mirror of
https://github.com/brl/mutter.git
synced 2024-11-12 17:27:03 -05:00
wayland: don't use fork() and SIGCHLD to spawn processes
It is a very bad idea in a glib program (especially one heavily using glib child watching facilities, like gnome-shell) to handle SIGCHLD. While we're there, let's also use g_spawn_async, which solves some malloc-after-fork problems and makes the code generally cleaner. https://bugzilla.gnome.org/show_bug.cgi?id=705816
This commit is contained in:
parent
152d896f75
commit
3803fd9511
@ -368,9 +368,6 @@ signal_handler (int signum)
|
||||
case SIGTERM:
|
||||
write (signal_pipe_fds[1], "T", 1);
|
||||
break;
|
||||
case SIGCHLD:
|
||||
write (signal_pipe_fds[1], "C", 1);
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
@ -407,11 +404,6 @@ on_signal (GIOChannel *source,
|
||||
case 'T': /* SIGTERM */
|
||||
meta_quit (META_EXIT_SUCCESS);
|
||||
break;
|
||||
#ifdef HAVE_WAYLAND
|
||||
case 'C': /* SIGCHLD */
|
||||
meta_wayland_handle_sig_child ();
|
||||
break;
|
||||
#endif
|
||||
default:
|
||||
g_warning ("Spurious character '%c' read from signal pipe", signal);
|
||||
}
|
||||
@ -460,13 +452,6 @@ meta_init (void)
|
||||
g_printerr ("Failed to register SIGTERM handler: %s\n",
|
||||
g_strerror (errno));
|
||||
|
||||
if (meta_is_wayland_compositor ())
|
||||
{
|
||||
if (sigaction (SIGCHLD, &act, NULL) < 0)
|
||||
g_printerr ("Failed to register SIGCHLD handler: %s\n",
|
||||
g_strerror (errno));
|
||||
}
|
||||
|
||||
if (g_getenv ("MUTTER_VERBOSE"))
|
||||
meta_set_verbose (TRUE);
|
||||
if (g_getenv ("MUTTER_DEBUG"))
|
||||
|
@ -349,8 +349,6 @@ void meta_wayland_finalize (void);
|
||||
* API after meta_wayland_init() has been called. */
|
||||
MetaWaylandCompositor *meta_wayland_compositor_get_default (void);
|
||||
|
||||
void meta_wayland_handle_sig_child (void);
|
||||
|
||||
void meta_wayland_compositor_repick (MetaWaylandCompositor *compositor);
|
||||
|
||||
void meta_wayland_compositor_set_input_focus (MetaWaylandCompositor *compositor,
|
||||
|
@ -1576,27 +1576,3 @@ meta_wayland_finalize (void)
|
||||
{
|
||||
meta_xwayland_stop (meta_wayland_compositor_get_default ());
|
||||
}
|
||||
|
||||
void
|
||||
meta_wayland_handle_sig_child (void)
|
||||
{
|
||||
int status;
|
||||
pid_t pid = waitpid (-1, &status, WNOHANG);
|
||||
MetaWaylandCompositor *compositor = &_meta_wayland_compositor;
|
||||
|
||||
/* The simplest measure to avoid infinitely re-spawning a crashing
|
||||
* X server */
|
||||
if (pid == compositor->xwayland_pid)
|
||||
{
|
||||
if (!WIFEXITED (status))
|
||||
g_critical ("X Wayland crashed; aborting");
|
||||
else
|
||||
{
|
||||
/* For now we simply abort if we see the server exit.
|
||||
*
|
||||
* In the future X will only be loaded lazily for legacy X support
|
||||
* but for now it's a hard requirement. */
|
||||
g_critical ("Spurious exit of X Wayland server");
|
||||
}
|
||||
}
|
||||
}
|
||||
|
@ -28,6 +28,8 @@
|
||||
#include <errno.h>
|
||||
#include <sys/socket.h>
|
||||
#include <sys/un.h>
|
||||
#include <sys/wait.h>
|
||||
#include <stdlib.h>
|
||||
|
||||
static char *
|
||||
create_lockfile (int display, int *display_out)
|
||||
@ -183,6 +185,39 @@ bind_to_unix_socket (int display)
|
||||
return fd;
|
||||
}
|
||||
|
||||
static void
|
||||
uncloexec_and_setpgid (gpointer user_data)
|
||||
{
|
||||
int fd = GPOINTER_TO_INT (user_data);
|
||||
|
||||
/* Make sure the client end of the socket pair doesn't get closed
|
||||
* when we exec xwayland. */
|
||||
int flags = fcntl (fd, F_GETFD);
|
||||
if (flags != -1)
|
||||
fcntl (fd, F_SETFD, flags & ~FD_CLOEXEC);
|
||||
|
||||
/* Put this process in a background process group, so that Ctrl-C
|
||||
goes to mutter only */
|
||||
setpgid (0, 0);
|
||||
}
|
||||
|
||||
static void
|
||||
xserver_died (GPid pid,
|
||||
gint status,
|
||||
gpointer user_data)
|
||||
{
|
||||
if (!WIFEXITED (status))
|
||||
g_error ("X Wayland crashed; aborting");
|
||||
else
|
||||
{
|
||||
/* For now we simply abort if we see the server exit.
|
||||
*
|
||||
* In the future X will only be loaded lazily for legacy X support
|
||||
* but for now it's a hard requirement. */
|
||||
g_error ("Spurious exit of X Wayland server");
|
||||
}
|
||||
}
|
||||
|
||||
gboolean
|
||||
meta_xwayland_start (MetaWaylandCompositor *compositor)
|
||||
{
|
||||
@ -190,6 +225,11 @@ meta_xwayland_start (MetaWaylandCompositor *compositor)
|
||||
char *lockfile = NULL;
|
||||
int sp[2];
|
||||
pid_t pid;
|
||||
char **env;
|
||||
char *fd_string;
|
||||
char *display_name;
|
||||
char *args[11];
|
||||
GError *error;
|
||||
|
||||
do
|
||||
{
|
||||
@ -238,45 +278,39 @@ meta_xwayland_start (MetaWaylandCompositor *compositor)
|
||||
return 1;
|
||||
}
|
||||
|
||||
switch ((pid = fork()))
|
||||
env = g_get_environ ();
|
||||
fd_string = g_strdup_printf ("%d", sp[1]);
|
||||
env = g_environ_setenv (env, "WAYLAND_SOCKET", fd_string, TRUE);
|
||||
g_free (fd_string);
|
||||
|
||||
display_name = g_strdup_printf (":%d",
|
||||
compositor->xwayland_display_index);
|
||||
|
||||
args[0] = XWAYLAND_PATH;
|
||||
args[1] = display_name;
|
||||
args[2] = "-wayland";
|
||||
args[3] = "-rootless";
|
||||
args[4] = "-retro";
|
||||
args[5] = "-noreset";
|
||||
args[6] = "-logfile";
|
||||
args[7] = g_build_filename (g_get_user_cache_dir (), "xwayland.log", NULL);
|
||||
args[8] = "-nolisten";
|
||||
args[9] = "all";
|
||||
args[10] = NULL;
|
||||
|
||||
error = NULL;
|
||||
if (g_spawn_async (NULL, /* cwd */
|
||||
args,
|
||||
env,
|
||||
G_SPAWN_LEAVE_DESCRIPTORS_OPEN |
|
||||
G_SPAWN_DO_NOT_REAP_CHILD |
|
||||
G_SPAWN_STDOUT_TO_DEV_NULL |
|
||||
G_SPAWN_STDERR_TO_DEV_NULL,
|
||||
uncloexec_and_setpgid,
|
||||
GINT_TO_POINTER (sp[1]),
|
||||
&pid,
|
||||
&error))
|
||||
{
|
||||
case 0:
|
||||
{
|
||||
char *fd_string;
|
||||
char *display_name;
|
||||
/* Make sure the client end of the socket pair doesn't get closed
|
||||
* when we exec xwayland. */
|
||||
int flags = fcntl (sp[1], F_GETFD);
|
||||
if (flags != -1)
|
||||
fcntl (sp[1], F_SETFD, flags & ~FD_CLOEXEC);
|
||||
|
||||
fd_string = g_strdup_printf ("%d", sp[1]);
|
||||
setenv ("WAYLAND_SOCKET", fd_string, 1);
|
||||
g_free (fd_string);
|
||||
|
||||
display_name = g_strdup_printf (":%d",
|
||||
compositor->xwayland_display_index);
|
||||
|
||||
if (execl (XWAYLAND_PATH,
|
||||
XWAYLAND_PATH,
|
||||
display_name,
|
||||
"-wayland",
|
||||
"-rootless",
|
||||
"-retro",
|
||||
"-noreset",
|
||||
/* FIXME: does it make sense to log to the filesystem by
|
||||
* default? */
|
||||
"-logfile", "/tmp/xwayland.log",
|
||||
"-nolisten", "all",
|
||||
NULL) < 0)
|
||||
{
|
||||
char *msg = strerror (errno);
|
||||
g_warning ("xwayland exec failed: %s", msg);
|
||||
}
|
||||
exit (-1);
|
||||
return FALSE;
|
||||
}
|
||||
default:
|
||||
g_message ("forked X server, pid %d\n", pid);
|
||||
|
||||
close (sp[1]);
|
||||
@ -284,12 +318,15 @@ meta_xwayland_start (MetaWaylandCompositor *compositor)
|
||||
wl_client_create (compositor->wayland_display, sp[0]);
|
||||
|
||||
compositor->xwayland_pid = pid;
|
||||
break;
|
||||
|
||||
case -1:
|
||||
g_error ("Failed to fork for xwayland server");
|
||||
return FALSE;
|
||||
g_child_watch_add (pid, xserver_died, NULL);
|
||||
}
|
||||
else
|
||||
{
|
||||
g_error ("Failed to fork for xwayland server: %s", error->message);
|
||||
}
|
||||
|
||||
g_strfreev (env);
|
||||
g_free (display_name);
|
||||
|
||||
return TRUE;
|
||||
}
|
||||
|
Loading…
Reference in New Issue
Block a user