1 /* Get Dwarf Frame state for target PID or core file.
2 Copyright (C) 2013, 2014 Red Hat, Inc.
3 This file is part of elfutils.
5 This file is free software; you can redistribute it and/or modify
6 it under the terms of either
8 * the GNU Lesser General Public License as published by the Free
9 Software Foundation; either version 3 of the License, or (at
10 your option) any later version
14 * the GNU General Public License as published by the Free
15 Software Foundation; either version 2 of the License, or (at
16 your option) any later version
18 or both in parallel, as here.
20 elfutils is distributed in the hope that it will be useful, but
21 WITHOUT ANY WARRANTY; without even the implied warranty of
22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 General Public License for more details.
25 You should have received copies of the GNU General Public License and
26 the GNU Lesser General Public License along with this program. If
27 not, see <http://www.gnu.org/licenses/>. */
30 #include <sys/ptrace.h>
33 /* Set STATE->pc_set from STATE->regs according to the backend. Return true on
34 success, false on error. */
36 state_fetch_pc (Dwfl_Frame *state)
38 switch (state->pc_state)
40 case DWFL_FRAME_STATE_PC_SET:
42 case DWFL_FRAME_STATE_PC_UNDEFINED:
44 case DWFL_FRAME_STATE_ERROR:
46 Ebl *ebl = state->thread->process->ebl;
48 if (ebl_abi_cfi (ebl, &abi_info) != 0)
50 __libdwfl_seterrno (DWFL_E_LIBEBL);
53 unsigned ra = abi_info.return_address_register;
54 /* dwarf_frame_state_reg_is_set is not applied here. */
55 if (ra >= ebl_frame_nregs (ebl))
57 __libdwfl_seterrno (DWFL_E_LIBEBL_BAD);
60 state->pc = state->regs[ra];
61 state->pc_state = DWFL_FRAME_STATE_PC_SET;
68 /* Do not call it on your own, to be used by thread_* functions only. */
71 state_free (Dwfl_Frame *state)
73 Dwfl_Thread *thread = state->thread;
74 assert (thread->unwound == state);
75 thread->unwound = state->unwound;
80 thread_free_all_states (Dwfl_Thread *thread)
82 while (thread->unwound)
83 state_free (thread->unwound);
87 state_alloc (Dwfl_Thread *thread)
89 assert (thread->unwound == NULL);
90 Ebl *ebl = thread->process->ebl;
91 size_t nregs = ebl_frame_nregs (ebl);
94 assert (nregs < sizeof (((Dwfl_Frame *) NULL)->regs_set) * 8);
95 Dwfl_Frame *state = malloc (sizeof (*state) + sizeof (*state->regs) * nregs);
98 state->thread = thread;
99 state->signal_frame = false;
100 state->initial_frame = true;
101 state->pc_state = DWFL_FRAME_STATE_ERROR;
102 memset (state->regs_set, 0, sizeof (state->regs_set));
103 thread->unwound = state;
104 state->unwound = NULL;
110 __libdwfl_process_free (Dwfl_Process *process)
112 Dwfl *dwfl = process->dwfl;
113 if (process->callbacks->detach != NULL)
114 process->callbacks->detach (dwfl, process->callbacks_arg);
115 assert (dwfl->process == process);
116 dwfl->process = NULL;
117 if (process->ebl_close)
118 ebl_closebackend (process->ebl);
120 dwfl->attacherr = DWFL_E_NOERROR;
123 /* Allocate new Dwfl_Process for DWFL. */
125 process_alloc (Dwfl *dwfl)
127 Dwfl_Process *process = malloc (sizeof (*process));
130 process->dwfl = dwfl;
131 dwfl->process = process;
135 dwfl_attach_state (Dwfl *dwfl, Elf *elf, pid_t pid,
136 const Dwfl_Thread_Callbacks *thread_callbacks, void *arg)
138 if (dwfl->process != NULL)
140 __libdwfl_seterrno (DWFL_E_ATTACH_STATE_CONFLICT);
144 /* Reset any previous error, we are just going to try again. */
145 dwfl->attacherr = DWFL_E_NOERROR;
146 if (thread_callbacks == NULL || thread_callbacks->next_thread == NULL
147 || thread_callbacks->set_initial_registers == NULL)
149 dwfl->attacherr = DWFL_E_INVALID_ARGUMENT;
151 dwfl->attacherr = __libdwfl_canon_error (dwfl->attacherr);
152 __libdwfl_seterrno (dwfl->attacherr);
160 ebl = ebl_openbackend (elf);
166 for (Dwfl_Module *mod = dwfl->modulelist; mod != NULL; mod = mod->next)
168 /* Reading of the vDSO or (deleted) modules may fail as
169 /proc/PID/mem is unreadable without PTRACE_ATTACH and
170 we may not be PTRACE_ATTACH-ed now. MOD would not be
171 re-read later to unwind it when we are already
172 PTRACE_ATTACH-ed to PID. This happens when this function
173 is called from dwfl_linux_proc_attach with elf == NULL.
174 __libdwfl_module_getebl will call __libdwfl_getelf which
175 will call the find_elf callback. */
176 if (strncmp (mod->name, "[vdso: ", 7) == 0
177 || strcmp (strrchr (mod->name, ' ') ?: "",
180 Dwfl_Error error = __libdwfl_module_getebl (mod);
181 if (error != DWFL_E_NOERROR)
190 /* Not identified EBL from any of the modules. */
191 dwfl->attacherr = DWFL_E_PROCESS_NO_ARCH;
194 process_alloc (dwfl);
195 Dwfl_Process *process = dwfl->process;
199 ebl_closebackend (ebl);
200 dwfl->attacherr = DWFL_E_NOMEM;
204 process->ebl_close = ebl_close;
206 process->callbacks = thread_callbacks;
207 process->callbacks_arg = arg;
210 INTDEF(dwfl_attach_state)
213 dwfl_pid (Dwfl *dwfl)
215 if (dwfl->attacherr != DWFL_E_NOERROR)
217 __libdwfl_seterrno (dwfl->attacherr);
221 if (dwfl->process == NULL)
223 __libdwfl_seterrno (DWFL_E_NO_ATTACH_STATE);
226 return dwfl->process->pid;
231 dwfl_thread_dwfl (Dwfl_Thread *thread)
233 return thread->process->dwfl;
235 INTDEF(dwfl_thread_dwfl)
238 dwfl_thread_tid (Dwfl_Thread *thread)
242 INTDEF(dwfl_thread_tid)
245 dwfl_frame_thread (Dwfl_Frame *state)
247 return state->thread;
249 INTDEF(dwfl_frame_thread)
252 dwfl_getthreads (Dwfl *dwfl, int (*callback) (Dwfl_Thread *thread, void *arg),
255 if (dwfl->attacherr != DWFL_E_NOERROR)
257 __libdwfl_seterrno (dwfl->attacherr);
261 Dwfl_Process *process = dwfl->process;
264 __libdwfl_seterrno (DWFL_E_NO_ATTACH_STATE);
269 thread.process = process;
270 thread.unwound = NULL;
271 thread.callbacks_arg = NULL;
274 thread.tid = process->callbacks->next_thread (dwfl,
275 process->callbacks_arg,
276 &thread.callbacks_arg);
279 Dwfl_Error saved_errno = dwfl_errno ();
280 thread_free_all_states (&thread);
281 __libdwfl_seterrno (saved_errno);
286 thread_free_all_states (&thread);
287 __libdwfl_seterrno (DWFL_E_NOERROR);
290 int err = callback (&thread, arg);
291 if (err != DWARF_CB_OK)
293 thread_free_all_states (&thread);
296 assert (thread.unwound == NULL);
300 INTDEF(dwfl_getthreads)
306 int (*callback) (Dwfl_Thread *thread, void *arg);
312 get_one_thread_cb (Dwfl_Thread *thread, void *arg)
314 struct one_arg *oa = (struct one_arg *) arg;
315 if (! oa->seen && INTUSE(dwfl_thread_tid) (thread) == oa->tid)
318 oa->ret = oa->callback (thread, oa->arg);
319 return DWARF_CB_ABORT;
325 /* Note not currently exported, will be when there are more Dwfl_Thread
326 properties to query. Use dwfl_getthread_frames for now directly. */
328 getthread (Dwfl *dwfl, pid_t tid,
329 int (*callback) (Dwfl_Thread *thread, void *arg),
332 if (dwfl->attacherr != DWFL_E_NOERROR)
334 __libdwfl_seterrno (dwfl->attacherr);
338 Dwfl_Process *process = dwfl->process;
341 __libdwfl_seterrno (DWFL_E_NO_ATTACH_STATE);
345 if (process->callbacks->get_thread != NULL)
348 thread.process = process;
349 thread.unwound = NULL;
350 thread.callbacks_arg = NULL;
352 if (process->callbacks->get_thread (dwfl, tid, process->callbacks_arg,
353 &thread.callbacks_arg))
357 err = callback (&thread, arg);
358 thread_free_all_states (&thread);
365 struct one_arg oa = { .tid = tid, .callback = callback,
366 .arg = arg, .seen = false };
367 int err = INTUSE(dwfl_getthreads) (dwfl, get_one_thread_cb, &oa);
369 if (err == DWARF_CB_ABORT && oa.seen)
372 if (err == DWARF_CB_OK && ! oa.seen)
375 __libdwfl_seterrno (DWFL_E_ERRNO);
384 int (*callback) (Dwfl_Frame *frame, void *arg);
389 get_one_thread_frames_cb (Dwfl_Thread *thread, void *arg)
391 struct one_thread *ot = (struct one_thread *) arg;
392 return INTUSE(dwfl_thread_getframes) (thread, ot->callback, ot->arg);
396 dwfl_getthread_frames (Dwfl *dwfl, pid_t tid,
397 int (*callback) (Dwfl_Frame *frame, void *arg),
400 struct one_thread ot = { .callback = callback, .arg = arg };
401 return getthread (dwfl, tid, get_one_thread_frames_cb, &ot);
403 INTDEF(dwfl_getthread_frames)
406 dwfl_thread_getframes (Dwfl_Thread *thread,
407 int (*callback) (Dwfl_Frame *state, void *arg),
410 if (thread->unwound != NULL)
412 /* We had to be called from inside CALLBACK. */
413 __libdwfl_seterrno (DWFL_E_ATTACH_STATE_CONFLICT);
416 Ebl *ebl = thread->process->ebl;
417 if (ebl_frame_nregs (ebl) == 0)
419 __libdwfl_seterrno (DWFL_E_NO_UNWIND);
422 if (state_alloc (thread) == NULL)
424 __libdwfl_seterrno (DWFL_E_NOMEM);
427 Dwfl_Process *process = thread->process;
428 if (! process->callbacks->set_initial_registers (thread,
429 thread->callbacks_arg))
431 thread_free_all_states (thread);
434 if (! state_fetch_pc (thread->unwound))
436 if (process->callbacks->thread_detach)
437 process->callbacks->thread_detach (thread, thread->callbacks_arg);
438 thread_free_all_states (thread);
445 state = thread->unwound;
446 int err = callback (state, arg);
447 if (err != DWARF_CB_OK)
449 if (process->callbacks->thread_detach)
450 process->callbacks->thread_detach (thread, thread->callbacks_arg);
451 thread_free_all_states (thread);
454 __libdwfl_frame_unwind (state);
455 /* The old frame is no longer needed. */
456 state_free (thread->unwound);
457 state = thread->unwound;
459 while (state && state->pc_state == DWFL_FRAME_STATE_PC_SET);
461 Dwfl_Error err = dwfl_errno ();
462 if (process->callbacks->thread_detach)
463 process->callbacks->thread_detach (thread, thread->callbacks_arg);
464 if (state == NULL || state->pc_state == DWFL_FRAME_STATE_ERROR)
466 thread_free_all_states (thread);
467 __libdwfl_seterrno (err);
470 assert (state->pc_state == DWFL_FRAME_STATE_PC_UNDEFINED);
471 thread_free_all_states (thread);
474 INTDEF(dwfl_thread_getframes)