From c1974d32e101e4b68bc6987670abdc8e105c4501 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 2 Jul 2020 22:10:15 +0100
Subject: drm/i915: Also drop vm.ref along error paths for vma construction
Git-commit: cf1976b11372cac3b57fbae1831f66a4486355d3
Patch-mainline: v5.8-rc5
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

Not only do we need to release the vm.ref we acquired for the vma on the
duplicate insert branch, but also for the normal error paths, so roll
them all into one.

Reported-by: Andi Shyti <andi.shyti@intel.com>
Suggested-by: Andi Shyti <andi.shyti@intel.com>
Fixes: 2850748ef876 ("drm/i915: Pull i915_vma_pin under the vm->mutex")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Cc: <stable@vger.kernel.org> # v5.5+
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200702211015.29604-1-chris@chris-wilson.co.uk
(cherry picked from commit 03fca66b7a36b52da8915341eee388267f6d5b73)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/i915_vma.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 2d60fd1f3637..1f9cd33b35cb 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -104,6 +104,7 @@ vma_create(struct drm_i915_gem_object *obj,
 	   struct i915_address_space *vm,
 	   const struct i915_ggtt_view *view)
 {
+	struct i915_vma *pos = ERR_PTR(-E2BIG);
 	struct i915_vma *vma;
 	struct rb_node *rb, **p;
 
@@ -184,7 +185,6 @@ vma_create(struct drm_i915_gem_object *obj,
 	rb = NULL;
 	p = &obj->vma.tree.rb_node;
 	while (*p) {
-		struct i915_vma *pos;
 		long cmp;
 
 		rb = *p;
@@ -196,17 +196,12 @@ vma_create(struct drm_i915_gem_object *obj,
 		 * and dispose of ours.
 		 */
 		cmp = i915_vma_compare(pos, vm, view);
-		if (cmp == 0) {
-			spin_unlock(&obj->vma.lock);
-			i915_vm_put(vm);
-			i915_vma_free(vma);
-			return pos;
-		}
-
 		if (cmp < 0)
 			p = &rb->rb_right;
-		else
+		else if (cmp > 0)
 			p = &rb->rb_left;
+		else
+			goto err_unlock;
 	}
 	rb_link_node(&vma->obj_node, rb, p);
 	rb_insert_color(&vma->obj_node, &obj->vma.tree);
@@ -229,8 +224,9 @@ vma_create(struct drm_i915_gem_object *obj,
 err_unlock:
 	spin_unlock(&obj->vma.lock);
 err_vma:
+	i915_vm_put(vm);
 	i915_vma_free(vma);
-	return ERR_PTR(-E2BIG);
+	return pos;
 }
 
 static struct i915_vma *
-- 
2.28.0