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c5394b80 JM |
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 | ||
6 | This file is part of GDB. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 59 Temple Place - Suite 330, | |
21 | Boston, MA 02111-1307, USA. */ | |
22 | ||
23 | ||
24 | /* Like many systems, UnixWare implements two classes of threads: | |
25 | kernel-mode threads, which are scheduled by the kernel; and | |
26 | user-mode threads, which are scheduled by a library. UnixWare | |
27 | calls these two classes lightweight processes (LWPs) and threads, | |
28 | respectively. | |
29 | ||
30 | This module deals with user-mode threads. It calls procfs_ops | |
31 | functions to deal with LWPs and processes and core_ops functions to | |
32 | deal with core files. | |
33 | ||
34 | As of this writing, the user-mode thread debugging interface is not | |
35 | documented beyond the comments in <thread.h>. The following | |
36 | description has been gleaned from experience and from information | |
37 | provided by SCO. | |
38 | ||
39 | libthread.so, against which all UnixWare user-mode thread programs | |
40 | link, provides a global thread_debug structure named _thr_debug. | |
41 | It has three fields: | |
42 | ||
43 | (1) thr_map is a pointer to a pointer to an element of a | |
44 | thread_map ring. A thread_map contains a single thread's id | |
45 | number, state, LWP pointer, recent register state, and other | |
46 | useful information. | |
47 | ||
48 | (2) thr_brk is a pointer to a stub function that libthread.so | |
49 | calls when it changes a thread's state, e.g. by creating it, | |
50 | switching it to an LWP, or causing it to exit. | |
51 | ||
52 | (3) thr_debug_on controls whether libthread.so calls thr_brk(). | |
53 | ||
54 | Debuggers are able to track thread activity by setting a private | |
55 | breakpoint on thr_brk() and setting thr_debug_on to 1. | |
56 | ||
57 | thr_brk() receives two arguments: | |
58 | ||
59 | (1) a pointer to a thread_map describing the thread being | |
60 | changed; and | |
61 | ||
62 | (2) an enum thread_change specifying one of the following | |
63 | changes: | |
64 | ||
65 | invalid unknown | |
66 | thread_create thread has just been created | |
67 | thread_exit thread has just exited | |
68 | switch_begin thread will be switched to an LWP | |
69 | switch_complete thread has been switched to an LWP | |
70 | cancel_complete thread wasn't switched to an LWP | |
71 | thread_suspend thread has been thr_suspend()ed | |
72 | thread_suspend_pending thread will be thr_suspend()ed | |
73 | thread_continue thread has been thr_continue()d | |
74 | ||
75 | The thread_map argument to thr_brk() is NULL under the following | |
76 | circumstances: | |
77 | ||
78 | - The main thread is being acted upon. The main thread always | |
79 | has id 1, so its thread_map is easy to find by scanning through | |
80 | _thr_debug.thr_map. | |
81 | ||
82 | - A "switch_complete" change is occurring, which means that the | |
83 | thread specified in the most recent "switch_begin" change has | |
84 | moved to an LWP. | |
85 | ||
86 | - A "cancel_complete" change is occurring, which means that the | |
87 | thread specified in the most recent "switch_begin" change has | |
88 | not moved to an LWP after all. | |
89 | ||
90 | - A spurious "switch_begin" change is occurring after a | |
91 | "thread_exit" change. | |
92 | ||
93 | Between switch_begin and switch_complete or cancel_complete, the | |
94 | affected thread's LWP pointer is not reliable. It is possible that | |
95 | other parts of the thread's thread_map are also unreliable during | |
96 | that time. */ | |
97 | ||
98 | ||
99 | #include "defs.h" | |
100 | #include "gdbthread.h" | |
101 | #include "target.h" | |
102 | #include "inferior.h" | |
103 | #include <fcntl.h> | |
104 | ||
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 | ||
116 | /* | |
117 | * Whether to emit debugging output. | |
118 | */ | |
119 | #define DEBUG 0 | |
120 | ||
121 | /* | |
122 | * Default debugging output file, overridden by envvar UWTHR_DEBUG. | |
123 | */ | |
124 | #define DEBUG_FILE "/dev/tty" | |
125 | ||
126 | /* | |
127 | * #if DEBUG, write string S to the debugging output channel. | |
128 | */ | |
129 | #if !DEBUG | |
130 | # define DBG(fmt_and_args) | |
131 | # define DBG2(fmt_and_args) | |
132 | #else | |
133 | # define DBG(fmt_and_args) dbg fmt_and_args | |
134 | # define DBG2(fmt_and_args) | |
135 | #endif | |
136 | ||
137 | /* | |
138 | * Back end to CALL_BASE() and TRY_BASE(): evaluate CALL, then convert | |
139 | * inferior_pid to a composite thread/process id. | |
140 | */ | |
141 | #define CALL_BASE_1(call) \ | |
142 | do { \ | |
143 | DBG2(("CALL_BASE(" #call ")")); \ | |
144 | call; \ | |
145 | do_cleanups (infpid_cleanup); \ | |
146 | } while (0) | |
147 | ||
148 | /* | |
149 | * If inferior_pid can be converted to a composite lwp/process id, do so, | |
150 | * evaluate base_ops function CALL, and then convert inferior_pid back to a | |
151 | * composite thread/process id. | |
152 | * | |
153 | * Otherwise, issue an error message and return nonlocally. | |
154 | */ | |
155 | #define CALL_BASE(call) \ | |
156 | do { \ | |
157 | if (!lwp_infpid ()) \ | |
158 | error ("uw-thread: "__FUNCTION__": no lwp"); \ | |
159 | CALL_BASE_1 (call); \ | |
160 | } while (0) | |
161 | ||
162 | /* | |
163 | * Like CALL_BASE(), but instead of returning nonlocally on error, set | |
164 | * *CALLED to whether the inferior_pid conversion was successful. | |
165 | */ | |
166 | #define TRY_BASE(call, called) \ | |
167 | do { \ | |
168 | if ((*(called) = lwp_infpid ())) \ | |
169 | CALL_BASE_1 (call); \ | |
170 | } while (0) | |
171 | ||
172 | /* | |
173 | * Information passed by thread_iter() to its callback parameter. | |
174 | */ | |
175 | typedef struct { | |
176 | struct thread_map map; | |
177 | __lwp_desc_t lwp; | |
178 | CORE_ADDR mapp; | |
179 | } iter_t; | |
180 | ||
181 | /* | |
182 | * Private thread data for the thread_info struct. | |
183 | */ | |
184 | struct private_thread_info { | |
185 | int stable; /* 0 if libthread.so is modifying thread map */ | |
186 | int thrid; /* thread id assigned by libthread.so */ | |
187 | int lwpid; /* thread's lwp if .stable, 0 means no lwp */ | |
188 | CORE_ADDR mapp; /* address of thread's map structure */ | |
189 | }; | |
190 | ||
191 | ||
192 | /* procfs.c's target-specific operations. */ | |
193 | extern struct target_ops procfs_ops; | |
194 | ||
195 | /* Flag to prevent procfs.c from starting inferior processes. */ | |
196 | extern int procfs_suppress_run; | |
197 | ||
198 | /* This module's target-specific operations. */ | |
199 | static struct target_ops uw_thread_ops; | |
200 | ||
201 | /* Copy of the target over which uw_thread_ops is pushed. This is | |
202 | more convenient than a pointer to procfs_ops or core_ops, because | |
203 | they lack current_target's default callbacks. */ | |
204 | static struct target_ops base_ops; | |
205 | ||
206 | /* Saved pointer to previous owner of target_new_objfile_hook. */ | |
207 | static void (*target_new_objfile_chain)(struct objfile *); | |
208 | ||
209 | /* Whether we are debugging a user-space thread program. This isn't | |
210 | set until after libthread.so is loaded by the program being | |
211 | debugged. | |
212 | ||
213 | Except for module one-time intialization and where otherwise | |
214 | documented, no functions in this module get called when | |
215 | !uw_thread_active. */ | |
216 | static int uw_thread_active; | |
217 | ||
218 | /* For efficiency, cache the addresses of libthread.so's _thr_debug | |
219 | structure, its thr_brk stub function, and the main thread's map. */ | |
220 | static CORE_ADDR thr_debug_addr; | |
221 | static CORE_ADDR thr_brk_addr; | |
222 | static CORE_ADDR thr_map_main; | |
223 | ||
224 | /* Remember the thread most recently marked as switching. Necessary because | |
225 | libthread.so passes null map when calling stub with tc_*_complete. */ | |
226 | static struct thread_info *switchto_thread; | |
227 | ||
228 | /* Cleanup chain for safely restoring inferior_pid after CALL_BASE. */ | |
229 | static struct cleanup *infpid_cleanup; | |
230 | ||
231 | ||
232 | #if DEBUG | |
233 | /* | |
234 | * Helper function for DBG() macro: if printf-style FMT is non-null, format it | |
235 | * with args and display the result on the debugging output channel. | |
236 | */ | |
237 | static void | |
238 | dbg (char *fmt, ...) | |
239 | { | |
240 | static int fd = -1, len; | |
241 | va_list args; | |
242 | char buf[1024]; | |
243 | char *path; | |
244 | ||
245 | if (!fmt) | |
246 | return; | |
247 | ||
248 | if (fd < 0) | |
249 | { | |
250 | path = getenv ("UWTHR_DEBUG"); | |
251 | if (!path) | |
252 | path = DEBUG_FILE; | |
253 | if ((fd = open (path, O_WRONLY | O_CREAT | O_TRUNC, 0664)) < 0) | |
254 | error ("can't open %s\n", path); | |
255 | } | |
256 | ||
257 | va_start (args, fmt); | |
258 | vsprintf (buf, fmt, args); | |
259 | va_end (args); | |
260 | ||
261 | len = strlen (buf); | |
262 | buf[len] = '\n'; | |
263 | (void)write (fd, buf, len + 1); | |
264 | } | |
265 | ||
266 | #if 0 | |
267 | /* | |
268 | * Return a string representing composite PID's components. | |
269 | */ | |
270 | static char * | |
271 | dbgpid (int pid) | |
272 | { | |
273 | static char *buf, buf1[80], buf2[80]; | |
274 | if (!buf || buf == buf2) | |
275 | buf = buf1; | |
276 | else | |
277 | buf = buf2; | |
278 | ||
279 | if (pid <= 0) | |
280 | sprintf (buf, "%d", pid); | |
281 | else | |
282 | sprintf (buf, "%s %d/%d", ISTID (pid) ? "thr" : "lwp", | |
283 | TIDGET (pid), PIDGET (pid)); | |
284 | ||
285 | return buf; | |
286 | } | |
287 | ||
288 | /* | |
289 | * Return a string representing thread state CHANGE. | |
290 | */ | |
291 | static char * | |
292 | dbgchange (enum thread_change change) | |
293 | { | |
294 | switch (change) { | |
295 | case tc_invalid: return "invalid"; | |
296 | case tc_thread_create: return "thread_create"; | |
297 | case tc_thread_exit: return "thread_exit"; | |
298 | case tc_switch_begin: return "switch_begin"; | |
299 | case tc_switch_complete: return "switch_complete"; | |
300 | case tc_cancel_complete: return "cancel_complete"; | |
301 | case tc_thread_suspend: return "thread_suspend"; | |
302 | case tc_thread_suspend_pending: return "thread_suspend_pending"; | |
303 | case tc_thread_continue: return "thread_continue"; | |
304 | default: return "unknown"; | |
305 | } | |
306 | } | |
307 | ||
308 | /* | |
309 | * Return a string representing thread STATE. | |
310 | */ | |
311 | static char * | |
312 | dbgstate (int state) | |
313 | { | |
314 | switch (state) { | |
315 | case TS_ONPROC: return "running"; | |
316 | case TS_SLEEP: return "sleeping"; | |
317 | case TS_RUNNABLE: return "runnable"; | |
318 | case TS_ZOMBIE: return "zombie"; | |
319 | case TS_SUSPENDED: return "suspended"; | |
320 | #ifdef TS_FORK | |
321 | case TS_FORK: return "forking"; | |
322 | #endif | |
323 | default: return "confused"; | |
324 | } | |
325 | } | |
326 | #endif /* 0 */ | |
327 | #endif /* DEBUG */ | |
328 | ||
329 | ||
330 | /* | |
331 | * Read the contents of _thr_debug into *DEBUGP. Return success. | |
332 | */ | |
333 | static int | |
334 | read_thr_debug (struct thread_debug *debugp) | |
335 | { | |
336 | return base_ops.to_xfer_memory (thr_debug_addr, (char *)debugp, | |
337 | sizeof (*debugp), 0, &base_ops); | |
338 | } | |
339 | ||
340 | /* | |
341 | * Read into MAP the contents of the thread map at inferior process address | |
342 | * MAPP. Return success. | |
343 | */ | |
344 | static int | |
345 | read_map (CORE_ADDR mapp, struct thread_map *map) | |
346 | { | |
347 | return base_ops.to_xfer_memory ((CORE_ADDR)THR_MAP (mapp), (char *)map, | |
348 | sizeof (*map), 0, &base_ops); | |
349 | } | |
350 | ||
351 | /* | |
352 | * Read into LWP the contents of the lwp decriptor at inferior process address | |
353 | * LWPP. Return success. | |
354 | */ | |
355 | static int | |
356 | read_lwp (CORE_ADDR lwpp, __lwp_desc_t *lwp) | |
357 | { | |
358 | return base_ops.to_xfer_memory (lwpp, (char *)lwp, | |
359 | sizeof (*lwp), 0, &base_ops); | |
360 | } | |
361 | ||
362 | /* | |
363 | * Iterate through all user threads, applying FUNC(<map>, <lwp>, DATA) until | |
364 | * (a) FUNC returns nonzero, | |
365 | * (b) FUNC has been applied to all threads, or | |
366 | * (c) an error occurs, | |
367 | * where <map> is the thread's struct thread_map and <lwp> if non-null is the | |
368 | * thread's current __lwp_desc_t. | |
369 | * | |
370 | * If a call to FUNC returns nonzero, return that value; otherwise, return 0. | |
371 | */ | |
372 | static int | |
373 | thread_iter (int (*func)(iter_t *, void *), void *data) | |
374 | { | |
375 | struct thread_debug debug; | |
376 | CORE_ADDR first, mapp; | |
377 | iter_t iter; | |
378 | int ret; | |
379 | ||
380 | if (!read_thr_debug (&debug)) | |
381 | return 0; | |
382 | if (!base_ops.to_xfer_memory ((CORE_ADDR)debug.thr_map, (char *)&mapp, | |
383 | sizeof (mapp), 0, &base_ops)) | |
384 | return 0; | |
385 | if (!mapp) | |
386 | return 0; | |
387 | ||
388 | for (first = mapp;;) | |
389 | { | |
390 | if (!read_map (mapp, &iter.map)) | |
391 | return 0; | |
392 | ||
393 | if (iter.map.thr_lwpp) | |
394 | if (!read_lwp ((CORE_ADDR)iter.map.thr_lwpp, &iter.lwp)) | |
395 | return 0; | |
396 | ||
397 | iter.mapp = mapp; | |
398 | if ((ret = func (&iter, data))) | |
399 | return ret; | |
400 | ||
401 | mapp = (CORE_ADDR)iter.map.thr_next; | |
402 | if (mapp == first) | |
403 | return 0; | |
404 | } | |
405 | } | |
406 | ||
407 | /* | |
408 | * Deactivate user-mode thread support. | |
409 | */ | |
410 | static void | |
411 | deactivate_uw_thread (void) | |
412 | { | |
413 | uw_thread_active = 0; | |
414 | unpush_target (&uw_thread_ops); | |
415 | } | |
416 | ||
417 | /* | |
418 | * Return the composite lwp/process id corresponding to composite | |
419 | * id PID. If PID is a thread with no lwp, return 0. | |
420 | */ | |
421 | static int | |
422 | thr_to_lwp (int pid) | |
423 | { | |
424 | struct thread_info *info; | |
425 | int lid; | |
426 | ||
427 | if (!ISTID (pid)) | |
428 | lid = pid; | |
429 | else if (!(info = find_thread_pid (pid))) | |
430 | lid = 0; | |
431 | else if (!info->private->lwpid) | |
432 | lid = 0; | |
433 | else | |
434 | lid = MKLID (pid, info->private->lwpid); | |
435 | ||
436 | DBG2((" thr_to_lwp(%s) = %s", dbgpid (pid), dbgpid (lid))); | |
437 | return lid; | |
438 | } | |
439 | ||
440 | /* | |
441 | * find_thread_lwp() callback: return whether TP describes a thread | |
442 | * associated with lwp id DATA. | |
443 | */ | |
444 | static int | |
445 | find_thread_lwp_callback (struct thread_info *tp, void *data) | |
446 | { | |
447 | int lwpid = (int)data; | |
448 | ||
449 | if (!ISTID (tp->pid)) | |
450 | return 0; | |
451 | if (!tp->private->stable) | |
452 | return 0; | |
453 | if (lwpid != tp->private->lwpid) | |
454 | return 0; | |
455 | ||
456 | /* match */ | |
457 | return 1; | |
458 | } | |
459 | ||
460 | /* | |
461 | * If a thread is associated with lwp id LWPID, return the corresponding | |
462 | * member of the global thread list; otherwise, return null. | |
463 | */ | |
464 | static struct thread_info * | |
465 | find_thread_lwp (int lwpid) | |
466 | { | |
467 | return iterate_over_threads (find_thread_lwp_callback, (void *)lwpid); | |
468 | } | |
469 | ||
470 | /* | |
471 | * Return the composite thread/process id corresponding to composite | |
472 | * id PID. If PID is an lwp with no thread, return PID. | |
473 | */ | |
474 | static int | |
475 | lwp_to_thr (int pid) | |
476 | { | |
477 | struct thread_info *info; | |
478 | int tid = pid, lwpid; | |
479 | ||
480 | if (ISTID (pid)) | |
481 | goto done; | |
482 | if (!(lwpid = LIDGET (pid))) | |
483 | goto done; | |
484 | if (!(info = find_thread_lwp (lwpid))) | |
485 | goto done; | |
486 | tid = MKTID (pid, info->private->thrid); | |
487 | ||
488 | done: | |
489 | DBG2((ISTID (tid) ? NULL : "lwp_to_thr: no thr for %s", dbgpid (pid))); | |
490 | return tid; | |
491 | } | |
492 | ||
493 | /* | |
494 | * do_cleanups() callback: convert inferior_pid to a composite | |
495 | * thread/process id after having made a procfs call. | |
496 | */ | |
497 | static void | |
498 | thr_infpid (void *unused) | |
499 | { | |
500 | int pid = lwp_to_thr (inferior_pid); | |
501 | DBG2((" inferior_pid from procfs: %s => %s", | |
502 | dbgpid (inferior_pid), dbgpid (pid))); | |
503 | inferior_pid = pid; | |
504 | } | |
505 | ||
506 | /* | |
507 | * If possible, convert inferior_pid to a composite lwp/process id in | |
508 | * preparation for making a procfs call. Return success. | |
509 | */ | |
510 | static int | |
511 | lwp_infpid (void) | |
512 | { | |
513 | int pid = thr_to_lwp (inferior_pid); | |
514 | DBG2((" inferior_pid to procfs: %s => %s", | |
515 | dbgpid (inferior_pid), dbgpid (pid))); | |
516 | ||
517 | if (!pid) | |
518 | return 0; | |
519 | ||
520 | inferior_pid = pid; | |
521 | infpid_cleanup = make_cleanup (thr_infpid, NULL); | |
522 | return 1; | |
523 | } | |
524 | ||
525 | /* | |
526 | * Add to the global thread list a new user-mode thread with system id THRID, | |
527 | * lwp id LWPID, map address MAPP, and composite thread/process PID. | |
528 | */ | |
529 | static void | |
530 | add_thread_uw (int thrid, int lwpid, CORE_ADDR mapp, int pid) | |
531 | { | |
532 | struct thread_info *newthread; | |
533 | ||
534 | if ((newthread = add_thread (pid)) == NULL) | |
535 | error ("failed to create new thread structure"); | |
536 | ||
537 | newthread->private = xmalloc (sizeof (struct private_thread_info)); | |
538 | newthread->private->stable = 1; | |
539 | newthread->private->thrid = thrid; | |
540 | newthread->private->lwpid = lwpid; | |
541 | newthread->private->mapp = mapp; | |
542 | ||
543 | if (target_has_execution) | |
544 | printf_unfiltered ("[New %s]\n", target_pid_to_str (pid)); | |
545 | } | |
546 | ||
547 | /* | |
548 | * notice_threads() and find_main() callback: if the thread list doesn't | |
549 | * already contain the thread described by ITER, add it if it's the main | |
550 | * thread or if !DATA. | |
551 | */ | |
552 | static int | |
553 | notice_thread (iter_t *iter, void *data) | |
554 | { | |
555 | int thrid = iter->map.thr_tid; | |
556 | int lwpid = !iter->map.thr_lwpp ? 0 : iter->lwp.lwp_id; | |
557 | int pid = MKTID (inferior_pid, thrid); | |
558 | ||
559 | if (!find_thread_pid (pid) && (!data || thrid == 1)) | |
560 | add_thread_uw (thrid, lwpid, iter->mapp, pid); | |
561 | ||
562 | return 0; | |
563 | } | |
564 | ||
565 | /* | |
566 | * Add to the thread list any threads it doesn't already contain. | |
567 | */ | |
568 | static void | |
569 | notice_threads (void) | |
570 | { | |
571 | thread_iter (notice_thread, NULL); | |
572 | } | |
573 | ||
574 | /* | |
575 | * Return the address of the main thread's map. On error, return 0. | |
576 | */ | |
577 | static CORE_ADDR | |
578 | find_main (void) | |
579 | { | |
580 | if (!thr_map_main) | |
581 | { | |
582 | struct thread_info *info; | |
583 | thread_iter (notice_thread, (void *)1); | |
584 | if ((info = find_thread_pid (MKTID (inferior_pid, 1)))) | |
585 | thr_map_main = info->private->mapp; | |
586 | } | |
587 | return thr_map_main; | |
588 | } | |
589 | ||
590 | /* | |
591 | * Attach to process specified by ARGS, then initialize for debugging it | |
592 | * and wait for the trace-trap that results from attaching. | |
593 | * | |
594 | * This function only gets called with uw_thread_active == 0. | |
595 | */ | |
596 | static void | |
597 | uw_thread_attach (char *args, int from_tty) | |
598 | { | |
599 | procfs_ops.to_attach (args, from_tty); | |
600 | if (uw_thread_active) | |
601 | thr_infpid (NULL); | |
602 | } | |
603 | ||
604 | /* | |
605 | * Detach from the process attached to by uw_thread_attach(). | |
606 | */ | |
607 | static void | |
608 | uw_thread_detach (char *args, int from_tty) | |
609 | { | |
610 | deactivate_uw_thread (); | |
611 | base_ops.to_detach (args, from_tty); | |
612 | } | |
613 | ||
614 | /* | |
615 | * Tell the inferior process to continue running thread PID if >= 0 | |
616 | * and all threads otherwise. | |
617 | */ | |
618 | static void | |
619 | uw_thread_resume (int pid, int step, enum target_signal signo) | |
620 | { | |
621 | if (pid > 0 && !(pid = thr_to_lwp (pid))) | |
622 | pid = -1; | |
623 | ||
624 | CALL_BASE (base_ops.to_resume (pid, step, signo)); | |
625 | } | |
626 | ||
627 | /* | |
628 | * If the trap we just received from lwp PID was due to a breakpoint | |
629 | * on the libthread.so debugging stub, update this module's state | |
630 | * accordingly. | |
631 | */ | |
632 | static void | |
633 | libthread_stub (int pid) | |
634 | { | |
635 | CORE_ADDR sp, mapp, mapp_main; | |
636 | enum thread_change change; | |
637 | struct thread_map map; | |
638 | __lwp_desc_t lwp; | |
639 | int tid = 0, lwpid; | |
640 | struct thread_info *info; | |
641 | ||
642 | /* Check for stub breakpoint. */ | |
643 | if (read_pc_pid (pid) - DECR_PC_AFTER_BREAK != thr_brk_addr) | |
644 | return; | |
645 | ||
646 | /* Retrieve stub args. */ | |
647 | sp = read_register_pid (SP_REGNUM, pid); | |
648 | if (!base_ops.to_xfer_memory (sp + SP_ARG0, (char *)&mapp, | |
649 | sizeof (mapp), 0, &base_ops)) | |
650 | goto err; | |
651 | if (!base_ops.to_xfer_memory (sp + SP_ARG0 + sizeof (mapp), (char *)&change, | |
652 | sizeof (change), 0, &base_ops)) | |
653 | goto err; | |
654 | ||
655 | /* create_inferior() may not have finished yet, so notice the main | |
656 | thread to ensure that it's displayed first by add_thread(). */ | |
657 | mapp_main = find_main (); | |
658 | ||
659 | /* Notice thread creation, deletion, or stability change. */ | |
660 | switch (change) { | |
661 | case tc_switch_begin: | |
662 | if (!mapp) /* usually means main thread */ | |
663 | mapp = mapp_main; | |
664 | /* fall through */ | |
665 | ||
666 | case tc_thread_create: | |
667 | case tc_thread_exit: | |
668 | if (!mapp) | |
669 | break; | |
670 | if (!read_map (mapp, &map)) | |
671 | goto err; | |
672 | tid = MKTID (pid, map.thr_tid); | |
673 | ||
674 | switch (change) { | |
675 | case tc_thread_create: /* new thread */ | |
676 | if (!map.thr_lwpp) | |
677 | lwpid = 0; | |
678 | else if (!read_lwp ((CORE_ADDR)map.thr_lwpp, &lwp)) | |
679 | goto err; | |
680 | else | |
681 | lwpid = lwp.lwp_id; | |
682 | add_thread_uw (map.thr_tid, lwpid, mapp, tid); | |
683 | break; | |
684 | ||
685 | case tc_thread_exit: /* thread has exited */ | |
686 | printf_unfiltered ("[Exited %s]\n", target_pid_to_str (tid)); | |
687 | delete_thread (tid); | |
688 | if (tid == inferior_pid) | |
689 | inferior_pid = pid; | |
690 | break; | |
691 | ||
692 | case tc_switch_begin: /* lwp is switching threads */ | |
693 | if (switchto_thread) | |
694 | goto err; | |
695 | if (!(switchto_thread = find_thread_pid (tid))) | |
696 | goto err; | |
697 | switchto_thread->private->stable = 0; | |
698 | break; | |
699 | ||
700 | default: | |
701 | break; | |
702 | } | |
703 | break; | |
704 | ||
705 | case tc_switch_complete: /* lwp has switched threads */ | |
706 | case tc_cancel_complete: /* lwp didn't switch threads */ | |
707 | if (!switchto_thread) | |
708 | goto err; | |
709 | ||
710 | if (change == tc_switch_complete) | |
711 | { | |
712 | /* | |
713 | * If switchto_thread is the main thread, then (a) the corresponding | |
714 | * tc_switch_begin probably received a null map argument and therefore | |
715 | * (b) it may have been a spurious switch following a tc_thread_exit. | |
716 | * | |
717 | * Therefore, explicitly query the thread's lwp before caching it in | |
718 | * its thread list entry. | |
719 | */ | |
720 | if (!read_map (switchto_thread->private->mapp, &map)) | |
721 | goto err; | |
722 | if (map.thr_lwpp) | |
723 | { | |
724 | if (!read_lwp ((CORE_ADDR)map.thr_lwpp, &lwp)) | |
725 | goto err; | |
726 | if ((info = find_thread_lwp (lwp.lwp_id))) | |
727 | info->private->lwpid = 0; | |
728 | switchto_thread->private->lwpid = lwp.lwp_id; | |
729 | } | |
730 | } | |
731 | ||
732 | switchto_thread->private->stable = 1; | |
733 | switchto_thread = NULL; | |
734 | break; | |
735 | ||
736 | case tc_invalid: | |
737 | case tc_thread_suspend: | |
738 | case tc_thread_suspend_pending: | |
739 | case tc_thread_continue: | |
740 | err: | |
741 | DBG(("unexpected condition in libthread_stub()")); | |
742 | break; | |
743 | } | |
744 | ||
745 | DBG2(("libthread_stub(%s): %s %s %s", dbgpid (pid), dbgpid (tid), | |
746 | dbgchange (change), tid ? dbgstate (map.thr_state) : "")); | |
747 | } | |
748 | ||
749 | /* | |
750 | * Wait for thread/lwp/process ID if >= 0 or for any thread otherwise. | |
751 | */ | |
752 | static int | |
753 | uw_thread_wait (int pid, struct target_waitstatus *status) | |
754 | { | |
755 | if (pid > 0) | |
756 | pid = thr_to_lwp (pid); | |
757 | CALL_BASE (pid = base_ops.to_wait (pid > 0 ? pid : -1, status)); | |
758 | ||
759 | if (status->kind == TARGET_WAITKIND_STOPPED && | |
760 | status->value.sig == TARGET_SIGNAL_TRAP) | |
761 | libthread_stub (pid); | |
762 | ||
763 | return lwp_to_thr (pid); | |
764 | } | |
765 | ||
766 | /* | |
767 | * Tell gdb about the registers in the thread/lwp/process specified by | |
768 | * inferior_pid. | |
769 | */ | |
770 | static void | |
771 | uw_thread_fetch_registers (int regno) | |
772 | { | |
773 | int called; | |
774 | struct thread_info *info; | |
775 | struct thread_map map; | |
776 | ||
777 | TRY_BASE (base_ops.to_fetch_registers (regno), &called); | |
778 | if (called) | |
779 | return; | |
780 | ||
781 | if (!(info = find_thread_pid (inferior_pid))) | |
782 | return; | |
783 | if (!read_map (info->private->mapp, &map)) | |
784 | return; | |
785 | ||
786 | supply_gregset (&map.thr_ucontext.uc_mcontext.gregs); | |
787 | supply_fpregset (&map.thr_ucontext.uc_mcontext.fpregs); | |
788 | } | |
789 | ||
790 | /* | |
791 | * Store gdb's current view of the register set into the thread/lwp/process | |
792 | * specified by inferior_pid. | |
793 | */ | |
794 | static void | |
795 | uw_thread_store_registers (int regno) | |
796 | { | |
797 | CALL_BASE (base_ops.to_store_registers (regno)); | |
798 | } | |
799 | ||
800 | /* | |
801 | * Prepare to modify the registers array. | |
802 | */ | |
803 | static void | |
804 | uw_thread_prepare_to_store (void) | |
805 | { | |
806 | CALL_BASE (base_ops.to_prepare_to_store ()); | |
807 | } | |
808 | ||
809 | /* | |
810 | * Fork an inferior process and start debugging it. | |
811 | * | |
812 | * This function only gets called with uw_thread_active == 0. | |
813 | */ | |
814 | static void | |
815 | uw_thread_create_inferior (char *exec_file, char *allargs, char **env) | |
816 | { | |
817 | if (uw_thread_active) | |
818 | deactivate_uw_thread (); | |
819 | ||
820 | procfs_ops.to_create_inferior (exec_file, allargs, env); | |
821 | if (uw_thread_active) | |
822 | { | |
823 | find_main (); | |
824 | thr_infpid (NULL); | |
825 | } | |
826 | } | |
827 | ||
828 | /* | |
829 | * Kill and forget about the inferior process. | |
830 | */ | |
831 | static void | |
832 | uw_thread_kill (void) | |
833 | { | |
834 | base_ops.to_kill (); | |
835 | } | |
836 | ||
837 | /* | |
838 | * Clean up after the inferior exits. | |
839 | */ | |
840 | static void | |
841 | uw_thread_mourn_inferior (void) | |
842 | { | |
843 | remove_thread_event_breakpoints (); | |
844 | deactivate_uw_thread (); | |
845 | base_ops.to_mourn_inferior (); | |
846 | } | |
847 | ||
848 | /* | |
849 | * Return whether this module can attach to and run processes. | |
850 | * | |
851 | * This function only gets called with uw_thread_active == 0. | |
852 | */ | |
853 | static int | |
854 | uw_thread_can_run (void) | |
855 | { | |
856 | return procfs_suppress_run; | |
857 | } | |
858 | ||
859 | /* | |
860 | * Return whether thread PID is still valid. | |
861 | */ | |
862 | static int | |
863 | uw_thread_alive (int pid) | |
864 | { | |
865 | if (!ISTID (pid)) | |
866 | return base_ops.to_thread_alive (pid); | |
867 | ||
868 | /* If it's in the thread list, it's valid, because otherwise | |
869 | libthread_stub() would have deleted it. */ | |
870 | return in_thread_list (pid); | |
871 | } | |
872 | ||
873 | /* | |
874 | * Add to the thread list any threads and lwps it doesn't already contain. | |
875 | */ | |
876 | static void | |
877 | uw_thread_find_new_threads (void) | |
878 | { | |
879 | CALL_BASE (if (base_ops.to_find_new_threads) | |
880 | base_ops.to_find_new_threads ()); | |
881 | notice_threads (); | |
882 | } | |
883 | ||
884 | /* | |
885 | * Return a string for pretty-printing PID in "info threads" output. | |
886 | * This may be called by either procfs.c or by generic gdb. | |
887 | */ | |
888 | static char * | |
889 | uw_thread_pid_to_str (int pid) | |
890 | { | |
891 | #define FMT "Thread %d" | |
892 | static char buf[sizeof (FMT) + 3 * sizeof (pid)]; | |
893 | ||
894 | if (!ISTID (pid)) | |
895 | /* core_ops says "process foo", so call procfs_ops explicitly. */ | |
896 | return procfs_ops.to_pid_to_str (pid); | |
897 | ||
898 | sprintf (buf, FMT, TIDGET (pid)); | |
899 | #undef FMT | |
900 | return buf; | |
901 | } | |
902 | ||
903 | /* | |
904 | * Return a string displaying INFO state information in "info threads" | |
905 | * output. | |
906 | */ | |
907 | static char * | |
908 | uw_extra_thread_info (struct thread_info *info) | |
909 | { | |
910 | static char buf[80]; | |
911 | struct thread_map map; | |
912 | __lwp_desc_t lwp; | |
913 | int lwpid; | |
914 | char *name; | |
915 | ||
916 | if (!ISTID (info->pid)) | |
917 | return NULL; | |
918 | ||
919 | if (!info->private->stable) | |
920 | return "switching"; | |
921 | ||
922 | if (!read_map (info->private->mapp, &map)) | |
923 | return NULL; | |
924 | ||
925 | if (!map.thr_lwpp || !read_lwp ((CORE_ADDR)map.thr_lwpp, &lwp)) | |
926 | lwpid = 0; | |
927 | else | |
928 | lwpid = lwp.lwp_id; | |
929 | ||
930 | switch (map.thr_state) { | |
931 | case TS_ONPROC: name = "running"; break; | |
932 | case TS_SLEEP: name = "sleeping"; break; | |
933 | case TS_RUNNABLE: name = "runnable"; break; | |
934 | case TS_ZOMBIE: name = "zombie"; break; | |
935 | case TS_SUSPENDED: name = "suspended"; break; | |
936 | #ifdef TS_FORK | |
937 | case TS_FORK: name = "forking"; break; | |
938 | #endif | |
939 | default: name = "confused"; break; | |
940 | } | |
941 | ||
942 | if (!lwpid) | |
943 | return name; | |
944 | ||
945 | sprintf (buf, "%s, LWP %d", name, lwpid); | |
946 | return buf; | |
947 | } | |
948 | ||
949 | /* | |
950 | * Check whether libthread.so has just been loaded, and if so, try to | |
951 | * initialize user-space thread debugging support. | |
952 | * | |
953 | * libthread.so loading happens while (a) an inferior process is being | |
954 | * started by procfs and (b) a core image is being loaded. | |
955 | * | |
956 | * This function often gets called with uw_thread_active == 0. | |
957 | */ | |
958 | static void | |
959 | libthread_init (void) | |
960 | { | |
961 | struct minimal_symbol *ms; | |
962 | struct thread_debug debug; | |
963 | CORE_ADDR onp; | |
964 | struct breakpoint *b; | |
965 | int one = 1; | |
966 | ||
967 | /* Don't initialize twice. */ | |
968 | if (uw_thread_active) | |
969 | return; | |
970 | ||
971 | /* Check whether libthread.so has been loaded. */ | |
972 | if (!(ms = lookup_minimal_symbol ("_thr_debug", NULL, NULL))) | |
973 | return; | |
974 | ||
975 | /* Cache _thr_debug's address. */ | |
976 | if (!(thr_debug_addr = SYMBOL_VALUE_ADDRESS (ms))) | |
977 | return; | |
978 | ||
979 | /* Initialize base_ops.to_xfer_memory(). */ | |
980 | base_ops = current_target; | |
981 | ||
982 | /* Load _thr_debug's current contents. */ | |
983 | if (!read_thr_debug (&debug)) | |
984 | return; | |
985 | ||
986 | /* User code (e.g. my test programs) may dereference _thr_debug, | |
987 | making it availble to GDB before shared libs are loaded. */ | |
988 | if (!debug.thr_map) | |
989 | return; | |
990 | ||
991 | /* libthread.so has been loaded, and the current_target should now | |
992 | reflect core_ops or procfs_ops. */ | |
993 | push_target (&uw_thread_ops); /* must precede notice_threads() */ | |
994 | uw_thread_active = 1; | |
995 | ||
996 | if (!target_has_execution) | |
997 | ||
998 | /* Locate threads in core file. */ | |
999 | notice_threads (); | |
1000 | ||
1001 | else | |
1002 | { | |
1003 | /* Set a breakpoint on the stub function provided by libthread.so. */ | |
1004 | thr_brk_addr = (CORE_ADDR)debug.thr_brk; | |
1005 | if (!(b = create_thread_event_breakpoint (thr_brk_addr))) | |
1006 | goto err; | |
1007 | ||
1008 | /* Activate the stub function. */ | |
1009 | onp = (CORE_ADDR)&((struct thread_debug *)thr_debug_addr)->thr_debug_on; | |
1010 | if (!base_ops.to_xfer_memory ((CORE_ADDR)onp, (char *)&one, | |
1011 | sizeof (one), 1, &base_ops)) | |
1012 | { | |
1013 | delete_breakpoint (b); | |
1014 | goto err; | |
1015 | } | |
1016 | ||
1017 | /* Prepare for finding the main thread, which doesn't yet exist. */ | |
1018 | thr_map_main = 0; | |
1019 | } | |
1020 | ||
1021 | return; | |
1022 | ||
1023 | err: | |
1024 | warning ("uw-thread: unable to initialize user-mode thread debugging\n"); | |
1025 | deactivate_uw_thread (); | |
1026 | } | |
1027 | ||
1028 | /* | |
1029 | * target_new_objfile_hook callback. | |
1030 | * | |
1031 | * If OBJFILE is non-null, check whether libthread.so was just loaded, | |
1032 | * and if so, prepare for user-mode thread debugging. | |
1033 | * | |
1034 | * If OBJFILE is null, libthread.so has gone away, so stop debugging | |
1035 | * user-mode threads. | |
1036 | * | |
1037 | * This function often gets called with uw_thread_active == 0. | |
1038 | */ | |
1039 | static void | |
1040 | uw_thread_new_objfile (struct objfile *objfile) | |
1041 | { | |
1042 | if (objfile) | |
1043 | libthread_init (); | |
1044 | ||
1045 | else if (uw_thread_active) | |
1046 | deactivate_uw_thread (); | |
1047 | ||
1048 | if (target_new_objfile_chain) | |
1049 | target_new_objfile_chain (objfile); | |
1050 | } | |
1051 | ||
1052 | /* | |
1053 | * Initialize uw_thread_ops. | |
1054 | */ | |
1055 | static void | |
1056 | init_uw_thread_ops (void) | |
1057 | { | |
1058 | uw_thread_ops.to_shortname = "unixware-threads"; | |
1059 | uw_thread_ops.to_longname = "UnixWare threads and pthread."; | |
1060 | uw_thread_ops.to_doc = "UnixWare threads and pthread support."; | |
1061 | uw_thread_ops.to_attach = uw_thread_attach; | |
1062 | uw_thread_ops.to_detach = uw_thread_detach; | |
1063 | uw_thread_ops.to_resume = uw_thread_resume; | |
1064 | uw_thread_ops.to_wait = uw_thread_wait; | |
1065 | uw_thread_ops.to_fetch_registers = uw_thread_fetch_registers; | |
1066 | uw_thread_ops.to_store_registers = uw_thread_store_registers; | |
1067 | uw_thread_ops.to_prepare_to_store = uw_thread_prepare_to_store; | |
1068 | uw_thread_ops.to_create_inferior = uw_thread_create_inferior; | |
1069 | uw_thread_ops.to_kill = uw_thread_kill; | |
1070 | uw_thread_ops.to_mourn_inferior = uw_thread_mourn_inferior; | |
1071 | uw_thread_ops.to_can_run = uw_thread_can_run; | |
1072 | uw_thread_ops.to_thread_alive = uw_thread_alive; | |
1073 | uw_thread_ops.to_find_new_threads = uw_thread_find_new_threads; | |
1074 | uw_thread_ops.to_pid_to_str = uw_thread_pid_to_str; | |
1075 | uw_thread_ops.to_extra_thread_info = uw_extra_thread_info; | |
1076 | uw_thread_ops.to_stratum = thread_stratum; | |
1077 | uw_thread_ops.to_magic = OPS_MAGIC; | |
1078 | } | |
1079 | ||
1080 | /* | |
1081 | * Module startup initialization function, automagically called by | |
1082 | * init.c. | |
1083 | */ | |
1084 | void | |
1085 | _initialize_uw_thread (void) | |
1086 | { | |
1087 | init_uw_thread_ops (); | |
1088 | add_target (&uw_thread_ops); | |
1089 | ||
1090 | procfs_suppress_run = 1; | |
1091 | ||
1092 | /* Notice when libthread.so gets loaded. */ | |
1093 | target_new_objfile_chain = target_new_objfile_hook; | |
1094 | target_new_objfile_hook = uw_thread_new_objfile; | |
1095 | } |