From: Alice Ryhl <aliceryhl@google.com>
Date: Thu, 16 Apr 2026 13:10:54 +0000 (+0000)
Subject: drm/gpuvm: take refcount on DRM device
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=c2d72717e0a9dd01c6a1bac61a1462a8e04bd179;p=thirdparty%2Fkernel%2Flinux.git

drm/gpuvm: take refcount on DRM device

Currently GPUVM relies on the owner implicitly holding a refcount to the
drm device, and it does not implicitly take a refcount on the drm
device. This design is error-prone, so take a refcount on the device.

Suggested-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Fixes: 546ca4d35dcc ("drm/gpuvm: convert WARN() to drm_WARN() variants")
Link: https://patch.msgid.link/20260416-gpuvm-drm-dev-get-v1-1-f3bc06571e73@google.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---

diff --git a/drivers/gpu/drm/drm_gpuvm.c b/drivers/gpu/drm/drm_gpuvm.c
index 44acfe4120d24..000e7910a8999 100644
--- a/drivers/gpu/drm/drm_gpuvm.c
+++ b/drivers/gpu/drm/drm_gpuvm.c
@@ -25,6 +25,7 @@
  *
  */
 
+#include <drm/drm_drv.h>
 #include <drm/drm_gpuvm.h>
 #include <drm/drm_print.h>
 
@@ -1117,6 +1118,7 @@ drm_gpuvm_init(struct drm_gpuvm *gpuvm, const char *name,
 	gpuvm->drm = drm;
 	gpuvm->r_obj = r_obj;
 
+	drm_dev_get(drm);
 	drm_gem_object_get(r_obj);
 
 	drm_gpuvm_warn_check_overflow(gpuvm, start_offset, range);
@@ -1160,13 +1162,15 @@ static void
 drm_gpuvm_free(struct kref *kref)
 {
 	struct drm_gpuvm *gpuvm = container_of(kref, struct drm_gpuvm, kref);
+	struct drm_device *drm = gpuvm->drm;
 
 	drm_gpuvm_fini(gpuvm);
 
-	if (drm_WARN_ON(gpuvm->drm, !gpuvm->ops->vm_free))
+	if (drm_WARN_ON(drm, !gpuvm->ops->vm_free))
 		return;
 
 	gpuvm->ops->vm_free(gpuvm);
+	drm_dev_put(drm);
 }
 
 /**