binutils-gdb/gdbserver/server.h
Andrew Burgess 442131c1be gdbserver: Add mechanism to prevent sending T stop packets
There is a developer only feature in gdbserver that provides a
command line option --disable-packet that prevents some packets from
being sent, which is used to increase test coverage within GDB.

This commit extends this mechanism to prevent GDBserver from sending
the T stop reply packets, instead limiting GDBserver to only send the
S stop reply packets.

The S stop reply packet is part of the older target control mechanism,
which has design flaws that were worked around with the introduction
of the newer target control mechanism, which uses the T stop reply
packet.

Limiting GDBserver to use S stop packets instead of T stop packets
will, inevitably, mean that GDBserver doesn't function correctly in
many cases involving multiple threads, however, I don't think this is
too important, this is a developer only feature, intended to allow us
to test GDB.

A new test that makes use of this feature will be added in the next
commit.

gdbserver/ChangeLog:

	* remote-utils.cc (prepare_resume_reply): Add ability to convert T
	reply into an S reply.
	* server.cc (disable_packet_T): New global.
	(captured_main): Set new global when appropriate.
	* server.h (disable_packet_T): Declare.
2020-03-02 15:06:35 +00:00

212 lines
6.2 KiB
C

/* Common definitions for remote server for GDB.
Copyright (C) 1993-2020 Free Software Foundation, Inc.
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/>. */
#ifndef GDBSERVER_SERVER_H
#define GDBSERVER_SERVER_H
#include "gdbsupport/common-defs.h"
#undef PACKAGE
#undef PACKAGE_NAME
#undef PACKAGE_VERSION
#undef PACKAGE_STRING
#undef PACKAGE_TARNAME
#include <config.h>
gdb_static_assert (sizeof (CORE_ADDR) >= sizeof (void *));
#ifdef __MINGW32CE__
#include "wincecompat.h"
#endif
#include "gdbsupport/version.h"
#if !HAVE_DECL_PERROR
#ifndef perror
extern void perror (const char *);
#endif
#endif
#if !HAVE_DECL_VASPRINTF
extern int vasprintf(char **strp, const char *fmt, va_list ap);
#endif
#if !HAVE_DECL_VSNPRINTF
int vsnprintf(char *str, size_t size, const char *format, va_list ap);
#endif
#ifdef IN_PROCESS_AGENT
# define PROG "ipa"
#else
# define PROG "gdbserver"
#endif
#include "gdbsupport/buffer.h"
#include "gdbsupport/xml-utils.h"
#include "regcache.h"
#include "gdbsupport/gdb_signals.h"
#include "target.h"
#include "mem-break.h"
#include "gdbsupport/environ.h"
/* Target-specific functions */
void initialize_low ();
/* Public variables in server.c */
extern bool server_waiting;
extern bool disable_packet_vCont;
extern bool disable_packet_Tthread;
extern bool disable_packet_qC;
extern bool disable_packet_qfThreadInfo;
extern bool disable_packet_T;
extern bool run_once;
extern bool non_stop;
#if USE_WIN32API
#include <winsock2.h>
typedef SOCKET gdb_fildes_t;
#else
typedef int gdb_fildes_t;
#endif
#include "event-loop.h"
/* Functions from server.c. */
extern void handle_v_requests (char *own_buf, int packet_len,
int *new_packet_len);
extern int handle_serial_event (int err, gdb_client_data client_data);
extern int handle_target_event (int err, gdb_client_data client_data);
/* Get rid of the currently pending stop replies that match PTID. */
extern void discard_queued_stop_replies (ptid_t ptid);
/* Returns true if there's a pending stop reply that matches PTID in
the vStopped notifications queue. */
extern int in_queued_stop_replies (ptid_t ptid);
#include "remote-utils.h"
#include "utils.h"
#include "debug.h"
#include "gdbsupport/gdb_vecs.h"
/* Maximum number of bytes to read/write at once. The value here
is chosen to fill up a packet (the headers account for the 32). */
#define MAXBUFBYTES(N) (((N)-32)/2)
/* Buffer sizes for transferring memory, registers, etc. Set to a constant
value to accomodate multiple register formats. This value must be at least
as large as the largest register set supported by gdbserver. */
#define PBUFSIZ 18432
/* Definition for an unknown syscall, used basically in error-cases. */
#define UNKNOWN_SYSCALL (-1)
/* Definition for any syscall, used for unfiltered syscall reporting. */
#define ANY_SYSCALL (-2)
/* After fork_inferior has been called, we need to adjust a few
signals and call startup_inferior to start the inferior and consume
its first events. This is done here. PID is the pid of the new
inferior and PROGRAM is its name. */
extern void post_fork_inferior (int pid, const char *program);
/* Get the gdb_environ being used in the current session. */
extern gdb_environ *get_environ ();
extern unsigned long signal_pid;
/* Description of the client remote protocol state for the currently
connected client. */
struct client_state
{
client_state ():
own_buf ((char *) xmalloc (PBUFSIZ + 1))
{}
/* The thread set with an `Hc' packet. `Hc' is deprecated in favor of
`vCont'. Note the multi-process extensions made `vCont' a
requirement, so `Hc pPID.TID' is pretty much undefined. So
CONT_THREAD can be null_ptid for no `Hc' thread, minus_one_ptid for
resuming all threads of the process (again, `Hc' isn't used for
multi-process), or a specific thread ptid_t. */
ptid_t cont_thread;
/* The thread set with an `Hg' packet. */
ptid_t general_thread;
int multi_process = 0;
int report_fork_events = 0;
int report_vfork_events = 0;
int report_exec_events = 0;
int report_thread_events = 0;
/* True if the "swbreak+" feature is active. In that case, GDB wants
us to report whether a trap is explained by a software breakpoint
and for the server to handle PC adjustment if necessary on this
target. Only enabled if the target supports it. */
int swbreak_feature = 0;
/* True if the "hwbreak+" feature is active. In that case, GDB wants
us to report whether a trap is explained by a hardware breakpoint.
Only enabled if the target supports it. */
int hwbreak_feature = 0;
/* True if the "vContSupported" feature is active. In that case, GDB
wants us to report whether single step is supported in the reply to
"vCont?" packet. */
int vCont_supported = 0;
/* Whether we should attempt to disable the operating system's address
space randomization feature before starting an inferior. */
int disable_randomization = 1;
int pass_signals[GDB_SIGNAL_LAST];
int program_signals[GDB_SIGNAL_LAST];
int program_signals_p = 0;
/* Last status reported to GDB. */
struct target_waitstatus last_status;
ptid_t last_ptid;
char *own_buf;
/* If true, then GDB has requested noack mode. */
int noack_mode = 0;
/* If true, then we tell GDB to use noack mode by default. */
int transport_is_reliable = 0;
/* The traceframe to be used as the source of data to send back to
GDB. A value of -1 means to get data from the live program. */
int current_traceframe = -1;
};
client_state &get_client_state ();
#include "gdbthread.h"
#include "inferiors.h"
#endif /* GDBSERVER_SERVER_H */