/* Target-vector operations for controlling Unix child processes, for GDB. Copyright 1990-1996, 1998, 1999 Free Software Foundation, Inc. Contributed by Cygnus Support. ## Contains temporary hacks.. 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "defs.h" #include "frame.h" /* required by inferior.h */ #include "inferior.h" #include "target.h" #include "gdbcore.h" #include "command.h" #include "gdb_stat.h" #include #include #include #ifdef HAVE_WAIT_H # include #else # ifdef HAVE_SYS_WAIT_H # include # endif #endif /* "wait.h" fills in the gaps left by */ #include "wait.h" #ifdef HAVE_UNISTD_H #include #endif extern struct symtab_and_line * child_enable_exception_callback PARAMS ((enum exception_event_kind, int)); extern struct exception_event_record * child_get_current_exception_event PARAMS ((void)); extern void _initialize_inftarg PARAMS ((void)); static void child_prepare_to_store PARAMS ((void)); #ifndef CHILD_WAIT static int child_wait PARAMS ((int, struct target_waitstatus *)); #endif /* CHILD_WAIT */ #if !defined(CHILD_POST_WAIT) void child_post_wait PARAMS ((int, int)); #endif static void child_open PARAMS ((char *, int)); static void child_files_info PARAMS ((struct target_ops *)); static void child_detach PARAMS ((char *, int)); static void child_detach_from_process PARAMS ((int, char *, int, int)); static void child_attach PARAMS ((char *, int)); static void child_attach_to_process PARAMS ((char *, int, int)); #if !defined(CHILD_POST_ATTACH) extern void child_post_attach PARAMS ((int)); #endif static void child_require_attach PARAMS ((char *, int)); static void child_require_detach PARAMS ((int, char *, int)); static void ptrace_me PARAMS ((void)); static void ptrace_him PARAMS ((int)); static void child_create_inferior PARAMS ((char *, char *, char **)); static void child_mourn_inferior PARAMS ((void)); static int child_can_run PARAMS ((void)); static void child_stop PARAMS ((void)); #ifndef CHILD_THREAD_ALIVE int child_thread_alive PARAMS ((int)); #endif static void init_child_ops PARAMS ((void)); extern char **environ; struct target_ops child_ops; int child_suppress_run = 0; /* Non-zero if inftarg should pretend not to be a runnable target. Used by targets that can sit atop inftarg, such as HPUX thread support. */ #ifndef CHILD_WAIT /*##*/ /* Enable HACK for ttrace work. In * infttrace.c/require_notification_of_events, * this is set to 0 so that the loop in child_wait * won't loop. */ int not_same_real_pid = 1; /*##*/ /* Wait for child to do something. Return pid of child, or -1 in case of error; store status through argument pointer OURSTATUS. */ static int child_wait (pid, ourstatus) int pid; struct target_waitstatus *ourstatus; { int save_errno; int status; char * execd_pathname; int exit_status; int related_pid; int syscall_id; enum target_waitkind kind; do { set_sigint_trap(); /* Causes SIGINT to be passed on to the attached process. */ set_sigio_trap (); pid = ptrace_wait (inferior_pid, &status); save_errno = errno; clear_sigio_trap (); clear_sigint_trap(); if (pid == -1) { if (save_errno == EINTR) continue; fprintf_unfiltered (gdb_stderr, "Child process unexpectedly missing: %s.\n", safe_strerror (save_errno)); /* Claim it exited with unknown signal. */ ourstatus->kind = TARGET_WAITKIND_SIGNALLED; ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN; return -1; } /* Did it exit? */ if (target_has_exited (pid, status, &exit_status)) { /* ??rehrauer: For now, ignore this. */ continue; } if (!target_thread_alive (pid)) { ourstatus->kind = TARGET_WAITKIND_SPURIOUS; return pid; } if (target_has_forked (pid, &related_pid) && ((pid == inferior_pid) || (related_pid == inferior_pid))) { ourstatus->kind = TARGET_WAITKIND_FORKED; ourstatus->value.related_pid = related_pid; return pid; } if (target_has_vforked (pid, &related_pid) && ((pid == inferior_pid) || (related_pid == inferior_pid))) { ourstatus->kind = TARGET_WAITKIND_VFORKED; ourstatus->value.related_pid = related_pid; return pid; } if (target_has_execd (pid, &execd_pathname)) { /* Are we ignoring initial exec events? (This is likely because we're in the process of starting up the inferior, and another (older) mechanism handles those.) If so, we'll report this as a regular stop, not an exec. */ if (inferior_ignoring_startup_exec_events) { inferior_ignoring_startup_exec_events--; } else { ourstatus->kind = TARGET_WAITKIND_EXECD; ourstatus->value.execd_pathname = execd_pathname; return pid; } } /* All we must do with these is communicate their occurrence to wait_for_inferior... */ if (target_has_syscall_event (pid, &kind, &syscall_id)) { ourstatus->kind = kind; ourstatus->value.syscall_id = syscall_id; return pid; } /*## } while (pid != inferior_pid); ##*/ /* Some other child died or stopped */ /* hack for thread testing */ } while( (pid != inferior_pid) && not_same_real_pid ); /*##*/ store_waitstatus (ourstatus, status); return pid; } #endif /* CHILD_WAIT */ #if !defined(CHILD_POST_WAIT) void child_post_wait (pid, wait_status) int pid; int wait_status; { /* This version of Unix doesn't require a meaningful "post wait" operation. */ } #endif #ifndef CHILD_THREAD_ALIVE /* Check to see if the given thread is alive. FIXME: Is kill() ever the right way to do this? I doubt it, but for now we're going to try and be compatable with the old thread code. */ int child_thread_alive (pid) int pid; { return (kill (pid, 0) != -1); } #endif static void child_attach_to_process (args, from_tty, after_fork) char * args; int from_tty; int after_fork; { if (!args) error_no_arg ("process-id to attach"); #ifndef ATTACH_DETACH error ("Can't attach to a process on this machine."); #else { char *exec_file; int pid; char *dummy; dummy = args; pid = strtol (args, &dummy, 0); /* Some targets don't set errno on errors, grrr! */ if ((pid == 0) && (args == dummy)) error ("Illegal process-id: %s\n", args); if (pid == getpid()) /* Trying to masturbate? */ error ("I refuse to debug myself!"); if (from_tty) { exec_file = (char *) get_exec_file (0); if (after_fork) printf_unfiltered ("Attaching after fork to %s\n", target_pid_to_str (pid)); else if (exec_file) printf_unfiltered ("Attaching to program: %s, %s\n", exec_file, target_pid_to_str (pid)); else printf_unfiltered ("Attaching to %s\n", target_pid_to_str (pid)); gdb_flush (gdb_stdout); } if (!after_fork) attach (pid); else REQUIRE_ATTACH (pid); inferior_pid = pid; push_target (&child_ops); } #endif /* ATTACH_DETACH */ } /* Attach to process PID, then initialize for debugging it. */ static void child_attach (args, from_tty) char *args; int from_tty; { child_attach_to_process (args, from_tty, 0); } #if !defined(CHILD_POST_ATTACH) void child_post_attach (pid) int pid; { /* This version of Unix doesn't require a meaningful "post attach" operation by a debugger. */ } #endif static void child_require_attach (args, from_tty) char *args; int from_tty; { child_attach_to_process (args, from_tty, 1); } static void child_detach_from_process (pid, args, from_tty, after_fork) int pid; char * args; int from_tty; int after_fork; { #ifdef ATTACH_DETACH { int siggnal = 0; if (from_tty) { char *exec_file = get_exec_file (0); if (exec_file == 0) exec_file = ""; if (after_fork) printf_unfiltered ("Detaching after fork from %s\n", target_pid_to_str (pid)); else printf_unfiltered ("Detaching from program: %s, %s\n", exec_file, target_pid_to_str (pid)); gdb_flush (gdb_stdout); } if (args) siggnal = atoi (args); if (!after_fork) detach (siggnal); else REQUIRE_DETACH (pid, siggnal); } #else error ("This version of Unix does not support detaching a process."); #endif } /* Take a program previously attached to and detaches it. The program resumes execution and will no longer stop on signals, etc. We'd better not have left any breakpoints in the program or it'll die when it hits one. For this to work, it may be necessary for the process to have been previously attached. It *might* work if the program was started via the normal ptrace (PTRACE_TRACEME). */ static void child_detach (args, from_tty) char *args; int from_tty; { child_detach_from_process (inferior_pid, args, from_tty, 0); inferior_pid = 0; unpush_target (&child_ops); } static void child_require_detach (pid, args, from_tty) int pid; char * args; int from_tty; { child_detach_from_process (pid, args, from_tty, 1); } /* Get ready to modify the registers array. On machines which store individual registers, this doesn't need to do anything. On machines which store all the registers in one fell swoop, this makes sure that registers contains all the registers from the program being debugged. */ static void child_prepare_to_store () { #ifdef CHILD_PREPARE_TO_STORE CHILD_PREPARE_TO_STORE (); #endif } /* Print status information about what we're accessing. */ static void child_files_info (ignore) struct target_ops *ignore; { printf_unfiltered ("\tUsing the running image of %s %s.\n", attach_flag? "attached": "child", target_pid_to_str (inferior_pid)); } /* ARGSUSED */ static void child_open (arg, from_tty) char *arg; int from_tty; { error ("Use the \"run\" command to start a Unix child process."); } /* Stub function which causes the inferior that runs it, to be ptrace-able by its parent process. */ static void ptrace_me () { /* "Trace me, Dr. Memory!" */ call_ptrace (0, 0, (PTRACE_ARG3_TYPE) 0, 0); } /* Stub function which causes the GDB that runs it, to start ptrace-ing the child process. */ static void ptrace_him (pid) int pid; { push_target (&child_ops); /* On some targets, there must be some explicit synchronization between the parent and child processes after the debugger forks, and before the child execs the debuggee program. This call basically gives permission for the child to exec. */ target_acknowledge_created_inferior (pid); /* START_INFERIOR_TRAPS_EXPECTED is defined in inferior.h, * and will be 1 or 2 depending on whether we're starting * without or with a shell. */ startup_inferior (START_INFERIOR_TRAPS_EXPECTED); /* On some targets, there must be some explicit actions taken after the inferior has been started up. */ target_post_startup_inferior (pid); } /* Start an inferior Unix child process and sets inferior_pid to its pid. EXEC_FILE is the file to run. ALLARGS is a string containing the arguments to the program. ENV is the environment vector to pass. Errors reported with error(). */ static void child_create_inferior (exec_file, allargs, env) char *exec_file; char *allargs; char **env; { #ifdef HPUXHPPA char *tryname; char *shell_file; char *p; char *p1; char *path = getenv ("PATH"); int len; struct stat statbuf; /* On HP-UX, we have a possible bad interaction between * the start-up-with-shell code and our catch-fork/catch-exec * logic. To avoid the bad interaction, we start up with the * C shell ("csh") and pass it the "-f" flag (fast start-up, * don't run .cshrc code). * See further comments in inferior.h toward the bottom * (STARTUP_WITH_SHELL flag) and in fork-child.c */ /* Rather than passing in a hard-wired path like "/bin/csh", * we look down the PATH to find csh. I took this code from * procfs.c, which is the file in the Sun-specific part of GDB * analogous to inftarg.c. See procfs.c for more detailed * comments. - RT */ shell_file = "csh"; if (path == NULL) path = "/bin:/usr/bin"; tryname = alloca (strlen (path) + strlen (shell_file) + 2); for (p = path; p != NULL; p = p1 ? p1 + 1: NULL) { p1 = strchr (p, ':'); if (p1 != NULL) len = p1 - p; else len = strlen (p); strncpy (tryname, p, len); tryname[len] = '\0'; strcat (tryname, "/"); strcat (tryname, shell_file); if (access (tryname, X_OK) < 0) continue; if (stat (tryname, &statbuf) < 0) continue; if (!S_ISREG (statbuf.st_mode)) /* We certainly need to reject directories. I'm not quite as sure about FIFOs, sockets, etc., but I kind of doubt that people want to exec() these things. */ continue; break; } if (p == NULL) /* Not found. I replaced the error() which existed in procfs.c * with simply passing in NULL and hoping fork_inferior() * can deal with it. - RT */ /* error ("Can't find shell %s in PATH", shell_file); */ shell_file = NULL; else shell_file = tryname; fork_inferior (exec_file, allargs, env, ptrace_me, ptrace_him, pre_fork_inferior, NULL); #else fork_inferior (exec_file, allargs, env, ptrace_me, ptrace_him, NULL, NULL); #endif /* We are at the first instruction we care about. */ /* Pedal to the metal... */ proceed ((CORE_ADDR) -1, TARGET_SIGNAL_0, 0); } #if !defined(CHILD_POST_STARTUP_INFERIOR) void child_post_startup_inferior (pid) int pid; { /* This version of Unix doesn't require a meaningful "post startup inferior" operation by a debugger. */ } #endif #if !defined(CHILD_ACKNOWLEDGE_CREATED_INFERIOR) void child_acknowledge_created_inferior (pid) int pid; { /* This version of Unix doesn't require a meaningful "acknowledge created inferior" operation by a debugger. */ } #endif void child_clone_and_follow_inferior (child_pid, followed_child) int child_pid; int *followed_child; { clone_and_follow_inferior (child_pid, followed_child); /* Don't resume CHILD_PID; it's stopped where it ought to be, until the decision gets made elsewhere how to continue it. */ } #if !defined(CHILD_POST_FOLLOW_INFERIOR_BY_CLONE) void child_post_follow_inferior_by_clone () { /* This version of Unix doesn't require a meaningful "post follow inferior" operation by a clone debugger. */ } #endif #if !defined(CHILD_INSERT_FORK_CATCHPOINT) int child_insert_fork_catchpoint (pid) int pid; { /* This version of Unix doesn't support notification of fork events. */ return 0; } #endif #if !defined(CHILD_REMOVE_FORK_CATCHPOINT) int child_remove_fork_catchpoint (pid) int pid; { /* This version of Unix doesn't support notification of fork events. */ return 0; } #endif #if !defined(CHILD_INSERT_VFORK_CATCHPOINT) int child_insert_vfork_catchpoint (pid) int pid; { /* This version of Unix doesn't support notification of vfork events. */ return 0; } #endif #if !defined(CHILD_REMOVE_VFORK_CATCHPOINT) int child_remove_vfork_catchpoint (pid) int pid; { /* This version of Unix doesn't support notification of vfork events. */ return 0; } #endif #if !defined(CHILD_HAS_FORKED) int child_has_forked (pid, child_pid) int pid; int *child_pid; { /* This version of Unix doesn't support notification of fork events. */ return 0; } #endif #if !defined(CHILD_HAS_VFORKED) int child_has_vforked (pid, child_pid) int pid; int * child_pid; { /* This version of Unix doesn't support notification of vfork events. */ return 0; } #endif #if !defined(CHILD_CAN_FOLLOW_VFORK_PRIOR_TO_EXEC) int child_can_follow_vfork_prior_to_exec () { /* This version of Unix doesn't support notification of vfork events. However, if it did, it probably wouldn't allow vforks to be followed before the following exec. */ return 0; } #endif #if !defined(CHILD_POST_FOLLOW_VFORK) void child_post_follow_vfork (parent_pid, followed_parent, child_pid, followed_child) int parent_pid; int followed_parent; int child_pid; int followed_child; { /* This version of Unix doesn't require a meaningful "post follow vfork" operation by a clone debugger. */ } #endif #if !defined(CHILD_INSERT_EXEC_CATCHPOINT) int child_insert_exec_catchpoint (pid) int pid; { /* This version of Unix doesn't support notification of exec events. */ return 0; } #endif #if !defined(CHILD_REMOVE_EXEC_CATCHPOINT) int child_remove_exec_catchpoint (pid) int pid; { /* This version of Unix doesn't support notification of exec events. */ return 0; } #endif #if !defined(CHILD_HAS_EXECD) int child_has_execd (pid, execd_pathname) int pid; char ** execd_pathname; { /* This version of Unix doesn't support notification of exec events. */ return 0; } #endif #if !defined(CHILD_REPORTED_EXEC_EVENTS_PER_EXEC_CALL) int child_reported_exec_events_per_exec_call () { /* This version of Unix doesn't support notification of exec events. */ return 1; } #endif #if !defined(CHILD_HAS_SYSCALL_EVENT) int child_has_syscall_event (pid, kind, syscall_id) int pid; enum target_waitkind * kind; int * syscall_id; { /* This version of Unix doesn't support notification of syscall events. */ return 0; } #endif #if !defined(CHILD_HAS_EXITED) int child_has_exited (pid, wait_status, exit_status) int pid; int wait_status; int * exit_status; { if (WIFEXITED (wait_status)) { *exit_status = WEXITSTATUS (wait_status); return 1; } if (WIFSIGNALED (wait_status)) { *exit_status = 0; /* ?? Don't know what else to say here. */ return 1; } /* ?? Do we really need to consult the event state, too? Assume the wait_state alone suffices. */ return 0; } #endif static void child_mourn_inferior () { /* FIXME: Should be in a header file */ extern void proc_remove_foreign PARAMS ((int)); unpush_target (&child_ops); proc_remove_foreign (inferior_pid); generic_mourn_inferior (); } static int child_can_run () { /* This variable is controlled by modules that sit atop inftarg that may layer their own process structure atop that provided here. hpux-thread.c does this because of the Hpux user-mode level thread model. */ return !child_suppress_run; } /* Send a SIGINT to the process group. This acts just like the user typed a ^C on the controlling terminal. XXX - This may not be correct for all systems. Some may want to use killpg() instead of kill (-pgrp). */ static void child_stop () { extern pid_t inferior_process_group; kill (-inferior_process_group, SIGINT); } #if !defined(CHILD_ENABLE_EXCEPTION_CALLBACK) struct symtab_and_line * child_enable_exception_callback (kind, enable) enum exception_event_kind kind; int enable; { return (struct symtab_and_line *) NULL; } #endif #if !defined(CHILD_GET_CURRENT_EXCEPTION_EVENT) struct exception_event_record * child_get_current_exception_event () { return (struct exception_event_record *) NULL; } #endif #if !defined(CHILD_PID_TO_EXEC_FILE) char * child_pid_to_exec_file (pid) int pid; { /* This version of Unix doesn't support translation of a process ID to the filename of the executable file. */ return NULL; } #endif char * child_core_file_to_sym_file (core) char * core; { /* The target stratum for a running executable need not support this operation. */ return NULL; } static void init_child_ops () { child_ops.to_shortname = "child"; child_ops.to_longname = "Unix child process"; child_ops.to_doc = "Unix child process (started by the \"run\" command)."; child_ops.to_open = child_open; child_ops.to_attach = child_attach; child_ops.to_post_attach = child_post_attach; child_ops.to_require_attach = child_require_attach; child_ops.to_detach = child_detach; child_ops.to_require_detach = child_require_detach; child_ops.to_resume = child_resume; child_ops.to_wait = child_wait; child_ops.to_post_wait = child_post_wait; child_ops.to_fetch_registers = fetch_inferior_registers; child_ops.to_store_registers = store_inferior_registers; child_ops.to_prepare_to_store = child_prepare_to_store; child_ops.to_xfer_memory = child_xfer_memory; child_ops.to_files_info = child_files_info; child_ops.to_insert_breakpoint = memory_insert_breakpoint; child_ops.to_remove_breakpoint = memory_remove_breakpoint; child_ops.to_terminal_init = terminal_init_inferior; child_ops.to_terminal_inferior = terminal_inferior; child_ops.to_terminal_ours_for_output = terminal_ours_for_output; child_ops.to_terminal_ours = terminal_ours; child_ops.to_terminal_info = child_terminal_info; child_ops.to_kill = kill_inferior; child_ops.to_create_inferior = child_create_inferior; child_ops.to_post_startup_inferior = child_post_startup_inferior; child_ops.to_acknowledge_created_inferior = child_acknowledge_created_inferior; child_ops.to_clone_and_follow_inferior = child_clone_and_follow_inferior; child_ops.to_post_follow_inferior_by_clone = child_post_follow_inferior_by_clone; child_ops.to_insert_fork_catchpoint = child_insert_fork_catchpoint; child_ops.to_remove_fork_catchpoint = child_remove_fork_catchpoint; child_ops.to_insert_vfork_catchpoint = child_insert_vfork_catchpoint; child_ops.to_remove_vfork_catchpoint = child_remove_vfork_catchpoint; child_ops.to_has_forked = child_has_forked; child_ops.to_has_vforked = child_has_vforked; child_ops.to_can_follow_vfork_prior_to_exec = child_can_follow_vfork_prior_to_exec; child_ops.to_post_follow_vfork = child_post_follow_vfork; child_ops.to_insert_exec_catchpoint = child_insert_exec_catchpoint; child_ops.to_remove_exec_catchpoint = child_remove_exec_catchpoint; child_ops.to_has_execd = child_has_execd; child_ops.to_reported_exec_events_per_exec_call = child_reported_exec_events_per_exec_call; child_ops.to_has_syscall_event = child_has_syscall_event; child_ops.to_has_exited = child_has_exited; child_ops.to_mourn_inferior = child_mourn_inferior; child_ops.to_can_run = child_can_run; child_ops.to_thread_alive = child_thread_alive; child_ops.to_stop = child_stop; child_ops.to_enable_exception_callback = child_enable_exception_callback; child_ops.to_get_current_exception_event = child_get_current_exception_event; child_ops.to_pid_to_exec_file = child_pid_to_exec_file; child_ops.to_core_file_to_sym_file = child_core_file_to_sym_file; child_ops.to_stratum = process_stratum; child_ops.to_has_all_memory = 1; child_ops.to_has_memory = 1; child_ops.to_has_stack = 1; child_ops.to_has_registers = 1; child_ops.to_has_execution = 1; child_ops.to_magic = OPS_MAGIC; } void _initialize_inftarg () { #ifdef HAVE_OPTIONAL_PROC_FS char procname[32]; int fd; /* If we have an optional /proc filesystem (e.g. under OSF/1), don't add ptrace support if we can access the running GDB via /proc. */ #ifndef PROC_NAME_FMT #define PROC_NAME_FMT "/proc/%05d" #endif sprintf (procname, PROC_NAME_FMT, getpid ()); if ((fd = open (procname, O_RDONLY)) >= 0) { close (fd); return; } #endif init_child_ops (); add_target (&child_ops); }