[deliverable/binutils-gdb.git] / gdbserver / target.cc

/* Target operations for the remote server for GDB.
   Copyright (C) 2002-2020 Free Software Foundation, Inc.

   Contributed by MontaVista Software.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "server.h"
#include "tracepoint.h"
#include "gdbsupport/byte-vector.h"

process_stratum_target *the_target;

int
set_desired_thread ()
{
  client_state &cs = get_client_state ();
  thread_info *found = find_thread_ptid (cs.general_thread);

  current_thread = found;
  return (current_thread != NULL);
}

/* The thread that was current before prepare_to_access_memory was
   called.  done_accessing_memory uses this to restore the previous
   selected thread.  */
static ptid_t prev_general_thread;

/* See target.h.  */

int
prepare_to_access_memory (void)
{
  client_state &cs = get_client_state ();

  /* The first thread found.  */
  struct thread_info *first = NULL;
  /* The first stopped thread found.  */
  struct thread_info *stopped = NULL;
  /* The current general thread, if found.  */
  struct thread_info *current = NULL;

  /* Save the general thread value, since prepare_to_access_memory could change
     it.  */
  prev_general_thread = cs.general_thread;

  if (the_target->prepare_to_access_memory != NULL)
    {
      int res;

      res = the_target->prepare_to_access_memory ();
      if (res != 0)
	return res;
    }

  for_each_thread (prev_general_thread.pid (), [&] (thread_info *thread)
    {
      if (mythread_alive (thread->id))
	{
	  if (stopped == NULL && the_target->thread_stopped != NULL
	      && thread_stopped (thread))
	    stopped = thread;

	  if (first == NULL)
	    first = thread;

	  if (current == NULL && prev_general_thread == thread->id)
	    current = thread;
	}
    });

  /* The thread we end up choosing.  */
  struct thread_info *thread;

  /* Prefer a stopped thread.  If none is found, try the current
     thread.  Otherwise, take the first thread in the process.  If
     none is found, undo the effects of
     target->prepare_to_access_memory() and return error.  */
  if (stopped != NULL)
    thread = stopped;
  else if (current != NULL)
    thread = current;
  else if (first != NULL)
    thread = first;
  else
    {
      done_accessing_memory ();
      return 1;
    }

  current_thread = thread;
  cs.general_thread = ptid_of (thread);

  return 0;
}

/* See target.h.  */

void
done_accessing_memory (void)
{
  client_state &cs = get_client_state ();

  if (the_target->done_accessing_memory != NULL)
    the_target->done_accessing_memory ();

  /* Restore the previous selected thread.  */
  cs.general_thread = prev_general_thread;
  switch_to_thread (the_target, cs.general_thread);
}

int
read_inferior_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
{
  int res;
  res = (*the_target->read_memory) (memaddr, myaddr, len);
  check_mem_read (memaddr, myaddr, len);
  return res;
}

/* See target/target.h.  */

int
target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
{
  return read_inferior_memory (memaddr, myaddr, len);
}

/* See target/target.h.  */

int
target_read_uint32 (CORE_ADDR memaddr, uint32_t *result)
{
  return read_inferior_memory (memaddr, (gdb_byte *) result, sizeof (*result));
}

/* See target/target.h.  */

int
target_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr,
		     ssize_t len)
{
  /* Make a copy of the data because check_mem_write may need to
     update it.  */
  gdb::byte_vector buffer (myaddr, myaddr + len);
  check_mem_write (memaddr, buffer.data (), myaddr, len);
  return (*the_target->write_memory) (memaddr, buffer.data (), len);
}

ptid_t
mywait (ptid_t ptid, struct target_waitstatus *ourstatus, int options,
	int connected_wait)
{
  ptid_t ret;

  if (connected_wait)
    server_waiting = 1;

  ret = target_wait (ptid, ourstatus, options);

  /* We don't expose _LOADED events to gdbserver core.  See the
     `dlls_changed' global.  */
  if (ourstatus->kind == TARGET_WAITKIND_LOADED)
    ourstatus->kind = TARGET_WAITKIND_STOPPED;

  /* If GDB is connected through TCP/serial, then GDBserver will most
     probably be running on its own terminal/console, so it's nice to
     print there why is GDBserver exiting.  If however, GDB is
     connected through stdio, then there's no need to spam the GDB
     console with this -- the user will already see the exit through
     regular GDB output, in that same terminal.  */
  if (!remote_connection_is_stdio ())
    {
      if (ourstatus->kind == TARGET_WAITKIND_EXITED)
	fprintf (stderr,
		 "\nChild exited with status %d\n", ourstatus->value.integer);
      else if (ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
	fprintf (stderr, "\nChild terminated with signal = 0x%x (%s)\n",
		 gdb_signal_to_host (ourstatus->value.sig),
		 gdb_signal_to_name (ourstatus->value.sig));
    }

  if (connected_wait)
    server_waiting = 0;

  return ret;
}

/* See target/target.h.  */

void
target_stop_and_wait (ptid_t ptid)
{
  struct target_waitstatus status;
  bool was_non_stop = non_stop;
  struct thread_resume resume_info;

  resume_info.thread = ptid;
  resume_info.kind = resume_stop;
  resume_info.sig = GDB_SIGNAL_0;
  (*the_target->resume) (&resume_info, 1);

  non_stop = true;
  mywait (ptid, &status, 0, 0);
  non_stop = was_non_stop;
}

/* See target/target.h.  */

ptid_t
target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
{
  return (*the_target->wait) (ptid, status, options);
}

/* See target/target.h.  */

void
target_mourn_inferior (ptid_t ptid)
{
  (*the_target->mourn) (find_process_pid (ptid.pid ()));
}

/* See target/target.h.  */

void
target_continue_no_signal (ptid_t ptid)
{
  struct thread_resume resume_info;

  resume_info.thread = ptid;
  resume_info.kind = resume_continue;
  resume_info.sig = GDB_SIGNAL_0;
  (*the_target->resume) (&resume_info, 1);
}

/* See target/target.h.  */

void
target_continue (ptid_t ptid, enum gdb_signal signal)
{
  struct thread_resume resume_info;

  resume_info.thread = ptid;
  resume_info.kind = resume_continue;
  resume_info.sig = gdb_signal_to_host (signal);
  (*the_target->resume) (&resume_info, 1);
}

/* See target/target.h.  */

int
target_supports_multi_process (void)
{
  return (the_target->supports_multi_process != NULL ?
	  (*the_target->supports_multi_process) () : 0);
}

int
start_non_stop (int nonstop)
{
  if (the_target->start_non_stop == NULL)
    {
      if (nonstop)
	return -1;
      else
	return 0;
    }

  return (*the_target->start_non_stop) (nonstop);
}

void
set_target_ops (process_stratum_target *target)
{
  the_target = XNEW (process_stratum_target);
  memcpy (the_target, target, sizeof (*the_target));
}

/* Convert pid to printable format.  */

const char *
target_pid_to_str (ptid_t ptid)
{
  static char buf[80];

  if (ptid == minus_one_ptid)
    xsnprintf (buf, sizeof (buf), "<all threads>");
  else if (ptid == null_ptid)
    xsnprintf (buf, sizeof (buf), "<null thread>");
  else if (ptid.tid () != 0)
    xsnprintf (buf, sizeof (buf), "Thread %d.0x%lx",
	       ptid.pid (), ptid.tid ());
  else if (ptid.lwp () != 0)
    xsnprintf (buf, sizeof (buf), "LWP %d.%ld",
	       ptid.pid (), ptid.lwp ());
  else
    xsnprintf (buf, sizeof (buf), "Process %d",
	       ptid.pid ());

  return buf;
}

int
kill_inferior (process_info *proc)
{
  gdb_agent_about_to_close (proc->pid);

  return (*the_target->kill) (proc);
}

/* Target can do hardware single step.  */

int
target_can_do_hardware_single_step (void)
{
  return 1;
}

/* Default implementation for breakpoint_kind_for_pc.

   The default behavior for targets that don't implement breakpoint_kind_for_pc
   is to use the size of a breakpoint as the kind.  */

int
default_breakpoint_kind_from_pc (CORE_ADDR *pcptr)
{
  int size = 0;

  gdb_assert (the_target->sw_breakpoint_from_kind != NULL);

  (*the_target->sw_breakpoint_from_kind) (0, &size);
  return size;
}

/* Define it.  */

target_terminal_state target_terminal::m_terminal_state
  = target_terminal_state::is_ours;

/* See target/target.h.  */

void
target_terminal::init ()
{
  /* Placeholder needed because of fork_inferior.  Not necessary on
     GDBserver.  */
}

/* See target/target.h.  */

void
target_terminal::inferior ()
{
  /* Placeholder needed because of fork_inferior.  Not necessary on
     GDBserver.  */
}

/* See target/target.h.  */

void
target_terminal::ours ()
{
  /* Placeholder needed because of fork_inferior.  Not necessary on
     GDBserver.  */
}

/* See target/target.h.  */

void
target_terminal::ours_for_output (void)
{
  /* Placeholder.  */
}

/* See target/target.h.  */

void
target_terminal::info (const char *arg, int from_tty)
{
  /* Placeholder.  */
}
Commit	Line	Data
	1	/* Target operations for the remote server for GDB.
	2	Copyright (C) 2002-2020 Free Software Foundation, Inc.
	3
	4	Contributed by MontaVista Software.
	5
	6	This file is part of GDB.
	7
	8	This program is free software; you can redistribute it and/or modify
	9	it under the terms of the GNU General Public License as published by
	10	the Free Software Foundation; either version 3 of the License, or
	11	(at your option) any later version.
	12
	13	This program is distributed in the hope that it will be useful,
	14	but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	GNU General Public License for more details.
	17
	18	You should have received a copy of the GNU General Public License
	19	along with this program. If not, see <http://www.gnu.org/licenses/>. */
	20
	21	#include "server.h"
	22	#include "tracepoint.h"
	23	#include "gdbsupport/byte-vector.h"
	24
	25	process_stratum_target *the_target;
	26
	27	int
	28	set_desired_thread ()
	29	{
	30	client_state &cs = get_client_state ();
	31	thread_info *found = find_thread_ptid (cs.general_thread);
	32
	33	current_thread = found;
	34	return (current_thread != NULL);
	35	}
	36
	37	/* The thread that was current before prepare_to_access_memory was
	38	called. done_accessing_memory uses this to restore the previous
	39	selected thread. */
	40	static ptid_t prev_general_thread;
	41
	42	/* See target.h. */
	43
	44	int
	45	prepare_to_access_memory (void)
	46	{
	47	client_state &cs = get_client_state ();
	48
	49	/* The first thread found. */
	50	struct thread_info *first = NULL;
	51	/* The first stopped thread found. */
	52	struct thread_info *stopped = NULL;
	53	/* The current general thread, if found. */
	54	struct thread_info *current = NULL;
	55
	56	/* Save the general thread value, since prepare_to_access_memory could change
	57	it. */
	58	prev_general_thread = cs.general_thread;
	59
	60	if (the_target->prepare_to_access_memory != NULL)
	61	{
	62	int res;
	63
	64	res = the_target->prepare_to_access_memory ();
	65	if (res != 0)
	66	return res;
	67	}
	68
	69	for_each_thread (prev_general_thread.pid (), [&] (thread_info *thread)
	70	{
	71	if (mythread_alive (thread->id))
	72	{
	73	if (stopped == NULL && the_target->thread_stopped != NULL
	74	&& thread_stopped (thread))
	75	stopped = thread;
	76
	77	if (first == NULL)
	78	first = thread;
	79
	80	if (current == NULL && prev_general_thread == thread->id)
	81	current = thread;
	82	}
	83	});
	84
	85	/* The thread we end up choosing. */
	86	struct thread_info *thread;
	87
	88	/* Prefer a stopped thread. If none is found, try the current
	89	thread. Otherwise, take the first thread in the process. If
	90	none is found, undo the effects of
	91	target->prepare_to_access_memory() and return error. */
	92	if (stopped != NULL)
	93	thread = stopped;
	94	else if (current != NULL)
	95	thread = current;
	96	else if (first != NULL)
	97	thread = first;
	98	else
	99	{
	100	done_accessing_memory ();
	101	return 1;
	102	}
	103
	104	current_thread = thread;
	105	cs.general_thread = ptid_of (thread);
	106
	107	return 0;
	108	}
	109
	110	/* See target.h. */
	111
	112	void
	113	done_accessing_memory (void)
	114	{
	115	client_state &cs = get_client_state ();
	116
	117	if (the_target->done_accessing_memory != NULL)
	118	the_target->done_accessing_memory ();
	119
	120	/* Restore the previous selected thread. */
	121	cs.general_thread = prev_general_thread;
	122	switch_to_thread (the_target, cs.general_thread);
	123	}
	124
	125	int
	126	read_inferior_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
	127	{
	128	int res;
	129	res = (*the_target->read_memory) (memaddr, myaddr, len);
	130	check_mem_read (memaddr, myaddr, len);
	131	return res;
	132	}
	133
	134	/* See target/target.h. */
	135
	136	int
	137	target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
	138	{
	139	return read_inferior_memory (memaddr, myaddr, len);
	140	}
	141
	142	/* See target/target.h. */
	143
	144	int
	145	target_read_uint32 (CORE_ADDR memaddr, uint32_t *result)
	146	{
	147	return read_inferior_memory (memaddr, (gdb_byte ) result, sizeof (result));
	148	}
	149
	150	/* See target/target.h. */
	151
	152	int
	153	target_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr,
	154	ssize_t len)
	155	{
	156	/* Make a copy of the data because check_mem_write may need to
	157	update it. */
	158	gdb::byte_vector buffer (myaddr, myaddr + len);
	159	check_mem_write (memaddr, buffer.data (), myaddr, len);
	160	return (*the_target->write_memory) (memaddr, buffer.data (), len);
	161	}
	162
	163	ptid_t
	164	mywait (ptid_t ptid, struct target_waitstatus *ourstatus, int options,
	165	int connected_wait)
	166	{
	167	ptid_t ret;
	168
	169	if (connected_wait)
	170	server_waiting = 1;
	171
	172	ret = target_wait (ptid, ourstatus, options);
	173
	174	/* We don't expose _LOADED events to gdbserver core. See the
	175	`dlls_changed' global. */
	176	if (ourstatus->kind == TARGET_WAITKIND_LOADED)
	177	ourstatus->kind = TARGET_WAITKIND_STOPPED;
	178
	179	/* If GDB is connected through TCP/serial, then GDBserver will most
	180	probably be running on its own terminal/console, so it's nice to
	181	print there why is GDBserver exiting. If however, GDB is
	182	connected through stdio, then there's no need to spam the GDB
	183	console with this -- the user will already see the exit through
	184	regular GDB output, in that same terminal. */
	185	if (!remote_connection_is_stdio ())
	186	{
	187	if (ourstatus->kind == TARGET_WAITKIND_EXITED)
	188	fprintf (stderr,
	189	"\nChild exited with status %d\n", ourstatus->value.integer);
	190	else if (ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
	191	fprintf (stderr, "\nChild terminated with signal = 0x%x (%s)\n",
	192	gdb_signal_to_host (ourstatus->value.sig),
	193	gdb_signal_to_name (ourstatus->value.sig));
	194	}
	195
	196	if (connected_wait)
	197	server_waiting = 0;
	198
	199	return ret;
	200	}
	201
	202	/* See target/target.h. */
	203
	204	void
	205	target_stop_and_wait (ptid_t ptid)
	206	{
	207	struct target_waitstatus status;
	208	bool was_non_stop = non_stop;
	209	struct thread_resume resume_info;
	210
	211	resume_info.thread = ptid;
	212	resume_info.kind = resume_stop;
	213	resume_info.sig = GDB_SIGNAL_0;
	214	(*the_target->resume) (&resume_info, 1);
	215
	216	non_stop = true;
	217	mywait (ptid, &status, 0, 0);
	218	non_stop = was_non_stop;
	219	}
	220
	221	/* See target/target.h. */
	222
	223	ptid_t
	224	target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
	225	{
	226	return (*the_target->wait) (ptid, status, options);
	227	}
	228
	229	/* See target/target.h. */
	230
	231	void
	232	target_mourn_inferior (ptid_t ptid)
	233	{
	234	(*the_target->mourn) (find_process_pid (ptid.pid ()));
	235	}
	236
	237	/* See target/target.h. */
	238
	239	void
	240	target_continue_no_signal (ptid_t ptid)
	241	{
	242	struct thread_resume resume_info;
	243
	244	resume_info.thread = ptid;
	245	resume_info.kind = resume_continue;
	246	resume_info.sig = GDB_SIGNAL_0;
	247	(*the_target->resume) (&resume_info, 1);
	248	}
	249
	250	/* See target/target.h. */
	251
	252	void
	253	target_continue (ptid_t ptid, enum gdb_signal signal)
	254	{
	255	struct thread_resume resume_info;
	256
	257	resume_info.thread = ptid;
	258	resume_info.kind = resume_continue;
	259	resume_info.sig = gdb_signal_to_host (signal);
	260	(*the_target->resume) (&resume_info, 1);
	261	}
	262
	263	/* See target/target.h. */
	264
	265	int
	266	target_supports_multi_process (void)
	267	{
	268	return (the_target->supports_multi_process != NULL ?
	269	(*the_target->supports_multi_process) () : 0);
	270	}
	271
	272	int
	273	start_non_stop (int nonstop)
	274	{
	275	if (the_target->start_non_stop == NULL)
	276	{
	277	if (nonstop)
	278	return -1;
	279	else
	280	return 0;
	281	}
	282
	283	return (*the_target->start_non_stop) (nonstop);
	284	}
	285
	286	void
	287	set_target_ops (process_stratum_target *target)
	288	{
	289	the_target = XNEW (process_stratum_target);
	290	memcpy (the_target, target, sizeof (*the_target));
	291	}
	292
	293	/* Convert pid to printable format. */
	294
	295	const char *
	296	target_pid_to_str (ptid_t ptid)
	297	{
	298	static char buf[80];
	299
	300	if (ptid == minus_one_ptid)
	301	xsnprintf (buf, sizeof (buf), "<all threads>");
	302	else if (ptid == null_ptid)
	303	xsnprintf (buf, sizeof (buf), "<null thread>");
	304	else if (ptid.tid () != 0)
	305	xsnprintf (buf, sizeof (buf), "Thread %d.0x%lx",
	306	ptid.pid (), ptid.tid ());
	307	else if (ptid.lwp () != 0)
	308	xsnprintf (buf, sizeof (buf), "LWP %d.%ld",
	309	ptid.pid (), ptid.lwp ());
	310	else
	311	xsnprintf (buf, sizeof (buf), "Process %d",
	312	ptid.pid ());
	313
	314	return buf;
	315	}
	316
	317	int
	318	kill_inferior (process_info *proc)
	319	{
	320	gdb_agent_about_to_close (proc->pid);
	321
	322	return (*the_target->kill) (proc);
	323	}
	324
	325	/* Target can do hardware single step. */
	326
	327	int
	328	target_can_do_hardware_single_step (void)
	329	{
	330	return 1;
	331	}
	332
	333	/* Default implementation for breakpoint_kind_for_pc.
	334
	335	The default behavior for targets that don't implement breakpoint_kind_for_pc
	336	is to use the size of a breakpoint as the kind. */
	337
	338	int
	339	default_breakpoint_kind_from_pc (CORE_ADDR *pcptr)
	340	{
	341	int size = 0;
	342
	343	gdb_assert (the_target->sw_breakpoint_from_kind != NULL);
	344
	345	(*the_target->sw_breakpoint_from_kind) (0, &size);
	346	return size;
	347	}
	348
	349	/* Define it. */
	350
	351	target_terminal_state target_terminal::m_terminal_state
	352	= target_terminal_state::is_ours;
	353
	354	/* See target/target.h. */
	355
	356	void
	357	target_terminal::init ()
	358	{
	359	/* Placeholder needed because of fork_inferior. Not necessary on
	360	GDBserver. */
	361	}
	362
	363	/* See target/target.h. */
	364
	365	void
	366	target_terminal::inferior ()
	367	{
	368	/* Placeholder needed because of fork_inferior. Not necessary on
	369	GDBserver. */
	370	}
	371
	372	/* See target/target.h. */
	373
	374	void
	375	target_terminal::ours ()
	376	{
	377	/* Placeholder needed because of fork_inferior. Not necessary on
	378	GDBserver. */
	379	}
	380
	381	/* See target/target.h. */
	382
	383	void
	384	target_terminal::ours_for_output (void)
	385	{
	386	/* Placeholder. */
	387	}
	388
	389	/* See target/target.h. */
	390
	391	void
	392	target_terminal::info (const char *arg, int from_tty)
	393	{
	394	/* Placeholder. */
	395	}