From 30c8afd17523f48d859277525226dfda04011174 Mon Sep 17 00:00:00 2001 From: Simon McVittie Date: Fri, 21 Jan 2011 16:48:37 +0000 Subject: [PATCH 1/2] Always remove, invalidate and free watches before closing watched sockets This should mean we don't get invalid fds in the main loop. The BSD (kqueue) and Windows code paths are untested, but follow the same patterns as the tested Linux/generic Unix versions. DBusTransportSocket was already OK (it called free_watches() before _dbus_close_socket, and that did the remove, invalidate, unref dance). Bug: https://bugs.freedesktop.org/show_bug.cgi?id=33336 --- bus/dir-watch-inotify.c | 6 ++- bus/dir-watch-kqueue.c | 6 ++- bus/main.c | 22 ++++++-- dbus/dbus-server-socket.c | 1 + dbus/dbus-spawn-win.c | 36 ++++++++++--- dbus/dbus-spawn.c | 122 +++++++++++++++++++++--------------------- dbus/dbus-transport-socket.c | 2 + 7 files changed, 119 insertions(+), 76 deletions(-) diff --git a/bus/dir-watch-inotify.c b/bus/dir-watch-inotify.c index 461b8ee..54704a4 100644 --- a/bus/dir-watch-inotify.c +++ b/bus/dir-watch-inotify.c @@ -204,16 +204,18 @@ _shutdown_inotify (void *data) _set_watched_dirs_internal (&empty); - close (inotify_fd); - inotify_fd = -1; if (watch != NULL) { _dbus_loop_remove_watch (loop, watch, _inotify_watch_callback, NULL); + _dbus_watch_invalidate (watch); _dbus_watch_unref (watch); _dbus_loop_unref (loop); } watch = NULL; loop = NULL; + + close (inotify_fd); + inotify_fd = -1; } static int diff --git a/bus/dir-watch-kqueue.c b/bus/dir-watch-kqueue.c index 4e436eb..62f7b3d 100644 --- a/bus/dir-watch-kqueue.c +++ b/bus/dir-watch-kqueue.c @@ -81,6 +81,7 @@ _handle_kqueue_watch (DBusWatch *watch, unsigned int flags, void *data) if (watch != NULL) { _dbus_loop_remove_watch (loop, watch, _kqueue_watch_callback, NULL); + _dbus_watch_invalidate (watch); _dbus_watch_unref (watch); watch = NULL; } @@ -124,10 +125,11 @@ _init_kqueue (BusContext *context) NULL, NULL)) { _dbus_warn ("Unable to add reload watch to main loop"); - close (kq); - kq = -1; + _dbus_watch_invalidate (watch); _dbus_watch_unref (watch); watch = NULL; + close (kq); + kq = -1; goto out; } } diff --git a/bus/main.c b/bus/main.c index 53038db..1af588e 100644 --- a/bus/main.c +++ b/bus/main.c @@ -43,7 +43,8 @@ static int reload_pipe[2]; #define RELOAD_READ_END 0 #define RELOAD_WRITE_END 1 -static void close_reload_pipe (void); +static void close_reload_pipe (DBusWatch **); +static void close_reload_pipe_write (void); static void signal_handler (int sig) @@ -64,7 +65,7 @@ signal_handler (int sig) !_dbus_write_socket (reload_pipe[RELOAD_WRITE_END], &str, 0, 1)) { _dbus_warn ("Unable to write to reload pipe.\n"); - close_reload_pipe (); + close_reload_pipe_write (); } } break; @@ -178,7 +179,7 @@ handle_reload_watch (DBusWatch *watch, _dbus_read_socket (reload_pipe[RELOAD_READ_END], &str, 1) != 1) { _dbus_warn ("Couldn't read from reload pipe.\n"); - close_reload_pipe (); + close_reload_pipe (&watch); return TRUE; } _dbus_string_free (&str); @@ -249,11 +250,24 @@ setup_reload_pipe (DBusLoop *loop) } static void -close_reload_pipe (void) +close_reload_pipe (DBusWatch **watch) { + _dbus_loop_remove_watch (bus_context_get_loop (context), + *watch, reload_watch_callback, NULL); + _dbus_watch_invalidate (*watch); + _dbus_watch_unref (*watch); + *watch = NULL; + _dbus_close_socket (reload_pipe[RELOAD_READ_END], NULL); reload_pipe[RELOAD_READ_END] = -1; + close_reload_pipe_write (); +} + +/* this is the only bit that's safe to do from an async signal handler */ +static void +close_reload_pipe_write (void) +{ _dbus_close_socket (reload_pipe[RELOAD_WRITE_END], NULL); reload_pipe[RELOAD_WRITE_END] = -1; } diff --git a/dbus/dbus-server-socket.c b/dbus/dbus-server-socket.c index 758742d..057f7c2 100644 --- a/dbus/dbus-server-socket.c +++ b/dbus/dbus-server-socket.c @@ -236,6 +236,7 @@ socket_disconnect (DBusServer *server) { _dbus_server_remove_watch (server, socket_server->watch[i]); + _dbus_watch_invalidate (socket_server->watch[i]); _dbus_watch_unref (socket_server->watch[i]); socket_server->watch[i] = NULL; } diff --git a/dbus/dbus-spawn-win.c b/dbus/dbus-spawn-win.c index 8ac837e..dfeb44f 100644 --- a/dbus/dbus-spawn-win.c +++ b/dbus/dbus-spawn-win.c @@ -154,6 +154,27 @@ _dbus_babysitter_ref (DBusBabysitter *sitter) return sitter; } +static void +close_socket_to_babysitter (DBusBabysitter *sitter) +{ + _dbus_verbose ("Closing babysitter\n"); + + if (sitter->sitter_watch != NULL) + { + _dbus_assert (sitter->watches != NULL); + _dbus_watch_list_remove_watch (sitter->watches, sitter->sitter_watch); + _dbus_watch_invalidate (sitter->sitter_watch); + _dbus_watch_unref (sitter->sitter_watch); + sitter->sitter_watch = NULL; + } + + if (sitter->socket_to_babysitter != -1) + { + _dbus_close_socket (sitter->socket_to_babysitter, NULL); + sitter->socket_to_babysitter = -1; + } +} + /** * Decrement the reference count on the babysitter object. * @@ -172,11 +193,7 @@ _dbus_babysitter_unref (DBusBabysitter *sitter) if (sitter->refcount == 0) { - if (sitter->socket_to_babysitter != -1) - { - _dbus_close_socket (sitter->socket_to_babysitter, NULL); - sitter->socket_to_babysitter = -1; - } + close_socket_to_babysitter (sitter); if (sitter->socket_to_main != -1) { @@ -372,9 +389,8 @@ handle_watch (DBusWatch *watch, */ PING(); - _dbus_close_socket (sitter->socket_to_babysitter, NULL); + close_socket_to_babysitter (sitter); PING(); - sitter->socket_to_babysitter = -1; return TRUE; } @@ -668,6 +684,12 @@ _dbus_spawn_async_with_babysitter (DBusBabysitter **sitter_p, PING(); if (!_dbus_watch_list_add_watch (sitter->watches, sitter->sitter_watch)) { + /* we need to free it early so the destructor won't try to remove it + * without it having been added, which DBusLoop doesn't allow */ + _dbus_watch_invalidate (sitter->sitter_watch); + _dbus_watch_unref (sitter->sitter_watch); + sitter->sitter_watch = NULL; + _DBUS_SET_OOM (error); goto out0; } diff --git a/dbus/dbus-spawn.c b/dbus/dbus-spawn.c index a1bab3d..5654380 100644 --- a/dbus/dbus-spawn.c +++ b/dbus/dbus-spawn.c @@ -257,6 +257,9 @@ _dbus_babysitter_ref (DBusBabysitter *sitter) return sitter; } +static void close_socket_to_babysitter (DBusBabysitter *sitter); +static void close_error_pipe_from_child (DBusBabysitter *sitter); + /** * Decrement the reference count on the babysitter object. * When the reference count of the babysitter object reaches @@ -273,25 +276,17 @@ _dbus_babysitter_unref (DBusBabysitter *sitter) sitter->refcount -= 1; if (sitter->refcount == 0) - { - if (sitter->socket_to_babysitter >= 0) - { - /* If we haven't forked other babysitters - * since this babysitter and socket were - * created then this close will cause the - * babysitter to wake up from poll with - * a hangup and then the babysitter will - * quit itself. - */ - _dbus_close_socket (sitter->socket_to_babysitter, NULL); - sitter->socket_to_babysitter = -1; - } + { + /* If we haven't forked other babysitters + * since this babysitter and socket were + * created then this close will cause the + * babysitter to wake up from poll with + * a hangup and then the babysitter will + * quit itself. + */ + close_socket_to_babysitter (sitter); - if (sitter->error_pipe_from_child >= 0) - { - _dbus_close_socket (sitter->error_pipe_from_child, NULL); - sitter->error_pipe_from_child = -1; - } + close_error_pipe_from_child (sitter); if (sitter->sitter_pid > 0) { @@ -341,21 +336,7 @@ _dbus_babysitter_unref (DBusBabysitter *sitter) sitter->sitter_pid = -1; } - - if (sitter->error_watch) - { - _dbus_watch_invalidate (sitter->error_watch); - _dbus_watch_unref (sitter->error_watch); - sitter->error_watch = NULL; - } - if (sitter->sitter_watch) - { - _dbus_watch_invalidate (sitter->sitter_watch); - _dbus_watch_unref (sitter->sitter_watch); - sitter->sitter_watch = NULL; - } - if (sitter->watches) _dbus_watch_list_free (sitter->watches); @@ -476,16 +457,42 @@ static void close_socket_to_babysitter (DBusBabysitter *sitter) { _dbus_verbose ("Closing babysitter\n"); - _dbus_close_socket (sitter->socket_to_babysitter, NULL); - sitter->socket_to_babysitter = -1; + + if (sitter->sitter_watch != NULL) + { + _dbus_assert (sitter->watches != NULL); + _dbus_watch_list_remove_watch (sitter->watches, sitter->sitter_watch); + _dbus_watch_invalidate (sitter->sitter_watch); + _dbus_watch_unref (sitter->sitter_watch); + sitter->sitter_watch = NULL; + } + + if (sitter->socket_to_babysitter >= 0) + { + _dbus_close_socket (sitter->socket_to_babysitter, NULL); + sitter->socket_to_babysitter = -1; + } } static void close_error_pipe_from_child (DBusBabysitter *sitter) { _dbus_verbose ("Closing child error\n"); - _dbus_close_socket (sitter->error_pipe_from_child, NULL); - sitter->error_pipe_from_child = -1; + + if (sitter->error_watch != NULL) + { + _dbus_assert (sitter->watches != NULL); + _dbus_watch_list_remove_watch (sitter->watches, sitter->error_watch); + _dbus_watch_invalidate (sitter->error_watch); + _dbus_watch_unref (sitter->error_watch); + sitter->error_watch = NULL; + } + + if (sitter->error_pipe_from_child >= 0) + { + _dbus_close_socket (sitter->error_pipe_from_child, NULL); + sitter->error_pipe_from_child = -1; + } } static void @@ -752,7 +759,7 @@ handle_watch (DBusWatch *watch, unsigned int condition, void *data) { - DBusBabysitter *sitter = data; + DBusBabysitter *sitter = _dbus_babysitter_ref (data); int revents; int fd; @@ -775,31 +782,12 @@ handle_watch (DBusWatch *watch, babysitter_iteration (sitter, FALSE)) ; - /* Those might have closed the sockets we're watching. Before returning - * to the main loop, we must sort that out. */ - - if (sitter->error_watch != NULL && sitter->error_pipe_from_child == -1) - { - _dbus_watch_invalidate (sitter->error_watch); - - if (sitter->watches != NULL) - _dbus_watch_list_remove_watch (sitter->watches, sitter->error_watch); - - _dbus_watch_unref (sitter->error_watch); - sitter->error_watch = NULL; - } - - if (sitter->sitter_watch != NULL && sitter->socket_to_babysitter == -1) - { - _dbus_watch_invalidate (sitter->sitter_watch); - - if (sitter->watches != NULL) - _dbus_watch_list_remove_watch (sitter->watches, sitter->sitter_watch); - - _dbus_watch_unref (sitter->sitter_watch); - sitter->sitter_watch = NULL; - } + /* fd.o #32992: if the handle_* methods closed their sockets, they previously + * didn't always remove the watches. Check that we don't regress. */ + _dbus_assert (sitter->socket_to_babysitter != -1 || sitter->sitter_watch == NULL); + _dbus_assert (sitter->error_pipe_from_child != -1 || sitter->error_watch == NULL); + _dbus_babysitter_unref (sitter); return TRUE; } @@ -1189,6 +1177,12 @@ _dbus_spawn_async_with_babysitter (DBusBabysitter **sitter_p, if (!_dbus_watch_list_add_watch (sitter->watches, sitter->error_watch)) { + /* we need to free it early so the destructor won't try to remove it + * without it having been added, which DBusLoop doesn't allow */ + _dbus_watch_invalidate (sitter->error_watch); + _dbus_watch_unref (sitter->error_watch); + sitter->error_watch = NULL; + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL); goto cleanup_and_fail; } @@ -1204,6 +1198,12 @@ _dbus_spawn_async_with_babysitter (DBusBabysitter **sitter_p, if (!_dbus_watch_list_add_watch (sitter->watches, sitter->sitter_watch)) { + /* we need to free it early so the destructor won't try to remove it + * without it having been added, which DBusLoop doesn't allow */ + _dbus_watch_invalidate (sitter->sitter_watch); + _dbus_watch_unref (sitter->sitter_watch); + sitter->sitter_watch = NULL; + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL); goto cleanup_and_fail; } diff --git a/dbus/dbus-transport-socket.c b/dbus/dbus-transport-socket.c index 1d4c2bf..1dfb140 100644 --- a/dbus/dbus-transport-socket.c +++ b/dbus/dbus-transport-socket.c @@ -1278,8 +1278,10 @@ _dbus_transport_new_for_socket (int fd, return (DBusTransport*) socket_transport; failed_4: + _dbus_watch_invalidate (socket_transport->read_watch); _dbus_watch_unref (socket_transport->read_watch); failed_3: + _dbus_watch_invalidate (socket_transport->write_watch); _dbus_watch_unref (socket_transport->write_watch); failed_2: _dbus_string_free (&socket_transport->encoded_incoming); -- 1.7.2.3