gdb/
[binutils-gdb.git] / gdb / gdbserver / linux-low.c
1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
3 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4
5 This file is part of GDB.
6
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.
11
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.
16
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/>. */
19
20 #include "server.h"
21 #include "linux-low.h"
22
23 #include <sys/wait.h>
24 #include <stdio.h>
25 #include <sys/param.h>
26 #include <sys/ptrace.h>
27 #include <signal.h>
28 #include <sys/ioctl.h>
29 #include <fcntl.h>
30 #include <string.h>
31 #include <stdlib.h>
32 #include <unistd.h>
33 #include <errno.h>
34 #include <sys/syscall.h>
35 #include <sched.h>
36 #include <ctype.h>
37 #include <pwd.h>
38 #include <sys/types.h>
39 #include <dirent.h>
40 #include <sys/stat.h>
41 #include <sys/vfs.h>
42 #ifndef ELFMAG0
43 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
44 then ELFMAG0 will have been defined. If it didn't get included by
45 gdb_proc_service.h then including it will likely introduce a duplicate
46 definition of elf_fpregset_t. */
47 #include <elf.h>
48 #endif
49
50 #ifndef SPUFS_MAGIC
51 #define SPUFS_MAGIC 0x23c9b64e
52 #endif
53
54 #ifndef PTRACE_GETSIGINFO
55 # define PTRACE_GETSIGINFO 0x4202
56 # define PTRACE_SETSIGINFO 0x4203
57 #endif
58
59 #ifndef O_LARGEFILE
60 #define O_LARGEFILE 0
61 #endif
62
63 /* If the system headers did not provide the constants, hard-code the normal
64 values. */
65 #ifndef PTRACE_EVENT_FORK
66
67 #define PTRACE_SETOPTIONS 0x4200
68 #define PTRACE_GETEVENTMSG 0x4201
69
70 /* options set using PTRACE_SETOPTIONS */
71 #define PTRACE_O_TRACESYSGOOD 0x00000001
72 #define PTRACE_O_TRACEFORK 0x00000002
73 #define PTRACE_O_TRACEVFORK 0x00000004
74 #define PTRACE_O_TRACECLONE 0x00000008
75 #define PTRACE_O_TRACEEXEC 0x00000010
76 #define PTRACE_O_TRACEVFORKDONE 0x00000020
77 #define PTRACE_O_TRACEEXIT 0x00000040
78
79 /* Wait extended result codes for the above trace options. */
80 #define PTRACE_EVENT_FORK 1
81 #define PTRACE_EVENT_VFORK 2
82 #define PTRACE_EVENT_CLONE 3
83 #define PTRACE_EVENT_EXEC 4
84 #define PTRACE_EVENT_VFORK_DONE 5
85 #define PTRACE_EVENT_EXIT 6
86
87 #endif /* PTRACE_EVENT_FORK */
88
89 /* We can't always assume that this flag is available, but all systems
90 with the ptrace event handlers also have __WALL, so it's safe to use
91 in some contexts. */
92 #ifndef __WALL
93 #define __WALL 0x40000000 /* Wait for any child. */
94 #endif
95
96 #ifndef W_STOPCODE
97 #define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
98 #endif
99
100 #ifdef __UCLIBC__
101 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
102 #define HAS_NOMMU
103 #endif
104 #endif
105
106 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
107 representation of the thread ID.
108
109 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
110 the same as the LWP ID.
111
112 ``all_processes'' is keyed by the "overall process ID", which
113 GNU/Linux calls tgid, "thread group ID". */
114
115 struct inferior_list all_lwps;
116
117 /* A list of all unknown processes which receive stop signals. Some other
118 process will presumably claim each of these as forked children
119 momentarily. */
120
121 struct inferior_list stopped_pids;
122
123 /* FIXME this is a bit of a hack, and could be removed. */
124 int stopping_threads;
125
126 /* FIXME make into a target method? */
127 int using_threads = 1;
128
129 /* This flag is true iff we've just created or attached to our first
130 inferior but it has not stopped yet. As soon as it does, we need
131 to call the low target's arch_setup callback. Doing this only on
132 the first inferior avoids reinializing the architecture on every
133 inferior, and avoids messing with the register caches of the
134 already running inferiors. NOTE: this assumes all inferiors under
135 control of gdbserver have the same architecture. */
136 static int new_inferior;
137
138 static void linux_resume_one_lwp (struct lwp_info *lwp,
139 int step, int signal, siginfo_t *info);
140 static void linux_resume (struct thread_resume *resume_info, size_t n);
141 static void stop_all_lwps (void);
142 static int linux_wait_for_event (ptid_t ptid, int *wstat, int options);
143 static int check_removed_breakpoint (struct lwp_info *event_child);
144 static void *add_lwp (ptid_t ptid);
145 static int linux_stopped_by_watchpoint (void);
146 static void mark_lwp_dead (struct lwp_info *lwp, int wstat);
147 static int linux_core_of_thread (ptid_t ptid);
148
149 struct pending_signals
150 {
151 int signal;
152 siginfo_t info;
153 struct pending_signals *prev;
154 };
155
156 #define PTRACE_ARG3_TYPE void *
157 #define PTRACE_ARG4_TYPE void *
158 #define PTRACE_XFER_TYPE long
159
160 #ifdef HAVE_LINUX_REGSETS
161 static char *disabled_regsets;
162 static int num_regsets;
163 #endif
164
165 /* The read/write ends of the pipe registered as waitable file in the
166 event loop. */
167 static int linux_event_pipe[2] = { -1, -1 };
168
169 /* True if we're currently in async mode. */
170 #define target_is_async_p() (linux_event_pipe[0] != -1)
171
172 static void send_sigstop (struct inferior_list_entry *entry);
173 static void wait_for_sigstop (struct inferior_list_entry *entry);
174
175 /* Accepts an integer PID; Returns a string representing a file that
176 can be opened to get info for the child process.
177 Space for the result is malloc'd, caller must free. */
178
179 char *
180 linux_child_pid_to_exec_file (int pid)
181 {
182 char *name1, *name2;
183
184 name1 = xmalloc (MAXPATHLEN);
185 name2 = xmalloc (MAXPATHLEN);
186 memset (name2, 0, MAXPATHLEN);
187
188 sprintf (name1, "/proc/%d/exe", pid);
189 if (readlink (name1, name2, MAXPATHLEN) > 0)
190 {
191 free (name1);
192 return name2;
193 }
194 else
195 {
196 free (name2);
197 return name1;
198 }
199 }
200
201 /* Return non-zero if HEADER is a 64-bit ELF file. */
202
203 static int
204 elf_64_header_p (const Elf64_Ehdr *header)
205 {
206 return (header->e_ident[EI_MAG0] == ELFMAG0
207 && header->e_ident[EI_MAG1] == ELFMAG1
208 && header->e_ident[EI_MAG2] == ELFMAG2
209 && header->e_ident[EI_MAG3] == ELFMAG3
210 && header->e_ident[EI_CLASS] == ELFCLASS64);
211 }
212
213 /* Return non-zero if FILE is a 64-bit ELF file,
214 zero if the file is not a 64-bit ELF file,
215 and -1 if the file is not accessible or doesn't exist. */
216
217 int
218 elf_64_file_p (const char *file)
219 {
220 Elf64_Ehdr header;
221 int fd;
222
223 fd = open (file, O_RDONLY);
224 if (fd < 0)
225 return -1;
226
227 if (read (fd, &header, sizeof (header)) != sizeof (header))
228 {
229 close (fd);
230 return 0;
231 }
232 close (fd);
233
234 return elf_64_header_p (&header);
235 }
236
237 static void
238 delete_lwp (struct lwp_info *lwp)
239 {
240 remove_thread (get_lwp_thread (lwp));
241 remove_inferior (&all_lwps, &lwp->head);
242 free (lwp->arch_private);
243 free (lwp);
244 }
245
246 /* Add a process to the common process list, and set its private
247 data. */
248
249 static struct process_info *
250 linux_add_process (int pid, int attached)
251 {
252 struct process_info *proc;
253
254 /* Is this the first process? If so, then set the arch. */
255 if (all_processes.head == NULL)
256 new_inferior = 1;
257
258 proc = add_process (pid, attached);
259 proc->private = xcalloc (1, sizeof (*proc->private));
260
261 if (the_low_target.new_process != NULL)
262 proc->private->arch_private = the_low_target.new_process ();
263
264 return proc;
265 }
266
267 /* Remove a process from the common process list,
268 also freeing all private data. */
269
270 static void
271 linux_remove_process (struct process_info *process)
272 {
273 struct process_info_private *priv = process->private;
274
275 free (priv->arch_private);
276 free (priv);
277 remove_process (process);
278 }
279
280 /* Wrapper function for waitpid which handles EINTR, and emulates
281 __WALL for systems where that is not available. */
282
283 static int
284 my_waitpid (int pid, int *status, int flags)
285 {
286 int ret, out_errno;
287
288 if (debug_threads)
289 fprintf (stderr, "my_waitpid (%d, 0x%x)\n", pid, flags);
290
291 if (flags & __WALL)
292 {
293 sigset_t block_mask, org_mask, wake_mask;
294 int wnohang;
295
296 wnohang = (flags & WNOHANG) != 0;
297 flags &= ~(__WALL | __WCLONE);
298 flags |= WNOHANG;
299
300 /* Block all signals while here. This avoids knowing about
301 LinuxThread's signals. */
302 sigfillset (&block_mask);
303 sigprocmask (SIG_BLOCK, &block_mask, &org_mask);
304
305 /* ... except during the sigsuspend below. */
306 sigemptyset (&wake_mask);
307
308 while (1)
309 {
310 /* Since all signals are blocked, there's no need to check
311 for EINTR here. */
312 ret = waitpid (pid, status, flags);
313 out_errno = errno;
314
315 if (ret == -1 && out_errno != ECHILD)
316 break;
317 else if (ret > 0)
318 break;
319
320 if (flags & __WCLONE)
321 {
322 /* We've tried both flavors now. If WNOHANG is set,
323 there's nothing else to do, just bail out. */
324 if (wnohang)
325 break;
326
327 if (debug_threads)
328 fprintf (stderr, "blocking\n");
329
330 /* Block waiting for signals. */
331 sigsuspend (&wake_mask);
332 }
333
334 flags ^= __WCLONE;
335 }
336
337 sigprocmask (SIG_SETMASK, &org_mask, NULL);
338 }
339 else
340 {
341 do
342 ret = waitpid (pid, status, flags);
343 while (ret == -1 && errno == EINTR);
344 out_errno = errno;
345 }
346
347 if (debug_threads)
348 fprintf (stderr, "my_waitpid (%d, 0x%x): status(%x), %d\n",
349 pid, flags, status ? *status : -1, ret);
350
351 errno = out_errno;
352 return ret;
353 }
354
355 /* Handle a GNU/Linux extended wait response. If we see a clone
356 event, we need to add the new LWP to our list (and not report the
357 trap to higher layers). */
358
359 static void
360 handle_extended_wait (struct lwp_info *event_child, int wstat)
361 {
362 int event = wstat >> 16;
363 struct lwp_info *new_lwp;
364
365 if (event == PTRACE_EVENT_CLONE)
366 {
367 ptid_t ptid;
368 unsigned long new_pid;
369 int ret, status = W_STOPCODE (SIGSTOP);
370
371 ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_child), 0, &new_pid);
372
373 /* If we haven't already seen the new PID stop, wait for it now. */
374 if (! pull_pid_from_list (&stopped_pids, new_pid))
375 {
376 /* The new child has a pending SIGSTOP. We can't affect it until it
377 hits the SIGSTOP, but we're already attached. */
378
379 ret = my_waitpid (new_pid, &status, __WALL);
380
381 if (ret == -1)
382 perror_with_name ("waiting for new child");
383 else if (ret != new_pid)
384 warning ("wait returned unexpected PID %d", ret);
385 else if (!WIFSTOPPED (status))
386 warning ("wait returned unexpected status 0x%x", status);
387 }
388
389 ptrace (PTRACE_SETOPTIONS, new_pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
390
391 ptid = ptid_build (pid_of (event_child), new_pid, 0);
392 new_lwp = (struct lwp_info *) add_lwp (ptid);
393 add_thread (ptid, new_lwp);
394
395 /* Either we're going to immediately resume the new thread
396 or leave it stopped. linux_resume_one_lwp is a nop if it
397 thinks the thread is currently running, so set this first
398 before calling linux_resume_one_lwp. */
399 new_lwp->stopped = 1;
400
401 /* Normally we will get the pending SIGSTOP. But in some cases
402 we might get another signal delivered to the group first.
403 If we do get another signal, be sure not to lose it. */
404 if (WSTOPSIG (status) == SIGSTOP)
405 {
406 if (! stopping_threads)
407 linux_resume_one_lwp (new_lwp, 0, 0, NULL);
408 }
409 else
410 {
411 new_lwp->stop_expected = 1;
412 if (stopping_threads)
413 {
414 new_lwp->status_pending_p = 1;
415 new_lwp->status_pending = status;
416 }
417 else
418 /* Pass the signal on. This is what GDB does - except
419 shouldn't we really report it instead? */
420 linux_resume_one_lwp (new_lwp, 0, WSTOPSIG (status), NULL);
421 }
422
423 /* Always resume the current thread. If we are stopping
424 threads, it will have a pending SIGSTOP; we may as well
425 collect it now. */
426 linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL);
427 }
428 }
429
430 /* This function should only be called if the process got a SIGTRAP.
431 The SIGTRAP could mean several things.
432
433 On i386, where decr_pc_after_break is non-zero:
434 If we were single-stepping this process using PTRACE_SINGLESTEP,
435 we will get only the one SIGTRAP (even if the instruction we
436 stepped over was a breakpoint). The value of $eip will be the
437 next instruction.
438 If we continue the process using PTRACE_CONT, we will get a
439 SIGTRAP when we hit a breakpoint. The value of $eip will be
440 the instruction after the breakpoint (i.e. needs to be
441 decremented). If we report the SIGTRAP to GDB, we must also
442 report the undecremented PC. If we cancel the SIGTRAP, we
443 must resume at the decremented PC.
444
445 (Presumably, not yet tested) On a non-decr_pc_after_break machine
446 with hardware or kernel single-step:
447 If we single-step over a breakpoint instruction, our PC will
448 point at the following instruction. If we continue and hit a
449 breakpoint instruction, our PC will point at the breakpoint
450 instruction. */
451
452 static CORE_ADDR
453 get_stop_pc (void)
454 {
455 struct regcache *regcache = get_thread_regcache (current_inferior, 1);
456 CORE_ADDR stop_pc = (*the_low_target.get_pc) (regcache);
457
458 if (! get_thread_lwp (current_inferior)->stepping
459 && WSTOPSIG (get_thread_lwp (current_inferior)->last_status) == SIGTRAP)
460 stop_pc -= the_low_target.decr_pc_after_break;
461
462 if (debug_threads)
463 fprintf (stderr, "stop pc is 0x%lx\n", (long) stop_pc);
464
465 return stop_pc;
466 }
467
468 static void *
469 add_lwp (ptid_t ptid)
470 {
471 struct lwp_info *lwp;
472
473 lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
474 memset (lwp, 0, sizeof (*lwp));
475
476 lwp->head.id = ptid;
477
478 if (the_low_target.new_thread != NULL)
479 lwp->arch_private = the_low_target.new_thread ();
480
481 add_inferior_to_list (&all_lwps, &lwp->head);
482
483 return lwp;
484 }
485
486 /* Start an inferior process and returns its pid.
487 ALLARGS is a vector of program-name and args. */
488
489 static int
490 linux_create_inferior (char *program, char **allargs)
491 {
492 struct lwp_info *new_lwp;
493 int pid;
494 ptid_t ptid;
495
496 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
497 pid = vfork ();
498 #else
499 pid = fork ();
500 #endif
501 if (pid < 0)
502 perror_with_name ("fork");
503
504 if (pid == 0)
505 {
506 ptrace (PTRACE_TRACEME, 0, 0, 0);
507
508 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
509 signal (__SIGRTMIN + 1, SIG_DFL);
510 #endif
511
512 setpgid (0, 0);
513
514 execv (program, allargs);
515 if (errno == ENOENT)
516 execvp (program, allargs);
517
518 fprintf (stderr, "Cannot exec %s: %s.\n", program,
519 strerror (errno));
520 fflush (stderr);
521 _exit (0177);
522 }
523
524 linux_add_process (pid, 0);
525
526 ptid = ptid_build (pid, pid, 0);
527 new_lwp = add_lwp (ptid);
528 add_thread (ptid, new_lwp);
529 new_lwp->must_set_ptrace_flags = 1;
530
531 return pid;
532 }
533
534 /* Attach to an inferior process. */
535
536 static void
537 linux_attach_lwp_1 (unsigned long lwpid, int initial)
538 {
539 ptid_t ptid;
540 struct lwp_info *new_lwp;
541
542 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0)
543 {
544 if (!initial)
545 {
546 /* If we fail to attach to an LWP, just warn. */
547 fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", lwpid,
548 strerror (errno), errno);
549 fflush (stderr);
550 return;
551 }
552 else
553 /* If we fail to attach to a process, report an error. */
554 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid,
555 strerror (errno), errno);
556 }
557
558 if (initial)
559 /* NOTE/FIXME: This lwp might have not been the tgid. */
560 ptid = ptid_build (lwpid, lwpid, 0);
561 else
562 {
563 /* Note that extracting the pid from the current inferior is
564 safe, since we're always called in the context of the same
565 process as this new thread. */
566 int pid = pid_of (get_thread_lwp (current_inferior));
567 ptid = ptid_build (pid, lwpid, 0);
568 }
569
570 new_lwp = (struct lwp_info *) add_lwp (ptid);
571 add_thread (ptid, new_lwp);
572
573 /* We need to wait for SIGSTOP before being able to make the next
574 ptrace call on this LWP. */
575 new_lwp->must_set_ptrace_flags = 1;
576
577 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
578 brings it to a halt.
579
580 There are several cases to consider here:
581
582 1) gdbserver has already attached to the process and is being notified
583 of a new thread that is being created.
584 In this case we should ignore that SIGSTOP and resume the process.
585 This is handled below by setting stop_expected = 1.
586
587 2) This is the first thread (the process thread), and we're attaching
588 to it via attach_inferior.
589 In this case we want the process thread to stop.
590 This is handled by having linux_attach clear stop_expected after
591 we return.
592 ??? If the process already has several threads we leave the other
593 threads running.
594
595 3) GDB is connecting to gdbserver and is requesting an enumeration of all
596 existing threads.
597 In this case we want the thread to stop.
598 FIXME: This case is currently not properly handled.
599 We should wait for the SIGSTOP but don't. Things work apparently
600 because enough time passes between when we ptrace (ATTACH) and when
601 gdb makes the next ptrace call on the thread.
602
603 On the other hand, if we are currently trying to stop all threads, we
604 should treat the new thread as if we had sent it a SIGSTOP. This works
605 because we are guaranteed that the add_lwp call above added us to the
606 end of the list, and so the new thread has not yet reached
607 wait_for_sigstop (but will). */
608 if (! stopping_threads)
609 new_lwp->stop_expected = 1;
610 }
611
612 void
613 linux_attach_lwp (unsigned long lwpid)
614 {
615 linux_attach_lwp_1 (lwpid, 0);
616 }
617
618 int
619 linux_attach (unsigned long pid)
620 {
621 struct lwp_info *lwp;
622
623 linux_attach_lwp_1 (pid, 1);
624
625 linux_add_process (pid, 1);
626
627 if (!non_stop)
628 {
629 /* Don't ignore the initial SIGSTOP if we just attached to this
630 process. It will be collected by wait shortly. */
631 lwp = (struct lwp_info *) find_inferior_id (&all_lwps,
632 ptid_build (pid, pid, 0));
633 lwp->stop_expected = 0;
634 }
635
636 return 0;
637 }
638
639 struct counter
640 {
641 int pid;
642 int count;
643 };
644
645 static int
646 second_thread_of_pid_p (struct inferior_list_entry *entry, void *args)
647 {
648 struct counter *counter = args;
649
650 if (ptid_get_pid (entry->id) == counter->pid)
651 {
652 if (++counter->count > 1)
653 return 1;
654 }
655
656 return 0;
657 }
658
659 static int
660 last_thread_of_process_p (struct thread_info *thread)
661 {
662 ptid_t ptid = ((struct inferior_list_entry *)thread)->id;
663 int pid = ptid_get_pid (ptid);
664 struct counter counter = { pid , 0 };
665
666 return (find_inferior (&all_threads,
667 second_thread_of_pid_p, &counter) == NULL);
668 }
669
670 /* Kill the inferior lwp. */
671
672 static int
673 linux_kill_one_lwp (struct inferior_list_entry *entry, void *args)
674 {
675 struct thread_info *thread = (struct thread_info *) entry;
676 struct lwp_info *lwp = get_thread_lwp (thread);
677 int wstat;
678 int pid = * (int *) args;
679
680 if (ptid_get_pid (entry->id) != pid)
681 return 0;
682
683 /* We avoid killing the first thread here, because of a Linux kernel (at
684 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
685 the children get a chance to be reaped, it will remain a zombie
686 forever. */
687
688 if (lwpid_of (lwp) == pid)
689 {
690 if (debug_threads)
691 fprintf (stderr, "lkop: is last of process %s\n",
692 target_pid_to_str (entry->id));
693 return 0;
694 }
695
696 /* If we're killing a running inferior, make sure it is stopped
697 first, as PTRACE_KILL will not work otherwise. */
698 if (!lwp->stopped)
699 send_sigstop (&lwp->head);
700
701 do
702 {
703 ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
704
705 /* Make sure it died. The loop is most likely unnecessary. */
706 pid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
707 } while (pid > 0 && WIFSTOPPED (wstat));
708
709 return 0;
710 }
711
712 static int
713 linux_kill (int pid)
714 {
715 struct process_info *process;
716 struct lwp_info *lwp;
717 struct thread_info *thread;
718 int wstat;
719 int lwpid;
720
721 process = find_process_pid (pid);
722 if (process == NULL)
723 return -1;
724
725 find_inferior (&all_threads, linux_kill_one_lwp, &pid);
726
727 /* See the comment in linux_kill_one_lwp. We did not kill the first
728 thread in the list, so do so now. */
729 lwp = find_lwp_pid (pid_to_ptid (pid));
730 thread = get_lwp_thread (lwp);
731
732 if (debug_threads)
733 fprintf (stderr, "lk_1: killing lwp %ld, for pid: %d\n",
734 lwpid_of (lwp), pid);
735
736 /* If we're killing a running inferior, make sure it is stopped
737 first, as PTRACE_KILL will not work otherwise. */
738 if (!lwp->stopped)
739 send_sigstop (&lwp->head);
740
741 do
742 {
743 ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
744
745 /* Make sure it died. The loop is most likely unnecessary. */
746 lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
747 } while (lwpid > 0 && WIFSTOPPED (wstat));
748
749 #ifdef USE_THREAD_DB
750 thread_db_free (process, 0);
751 #endif
752 delete_lwp (lwp);
753 linux_remove_process (process);
754 return 0;
755 }
756
757 static int
758 linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
759 {
760 struct thread_info *thread = (struct thread_info *) entry;
761 struct lwp_info *lwp = get_thread_lwp (thread);
762 int pid = * (int *) args;
763
764 if (ptid_get_pid (entry->id) != pid)
765 return 0;
766
767 /* If we're detaching from a running inferior, make sure it is
768 stopped first, as PTRACE_DETACH will not work otherwise. */
769 if (!lwp->stopped)
770 {
771 int lwpid = lwpid_of (lwp);
772
773 stopping_threads = 1;
774 send_sigstop (&lwp->head);
775
776 /* If this detects a new thread through a clone event, the new
777 thread is appended to the end of the lwp list, so we'll
778 eventually detach from it. */
779 wait_for_sigstop (&lwp->head);
780 stopping_threads = 0;
781
782 /* If LWP exits while we're trying to stop it, there's nothing
783 left to do. */
784 lwp = find_lwp_pid (pid_to_ptid (lwpid));
785 if (lwp == NULL)
786 return 0;
787 }
788
789 /* Make sure the process isn't stopped at a breakpoint that's
790 no longer there. */
791 check_removed_breakpoint (lwp);
792
793 /* If this process is stopped but is expecting a SIGSTOP, then make
794 sure we take care of that now. This isn't absolutely guaranteed
795 to collect the SIGSTOP, but is fairly likely to. */
796 if (lwp->stop_expected)
797 {
798 int wstat;
799 /* Clear stop_expected, so that the SIGSTOP will be reported. */
800 lwp->stop_expected = 0;
801 if (lwp->stopped)
802 linux_resume_one_lwp (lwp, 0, 0, NULL);
803 linux_wait_for_event (lwp->head.id, &wstat, __WALL);
804 }
805
806 /* Flush any pending changes to the process's registers. */
807 regcache_invalidate_one ((struct inferior_list_entry *)
808 get_lwp_thread (lwp));
809
810 /* Finally, let it resume. */
811 ptrace (PTRACE_DETACH, lwpid_of (lwp), 0, 0);
812
813 delete_lwp (lwp);
814 return 0;
815 }
816
817 static int
818 any_thread_of (struct inferior_list_entry *entry, void *args)
819 {
820 int *pid_p = args;
821
822 if (ptid_get_pid (entry->id) == *pid_p)
823 return 1;
824
825 return 0;
826 }
827
828 static int
829 linux_detach (int pid)
830 {
831 struct process_info *process;
832
833 process = find_process_pid (pid);
834 if (process == NULL)
835 return -1;
836
837 #ifdef USE_THREAD_DB
838 thread_db_free (process, 1);
839 #endif
840
841 current_inferior =
842 (struct thread_info *) find_inferior (&all_threads, any_thread_of, &pid);
843
844 delete_all_breakpoints ();
845 find_inferior (&all_threads, linux_detach_one_lwp, &pid);
846 linux_remove_process (process);
847 return 0;
848 }
849
850 static void
851 linux_join (int pid)
852 {
853 int status, ret;
854 struct process_info *process;
855
856 process = find_process_pid (pid);
857 if (process == NULL)
858 return;
859
860 do {
861 ret = my_waitpid (pid, &status, 0);
862 if (WIFEXITED (status) || WIFSIGNALED (status))
863 break;
864 } while (ret != -1 || errno != ECHILD);
865 }
866
867 /* Return nonzero if the given thread is still alive. */
868 static int
869 linux_thread_alive (ptid_t ptid)
870 {
871 struct lwp_info *lwp = find_lwp_pid (ptid);
872
873 /* We assume we always know if a thread exits. If a whole process
874 exited but we still haven't been able to report it to GDB, we'll
875 hold on to the last lwp of the dead process. */
876 if (lwp != NULL)
877 return !lwp->dead;
878 else
879 return 0;
880 }
881
882 /* Return nonzero if this process stopped at a breakpoint which
883 no longer appears to be inserted. Also adjust the PC
884 appropriately to resume where the breakpoint used to be. */
885 static int
886 check_removed_breakpoint (struct lwp_info *event_child)
887 {
888 CORE_ADDR stop_pc;
889 struct thread_info *saved_inferior;
890 struct regcache *regcache;
891
892 if (event_child->pending_is_breakpoint == 0)
893 return 0;
894
895 if (debug_threads)
896 fprintf (stderr, "Checking for breakpoint in lwp %ld.\n",
897 lwpid_of (event_child));
898
899 saved_inferior = current_inferior;
900 current_inferior = get_lwp_thread (event_child);
901 regcache = get_thread_regcache (current_inferior, 1);
902 stop_pc = get_stop_pc ();
903
904 /* If the PC has changed since we stopped, then we shouldn't do
905 anything. This happens if, for instance, GDB handled the
906 decr_pc_after_break subtraction itself. */
907 if (stop_pc != event_child->pending_stop_pc)
908 {
909 if (debug_threads)
910 fprintf (stderr, "Ignoring, PC was changed. Old PC was 0x%08llx\n",
911 event_child->pending_stop_pc);
912
913 event_child->pending_is_breakpoint = 0;
914 current_inferior = saved_inferior;
915 return 0;
916 }
917
918 /* If the breakpoint is still there, we will report hitting it. */
919 if ((*the_low_target.breakpoint_at) (stop_pc))
920 {
921 if (debug_threads)
922 fprintf (stderr, "Ignoring, breakpoint is still present.\n");
923 current_inferior = saved_inferior;
924 return 0;
925 }
926
927 if (debug_threads)
928 fprintf (stderr, "Removed breakpoint.\n");
929
930 /* For decr_pc_after_break targets, here is where we perform the
931 decrement. We go immediately from this function to resuming,
932 and can not safely call get_stop_pc () again. */
933 if (the_low_target.set_pc != NULL)
934 {
935 if (debug_threads)
936 fprintf (stderr, "Set pc to 0x%lx\n", (long) stop_pc);
937 (*the_low_target.set_pc) (regcache, stop_pc);
938 }
939
940 /* We consumed the pending SIGTRAP. */
941 event_child->pending_is_breakpoint = 0;
942 event_child->status_pending_p = 0;
943 event_child->status_pending = 0;
944
945 current_inferior = saved_inferior;
946 return 1;
947 }
948
949 /* Return 1 if this lwp has an interesting status pending. This
950 function may silently resume an inferior lwp. */
951 static int
952 status_pending_p (struct inferior_list_entry *entry, void *arg)
953 {
954 struct lwp_info *lwp = (struct lwp_info *) entry;
955 ptid_t ptid = * (ptid_t *) arg;
956
957 /* Check if we're only interested in events from a specific process
958 or its lwps. */
959 if (!ptid_equal (minus_one_ptid, ptid)
960 && ptid_get_pid (ptid) != ptid_get_pid (lwp->head.id))
961 return 0;
962
963 if (lwp->status_pending_p && !lwp->suspended)
964 if (check_removed_breakpoint (lwp))
965 {
966 /* This thread was stopped at a breakpoint, and the breakpoint
967 is now gone. We were told to continue (or step...) all threads,
968 so GDB isn't trying to single-step past this breakpoint.
969 So instead of reporting the old SIGTRAP, pretend we got to
970 the breakpoint just after it was removed instead of just
971 before; resume the process. */
972 linux_resume_one_lwp (lwp, 0, 0, NULL);
973 return 0;
974 }
975
976 return (lwp->status_pending_p && !lwp->suspended);
977 }
978
979 static int
980 same_lwp (struct inferior_list_entry *entry, void *data)
981 {
982 ptid_t ptid = *(ptid_t *) data;
983 int lwp;
984
985 if (ptid_get_lwp (ptid) != 0)
986 lwp = ptid_get_lwp (ptid);
987 else
988 lwp = ptid_get_pid (ptid);
989
990 if (ptid_get_lwp (entry->id) == lwp)
991 return 1;
992
993 return 0;
994 }
995
996 struct lwp_info *
997 find_lwp_pid (ptid_t ptid)
998 {
999 return (struct lwp_info*) find_inferior (&all_lwps, same_lwp, &ptid);
1000 }
1001
1002 static struct lwp_info *
1003 linux_wait_for_lwp (ptid_t ptid, int *wstatp, int options)
1004 {
1005 int ret;
1006 int to_wait_for = -1;
1007 struct lwp_info *child = NULL;
1008
1009 if (debug_threads)
1010 fprintf (stderr, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid));
1011
1012 if (ptid_equal (ptid, minus_one_ptid))
1013 to_wait_for = -1; /* any child */
1014 else
1015 to_wait_for = ptid_get_lwp (ptid); /* this lwp only */
1016
1017 options |= __WALL;
1018
1019 retry:
1020
1021 ret = my_waitpid (to_wait_for, wstatp, options);
1022 if (ret == 0 || (ret == -1 && errno == ECHILD && (options & WNOHANG)))
1023 return NULL;
1024 else if (ret == -1)
1025 perror_with_name ("waitpid");
1026
1027 if (debug_threads
1028 && (!WIFSTOPPED (*wstatp)
1029 || (WSTOPSIG (*wstatp) != 32
1030 && WSTOPSIG (*wstatp) != 33)))
1031 fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp);
1032
1033 child = find_lwp_pid (pid_to_ptid (ret));
1034
1035 /* If we didn't find a process, one of two things presumably happened:
1036 - A process we started and then detached from has exited. Ignore it.
1037 - A process we are controlling has forked and the new child's stop
1038 was reported to us by the kernel. Save its PID. */
1039 if (child == NULL && WIFSTOPPED (*wstatp))
1040 {
1041 add_pid_to_list (&stopped_pids, ret);
1042 goto retry;
1043 }
1044 else if (child == NULL)
1045 goto retry;
1046
1047 child->stopped = 1;
1048 child->pending_is_breakpoint = 0;
1049
1050 child->last_status = *wstatp;
1051
1052 /* Architecture-specific setup after inferior is running.
1053 This needs to happen after we have attached to the inferior
1054 and it is stopped for the first time, but before we access
1055 any inferior registers. */
1056 if (new_inferior)
1057 {
1058 the_low_target.arch_setup ();
1059 #ifdef HAVE_LINUX_REGSETS
1060 memset (disabled_regsets, 0, num_regsets);
1061 #endif
1062 new_inferior = 0;
1063 }
1064
1065 if (debug_threads
1066 && WIFSTOPPED (*wstatp)
1067 && the_low_target.get_pc != NULL)
1068 {
1069 struct thread_info *saved_inferior = current_inferior;
1070 struct regcache *regcache = get_thread_regcache (current_inferior, 1);
1071 CORE_ADDR pc;
1072
1073 current_inferior = (struct thread_info *)
1074 find_inferior_id (&all_threads, child->head.id);
1075 pc = (*the_low_target.get_pc) (regcache);
1076 fprintf (stderr, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc);
1077 current_inferior = saved_inferior;
1078 }
1079
1080 return child;
1081 }
1082
1083 /* Wait for an event from child PID. If PID is -1, wait for any
1084 child. Store the stop status through the status pointer WSTAT.
1085 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1086 event was found and OPTIONS contains WNOHANG. Return the PID of
1087 the stopped child otherwise. */
1088
1089 static int
1090 linux_wait_for_event_1 (ptid_t ptid, int *wstat, int options)
1091 {
1092 CORE_ADDR stop_pc;
1093 struct lwp_info *event_child = NULL;
1094 int bp_status;
1095 struct lwp_info *requested_child = NULL;
1096
1097 /* Check for a lwp with a pending status. */
1098 /* It is possible that the user changed the pending task's registers since
1099 it stopped. We correctly handle the change of PC if we hit a breakpoint
1100 (in check_removed_breakpoint); signals should be reported anyway. */
1101
1102 if (ptid_equal (ptid, minus_one_ptid)
1103 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid)), ptid))
1104 {
1105 event_child = (struct lwp_info *)
1106 find_inferior (&all_lwps, status_pending_p, &ptid);
1107 if (debug_threads && event_child)
1108 fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
1109 }
1110 else
1111 {
1112 requested_child = find_lwp_pid (ptid);
1113 if (requested_child->status_pending_p
1114 && !check_removed_breakpoint (requested_child))
1115 event_child = requested_child;
1116 }
1117
1118 if (event_child != NULL)
1119 {
1120 if (debug_threads)
1121 fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
1122 lwpid_of (event_child), event_child->status_pending);
1123 *wstat = event_child->status_pending;
1124 event_child->status_pending_p = 0;
1125 event_child->status_pending = 0;
1126 current_inferior = get_lwp_thread (event_child);
1127 return lwpid_of (event_child);
1128 }
1129
1130 /* We only enter this loop if no process has a pending wait status. Thus
1131 any action taken in response to a wait status inside this loop is
1132 responding as soon as we detect the status, not after any pending
1133 events. */
1134 while (1)
1135 {
1136 event_child = linux_wait_for_lwp (ptid, wstat, options);
1137
1138 if ((options & WNOHANG) && event_child == NULL)
1139 return 0;
1140
1141 if (event_child == NULL)
1142 error ("event from unknown child");
1143
1144 current_inferior = get_lwp_thread (event_child);
1145
1146 /* Check for thread exit. */
1147 if (! WIFSTOPPED (*wstat))
1148 {
1149 if (debug_threads)
1150 fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child));
1151
1152 /* If the last thread is exiting, just return. */
1153 if (last_thread_of_process_p (current_inferior))
1154 {
1155 if (debug_threads)
1156 fprintf (stderr, "LWP %ld is last lwp of process\n",
1157 lwpid_of (event_child));
1158 return lwpid_of (event_child);
1159 }
1160
1161 delete_lwp (event_child);
1162
1163 if (!non_stop)
1164 {
1165 current_inferior = (struct thread_info *) all_threads.head;
1166 if (debug_threads)
1167 fprintf (stderr, "Current inferior is now %ld\n",
1168 lwpid_of (get_thread_lwp (current_inferior)));
1169 }
1170 else
1171 {
1172 current_inferior = NULL;
1173 if (debug_threads)
1174 fprintf (stderr, "Current inferior is now <NULL>\n");
1175 }
1176
1177 /* If we were waiting for this particular child to do something...
1178 well, it did something. */
1179 if (requested_child != NULL)
1180 return lwpid_of (event_child);
1181
1182 /* Wait for a more interesting event. */
1183 continue;
1184 }
1185
1186 if (event_child->must_set_ptrace_flags)
1187 {
1188 ptrace (PTRACE_SETOPTIONS, lwpid_of (event_child),
1189 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
1190 event_child->must_set_ptrace_flags = 0;
1191 }
1192
1193 if (WIFSTOPPED (*wstat)
1194 && WSTOPSIG (*wstat) == SIGSTOP
1195 && event_child->stop_expected)
1196 {
1197 if (debug_threads)
1198 fprintf (stderr, "Expected stop.\n");
1199 event_child->stop_expected = 0;
1200 linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL);
1201 continue;
1202 }
1203
1204 if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
1205 && *wstat >> 16 != 0)
1206 {
1207 handle_extended_wait (event_child, *wstat);
1208 continue;
1209 }
1210
1211 /* If GDB is not interested in this signal, don't stop other
1212 threads, and don't report it to GDB. Just resume the
1213 inferior right away. We do this for threading-related
1214 signals as well as any that GDB specifically requested we
1215 ignore. But never ignore SIGSTOP if we sent it ourselves,
1216 and do not ignore signals when stepping - they may require
1217 special handling to skip the signal handler. */
1218 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
1219 thread library? */
1220 if (WIFSTOPPED (*wstat)
1221 && !event_child->stepping
1222 && (
1223 #if defined (USE_THREAD_DB) && defined (__SIGRTMIN)
1224 (current_process ()->private->thread_db != NULL
1225 && (WSTOPSIG (*wstat) == __SIGRTMIN
1226 || WSTOPSIG (*wstat) == __SIGRTMIN + 1))
1227 ||
1228 #endif
1229 (pass_signals[target_signal_from_host (WSTOPSIG (*wstat))]
1230 && (WSTOPSIG (*wstat) != SIGSTOP || !stopping_threads))))
1231 {
1232 siginfo_t info, *info_p;
1233
1234 if (debug_threads)
1235 fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
1236 WSTOPSIG (*wstat), lwpid_of (event_child));
1237
1238 if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0)
1239 info_p = &info;
1240 else
1241 info_p = NULL;
1242 linux_resume_one_lwp (event_child,
1243 event_child->stepping,
1244 WSTOPSIG (*wstat), info_p);
1245 continue;
1246 }
1247
1248 /* If this event was not handled above, and is not a SIGTRAP,
1249 report it. SIGILL and SIGSEGV are also treated as traps in case
1250 a breakpoint is inserted at the current PC. */
1251 if (!WIFSTOPPED (*wstat)
1252 || (WSTOPSIG (*wstat) != SIGTRAP && WSTOPSIG (*wstat) != SIGILL
1253 && WSTOPSIG (*wstat) != SIGSEGV))
1254 return lwpid_of (event_child);
1255
1256 /* If this target does not support breakpoints, we simply report the
1257 signal; it's of no concern to us. */
1258 if (the_low_target.get_pc == NULL)
1259 return lwpid_of (event_child);
1260
1261 stop_pc = get_stop_pc ();
1262
1263 /* Only handle SIGILL or SIGSEGV if we've hit a recognized
1264 breakpoint. */
1265 if (WSTOPSIG (*wstat) != SIGTRAP
1266 && (event_child->stepping
1267 || ! (*the_low_target.breakpoint_at) (stop_pc)))
1268 return lwpid_of (event_child);
1269
1270 /* bp_reinsert will only be set if we were single-stepping.
1271 Notice that we will resume the process after hitting
1272 a gdbserver breakpoint; single-stepping to/over one
1273 is not supported (yet). */
1274 if (event_child->bp_reinsert != 0)
1275 {
1276 if (debug_threads)
1277 fprintf (stderr, "Reinserted breakpoint.\n");
1278 reinsert_breakpoint (event_child->bp_reinsert);
1279 event_child->bp_reinsert = 0;
1280
1281 /* Clear the single-stepping flag and SIGTRAP as we resume. */
1282 linux_resume_one_lwp (event_child, 0, 0, NULL);
1283 continue;
1284 }
1285
1286 bp_status = check_breakpoints (stop_pc);
1287
1288 if (bp_status != 0)
1289 {
1290 if (debug_threads)
1291 fprintf (stderr, "Hit a gdbserver breakpoint.\n");
1292
1293 /* We hit one of our own breakpoints. We mark it as a pending
1294 breakpoint, so that check_removed_breakpoint () will do the PC
1295 adjustment for us at the appropriate time. */
1296 event_child->pending_is_breakpoint = 1;
1297 event_child->pending_stop_pc = stop_pc;
1298
1299 /* We may need to put the breakpoint back. We continue in the event
1300 loop instead of simply replacing the breakpoint right away,
1301 in order to not lose signals sent to the thread that hit the
1302 breakpoint. Unfortunately this increases the window where another
1303 thread could sneak past the removed breakpoint. For the current
1304 use of server-side breakpoints (thread creation) this is
1305 acceptable; but it needs to be considered before this breakpoint
1306 mechanism can be used in more general ways. For some breakpoints
1307 it may be necessary to stop all other threads, but that should
1308 be avoided where possible.
1309
1310 If breakpoint_reinsert_addr is NULL, that means that we can
1311 use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
1312 mark it for reinsertion, and single-step.
1313
1314 Otherwise, call the target function to figure out where we need
1315 our temporary breakpoint, create it, and continue executing this
1316 process. */
1317
1318 /* NOTE: we're lifting breakpoints in non-stop mode. This
1319 is currently only used for thread event breakpoints, so
1320 it isn't that bad as long as we have PTRACE_EVENT_CLONE
1321 events. */
1322 if (bp_status == 2)
1323 /* No need to reinsert. */
1324 linux_resume_one_lwp (event_child, 0, 0, NULL);
1325 else if (the_low_target.breakpoint_reinsert_addr == NULL)
1326 {
1327 event_child->bp_reinsert = stop_pc;
1328 uninsert_breakpoint (stop_pc);
1329 linux_resume_one_lwp (event_child, 1, 0, NULL);
1330 }
1331 else
1332 {
1333 reinsert_breakpoint_by_bp
1334 (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ());
1335 linux_resume_one_lwp (event_child, 0, 0, NULL);
1336 }
1337
1338 continue;
1339 }
1340
1341 if (debug_threads)
1342 fprintf (stderr, "Hit a non-gdbserver breakpoint.\n");
1343
1344 /* If we were single-stepping, we definitely want to report the
1345 SIGTRAP. Although the single-step operation has completed,
1346 do not clear clear the stepping flag yet; we need to check it
1347 in wait_for_sigstop. */
1348 if (event_child->stepping)
1349 return lwpid_of (event_child);
1350
1351 /* A SIGTRAP that we can't explain. It may have been a breakpoint.
1352 Check if it is a breakpoint, and if so mark the process information
1353 accordingly. This will handle both the necessary fiddling with the
1354 PC on decr_pc_after_break targets and suppressing extra threads
1355 hitting a breakpoint if two hit it at once and then GDB removes it
1356 after the first is reported. Arguably it would be better to report
1357 multiple threads hitting breakpoints simultaneously, but the current
1358 remote protocol does not allow this. */
1359 if ((*the_low_target.breakpoint_at) (stop_pc))
1360 {
1361 event_child->pending_is_breakpoint = 1;
1362 event_child->pending_stop_pc = stop_pc;
1363 }
1364
1365 return lwpid_of (event_child);
1366 }
1367
1368 /* NOTREACHED */
1369 return 0;
1370 }
1371
1372 static int
1373 linux_wait_for_event (ptid_t ptid, int *wstat, int options)
1374 {
1375 ptid_t wait_ptid;
1376
1377 if (ptid_is_pid (ptid))
1378 {
1379 /* A request to wait for a specific tgid. This is not possible
1380 with waitpid, so instead, we wait for any child, and leave
1381 children we're not interested in right now with a pending
1382 status to report later. */
1383 wait_ptid = minus_one_ptid;
1384 }
1385 else
1386 wait_ptid = ptid;
1387
1388 while (1)
1389 {
1390 int event_pid;
1391
1392 event_pid = linux_wait_for_event_1 (wait_ptid, wstat, options);
1393
1394 if (event_pid > 0
1395 && ptid_is_pid (ptid) && ptid_get_pid (ptid) != event_pid)
1396 {
1397 struct lwp_info *event_child = find_lwp_pid (pid_to_ptid (event_pid));
1398
1399 if (! WIFSTOPPED (*wstat))
1400 mark_lwp_dead (event_child, *wstat);
1401 else
1402 {
1403 event_child->status_pending_p = 1;
1404 event_child->status_pending = *wstat;
1405 }
1406 }
1407 else
1408 return event_pid;
1409 }
1410 }
1411
1412 /* Wait for process, returns status. */
1413
1414 static ptid_t
1415 linux_wait_1 (ptid_t ptid,
1416 struct target_waitstatus *ourstatus, int target_options)
1417 {
1418 int w;
1419 struct thread_info *thread = NULL;
1420 struct lwp_info *lwp = NULL;
1421 int options;
1422 int pid;
1423
1424 /* Translate generic target options into linux options. */
1425 options = __WALL;
1426 if (target_options & TARGET_WNOHANG)
1427 options |= WNOHANG;
1428
1429 retry:
1430 ourstatus->kind = TARGET_WAITKIND_IGNORE;
1431
1432 /* If we were only supposed to resume one thread, only wait for
1433 that thread - if it's still alive. If it died, however - which
1434 can happen if we're coming from the thread death case below -
1435 then we need to make sure we restart the other threads. We could
1436 pick a thread at random or restart all; restarting all is less
1437 arbitrary. */
1438 if (!non_stop
1439 && !ptid_equal (cont_thread, null_ptid)
1440 && !ptid_equal (cont_thread, minus_one_ptid))
1441 {
1442 thread = (struct thread_info *) find_inferior_id (&all_threads,
1443 cont_thread);
1444
1445 /* No stepping, no signal - unless one is pending already, of course. */
1446 if (thread == NULL)
1447 {
1448 struct thread_resume resume_info;
1449 resume_info.thread = minus_one_ptid;
1450 resume_info.kind = resume_continue;
1451 resume_info.sig = 0;
1452 linux_resume (&resume_info, 1);
1453 }
1454 else
1455 ptid = cont_thread;
1456 }
1457
1458 pid = linux_wait_for_event (ptid, &w, options);
1459 if (pid == 0) /* only if TARGET_WNOHANG */
1460 return null_ptid;
1461
1462 lwp = get_thread_lwp (current_inferior);
1463
1464 /* If we are waiting for a particular child, and it exited,
1465 linux_wait_for_event will return its exit status. Similarly if
1466 the last child exited. If this is not the last child, however,
1467 do not report it as exited until there is a 'thread exited' response
1468 available in the remote protocol. Instead, just wait for another event.
1469 This should be safe, because if the thread crashed we will already
1470 have reported the termination signal to GDB; that should stop any
1471 in-progress stepping operations, etc.
1472
1473 Report the exit status of the last thread to exit. This matches
1474 LinuxThreads' behavior. */
1475
1476 if (last_thread_of_process_p (current_inferior))
1477 {
1478 if (WIFEXITED (w) || WIFSIGNALED (w))
1479 {
1480 int pid = pid_of (lwp);
1481 struct process_info *process = find_process_pid (pid);
1482
1483 #ifdef USE_THREAD_DB
1484 thread_db_free (process, 0);
1485 #endif
1486 delete_lwp (lwp);
1487 linux_remove_process (process);
1488
1489 current_inferior = NULL;
1490
1491 if (WIFEXITED (w))
1492 {
1493 ourstatus->kind = TARGET_WAITKIND_EXITED;
1494 ourstatus->value.integer = WEXITSTATUS (w);
1495
1496 if (debug_threads)
1497 fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
1498 }
1499 else
1500 {
1501 ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
1502 ourstatus->value.sig = target_signal_from_host (WTERMSIG (w));
1503
1504 if (debug_threads)
1505 fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
1506
1507 }
1508
1509 return pid_to_ptid (pid);
1510 }
1511 }
1512 else
1513 {
1514 if (!WIFSTOPPED (w))
1515 goto retry;
1516 }
1517
1518 /* In all-stop, stop all threads. Be careful to only do this if
1519 we're about to report an event to GDB. */
1520 if (!non_stop)
1521 stop_all_lwps ();
1522
1523 ourstatus->kind = TARGET_WAITKIND_STOPPED;
1524
1525 if (lwp->suspended && WSTOPSIG (w) == SIGSTOP)
1526 {
1527 /* A thread that has been requested to stop by GDB with vCont;t,
1528 and it stopped cleanly, so report as SIG0. The use of
1529 SIGSTOP is an implementation detail. */
1530 ourstatus->value.sig = TARGET_SIGNAL_0;
1531 }
1532 else if (lwp->suspended && WSTOPSIG (w) != SIGSTOP)
1533 {
1534 /* A thread that has been requested to stop by GDB with vCont;t,
1535 but, it stopped for other reasons. Set stop_expected so the
1536 pending SIGSTOP is ignored and the LWP is resumed. */
1537 lwp->stop_expected = 1;
1538 ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
1539 }
1540 else
1541 {
1542 ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
1543 }
1544
1545 if (debug_threads)
1546 fprintf (stderr, "linux_wait ret = %s, %d, %d\n",
1547 target_pid_to_str (lwp->head.id),
1548 ourstatus->kind,
1549 ourstatus->value.sig);
1550
1551 return lwp->head.id;
1552 }
1553
1554 /* Get rid of any pending event in the pipe. */
1555 static void
1556 async_file_flush (void)
1557 {
1558 int ret;
1559 char buf;
1560
1561 do
1562 ret = read (linux_event_pipe[0], &buf, 1);
1563 while (ret >= 0 || (ret == -1 && errno == EINTR));
1564 }
1565
1566 /* Put something in the pipe, so the event loop wakes up. */
1567 static void
1568 async_file_mark (void)
1569 {
1570 int ret;
1571
1572 async_file_flush ();
1573
1574 do
1575 ret = write (linux_event_pipe[1], "+", 1);
1576 while (ret == 0 || (ret == -1 && errno == EINTR));
1577
1578 /* Ignore EAGAIN. If the pipe is full, the event loop will already
1579 be awakened anyway. */
1580 }
1581
1582 static ptid_t
1583 linux_wait (ptid_t ptid,
1584 struct target_waitstatus *ourstatus, int target_options)
1585 {
1586 ptid_t event_ptid;
1587
1588 if (debug_threads)
1589 fprintf (stderr, "linux_wait: [%s]\n", target_pid_to_str (ptid));
1590
1591 /* Flush the async file first. */
1592 if (target_is_async_p ())
1593 async_file_flush ();
1594
1595 event_ptid = linux_wait_1 (ptid, ourstatus, target_options);
1596
1597 /* If at least one stop was reported, there may be more. A single
1598 SIGCHLD can signal more than one child stop. */
1599 if (target_is_async_p ()
1600 && (target_options & TARGET_WNOHANG) != 0
1601 && !ptid_equal (event_ptid, null_ptid))
1602 async_file_mark ();
1603
1604 return event_ptid;
1605 }
1606
1607 /* Send a signal to an LWP. */
1608
1609 static int
1610 kill_lwp (unsigned long lwpid, int signo)
1611 {
1612 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1613 fails, then we are not using nptl threads and we should be using kill. */
1614
1615 #ifdef __NR_tkill
1616 {
1617 static int tkill_failed;
1618
1619 if (!tkill_failed)
1620 {
1621 int ret;
1622
1623 errno = 0;
1624 ret = syscall (__NR_tkill, lwpid, signo);
1625 if (errno != ENOSYS)
1626 return ret;
1627 tkill_failed = 1;
1628 }
1629 }
1630 #endif
1631
1632 return kill (lwpid, signo);
1633 }
1634
1635 static void
1636 send_sigstop (struct inferior_list_entry *entry)
1637 {
1638 struct lwp_info *lwp = (struct lwp_info *) entry;
1639 int pid;
1640
1641 if (lwp->stopped)
1642 return;
1643
1644 pid = lwpid_of (lwp);
1645
1646 /* If we already have a pending stop signal for this process, don't
1647 send another. */
1648 if (lwp->stop_expected)
1649 {
1650 if (debug_threads)
1651 fprintf (stderr, "Have pending sigstop for lwp %d\n", pid);
1652
1653 /* We clear the stop_expected flag so that wait_for_sigstop
1654 will receive the SIGSTOP event (instead of silently resuming and
1655 waiting again). It'll be reset below. */
1656 lwp->stop_expected = 0;
1657 return;
1658 }
1659
1660 if (debug_threads)
1661 fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
1662
1663 kill_lwp (pid, SIGSTOP);
1664 }
1665
1666 static void
1667 mark_lwp_dead (struct lwp_info *lwp, int wstat)
1668 {
1669 /* It's dead, really. */
1670 lwp->dead = 1;
1671
1672 /* Store the exit status for later. */
1673 lwp->status_pending_p = 1;
1674 lwp->status_pending = wstat;
1675
1676 /* So that check_removed_breakpoint doesn't try to figure out if
1677 this is stopped at a breakpoint. */
1678 lwp->pending_is_breakpoint = 0;
1679
1680 /* Prevent trying to stop it. */
1681 lwp->stopped = 1;
1682
1683 /* No further stops are expected from a dead lwp. */
1684 lwp->stop_expected = 0;
1685 }
1686
1687 static void
1688 wait_for_sigstop (struct inferior_list_entry *entry)
1689 {
1690 struct lwp_info *lwp = (struct lwp_info *) entry;
1691 struct thread_info *saved_inferior;
1692 int wstat;
1693 ptid_t saved_tid;
1694 ptid_t ptid;
1695
1696 if (lwp->stopped)
1697 return;
1698
1699 saved_inferior = current_inferior;
1700 if (saved_inferior != NULL)
1701 saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
1702 else
1703 saved_tid = null_ptid; /* avoid bogus unused warning */
1704
1705 ptid = lwp->head.id;
1706
1707 linux_wait_for_event (ptid, &wstat, __WALL);
1708
1709 /* If we stopped with a non-SIGSTOP signal, save it for later
1710 and record the pending SIGSTOP. If the process exited, just
1711 return. */
1712 if (WIFSTOPPED (wstat)
1713 && WSTOPSIG (wstat) != SIGSTOP)
1714 {
1715 if (debug_threads)
1716 fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
1717 lwpid_of (lwp), wstat);
1718
1719 /* Do not leave a pending single-step finish to be reported to
1720 the client. The client will give us a new action for this
1721 thread, possibly a continue request --- otherwise, the client
1722 would consider this pending SIGTRAP reported later a spurious
1723 signal. */
1724 if (WSTOPSIG (wstat) == SIGTRAP
1725 && lwp->stepping
1726 && !linux_stopped_by_watchpoint ())
1727 {
1728 if (debug_threads)
1729 fprintf (stderr, " single-step SIGTRAP ignored\n");
1730 }
1731 else
1732 {
1733 lwp->status_pending_p = 1;
1734 lwp->status_pending = wstat;
1735 }
1736 lwp->stop_expected = 1;
1737 }
1738 else if (!WIFSTOPPED (wstat))
1739 {
1740 if (debug_threads)
1741 fprintf (stderr, "Process %ld exited while stopping LWPs\n",
1742 lwpid_of (lwp));
1743
1744 /* Leave this status pending for the next time we're able to
1745 report it. In the mean time, we'll report this lwp as dead
1746 to GDB, so GDB doesn't try to read registers and memory from
1747 it. */
1748 mark_lwp_dead (lwp, wstat);
1749 }
1750
1751 if (saved_inferior == NULL || linux_thread_alive (saved_tid))
1752 current_inferior = saved_inferior;
1753 else
1754 {
1755 if (debug_threads)
1756 fprintf (stderr, "Previously current thread died.\n");
1757
1758 if (non_stop)
1759 {
1760 /* We can't change the current inferior behind GDB's back,
1761 otherwise, a subsequent command may apply to the wrong
1762 process. */
1763 current_inferior = NULL;
1764 }
1765 else
1766 {
1767 /* Set a valid thread as current. */
1768 set_desired_inferior (0);
1769 }
1770 }
1771 }
1772
1773 static void
1774 stop_all_lwps (void)
1775 {
1776 stopping_threads = 1;
1777 for_each_inferior (&all_lwps, send_sigstop);
1778 for_each_inferior (&all_lwps, wait_for_sigstop);
1779 stopping_threads = 0;
1780 }
1781
1782 /* Resume execution of the inferior process.
1783 If STEP is nonzero, single-step it.
1784 If SIGNAL is nonzero, give it that signal. */
1785
1786 static void
1787 linux_resume_one_lwp (struct lwp_info *lwp,
1788 int step, int signal, siginfo_t *info)
1789 {
1790 struct thread_info *saved_inferior;
1791
1792 if (lwp->stopped == 0)
1793 return;
1794
1795 /* If we have pending signals or status, and a new signal, enqueue the
1796 signal. Also enqueue the signal if we are waiting to reinsert a
1797 breakpoint; it will be picked up again below. */
1798 if (signal != 0
1799 && (lwp->status_pending_p || lwp->pending_signals != NULL
1800 || lwp->bp_reinsert != 0))
1801 {
1802 struct pending_signals *p_sig;
1803 p_sig = xmalloc (sizeof (*p_sig));
1804 p_sig->prev = lwp->pending_signals;
1805 p_sig->signal = signal;
1806 if (info == NULL)
1807 memset (&p_sig->info, 0, sizeof (siginfo_t));
1808 else
1809 memcpy (&p_sig->info, info, sizeof (siginfo_t));
1810 lwp->pending_signals = p_sig;
1811 }
1812
1813 if (lwp->status_pending_p && !check_removed_breakpoint (lwp))
1814 return;
1815
1816 saved_inferior = current_inferior;
1817 current_inferior = get_lwp_thread (lwp);
1818
1819 if (debug_threads)
1820 fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
1821 lwpid_of (lwp), step ? "step" : "continue", signal,
1822 lwp->stop_expected ? "expected" : "not expected");
1823
1824 /* This bit needs some thinking about. If we get a signal that
1825 we must report while a single-step reinsert is still pending,
1826 we often end up resuming the thread. It might be better to
1827 (ew) allow a stack of pending events; then we could be sure that
1828 the reinsert happened right away and not lose any signals.
1829
1830 Making this stack would also shrink the window in which breakpoints are
1831 uninserted (see comment in linux_wait_for_lwp) but not enough for
1832 complete correctness, so it won't solve that problem. It may be
1833 worthwhile just to solve this one, however. */
1834 if (lwp->bp_reinsert != 0)
1835 {
1836 if (debug_threads)
1837 fprintf (stderr, " pending reinsert at %08lx", (long)lwp->bp_reinsert);
1838 if (step == 0)
1839 fprintf (stderr, "BAD - reinserting but not stepping.\n");
1840 step = 1;
1841
1842 /* Postpone any pending signal. It was enqueued above. */
1843 signal = 0;
1844 }
1845
1846 check_removed_breakpoint (lwp);
1847
1848 if (debug_threads && the_low_target.get_pc != NULL)
1849 {
1850 struct regcache *regcache = get_thread_regcache (current_inferior, 1);
1851 CORE_ADDR pc = (*the_low_target.get_pc) (regcache);
1852 fprintf (stderr, " resuming from pc 0x%lx\n", (long) pc);
1853 }
1854
1855 /* If we have pending signals, consume one unless we are trying to reinsert
1856 a breakpoint. */
1857 if (lwp->pending_signals != NULL && lwp->bp_reinsert == 0)
1858 {
1859 struct pending_signals **p_sig;
1860
1861 p_sig = &lwp->pending_signals;
1862 while ((*p_sig)->prev != NULL)
1863 p_sig = &(*p_sig)->prev;
1864
1865 signal = (*p_sig)->signal;
1866 if ((*p_sig)->info.si_signo != 0)
1867 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
1868
1869 free (*p_sig);
1870 *p_sig = NULL;
1871 }
1872
1873 if (the_low_target.prepare_to_resume != NULL)
1874 the_low_target.prepare_to_resume (lwp);
1875
1876 regcache_invalidate_one ((struct inferior_list_entry *)
1877 get_lwp_thread (lwp));
1878 errno = 0;
1879 lwp->stopped = 0;
1880 lwp->stepping = step;
1881 ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0,
1882 /* Coerce to a uintptr_t first to avoid potential gcc warning
1883 of coercing an 8 byte integer to a 4 byte pointer. */
1884 (PTRACE_ARG4_TYPE) (uintptr_t) signal);
1885
1886 current_inferior = saved_inferior;
1887 if (errno)
1888 {
1889 /* ESRCH from ptrace either means that the thread was already
1890 running (an error) or that it is gone (a race condition). If
1891 it's gone, we will get a notification the next time we wait,
1892 so we can ignore the error. We could differentiate these
1893 two, but it's tricky without waiting; the thread still exists
1894 as a zombie, so sending it signal 0 would succeed. So just
1895 ignore ESRCH. */
1896 if (errno == ESRCH)
1897 return;
1898
1899 perror_with_name ("ptrace");
1900 }
1901 }
1902
1903 struct thread_resume_array
1904 {
1905 struct thread_resume *resume;
1906 size_t n;
1907 };
1908
1909 /* This function is called once per thread. We look up the thread
1910 in RESUME_PTR, and mark the thread with a pointer to the appropriate
1911 resume request.
1912
1913 This algorithm is O(threads * resume elements), but resume elements
1914 is small (and will remain small at least until GDB supports thread
1915 suspension). */
1916 static int
1917 linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
1918 {
1919 struct lwp_info *lwp;
1920 struct thread_info *thread;
1921 int ndx;
1922 struct thread_resume_array *r;
1923
1924 thread = (struct thread_info *) entry;
1925 lwp = get_thread_lwp (thread);
1926 r = arg;
1927
1928 for (ndx = 0; ndx < r->n; ndx++)
1929 {
1930 ptid_t ptid = r->resume[ndx].thread;
1931 if (ptid_equal (ptid, minus_one_ptid)
1932 || ptid_equal (ptid, entry->id)
1933 || (ptid_is_pid (ptid)
1934 && (ptid_get_pid (ptid) == pid_of (lwp)))
1935 || (ptid_get_lwp (ptid) == -1
1936 && (ptid_get_pid (ptid) == pid_of (lwp))))
1937 {
1938 lwp->resume = &r->resume[ndx];
1939 return 0;
1940 }
1941 }
1942
1943 /* No resume action for this thread. */
1944 lwp->resume = NULL;
1945
1946 return 0;
1947 }
1948
1949
1950 /* Set *FLAG_P if this lwp has an interesting status pending. */
1951 static int
1952 resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
1953 {
1954 struct lwp_info *lwp = (struct lwp_info *) entry;
1955
1956 /* LWPs which will not be resumed are not interesting, because
1957 we might not wait for them next time through linux_wait. */
1958 if (lwp->resume == NULL)
1959 return 0;
1960
1961 /* If this thread has a removed breakpoint, we won't have any
1962 events to report later, so check now. check_removed_breakpoint
1963 may clear status_pending_p. We avoid calling check_removed_breakpoint
1964 for any thread that we are not otherwise going to resume - this
1965 lets us preserve stopped status when two threads hit a breakpoint.
1966 GDB removes the breakpoint to single-step a particular thread
1967 past it, then re-inserts it and resumes all threads. We want
1968 to report the second thread without resuming it in the interim. */
1969 if (lwp->status_pending_p)
1970 check_removed_breakpoint (lwp);
1971
1972 if (lwp->status_pending_p)
1973 * (int *) flag_p = 1;
1974
1975 return 0;
1976 }
1977
1978 /* This function is called once per thread. We check the thread's resume
1979 request, which will tell us whether to resume, step, or leave the thread
1980 stopped; and what signal, if any, it should be sent.
1981
1982 For threads which we aren't explicitly told otherwise, we preserve
1983 the stepping flag; this is used for stepping over gdbserver-placed
1984 breakpoints.
1985
1986 If pending_flags was set in any thread, we queue any needed
1987 signals, since we won't actually resume. We already have a pending
1988 event to report, so we don't need to preserve any step requests;
1989 they should be re-issued if necessary. */
1990
1991 static int
1992 linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
1993 {
1994 struct lwp_info *lwp;
1995 struct thread_info *thread;
1996 int step;
1997 int pending_flag = * (int *) arg;
1998
1999 thread = (struct thread_info *) entry;
2000 lwp = get_thread_lwp (thread);
2001
2002 if (lwp->resume == NULL)
2003 return 0;
2004
2005 if (lwp->resume->kind == resume_stop)
2006 {
2007 if (debug_threads)
2008 fprintf (stderr, "suspending LWP %ld\n", lwpid_of (lwp));
2009
2010 if (!lwp->stopped)
2011 {
2012 if (debug_threads)
2013 fprintf (stderr, "running -> suspending LWP %ld\n", lwpid_of (lwp));
2014
2015 lwp->suspended = 1;
2016 send_sigstop (&lwp->head);
2017 }
2018 else
2019 {
2020 if (debug_threads)
2021 {
2022 if (lwp->suspended)
2023 fprintf (stderr, "already stopped/suspended LWP %ld\n",
2024 lwpid_of (lwp));
2025 else
2026 fprintf (stderr, "already stopped/not suspended LWP %ld\n",
2027 lwpid_of (lwp));
2028 }
2029
2030 /* Make sure we leave the LWP suspended, so we don't try to
2031 resume it without GDB telling us to. FIXME: The LWP may
2032 have been stopped in an internal event that was not meant
2033 to be notified back to GDB (e.g., gdbserver breakpoint),
2034 so we should be reporting a stop event in that case
2035 too. */
2036 lwp->suspended = 1;
2037 }
2038
2039 /* For stop requests, we're done. */
2040 lwp->resume = NULL;
2041 return 0;
2042 }
2043 else
2044 lwp->suspended = 0;
2045
2046 /* If this thread which is about to be resumed has a pending status,
2047 then don't resume any threads - we can just report the pending
2048 status. Make sure to queue any signals that would otherwise be
2049 sent. In all-stop mode, we do this decision based on if *any*
2050 thread has a pending status. */
2051 if (non_stop)
2052 resume_status_pending_p (&lwp->head, &pending_flag);
2053
2054 if (!pending_flag)
2055 {
2056 if (debug_threads)
2057 fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp));
2058
2059 if (ptid_equal (lwp->resume->thread, minus_one_ptid)
2060 && lwp->stepping
2061 && lwp->pending_is_breakpoint)
2062 step = 1;
2063 else
2064 step = (lwp->resume->kind == resume_step);
2065
2066 linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
2067 }
2068 else
2069 {
2070 if (debug_threads)
2071 fprintf (stderr, "leaving LWP %ld stopped\n", lwpid_of (lwp));
2072
2073 /* If we have a new signal, enqueue the signal. */
2074 if (lwp->resume->sig != 0)
2075 {
2076 struct pending_signals *p_sig;
2077 p_sig = xmalloc (sizeof (*p_sig));
2078 p_sig->prev = lwp->pending_signals;
2079 p_sig->signal = lwp->resume->sig;
2080 memset (&p_sig->info, 0, sizeof (siginfo_t));
2081
2082 /* If this is the same signal we were previously stopped by,
2083 make sure to queue its siginfo. We can ignore the return
2084 value of ptrace; if it fails, we'll skip
2085 PTRACE_SETSIGINFO. */
2086 if (WIFSTOPPED (lwp->last_status)
2087 && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
2088 ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
2089
2090 lwp->pending_signals = p_sig;
2091 }
2092 }
2093
2094 lwp->resume = NULL;
2095 return 0;
2096 }
2097
2098 static void
2099 linux_resume (struct thread_resume *resume_info, size_t n)
2100 {
2101 int pending_flag;
2102 struct thread_resume_array array = { resume_info, n };
2103
2104 find_inferior (&all_threads, linux_set_resume_request, &array);
2105
2106 /* If there is a thread which would otherwise be resumed, which
2107 has a pending status, then don't resume any threads - we can just
2108 report the pending status. Make sure to queue any signals
2109 that would otherwise be sent. In non-stop mode, we'll apply this
2110 logic to each thread individually. */
2111 pending_flag = 0;
2112 if (!non_stop)
2113 find_inferior (&all_lwps, resume_status_pending_p, &pending_flag);
2114
2115 if (debug_threads)
2116 {
2117 if (pending_flag)
2118 fprintf (stderr, "Not resuming, pending status\n");
2119 else
2120 fprintf (stderr, "Resuming, no pending status\n");
2121 }
2122
2123 find_inferior (&all_threads, linux_resume_one_thread, &pending_flag);
2124 }
2125
2126 #ifdef HAVE_LINUX_USRREGS
2127
2128 int
2129 register_addr (int regnum)
2130 {
2131 int addr;
2132
2133 if (regnum < 0 || regnum >= the_low_target.num_regs)
2134 error ("Invalid register number %d.", regnum);
2135
2136 addr = the_low_target.regmap[regnum];
2137
2138 return addr;
2139 }
2140
2141 /* Fetch one register. */
2142 static void
2143 fetch_register (struct regcache *regcache, int regno)
2144 {
2145 CORE_ADDR regaddr;
2146 int i, size;
2147 char *buf;
2148 int pid;
2149
2150 if (regno >= the_low_target.num_regs)
2151 return;
2152 if ((*the_low_target.cannot_fetch_register) (regno))
2153 return;
2154
2155 regaddr = register_addr (regno);
2156 if (regaddr == -1)
2157 return;
2158
2159 pid = lwpid_of (get_thread_lwp (current_inferior));
2160 size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
2161 & - sizeof (PTRACE_XFER_TYPE));
2162 buf = alloca (size);
2163 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
2164 {
2165 errno = 0;
2166 *(PTRACE_XFER_TYPE *) (buf + i) =
2167 ptrace (PTRACE_PEEKUSER, pid,
2168 /* Coerce to a uintptr_t first to avoid potential gcc warning
2169 of coercing an 8 byte integer to a 4 byte pointer. */
2170 (PTRACE_ARG3_TYPE) (uintptr_t) regaddr, 0);
2171 regaddr += sizeof (PTRACE_XFER_TYPE);
2172 if (errno != 0)
2173 {
2174 /* Warning, not error, in case we are attached; sometimes the
2175 kernel doesn't let us at the registers. */
2176 char *err = strerror (errno);
2177 char *msg = alloca (strlen (err) + 128);
2178 sprintf (msg, "reading register %d: %s", regno, err);
2179 error (msg);
2180 goto error_exit;
2181 }
2182 }
2183
2184 if (the_low_target.supply_ptrace_register)
2185 the_low_target.supply_ptrace_register (regcache, regno, buf);
2186 else
2187 supply_register (regcache, regno, buf);
2188
2189 error_exit:;
2190 }
2191
2192 /* Fetch all registers, or just one, from the child process. */
2193 static void
2194 usr_fetch_inferior_registers (struct regcache *regcache, int regno)
2195 {
2196 if (regno == -1)
2197 for (regno = 0; regno < the_low_target.num_regs; regno++)
2198 fetch_register (regcache, regno);
2199 else
2200 fetch_register (regcache, regno);
2201 }
2202
2203 /* Store our register values back into the inferior.
2204 If REGNO is -1, do this for all registers.
2205 Otherwise, REGNO specifies which register (so we can save time). */
2206 static void
2207 usr_store_inferior_registers (struct regcache *regcache, int regno)
2208 {
2209 CORE_ADDR regaddr;
2210 int i, size;
2211 char *buf;
2212 int pid;
2213
2214 if (regno >= 0)
2215 {
2216 if (regno >= the_low_target.num_regs)
2217 return;
2218
2219 if ((*the_low_target.cannot_store_register) (regno) == 1)
2220 return;
2221
2222 regaddr = register_addr (regno);
2223 if (regaddr == -1)
2224 return;
2225 errno = 0;
2226 size = (register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
2227 & - sizeof (PTRACE_XFER_TYPE);
2228 buf = alloca (size);
2229 memset (buf, 0, size);
2230
2231 if (the_low_target.collect_ptrace_register)
2232 the_low_target.collect_ptrace_register (regcache, regno, buf);
2233 else
2234 collect_register (regcache, regno, buf);
2235
2236 pid = lwpid_of (get_thread_lwp (current_inferior));
2237 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
2238 {
2239 errno = 0;
2240 ptrace (PTRACE_POKEUSER, pid,
2241 /* Coerce to a uintptr_t first to avoid potential gcc warning
2242 about coercing an 8 byte integer to a 4 byte pointer. */
2243 (PTRACE_ARG3_TYPE) (uintptr_t) regaddr,
2244 (PTRACE_ARG4_TYPE) *(PTRACE_XFER_TYPE *) (buf + i));
2245 if (errno != 0)
2246 {
2247 /* At this point, ESRCH should mean the process is
2248 already gone, in which case we simply ignore attempts
2249 to change its registers. See also the related
2250 comment in linux_resume_one_lwp. */
2251 if (errno == ESRCH)
2252 return;
2253
2254 if ((*the_low_target.cannot_store_register) (regno) == 0)
2255 {
2256 char *err = strerror (errno);
2257 char *msg = alloca (strlen (err) + 128);
2258 sprintf (msg, "writing register %d: %s",
2259 regno, err);
2260 error (msg);
2261 return;
2262 }
2263 }
2264 regaddr += sizeof (PTRACE_XFER_TYPE);
2265 }
2266 }
2267 else
2268 for (regno = 0; regno < the_low_target.num_regs; regno++)
2269 usr_store_inferior_registers (regcache, regno);
2270 }
2271 #endif /* HAVE_LINUX_USRREGS */
2272
2273
2274
2275 #ifdef HAVE_LINUX_REGSETS
2276
2277 static int
2278 regsets_fetch_inferior_registers (struct regcache *regcache)
2279 {
2280 struct regset_info *regset;
2281 int saw_general_regs = 0;
2282 int pid;
2283
2284 regset = target_regsets;
2285
2286 pid = lwpid_of (get_thread_lwp (current_inferior));
2287 while (regset->size >= 0)
2288 {
2289 void *buf;
2290 int res;
2291
2292 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
2293 {
2294 regset ++;
2295 continue;
2296 }
2297
2298 buf = xmalloc (regset->size);
2299 #ifndef __sparc__
2300 res = ptrace (regset->get_request, pid, 0, buf);
2301 #else
2302 res = ptrace (regset->get_request, pid, buf, 0);
2303 #endif
2304 if (res < 0)
2305 {
2306 if (errno == EIO)
2307 {
2308 /* If we get EIO on a regset, do not try it again for
2309 this process. */
2310 disabled_regsets[regset - target_regsets] = 1;
2311 free (buf);
2312 continue;
2313 }
2314 else
2315 {
2316 char s[256];
2317 sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
2318 pid);
2319 perror (s);
2320 }
2321 }
2322 else if (regset->type == GENERAL_REGS)
2323 saw_general_regs = 1;
2324 regset->store_function (regcache, buf);
2325 regset ++;
2326 free (buf);
2327 }
2328 if (saw_general_regs)
2329 return 0;
2330 else
2331 return 1;
2332 }
2333
2334 static int
2335 regsets_store_inferior_registers (struct regcache *regcache)
2336 {
2337 struct regset_info *regset;
2338 int saw_general_regs = 0;
2339 int pid;
2340
2341 regset = target_regsets;
2342
2343 pid = lwpid_of (get_thread_lwp (current_inferior));
2344 while (regset->size >= 0)
2345 {
2346 void *buf;
2347 int res;
2348
2349 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
2350 {
2351 regset ++;
2352 continue;
2353 }
2354
2355 buf = xmalloc (regset->size);
2356
2357 /* First fill the buffer with the current register set contents,
2358 in case there are any items in the kernel's regset that are
2359 not in gdbserver's regcache. */
2360 #ifndef __sparc__
2361 res = ptrace (regset->get_request, pid, 0, buf);
2362 #else
2363 res = ptrace (regset->get_request, pid, buf, 0);
2364 #endif
2365
2366 if (res == 0)
2367 {
2368 /* Then overlay our cached registers on that. */
2369 regset->fill_function (regcache, buf);
2370
2371 /* Only now do we write the register set. */
2372 #ifndef __sparc__
2373 res = ptrace (regset->set_request, pid, 0, buf);
2374 #else
2375 res = ptrace (regset->set_request, pid, buf, 0);
2376 #endif
2377 }
2378
2379 if (res < 0)
2380 {
2381 if (errno == EIO)
2382 {
2383 /* If we get EIO on a regset, do not try it again for
2384 this process. */
2385 disabled_regsets[regset - target_regsets] = 1;
2386 free (buf);
2387 continue;
2388 }
2389 else if (errno == ESRCH)
2390 {
2391 /* At this point, ESRCH should mean the process is
2392 already gone, in which case we simply ignore attempts
2393 to change its registers. See also the related
2394 comment in linux_resume_one_lwp. */
2395 free (buf);
2396 return 0;
2397 }
2398 else
2399 {
2400 perror ("Warning: ptrace(regsets_store_inferior_registers)");
2401 }
2402 }
2403 else if (regset->type == GENERAL_REGS)
2404 saw_general_regs = 1;
2405 regset ++;
2406 free (buf);
2407 }
2408 if (saw_general_regs)
2409 return 0;
2410 else
2411 return 1;
2412 return 0;
2413 }
2414
2415 #endif /* HAVE_LINUX_REGSETS */
2416
2417
2418 void
2419 linux_fetch_registers (struct regcache *regcache, int regno)
2420 {
2421 #ifdef HAVE_LINUX_REGSETS
2422 if (regsets_fetch_inferior_registers (regcache) == 0)
2423 return;
2424 #endif
2425 #ifdef HAVE_LINUX_USRREGS
2426 usr_fetch_inferior_registers (regcache, regno);
2427 #endif
2428 }
2429
2430 void
2431 linux_store_registers (struct regcache *regcache, int regno)
2432 {
2433 #ifdef HAVE_LINUX_REGSETS
2434 if (regsets_store_inferior_registers (regcache) == 0)
2435 return;
2436 #endif
2437 #ifdef HAVE_LINUX_USRREGS
2438 usr_store_inferior_registers (regcache, regno);
2439 #endif
2440 }
2441
2442
2443 /* Copy LEN bytes from inferior's memory starting at MEMADDR
2444 to debugger memory starting at MYADDR. */
2445
2446 static int
2447 linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
2448 {
2449 register int i;
2450 /* Round starting address down to longword boundary. */
2451 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
2452 /* Round ending address up; get number of longwords that makes. */
2453 register int count
2454 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
2455 / sizeof (PTRACE_XFER_TYPE);
2456 /* Allocate buffer of that many longwords. */
2457 register PTRACE_XFER_TYPE *buffer
2458 = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
2459 int fd;
2460 char filename[64];
2461 int pid = lwpid_of (get_thread_lwp (current_inferior));
2462
2463 /* Try using /proc. Don't bother for one word. */
2464 if (len >= 3 * sizeof (long))
2465 {
2466 /* We could keep this file open and cache it - possibly one per
2467 thread. That requires some juggling, but is even faster. */
2468 sprintf (filename, "/proc/%d/mem", pid);
2469 fd = open (filename, O_RDONLY | O_LARGEFILE);
2470 if (fd == -1)
2471 goto no_proc;
2472
2473 /* If pread64 is available, use it. It's faster if the kernel
2474 supports it (only one syscall), and it's 64-bit safe even on
2475 32-bit platforms (for instance, SPARC debugging a SPARC64
2476 application). */
2477 #ifdef HAVE_PREAD64
2478 if (pread64 (fd, myaddr, len, memaddr) != len)
2479 #else
2480 if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, myaddr, len) != len)
2481 #endif
2482 {
2483 close (fd);
2484 goto no_proc;
2485 }
2486
2487 close (fd);
2488 return 0;
2489 }
2490
2491 no_proc:
2492 /* Read all the longwords */
2493 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
2494 {
2495 errno = 0;
2496 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
2497 about coercing an 8 byte integer to a 4 byte pointer. */
2498 buffer[i] = ptrace (PTRACE_PEEKTEXT, pid,
2499 (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
2500 if (errno)
2501 return errno;
2502 }
2503
2504 /* Copy appropriate bytes out of the buffer. */
2505 memcpy (myaddr,
2506 (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
2507 len);
2508
2509 return 0;
2510 }
2511
2512 /* Copy LEN bytes of data from debugger memory at MYADDR
2513 to inferior's memory at MEMADDR.
2514 On failure (cannot write the inferior)
2515 returns the value of errno. */
2516
2517 static int
2518 linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
2519 {
2520 register int i;
2521 /* Round starting address down to longword boundary. */
2522 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
2523 /* Round ending address up; get number of longwords that makes. */
2524 register int count
2525 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE);
2526 /* Allocate buffer of that many longwords. */
2527 register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
2528 int pid = lwpid_of (get_thread_lwp (current_inferior));
2529
2530 if (debug_threads)
2531 {
2532 /* Dump up to four bytes. */
2533 unsigned int val = * (unsigned int *) myaddr;
2534 if (len == 1)
2535 val = val & 0xff;
2536 else if (len == 2)
2537 val = val & 0xffff;
2538 else if (len == 3)
2539 val = val & 0xffffff;
2540 fprintf (stderr, "Writing %0*x to 0x%08lx\n", 2 * ((len < 4) ? len : 4),
2541 val, (long)memaddr);
2542 }
2543
2544 /* Fill start and end extra bytes of buffer with existing memory data. */
2545
2546 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
2547 about coercing an 8 byte integer to a 4 byte pointer. */
2548 buffer[0] = ptrace (PTRACE_PEEKTEXT, pid,
2549 (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
2550
2551 if (count > 1)
2552 {
2553 buffer[count - 1]
2554 = ptrace (PTRACE_PEEKTEXT, pid,
2555 /* Coerce to a uintptr_t first to avoid potential gcc warning
2556 about coercing an 8 byte integer to a 4 byte pointer. */
2557 (PTRACE_ARG3_TYPE) (uintptr_t) (addr + (count - 1)
2558 * sizeof (PTRACE_XFER_TYPE)),
2559 0);
2560 }
2561
2562 /* Copy data to be written over corresponding part of buffer */
2563
2564 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len);
2565
2566 /* Write the entire buffer. */
2567
2568 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
2569 {
2570 errno = 0;
2571 ptrace (PTRACE_POKETEXT, pid,
2572 /* Coerce to a uintptr_t first to avoid potential gcc warning
2573 about coercing an 8 byte integer to a 4 byte pointer. */
2574 (PTRACE_ARG3_TYPE) (uintptr_t) addr,
2575 (PTRACE_ARG4_TYPE) buffer[i]);
2576 if (errno)
2577 return errno;
2578 }
2579
2580 return 0;
2581 }
2582
2583 static int linux_supports_tracefork_flag;
2584
2585 /* Helper functions for linux_test_for_tracefork, called via clone (). */
2586
2587 static int
2588 linux_tracefork_grandchild (void *arg)
2589 {
2590 _exit (0);
2591 }
2592
2593 #define STACK_SIZE 4096
2594
2595 static int
2596 linux_tracefork_child (void *arg)
2597 {
2598 ptrace (PTRACE_TRACEME, 0, 0, 0);
2599 kill (getpid (), SIGSTOP);
2600
2601 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
2602
2603 if (fork () == 0)
2604 linux_tracefork_grandchild (NULL);
2605
2606 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
2607
2608 #ifdef __ia64__
2609 __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
2610 CLONE_VM | SIGCHLD, NULL);
2611 #else
2612 clone (linux_tracefork_grandchild, arg + STACK_SIZE,
2613 CLONE_VM | SIGCHLD, NULL);
2614 #endif
2615
2616 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
2617
2618 _exit (0);
2619 }
2620
2621 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
2622 sure that we can enable the option, and that it had the desired
2623 effect. */
2624
2625 static void
2626 linux_test_for_tracefork (void)
2627 {
2628 int child_pid, ret, status;
2629 long second_pid;
2630 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2631 char *stack = xmalloc (STACK_SIZE * 4);
2632 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
2633
2634 linux_supports_tracefork_flag = 0;
2635
2636 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
2637
2638 child_pid = fork ();
2639 if (child_pid == 0)
2640 linux_tracefork_child (NULL);
2641
2642 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
2643
2644 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
2645 #ifdef __ia64__
2646 child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
2647 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
2648 #else /* !__ia64__ */
2649 child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
2650 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
2651 #endif /* !__ia64__ */
2652
2653 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
2654
2655 if (child_pid == -1)
2656 perror_with_name ("clone");
2657
2658 ret = my_waitpid (child_pid, &status, 0);
2659 if (ret == -1)
2660 perror_with_name ("waitpid");
2661 else if (ret != child_pid)
2662 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
2663 if (! WIFSTOPPED (status))
2664 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
2665
2666 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
2667 (PTRACE_ARG4_TYPE) PTRACE_O_TRACEFORK);
2668 if (ret != 0)
2669 {
2670 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
2671 if (ret != 0)
2672 {
2673 warning ("linux_test_for_tracefork: failed to kill child");
2674 return;
2675 }
2676
2677 ret = my_waitpid (child_pid, &status, 0);
2678 if (ret != child_pid)
2679 warning ("linux_test_for_tracefork: failed to wait for killed child");
2680 else if (!WIFSIGNALED (status))
2681 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
2682 "killed child", status);
2683
2684 return;
2685 }
2686
2687 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
2688 if (ret != 0)
2689 warning ("linux_test_for_tracefork: failed to resume child");
2690
2691 ret = my_waitpid (child_pid, &status, 0);
2692
2693 if (ret == child_pid && WIFSTOPPED (status)
2694 && status >> 16 == PTRACE_EVENT_FORK)
2695 {
2696 second_pid = 0;
2697 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
2698 if (ret == 0 && second_pid != 0)
2699 {
2700 int second_status;
2701
2702 linux_supports_tracefork_flag = 1;
2703 my_waitpid (second_pid, &second_status, 0);
2704 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
2705 if (ret != 0)
2706 warning ("linux_test_for_tracefork: failed to kill second child");
2707 my_waitpid (second_pid, &status, 0);
2708 }
2709 }
2710 else
2711 warning ("linux_test_for_tracefork: unexpected result from waitpid "
2712 "(%d, status 0x%x)", ret, status);
2713
2714 do
2715 {
2716 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
2717 if (ret != 0)
2718 warning ("linux_test_for_tracefork: failed to kill child");
2719 my_waitpid (child_pid, &status, 0);
2720 }
2721 while (WIFSTOPPED (status));
2722
2723 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2724 free (stack);
2725 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
2726 }
2727
2728
2729 static void
2730 linux_look_up_symbols (void)
2731 {
2732 #ifdef USE_THREAD_DB
2733 struct process_info *proc = current_process ();
2734
2735 if (proc->private->thread_db != NULL)
2736 return;
2737
2738 thread_db_init (!linux_supports_tracefork_flag);
2739 #endif
2740 }
2741
2742 static void
2743 linux_request_interrupt (void)
2744 {
2745 extern unsigned long signal_pid;
2746
2747 if (!ptid_equal (cont_thread, null_ptid)
2748 && !ptid_equal (cont_thread, minus_one_ptid))
2749 {
2750 struct lwp_info *lwp;
2751 int lwpid;
2752
2753 lwp = get_thread_lwp (current_inferior);
2754 lwpid = lwpid_of (lwp);
2755 kill_lwp (lwpid, SIGINT);
2756 }
2757 else
2758 kill_lwp (signal_pid, SIGINT);
2759 }
2760
2761 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
2762 to debugger memory starting at MYADDR. */
2763
2764 static int
2765 linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
2766 {
2767 char filename[PATH_MAX];
2768 int fd, n;
2769 int pid = lwpid_of (get_thread_lwp (current_inferior));
2770
2771 snprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
2772
2773 fd = open (filename, O_RDONLY);
2774 if (fd < 0)
2775 return -1;
2776
2777 if (offset != (CORE_ADDR) 0
2778 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
2779 n = -1;
2780 else
2781 n = read (fd, myaddr, len);
2782
2783 close (fd);
2784
2785 return n;
2786 }
2787
2788 /* These breakpoint and watchpoint related wrapper functions simply
2789 pass on the function call if the target has registered a
2790 corresponding function. */
2791
2792 static int
2793 linux_insert_point (char type, CORE_ADDR addr, int len)
2794 {
2795 if (the_low_target.insert_point != NULL)
2796 return the_low_target.insert_point (type, addr, len);
2797 else
2798 /* Unsupported (see target.h). */
2799 return 1;
2800 }
2801
2802 static int
2803 linux_remove_point (char type, CORE_ADDR addr, int len)
2804 {
2805 if (the_low_target.remove_point != NULL)
2806 return the_low_target.remove_point (type, addr, len);
2807 else
2808 /* Unsupported (see target.h). */
2809 return 1;
2810 }
2811
2812 static int
2813 linux_stopped_by_watchpoint (void)
2814 {
2815 if (the_low_target.stopped_by_watchpoint != NULL)
2816 return the_low_target.stopped_by_watchpoint ();
2817 else
2818 return 0;
2819 }
2820
2821 static CORE_ADDR
2822 linux_stopped_data_address (void)
2823 {
2824 if (the_low_target.stopped_data_address != NULL)
2825 return the_low_target.stopped_data_address ();
2826 else
2827 return 0;
2828 }
2829
2830 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2831 #if defined(__mcoldfire__)
2832 /* These should really be defined in the kernel's ptrace.h header. */
2833 #define PT_TEXT_ADDR 49*4
2834 #define PT_DATA_ADDR 50*4
2835 #define PT_TEXT_END_ADDR 51*4
2836 #endif
2837
2838 /* Under uClinux, programs are loaded at non-zero offsets, which we need
2839 to tell gdb about. */
2840
2841 static int
2842 linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
2843 {
2844 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
2845 unsigned long text, text_end, data;
2846 int pid = lwpid_of (get_thread_lwp (current_inferior));
2847
2848 errno = 0;
2849
2850 text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0);
2851 text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0);
2852 data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0);
2853
2854 if (errno == 0)
2855 {
2856 /* Both text and data offsets produced at compile-time (and so
2857 used by gdb) are relative to the beginning of the program,
2858 with the data segment immediately following the text segment.
2859 However, the actual runtime layout in memory may put the data
2860 somewhere else, so when we send gdb a data base-address, we
2861 use the real data base address and subtract the compile-time
2862 data base-address from it (which is just the length of the
2863 text segment). BSS immediately follows data in both
2864 cases. */
2865 *text_p = text;
2866 *data_p = data - (text_end - text);
2867
2868 return 1;
2869 }
2870 #endif
2871 return 0;
2872 }
2873 #endif
2874
2875 static int
2876 compare_ints (const void *xa, const void *xb)
2877 {
2878 int a = *(const int *)xa;
2879 int b = *(const int *)xb;
2880
2881 return a - b;
2882 }
2883
2884 static int *
2885 unique (int *b, int *e)
2886 {
2887 int *d = b;
2888 while (++b != e)
2889 if (*d != *b)
2890 *++d = *b;
2891 return ++d;
2892 }
2893
2894 /* Given PID, iterates over all threads in that process.
2895
2896 Information about each thread, in a format suitable for qXfer:osdata:thread
2897 is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
2898 initialized, and the caller is responsible for finishing and appending '\0'
2899 to it.
2900
2901 The list of cores that threads are running on is assigned to *CORES, if it
2902 is not NULL. If no cores are found, *CORES will be set to NULL. Caller
2903 should free *CORES. */
2904
2905 static void
2906 list_threads (int pid, struct buffer *buffer, char **cores)
2907 {
2908 int count = 0;
2909 int allocated = 10;
2910 int *core_numbers = xmalloc (sizeof (int) * allocated);
2911 char pathname[128];
2912 DIR *dir;
2913 struct dirent *dp;
2914 struct stat statbuf;
2915
2916 sprintf (pathname, "/proc/%d/task", pid);
2917 if (stat (pathname, &statbuf) == 0 && S_ISDIR (statbuf.st_mode))
2918 {
2919 dir = opendir (pathname);
2920 if (!dir)
2921 {
2922 free (core_numbers);
2923 return;
2924 }
2925
2926 while ((dp = readdir (dir)) != NULL)
2927 {
2928 unsigned long lwp = strtoul (dp->d_name, NULL, 10);
2929
2930 if (lwp != 0)
2931 {
2932 unsigned core = linux_core_of_thread (ptid_build (pid, lwp, 0));
2933
2934 if (core != -1)
2935 {
2936 char s[sizeof ("4294967295")];
2937 sprintf (s, "%u", core);
2938
2939 if (count == allocated)
2940 {
2941 allocated *= 2;
2942 core_numbers = realloc (core_numbers,
2943 sizeof (int) * allocated);
2944 }
2945 core_numbers[count++] = core;
2946 if (buffer)
2947 buffer_xml_printf (buffer,
2948 "<item>"
2949 "<column name=\"pid\">%d</column>"
2950 "<column name=\"tid\">%s</column>"
2951 "<column name=\"core\">%s</column>"
2952 "</item>", pid, dp->d_name, s);
2953 }
2954 else
2955 {
2956 if (buffer)
2957 buffer_xml_printf (buffer,
2958 "<item>"
2959 "<column name=\"pid\">%d</column>"
2960 "<column name=\"tid\">%s</column>"
2961 "</item>", pid, dp->d_name);
2962 }
2963 }
2964 }
2965 }
2966
2967 if (cores)
2968 {
2969 *cores = NULL;
2970 if (count > 0)
2971 {
2972 struct buffer buffer2;
2973 int *b;
2974 int *e;
2975 qsort (core_numbers, count, sizeof (int), compare_ints);
2976
2977 /* Remove duplicates. */
2978 b = core_numbers;
2979 e = unique (b, core_numbers + count);
2980
2981 buffer_init (&buffer2);
2982
2983 for (b = core_numbers; b != e; ++b)
2984 {
2985 char number[sizeof ("4294967295")];
2986 sprintf (number, "%u", *b);
2987 buffer_xml_printf (&buffer2, "%s%s",
2988 (b == core_numbers) ? "" : ",", number);
2989 }
2990 buffer_grow_str0 (&buffer2, "");
2991
2992 *cores = buffer_finish (&buffer2);
2993 }
2994 }
2995 free (core_numbers);
2996 }
2997
2998 static void
2999 show_process (int pid, const char *username, struct buffer *buffer)
3000 {
3001 char pathname[128];
3002 FILE *f;
3003 char cmd[MAXPATHLEN + 1];
3004
3005 sprintf (pathname, "/proc/%d/cmdline", pid);
3006
3007 if ((f = fopen (pathname, "r")) != NULL)
3008 {
3009 size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
3010 if (len > 0)
3011 {
3012 char *cores = 0;
3013 int i;
3014 for (i = 0; i < len; i++)
3015 if (cmd[i] == '\0')
3016 cmd[i] = ' ';
3017 cmd[len] = '\0';
3018
3019 buffer_xml_printf (buffer,
3020 "<item>"
3021 "<column name=\"pid\">%d</column>"
3022 "<column name=\"user\">%s</column>"
3023 "<column name=\"command\">%s</column>",
3024 pid,
3025 username,
3026 cmd);
3027
3028 /* This only collects core numbers, and does not print threads. */
3029 list_threads (pid, NULL, &cores);
3030
3031 if (cores)
3032 {
3033 buffer_xml_printf (buffer,
3034 "<column name=\"cores\">%s</column>", cores);
3035 free (cores);
3036 }
3037
3038 buffer_xml_printf (buffer, "</item>");
3039 }
3040 fclose (f);
3041 }
3042 }
3043
3044 static int
3045 linux_qxfer_osdata (const char *annex,
3046 unsigned char *readbuf, unsigned const char *writebuf,
3047 CORE_ADDR offset, int len)
3048 {
3049 /* We make the process list snapshot when the object starts to be
3050 read. */
3051 static const char *buf;
3052 static long len_avail = -1;
3053 static struct buffer buffer;
3054 int processes = 0;
3055 int threads = 0;
3056
3057 DIR *dirp;
3058
3059 if (strcmp (annex, "processes") == 0)
3060 processes = 1;
3061 else if (strcmp (annex, "threads") == 0)
3062 threads = 1;
3063 else
3064 return 0;
3065
3066 if (!readbuf || writebuf)
3067 return 0;
3068
3069 if (offset == 0)
3070 {
3071 if (len_avail != -1 && len_avail != 0)
3072 buffer_free (&buffer);
3073 len_avail = 0;
3074 buf = NULL;
3075 buffer_init (&buffer);
3076 if (processes)
3077 buffer_grow_str (&buffer, "<osdata type=\"processes\">");
3078 else if (threads)
3079 buffer_grow_str (&buffer, "<osdata type=\"threads\">");
3080
3081 dirp = opendir ("/proc");
3082 if (dirp)
3083 {
3084 struct dirent *dp;
3085 while ((dp = readdir (dirp)) != NULL)
3086 {
3087 struct stat statbuf;
3088 char procentry[sizeof ("/proc/4294967295")];
3089
3090 if (!isdigit (dp->d_name[0])
3091 || strlen (dp->d_name) > sizeof ("4294967295") - 1)
3092 continue;
3093
3094 sprintf (procentry, "/proc/%s", dp->d_name);
3095 if (stat (procentry, &statbuf) == 0
3096 && S_ISDIR (statbuf.st_mode))
3097 {
3098 int pid = (int) strtoul (dp->d_name, NULL, 10);
3099
3100 if (processes)
3101 {
3102 struct passwd *entry = getpwuid (statbuf.st_uid);
3103 show_process (pid, entry ? entry->pw_name : "?", &buffer);
3104 }
3105 else if (threads)
3106 {
3107 list_threads (pid, &buffer, NULL);
3108 }
3109 }
3110 }
3111
3112 closedir (dirp);
3113 }
3114 buffer_grow_str0 (&buffer, "</osdata>\n");
3115 buf = buffer_finish (&buffer);
3116 len_avail = strlen (buf);
3117 }
3118
3119 if (offset >= len_avail)
3120 {
3121 /* Done. Get rid of the data. */
3122 buffer_free (&buffer);
3123 buf = NULL;
3124 len_avail = 0;
3125 return 0;
3126 }
3127
3128 if (len > len_avail - offset)
3129 len = len_avail - offset;
3130 memcpy (readbuf, buf + offset, len);
3131
3132 return len;
3133 }
3134
3135 /* Convert a native/host siginfo object, into/from the siginfo in the
3136 layout of the inferiors' architecture. */
3137
3138 static void
3139 siginfo_fixup (struct siginfo *siginfo, void *inf_siginfo, int direction)
3140 {
3141 int done = 0;
3142
3143 if (the_low_target.siginfo_fixup != NULL)
3144 done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction);
3145
3146 /* If there was no callback, or the callback didn't do anything,
3147 then just do a straight memcpy. */
3148 if (!done)
3149 {
3150 if (direction == 1)
3151 memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
3152 else
3153 memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
3154 }
3155 }
3156
3157 static int
3158 linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
3159 unsigned const char *writebuf, CORE_ADDR offset, int len)
3160 {
3161 int pid;
3162 struct siginfo siginfo;
3163 char inf_siginfo[sizeof (struct siginfo)];
3164
3165 if (current_inferior == NULL)
3166 return -1;
3167
3168 pid = lwpid_of (get_thread_lwp (current_inferior));
3169
3170 if (debug_threads)
3171 fprintf (stderr, "%s siginfo for lwp %d.\n",
3172 readbuf != NULL ? "Reading" : "Writing",
3173 pid);
3174
3175 if (offset > sizeof (siginfo))
3176 return -1;
3177
3178 if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
3179 return -1;
3180
3181 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
3182 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3183 inferior with a 64-bit GDBSERVER should look the same as debugging it
3184 with a 32-bit GDBSERVER, we need to convert it. */
3185 siginfo_fixup (&siginfo, inf_siginfo, 0);
3186
3187 if (offset + len > sizeof (siginfo))
3188 len = sizeof (siginfo) - offset;
3189
3190 if (readbuf != NULL)
3191 memcpy (readbuf, inf_siginfo + offset, len);
3192 else
3193 {
3194 memcpy (inf_siginfo + offset, writebuf, len);
3195
3196 /* Convert back to ptrace layout before flushing it out. */
3197 siginfo_fixup (&siginfo, inf_siginfo, 1);
3198
3199 if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0)
3200 return -1;
3201 }
3202
3203 return len;
3204 }
3205
3206 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
3207 so we notice when children change state; as the handler for the
3208 sigsuspend in my_waitpid. */
3209
3210 static void
3211 sigchld_handler (int signo)
3212 {
3213 int old_errno = errno;
3214
3215 if (debug_threads)
3216 /* fprintf is not async-signal-safe, so call write directly. */
3217 write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
3218
3219 if (target_is_async_p ())
3220 async_file_mark (); /* trigger a linux_wait */
3221
3222 errno = old_errno;
3223 }
3224
3225 static int
3226 linux_supports_non_stop (void)
3227 {
3228 return 1;
3229 }
3230
3231 static int
3232 linux_async (int enable)
3233 {
3234 int previous = (linux_event_pipe[0] != -1);
3235
3236 if (previous != enable)
3237 {
3238 sigset_t mask;
3239 sigemptyset (&mask);
3240 sigaddset (&mask, SIGCHLD);
3241
3242 sigprocmask (SIG_BLOCK, &mask, NULL);
3243
3244 if (enable)
3245 {
3246 if (pipe (linux_event_pipe) == -1)
3247 fatal ("creating event pipe failed.");
3248
3249 fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
3250 fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
3251
3252 /* Register the event loop handler. */
3253 add_file_handler (linux_event_pipe[0],
3254 handle_target_event, NULL);
3255
3256 /* Always trigger a linux_wait. */
3257 async_file_mark ();
3258 }
3259 else
3260 {
3261 delete_file_handler (linux_event_pipe[0]);
3262
3263 close (linux_event_pipe[0]);
3264 close (linux_event_pipe[1]);
3265 linux_event_pipe[0] = -1;
3266 linux_event_pipe[1] = -1;
3267 }
3268
3269 sigprocmask (SIG_UNBLOCK, &mask, NULL);
3270 }
3271
3272 return previous;
3273 }
3274
3275 static int
3276 linux_start_non_stop (int nonstop)
3277 {
3278 /* Register or unregister from event-loop accordingly. */
3279 linux_async (nonstop);
3280 return 0;
3281 }
3282
3283 static int
3284 linux_supports_multi_process (void)
3285 {
3286 return 1;
3287 }
3288
3289
3290 /* Enumerate spufs IDs for process PID. */
3291 static int
3292 spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
3293 {
3294 int pos = 0;
3295 int written = 0;
3296 char path[128];
3297 DIR *dir;
3298 struct dirent *entry;
3299
3300 sprintf (path, "/proc/%ld/fd", pid);
3301 dir = opendir (path);
3302 if (!dir)
3303 return -1;
3304
3305 rewinddir (dir);
3306 while ((entry = readdir (dir)) != NULL)
3307 {
3308 struct stat st;
3309 struct statfs stfs;
3310 int fd;
3311
3312 fd = atoi (entry->d_name);
3313 if (!fd)
3314 continue;
3315
3316 sprintf (path, "/proc/%ld/fd/%d", pid, fd);
3317 if (stat (path, &st) != 0)
3318 continue;
3319 if (!S_ISDIR (st.st_mode))
3320 continue;
3321
3322 if (statfs (path, &stfs) != 0)
3323 continue;
3324 if (stfs.f_type != SPUFS_MAGIC)
3325 continue;
3326
3327 if (pos >= offset && pos + 4 <= offset + len)
3328 {
3329 *(unsigned int *)(buf + pos - offset) = fd;
3330 written += 4;
3331 }
3332 pos += 4;
3333 }
3334
3335 closedir (dir);
3336 return written;
3337 }
3338
3339 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
3340 object type, using the /proc file system. */
3341 static int
3342 linux_qxfer_spu (const char *annex, unsigned char *readbuf,
3343 unsigned const char *writebuf,
3344 CORE_ADDR offset, int len)
3345 {
3346 long pid = lwpid_of (get_thread_lwp (current_inferior));
3347 char buf[128];
3348 int fd = 0;
3349 int ret = 0;
3350
3351 if (!writebuf && !readbuf)
3352 return -1;
3353
3354 if (!*annex)
3355 {
3356 if (!readbuf)
3357 return -1;
3358 else
3359 return spu_enumerate_spu_ids (pid, readbuf, offset, len);
3360 }
3361
3362 sprintf (buf, "/proc/%ld/fd/%s", pid, annex);
3363 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
3364 if (fd <= 0)
3365 return -1;
3366
3367 if (offset != 0
3368 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
3369 {
3370 close (fd);
3371 return 0;
3372 }
3373
3374 if (writebuf)
3375 ret = write (fd, writebuf, (size_t) len);
3376 else
3377 ret = read (fd, readbuf, (size_t) len);
3378
3379 close (fd);
3380 return ret;
3381 }
3382
3383 static int
3384 linux_core_of_thread (ptid_t ptid)
3385 {
3386 char filename[sizeof ("/proc//task//stat")
3387 + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
3388 + 1];
3389 FILE *f;
3390 char *content = NULL;
3391 char *p;
3392 char *ts = 0;
3393 int content_read = 0;
3394 int i;
3395 int core;
3396
3397 sprintf (filename, "/proc/%d/task/%ld/stat",
3398 ptid_get_pid (ptid), ptid_get_lwp (ptid));
3399 f = fopen (filename, "r");
3400 if (!f)
3401 return -1;
3402
3403 for (;;)
3404 {
3405 int n;
3406 content = realloc (content, content_read + 1024);
3407 n = fread (content + content_read, 1, 1024, f);
3408 content_read += n;
3409 if (n < 1024)
3410 {
3411 content[content_read] = '\0';
3412 break;
3413 }
3414 }
3415
3416 p = strchr (content, '(');
3417 p = strchr (p, ')') + 2; /* skip ")" and a whitespace. */
3418
3419 p = strtok_r (p, " ", &ts);
3420 for (i = 0; i != 36; ++i)
3421 p = strtok_r (NULL, " ", &ts);
3422
3423 if (sscanf (p, "%d", &core) == 0)
3424 core = -1;
3425
3426 free (content);
3427 fclose (f);
3428
3429 return core;
3430 }
3431
3432 static struct target_ops linux_target_ops = {
3433 linux_create_inferior,
3434 linux_attach,
3435 linux_kill,
3436 linux_detach,
3437 linux_join,
3438 linux_thread_alive,
3439 linux_resume,
3440 linux_wait,
3441 linux_fetch_registers,
3442 linux_store_registers,
3443 linux_read_memory,
3444 linux_write_memory,
3445 linux_look_up_symbols,
3446 linux_request_interrupt,
3447 linux_read_auxv,
3448 linux_insert_point,
3449 linux_remove_point,
3450 linux_stopped_by_watchpoint,
3451 linux_stopped_data_address,
3452 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3453 linux_read_offsets,
3454 #else
3455 NULL,
3456 #endif
3457 #ifdef USE_THREAD_DB
3458 thread_db_get_tls_address,
3459 #else
3460 NULL,
3461 #endif
3462 linux_qxfer_spu,
3463 hostio_last_error_from_errno,
3464 linux_qxfer_osdata,
3465 linux_xfer_siginfo,
3466 linux_supports_non_stop,
3467 linux_async,
3468 linux_start_non_stop,
3469 linux_supports_multi_process,
3470 #ifdef USE_THREAD_DB
3471 thread_db_handle_monitor_command,
3472 #else
3473 NULL,
3474 #endif
3475 linux_core_of_thread
3476 };
3477
3478 static void
3479 linux_init_signals ()
3480 {
3481 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
3482 to find what the cancel signal actually is. */
3483 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
3484 signal (__SIGRTMIN+1, SIG_IGN);
3485 #endif
3486 }
3487
3488 void
3489 initialize_low (void)
3490 {
3491 struct sigaction sigchld_action;
3492 memset (&sigchld_action, 0, sizeof (sigchld_action));
3493 set_target_ops (&linux_target_ops);
3494 set_breakpoint_data (the_low_target.breakpoint,
3495 the_low_target.breakpoint_len);
3496 linux_init_signals ();
3497 linux_test_for_tracefork ();
3498 #ifdef HAVE_LINUX_REGSETS
3499 for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++)
3500 ;
3501 disabled_regsets = xmalloc (num_regsets);
3502 #endif
3503
3504 sigchld_action.sa_handler = sigchld_handler;
3505 sigemptyset (&sigchld_action.sa_mask);
3506 sigchld_action.sa_flags = SA_RESTART;
3507 sigaction (SIGCHLD, &sigchld_action, NULL);
3508 }