+/* The child has exited or execed: resume threads of the parent the
+ user wanted to be executing. */
+
+static int
+proceed_after_vfork_done (struct thread_info *thread,
+ void *arg)
+{
+ int pid = * (int *) arg;
+
+ if (ptid_get_pid (thread->ptid) == pid
+ && is_running (thread->ptid)
+ && !is_executing (thread->ptid)
+ && !thread->stop_requested
+ && thread->stop_signal == TARGET_SIGNAL_0)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: resuming vfork parent thread %s\n",
+ target_pid_to_str (thread->ptid));
+
+ switch_to_thread (thread->ptid);
+ clear_proceed_status ();
+ proceed ((CORE_ADDR) -1, TARGET_SIGNAL_DEFAULT, 0);
+ }
+
+ return 0;
+}
+
+/* Called whenever we notice an exec or exit event, to handle
+ detaching or resuming a vfork parent. */
+
+static void
+handle_vfork_child_exec_or_exit (int exec)
+{
+ struct inferior *inf = current_inferior ();
+
+ if (inf->vfork_parent)
+ {
+ int resume_parent = -1;
+
+ /* This exec or exit marks the end of the shared memory region
+ between the parent and the child. If the user wanted to
+ detach from the parent, now is the time. */
+
+ if (inf->vfork_parent->pending_detach)
+ {
+ struct thread_info *tp;
+ struct cleanup *old_chain;
+ struct program_space *pspace;
+ struct address_space *aspace;
+
+ /* follow-fork child, detach-on-fork on */
+
+ old_chain = make_cleanup_restore_current_thread ();
+
+ /* We're letting loose of the parent. */
+ tp = any_live_thread_of_process (inf->vfork_parent->pid);
+ switch_to_thread (tp->ptid);
+
+ /* We're about to detach from the parent, which implicitly
+ removes breakpoints from its address space. There's a
+ catch here: we want to reuse the spaces for the child,
+ but, parent/child are still sharing the pspace at this
+ point, although the exec in reality makes the kernel give
+ the child a fresh set of new pages. The problem here is
+ that the breakpoints module being unaware of this, would
+ likely chose the child process to write to the parent
+ address space. Swapping the child temporarily away from
+ the spaces has the desired effect. Yes, this is "sort
+ of" a hack. */
+
+ pspace = inf->pspace;
+ aspace = inf->aspace;
+ inf->aspace = NULL;
+ inf->pspace = NULL;
+
+ if (debug_infrun || info_verbose)
+ {
+ target_terminal_ours ();
+
+ if (exec)
+ fprintf_filtered (gdb_stdlog,
+ "Detaching vfork parent process %d after child exec.\n",
+ inf->vfork_parent->pid);
+ else
+ fprintf_filtered (gdb_stdlog,
+ "Detaching vfork parent process %d after child exit.\n",
+ inf->vfork_parent->pid);
+ }
+
+ target_detach (NULL, 0);
+
+ /* Put it back. */
+ inf->pspace = pspace;
+ inf->aspace = aspace;
+
+ do_cleanups (old_chain);
+ }
+ else if (exec)
+ {
+ /* We're staying attached to the parent, so, really give the
+ child a new address space. */
+ inf->pspace = add_program_space (maybe_new_address_space ());
+ inf->aspace = inf->pspace->aspace;
+ inf->removable = 1;
+ set_current_program_space (inf->pspace);
+
+ resume_parent = inf->vfork_parent->pid;
+
+ /* Break the bonds. */
+ inf->vfork_parent->vfork_child = NULL;
+ }
+ else
+ {
+ struct cleanup *old_chain;
+ struct program_space *pspace;
+
+ /* If this is a vfork child exiting, then the pspace and
+ aspaces were shared with the parent. Since we're
+ reporting the process exit, we'll be mourning all that is
+ found in the address space, and switching to null_ptid,
+ preparing to start a new inferior. But, since we don't
+ want to clobber the parent's address/program spaces, we
+ go ahead and create a new one for this exiting
+ inferior. */
+
+ /* Switch to null_ptid, so that clone_program_space doesn't want
+ to read the selected frame of a dead process. */
+ old_chain = save_inferior_ptid ();
+ inferior_ptid = null_ptid;
+
+ /* This inferior is dead, so avoid giving the breakpoints
+ module the option to write through to it (cloning a
+ program space resets breakpoints). */
+ inf->aspace = NULL;
+ inf->pspace = NULL;
+ pspace = add_program_space (maybe_new_address_space ());
+ set_current_program_space (pspace);
+ inf->removable = 1;
+ clone_program_space (pspace, inf->vfork_parent->pspace);
+ inf->pspace = pspace;
+ inf->aspace = pspace->aspace;
+
+ /* Put back inferior_ptid. We'll continue mourning this
+ inferior. */
+ do_cleanups (old_chain);
+
+ resume_parent = inf->vfork_parent->pid;
+ /* Break the bonds. */
+ inf->vfork_parent->vfork_child = NULL;
+ }
+
+ inf->vfork_parent = NULL;
+
+ gdb_assert (current_program_space == inf->pspace);
+
+ if (non_stop && resume_parent != -1)
+ {
+ /* If the user wanted the parent to be running, let it go
+ free now. */
+ struct cleanup *old_chain = make_cleanup_restore_current_thread ();
+
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog, "infrun: resuming vfork parent process %d\n",
+ resume_parent);
+
+ iterate_over_threads (proceed_after_vfork_done, &resume_parent);
+
+ do_cleanups (old_chain);
+ }
+ }
+}
+
+/* Enum strings for "set|show displaced-stepping". */
+
+static const char follow_exec_mode_new[] = "new";
+static const char follow_exec_mode_same[] = "same";
+static const char *follow_exec_mode_names[] =
+{
+ follow_exec_mode_new,
+ follow_exec_mode_same,
+ NULL,
+};
+
+static const char *follow_exec_mode_string = follow_exec_mode_same;
+static void
+show_follow_exec_mode_string (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
+}
+
projects / binutils-gdb.git / blobdiff