From: Dave Airlie <airlied@redhat.com>
Date: Wed, 1 Dec 2010 04:27:29 -0500
Subject: [char] drm: don't set signal blocker on master process
Message-id: <1291177649-4260-1-git-send-email-airlied@redhat.com>
Patchwork-id: 29759
O-Subject: [PATCH] [RHEL5.6 PATCH] drm: don't set the signal blocker on the
	master process.
Bugzilla: 570604

BZ: 570604
upstream-commit-id: 3e5fc80a404a24c858468030b63555cccfb3e79c
[straight backport]

There is a problem with debugging the X server and gdb crashes in
the xkb startup code.

This avoids the problem by allowing the master process to get signals.
It should be safe as the signal blocker is mainly so that you can
Ctrl-Z a 3D application without locking up the whole box. Ctrl-Z the
X server isn't something many people do.

Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/char/drm/drm_lock.c b/drivers/char/drm/drm_lock.c
index f9e4530..6e523da 100644
--- a/drivers/char/drm/drm_lock.c
+++ b/drivers/char/drm/drm_lock.c
@@ -108,14 +108,16 @@ int drm_lock(struct inode *inode, struct file *filp,
 	if (ret)
 		return ret;
 
-	sigemptyset(&dev->sigmask);
-	sigaddset(&dev->sigmask, SIGSTOP);
-	sigaddset(&dev->sigmask, SIGTSTP);
-	sigaddset(&dev->sigmask, SIGTTIN);
-	sigaddset(&dev->sigmask, SIGTTOU);
-	dev->sigdata.context = lock.context;
-	dev->sigdata.lock = dev->lock.hw_lock;
-	block_all_signals(drm_notifier, &dev->sigdata, &dev->sigmask);
+	if (!priv->master) {
+		sigemptyset(&dev->sigmask);
+		sigaddset(&dev->sigmask, SIGSTOP);
+		sigaddset(&dev->sigmask, SIGTSTP);
+		sigaddset(&dev->sigmask, SIGTTIN);
+		sigaddset(&dev->sigmask, SIGTTOU);
+		dev->sigdata.context = lock.context;
+		dev->sigdata.lock = dev->lock.hw_lock;
+		block_all_signals(drm_notifier, &dev->sigdata, &dev->sigmask);
+	}
 
 	if (dev->driver->dma_ready && (lock.flags & _DRM_LOCK_READY))
 		dev->driver->dma_ready(dev);