#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)
/*
* Switching-from response
*/
+ acquire_console_sem();
if (vc->vt_newvt >= 0) {
if (arg == 0)
/*
* complete the switch.
*/
int newvt;
- acquire_console_sem();
newvt = vc->vt_newvt;
vc->vt_newvt = -1;
i = vc_allocate(newvt);
* other console switches..
*/
complete_change_console(vc_cons[newvt].d);
- release_console_sem();
}
}
/*
* If it's just an ACK, ignore it
*/
- if (arg != VT_ACKACQ)
+ if (arg != VT_ACKACQ) {
+ release_console_sem();
return -EINVAL;
+ }
}
+ release_console_sem();
return 0;
/*
* Sleeps until a vt is activated, or the task is interrupted. Returns
- * 0 if activation, -EINTR if interrupted.
+ * 0 if activation, -EINTR if interrupted by a signal handler.
*/
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;
- retval = -EINTR;
+ }
+ release_console_sem();
+ retval = -ERESTARTNOHAND;
if (signal_pending(current))
break;
schedule();
}
remove_wait_queue(&vt_activate_queue, &wait);
- current->state = TASK_RUNNING;
+ __set_current_state(TASK_RUNNING);
return retval;
}
/*
* Send the signal as privileged - kill_pid() will
* tell us if the process has gone or something else
- * is awry
+ * is awry.
+ *
+ * We need to set vt_newvt *before* sending the signal or we
+ * have a race.
*/
+ vc->vt_newvt = new_vc->vc_num;
if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
/*
* It worked. Mark the vt to switch to and
* return. The process needs to send us a
* VT_RELDISP ioctl to complete the switch.
*/
- vc->vt_newvt = new_vc->vc_num;
return;
}