[PATCH 3.16.y-ckt 038/128] vgaarb: fix signal handling in vga_get()

[Luis Henriques]

3.16.7-ckt23 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx>

commit 9f5bd30818c42c6c36a51f93b4df75a2ea2bd85e upstream.

There are few defects in vga_get() related to signal hadning:

  - we shouldn't check for pending signals for TASK_UNINTERRUPTIBLE
    case;

  - if we found pending signal we must remove ourself from wait queue
    and change task state back to running;

  - -ERESTARTSYS is more appropriate, I guess.

Signed-off-by: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Reviewed-by: David Herrmann <dh.herrmann@xxxxxxxxx>
Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
 drivers/gpu/vga/vgaarb.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
index 366641d0483f..5b9eccd3e9ff 100644
--- a/drivers/gpu/vga/vgaarb.c
+++ b/drivers/gpu/vga/vgaarb.c
@@ -393,8 +393,10 @@ int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible)
 		set_current_state(interruptible ?
 				  TASK_INTERRUPTIBLE :
 				  TASK_UNINTERRUPTIBLE);
-		if (signal_pending(current)) {
-			rc = -EINTR;
+		if (interruptible && signal_pending(current)) {
+			__set_current_state(TASK_RUNNING);
+			remove_wait_queue(&vga_wait_queue, &wait);
+			rc = -ERESTARTSYS;
 			break;
 		}
 		schedule();