diff options
Diffstat (limited to 'drivers/char/vt_ioctl.c')
| -rw-r--r-- | drivers/char/vt_ioctl.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c index 3a5d301e783b..c9f2dd620e87 100644 --- a/drivers/char/vt_ioctl.c +++ b/drivers/char/vt_ioctl.c @@ -34,7 +34,7 @@ #include <linux/kbd_diacr.h> #include <linux/selection.h> -static char vt_dont_switch; +char vt_dont_switch; extern struct tty_driver *console_driver; #define VT_IS_IN_USE(i) (console_driver->ttys[i] && console_driver->ttys[i]->count) @@ -1039,10 +1039,22 @@ int vt_waitactive(int vt) add_wait_queue(&vt_activate_queue, &wait); for (;;) { - set_current_state(TASK_INTERRUPTIBLE); retval = 0; - if (vt == fg_console) + + /* + * Synchronize with redraw_screen(). By acquiring the console + * semaphore we make sure that the console switch is completed + * before we return. If we didn't wait for the semaphore, we + * could return at a point where fg_console has already been + * updated, but the console switch hasn't been completed. + */ + acquire_console_sem(); + set_current_state(TASK_INTERRUPTIBLE); + if (vt == fg_console) { + release_console_sem(); break; + } + release_console_sem(); retval = -EINTR; if (signal_pending(current)) break; |