binutils-gdb/gdbserver/target.cc
Tankut Baris Aktemur 24583e45ef gdbserver: replace direct assignments to current_thread
Replace the direct assignments to current_thread with
switch_to_thread.  Use scoped_restore_current_thread when appropriate.
There is one instance remaining in linux-low.cc's wait_for_sigstop.
This will be handled in a separate patch.

Regression-tested on X86-64 Linux using the native-gdbserver and
native-extended-gdbserver board files.
2021-12-13 12:22:48 +01:00

867 lines
17 KiB
C++

/* Target operations for the remote server for GDB.
Copyright (C) 2002-2021 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"
#include "hostio.h"
#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.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);
switch_to_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;
int 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->supports_thread_stopped ()
&& target_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;
}
switch_to_thread (thread);
cs.general_thread = ptid_of (thread);
return 0;
}
/* See target.h. */
void
done_accessing_memory (void)
{
client_state &cs = get_client_state ();
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,
target_wait_flags 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->set_stopped (GDB_SIGNAL_0);
/* 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->exit_status ());
else if (ourstatus->kind () == TARGET_WAITKIND_SIGNALLED)
fprintf (stderr, "\nChild terminated with signal = 0x%x (%s)\n",
gdb_signal_to_host (ourstatus->sig ()),
gdb_signal_to_name (ourstatus->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,
target_wait_flags 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 ();
}
void
set_target_ops (process_stratum_target *target)
{
the_target = target;
}
/* Convert pid to printable format. */
std::string
target_pid_to_str (ptid_t ptid)
{
if (ptid == minus_one_ptid)
return string_printf("<all threads>");
else if (ptid == null_ptid)
return string_printf("<null thread>");
else if (ptid.tid () != 0)
return string_printf("Thread %d.0x%s",
ptid.pid (),
phex_nz (ptid.tid (), sizeof (ULONGEST)));
else if (ptid.lwp () != 0)
return string_printf("LWP %d.%ld",
ptid.pid (), ptid.lwp ());
else
return string_printf("Process %d",
ptid.pid ());
}
int
kill_inferior (process_info *proc)
{
gdb_agent_about_to_close (proc->pid);
return the_target->kill (proc);
}
/* 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. */
}
/* Default implementations of target ops.
See target.h for definitions. */
void
process_stratum_target::post_create_inferior ()
{
/* Nop. */
}
int
process_stratum_target::prepare_to_access_memory ()
{
return 0;
}
void
process_stratum_target::done_accessing_memory ()
{
/* Nop. */
}
void
process_stratum_target::look_up_symbols ()
{
/* Nop. */
}
bool
process_stratum_target::supports_read_auxv ()
{
return false;
}
int
process_stratum_target::read_auxv (CORE_ADDR offset, unsigned char *myaddr,
unsigned int len)
{
gdb_assert_not_reached ("target op read_auxv not supported");
}
bool
process_stratum_target::supports_z_point_type (char z_type)
{
return false;
}
int
process_stratum_target::insert_point (enum raw_bkpt_type type,
CORE_ADDR addr,
int size, raw_breakpoint *bp)
{
return 1;
}
int
process_stratum_target::remove_point (enum raw_bkpt_type type,
CORE_ADDR addr,
int size, raw_breakpoint *bp)
{
return 1;
}
bool
process_stratum_target::stopped_by_sw_breakpoint ()
{
return false;
}
bool
process_stratum_target::supports_stopped_by_sw_breakpoint ()
{
return false;
}
bool
process_stratum_target::stopped_by_hw_breakpoint ()
{
return false;
}
bool
process_stratum_target::supports_stopped_by_hw_breakpoint ()
{
return false;
}
bool
process_stratum_target::supports_hardware_single_step ()
{
return false;
}
bool
process_stratum_target::stopped_by_watchpoint ()
{
return false;
}
CORE_ADDR
process_stratum_target::stopped_data_address ()
{
return 0;
}
bool
process_stratum_target::supports_read_offsets ()
{
return false;
}
bool
process_stratum_target::supports_memory_tagging ()
{
return false;
}
bool
process_stratum_target::fetch_memtags (CORE_ADDR address, size_t len,
gdb::byte_vector &tags, int type)
{
gdb_assert_not_reached ("target op fetch_memtags not supported");
}
bool
process_stratum_target::store_memtags (CORE_ADDR address, size_t len,
const gdb::byte_vector &tags, int type)
{
gdb_assert_not_reached ("target op store_memtags not supported");
}
int
process_stratum_target::read_offsets (CORE_ADDR *text, CORE_ADDR *data)
{
gdb_assert_not_reached ("target op read_offsets not supported");
}
bool
process_stratum_target::supports_get_tls_address ()
{
return false;
}
int
process_stratum_target::get_tls_address (thread_info *thread,
CORE_ADDR offset,
CORE_ADDR load_module,
CORE_ADDR *address)
{
gdb_assert_not_reached ("target op get_tls_address not supported");
}
bool
process_stratum_target::supports_qxfer_osdata ()
{
return false;
}
int
process_stratum_target::qxfer_osdata (const char *annex,
unsigned char *readbuf,
unsigned const char *writebuf,
CORE_ADDR offset, int len)
{
gdb_assert_not_reached ("target op qxfer_osdata not supported");
}
bool
process_stratum_target::supports_qxfer_siginfo ()
{
return false;
}
int
process_stratum_target::qxfer_siginfo (const char *annex,
unsigned char *readbuf,
unsigned const char *writebuf,
CORE_ADDR offset, int len)
{
gdb_assert_not_reached ("target op qxfer_siginfo not supported");
}
bool
process_stratum_target::supports_non_stop ()
{
return false;
}
bool
process_stratum_target::async (bool enable)
{
return false;
}
int
process_stratum_target::start_non_stop (bool enable)
{
if (enable)
return -1;
else
return 0;
}
bool
process_stratum_target::supports_multi_process ()
{
return false;
}
bool
process_stratum_target::supports_fork_events ()
{
return false;
}
bool
process_stratum_target::supports_vfork_events ()
{
return false;
}
bool
process_stratum_target::supports_exec_events ()
{
return false;
}
void
process_stratum_target::handle_new_gdb_connection ()
{
/* Nop. */
}
int
process_stratum_target::handle_monitor_command (char *mon)
{
return 0;
}
int
process_stratum_target::core_of_thread (ptid_t ptid)
{
return -1;
}
bool
process_stratum_target::supports_read_loadmap ()
{
return false;
}
int
process_stratum_target::read_loadmap (const char *annex,
CORE_ADDR offset,
unsigned char *myaddr,
unsigned int len)
{
gdb_assert_not_reached ("target op read_loadmap not supported");
}
void
process_stratum_target::process_qsupported
(gdb::array_view<const char * const> features)
{
/* Nop. */
}
bool
process_stratum_target::supports_tracepoints ()
{
return false;
}
CORE_ADDR
process_stratum_target::read_pc (regcache *regcache)
{
gdb_assert_not_reached ("process_target::read_pc: Unable to find PC");
}
void
process_stratum_target::write_pc (regcache *regcache, CORE_ADDR pc)
{
gdb_assert_not_reached ("process_target::write_pc: Unable to update PC");
}
bool
process_stratum_target::supports_thread_stopped ()
{
return false;
}
bool
process_stratum_target::thread_stopped (thread_info *thread)
{
gdb_assert_not_reached ("target op thread_stopped not supported");
}
bool
process_stratum_target::supports_get_tib_address ()
{
return false;
}
int
process_stratum_target::get_tib_address (ptid_t ptid, CORE_ADDR *address)
{
gdb_assert_not_reached ("target op get_tib_address not supported");
}
void
process_stratum_target::pause_all (bool freeze)
{
/* Nop. */
}
void
process_stratum_target::unpause_all (bool unfreeze)
{
/* Nop. */
}
void
process_stratum_target::stabilize_threads ()
{
/* Nop. */
}
bool
process_stratum_target::supports_fast_tracepoints ()
{
return false;
}
int
process_stratum_target::install_fast_tracepoint_jump_pad
(CORE_ADDR tpoint, CORE_ADDR tpaddr, CORE_ADDR collector,
CORE_ADDR lockaddr, ULONGEST orig_size, CORE_ADDR *jump_entry,
CORE_ADDR *trampoline, ULONGEST *trampoline_size,
unsigned char *jjump_pad_insn, ULONGEST *jjump_pad_insn_size,
CORE_ADDR *adjusted_insn_addr, CORE_ADDR *adjusted_insn_addr_end,
char *err)
{
gdb_assert_not_reached ("target op install_fast_tracepoint_jump_pad "
"not supported");
}
int
process_stratum_target::get_min_fast_tracepoint_insn_len ()
{
return 0;
}
struct emit_ops *
process_stratum_target::emit_ops ()
{
return nullptr;
}
bool
process_stratum_target::supports_disable_randomization ()
{
return false;
}
bool
process_stratum_target::supports_qxfer_libraries_svr4 ()
{
return false;
}
int
process_stratum_target::qxfer_libraries_svr4 (const char *annex,
unsigned char *readbuf,
unsigned const char *writebuf,
CORE_ADDR offset, int len)
{
gdb_assert_not_reached ("target op qxfer_libraries_svr4 not supported");
}
bool
process_stratum_target::supports_agent ()
{
return false;
}
btrace_target_info *
process_stratum_target::enable_btrace (ptid_t ptid, const btrace_config *conf)
{
error (_("Target does not support branch tracing."));
}
int
process_stratum_target::disable_btrace (btrace_target_info *tinfo)
{
error (_("Target does not support branch tracing."));
}
int
process_stratum_target::read_btrace (btrace_target_info *tinfo,
buffer *buffer,
enum btrace_read_type type)
{
error (_("Target does not support branch tracing."));
}
int
process_stratum_target::read_btrace_conf (const btrace_target_info *tinfo,
buffer *buffer)
{
error (_("Target does not support branch tracing."));
}
bool
process_stratum_target::supports_range_stepping ()
{
return false;
}
bool
process_stratum_target::supports_pid_to_exec_file ()
{
return false;
}
const char *
process_stratum_target::pid_to_exec_file (int pid)
{
gdb_assert_not_reached ("target op pid_to_exec_file not supported");
}
bool
process_stratum_target::supports_multifs ()
{
return false;
}
int
process_stratum_target::multifs_open (int pid, const char *filename,
int flags, mode_t mode)
{
return open (filename, flags, mode);
}
int
process_stratum_target::multifs_unlink (int pid, const char *filename)
{
return unlink (filename);
}
ssize_t
process_stratum_target::multifs_readlink (int pid, const char *filename,
char *buf, size_t bufsiz)
{
return readlink (filename, buf, bufsiz);
}
int
process_stratum_target::breakpoint_kind_from_pc (CORE_ADDR *pcptr)
{
/* The default behavior is to use the size of a breakpoint as the
kind. */
int size = 0;
sw_breakpoint_from_kind (0, &size);
return size;
}
int
process_stratum_target::breakpoint_kind_from_current_state (CORE_ADDR *pcptr)
{
return breakpoint_kind_from_pc (pcptr);
}
const char *
process_stratum_target::thread_name (ptid_t thread)
{
return nullptr;
}
bool
process_stratum_target::thread_handle (ptid_t ptid, gdb_byte **handle,
int *handle_len)
{
return false;
}
thread_info *
process_stratum_target::thread_pending_parent (thread_info *thread)
{
return nullptr;
}
thread_info *
process_stratum_target::thread_pending_child (thread_info *thread)
{
return nullptr;
}
bool
process_stratum_target::supports_software_single_step ()
{
return false;
}
bool
process_stratum_target::supports_catch_syscall ()
{
return false;
}
int
process_stratum_target::get_ipa_tdesc_idx ()
{
return 0;
}