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0d62e5e8 | 1 | /* Thread management interface, for the remote server for GDB. |
3db0444b | 2 | Copyright 2002, 2004, 2005 |
0d62e5e8 DJ |
3 | Free Software Foundation, Inc. |
4 | ||
5 | Contributed by MontaVista Software. | |
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 | #include "server.h" | |
25 | ||
26 | #include "linux-low.h" | |
27 | ||
28 | extern int debug_threads; | |
29 | ||
30 | #ifdef HAVE_THREAD_DB_H | |
31 | #include <thread_db.h> | |
32 | #endif | |
33 | ||
34 | /* Correct for all GNU/Linux targets (for quite some time). */ | |
35 | #define GDB_GREGSET_T elf_gregset_t | |
36 | #define GDB_FPREGSET_T elf_fpregset_t | |
37 | ||
38 | #ifndef HAVE_ELF_FPREGSET_T | |
39 | /* Make sure we have said types. Not all platforms bring in <linux/elf.h> | |
40 | via <sys/procfs.h>. */ | |
41 | #ifdef HAVE_LINUX_ELF_H | |
42 | #include <linux/elf.h> | |
43 | #endif | |
44 | #endif | |
45 | ||
46 | #include "../gdb_proc_service.h" | |
47 | ||
48 | /* Structure that identifies the child process for the | |
49 | <proc_service.h> interface. */ | |
50 | static struct ps_prochandle proc_handle; | |
51 | ||
52 | /* Connection to the libthread_db library. */ | |
53 | static td_thragent_t *thread_agent; | |
54 | ||
55 | static int find_new_threads_callback (const td_thrhandle_t *th_p, void *data); | |
56 | ||
57 | static char * | |
58 | thread_db_err_str (td_err_e err) | |
59 | { | |
60 | static char buf[64]; | |
61 | ||
62 | switch (err) | |
63 | { | |
64 | case TD_OK: | |
65 | return "generic 'call succeeded'"; | |
66 | case TD_ERR: | |
67 | return "generic error"; | |
68 | case TD_NOTHR: | |
69 | return "no thread to satisfy query"; | |
70 | case TD_NOSV: | |
71 | return "no sync handle to satisfy query"; | |
72 | case TD_NOLWP: | |
73 | return "no LWP to satisfy query"; | |
74 | case TD_BADPH: | |
75 | return "invalid process handle"; | |
76 | case TD_BADTH: | |
77 | return "invalid thread handle"; | |
78 | case TD_BADSH: | |
79 | return "invalid synchronization handle"; | |
80 | case TD_BADTA: | |
81 | return "invalid thread agent"; | |
82 | case TD_BADKEY: | |
83 | return "invalid key"; | |
84 | case TD_NOMSG: | |
85 | return "no event message for getmsg"; | |
86 | case TD_NOFPREGS: | |
87 | return "FPU register set not available"; | |
88 | case TD_NOLIBTHREAD: | |
89 | return "application not linked with libthread"; | |
90 | case TD_NOEVENT: | |
91 | return "requested event is not supported"; | |
92 | case TD_NOCAPAB: | |
93 | return "capability not available"; | |
94 | case TD_DBERR: | |
95 | return "debugger service failed"; | |
96 | case TD_NOAPLIC: | |
97 | return "operation not applicable to"; | |
98 | case TD_NOTSD: | |
99 | return "no thread-specific data for this thread"; | |
100 | case TD_MALLOC: | |
101 | return "malloc failed"; | |
102 | case TD_PARTIALREG: | |
103 | return "only part of register set was written/read"; | |
104 | case TD_NOXREGS: | |
105 | return "X register set not available for this thread"; | |
3db0444b DJ |
106 | #ifdef HAVE_TD_VERSION |
107 | case TD_VERSION: | |
108 | return "version mismatch between libthread_db and libpthread"; | |
109 | #endif | |
0d62e5e8 DJ |
110 | default: |
111 | snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err); | |
112 | return buf; | |
113 | } | |
114 | } | |
115 | ||
116 | #if 0 | |
117 | static char * | |
118 | thread_db_state_str (td_thr_state_e state) | |
119 | { | |
120 | static char buf[64]; | |
121 | ||
122 | switch (state) | |
123 | { | |
124 | case TD_THR_STOPPED: | |
125 | return "stopped by debugger"; | |
126 | case TD_THR_RUN: | |
127 | return "runnable"; | |
128 | case TD_THR_ACTIVE: | |
129 | return "active"; | |
130 | case TD_THR_ZOMBIE: | |
131 | return "zombie"; | |
132 | case TD_THR_SLEEP: | |
133 | return "sleeping"; | |
134 | case TD_THR_STOPPED_ASLEEP: | |
135 | return "stopped by debugger AND blocked"; | |
136 | default: | |
137 | snprintf (buf, sizeof (buf), "unknown thread_db state %d", state); | |
138 | return buf; | |
139 | } | |
140 | } | |
141 | #endif | |
142 | ||
143 | static void | |
144 | thread_db_create_event (CORE_ADDR where) | |
145 | { | |
146 | td_event_msg_t msg; | |
147 | td_err_e err; | |
148 | struct inferior_linux_data *tdata; | |
149 | ||
150 | if (debug_threads) | |
151 | fprintf (stderr, "Thread creation event.\n"); | |
152 | ||
153 | tdata = inferior_target_data (current_inferior); | |
154 | ||
155 | /* FIXME: This assumes we don't get another event. | |
156 | In the LinuxThreads implementation, this is safe, | |
157 | because all events come from the manager thread | |
158 | (except for its own creation, of course). */ | |
159 | err = td_ta_event_getmsg (thread_agent, &msg); | |
160 | if (err != TD_OK) | |
161 | fprintf (stderr, "thread getmsg err: %s\n", | |
162 | thread_db_err_str (err)); | |
163 | ||
164 | /* msg.event == TD_EVENT_CREATE */ | |
165 | ||
166 | find_new_threads_callback (msg.th_p, NULL); | |
167 | } | |
168 | ||
169 | #if 0 | |
170 | static void | |
171 | thread_db_death_event (CORE_ADDR where) | |
172 | { | |
173 | if (debug_threads) | |
174 | fprintf (stderr, "Thread death event.\n"); | |
175 | } | |
176 | #endif | |
177 | ||
178 | static int | |
179 | thread_db_enable_reporting () | |
180 | { | |
181 | td_thr_events_t events; | |
182 | td_notify_t notify; | |
183 | td_err_e err; | |
184 | ||
185 | /* Set the process wide mask saying which events we're interested in. */ | |
186 | td_event_emptyset (&events); | |
187 | td_event_addset (&events, TD_CREATE); | |
188 | ||
189 | #if 0 | |
190 | /* This is reported to be broken in glibc 2.1.3. A different approach | |
191 | will be necessary to support that. */ | |
192 | td_event_addset (&events, TD_DEATH); | |
193 | #endif | |
194 | ||
195 | err = td_ta_set_event (thread_agent, &events); | |
196 | if (err != TD_OK) | |
197 | { | |
198 | warning ("Unable to set global thread event mask: %s", | |
199 | thread_db_err_str (err)); | |
200 | return 0; | |
201 | } | |
202 | ||
203 | /* Get address for thread creation breakpoint. */ | |
204 | err = td_ta_event_addr (thread_agent, TD_CREATE, ¬ify); | |
205 | if (err != TD_OK) | |
206 | { | |
207 | warning ("Unable to get location for thread creation breakpoint: %s", | |
208 | thread_db_err_str (err)); | |
209 | return 0; | |
210 | } | |
211 | set_breakpoint_at ((CORE_ADDR) (unsigned long) notify.u.bptaddr, | |
212 | thread_db_create_event); | |
213 | ||
214 | #if 0 | |
215 | /* Don't concern ourselves with reported thread deaths, only | |
216 | with actual thread deaths (via wait). */ | |
217 | ||
218 | /* Get address for thread death breakpoint. */ | |
219 | err = td_ta_event_addr (thread_agent, TD_DEATH, ¬ify); | |
220 | if (err != TD_OK) | |
221 | { | |
222 | warning ("Unable to get location for thread death breakpoint: %s", | |
223 | thread_db_err_str (err)); | |
224 | return; | |
225 | } | |
226 | set_breakpoint_at ((CORE_ADDR) (unsigned long) notify.u.bptaddr, | |
227 | thread_db_death_event); | |
228 | #endif | |
229 | ||
230 | return 1; | |
231 | } | |
232 | ||
233 | static void | |
234 | maybe_attach_thread (const td_thrhandle_t *th_p, td_thrinfo_t *ti_p) | |
235 | { | |
236 | td_err_e err; | |
237 | struct thread_info *inferior; | |
238 | struct process_info *process; | |
239 | ||
240 | /* If we are attaching to our first thread, things are a little | |
241 | different. */ | |
242 | if (all_threads.head == all_threads.tail) | |
243 | { | |
244 | inferior = (struct thread_info *) all_threads.head; | |
245 | process = get_thread_process (inferior); | |
246 | if (process->thread_known == 0) | |
247 | { | |
248 | /* Switch to indexing the threads list by TID. */ | |
249 | change_inferior_id (&all_threads, ti_p->ti_tid); | |
250 | goto found; | |
251 | } | |
252 | } | |
253 | ||
254 | inferior = (struct thread_info *) find_inferior_id (&all_threads, | |
255 | ti_p->ti_tid); | |
256 | if (inferior != NULL) | |
257 | return; | |
258 | ||
259 | if (debug_threads) | |
260 | fprintf (stderr, "Attaching to thread %ld (LWP %d)\n", | |
261 | ti_p->ti_tid, ti_p->ti_lid); | |
262 | linux_attach_lwp (ti_p->ti_lid, ti_p->ti_tid); | |
263 | inferior = (struct thread_info *) find_inferior_id (&all_threads, | |
264 | ti_p->ti_tid); | |
265 | if (inferior == NULL) | |
266 | { | |
267 | warning ("Could not attach to thread %ld (LWP %d)\n", | |
268 | ti_p->ti_tid, ti_p->ti_lid); | |
269 | return; | |
270 | } | |
271 | ||
272 | process = inferior_target_data (inferior); | |
273 | ||
274 | found: | |
275 | new_thread_notify (ti_p->ti_tid); | |
276 | ||
277 | process->tid = ti_p->ti_tid; | |
278 | process->lwpid = ti_p->ti_lid; | |
279 | ||
280 | process->thread_known = 1; | |
281 | err = td_thr_event_enable (th_p, 1); | |
282 | if (err != TD_OK) | |
283 | error ("Cannot enable thread event reporting for %d: %s", | |
284 | ti_p->ti_lid, thread_db_err_str (err)); | |
285 | } | |
286 | ||
287 | static int | |
288 | find_new_threads_callback (const td_thrhandle_t *th_p, void *data) | |
289 | { | |
290 | td_thrinfo_t ti; | |
291 | td_err_e err; | |
292 | ||
293 | err = td_thr_get_info (th_p, &ti); | |
294 | if (err != TD_OK) | |
295 | error ("Cannot get thread info: %s", thread_db_err_str (err)); | |
296 | ||
297 | /* Check for zombies. */ | |
298 | if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE) | |
299 | return 0; | |
300 | ||
301 | maybe_attach_thread (th_p, &ti); | |
302 | ||
303 | return 0; | |
304 | } | |
305 | ||
306 | static void | |
307 | thread_db_find_new_threads (void) | |
308 | { | |
309 | td_err_e err; | |
310 | ||
311 | /* Iterate over all user-space threads to discover new threads. */ | |
312 | err = td_ta_thr_iter (thread_agent, find_new_threads_callback, NULL, | |
313 | TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY, | |
314 | TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS); | |
315 | if (err != TD_OK) | |
316 | error ("Cannot find new threads: %s", thread_db_err_str (err)); | |
317 | } | |
318 | ||
fd500816 DJ |
319 | /* Cache all future symbols that thread_db might request. We can not |
320 | request symbols at arbitrary states in the remote protocol, only | |
321 | when the client tells us that new symbols are available. So when | |
322 | we load the thread library, make sure to check the entire list. */ | |
323 | ||
324 | static void | |
325 | thread_db_look_up_symbols (void) | |
326 | { | |
327 | const char **sym_list = td_symbol_list (); | |
328 | CORE_ADDR unused; | |
329 | ||
330 | for (sym_list = td_symbol_list (); *sym_list; sym_list++) | |
331 | look_up_one_symbol (*sym_list, &unused); | |
332 | } | |
333 | ||
0d62e5e8 DJ |
334 | int |
335 | thread_db_init () | |
336 | { | |
337 | int err; | |
338 | ||
fd500816 DJ |
339 | /* FIXME drow/2004-10-16: This is the "overall process ID", which |
340 | GNU/Linux calls tgid, "thread group ID". When we support | |
341 | attaching to threads, the original thread may not be the correct | |
342 | thread. We would have to get the process ID from /proc for NPTL. | |
343 | For LinuxThreads we could do something similar: follow the chain | |
344 | of parent processes until we find the highest one we're attached | |
345 | to, and use its tgid. | |
346 | ||
347 | This isn't the only place in gdbserver that assumes that the first | |
348 | process in the list is the thread group leader. */ | |
0d62e5e8 DJ |
349 | proc_handle.pid = ((struct inferior_list_entry *)current_inferior)->id; |
350 | ||
351 | err = td_ta_new (&proc_handle, &thread_agent); | |
352 | switch (err) | |
353 | { | |
354 | case TD_NOLIBTHREAD: | |
355 | /* No thread library was detected. */ | |
356 | return 0; | |
357 | ||
358 | case TD_OK: | |
359 | /* The thread library was detected. */ | |
360 | ||
361 | if (thread_db_enable_reporting () == 0) | |
362 | return 0; | |
363 | thread_db_find_new_threads (); | |
fd500816 | 364 | thread_db_look_up_symbols (); |
0d62e5e8 DJ |
365 | return 1; |
366 | ||
367 | default: | |
3db0444b DJ |
368 | warning ("error initializing thread_db library: %s", |
369 | thread_db_err_str (err)); | |
0d62e5e8 DJ |
370 | } |
371 | ||
372 | return 0; | |
373 | } |