lguest: remove obsolete LHREQ_BREAK call

We no longer need an efficient mechanism to force the Guest back into
host userspace, as each device is serviced without bothering the main
Guest process (aka. the Launcher).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 0 insertions, 31 deletions

diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c
index f6bf255..32e2971 100644
--- a/drivers/lguest/lguest_user.c
+++ b/drivers/lguest/lguest_user.c
@@ -11,32 +11,6 @@
 #include <linux/file.h>
 #include "lg.h"
 
-/*L:055 When something happens, the Waker process needs a way to stop the
- * kernel running the Guest and return to the Launcher.  So the Waker writes
- * LHREQ_BREAK and the value "1" to /dev/lguest to do this.  Once the Launcher
- * has done whatever needs attention, it writes LHREQ_BREAK and "0" to release
- * the Waker. */
-static int break_guest_out(struct lg_cpu *cpu, const unsigned long __user*input)
-{
-	unsigned long on;
-
-	/* Fetch whether they're turning break on or off. */
-	if (get_user(on, input) != 0)
-		return -EFAULT;
-
-	if (on) {
-		cpu->break_out = 1;
-		if (!wake_up_process(cpu->tsk))
-			kick_process(cpu->tsk);
-		/* Wait for them to reset it */
-		return wait_event_interruptible(cpu->break_wq, !cpu->break_out);
-	} else {
-		cpu->break_out = 0;
-		wake_up(&cpu->break_wq);
-		return 0;
-	}
-}
-
 bool send_notify_to_eventfd(struct lg_cpu *cpu)
 {
 	unsigned int i;
@@ -202,9 +176,6 @@ static int lg_cpu_start(struct lg_cpu *cpu, unsigned id, unsigned long start_ip)
 	 * address. */
 	lguest_arch_setup_regs(cpu, start_ip);
 
-	/* Initialize the queue for the Waker to wait on */
-	init_waitqueue_head(&cpu->break_wq);
-
 	/* We keep a pointer to the Launcher task (ie. current task) for when
 	 * other Guests want to wake this one (eg. console input). */
 	cpu->tsk = current;
@@ -344,8 +315,6 @@ static ssize_t write(struct file *file, const char __user *in,
 		return initialize(file, input);
 	case LHREQ_IRQ:
 		return user_send_irq(cpu, input);
-	case LHREQ_BREAK:
-		return break_guest_out(cpu, input);
 	case LHREQ_EVENTFD:
 		return attach_eventfd(lg, input);
 	default: