drm/vmwgfx: Kill unneeded legacy security features

At one point, the GPU command verifier and user-space handle manager
couldn't properly protect GPU clients from accessing each other's data.
Instead there was an elaborate mechanism to make sure only the active
master's primary clients could render. The other clients were either
put to sleep or even killed (if the master had exited). VRAM was
evicted on master switch. With the advent of render-node functionality,
we relaxed the VRAM eviction, but the other mechanisms stayed in place.

Now that the GPU  command verifier and ttm object manager properly
isolates primary clients from different master realms we can remove the
master switch related code and drop those legacy features.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Deepak Rawat <drawat@vmware.com>

1 files changed, 0 insertions, 100 deletions

diff --git a/drivers/gpu/drm/vmwgfx/ttm_lock.c b/drivers/gpu/drm/vmwgfx/ttm_lock.c
index 16b2083cb9d4..5971c72e6d10 100644
--- a/drivers/gpu/drm/vmwgfx/ttm_lock.c
+++ b/drivers/gpu/drm/vmwgfx/ttm_lock.c
@@ -29,7 +29,6 @@
  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  */
 
-#include <drm/ttm/ttm_module.h>
 #include <linux/atomic.h>
 #include <linux/errno.h>
 #include <linux/wait.h>
@@ -49,8 +48,6 @@ void ttm_lock_init(struct ttm_lock *lock)
 	init_waitqueue_head(&lock->queue);
 	lock->rw = 0;
 	lock->flags = 0;
-	lock->kill_takers = false;
-	lock->signal = SIGKILL;
 }
 
 void ttm_read_unlock(struct ttm_lock *lock)
@@ -66,11 +63,6 @@ static bool __ttm_read_lock(struct ttm_lock *lock)
 	bool locked = false;
 
 	spin_lock(&lock->lock);
-	if (unlikely(lock->kill_takers)) {
-		send_sig(lock->signal, current, 0);
-		spin_unlock(&lock->lock);
-		return false;
-	}
 	if (lock->rw >= 0 && lock->flags == 0) {
 		++lock->rw;
 		locked = true;
@@ -98,11 +90,6 @@ static bool __ttm_read_trylock(struct ttm_lock *lock, bool *locked)
 	*locked = false;
 
 	spin_lock(&lock->lock);
-	if (unlikely(lock->kill_takers)) {
-		send_sig(lock->signal, current, 0);
-		spin_unlock(&lock->lock);
-		return false;
-	}
 	if (lock->rw >= 0 && lock->flags == 0) {
 		++lock->rw;
 		block = false;
@@ -147,11 +134,6 @@ static bool __ttm_write_lock(struct ttm_lock *lock)
 	bool locked = false;
 
 	spin_lock(&lock->lock);
-	if (unlikely(lock->kill_takers)) {
-		send_sig(lock->signal, current, 0);
-		spin_unlock(&lock->lock);
-		return false;
-	}
 	if (lock->rw == 0 && ((lock->flags & ~TTM_WRITE_LOCK_PENDING) == 0)) {
 		lock->rw = -1;
 		lock->flags &= ~TTM_WRITE_LOCK_PENDING;
@@ -182,88 +164,6 @@ int ttm_write_lock(struct ttm_lock *lock, bool interruptible)
 	return ret;
 }
 
-static int __ttm_vt_unlock(struct ttm_lock *lock)
-{
-	int ret = 0;
-
-	spin_lock(&lock->lock);
-	if (unlikely(!(lock->flags & TTM_VT_LOCK)))
-		ret = -EINVAL;
-	lock->flags &= ~TTM_VT_LOCK;
-	wake_up_all(&lock->queue);
-	spin_unlock(&lock->lock);
-
-	return ret;
-}
-
-static void ttm_vt_lock_remove(struct ttm_base_object **p_base)
-{
-	struct ttm_base_object *base = *p_base;
-	struct ttm_lock *lock = container_of(base, struct ttm_lock, base);
-	int ret;
-
-	*p_base = NULL;
-	ret = __ttm_vt_unlock(lock);
-	BUG_ON(ret != 0);
-}
-
-static bool __ttm_vt_lock(struct ttm_lock *lock)
-{
-	bool locked = false;
-
-	spin_lock(&lock->lock);
-	if (lock->rw == 0) {
-		lock->flags &= ~TTM_VT_LOCK_PENDING;
-		lock->flags |= TTM_VT_LOCK;
-		locked = true;
-	} else {
-		lock->flags |= TTM_VT_LOCK_PENDING;
-	}
-	spin_unlock(&lock->lock);
-	return locked;
-}
-
-int ttm_vt_lock(struct ttm_lock *lock,
-		bool interruptible,
-		struct ttm_object_file *tfile)
-{
-	int ret = 0;
-
-	if (interruptible) {
-		ret = wait_event_interruptible(lock->queue,
-					       __ttm_vt_lock(lock));
-		if (unlikely(ret != 0)) {
-			spin_lock(&lock->lock);
-			lock->flags &= ~TTM_VT_LOCK_PENDING;
-			wake_up_all(&lock->queue);
-			spin_unlock(&lock->lock);
-			return ret;
-		}
-	} else
-		wait_event(lock->queue, __ttm_vt_lock(lock));
-
-	/*
-	 * Add a base-object, the destructor of which will
-	 * make sure the lock is released if the client dies
-	 * while holding it.
-	 */
-
-	ret = ttm_base_object_init(tfile, &lock->base, false,
-				   ttm_lock_type, &ttm_vt_lock_remove, NULL);
-	if (ret)
-		(void)__ttm_vt_unlock(lock);
-	else
-		lock->vt_holder = tfile;
-
-	return ret;
-}
-
-int ttm_vt_unlock(struct ttm_lock *lock)
-{
-	return ttm_ref_object_base_unref(lock->vt_holder,
-					 lock->base.handle, TTM_REF_USAGE);
-}
-
 void ttm_suspend_unlock(struct ttm_lock *lock)
 {
 	spin_lock(&lock->lock);