/* Main code for remote server for GDB. Copyright (C) 1989, 1993, 1994, 1995, 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006, 2007 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 2 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, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include "server.h" #include #include #if HAVE_SYS_WAIT_H #include #endif unsigned long cont_thread; unsigned long general_thread; unsigned long step_thread; unsigned long thread_from_wait; unsigned long old_thread_from_wait; int extended_protocol; int server_waiting; /* Enable miscellaneous debugging output. The name is historical - it was originally used to debug LinuxThreads support. */ int debug_threads; int pass_signals[TARGET_SIGNAL_LAST]; jmp_buf toplevel; /* The PID of the originally created or attached inferior. Used to send signals to the process when GDB sends us an asynchronous interrupt (user hitting Control-C in the client), and to wait for the child to exit when no longer debugging it. */ unsigned long signal_pid; #ifdef SIGTTOU /* A file descriptor for the controlling terminal. */ int terminal_fd; /* TERMINAL_FD's original foreground group. */ pid_t old_foreground_pgrp; /* Hand back terminal ownership to the original foreground group. */ static void restore_old_foreground_pgrp (void) { tcsetpgrp (terminal_fd, old_foreground_pgrp); } #endif static int start_inferior (char *argv[], char *statusptr) { #ifdef SIGTTOU signal (SIGTTOU, SIG_DFL); signal (SIGTTIN, SIG_DFL); #endif signal_pid = create_inferior (argv[0], argv); fprintf (stderr, "Process %s created; pid = %ld\n", argv[0], signal_pid); fflush (stderr); #ifdef SIGTTOU signal (SIGTTOU, SIG_IGN); signal (SIGTTIN, SIG_IGN); terminal_fd = fileno (stderr); old_foreground_pgrp = tcgetpgrp (terminal_fd); tcsetpgrp (terminal_fd, signal_pid); atexit (restore_old_foreground_pgrp); #endif /* Wait till we are at 1st instruction in program, return signal number. */ return mywait (statusptr, 0); } static int attach_inferior (int pid, char *statusptr, int *sigptr) { /* myattach should return -1 if attaching is unsupported, 0 if it succeeded, and call error() otherwise. */ if (myattach (pid) != 0) return -1; fprintf (stderr, "Attached; pid = %d\n", pid); fflush (stderr); /* FIXME - It may be that we should get the SIGNAL_PID from the attach function, so that it can be the main thread instead of whichever we were told to attach to. */ signal_pid = pid; *sigptr = mywait (statusptr, 0); /* GDB knows to ignore the first SIGSTOP after attaching to a running process using the "attach" command, but this is different; it's just using "target remote". Pretend it's just starting up. */ if (*statusptr == 'T' && *sigptr == TARGET_SIGNAL_STOP) *sigptr = TARGET_SIGNAL_TRAP; return 0; } extern int remote_debug; /* Decode a qXfer read request. Return 0 if everything looks OK, or -1 otherwise. */ static int decode_xfer_read (char *buf, char **annex, CORE_ADDR *ofs, unsigned int *len) { /* Extract and NUL-terminate the annex. */ *annex = buf; while (*buf && *buf != ':') buf++; if (*buf == '\0') return -1; *buf++ = 0; /* After the read/write marker and annex, qXfer looks like a traditional 'm' packet. */ decode_m_packet (buf, ofs, len); return 0; } /* Write the response to a successful qXfer read. Returns the length of the (binary) data stored in BUF, corresponding to as much of DATA/LEN as we could fit. IS_MORE controls the first character of the response. */ static int write_qxfer_response (char *buf, const void *data, int len, int is_more) { int out_len; if (is_more) buf[0] = 'm'; else buf[0] = 'l'; return remote_escape_output (data, len, (unsigned char *) buf + 1, &out_len, PBUFSIZ - 2) + 1; } /* Handle all of the extended 'Q' packets. */ void handle_general_set (char *own_buf) { if (strncmp ("QPassSignals:", own_buf, strlen ("QPassSignals:")) == 0) { int numsigs = (int) TARGET_SIGNAL_LAST, i; const char *p = own_buf + strlen ("QPassSignals:"); CORE_ADDR cursig; p = decode_address_to_semicolon (&cursig, p); for (i = 0; i < numsigs; i++) { if (i == cursig) { pass_signals[i] = 1; if (*p == '\0') /* Keep looping, to clear the remaining signals. */ cursig = -1; else p = decode_address_to_semicolon (&cursig, p); } else pass_signals[i] = 0; } strcpy (own_buf, "OK"); return; } /* Otherwise we didn't know what packet it was. Say we didn't understand it. */ own_buf[0] = 0; } static const char * get_features_xml (const char *annex) { static int features_supported = -1; static char *document; #ifdef USE_XML extern const char *const xml_builtin[][2]; int i; /* Look for the annex. */ for (i = 0; xml_builtin[i][0] != NULL; i++) if (strcmp (annex, xml_builtin[i][0]) == 0) break; if (xml_builtin[i][0] != NULL) return xml_builtin[i][1]; #endif if (strcmp (annex, "target.xml") != 0) return NULL; if (features_supported == -1) { const char *arch = NULL; if (the_target->arch_string != NULL) arch = (*the_target->arch_string) (); if (arch == NULL) features_supported = 0; else { features_supported = 1; document = malloc (64 + strlen (arch)); snprintf (document, 64 + strlen (arch), "%s", arch); } } return document; } void monitor_show_help (void) { monitor_output ("The following monitor commands are supported:\n"); monitor_output (" set debug <0|1>\n"); monitor_output (" Enable general debugging messages\n"); monitor_output (" set remote-debug <0|1>\n"); monitor_output (" Enable remote protocol debugging messages\n"); } /* Handle all of the extended 'q' packets. */ void handle_query (char *own_buf, int *new_packet_len_p) { static struct inferior_list_entry *thread_ptr; if (strcmp ("qSymbol::", own_buf) == 0) { if (the_target->look_up_symbols != NULL) (*the_target->look_up_symbols) (); strcpy (own_buf, "OK"); return; } if (strcmp ("qfThreadInfo", own_buf) == 0) { thread_ptr = all_threads.head; sprintf (own_buf, "m%x", thread_to_gdb_id ((struct thread_info *)thread_ptr)); thread_ptr = thread_ptr->next; return; } if (strcmp ("qsThreadInfo", own_buf) == 0) { if (thread_ptr != NULL) { sprintf (own_buf, "m%x", thread_to_gdb_id ((struct thread_info *)thread_ptr)); thread_ptr = thread_ptr->next; return; } else { sprintf (own_buf, "l"); return; } } if (the_target->read_offsets != NULL && strcmp ("qOffsets", own_buf) == 0) { CORE_ADDR text, data; if (the_target->read_offsets (&text, &data)) sprintf (own_buf, "Text=%lX;Data=%lX;Bss=%lX", (long)text, (long)data, (long)data); else write_enn (own_buf); return; } if (the_target->read_auxv != NULL && strncmp ("qXfer:auxv:read:", own_buf, 16) == 0) { unsigned char *data; int n; CORE_ADDR ofs; unsigned int len; char *annex; /* Reject any annex; grab the offset and length. */ if (decode_xfer_read (own_buf + 16, &annex, &ofs, &len) < 0 || annex[0] != '\0') { strcpy (own_buf, "E00"); return; } /* Read one extra byte, as an indicator of whether there is more. */ if (len > PBUFSIZ - 2) len = PBUFSIZ - 2; data = malloc (len + 1); n = (*the_target->read_auxv) (ofs, data, len + 1); if (n < 0) write_enn (own_buf); else if (n > len) *new_packet_len_p = write_qxfer_response (own_buf, data, len, 1); else *new_packet_len_p = write_qxfer_response (own_buf, data, n, 0); free (data); return; } if (strncmp ("qXfer:features:read:", own_buf, 20) == 0) { CORE_ADDR ofs; unsigned int len, total_len; const char *document; char *annex; /* Check for support. */ document = get_features_xml ("target.xml"); if (document == NULL) { own_buf[0] = '\0'; return; } /* Grab the annex, offset, and length. */ if (decode_xfer_read (own_buf + 20, &annex, &ofs, &len) < 0) { strcpy (own_buf, "E00"); return; } /* Now grab the correct annex. */ document = get_features_xml (annex); if (document == NULL) { strcpy (own_buf, "E00"); return; } total_len = strlen (document); if (len > PBUFSIZ - 2) len = PBUFSIZ - 2; if (ofs > total_len) write_enn (own_buf); else if (len < total_len - ofs) *new_packet_len_p = write_qxfer_response (own_buf, document + ofs, len, 1); else *new_packet_len_p = write_qxfer_response (own_buf, document + ofs, total_len - ofs, 0); return; } /* Protocol features query. */ if (strncmp ("qSupported", own_buf, 10) == 0 && (own_buf[10] == ':' || own_buf[10] == '\0')) { sprintf (own_buf, "PacketSize=%x;QPassSignals+", PBUFSIZ - 1); if (the_target->read_auxv != NULL) strcat (own_buf, ";qXfer:auxv:read+"); if (get_features_xml ("target.xml") != NULL) strcat (own_buf, ";qXfer:features:read+"); return; } /* Thread-local storage support. */ if (the_target->get_tls_address != NULL && strncmp ("qGetTLSAddr:", own_buf, 12) == 0) { char *p = own_buf + 12; CORE_ADDR parts[3], address = 0; int i, err; for (i = 0; i < 3; i++) { char *p2; int len; if (p == NULL) break; p2 = strchr (p, ','); if (p2) { len = p2 - p; p2++; } else { len = strlen (p); p2 = NULL; } decode_address (&parts[i], p, len); p = p2; } if (p != NULL || i < 3) err = 1; else { struct thread_info *thread = gdb_id_to_thread (parts[0]); if (thread == NULL) err = 2; else err = the_target->get_tls_address (thread, parts[1], parts[2], &address); } if (err == 0) { sprintf (own_buf, "%llx", address); return; } else if (err > 0) { write_enn (own_buf); return; } /* Otherwise, pretend we do not understand this packet. */ } /* Handle "monitor" commands. */ if (strncmp ("qRcmd,", own_buf, 6) == 0) { char *mon = malloc (PBUFSIZ); int len = strlen (own_buf + 6); if ((len % 1) != 0 || unhexify (mon, own_buf + 6, len / 2) != len / 2) { write_enn (own_buf); free (mon); return; } mon[len / 2] = '\0'; write_ok (own_buf); if (strcmp (mon, "set debug 1") == 0) { debug_threads = 1; monitor_output ("Debug output enabled.\n"); } else if (strcmp (mon, "set debug 0") == 0) { debug_threads = 0; monitor_output ("Debug output disabled.\n"); } else if (strcmp (mon, "set remote-debug 1") == 0) { remote_debug = 1; monitor_output ("Protocol debug output enabled.\n"); } else if (strcmp (mon, "set remote-debug 0") == 0) { remote_debug = 0; monitor_output ("Protocol debug output disabled.\n"); } else if (strcmp (mon, "help") == 0) monitor_show_help (); else { monitor_output ("Unknown monitor command.\n\n"); monitor_show_help (); write_enn (own_buf); } free (mon); return; } /* Otherwise we didn't know what packet it was. Say we didn't understand it. */ own_buf[0] = 0; } /* Parse vCont packets. */ void handle_v_cont (char *own_buf, char *status, int *signal) { char *p, *q; int n = 0, i = 0; struct thread_resume *resume_info, default_action; /* Count the number of semicolons in the packet. There should be one for every action. */ p = &own_buf[5]; while (p) { n++; p++; p = strchr (p, ';'); } /* Allocate room for one extra action, for the default remain-stopped behavior; if no default action is in the list, we'll need the extra slot. */ resume_info = malloc ((n + 1) * sizeof (resume_info[0])); default_action.thread = -1; default_action.leave_stopped = 1; default_action.step = 0; default_action.sig = 0; p = &own_buf[5]; i = 0; while (*p) { p++; resume_info[i].leave_stopped = 0; if (p[0] == 's' || p[0] == 'S') resume_info[i].step = 1; else if (p[0] == 'c' || p[0] == 'C') resume_info[i].step = 0; else goto err; if (p[0] == 'S' || p[0] == 'C') { int sig; sig = strtol (p + 1, &q, 16); if (p == q) goto err; p = q; if (!target_signal_to_host_p (sig)) goto err; resume_info[i].sig = target_signal_to_host (sig); } else { resume_info[i].sig = 0; p = p + 1; } if (p[0] == 0) { resume_info[i].thread = -1; default_action = resume_info[i]; /* Note: we don't increment i here, we'll overwrite this entry the next time through. */ } else if (p[0] == ':') { unsigned int gdb_id = strtoul (p + 1, &q, 16); unsigned long thread_id; if (p == q) goto err; p = q; if (p[0] != ';' && p[0] != 0) goto err; thread_id = gdb_id_to_thread_id (gdb_id); if (thread_id) resume_info[i].thread = thread_id; else goto err; i++; } } resume_info[i] = default_action; /* Still used in occasional places in the backend. */ if (n == 1 && resume_info[0].thread != -1) cont_thread = resume_info[0].thread; else cont_thread = -1; set_desired_inferior (0); (*the_target->resume) (resume_info); free (resume_info); *signal = mywait (status, 1); prepare_resume_reply (own_buf, *status, *signal); return; err: /* No other way to report an error... */ strcpy (own_buf, ""); free (resume_info); return; } /* Handle all of the extended 'v' packets. */ void handle_v_requests (char *own_buf, char *status, int *signal) { if (strncmp (own_buf, "vCont;", 6) == 0) { handle_v_cont (own_buf, status, signal); return; } if (strncmp (own_buf, "vCont?", 6) == 0) { strcpy (own_buf, "vCont;c;C;s;S"); return; } /* Otherwise we didn't know what packet it was. Say we didn't understand it. */ own_buf[0] = 0; return; } void myresume (int step, int sig) { struct thread_resume resume_info[2]; int n = 0; if (step || sig || (cont_thread != 0 && cont_thread != -1)) { resume_info[0].thread = ((struct inferior_list_entry *) current_inferior)->id; resume_info[0].step = step; resume_info[0].sig = sig; resume_info[0].leave_stopped = 0; n++; } resume_info[n].thread = -1; resume_info[n].step = 0; resume_info[n].sig = 0; resume_info[n].leave_stopped = (cont_thread != 0 && cont_thread != -1); (*the_target->resume) (resume_info); } static int attached; static void gdbserver_version (void) { printf ("GNU gdbserver %s\n" "Copyright (C) 2006 Free Software Foundation, Inc.\n" "gdbserver is free software, covered by the GNU General Public License.\n" "This gdbserver was configured as \"%s\"\n", version, host_name); } static void gdbserver_usage (void) { printf ("Usage:\tgdbserver COMM PROG [ARGS ...]\n" "\tgdbserver COMM --attach PID\n" "\n" "COMM may either be a tty device (for serial debugging), or \n" "HOST:PORT to listen for a TCP connection.\n"); } int main (int argc, char *argv[]) { char ch, status, *own_buf; unsigned char *mem_buf; int i = 0; int signal; unsigned int len; CORE_ADDR mem_addr; int bad_attach; int pid; char *arg_end; if (argc >= 2 && strcmp (argv[1], "--version") == 0) { gdbserver_version (); exit (0); } if (argc >= 2 && strcmp (argv[1], "--help") == 0) { gdbserver_usage (); exit (0); } if (setjmp (toplevel)) { fprintf (stderr, "Exiting\n"); exit (1); } bad_attach = 0; pid = 0; attached = 0; if (argc >= 3 && strcmp (argv[2], "--attach") == 0) { if (argc == 4 && argv[3] != '\0' && (pid = strtoul (argv[3], &arg_end, 10)) != 0 && *arg_end == '\0') { ; } else bad_attach = 1; } if (argc < 3 || bad_attach) { gdbserver_usage (); exit (1); } initialize_low (); own_buf = malloc (PBUFSIZ); mem_buf = malloc (PBUFSIZ); if (pid == 0) { /* Wait till we are at first instruction in program. */ signal = start_inferior (&argv[2], &status); /* We are now stopped at the first instruction of the target process */ } else { switch (attach_inferior (pid, &status, &signal)) { case -1: error ("Attaching not supported on this target"); break; default: attached = 1; break; } } if (setjmp (toplevel)) { fprintf (stderr, "Killing inferior\n"); kill_inferior (); exit (1); } while (1) { remote_open (argv[1]); restart: setjmp (toplevel); while (1) { unsigned char sig; int packet_len; int new_packet_len = -1; packet_len = getpkt (own_buf); if (packet_len <= 0) break; i = 0; ch = own_buf[i++]; switch (ch) { case 'q': handle_query (own_buf, &new_packet_len); break; case 'Q': handle_general_set (own_buf); break; #ifndef USE_WIN32API /* Skip "detach" support on mingw32, since we don't have waitpid. */ case 'D': fprintf (stderr, "Detaching from inferior\n"); detach_inferior (); write_ok (own_buf); putpkt (own_buf); remote_close (); /* If we are attached, then we can exit. Otherwise, we need to hang around doing nothing, until the child is gone. */ if (!attached) { int status, ret; do { ret = waitpid (signal_pid, &status, 0); if (WIFEXITED (status) || WIFSIGNALED (status)) break; } while (ret != -1 || errno != ECHILD); } exit (0); #endif case '!': if (attached == 0) { extended_protocol = 1; prepare_resume_reply (own_buf, status, signal); } else { /* We can not use the extended protocol if we are attached, because we can not restart the running program. So return unrecognized. */ own_buf[0] = '\0'; } break; case '?': prepare_resume_reply (own_buf, status, signal); break; case 'H': if (own_buf[1] == 'c' || own_buf[1] == 'g' || own_buf[1] == 's') { unsigned long gdb_id, thread_id; gdb_id = strtoul (&own_buf[2], NULL, 16); thread_id = gdb_id_to_thread_id (gdb_id); if (thread_id == 0) { write_enn (own_buf); break; } if (own_buf[1] == 'g') { general_thread = thread_id; set_desired_inferior (1); } else if (own_buf[1] == 'c') cont_thread = thread_id; else if (own_buf[1] == 's') step_thread = thread_id; write_ok (own_buf); } else { /* Silently ignore it so that gdb can extend the protocol without compatibility headaches. */ own_buf[0] = '\0'; } break; case 'g': set_desired_inferior (1); registers_to_string (own_buf); break; case 'G': set_desired_inferior (1); registers_from_string (&own_buf[1]); write_ok (own_buf); break; case 'm': decode_m_packet (&own_buf[1], &mem_addr, &len); if (read_inferior_memory (mem_addr, mem_buf, len) == 0) convert_int_to_ascii (mem_buf, own_buf, len); else write_enn (own_buf); break; case 'M': decode_M_packet (&own_buf[1], &mem_addr, &len, mem_buf); if (write_inferior_memory (mem_addr, mem_buf, len) == 0) write_ok (own_buf); else write_enn (own_buf); break; case 'X': if (decode_X_packet (&own_buf[1], packet_len - 1, &mem_addr, &len, mem_buf) < 0 || write_inferior_memory (mem_addr, mem_buf, len) != 0) write_enn (own_buf); else write_ok (own_buf); break; case 'C': convert_ascii_to_int (own_buf + 1, &sig, 1); if (target_signal_to_host_p (sig)) signal = target_signal_to_host (sig); else signal = 0; set_desired_inferior (0); myresume (0, signal); signal = mywait (&status, 1); prepare_resume_reply (own_buf, status, signal); break; case 'S': convert_ascii_to_int (own_buf + 1, &sig, 1); if (target_signal_to_host_p (sig)) signal = target_signal_to_host (sig); else signal = 0; set_desired_inferior (0); myresume (1, signal); signal = mywait (&status, 1); prepare_resume_reply (own_buf, status, signal); break; case 'c': set_desired_inferior (0); myresume (0, 0); signal = mywait (&status, 1); prepare_resume_reply (own_buf, status, signal); break; case 's': set_desired_inferior (0); myresume (1, 0); signal = mywait (&status, 1); prepare_resume_reply (own_buf, status, signal); break; case 'Z': { char *lenptr; char *dataptr; CORE_ADDR addr = strtoul (&own_buf[3], &lenptr, 16); int len = strtol (lenptr + 1, &dataptr, 16); char type = own_buf[1]; if (the_target->insert_watchpoint == NULL || (type < '2' || type > '4')) { /* No watchpoint support or not a watchpoint command; unrecognized either way. */ own_buf[0] = '\0'; } else { int res; res = (*the_target->insert_watchpoint) (type, addr, len); if (res == 0) write_ok (own_buf); else if (res == 1) /* Unsupported. */ own_buf[0] = '\0'; else write_enn (own_buf); } break; } case 'z': { char *lenptr; char *dataptr; CORE_ADDR addr = strtoul (&own_buf[3], &lenptr, 16); int len = strtol (lenptr + 1, &dataptr, 16); char type = own_buf[1]; if (the_target->remove_watchpoint == NULL || (type < '2' || type > '4')) { /* No watchpoint support or not a watchpoint command; unrecognized either way. */ own_buf[0] = '\0'; } else { int res; res = (*the_target->remove_watchpoint) (type, addr, len); if (res == 0) write_ok (own_buf); else if (res == 1) /* Unsupported. */ own_buf[0] = '\0'; else write_enn (own_buf); } break; } case 'k': fprintf (stderr, "Killing inferior\n"); kill_inferior (); /* When using the extended protocol, we start up a new debugging session. The traditional protocol will exit instead. */ if (extended_protocol) { write_ok (own_buf); fprintf (stderr, "GDBserver restarting\n"); /* Wait till we are at 1st instruction in prog. */ signal = start_inferior (&argv[2], &status); goto restart; break; } else { exit (0); break; } case 'T': { unsigned long gdb_id, thread_id; gdb_id = strtoul (&own_buf[1], NULL, 16); thread_id = gdb_id_to_thread_id (gdb_id); if (thread_id == 0) { write_enn (own_buf); break; } if (mythread_alive (thread_id)) write_ok (own_buf); else write_enn (own_buf); } break; case 'R': /* Restarting the inferior is only supported in the extended protocol. */ if (extended_protocol) { kill_inferior (); write_ok (own_buf); fprintf (stderr, "GDBserver restarting\n"); /* Wait till we are at 1st instruction in prog. */ signal = start_inferior (&argv[2], &status); goto restart; break; } else { /* It is a request we don't understand. Respond with an empty packet so that gdb knows that we don't support this request. */ own_buf[0] = '\0'; break; } case 'v': /* Extended (long) request. */ handle_v_requests (own_buf, &status, &signal); break; default: /* It is a request we don't understand. Respond with an empty packet so that gdb knows that we don't support this request. */ own_buf[0] = '\0'; break; } if (new_packet_len != -1) putpkt_binary (own_buf, new_packet_len); else putpkt (own_buf); if (status == 'W') fprintf (stderr, "\nChild exited with status %d\n", signal); if (status == 'X') fprintf (stderr, "\nChild terminated with signal = 0x%x (%s)\n", target_signal_to_host (signal), target_signal_to_name (signal)); if (status == 'W' || status == 'X') { if (extended_protocol) { fprintf (stderr, "Killing inferior\n"); kill_inferior (); write_ok (own_buf); fprintf (stderr, "GDBserver restarting\n"); /* Wait till we are at 1st instruction in prog. */ signal = start_inferior (&argv[2], &status); goto restart; break; } else { fprintf (stderr, "GDBserver exiting\n"); exit (0); } } } /* We come here when getpkt fails. For the extended remote protocol we exit (and this is the only way we gracefully exit!). For the traditional remote protocol close the connection, and re-open it at the top of the loop. */ if (extended_protocol) { remote_close (); exit (0); } else { fprintf (stderr, "Remote side has terminated connection. " "GDBserver will reopen the connection.\n"); remote_close (); } } }