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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. | |
f086451a | 5 | Written by Nick Duffek <nsd@cygnus.com>. |
c5394b80 JM |
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 | ||
6c7e601e ND |
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 | ||
c5394b80 JM |
109 | #define boolean_t int |
110 | #include <thread.h> | |
111 | #undef boolean_t | |
112 | ||
113 | #include <synch.h> /* for UnixWare 2.x */ | |
114 | ||
c60c0f5f MS |
115 | /* Prototypes for supply_gregset etc. */ |
116 | #include "gregset.h" | |
c5394b80 | 117 | |
6c7e601e ND |
118 | /* Whether to emit debugging output. */ |
119 | ||
c5394b80 JM |
120 | #define DEBUG 0 |
121 | ||
6c7e601e ND |
122 | /* Default debugging output file, overridden by envvar UWTHR_DEBUG. */ |
123 | ||
c5394b80 JM |
124 | #define DEBUG_FILE "/dev/tty" |
125 | ||
6c7e601e ND |
126 | /* #if DEBUG, write string S to the debugging output channel. */ |
127 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
136 | /* Back end to CALL_BASE() and TRY_BASE(): evaluate CALL, then convert |
137 | inferior_pid to a composite thread/process id. */ | |
138 | ||
c5394b80 JM |
139 | #define CALL_BASE_1(call) \ |
140 | do { \ | |
141 | DBG2(("CALL_BASE(" #call ")")); \ | |
142 | call; \ | |
143 | do_cleanups (infpid_cleanup); \ | |
144 | } while (0) | |
145 | ||
6c7e601e ND |
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 | ||
f086451a ND |
152 | #define CALL_BASE(call) \ |
153 | do { \ | |
154 | if (!lwp_infpid ()) \ | |
155 | error ("uw-thread: no lwp"); \ | |
156 | CALL_BASE_1 (call); \ | |
c5394b80 JM |
157 | } while (0) |
158 | ||
6c7e601e ND |
159 | /* Like CALL_BASE(), but instead of returning nonlocally on error, set |
160 | *CALLED to whether the inferior_pid conversion was successful. */ | |
161 | ||
c5394b80 JM |
162 | #define TRY_BASE(call, called) \ |
163 | do { \ | |
164 | if ((*(called) = lwp_infpid ())) \ | |
165 | CALL_BASE_1 (call); \ | |
166 | } while (0) | |
167 | ||
6c7e601e ND |
168 | /* Information passed by thread_iter() to its callback parameter. */ |
169 | ||
c5394b80 JM |
170 | typedef struct { |
171 | struct thread_map map; | |
172 | __lwp_desc_t lwp; | |
173 | CORE_ADDR mapp; | |
174 | } iter_t; | |
175 | ||
6c7e601e ND |
176 | /* Private thread data for the thread_info struct. */ |
177 | ||
c5394b80 JM |
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 | |
6c7e601e ND |
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 | ||
c5394b80 JM |
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 | |
6c7e601e ND |
260 | /* Return a string representing composite PID's components. */ |
261 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
280 | /* Return a string representing thread state CHANGE. */ |
281 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
299 | /* Return a string representing thread STATE. */ |
300 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
320 | /* Read the contents of _thr_debug into *DEBUGP. Return success. */ |
321 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
329 | /* Read into MAP the contents of the thread map at inferior process address |
330 | MAPP. Return success. */ | |
331 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
339 | /* Read into LWP the contents of the lwp decriptor at inferior process address |
340 | LWPP. Return success. */ | |
341 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
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 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
393 | /* Deactivate user-mode thread support. */ |
394 | ||
c5394b80 JM |
395 | static void |
396 | deactivate_uw_thread (void) | |
397 | { | |
6c7e601e | 398 | remove_thread_event_breakpoints (); |
c5394b80 JM |
399 | uw_thread_active = 0; |
400 | unpush_target (&uw_thread_ops); | |
401 | } | |
402 | ||
6c7e601e ND |
403 | /* Return the composite lwp/process id corresponding to composite |
404 | id PID. If PID is a thread with no lwp, return 0. */ | |
405 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
425 | /* find_thread_lwp() callback: return whether TP describes a thread |
426 | associated with lwp id DATA. */ | |
427 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
444 | /* If a thread is associated with lwp id LWPID, return the corresponding |
445 | member of the global thread list; otherwise, return null. */ | |
446 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
453 | /* Return the composite thread/process id corresponding to composite |
454 | id PID. If PID is an lwp with no thread, return PID. */ | |
455 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
475 | /* do_cleanups() callback: convert inferior_pid to a composite |
476 | thread/process id after having made a procfs call. */ | |
477 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
487 | /* If possible, convert inferior_pid to a composite lwp/process id in |
488 | preparation for making a procfs call. Return success. */ | |
489 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
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 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
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 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
543 | /* Add to the thread list any threads it doesn't already contain. */ |
544 | ||
c5394b80 JM |
545 | static void |
546 | notice_threads (void) | |
547 | { | |
548 | thread_iter (notice_thread, NULL); | |
549 | } | |
550 | ||
6c7e601e ND |
551 | /* Return the address of the main thread's map. On error, return 0. */ |
552 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
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 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
579 | /* Detach from the process attached to by uw_thread_attach(). */ |
580 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
588 | /* Tell the inferior process to continue running thread PID if >= 0 |
589 | and all threads otherwise. */ | |
590 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
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 | ||
c5394b80 JM |
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 | { | |
6c7e601e ND |
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 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
720 | /* Wait for thread/lwp/process ID if >= 0 or for any thread otherwise. */ |
721 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
736 | /* Tell gdb about the registers in the thread/lwp/process specified by |
737 | inferior_pid. */ | |
738 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
759 | /* Store gdb's current view of the register set into the thread/lwp/process |
760 | specified by inferior_pid. */ | |
761 | ||
c5394b80 JM |
762 | static void |
763 | uw_thread_store_registers (int regno) | |
764 | { | |
765 | CALL_BASE (base_ops.to_store_registers (regno)); | |
766 | } | |
767 | ||
6c7e601e ND |
768 | /* Prepare to modify the registers array. */ |
769 | ||
c5394b80 JM |
770 | static void |
771 | uw_thread_prepare_to_store (void) | |
772 | { | |
773 | CALL_BASE (base_ops.to_prepare_to_store ()); | |
774 | } | |
775 | ||
6c7e601e ND |
776 | /* Fork an inferior process and start debugging it. |
777 | ||
778 | This function only gets called with uw_thread_active == 0. */ | |
779 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
794 | /* Kill and forget about the inferior process. */ |
795 | ||
c5394b80 JM |
796 | static void |
797 | uw_thread_kill (void) | |
798 | { | |
799 | base_ops.to_kill (); | |
800 | } | |
801 | ||
6c7e601e ND |
802 | /* Clean up after the inferior exits. */ |
803 | ||
c5394b80 JM |
804 | static void |
805 | uw_thread_mourn_inferior (void) | |
806 | { | |
c5394b80 JM |
807 | deactivate_uw_thread (); |
808 | base_ops.to_mourn_inferior (); | |
809 | } | |
810 | ||
6c7e601e ND |
811 | /* Return whether this module can attach to and run processes. |
812 | ||
813 | This function only gets called with uw_thread_active == 0. */ | |
814 | ||
c5394b80 JM |
815 | static int |
816 | uw_thread_can_run (void) | |
817 | { | |
818 | return procfs_suppress_run; | |
819 | } | |
820 | ||
6c7e601e ND |
821 | /* Return whether thread PID is still valid. */ |
822 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
834 | /* Add to the thread list any threads and lwps it doesn't already contain. */ |
835 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
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 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
862 | /* Return a string displaying INFO state information in "info threads" |
863 | output. */ | |
864 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
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 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
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 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
1008 | /* Initialize uw_thread_ops. */ |
1009 | ||
c5394b80 JM |
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 | ||
6c7e601e ND |
1035 | /* Module startup initialization function, automagically called by |
1036 | init.c. */ | |
1037 | ||
c5394b80 JM |
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 | } |