its process ID...  */
 602   proc_handle.pid = GET_PID (inferior_ptid);
 603
 604   /* ...and perform the remaining initialization steps.  */
 605   enable_thread_event_reporting ();
 606   thread_db_find_new_threads();
 607 }
 608
 609 static void
 610 detach_thread (ptid_t ptid, int verbose)
 611 {
 612   if (verbose)
 613     printf_unfiltered ("[%s exited]\n", target_pid_to_str (ptid));
 614 }
 615
 616 static void
 617 thread_db_detach (char *args, int from_tty)
 618 {
 619   disable_thread_event_reporting ();
 620
 621   /* There's no need to save & restore inferior_ptid here, since the
 622      inferior is supposed to be survive this function call.  */
 623   inferior_ptid = lwp_from_thread (inferior_ptid);
 624
 625   /* Forget about the child's process ID.  We shouldn't need it
 626      anymore.  */
 627   proc_handle.pid = 0;
 628
 629   target_beneath->to_detach (args, from_tty);
 630 }
 631
 632 static void
 633 thread_db_resume (ptid_t ptid, int step, enum target_signal signo)
 634 {
 635   struct cleanup *old_chain = save_inferior_ptid ();
 636
 637   if (GET_PID (ptid) == -1)
 638     inferior_ptid = lwp_from_thread (inferior_ptid);
 639   else if (is_thread (ptid))
 640     ptid = lwp_from_thread (ptid);
 641
 642   target_beneath->to_resume (ptid, step, signo);
 643
 644   do_cleanups (old_chain);
 645 }
 646
 647 /* Check if PID is currently stopped at the location of a thread event
 648    breakpoint location.  If it is, read the event message and act upon
 649    the event.  */
 650
 651 static void
 652 check_event (ptid_t ptid)
 653 {
 654   td_event_msg_t msg;
 655   td_thrinfo_t ti;
 656   td_err_e err;
 657   CORE_ADDR stop_pc;
 658
 659   /* Bail out early if we're not at a thread event breakpoint.  */
 660   stop_pc = read_pc_pid (ptid) - DECR_PC_AFTER_BREAK;
 661   if (stop_pc != td_create_bp_addr && stop_pc != td_death_bp_addr)
 662     return;
 663
 664   err = td_ta_event_getmsg_p (thread_agent, &msg);
 665   if (err != TD_OK)
 666     {
 667       if (err == TD_NOMSG)
 668         return;
 669
 670       error ("Cannot get thread event message: %s", thread_db_err_str (err));
 671     }
 672
 673   err = td_thr_get_info_p (msg.th_p, &ti);
 674   if (err != TD_OK)
 675     error ("Cannot get thread info: %s", thread_db_err_str (err));
 676
 677   ptid = BUILD_THREAD (ti.ti_tid, GET_PID (ptid));
 678
 679   switch (msg.event)
 680     {
 681     case TD_CREATE:
 682 #if 0
 683       /* FIXME: kettenis/2000-08-26: Since we use td_ta_event_getmsg,
 684          there is no guarantee that the breakpoint will match the
 685          event.  Should we use td_thr_event_getmsg instead?  */
 686
 687       if (stop_pc != td_create_bp_addr)
 688         error ("Thread creation event doesn't match breakpoint.");
 689 #endif
 690
 691       /* We may already know about this thread, for instance when the
 692          user has issued the `info threads' command before the SIGTRAP
 693          for hitting the thread creation breakpoint was reported.  */
 694       if (!in_thread_list (ptid))
 695         attach_thread (ptid, msg.th_p, &ti, 1);
 696       return;
 697
 698     case TD_DEATH:
 699 #if 0
 700       /* FIXME: See TD_CREATE.  */
 701
 702       if (stop_pc != td_death_bp_addr)
 703         error ("Thread death event doesn't match breakpoint.");
 704 #endif
 705
 706       if (!in_thread_list (ptid))
 707         error ("Spurious thread death event.");
 708
 709       detach_thread (ptid, 1);
 710       return;
 711
 712     default:
 713       error ("Spurious thread event.");
 714     }
 715 }
 716
 717 static ptid_t
 718 thread_db_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
 719 {
 720   extern ptid_t trap_ptid;
 721
 722   if (GET_PID (ptid) != -1 && is_thread (ptid))
 723     ptid = lwp_from_thread (ptid);
 724
 725   ptid = target_beneath->to_wait (ptid, ourstatus);
 726
 727   if (proc_handle.pid == 0)
 728     /* The current child process isn't the actual multi-threaded
 729        program yet, so don't try to do any special thread-specific
 730        post-processing and bail out early.  */
 731     return ptid;
 732
 733   if (ourstatus->kind == TARGET_WAITKIND_EXITED)
 734     return pid_to_ptid (-1);
 735
 736   if (ourstatus->kind == TARGET_WAITKIND_STOPPED
 737       && ourstatus->value.sig == TARGET_SIGNAL_TRAP)
 738     /* Check for a thread event.  */
 739     check_event (ptid);
 740
 741   if (!ptid_equal (trap_ptid, null_ptid))
 742     trap_ptid = thread_from_lwp (trap_ptid);
 743
 744   return thread_from_lwp (ptid);
 745 }
 746
 747 static int
 748 thread_db_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
 749                        struct mem_attrib *attrib,
 750                        struct target_ops *target)
 751 {
 752   struct cleanup *old_chain = save_inferior_ptid ();
 753   int xfer;
 754
 755   if (is_thread (inferior_ptid))
 756     {
 757       /* FIXME: This seems to be necessary to make sure breakpoints
 758          are removed.  */
 759       if (!target_thread_alive (inferior_ptid))
 760         inferior_ptid = pid_to_ptid (GET_PID (inferior_ptid));
 761       else
 762         inferior_ptid = lwp_from_thread (inferior_ptid);
 763     }
 764
 765   xfer = target_beneath->to_xfer_memory (memaddr, myaddr, len, write, attrib, target);
 766
 767   do_cleanups (old_chain);
 768   return xfer;
 769 }
 770
 771 static void
 772 thread_db_fetch_registers (int regno)
 773 {
 774   td_thrhandle_t th;
 775   prgregset_t gregset;
 776   gdb_prfpregset_t fpregset;
 777   td_err_e err;
 778
 779   if (!is_thread (inferior_ptid))
 780     {
 781       /* Pass the request to the target beneath us.  */
 782       target_beneath->to_fetch_registers (regno);
 783       return;
 784     }
 785
 786   err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (inferior_ptid), &th);
 787   if (err != TD_OK)
 788     error ("Cannot find thread %ld: %s",
 789            (long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
 790
 791   err = td_thr_getgregs_p (&th, gregset);
 792   if (err != TD_OK)
 793     error ("Cannot fetch general-purpose registers for thread %ld: %s",
 794            (long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
 795
 796   err = td_thr_getfpregs_p (&th, &fpregset);
 797   if (err != TD_OK)
 798     error ("Cannot get floating-point registers for thread %ld: %s",
 799            (long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
 800
 801   /* Note that we must call supply_gregset after calling the thread_db
 802      routines because the thread_db routines call ps_lgetgregs and
 803      friends which clobber GDB's register cache.  */
 804   supply_gregset ((gdb_gregset_t *) gregset);
 805   supply_fpregset (&fpregset);
 806 }
 807
 808 static void
 809 thread_db_store_registers (int regno)
 810 {
 811   td_thrhandle_t th;
 812   prgregset_t gregset;
 813   gdb_prfpregset_t fpregset;
 814   td_err_e err;
 815
 816   if (!is_thread (inferior_ptid))
 817     {
 818       /* Pass the request to the target beneath us.  */
 819       target_beneath->to_store_registers (regno);
 820       return;
 821     }
 822
 823   err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (inferior_ptid), &th);
 824   if (err != TD_OK)
 825     error ("Cannot find thread %ld: %s",
 826            (long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
 827
 828   if (regno != -1)
 829     {
 830       char raw[MAX_REGISTER_RAW_SIZE];
 831
 832       read_register_gen (regno, raw);
 833       thread_db_fetch_registers (-1);
 834       supply_register (regno, raw);
 835     }
 836
 837   fill_gregset ((gdb_gregset_t *) gregset, -1);
 838   fill_fpregset (&fpregset, -1);
 839
 840   err = td_thr_setgregs_p (&th, gregset);
 841   if (err != TD_OK)
 842     error ("Cannot store general-purpose registers for thread %ld: %s",
 843            (long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
 844   err = td_thr_setfpregs_p (&th, &fpregset);
 845   if (err != TD_OK)
 846     error ("Cannot store floating-point registers  for thread %ld: %s",
 847            (long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
 848 }
 849
 850 static void
 851 thread_db_kill (void)
 852 {
 853   /* There's no need to save & restore inferior_ptid here, since the
 854      inferior isn't supposed to survive this function call.  */
 855   inferior_ptid = lwp_from_thread (inferior_ptid);
 856   target_beneath->to_kill ();
 857 }
 858
 859 static void
 860 thread_db_create_inferior (char *exec_file, char *allargs, char **env)
 861 {
 862   if (!keep_thread_db)
 863     {
 864       unpush_target (&thread_db_ops);
 865       using_thread_db = 0;
 866     }
 867
 868   target_beneath->to_create_inferior (exec_file, allargs, env);
 869 }
 870
 871 static void
 872 thread_db_post_startup_inferior (ptid_t ptid)
 873 {
 874   if (proc_handle.pid == 0)
 875     {
 876       /* The child process is now the actual multi-threaded
 877          program.  Snatch its process ID...  */
 878       proc_handle.pid = GET_PID (ptid);
 879
 880       /* ...and perform the remaining initialization steps.  */
 881       enable_thread_event_reporting ();
 882       thread_db_find_new_threads ();
 883     }
 884 }
 885
 886 static void
 887 thread_db_mourn_inferior (void)
 888 {
 889   remove_thread_event_breakpoints ();
 890
 891   /* Forget about the child's process ID.  We shouldn't need it
 892      anymore.  */
 893   proc_handle.pid = 0;
 894
 895   target_beneath->to_mourn_inferior ();
 896 }
 897
 898 static int
 899 thread_db_thread_alive (ptid_t ptid)
 900 {
 901   td_thrhandle_t th;
 902   td_thrinfo_t ti;
 903   td_err_e err;
 904
 905   if (is_thread (ptid))
 906     {
 907       err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (ptid), &th);
 908       if (err != TD_OK)
 909         return 0;
 910
 911       err = td_thr_validate_p (&th);
 912       if (err != TD_OK)
 913         return 0;
 914
 915       err = td_thr_get_info_p (&th, &ti);
 916       if (err != TD_OK)
 917         return 0;
 918
 919       if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
 920         return 0;               /* A zombie thread.  */
 921
 922       return 1;
 923     }
 924
 925   if (target_beneath->to_thread_alive)
 926     return target_beneath->to_thread_alive (ptid);
 927
 928   return 0;
 929 }
 930
 931 static int
 932 find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
 933 {
 934   td_thrinfo_t ti;
 935   td_err_e err;
 936   ptid_t ptid;
 937
 938   err = td_thr_get_info_p (th_p, &ti);
 939   if (err != TD_OK)
 940     error ("Cannot get thread info: %s", thread_db_err_str (err));
 941
 942   if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
 943     return 0;                   /* A zombie -- ignore.  */
 944
 945   ptid = BUILD_THREAD (ti.ti_tid, GET_PID (inferior_ptid));
 946
 947   if (!in_thread_list (ptid))
 948     attach_thread (ptid, th_p, &ti, 1);
 949
 950   return 0;
 951 }
 952
 953 static void
 954 thread_db_find_new_threads (void)
 955 {
 956   td_err_e err;
 957
 958   /* Iterate over all user-space threads to discover new threads.  */
 959   err = td_ta_thr_iter_p (thread_agent, find_new_threads_callback, NULL,
 960                           TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
 961                           TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS);
 962   if (err != TD_OK)
 963     error ("Cannot find new threads: %s", thread_db_err_str (err));
 964 }
 965
 966 static char *
 967 thread_db_pid_to_str (ptid_t ptid)
 968 {
 969   if (is_thread (ptid))
 970     {
 971       static char buf[64];
 972       td_thrhandle_t th;
 973       td_thrinfo_t ti;
 974       td_err_e err;
 975
 976       err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (ptid), &th);
 977       if (err != TD_OK)
 978         error ("Cannot find thread %ld: %s",
 979                (long) GET_THREAD (ptid), thread_db_err_str (err));
 980
 981       err = td_thr_get_info_p (&th, &ti);
 982       if (err != TD_OK)
 983         error ("Cannot get thread info for thread %ld: %s",
 984                (long) GET_THREAD (ptid), thread_db_err_str (err));
 985
 986       if (ti.ti_state == TD_THR_ACTIVE && ti.ti_lid != 0)
 987         {
 988           snprintf (buf, sizeof (buf), "Thread %ld (LWP %d)",
 989                     (long) ti.ti_tid, ti.ti_lid);
 990         }
 991       else
 992         {
 993           snprintf (buf, sizeof (buf), "Thread %ld (%s)",
 994                     (long) ti.ti_tid, thread_db_state_str (ti.ti_state));
 995         }
 996
 997       return buf;
 998     }
 999
1000   if (target_beneath->to_pid_to_str (ptid))
1001     return target_beneath->to_pid_to_str (ptid);
1002
1003   return normal_pid_to_str (ptid);
1004 }
1005
1006 static void
1007 init_thread_db_ops (void)
1008 {
1009   thread_db_ops.to_shortname = "multi-thread";
1010   thread_db_ops.to_longname = "multi-threaded child process.";
1011   thread_db_ops.to_doc = "Threads and pthreads support.";
1012   thread_db_ops.to_attach = thread_db_attach;
1013   thread_db_ops.to_detach = thread_db_detach;
1014   thread_db_ops.to_resume = thread_db_resume;
1015   thread_db_ops.to_wait = thread_db_wait;
1016   thread_db_ops.to_fetch_registers = thread_db_fetch_registers;
1017   thread_db_ops.to_store_registers = thread_db_store_registers;
1018   thread_db_ops.to_xfer_memory = thread_db_xfer_memory;
1019   thread_db_ops.to_kill = thread_db_kill;
1020   thread_db_ops.to_create_inferior = thread_db_create_inferior;
1021   thread_db_ops.to_post_startup_inferior = thread_db_post_startup_inferior;
1022   thread_db_ops.to_mourn_inferior = thread_db_mourn_inferior;
1023   thread_db_ops.to_thread_alive = thread_db_thread_alive;
1024   thread_db_ops.to_find_new_threads = thread_db_find_new_threads;
1025   thread_db_ops.to_pid_to_str = thread_db_pid_to_str;
1026   thread_db_ops.to_stratum = thread_stratum;
1027   thread_db_ops.to_has_thread_control = tc_schedlock;
1028   thread_db_ops.to_magic = OPS_MAGIC;
1029 }
1030
1031 void
1032 _initialize_thread_db (void)
1033 {
1034   /* Only initialize the module if we can load libthread_db.  */
1035   if (thread_db_load ())
1036     {
1037       init_thread_db_ops ();
1038       add_target (&thread_db_ops);
1039
1040       /* Add ourselves to objfile event chain.  */
1041       target_new_objfile_chain = target_new_objfile_hook;
1042       target_new_objfile_hook = thread_db_new_objfile;
1043     }
1044 }