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- /* Shared utility routines for GDB to interact with agent.
- Copyright (C) 2009-2022 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/>. */
- #include "common-defs.h"
- #include "target/target.h"
- #include "gdbsupport/symbol.h"
- #include <unistd.h>
- #include "filestuff.h"
- #define IPA_SYM_STRUCT_NAME ipa_sym_addresses_common
- #include "agent.h"
- bool debug_agent = false;
- /* A stdarg wrapper for debug_vprintf. */
- static void ATTRIBUTE_PRINTF (1, 2)
- debug_agent_printf (const char *fmt, ...)
- {
- va_list ap;
- if (!debug_agent)
- return;
- va_start (ap, fmt);
- debug_vprintf (fmt, ap);
- va_end (ap);
- }
- #define DEBUG_AGENT debug_agent_printf
- /* Global flag to determine using agent or not. */
- bool use_agent = false;
- /* Addresses of in-process agent's symbols both GDB and GDBserver cares
- about. */
- struct ipa_sym_addresses_common
- {
- CORE_ADDR addr_helper_thread_id;
- CORE_ADDR addr_cmd_buf;
- CORE_ADDR addr_capability;
- };
- /* Cache of the helper thread id. FIXME: this global should be made
- per-process. */
- static uint32_t helper_thread_id = 0;
- static struct
- {
- const char *name;
- int offset;
- } symbol_list[] = {
- IPA_SYM(helper_thread_id),
- IPA_SYM(cmd_buf),
- IPA_SYM(capability),
- };
- static struct ipa_sym_addresses_common ipa_sym_addrs;
- static bool all_agent_symbols_looked_up = false;
- bool
- agent_loaded_p (void)
- {
- return all_agent_symbols_looked_up;
- }
- /* Look up all symbols needed by agent. Return 0 if all the symbols are
- found, return non-zero otherwise. */
- int
- agent_look_up_symbols (void *arg)
- {
- all_agent_symbols_looked_up = false;
- for (int i = 0; i < sizeof (symbol_list) / sizeof (symbol_list[0]); i++)
- {
- CORE_ADDR *addrp =
- (CORE_ADDR *) ((char *) &ipa_sym_addrs + symbol_list[i].offset);
- struct objfile *objfile = (struct objfile *) arg;
- if (find_minimal_symbol_address (symbol_list[i].name, addrp,
- objfile) != 0)
- {
- DEBUG_AGENT ("symbol `%s' not found\n", symbol_list[i].name);
- return -1;
- }
- }
- all_agent_symbols_looked_up = true;
- return 0;
- }
- static unsigned int
- agent_get_helper_thread_id (void)
- {
- if (helper_thread_id == 0)
- {
- if (target_read_uint32 (ipa_sym_addrs.addr_helper_thread_id,
- &helper_thread_id))
- warning (_("Error reading helper thread's id in lib"));
- }
- return helper_thread_id;
- }
- #ifdef HAVE_SYS_UN_H
- #include <sys/socket.h>
- #include <sys/un.h>
- #define SOCK_DIR P_tmpdir
- #ifndef UNIX_PATH_MAX
- #define UNIX_PATH_MAX sizeof(((struct sockaddr_un *) NULL)->sun_path)
- #endif
- #endif
- /* Connects to synchronization socket. PID is the pid of inferior, which is
- used to set up the connection socket. */
- static int
- gdb_connect_sync_socket (int pid)
- {
- #ifdef HAVE_SYS_UN_H
- struct sockaddr_un addr = {};
- int res, fd;
- char path[UNIX_PATH_MAX];
- res = xsnprintf (path, UNIX_PATH_MAX, "%s/gdb_ust%d", P_tmpdir, pid);
- if (res >= UNIX_PATH_MAX)
- return -1;
- res = fd = gdb_socket_cloexec (PF_UNIX, SOCK_STREAM, 0);
- if (res == -1)
- {
- warning (_("error opening sync socket: %s"), safe_strerror (errno));
- return -1;
- }
- addr.sun_family = AF_UNIX;
- res = xsnprintf (addr.sun_path, UNIX_PATH_MAX, "%s", path);
- if (res >= UNIX_PATH_MAX)
- {
- warning (_("string overflow allocating socket name"));
- close (fd);
- return -1;
- }
- res = connect (fd, (struct sockaddr *) &addr, sizeof (addr));
- if (res == -1)
- {
- warning (_("error connecting sync socket (%s): %s. "
- "Make sure the directory exists and that it is writable."),
- path, safe_strerror (errno));
- close (fd);
- return -1;
- }
- return fd;
- #else
- return -1;
- #endif
- }
- /* Execute an agent command in the inferior. PID is the value of pid of the
- inferior. CMD is the buffer for command. GDB or GDBserver will store the
- command into it and fetch the return result from CMD. The interaction
- between GDB/GDBserver and the agent is synchronized by a synchronization
- socket. Return zero if success, otherwise return non-zero. */
- int
- agent_run_command (int pid, const char *cmd, int len)
- {
- int fd;
- int tid = agent_get_helper_thread_id ();
- ptid_t ptid = ptid_t (pid, tid);
- int ret = target_write_memory (ipa_sym_addrs.addr_cmd_buf,
- (gdb_byte *) cmd, len);
- if (ret != 0)
- {
- warning (_("unable to write"));
- return -1;
- }
- DEBUG_AGENT ("agent: resumed helper thread\n");
- /* Resume helper thread. */
- target_continue_no_signal (ptid);
- fd = gdb_connect_sync_socket (pid);
- if (fd >= 0)
- {
- char buf[1] = "";
- DEBUG_AGENT ("agent: signalling helper thread\n");
- do
- {
- ret = write (fd, buf, 1);
- } while (ret == -1 && errno == EINTR);
- DEBUG_AGENT ("agent: waiting for helper thread's response\n");
- do
- {
- ret = read (fd, buf, 1);
- } while (ret == -1 && errno == EINTR);
- close (fd);
- DEBUG_AGENT ("agent: helper thread's response received\n");
- }
- else
- return -1;
- /* Need to read response with the inferior stopped. */
- if (ptid != null_ptid)
- {
- /* Stop thread PTID. */
- DEBUG_AGENT ("agent: stop helper thread\n");
- target_stop_and_wait (ptid);
- }
- if (fd >= 0)
- {
- if (target_read_memory (ipa_sym_addrs.addr_cmd_buf, (gdb_byte *) cmd,
- IPA_CMD_BUF_SIZE))
- {
- warning (_("Error reading command response"));
- return -1;
- }
- }
- return 0;
- }
- /* Each bit of it stands for a capability of agent. */
- static uint32_t agent_capability = 0;
- /* Return true if agent has capability AGENT_CAP, otherwise return false. */
- bool
- agent_capability_check (enum agent_capa agent_capa)
- {
- if (agent_capability == 0)
- {
- if (target_read_uint32 (ipa_sym_addrs.addr_capability,
- &agent_capability))
- warning (_("Error reading capability of agent"));
- }
- return (agent_capability & agent_capa) != 0;
- }
- /* Invalidate the cache of agent capability, so we'll read it from inferior
- again. Call it when launches a new program or reconnect to remote stub. */
- void
- agent_capability_invalidate (void)
- {
- agent_capability = 0;
- }
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