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da6d8c04 1/* Low level interface to ptrace, for the remote server for GDB.
545587ee 2 Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4c38e0a4 3 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
da6d8c04
DJ
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
a9762ec7 9 the Free Software Foundation; either version 3 of the License, or
da6d8c04
DJ
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
a9762ec7 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
da6d8c04
DJ
19
20#include "server.h"
58caa3dc 21#include "linux-low.h"
da6d8c04 22
58caa3dc 23#include <sys/wait.h>
da6d8c04
DJ
24#include <stdio.h>
25#include <sys/param.h>
da6d8c04 26#include <sys/ptrace.h>
da6d8c04
DJ
27#include <signal.h>
28#include <sys/ioctl.h>
29#include <fcntl.h>
d07c63e7 30#include <string.h>
0a30fbc4
DJ
31#include <stdlib.h>
32#include <unistd.h>
fa6a77dc 33#include <errno.h>
fd500816 34#include <sys/syscall.h>
f9387fc3 35#include <sched.h>
07e059b5
VP
36#include <ctype.h>
37#include <pwd.h>
38#include <sys/types.h>
39#include <dirent.h>
efcbbd14
UW
40#include <sys/stat.h>
41#include <sys/vfs.h>
1570b33e 42#include <sys/uio.h>
957f3f49
DE
43#ifndef ELFMAG0
44/* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
45 then ELFMAG0 will have been defined. If it didn't get included by
46 gdb_proc_service.h then including it will likely introduce a duplicate
47 definition of elf_fpregset_t. */
48#include <elf.h>
49#endif
efcbbd14
UW
50
51#ifndef SPUFS_MAGIC
52#define SPUFS_MAGIC 0x23c9b64e
53#endif
da6d8c04 54
32ca6d61
DJ
55#ifndef PTRACE_GETSIGINFO
56# define PTRACE_GETSIGINFO 0x4202
57# define PTRACE_SETSIGINFO 0x4203
58#endif
59
fd462a61
DJ
60#ifndef O_LARGEFILE
61#define O_LARGEFILE 0
62#endif
63
24a09b5f
DJ
64/* If the system headers did not provide the constants, hard-code the normal
65 values. */
66#ifndef PTRACE_EVENT_FORK
67
68#define PTRACE_SETOPTIONS 0x4200
69#define PTRACE_GETEVENTMSG 0x4201
70
71/* options set using PTRACE_SETOPTIONS */
72#define PTRACE_O_TRACESYSGOOD 0x00000001
73#define PTRACE_O_TRACEFORK 0x00000002
74#define PTRACE_O_TRACEVFORK 0x00000004
75#define PTRACE_O_TRACECLONE 0x00000008
76#define PTRACE_O_TRACEEXEC 0x00000010
77#define PTRACE_O_TRACEVFORKDONE 0x00000020
78#define PTRACE_O_TRACEEXIT 0x00000040
79
80/* Wait extended result codes for the above trace options. */
81#define PTRACE_EVENT_FORK 1
82#define PTRACE_EVENT_VFORK 2
83#define PTRACE_EVENT_CLONE 3
84#define PTRACE_EVENT_EXEC 4
85#define PTRACE_EVENT_VFORK_DONE 5
86#define PTRACE_EVENT_EXIT 6
87
88#endif /* PTRACE_EVENT_FORK */
89
90/* We can't always assume that this flag is available, but all systems
91 with the ptrace event handlers also have __WALL, so it's safe to use
92 in some contexts. */
93#ifndef __WALL
94#define __WALL 0x40000000 /* Wait for any child. */
95#endif
96
ec8ebe72
DE
97#ifndef W_STOPCODE
98#define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
99#endif
100
42c81e2a
DJ
101#ifdef __UCLIBC__
102#if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
103#define HAS_NOMMU
104#endif
105#endif
106
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DJ
107/* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
108 representation of the thread ID.
611cb4a5 109
54a0b537 110 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
95954743
PA
111 the same as the LWP ID.
112
113 ``all_processes'' is keyed by the "overall process ID", which
114 GNU/Linux calls tgid, "thread group ID". */
0d62e5e8 115
54a0b537 116struct inferior_list all_lwps;
0d62e5e8 117
24a09b5f
DJ
118/* A list of all unknown processes which receive stop signals. Some other
119 process will presumably claim each of these as forked children
120 momentarily. */
121
122struct inferior_list stopped_pids;
123
0d62e5e8
DJ
124/* FIXME this is a bit of a hack, and could be removed. */
125int stopping_threads;
126
127/* FIXME make into a target method? */
24a09b5f 128int using_threads = 1;
24a09b5f 129
fa593d66
PA
130/* True if we're presently stabilizing threads (moving them out of
131 jump pads). */
132static int stabilizing_threads;
133
95954743
PA
134/* This flag is true iff we've just created or attached to our first
135 inferior but it has not stopped yet. As soon as it does, we need
136 to call the low target's arch_setup callback. Doing this only on
137 the first inferior avoids reinializing the architecture on every
138 inferior, and avoids messing with the register caches of the
139 already running inferiors. NOTE: this assumes all inferiors under
140 control of gdbserver have the same architecture. */
d61ddec4
UW
141static int new_inferior;
142
2acc282a 143static void linux_resume_one_lwp (struct lwp_info *lwp,
54a0b537 144 int step, int signal, siginfo_t *info);
2bd7c093 145static void linux_resume (struct thread_resume *resume_info, size_t n);
7984d532
PA
146static void stop_all_lwps (int suspend, struct lwp_info *except);
147static void unstop_all_lwps (int unsuspend, struct lwp_info *except);
95954743 148static int linux_wait_for_event (ptid_t ptid, int *wstat, int options);
95954743 149static void *add_lwp (ptid_t ptid);
c35fafde 150static int linux_stopped_by_watchpoint (void);
95954743 151static void mark_lwp_dead (struct lwp_info *lwp, int wstat);
dc146f7c 152static int linux_core_of_thread (ptid_t ptid);
d50171e4 153static void proceed_all_lwps (void);
d50171e4
PA
154static int finish_step_over (struct lwp_info *lwp);
155static CORE_ADDR get_stop_pc (struct lwp_info *lwp);
156static int kill_lwp (unsigned long lwpid, int signo);
1e7fc18c 157static void linux_enable_event_reporting (int pid);
d50171e4
PA
158
159/* True if the low target can hardware single-step. Such targets
160 don't need a BREAKPOINT_REINSERT_ADDR callback. */
161
162static int
163can_hardware_single_step (void)
164{
165 return (the_low_target.breakpoint_reinsert_addr == NULL);
166}
167
168/* True if the low target supports memory breakpoints. If so, we'll
169 have a GET_PC implementation. */
170
171static int
172supports_breakpoints (void)
173{
174 return (the_low_target.get_pc != NULL);
175}
0d62e5e8 176
fa593d66
PA
177/* Returns true if this target can support fast tracepoints. This
178 does not mean that the in-process agent has been loaded in the
179 inferior. */
180
181static int
182supports_fast_tracepoints (void)
183{
184 return the_low_target.install_fast_tracepoint_jump_pad != NULL;
185}
186
0d62e5e8
DJ
187struct pending_signals
188{
189 int signal;
32ca6d61 190 siginfo_t info;
0d62e5e8
DJ
191 struct pending_signals *prev;
192};
611cb4a5 193
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DE
194#define PTRACE_ARG3_TYPE void *
195#define PTRACE_ARG4_TYPE void *
c6ecbae5 196#define PTRACE_XFER_TYPE long
da6d8c04 197
58caa3dc 198#ifdef HAVE_LINUX_REGSETS
52fa2412
UW
199static char *disabled_regsets;
200static int num_regsets;
58caa3dc
DJ
201#endif
202
bd99dc85
PA
203/* The read/write ends of the pipe registered as waitable file in the
204 event loop. */
205static int linux_event_pipe[2] = { -1, -1 };
206
207/* True if we're currently in async mode. */
208#define target_is_async_p() (linux_event_pipe[0] != -1)
209
02fc4de7 210static void send_sigstop (struct lwp_info *lwp);
bd99dc85
PA
211static void wait_for_sigstop (struct inferior_list_entry *entry);
212
d0722149
DE
213/* Accepts an integer PID; Returns a string representing a file that
214 can be opened to get info for the child process.
215 Space for the result is malloc'd, caller must free. */
216
217char *
218linux_child_pid_to_exec_file (int pid)
219{
220 char *name1, *name2;
221
222 name1 = xmalloc (MAXPATHLEN);
223 name2 = xmalloc (MAXPATHLEN);
224 memset (name2, 0, MAXPATHLEN);
225
226 sprintf (name1, "/proc/%d/exe", pid);
227 if (readlink (name1, name2, MAXPATHLEN) > 0)
228 {
229 free (name1);
230 return name2;
231 }
232 else
233 {
234 free (name2);
235 return name1;
236 }
237}
238
239/* Return non-zero if HEADER is a 64-bit ELF file. */
240
241static int
957f3f49 242elf_64_header_p (const Elf64_Ehdr *header)
d0722149
DE
243{
244 return (header->e_ident[EI_MAG0] == ELFMAG0
245 && header->e_ident[EI_MAG1] == ELFMAG1
246 && header->e_ident[EI_MAG2] == ELFMAG2
247 && header->e_ident[EI_MAG3] == ELFMAG3
248 && header->e_ident[EI_CLASS] == ELFCLASS64);
249}
250
251/* Return non-zero if FILE is a 64-bit ELF file,
252 zero if the file is not a 64-bit ELF file,
253 and -1 if the file is not accessible or doesn't exist. */
254
255int
256elf_64_file_p (const char *file)
257{
957f3f49 258 Elf64_Ehdr header;
d0722149
DE
259 int fd;
260
261 fd = open (file, O_RDONLY);
262 if (fd < 0)
263 return -1;
264
265 if (read (fd, &header, sizeof (header)) != sizeof (header))
266 {
267 close (fd);
268 return 0;
269 }
270 close (fd);
271
272 return elf_64_header_p (&header);
273}
274
bd99dc85
PA
275static void
276delete_lwp (struct lwp_info *lwp)
277{
278 remove_thread (get_lwp_thread (lwp));
279 remove_inferior (&all_lwps, &lwp->head);
aa5ca48f 280 free (lwp->arch_private);
bd99dc85
PA
281 free (lwp);
282}
283
95954743
PA
284/* Add a process to the common process list, and set its private
285 data. */
286
287static struct process_info *
288linux_add_process (int pid, int attached)
289{
290 struct process_info *proc;
291
292 /* Is this the first process? If so, then set the arch. */
293 if (all_processes.head == NULL)
294 new_inferior = 1;
295
296 proc = add_process (pid, attached);
297 proc->private = xcalloc (1, sizeof (*proc->private));
298
aa5ca48f
DE
299 if (the_low_target.new_process != NULL)
300 proc->private->arch_private = the_low_target.new_process ();
301
95954743
PA
302 return proc;
303}
304
07d4f67e
DE
305/* Wrapper function for waitpid which handles EINTR, and emulates
306 __WALL for systems where that is not available. */
307
308static int
309my_waitpid (int pid, int *status, int flags)
310{
311 int ret, out_errno;
312
313 if (debug_threads)
314 fprintf (stderr, "my_waitpid (%d, 0x%x)\n", pid, flags);
315
316 if (flags & __WALL)
317 {
318 sigset_t block_mask, org_mask, wake_mask;
319 int wnohang;
320
321 wnohang = (flags & WNOHANG) != 0;
322 flags &= ~(__WALL | __WCLONE);
323 flags |= WNOHANG;
324
325 /* Block all signals while here. This avoids knowing about
326 LinuxThread's signals. */
327 sigfillset (&block_mask);
328 sigprocmask (SIG_BLOCK, &block_mask, &org_mask);
329
330 /* ... except during the sigsuspend below. */
331 sigemptyset (&wake_mask);
332
333 while (1)
334 {
335 /* Since all signals are blocked, there's no need to check
336 for EINTR here. */
337 ret = waitpid (pid, status, flags);
338 out_errno = errno;
339
340 if (ret == -1 && out_errno != ECHILD)
341 break;
342 else if (ret > 0)
343 break;
344
345 if (flags & __WCLONE)
346 {
347 /* We've tried both flavors now. If WNOHANG is set,
348 there's nothing else to do, just bail out. */
349 if (wnohang)
350 break;
351
352 if (debug_threads)
353 fprintf (stderr, "blocking\n");
354
355 /* Block waiting for signals. */
356 sigsuspend (&wake_mask);
357 }
358
359 flags ^= __WCLONE;
360 }
361
362 sigprocmask (SIG_SETMASK, &org_mask, NULL);
363 }
364 else
365 {
366 do
367 ret = waitpid (pid, status, flags);
368 while (ret == -1 && errno == EINTR);
369 out_errno = errno;
370 }
371
372 if (debug_threads)
373 fprintf (stderr, "my_waitpid (%d, 0x%x): status(%x), %d\n",
374 pid, flags, status ? *status : -1, ret);
375
376 errno = out_errno;
377 return ret;
378}
379
bd99dc85
PA
380/* Handle a GNU/Linux extended wait response. If we see a clone
381 event, we need to add the new LWP to our list (and not report the
382 trap to higher layers). */
0d62e5e8 383
24a09b5f 384static void
54a0b537 385handle_extended_wait (struct lwp_info *event_child, int wstat)
24a09b5f
DJ
386{
387 int event = wstat >> 16;
54a0b537 388 struct lwp_info *new_lwp;
24a09b5f
DJ
389
390 if (event == PTRACE_EVENT_CLONE)
391 {
95954743 392 ptid_t ptid;
24a09b5f 393 unsigned long new_pid;
836acd6d 394 int ret, status = W_STOPCODE (SIGSTOP);
24a09b5f 395
bd99dc85 396 ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_child), 0, &new_pid);
24a09b5f
DJ
397
398 /* If we haven't already seen the new PID stop, wait for it now. */
399 if (! pull_pid_from_list (&stopped_pids, new_pid))
400 {
401 /* The new child has a pending SIGSTOP. We can't affect it until it
402 hits the SIGSTOP, but we're already attached. */
403
97438e3f 404 ret = my_waitpid (new_pid, &status, __WALL);
24a09b5f
DJ
405
406 if (ret == -1)
407 perror_with_name ("waiting for new child");
408 else if (ret != new_pid)
409 warning ("wait returned unexpected PID %d", ret);
da5898ce 410 else if (!WIFSTOPPED (status))
24a09b5f
DJ
411 warning ("wait returned unexpected status 0x%x", status);
412 }
413
1e7fc18c 414 linux_enable_event_reporting (new_pid);
24a09b5f 415
95954743
PA
416 ptid = ptid_build (pid_of (event_child), new_pid, 0);
417 new_lwp = (struct lwp_info *) add_lwp (ptid);
418 add_thread (ptid, new_lwp);
24a09b5f 419
e27d73f6
DE
420 /* Either we're going to immediately resume the new thread
421 or leave it stopped. linux_resume_one_lwp is a nop if it
422 thinks the thread is currently running, so set this first
423 before calling linux_resume_one_lwp. */
424 new_lwp->stopped = 1;
425
da5898ce
DJ
426 /* Normally we will get the pending SIGSTOP. But in some cases
427 we might get another signal delivered to the group first.
f21cc1a2 428 If we do get another signal, be sure not to lose it. */
da5898ce
DJ
429 if (WSTOPSIG (status) == SIGSTOP)
430 {
d50171e4
PA
431 if (stopping_threads)
432 new_lwp->stop_pc = get_stop_pc (new_lwp);
433 else
e27d73f6 434 linux_resume_one_lwp (new_lwp, 0, 0, NULL);
da5898ce 435 }
24a09b5f 436 else
da5898ce 437 {
54a0b537 438 new_lwp->stop_expected = 1;
d50171e4 439
da5898ce
DJ
440 if (stopping_threads)
441 {
d50171e4 442 new_lwp->stop_pc = get_stop_pc (new_lwp);
54a0b537
PA
443 new_lwp->status_pending_p = 1;
444 new_lwp->status_pending = status;
da5898ce
DJ
445 }
446 else
447 /* Pass the signal on. This is what GDB does - except
448 shouldn't we really report it instead? */
e27d73f6 449 linux_resume_one_lwp (new_lwp, 0, WSTOPSIG (status), NULL);
da5898ce 450 }
24a09b5f
DJ
451
452 /* Always resume the current thread. If we are stopping
453 threads, it will have a pending SIGSTOP; we may as well
454 collect it now. */
2acc282a 455 linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL);
24a09b5f
DJ
456 }
457}
458
d50171e4
PA
459/* Return the PC as read from the regcache of LWP, without any
460 adjustment. */
461
462static CORE_ADDR
463get_pc (struct lwp_info *lwp)
464{
465 struct thread_info *saved_inferior;
466 struct regcache *regcache;
467 CORE_ADDR pc;
468
469 if (the_low_target.get_pc == NULL)
470 return 0;
471
472 saved_inferior = current_inferior;
473 current_inferior = get_lwp_thread (lwp);
474
475 regcache = get_thread_regcache (current_inferior, 1);
476 pc = (*the_low_target.get_pc) (regcache);
477
478 if (debug_threads)
479 fprintf (stderr, "pc is 0x%lx\n", (long) pc);
480
481 current_inferior = saved_inferior;
482 return pc;
483}
484
485/* This function should only be called if LWP got a SIGTRAP.
0d62e5e8
DJ
486 The SIGTRAP could mean several things.
487
488 On i386, where decr_pc_after_break is non-zero:
489 If we were single-stepping this process using PTRACE_SINGLESTEP,
490 we will get only the one SIGTRAP (even if the instruction we
491 stepped over was a breakpoint). The value of $eip will be the
492 next instruction.
493 If we continue the process using PTRACE_CONT, we will get a
494 SIGTRAP when we hit a breakpoint. The value of $eip will be
495 the instruction after the breakpoint (i.e. needs to be
496 decremented). If we report the SIGTRAP to GDB, we must also
497 report the undecremented PC. If we cancel the SIGTRAP, we
498 must resume at the decremented PC.
499
500 (Presumably, not yet tested) On a non-decr_pc_after_break machine
501 with hardware or kernel single-step:
502 If we single-step over a breakpoint instruction, our PC will
503 point at the following instruction. If we continue and hit a
504 breakpoint instruction, our PC will point at the breakpoint
505 instruction. */
506
507static CORE_ADDR
d50171e4 508get_stop_pc (struct lwp_info *lwp)
0d62e5e8 509{
d50171e4
PA
510 CORE_ADDR stop_pc;
511
512 if (the_low_target.get_pc == NULL)
513 return 0;
0d62e5e8 514
d50171e4
PA
515 stop_pc = get_pc (lwp);
516
bdabb078
PA
517 if (WSTOPSIG (lwp->last_status) == SIGTRAP
518 && !lwp->stepping
519 && !lwp->stopped_by_watchpoint
520 && lwp->last_status >> 16 == 0)
47c0c975
DE
521 stop_pc -= the_low_target.decr_pc_after_break;
522
523 if (debug_threads)
524 fprintf (stderr, "stop pc is 0x%lx\n", (long) stop_pc);
525
526 return stop_pc;
0d62e5e8 527}
ce3a066d 528
0d62e5e8 529static void *
95954743 530add_lwp (ptid_t ptid)
611cb4a5 531{
54a0b537 532 struct lwp_info *lwp;
0d62e5e8 533
54a0b537
PA
534 lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
535 memset (lwp, 0, sizeof (*lwp));
0d62e5e8 536
95954743 537 lwp->head.id = ptid;
0d62e5e8 538
aa5ca48f
DE
539 if (the_low_target.new_thread != NULL)
540 lwp->arch_private = the_low_target.new_thread ();
541
54a0b537 542 add_inferior_to_list (&all_lwps, &lwp->head);
0d62e5e8 543
54a0b537 544 return lwp;
0d62e5e8 545}
611cb4a5 546
da6d8c04
DJ
547/* Start an inferior process and returns its pid.
548 ALLARGS is a vector of program-name and args. */
549
ce3a066d
DJ
550static int
551linux_create_inferior (char *program, char **allargs)
da6d8c04 552{
a6dbe5df 553 struct lwp_info *new_lwp;
da6d8c04 554 int pid;
95954743 555 ptid_t ptid;
da6d8c04 556
42c81e2a 557#if defined(__UCLIBC__) && defined(HAS_NOMMU)
52fb6437
NS
558 pid = vfork ();
559#else
da6d8c04 560 pid = fork ();
52fb6437 561#endif
da6d8c04
DJ
562 if (pid < 0)
563 perror_with_name ("fork");
564
565 if (pid == 0)
566 {
567 ptrace (PTRACE_TRACEME, 0, 0, 0);
568
60c3d7b0 569#ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
254787d4 570 signal (__SIGRTMIN + 1, SIG_DFL);
60c3d7b0 571#endif
0d62e5e8 572
a9fa9f7d
DJ
573 setpgid (0, 0);
574
2b876972
DJ
575 execv (program, allargs);
576 if (errno == ENOENT)
577 execvp (program, allargs);
da6d8c04
DJ
578
579 fprintf (stderr, "Cannot exec %s: %s.\n", program,
d07c63e7 580 strerror (errno));
da6d8c04
DJ
581 fflush (stderr);
582 _exit (0177);
583 }
584
95954743
PA
585 linux_add_process (pid, 0);
586
587 ptid = ptid_build (pid, pid, 0);
588 new_lwp = add_lwp (ptid);
589 add_thread (ptid, new_lwp);
a6dbe5df 590 new_lwp->must_set_ptrace_flags = 1;
611cb4a5 591
a9fa9f7d 592 return pid;
da6d8c04
DJ
593}
594
595/* Attach to an inferior process. */
596
95954743
PA
597static void
598linux_attach_lwp_1 (unsigned long lwpid, int initial)
da6d8c04 599{
95954743 600 ptid_t ptid;
54a0b537 601 struct lwp_info *new_lwp;
611cb4a5 602
95954743 603 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0)
da6d8c04 604 {
95954743 605 if (!initial)
2d717e4f
DJ
606 {
607 /* If we fail to attach to an LWP, just warn. */
95954743 608 fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", lwpid,
2d717e4f
DJ
609 strerror (errno), errno);
610 fflush (stderr);
611 return;
612 }
613 else
614 /* If we fail to attach to a process, report an error. */
95954743 615 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid,
43d5792c 616 strerror (errno), errno);
da6d8c04
DJ
617 }
618
95954743
PA
619 if (initial)
620 /* NOTE/FIXME: This lwp might have not been the tgid. */
621 ptid = ptid_build (lwpid, lwpid, 0);
622 else
623 {
624 /* Note that extracting the pid from the current inferior is
625 safe, since we're always called in the context of the same
626 process as this new thread. */
627 int pid = pid_of (get_thread_lwp (current_inferior));
628 ptid = ptid_build (pid, lwpid, 0);
629 }
24a09b5f 630
95954743
PA
631 new_lwp = (struct lwp_info *) add_lwp (ptid);
632 add_thread (ptid, new_lwp);
0d62e5e8 633
a6dbe5df
PA
634 /* We need to wait for SIGSTOP before being able to make the next
635 ptrace call on this LWP. */
636 new_lwp->must_set_ptrace_flags = 1;
637
0d62e5e8 638 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
0e21c1ec
DE
639 brings it to a halt.
640
641 There are several cases to consider here:
642
643 1) gdbserver has already attached to the process and is being notified
1b3f6016 644 of a new thread that is being created.
d50171e4
PA
645 In this case we should ignore that SIGSTOP and resume the
646 process. This is handled below by setting stop_expected = 1,
8336d594 647 and the fact that add_thread sets last_resume_kind ==
d50171e4 648 resume_continue.
0e21c1ec
DE
649
650 2) This is the first thread (the process thread), and we're attaching
1b3f6016
PA
651 to it via attach_inferior.
652 In this case we want the process thread to stop.
d50171e4
PA
653 This is handled by having linux_attach set last_resume_kind ==
654 resume_stop after we return.
1b3f6016
PA
655 ??? If the process already has several threads we leave the other
656 threads running.
0e21c1ec
DE
657
658 3) GDB is connecting to gdbserver and is requesting an enumeration of all
1b3f6016
PA
659 existing threads.
660 In this case we want the thread to stop.
661 FIXME: This case is currently not properly handled.
662 We should wait for the SIGSTOP but don't. Things work apparently
663 because enough time passes between when we ptrace (ATTACH) and when
664 gdb makes the next ptrace call on the thread.
0d62e5e8
DJ
665
666 On the other hand, if we are currently trying to stop all threads, we
667 should treat the new thread as if we had sent it a SIGSTOP. This works
54a0b537 668 because we are guaranteed that the add_lwp call above added us to the
0e21c1ec
DE
669 end of the list, and so the new thread has not yet reached
670 wait_for_sigstop (but will). */
d50171e4 671 new_lwp->stop_expected = 1;
0d62e5e8
DJ
672}
673
95954743
PA
674void
675linux_attach_lwp (unsigned long lwpid)
676{
677 linux_attach_lwp_1 (lwpid, 0);
678}
679
0d62e5e8 680int
a1928bad 681linux_attach (unsigned long pid)
0d62e5e8 682{
95954743 683 linux_attach_lwp_1 (pid, 1);
95954743 684 linux_add_process (pid, 1);
0d62e5e8 685
bd99dc85
PA
686 if (!non_stop)
687 {
8336d594
PA
688 struct thread_info *thread;
689
690 /* Don't ignore the initial SIGSTOP if we just attached to this
691 process. It will be collected by wait shortly. */
692 thread = find_thread_ptid (ptid_build (pid, pid, 0));
693 thread->last_resume_kind = resume_stop;
bd99dc85 694 }
0d62e5e8 695
95954743
PA
696 return 0;
697}
698
699struct counter
700{
701 int pid;
702 int count;
703};
704
705static int
706second_thread_of_pid_p (struct inferior_list_entry *entry, void *args)
707{
708 struct counter *counter = args;
709
710 if (ptid_get_pid (entry->id) == counter->pid)
711 {
712 if (++counter->count > 1)
713 return 1;
714 }
d61ddec4 715
da6d8c04
DJ
716 return 0;
717}
718
95954743
PA
719static int
720last_thread_of_process_p (struct thread_info *thread)
721{
722 ptid_t ptid = ((struct inferior_list_entry *)thread)->id;
723 int pid = ptid_get_pid (ptid);
724 struct counter counter = { pid , 0 };
da6d8c04 725
95954743
PA
726 return (find_inferior (&all_threads,
727 second_thread_of_pid_p, &counter) == NULL);
728}
729
730/* Kill the inferior lwp. */
731
732static int
733linux_kill_one_lwp (struct inferior_list_entry *entry, void *args)
da6d8c04 734{
0d62e5e8 735 struct thread_info *thread = (struct thread_info *) entry;
54a0b537 736 struct lwp_info *lwp = get_thread_lwp (thread);
0d62e5e8 737 int wstat;
95954743
PA
738 int pid = * (int *) args;
739
740 if (ptid_get_pid (entry->id) != pid)
741 return 0;
0d62e5e8 742
fd500816
DJ
743 /* We avoid killing the first thread here, because of a Linux kernel (at
744 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
745 the children get a chance to be reaped, it will remain a zombie
746 forever. */
95954743 747
12b42a12 748 if (lwpid_of (lwp) == pid)
95954743
PA
749 {
750 if (debug_threads)
751 fprintf (stderr, "lkop: is last of process %s\n",
752 target_pid_to_str (entry->id));
753 return 0;
754 }
fd500816 755
0d62e5e8
DJ
756 do
757 {
bd99dc85 758 ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
0d62e5e8
DJ
759
760 /* Make sure it died. The loop is most likely unnecessary. */
95954743 761 pid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
bd99dc85 762 } while (pid > 0 && WIFSTOPPED (wstat));
95954743
PA
763
764 return 0;
da6d8c04
DJ
765}
766
95954743
PA
767static int
768linux_kill (int pid)
0d62e5e8 769{
95954743 770 struct process_info *process;
54a0b537 771 struct lwp_info *lwp;
95954743 772 struct thread_info *thread;
fd500816 773 int wstat;
95954743 774 int lwpid;
fd500816 775
95954743
PA
776 process = find_process_pid (pid);
777 if (process == NULL)
778 return -1;
9d606399 779
f9e39928
PA
780 /* If we're killing a running inferior, make sure it is stopped
781 first, as PTRACE_KILL will not work otherwise. */
7984d532 782 stop_all_lwps (0, NULL);
f9e39928 783
95954743 784 find_inferior (&all_threads, linux_kill_one_lwp, &pid);
fd500816 785
54a0b537 786 /* See the comment in linux_kill_one_lwp. We did not kill the first
fd500816 787 thread in the list, so do so now. */
95954743
PA
788 lwp = find_lwp_pid (pid_to_ptid (pid));
789 thread = get_lwp_thread (lwp);
bd99dc85
PA
790
791 if (debug_threads)
95954743
PA
792 fprintf (stderr, "lk_1: killing lwp %ld, for pid: %d\n",
793 lwpid_of (lwp), pid);
bd99dc85 794
fd500816
DJ
795 do
796 {
bd99dc85 797 ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
fd500816
DJ
798
799 /* Make sure it died. The loop is most likely unnecessary. */
95954743
PA
800 lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
801 } while (lwpid > 0 && WIFSTOPPED (wstat));
2d717e4f 802
8336d594 803 the_target->mourn (process);
f9e39928
PA
804
805 /* Since we presently can only stop all lwps of all processes, we
806 need to unstop lwps of other processes. */
7984d532 807 unstop_all_lwps (0, NULL);
95954743 808 return 0;
0d62e5e8
DJ
809}
810
95954743
PA
811static int
812linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
6ad8ae5c
DJ
813{
814 struct thread_info *thread = (struct thread_info *) entry;
54a0b537 815 struct lwp_info *lwp = get_thread_lwp (thread);
95954743
PA
816 int pid = * (int *) args;
817
818 if (ptid_get_pid (entry->id) != pid)
819 return 0;
6ad8ae5c 820
ae13219e
DJ
821 /* If this process is stopped but is expecting a SIGSTOP, then make
822 sure we take care of that now. This isn't absolutely guaranteed
823 to collect the SIGSTOP, but is fairly likely to. */
54a0b537 824 if (lwp->stop_expected)
ae13219e 825 {
bd99dc85 826 int wstat;
ae13219e 827 /* Clear stop_expected, so that the SIGSTOP will be reported. */
54a0b537 828 lwp->stop_expected = 0;
f9e39928 829 linux_resume_one_lwp (lwp, 0, 0, NULL);
95954743 830 linux_wait_for_event (lwp->head.id, &wstat, __WALL);
ae13219e
DJ
831 }
832
833 /* Flush any pending changes to the process's registers. */
834 regcache_invalidate_one ((struct inferior_list_entry *)
54a0b537 835 get_lwp_thread (lwp));
ae13219e
DJ
836
837 /* Finally, let it resume. */
bd99dc85
PA
838 ptrace (PTRACE_DETACH, lwpid_of (lwp), 0, 0);
839
840 delete_lwp (lwp);
95954743 841 return 0;
6ad8ae5c
DJ
842}
843
95954743
PA
844static int
845linux_detach (int pid)
846{
847 struct process_info *process;
848
849 process = find_process_pid (pid);
850 if (process == NULL)
851 return -1;
852
f9e39928
PA
853 /* Stop all threads before detaching. First, ptrace requires that
854 the thread is stopped to sucessfully detach. Second, thread_db
855 may need to uninstall thread event breakpoints from memory, which
856 only works with a stopped process anyway. */
7984d532 857 stop_all_lwps (0, NULL);
f9e39928 858
ca5c370d 859#ifdef USE_THREAD_DB
8336d594 860 thread_db_detach (process);
ca5c370d
PA
861#endif
862
fa593d66
PA
863 /* Stabilize threads (move out of jump pads). */
864 stabilize_threads ();
865
95954743 866 find_inferior (&all_threads, linux_detach_one_lwp, &pid);
8336d594
PA
867
868 the_target->mourn (process);
f9e39928
PA
869
870 /* Since we presently can only stop all lwps of all processes, we
871 need to unstop lwps of other processes. */
7984d532 872 unstop_all_lwps (0, NULL);
f9e39928
PA
873 return 0;
874}
875
876/* Remove all LWPs that belong to process PROC from the lwp list. */
877
878static int
879delete_lwp_callback (struct inferior_list_entry *entry, void *proc)
880{
881 struct lwp_info *lwp = (struct lwp_info *) entry;
882 struct process_info *process = proc;
883
884 if (pid_of (lwp) == pid_of (process))
885 delete_lwp (lwp);
886
dd6953e1 887 return 0;
6ad8ae5c
DJ
888}
889
8336d594
PA
890static void
891linux_mourn (struct process_info *process)
892{
893 struct process_info_private *priv;
894
895#ifdef USE_THREAD_DB
896 thread_db_mourn (process);
897#endif
898
f9e39928
PA
899 find_inferior (&all_lwps, delete_lwp_callback, process);
900
8336d594
PA
901 /* Freeing all private data. */
902 priv = process->private;
903 free (priv->arch_private);
904 free (priv);
905 process->private = NULL;
505106cd
PA
906
907 remove_process (process);
8336d594
PA
908}
909
444d6139 910static void
95954743 911linux_join (int pid)
444d6139 912{
444d6139 913 int status, ret;
95954743 914 struct process_info *process;
bd99dc85 915
95954743
PA
916 process = find_process_pid (pid);
917 if (process == NULL)
918 return;
444d6139
PA
919
920 do {
95954743 921 ret = my_waitpid (pid, &status, 0);
444d6139
PA
922 if (WIFEXITED (status) || WIFSIGNALED (status))
923 break;
924 } while (ret != -1 || errno != ECHILD);
925}
926
6ad8ae5c 927/* Return nonzero if the given thread is still alive. */
0d62e5e8 928static int
95954743 929linux_thread_alive (ptid_t ptid)
0d62e5e8 930{
95954743
PA
931 struct lwp_info *lwp = find_lwp_pid (ptid);
932
933 /* We assume we always know if a thread exits. If a whole process
934 exited but we still haven't been able to report it to GDB, we'll
935 hold on to the last lwp of the dead process. */
936 if (lwp != NULL)
937 return !lwp->dead;
0d62e5e8
DJ
938 else
939 return 0;
940}
941
6bf5e0ba 942/* Return 1 if this lwp has an interesting status pending. */
611cb4a5 943static int
d50171e4 944status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
0d62e5e8 945{
54a0b537 946 struct lwp_info *lwp = (struct lwp_info *) entry;
95954743 947 ptid_t ptid = * (ptid_t *) arg;
7984d532 948 struct thread_info *thread;
95954743
PA
949
950 /* Check if we're only interested in events from a specific process
951 or its lwps. */
952 if (!ptid_equal (minus_one_ptid, ptid)
953 && ptid_get_pid (ptid) != ptid_get_pid (lwp->head.id))
954 return 0;
0d62e5e8 955
d50171e4
PA
956 thread = get_lwp_thread (lwp);
957
958 /* If we got a `vCont;t', but we haven't reported a stop yet, do
959 report any status pending the LWP may have. */
8336d594 960 if (thread->last_resume_kind == resume_stop
7984d532 961 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
d50171e4 962 return 0;
0d62e5e8 963
d50171e4 964 return lwp->status_pending_p;
0d62e5e8
DJ
965}
966
95954743
PA
967static int
968same_lwp (struct inferior_list_entry *entry, void *data)
969{
970 ptid_t ptid = *(ptid_t *) data;
971 int lwp;
972
973 if (ptid_get_lwp (ptid) != 0)
974 lwp = ptid_get_lwp (ptid);
975 else
976 lwp = ptid_get_pid (ptid);
977
978 if (ptid_get_lwp (entry->id) == lwp)
979 return 1;
980
981 return 0;
982}
983
984struct lwp_info *
985find_lwp_pid (ptid_t ptid)
986{
987 return (struct lwp_info*) find_inferior (&all_lwps, same_lwp, &ptid);
988}
989
bd99dc85 990static struct lwp_info *
95954743 991linux_wait_for_lwp (ptid_t ptid, int *wstatp, int options)
611cb4a5 992{
0d62e5e8 993 int ret;
95954743 994 int to_wait_for = -1;
bd99dc85 995 struct lwp_info *child = NULL;
0d62e5e8 996
bd99dc85 997 if (debug_threads)
95954743
PA
998 fprintf (stderr, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid));
999
1000 if (ptid_equal (ptid, minus_one_ptid))
1001 to_wait_for = -1; /* any child */
1002 else
1003 to_wait_for = ptid_get_lwp (ptid); /* this lwp only */
0d62e5e8 1004
bd99dc85 1005 options |= __WALL;
0d62e5e8 1006
bd99dc85 1007retry:
0d62e5e8 1008
bd99dc85
PA
1009 ret = my_waitpid (to_wait_for, wstatp, options);
1010 if (ret == 0 || (ret == -1 && errno == ECHILD && (options & WNOHANG)))
1011 return NULL;
1012 else if (ret == -1)
1013 perror_with_name ("waitpid");
0d62e5e8
DJ
1014
1015 if (debug_threads
1016 && (!WIFSTOPPED (*wstatp)
1017 || (WSTOPSIG (*wstatp) != 32
1018 && WSTOPSIG (*wstatp) != 33)))
1019 fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp);
1020
95954743 1021 child = find_lwp_pid (pid_to_ptid (ret));
0d62e5e8 1022
24a09b5f
DJ
1023 /* If we didn't find a process, one of two things presumably happened:
1024 - A process we started and then detached from has exited. Ignore it.
1025 - A process we are controlling has forked and the new child's stop
1026 was reported to us by the kernel. Save its PID. */
bd99dc85 1027 if (child == NULL && WIFSTOPPED (*wstatp))
24a09b5f
DJ
1028 {
1029 add_pid_to_list (&stopped_pids, ret);
1030 goto retry;
1031 }
bd99dc85 1032 else if (child == NULL)
24a09b5f
DJ
1033 goto retry;
1034
bd99dc85 1035 child->stopped = 1;
0d62e5e8 1036
bd99dc85 1037 child->last_status = *wstatp;
32ca6d61 1038
d61ddec4
UW
1039 /* Architecture-specific setup after inferior is running.
1040 This needs to happen after we have attached to the inferior
1041 and it is stopped for the first time, but before we access
1042 any inferior registers. */
1043 if (new_inferior)
1044 {
1045 the_low_target.arch_setup ();
52fa2412
UW
1046#ifdef HAVE_LINUX_REGSETS
1047 memset (disabled_regsets, 0, num_regsets);
1048#endif
d61ddec4
UW
1049 new_inferior = 0;
1050 }
1051
c3adc08c
PA
1052 /* Fetch the possibly triggered data watchpoint info and store it in
1053 CHILD.
1054
1055 On some archs, like x86, that use debug registers to set
1056 watchpoints, it's possible that the way to know which watched
1057 address trapped, is to check the register that is used to select
1058 which address to watch. Problem is, between setting the
1059 watchpoint and reading back which data address trapped, the user
1060 may change the set of watchpoints, and, as a consequence, GDB
1061 changes the debug registers in the inferior. To avoid reading
1062 back a stale stopped-data-address when that happens, we cache in
1063 LP the fact that a watchpoint trapped, and the corresponding data
1064 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1065 changes the debug registers meanwhile, we have the cached data we
1066 can rely on. */
1067
1068 if (WIFSTOPPED (*wstatp) && WSTOPSIG (*wstatp) == SIGTRAP)
1069 {
1070 if (the_low_target.stopped_by_watchpoint == NULL)
1071 {
1072 child->stopped_by_watchpoint = 0;
1073 }
1074 else
1075 {
1076 struct thread_info *saved_inferior;
1077
1078 saved_inferior = current_inferior;
1079 current_inferior = get_lwp_thread (child);
1080
1081 child->stopped_by_watchpoint
1082 = the_low_target.stopped_by_watchpoint ();
1083
1084 if (child->stopped_by_watchpoint)
1085 {
1086 if (the_low_target.stopped_data_address != NULL)
1087 child->stopped_data_address
1088 = the_low_target.stopped_data_address ();
1089 else
1090 child->stopped_data_address = 0;
1091 }
1092
1093 current_inferior = saved_inferior;
1094 }
1095 }
1096
d50171e4
PA
1097 /* Store the STOP_PC, with adjustment applied. This depends on the
1098 architecture being defined already (so that CHILD has a valid
1099 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1100 not). */
1101 if (WIFSTOPPED (*wstatp))
1102 child->stop_pc = get_stop_pc (child);
1103
0d62e5e8 1104 if (debug_threads
47c0c975
DE
1105 && WIFSTOPPED (*wstatp)
1106 && the_low_target.get_pc != NULL)
0d62e5e8 1107 {
896c7fbb 1108 struct thread_info *saved_inferior = current_inferior;
bce522a2 1109 struct regcache *regcache;
47c0c975
DE
1110 CORE_ADDR pc;
1111
d50171e4 1112 current_inferior = get_lwp_thread (child);
bce522a2 1113 regcache = get_thread_regcache (current_inferior, 1);
442ea881 1114 pc = (*the_low_target.get_pc) (regcache);
47c0c975 1115 fprintf (stderr, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc);
896c7fbb 1116 current_inferior = saved_inferior;
0d62e5e8 1117 }
bd99dc85
PA
1118
1119 return child;
0d62e5e8 1120}
611cb4a5 1121
219f2f23
PA
1122/* This function should only be called if the LWP got a SIGTRAP.
1123
1124 Handle any tracepoint steps or hits. Return true if a tracepoint
1125 event was handled, 0 otherwise. */
1126
1127static int
1128handle_tracepoints (struct lwp_info *lwp)
1129{
1130 struct thread_info *tinfo = get_lwp_thread (lwp);
1131 int tpoint_related_event = 0;
1132
7984d532
PA
1133 /* If this tracepoint hit causes a tracing stop, we'll immediately
1134 uninsert tracepoints. To do this, we temporarily pause all
1135 threads, unpatch away, and then unpause threads. We need to make
1136 sure the unpausing doesn't resume LWP too. */
1137 lwp->suspended++;
1138
219f2f23
PA
1139 /* And we need to be sure that any all-threads-stopping doesn't try
1140 to move threads out of the jump pads, as it could deadlock the
1141 inferior (LWP could be in the jump pad, maybe even holding the
1142 lock.) */
1143
1144 /* Do any necessary step collect actions. */
1145 tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc);
1146
fa593d66
PA
1147 tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc);
1148
219f2f23
PA
1149 /* See if we just hit a tracepoint and do its main collect
1150 actions. */
1151 tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc);
1152
7984d532
PA
1153 lwp->suspended--;
1154
1155 gdb_assert (lwp->suspended == 0);
fa593d66 1156 gdb_assert (!stabilizing_threads || lwp->collecting_fast_tracepoint);
7984d532 1157
219f2f23
PA
1158 if (tpoint_related_event)
1159 {
1160 if (debug_threads)
1161 fprintf (stderr, "got a tracepoint event\n");
1162 return 1;
1163 }
1164
1165 return 0;
1166}
1167
fa593d66
PA
1168/* Convenience wrapper. Returns true if LWP is presently collecting a
1169 fast tracepoint. */
1170
1171static int
1172linux_fast_tracepoint_collecting (struct lwp_info *lwp,
1173 struct fast_tpoint_collect_status *status)
1174{
1175 CORE_ADDR thread_area;
1176
1177 if (the_low_target.get_thread_area == NULL)
1178 return 0;
1179
1180 /* Get the thread area address. This is used to recognize which
1181 thread is which when tracing with the in-process agent library.
1182 We don't read anything from the address, and treat it as opaque;
1183 it's the address itself that we assume is unique per-thread. */
1184 if ((*the_low_target.get_thread_area) (lwpid_of (lwp), &thread_area) == -1)
1185 return 0;
1186
1187 return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status);
1188}
1189
1190/* The reason we resume in the caller, is because we want to be able
1191 to pass lwp->status_pending as WSTAT, and we need to clear
1192 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1193 refuses to resume. */
1194
1195static int
1196maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat)
1197{
1198 struct thread_info *saved_inferior;
1199
1200 saved_inferior = current_inferior;
1201 current_inferior = get_lwp_thread (lwp);
1202
1203 if ((wstat == NULL
1204 || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP))
1205 && supports_fast_tracepoints ()
1206 && in_process_agent_loaded ())
1207 {
1208 struct fast_tpoint_collect_status status;
1209 int r;
1210
1211 if (debug_threads)
1212 fprintf (stderr, "\
1213Checking whether LWP %ld needs to move out of the jump pad.\n",
1214 lwpid_of (lwp));
1215
1216 r = linux_fast_tracepoint_collecting (lwp, &status);
1217
1218 if (wstat == NULL
1219 || (WSTOPSIG (*wstat) != SIGILL
1220 && WSTOPSIG (*wstat) != SIGFPE
1221 && WSTOPSIG (*wstat) != SIGSEGV
1222 && WSTOPSIG (*wstat) != SIGBUS))
1223 {
1224 lwp->collecting_fast_tracepoint = r;
1225
1226 if (r != 0)
1227 {
1228 if (r == 1 && lwp->exit_jump_pad_bkpt == NULL)
1229 {
1230 /* Haven't executed the original instruction yet.
1231 Set breakpoint there, and wait till it's hit,
1232 then single-step until exiting the jump pad. */
1233 lwp->exit_jump_pad_bkpt
1234 = set_breakpoint_at (status.adjusted_insn_addr, NULL);
1235 }
1236
1237 if (debug_threads)
1238 fprintf (stderr, "\
1239Checking whether LWP %ld needs to move out of the jump pad...it does\n",
1240 lwpid_of (lwp));
1241
1242 return 1;
1243 }
1244 }
1245 else
1246 {
1247 /* If we get a synchronous signal while collecting, *and*
1248 while executing the (relocated) original instruction,
1249 reset the PC to point at the tpoint address, before
1250 reporting to GDB. Otherwise, it's an IPA lib bug: just
1251 report the signal to GDB, and pray for the best. */
1252
1253 lwp->collecting_fast_tracepoint = 0;
1254
1255 if (r != 0
1256 && (status.adjusted_insn_addr <= lwp->stop_pc
1257 && lwp->stop_pc < status.adjusted_insn_addr_end))
1258 {
1259 siginfo_t info;
1260 struct regcache *regcache;
1261
1262 /* The si_addr on a few signals references the address
1263 of the faulting instruction. Adjust that as
1264 well. */
1265 if ((WSTOPSIG (*wstat) == SIGILL
1266 || WSTOPSIG (*wstat) == SIGFPE
1267 || WSTOPSIG (*wstat) == SIGBUS
1268 || WSTOPSIG (*wstat) == SIGSEGV)
1269 && ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &info) == 0
1270 /* Final check just to make sure we don't clobber
1271 the siginfo of non-kernel-sent signals. */
1272 && (uintptr_t) info.si_addr == lwp->stop_pc)
1273 {
1274 info.si_addr = (void *) (uintptr_t) status.tpoint_addr;
1275 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &info);
1276 }
1277
1278 regcache = get_thread_regcache (get_lwp_thread (lwp), 1);
1279 (*the_low_target.set_pc) (regcache, status.tpoint_addr);
1280 lwp->stop_pc = status.tpoint_addr;
1281
1282 /* Cancel any fast tracepoint lock this thread was
1283 holding. */
1284 force_unlock_trace_buffer ();
1285 }
1286
1287 if (lwp->exit_jump_pad_bkpt != NULL)
1288 {
1289 if (debug_threads)
1290 fprintf (stderr,
1291 "Cancelling fast exit-jump-pad: removing bkpt. "
1292 "stopping all threads momentarily.\n");
1293
1294 stop_all_lwps (1, lwp);
1295 cancel_breakpoints ();
1296
1297 delete_breakpoint (lwp->exit_jump_pad_bkpt);
1298 lwp->exit_jump_pad_bkpt = NULL;
1299
1300 unstop_all_lwps (1, lwp);
1301
1302 gdb_assert (lwp->suspended >= 0);
1303 }
1304 }
1305 }
1306
1307 if (debug_threads)
1308 fprintf (stderr, "\
1309Checking whether LWP %ld needs to move out of the jump pad...no\n",
1310 lwpid_of (lwp));
1311 return 0;
1312}
1313
1314/* Enqueue one signal in the "signals to report later when out of the
1315 jump pad" list. */
1316
1317static void
1318enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1319{
1320 struct pending_signals *p_sig;
1321
1322 if (debug_threads)
1323 fprintf (stderr, "\
1324Deferring signal %d for LWP %ld.\n", WSTOPSIG (*wstat), lwpid_of (lwp));
1325
1326 if (debug_threads)
1327 {
1328 struct pending_signals *sig;
1329
1330 for (sig = lwp->pending_signals_to_report;
1331 sig != NULL;
1332 sig = sig->prev)
1333 fprintf (stderr,
1334 " Already queued %d\n",
1335 sig->signal);
1336
1337 fprintf (stderr, " (no more currently queued signals)\n");
1338 }
1339
1340 p_sig = xmalloc (sizeof (*p_sig));
1341 p_sig->prev = lwp->pending_signals_to_report;
1342 p_sig->signal = WSTOPSIG (*wstat);
1343 memset (&p_sig->info, 0, sizeof (siginfo_t));
1344 ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
1345
1346 lwp->pending_signals_to_report = p_sig;
1347}
1348
1349/* Dequeue one signal from the "signals to report later when out of
1350 the jump pad" list. */
1351
1352static int
1353dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1354{
1355 if (lwp->pending_signals_to_report != NULL)
1356 {
1357 struct pending_signals **p_sig;
1358
1359 p_sig = &lwp->pending_signals_to_report;
1360 while ((*p_sig)->prev != NULL)
1361 p_sig = &(*p_sig)->prev;
1362
1363 *wstat = W_STOPCODE ((*p_sig)->signal);
1364 if ((*p_sig)->info.si_signo != 0)
1365 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
1366 free (*p_sig);
1367 *p_sig = NULL;
1368
1369 if (debug_threads)
1370 fprintf (stderr, "Reporting deferred signal %d for LWP %ld.\n",
1371 WSTOPSIG (*wstat), lwpid_of (lwp));
1372
1373 if (debug_threads)
1374 {
1375 struct pending_signals *sig;
1376
1377 for (sig = lwp->pending_signals_to_report;
1378 sig != NULL;
1379 sig = sig->prev)
1380 fprintf (stderr,
1381 " Still queued %d\n",
1382 sig->signal);
1383
1384 fprintf (stderr, " (no more queued signals)\n");
1385 }
1386
1387 return 1;
1388 }
1389
1390 return 0;
1391}
1392
d50171e4
PA
1393/* Arrange for a breakpoint to be hit again later. We don't keep the
1394 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1395 will handle the current event, eventually we will resume this LWP,
1396 and this breakpoint will trap again. */
1397
1398static int
1399cancel_breakpoint (struct lwp_info *lwp)
1400{
1401 struct thread_info *saved_inferior;
d50171e4
PA
1402
1403 /* There's nothing to do if we don't support breakpoints. */
1404 if (!supports_breakpoints ())
1405 return 0;
1406
d50171e4
PA
1407 /* breakpoint_at reads from current inferior. */
1408 saved_inferior = current_inferior;
1409 current_inferior = get_lwp_thread (lwp);
1410
1411 if ((*the_low_target.breakpoint_at) (lwp->stop_pc))
1412 {
1413 if (debug_threads)
1414 fprintf (stderr,
1415 "CB: Push back breakpoint for %s\n",
fc7238bb 1416 target_pid_to_str (ptid_of (lwp)));
d50171e4
PA
1417
1418 /* Back up the PC if necessary. */
1419 if (the_low_target.decr_pc_after_break)
1420 {
1421 struct regcache *regcache
fc7238bb 1422 = get_thread_regcache (current_inferior, 1);
d50171e4
PA
1423 (*the_low_target.set_pc) (regcache, lwp->stop_pc);
1424 }
1425
1426 current_inferior = saved_inferior;
1427 return 1;
1428 }
1429 else
1430 {
1431 if (debug_threads)
1432 fprintf (stderr,
1433 "CB: No breakpoint found at %s for [%s]\n",
1434 paddress (lwp->stop_pc),
fc7238bb 1435 target_pid_to_str (ptid_of (lwp)));
d50171e4
PA
1436 }
1437
1438 current_inferior = saved_inferior;
1439 return 0;
1440}
1441
1442/* When the event-loop is doing a step-over, this points at the thread
1443 being stepped. */
1444ptid_t step_over_bkpt;
1445
bd99dc85
PA
1446/* Wait for an event from child PID. If PID is -1, wait for any
1447 child. Store the stop status through the status pointer WSTAT.
1448 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1449 event was found and OPTIONS contains WNOHANG. Return the PID of
1450 the stopped child otherwise. */
1451
0d62e5e8 1452static int
95954743 1453linux_wait_for_event_1 (ptid_t ptid, int *wstat, int options)
0d62e5e8 1454{
d50171e4
PA
1455 struct lwp_info *event_child, *requested_child;
1456
d50171e4
PA
1457 event_child = NULL;
1458 requested_child = NULL;
0d62e5e8 1459
95954743 1460 /* Check for a lwp with a pending status. */
bd99dc85 1461
95954743
PA
1462 if (ptid_equal (ptid, minus_one_ptid)
1463 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid)), ptid))
0d62e5e8 1464 {
54a0b537 1465 event_child = (struct lwp_info *)
d50171e4 1466 find_inferior (&all_lwps, status_pending_p_callback, &ptid);
0d62e5e8 1467 if (debug_threads && event_child)
bd99dc85 1468 fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
0d62e5e8
DJ
1469 }
1470 else
1471 {
95954743 1472 requested_child = find_lwp_pid (ptid);
d50171e4 1473
fa593d66
PA
1474 if (!stopping_threads
1475 && requested_child->status_pending_p
1476 && requested_child->collecting_fast_tracepoint)
1477 {
1478 enqueue_one_deferred_signal (requested_child,
1479 &requested_child->status_pending);
1480 requested_child->status_pending_p = 0;
1481 requested_child->status_pending = 0;
1482 linux_resume_one_lwp (requested_child, 0, 0, NULL);
1483 }
1484
1485 if (requested_child->suspended
1486 && requested_child->status_pending_p)
1487 fatal ("requesting an event out of a suspended child?");
1488
d50171e4 1489 if (requested_child->status_pending_p)
bd99dc85 1490 event_child = requested_child;
0d62e5e8 1491 }
611cb4a5 1492
0d62e5e8
DJ
1493 if (event_child != NULL)
1494 {
bd99dc85
PA
1495 if (debug_threads)
1496 fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
1497 lwpid_of (event_child), event_child->status_pending);
1498 *wstat = event_child->status_pending;
1499 event_child->status_pending_p = 0;
1500 event_child->status_pending = 0;
1501 current_inferior = get_lwp_thread (event_child);
1502 return lwpid_of (event_child);
0d62e5e8
DJ
1503 }
1504
1505 /* We only enter this loop if no process has a pending wait status. Thus
1506 any action taken in response to a wait status inside this loop is
1507 responding as soon as we detect the status, not after any pending
1508 events. */
1509 while (1)
1510 {
6bf5e0ba 1511 event_child = linux_wait_for_lwp (ptid, wstat, options);
0d62e5e8 1512
bd99dc85 1513 if ((options & WNOHANG) && event_child == NULL)
d50171e4
PA
1514 {
1515 if (debug_threads)
1516 fprintf (stderr, "WNOHANG set, no event found\n");
1517 return 0;
1518 }
0d62e5e8
DJ
1519
1520 if (event_child == NULL)
1521 error ("event from unknown child");
611cb4a5 1522
bd99dc85 1523 current_inferior = get_lwp_thread (event_child);
0d62e5e8 1524
89be2091 1525 /* Check for thread exit. */
bd99dc85 1526 if (! WIFSTOPPED (*wstat))
0d62e5e8 1527 {
89be2091 1528 if (debug_threads)
95954743 1529 fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child));
89be2091
DJ
1530
1531 /* If the last thread is exiting, just return. */
95954743 1532 if (last_thread_of_process_p (current_inferior))
bd99dc85
PA
1533 {
1534 if (debug_threads)
95954743
PA
1535 fprintf (stderr, "LWP %ld is last lwp of process\n",
1536 lwpid_of (event_child));
bd99dc85
PA
1537 return lwpid_of (event_child);
1538 }
89be2091 1539
bd99dc85
PA
1540 if (!non_stop)
1541 {
1542 current_inferior = (struct thread_info *) all_threads.head;
1543 if (debug_threads)
1544 fprintf (stderr, "Current inferior is now %ld\n",
1545 lwpid_of (get_thread_lwp (current_inferior)));
1546 }
1547 else
1548 {
1549 current_inferior = NULL;
1550 if (debug_threads)
1551 fprintf (stderr, "Current inferior is now <NULL>\n");
1552 }
89be2091
DJ
1553
1554 /* If we were waiting for this particular child to do something...
1555 well, it did something. */
bd99dc85 1556 if (requested_child != NULL)
d50171e4
PA
1557 {
1558 int lwpid = lwpid_of (event_child);
1559
1560 /* Cancel the step-over operation --- the thread that
1561 started it is gone. */
1562 if (finish_step_over (event_child))
7984d532 1563 unstop_all_lwps (1, event_child);
d50171e4
PA
1564 delete_lwp (event_child);
1565 return lwpid;
1566 }
1567
1568 delete_lwp (event_child);
89be2091
DJ
1569
1570 /* Wait for a more interesting event. */
1571 continue;
1572 }
1573
a6dbe5df
PA
1574 if (event_child->must_set_ptrace_flags)
1575 {
1e7fc18c 1576 linux_enable_event_reporting (lwpid_of (event_child));
a6dbe5df
PA
1577 event_child->must_set_ptrace_flags = 0;
1578 }
1579
bd99dc85
PA
1580 if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
1581 && *wstat >> 16 != 0)
24a09b5f 1582 {
bd99dc85 1583 handle_extended_wait (event_child, *wstat);
24a09b5f
DJ
1584 continue;
1585 }
1586
d50171e4
PA
1587 if (WIFSTOPPED (*wstat)
1588 && WSTOPSIG (*wstat) == SIGSTOP
1589 && event_child->stop_expected)
1590 {
1591 int should_stop;
1592
1593 if (debug_threads)
1594 fprintf (stderr, "Expected stop.\n");
1595 event_child->stop_expected = 0;
1596
8336d594 1597 should_stop = (current_inferior->last_resume_kind == resume_stop
d50171e4
PA
1598 || stopping_threads);
1599
1600 if (!should_stop)
1601 {
1602 linux_resume_one_lwp (event_child,
1603 event_child->stepping, 0, NULL);
1604 continue;
1605 }
1606 }
1607
bd99dc85 1608 return lwpid_of (event_child);
611cb4a5 1609 }
0d62e5e8 1610
611cb4a5
DJ
1611 /* NOTREACHED */
1612 return 0;
1613}
1614
95954743
PA
1615static int
1616linux_wait_for_event (ptid_t ptid, int *wstat, int options)
1617{
1618 ptid_t wait_ptid;
1619
1620 if (ptid_is_pid (ptid))
1621 {
1622 /* A request to wait for a specific tgid. This is not possible
1623 with waitpid, so instead, we wait for any child, and leave
1624 children we're not interested in right now with a pending
1625 status to report later. */
1626 wait_ptid = minus_one_ptid;
1627 }
1628 else
1629 wait_ptid = ptid;
1630
1631 while (1)
1632 {
1633 int event_pid;
1634
1635 event_pid = linux_wait_for_event_1 (wait_ptid, wstat, options);
1636
1637 if (event_pid > 0
1638 && ptid_is_pid (ptid) && ptid_get_pid (ptid) != event_pid)
1639 {
1640 struct lwp_info *event_child = find_lwp_pid (pid_to_ptid (event_pid));
1641
1642 if (! WIFSTOPPED (*wstat))
1643 mark_lwp_dead (event_child, *wstat);
1644 else
1645 {
1646 event_child->status_pending_p = 1;
1647 event_child->status_pending = *wstat;
1648 }
1649 }
1650 else
1651 return event_pid;
1652 }
1653}
1654
6bf5e0ba
PA
1655
1656/* Count the LWP's that have had events. */
1657
1658static int
1659count_events_callback (struct inferior_list_entry *entry, void *data)
1660{
1661 struct lwp_info *lp = (struct lwp_info *) entry;
8336d594 1662 struct thread_info *thread = get_lwp_thread (lp);
6bf5e0ba
PA
1663 int *count = data;
1664
1665 gdb_assert (count != NULL);
1666
1667 /* Count only resumed LWPs that have a SIGTRAP event pending that
1668 should be reported to GDB. */
8336d594
PA
1669 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
1670 && thread->last_resume_kind != resume_stop
6bf5e0ba
PA
1671 && lp->status_pending_p
1672 && WIFSTOPPED (lp->status_pending)
1673 && WSTOPSIG (lp->status_pending) == SIGTRAP
1674 && !breakpoint_inserted_here (lp->stop_pc))
1675 (*count)++;
1676
1677 return 0;
1678}
1679
1680/* Select the LWP (if any) that is currently being single-stepped. */
1681
1682static int
1683select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data)
1684{
1685 struct lwp_info *lp = (struct lwp_info *) entry;
8336d594 1686 struct thread_info *thread = get_lwp_thread (lp);
6bf5e0ba 1687
8336d594
PA
1688 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
1689 && thread->last_resume_kind == resume_step
6bf5e0ba
PA
1690 && lp->status_pending_p)
1691 return 1;
1692 else
1693 return 0;
1694}
1695
1696/* Select the Nth LWP that has had a SIGTRAP event that should be
1697 reported to GDB. */
1698
1699static int
1700select_event_lwp_callback (struct inferior_list_entry *entry, void *data)
1701{
1702 struct lwp_info *lp = (struct lwp_info *) entry;
8336d594 1703 struct thread_info *thread = get_lwp_thread (lp);
6bf5e0ba
PA
1704 int *selector = data;
1705
1706 gdb_assert (selector != NULL);
1707
1708 /* Select only resumed LWPs that have a SIGTRAP event pending. */
8336d594
PA
1709 if (thread->last_resume_kind != resume_stop
1710 && thread->last_status.kind == TARGET_WAITKIND_IGNORE
6bf5e0ba
PA
1711 && lp->status_pending_p
1712 && WIFSTOPPED (lp->status_pending)
1713 && WSTOPSIG (lp->status_pending) == SIGTRAP
1714 && !breakpoint_inserted_here (lp->stop_pc))
1715 if ((*selector)-- == 0)
1716 return 1;
1717
1718 return 0;
1719}
1720
1721static int
1722cancel_breakpoints_callback (struct inferior_list_entry *entry, void *data)
1723{
1724 struct lwp_info *lp = (struct lwp_info *) entry;
8336d594 1725 struct thread_info *thread = get_lwp_thread (lp);
6bf5e0ba
PA
1726 struct lwp_info *event_lp = data;
1727
1728 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
1729 if (lp == event_lp)
1730 return 0;
1731
1732 /* If a LWP other than the LWP that we're reporting an event for has
1733 hit a GDB breakpoint (as opposed to some random trap signal),
1734 then just arrange for it to hit it again later. We don't keep
1735 the SIGTRAP status and don't forward the SIGTRAP signal to the
1736 LWP. We will handle the current event, eventually we will resume
1737 all LWPs, and this one will get its breakpoint trap again.
1738
1739 If we do not do this, then we run the risk that the user will
1740 delete or disable the breakpoint, but the LWP will have already
1741 tripped on it. */
1742
8336d594
PA
1743 if (thread->last_resume_kind != resume_stop
1744 && thread->last_status.kind == TARGET_WAITKIND_IGNORE
6bf5e0ba
PA
1745 && lp->status_pending_p
1746 && WIFSTOPPED (lp->status_pending)
1747 && WSTOPSIG (lp->status_pending) == SIGTRAP
bdabb078
PA
1748 && !lp->stepping
1749 && !lp->stopped_by_watchpoint
6bf5e0ba
PA
1750 && cancel_breakpoint (lp))
1751 /* Throw away the SIGTRAP. */
1752 lp->status_pending_p = 0;
1753
1754 return 0;
1755}
1756
7984d532
PA
1757static void
1758linux_cancel_breakpoints (void)
1759{
1760 find_inferior (&all_lwps, cancel_breakpoints_callback, NULL);
1761}
1762
6bf5e0ba
PA
1763/* Select one LWP out of those that have events pending. */
1764
1765static void
1766select_event_lwp (struct lwp_info **orig_lp)
1767{
1768 int num_events = 0;
1769 int random_selector;
1770 struct lwp_info *event_lp;
1771
1772 /* Give preference to any LWP that is being single-stepped. */
1773 event_lp
1774 = (struct lwp_info *) find_inferior (&all_lwps,
1775 select_singlestep_lwp_callback, NULL);
1776 if (event_lp != NULL)
1777 {
1778 if (debug_threads)
1779 fprintf (stderr,
1780 "SEL: Select single-step %s\n",
1781 target_pid_to_str (ptid_of (event_lp)));
1782 }
1783 else
1784 {
1785 /* No single-stepping LWP. Select one at random, out of those
1786 which have had SIGTRAP events. */
1787
1788 /* First see how many SIGTRAP events we have. */
1789 find_inferior (&all_lwps, count_events_callback, &num_events);
1790
1791 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
1792 random_selector = (int)
1793 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
1794
1795 if (debug_threads && num_events > 1)
1796 fprintf (stderr,
1797 "SEL: Found %d SIGTRAP events, selecting #%d\n",
1798 num_events, random_selector);
1799
1800 event_lp = (struct lwp_info *) find_inferior (&all_lwps,
1801 select_event_lwp_callback,
1802 &random_selector);
1803 }
1804
1805 if (event_lp != NULL)
1806 {
1807 /* Switch the event LWP. */
1808 *orig_lp = event_lp;
1809 }
1810}
1811
7984d532
PA
1812/* Decrement the suspend count of an LWP. */
1813
1814static int
1815unsuspend_one_lwp (struct inferior_list_entry *entry, void *except)
1816{
1817 struct lwp_info *lwp = (struct lwp_info *) entry;
1818
1819 /* Ignore EXCEPT. */
1820 if (lwp == except)
1821 return 0;
1822
1823 lwp->suspended--;
1824
1825 gdb_assert (lwp->suspended >= 0);
1826 return 0;
1827}
1828
1829/* Decrement the suspend count of all LWPs, except EXCEPT, if non
1830 NULL. */
1831
1832static void
1833unsuspend_all_lwps (struct lwp_info *except)
1834{
1835 find_inferior (&all_lwps, unsuspend_one_lwp, except);
1836}
1837
fa593d66
PA
1838static void move_out_of_jump_pad_callback (struct inferior_list_entry *entry);
1839static int stuck_in_jump_pad_callback (struct inferior_list_entry *entry,
1840 void *data);
1841static int lwp_running (struct inferior_list_entry *entry, void *data);
1842static ptid_t linux_wait_1 (ptid_t ptid,
1843 struct target_waitstatus *ourstatus,
1844 int target_options);
1845
1846/* Stabilize threads (move out of jump pads).
1847
1848 If a thread is midway collecting a fast tracepoint, we need to
1849 finish the collection and move it out of the jump pad before
1850 reporting the signal.
1851
1852 This avoids recursion while collecting (when a signal arrives
1853 midway, and the signal handler itself collects), which would trash
1854 the trace buffer. In case the user set a breakpoint in a signal
1855 handler, this avoids the backtrace showing the jump pad, etc..
1856 Most importantly, there are certain things we can't do safely if
1857 threads are stopped in a jump pad (or in its callee's). For
1858 example:
1859
1860 - starting a new trace run. A thread still collecting the
1861 previous run, could trash the trace buffer when resumed. The trace
1862 buffer control structures would have been reset but the thread had
1863 no way to tell. The thread could even midway memcpy'ing to the
1864 buffer, which would mean that when resumed, it would clobber the
1865 trace buffer that had been set for a new run.
1866
1867 - we can't rewrite/reuse the jump pads for new tracepoints
1868 safely. Say you do tstart while a thread is stopped midway while
1869 collecting. When the thread is later resumed, it finishes the
1870 collection, and returns to the jump pad, to execute the original
1871 instruction that was under the tracepoint jump at the time the
1872 older run had been started. If the jump pad had been rewritten
1873 since for something else in the new run, the thread would now
1874 execute the wrong / random instructions. */
1875
1876static void
1877linux_stabilize_threads (void)
1878{
1879 struct thread_info *save_inferior;
1880 struct lwp_info *lwp_stuck;
1881
1882 lwp_stuck
1883 = (struct lwp_info *) find_inferior (&all_lwps,
1884 stuck_in_jump_pad_callback, NULL);
1885 if (lwp_stuck != NULL)
1886 {
1887 fprintf (stderr, "can't stabilize, LWP %ld is stuck in jump pad\n",
1888 lwpid_of (lwp_stuck));
1889 return;
1890 }
1891
1892 save_inferior = current_inferior;
1893
1894 stabilizing_threads = 1;
1895
1896 /* Kick 'em all. */
1897 for_each_inferior (&all_lwps, move_out_of_jump_pad_callback);
1898
1899 /* Loop until all are stopped out of the jump pads. */
1900 while (find_inferior (&all_lwps, lwp_running, NULL) != NULL)
1901 {
1902 struct target_waitstatus ourstatus;
1903 struct lwp_info *lwp;
1904 ptid_t ptid;
1905 int wstat;
1906
1907 /* Note that we go through the full wait even loop. While
1908 moving threads out of jump pad, we need to be able to step
1909 over internal breakpoints and such. */
1910 ptid = linux_wait_1 (minus_one_ptid, &ourstatus, 0);
1911
1912 if (ourstatus.kind == TARGET_WAITKIND_STOPPED)
1913 {
1914 lwp = get_thread_lwp (current_inferior);
1915
1916 /* Lock it. */
1917 lwp->suspended++;
1918
1919 if (ourstatus.value.sig != TARGET_SIGNAL_0
1920 || current_inferior->last_resume_kind == resume_stop)
1921 {
1922 wstat = W_STOPCODE (target_signal_to_host (ourstatus.value.sig));
1923 enqueue_one_deferred_signal (lwp, &wstat);
1924 }
1925 }
1926 }
1927
1928 find_inferior (&all_lwps, unsuspend_one_lwp, NULL);
1929
1930 stabilizing_threads = 0;
1931
1932 current_inferior = save_inferior;
1933
1934 lwp_stuck
1935 = (struct lwp_info *) find_inferior (&all_lwps,
1936 stuck_in_jump_pad_callback, NULL);
1937 if (lwp_stuck != NULL)
1938 {
1939 if (debug_threads)
1940 fprintf (stderr, "couldn't stabilize, LWP %ld got stuck in jump pad\n",
1941 lwpid_of (lwp_stuck));
1942 }
1943}
1944
0d62e5e8 1945/* Wait for process, returns status. */
da6d8c04 1946
95954743
PA
1947static ptid_t
1948linux_wait_1 (ptid_t ptid,
1949 struct target_waitstatus *ourstatus, int target_options)
da6d8c04 1950{
e5f1222d 1951 int w;
fc7238bb 1952 struct lwp_info *event_child;
bd99dc85 1953 int options;
bd99dc85 1954 int pid;
6bf5e0ba
PA
1955 int step_over_finished;
1956 int bp_explains_trap;
1957 int maybe_internal_trap;
1958 int report_to_gdb;
219f2f23 1959 int trace_event;
bd99dc85
PA
1960
1961 /* Translate generic target options into linux options. */
1962 options = __WALL;
1963 if (target_options & TARGET_WNOHANG)
1964 options |= WNOHANG;
0d62e5e8
DJ
1965
1966retry:
fa593d66
PA
1967 bp_explains_trap = 0;
1968 trace_event = 0;
bd99dc85
PA
1969 ourstatus->kind = TARGET_WAITKIND_IGNORE;
1970
0d62e5e8
DJ
1971 /* If we were only supposed to resume one thread, only wait for
1972 that thread - if it's still alive. If it died, however - which
1973 can happen if we're coming from the thread death case below -
1974 then we need to make sure we restart the other threads. We could
1975 pick a thread at random or restart all; restarting all is less
1976 arbitrary. */
95954743
PA
1977 if (!non_stop
1978 && !ptid_equal (cont_thread, null_ptid)
1979 && !ptid_equal (cont_thread, minus_one_ptid))
0d62e5e8 1980 {
fc7238bb
PA
1981 struct thread_info *thread;
1982
bd99dc85
PA
1983 thread = (struct thread_info *) find_inferior_id (&all_threads,
1984 cont_thread);
0d62e5e8
DJ
1985
1986 /* No stepping, no signal - unless one is pending already, of course. */
bd99dc85 1987 if (thread == NULL)
64386c31
DJ
1988 {
1989 struct thread_resume resume_info;
95954743 1990 resume_info.thread = minus_one_ptid;
bd99dc85
PA
1991 resume_info.kind = resume_continue;
1992 resume_info.sig = 0;
2bd7c093 1993 linux_resume (&resume_info, 1);
64386c31 1994 }
bd99dc85 1995 else
95954743 1996 ptid = cont_thread;
0d62e5e8 1997 }
da6d8c04 1998
6bf5e0ba
PA
1999 if (ptid_equal (step_over_bkpt, null_ptid))
2000 pid = linux_wait_for_event (ptid, &w, options);
2001 else
2002 {
2003 if (debug_threads)
2004 fprintf (stderr, "step_over_bkpt set [%s], doing a blocking wait\n",
2005 target_pid_to_str (step_over_bkpt));
2006 pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG);
2007 }
2008
bd99dc85 2009 if (pid == 0) /* only if TARGET_WNOHANG */
95954743 2010 return null_ptid;
bd99dc85 2011
6bf5e0ba 2012 event_child = get_thread_lwp (current_inferior);
da6d8c04 2013
0d62e5e8
DJ
2014 /* If we are waiting for a particular child, and it exited,
2015 linux_wait_for_event will return its exit status. Similarly if
2016 the last child exited. If this is not the last child, however,
2017 do not report it as exited until there is a 'thread exited' response
2018 available in the remote protocol. Instead, just wait for another event.
2019 This should be safe, because if the thread crashed we will already
2020 have reported the termination signal to GDB; that should stop any
2021 in-progress stepping operations, etc.
2022
2023 Report the exit status of the last thread to exit. This matches
2024 LinuxThreads' behavior. */
2025
95954743 2026 if (last_thread_of_process_p (current_inferior))
da6d8c04 2027 {
bd99dc85 2028 if (WIFEXITED (w) || WIFSIGNALED (w))
0d62e5e8 2029 {
bd99dc85
PA
2030 if (WIFEXITED (w))
2031 {
2032 ourstatus->kind = TARGET_WAITKIND_EXITED;
2033 ourstatus->value.integer = WEXITSTATUS (w);
2034
2035 if (debug_threads)
2036 fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
2037 }
2038 else
2039 {
2040 ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
2041 ourstatus->value.sig = target_signal_from_host (WTERMSIG (w));
2042
2043 if (debug_threads)
2044 fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
2045
2046 }
5b1c542e 2047
3e4c1235 2048 return ptid_of (event_child);
0d62e5e8 2049 }
da6d8c04 2050 }
0d62e5e8 2051 else
da6d8c04 2052 {
0d62e5e8
DJ
2053 if (!WIFSTOPPED (w))
2054 goto retry;
da6d8c04
DJ
2055 }
2056
6bf5e0ba
PA
2057 /* If this event was not handled before, and is not a SIGTRAP, we
2058 report it. SIGILL and SIGSEGV are also treated as traps in case
2059 a breakpoint is inserted at the current PC. If this target does
2060 not support internal breakpoints at all, we also report the
2061 SIGTRAP without further processing; it's of no concern to us. */
2062 maybe_internal_trap
2063 = (supports_breakpoints ()
2064 && (WSTOPSIG (w) == SIGTRAP
2065 || ((WSTOPSIG (w) == SIGILL
2066 || WSTOPSIG (w) == SIGSEGV)
2067 && (*the_low_target.breakpoint_at) (event_child->stop_pc))));
2068
2069 if (maybe_internal_trap)
2070 {
2071 /* Handle anything that requires bookkeeping before deciding to
2072 report the event or continue waiting. */
2073
2074 /* First check if we can explain the SIGTRAP with an internal
2075 breakpoint, or if we should possibly report the event to GDB.
2076 Do this before anything that may remove or insert a
2077 breakpoint. */
2078 bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc);
2079
2080 /* We have a SIGTRAP, possibly a step-over dance has just
2081 finished. If so, tweak the state machine accordingly,
2082 reinsert breakpoints and delete any reinsert (software
2083 single-step) breakpoints. */
2084 step_over_finished = finish_step_over (event_child);
2085
2086 /* Now invoke the callbacks of any internal breakpoints there. */
2087 check_breakpoints (event_child->stop_pc);
2088
219f2f23
PA
2089 /* Handle tracepoint data collecting. This may overflow the
2090 trace buffer, and cause a tracing stop, removing
2091 breakpoints. */
2092 trace_event = handle_tracepoints (event_child);
2093
6bf5e0ba
PA
2094 if (bp_explains_trap)
2095 {
2096 /* If we stepped or ran into an internal breakpoint, we've
2097 already handled it. So next time we resume (from this
2098 PC), we should step over it. */
2099 if (debug_threads)
2100 fprintf (stderr, "Hit a gdbserver breakpoint.\n");
2101
8b07ae33
PA
2102 if (breakpoint_here (event_child->stop_pc))
2103 event_child->need_step_over = 1;
6bf5e0ba
PA
2104 }
2105 }
2106 else
2107 {
2108 /* We have some other signal, possibly a step-over dance was in
2109 progress, and it should be cancelled too. */
2110 step_over_finished = finish_step_over (event_child);
fa593d66
PA
2111 }
2112
2113 /* We have all the data we need. Either report the event to GDB, or
2114 resume threads and keep waiting for more. */
2115
2116 /* If we're collecting a fast tracepoint, finish the collection and
2117 move out of the jump pad before delivering a signal. See
2118 linux_stabilize_threads. */
2119
2120 if (WIFSTOPPED (w)
2121 && WSTOPSIG (w) != SIGTRAP
2122 && supports_fast_tracepoints ()
2123 && in_process_agent_loaded ())
2124 {
2125 if (debug_threads)
2126 fprintf (stderr,
2127 "Got signal %d for LWP %ld. Check if we need "
2128 "to defer or adjust it.\n",
2129 WSTOPSIG (w), lwpid_of (event_child));
2130
2131 /* Allow debugging the jump pad itself. */
2132 if (current_inferior->last_resume_kind != resume_step
2133 && maybe_move_out_of_jump_pad (event_child, &w))
2134 {
2135 enqueue_one_deferred_signal (event_child, &w);
2136
2137 if (debug_threads)
2138 fprintf (stderr,
2139 "Signal %d for LWP %ld deferred (in jump pad)\n",
2140 WSTOPSIG (w), lwpid_of (event_child));
2141
2142 linux_resume_one_lwp (event_child, 0, 0, NULL);
2143 goto retry;
2144 }
2145 }
219f2f23 2146
fa593d66
PA
2147 if (event_child->collecting_fast_tracepoint)
2148 {
2149 if (debug_threads)
2150 fprintf (stderr, "\
2151LWP %ld was trying to move out of the jump pad (%d). \
2152Check if we're already there.\n",
2153 lwpid_of (event_child),
2154 event_child->collecting_fast_tracepoint);
2155
2156 trace_event = 1;
2157
2158 event_child->collecting_fast_tracepoint
2159 = linux_fast_tracepoint_collecting (event_child, NULL);
2160
2161 if (event_child->collecting_fast_tracepoint != 1)
2162 {
2163 /* No longer need this breakpoint. */
2164 if (event_child->exit_jump_pad_bkpt != NULL)
2165 {
2166 if (debug_threads)
2167 fprintf (stderr,
2168 "No longer need exit-jump-pad bkpt; removing it."
2169 "stopping all threads momentarily.\n");
2170
2171 /* Other running threads could hit this breakpoint.
2172 We don't handle moribund locations like GDB does,
2173 instead we always pause all threads when removing
2174 breakpoints, so that any step-over or
2175 decr_pc_after_break adjustment is always taken
2176 care of while the breakpoint is still
2177 inserted. */
2178 stop_all_lwps (1, event_child);
2179 cancel_breakpoints ();
2180
2181 delete_breakpoint (event_child->exit_jump_pad_bkpt);
2182 event_child->exit_jump_pad_bkpt = NULL;
2183
2184 unstop_all_lwps (1, event_child);
2185
2186 gdb_assert (event_child->suspended >= 0);
2187 }
2188 }
2189
2190 if (event_child->collecting_fast_tracepoint == 0)
2191 {
2192 if (debug_threads)
2193 fprintf (stderr,
2194 "fast tracepoint finished "
2195 "collecting successfully.\n");
2196
2197 /* We may have a deferred signal to report. */
2198 if (dequeue_one_deferred_signal (event_child, &w))
2199 {
2200 if (debug_threads)
2201 fprintf (stderr, "dequeued one signal.\n");
2202 }
2203 else if (debug_threads)
2204 {
2205 fprintf (stderr, "no deferred signals.\n");
2206
2207 if (stabilizing_threads)
2208 {
2209 ourstatus->kind = TARGET_WAITKIND_STOPPED;
2210 ourstatus->value.sig = TARGET_SIGNAL_0;
2211 return ptid_of (event_child);
2212 }
2213 }
2214 }
6bf5e0ba
PA
2215 }
2216
e471f25b
PA
2217 /* Check whether GDB would be interested in this event. */
2218
2219 /* If GDB is not interested in this signal, don't stop other
2220 threads, and don't report it to GDB. Just resume the inferior
2221 right away. We do this for threading-related signals as well as
2222 any that GDB specifically requested we ignore. But never ignore
2223 SIGSTOP if we sent it ourselves, and do not ignore signals when
2224 stepping - they may require special handling to skip the signal
2225 handler. */
2226 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
2227 thread library? */
2228 if (WIFSTOPPED (w)
2229 && current_inferior->last_resume_kind != resume_step
2230 && (
2231#if defined (USE_THREAD_DB) && defined (__SIGRTMIN)
2232 (current_process ()->private->thread_db != NULL
2233 && (WSTOPSIG (w) == __SIGRTMIN
2234 || WSTOPSIG (w) == __SIGRTMIN + 1))
2235 ||
2236#endif
2237 (pass_signals[target_signal_from_host (WSTOPSIG (w))]
2238 && !(WSTOPSIG (w) == SIGSTOP
2239 && current_inferior->last_resume_kind == resume_stop))))
2240 {
2241 siginfo_t info, *info_p;
2242
2243 if (debug_threads)
2244 fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
2245 WSTOPSIG (w), lwpid_of (event_child));
2246
2247 if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0)
2248 info_p = &info;
2249 else
2250 info_p = NULL;
2251 linux_resume_one_lwp (event_child, event_child->stepping,
2252 WSTOPSIG (w), info_p);
2253 goto retry;
2254 }
2255
2256 /* If GDB wanted this thread to single step, we always want to
2257 report the SIGTRAP, and let GDB handle it. Watchpoints should
2258 always be reported. So should signals we can't explain. A
2259 SIGTRAP we can't explain could be a GDB breakpoint --- we may or
2260 not support Z0 breakpoints. If we do, we're be able to handle
2261 GDB breakpoints on top of internal breakpoints, by handling the
2262 internal breakpoint and still reporting the event to GDB. If we
2263 don't, we're out of luck, GDB won't see the breakpoint hit. */
6bf5e0ba 2264 report_to_gdb = (!maybe_internal_trap
8336d594 2265 || current_inferior->last_resume_kind == resume_step
6bf5e0ba 2266 || event_child->stopped_by_watchpoint
219f2f23 2267 || (!step_over_finished && !bp_explains_trap && !trace_event)
8b07ae33 2268 || gdb_breakpoint_here (event_child->stop_pc));
6bf5e0ba
PA
2269
2270 /* We found no reason GDB would want us to stop. We either hit one
2271 of our own breakpoints, or finished an internal step GDB
2272 shouldn't know about. */
2273 if (!report_to_gdb)
2274 {
2275 if (debug_threads)
2276 {
2277 if (bp_explains_trap)
2278 fprintf (stderr, "Hit a gdbserver breakpoint.\n");
2279 if (step_over_finished)
2280 fprintf (stderr, "Step-over finished.\n");
219f2f23
PA
2281 if (trace_event)
2282 fprintf (stderr, "Tracepoint event.\n");
6bf5e0ba
PA
2283 }
2284
2285 /* We're not reporting this breakpoint to GDB, so apply the
2286 decr_pc_after_break adjustment to the inferior's regcache
2287 ourselves. */
2288
2289 if (the_low_target.set_pc != NULL)
2290 {
2291 struct regcache *regcache
2292 = get_thread_regcache (get_lwp_thread (event_child), 1);
2293 (*the_low_target.set_pc) (regcache, event_child->stop_pc);
2294 }
2295
7984d532
PA
2296 /* We may have finished stepping over a breakpoint. If so,
2297 we've stopped and suspended all LWPs momentarily except the
2298 stepping one. This is where we resume them all again. We're
2299 going to keep waiting, so use proceed, which handles stepping
2300 over the next breakpoint. */
6bf5e0ba
PA
2301 if (debug_threads)
2302 fprintf (stderr, "proceeding all threads.\n");
7984d532
PA
2303
2304 if (step_over_finished)
2305 unsuspend_all_lwps (event_child);
2306
6bf5e0ba
PA
2307 proceed_all_lwps ();
2308 goto retry;
2309 }
2310
2311 if (debug_threads)
2312 {
8336d594 2313 if (current_inferior->last_resume_kind == resume_step)
6bf5e0ba
PA
2314 fprintf (stderr, "GDB wanted to single-step, reporting event.\n");
2315 if (event_child->stopped_by_watchpoint)
2316 fprintf (stderr, "Stopped by watchpoint.\n");
8b07ae33
PA
2317 if (gdb_breakpoint_here (event_child->stop_pc))
2318 fprintf (stderr, "Stopped by GDB breakpoint.\n");
6bf5e0ba
PA
2319 if (debug_threads)
2320 fprintf (stderr, "Hit a non-gdbserver trap event.\n");
2321 }
2322
2323 /* Alright, we're going to report a stop. */
2324
fa593d66 2325 if (!non_stop && !stabilizing_threads)
6bf5e0ba
PA
2326 {
2327 /* In all-stop, stop all threads. */
7984d532 2328 stop_all_lwps (0, NULL);
6bf5e0ba
PA
2329
2330 /* If we're not waiting for a specific LWP, choose an event LWP
2331 from among those that have had events. Giving equal priority
2332 to all LWPs that have had events helps prevent
2333 starvation. */
2334 if (ptid_equal (ptid, minus_one_ptid))
2335 {
2336 event_child->status_pending_p = 1;
2337 event_child->status_pending = w;
2338
2339 select_event_lwp (&event_child);
2340
2341 event_child->status_pending_p = 0;
2342 w = event_child->status_pending;
2343 }
2344
2345 /* Now that we've selected our final event LWP, cancel any
2346 breakpoints in other LWPs that have hit a GDB breakpoint.
2347 See the comment in cancel_breakpoints_callback to find out
2348 why. */
2349 find_inferior (&all_lwps, cancel_breakpoints_callback, event_child);
fa593d66
PA
2350
2351 /* Stabilize threads (move out of jump pads). */
2352 stabilize_threads ();
6bf5e0ba
PA
2353 }
2354 else
2355 {
2356 /* If we just finished a step-over, then all threads had been
2357 momentarily paused. In all-stop, that's fine, we want
2358 threads stopped by now anyway. In non-stop, we need to
2359 re-resume threads that GDB wanted to be running. */
2360 if (step_over_finished)
7984d532 2361 unstop_all_lwps (1, event_child);
6bf5e0ba
PA
2362 }
2363
5b1c542e 2364 ourstatus->kind = TARGET_WAITKIND_STOPPED;
5b1c542e 2365
8336d594
PA
2366 if (current_inferior->last_resume_kind == resume_stop
2367 && WSTOPSIG (w) == SIGSTOP)
bd99dc85
PA
2368 {
2369 /* A thread that has been requested to stop by GDB with vCont;t,
2370 and it stopped cleanly, so report as SIG0. The use of
2371 SIGSTOP is an implementation detail. */
2372 ourstatus->value.sig = TARGET_SIGNAL_0;
2373 }
8336d594
PA
2374 else if (current_inferior->last_resume_kind == resume_stop
2375 && WSTOPSIG (w) != SIGSTOP)
bd99dc85
PA
2376 {
2377 /* A thread that has been requested to stop by GDB with vCont;t,
d50171e4 2378 but, it stopped for other reasons. */
bd99dc85
PA
2379 ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
2380 }
2381 else
2382 {
2383 ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
2384 }
2385
d50171e4
PA
2386 gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
2387
bd99dc85 2388 if (debug_threads)
95954743 2389 fprintf (stderr, "linux_wait ret = %s, %d, %d\n",
6bf5e0ba 2390 target_pid_to_str (ptid_of (event_child)),
bd99dc85
PA
2391 ourstatus->kind,
2392 ourstatus->value.sig);
2393
1971b033
PA
2394 if (!stabilizing_threads)
2395 current_inferior->last_status = *ourstatus;
7984d532 2396
6bf5e0ba 2397 return ptid_of (event_child);
bd99dc85
PA
2398}
2399
2400/* Get rid of any pending event in the pipe. */
2401static void
2402async_file_flush (void)
2403{
2404 int ret;
2405 char buf;
2406
2407 do
2408 ret = read (linux_event_pipe[0], &buf, 1);
2409 while (ret >= 0 || (ret == -1 && errno == EINTR));
2410}
2411
2412/* Put something in the pipe, so the event loop wakes up. */
2413static void
2414async_file_mark (void)
2415{
2416 int ret;
2417
2418 async_file_flush ();
2419
2420 do
2421 ret = write (linux_event_pipe[1], "+", 1);
2422 while (ret == 0 || (ret == -1 && errno == EINTR));
2423
2424 /* Ignore EAGAIN. If the pipe is full, the event loop will already
2425 be awakened anyway. */
2426}
2427
95954743
PA
2428static ptid_t
2429linux_wait (ptid_t ptid,
2430 struct target_waitstatus *ourstatus, int target_options)
bd99dc85 2431{
95954743 2432 ptid_t event_ptid;
bd99dc85
PA
2433
2434 if (debug_threads)
95954743 2435 fprintf (stderr, "linux_wait: [%s]\n", target_pid_to_str (ptid));
bd99dc85
PA
2436
2437 /* Flush the async file first. */
2438 if (target_is_async_p ())
2439 async_file_flush ();
2440
95954743 2441 event_ptid = linux_wait_1 (ptid, ourstatus, target_options);
bd99dc85
PA
2442
2443 /* If at least one stop was reported, there may be more. A single
2444 SIGCHLD can signal more than one child stop. */
2445 if (target_is_async_p ()
2446 && (target_options & TARGET_WNOHANG) != 0
95954743 2447 && !ptid_equal (event_ptid, null_ptid))
bd99dc85
PA
2448 async_file_mark ();
2449
2450 return event_ptid;
da6d8c04
DJ
2451}
2452
c5f62d5f 2453/* Send a signal to an LWP. */
fd500816
DJ
2454
2455static int
a1928bad 2456kill_lwp (unsigned long lwpid, int signo)
fd500816 2457{
c5f62d5f
DE
2458 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2459 fails, then we are not using nptl threads and we should be using kill. */
fd500816 2460
c5f62d5f
DE
2461#ifdef __NR_tkill
2462 {
2463 static int tkill_failed;
fd500816 2464
c5f62d5f
DE
2465 if (!tkill_failed)
2466 {
2467 int ret;
2468
2469 errno = 0;
2470 ret = syscall (__NR_tkill, lwpid, signo);
2471 if (errno != ENOSYS)
2472 return ret;
2473 tkill_failed = 1;
2474 }
2475 }
fd500816
DJ
2476#endif
2477
2478 return kill (lwpid, signo);
2479}
2480
0d62e5e8 2481static void
02fc4de7 2482send_sigstop (struct lwp_info *lwp)
0d62e5e8 2483{
bd99dc85 2484 int pid;
0d62e5e8 2485
bd99dc85
PA
2486 pid = lwpid_of (lwp);
2487
0d62e5e8
DJ
2488 /* If we already have a pending stop signal for this process, don't
2489 send another. */
54a0b537 2490 if (lwp->stop_expected)
0d62e5e8 2491 {
ae13219e 2492 if (debug_threads)
bd99dc85 2493 fprintf (stderr, "Have pending sigstop for lwp %d\n", pid);
ae13219e 2494
0d62e5e8
DJ
2495 return;
2496 }
2497
2498 if (debug_threads)
bd99dc85 2499 fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
0d62e5e8 2500
d50171e4 2501 lwp->stop_expected = 1;
bd99dc85 2502 kill_lwp (pid, SIGSTOP);
0d62e5e8
DJ
2503}
2504
7984d532
PA
2505static int
2506send_sigstop_callback (struct inferior_list_entry *entry, void *except)
02fc4de7
PA
2507{
2508 struct lwp_info *lwp = (struct lwp_info *) entry;
2509
7984d532
PA
2510 /* Ignore EXCEPT. */
2511 if (lwp == except)
2512 return 0;
2513
02fc4de7 2514 if (lwp->stopped)
7984d532 2515 return 0;
02fc4de7
PA
2516
2517 send_sigstop (lwp);
7984d532
PA
2518 return 0;
2519}
2520
2521/* Increment the suspend count of an LWP, and stop it, if not stopped
2522 yet. */
2523static int
2524suspend_and_send_sigstop_callback (struct inferior_list_entry *entry,
2525 void *except)
2526{
2527 struct lwp_info *lwp = (struct lwp_info *) entry;
2528
2529 /* Ignore EXCEPT. */
2530 if (lwp == except)
2531 return 0;
2532
2533 lwp->suspended++;
2534
2535 return send_sigstop_callback (entry, except);
02fc4de7
PA
2536}
2537
95954743
PA
2538static void
2539mark_lwp_dead (struct lwp_info *lwp, int wstat)
2540{
2541 /* It's dead, really. */
2542 lwp->dead = 1;
2543
2544 /* Store the exit status for later. */
2545 lwp->status_pending_p = 1;
2546 lwp->status_pending = wstat;
2547
95954743
PA
2548 /* Prevent trying to stop it. */
2549 lwp->stopped = 1;
2550
2551 /* No further stops are expected from a dead lwp. */
2552 lwp->stop_expected = 0;
2553}
2554
0d62e5e8
DJ
2555static void
2556wait_for_sigstop (struct inferior_list_entry *entry)
2557{
54a0b537 2558 struct lwp_info *lwp = (struct lwp_info *) entry;
bd99dc85 2559 struct thread_info *saved_inferior;
a1928bad 2560 int wstat;
95954743
PA
2561 ptid_t saved_tid;
2562 ptid_t ptid;
d50171e4 2563 int pid;
0d62e5e8 2564
54a0b537 2565 if (lwp->stopped)
d50171e4
PA
2566 {
2567 if (debug_threads)
2568 fprintf (stderr, "wait_for_sigstop: LWP %ld already stopped\n",
2569 lwpid_of (lwp));
2570 return;
2571 }
0d62e5e8
DJ
2572
2573 saved_inferior = current_inferior;
bd99dc85
PA
2574 if (saved_inferior != NULL)
2575 saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
2576 else
95954743 2577 saved_tid = null_ptid; /* avoid bogus unused warning */
bd99dc85 2578
95954743 2579 ptid = lwp->head.id;
bd99dc85 2580
d50171e4
PA
2581 if (debug_threads)
2582 fprintf (stderr, "wait_for_sigstop: pulling one event\n");
2583
2584 pid = linux_wait_for_event (ptid, &wstat, __WALL);
0d62e5e8
DJ
2585
2586 /* If we stopped with a non-SIGSTOP signal, save it for later
2587 and record the pending SIGSTOP. If the process exited, just
2588 return. */
d50171e4 2589 if (WIFSTOPPED (wstat))
0d62e5e8
DJ
2590 {
2591 if (debug_threads)
d50171e4
PA
2592 fprintf (stderr, "LWP %ld stopped with signal %d\n",
2593 lwpid_of (lwp), WSTOPSIG (wstat));
c35fafde 2594
d50171e4 2595 if (WSTOPSIG (wstat) != SIGSTOP)
c35fafde
PA
2596 {
2597 if (debug_threads)
d50171e4
PA
2598 fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
2599 lwpid_of (lwp), wstat);
2600
c35fafde
PA
2601 lwp->status_pending_p = 1;
2602 lwp->status_pending = wstat;
2603 }
0d62e5e8 2604 }
d50171e4 2605 else
95954743
PA
2606 {
2607 if (debug_threads)
d50171e4 2608 fprintf (stderr, "Process %d exited while stopping LWPs\n", pid);
95954743 2609
d50171e4
PA
2610 lwp = find_lwp_pid (pid_to_ptid (pid));
2611 if (lwp)
2612 {
2613 /* Leave this status pending for the next time we're able to
2614 report it. In the mean time, we'll report this lwp as
2615 dead to GDB, so GDB doesn't try to read registers and
2616 memory from it. This can only happen if this was the
2617 last thread of the process; otherwise, PID is removed
2618 from the thread tables before linux_wait_for_event
2619 returns. */
2620 mark_lwp_dead (lwp, wstat);
2621 }
95954743 2622 }
0d62e5e8 2623
bd99dc85 2624 if (saved_inferior == NULL || linux_thread_alive (saved_tid))
0d62e5e8
DJ
2625 current_inferior = saved_inferior;
2626 else
2627 {
2628 if (debug_threads)
2629 fprintf (stderr, "Previously current thread died.\n");
2630
bd99dc85
PA
2631 if (non_stop)
2632 {
2633 /* We can't change the current inferior behind GDB's back,
2634 otherwise, a subsequent command may apply to the wrong
2635 process. */
2636 current_inferior = NULL;
2637 }
2638 else
2639 {
2640 /* Set a valid thread as current. */
2641 set_desired_inferior (0);
2642 }
0d62e5e8
DJ
2643 }
2644}
2645
fa593d66
PA
2646/* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
2647 move it out, because we need to report the stop event to GDB. For
2648 example, if the user puts a breakpoint in the jump pad, it's
2649 because she wants to debug it. */
2650
2651static int
2652stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data)
2653{
2654 struct lwp_info *lwp = (struct lwp_info *) entry;
2655 struct thread_info *thread = get_lwp_thread (lwp);
2656
2657 gdb_assert (lwp->suspended == 0);
2658 gdb_assert (lwp->stopped);
2659
2660 /* Allow debugging the jump pad, gdb_collect, etc.. */
2661 return (supports_fast_tracepoints ()
2662 && in_process_agent_loaded ()
2663 && (gdb_breakpoint_here (lwp->stop_pc)
2664 || lwp->stopped_by_watchpoint
2665 || thread->last_resume_kind == resume_step)
2666 && linux_fast_tracepoint_collecting (lwp, NULL));
2667}
2668
2669static void
2670move_out_of_jump_pad_callback (struct inferior_list_entry *entry)
2671{
2672 struct lwp_info *lwp = (struct lwp_info *) entry;
2673 struct thread_info *thread = get_lwp_thread (lwp);
2674 int *wstat;
2675
2676 gdb_assert (lwp->suspended == 0);
2677 gdb_assert (lwp->stopped);
2678
2679 wstat = lwp->status_pending_p ? &lwp->status_pending : NULL;
2680
2681 /* Allow debugging the jump pad, gdb_collect, etc. */
2682 if (!gdb_breakpoint_here (lwp->stop_pc)
2683 && !lwp->stopped_by_watchpoint
2684 && thread->last_resume_kind != resume_step
2685 && maybe_move_out_of_jump_pad (lwp, wstat))
2686 {
2687 if (debug_threads)
2688 fprintf (stderr,
2689 "LWP %ld needs stabilizing (in jump pad)\n",
2690 lwpid_of (lwp));
2691
2692 if (wstat)
2693 {
2694 lwp->status_pending_p = 0;
2695 enqueue_one_deferred_signal (lwp, wstat);
2696
2697 if (debug_threads)
2698 fprintf (stderr,
2699 "Signal %d for LWP %ld deferred "
2700 "(in jump pad)\n",
2701 WSTOPSIG (*wstat), lwpid_of (lwp));
2702 }
2703
2704 linux_resume_one_lwp (lwp, 0, 0, NULL);
2705 }
2706 else
2707 lwp->suspended++;
2708}
2709
2710static int
2711lwp_running (struct inferior_list_entry *entry, void *data)
2712{
2713 struct lwp_info *lwp = (struct lwp_info *) entry;
2714
2715 if (lwp->dead)
2716 return 0;
2717 if (lwp->stopped)
2718 return 0;
2719 return 1;
2720}
2721
7984d532
PA
2722/* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
2723 If SUSPEND, then also increase the suspend count of every LWP,
2724 except EXCEPT. */
2725
0d62e5e8 2726static void
7984d532 2727stop_all_lwps (int suspend, struct lwp_info *except)
0d62e5e8
DJ
2728{
2729 stopping_threads = 1;
7984d532
PA
2730
2731 if (suspend)
2732 find_inferior (&all_lwps, suspend_and_send_sigstop_callback, except);
2733 else
2734 find_inferior (&all_lwps, send_sigstop_callback, except);
54a0b537 2735 for_each_inferior (&all_lwps, wait_for_sigstop);
0d62e5e8
DJ
2736 stopping_threads = 0;
2737}
2738
da6d8c04
DJ
2739/* Resume execution of the inferior process.
2740 If STEP is nonzero, single-step it.
2741 If SIGNAL is nonzero, give it that signal. */
2742
ce3a066d 2743static void
2acc282a 2744linux_resume_one_lwp (struct lwp_info *lwp,
54a0b537 2745 int step, int signal, siginfo_t *info)
da6d8c04 2746{
0d62e5e8 2747 struct thread_info *saved_inferior;
fa593d66 2748 int fast_tp_collecting;
0d62e5e8 2749
54a0b537 2750 if (lwp->stopped == 0)
0d62e5e8
DJ
2751 return;
2752
fa593d66
PA
2753 fast_tp_collecting = lwp->collecting_fast_tracepoint;
2754
2755 gdb_assert (!stabilizing_threads || fast_tp_collecting);
2756
219f2f23
PA
2757 /* Cancel actions that rely on GDB not changing the PC (e.g., the
2758 user used the "jump" command, or "set $pc = foo"). */
2759 if (lwp->stop_pc != get_pc (lwp))
2760 {
2761 /* Collecting 'while-stepping' actions doesn't make sense
2762 anymore. */
2763 release_while_stepping_state_list (get_lwp_thread (lwp));
2764 }
2765
0d62e5e8
DJ
2766 /* If we have pending signals or status, and a new signal, enqueue the
2767 signal. Also enqueue the signal if we are waiting to reinsert a
2768 breakpoint; it will be picked up again below. */
2769 if (signal != 0
fa593d66
PA
2770 && (lwp->status_pending_p
2771 || lwp->pending_signals != NULL
2772 || lwp->bp_reinsert != 0
2773 || fast_tp_collecting))
0d62e5e8
DJ
2774 {
2775 struct pending_signals *p_sig;
bca929d3 2776 p_sig = xmalloc (sizeof (*p_sig));
54a0b537 2777 p_sig->prev = lwp->pending_signals;
0d62e5e8 2778 p_sig->signal = signal;
32ca6d61
DJ
2779 if (info == NULL)
2780 memset (&p_sig->info, 0, sizeof (siginfo_t));
2781 else
2782 memcpy (&p_sig->info, info, sizeof (siginfo_t));
54a0b537 2783 lwp->pending_signals = p_sig;
0d62e5e8
DJ
2784 }
2785
d50171e4
PA
2786 if (lwp->status_pending_p)
2787 {
2788 if (debug_threads)
2789 fprintf (stderr, "Not resuming lwp %ld (%s, signal %d, stop %s);"
2790 " has pending status\n",
2791 lwpid_of (lwp), step ? "step" : "continue", signal,
2792 lwp->stop_expected ? "expected" : "not expected");
2793 return;
2794 }
0d62e5e8
DJ
2795
2796 saved_inferior = current_inferior;
54a0b537 2797 current_inferior = get_lwp_thread (lwp);
0d62e5e8
DJ
2798
2799 if (debug_threads)
1b3f6016 2800 fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
bd99dc85 2801 lwpid_of (lwp), step ? "step" : "continue", signal,
54a0b537 2802 lwp->stop_expected ? "expected" : "not expected");
0d62e5e8
DJ
2803
2804 /* This bit needs some thinking about. If we get a signal that
2805 we must report while a single-step reinsert is still pending,
2806 we often end up resuming the thread. It might be better to
2807 (ew) allow a stack of pending events; then we could be sure that
2808 the reinsert happened right away and not lose any signals.
2809
2810 Making this stack would also shrink the window in which breakpoints are
54a0b537 2811 uninserted (see comment in linux_wait_for_lwp) but not enough for
0d62e5e8
DJ
2812 complete correctness, so it won't solve that problem. It may be
2813 worthwhile just to solve this one, however. */
54a0b537 2814 if (lwp->bp_reinsert != 0)
0d62e5e8
DJ
2815 {
2816 if (debug_threads)
d50171e4
PA
2817 fprintf (stderr, " pending reinsert at 0x%s\n",
2818 paddress (lwp->bp_reinsert));
2819
2820 if (lwp->bp_reinsert != 0 && can_hardware_single_step ())
2821 {
fa593d66
PA
2822 if (fast_tp_collecting == 0)
2823 {
2824 if (step == 0)
2825 fprintf (stderr, "BAD - reinserting but not stepping.\n");
2826 if (lwp->suspended)
2827 fprintf (stderr, "BAD - reinserting and suspended(%d).\n",
2828 lwp->suspended);
2829 }
d50171e4
PA
2830
2831 step = 1;
2832 }
0d62e5e8
DJ
2833
2834 /* Postpone any pending signal. It was enqueued above. */
2835 signal = 0;
2836 }
2837
fa593d66
PA
2838 if (fast_tp_collecting == 1)
2839 {
2840 if (debug_threads)
2841 fprintf (stderr, "\
2842lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n",
2843 lwpid_of (lwp));
2844
2845 /* Postpone any pending signal. It was enqueued above. */
2846 signal = 0;
2847 }
2848 else if (fast_tp_collecting == 2)
2849 {
2850 if (debug_threads)
2851 fprintf (stderr, "\
2852lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n",
2853 lwpid_of (lwp));
2854
2855 if (can_hardware_single_step ())
2856 step = 1;
2857 else
2858 fatal ("moving out of jump pad single-stepping"
2859 " not implemented on this target");
2860
2861 /* Postpone any pending signal. It was enqueued above. */
2862 signal = 0;
2863 }
2864
219f2f23
PA
2865 /* If we have while-stepping actions in this thread set it stepping.
2866 If we have a signal to deliver, it may or may not be set to
2867 SIG_IGN, we don't know. Assume so, and allow collecting
2868 while-stepping into a signal handler. A possible smart thing to
2869 do would be to set an internal breakpoint at the signal return
2870 address, continue, and carry on catching this while-stepping
2871 action only when that breakpoint is hit. A future
2872 enhancement. */
2873 if (get_lwp_thread (lwp)->while_stepping != NULL
2874 && can_hardware_single_step ())
2875 {
2876 if (debug_threads)
2877 fprintf (stderr,
2878 "lwp %ld has a while-stepping action -> forcing step.\n",
2879 lwpid_of (lwp));
2880 step = 1;
2881 }
2882
aa691b87 2883 if (debug_threads && the_low_target.get_pc != NULL)
0d62e5e8 2884 {
442ea881
PA
2885 struct regcache *regcache = get_thread_regcache (current_inferior, 1);
2886 CORE_ADDR pc = (*the_low_target.get_pc) (regcache);
47c0c975 2887 fprintf (stderr, " resuming from pc 0x%lx\n", (long) pc);
0d62e5e8
DJ
2888 }
2889
fa593d66
PA
2890 /* If we have pending signals, consume one unless we are trying to
2891 reinsert a breakpoint or we're trying to finish a fast tracepoint
2892 collect. */
2893 if (lwp->pending_signals != NULL
2894 && lwp->bp_reinsert == 0
2895 && fast_tp_collecting == 0)
0d62e5e8
DJ
2896 {
2897 struct pending_signals **p_sig;
2898
54a0b537 2899 p_sig = &lwp->pending_signals;
0d62e5e8
DJ
2900 while ((*p_sig)->prev != NULL)
2901 p_sig = &(*p_sig)->prev;
2902
2903 signal = (*p_sig)->signal;
32ca6d61 2904 if ((*p_sig)->info.si_signo != 0)
bd99dc85 2905 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
32ca6d61 2906
0d62e5e8
DJ
2907 free (*p_sig);
2908 *p_sig = NULL;
2909 }
2910
aa5ca48f
DE
2911 if (the_low_target.prepare_to_resume != NULL)
2912 the_low_target.prepare_to_resume (lwp);
2913
0d62e5e8 2914 regcache_invalidate_one ((struct inferior_list_entry *)
54a0b537 2915 get_lwp_thread (lwp));
da6d8c04 2916 errno = 0;
54a0b537 2917 lwp->stopped = 0;
c3adc08c 2918 lwp->stopped_by_watchpoint = 0;
54a0b537 2919 lwp->stepping = step;
14ce3065
DE
2920 ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0,
2921 /* Coerce to a uintptr_t first to avoid potential gcc warning
2922 of coercing an 8 byte integer to a 4 byte pointer. */
2923 (PTRACE_ARG4_TYPE) (uintptr_t) signal);
0d62e5e8
DJ
2924
2925 current_inferior = saved_inferior;
da6d8c04 2926 if (errno)
3221518c
UW
2927 {
2928 /* ESRCH from ptrace either means that the thread was already
2929 running (an error) or that it is gone (a race condition). If
2930 it's gone, we will get a notification the next time we wait,
2931 so we can ignore the error. We could differentiate these
2932 two, but it's tricky without waiting; the thread still exists
2933 as a zombie, so sending it signal 0 would succeed. So just
2934 ignore ESRCH. */
2935 if (errno == ESRCH)
2936 return;
2937
2938 perror_with_name ("ptrace");
2939 }
da6d8c04
DJ
2940}
2941
2bd7c093
PA
2942struct thread_resume_array
2943{
2944 struct thread_resume *resume;
2945 size_t n;
2946};
64386c31
DJ
2947
2948/* This function is called once per thread. We look up the thread
5544ad89
DJ
2949 in RESUME_PTR, and mark the thread with a pointer to the appropriate
2950 resume request.
2951
2952 This algorithm is O(threads * resume elements), but resume elements
2953 is small (and will remain small at least until GDB supports thread
2954 suspension). */
2bd7c093
PA
2955static int
2956linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
0d62e5e8 2957{
54a0b537 2958 struct lwp_info *lwp;
64386c31 2959 struct thread_info *thread;
5544ad89 2960 int ndx;
2bd7c093 2961 struct thread_resume_array *r;
64386c31
DJ
2962
2963 thread = (struct thread_info *) entry;
54a0b537 2964 lwp = get_thread_lwp (thread);
2bd7c093 2965 r = arg;
64386c31 2966
2bd7c093 2967 for (ndx = 0; ndx < r->n; ndx++)
95954743
PA
2968 {
2969 ptid_t ptid = r->resume[ndx].thread;
2970 if (ptid_equal (ptid, minus_one_ptid)
2971 || ptid_equal (ptid, entry->id)
2972 || (ptid_is_pid (ptid)
2973 && (ptid_get_pid (ptid) == pid_of (lwp)))
2974 || (ptid_get_lwp (ptid) == -1
2975 && (ptid_get_pid (ptid) == pid_of (lwp))))
2976 {
d50171e4 2977 if (r->resume[ndx].kind == resume_stop
8336d594 2978 && thread->last_resume_kind == resume_stop)
d50171e4
PA
2979 {
2980 if (debug_threads)
2981 fprintf (stderr, "already %s LWP %ld at GDB's request\n",
2982 thread->last_status.kind == TARGET_WAITKIND_STOPPED
2983 ? "stopped"
2984 : "stopping",
2985 lwpid_of (lwp));
2986
2987 continue;
2988 }
2989
95954743 2990 lwp->resume = &r->resume[ndx];
8336d594 2991 thread->last_resume_kind = lwp->resume->kind;
fa593d66
PA
2992
2993 /* If we had a deferred signal to report, dequeue one now.
2994 This can happen if LWP gets more than one signal while
2995 trying to get out of a jump pad. */
2996 if (lwp->stopped
2997 && !lwp->status_pending_p
2998 && dequeue_one_deferred_signal (lwp, &lwp->status_pending))
2999 {
3000 lwp->status_pending_p = 1;
3001
3002 if (debug_threads)
3003 fprintf (stderr,
3004 "Dequeueing deferred signal %d for LWP %ld, "
3005 "leaving status pending.\n",
3006 WSTOPSIG (lwp->status_pending), lwpid_of (lwp));
3007 }
3008
95954743
PA
3009 return 0;
3010 }
3011 }
2bd7c093
PA
3012
3013 /* No resume action for this thread. */
3014 lwp->resume = NULL;
64386c31 3015
2bd7c093 3016 return 0;
5544ad89
DJ
3017}
3018
5544ad89 3019
bd99dc85
PA
3020/* Set *FLAG_P if this lwp has an interesting status pending. */
3021static int
3022resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
5544ad89 3023{
bd99dc85 3024 struct lwp_info *lwp = (struct lwp_info *) entry;
5544ad89 3025
bd99dc85
PA
3026 /* LWPs which will not be resumed are not interesting, because
3027 we might not wait for them next time through linux_wait. */
2bd7c093 3028 if (lwp->resume == NULL)
bd99dc85 3029 return 0;
64386c31 3030
bd99dc85 3031 if (lwp->status_pending_p)
d50171e4
PA
3032 * (int *) flag_p = 1;
3033
3034 return 0;
3035}
3036
3037/* Return 1 if this lwp that GDB wants running is stopped at an
3038 internal breakpoint that we need to step over. It assumes that any
3039 required STOP_PC adjustment has already been propagated to the
3040 inferior's regcache. */
3041
3042static int
3043need_step_over_p (struct inferior_list_entry *entry, void *dummy)
3044{
3045 struct lwp_info *lwp = (struct lwp_info *) entry;
8336d594 3046 struct thread_info *thread;
d50171e4
PA
3047 struct thread_info *saved_inferior;
3048 CORE_ADDR pc;
3049
3050 /* LWPs which will not be resumed are not interesting, because we
3051 might not wait for them next time through linux_wait. */
3052
3053 if (!lwp->stopped)
3054 {
3055 if (debug_threads)
3056 fprintf (stderr,
3057 "Need step over [LWP %ld]? Ignoring, not stopped\n",
3058 lwpid_of (lwp));
3059 return 0;
3060 }
3061
8336d594
PA
3062 thread = get_lwp_thread (lwp);
3063
3064 if (thread->last_resume_kind == resume_stop)
d50171e4
PA
3065 {
3066 if (debug_threads)
3067 fprintf (stderr,
3068 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
3069 lwpid_of (lwp));
3070 return 0;
3071 }
3072
7984d532
PA
3073 gdb_assert (lwp->suspended >= 0);
3074
3075 if (lwp->suspended)
3076 {
3077 if (debug_threads)
3078 fprintf (stderr,
3079 "Need step over [LWP %ld]? Ignoring, suspended\n",
3080 lwpid_of (lwp));
3081 return 0;
3082 }
3083
d50171e4
PA
3084 if (!lwp->need_step_over)
3085 {
3086 if (debug_threads)
3087 fprintf (stderr,
3088 "Need step over [LWP %ld]? No\n", lwpid_of (lwp));
3089 }
5544ad89 3090
bd99dc85 3091 if (lwp->status_pending_p)
d50171e4
PA
3092 {
3093 if (debug_threads)
3094 fprintf (stderr,
3095 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
3096 lwpid_of (lwp));
3097 return 0;
3098 }
3099
3100 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
3101 or we have. */
3102 pc = get_pc (lwp);
3103
3104 /* If the PC has changed since we stopped, then don't do anything,
3105 and let the breakpoint/tracepoint be hit. This happens if, for
3106 instance, GDB handled the decr_pc_after_break subtraction itself,
3107 GDB is OOL stepping this thread, or the user has issued a "jump"
3108 command, or poked thread's registers herself. */
3109 if (pc != lwp->stop_pc)
3110 {
3111 if (debug_threads)
3112 fprintf (stderr,
3113 "Need step over [LWP %ld]? Cancelling, PC was changed. "
3114 "Old stop_pc was 0x%s, PC is now 0x%s\n",
3115 lwpid_of (lwp), paddress (lwp->stop_pc), paddress (pc));
3116
3117 lwp->need_step_over = 0;
3118 return 0;
3119 }
3120
3121 saved_inferior = current_inferior;
8336d594 3122 current_inferior = thread;
d50171e4 3123
8b07ae33 3124 /* We can only step over breakpoints we know about. */
fa593d66 3125 if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc))
d50171e4 3126 {
8b07ae33
PA
3127 /* Don't step over a breakpoint that GDB expects to hit
3128 though. */
3129 if (gdb_breakpoint_here (pc))
3130 {
3131 if (debug_threads)
3132 fprintf (stderr,
3133 "Need step over [LWP %ld]? yes, but found"
3134 " GDB breakpoint at 0x%s; skipping step over\n",
3135 lwpid_of (lwp), paddress (pc));
d50171e4 3136
8b07ae33
PA
3137 current_inferior = saved_inferior;
3138 return 0;
3139 }
3140 else
3141 {
3142 if (debug_threads)
3143 fprintf (stderr,
3144 "Need step over [LWP %ld]? yes, found breakpoint at 0x%s\n",
3145 lwpid_of (lwp), paddress (pc));
d50171e4 3146
8b07ae33
PA
3147 /* We've found an lwp that needs stepping over --- return 1 so
3148 that find_inferior stops looking. */
3149 current_inferior = saved_inferior;
3150
3151 /* If the step over is cancelled, this is set again. */
3152 lwp->need_step_over = 0;
3153 return 1;
3154 }
d50171e4
PA
3155 }
3156
3157 current_inferior = saved_inferior;
3158
3159 if (debug_threads)
3160 fprintf (stderr,
3161 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
3162 lwpid_of (lwp), paddress (pc));
c6ecbae5 3163
bd99dc85 3164 return 0;
5544ad89
DJ
3165}
3166
d50171e4
PA
3167/* Start a step-over operation on LWP. When LWP stopped at a
3168 breakpoint, to make progress, we need to remove the breakpoint out
3169 of the way. If we let other threads run while we do that, they may
3170 pass by the breakpoint location and miss hitting it. To avoid
3171 that, a step-over momentarily stops all threads while LWP is
3172 single-stepped while the breakpoint is temporarily uninserted from
3173 the inferior. When the single-step finishes, we reinsert the
3174 breakpoint, and let all threads that are supposed to be running,
3175 run again.
3176
3177 On targets that don't support hardware single-step, we don't
3178 currently support full software single-stepping. Instead, we only
3179 support stepping over the thread event breakpoint, by asking the
3180 low target where to place a reinsert breakpoint. Since this
3181 routine assumes the breakpoint being stepped over is a thread event
3182 breakpoint, it usually assumes the return address of the current
3183 function is a good enough place to set the reinsert breakpoint. */
3184
3185static int
3186start_step_over (struct lwp_info *lwp)
3187{
3188 struct thread_info *saved_inferior;
3189 CORE_ADDR pc;
3190 int step;
3191
3192 if (debug_threads)
3193 fprintf (stderr,
3194 "Starting step-over on LWP %ld. Stopping all threads\n",
3195 lwpid_of (lwp));
3196
7984d532
PA
3197 stop_all_lwps (1, lwp);
3198 gdb_assert (lwp->suspended == 0);
d50171e4
PA
3199
3200 if (debug_threads)
3201 fprintf (stderr, "Done stopping all threads for step-over.\n");
3202
3203 /* Note, we should always reach here with an already adjusted PC,
3204 either by GDB (if we're resuming due to GDB's request), or by our
3205 caller, if we just finished handling an internal breakpoint GDB
3206 shouldn't care about. */
3207 pc = get_pc (lwp);
3208
3209 saved_inferior = current_inferior;
3210 current_inferior = get_lwp_thread (lwp);
3211
3212 lwp->bp_reinsert = pc;
3213 uninsert_breakpoints_at (pc);
fa593d66 3214 uninsert_fast_tracepoint_jumps_at (pc);
d50171e4
PA
3215
3216 if (can_hardware_single_step ())
3217 {
3218 step = 1;
3219 }
3220 else
3221 {
3222 CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
3223 set_reinsert_breakpoint (raddr);
3224 step = 0;
3225 }
3226
3227 current_inferior = saved_inferior;
3228
3229 linux_resume_one_lwp (lwp, step, 0, NULL);
3230
3231 /* Require next event from this LWP. */
3232 step_over_bkpt = lwp->head.id;
3233 return 1;
3234}
3235
3236/* Finish a step-over. Reinsert the breakpoint we had uninserted in
3237 start_step_over, if still there, and delete any reinsert
3238 breakpoints we've set, on non hardware single-step targets. */
3239
3240static int
3241finish_step_over (struct lwp_info *lwp)
3242{
3243 if (lwp->bp_reinsert != 0)
3244 {
3245 if (debug_threads)
3246 fprintf (stderr, "Finished step over.\n");
3247
3248 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
3249 may be no breakpoint to reinsert there by now. */
3250 reinsert_breakpoints_at (lwp->bp_reinsert);
fa593d66 3251 reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert);
d50171e4
PA
3252
3253 lwp->bp_reinsert = 0;
3254
3255 /* Delete any software-single-step reinsert breakpoints. No
3256 longer needed. We don't have to worry about other threads
3257 hitting this trap, and later not being able to explain it,
3258 because we were stepping over a breakpoint, and we hold all
3259 threads but LWP stopped while doing that. */
3260 if (!can_hardware_single_step ())
3261 delete_reinsert_breakpoints ();
3262
3263 step_over_bkpt = null_ptid;
3264 return 1;
3265 }
3266 else
3267 return 0;
3268}
3269
5544ad89
DJ
3270/* This function is called once per thread. We check the thread's resume
3271 request, which will tell us whether to resume, step, or leave the thread
bd99dc85 3272 stopped; and what signal, if any, it should be sent.
5544ad89 3273
bd99dc85
PA
3274 For threads which we aren't explicitly told otherwise, we preserve
3275 the stepping flag; this is used for stepping over gdbserver-placed
3276 breakpoints.
3277
3278 If pending_flags was set in any thread, we queue any needed
3279 signals, since we won't actually resume. We already have a pending
3280 event to report, so we don't need to preserve any step requests;
3281 they should be re-issued if necessary. */
3282
3283static int
3284linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
5544ad89 3285{
54a0b537 3286 struct lwp_info *lwp;
5544ad89 3287 struct thread_info *thread;
bd99dc85 3288 int step;
d50171e4
PA
3289 int leave_all_stopped = * (int *) arg;
3290 int leave_pending;
5544ad89
DJ
3291
3292 thread = (struct thread_info *) entry;
54a0b537 3293 lwp = get_thread_lwp (thread);
5544ad89 3294
2bd7c093 3295 if (lwp->resume == NULL)
bd99dc85 3296 return 0;
5544ad89 3297
bd99dc85 3298 if (lwp->resume->kind == resume_stop)
5544ad89 3299 {
bd99dc85 3300 if (debug_threads)
d50171e4 3301 fprintf (stderr, "resume_stop request for LWP %ld\n", lwpid_of (lwp));
bd99dc85
PA
3302
3303 if (!lwp->stopped)
3304 {
3305 if (debug_threads)
d50171e4 3306 fprintf (stderr, "stopping LWP %ld\n", lwpid_of (lwp));
bd99dc85 3307
d50171e4
PA
3308 /* Stop the thread, and wait for the event asynchronously,
3309 through the event loop. */
02fc4de7 3310 send_sigstop (lwp);
bd99dc85
PA
3311 }
3312 else
3313 {
3314 if (debug_threads)
d50171e4
PA
3315 fprintf (stderr, "already stopped LWP %ld\n",
3316 lwpid_of (lwp));
3317
3318 /* The LWP may have been stopped in an internal event that
3319 was not meant to be notified back to GDB (e.g., gdbserver
3320 breakpoint), so we should be reporting a stop event in
3321 this case too. */
3322
3323 /* If the thread already has a pending SIGSTOP, this is a
3324 no-op. Otherwise, something later will presumably resume
3325 the thread and this will cause it to cancel any pending
3326 operation, due to last_resume_kind == resume_stop. If
3327 the thread already has a pending status to report, we
3328 will still report it the next time we wait - see
3329 status_pending_p_callback. */
02fc4de7 3330 send_sigstop (lwp);
bd99dc85 3331 }
32ca6d61 3332
bd99dc85
PA
3333 /* For stop requests, we're done. */
3334 lwp->resume = NULL;
fc7238bb 3335 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
bd99dc85 3336 return 0;
5544ad89
DJ
3337 }
3338
bd99dc85
PA
3339 /* If this thread which is about to be resumed has a pending status,
3340 then don't resume any threads - we can just report the pending
3341 status. Make sure to queue any signals that would otherwise be
3342 sent. In all-stop mode, we do this decision based on if *any*
d50171e4
PA
3343 thread has a pending status. If there's a thread that needs the
3344 step-over-breakpoint dance, then don't resume any other thread
3345 but that particular one. */
3346 leave_pending = (lwp->status_pending_p || leave_all_stopped);
5544ad89 3347
d50171e4 3348 if (!leave_pending)
bd99dc85
PA
3349 {
3350 if (debug_threads)
3351 fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp));
5544ad89 3352
d50171e4 3353 step = (lwp->resume->kind == resume_step);
2acc282a 3354 linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
bd99dc85
PA
3355 }
3356 else
3357 {
3358 if (debug_threads)
3359 fprintf (stderr, "leaving LWP %ld stopped\n", lwpid_of (lwp));
5544ad89 3360
bd99dc85
PA
3361 /* If we have a new signal, enqueue the signal. */
3362 if (lwp->resume->sig != 0)
3363 {
3364 struct pending_signals *p_sig;
3365 p_sig = xmalloc (sizeof (*p_sig));
3366 p_sig->prev = lwp->pending_signals;
3367 p_sig->signal = lwp->resume->sig;
3368 memset (&p_sig->info, 0, sizeof (siginfo_t));
3369
3370 /* If this is the same signal we were previously stopped by,
3371 make sure to queue its siginfo. We can ignore the return
3372 value of ptrace; if it fails, we'll skip
3373 PTRACE_SETSIGINFO. */
3374 if (WIFSTOPPED (lwp->last_status)
3375 && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
3376 ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
3377
3378 lwp->pending_signals = p_sig;
3379 }
3380 }
5544ad89 3381
fc7238bb 3382 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
bd99dc85 3383 lwp->resume = NULL;
5544ad89 3384 return 0;
0d62e5e8
DJ
3385}
3386
3387static void
2bd7c093 3388linux_resume (struct thread_resume *resume_info, size_t n)
0d62e5e8 3389{
2bd7c093 3390 struct thread_resume_array array = { resume_info, n };
d50171e4
PA
3391 struct lwp_info *need_step_over = NULL;
3392 int any_pending;
3393 int leave_all_stopped;
c6ecbae5 3394
2bd7c093 3395 find_inferior (&all_threads, linux_set_resume_request, &array);
5544ad89 3396
d50171e4
PA
3397 /* If there is a thread which would otherwise be resumed, which has
3398 a pending status, then don't resume any threads - we can just
3399 report the pending status. Make sure to queue any signals that
3400 would otherwise be sent. In non-stop mode, we'll apply this
3401 logic to each thread individually. We consume all pending events
3402 before considering to start a step-over (in all-stop). */
3403 any_pending = 0;
bd99dc85 3404 if (!non_stop)
d50171e4
PA
3405 find_inferior (&all_lwps, resume_status_pending_p, &any_pending);
3406
3407 /* If there is a thread which would otherwise be resumed, which is
3408 stopped at a breakpoint that needs stepping over, then don't
3409 resume any threads - have it step over the breakpoint with all
3410 other threads stopped, then resume all threads again. Make sure
3411 to queue any signals that would otherwise be delivered or
3412 queued. */
3413 if (!any_pending && supports_breakpoints ())
3414 need_step_over
3415 = (struct lwp_info *) find_inferior (&all_lwps,
3416 need_step_over_p, NULL);
3417
3418 leave_all_stopped = (need_step_over != NULL || any_pending);
3419
3420 if (debug_threads)
3421 {
3422 if (need_step_over != NULL)
3423 fprintf (stderr, "Not resuming all, need step over\n");
3424 else if (any_pending)
3425 fprintf (stderr,
3426 "Not resuming, all-stop and found "
3427 "an LWP with pending status\n");
3428 else
3429 fprintf (stderr, "Resuming, no pending status or step over needed\n");
3430 }
3431
3432 /* Even if we're leaving threads stopped, queue all signals we'd
3433 otherwise deliver. */
3434 find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped);
3435
3436 if (need_step_over)
3437 start_step_over (need_step_over);
3438}
3439
3440/* This function is called once per thread. We check the thread's
3441 last resume request, which will tell us whether to resume, step, or
3442 leave the thread stopped. Any signal the client requested to be
3443 delivered has already been enqueued at this point.
3444
3445 If any thread that GDB wants running is stopped at an internal
3446 breakpoint that needs stepping over, we start a step-over operation
3447 on that particular thread, and leave all others stopped. */
3448
7984d532
PA
3449static int
3450proceed_one_lwp (struct inferior_list_entry *entry, void *except)
d50171e4 3451{
7984d532 3452 struct lwp_info *lwp = (struct lwp_info *) entry;
8336d594 3453 struct thread_info *thread;
d50171e4
PA
3454 int step;
3455
7984d532
PA
3456 if (lwp == except)
3457 return 0;
d50171e4
PA
3458
3459 if (debug_threads)
3460 fprintf (stderr,
3461 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp));
3462
3463 if (!lwp->stopped)
3464 {
3465 if (debug_threads)
3466 fprintf (stderr, " LWP %ld already running\n", lwpid_of (lwp));
7984d532 3467 return 0;
d50171e4
PA
3468 }
3469
8336d594
PA
3470 thread = get_lwp_thread (lwp);
3471
02fc4de7
PA
3472 if (thread->last_resume_kind == resume_stop
3473 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
d50171e4
PA
3474 {
3475 if (debug_threads)
02fc4de7
PA
3476 fprintf (stderr, " client wants LWP to remain %ld stopped\n",
3477 lwpid_of (lwp));
7984d532 3478 return 0;
d50171e4
PA
3479 }
3480
3481 if (lwp->status_pending_p)
3482 {
3483 if (debug_threads)
3484 fprintf (stderr, " LWP %ld has pending status, leaving stopped\n",
3485 lwpid_of (lwp));
7984d532 3486 return 0;
d50171e4
PA
3487 }
3488
7984d532
PA
3489 gdb_assert (lwp->suspended >= 0);
3490
d50171e4
PA
3491 if (lwp->suspended)
3492 {
3493 if (debug_threads)
3494 fprintf (stderr, " LWP %ld is suspended\n", lwpid_of (lwp));
7984d532 3495 return 0;
d50171e4
PA
3496 }
3497
02fc4de7
PA
3498 if (thread->last_resume_kind == resume_stop)
3499 {
3500 /* We haven't reported this LWP as stopped yet (otherwise, the
3501 last_status.kind check above would catch it, and we wouldn't
3502 reach here. This LWP may have been momentarily paused by a
3503 stop_all_lwps call while handling for example, another LWP's
3504 step-over. In that case, the pending expected SIGSTOP signal
3505 that was queued at vCont;t handling time will have already
3506 been consumed by wait_for_sigstop, and so we need to requeue
3507 another one here. Note that if the LWP already has a SIGSTOP
3508 pending, this is a no-op. */
3509
3510 if (debug_threads)
3511 fprintf (stderr,
3512 "Client wants LWP %ld to stop. "
3513 "Making sure it has a SIGSTOP pending\n",
3514 lwpid_of (lwp));
3515
3516 send_sigstop (lwp);
3517 }
3518
8336d594 3519 step = thread->last_resume_kind == resume_step;
d50171e4 3520 linux_resume_one_lwp (lwp, step, 0, NULL);
7984d532
PA
3521 return 0;
3522}
3523
3524static int
3525unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except)
3526{
3527 struct lwp_info *lwp = (struct lwp_info *) entry;
3528
3529 if (lwp == except)
3530 return 0;
3531
3532 lwp->suspended--;
3533 gdb_assert (lwp->suspended >= 0);
3534
3535 return proceed_one_lwp (entry, except);
d50171e4
PA
3536}
3537
3538/* When we finish a step-over, set threads running again. If there's
3539 another thread that may need a step-over, now's the time to start
3540 it. Eventually, we'll move all threads past their breakpoints. */
3541
3542static void
3543proceed_all_lwps (void)
3544{
3545 struct lwp_info *need_step_over;
3546
3547 /* If there is a thread which would otherwise be resumed, which is
3548 stopped at a breakpoint that needs stepping over, then don't
3549 resume any threads - have it step over the breakpoint with all
3550 other threads stopped, then resume all threads again. */
3551
3552 if (supports_breakpoints ())
3553 {
3554 need_step_over
3555 = (struct lwp_info *) find_inferior (&all_lwps,
3556 need_step_over_p, NULL);
3557
3558 if (need_step_over != NULL)
3559 {
3560 if (debug_threads)
3561 fprintf (stderr, "proceed_all_lwps: found "
3562 "thread %ld needing a step-over\n",
3563 lwpid_of (need_step_over));
3564
3565 start_step_over (need_step_over);
3566 return;
3567 }
3568 }
5544ad89 3569
d50171e4
PA
3570 if (debug_threads)
3571 fprintf (stderr, "Proceeding, no step-over needed\n");
3572
7984d532 3573 find_inferior (&all_lwps, proceed_one_lwp, NULL);
d50171e4
PA
3574}
3575
3576/* Stopped LWPs that the client wanted to be running, that don't have
3577 pending statuses, are set to run again, except for EXCEPT, if not
3578 NULL. This undoes a stop_all_lwps call. */
3579
3580static void
7984d532 3581unstop_all_lwps (int unsuspend, struct lwp_info *except)
d50171e4 3582{
5544ad89
DJ
3583 if (debug_threads)
3584 {
d50171e4
PA
3585 if (except)
3586 fprintf (stderr,
3587 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except));
5544ad89 3588 else
d50171e4
PA
3589 fprintf (stderr,
3590 "unstopping all lwps\n");
5544ad89
DJ
3591 }
3592
7984d532
PA
3593 if (unsuspend)
3594 find_inferior (&all_lwps, unsuspend_and_proceed_one_lwp, except);
3595 else
3596 find_inferior (&all_lwps, proceed_one_lwp, except);
0d62e5e8
DJ
3597}
3598
3599#ifdef HAVE_LINUX_USRREGS
da6d8c04
DJ
3600
3601int
0a30fbc4 3602register_addr (int regnum)
da6d8c04
DJ
3603{
3604 int addr;
3605
2ec06d2e 3606 if (regnum < 0 || regnum >= the_low_target.num_regs)
da6d8c04
DJ
3607 error ("Invalid register number %d.", regnum);
3608
2ec06d2e 3609 addr = the_low_target.regmap[regnum];
da6d8c04
DJ
3610
3611 return addr;
3612}
3613
58caa3dc 3614/* Fetch one register. */
da6d8c04 3615static void
442ea881 3616fetch_register (struct regcache *regcache, int regno)
da6d8c04
DJ
3617{
3618 CORE_ADDR regaddr;
48d93c75 3619 int i, size;
0d62e5e8 3620 char *buf;
95954743 3621 int pid;
da6d8c04 3622
2ec06d2e 3623 if (regno >= the_low_target.num_regs)
0a30fbc4 3624 return;
2ec06d2e 3625 if ((*the_low_target.cannot_fetch_register) (regno))
0a30fbc4 3626 return;
da6d8c04 3627
0a30fbc4
DJ
3628 regaddr = register_addr (regno);
3629 if (regaddr == -1)
3630 return;
95954743
PA
3631
3632 pid = lwpid_of (get_thread_lwp (current_inferior));
1b3f6016
PA
3633 size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
3634 & - sizeof (PTRACE_XFER_TYPE));
48d93c75
UW
3635 buf = alloca (size);
3636 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
da6d8c04
DJ
3637 {
3638 errno = 0;
0d62e5e8 3639 *(PTRACE_XFER_TYPE *) (buf + i) =
14ce3065
DE
3640 ptrace (PTRACE_PEEKUSER, pid,
3641 /* Coerce to a uintptr_t first to avoid potential gcc warning
3642 of coercing an 8 byte integer to a 4 byte pointer. */
3643 (PTRACE_ARG3_TYPE) (uintptr_t) regaddr, 0);
da6d8c04
DJ
3644 regaddr += sizeof (PTRACE_XFER_TYPE);
3645 if (errno != 0)
f52cd8cd 3646 error ("reading register %d: %s", regno, strerror (errno));
da6d8c04 3647 }
ee1a7ae4
UW
3648
3649 if (the_low_target.supply_ptrace_register)
442ea881 3650 the_low_target.supply_ptrace_register (regcache, regno, buf);
5a1f5858 3651 else
442ea881 3652 supply_register (regcache, regno, buf);
da6d8c04
DJ
3653}
3654
3655/* Fetch all registers, or just one, from the child process. */
58caa3dc 3656static void
442ea881 3657usr_fetch_inferior_registers (struct regcache *regcache, int regno)
da6d8c04 3658{
4463ce24 3659 if (regno == -1)
2ec06d2e 3660 for (regno = 0; regno < the_low_target.num_regs; regno++)
442ea881 3661 fetch_register (regcache, regno);
da6d8c04 3662 else
442ea881 3663 fetch_register (regcache, regno);
da6d8c04
DJ
3664}
3665
3666/* Store our register values back into the inferior.
3667 If REGNO is -1, do this for all registers.
3668 Otherwise, REGNO specifies which register (so we can save time). */
58caa3dc 3669static void
442ea881 3670usr_store_inferior_registers (struct regcache *regcache, int regno)
da6d8c04
DJ
3671{
3672 CORE_ADDR regaddr;
48d93c75 3673 int i, size;
0d62e5e8 3674 char *buf;
55ac2b99 3675 int pid;
da6d8c04
DJ
3676
3677 if (regno >= 0)
3678 {
2ec06d2e 3679 if (regno >= the_low_target.num_regs)
0a30fbc4
DJ
3680 return;
3681
bc1e36ca 3682 if ((*the_low_target.cannot_store_register) (regno) == 1)
0a30fbc4
DJ
3683 return;
3684
3685 regaddr = register_addr (regno);
3686 if (regaddr == -1)
da6d8c04 3687 return;
da6d8c04 3688 errno = 0;
48d93c75
UW
3689 size = (register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
3690 & - sizeof (PTRACE_XFER_TYPE);
3691 buf = alloca (size);
3692 memset (buf, 0, size);
ee1a7ae4
UW
3693
3694 if (the_low_target.collect_ptrace_register)
442ea881 3695 the_low_target.collect_ptrace_register (regcache, regno, buf);
5a1f5858 3696 else
442ea881 3697 collect_register (regcache, regno, buf);
ee1a7ae4 3698
95954743 3699 pid = lwpid_of (get_thread_lwp (current_inferior));
48d93c75 3700 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
da6d8c04 3701 {
0a30fbc4 3702 errno = 0;
14ce3065
DE
3703 ptrace (PTRACE_POKEUSER, pid,
3704 /* Coerce to a uintptr_t first to avoid potential gcc warning
3705 about coercing an 8 byte integer to a 4 byte pointer. */
3706 (PTRACE_ARG3_TYPE) (uintptr_t) regaddr,
3707 (PTRACE_ARG4_TYPE) *(PTRACE_XFER_TYPE *) (buf + i));
da6d8c04
DJ
3708 if (errno != 0)
3709 {
1b3f6016
PA
3710 /* At this point, ESRCH should mean the process is
3711 already gone, in which case we simply ignore attempts
3712 to change its registers. See also the related
3713 comment in linux_resume_one_lwp. */
3221518c
UW
3714 if (errno == ESRCH)
3715 return;
3716
bc1e36ca 3717 if ((*the_low_target.cannot_store_register) (regno) == 0)
f52cd8cd 3718 error ("writing register %d: %s", regno, strerror (errno));
da6d8c04 3719 }
2ff29de4 3720 regaddr += sizeof (PTRACE_XFER_TYPE);
da6d8c04 3721 }
da6d8c04
DJ
3722 }
3723 else
2ec06d2e 3724 for (regno = 0; regno < the_low_target.num_regs; regno++)
442ea881 3725 usr_store_inferior_registers (regcache, regno);
da6d8c04 3726}
58caa3dc
DJ
3727#endif /* HAVE_LINUX_USRREGS */
3728
3729
3730
3731#ifdef HAVE_LINUX_REGSETS
3732
3733static int
442ea881 3734regsets_fetch_inferior_registers (struct regcache *regcache)
58caa3dc
DJ
3735{
3736 struct regset_info *regset;
e9d25b98 3737 int saw_general_regs = 0;
95954743 3738 int pid;
1570b33e 3739 struct iovec iov;
58caa3dc
DJ
3740
3741 regset = target_regsets;
3742
95954743 3743 pid = lwpid_of (get_thread_lwp (current_inferior));
58caa3dc
DJ
3744 while (regset->size >= 0)
3745 {
1570b33e
L
3746 void *buf, *data;
3747 int nt_type, res;
58caa3dc 3748
52fa2412 3749 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
58caa3dc
DJ
3750 {
3751 regset ++;
3752 continue;
3753 }
3754
bca929d3 3755 buf = xmalloc (regset->size);
1570b33e
L
3756
3757 nt_type = regset->nt_type;
3758 if (nt_type)
3759 {
3760 iov.iov_base = buf;
3761 iov.iov_len = regset->size;
3762 data = (void *) &iov;
3763 }
3764 else
3765 data = buf;
3766
dfb64f85 3767#ifndef __sparc__
1570b33e 3768 res = ptrace (regset->get_request, pid, nt_type, data);
dfb64f85 3769#else
1570b33e 3770 res = ptrace (regset->get_request, pid, data, nt_type);
dfb64f85 3771#endif
58caa3dc
DJ
3772 if (res < 0)
3773 {
3774 if (errno == EIO)
3775 {
52fa2412
UW
3776 /* If we get EIO on a regset, do not try it again for
3777 this process. */
3778 disabled_regsets[regset - target_regsets] = 1;
fdeb2a12 3779 free (buf);
52fa2412 3780 continue;
58caa3dc
DJ
3781 }
3782 else
3783 {
0d62e5e8 3784 char s[256];
95954743
PA
3785 sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3786 pid);
0d62e5e8 3787 perror (s);
58caa3dc
DJ
3788 }
3789 }
e9d25b98
DJ
3790 else if (regset->type == GENERAL_REGS)
3791 saw_general_regs = 1;
442ea881 3792 regset->store_function (regcache, buf);
58caa3dc 3793 regset ++;
fdeb2a12 3794 free (buf);
58caa3dc 3795 }
e9d25b98
DJ
3796 if (saw_general_regs)
3797 return 0;
3798 else
3799 return 1;
58caa3dc
DJ
3800}
3801
3802static int
442ea881 3803regsets_store_inferior_registers (struct regcache *regcache)
58caa3dc
DJ
3804{
3805 struct regset_info *regset;
e9d25b98 3806 int saw_general_regs = 0;
95954743 3807 int pid;
1570b33e 3808 struct iovec iov;
58caa3dc
DJ
3809
3810 regset = target_regsets;
3811
95954743 3812 pid = lwpid_of (get_thread_lwp (current_inferior));
58caa3dc
DJ
3813 while (regset->size >= 0)
3814 {
1570b33e
L
3815 void *buf, *data;
3816 int nt_type, res;
58caa3dc 3817
52fa2412 3818 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
58caa3dc
DJ
3819 {
3820 regset ++;
3821 continue;
3822 }
3823
bca929d3 3824 buf = xmalloc (regset->size);
545587ee
DJ
3825
3826 /* First fill the buffer with the current register set contents,
3827 in case there are any items in the kernel's regset that are
3828 not in gdbserver's regcache. */
1570b33e
L
3829
3830 nt_type = regset->nt_type;
3831 if (nt_type)
3832 {
3833 iov.iov_base = buf;
3834 iov.iov_len = regset->size;
3835 data = (void *) &iov;
3836 }
3837 else
3838 data = buf;
3839
dfb64f85 3840#ifndef __sparc__
1570b33e 3841 res = ptrace (regset->get_request, pid, nt_type, data);
dfb64f85 3842#else
1570b33e 3843 res = ptrace (regset->get_request, pid, &iov, data);
dfb64f85 3844#endif
545587ee
DJ
3845
3846 if (res == 0)
3847 {
3848 /* Then overlay our cached registers on that. */
442ea881 3849 regset->fill_function (regcache, buf);
545587ee
DJ
3850
3851 /* Only now do we write the register set. */
dfb64f85 3852#ifndef __sparc__
1570b33e 3853 res = ptrace (regset->set_request, pid, nt_type, data);
dfb64f85 3854#else
1570b33e 3855 res = ptrace (regset->set_request, pid, data, nt_type);
dfb64f85 3856#endif
545587ee
DJ
3857 }
3858
58caa3dc
DJ
3859 if (res < 0)
3860 {
3861 if (errno == EIO)
3862 {
52fa2412
UW
3863 /* If we get EIO on a regset, do not try it again for
3864 this process. */
3865 disabled_regsets[regset - target_regsets] = 1;
fdeb2a12 3866 free (buf);
52fa2412 3867 continue;
58caa3dc 3868 }
3221518c
UW
3869 else if (errno == ESRCH)
3870 {
1b3f6016
PA
3871 /* At this point, ESRCH should mean the process is
3872 already gone, in which case we simply ignore attempts
3873 to change its registers. See also the related
3874 comment in linux_resume_one_lwp. */
fdeb2a12 3875 free (buf);
3221518c
UW
3876 return 0;
3877 }
58caa3dc
DJ
3878 else
3879 {
ce3a066d 3880 perror ("Warning: ptrace(regsets_store_inferior_registers)");
58caa3dc
DJ
3881 }
3882 }
e9d25b98
DJ
3883 else if (regset->type == GENERAL_REGS)
3884 saw_general_regs = 1;
58caa3dc 3885 regset ++;
09ec9b38 3886 free (buf);
58caa3dc 3887 }
e9d25b98
DJ
3888 if (saw_general_regs)
3889 return 0;
3890 else
3891 return 1;
ce3a066d 3892 return 0;
58caa3dc
DJ
3893}
3894
3895#endif /* HAVE_LINUX_REGSETS */
3896
3897
3898void
442ea881 3899linux_fetch_registers (struct regcache *regcache, int regno)
58caa3dc
DJ
3900{
3901#ifdef HAVE_LINUX_REGSETS
442ea881 3902 if (regsets_fetch_inferior_registers (regcache) == 0)
52fa2412 3903 return;
58caa3dc
DJ
3904#endif
3905#ifdef HAVE_LINUX_USRREGS
442ea881 3906 usr_fetch_inferior_registers (regcache, regno);
58caa3dc
DJ
3907#endif
3908}
3909
3910void
442ea881 3911linux_store_registers (struct regcache *regcache, int regno)
58caa3dc
DJ
3912{
3913#ifdef HAVE_LINUX_REGSETS
442ea881 3914 if (regsets_store_inferior_registers (regcache) == 0)
52fa2412 3915 return;
58caa3dc
DJ
3916#endif
3917#ifdef HAVE_LINUX_USRREGS
442ea881 3918 usr_store_inferior_registers (regcache, regno);
58caa3dc
DJ
3919#endif
3920}
3921
da6d8c04 3922
da6d8c04
DJ
3923/* Copy LEN bytes from inferior's memory starting at MEMADDR
3924 to debugger memory starting at MYADDR. */
3925
c3e735a6 3926static int
f450004a 3927linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
da6d8c04
DJ
3928{
3929 register int i;
3930 /* Round starting address down to longword boundary. */
3931 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
3932 /* Round ending address up; get number of longwords that makes. */
aa691b87
RM
3933 register int count
3934 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
da6d8c04
DJ
3935 / sizeof (PTRACE_XFER_TYPE);
3936 /* Allocate buffer of that many longwords. */
aa691b87 3937 register PTRACE_XFER_TYPE *buffer
da6d8c04 3938 = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
fd462a61
DJ
3939 int fd;
3940 char filename[64];
95954743 3941 int pid = lwpid_of (get_thread_lwp (current_inferior));
fd462a61
DJ
3942
3943 /* Try using /proc. Don't bother for one word. */
3944 if (len >= 3 * sizeof (long))
3945 {
3946 /* We could keep this file open and cache it - possibly one per
3947 thread. That requires some juggling, but is even faster. */
95954743 3948 sprintf (filename, "/proc/%d/mem", pid);
fd462a61
DJ
3949 fd = open (filename, O_RDONLY | O_LARGEFILE);
3950 if (fd == -1)
3951 goto no_proc;
3952
3953 /* If pread64 is available, use it. It's faster if the kernel
3954 supports it (only one syscall), and it's 64-bit safe even on
3955 32-bit platforms (for instance, SPARC debugging a SPARC64
3956 application). */
3957#ifdef HAVE_PREAD64
3958 if (pread64 (fd, myaddr, len, memaddr) != len)
3959#else
1de1badb 3960 if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, myaddr, len) != len)
fd462a61
DJ
3961#endif
3962 {
3963 close (fd);
3964 goto no_proc;
3965 }
3966
3967 close (fd);
3968 return 0;
3969 }
da6d8c04 3970
fd462a61 3971 no_proc:
da6d8c04
DJ
3972 /* Read all the longwords */
3973 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
3974 {
c3e735a6 3975 errno = 0;
14ce3065
DE
3976 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
3977 about coercing an 8 byte integer to a 4 byte pointer. */
3978 buffer[i] = ptrace (PTRACE_PEEKTEXT, pid,
3979 (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
c3e735a6
DJ
3980 if (errno)
3981 return errno;
da6d8c04
DJ
3982 }
3983
3984 /* Copy appropriate bytes out of the buffer. */
1b3f6016
PA
3985 memcpy (myaddr,
3986 (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
3987 len);
c3e735a6
DJ
3988
3989 return 0;
da6d8c04
DJ
3990}
3991
93ae6fdc
PA
3992/* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
3993 memory at MEMADDR. On failure (cannot write to the inferior)
da6d8c04
DJ
3994 returns the value of errno. */
3995
ce3a066d 3996static int
f450004a 3997linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
da6d8c04
DJ
3998{
3999 register int i;
4000 /* Round starting address down to longword boundary. */
4001 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
4002 /* Round ending address up; get number of longwords that makes. */
4003 register int count
4004 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE);
4005 /* Allocate buffer of that many longwords. */
4006 register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
95954743 4007 int pid = lwpid_of (get_thread_lwp (current_inferior));
da6d8c04 4008
0d62e5e8
DJ
4009 if (debug_threads)
4010 {
58d6951d
DJ
4011 /* Dump up to four bytes. */
4012 unsigned int val = * (unsigned int *) myaddr;
4013 if (len == 1)
4014 val = val & 0xff;
4015 else if (len == 2)
4016 val = val & 0xffff;
4017 else if (len == 3)
4018 val = val & 0xffffff;
4019 fprintf (stderr, "Writing %0*x to 0x%08lx\n", 2 * ((len < 4) ? len : 4),
4020 val, (long)memaddr);
0d62e5e8
DJ
4021 }
4022
da6d8c04
DJ
4023 /* Fill start and end extra bytes of buffer with existing memory data. */
4024
93ae6fdc 4025 errno = 0;
14ce3065
DE
4026 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4027 about coercing an 8 byte integer to a 4 byte pointer. */
4028 buffer[0] = ptrace (PTRACE_PEEKTEXT, pid,
4029 (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
93ae6fdc
PA
4030 if (errno)
4031 return errno;
da6d8c04
DJ
4032
4033 if (count > 1)
4034 {
93ae6fdc 4035 errno = 0;
da6d8c04 4036 buffer[count - 1]
95954743 4037 = ptrace (PTRACE_PEEKTEXT, pid,
14ce3065
DE
4038 /* Coerce to a uintptr_t first to avoid potential gcc warning
4039 about coercing an 8 byte integer to a 4 byte pointer. */
4040 (PTRACE_ARG3_TYPE) (uintptr_t) (addr + (count - 1)
4041 * sizeof (PTRACE_XFER_TYPE)),
d844cde6 4042 0);
93ae6fdc
PA
4043 if (errno)
4044 return errno;
da6d8c04
DJ
4045 }
4046
93ae6fdc 4047 /* Copy data to be written over corresponding part of buffer. */
da6d8c04
DJ
4048
4049 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len);
4050
4051 /* Write the entire buffer. */
4052
4053 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
4054 {
4055 errno = 0;
14ce3065
DE
4056 ptrace (PTRACE_POKETEXT, pid,
4057 /* Coerce to a uintptr_t first to avoid potential gcc warning
4058 about coercing an 8 byte integer to a 4 byte pointer. */
4059 (PTRACE_ARG3_TYPE) (uintptr_t) addr,
4060 (PTRACE_ARG4_TYPE) buffer[i]);
da6d8c04
DJ
4061 if (errno)
4062 return errno;
4063 }
4064
4065 return 0;
4066}
2f2893d9 4067
6076632b 4068/* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
24a09b5f
DJ
4069static int linux_supports_tracefork_flag;
4070
1e7fc18c
PA
4071static void
4072linux_enable_event_reporting (int pid)
4073{
4074 if (!linux_supports_tracefork_flag)
4075 return;
4076
4077 ptrace (PTRACE_SETOPTIONS, pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
4078}
4079
51c2684e 4080/* Helper functions for linux_test_for_tracefork, called via clone (). */
24a09b5f 4081
51c2684e
DJ
4082static int
4083linux_tracefork_grandchild (void *arg)
4084{
4085 _exit (0);
4086}
4087
7407e2de
AS
4088#define STACK_SIZE 4096
4089
51c2684e
DJ
4090static int
4091linux_tracefork_child (void *arg)
24a09b5f
DJ
4092{
4093 ptrace (PTRACE_TRACEME, 0, 0, 0);
4094 kill (getpid (), SIGSTOP);
e4b7f41c
JK
4095
4096#if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4097
4098 if (fork () == 0)
4099 linux_tracefork_grandchild (NULL);
4100
4101#else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4102
7407e2de
AS
4103#ifdef __ia64__
4104 __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
4105 CLONE_VM | SIGCHLD, NULL);
4106#else
4107 clone (linux_tracefork_grandchild, arg + STACK_SIZE,
4108 CLONE_VM | SIGCHLD, NULL);
4109#endif
e4b7f41c
JK
4110
4111#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4112
24a09b5f
DJ
4113 _exit (0);
4114}
4115
24a09b5f
DJ
4116/* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
4117 sure that we can enable the option, and that it had the desired
4118 effect. */
4119
4120static void
4121linux_test_for_tracefork (void)
4122{
4123 int child_pid, ret, status;
4124 long second_pid;
e4b7f41c 4125#if defined(__UCLIBC__) && defined(HAS_NOMMU)
bca929d3 4126 char *stack = xmalloc (STACK_SIZE * 4);
e4b7f41c 4127#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
24a09b5f
DJ
4128
4129 linux_supports_tracefork_flag = 0;
4130
e4b7f41c
JK
4131#if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4132
4133 child_pid = fork ();
4134 if (child_pid == 0)
4135 linux_tracefork_child (NULL);
4136
4137#else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4138
51c2684e 4139 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
7407e2de
AS
4140#ifdef __ia64__
4141 child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
4142 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
e4b7f41c 4143#else /* !__ia64__ */
7407e2de
AS
4144 child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
4145 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
e4b7f41c
JK
4146#endif /* !__ia64__ */
4147
4148#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4149
24a09b5f 4150 if (child_pid == -1)
51c2684e 4151 perror_with_name ("clone");
24a09b5f
DJ
4152
4153 ret = my_waitpid (child_pid, &status, 0);
4154 if (ret == -1)
4155 perror_with_name ("waitpid");
4156 else if (ret != child_pid)
4157 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
4158 if (! WIFSTOPPED (status))
4159 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
4160
14ce3065
DE
4161 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
4162 (PTRACE_ARG4_TYPE) PTRACE_O_TRACEFORK);
24a09b5f
DJ
4163 if (ret != 0)
4164 {
4165 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
4166 if (ret != 0)
4167 {
4168 warning ("linux_test_for_tracefork: failed to kill child");
4169 return;
4170 }
4171
4172 ret = my_waitpid (child_pid, &status, 0);
4173 if (ret != child_pid)
4174 warning ("linux_test_for_tracefork: failed to wait for killed child");
4175 else if (!WIFSIGNALED (status))
4176 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
4177 "killed child", status);
4178
4179 return;
4180 }
4181
4182 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
4183 if (ret != 0)
4184 warning ("linux_test_for_tracefork: failed to resume child");
4185
4186 ret = my_waitpid (child_pid, &status, 0);
4187
4188 if (ret == child_pid && WIFSTOPPED (status)
4189 && status >> 16 == PTRACE_EVENT_FORK)
4190 {
4191 second_pid = 0;
4192 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
4193 if (ret == 0 && second_pid != 0)
4194 {
4195 int second_status;
4196
4197 linux_supports_tracefork_flag = 1;
4198 my_waitpid (second_pid, &second_status, 0);
4199 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
4200 if (ret != 0)
4201 warning ("linux_test_for_tracefork: failed to kill second child");
4202 my_waitpid (second_pid, &status, 0);
4203 }
4204 }
4205 else
4206 warning ("linux_test_for_tracefork: unexpected result from waitpid "
4207 "(%d, status 0x%x)", ret, status);
4208
4209 do
4210 {
4211 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
4212 if (ret != 0)
4213 warning ("linux_test_for_tracefork: failed to kill child");
4214 my_waitpid (child_pid, &status, 0);
4215 }
4216 while (WIFSTOPPED (status));
51c2684e 4217
e4b7f41c 4218#if defined(__UCLIBC__) && defined(HAS_NOMMU)
51c2684e 4219 free (stack);
e4b7f41c 4220#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
24a09b5f
DJ
4221}
4222
4223
2f2893d9
DJ
4224static void
4225linux_look_up_symbols (void)
4226{
0d62e5e8 4227#ifdef USE_THREAD_DB
95954743
PA
4228 struct process_info *proc = current_process ();
4229
cdbfd419 4230 if (proc->private->thread_db != NULL)
0d62e5e8
DJ
4231 return;
4232
6076632b
DE
4233 /* If the kernel supports tracing forks then it also supports tracing
4234 clones, and then we don't need to use the magic thread event breakpoint
4235 to learn about threads. */
cdbfd419 4236 thread_db_init (!linux_supports_tracefork_flag);
0d62e5e8
DJ
4237#endif
4238}
4239
e5379b03 4240static void
ef57601b 4241linux_request_interrupt (void)
e5379b03 4242{
a1928bad 4243 extern unsigned long signal_pid;
e5379b03 4244
95954743
PA
4245 if (!ptid_equal (cont_thread, null_ptid)
4246 && !ptid_equal (cont_thread, minus_one_ptid))
e5379b03 4247 {
54a0b537 4248 struct lwp_info *lwp;
bd99dc85 4249 int lwpid;
e5379b03 4250
54a0b537 4251 lwp = get_thread_lwp (current_inferior);
bd99dc85
PA
4252 lwpid = lwpid_of (lwp);
4253 kill_lwp (lwpid, SIGINT);
e5379b03
DJ
4254 }
4255 else
ef57601b 4256 kill_lwp (signal_pid, SIGINT);
e5379b03
DJ
4257}
4258
aa691b87
RM
4259/* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
4260 to debugger memory starting at MYADDR. */
4261
4262static int
f450004a 4263linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
aa691b87
RM
4264{
4265 char filename[PATH_MAX];
4266 int fd, n;
95954743 4267 int pid = lwpid_of (get_thread_lwp (current_inferior));
aa691b87 4268
95954743 4269 snprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
aa691b87
RM
4270
4271 fd = open (filename, O_RDONLY);
4272 if (fd < 0)
4273 return -1;
4274
4275 if (offset != (CORE_ADDR) 0
4276 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4277 n = -1;
4278 else
4279 n = read (fd, myaddr, len);
4280
4281 close (fd);
4282
4283 return n;
4284}
4285
d993e290
PA
4286/* These breakpoint and watchpoint related wrapper functions simply
4287 pass on the function call if the target has registered a
4288 corresponding function. */
e013ee27
OF
4289
4290static int
d993e290 4291linux_insert_point (char type, CORE_ADDR addr, int len)
e013ee27 4292{
d993e290
PA
4293 if (the_low_target.insert_point != NULL)
4294 return the_low_target.insert_point (type, addr, len);
e013ee27
OF
4295 else
4296 /* Unsupported (see target.h). */
4297 return 1;
4298}
4299
4300static int
d993e290 4301linux_remove_point (char type, CORE_ADDR addr, int len)
e013ee27 4302{
d993e290
PA
4303 if (the_low_target.remove_point != NULL)
4304 return the_low_target.remove_point (type, addr, len);
e013ee27
OF
4305 else
4306 /* Unsupported (see target.h). */
4307 return 1;
4308}
4309
4310static int
4311linux_stopped_by_watchpoint (void)
4312{
c3adc08c
PA
4313 struct lwp_info *lwp = get_thread_lwp (current_inferior);
4314
4315 return lwp->stopped_by_watchpoint;
e013ee27
OF
4316}
4317
4318static CORE_ADDR
4319linux_stopped_data_address (void)
4320{
c3adc08c
PA
4321 struct lwp_info *lwp = get_thread_lwp (current_inferior);
4322
4323 return lwp->stopped_data_address;
e013ee27
OF
4324}
4325
42c81e2a 4326#if defined(__UCLIBC__) && defined(HAS_NOMMU)
52fb6437
NS
4327#if defined(__mcoldfire__)
4328/* These should really be defined in the kernel's ptrace.h header. */
4329#define PT_TEXT_ADDR 49*4
4330#define PT_DATA_ADDR 50*4
4331#define PT_TEXT_END_ADDR 51*4
4332#endif
4333
4334/* Under uClinux, programs are loaded at non-zero offsets, which we need
4335 to tell gdb about. */
4336
4337static int
4338linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
4339{
4340#if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
4341 unsigned long text, text_end, data;
bd99dc85 4342 int pid = lwpid_of (get_thread_lwp (current_inferior));
52fb6437
NS
4343
4344 errno = 0;
4345
4346 text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0);
4347 text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0);
4348 data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0);
4349
4350 if (errno == 0)
4351 {
4352 /* Both text and data offsets produced at compile-time (and so
1b3f6016
PA
4353 used by gdb) are relative to the beginning of the program,
4354 with the data segment immediately following the text segment.
4355 However, the actual runtime layout in memory may put the data
4356 somewhere else, so when we send gdb a data base-address, we
4357 use the real data base address and subtract the compile-time
4358 data base-address from it (which is just the length of the
4359 text segment). BSS immediately follows data in both
4360 cases. */
52fb6437
NS
4361 *text_p = text;
4362 *data_p = data - (text_end - text);
1b3f6016 4363
52fb6437
NS
4364 return 1;
4365 }
4366#endif
4367 return 0;
4368}
4369#endif
4370
dc146f7c
VP
4371static int
4372compare_ints (const void *xa, const void *xb)
4373{
4374 int a = *(const int *)xa;
4375 int b = *(const int *)xb;
4376
4377 return a - b;
4378}
4379
4380static int *
4381unique (int *b, int *e)
4382{
4383 int *d = b;
4384 while (++b != e)
4385 if (*d != *b)
4386 *++d = *b;
4387 return ++d;
4388}
4389
4390/* Given PID, iterates over all threads in that process.
4391
4392 Information about each thread, in a format suitable for qXfer:osdata:thread
4393 is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
4394 initialized, and the caller is responsible for finishing and appending '\0'
4395 to it.
4396
4397 The list of cores that threads are running on is assigned to *CORES, if it
4398 is not NULL. If no cores are found, *CORES will be set to NULL. Caller
4399 should free *CORES. */
4400
4401static void
4402list_threads (int pid, struct buffer *buffer, char **cores)
4403{
4404 int count = 0;
4405 int allocated = 10;
4406 int *core_numbers = xmalloc (sizeof (int) * allocated);
4407 char pathname[128];
4408 DIR *dir;
4409 struct dirent *dp;
4410 struct stat statbuf;
4411
4412 sprintf (pathname, "/proc/%d/task", pid);
4413 if (stat (pathname, &statbuf) == 0 && S_ISDIR (statbuf.st_mode))
4414 {
4415 dir = opendir (pathname);
4416 if (!dir)
4417 {
4418 free (core_numbers);
4419 return;
4420 }
4421
4422 while ((dp = readdir (dir)) != NULL)
4423 {
4424 unsigned long lwp = strtoul (dp->d_name, NULL, 10);
4425
4426 if (lwp != 0)
4427 {
4428 unsigned core = linux_core_of_thread (ptid_build (pid, lwp, 0));
4429
4430 if (core != -1)
4431 {
4432 char s[sizeof ("4294967295")];
4433 sprintf (s, "%u", core);
4434
4435 if (count == allocated)
4436 {
4437 allocated *= 2;
4438 core_numbers = realloc (core_numbers,
4439 sizeof (int) * allocated);
4440 }
4441 core_numbers[count++] = core;
4442 if (buffer)
4443 buffer_xml_printf (buffer,
4444 "<item>"
4445 "<column name=\"pid\">%d</column>"
4446 "<column name=\"tid\">%s</column>"
4447 "<column name=\"core\">%s</column>"
4448 "</item>", pid, dp->d_name, s);
4449 }
4450 else
4451 {
4452 if (buffer)
4453 buffer_xml_printf (buffer,
4454 "<item>"
4455 "<column name=\"pid\">%d</column>"
4456 "<column name=\"tid\">%s</column>"
4457 "</item>", pid, dp->d_name);
4458 }
4459 }
4460 }
4461 }
4462
4463 if (cores)
4464 {
4465 *cores = NULL;
4466 if (count > 0)
4467 {
4468 struct buffer buffer2;
4469 int *b;
4470 int *e;
4471 qsort (core_numbers, count, sizeof (int), compare_ints);
4472
4473 /* Remove duplicates. */
4474 b = core_numbers;
4475 e = unique (b, core_numbers + count);
4476
4477 buffer_init (&buffer2);
4478
4479 for (b = core_numbers; b != e; ++b)
4480 {
4481 char number[sizeof ("4294967295")];
4482 sprintf (number, "%u", *b);
4483 buffer_xml_printf (&buffer2, "%s%s",
4484 (b == core_numbers) ? "" : ",", number);
4485 }
4486 buffer_grow_str0 (&buffer2, "");
4487
4488 *cores = buffer_finish (&buffer2);
4489 }
4490 }
4491 free (core_numbers);
4492}
4493
4494static void
4495show_process (int pid, const char *username, struct buffer *buffer)
4496{
4497 char pathname[128];
4498 FILE *f;
4499 char cmd[MAXPATHLEN + 1];
4500
4501 sprintf (pathname, "/proc/%d/cmdline", pid);
4502
4503 if ((f = fopen (pathname, "r")) != NULL)
4504 {
4505 size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
4506 if (len > 0)
4507 {
4508 char *cores = 0;
4509 int i;
4510 for (i = 0; i < len; i++)
4511 if (cmd[i] == '\0')
4512 cmd[i] = ' ';
4513 cmd[len] = '\0';
4514
4515 buffer_xml_printf (buffer,
4516 "<item>"
4517 "<column name=\"pid\">%d</column>"
4518 "<column name=\"user\">%s</column>"
4519 "<column name=\"command\">%s</column>",
4520 pid,
4521 username,
4522 cmd);
4523
4524 /* This only collects core numbers, and does not print threads. */
4525 list_threads (pid, NULL, &cores);
4526
4527 if (cores)
4528 {
4529 buffer_xml_printf (buffer,
4530 "<column name=\"cores\">%s</column>", cores);
4531 free (cores);
4532 }
4533
4534 buffer_xml_printf (buffer, "</item>");
4535 }
4536 fclose (f);
4537 }
4538}
4539
07e059b5
VP
4540static int
4541linux_qxfer_osdata (const char *annex,
1b3f6016
PA
4542 unsigned char *readbuf, unsigned const char *writebuf,
4543 CORE_ADDR offset, int len)
07e059b5
VP
4544{
4545 /* We make the process list snapshot when the object starts to be
4546 read. */
4547 static const char *buf;
4548 static long len_avail = -1;
4549 static struct buffer buffer;
dc146f7c
VP
4550 int processes = 0;
4551 int threads = 0;
07e059b5
VP
4552
4553 DIR *dirp;
4554
dc146f7c
VP
4555 if (strcmp (annex, "processes") == 0)
4556 processes = 1;
4557 else if (strcmp (annex, "threads") == 0)
4558 threads = 1;
4559 else
07e059b5
VP
4560 return 0;
4561
4562 if (!readbuf || writebuf)
4563 return 0;
4564
4565 if (offset == 0)
4566 {
4567 if (len_avail != -1 && len_avail != 0)
4568 buffer_free (&buffer);
4569 len_avail = 0;
4570 buf = NULL;
4571 buffer_init (&buffer);
dc146f7c
VP
4572 if (processes)
4573 buffer_grow_str (&buffer, "<osdata type=\"processes\">");
4574 else if (threads)
4575 buffer_grow_str (&buffer, "<osdata type=\"threads\">");
07e059b5
VP
4576
4577 dirp = opendir ("/proc");
4578 if (dirp)
4579 {
1b3f6016
PA
4580 struct dirent *dp;
4581 while ((dp = readdir (dirp)) != NULL)
4582 {
4583 struct stat statbuf;
4584 char procentry[sizeof ("/proc/4294967295")];
4585
4586 if (!isdigit (dp->d_name[0])
4587 || strlen (dp->d_name) > sizeof ("4294967295") - 1)
4588 continue;
4589
4590 sprintf (procentry, "/proc/%s", dp->d_name);
4591 if (stat (procentry, &statbuf) == 0
4592 && S_ISDIR (statbuf.st_mode))
4593 {
dc146f7c 4594 int pid = (int) strtoul (dp->d_name, NULL, 10);
1b3f6016 4595
dc146f7c 4596 if (processes)
1b3f6016 4597 {
dc146f7c
VP
4598 struct passwd *entry = getpwuid (statbuf.st_uid);
4599 show_process (pid, entry ? entry->pw_name : "?", &buffer);
4600 }
4601 else if (threads)
4602 {
4603 list_threads (pid, &buffer, NULL);
1b3f6016
PA
4604 }
4605 }
4606 }
07e059b5 4607
1b3f6016 4608 closedir (dirp);
07e059b5
VP
4609 }
4610 buffer_grow_str0 (&buffer, "</osdata>\n");
4611 buf = buffer_finish (&buffer);
4612 len_avail = strlen (buf);
4613 }
4614
4615 if (offset >= len_avail)
4616 {
4617 /* Done. Get rid of the data. */
4618 buffer_free (&buffer);
4619 buf = NULL;
4620 len_avail = 0;
4621 return 0;
4622 }
4623
4624 if (len > len_avail - offset)
4625 len = len_avail - offset;
4626 memcpy (readbuf, buf + offset, len);
4627
4628 return len;
4629}
4630
d0722149
DE
4631/* Convert a native/host siginfo object, into/from the siginfo in the
4632 layout of the inferiors' architecture. */
4633
4634static void
4635siginfo_fixup (struct siginfo *siginfo, void *inf_siginfo, int direction)
4636{
4637 int done = 0;
4638
4639 if (the_low_target.siginfo_fixup != NULL)
4640 done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction);
4641
4642 /* If there was no callback, or the callback didn't do anything,
4643 then just do a straight memcpy. */
4644 if (!done)
4645 {
4646 if (direction == 1)
4647 memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
4648 else
4649 memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
4650 }
4651}
4652
4aa995e1
PA
4653static int
4654linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
4655 unsigned const char *writebuf, CORE_ADDR offset, int len)
4656{
d0722149 4657 int pid;
4aa995e1 4658 struct siginfo siginfo;
d0722149 4659 char inf_siginfo[sizeof (struct siginfo)];
4aa995e1
PA
4660
4661 if (current_inferior == NULL)
4662 return -1;
4663
bd99dc85 4664 pid = lwpid_of (get_thread_lwp (current_inferior));
4aa995e1
PA
4665
4666 if (debug_threads)
d0722149 4667 fprintf (stderr, "%s siginfo for lwp %d.\n",
4aa995e1
PA
4668 readbuf != NULL ? "Reading" : "Writing",
4669 pid);
4670
4671 if (offset > sizeof (siginfo))
4672 return -1;
4673
4674 if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
4675 return -1;
4676
d0722149
DE
4677 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
4678 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4679 inferior with a 64-bit GDBSERVER should look the same as debugging it
4680 with a 32-bit GDBSERVER, we need to convert it. */
4681 siginfo_fixup (&siginfo, inf_siginfo, 0);
4682
4aa995e1
PA
4683 if (offset + len > sizeof (siginfo))
4684 len = sizeof (siginfo) - offset;
4685
4686 if (readbuf != NULL)
d0722149 4687 memcpy (readbuf, inf_siginfo + offset, len);
4aa995e1
PA
4688 else
4689 {
d0722149
DE
4690 memcpy (inf_siginfo + offset, writebuf, len);
4691
4692 /* Convert back to ptrace layout before flushing it out. */
4693 siginfo_fixup (&siginfo, inf_siginfo, 1);
4694
4aa995e1
PA
4695 if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0)
4696 return -1;
4697 }
4698
4699 return len;
4700}
4701
bd99dc85
PA
4702/* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4703 so we notice when children change state; as the handler for the
4704 sigsuspend in my_waitpid. */
4705
4706static void
4707sigchld_handler (int signo)
4708{
4709 int old_errno = errno;
4710
4711 if (debug_threads)
4712 /* fprintf is not async-signal-safe, so call write directly. */
4713 write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
4714
4715 if (target_is_async_p ())
4716 async_file_mark (); /* trigger a linux_wait */
4717
4718 errno = old_errno;
4719}
4720
4721static int
4722linux_supports_non_stop (void)
4723{
4724 return 1;
4725}
4726
4727static int
4728linux_async (int enable)
4729{
4730 int previous = (linux_event_pipe[0] != -1);
4731
8336d594
PA
4732 if (debug_threads)
4733 fprintf (stderr, "linux_async (%d), previous=%d\n",
4734 enable, previous);
4735
bd99dc85
PA
4736 if (previous != enable)
4737 {
4738 sigset_t mask;
4739 sigemptyset (&mask);
4740 sigaddset (&mask, SIGCHLD);
4741
4742 sigprocmask (SIG_BLOCK, &mask, NULL);
4743
4744 if (enable)
4745 {
4746 if (pipe (linux_event_pipe) == -1)
4747 fatal ("creating event pipe failed.");
4748
4749 fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
4750 fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
4751
4752 /* Register the event loop handler. */
4753 add_file_handler (linux_event_pipe[0],
4754 handle_target_event, NULL);
4755
4756 /* Always trigger a linux_wait. */
4757 async_file_mark ();
4758 }
4759 else
4760 {
4761 delete_file_handler (linux_event_pipe[0]);
4762
4763 close (linux_event_pipe[0]);
4764 close (linux_event_pipe[1]);
4765 linux_event_pipe[0] = -1;
4766 linux_event_pipe[1] = -1;
4767 }
4768
4769 sigprocmask (SIG_UNBLOCK, &mask, NULL);
4770 }
4771
4772 return previous;
4773}
4774
4775static int
4776linux_start_non_stop (int nonstop)
4777{
4778 /* Register or unregister from event-loop accordingly. */
4779 linux_async (nonstop);
4780 return 0;
4781}
4782
cf8fd78b
PA
4783static int
4784linux_supports_multi_process (void)
4785{
4786 return 1;
4787}
4788
efcbbd14
UW
4789
4790/* Enumerate spufs IDs for process PID. */
4791static int
4792spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
4793{
4794 int pos = 0;
4795 int written = 0;
4796 char path[128];
4797 DIR *dir;
4798 struct dirent *entry;
4799
4800 sprintf (path, "/proc/%ld/fd", pid);
4801 dir = opendir (path);
4802 if (!dir)
4803 return -1;
4804
4805 rewinddir (dir);
4806 while ((entry = readdir (dir)) != NULL)
4807 {
4808 struct stat st;
4809 struct statfs stfs;
4810 int fd;
4811
4812 fd = atoi (entry->d_name);
4813 if (!fd)
4814 continue;
4815
4816 sprintf (path, "/proc/%ld/fd/%d", pid, fd);
4817 if (stat (path, &st) != 0)
4818 continue;
4819 if (!S_ISDIR (st.st_mode))
4820 continue;
4821
4822 if (statfs (path, &stfs) != 0)
4823 continue;
4824 if (stfs.f_type != SPUFS_MAGIC)
4825 continue;
4826
4827 if (pos >= offset && pos + 4 <= offset + len)
4828 {
4829 *(unsigned int *)(buf + pos - offset) = fd;
4830 written += 4;
4831 }
4832 pos += 4;
4833 }
4834
4835 closedir (dir);
4836 return written;
4837}
4838
4839/* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
4840 object type, using the /proc file system. */
4841static int
4842linux_qxfer_spu (const char *annex, unsigned char *readbuf,
4843 unsigned const char *writebuf,
4844 CORE_ADDR offset, int len)
4845{
4846 long pid = lwpid_of (get_thread_lwp (current_inferior));
4847 char buf[128];
4848 int fd = 0;
4849 int ret = 0;
4850
4851 if (!writebuf && !readbuf)
4852 return -1;
4853
4854 if (!*annex)
4855 {
4856 if (!readbuf)
4857 return -1;
4858 else
4859 return spu_enumerate_spu_ids (pid, readbuf, offset, len);
4860 }
4861
4862 sprintf (buf, "/proc/%ld/fd/%s", pid, annex);
4863 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
4864 if (fd <= 0)
4865 return -1;
4866
4867 if (offset != 0
4868 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4869 {
4870 close (fd);
4871 return 0;
4872 }
4873
4874 if (writebuf)
4875 ret = write (fd, writebuf, (size_t) len);
4876 else
4877 ret = read (fd, readbuf, (size_t) len);
4878
4879 close (fd);
4880 return ret;
4881}
4882
dc146f7c
VP
4883static int
4884linux_core_of_thread (ptid_t ptid)
4885{
4886 char filename[sizeof ("/proc//task//stat")
4887 + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
4888 + 1];
4889 FILE *f;
4890 char *content = NULL;
4891 char *p;
4892 char *ts = 0;
4893 int content_read = 0;
4894 int i;
4895 int core;
4896
4897 sprintf (filename, "/proc/%d/task/%ld/stat",
4898 ptid_get_pid (ptid), ptid_get_lwp (ptid));
4899 f = fopen (filename, "r");
4900 if (!f)
4901 return -1;
4902
4903 for (;;)
4904 {
4905 int n;
4906 content = realloc (content, content_read + 1024);
4907 n = fread (content + content_read, 1, 1024, f);
4908 content_read += n;
4909 if (n < 1024)
4910 {
4911 content[content_read] = '\0';
4912 break;
4913 }
4914 }
4915
4916 p = strchr (content, '(');
dc146f7c 4917
ca2a87a0
JK
4918 /* Skip ")". */
4919 if (p != NULL)
4920 p = strchr (p, ')');
4921 if (p != NULL)
4922 p++;
4923
4924 /* If the first field after program name has index 0, then core number is
4925 the field with index 36. There's no constant for that anywhere. */
4926 if (p != NULL)
4927 p = strtok_r (p, " ", &ts);
4928 for (i = 0; p != NULL && i != 36; ++i)
dc146f7c
VP
4929 p = strtok_r (NULL, " ", &ts);
4930
ca2a87a0 4931 if (p == NULL || sscanf (p, "%d", &core) == 0)
dc146f7c
VP
4932 core = -1;
4933
4934 free (content);
4935 fclose (f);
4936
4937 return core;
4938}
4939
1570b33e
L
4940static void
4941linux_process_qsupported (const char *query)
4942{
4943 if (the_low_target.process_qsupported != NULL)
4944 the_low_target.process_qsupported (query);
4945}
4946
219f2f23
PA
4947static int
4948linux_supports_tracepoints (void)
4949{
4950 if (*the_low_target.supports_tracepoints == NULL)
4951 return 0;
4952
4953 return (*the_low_target.supports_tracepoints) ();
4954}
4955
4956static CORE_ADDR
4957linux_read_pc (struct regcache *regcache)
4958{
4959 if (the_low_target.get_pc == NULL)
4960 return 0;
4961
4962 return (*the_low_target.get_pc) (regcache);
4963}
4964
4965static void
4966linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
4967{
4968 gdb_assert (the_low_target.set_pc != NULL);
4969
4970 (*the_low_target.set_pc) (regcache, pc);
4971}
4972
8336d594
PA
4973static int
4974linux_thread_stopped (struct thread_info *thread)
4975{
4976 return get_thread_lwp (thread)->stopped;
4977}
4978
4979/* This exposes stop-all-threads functionality to other modules. */
4980
4981static void
7984d532 4982linux_pause_all (int freeze)
8336d594 4983{
7984d532
PA
4984 stop_all_lwps (freeze, NULL);
4985}
4986
4987/* This exposes unstop-all-threads functionality to other gdbserver
4988 modules. */
4989
4990static void
4991linux_unpause_all (int unfreeze)
4992{
4993 unstop_all_lwps (unfreeze, NULL);
8336d594
PA
4994}
4995
fa593d66
PA
4996static int
4997linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
4998 CORE_ADDR collector,
4999 CORE_ADDR lockaddr,
5000 ULONGEST orig_size,
5001 CORE_ADDR *jump_entry,
5002 unsigned char *jjump_pad_insn,
5003 ULONGEST *jjump_pad_insn_size,
5004 CORE_ADDR *adjusted_insn_addr,
5005 CORE_ADDR *adjusted_insn_addr_end)
5006{
5007 return (*the_low_target.install_fast_tracepoint_jump_pad)
5008 (tpoint, tpaddr, collector, lockaddr, orig_size,
5009 jump_entry, jjump_pad_insn, jjump_pad_insn_size,
5010 adjusted_insn_addr, adjusted_insn_addr_end);
5011}
5012
6a271cae
PA
5013static struct emit_ops *
5014linux_emit_ops (void)
5015{
5016 if (the_low_target.emit_ops != NULL)
5017 return (*the_low_target.emit_ops) ();
5018 else
5019 return NULL;
5020}
5021
ce3a066d
DJ
5022static struct target_ops linux_target_ops = {
5023 linux_create_inferior,
5024 linux_attach,
5025 linux_kill,
6ad8ae5c 5026 linux_detach,
8336d594 5027 linux_mourn,
444d6139 5028 linux_join,
ce3a066d
DJ
5029 linux_thread_alive,
5030 linux_resume,
5031 linux_wait,
5032 linux_fetch_registers,
5033 linux_store_registers,
5034 linux_read_memory,
5035 linux_write_memory,
2f2893d9 5036 linux_look_up_symbols,
ef57601b 5037 linux_request_interrupt,
aa691b87 5038 linux_read_auxv,
d993e290
PA
5039 linux_insert_point,
5040 linux_remove_point,
e013ee27
OF
5041 linux_stopped_by_watchpoint,
5042 linux_stopped_data_address,
42c81e2a 5043#if defined(__UCLIBC__) && defined(HAS_NOMMU)
52fb6437 5044 linux_read_offsets,
dae5f5cf
DJ
5045#else
5046 NULL,
5047#endif
5048#ifdef USE_THREAD_DB
5049 thread_db_get_tls_address,
5050#else
5051 NULL,
52fb6437 5052#endif
efcbbd14 5053 linux_qxfer_spu,
59a016f0 5054 hostio_last_error_from_errno,
07e059b5 5055 linux_qxfer_osdata,
4aa995e1 5056 linux_xfer_siginfo,
bd99dc85
PA
5057 linux_supports_non_stop,
5058 linux_async,
5059 linux_start_non_stop,
cdbfd419
PP
5060 linux_supports_multi_process,
5061#ifdef USE_THREAD_DB
dc146f7c 5062 thread_db_handle_monitor_command,
cdbfd419 5063#else
dc146f7c 5064 NULL,
cdbfd419 5065#endif
1570b33e 5066 linux_core_of_thread,
219f2f23
PA
5067 linux_process_qsupported,
5068 linux_supports_tracepoints,
5069 linux_read_pc,
8336d594
PA
5070 linux_write_pc,
5071 linux_thread_stopped,
7984d532 5072 NULL,
711e434b 5073 linux_pause_all,
7984d532 5074 linux_unpause_all,
fa593d66
PA
5075 linux_cancel_breakpoints,
5076 linux_stabilize_threads,
6a271cae
PA
5077 linux_install_fast_tracepoint_jump_pad,
5078 linux_emit_ops
ce3a066d
DJ
5079};
5080
0d62e5e8
DJ
5081static void
5082linux_init_signals ()
5083{
5084 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
5085 to find what the cancel signal actually is. */
60c3d7b0 5086#ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
254787d4 5087 signal (__SIGRTMIN+1, SIG_IGN);
60c3d7b0 5088#endif
0d62e5e8
DJ
5089}
5090
da6d8c04
DJ
5091void
5092initialize_low (void)
5093{
bd99dc85
PA
5094 struct sigaction sigchld_action;
5095 memset (&sigchld_action, 0, sizeof (sigchld_action));
ce3a066d 5096 set_target_ops (&linux_target_ops);
611cb4a5
DJ
5097 set_breakpoint_data (the_low_target.breakpoint,
5098 the_low_target.breakpoint_len);
0d62e5e8 5099 linux_init_signals ();
24a09b5f 5100 linux_test_for_tracefork ();
52fa2412
UW
5101#ifdef HAVE_LINUX_REGSETS
5102 for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++)
5103 ;
bca929d3 5104 disabled_regsets = xmalloc (num_regsets);
52fa2412 5105#endif
bd99dc85
PA
5106
5107 sigchld_action.sa_handler = sigchld_handler;
5108 sigemptyset (&sigchld_action.sa_mask);
5109 sigchld_action.sa_flags = SA_RESTART;
5110 sigaction (SIGCHLD, &sigchld_action, NULL);
da6d8c04 5111}