Add --kill-on-exit option

src/cli/proot.c

@@ -174,6 +174,12 @@ static int handle_option_0(Tracee *tracee, const Cli *cli, const char *value UNU
 	return handle_option_i(tracee, cli, "0:0");
 }
 
+static int handle_option_kill_on_exit(Tracee *tracee, const Cli *cli UNUSED, const char *value UNUSED)
+{
+        tracee->killall_on_exit = true;
+	return 0;
+}
+
 static int handle_option_v(Tracee *tracee, const Cli *cli UNUSED, const char *value)
 {
 	int status;

src/cli/proot.h

@@ -60,6 +60,7 @@ static int handle_option_0(Tracee *tracee, const Cli *cli, const char *value);
 static int handle_option_i(Tracee *tracee, const Cli *cli, const char *value);
 static int handle_option_R(Tracee *tracee, const Cli *cli, const char *value);
 static int handle_option_S(Tracee *tracee, const Cli *cli, const char *value);
+static int handle_option_kill_on_exit(Tracee *tracee, const Cli *cli, const char *value);
 
 static int pre_initialize_bindings(Tracee *, const Cli *, size_t, char *const *, size_t);
 static int post_initialize_exe(Tracee *, const Cli *, size_t, char *const *, size_t);
@@ -142,6 +143,16 @@ Copyright (C) 2014 STMicroelectronics, licensed under GPL v2 or later.",
 	  .detail = "\tSome programs expect to be launched from a given directory but do\n\
 \tnot perform any chdir by themselves.  This option avoids the\n\
 \tneed for running a shell and then entering the directory manually.",
+	},
+	{ .class = "Regular options",
+	  .arguments = {
+		{ .name = "--kill-on-exit", .separator = '\0', .value = NULL },
+		{ .name = NULL, .separator = '\0', .value = NULL } },
+	  .handler = handle_option_kill_on_exit,
+	  .description = "Kill all processes on command exit.",
+	  .detail = "\tWhen the executed command leaves orphean or detached processes\n\
+\taround, proot waits until all processes possibly terminate. This option forces\n\
+\tthe immediate termination of all tracee processes when the main command exits.",
 	},
 	{ .class = "Regular options",
 	  .arguments = {

src/tracee/event.c

@@ -389,13 +389,13 @@ int handle_tracee_event(Tracee *tracee, int tracee_status)
 	if (WIFEXITED(tracee_status)) {
 		last_exit_status = WEXITSTATUS(tracee_status);
 		VERBOSE(tracee, 1, "pid %d: exited with status %d", pid, last_exit_status);
-		tracee->terminated = true;
+		terminate_tracee(tracee);
 	}
 	else if (WIFSIGNALED(tracee_status)) {
 		check_architecture(tracee);
 		VERBOSE(tracee, (int) (last_exit_status != -1),
 			"pid %d: terminated with signal %d", pid, WTERMSIG(tracee_status));
-		tracee->terminated = true;
+                terminate_tracee(tracee);
 	}
 	else if (WIFSTOPPED(tracee_status)) {
 		/* Don't use WSTOPSIG() to extract the signal

src/tracee/tracee.c

@@ -335,6 +335,22 @@ Tracee *get_tracee(const Tracee *current_tracee, pid_t pid, bool create)
 	return (create ? new_tracee(pid) : NULL);
 }
 
+/**
+ * Mark tracee as terminated and optionally take action.
+ */
+void terminate_tracee(Tracee *tracee)
+{
+        tracee->terminated = true;
+
+        /* Case where the terminated tracee is marked
+           to kill all tracees on exit.
+        */
+        if (tracee->killall_on_exit) {
+                VERBOSE(tracee, 1, "terminating all tracees on exit");
+                kill_all_tracees();
+        }
+}
+
 /**
  * Free all tracees marked as terminated.
  */

src/tracee/tracee.h

@@ -89,6 +89,10 @@ typedef struct tracee {
 	 * dedicated to terminated tracees instead.  */
 	bool terminated;
 
+        /* Whether termination of this tracee implies an immediate kill
+         * of all tracees. */
+        bool killall_on_exit;
+
 	/* Parent of this tracee, NULL if none.  */
 	struct tracee *parent;
 
@@ -266,6 +270,7 @@ extern Tracee *get_stopped_ptracee(const Tracee *ptracer, pid_t pid,
 extern bool has_ptracees(const Tracee *ptracer, pid_t pid, word_t wait_options);
 extern int new_child(Tracee *parent, word_t clone_flags);
 extern Tracee *new_dummy_tracee(TALLOC_CTX *context);
+extern void terminate_tracee(Tracee *tracee);
 extern void free_terminated_tracees();
 extern int swap_config(Tracee *tracee1, Tracee *tracee2);
 extern void kill_all_tracees();

tests/test-killexit.sh

@@ -0,0 +1,23 @@
+if [ -z `which setsid` ]; then
+    exit 125
+fi
+
+cleanup() {
+    _code=$?
+    trap - INT TERM EXIT
+    [ ! -f "${tmpfile-}" ] || rm -f "$tmpfile"
+    exit $_code
+}
+trap cleanup INT TERM EXIT
+
+tmpfile=`mktemp`
+
+# Check that kill on exit option is recognized
+${PROOT} --kill-on-exit true
+
+# Check that detached sleep does not block proot
+# I.e. in the file we must have "success" first, not "fail"
+${PROOT} --kill-on-exit sh -c "setsid sh -c \"sleep 2; echo fail >>$tmpfile\" &"
+echo "success" >>$tmpfile
+read status <$tmpfile
+[ "$status" = success ] || exit 1