from netbsd:

Prevent endless loop (-> kernel crash) when a signal is sent to a process
waiting for a vt to become active. Move one ifdef XSERVER to the right place.

3 files changed, 8 insertions, 7 deletions

diff --git a/sys/arch/i386/isa/pcvt/pcvt_drv.c b/sys/arch/i386/isa/pcvt/pcvt_drv.c
index ad0cc727d95..fe7af81895c 100644
--- a/sys/arch/i386/isa/pcvt/pcvt_drv.c
+++ b/sys/arch/i386/isa/pcvt/pcvt_drv.c
@@ -611,11 +611,11 @@ pcioctl(Dev_t dev, int cmd, caddr_t data, int flag, struct proc *p)
 	}
 #endif /* PCVT_EMU_MOUSE */
 
-#ifdef XSERVER
 
 	if((error = usl_vt_ioctl(dev, cmd, data, flag, p)) >= 0)
-		return error;
+		return (error == PCVT_ERESTART) ? ERESTART : error;
 
+#ifdef XSERVER
 	/*
 	 * just for compatibility:
 	 * XFree86 < 2.0 and SuperProbe still might use it
diff --git a/sys/arch/i386/isa/pcvt/pcvt_ext.c b/sys/arch/i386/isa/pcvt/pcvt_ext.c
index 9bbe8dd022b..4b031d60b2b 100644
--- a/sys/arch/i386/isa/pcvt/pcvt_ext.c
+++ b/sys/arch/i386/isa/pcvt/pcvt_ext.c
@@ -2722,8 +2722,7 @@ usl_vt_ioctl(Dev_t dev, int cmd, caddr_t data, int flag, struct proc *p)
 			int x = spltty();
 			i = current_video_screen;
 			error = 0;
-			while (current_video_screen == i &&
-			       (error == 0 || error == ERESTART))
+			while (current_video_screen == i && error == 0)
 			{
 				vs[i].vt_status |= VT_WAIT_ACT;
 				error = tsleep((caddr_t)&vs[i].smode,
@@ -2735,8 +2734,7 @@ usl_vt_ioctl(Dev_t dev, int cmd, caddr_t data, int flag, struct proc *p)
 		{
 			int x = spltty();
 			error = 0;
-			while (current_video_screen != i &&
-			       (error == 0 || error == ERESTART))
+			while (current_video_screen != i && error == 0)
 			{
 				vs[i].vt_status |= VT_WAIT_ACT;
 				error = tsleep((caddr_t)&vs[i].smode,
@@ -2744,7 +2742,7 @@ usl_vt_ioctl(Dev_t dev, int cmd, caddr_t data, int flag, struct proc *p)
 			}
 			splx(x);
 		}
-		return error;
+		return (error == ERESTART) ? PCVT_ERESTART : error;
 
 	case KDENABIO:
 		/* grant the process IO access; only allowed if euid == 0 */
diff --git a/sys/arch/i386/isa/pcvt/pcvt_hdr.h b/sys/arch/i386/isa/pcvt/pcvt_hdr.h
index 86ec7c8e03b..6286e439132 100644
--- a/sys/arch/i386/isa/pcvt/pcvt_hdr.h
+++ b/sys/arch/i386/isa/pcvt/pcvt_hdr.h
@@ -914,6 +914,9 @@ typedef struct video_state {
 
 EXTERN video_state vs[PCVT_NSCREENS];	/* parameters for screens */
 
+/* used to be able to pass ERESTART on properly */
+#define PCVT_ERESTART (ELAST + 1)
+
 /* possible states for video_state.vt_status: */
 
 #define	VT_WAIT_REL 1			/* wait till process released vt */