1 /* BSD user-level threads support.
3 Copyright (C) 2005, 2007, 2008 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "gdbthread.h"
32 #include "gdb_assert.h"
33 #include "gdb_obstack.h"
35 #include "bsd-uthread.h"
37 /* HACK: Save the bsd_uthreads ops returned by bsd_uthread_target. */
38 static struct target_ops *bsd_uthread_ops_hack;
41 /* Architecture-specific operations. */
43 /* Per-architecture data key. */
44 static struct gdbarch_data *bsd_uthread_data;
46 struct bsd_uthread_ops
48 /* Supply registers for an inactive thread to a register cache. */
49 void (*supply_uthread)(struct regcache *, int, CORE_ADDR);
51 /* Collect registers for an inactive thread from a register cache. */
52 void (*collect_uthread)(const struct regcache *, int, CORE_ADDR);
56 bsd_uthread_init (struct obstack *obstack)
58 struct bsd_uthread_ops *ops;
60 ops = OBSTACK_ZALLOC (obstack, struct bsd_uthread_ops);
64 /* Set the function that supplies registers from an inactive thread
65 for architecture GDBARCH to SUPPLY_UTHREAD. */
68 bsd_uthread_set_supply_uthread (struct gdbarch *gdbarch,
69 void (*supply_uthread) (struct regcache *,
72 struct bsd_uthread_ops *ops = gdbarch_data (gdbarch, bsd_uthread_data);
73 ops->supply_uthread = supply_uthread;
76 /* Set the function that collects registers for an inactive thread for
77 architecture GDBARCH to SUPPLY_UTHREAD. */
80 bsd_uthread_set_collect_uthread (struct gdbarch *gdbarch,
81 void (*collect_uthread) (const struct regcache *,
84 struct bsd_uthread_ops *ops = gdbarch_data (gdbarch, bsd_uthread_data);
85 ops->collect_uthread = collect_uthread;
88 /* Magic number to help recognize a valid thread structure. */
89 #define BSD_UTHREAD_PTHREAD_MAGIC 0xd09ba115
91 /* Check whether the thread structure at ADDR is valid. */
94 bsd_uthread_check_magic (CORE_ADDR addr)
96 ULONGEST magic = read_memory_unsigned_integer (addr, 4);
98 if (magic != BSD_UTHREAD_PTHREAD_MAGIC)
99 error (_("Bad magic"));
103 #define BSD_UTHREAD_PS_RUNNING 0
104 #define BSD_UTHREAD_PS_DEAD 18
106 /* Address of the pointer to the the thread structure for the running
108 static CORE_ADDR bsd_uthread_thread_run_addr;
110 /* Address of the list of all threads. */
111 static CORE_ADDR bsd_uthread_thread_list_addr;
113 /* Offsets of various "interesting" bits in the thread structure. */
114 static int bsd_uthread_thread_state_offset = -1;
115 static int bsd_uthread_thread_next_offset = -1;
116 static int bsd_uthread_thread_ctx_offset;
118 /* Name of shared threads library. */
119 static const char *bsd_uthread_solib_name;
121 /* Non-zero if the thread startum implemented by this module is active. */
122 static int bsd_uthread_active;
125 bsd_uthread_lookup_address (const char *name, struct objfile *objfile)
127 struct minimal_symbol *sym;
129 sym = lookup_minimal_symbol (name, NULL, objfile);
131 return SYMBOL_VALUE_ADDRESS (sym);
137 bsd_uthread_lookup_offset (const char *name, struct objfile *objfile)
141 addr = bsd_uthread_lookup_address (name, objfile);
145 return read_memory_unsigned_integer (addr, 4);
148 /* If OBJFILE contains the symbols corresponding to one of the
149 supported user-level threads libraries, activate the thread stratum
150 implemented by this module. */
153 bsd_uthread_activate (struct objfile *objfile)
155 struct gdbarch *gdbarch = current_gdbarch;
156 struct bsd_uthread_ops *ops = gdbarch_data (gdbarch, bsd_uthread_data);
158 /* Skip if the thread stratum has already been activated. */
159 if (bsd_uthread_active)
162 /* There's no point in enabling this module if no
163 architecture-specific operations are provided. */
164 if (!ops->supply_uthread)
167 bsd_uthread_thread_run_addr =
168 bsd_uthread_lookup_address ("_thread_run", objfile);
169 if (bsd_uthread_thread_run_addr == 0)
172 bsd_uthread_thread_list_addr =
173 bsd_uthread_lookup_address ("_thread_list", objfile);
174 if (bsd_uthread_thread_list_addr == 0)
177 bsd_uthread_thread_state_offset =
178 bsd_uthread_lookup_offset ("_thread_state_offset", objfile);
179 if (bsd_uthread_thread_state_offset == 0)
182 bsd_uthread_thread_next_offset =
183 bsd_uthread_lookup_offset ("_thread_next_offset", objfile);
184 if (bsd_uthread_thread_next_offset == 0)
187 bsd_uthread_thread_ctx_offset =
188 bsd_uthread_lookup_offset ("_thread_ctx_offset", objfile);
190 push_target (bsd_uthread_ops_hack);
191 bsd_uthread_active = 1;
195 /* Deactivate the thread stratum implemented by this module. */
198 bsd_uthread_deactivate (void)
200 /* Skip if the thread stratum has already been deactivated. */
201 if (!bsd_uthread_active)
204 bsd_uthread_active = 0;
205 unpush_target (bsd_uthread_ops_hack);
207 bsd_uthread_thread_run_addr = 0;
208 bsd_uthread_thread_list_addr = 0;
209 bsd_uthread_thread_state_offset = 0;
210 bsd_uthread_thread_next_offset = 0;
211 bsd_uthread_thread_ctx_offset = 0;
212 bsd_uthread_solib_name = NULL;
216 bsd_uthread_inferior_created (struct target_ops *ops, int from_tty)
218 bsd_uthread_activate (NULL);
221 /* Likely candidates for the threads library. */
222 static const char *bsd_uthread_solib_names[] =
224 "/usr/lib/libc_r.so", /* FreeBSD */
225 "/usr/lib/libpthread.so", /* OpenBSD */
230 bsd_uthread_solib_loaded (struct so_list *so)
232 const char **names = bsd_uthread_solib_names;
234 for (names = bsd_uthread_solib_names; *names; names++)
236 if (strncmp (so->so_original_name, *names, strlen (*names)) == 0)
238 solib_read_symbols (so, so->from_tty);
240 if (bsd_uthread_activate (so->objfile))
242 bsd_uthread_solib_name == so->so_original_name;
250 bsd_uthread_solib_unloaded (struct so_list *so)
252 if (!bsd_uthread_solib_name)
255 if (strcmp (so->so_original_name, bsd_uthread_solib_name) == 0)
256 bsd_uthread_deactivate ();
260 bsd_uthread_mourn_inferior (void)
262 find_target_beneath (bsd_uthread_ops_hack)->to_mourn_inferior ();
263 bsd_uthread_deactivate ();
267 bsd_uthread_fetch_registers (struct regcache *regcache, int regnum)
269 struct gdbarch *gdbarch = get_regcache_arch (regcache);
270 struct bsd_uthread_ops *ops = gdbarch_data (gdbarch, bsd_uthread_data);
271 CORE_ADDR addr = ptid_get_tid (inferior_ptid);
272 CORE_ADDR active_addr;
274 /* Always fetch the appropriate registers from the layer beneath. */
275 find_target_beneath (bsd_uthread_ops_hack)->to_fetch_registers (regcache, regnum);
277 /* FIXME: That might have gotten us more than we asked for. Make
278 sure we overwrite all relevant registers with values from the
279 thread structure. This can go once we fix the underlying target. */
282 active_addr = read_memory_typed_address (bsd_uthread_thread_run_addr,
283 builtin_type_void_data_ptr);
284 if (addr != 0 && addr != active_addr)
286 bsd_uthread_check_magic (addr);
287 ops->supply_uthread (regcache, regnum,
288 addr + bsd_uthread_thread_ctx_offset);
293 bsd_uthread_store_registers (struct regcache *regcache, int regnum)
295 struct gdbarch *gdbarch = get_regcache_arch (regcache);
296 struct bsd_uthread_ops *ops = gdbarch_data (gdbarch, bsd_uthread_data);
297 CORE_ADDR addr = ptid_get_tid (inferior_ptid);
298 CORE_ADDR active_addr;
300 active_addr = read_memory_typed_address (bsd_uthread_thread_run_addr,
301 builtin_type_void_data_ptr);
302 if (addr != 0 && addr != active_addr)
304 bsd_uthread_check_magic (addr);
305 ops->collect_uthread (regcache, regnum,
306 addr + bsd_uthread_thread_ctx_offset);
310 /* Updating the thread that is currently running; pass the
311 request to the layer beneath. */
312 find_target_beneath (bsd_uthread_ops_hack)->to_store_registers (regcache, regnum);
316 /* FIXME: This function is only there because otherwise GDB tries to
317 invoke deprecate_xfer_memory. */
320 bsd_uthread_xfer_partial (struct target_ops *ops, enum target_object object,
321 const char *annex, gdb_byte *readbuf,
322 const gdb_byte *writebuf,
323 ULONGEST offset, LONGEST len)
325 gdb_assert (ops->beneath->to_xfer_partial);
326 return ops->beneath->to_xfer_partial (ops->beneath, object, annex, readbuf,
327 writebuf, offset, len);
331 bsd_uthread_wait (ptid_t ptid, struct target_waitstatus *status)
335 /* Pass the request to the layer beneath. */
336 ptid = find_target_beneath (bsd_uthread_ops_hack)->to_wait (ptid, status);
338 /* If the process is no longer alive, there's no point in figuring
339 out the thread ID. It will fail anyway. */
340 if (status->kind == TARGET_WAITKIND_SIGNALLED
341 || status->kind == TARGET_WAITKIND_EXITED)
344 /* Fetch the corresponding thread ID, and augment the returned
345 process ID with it. */
346 addr = read_memory_typed_address (bsd_uthread_thread_run_addr,
347 builtin_type_void_data_ptr);
352 /* FIXME: For executables linked statically with the threads
353 library, we end up here before the program has actually been
354 executed. In that case ADDR will be garbage since it has
355 been read from the wrong virtual memory image. */
356 if (target_read_memory (addr, buf, 4) == 0)
358 ULONGEST magic = extract_unsigned_integer (buf, 4);
359 if (magic == BSD_UTHREAD_PTHREAD_MAGIC)
360 ptid = ptid_build (ptid_get_pid (ptid), 0, addr);
364 /* HACK: Twiddle INFERIOR_PTID such that the initial thread of a
365 process isn't recognized as a new thread. */
366 if (ptid_get_tid (ptid) != 0 && !in_thread_list (ptid)
367 && ptid_get_tid (inferior_ptid) == 0)
369 add_thread_silent (ptid);
370 inferior_ptid = ptid;
377 bsd_uthread_resume (ptid_t ptid, int step, enum target_signal sig)
379 /* Pass the request to the layer beneath. */
380 find_target_beneath (bsd_uthread_ops_hack)->to_resume (ptid, step, sig);
384 bsd_uthread_thread_alive (ptid_t ptid)
386 CORE_ADDR addr = ptid_get_tid (inferior_ptid);
390 int offset = bsd_uthread_thread_state_offset;
393 bsd_uthread_check_magic (addr);
395 state = read_memory_unsigned_integer (addr + offset, 4);
396 if (state == BSD_UTHREAD_PS_DEAD)
400 return find_target_beneath (bsd_uthread_ops_hack)->to_thread_alive (ptid);
404 bsd_uthread_find_new_threads (void)
406 pid_t pid = ptid_get_pid (inferior_ptid);
407 int offset = bsd_uthread_thread_next_offset;
410 addr = read_memory_typed_address (bsd_uthread_thread_list_addr,
411 builtin_type_void_data_ptr);
414 ptid_t ptid = ptid_build (pid, 0, addr);
416 if (!in_thread_list (ptid))
419 addr = read_memory_typed_address (addr + offset,
420 builtin_type_void_data_ptr);
424 /* Possible states a thread can be in. */
425 static char *bsd_uthread_state[] =
449 /* Return a string describing th state of the thread specified by
453 bsd_uthread_extra_thread_info (struct thread_info *info)
455 CORE_ADDR addr = ptid_get_tid (info->ptid);
459 int offset = bsd_uthread_thread_state_offset;
462 state = read_memory_unsigned_integer (addr + offset, 4);
463 if (state < ARRAY_SIZE (bsd_uthread_state))
464 return bsd_uthread_state[state];
471 bsd_uthread_pid_to_str (ptid_t ptid)
473 if (ptid_get_tid (ptid) != 0)
477 xsnprintf (buf, sizeof buf, "process %d, thread 0x%lx",
478 ptid_get_pid (ptid), ptid_get_tid (ptid));
482 return normal_pid_to_str (ptid);
486 bsd_uthread_target (void)
488 struct target_ops *t = XZALLOC (struct target_ops);
490 t->to_shortname = "bsd-uthreads";
491 t->to_longname = "BSD user-level threads";
492 t->to_doc = "BSD user-level threads";
493 t->to_mourn_inferior = bsd_uthread_mourn_inferior;
494 t->to_fetch_registers = bsd_uthread_fetch_registers;
495 t->to_store_registers = bsd_uthread_store_registers;
496 t->to_xfer_partial = bsd_uthread_xfer_partial;
497 t->to_wait = bsd_uthread_wait;
498 t->to_resume = bsd_uthread_resume;
499 t->to_thread_alive = bsd_uthread_thread_alive;
500 t->to_find_new_threads = bsd_uthread_find_new_threads;
501 t->to_extra_thread_info = bsd_uthread_extra_thread_info;
502 t->to_pid_to_str = bsd_uthread_pid_to_str;
503 t->to_stratum = thread_stratum;
504 t->to_magic = OPS_MAGIC;
505 bsd_uthread_ops_hack = t;
511 _initialize_bsd_uthread (void)
513 add_target (bsd_uthread_target ());
515 bsd_uthread_data = gdbarch_data_register_pre_init (bsd_uthread_init);
517 observer_attach_inferior_created (bsd_uthread_inferior_created);
518 observer_attach_solib_loaded (bsd_uthread_solib_loaded);
519 observer_attach_solib_unloaded (bsd_uthread_solib_unloaded);