| 1 | /* Target-vector operations for controlling Unix child processes, for GDB. |
| 2 | Copyright 1990, 1991, 1992 Free Software Foundation, Inc. |
| 3 | Contributed by Cygnus Support. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "frame.h" /* required by inferior.h */ |
| 23 | #include "inferior.h" |
| 24 | #include "target.h" |
| 25 | #include "wait.h" |
| 26 | #include "gdbcore.h" |
| 27 | #include "command.h" |
| 28 | #include <signal.h> |
| 29 | |
| 30 | static void |
| 31 | child_prepare_to_store PARAMS ((void)); |
| 32 | |
| 33 | #ifndef CHILD_WAIT |
| 34 | static int child_wait PARAMS ((int, struct target_waitstatus *)); |
| 35 | #endif /* CHILD_WAIT */ |
| 36 | |
| 37 | static void child_open PARAMS ((char *, int)); |
| 38 | |
| 39 | static void |
| 40 | child_files_info PARAMS ((struct target_ops *)); |
| 41 | |
| 42 | static void |
| 43 | child_detach PARAMS ((char *, int)); |
| 44 | |
| 45 | static void |
| 46 | child_attach PARAMS ((char *, int)); |
| 47 | |
| 48 | static void |
| 49 | ptrace_me PARAMS ((void)); |
| 50 | |
| 51 | static void |
| 52 | ptrace_him PARAMS ((int)); |
| 53 | |
| 54 | static void child_create_inferior PARAMS ((char *, char *, char **)); |
| 55 | |
| 56 | static void |
| 57 | child_mourn_inferior PARAMS ((void)); |
| 58 | |
| 59 | static int |
| 60 | child_can_run PARAMS ((void)); |
| 61 | |
| 62 | extern char **environ; |
| 63 | |
| 64 | /* Forward declaration */ |
| 65 | extern struct target_ops child_ops; |
| 66 | |
| 67 | #ifndef CHILD_WAIT |
| 68 | |
| 69 | /* Wait for child to do something. Return pid of child, or -1 in case |
| 70 | of error; store status through argument pointer OURSTATUS. */ |
| 71 | |
| 72 | static int |
| 73 | child_wait (pid, ourstatus) |
| 74 | int pid; |
| 75 | struct target_waitstatus *ourstatus; |
| 76 | { |
| 77 | int save_errno; |
| 78 | int status; |
| 79 | |
| 80 | do { |
| 81 | if (attach_flag) |
| 82 | set_sigint_trap(); /* Causes SIGINT to be passed on to the |
| 83 | attached process. */ |
| 84 | set_sigio_trap (); |
| 85 | |
| 86 | pid = wait (&status); |
| 87 | save_errno = errno; |
| 88 | |
| 89 | clear_sigio_trap (); |
| 90 | |
| 91 | if (attach_flag) |
| 92 | clear_sigint_trap(); |
| 93 | |
| 94 | if (pid == -1) |
| 95 | { |
| 96 | if (save_errno == EINTR) |
| 97 | continue; |
| 98 | fprintf_unfiltered (gdb_stderr, "Child process unexpectedly missing: %s.\n", |
| 99 | safe_strerror (save_errno)); |
| 100 | /* Claim it exited with unknown signal. */ |
| 101 | ourstatus->kind = TARGET_WAITKIND_SIGNALLED; |
| 102 | ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN; |
| 103 | return -1; |
| 104 | } |
| 105 | } while (pid != inferior_pid); /* Some other child died or stopped */ |
| 106 | store_waitstatus (ourstatus, status); |
| 107 | return pid; |
| 108 | } |
| 109 | #endif /* CHILD_WAIT */ |
| 110 | |
| 111 | /* Attach to process PID, then initialize for debugging it. */ |
| 112 | |
| 113 | static void |
| 114 | child_attach (args, from_tty) |
| 115 | char *args; |
| 116 | int from_tty; |
| 117 | { |
| 118 | if (!args) |
| 119 | error_no_arg ("process-id to attach"); |
| 120 | |
| 121 | #ifndef ATTACH_DETACH |
| 122 | error ("Can't attach to a process on this machine."); |
| 123 | #else |
| 124 | { |
| 125 | char *exec_file; |
| 126 | int pid; |
| 127 | |
| 128 | pid = atoi (args); |
| 129 | |
| 130 | if (pid == getpid()) /* Trying to masturbate? */ |
| 131 | error ("I refuse to debug myself!"); |
| 132 | |
| 133 | if (from_tty) |
| 134 | { |
| 135 | exec_file = (char *) get_exec_file (0); |
| 136 | |
| 137 | if (exec_file) |
| 138 | printf_unfiltered ("Attaching to program `%s', %s\n", exec_file, |
| 139 | target_pid_to_str (pid)); |
| 140 | else |
| 141 | printf_unfiltered ("Attaching to %s\n", target_pid_to_str (pid)); |
| 142 | |
| 143 | gdb_flush (gdb_stdout); |
| 144 | } |
| 145 | |
| 146 | attach (pid); |
| 147 | inferior_pid = pid; |
| 148 | push_target (&child_ops); |
| 149 | } |
| 150 | #endif /* ATTACH_DETACH */ |
| 151 | } |
| 152 | |
| 153 | |
| 154 | /* Take a program previously attached to and detaches it. |
| 155 | The program resumes execution and will no longer stop |
| 156 | on signals, etc. We'd better not have left any breakpoints |
| 157 | in the program or it'll die when it hits one. For this |
| 158 | to work, it may be necessary for the process to have been |
| 159 | previously attached. It *might* work if the program was |
| 160 | started via the normal ptrace (PTRACE_TRACEME). */ |
| 161 | |
| 162 | static void |
| 163 | child_detach (args, from_tty) |
| 164 | char *args; |
| 165 | int from_tty; |
| 166 | { |
| 167 | #ifdef ATTACH_DETACH |
| 168 | { |
| 169 | int siggnal = 0; |
| 170 | |
| 171 | if (from_tty) |
| 172 | { |
| 173 | char *exec_file = get_exec_file (0); |
| 174 | if (exec_file == 0) |
| 175 | exec_file = ""; |
| 176 | printf_unfiltered ("Detaching from program: %s %s\n", exec_file, |
| 177 | target_pid_to_str (inferior_pid)); |
| 178 | gdb_flush (gdb_stdout); |
| 179 | } |
| 180 | if (args) |
| 181 | siggnal = atoi (args); |
| 182 | |
| 183 | detach (siggnal); |
| 184 | inferior_pid = 0; |
| 185 | unpush_target (&child_ops); |
| 186 | } |
| 187 | #else |
| 188 | error ("This version of Unix does not support detaching a process."); |
| 189 | #endif |
| 190 | } |
| 191 | |
| 192 | /* Get ready to modify the registers array. On machines which store |
| 193 | individual registers, this doesn't need to do anything. On machines |
| 194 | which store all the registers in one fell swoop, this makes sure |
| 195 | that registers contains all the registers from the program being |
| 196 | debugged. */ |
| 197 | |
| 198 | static void |
| 199 | child_prepare_to_store () |
| 200 | { |
| 201 | #ifdef CHILD_PREPARE_TO_STORE |
| 202 | CHILD_PREPARE_TO_STORE (); |
| 203 | #endif |
| 204 | } |
| 205 | |
| 206 | /* Print status information about what we're accessing. */ |
| 207 | |
| 208 | static void |
| 209 | child_files_info (ignore) |
| 210 | struct target_ops *ignore; |
| 211 | { |
| 212 | printf_unfiltered ("\tUsing the running image of %s %s.\n", |
| 213 | attach_flag? "attached": "child", target_pid_to_str (inferior_pid)); |
| 214 | } |
| 215 | |
| 216 | /* ARGSUSED */ |
| 217 | static void |
| 218 | child_open (arg, from_tty) |
| 219 | char *arg; |
| 220 | int from_tty; |
| 221 | { |
| 222 | error ("Use the \"run\" command to start a Unix child process."); |
| 223 | } |
| 224 | |
| 225 | /* Stub function which causes the inferior that runs it, to be ptrace-able |
| 226 | by its parent process. */ |
| 227 | |
| 228 | static void |
| 229 | ptrace_me () |
| 230 | { |
| 231 | /* "Trace me, Dr. Memory!" */ |
| 232 | call_ptrace (0, 0, (PTRACE_ARG3_TYPE) 0, 0); |
| 233 | } |
| 234 | |
| 235 | /* Stub function which causes the GDB that runs it, to start ptrace-ing |
| 236 | the child process. */ |
| 237 | |
| 238 | static void |
| 239 | ptrace_him (pid) |
| 240 | int pid; |
| 241 | { |
| 242 | push_target (&child_ops); |
| 243 | |
| 244 | #ifdef START_INFERIOR_TRAPS_EXPECTED |
| 245 | startup_inferior (START_INFERIOR_TRAPS_EXPECTED); |
| 246 | #else |
| 247 | /* One trap to exec the shell, one to exec the program being debugged. */ |
| 248 | startup_inferior (2); |
| 249 | #endif |
| 250 | } |
| 251 | |
| 252 | /* Start an inferior Unix child process and sets inferior_pid to its pid. |
| 253 | EXEC_FILE is the file to run. |
| 254 | ALLARGS is a string containing the arguments to the program. |
| 255 | ENV is the environment vector to pass. Errors reported with error(). */ |
| 256 | |
| 257 | static void |
| 258 | child_create_inferior (exec_file, allargs, env) |
| 259 | char *exec_file; |
| 260 | char *allargs; |
| 261 | char **env; |
| 262 | { |
| 263 | fork_inferior (exec_file, allargs, env, ptrace_me, ptrace_him, NULL); |
| 264 | /* We are at the first instruction we care about. */ |
| 265 | /* Pedal to the metal... */ |
| 266 | proceed ((CORE_ADDR) -1, TARGET_SIGNAL_0, 0); |
| 267 | } |
| 268 | |
| 269 | static void |
| 270 | child_mourn_inferior () |
| 271 | { |
| 272 | unpush_target (&child_ops); |
| 273 | generic_mourn_inferior (); |
| 274 | } |
| 275 | |
| 276 | static int |
| 277 | child_can_run () |
| 278 | { |
| 279 | return(1); |
| 280 | } |
| 281 | \f |
| 282 | struct target_ops child_ops = { |
| 283 | "child", /* to_shortname */ |
| 284 | "Unix child process", /* to_longname */ |
| 285 | "Unix child process (started by the \"run\" command).", /* to_doc */ |
| 286 | child_open, /* to_open */ |
| 287 | 0, /* to_close */ |
| 288 | child_attach, /* to_attach */ |
| 289 | child_detach, /* to_detach */ |
| 290 | child_resume, /* to_resume */ |
| 291 | child_wait, /* to_wait */ |
| 292 | fetch_inferior_registers, /* to_fetch_registers */ |
| 293 | store_inferior_registers, /* to_store_registers */ |
| 294 | child_prepare_to_store, /* to_prepare_to_store */ |
| 295 | child_xfer_memory, /* to_xfer_memory */ |
| 296 | child_files_info, /* to_files_info */ |
| 297 | memory_insert_breakpoint, /* to_insert_breakpoint */ |
| 298 | memory_remove_breakpoint, /* to_remove_breakpoint */ |
| 299 | terminal_init_inferior, /* to_terminal_init */ |
| 300 | terminal_inferior, /* to_terminal_inferior */ |
| 301 | terminal_ours_for_output, /* to_terminal_ours_for_output */ |
| 302 | terminal_ours, /* to_terminal_ours */ |
| 303 | child_terminal_info, /* to_terminal_info */ |
| 304 | kill_inferior, /* to_kill */ |
| 305 | 0, /* to_load */ |
| 306 | 0, /* to_lookup_symbol */ |
| 307 | child_create_inferior, /* to_create_inferior */ |
| 308 | child_mourn_inferior, /* to_mourn_inferior */ |
| 309 | child_can_run, /* to_can_run */ |
| 310 | 0, /* to_notice_signals */ |
| 311 | process_stratum, /* to_stratum */ |
| 312 | 0, /* to_next */ |
| 313 | 1, /* to_has_all_memory */ |
| 314 | 1, /* to_has_memory */ |
| 315 | 1, /* to_has_stack */ |
| 316 | 1, /* to_has_registers */ |
| 317 | 1, /* to_has_execution */ |
| 318 | 0, /* sections */ |
| 319 | 0, /* sections_end */ |
| 320 | OPS_MAGIC /* to_magic */ |
| 321 | }; |
| 322 | |
| 323 | void |
| 324 | _initialize_inftarg () |
| 325 | { |
| 326 | add_target (&child_ops); |
| 327 | } |