[PATCH 4.2.y-ckt 171/305] vgaarb: fix signal handling in vga_get()

From: Kamal Mostafa
Date: Fri Jan 15 2016 - 19:05:41 EST


4.2.8-ckt2 -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: Kamal Mostafa <kamal@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 7bcbf86..17cd475 100644
--- a/drivers/gpu/vga/vgaarb.c
+++ b/drivers/gpu/vga/vgaarb.c
@@ -394,8 +394,10 @@ 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();
--
1.9.1