| 1 | /* Low level interface for debugging UnixWare user-mode threads for |
| 2 | GDB, the GNU debugger. |
| 3 | |
| 4 | Copyright 1999, 2000 Free Software Foundation, Inc. |
| 5 | Written by Nick Duffek <nsd@cygnus.com>. |
| 6 | |
| 7 | This file is part of GDB. |
| 8 | |
| 9 | This program is free software; you can redistribute it and/or modify |
| 10 | it under the terms of the GNU General Public License as published by |
| 11 | the Free Software Foundation; either version 2 of the License, or |
| 12 | (at your option) any later version. |
| 13 | |
| 14 | This program is distributed in the hope that it will be useful, |
| 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | GNU General Public License for more details. |
| 18 | |
| 19 | You should have received a copy of the GNU General Public License |
| 20 | along with this program; if not, write to the Free Software |
| 21 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 22 | Boston, MA 02111-1307, USA. */ |
| 23 | |
| 24 | |
| 25 | /* Like many systems, UnixWare implements two classes of threads: |
| 26 | kernel-mode threads, which are scheduled by the kernel; and |
| 27 | user-mode threads, which are scheduled by a library. UnixWare |
| 28 | calls these two classes lightweight processes (LWPs) and threads, |
| 29 | respectively. |
| 30 | |
| 31 | This module deals with user-mode threads. It calls procfs_ops |
| 32 | functions to deal with LWPs and processes and core_ops functions to |
| 33 | deal with core files. |
| 34 | |
| 35 | As of this writing, the user-mode thread debugging interface is not |
| 36 | documented beyond the comments in <thread.h>. The following |
| 37 | description has been gleaned from experience and from information |
| 38 | provided by SCO. |
| 39 | |
| 40 | libthread.so, against which all UnixWare user-mode thread programs |
| 41 | link, provides a global thread_debug structure named _thr_debug. |
| 42 | It has three fields: |
| 43 | |
| 44 | (1) thr_map is a pointer to a pointer to an element of a |
| 45 | thread_map ring. A thread_map contains a single thread's id |
| 46 | number, state, LWP pointer, recent register state, and other |
| 47 | useful information. |
| 48 | |
| 49 | (2) thr_brk is a pointer to a stub function that libthread.so |
| 50 | calls when it changes a thread's state, e.g. by creating it, |
| 51 | switching it to an LWP, or causing it to exit. |
| 52 | |
| 53 | (3) thr_debug_on controls whether libthread.so calls thr_brk(). |
| 54 | |
| 55 | Debuggers are able to track thread activity by setting a private |
| 56 | breakpoint on thr_brk() and setting thr_debug_on to 1. |
| 57 | |
| 58 | thr_brk() receives two arguments: |
| 59 | |
| 60 | (1) a pointer to a thread_map describing the thread being |
| 61 | changed; and |
| 62 | |
| 63 | (2) an enum thread_change specifying one of the following |
| 64 | changes: |
| 65 | |
| 66 | invalid unknown |
| 67 | thread_create thread has just been created |
| 68 | thread_exit thread has just exited |
| 69 | switch_begin thread will be switched to an LWP |
| 70 | switch_complete thread has been switched to an LWP |
| 71 | cancel_complete thread wasn't switched to an LWP |
| 72 | thread_suspend thread has been thr_suspend()ed |
| 73 | thread_suspend_pending thread will be thr_suspend()ed |
| 74 | thread_continue thread has been thr_continue()d |
| 75 | |
| 76 | The thread_map argument to thr_brk() is NULL under the following |
| 77 | circumstances: |
| 78 | |
| 79 | - The main thread is being acted upon. The main thread always |
| 80 | has id 1, so its thread_map is easy to find by scanning through |
| 81 | _thr_debug.thr_map. |
| 82 | |
| 83 | - A "switch_complete" change is occurring, which means that the |
| 84 | thread specified in the most recent "switch_begin" change has |
| 85 | moved to an LWP. |
| 86 | |
| 87 | - A "cancel_complete" change is occurring, which means that the |
| 88 | thread specified in the most recent "switch_begin" change has |
| 89 | not moved to an LWP after all. |
| 90 | |
| 91 | - A spurious "switch_begin" change is occurring after a |
| 92 | "thread_exit" change. |
| 93 | |
| 94 | Between switch_begin and switch_complete or cancel_complete, the |
| 95 | affected thread's LWP pointer is not reliable. It is possible that |
| 96 | other parts of the thread's thread_map are also unreliable during |
| 97 | that time. */ |
| 98 | |
| 99 | |
| 100 | #include "defs.h" |
| 101 | #include "gdbthread.h" |
| 102 | #include "target.h" |
| 103 | #include "inferior.h" |
| 104 | #include <fcntl.h> |
| 105 | |
| 106 | /* <thread.h> includes <sys/priocntl.h>, which requires boolean_t from |
| 107 | <sys/types.h>, which doesn't typedef boolean_t with gcc. */ |
| 108 | |
| 109 | #define boolean_t int |
| 110 | #include <thread.h> |
| 111 | #undef boolean_t |
| 112 | |
| 113 | #include <synch.h> /* for UnixWare 2.x */ |
| 114 | |
| 115 | /* Prototypes for supply_gregset etc. */ |
| 116 | #include "gregset.h" |
| 117 | |
| 118 | /* Whether to emit debugging output. */ |
| 119 | |
| 120 | #define DEBUG 0 |
| 121 | |
| 122 | /* Default debugging output file, overridden by envvar UWTHR_DEBUG. */ |
| 123 | |
| 124 | #define DEBUG_FILE "/dev/tty" |
| 125 | |
| 126 | /* #if DEBUG, write string S to the debugging output channel. */ |
| 127 | |
| 128 | #if !DEBUG |
| 129 | # define DBG(fmt_and_args) |
| 130 | # define DBG2(fmt_and_args) |
| 131 | #else |
| 132 | # define DBG(fmt_and_args) dbg fmt_and_args |
| 133 | # define DBG2(fmt_and_args) |
| 134 | #endif |
| 135 | |
| 136 | /* Back end to CALL_BASE() and TRY_BASE(): evaluate CALL, then convert |
| 137 | inferior_pid to a composite thread/process id. */ |
| 138 | |
| 139 | #define CALL_BASE_1(call) \ |
| 140 | do { \ |
| 141 | DBG2(("CALL_BASE(" #call ")")); \ |
| 142 | call; \ |
| 143 | do_cleanups (infpid_cleanup); \ |
| 144 | } while (0) |
| 145 | |
| 146 | /* If inferior_pid can be converted to a composite lwp/process id, do so, |
| 147 | evaluate base_ops function CALL, and then convert inferior_pid back to a |
| 148 | composite thread/process id. |
| 149 | |
| 150 | Otherwise, issue an error message and return nonlocally. */ |
| 151 | |
| 152 | #define CALL_BASE(call) \ |
| 153 | do { \ |
| 154 | if (!lwp_infpid ()) \ |
| 155 | error ("uw-thread: no lwp"); \ |
| 156 | CALL_BASE_1 (call); \ |
| 157 | } while (0) |
| 158 | |
| 159 | /* Like CALL_BASE(), but instead of returning nonlocally on error, set |
| 160 | *CALLED to whether the inferior_pid conversion was successful. */ |
| 161 | |
| 162 | #define TRY_BASE(call, called) \ |
| 163 | do { \ |
| 164 | if ((*(called) = lwp_infpid ())) \ |
| 165 | CALL_BASE_1 (call); \ |
| 166 | } while (0) |
| 167 | |
| 168 | /* Information passed by thread_iter() to its callback parameter. */ |
| 169 | |
| 170 | typedef struct { |
| 171 | struct thread_map map; |
| 172 | __lwp_desc_t lwp; |
| 173 | CORE_ADDR mapp; |
| 174 | } iter_t; |
| 175 | |
| 176 | /* Private thread data for the thread_info struct. */ |
| 177 | |
| 178 | struct private_thread_info { |
| 179 | int stable; /* 0 if libthread.so is modifying thread map */ |
| 180 | int thrid; /* thread id assigned by libthread.so */ |
| 181 | int lwpid; /* thread's lwp if .stable, 0 means no lwp */ |
| 182 | CORE_ADDR mapp; /* address of thread's map structure */ |
| 183 | }; |
| 184 | |
| 185 | |
| 186 | /* procfs.c's target-specific operations. */ |
| 187 | extern struct target_ops procfs_ops; |
| 188 | |
| 189 | /* Flag to prevent procfs.c from starting inferior processes. */ |
| 190 | extern int procfs_suppress_run; |
| 191 | |
| 192 | /* This module's target-specific operations. */ |
| 193 | static struct target_ops uw_thread_ops; |
| 194 | |
| 195 | /* Copy of the target over which uw_thread_ops is pushed. This is |
| 196 | more convenient than a pointer to procfs_ops or core_ops, because |
| 197 | they lack current_target's default callbacks. */ |
| 198 | static struct target_ops base_ops; |
| 199 | |
| 200 | /* Saved pointer to previous owner of target_new_objfile_hook. */ |
| 201 | static void (*target_new_objfile_chain)(struct objfile *); |
| 202 | |
| 203 | /* Whether we are debugging a user-space thread program. This isn't |
| 204 | set until after libthread.so is loaded by the program being |
| 205 | debugged. |
| 206 | |
| 207 | Except for module one-time intialization and where otherwise |
| 208 | documented, no functions in this module get called when |
| 209 | !uw_thread_active. */ |
| 210 | static int uw_thread_active; |
| 211 | |
| 212 | /* For efficiency, cache the addresses of libthread.so's _thr_debug |
| 213 | structure, its thr_brk stub function, and the main thread's map. */ |
| 214 | static CORE_ADDR thr_debug_addr; |
| 215 | static CORE_ADDR thr_brk_addr; |
| 216 | static CORE_ADDR thr_map_main; |
| 217 | |
| 218 | /* Remember the thread most recently marked as switching. Necessary because |
| 219 | libthread.so passes null map when calling stub with tc_*_complete. */ |
| 220 | static struct thread_info *switchto_thread; |
| 221 | |
| 222 | /* Cleanup chain for safely restoring inferior_pid after CALL_BASE. */ |
| 223 | static struct cleanup *infpid_cleanup; |
| 224 | |
| 225 | |
| 226 | #if DEBUG |
| 227 | /* Helper function for DBG() macro: if printf-style FMT is non-null, format it |
| 228 | with args and display the result on the debugging output channel. */ |
| 229 | |
| 230 | static void |
| 231 | dbg (char *fmt, ...) |
| 232 | { |
| 233 | static int fd = -1, len; |
| 234 | va_list args; |
| 235 | char buf[1024]; |
| 236 | char *path; |
| 237 | |
| 238 | if (!fmt) |
| 239 | return; |
| 240 | |
| 241 | if (fd < 0) |
| 242 | { |
| 243 | path = getenv ("UWTHR_DEBUG"); |
| 244 | if (!path) |
| 245 | path = DEBUG_FILE; |
| 246 | if ((fd = open (path, O_WRONLY | O_CREAT | O_TRUNC, 0664)) < 0) |
| 247 | error ("can't open %s\n", path); |
| 248 | } |
| 249 | |
| 250 | va_start (args, fmt); |
| 251 | vsprintf (buf, fmt, args); |
| 252 | va_end (args); |
| 253 | |
| 254 | len = strlen (buf); |
| 255 | buf[len] = '\n'; |
| 256 | (void)write (fd, buf, len + 1); |
| 257 | } |
| 258 | |
| 259 | #if 0 |
| 260 | /* Return a string representing composite PID's components. */ |
| 261 | |
| 262 | static char * |
| 263 | dbgpid (int pid) |
| 264 | { |
| 265 | static char *buf, buf1[80], buf2[80]; |
| 266 | if (!buf || buf == buf2) |
| 267 | buf = buf1; |
| 268 | else |
| 269 | buf = buf2; |
| 270 | |
| 271 | if (pid <= 0) |
| 272 | sprintf (buf, "%d", pid); |
| 273 | else |
| 274 | sprintf (buf, "%s %d/%d", ISTID (pid) ? "thr" : "lwp", |
| 275 | TIDGET (pid), PIDGET (pid)); |
| 276 | |
| 277 | return buf; |
| 278 | } |
| 279 | |
| 280 | /* Return a string representing thread state CHANGE. */ |
| 281 | |
| 282 | static char * |
| 283 | dbgchange (enum thread_change change) |
| 284 | { |
| 285 | switch (change) { |
| 286 | case tc_invalid: return "invalid"; |
| 287 | case tc_thread_create: return "thread_create"; |
| 288 | case tc_thread_exit: return "thread_exit"; |
| 289 | case tc_switch_begin: return "switch_begin"; |
| 290 | case tc_switch_complete: return "switch_complete"; |
| 291 | case tc_cancel_complete: return "cancel_complete"; |
| 292 | case tc_thread_suspend: return "thread_suspend"; |
| 293 | case tc_thread_suspend_pending: return "thread_suspend_pending"; |
| 294 | case tc_thread_continue: return "thread_continue"; |
| 295 | default: return "unknown"; |
| 296 | } |
| 297 | } |
| 298 | |
| 299 | /* Return a string representing thread STATE. */ |
| 300 | |
| 301 | static char * |
| 302 | dbgstate (int state) |
| 303 | { |
| 304 | switch (state) { |
| 305 | case TS_ONPROC: return "running"; |
| 306 | case TS_SLEEP: return "sleeping"; |
| 307 | case TS_RUNNABLE: return "runnable"; |
| 308 | case TS_ZOMBIE: return "zombie"; |
| 309 | case TS_SUSPENDED: return "suspended"; |
| 310 | #ifdef TS_FORK |
| 311 | case TS_FORK: return "forking"; |
| 312 | #endif |
| 313 | default: return "confused"; |
| 314 | } |
| 315 | } |
| 316 | #endif /* 0 */ |
| 317 | #endif /* DEBUG */ |
| 318 | |
| 319 | |
| 320 | /* Read the contents of _thr_debug into *DEBUGP. Return success. */ |
| 321 | |
| 322 | static int |
| 323 | read_thr_debug (struct thread_debug *debugp) |
| 324 | { |
| 325 | return base_ops.to_xfer_memory (thr_debug_addr, (char *)debugp, |
| 326 | sizeof (*debugp), 0, &base_ops); |
| 327 | } |
| 328 | |
| 329 | /* Read into MAP the contents of the thread map at inferior process address |
| 330 | MAPP. Return success. */ |
| 331 | |
| 332 | static int |
| 333 | read_map (CORE_ADDR mapp, struct thread_map *map) |
| 334 | { |
| 335 | return base_ops.to_xfer_memory ((CORE_ADDR)THR_MAP (mapp), (char *)map, |
| 336 | sizeof (*map), 0, &base_ops); |
| 337 | } |
| 338 | |
| 339 | /* Read into LWP the contents of the lwp decriptor at inferior process address |
| 340 | LWPP. Return success. */ |
| 341 | |
| 342 | static int |
| 343 | read_lwp (CORE_ADDR lwpp, __lwp_desc_t *lwp) |
| 344 | { |
| 345 | return base_ops.to_xfer_memory (lwpp, (char *)lwp, |
| 346 | sizeof (*lwp), 0, &base_ops); |
| 347 | } |
| 348 | |
| 349 | /* Iterate through all user threads, applying FUNC(<map>, <lwp>, DATA) until |
| 350 | (a) FUNC returns nonzero, |
| 351 | (b) FUNC has been applied to all threads, or |
| 352 | (c) an error occurs, |
| 353 | where <map> is the thread's struct thread_map and <lwp> if non-null is the |
| 354 | thread's current __lwp_desc_t. |
| 355 | |
| 356 | If a call to FUNC returns nonzero, return that value; otherwise, return 0. */ |
| 357 | |
| 358 | static int |
| 359 | thread_iter (int (*func)(iter_t *, void *), void *data) |
| 360 | { |
| 361 | struct thread_debug debug; |
| 362 | CORE_ADDR first, mapp; |
| 363 | iter_t iter; |
| 364 | int ret; |
| 365 | |
| 366 | if (!read_thr_debug (&debug)) |
| 367 | return 0; |
| 368 | if (!base_ops.to_xfer_memory ((CORE_ADDR)debug.thr_map, (char *)&mapp, |
| 369 | sizeof (mapp), 0, &base_ops)) |
| 370 | return 0; |
| 371 | if (!mapp) |
| 372 | return 0; |
| 373 | |
| 374 | for (first = mapp;;) |
| 375 | { |
| 376 | if (!read_map (mapp, &iter.map)) |
| 377 | return 0; |
| 378 | |
| 379 | if (iter.map.thr_lwpp) |
| 380 | if (!read_lwp ((CORE_ADDR)iter.map.thr_lwpp, &iter.lwp)) |
| 381 | return 0; |
| 382 | |
| 383 | iter.mapp = mapp; |
| 384 | if ((ret = func (&iter, data))) |
| 385 | return ret; |
| 386 | |
| 387 | mapp = (CORE_ADDR)iter.map.thr_next; |
| 388 | if (mapp == first) |
| 389 | return 0; |
| 390 | } |
| 391 | } |
| 392 | |
| 393 | /* Deactivate user-mode thread support. */ |
| 394 | |
| 395 | static void |
| 396 | deactivate_uw_thread (void) |
| 397 | { |
| 398 | remove_thread_event_breakpoints (); |
| 399 | uw_thread_active = 0; |
| 400 | unpush_target (&uw_thread_ops); |
| 401 | } |
| 402 | |
| 403 | /* Return the composite lwp/process id corresponding to composite |
| 404 | id PID. If PID is a thread with no lwp, return 0. */ |
| 405 | |
| 406 | static int |
| 407 | thr_to_lwp (int pid) |
| 408 | { |
| 409 | struct thread_info *info; |
| 410 | int lid; |
| 411 | |
| 412 | if (!ISTID (pid)) |
| 413 | lid = pid; |
| 414 | else if (!(info = find_thread_pid (pid))) |
| 415 | lid = 0; |
| 416 | else if (!info->private->lwpid) |
| 417 | lid = 0; |
| 418 | else |
| 419 | lid = MKLID (pid, info->private->lwpid); |
| 420 | |
| 421 | DBG2((" thr_to_lwp(%s) = %s", dbgpid (pid), dbgpid (lid))); |
| 422 | return lid; |
| 423 | } |
| 424 | |
| 425 | /* find_thread_lwp() callback: return whether TP describes a thread |
| 426 | associated with lwp id DATA. */ |
| 427 | |
| 428 | static int |
| 429 | find_thread_lwp_callback (struct thread_info *tp, void *data) |
| 430 | { |
| 431 | int lwpid = (int)data; |
| 432 | |
| 433 | if (!ISTID (tp->pid)) |
| 434 | return 0; |
| 435 | if (!tp->private->stable) |
| 436 | return 0; |
| 437 | if (lwpid != tp->private->lwpid) |
| 438 | return 0; |
| 439 | |
| 440 | /* match */ |
| 441 | return 1; |
| 442 | } |
| 443 | |
| 444 | /* If a thread is associated with lwp id LWPID, return the corresponding |
| 445 | member of the global thread list; otherwise, return null. */ |
| 446 | |
| 447 | static struct thread_info * |
| 448 | find_thread_lwp (int lwpid) |
| 449 | { |
| 450 | return iterate_over_threads (find_thread_lwp_callback, (void *)lwpid); |
| 451 | } |
| 452 | |
| 453 | /* Return the composite thread/process id corresponding to composite |
| 454 | id PID. If PID is an lwp with no thread, return PID. */ |
| 455 | |
| 456 | static int |
| 457 | lwp_to_thr (int pid) |
| 458 | { |
| 459 | struct thread_info *info; |
| 460 | int tid = pid, lwpid; |
| 461 | |
| 462 | if (ISTID (pid)) |
| 463 | goto done; |
| 464 | if (!(lwpid = LIDGET (pid))) |
| 465 | goto done; |
| 466 | if (!(info = find_thread_lwp (lwpid))) |
| 467 | goto done; |
| 468 | tid = MKTID (pid, info->private->thrid); |
| 469 | |
| 470 | done: |
| 471 | DBG2((ISTID (tid) ? NULL : "lwp_to_thr: no thr for %s", dbgpid (pid))); |
| 472 | return tid; |
| 473 | } |
| 474 | |
| 475 | /* do_cleanups() callback: convert inferior_pid to a composite |
| 476 | thread/process id after having made a procfs call. */ |
| 477 | |
| 478 | static void |
| 479 | thr_infpid (void *unused) |
| 480 | { |
| 481 | int pid = lwp_to_thr (inferior_pid); |
| 482 | DBG2((" inferior_pid from procfs: %s => %s", |
| 483 | dbgpid (inferior_pid), dbgpid (pid))); |
| 484 | inferior_pid = pid; |
| 485 | } |
| 486 | |
| 487 | /* If possible, convert inferior_pid to a composite lwp/process id in |
| 488 | preparation for making a procfs call. Return success. */ |
| 489 | |
| 490 | static int |
| 491 | lwp_infpid (void) |
| 492 | { |
| 493 | int pid = thr_to_lwp (inferior_pid); |
| 494 | DBG2((" inferior_pid to procfs: %s => %s", |
| 495 | dbgpid (inferior_pid), dbgpid (pid))); |
| 496 | |
| 497 | if (!pid) |
| 498 | return 0; |
| 499 | |
| 500 | inferior_pid = pid; |
| 501 | infpid_cleanup = make_cleanup (thr_infpid, NULL); |
| 502 | return 1; |
| 503 | } |
| 504 | |
| 505 | /* Add to the global thread list a new user-mode thread with system id THRID, |
| 506 | lwp id LWPID, map address MAPP, and composite thread/process PID. */ |
| 507 | |
| 508 | static void |
| 509 | add_thread_uw (int thrid, int lwpid, CORE_ADDR mapp, int pid) |
| 510 | { |
| 511 | struct thread_info *newthread; |
| 512 | |
| 513 | if ((newthread = add_thread (pid)) == NULL) |
| 514 | error ("failed to create new thread structure"); |
| 515 | |
| 516 | newthread->private = xmalloc (sizeof (struct private_thread_info)); |
| 517 | newthread->private->stable = 1; |
| 518 | newthread->private->thrid = thrid; |
| 519 | newthread->private->lwpid = lwpid; |
| 520 | newthread->private->mapp = mapp; |
| 521 | |
| 522 | if (target_has_execution) |
| 523 | printf_unfiltered ("[New %s]\n", target_pid_to_str (pid)); |
| 524 | } |
| 525 | |
| 526 | /* notice_threads() and find_main() callback: if the thread list doesn't |
| 527 | already contain the thread described by ITER, add it if it's the main |
| 528 | thread or if !DATA. */ |
| 529 | |
| 530 | static int |
| 531 | notice_thread (iter_t *iter, void *data) |
| 532 | { |
| 533 | int thrid = iter->map.thr_tid; |
| 534 | int lwpid = !iter->map.thr_lwpp ? 0 : iter->lwp.lwp_id; |
| 535 | int pid = MKTID (inferior_pid, thrid); |
| 536 | |
| 537 | if (!find_thread_pid (pid) && (!data || thrid == 1)) |
| 538 | add_thread_uw (thrid, lwpid, iter->mapp, pid); |
| 539 | |
| 540 | return 0; |
| 541 | } |
| 542 | |
| 543 | /* Add to the thread list any threads it doesn't already contain. */ |
| 544 | |
| 545 | static void |
| 546 | notice_threads (void) |
| 547 | { |
| 548 | thread_iter (notice_thread, NULL); |
| 549 | } |
| 550 | |
| 551 | /* Return the address of the main thread's map. On error, return 0. */ |
| 552 | |
| 553 | static CORE_ADDR |
| 554 | find_main (void) |
| 555 | { |
| 556 | if (!thr_map_main) |
| 557 | { |
| 558 | struct thread_info *info; |
| 559 | thread_iter (notice_thread, (void *)1); |
| 560 | if ((info = find_thread_pid (MKTID (inferior_pid, 1)))) |
| 561 | thr_map_main = info->private->mapp; |
| 562 | } |
| 563 | return thr_map_main; |
| 564 | } |
| 565 | |
| 566 | /* Attach to process specified by ARGS, then initialize for debugging it |
| 567 | and wait for the trace-trap that results from attaching. |
| 568 | |
| 569 | This function only gets called with uw_thread_active == 0. */ |
| 570 | |
| 571 | static void |
| 572 | uw_thread_attach (char *args, int from_tty) |
| 573 | { |
| 574 | procfs_ops.to_attach (args, from_tty); |
| 575 | if (uw_thread_active) |
| 576 | thr_infpid (NULL); |
| 577 | } |
| 578 | |
| 579 | /* Detach from the process attached to by uw_thread_attach(). */ |
| 580 | |
| 581 | static void |
| 582 | uw_thread_detach (char *args, int from_tty) |
| 583 | { |
| 584 | deactivate_uw_thread (); |
| 585 | base_ops.to_detach (args, from_tty); |
| 586 | } |
| 587 | |
| 588 | /* Tell the inferior process to continue running thread PID if >= 0 |
| 589 | and all threads otherwise. */ |
| 590 | |
| 591 | static void |
| 592 | uw_thread_resume (int pid, int step, enum target_signal signo) |
| 593 | { |
| 594 | if (pid > 0 && !(pid = thr_to_lwp (pid))) |
| 595 | pid = -1; |
| 596 | |
| 597 | CALL_BASE (base_ops.to_resume (pid, step, signo)); |
| 598 | } |
| 599 | |
| 600 | /* If the trap we just received from lwp PID was due to a breakpoint |
| 601 | on the libthread.so debugging stub, update this module's state |
| 602 | accordingly. */ |
| 603 | |
| 604 | static void |
| 605 | libthread_stub (int pid) |
| 606 | { |
| 607 | CORE_ADDR sp, mapp, mapp_main; |
| 608 | enum thread_change change; |
| 609 | struct thread_map map; |
| 610 | __lwp_desc_t lwp; |
| 611 | int tid = 0, lwpid; |
| 612 | struct thread_info *info; |
| 613 | |
| 614 | /* Check for stub breakpoint. */ |
| 615 | if (read_pc_pid (pid) - DECR_PC_AFTER_BREAK != thr_brk_addr) |
| 616 | return; |
| 617 | |
| 618 | /* Retrieve stub args. */ |
| 619 | sp = read_register_pid (SP_REGNUM, pid); |
| 620 | if (!base_ops.to_xfer_memory (sp + SP_ARG0, (char *)&mapp, |
| 621 | sizeof (mapp), 0, &base_ops)) |
| 622 | goto err; |
| 623 | if (!base_ops.to_xfer_memory (sp + SP_ARG0 + sizeof (mapp), (char *)&change, |
| 624 | sizeof (change), 0, &base_ops)) |
| 625 | goto err; |
| 626 | |
| 627 | /* create_inferior() may not have finished yet, so notice the main |
| 628 | thread to ensure that it's displayed first by add_thread(). */ |
| 629 | mapp_main = find_main (); |
| 630 | |
| 631 | /* Notice thread creation, deletion, or stability change. */ |
| 632 | switch (change) { |
| 633 | case tc_switch_begin: |
| 634 | if (!mapp) /* usually means main thread */ |
| 635 | mapp = mapp_main; |
| 636 | /* fall through */ |
| 637 | |
| 638 | case tc_thread_create: |
| 639 | case tc_thread_exit: |
| 640 | if (!mapp) |
| 641 | break; |
| 642 | if (!read_map (mapp, &map)) |
| 643 | goto err; |
| 644 | tid = MKTID (pid, map.thr_tid); |
| 645 | |
| 646 | switch (change) { |
| 647 | case tc_thread_create: /* new thread */ |
| 648 | if (!map.thr_lwpp) |
| 649 | lwpid = 0; |
| 650 | else if (!read_lwp ((CORE_ADDR)map.thr_lwpp, &lwp)) |
| 651 | goto err; |
| 652 | else |
| 653 | lwpid = lwp.lwp_id; |
| 654 | add_thread_uw (map.thr_tid, lwpid, mapp, tid); |
| 655 | break; |
| 656 | |
| 657 | case tc_thread_exit: /* thread has exited */ |
| 658 | printf_unfiltered ("[Exited %s]\n", target_pid_to_str (tid)); |
| 659 | delete_thread (tid); |
| 660 | if (tid == inferior_pid) |
| 661 | inferior_pid = pid; |
| 662 | break; |
| 663 | |
| 664 | case tc_switch_begin: /* lwp is switching threads */ |
| 665 | if (switchto_thread) |
| 666 | goto err; |
| 667 | if (!(switchto_thread = find_thread_pid (tid))) |
| 668 | goto err; |
| 669 | switchto_thread->private->stable = 0; |
| 670 | break; |
| 671 | |
| 672 | default: |
| 673 | break; |
| 674 | } |
| 675 | break; |
| 676 | |
| 677 | case tc_switch_complete: /* lwp has switched threads */ |
| 678 | case tc_cancel_complete: /* lwp didn't switch threads */ |
| 679 | if (!switchto_thread) |
| 680 | goto err; |
| 681 | |
| 682 | if (change == tc_switch_complete) |
| 683 | { |
| 684 | /* If switchto_thread is the main thread, then (a) the corresponding |
| 685 | tc_switch_begin probably received a null map argument and therefore |
| 686 | (b) it may have been a spurious switch following a tc_thread_exit. |
| 687 | |
| 688 | Therefore, explicitly query the thread's lwp before caching it in |
| 689 | its thread list entry. */ |
| 690 | |
| 691 | if (!read_map (switchto_thread->private->mapp, &map)) |
| 692 | goto err; |
| 693 | if (map.thr_lwpp) |
| 694 | { |
| 695 | if (!read_lwp ((CORE_ADDR)map.thr_lwpp, &lwp)) |
| 696 | goto err; |
| 697 | if ((info = find_thread_lwp (lwp.lwp_id))) |
| 698 | info->private->lwpid = 0; |
| 699 | switchto_thread->private->lwpid = lwp.lwp_id; |
| 700 | } |
| 701 | } |
| 702 | |
| 703 | switchto_thread->private->stable = 1; |
| 704 | switchto_thread = NULL; |
| 705 | break; |
| 706 | |
| 707 | case tc_invalid: |
| 708 | case tc_thread_suspend: |
| 709 | case tc_thread_suspend_pending: |
| 710 | case tc_thread_continue: |
| 711 | err: |
| 712 | DBG(("unexpected condition in libthread_stub()")); |
| 713 | break; |
| 714 | } |
| 715 | |
| 716 | DBG2(("libthread_stub(%s): %s %s %s", dbgpid (pid), dbgpid (tid), |
| 717 | dbgchange (change), tid ? dbgstate (map.thr_state) : "")); |
| 718 | } |
| 719 | |
| 720 | /* Wait for thread/lwp/process ID if >= 0 or for any thread otherwise. */ |
| 721 | |
| 722 | static int |
| 723 | uw_thread_wait (int pid, struct target_waitstatus *status) |
| 724 | { |
| 725 | if (pid > 0) |
| 726 | pid = thr_to_lwp (pid); |
| 727 | CALL_BASE (pid = base_ops.to_wait (pid > 0 ? pid : -1, status)); |
| 728 | |
| 729 | if (status->kind == TARGET_WAITKIND_STOPPED && |
| 730 | status->value.sig == TARGET_SIGNAL_TRAP) |
| 731 | libthread_stub (pid); |
| 732 | |
| 733 | return lwp_to_thr (pid); |
| 734 | } |
| 735 | |
| 736 | /* Tell gdb about the registers in the thread/lwp/process specified by |
| 737 | inferior_pid. */ |
| 738 | |
| 739 | static void |
| 740 | uw_thread_fetch_registers (int regno) |
| 741 | { |
| 742 | int called; |
| 743 | struct thread_info *info; |
| 744 | struct thread_map map; |
| 745 | |
| 746 | TRY_BASE (base_ops.to_fetch_registers (regno), &called); |
| 747 | if (called) |
| 748 | return; |
| 749 | |
| 750 | if (!(info = find_thread_pid (inferior_pid))) |
| 751 | return; |
| 752 | if (!read_map (info->private->mapp, &map)) |
| 753 | return; |
| 754 | |
| 755 | supply_gregset (&map.thr_ucontext.uc_mcontext.gregs); |
| 756 | supply_fpregset (&map.thr_ucontext.uc_mcontext.fpregs); |
| 757 | } |
| 758 | |
| 759 | /* Store gdb's current view of the register set into the thread/lwp/process |
| 760 | specified by inferior_pid. */ |
| 761 | |
| 762 | static void |
| 763 | uw_thread_store_registers (int regno) |
| 764 | { |
| 765 | CALL_BASE (base_ops.to_store_registers (regno)); |
| 766 | } |
| 767 | |
| 768 | /* Prepare to modify the registers array. */ |
| 769 | |
| 770 | static void |
| 771 | uw_thread_prepare_to_store (void) |
| 772 | { |
| 773 | CALL_BASE (base_ops.to_prepare_to_store ()); |
| 774 | } |
| 775 | |
| 776 | /* Fork an inferior process and start debugging it. |
| 777 | |
| 778 | This function only gets called with uw_thread_active == 0. */ |
| 779 | |
| 780 | static void |
| 781 | uw_thread_create_inferior (char *exec_file, char *allargs, char **env) |
| 782 | { |
| 783 | if (uw_thread_active) |
| 784 | deactivate_uw_thread (); |
| 785 | |
| 786 | procfs_ops.to_create_inferior (exec_file, allargs, env); |
| 787 | if (uw_thread_active) |
| 788 | { |
| 789 | find_main (); |
| 790 | thr_infpid (NULL); |
| 791 | } |
| 792 | } |
| 793 | |
| 794 | /* Kill and forget about the inferior process. */ |
| 795 | |
| 796 | static void |
| 797 | uw_thread_kill (void) |
| 798 | { |
| 799 | base_ops.to_kill (); |
| 800 | } |
| 801 | |
| 802 | /* Clean up after the inferior exits. */ |
| 803 | |
| 804 | static void |
| 805 | uw_thread_mourn_inferior (void) |
| 806 | { |
| 807 | deactivate_uw_thread (); |
| 808 | base_ops.to_mourn_inferior (); |
| 809 | } |
| 810 | |
| 811 | /* Return whether this module can attach to and run processes. |
| 812 | |
| 813 | This function only gets called with uw_thread_active == 0. */ |
| 814 | |
| 815 | static int |
| 816 | uw_thread_can_run (void) |
| 817 | { |
| 818 | return procfs_suppress_run; |
| 819 | } |
| 820 | |
| 821 | /* Return whether thread PID is still valid. */ |
| 822 | |
| 823 | static int |
| 824 | uw_thread_alive (int pid) |
| 825 | { |
| 826 | if (!ISTID (pid)) |
| 827 | return base_ops.to_thread_alive (pid); |
| 828 | |
| 829 | /* If it's in the thread list, it's valid, because otherwise |
| 830 | libthread_stub() would have deleted it. */ |
| 831 | return in_thread_list (pid); |
| 832 | } |
| 833 | |
| 834 | /* Add to the thread list any threads and lwps it doesn't already contain. */ |
| 835 | |
| 836 | static void |
| 837 | uw_thread_find_new_threads (void) |
| 838 | { |
| 839 | CALL_BASE (if (base_ops.to_find_new_threads) |
| 840 | base_ops.to_find_new_threads ()); |
| 841 | notice_threads (); |
| 842 | } |
| 843 | |
| 844 | /* Return a string for pretty-printing PID in "info threads" output. |
| 845 | This may be called by either procfs.c or by generic gdb. */ |
| 846 | |
| 847 | static char * |
| 848 | uw_thread_pid_to_str (int pid) |
| 849 | { |
| 850 | #define FMT "Thread %d" |
| 851 | static char buf[sizeof (FMT) + 3 * sizeof (pid)]; |
| 852 | |
| 853 | if (!ISTID (pid)) |
| 854 | /* core_ops says "process foo", so call procfs_ops explicitly. */ |
| 855 | return procfs_ops.to_pid_to_str (pid); |
| 856 | |
| 857 | sprintf (buf, FMT, TIDGET (pid)); |
| 858 | #undef FMT |
| 859 | return buf; |
| 860 | } |
| 861 | |
| 862 | /* Return a string displaying INFO state information in "info threads" |
| 863 | output. */ |
| 864 | |
| 865 | static char * |
| 866 | uw_extra_thread_info (struct thread_info *info) |
| 867 | { |
| 868 | static char buf[80]; |
| 869 | struct thread_map map; |
| 870 | __lwp_desc_t lwp; |
| 871 | int lwpid; |
| 872 | char *name; |
| 873 | |
| 874 | if (!ISTID (info->pid)) |
| 875 | return NULL; |
| 876 | |
| 877 | if (!info->private->stable) |
| 878 | return "switching"; |
| 879 | |
| 880 | if (!read_map (info->private->mapp, &map)) |
| 881 | return NULL; |
| 882 | |
| 883 | if (!map.thr_lwpp || !read_lwp ((CORE_ADDR)map.thr_lwpp, &lwp)) |
| 884 | lwpid = 0; |
| 885 | else |
| 886 | lwpid = lwp.lwp_id; |
| 887 | |
| 888 | switch (map.thr_state) { |
| 889 | case TS_ONPROC: name = "running"; break; |
| 890 | case TS_SLEEP: name = "sleeping"; break; |
| 891 | case TS_RUNNABLE: name = "runnable"; break; |
| 892 | case TS_ZOMBIE: name = "zombie"; break; |
| 893 | case TS_SUSPENDED: name = "suspended"; break; |
| 894 | #ifdef TS_FORK |
| 895 | case TS_FORK: name = "forking"; break; |
| 896 | #endif |
| 897 | default: name = "confused"; break; |
| 898 | } |
| 899 | |
| 900 | if (!lwpid) |
| 901 | return name; |
| 902 | |
| 903 | sprintf (buf, "%s, LWP %d", name, lwpid); |
| 904 | return buf; |
| 905 | } |
| 906 | |
| 907 | /* Check whether libthread.so has just been loaded, and if so, try to |
| 908 | initialize user-space thread debugging support. |
| 909 | |
| 910 | libthread.so loading happens while (a) an inferior process is being |
| 911 | started by procfs and (b) a core image is being loaded. |
| 912 | |
| 913 | This function often gets called with uw_thread_active == 0. */ |
| 914 | |
| 915 | static void |
| 916 | libthread_init (void) |
| 917 | { |
| 918 | struct minimal_symbol *ms; |
| 919 | struct thread_debug debug; |
| 920 | CORE_ADDR onp; |
| 921 | struct breakpoint *b; |
| 922 | int one = 1; |
| 923 | |
| 924 | /* Don't initialize twice. */ |
| 925 | if (uw_thread_active) |
| 926 | return; |
| 927 | |
| 928 | /* Check whether libthread.so has been loaded. */ |
| 929 | if (!(ms = lookup_minimal_symbol ("_thr_debug", NULL, NULL))) |
| 930 | return; |
| 931 | |
| 932 | /* Cache _thr_debug's address. */ |
| 933 | if (!(thr_debug_addr = SYMBOL_VALUE_ADDRESS (ms))) |
| 934 | return; |
| 935 | |
| 936 | /* Initialize base_ops.to_xfer_memory(). */ |
| 937 | base_ops = current_target; |
| 938 | |
| 939 | /* Load _thr_debug's current contents. */ |
| 940 | if (!read_thr_debug (&debug)) |
| 941 | return; |
| 942 | |
| 943 | /* User code (e.g. my test programs) may dereference _thr_debug, |
| 944 | making it availble to GDB before shared libs are loaded. */ |
| 945 | if (!debug.thr_map) |
| 946 | return; |
| 947 | |
| 948 | /* libthread.so has been loaded, and the current_target should now |
| 949 | reflect core_ops or procfs_ops. */ |
| 950 | push_target (&uw_thread_ops); /* must precede notice_threads() */ |
| 951 | uw_thread_active = 1; |
| 952 | |
| 953 | if (!target_has_execution) |
| 954 | |
| 955 | /* Locate threads in core file. */ |
| 956 | notice_threads (); |
| 957 | |
| 958 | else |
| 959 | { |
| 960 | /* Set a breakpoint on the stub function provided by libthread.so. */ |
| 961 | thr_brk_addr = (CORE_ADDR)debug.thr_brk; |
| 962 | if (!(b = create_thread_event_breakpoint (thr_brk_addr))) |
| 963 | goto err; |
| 964 | |
| 965 | /* Activate the stub function. */ |
| 966 | onp = (CORE_ADDR)&((struct thread_debug *)thr_debug_addr)->thr_debug_on; |
| 967 | if (!base_ops.to_xfer_memory ((CORE_ADDR)onp, (char *)&one, |
| 968 | sizeof (one), 1, &base_ops)) |
| 969 | { |
| 970 | delete_breakpoint (b); |
| 971 | goto err; |
| 972 | } |
| 973 | |
| 974 | /* Prepare for finding the main thread, which doesn't yet exist. */ |
| 975 | thr_map_main = 0; |
| 976 | } |
| 977 | |
| 978 | return; |
| 979 | |
| 980 | err: |
| 981 | warning ("uw-thread: unable to initialize user-mode thread debugging\n"); |
| 982 | deactivate_uw_thread (); |
| 983 | } |
| 984 | |
| 985 | /* target_new_objfile_hook callback. |
| 986 | |
| 987 | If OBJFILE is non-null, check whether libthread.so was just loaded, |
| 988 | and if so, prepare for user-mode thread debugging. |
| 989 | |
| 990 | If OBJFILE is null, libthread.so has gone away, so stop debugging |
| 991 | user-mode threads. |
| 992 | |
| 993 | This function often gets called with uw_thread_active == 0. */ |
| 994 | |
| 995 | static void |
| 996 | uw_thread_new_objfile (struct objfile *objfile) |
| 997 | { |
| 998 | if (objfile) |
| 999 | libthread_init (); |
| 1000 | |
| 1001 | else if (uw_thread_active) |
| 1002 | deactivate_uw_thread (); |
| 1003 | |
| 1004 | if (target_new_objfile_chain) |
| 1005 | target_new_objfile_chain (objfile); |
| 1006 | } |
| 1007 | |
| 1008 | /* Initialize uw_thread_ops. */ |
| 1009 | |
| 1010 | static void |
| 1011 | init_uw_thread_ops (void) |
| 1012 | { |
| 1013 | uw_thread_ops.to_shortname = "unixware-threads"; |
| 1014 | uw_thread_ops.to_longname = "UnixWare threads and pthread."; |
| 1015 | uw_thread_ops.to_doc = "UnixWare threads and pthread support."; |
| 1016 | uw_thread_ops.to_attach = uw_thread_attach; |
| 1017 | uw_thread_ops.to_detach = uw_thread_detach; |
| 1018 | uw_thread_ops.to_resume = uw_thread_resume; |
| 1019 | uw_thread_ops.to_wait = uw_thread_wait; |
| 1020 | uw_thread_ops.to_fetch_registers = uw_thread_fetch_registers; |
| 1021 | uw_thread_ops.to_store_registers = uw_thread_store_registers; |
| 1022 | uw_thread_ops.to_prepare_to_store = uw_thread_prepare_to_store; |
| 1023 | uw_thread_ops.to_create_inferior = uw_thread_create_inferior; |
| 1024 | uw_thread_ops.to_kill = uw_thread_kill; |
| 1025 | uw_thread_ops.to_mourn_inferior = uw_thread_mourn_inferior; |
| 1026 | uw_thread_ops.to_can_run = uw_thread_can_run; |
| 1027 | uw_thread_ops.to_thread_alive = uw_thread_alive; |
| 1028 | uw_thread_ops.to_find_new_threads = uw_thread_find_new_threads; |
| 1029 | uw_thread_ops.to_pid_to_str = uw_thread_pid_to_str; |
| 1030 | uw_thread_ops.to_extra_thread_info = uw_extra_thread_info; |
| 1031 | uw_thread_ops.to_stratum = thread_stratum; |
| 1032 | uw_thread_ops.to_magic = OPS_MAGIC; |
| 1033 | } |
| 1034 | |
| 1035 | /* Module startup initialization function, automagically called by |
| 1036 | init.c. */ |
| 1037 | |
| 1038 | void |
| 1039 | _initialize_uw_thread (void) |
| 1040 | { |
| 1041 | init_uw_thread_ops (); |
| 1042 | add_target (&uw_thread_ops); |
| 1043 | |
| 1044 | procfs_suppress_run = 1; |
| 1045 | |
| 1046 | /* Notice when libthread.so gets loaded. */ |
| 1047 | target_new_objfile_chain = target_new_objfile_hook; |
| 1048 | target_new_objfile_hook = uw_thread_new_objfile; |
| 1049 | } |